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1/*
2 * Kernel-based Virtual Machine driver for Linux
3 *
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
6 *
7 * Copyright (C) 2006 Qumranet, Inc.
8 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
9 *
10 * Authors:
11 * Avi Kivity <avi@qumranet.com>
12 * Yaniv Kamay <yaniv@qumranet.com>
13 *
14 * This work is licensed under the terms of the GNU GPL, version 2. See
15 * the COPYING file in the top-level directory.
16 *
17 */
18
19#include "iodev.h"
20
21#include <linux/kvm_host.h>
22#include <linux/kvm.h>
23#include <linux/module.h>
24#include <linux/errno.h>
25#include <linux/percpu.h>
26#include <linux/mm.h>
27#include <linux/miscdevice.h>
28#include <linux/vmalloc.h>
29#include <linux/reboot.h>
30#include <linux/debugfs.h>
31#include <linux/highmem.h>
32#include <linux/file.h>
33#include <linux/syscore_ops.h>
34#include <linux/cpu.h>
35#include <linux/sched.h>
36#include <linux/cpumask.h>
37#include <linux/smp.h>
38#include <linux/anon_inodes.h>
39#include <linux/profile.h>
40#include <linux/kvm_para.h>
41#include <linux/pagemap.h>
42#include <linux/mman.h>
43#include <linux/swap.h>
44#include <linux/bitops.h>
45#include <linux/spinlock.h>
46#include <linux/compat.h>
47#include <linux/srcu.h>
48#include <linux/hugetlb.h>
49#include <linux/slab.h>
50
51#include <asm/processor.h>
52#include <asm/io.h>
53#include <asm/uaccess.h>
54#include <asm/pgtable.h>
55
56#include "coalesced_mmio.h"
57#include "async_pf.h"
58
59#define CREATE_TRACE_POINTS
60#include <trace/events/kvm.h>
61
62MODULE_AUTHOR("Qumranet");
63MODULE_LICENSE("GPL");
64
65/*
66 * Ordering of locks:
67 *
68 * kvm->lock --> kvm->slots_lock --> kvm->irq_lock
69 */
70
71DEFINE_RAW_SPINLOCK(kvm_lock);
72LIST_HEAD(vm_list);
73
74static cpumask_var_t cpus_hardware_enabled;
75static int kvm_usage_count = 0;
76static atomic_t hardware_enable_failed;
77
78struct kmem_cache *kvm_vcpu_cache;
79EXPORT_SYMBOL_GPL(kvm_vcpu_cache);
80
81static __read_mostly struct preempt_ops kvm_preempt_ops;
82
83struct dentry *kvm_debugfs_dir;
84
85static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
86 unsigned long arg);
87#ifdef CONFIG_COMPAT
88static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
89 unsigned long arg);
90#endif
91static int hardware_enable_all(void);
92static void hardware_disable_all(void);
93
94static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
95
96bool kvm_rebooting;
97EXPORT_SYMBOL_GPL(kvm_rebooting);
98
99static bool largepages_enabled = true;
100
101static struct page *hwpoison_page;
102static pfn_t hwpoison_pfn;
103
104struct page *fault_page;
105pfn_t fault_pfn;
106
107inline int kvm_is_mmio_pfn(pfn_t pfn)
108{
109 if (pfn_valid(pfn)) {
110 int reserved;
111 struct page *tail = pfn_to_page(pfn);
112 struct page *head = compound_trans_head(tail);
113 reserved = PageReserved(head);
114 if (head != tail) {
115 /*
116 * "head" is not a dangling pointer
117 * (compound_trans_head takes care of that)
118 * but the hugepage may have been splitted
119 * from under us (and we may not hold a
120 * reference count on the head page so it can
121 * be reused before we run PageReferenced), so
122 * we've to check PageTail before returning
123 * what we just read.
124 */
125 smp_rmb();
126 if (PageTail(tail))
127 return reserved;
128 }
129 return PageReserved(tail);
130 }
131
132 return true;
133}
134
135/*
136 * Switches to specified vcpu, until a matching vcpu_put()
137 */
138void vcpu_load(struct kvm_vcpu *vcpu)
139{
140 int cpu;
141
142 mutex_lock(&vcpu->mutex);
143 if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
144 /* The thread running this VCPU changed. */
145 struct pid *oldpid = vcpu->pid;
146 struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
147 rcu_assign_pointer(vcpu->pid, newpid);
148 synchronize_rcu();
149 put_pid(oldpid);
150 }
151 cpu = get_cpu();
152 preempt_notifier_register(&vcpu->preempt_notifier);
153 kvm_arch_vcpu_load(vcpu, cpu);
154 put_cpu();
155}
156
157void vcpu_put(struct kvm_vcpu *vcpu)
158{
159 preempt_disable();
160 kvm_arch_vcpu_put(vcpu);
161 preempt_notifier_unregister(&vcpu->preempt_notifier);
162 preempt_enable();
163 mutex_unlock(&vcpu->mutex);
164}
165
166static void ack_flush(void *_completed)
167{
168}
169
170static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
171{
172 int i, cpu, me;
173 cpumask_var_t cpus;
174 bool called = true;
175 struct kvm_vcpu *vcpu;
176
177 zalloc_cpumask_var(&cpus, GFP_ATOMIC);
178
179 me = get_cpu();
180 kvm_for_each_vcpu(i, vcpu, kvm) {
181 kvm_make_request(req, vcpu);
182 cpu = vcpu->cpu;
183
184 /* Set ->requests bit before we read ->mode */
185 smp_mb();
186
187 if (cpus != NULL && cpu != -1 && cpu != me &&
188 kvm_vcpu_exiting_guest_mode(vcpu) != OUTSIDE_GUEST_MODE)
189 cpumask_set_cpu(cpu, cpus);
190 }
191 if (unlikely(cpus == NULL))
192 smp_call_function_many(cpu_online_mask, ack_flush, NULL, 1);
193 else if (!cpumask_empty(cpus))
194 smp_call_function_many(cpus, ack_flush, NULL, 1);
195 else
196 called = false;
197 put_cpu();
198 free_cpumask_var(cpus);
199 return called;
200}
201
202void kvm_flush_remote_tlbs(struct kvm *kvm)
203{
204 int dirty_count = kvm->tlbs_dirty;
205
206 smp_mb();
207 if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
208 ++kvm->stat.remote_tlb_flush;
209 cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
210}
211
212void kvm_reload_remote_mmus(struct kvm *kvm)
213{
214 make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
215}
216
217int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
218{
219 struct page *page;
220 int r;
221
222 mutex_init(&vcpu->mutex);
223 vcpu->cpu = -1;
224 vcpu->kvm = kvm;
225 vcpu->vcpu_id = id;
226 vcpu->pid = NULL;
227 init_waitqueue_head(&vcpu->wq);
228 kvm_async_pf_vcpu_init(vcpu);
229
230 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
231 if (!page) {
232 r = -ENOMEM;
233 goto fail;
234 }
235 vcpu->run = page_address(page);
236
237 r = kvm_arch_vcpu_init(vcpu);
238 if (r < 0)
239 goto fail_free_run;
240 return 0;
241
242fail_free_run:
243 free_page((unsigned long)vcpu->run);
244fail:
245 return r;
246}
247EXPORT_SYMBOL_GPL(kvm_vcpu_init);
248
249void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
250{
251 put_pid(vcpu->pid);
252 kvm_arch_vcpu_uninit(vcpu);
253 free_page((unsigned long)vcpu->run);
254}
255EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
256
257#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
258static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
259{
260 return container_of(mn, struct kvm, mmu_notifier);
261}
262
263static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
264 struct mm_struct *mm,
265 unsigned long address)
266{
267 struct kvm *kvm = mmu_notifier_to_kvm(mn);
268 int need_tlb_flush, idx;
269
270 /*
271 * When ->invalidate_page runs, the linux pte has been zapped
272 * already but the page is still allocated until
273 * ->invalidate_page returns. So if we increase the sequence
274 * here the kvm page fault will notice if the spte can't be
275 * established because the page is going to be freed. If
276 * instead the kvm page fault establishes the spte before
277 * ->invalidate_page runs, kvm_unmap_hva will release it
278 * before returning.
279 *
280 * The sequence increase only need to be seen at spin_unlock
281 * time, and not at spin_lock time.
282 *
283 * Increasing the sequence after the spin_unlock would be
284 * unsafe because the kvm page fault could then establish the
285 * pte after kvm_unmap_hva returned, without noticing the page
286 * is going to be freed.
287 */
288 idx = srcu_read_lock(&kvm->srcu);
289 spin_lock(&kvm->mmu_lock);
290 kvm->mmu_notifier_seq++;
291 need_tlb_flush = kvm_unmap_hva(kvm, address) | kvm->tlbs_dirty;
292 spin_unlock(&kvm->mmu_lock);
293 srcu_read_unlock(&kvm->srcu, idx);
294
295 /* we've to flush the tlb before the pages can be freed */
296 if (need_tlb_flush)
297 kvm_flush_remote_tlbs(kvm);
298
299}
300
301static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
302 struct mm_struct *mm,
303 unsigned long address,
304 pte_t pte)
305{
306 struct kvm *kvm = mmu_notifier_to_kvm(mn);
307 int idx;
308
309 idx = srcu_read_lock(&kvm->srcu);
310 spin_lock(&kvm->mmu_lock);
311 kvm->mmu_notifier_seq++;
312 kvm_set_spte_hva(kvm, address, pte);
313 spin_unlock(&kvm->mmu_lock);
314 srcu_read_unlock(&kvm->srcu, idx);
315}
316
317static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
318 struct mm_struct *mm,
319 unsigned long start,
320 unsigned long end)
321{
322 struct kvm *kvm = mmu_notifier_to_kvm(mn);
323 int need_tlb_flush = 0, idx;
324
325 idx = srcu_read_lock(&kvm->srcu);
326 spin_lock(&kvm->mmu_lock);
327 /*
328 * The count increase must become visible at unlock time as no
329 * spte can be established without taking the mmu_lock and
330 * count is also read inside the mmu_lock critical section.
331 */
332 kvm->mmu_notifier_count++;
333 for (; start < end; start += PAGE_SIZE)
334 need_tlb_flush |= kvm_unmap_hva(kvm, start);
335 need_tlb_flush |= kvm->tlbs_dirty;
336 spin_unlock(&kvm->mmu_lock);
337 srcu_read_unlock(&kvm->srcu, idx);
338
339 /* we've to flush the tlb before the pages can be freed */
340 if (need_tlb_flush)
341 kvm_flush_remote_tlbs(kvm);
342}
343
344static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
345 struct mm_struct *mm,
346 unsigned long start,
347 unsigned long end)
348{
349 struct kvm *kvm = mmu_notifier_to_kvm(mn);
350
351 spin_lock(&kvm->mmu_lock);
352 /*
353 * This sequence increase will notify the kvm page fault that
354 * the page that is going to be mapped in the spte could have
355 * been freed.
356 */
357 kvm->mmu_notifier_seq++;
358 /*
359 * The above sequence increase must be visible before the
360 * below count decrease but both values are read by the kvm
361 * page fault under mmu_lock spinlock so we don't need to add
362 * a smb_wmb() here in between the two.
363 */
364 kvm->mmu_notifier_count--;
365 spin_unlock(&kvm->mmu_lock);
366
367 BUG_ON(kvm->mmu_notifier_count < 0);
368}
369
370static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
371 struct mm_struct *mm,
372 unsigned long address)
373{
374 struct kvm *kvm = mmu_notifier_to_kvm(mn);
375 int young, idx;
376
377 idx = srcu_read_lock(&kvm->srcu);
378 spin_lock(&kvm->mmu_lock);
379 young = kvm_age_hva(kvm, address);
380 spin_unlock(&kvm->mmu_lock);
381 srcu_read_unlock(&kvm->srcu, idx);
382
383 if (young)
384 kvm_flush_remote_tlbs(kvm);
385
386 return young;
387}
388
389static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
390 struct mm_struct *mm,
391 unsigned long address)
392{
393 struct kvm *kvm = mmu_notifier_to_kvm(mn);
394 int young, idx;
395
396 idx = srcu_read_lock(&kvm->srcu);
397 spin_lock(&kvm->mmu_lock);
398 young = kvm_test_age_hva(kvm, address);
399 spin_unlock(&kvm->mmu_lock);
400 srcu_read_unlock(&kvm->srcu, idx);
401
402 return young;
403}
404
405static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
406 struct mm_struct *mm)
407{
408 struct kvm *kvm = mmu_notifier_to_kvm(mn);
409 int idx;
410
411 idx = srcu_read_lock(&kvm->srcu);
412 kvm_arch_flush_shadow(kvm);
413 srcu_read_unlock(&kvm->srcu, idx);
414}
415
416static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
417 .invalidate_page = kvm_mmu_notifier_invalidate_page,
418 .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
419 .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
420 .clear_flush_young = kvm_mmu_notifier_clear_flush_young,
421 .test_young = kvm_mmu_notifier_test_young,
422 .change_pte = kvm_mmu_notifier_change_pte,
423 .release = kvm_mmu_notifier_release,
424};
425
426static int kvm_init_mmu_notifier(struct kvm *kvm)
427{
428 kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
429 return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
430}
431
432#else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
433
434static int kvm_init_mmu_notifier(struct kvm *kvm)
435{
436 return 0;
437}
438
439#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
440
441static struct kvm *kvm_create_vm(void)
442{
443 int r, i;
444 struct kvm *kvm = kvm_arch_alloc_vm();
445
446 if (!kvm)
447 return ERR_PTR(-ENOMEM);
448
449 r = kvm_arch_init_vm(kvm);
450 if (r)
451 goto out_err_nodisable;
452
453 r = hardware_enable_all();
454 if (r)
455 goto out_err_nodisable;
456
457#ifdef CONFIG_HAVE_KVM_IRQCHIP
458 INIT_HLIST_HEAD(&kvm->mask_notifier_list);
459 INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
460#endif
461
462 r = -ENOMEM;
463 kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
464 if (!kvm->memslots)
465 goto out_err_nosrcu;
466 if (init_srcu_struct(&kvm->srcu))
467 goto out_err_nosrcu;
468 for (i = 0; i < KVM_NR_BUSES; i++) {
469 kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
470 GFP_KERNEL);
471 if (!kvm->buses[i])
472 goto out_err;
473 }
474
475 spin_lock_init(&kvm->mmu_lock);
476 kvm->mm = current->mm;
477 atomic_inc(&kvm->mm->mm_count);
478 kvm_eventfd_init(kvm);
479 mutex_init(&kvm->lock);
480 mutex_init(&kvm->irq_lock);
481 mutex_init(&kvm->slots_lock);
482 atomic_set(&kvm->users_count, 1);
483
484 r = kvm_init_mmu_notifier(kvm);
485 if (r)
486 goto out_err;
487
488 raw_spin_lock(&kvm_lock);
489 list_add(&kvm->vm_list, &vm_list);
490 raw_spin_unlock(&kvm_lock);
491
492 return kvm;
493
494out_err:
495 cleanup_srcu_struct(&kvm->srcu);
496out_err_nosrcu:
497 hardware_disable_all();
498out_err_nodisable:
499 for (i = 0; i < KVM_NR_BUSES; i++)
500 kfree(kvm->buses[i]);
501 kfree(kvm->memslots);
502 kvm_arch_free_vm(kvm);
503 return ERR_PTR(r);
504}
505
506static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
507{
508 if (!memslot->dirty_bitmap)
509 return;
510
511 if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
512 vfree(memslot->dirty_bitmap_head);
513 else
514 kfree(memslot->dirty_bitmap_head);
515
516 memslot->dirty_bitmap = NULL;
517 memslot->dirty_bitmap_head = NULL;
518}
519
520/*
521 * Free any memory in @free but not in @dont.
522 */
523static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
524 struct kvm_memory_slot *dont)
525{
526 int i;
527
528 if (!dont || free->rmap != dont->rmap)
529 vfree(free->rmap);
530
531 if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
532 kvm_destroy_dirty_bitmap(free);
533
534
535 for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
536 if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
537 vfree(free->lpage_info[i]);
538 free->lpage_info[i] = NULL;
539 }
540 }
541
542 free->npages = 0;
543 free->rmap = NULL;
544}
545
546void kvm_free_physmem(struct kvm *kvm)
547{
548 int i;
549 struct kvm_memslots *slots = kvm->memslots;
550
551 for (i = 0; i < slots->nmemslots; ++i)
552 kvm_free_physmem_slot(&slots->memslots[i], NULL);
553
554 kfree(kvm->memslots);
555}
556
557static void kvm_destroy_vm(struct kvm *kvm)
558{
559 int i;
560 struct mm_struct *mm = kvm->mm;
561
562 kvm_arch_sync_events(kvm);
563 raw_spin_lock(&kvm_lock);
564 list_del(&kvm->vm_list);
565 raw_spin_unlock(&kvm_lock);
566 kvm_free_irq_routing(kvm);
567 for (i = 0; i < KVM_NR_BUSES; i++)
568 kvm_io_bus_destroy(kvm->buses[i]);
569 kvm_coalesced_mmio_free(kvm);
570#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
571 mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
572#else
573 kvm_arch_flush_shadow(kvm);
574#endif
575 kvm_arch_destroy_vm(kvm);
576 kvm_free_physmem(kvm);
577 cleanup_srcu_struct(&kvm->srcu);
578 kvm_arch_free_vm(kvm);
579 hardware_disable_all();
580 mmdrop(mm);
581}
582
583void kvm_get_kvm(struct kvm *kvm)
584{
585 atomic_inc(&kvm->users_count);
586}
587EXPORT_SYMBOL_GPL(kvm_get_kvm);
588
589void kvm_put_kvm(struct kvm *kvm)
590{
591 if (atomic_dec_and_test(&kvm->users_count))
592 kvm_destroy_vm(kvm);
593}
594EXPORT_SYMBOL_GPL(kvm_put_kvm);
595
596
597static int kvm_vm_release(struct inode *inode, struct file *filp)
598{
599 struct kvm *kvm = filp->private_data;
600
601 kvm_irqfd_release(kvm);
602
603 kvm_put_kvm(kvm);
604 return 0;
605}
606
607#ifndef CONFIG_S390
608/*
609 * Allocation size is twice as large as the actual dirty bitmap size.
610 * This makes it possible to do double buffering: see x86's
611 * kvm_vm_ioctl_get_dirty_log().
612 */
613static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
614{
615 unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
616
617 if (dirty_bytes > PAGE_SIZE)
618 memslot->dirty_bitmap = vzalloc(dirty_bytes);
619 else
620 memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
621
622 if (!memslot->dirty_bitmap)
623 return -ENOMEM;
624
625 memslot->dirty_bitmap_head = memslot->dirty_bitmap;
626 return 0;
627}
628#endif /* !CONFIG_S390 */
629
630/*
631 * Allocate some memory and give it an address in the guest physical address
632 * space.
633 *
634 * Discontiguous memory is allowed, mostly for framebuffers.
635 *
636 * Must be called holding mmap_sem for write.
637 */
638int __kvm_set_memory_region(struct kvm *kvm,
639 struct kvm_userspace_memory_region *mem,
640 int user_alloc)
641{
642 int r;
643 gfn_t base_gfn;
644 unsigned long npages;
645 unsigned long i;
646 struct kvm_memory_slot *memslot;
647 struct kvm_memory_slot old, new;
648 struct kvm_memslots *slots, *old_memslots;
649
650 r = -EINVAL;
651 /* General sanity checks */
652 if (mem->memory_size & (PAGE_SIZE - 1))
653 goto out;
654 if (mem->guest_phys_addr & (PAGE_SIZE - 1))
655 goto out;
656 /* We can read the guest memory with __xxx_user() later on. */
657 if (user_alloc &&
658 ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
659 !access_ok(VERIFY_WRITE,
660 (void __user *)(unsigned long)mem->userspace_addr,
661 mem->memory_size)))
662 goto out;
663 if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
664 goto out;
665 if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
666 goto out;
667
668 memslot = &kvm->memslots->memslots[mem->slot];
669 base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
670 npages = mem->memory_size >> PAGE_SHIFT;
671
672 r = -EINVAL;
673 if (npages > KVM_MEM_MAX_NR_PAGES)
674 goto out;
675
676 if (!npages)
677 mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;
678
679 new = old = *memslot;
680
681 new.id = mem->slot;
682 new.base_gfn = base_gfn;
683 new.npages = npages;
684 new.flags = mem->flags;
685
686 /* Disallow changing a memory slot's size. */
687 r = -EINVAL;
688 if (npages && old.npages && npages != old.npages)
689 goto out_free;
690
691 /* Check for overlaps */
692 r = -EEXIST;
693 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
694 struct kvm_memory_slot *s = &kvm->memslots->memslots[i];
695
696 if (s == memslot || !s->npages)
697 continue;
698 if (!((base_gfn + npages <= s->base_gfn) ||
699 (base_gfn >= s->base_gfn + s->npages)))
700 goto out_free;
701 }
702
703 /* Free page dirty bitmap if unneeded */
704 if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
705 new.dirty_bitmap = NULL;
706
707 r = -ENOMEM;
708
709 /* Allocate if a slot is being created */
710#ifndef CONFIG_S390
711 if (npages && !new.rmap) {
712 new.rmap = vzalloc(npages * sizeof(*new.rmap));
713
714 if (!new.rmap)
715 goto out_free;
716
717 new.user_alloc = user_alloc;
718 new.userspace_addr = mem->userspace_addr;
719 }
720 if (!npages)
721 goto skip_lpage;
722
723 for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
724 unsigned long ugfn;
725 unsigned long j;
726 int lpages;
727 int level = i + 2;
728
729 /* Avoid unused variable warning if no large pages */
730 (void)level;
731
732 if (new.lpage_info[i])
733 continue;
734
735 lpages = 1 + ((base_gfn + npages - 1)
736 >> KVM_HPAGE_GFN_SHIFT(level));
737 lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
738
739 new.lpage_info[i] = vzalloc(lpages * sizeof(*new.lpage_info[i]));
740
741 if (!new.lpage_info[i])
742 goto out_free;
743
744 if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
745 new.lpage_info[i][0].write_count = 1;
746 if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
747 new.lpage_info[i][lpages - 1].write_count = 1;
748 ugfn = new.userspace_addr >> PAGE_SHIFT;
749 /*
750 * If the gfn and userspace address are not aligned wrt each
751 * other, or if explicitly asked to, disable large page
752 * support for this slot
753 */
754 if ((base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
755 !largepages_enabled)
756 for (j = 0; j < lpages; ++j)
757 new.lpage_info[i][j].write_count = 1;
758 }
759
760skip_lpage:
761
762 /* Allocate page dirty bitmap if needed */
763 if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
764 if (kvm_create_dirty_bitmap(&new) < 0)
765 goto out_free;
766 /* destroy any largepage mappings for dirty tracking */
767 }
768#else /* not defined CONFIG_S390 */
769 new.user_alloc = user_alloc;
770 if (user_alloc)
771 new.userspace_addr = mem->userspace_addr;
772#endif /* not defined CONFIG_S390 */
773
774 if (!npages) {
775 r = -ENOMEM;
776 slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
777 if (!slots)
778 goto out_free;
779 memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
780 if (mem->slot >= slots->nmemslots)
781 slots->nmemslots = mem->slot + 1;
782 slots->generation++;
783 slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
784
785 old_memslots = kvm->memslots;
786 rcu_assign_pointer(kvm->memslots, slots);
787 synchronize_srcu_expedited(&kvm->srcu);
788 /* From this point no new shadow pages pointing to a deleted
789 * memslot will be created.
790 *
791 * validation of sp->gfn happens in:
792 * - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
793 * - kvm_is_visible_gfn (mmu_check_roots)
794 */
795 kvm_arch_flush_shadow(kvm);
796 kfree(old_memslots);
797 }
798
799 r = kvm_arch_prepare_memory_region(kvm, &new, old, mem, user_alloc);
800 if (r)
801 goto out_free;
802
803 /* map the pages in iommu page table */
804 if (npages) {
805 r = kvm_iommu_map_pages(kvm, &new);
806 if (r)
807 goto out_free;
808 }
809
810 r = -ENOMEM;
811 slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
812 if (!slots)
813 goto out_free;
814 memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
815 if (mem->slot >= slots->nmemslots)
816 slots->nmemslots = mem->slot + 1;
817 slots->generation++;
818
819 /* actual memory is freed via old in kvm_free_physmem_slot below */
820 if (!npages) {
821 new.rmap = NULL;
822 new.dirty_bitmap = NULL;
823 for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i)
824 new.lpage_info[i] = NULL;
825 }
826
827 slots->memslots[mem->slot] = new;
828 old_memslots = kvm->memslots;
829 rcu_assign_pointer(kvm->memslots, slots);
830 synchronize_srcu_expedited(&kvm->srcu);
831
832 kvm_arch_commit_memory_region(kvm, mem, old, user_alloc);
833
834 /*
835 * If the new memory slot is created, we need to clear all
836 * mmio sptes.
837 */
838 if (npages && old.base_gfn != mem->guest_phys_addr >> PAGE_SHIFT)
839 kvm_arch_flush_shadow(kvm);
840
841 kvm_free_physmem_slot(&old, &new);
842 kfree(old_memslots);
843
844 return 0;
845
846out_free:
847 kvm_free_physmem_slot(&new, &old);
848out:
849 return r;
850
851}
852EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
853
854int kvm_set_memory_region(struct kvm *kvm,
855 struct kvm_userspace_memory_region *mem,
856 int user_alloc)
857{
858 int r;
859
860 mutex_lock(&kvm->slots_lock);
861 r = __kvm_set_memory_region(kvm, mem, user_alloc);
862 mutex_unlock(&kvm->slots_lock);
863 return r;
864}
865EXPORT_SYMBOL_GPL(kvm_set_memory_region);
866
867int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
868 struct
869 kvm_userspace_memory_region *mem,
870 int user_alloc)
871{
872 if (mem->slot >= KVM_MEMORY_SLOTS)
873 return -EINVAL;
874 return kvm_set_memory_region(kvm, mem, user_alloc);
875}
876
877int kvm_get_dirty_log(struct kvm *kvm,
878 struct kvm_dirty_log *log, int *is_dirty)
879{
880 struct kvm_memory_slot *memslot;
881 int r, i;
882 unsigned long n;
883 unsigned long any = 0;
884
885 r = -EINVAL;
886 if (log->slot >= KVM_MEMORY_SLOTS)
887 goto out;
888
889 memslot = &kvm->memslots->memslots[log->slot];
890 r = -ENOENT;
891 if (!memslot->dirty_bitmap)
892 goto out;
893
894 n = kvm_dirty_bitmap_bytes(memslot);
895
896 for (i = 0; !any && i < n/sizeof(long); ++i)
897 any = memslot->dirty_bitmap[i];
898
899 r = -EFAULT;
900 if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
901 goto out;
902
903 if (any)
904 *is_dirty = 1;
905
906 r = 0;
907out:
908 return r;
909}
910
911void kvm_disable_largepages(void)
912{
913 largepages_enabled = false;
914}
915EXPORT_SYMBOL_GPL(kvm_disable_largepages);
916
917int is_error_page(struct page *page)
918{
919 return page == bad_page || page == hwpoison_page || page == fault_page;
920}
921EXPORT_SYMBOL_GPL(is_error_page);
922
923int is_error_pfn(pfn_t pfn)
924{
925 return pfn == bad_pfn || pfn == hwpoison_pfn || pfn == fault_pfn;
926}
927EXPORT_SYMBOL_GPL(is_error_pfn);
928
929int is_hwpoison_pfn(pfn_t pfn)
930{
931 return pfn == hwpoison_pfn;
932}
933EXPORT_SYMBOL_GPL(is_hwpoison_pfn);
934
935int is_fault_pfn(pfn_t pfn)
936{
937 return pfn == fault_pfn;
938}
939EXPORT_SYMBOL_GPL(is_fault_pfn);
940
941int is_noslot_pfn(pfn_t pfn)
942{
943 return pfn == bad_pfn;
944}
945EXPORT_SYMBOL_GPL(is_noslot_pfn);
946
947int is_invalid_pfn(pfn_t pfn)
948{
949 return pfn == hwpoison_pfn || pfn == fault_pfn;
950}
951EXPORT_SYMBOL_GPL(is_invalid_pfn);
952
953static inline unsigned long bad_hva(void)
954{
955 return PAGE_OFFSET;
956}
957
958int kvm_is_error_hva(unsigned long addr)
959{
960 return addr == bad_hva();
961}
962EXPORT_SYMBOL_GPL(kvm_is_error_hva);
963
964static struct kvm_memory_slot *__gfn_to_memslot(struct kvm_memslots *slots,
965 gfn_t gfn)
966{
967 int i;
968
969 for (i = 0; i < slots->nmemslots; ++i) {
970 struct kvm_memory_slot *memslot = &slots->memslots[i];
971
972 if (gfn >= memslot->base_gfn
973 && gfn < memslot->base_gfn + memslot->npages)
974 return memslot;
975 }
976 return NULL;
977}
978
979struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
980{
981 return __gfn_to_memslot(kvm_memslots(kvm), gfn);
982}
983EXPORT_SYMBOL_GPL(gfn_to_memslot);
984
985int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
986{
987 int i;
988 struct kvm_memslots *slots = kvm_memslots(kvm);
989
990 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
991 struct kvm_memory_slot *memslot = &slots->memslots[i];
992
993 if (memslot->flags & KVM_MEMSLOT_INVALID)
994 continue;
995
996 if (gfn >= memslot->base_gfn
997 && gfn < memslot->base_gfn + memslot->npages)
998 return 1;
999 }
1000 return 0;
1001}
1002EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
1003
1004unsigned long kvm_host_page_size(struct kvm *kvm, gfn_t gfn)
1005{
1006 struct vm_area_struct *vma;
1007 unsigned long addr, size;
1008
1009 size = PAGE_SIZE;
1010
1011 addr = gfn_to_hva(kvm, gfn);
1012 if (kvm_is_error_hva(addr))
1013 return PAGE_SIZE;
1014
1015 down_read(¤t->mm->mmap_sem);
1016 vma = find_vma(current->mm, addr);
1017 if (!vma)
1018 goto out;
1019
1020 size = vma_kernel_pagesize(vma);
1021
1022out:
1023 up_read(¤t->mm->mmap_sem);
1024
1025 return size;
1026}
1027
1028static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
1029 gfn_t *nr_pages)
1030{
1031 if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
1032 return bad_hva();
1033
1034 if (nr_pages)
1035 *nr_pages = slot->npages - (gfn - slot->base_gfn);
1036
1037 return gfn_to_hva_memslot(slot, gfn);
1038}
1039
1040unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
1041{
1042 return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
1043}
1044EXPORT_SYMBOL_GPL(gfn_to_hva);
1045
1046static pfn_t get_fault_pfn(void)
1047{
1048 get_page(fault_page);
1049 return fault_pfn;
1050}
1051
1052int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1053 unsigned long start, int write, struct page **page)
1054{
1055 int flags = FOLL_TOUCH | FOLL_NOWAIT | FOLL_HWPOISON | FOLL_GET;
1056
1057 if (write)
1058 flags |= FOLL_WRITE;
1059
1060 return __get_user_pages(tsk, mm, start, 1, flags, page, NULL, NULL);
1061}
1062
1063static inline int check_user_page_hwpoison(unsigned long addr)
1064{
1065 int rc, flags = FOLL_TOUCH | FOLL_HWPOISON | FOLL_WRITE;
1066
1067 rc = __get_user_pages(current, current->mm, addr, 1,
1068 flags, NULL, NULL, NULL);
1069 return rc == -EHWPOISON;
1070}
1071
1072static pfn_t hva_to_pfn(struct kvm *kvm, unsigned long addr, bool atomic,
1073 bool *async, bool write_fault, bool *writable)
1074{
1075 struct page *page[1];
1076 int npages = 0;
1077 pfn_t pfn;
1078
1079 /* we can do it either atomically or asynchronously, not both */
1080 BUG_ON(atomic && async);
1081
1082 BUG_ON(!write_fault && !writable);
1083
1084 if (writable)
1085 *writable = true;
1086
1087 if (atomic || async)
1088 npages = __get_user_pages_fast(addr, 1, 1, page);
1089
1090 if (unlikely(npages != 1) && !atomic) {
1091 might_sleep();
1092
1093 if (writable)
1094 *writable = write_fault;
1095
1096 if (async) {
1097 down_read(¤t->mm->mmap_sem);
1098 npages = get_user_page_nowait(current, current->mm,
1099 addr, write_fault, page);
1100 up_read(¤t->mm->mmap_sem);
1101 } else
1102 npages = get_user_pages_fast(addr, 1, write_fault,
1103 page);
1104
1105 /* map read fault as writable if possible */
1106 if (unlikely(!write_fault) && npages == 1) {
1107 struct page *wpage[1];
1108
1109 npages = __get_user_pages_fast(addr, 1, 1, wpage);
1110 if (npages == 1) {
1111 *writable = true;
1112 put_page(page[0]);
1113 page[0] = wpage[0];
1114 }
1115 npages = 1;
1116 }
1117 }
1118
1119 if (unlikely(npages != 1)) {
1120 struct vm_area_struct *vma;
1121
1122 if (atomic)
1123 return get_fault_pfn();
1124
1125 down_read(¤t->mm->mmap_sem);
1126 if (npages == -EHWPOISON ||
1127 (!async && check_user_page_hwpoison(addr))) {
1128 up_read(¤t->mm->mmap_sem);
1129 get_page(hwpoison_page);
1130 return page_to_pfn(hwpoison_page);
1131 }
1132
1133 vma = find_vma_intersection(current->mm, addr, addr+1);
1134
1135 if (vma == NULL)
1136 pfn = get_fault_pfn();
1137 else if ((vma->vm_flags & VM_PFNMAP)) {
1138 pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) +
1139 vma->vm_pgoff;
1140 BUG_ON(!kvm_is_mmio_pfn(pfn));
1141 } else {
1142 if (async && (vma->vm_flags & VM_WRITE))
1143 *async = true;
1144 pfn = get_fault_pfn();
1145 }
1146 up_read(¤t->mm->mmap_sem);
1147 } else
1148 pfn = page_to_pfn(page[0]);
1149
1150 return pfn;
1151}
1152
1153pfn_t hva_to_pfn_atomic(struct kvm *kvm, unsigned long addr)
1154{
1155 return hva_to_pfn(kvm, addr, true, NULL, true, NULL);
1156}
1157EXPORT_SYMBOL_GPL(hva_to_pfn_atomic);
1158
1159static pfn_t __gfn_to_pfn(struct kvm *kvm, gfn_t gfn, bool atomic, bool *async,
1160 bool write_fault, bool *writable)
1161{
1162 unsigned long addr;
1163
1164 if (async)
1165 *async = false;
1166
1167 addr = gfn_to_hva(kvm, gfn);
1168 if (kvm_is_error_hva(addr)) {
1169 get_page(bad_page);
1170 return page_to_pfn(bad_page);
1171 }
1172
1173 return hva_to_pfn(kvm, addr, atomic, async, write_fault, writable);
1174}
1175
1176pfn_t gfn_to_pfn_atomic(struct kvm *kvm, gfn_t gfn)
1177{
1178 return __gfn_to_pfn(kvm, gfn, true, NULL, true, NULL);
1179}
1180EXPORT_SYMBOL_GPL(gfn_to_pfn_atomic);
1181
1182pfn_t gfn_to_pfn_async(struct kvm *kvm, gfn_t gfn, bool *async,
1183 bool write_fault, bool *writable)
1184{
1185 return __gfn_to_pfn(kvm, gfn, false, async, write_fault, writable);
1186}
1187EXPORT_SYMBOL_GPL(gfn_to_pfn_async);
1188
1189pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
1190{
1191 return __gfn_to_pfn(kvm, gfn, false, NULL, true, NULL);
1192}
1193EXPORT_SYMBOL_GPL(gfn_to_pfn);
1194
1195pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
1196 bool *writable)
1197{
1198 return __gfn_to_pfn(kvm, gfn, false, NULL, write_fault, writable);
1199}
1200EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
1201
1202pfn_t gfn_to_pfn_memslot(struct kvm *kvm,
1203 struct kvm_memory_slot *slot, gfn_t gfn)
1204{
1205 unsigned long addr = gfn_to_hva_memslot(slot, gfn);
1206 return hva_to_pfn(kvm, addr, false, NULL, true, NULL);
1207}
1208
1209int gfn_to_page_many_atomic(struct kvm *kvm, gfn_t gfn, struct page **pages,
1210 int nr_pages)
1211{
1212 unsigned long addr;
1213 gfn_t entry;
1214
1215 addr = gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, &entry);
1216 if (kvm_is_error_hva(addr))
1217 return -1;
1218
1219 if (entry < nr_pages)
1220 return 0;
1221
1222 return __get_user_pages_fast(addr, nr_pages, 1, pages);
1223}
1224EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
1225
1226struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
1227{
1228 pfn_t pfn;
1229
1230 pfn = gfn_to_pfn(kvm, gfn);
1231 if (!kvm_is_mmio_pfn(pfn))
1232 return pfn_to_page(pfn);
1233
1234 WARN_ON(kvm_is_mmio_pfn(pfn));
1235
1236 get_page(bad_page);
1237 return bad_page;
1238}
1239
1240EXPORT_SYMBOL_GPL(gfn_to_page);
1241
1242void kvm_release_page_clean(struct page *page)
1243{
1244 kvm_release_pfn_clean(page_to_pfn(page));
1245}
1246EXPORT_SYMBOL_GPL(kvm_release_page_clean);
1247
1248void kvm_release_pfn_clean(pfn_t pfn)
1249{
1250 if (!kvm_is_mmio_pfn(pfn))
1251 put_page(pfn_to_page(pfn));
1252}
1253EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
1254
1255void kvm_release_page_dirty(struct page *page)
1256{
1257 kvm_release_pfn_dirty(page_to_pfn(page));
1258}
1259EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
1260
1261void kvm_release_pfn_dirty(pfn_t pfn)
1262{
1263 kvm_set_pfn_dirty(pfn);
1264 kvm_release_pfn_clean(pfn);
1265}
1266EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
1267
1268void kvm_set_page_dirty(struct page *page)
1269{
1270 kvm_set_pfn_dirty(page_to_pfn(page));
1271}
1272EXPORT_SYMBOL_GPL(kvm_set_page_dirty);
1273
1274void kvm_set_pfn_dirty(pfn_t pfn)
1275{
1276 if (!kvm_is_mmio_pfn(pfn)) {
1277 struct page *page = pfn_to_page(pfn);
1278 if (!PageReserved(page))
1279 SetPageDirty(page);
1280 }
1281}
1282EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
1283
1284void kvm_set_pfn_accessed(pfn_t pfn)
1285{
1286 if (!kvm_is_mmio_pfn(pfn))
1287 mark_page_accessed(pfn_to_page(pfn));
1288}
1289EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
1290
1291void kvm_get_pfn(pfn_t pfn)
1292{
1293 if (!kvm_is_mmio_pfn(pfn))
1294 get_page(pfn_to_page(pfn));
1295}
1296EXPORT_SYMBOL_GPL(kvm_get_pfn);
1297
1298static int next_segment(unsigned long len, int offset)
1299{
1300 if (len > PAGE_SIZE - offset)
1301 return PAGE_SIZE - offset;
1302 else
1303 return len;
1304}
1305
1306int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
1307 int len)
1308{
1309 int r;
1310 unsigned long addr;
1311
1312 addr = gfn_to_hva(kvm, gfn);
1313 if (kvm_is_error_hva(addr))
1314 return -EFAULT;
1315 r = __copy_from_user(data, (void __user *)addr + offset, len);
1316 if (r)
1317 return -EFAULT;
1318 return 0;
1319}
1320EXPORT_SYMBOL_GPL(kvm_read_guest_page);
1321
1322int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
1323{
1324 gfn_t gfn = gpa >> PAGE_SHIFT;
1325 int seg;
1326 int offset = offset_in_page(gpa);
1327 int ret;
1328
1329 while ((seg = next_segment(len, offset)) != 0) {
1330 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
1331 if (ret < 0)
1332 return ret;
1333 offset = 0;
1334 len -= seg;
1335 data += seg;
1336 ++gfn;
1337 }
1338 return 0;
1339}
1340EXPORT_SYMBOL_GPL(kvm_read_guest);
1341
1342int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data,
1343 unsigned long len)
1344{
1345 int r;
1346 unsigned long addr;
1347 gfn_t gfn = gpa >> PAGE_SHIFT;
1348 int offset = offset_in_page(gpa);
1349
1350 addr = gfn_to_hva(kvm, gfn);
1351 if (kvm_is_error_hva(addr))
1352 return -EFAULT;
1353 pagefault_disable();
1354 r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
1355 pagefault_enable();
1356 if (r)
1357 return -EFAULT;
1358 return 0;
1359}
1360EXPORT_SYMBOL(kvm_read_guest_atomic);
1361
1362int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
1363 int offset, int len)
1364{
1365 int r;
1366 unsigned long addr;
1367
1368 addr = gfn_to_hva(kvm, gfn);
1369 if (kvm_is_error_hva(addr))
1370 return -EFAULT;
1371 r = __copy_to_user((void __user *)addr + offset, data, len);
1372 if (r)
1373 return -EFAULT;
1374 mark_page_dirty(kvm, gfn);
1375 return 0;
1376}
1377EXPORT_SYMBOL_GPL(kvm_write_guest_page);
1378
1379int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
1380 unsigned long len)
1381{
1382 gfn_t gfn = gpa >> PAGE_SHIFT;
1383 int seg;
1384 int offset = offset_in_page(gpa);
1385 int ret;
1386
1387 while ((seg = next_segment(len, offset)) != 0) {
1388 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
1389 if (ret < 0)
1390 return ret;
1391 offset = 0;
1392 len -= seg;
1393 data += seg;
1394 ++gfn;
1395 }
1396 return 0;
1397}
1398
1399int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1400 gpa_t gpa)
1401{
1402 struct kvm_memslots *slots = kvm_memslots(kvm);
1403 int offset = offset_in_page(gpa);
1404 gfn_t gfn = gpa >> PAGE_SHIFT;
1405
1406 ghc->gpa = gpa;
1407 ghc->generation = slots->generation;
1408 ghc->memslot = __gfn_to_memslot(slots, gfn);
1409 ghc->hva = gfn_to_hva_many(ghc->memslot, gfn, NULL);
1410 if (!kvm_is_error_hva(ghc->hva))
1411 ghc->hva += offset;
1412 else
1413 return -EFAULT;
1414
1415 return 0;
1416}
1417EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
1418
1419int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1420 void *data, unsigned long len)
1421{
1422 struct kvm_memslots *slots = kvm_memslots(kvm);
1423 int r;
1424
1425 if (slots->generation != ghc->generation)
1426 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1427
1428 if (kvm_is_error_hva(ghc->hva))
1429 return -EFAULT;
1430
1431 r = __copy_to_user((void __user *)ghc->hva, data, len);
1432 if (r)
1433 return -EFAULT;
1434 mark_page_dirty_in_slot(kvm, ghc->memslot, ghc->gpa >> PAGE_SHIFT);
1435
1436 return 0;
1437}
1438EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
1439
1440int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
1441 void *data, unsigned long len)
1442{
1443 struct kvm_memslots *slots = kvm_memslots(kvm);
1444 int r;
1445
1446 if (slots->generation != ghc->generation)
1447 kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa);
1448
1449 if (kvm_is_error_hva(ghc->hva))
1450 return -EFAULT;
1451
1452 r = __copy_from_user(data, (void __user *)ghc->hva, len);
1453 if (r)
1454 return -EFAULT;
1455
1456 return 0;
1457}
1458EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
1459
1460int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len)
1461{
1462 return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page,
1463 offset, len);
1464}
1465EXPORT_SYMBOL_GPL(kvm_clear_guest_page);
1466
1467int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
1468{
1469 gfn_t gfn = gpa >> PAGE_SHIFT;
1470 int seg;
1471 int offset = offset_in_page(gpa);
1472 int ret;
1473
1474 while ((seg = next_segment(len, offset)) != 0) {
1475 ret = kvm_clear_guest_page(kvm, gfn, offset, seg);
1476 if (ret < 0)
1477 return ret;
1478 offset = 0;
1479 len -= seg;
1480 ++gfn;
1481 }
1482 return 0;
1483}
1484EXPORT_SYMBOL_GPL(kvm_clear_guest);
1485
1486void mark_page_dirty_in_slot(struct kvm *kvm, struct kvm_memory_slot *memslot,
1487 gfn_t gfn)
1488{
1489 if (memslot && memslot->dirty_bitmap) {
1490 unsigned long rel_gfn = gfn - memslot->base_gfn;
1491
1492 __set_bit_le(rel_gfn, memslot->dirty_bitmap);
1493 }
1494}
1495
1496void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
1497{
1498 struct kvm_memory_slot *memslot;
1499
1500 memslot = gfn_to_memslot(kvm, gfn);
1501 mark_page_dirty_in_slot(kvm, memslot, gfn);
1502}
1503
1504/*
1505 * The vCPU has executed a HLT instruction with in-kernel mode enabled.
1506 */
1507void kvm_vcpu_block(struct kvm_vcpu *vcpu)
1508{
1509 DEFINE_WAIT(wait);
1510
1511 for (;;) {
1512 prepare_to_wait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
1513
1514 if (kvm_arch_vcpu_runnable(vcpu)) {
1515 kvm_make_request(KVM_REQ_UNHALT, vcpu);
1516 break;
1517 }
1518 if (kvm_cpu_has_pending_timer(vcpu))
1519 break;
1520 if (signal_pending(current))
1521 break;
1522
1523 schedule();
1524 }
1525
1526 finish_wait(&vcpu->wq, &wait);
1527}
1528
1529void kvm_resched(struct kvm_vcpu *vcpu)
1530{
1531 if (!need_resched())
1532 return;
1533 cond_resched();
1534}
1535EXPORT_SYMBOL_GPL(kvm_resched);
1536
1537void kvm_vcpu_on_spin(struct kvm_vcpu *me)
1538{
1539 struct kvm *kvm = me->kvm;
1540 struct kvm_vcpu *vcpu;
1541 int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
1542 int yielded = 0;
1543 int pass;
1544 int i;
1545
1546 /*
1547 * We boost the priority of a VCPU that is runnable but not
1548 * currently running, because it got preempted by something
1549 * else and called schedule in __vcpu_run. Hopefully that
1550 * VCPU is holding the lock that we need and will release it.
1551 * We approximate round-robin by starting at the last boosted VCPU.
1552 */
1553 for (pass = 0; pass < 2 && !yielded; pass++) {
1554 kvm_for_each_vcpu(i, vcpu, kvm) {
1555 struct task_struct *task = NULL;
1556 struct pid *pid;
1557 if (!pass && i < last_boosted_vcpu) {
1558 i = last_boosted_vcpu;
1559 continue;
1560 } else if (pass && i > last_boosted_vcpu)
1561 break;
1562 if (vcpu == me)
1563 continue;
1564 if (waitqueue_active(&vcpu->wq))
1565 continue;
1566 rcu_read_lock();
1567 pid = rcu_dereference(vcpu->pid);
1568 if (pid)
1569 task = get_pid_task(vcpu->pid, PIDTYPE_PID);
1570 rcu_read_unlock();
1571 if (!task)
1572 continue;
1573 if (task->flags & PF_VCPU) {
1574 put_task_struct(task);
1575 continue;
1576 }
1577 if (yield_to(task, 1)) {
1578 put_task_struct(task);
1579 kvm->last_boosted_vcpu = i;
1580 yielded = 1;
1581 break;
1582 }
1583 put_task_struct(task);
1584 }
1585 }
1586}
1587EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
1588
1589static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1590{
1591 struct kvm_vcpu *vcpu = vma->vm_file->private_data;
1592 struct page *page;
1593
1594 if (vmf->pgoff == 0)
1595 page = virt_to_page(vcpu->run);
1596#ifdef CONFIG_X86
1597 else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
1598 page = virt_to_page(vcpu->arch.pio_data);
1599#endif
1600#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
1601 else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
1602 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
1603#endif
1604 else
1605 return VM_FAULT_SIGBUS;
1606 get_page(page);
1607 vmf->page = page;
1608 return 0;
1609}
1610
1611static const struct vm_operations_struct kvm_vcpu_vm_ops = {
1612 .fault = kvm_vcpu_fault,
1613};
1614
1615static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
1616{
1617 vma->vm_ops = &kvm_vcpu_vm_ops;
1618 return 0;
1619}
1620
1621static int kvm_vcpu_release(struct inode *inode, struct file *filp)
1622{
1623 struct kvm_vcpu *vcpu = filp->private_data;
1624
1625 kvm_put_kvm(vcpu->kvm);
1626 return 0;
1627}
1628
1629static struct file_operations kvm_vcpu_fops = {
1630 .release = kvm_vcpu_release,
1631 .unlocked_ioctl = kvm_vcpu_ioctl,
1632#ifdef CONFIG_COMPAT
1633 .compat_ioctl = kvm_vcpu_compat_ioctl,
1634#endif
1635 .mmap = kvm_vcpu_mmap,
1636 .llseek = noop_llseek,
1637};
1638
1639/*
1640 * Allocates an inode for the vcpu.
1641 */
1642static int create_vcpu_fd(struct kvm_vcpu *vcpu)
1643{
1644 return anon_inode_getfd("kvm-vcpu", &kvm_vcpu_fops, vcpu, O_RDWR);
1645}
1646
1647/*
1648 * Creates some virtual cpus. Good luck creating more than one.
1649 */
1650static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
1651{
1652 int r;
1653 struct kvm_vcpu *vcpu, *v;
1654
1655 vcpu = kvm_arch_vcpu_create(kvm, id);
1656 if (IS_ERR(vcpu))
1657 return PTR_ERR(vcpu);
1658
1659 preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
1660
1661 r = kvm_arch_vcpu_setup(vcpu);
1662 if (r)
1663 goto vcpu_destroy;
1664
1665 mutex_lock(&kvm->lock);
1666 if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
1667 r = -EINVAL;
1668 goto unlock_vcpu_destroy;
1669 }
1670
1671 kvm_for_each_vcpu(r, v, kvm)
1672 if (v->vcpu_id == id) {
1673 r = -EEXIST;
1674 goto unlock_vcpu_destroy;
1675 }
1676
1677 BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
1678
1679 /* Now it's all set up, let userspace reach it */
1680 kvm_get_kvm(kvm);
1681 r = create_vcpu_fd(vcpu);
1682 if (r < 0) {
1683 kvm_put_kvm(kvm);
1684 goto unlock_vcpu_destroy;
1685 }
1686
1687 kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
1688 smp_wmb();
1689 atomic_inc(&kvm->online_vcpus);
1690
1691#ifdef CONFIG_KVM_APIC_ARCHITECTURE
1692 if (kvm->bsp_vcpu_id == id)
1693 kvm->bsp_vcpu = vcpu;
1694#endif
1695 mutex_unlock(&kvm->lock);
1696 return r;
1697
1698unlock_vcpu_destroy:
1699 mutex_unlock(&kvm->lock);
1700vcpu_destroy:
1701 kvm_arch_vcpu_destroy(vcpu);
1702 return r;
1703}
1704
1705static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
1706{
1707 if (sigset) {
1708 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
1709 vcpu->sigset_active = 1;
1710 vcpu->sigset = *sigset;
1711 } else
1712 vcpu->sigset_active = 0;
1713 return 0;
1714}
1715
1716static long kvm_vcpu_ioctl(struct file *filp,
1717 unsigned int ioctl, unsigned long arg)
1718{
1719 struct kvm_vcpu *vcpu = filp->private_data;
1720 void __user *argp = (void __user *)arg;
1721 int r;
1722 struct kvm_fpu *fpu = NULL;
1723 struct kvm_sregs *kvm_sregs = NULL;
1724
1725 if (vcpu->kvm->mm != current->mm)
1726 return -EIO;
1727
1728#if defined(CONFIG_S390) || defined(CONFIG_PPC)
1729 /*
1730 * Special cases: vcpu ioctls that are asynchronous to vcpu execution,
1731 * so vcpu_load() would break it.
1732 */
1733 if (ioctl == KVM_S390_INTERRUPT || ioctl == KVM_INTERRUPT)
1734 return kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1735#endif
1736
1737
1738 vcpu_load(vcpu);
1739 switch (ioctl) {
1740 case KVM_RUN:
1741 r = -EINVAL;
1742 if (arg)
1743 goto out;
1744 r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
1745 trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
1746 break;
1747 case KVM_GET_REGS: {
1748 struct kvm_regs *kvm_regs;
1749
1750 r = -ENOMEM;
1751 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1752 if (!kvm_regs)
1753 goto out;
1754 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
1755 if (r)
1756 goto out_free1;
1757 r = -EFAULT;
1758 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
1759 goto out_free1;
1760 r = 0;
1761out_free1:
1762 kfree(kvm_regs);
1763 break;
1764 }
1765 case KVM_SET_REGS: {
1766 struct kvm_regs *kvm_regs;
1767
1768 r = -ENOMEM;
1769 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
1770 if (!kvm_regs)
1771 goto out;
1772 r = -EFAULT;
1773 if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
1774 goto out_free2;
1775 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
1776 if (r)
1777 goto out_free2;
1778 r = 0;
1779out_free2:
1780 kfree(kvm_regs);
1781 break;
1782 }
1783 case KVM_GET_SREGS: {
1784 kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1785 r = -ENOMEM;
1786 if (!kvm_sregs)
1787 goto out;
1788 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
1789 if (r)
1790 goto out;
1791 r = -EFAULT;
1792 if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
1793 goto out;
1794 r = 0;
1795 break;
1796 }
1797 case KVM_SET_SREGS: {
1798 kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL);
1799 r = -ENOMEM;
1800 if (!kvm_sregs)
1801 goto out;
1802 r = -EFAULT;
1803 if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs)))
1804 goto out;
1805 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
1806 if (r)
1807 goto out;
1808 r = 0;
1809 break;
1810 }
1811 case KVM_GET_MP_STATE: {
1812 struct kvm_mp_state mp_state;
1813
1814 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
1815 if (r)
1816 goto out;
1817 r = -EFAULT;
1818 if (copy_to_user(argp, &mp_state, sizeof mp_state))
1819 goto out;
1820 r = 0;
1821 break;
1822 }
1823 case KVM_SET_MP_STATE: {
1824 struct kvm_mp_state mp_state;
1825
1826 r = -EFAULT;
1827 if (copy_from_user(&mp_state, argp, sizeof mp_state))
1828 goto out;
1829 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
1830 if (r)
1831 goto out;
1832 r = 0;
1833 break;
1834 }
1835 case KVM_TRANSLATE: {
1836 struct kvm_translation tr;
1837
1838 r = -EFAULT;
1839 if (copy_from_user(&tr, argp, sizeof tr))
1840 goto out;
1841 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
1842 if (r)
1843 goto out;
1844 r = -EFAULT;
1845 if (copy_to_user(argp, &tr, sizeof tr))
1846 goto out;
1847 r = 0;
1848 break;
1849 }
1850 case KVM_SET_GUEST_DEBUG: {
1851 struct kvm_guest_debug dbg;
1852
1853 r = -EFAULT;
1854 if (copy_from_user(&dbg, argp, sizeof dbg))
1855 goto out;
1856 r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
1857 if (r)
1858 goto out;
1859 r = 0;
1860 break;
1861 }
1862 case KVM_SET_SIGNAL_MASK: {
1863 struct kvm_signal_mask __user *sigmask_arg = argp;
1864 struct kvm_signal_mask kvm_sigmask;
1865 sigset_t sigset, *p;
1866
1867 p = NULL;
1868 if (argp) {
1869 r = -EFAULT;
1870 if (copy_from_user(&kvm_sigmask, argp,
1871 sizeof kvm_sigmask))
1872 goto out;
1873 r = -EINVAL;
1874 if (kvm_sigmask.len != sizeof sigset)
1875 goto out;
1876 r = -EFAULT;
1877 if (copy_from_user(&sigset, sigmask_arg->sigset,
1878 sizeof sigset))
1879 goto out;
1880 p = &sigset;
1881 }
1882 r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
1883 break;
1884 }
1885 case KVM_GET_FPU: {
1886 fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1887 r = -ENOMEM;
1888 if (!fpu)
1889 goto out;
1890 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
1891 if (r)
1892 goto out;
1893 r = -EFAULT;
1894 if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
1895 goto out;
1896 r = 0;
1897 break;
1898 }
1899 case KVM_SET_FPU: {
1900 fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL);
1901 r = -ENOMEM;
1902 if (!fpu)
1903 goto out;
1904 r = -EFAULT;
1905 if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu)))
1906 goto out;
1907 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
1908 if (r)
1909 goto out;
1910 r = 0;
1911 break;
1912 }
1913 default:
1914 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
1915 }
1916out:
1917 vcpu_put(vcpu);
1918 kfree(fpu);
1919 kfree(kvm_sregs);
1920 return r;
1921}
1922
1923#ifdef CONFIG_COMPAT
1924static long kvm_vcpu_compat_ioctl(struct file *filp,
1925 unsigned int ioctl, unsigned long arg)
1926{
1927 struct kvm_vcpu *vcpu = filp->private_data;
1928 void __user *argp = compat_ptr(arg);
1929 int r;
1930
1931 if (vcpu->kvm->mm != current->mm)
1932 return -EIO;
1933
1934 switch (ioctl) {
1935 case KVM_SET_SIGNAL_MASK: {
1936 struct kvm_signal_mask __user *sigmask_arg = argp;
1937 struct kvm_signal_mask kvm_sigmask;
1938 compat_sigset_t csigset;
1939 sigset_t sigset;
1940
1941 if (argp) {
1942 r = -EFAULT;
1943 if (copy_from_user(&kvm_sigmask, argp,
1944 sizeof kvm_sigmask))
1945 goto out;
1946 r = -EINVAL;
1947 if (kvm_sigmask.len != sizeof csigset)
1948 goto out;
1949 r = -EFAULT;
1950 if (copy_from_user(&csigset, sigmask_arg->sigset,
1951 sizeof csigset))
1952 goto out;
1953 }
1954 sigset_from_compat(&sigset, &csigset);
1955 r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
1956 break;
1957 }
1958 default:
1959 r = kvm_vcpu_ioctl(filp, ioctl, arg);
1960 }
1961
1962out:
1963 return r;
1964}
1965#endif
1966
1967static long kvm_vm_ioctl(struct file *filp,
1968 unsigned int ioctl, unsigned long arg)
1969{
1970 struct kvm *kvm = filp->private_data;
1971 void __user *argp = (void __user *)arg;
1972 int r;
1973
1974 if (kvm->mm != current->mm)
1975 return -EIO;
1976 switch (ioctl) {
1977 case KVM_CREATE_VCPU:
1978 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
1979 if (r < 0)
1980 goto out;
1981 break;
1982 case KVM_SET_USER_MEMORY_REGION: {
1983 struct kvm_userspace_memory_region kvm_userspace_mem;
1984
1985 r = -EFAULT;
1986 if (copy_from_user(&kvm_userspace_mem, argp,
1987 sizeof kvm_userspace_mem))
1988 goto out;
1989
1990 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
1991 if (r)
1992 goto out;
1993 break;
1994 }
1995 case KVM_GET_DIRTY_LOG: {
1996 struct kvm_dirty_log log;
1997
1998 r = -EFAULT;
1999 if (copy_from_user(&log, argp, sizeof log))
2000 goto out;
2001 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2002 if (r)
2003 goto out;
2004 break;
2005 }
2006#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2007 case KVM_REGISTER_COALESCED_MMIO: {
2008 struct kvm_coalesced_mmio_zone zone;
2009 r = -EFAULT;
2010 if (copy_from_user(&zone, argp, sizeof zone))
2011 goto out;
2012 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
2013 if (r)
2014 goto out;
2015 r = 0;
2016 break;
2017 }
2018 case KVM_UNREGISTER_COALESCED_MMIO: {
2019 struct kvm_coalesced_mmio_zone zone;
2020 r = -EFAULT;
2021 if (copy_from_user(&zone, argp, sizeof zone))
2022 goto out;
2023 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
2024 if (r)
2025 goto out;
2026 r = 0;
2027 break;
2028 }
2029#endif
2030 case KVM_IRQFD: {
2031 struct kvm_irqfd data;
2032
2033 r = -EFAULT;
2034 if (copy_from_user(&data, argp, sizeof data))
2035 goto out;
2036 r = kvm_irqfd(kvm, data.fd, data.gsi, data.flags);
2037 break;
2038 }
2039 case KVM_IOEVENTFD: {
2040 struct kvm_ioeventfd data;
2041
2042 r = -EFAULT;
2043 if (copy_from_user(&data, argp, sizeof data))
2044 goto out;
2045 r = kvm_ioeventfd(kvm, &data);
2046 break;
2047 }
2048#ifdef CONFIG_KVM_APIC_ARCHITECTURE
2049 case KVM_SET_BOOT_CPU_ID:
2050 r = 0;
2051 mutex_lock(&kvm->lock);
2052 if (atomic_read(&kvm->online_vcpus) != 0)
2053 r = -EBUSY;
2054 else
2055 kvm->bsp_vcpu_id = arg;
2056 mutex_unlock(&kvm->lock);
2057 break;
2058#endif
2059 default:
2060 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
2061 if (r == -ENOTTY)
2062 r = kvm_vm_ioctl_assigned_device(kvm, ioctl, arg);
2063 }
2064out:
2065 return r;
2066}
2067
2068#ifdef CONFIG_COMPAT
2069struct compat_kvm_dirty_log {
2070 __u32 slot;
2071 __u32 padding1;
2072 union {
2073 compat_uptr_t dirty_bitmap; /* one bit per page */
2074 __u64 padding2;
2075 };
2076};
2077
2078static long kvm_vm_compat_ioctl(struct file *filp,
2079 unsigned int ioctl, unsigned long arg)
2080{
2081 struct kvm *kvm = filp->private_data;
2082 int r;
2083
2084 if (kvm->mm != current->mm)
2085 return -EIO;
2086 switch (ioctl) {
2087 case KVM_GET_DIRTY_LOG: {
2088 struct compat_kvm_dirty_log compat_log;
2089 struct kvm_dirty_log log;
2090
2091 r = -EFAULT;
2092 if (copy_from_user(&compat_log, (void __user *)arg,
2093 sizeof(compat_log)))
2094 goto out;
2095 log.slot = compat_log.slot;
2096 log.padding1 = compat_log.padding1;
2097 log.padding2 = compat_log.padding2;
2098 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
2099
2100 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
2101 if (r)
2102 goto out;
2103 break;
2104 }
2105 default:
2106 r = kvm_vm_ioctl(filp, ioctl, arg);
2107 }
2108
2109out:
2110 return r;
2111}
2112#endif
2113
2114static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
2115{
2116 struct page *page[1];
2117 unsigned long addr;
2118 int npages;
2119 gfn_t gfn = vmf->pgoff;
2120 struct kvm *kvm = vma->vm_file->private_data;
2121
2122 addr = gfn_to_hva(kvm, gfn);
2123 if (kvm_is_error_hva(addr))
2124 return VM_FAULT_SIGBUS;
2125
2126 npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page,
2127 NULL);
2128 if (unlikely(npages != 1))
2129 return VM_FAULT_SIGBUS;
2130
2131 vmf->page = page[0];
2132 return 0;
2133}
2134
2135static const struct vm_operations_struct kvm_vm_vm_ops = {
2136 .fault = kvm_vm_fault,
2137};
2138
2139static int kvm_vm_mmap(struct file *file, struct vm_area_struct *vma)
2140{
2141 vma->vm_ops = &kvm_vm_vm_ops;
2142 return 0;
2143}
2144
2145static struct file_operations kvm_vm_fops = {
2146 .release = kvm_vm_release,
2147 .unlocked_ioctl = kvm_vm_ioctl,
2148#ifdef CONFIG_COMPAT
2149 .compat_ioctl = kvm_vm_compat_ioctl,
2150#endif
2151 .mmap = kvm_vm_mmap,
2152 .llseek = noop_llseek,
2153};
2154
2155static int kvm_dev_ioctl_create_vm(void)
2156{
2157 int r;
2158 struct kvm *kvm;
2159
2160 kvm = kvm_create_vm();
2161 if (IS_ERR(kvm))
2162 return PTR_ERR(kvm);
2163#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2164 r = kvm_coalesced_mmio_init(kvm);
2165 if (r < 0) {
2166 kvm_put_kvm(kvm);
2167 return r;
2168 }
2169#endif
2170 r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
2171 if (r < 0)
2172 kvm_put_kvm(kvm);
2173
2174 return r;
2175}
2176
2177static long kvm_dev_ioctl_check_extension_generic(long arg)
2178{
2179 switch (arg) {
2180 case KVM_CAP_USER_MEMORY:
2181 case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
2182 case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
2183#ifdef CONFIG_KVM_APIC_ARCHITECTURE
2184 case KVM_CAP_SET_BOOT_CPU_ID:
2185#endif
2186 case KVM_CAP_INTERNAL_ERROR_DATA:
2187 return 1;
2188#ifdef CONFIG_HAVE_KVM_IRQCHIP
2189 case KVM_CAP_IRQ_ROUTING:
2190 return KVM_MAX_IRQ_ROUTES;
2191#endif
2192 default:
2193 break;
2194 }
2195 return kvm_dev_ioctl_check_extension(arg);
2196}
2197
2198static long kvm_dev_ioctl(struct file *filp,
2199 unsigned int ioctl, unsigned long arg)
2200{
2201 long r = -EINVAL;
2202
2203 switch (ioctl) {
2204 case KVM_GET_API_VERSION:
2205 r = -EINVAL;
2206 if (arg)
2207 goto out;
2208 r = KVM_API_VERSION;
2209 break;
2210 case KVM_CREATE_VM:
2211 r = -EINVAL;
2212 if (arg)
2213 goto out;
2214 r = kvm_dev_ioctl_create_vm();
2215 break;
2216 case KVM_CHECK_EXTENSION:
2217 r = kvm_dev_ioctl_check_extension_generic(arg);
2218 break;
2219 case KVM_GET_VCPU_MMAP_SIZE:
2220 r = -EINVAL;
2221 if (arg)
2222 goto out;
2223 r = PAGE_SIZE; /* struct kvm_run */
2224#ifdef CONFIG_X86
2225 r += PAGE_SIZE; /* pio data page */
2226#endif
2227#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
2228 r += PAGE_SIZE; /* coalesced mmio ring page */
2229#endif
2230 break;
2231 case KVM_TRACE_ENABLE:
2232 case KVM_TRACE_PAUSE:
2233 case KVM_TRACE_DISABLE:
2234 r = -EOPNOTSUPP;
2235 break;
2236 default:
2237 return kvm_arch_dev_ioctl(filp, ioctl, arg);
2238 }
2239out:
2240 return r;
2241}
2242
2243static struct file_operations kvm_chardev_ops = {
2244 .unlocked_ioctl = kvm_dev_ioctl,
2245 .compat_ioctl = kvm_dev_ioctl,
2246 .llseek = noop_llseek,
2247};
2248
2249static struct miscdevice kvm_dev = {
2250 KVM_MINOR,
2251 "kvm",
2252 &kvm_chardev_ops,
2253};
2254
2255static void hardware_enable_nolock(void *junk)
2256{
2257 int cpu = raw_smp_processor_id();
2258 int r;
2259
2260 if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
2261 return;
2262
2263 cpumask_set_cpu(cpu, cpus_hardware_enabled);
2264
2265 r = kvm_arch_hardware_enable(NULL);
2266
2267 if (r) {
2268 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2269 atomic_inc(&hardware_enable_failed);
2270 printk(KERN_INFO "kvm: enabling virtualization on "
2271 "CPU%d failed\n", cpu);
2272 }
2273}
2274
2275static void hardware_enable(void *junk)
2276{
2277 raw_spin_lock(&kvm_lock);
2278 hardware_enable_nolock(junk);
2279 raw_spin_unlock(&kvm_lock);
2280}
2281
2282static void hardware_disable_nolock(void *junk)
2283{
2284 int cpu = raw_smp_processor_id();
2285
2286 if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
2287 return;
2288 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
2289 kvm_arch_hardware_disable(NULL);
2290}
2291
2292static void hardware_disable(void *junk)
2293{
2294 raw_spin_lock(&kvm_lock);
2295 hardware_disable_nolock(junk);
2296 raw_spin_unlock(&kvm_lock);
2297}
2298
2299static void hardware_disable_all_nolock(void)
2300{
2301 BUG_ON(!kvm_usage_count);
2302
2303 kvm_usage_count--;
2304 if (!kvm_usage_count)
2305 on_each_cpu(hardware_disable_nolock, NULL, 1);
2306}
2307
2308static void hardware_disable_all(void)
2309{
2310 raw_spin_lock(&kvm_lock);
2311 hardware_disable_all_nolock();
2312 raw_spin_unlock(&kvm_lock);
2313}
2314
2315static int hardware_enable_all(void)
2316{
2317 int r = 0;
2318
2319 raw_spin_lock(&kvm_lock);
2320
2321 kvm_usage_count++;
2322 if (kvm_usage_count == 1) {
2323 atomic_set(&hardware_enable_failed, 0);
2324 on_each_cpu(hardware_enable_nolock, NULL, 1);
2325
2326 if (atomic_read(&hardware_enable_failed)) {
2327 hardware_disable_all_nolock();
2328 r = -EBUSY;
2329 }
2330 }
2331
2332 raw_spin_unlock(&kvm_lock);
2333
2334 return r;
2335}
2336
2337static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
2338 void *v)
2339{
2340 int cpu = (long)v;
2341
2342 if (!kvm_usage_count)
2343 return NOTIFY_OK;
2344
2345 val &= ~CPU_TASKS_FROZEN;
2346 switch (val) {
2347 case CPU_DYING:
2348 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
2349 cpu);
2350 hardware_disable(NULL);
2351 break;
2352 case CPU_STARTING:
2353 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
2354 cpu);
2355 hardware_enable(NULL);
2356 break;
2357 }
2358 return NOTIFY_OK;
2359}
2360
2361
2362asmlinkage void kvm_spurious_fault(void)
2363{
2364 /* Fault while not rebooting. We want the trace. */
2365 BUG();
2366}
2367EXPORT_SYMBOL_GPL(kvm_spurious_fault);
2368
2369static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
2370 void *v)
2371{
2372 /*
2373 * Some (well, at least mine) BIOSes hang on reboot if
2374 * in vmx root mode.
2375 *
2376 * And Intel TXT required VMX off for all cpu when system shutdown.
2377 */
2378 printk(KERN_INFO "kvm: exiting hardware virtualization\n");
2379 kvm_rebooting = true;
2380 on_each_cpu(hardware_disable_nolock, NULL, 1);
2381 return NOTIFY_OK;
2382}
2383
2384static struct notifier_block kvm_reboot_notifier = {
2385 .notifier_call = kvm_reboot,
2386 .priority = 0,
2387};
2388
2389static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
2390{
2391 int i;
2392
2393 for (i = 0; i < bus->dev_count; i++) {
2394 struct kvm_io_device *pos = bus->devs[i];
2395
2396 kvm_iodevice_destructor(pos);
2397 }
2398 kfree(bus);
2399}
2400
2401/* kvm_io_bus_write - called under kvm->slots_lock */
2402int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2403 int len, const void *val)
2404{
2405 int i;
2406 struct kvm_io_bus *bus;
2407
2408 bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2409 for (i = 0; i < bus->dev_count; i++)
2410 if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
2411 return 0;
2412 return -EOPNOTSUPP;
2413}
2414
2415/* kvm_io_bus_read - called under kvm->slots_lock */
2416int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
2417 int len, void *val)
2418{
2419 int i;
2420 struct kvm_io_bus *bus;
2421
2422 bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
2423 for (i = 0; i < bus->dev_count; i++)
2424 if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
2425 return 0;
2426 return -EOPNOTSUPP;
2427}
2428
2429/* Caller must hold slots_lock. */
2430int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2431 struct kvm_io_device *dev)
2432{
2433 struct kvm_io_bus *new_bus, *bus;
2434
2435 bus = kvm->buses[bus_idx];
2436 if (bus->dev_count > NR_IOBUS_DEVS-1)
2437 return -ENOSPC;
2438
2439 new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2440 if (!new_bus)
2441 return -ENOMEM;
2442 memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2443 new_bus->devs[new_bus->dev_count++] = dev;
2444 rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2445 synchronize_srcu_expedited(&kvm->srcu);
2446 kfree(bus);
2447
2448 return 0;
2449}
2450
2451/* Caller must hold slots_lock. */
2452int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
2453 struct kvm_io_device *dev)
2454{
2455 int i, r;
2456 struct kvm_io_bus *new_bus, *bus;
2457
2458 new_bus = kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL);
2459 if (!new_bus)
2460 return -ENOMEM;
2461
2462 bus = kvm->buses[bus_idx];
2463 memcpy(new_bus, bus, sizeof(struct kvm_io_bus));
2464
2465 r = -ENOENT;
2466 for (i = 0; i < new_bus->dev_count; i++)
2467 if (new_bus->devs[i] == dev) {
2468 r = 0;
2469 new_bus->devs[i] = new_bus->devs[--new_bus->dev_count];
2470 break;
2471 }
2472
2473 if (r) {
2474 kfree(new_bus);
2475 return r;
2476 }
2477
2478 rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
2479 synchronize_srcu_expedited(&kvm->srcu);
2480 kfree(bus);
2481 return r;
2482}
2483
2484static struct notifier_block kvm_cpu_notifier = {
2485 .notifier_call = kvm_cpu_hotplug,
2486};
2487
2488static int vm_stat_get(void *_offset, u64 *val)
2489{
2490 unsigned offset = (long)_offset;
2491 struct kvm *kvm;
2492
2493 *val = 0;
2494 raw_spin_lock(&kvm_lock);
2495 list_for_each_entry(kvm, &vm_list, vm_list)
2496 *val += *(u32 *)((void *)kvm + offset);
2497 raw_spin_unlock(&kvm_lock);
2498 return 0;
2499}
2500
2501DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
2502
2503static int vcpu_stat_get(void *_offset, u64 *val)
2504{
2505 unsigned offset = (long)_offset;
2506 struct kvm *kvm;
2507 struct kvm_vcpu *vcpu;
2508 int i;
2509
2510 *val = 0;
2511 raw_spin_lock(&kvm_lock);
2512 list_for_each_entry(kvm, &vm_list, vm_list)
2513 kvm_for_each_vcpu(i, vcpu, kvm)
2514 *val += *(u32 *)((void *)vcpu + offset);
2515
2516 raw_spin_unlock(&kvm_lock);
2517 return 0;
2518}
2519
2520DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");
2521
2522static const struct file_operations *stat_fops[] = {
2523 [KVM_STAT_VCPU] = &vcpu_stat_fops,
2524 [KVM_STAT_VM] = &vm_stat_fops,
2525};
2526
2527static void kvm_init_debug(void)
2528{
2529 struct kvm_stats_debugfs_item *p;
2530
2531 kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
2532 for (p = debugfs_entries; p->name; ++p)
2533 p->dentry = debugfs_create_file(p->name, 0444, kvm_debugfs_dir,
2534 (void *)(long)p->offset,
2535 stat_fops[p->kind]);
2536}
2537
2538static void kvm_exit_debug(void)
2539{
2540 struct kvm_stats_debugfs_item *p;
2541
2542 for (p = debugfs_entries; p->name; ++p)
2543 debugfs_remove(p->dentry);
2544 debugfs_remove(kvm_debugfs_dir);
2545}
2546
2547static int kvm_suspend(void)
2548{
2549 if (kvm_usage_count)
2550 hardware_disable_nolock(NULL);
2551 return 0;
2552}
2553
2554static void kvm_resume(void)
2555{
2556 if (kvm_usage_count) {
2557 WARN_ON(raw_spin_is_locked(&kvm_lock));
2558 hardware_enable_nolock(NULL);
2559 }
2560}
2561
2562static struct syscore_ops kvm_syscore_ops = {
2563 .suspend = kvm_suspend,
2564 .resume = kvm_resume,
2565};
2566
2567struct page *bad_page;
2568pfn_t bad_pfn;
2569
2570static inline
2571struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
2572{
2573 return container_of(pn, struct kvm_vcpu, preempt_notifier);
2574}
2575
2576static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
2577{
2578 struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2579
2580 kvm_arch_vcpu_load(vcpu, cpu);
2581}
2582
2583static void kvm_sched_out(struct preempt_notifier *pn,
2584 struct task_struct *next)
2585{
2586 struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
2587
2588 kvm_arch_vcpu_put(vcpu);
2589}
2590
2591int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
2592 struct module *module)
2593{
2594 int r;
2595 int cpu;
2596
2597 r = kvm_arch_init(opaque);
2598 if (r)
2599 goto out_fail;
2600
2601 bad_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2602
2603 if (bad_page == NULL) {
2604 r = -ENOMEM;
2605 goto out;
2606 }
2607
2608 bad_pfn = page_to_pfn(bad_page);
2609
2610 hwpoison_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2611
2612 if (hwpoison_page == NULL) {
2613 r = -ENOMEM;
2614 goto out_free_0;
2615 }
2616
2617 hwpoison_pfn = page_to_pfn(hwpoison_page);
2618
2619 fault_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
2620
2621 if (fault_page == NULL) {
2622 r = -ENOMEM;
2623 goto out_free_0;
2624 }
2625
2626 fault_pfn = page_to_pfn(fault_page);
2627
2628 if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
2629 r = -ENOMEM;
2630 goto out_free_0;
2631 }
2632
2633 r = kvm_arch_hardware_setup();
2634 if (r < 0)
2635 goto out_free_0a;
2636
2637 for_each_online_cpu(cpu) {
2638 smp_call_function_single(cpu,
2639 kvm_arch_check_processor_compat,
2640 &r, 1);
2641 if (r < 0)
2642 goto out_free_1;
2643 }
2644
2645 r = register_cpu_notifier(&kvm_cpu_notifier);
2646 if (r)
2647 goto out_free_2;
2648 register_reboot_notifier(&kvm_reboot_notifier);
2649
2650 /* A kmem cache lets us meet the alignment requirements of fx_save. */
2651 if (!vcpu_align)
2652 vcpu_align = __alignof__(struct kvm_vcpu);
2653 kvm_vcpu_cache = kmem_cache_create("kvm_vcpu", vcpu_size, vcpu_align,
2654 0, NULL);
2655 if (!kvm_vcpu_cache) {
2656 r = -ENOMEM;
2657 goto out_free_3;
2658 }
2659
2660 r = kvm_async_pf_init();
2661 if (r)
2662 goto out_free;
2663
2664 kvm_chardev_ops.owner = module;
2665 kvm_vm_fops.owner = module;
2666 kvm_vcpu_fops.owner = module;
2667
2668 r = misc_register(&kvm_dev);
2669 if (r) {
2670 printk(KERN_ERR "kvm: misc device register failed\n");
2671 goto out_unreg;
2672 }
2673
2674 register_syscore_ops(&kvm_syscore_ops);
2675
2676 kvm_preempt_ops.sched_in = kvm_sched_in;
2677 kvm_preempt_ops.sched_out = kvm_sched_out;
2678
2679 kvm_init_debug();
2680
2681 return 0;
2682
2683out_unreg:
2684 kvm_async_pf_deinit();
2685out_free:
2686 kmem_cache_destroy(kvm_vcpu_cache);
2687out_free_3:
2688 unregister_reboot_notifier(&kvm_reboot_notifier);
2689 unregister_cpu_notifier(&kvm_cpu_notifier);
2690out_free_2:
2691out_free_1:
2692 kvm_arch_hardware_unsetup();
2693out_free_0a:
2694 free_cpumask_var(cpus_hardware_enabled);
2695out_free_0:
2696 if (fault_page)
2697 __free_page(fault_page);
2698 if (hwpoison_page)
2699 __free_page(hwpoison_page);
2700 __free_page(bad_page);
2701out:
2702 kvm_arch_exit();
2703out_fail:
2704 return r;
2705}
2706EXPORT_SYMBOL_GPL(kvm_init);
2707
2708void kvm_exit(void)
2709{
2710 kvm_exit_debug();
2711 misc_deregister(&kvm_dev);
2712 kmem_cache_destroy(kvm_vcpu_cache);
2713 kvm_async_pf_deinit();
2714 unregister_syscore_ops(&kvm_syscore_ops);
2715 unregister_reboot_notifier(&kvm_reboot_notifier);
2716 unregister_cpu_notifier(&kvm_cpu_notifier);
2717 on_each_cpu(hardware_disable_nolock, NULL, 1);
2718 kvm_arch_hardware_unsetup();
2719 kvm_arch_exit();
2720 free_cpumask_var(cpus_hardware_enabled);
2721 __free_page(hwpoison_page);
2722 __free_page(bad_page);
2723}
2724EXPORT_SYMBOL_GPL(kvm_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Kernel-based Virtual Machine driver for Linux
4 *
5 * This module enables machines with Intel VT-x extensions to run virtual
6 * machines without emulation or binary translation.
7 *
8 * Copyright (C) 2006 Qumranet, Inc.
9 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
10 *
11 * Authors:
12 * Avi Kivity <avi@qumranet.com>
13 * Yaniv Kamay <yaniv@qumranet.com>
14 */
15
16#include <kvm/iodev.h>
17
18#include <linux/kvm_host.h>
19#include <linux/kvm.h>
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/percpu.h>
23#include <linux/mm.h>
24#include <linux/miscdevice.h>
25#include <linux/vmalloc.h>
26#include <linux/reboot.h>
27#include <linux/debugfs.h>
28#include <linux/highmem.h>
29#include <linux/file.h>
30#include <linux/syscore_ops.h>
31#include <linux/cpu.h>
32#include <linux/sched/signal.h>
33#include <linux/sched/mm.h>
34#include <linux/sched/stat.h>
35#include <linux/cpumask.h>
36#include <linux/smp.h>
37#include <linux/anon_inodes.h>
38#include <linux/profile.h>
39#include <linux/kvm_para.h>
40#include <linux/pagemap.h>
41#include <linux/mman.h>
42#include <linux/swap.h>
43#include <linux/bitops.h>
44#include <linux/spinlock.h>
45#include <linux/compat.h>
46#include <linux/srcu.h>
47#include <linux/hugetlb.h>
48#include <linux/slab.h>
49#include <linux/sort.h>
50#include <linux/bsearch.h>
51#include <linux/io.h>
52#include <linux/lockdep.h>
53#include <linux/kthread.h>
54#include <linux/suspend.h>
55
56#include <asm/processor.h>
57#include <asm/ioctl.h>
58#include <linux/uaccess.h>
59
60#include "coalesced_mmio.h"
61#include "async_pf.h"
62#include "kvm_mm.h"
63#include "vfio.h"
64
65#define CREATE_TRACE_POINTS
66#include <trace/events/kvm.h>
67
68#include <linux/kvm_dirty_ring.h>
69
70/* Worst case buffer size needed for holding an integer. */
71#define ITOA_MAX_LEN 12
72
73MODULE_AUTHOR("Qumranet");
74MODULE_LICENSE("GPL");
75
76/* Architectures should define their poll value according to the halt latency */
77unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
78module_param(halt_poll_ns, uint, 0644);
79EXPORT_SYMBOL_GPL(halt_poll_ns);
80
81/* Default doubles per-vcpu halt_poll_ns. */
82unsigned int halt_poll_ns_grow = 2;
83module_param(halt_poll_ns_grow, uint, 0644);
84EXPORT_SYMBOL_GPL(halt_poll_ns_grow);
85
86/* The start value to grow halt_poll_ns from */
87unsigned int halt_poll_ns_grow_start = 10000; /* 10us */
88module_param(halt_poll_ns_grow_start, uint, 0644);
89EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start);
90
91/* Default resets per-vcpu halt_poll_ns . */
92unsigned int halt_poll_ns_shrink;
93module_param(halt_poll_ns_shrink, uint, 0644);
94EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
95
96/*
97 * Ordering of locks:
98 *
99 * kvm->lock --> kvm->slots_lock --> kvm->irq_lock
100 */
101
102DEFINE_MUTEX(kvm_lock);
103static DEFINE_RAW_SPINLOCK(kvm_count_lock);
104LIST_HEAD(vm_list);
105
106static cpumask_var_t cpus_hardware_enabled;
107static int kvm_usage_count;
108static atomic_t hardware_enable_failed;
109
110static struct kmem_cache *kvm_vcpu_cache;
111
112static __read_mostly struct preempt_ops kvm_preempt_ops;
113static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
114
115struct dentry *kvm_debugfs_dir;
116EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
117
118static const struct file_operations stat_fops_per_vm;
119
120static struct file_operations kvm_chardev_ops;
121
122static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
123 unsigned long arg);
124#ifdef CONFIG_KVM_COMPAT
125static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
126 unsigned long arg);
127#define KVM_COMPAT(c) .compat_ioctl = (c)
128#else
129/*
130 * For architectures that don't implement a compat infrastructure,
131 * adopt a double line of defense:
132 * - Prevent a compat task from opening /dev/kvm
133 * - If the open has been done by a 64bit task, and the KVM fd
134 * passed to a compat task, let the ioctls fail.
135 */
136static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl,
137 unsigned long arg) { return -EINVAL; }
138
139static int kvm_no_compat_open(struct inode *inode, struct file *file)
140{
141 return is_compat_task() ? -ENODEV : 0;
142}
143#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \
144 .open = kvm_no_compat_open
145#endif
146static int hardware_enable_all(void);
147static void hardware_disable_all(void);
148
149static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
150
151__visible bool kvm_rebooting;
152EXPORT_SYMBOL_GPL(kvm_rebooting);
153
154#define KVM_EVENT_CREATE_VM 0
155#define KVM_EVENT_DESTROY_VM 1
156static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
157static unsigned long long kvm_createvm_count;
158static unsigned long long kvm_active_vms;
159
160static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask);
161
162__weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
163 unsigned long start, unsigned long end)
164{
165}
166
167__weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm)
168{
169}
170
171bool kvm_is_zone_device_page(struct page *page)
172{
173 /*
174 * The metadata used by is_zone_device_page() to determine whether or
175 * not a page is ZONE_DEVICE is guaranteed to be valid if and only if
176 * the device has been pinned, e.g. by get_user_pages(). WARN if the
177 * page_count() is zero to help detect bad usage of this helper.
178 */
179 if (WARN_ON_ONCE(!page_count(page)))
180 return false;
181
182 return is_zone_device_page(page);
183}
184
185/*
186 * Returns a 'struct page' if the pfn is "valid" and backed by a refcounted
187 * page, NULL otherwise. Note, the list of refcounted PG_reserved page types
188 * is likely incomplete, it has been compiled purely through people wanting to
189 * back guest with a certain type of memory and encountering issues.
190 */
191struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn)
192{
193 struct page *page;
194
195 if (!pfn_valid(pfn))
196 return NULL;
197
198 page = pfn_to_page(pfn);
199 if (!PageReserved(page))
200 return page;
201
202 /* The ZERO_PAGE(s) is marked PG_reserved, but is refcounted. */
203 if (is_zero_pfn(pfn))
204 return page;
205
206 /*
207 * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting
208 * perspective they are "normal" pages, albeit with slightly different
209 * usage rules.
210 */
211 if (kvm_is_zone_device_page(page))
212 return page;
213
214 return NULL;
215}
216
217/*
218 * Switches to specified vcpu, until a matching vcpu_put()
219 */
220void vcpu_load(struct kvm_vcpu *vcpu)
221{
222 int cpu = get_cpu();
223
224 __this_cpu_write(kvm_running_vcpu, vcpu);
225 preempt_notifier_register(&vcpu->preempt_notifier);
226 kvm_arch_vcpu_load(vcpu, cpu);
227 put_cpu();
228}
229EXPORT_SYMBOL_GPL(vcpu_load);
230
231void vcpu_put(struct kvm_vcpu *vcpu)
232{
233 preempt_disable();
234 kvm_arch_vcpu_put(vcpu);
235 preempt_notifier_unregister(&vcpu->preempt_notifier);
236 __this_cpu_write(kvm_running_vcpu, NULL);
237 preempt_enable();
238}
239EXPORT_SYMBOL_GPL(vcpu_put);
240
241/* TODO: merge with kvm_arch_vcpu_should_kick */
242static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req)
243{
244 int mode = kvm_vcpu_exiting_guest_mode(vcpu);
245
246 /*
247 * We need to wait for the VCPU to reenable interrupts and get out of
248 * READING_SHADOW_PAGE_TABLES mode.
249 */
250 if (req & KVM_REQUEST_WAIT)
251 return mode != OUTSIDE_GUEST_MODE;
252
253 /*
254 * Need to kick a running VCPU, but otherwise there is nothing to do.
255 */
256 return mode == IN_GUEST_MODE;
257}
258
259static void ack_kick(void *_completed)
260{
261}
262
263static inline bool kvm_kick_many_cpus(struct cpumask *cpus, bool wait)
264{
265 if (cpumask_empty(cpus))
266 return false;
267
268 smp_call_function_many(cpus, ack_kick, NULL, wait);
269 return true;
270}
271
272static void kvm_make_vcpu_request(struct kvm_vcpu *vcpu, unsigned int req,
273 struct cpumask *tmp, int current_cpu)
274{
275 int cpu;
276
277 if (likely(!(req & KVM_REQUEST_NO_ACTION)))
278 __kvm_make_request(req, vcpu);
279
280 if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
281 return;
282
283 /*
284 * Note, the vCPU could get migrated to a different pCPU at any point
285 * after kvm_request_needs_ipi(), which could result in sending an IPI
286 * to the previous pCPU. But, that's OK because the purpose of the IPI
287 * is to ensure the vCPU returns to OUTSIDE_GUEST_MODE, which is
288 * satisfied if the vCPU migrates. Entering READING_SHADOW_PAGE_TABLES
289 * after this point is also OK, as the requirement is only that KVM wait
290 * for vCPUs that were reading SPTEs _before_ any changes were
291 * finalized. See kvm_vcpu_kick() for more details on handling requests.
292 */
293 if (kvm_request_needs_ipi(vcpu, req)) {
294 cpu = READ_ONCE(vcpu->cpu);
295 if (cpu != -1 && cpu != current_cpu)
296 __cpumask_set_cpu(cpu, tmp);
297 }
298}
299
300bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
301 unsigned long *vcpu_bitmap)
302{
303 struct kvm_vcpu *vcpu;
304 struct cpumask *cpus;
305 int i, me;
306 bool called;
307
308 me = get_cpu();
309
310 cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask);
311 cpumask_clear(cpus);
312
313 for_each_set_bit(i, vcpu_bitmap, KVM_MAX_VCPUS) {
314 vcpu = kvm_get_vcpu(kvm, i);
315 if (!vcpu)
316 continue;
317 kvm_make_vcpu_request(vcpu, req, cpus, me);
318 }
319
320 called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT));
321 put_cpu();
322
323 return called;
324}
325
326bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
327 struct kvm_vcpu *except)
328{
329 struct kvm_vcpu *vcpu;
330 struct cpumask *cpus;
331 unsigned long i;
332 bool called;
333 int me;
334
335 me = get_cpu();
336
337 cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask);
338 cpumask_clear(cpus);
339
340 kvm_for_each_vcpu(i, vcpu, kvm) {
341 if (vcpu == except)
342 continue;
343 kvm_make_vcpu_request(vcpu, req, cpus, me);
344 }
345
346 called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT));
347 put_cpu();
348
349 return called;
350}
351
352bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
353{
354 return kvm_make_all_cpus_request_except(kvm, req, NULL);
355}
356EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request);
357
358#ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
359void kvm_flush_remote_tlbs(struct kvm *kvm)
360{
361 ++kvm->stat.generic.remote_tlb_flush_requests;
362
363 /*
364 * We want to publish modifications to the page tables before reading
365 * mode. Pairs with a memory barrier in arch-specific code.
366 * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
367 * and smp_mb in walk_shadow_page_lockless_begin/end.
368 * - powerpc: smp_mb in kvmppc_prepare_to_enter.
369 *
370 * There is already an smp_mb__after_atomic() before
371 * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
372 * barrier here.
373 */
374 if (!kvm_arch_flush_remote_tlb(kvm)
375 || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
376 ++kvm->stat.generic.remote_tlb_flush;
377}
378EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
379#endif
380
381static void kvm_flush_shadow_all(struct kvm *kvm)
382{
383 kvm_arch_flush_shadow_all(kvm);
384 kvm_arch_guest_memory_reclaimed(kvm);
385}
386
387#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
388static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
389 gfp_t gfp_flags)
390{
391 gfp_flags |= mc->gfp_zero;
392
393 if (mc->kmem_cache)
394 return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
395 else
396 return (void *)__get_free_page(gfp_flags);
397}
398
399int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min)
400{
401 gfp_t gfp = mc->gfp_custom ? mc->gfp_custom : GFP_KERNEL_ACCOUNT;
402 void *obj;
403
404 if (mc->nobjs >= min)
405 return 0;
406
407 if (unlikely(!mc->objects)) {
408 if (WARN_ON_ONCE(!capacity))
409 return -EIO;
410
411 mc->objects = kvmalloc_array(sizeof(void *), capacity, gfp);
412 if (!mc->objects)
413 return -ENOMEM;
414
415 mc->capacity = capacity;
416 }
417
418 /* It is illegal to request a different capacity across topups. */
419 if (WARN_ON_ONCE(mc->capacity != capacity))
420 return -EIO;
421
422 while (mc->nobjs < mc->capacity) {
423 obj = mmu_memory_cache_alloc_obj(mc, gfp);
424 if (!obj)
425 return mc->nobjs >= min ? 0 : -ENOMEM;
426 mc->objects[mc->nobjs++] = obj;
427 }
428 return 0;
429}
430
431int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
432{
433 return __kvm_mmu_topup_memory_cache(mc, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE, min);
434}
435
436int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
437{
438 return mc->nobjs;
439}
440
441void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
442{
443 while (mc->nobjs) {
444 if (mc->kmem_cache)
445 kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
446 else
447 free_page((unsigned long)mc->objects[--mc->nobjs]);
448 }
449
450 kvfree(mc->objects);
451
452 mc->objects = NULL;
453 mc->capacity = 0;
454}
455
456void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
457{
458 void *p;
459
460 if (WARN_ON(!mc->nobjs))
461 p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
462 else
463 p = mc->objects[--mc->nobjs];
464 BUG_ON(!p);
465 return p;
466}
467#endif
468
469static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
470{
471 mutex_init(&vcpu->mutex);
472 vcpu->cpu = -1;
473 vcpu->kvm = kvm;
474 vcpu->vcpu_id = id;
475 vcpu->pid = NULL;
476#ifndef __KVM_HAVE_ARCH_WQP
477 rcuwait_init(&vcpu->wait);
478#endif
479 kvm_async_pf_vcpu_init(vcpu);
480
481 kvm_vcpu_set_in_spin_loop(vcpu, false);
482 kvm_vcpu_set_dy_eligible(vcpu, false);
483 vcpu->preempted = false;
484 vcpu->ready = false;
485 preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
486 vcpu->last_used_slot = NULL;
487
488 /* Fill the stats id string for the vcpu */
489 snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d",
490 task_pid_nr(current), id);
491}
492
493static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
494{
495 kvm_arch_vcpu_destroy(vcpu);
496 kvm_dirty_ring_free(&vcpu->dirty_ring);
497
498 /*
499 * No need for rcu_read_lock as VCPU_RUN is the only place that changes
500 * the vcpu->pid pointer, and at destruction time all file descriptors
501 * are already gone.
502 */
503 put_pid(rcu_dereference_protected(vcpu->pid, 1));
504
505 free_page((unsigned long)vcpu->run);
506 kmem_cache_free(kvm_vcpu_cache, vcpu);
507}
508
509void kvm_destroy_vcpus(struct kvm *kvm)
510{
511 unsigned long i;
512 struct kvm_vcpu *vcpu;
513
514 kvm_for_each_vcpu(i, vcpu, kvm) {
515 kvm_vcpu_destroy(vcpu);
516 xa_erase(&kvm->vcpu_array, i);
517 }
518
519 atomic_set(&kvm->online_vcpus, 0);
520}
521EXPORT_SYMBOL_GPL(kvm_destroy_vcpus);
522
523#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
524static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
525{
526 return container_of(mn, struct kvm, mmu_notifier);
527}
528
529static void kvm_mmu_notifier_invalidate_range(struct mmu_notifier *mn,
530 struct mm_struct *mm,
531 unsigned long start, unsigned long end)
532{
533 struct kvm *kvm = mmu_notifier_to_kvm(mn);
534 int idx;
535
536 idx = srcu_read_lock(&kvm->srcu);
537 kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
538 srcu_read_unlock(&kvm->srcu, idx);
539}
540
541typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
542
543typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start,
544 unsigned long end);
545
546typedef void (*on_unlock_fn_t)(struct kvm *kvm);
547
548struct kvm_hva_range {
549 unsigned long start;
550 unsigned long end;
551 pte_t pte;
552 hva_handler_t handler;
553 on_lock_fn_t on_lock;
554 on_unlock_fn_t on_unlock;
555 bool flush_on_ret;
556 bool may_block;
557};
558
559/*
560 * Use a dedicated stub instead of NULL to indicate that there is no callback
561 * function/handler. The compiler technically can't guarantee that a real
562 * function will have a non-zero address, and so it will generate code to
563 * check for !NULL, whereas comparing against a stub will be elided at compile
564 * time (unless the compiler is getting long in the tooth, e.g. gcc 4.9).
565 */
566static void kvm_null_fn(void)
567{
568
569}
570#define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
571
572/* Iterate over each memslot intersecting [start, last] (inclusive) range */
573#define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \
574 for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \
575 node; \
576 node = interval_tree_iter_next(node, start, last)) \
577
578static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
579 const struct kvm_hva_range *range)
580{
581 bool ret = false, locked = false;
582 struct kvm_gfn_range gfn_range;
583 struct kvm_memory_slot *slot;
584 struct kvm_memslots *slots;
585 int i, idx;
586
587 if (WARN_ON_ONCE(range->end <= range->start))
588 return 0;
589
590 /* A null handler is allowed if and only if on_lock() is provided. */
591 if (WARN_ON_ONCE(IS_KVM_NULL_FN(range->on_lock) &&
592 IS_KVM_NULL_FN(range->handler)))
593 return 0;
594
595 idx = srcu_read_lock(&kvm->srcu);
596
597 for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
598 struct interval_tree_node *node;
599
600 slots = __kvm_memslots(kvm, i);
601 kvm_for_each_memslot_in_hva_range(node, slots,
602 range->start, range->end - 1) {
603 unsigned long hva_start, hva_end;
604
605 slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]);
606 hva_start = max(range->start, slot->userspace_addr);
607 hva_end = min(range->end, slot->userspace_addr +
608 (slot->npages << PAGE_SHIFT));
609
610 /*
611 * To optimize for the likely case where the address
612 * range is covered by zero or one memslots, don't
613 * bother making these conditional (to avoid writes on
614 * the second or later invocation of the handler).
615 */
616 gfn_range.pte = range->pte;
617 gfn_range.may_block = range->may_block;
618
619 /*
620 * {gfn(page) | page intersects with [hva_start, hva_end)} =
621 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
622 */
623 gfn_range.start = hva_to_gfn_memslot(hva_start, slot);
624 gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot);
625 gfn_range.slot = slot;
626
627 if (!locked) {
628 locked = true;
629 KVM_MMU_LOCK(kvm);
630 if (!IS_KVM_NULL_FN(range->on_lock))
631 range->on_lock(kvm, range->start, range->end);
632 if (IS_KVM_NULL_FN(range->handler))
633 break;
634 }
635 ret |= range->handler(kvm, &gfn_range);
636 }
637 }
638
639 if (range->flush_on_ret && ret)
640 kvm_flush_remote_tlbs(kvm);
641
642 if (locked) {
643 KVM_MMU_UNLOCK(kvm);
644 if (!IS_KVM_NULL_FN(range->on_unlock))
645 range->on_unlock(kvm);
646 }
647
648 srcu_read_unlock(&kvm->srcu, idx);
649
650 /* The notifiers are averse to booleans. :-( */
651 return (int)ret;
652}
653
654static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
655 unsigned long start,
656 unsigned long end,
657 pte_t pte,
658 hva_handler_t handler)
659{
660 struct kvm *kvm = mmu_notifier_to_kvm(mn);
661 const struct kvm_hva_range range = {
662 .start = start,
663 .end = end,
664 .pte = pte,
665 .handler = handler,
666 .on_lock = (void *)kvm_null_fn,
667 .on_unlock = (void *)kvm_null_fn,
668 .flush_on_ret = true,
669 .may_block = false,
670 };
671
672 return __kvm_handle_hva_range(kvm, &range);
673}
674
675static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn,
676 unsigned long start,
677 unsigned long end,
678 hva_handler_t handler)
679{
680 struct kvm *kvm = mmu_notifier_to_kvm(mn);
681 const struct kvm_hva_range range = {
682 .start = start,
683 .end = end,
684 .pte = __pte(0),
685 .handler = handler,
686 .on_lock = (void *)kvm_null_fn,
687 .on_unlock = (void *)kvm_null_fn,
688 .flush_on_ret = false,
689 .may_block = false,
690 };
691
692 return __kvm_handle_hva_range(kvm, &range);
693}
694static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
695 struct mm_struct *mm,
696 unsigned long address,
697 pte_t pte)
698{
699 struct kvm *kvm = mmu_notifier_to_kvm(mn);
700
701 trace_kvm_set_spte_hva(address);
702
703 /*
704 * .change_pte() must be surrounded by .invalidate_range_{start,end}().
705 * If mmu_invalidate_in_progress is zero, then no in-progress
706 * invalidations, including this one, found a relevant memslot at
707 * start(); rechecking memslots here is unnecessary. Note, a false
708 * positive (count elevated by a different invalidation) is sub-optimal
709 * but functionally ok.
710 */
711 WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
712 if (!READ_ONCE(kvm->mmu_invalidate_in_progress))
713 return;
714
715 kvm_handle_hva_range(mn, address, address + 1, pte, kvm_set_spte_gfn);
716}
717
718void kvm_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
719 unsigned long end)
720{
721 /*
722 * The count increase must become visible at unlock time as no
723 * spte can be established without taking the mmu_lock and
724 * count is also read inside the mmu_lock critical section.
725 */
726 kvm->mmu_invalidate_in_progress++;
727 if (likely(kvm->mmu_invalidate_in_progress == 1)) {
728 kvm->mmu_invalidate_range_start = start;
729 kvm->mmu_invalidate_range_end = end;
730 } else {
731 /*
732 * Fully tracking multiple concurrent ranges has diminishing
733 * returns. Keep things simple and just find the minimal range
734 * which includes the current and new ranges. As there won't be
735 * enough information to subtract a range after its invalidate
736 * completes, any ranges invalidated concurrently will
737 * accumulate and persist until all outstanding invalidates
738 * complete.
739 */
740 kvm->mmu_invalidate_range_start =
741 min(kvm->mmu_invalidate_range_start, start);
742 kvm->mmu_invalidate_range_end =
743 max(kvm->mmu_invalidate_range_end, end);
744 }
745}
746
747static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
748 const struct mmu_notifier_range *range)
749{
750 struct kvm *kvm = mmu_notifier_to_kvm(mn);
751 const struct kvm_hva_range hva_range = {
752 .start = range->start,
753 .end = range->end,
754 .pte = __pte(0),
755 .handler = kvm_unmap_gfn_range,
756 .on_lock = kvm_mmu_invalidate_begin,
757 .on_unlock = kvm_arch_guest_memory_reclaimed,
758 .flush_on_ret = true,
759 .may_block = mmu_notifier_range_blockable(range),
760 };
761
762 trace_kvm_unmap_hva_range(range->start, range->end);
763
764 /*
765 * Prevent memslot modification between range_start() and range_end()
766 * so that conditionally locking provides the same result in both
767 * functions. Without that guarantee, the mmu_invalidate_in_progress
768 * adjustments will be imbalanced.
769 *
770 * Pairs with the decrement in range_end().
771 */
772 spin_lock(&kvm->mn_invalidate_lock);
773 kvm->mn_active_invalidate_count++;
774 spin_unlock(&kvm->mn_invalidate_lock);
775
776 /*
777 * Invalidate pfn caches _before_ invalidating the secondary MMUs, i.e.
778 * before acquiring mmu_lock, to avoid holding mmu_lock while acquiring
779 * each cache's lock. There are relatively few caches in existence at
780 * any given time, and the caches themselves can check for hva overlap,
781 * i.e. don't need to rely on memslot overlap checks for performance.
782 * Because this runs without holding mmu_lock, the pfn caches must use
783 * mn_active_invalidate_count (see above) instead of
784 * mmu_invalidate_in_progress.
785 */
786 gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end,
787 hva_range.may_block);
788
789 __kvm_handle_hva_range(kvm, &hva_range);
790
791 return 0;
792}
793
794void kvm_mmu_invalidate_end(struct kvm *kvm, unsigned long start,
795 unsigned long end)
796{
797 /*
798 * This sequence increase will notify the kvm page fault that
799 * the page that is going to be mapped in the spte could have
800 * been freed.
801 */
802 kvm->mmu_invalidate_seq++;
803 smp_wmb();
804 /*
805 * The above sequence increase must be visible before the
806 * below count decrease, which is ensured by the smp_wmb above
807 * in conjunction with the smp_rmb in mmu_invalidate_retry().
808 */
809 kvm->mmu_invalidate_in_progress--;
810}
811
812static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
813 const struct mmu_notifier_range *range)
814{
815 struct kvm *kvm = mmu_notifier_to_kvm(mn);
816 const struct kvm_hva_range hva_range = {
817 .start = range->start,
818 .end = range->end,
819 .pte = __pte(0),
820 .handler = (void *)kvm_null_fn,
821 .on_lock = kvm_mmu_invalidate_end,
822 .on_unlock = (void *)kvm_null_fn,
823 .flush_on_ret = false,
824 .may_block = mmu_notifier_range_blockable(range),
825 };
826 bool wake;
827
828 __kvm_handle_hva_range(kvm, &hva_range);
829
830 /* Pairs with the increment in range_start(). */
831 spin_lock(&kvm->mn_invalidate_lock);
832 wake = (--kvm->mn_active_invalidate_count == 0);
833 spin_unlock(&kvm->mn_invalidate_lock);
834
835 /*
836 * There can only be one waiter, since the wait happens under
837 * slots_lock.
838 */
839 if (wake)
840 rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
841
842 BUG_ON(kvm->mmu_invalidate_in_progress < 0);
843}
844
845static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
846 struct mm_struct *mm,
847 unsigned long start,
848 unsigned long end)
849{
850 trace_kvm_age_hva(start, end);
851
852 return kvm_handle_hva_range(mn, start, end, __pte(0), kvm_age_gfn);
853}
854
855static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
856 struct mm_struct *mm,
857 unsigned long start,
858 unsigned long end)
859{
860 trace_kvm_age_hva(start, end);
861
862 /*
863 * Even though we do not flush TLB, this will still adversely
864 * affect performance on pre-Haswell Intel EPT, where there is
865 * no EPT Access Bit to clear so that we have to tear down EPT
866 * tables instead. If we find this unacceptable, we can always
867 * add a parameter to kvm_age_hva so that it effectively doesn't
868 * do anything on clear_young.
869 *
870 * Also note that currently we never issue secondary TLB flushes
871 * from clear_young, leaving this job up to the regular system
872 * cadence. If we find this inaccurate, we might come up with a
873 * more sophisticated heuristic later.
874 */
875 return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn);
876}
877
878static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
879 struct mm_struct *mm,
880 unsigned long address)
881{
882 trace_kvm_test_age_hva(address);
883
884 return kvm_handle_hva_range_no_flush(mn, address, address + 1,
885 kvm_test_age_gfn);
886}
887
888static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
889 struct mm_struct *mm)
890{
891 struct kvm *kvm = mmu_notifier_to_kvm(mn);
892 int idx;
893
894 idx = srcu_read_lock(&kvm->srcu);
895 kvm_flush_shadow_all(kvm);
896 srcu_read_unlock(&kvm->srcu, idx);
897}
898
899static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
900 .invalidate_range = kvm_mmu_notifier_invalidate_range,
901 .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
902 .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
903 .clear_flush_young = kvm_mmu_notifier_clear_flush_young,
904 .clear_young = kvm_mmu_notifier_clear_young,
905 .test_young = kvm_mmu_notifier_test_young,
906 .change_pte = kvm_mmu_notifier_change_pte,
907 .release = kvm_mmu_notifier_release,
908};
909
910static int kvm_init_mmu_notifier(struct kvm *kvm)
911{
912 kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
913 return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
914}
915
916#else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
917
918static int kvm_init_mmu_notifier(struct kvm *kvm)
919{
920 return 0;
921}
922
923#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
924
925#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
926static int kvm_pm_notifier_call(struct notifier_block *bl,
927 unsigned long state,
928 void *unused)
929{
930 struct kvm *kvm = container_of(bl, struct kvm, pm_notifier);
931
932 return kvm_arch_pm_notifier(kvm, state);
933}
934
935static void kvm_init_pm_notifier(struct kvm *kvm)
936{
937 kvm->pm_notifier.notifier_call = kvm_pm_notifier_call;
938 /* Suspend KVM before we suspend ftrace, RCU, etc. */
939 kvm->pm_notifier.priority = INT_MAX;
940 register_pm_notifier(&kvm->pm_notifier);
941}
942
943static void kvm_destroy_pm_notifier(struct kvm *kvm)
944{
945 unregister_pm_notifier(&kvm->pm_notifier);
946}
947#else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */
948static void kvm_init_pm_notifier(struct kvm *kvm)
949{
950}
951
952static void kvm_destroy_pm_notifier(struct kvm *kvm)
953{
954}
955#endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
956
957static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
958{
959 if (!memslot->dirty_bitmap)
960 return;
961
962 kvfree(memslot->dirty_bitmap);
963 memslot->dirty_bitmap = NULL;
964}
965
966/* This does not remove the slot from struct kvm_memslots data structures */
967static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
968{
969 kvm_destroy_dirty_bitmap(slot);
970
971 kvm_arch_free_memslot(kvm, slot);
972
973 kfree(slot);
974}
975
976static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
977{
978 struct hlist_node *idnode;
979 struct kvm_memory_slot *memslot;
980 int bkt;
981
982 /*
983 * The same memslot objects live in both active and inactive sets,
984 * arbitrarily free using index '1' so the second invocation of this
985 * function isn't operating over a structure with dangling pointers
986 * (even though this function isn't actually touching them).
987 */
988 if (!slots->node_idx)
989 return;
990
991 hash_for_each_safe(slots->id_hash, bkt, idnode, memslot, id_node[1])
992 kvm_free_memslot(kvm, memslot);
993}
994
995static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc)
996{
997 switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) {
998 case KVM_STATS_TYPE_INSTANT:
999 return 0444;
1000 case KVM_STATS_TYPE_CUMULATIVE:
1001 case KVM_STATS_TYPE_PEAK:
1002 default:
1003 return 0644;
1004 }
1005}
1006
1007
1008static void kvm_destroy_vm_debugfs(struct kvm *kvm)
1009{
1010 int i;
1011 int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
1012 kvm_vcpu_stats_header.num_desc;
1013
1014 if (IS_ERR(kvm->debugfs_dentry))
1015 return;
1016
1017 debugfs_remove_recursive(kvm->debugfs_dentry);
1018
1019 if (kvm->debugfs_stat_data) {
1020 for (i = 0; i < kvm_debugfs_num_entries; i++)
1021 kfree(kvm->debugfs_stat_data[i]);
1022 kfree(kvm->debugfs_stat_data);
1023 }
1024}
1025
1026static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname)
1027{
1028 static DEFINE_MUTEX(kvm_debugfs_lock);
1029 struct dentry *dent;
1030 char dir_name[ITOA_MAX_LEN * 2];
1031 struct kvm_stat_data *stat_data;
1032 const struct _kvm_stats_desc *pdesc;
1033 int i, ret = -ENOMEM;
1034 int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
1035 kvm_vcpu_stats_header.num_desc;
1036
1037 if (!debugfs_initialized())
1038 return 0;
1039
1040 snprintf(dir_name, sizeof(dir_name), "%d-%s", task_pid_nr(current), fdname);
1041 mutex_lock(&kvm_debugfs_lock);
1042 dent = debugfs_lookup(dir_name, kvm_debugfs_dir);
1043 if (dent) {
1044 pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name);
1045 dput(dent);
1046 mutex_unlock(&kvm_debugfs_lock);
1047 return 0;
1048 }
1049 dent = debugfs_create_dir(dir_name, kvm_debugfs_dir);
1050 mutex_unlock(&kvm_debugfs_lock);
1051 if (IS_ERR(dent))
1052 return 0;
1053
1054 kvm->debugfs_dentry = dent;
1055 kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
1056 sizeof(*kvm->debugfs_stat_data),
1057 GFP_KERNEL_ACCOUNT);
1058 if (!kvm->debugfs_stat_data)
1059 goto out_err;
1060
1061 for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
1062 pdesc = &kvm_vm_stats_desc[i];
1063 stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
1064 if (!stat_data)
1065 goto out_err;
1066
1067 stat_data->kvm = kvm;
1068 stat_data->desc = pdesc;
1069 stat_data->kind = KVM_STAT_VM;
1070 kvm->debugfs_stat_data[i] = stat_data;
1071 debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
1072 kvm->debugfs_dentry, stat_data,
1073 &stat_fops_per_vm);
1074 }
1075
1076 for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
1077 pdesc = &kvm_vcpu_stats_desc[i];
1078 stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
1079 if (!stat_data)
1080 goto out_err;
1081
1082 stat_data->kvm = kvm;
1083 stat_data->desc = pdesc;
1084 stat_data->kind = KVM_STAT_VCPU;
1085 kvm->debugfs_stat_data[i + kvm_vm_stats_header.num_desc] = stat_data;
1086 debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
1087 kvm->debugfs_dentry, stat_data,
1088 &stat_fops_per_vm);
1089 }
1090
1091 ret = kvm_arch_create_vm_debugfs(kvm);
1092 if (ret)
1093 goto out_err;
1094
1095 return 0;
1096out_err:
1097 kvm_destroy_vm_debugfs(kvm);
1098 return ret;
1099}
1100
1101/*
1102 * Called after the VM is otherwise initialized, but just before adding it to
1103 * the vm_list.
1104 */
1105int __weak kvm_arch_post_init_vm(struct kvm *kvm)
1106{
1107 return 0;
1108}
1109
1110/*
1111 * Called just after removing the VM from the vm_list, but before doing any
1112 * other destruction.
1113 */
1114void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
1115{
1116}
1117
1118/*
1119 * Called after per-vm debugfs created. When called kvm->debugfs_dentry should
1120 * be setup already, so we can create arch-specific debugfs entries under it.
1121 * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so
1122 * a per-arch destroy interface is not needed.
1123 */
1124int __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
1125{
1126 return 0;
1127}
1128
1129static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
1130{
1131 struct kvm *kvm = kvm_arch_alloc_vm();
1132 struct kvm_memslots *slots;
1133 int r = -ENOMEM;
1134 int i, j;
1135
1136 if (!kvm)
1137 return ERR_PTR(-ENOMEM);
1138
1139 /* KVM is pinned via open("/dev/kvm"), the fd passed to this ioctl(). */
1140 __module_get(kvm_chardev_ops.owner);
1141
1142 KVM_MMU_LOCK_INIT(kvm);
1143 mmgrab(current->mm);
1144 kvm->mm = current->mm;
1145 kvm_eventfd_init(kvm);
1146 mutex_init(&kvm->lock);
1147 mutex_init(&kvm->irq_lock);
1148 mutex_init(&kvm->slots_lock);
1149 mutex_init(&kvm->slots_arch_lock);
1150 spin_lock_init(&kvm->mn_invalidate_lock);
1151 rcuwait_init(&kvm->mn_memslots_update_rcuwait);
1152 xa_init(&kvm->vcpu_array);
1153
1154 INIT_LIST_HEAD(&kvm->gpc_list);
1155 spin_lock_init(&kvm->gpc_lock);
1156
1157 INIT_LIST_HEAD(&kvm->devices);
1158 kvm->max_vcpus = KVM_MAX_VCPUS;
1159
1160 BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
1161
1162 /*
1163 * Force subsequent debugfs file creations to fail if the VM directory
1164 * is not created (by kvm_create_vm_debugfs()).
1165 */
1166 kvm->debugfs_dentry = ERR_PTR(-ENOENT);
1167
1168 snprintf(kvm->stats_id, sizeof(kvm->stats_id), "kvm-%d",
1169 task_pid_nr(current));
1170
1171 if (init_srcu_struct(&kvm->srcu))
1172 goto out_err_no_srcu;
1173 if (init_srcu_struct(&kvm->irq_srcu))
1174 goto out_err_no_irq_srcu;
1175
1176 refcount_set(&kvm->users_count, 1);
1177 for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
1178 for (j = 0; j < 2; j++) {
1179 slots = &kvm->__memslots[i][j];
1180
1181 atomic_long_set(&slots->last_used_slot, (unsigned long)NULL);
1182 slots->hva_tree = RB_ROOT_CACHED;
1183 slots->gfn_tree = RB_ROOT;
1184 hash_init(slots->id_hash);
1185 slots->node_idx = j;
1186
1187 /* Generations must be different for each address space. */
1188 slots->generation = i;
1189 }
1190
1191 rcu_assign_pointer(kvm->memslots[i], &kvm->__memslots[i][0]);
1192 }
1193
1194 for (i = 0; i < KVM_NR_BUSES; i++) {
1195 rcu_assign_pointer(kvm->buses[i],
1196 kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
1197 if (!kvm->buses[i])
1198 goto out_err_no_arch_destroy_vm;
1199 }
1200
1201 r = kvm_arch_init_vm(kvm, type);
1202 if (r)
1203 goto out_err_no_arch_destroy_vm;
1204
1205 r = hardware_enable_all();
1206 if (r)
1207 goto out_err_no_disable;
1208
1209#ifdef CONFIG_HAVE_KVM_IRQFD
1210 INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
1211#endif
1212
1213 r = kvm_init_mmu_notifier(kvm);
1214 if (r)
1215 goto out_err_no_mmu_notifier;
1216
1217 r = kvm_coalesced_mmio_init(kvm);
1218 if (r < 0)
1219 goto out_no_coalesced_mmio;
1220
1221 r = kvm_create_vm_debugfs(kvm, fdname);
1222 if (r)
1223 goto out_err_no_debugfs;
1224
1225 r = kvm_arch_post_init_vm(kvm);
1226 if (r)
1227 goto out_err;
1228
1229 mutex_lock(&kvm_lock);
1230 list_add(&kvm->vm_list, &vm_list);
1231 mutex_unlock(&kvm_lock);
1232
1233 preempt_notifier_inc();
1234 kvm_init_pm_notifier(kvm);
1235
1236 return kvm;
1237
1238out_err:
1239 kvm_destroy_vm_debugfs(kvm);
1240out_err_no_debugfs:
1241 kvm_coalesced_mmio_free(kvm);
1242out_no_coalesced_mmio:
1243#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
1244 if (kvm->mmu_notifier.ops)
1245 mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
1246#endif
1247out_err_no_mmu_notifier:
1248 hardware_disable_all();
1249out_err_no_disable:
1250 kvm_arch_destroy_vm(kvm);
1251out_err_no_arch_destroy_vm:
1252 WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
1253 for (i = 0; i < KVM_NR_BUSES; i++)
1254 kfree(kvm_get_bus(kvm, i));
1255 cleanup_srcu_struct(&kvm->irq_srcu);
1256out_err_no_irq_srcu:
1257 cleanup_srcu_struct(&kvm->srcu);
1258out_err_no_srcu:
1259 kvm_arch_free_vm(kvm);
1260 mmdrop(current->mm);
1261 module_put(kvm_chardev_ops.owner);
1262 return ERR_PTR(r);
1263}
1264
1265static void kvm_destroy_devices(struct kvm *kvm)
1266{
1267 struct kvm_device *dev, *tmp;
1268
1269 /*
1270 * We do not need to take the kvm->lock here, because nobody else
1271 * has a reference to the struct kvm at this point and therefore
1272 * cannot access the devices list anyhow.
1273 */
1274 list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
1275 list_del(&dev->vm_node);
1276 dev->ops->destroy(dev);
1277 }
1278}
1279
1280static void kvm_destroy_vm(struct kvm *kvm)
1281{
1282 int i;
1283 struct mm_struct *mm = kvm->mm;
1284
1285 kvm_destroy_pm_notifier(kvm);
1286 kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
1287 kvm_destroy_vm_debugfs(kvm);
1288 kvm_arch_sync_events(kvm);
1289 mutex_lock(&kvm_lock);
1290 list_del(&kvm->vm_list);
1291 mutex_unlock(&kvm_lock);
1292 kvm_arch_pre_destroy_vm(kvm);
1293
1294 kvm_free_irq_routing(kvm);
1295 for (i = 0; i < KVM_NR_BUSES; i++) {
1296 struct kvm_io_bus *bus = kvm_get_bus(kvm, i);
1297
1298 if (bus)
1299 kvm_io_bus_destroy(bus);
1300 kvm->buses[i] = NULL;
1301 }
1302 kvm_coalesced_mmio_free(kvm);
1303#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
1304 mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
1305 /*
1306 * At this point, pending calls to invalidate_range_start()
1307 * have completed but no more MMU notifiers will run, so
1308 * mn_active_invalidate_count may remain unbalanced.
1309 * No threads can be waiting in install_new_memslots as the
1310 * last reference on KVM has been dropped, but freeing
1311 * memslots would deadlock without this manual intervention.
1312 */
1313 WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait));
1314 kvm->mn_active_invalidate_count = 0;
1315#else
1316 kvm_flush_shadow_all(kvm);
1317#endif
1318 kvm_arch_destroy_vm(kvm);
1319 kvm_destroy_devices(kvm);
1320 for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
1321 kvm_free_memslots(kvm, &kvm->__memslots[i][0]);
1322 kvm_free_memslots(kvm, &kvm->__memslots[i][1]);
1323 }
1324 cleanup_srcu_struct(&kvm->irq_srcu);
1325 cleanup_srcu_struct(&kvm->srcu);
1326 kvm_arch_free_vm(kvm);
1327 preempt_notifier_dec();
1328 hardware_disable_all();
1329 mmdrop(mm);
1330 module_put(kvm_chardev_ops.owner);
1331}
1332
1333void kvm_get_kvm(struct kvm *kvm)
1334{
1335 refcount_inc(&kvm->users_count);
1336}
1337EXPORT_SYMBOL_GPL(kvm_get_kvm);
1338
1339/*
1340 * Make sure the vm is not during destruction, which is a safe version of
1341 * kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise.
1342 */
1343bool kvm_get_kvm_safe(struct kvm *kvm)
1344{
1345 return refcount_inc_not_zero(&kvm->users_count);
1346}
1347EXPORT_SYMBOL_GPL(kvm_get_kvm_safe);
1348
1349void kvm_put_kvm(struct kvm *kvm)
1350{
1351 if (refcount_dec_and_test(&kvm->users_count))
1352 kvm_destroy_vm(kvm);
1353}
1354EXPORT_SYMBOL_GPL(kvm_put_kvm);
1355
1356/*
1357 * Used to put a reference that was taken on behalf of an object associated
1358 * with a user-visible file descriptor, e.g. a vcpu or device, if installation
1359 * of the new file descriptor fails and the reference cannot be transferred to
1360 * its final owner. In such cases, the caller is still actively using @kvm and
1361 * will fail miserably if the refcount unexpectedly hits zero.
1362 */
1363void kvm_put_kvm_no_destroy(struct kvm *kvm)
1364{
1365 WARN_ON(refcount_dec_and_test(&kvm->users_count));
1366}
1367EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
1368
1369static int kvm_vm_release(struct inode *inode, struct file *filp)
1370{
1371 struct kvm *kvm = filp->private_data;
1372
1373 kvm_irqfd_release(kvm);
1374
1375 kvm_put_kvm(kvm);
1376 return 0;
1377}
1378
1379/*
1380 * Allocation size is twice as large as the actual dirty bitmap size.
1381 * See kvm_vm_ioctl_get_dirty_log() why this is needed.
1382 */
1383static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot)
1384{
1385 unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot);
1386
1387 memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT);
1388 if (!memslot->dirty_bitmap)
1389 return -ENOMEM;
1390
1391 return 0;
1392}
1393
1394static struct kvm_memslots *kvm_get_inactive_memslots(struct kvm *kvm, int as_id)
1395{
1396 struct kvm_memslots *active = __kvm_memslots(kvm, as_id);
1397 int node_idx_inactive = active->node_idx ^ 1;
1398
1399 return &kvm->__memslots[as_id][node_idx_inactive];
1400}
1401
1402/*
1403 * Helper to get the address space ID when one of memslot pointers may be NULL.
1404 * This also serves as a sanity that at least one of the pointers is non-NULL,
1405 * and that their address space IDs don't diverge.
1406 */
1407static int kvm_memslots_get_as_id(struct kvm_memory_slot *a,
1408 struct kvm_memory_slot *b)
1409{
1410 if (WARN_ON_ONCE(!a && !b))
1411 return 0;
1412
1413 if (!a)
1414 return b->as_id;
1415 if (!b)
1416 return a->as_id;
1417
1418 WARN_ON_ONCE(a->as_id != b->as_id);
1419 return a->as_id;
1420}
1421
1422static void kvm_insert_gfn_node(struct kvm_memslots *slots,
1423 struct kvm_memory_slot *slot)
1424{
1425 struct rb_root *gfn_tree = &slots->gfn_tree;
1426 struct rb_node **node, *parent;
1427 int idx = slots->node_idx;
1428
1429 parent = NULL;
1430 for (node = &gfn_tree->rb_node; *node; ) {
1431 struct kvm_memory_slot *tmp;
1432
1433 tmp = container_of(*node, struct kvm_memory_slot, gfn_node[idx]);
1434 parent = *node;
1435 if (slot->base_gfn < tmp->base_gfn)
1436 node = &(*node)->rb_left;
1437 else if (slot->base_gfn > tmp->base_gfn)
1438 node = &(*node)->rb_right;
1439 else
1440 BUG();
1441 }
1442
1443 rb_link_node(&slot->gfn_node[idx], parent, node);
1444 rb_insert_color(&slot->gfn_node[idx], gfn_tree);
1445}
1446
1447static void kvm_erase_gfn_node(struct kvm_memslots *slots,
1448 struct kvm_memory_slot *slot)
1449{
1450 rb_erase(&slot->gfn_node[slots->node_idx], &slots->gfn_tree);
1451}
1452
1453static void kvm_replace_gfn_node(struct kvm_memslots *slots,
1454 struct kvm_memory_slot *old,
1455 struct kvm_memory_slot *new)
1456{
1457 int idx = slots->node_idx;
1458
1459 WARN_ON_ONCE(old->base_gfn != new->base_gfn);
1460
1461 rb_replace_node(&old->gfn_node[idx], &new->gfn_node[idx],
1462 &slots->gfn_tree);
1463}
1464
1465/*
1466 * Replace @old with @new in the inactive memslots.
1467 *
1468 * With NULL @old this simply adds @new.
1469 * With NULL @new this simply removes @old.
1470 *
1471 * If @new is non-NULL its hva_node[slots_idx] range has to be set
1472 * appropriately.
1473 */
1474static void kvm_replace_memslot(struct kvm *kvm,
1475 struct kvm_memory_slot *old,
1476 struct kvm_memory_slot *new)
1477{
1478 int as_id = kvm_memslots_get_as_id(old, new);
1479 struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id);
1480 int idx = slots->node_idx;
1481
1482 if (old) {
1483 hash_del(&old->id_node[idx]);
1484 interval_tree_remove(&old->hva_node[idx], &slots->hva_tree);
1485
1486 if ((long)old == atomic_long_read(&slots->last_used_slot))
1487 atomic_long_set(&slots->last_used_slot, (long)new);
1488
1489 if (!new) {
1490 kvm_erase_gfn_node(slots, old);
1491 return;
1492 }
1493 }
1494
1495 /*
1496 * Initialize @new's hva range. Do this even when replacing an @old
1497 * slot, kvm_copy_memslot() deliberately does not touch node data.
1498 */
1499 new->hva_node[idx].start = new->userspace_addr;
1500 new->hva_node[idx].last = new->userspace_addr +
1501 (new->npages << PAGE_SHIFT) - 1;
1502
1503 /*
1504 * (Re)Add the new memslot. There is no O(1) interval_tree_replace(),
1505 * hva_node needs to be swapped with remove+insert even though hva can't
1506 * change when replacing an existing slot.
1507 */
1508 hash_add(slots->id_hash, &new->id_node[idx], new->id);
1509 interval_tree_insert(&new->hva_node[idx], &slots->hva_tree);
1510
1511 /*
1512 * If the memslot gfn is unchanged, rb_replace_node() can be used to
1513 * switch the node in the gfn tree instead of removing the old and
1514 * inserting the new as two separate operations. Replacement is a
1515 * single O(1) operation versus two O(log(n)) operations for
1516 * remove+insert.
1517 */
1518 if (old && old->base_gfn == new->base_gfn) {
1519 kvm_replace_gfn_node(slots, old, new);
1520 } else {
1521 if (old)
1522 kvm_erase_gfn_node(slots, old);
1523 kvm_insert_gfn_node(slots, new);
1524 }
1525}
1526
1527static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
1528{
1529 u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
1530
1531#ifdef __KVM_HAVE_READONLY_MEM
1532 valid_flags |= KVM_MEM_READONLY;
1533#endif
1534
1535 if (mem->flags & ~valid_flags)
1536 return -EINVAL;
1537
1538 return 0;
1539}
1540
1541static void kvm_swap_active_memslots(struct kvm *kvm, int as_id)
1542{
1543 struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id);
1544
1545 /* Grab the generation from the activate memslots. */
1546 u64 gen = __kvm_memslots(kvm, as_id)->generation;
1547
1548 WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS);
1549 slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
1550
1551 /*
1552 * Do not store the new memslots while there are invalidations in
1553 * progress, otherwise the locking in invalidate_range_start and
1554 * invalidate_range_end will be unbalanced.
1555 */
1556 spin_lock(&kvm->mn_invalidate_lock);
1557 prepare_to_rcuwait(&kvm->mn_memslots_update_rcuwait);
1558 while (kvm->mn_active_invalidate_count) {
1559 set_current_state(TASK_UNINTERRUPTIBLE);
1560 spin_unlock(&kvm->mn_invalidate_lock);
1561 schedule();
1562 spin_lock(&kvm->mn_invalidate_lock);
1563 }
1564 finish_rcuwait(&kvm->mn_memslots_update_rcuwait);
1565 rcu_assign_pointer(kvm->memslots[as_id], slots);
1566 spin_unlock(&kvm->mn_invalidate_lock);
1567
1568 /*
1569 * Acquired in kvm_set_memslot. Must be released before synchronize
1570 * SRCU below in order to avoid deadlock with another thread
1571 * acquiring the slots_arch_lock in an srcu critical section.
1572 */
1573 mutex_unlock(&kvm->slots_arch_lock);
1574
1575 synchronize_srcu_expedited(&kvm->srcu);
1576
1577 /*
1578 * Increment the new memslot generation a second time, dropping the
1579 * update in-progress flag and incrementing the generation based on
1580 * the number of address spaces. This provides a unique and easily
1581 * identifiable generation number while the memslots are in flux.
1582 */
1583 gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
1584
1585 /*
1586 * Generations must be unique even across address spaces. We do not need
1587 * a global counter for that, instead the generation space is evenly split
1588 * across address spaces. For example, with two address spaces, address
1589 * space 0 will use generations 0, 2, 4, ... while address space 1 will
1590 * use generations 1, 3, 5, ...
1591 */
1592 gen += KVM_ADDRESS_SPACE_NUM;
1593
1594 kvm_arch_memslots_updated(kvm, gen);
1595
1596 slots->generation = gen;
1597}
1598
1599static int kvm_prepare_memory_region(struct kvm *kvm,
1600 const struct kvm_memory_slot *old,
1601 struct kvm_memory_slot *new,
1602 enum kvm_mr_change change)
1603{
1604 int r;
1605
1606 /*
1607 * If dirty logging is disabled, nullify the bitmap; the old bitmap
1608 * will be freed on "commit". If logging is enabled in both old and
1609 * new, reuse the existing bitmap. If logging is enabled only in the
1610 * new and KVM isn't using a ring buffer, allocate and initialize a
1611 * new bitmap.
1612 */
1613 if (change != KVM_MR_DELETE) {
1614 if (!(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
1615 new->dirty_bitmap = NULL;
1616 else if (old && old->dirty_bitmap)
1617 new->dirty_bitmap = old->dirty_bitmap;
1618 else if (kvm_use_dirty_bitmap(kvm)) {
1619 r = kvm_alloc_dirty_bitmap(new);
1620 if (r)
1621 return r;
1622
1623 if (kvm_dirty_log_manual_protect_and_init_set(kvm))
1624 bitmap_set(new->dirty_bitmap, 0, new->npages);
1625 }
1626 }
1627
1628 r = kvm_arch_prepare_memory_region(kvm, old, new, change);
1629
1630 /* Free the bitmap on failure if it was allocated above. */
1631 if (r && new && new->dirty_bitmap && (!old || !old->dirty_bitmap))
1632 kvm_destroy_dirty_bitmap(new);
1633
1634 return r;
1635}
1636
1637static void kvm_commit_memory_region(struct kvm *kvm,
1638 struct kvm_memory_slot *old,
1639 const struct kvm_memory_slot *new,
1640 enum kvm_mr_change change)
1641{
1642 int old_flags = old ? old->flags : 0;
1643 int new_flags = new ? new->flags : 0;
1644 /*
1645 * Update the total number of memslot pages before calling the arch
1646 * hook so that architectures can consume the result directly.
1647 */
1648 if (change == KVM_MR_DELETE)
1649 kvm->nr_memslot_pages -= old->npages;
1650 else if (change == KVM_MR_CREATE)
1651 kvm->nr_memslot_pages += new->npages;
1652
1653 if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES) {
1654 int change = (new_flags & KVM_MEM_LOG_DIRTY_PAGES) ? 1 : -1;
1655 atomic_set(&kvm->nr_memslots_dirty_logging,
1656 atomic_read(&kvm->nr_memslots_dirty_logging) + change);
1657 }
1658
1659 kvm_arch_commit_memory_region(kvm, old, new, change);
1660
1661 switch (change) {
1662 case KVM_MR_CREATE:
1663 /* Nothing more to do. */
1664 break;
1665 case KVM_MR_DELETE:
1666 /* Free the old memslot and all its metadata. */
1667 kvm_free_memslot(kvm, old);
1668 break;
1669 case KVM_MR_MOVE:
1670 case KVM_MR_FLAGS_ONLY:
1671 /*
1672 * Free the dirty bitmap as needed; the below check encompasses
1673 * both the flags and whether a ring buffer is being used)
1674 */
1675 if (old->dirty_bitmap && !new->dirty_bitmap)
1676 kvm_destroy_dirty_bitmap(old);
1677
1678 /*
1679 * The final quirk. Free the detached, old slot, but only its
1680 * memory, not any metadata. Metadata, including arch specific
1681 * data, may be reused by @new.
1682 */
1683 kfree(old);
1684 break;
1685 default:
1686 BUG();
1687 }
1688}
1689
1690/*
1691 * Activate @new, which must be installed in the inactive slots by the caller,
1692 * by swapping the active slots and then propagating @new to @old once @old is
1693 * unreachable and can be safely modified.
1694 *
1695 * With NULL @old this simply adds @new to @active (while swapping the sets).
1696 * With NULL @new this simply removes @old from @active and frees it
1697 * (while also swapping the sets).
1698 */
1699static void kvm_activate_memslot(struct kvm *kvm,
1700 struct kvm_memory_slot *old,
1701 struct kvm_memory_slot *new)
1702{
1703 int as_id = kvm_memslots_get_as_id(old, new);
1704
1705 kvm_swap_active_memslots(kvm, as_id);
1706
1707 /* Propagate the new memslot to the now inactive memslots. */
1708 kvm_replace_memslot(kvm, old, new);
1709}
1710
1711static void kvm_copy_memslot(struct kvm_memory_slot *dest,
1712 const struct kvm_memory_slot *src)
1713{
1714 dest->base_gfn = src->base_gfn;
1715 dest->npages = src->npages;
1716 dest->dirty_bitmap = src->dirty_bitmap;
1717 dest->arch = src->arch;
1718 dest->userspace_addr = src->userspace_addr;
1719 dest->flags = src->flags;
1720 dest->id = src->id;
1721 dest->as_id = src->as_id;
1722}
1723
1724static void kvm_invalidate_memslot(struct kvm *kvm,
1725 struct kvm_memory_slot *old,
1726 struct kvm_memory_slot *invalid_slot)
1727{
1728 /*
1729 * Mark the current slot INVALID. As with all memslot modifications,
1730 * this must be done on an unreachable slot to avoid modifying the
1731 * current slot in the active tree.
1732 */
1733 kvm_copy_memslot(invalid_slot, old);
1734 invalid_slot->flags |= KVM_MEMSLOT_INVALID;
1735 kvm_replace_memslot(kvm, old, invalid_slot);
1736
1737 /*
1738 * Activate the slot that is now marked INVALID, but don't propagate
1739 * the slot to the now inactive slots. The slot is either going to be
1740 * deleted or recreated as a new slot.
1741 */
1742 kvm_swap_active_memslots(kvm, old->as_id);
1743
1744 /*
1745 * From this point no new shadow pages pointing to a deleted, or moved,
1746 * memslot will be created. Validation of sp->gfn happens in:
1747 * - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
1748 * - kvm_is_visible_gfn (mmu_check_root)
1749 */
1750 kvm_arch_flush_shadow_memslot(kvm, old);
1751 kvm_arch_guest_memory_reclaimed(kvm);
1752
1753 /* Was released by kvm_swap_active_memslots, reacquire. */
1754 mutex_lock(&kvm->slots_arch_lock);
1755
1756 /*
1757 * Copy the arch-specific field of the newly-installed slot back to the
1758 * old slot as the arch data could have changed between releasing
1759 * slots_arch_lock in install_new_memslots() and re-acquiring the lock
1760 * above. Writers are required to retrieve memslots *after* acquiring
1761 * slots_arch_lock, thus the active slot's data is guaranteed to be fresh.
1762 */
1763 old->arch = invalid_slot->arch;
1764}
1765
1766static void kvm_create_memslot(struct kvm *kvm,
1767 struct kvm_memory_slot *new)
1768{
1769 /* Add the new memslot to the inactive set and activate. */
1770 kvm_replace_memslot(kvm, NULL, new);
1771 kvm_activate_memslot(kvm, NULL, new);
1772}
1773
1774static void kvm_delete_memslot(struct kvm *kvm,
1775 struct kvm_memory_slot *old,
1776 struct kvm_memory_slot *invalid_slot)
1777{
1778 /*
1779 * Remove the old memslot (in the inactive memslots) by passing NULL as
1780 * the "new" slot, and for the invalid version in the active slots.
1781 */
1782 kvm_replace_memslot(kvm, old, NULL);
1783 kvm_activate_memslot(kvm, invalid_slot, NULL);
1784}
1785
1786static void kvm_move_memslot(struct kvm *kvm,
1787 struct kvm_memory_slot *old,
1788 struct kvm_memory_slot *new,
1789 struct kvm_memory_slot *invalid_slot)
1790{
1791 /*
1792 * Replace the old memslot in the inactive slots, and then swap slots
1793 * and replace the current INVALID with the new as well.
1794 */
1795 kvm_replace_memslot(kvm, old, new);
1796 kvm_activate_memslot(kvm, invalid_slot, new);
1797}
1798
1799static void kvm_update_flags_memslot(struct kvm *kvm,
1800 struct kvm_memory_slot *old,
1801 struct kvm_memory_slot *new)
1802{
1803 /*
1804 * Similar to the MOVE case, but the slot doesn't need to be zapped as
1805 * an intermediate step. Instead, the old memslot is simply replaced
1806 * with a new, updated copy in both memslot sets.
1807 */
1808 kvm_replace_memslot(kvm, old, new);
1809 kvm_activate_memslot(kvm, old, new);
1810}
1811
1812static int kvm_set_memslot(struct kvm *kvm,
1813 struct kvm_memory_slot *old,
1814 struct kvm_memory_slot *new,
1815 enum kvm_mr_change change)
1816{
1817 struct kvm_memory_slot *invalid_slot;
1818 int r;
1819
1820 /*
1821 * Released in kvm_swap_active_memslots.
1822 *
1823 * Must be held from before the current memslots are copied until
1824 * after the new memslots are installed with rcu_assign_pointer,
1825 * then released before the synchronize srcu in kvm_swap_active_memslots.
1826 *
1827 * When modifying memslots outside of the slots_lock, must be held
1828 * before reading the pointer to the current memslots until after all
1829 * changes to those memslots are complete.
1830 *
1831 * These rules ensure that installing new memslots does not lose
1832 * changes made to the previous memslots.
1833 */
1834 mutex_lock(&kvm->slots_arch_lock);
1835
1836 /*
1837 * Invalidate the old slot if it's being deleted or moved. This is
1838 * done prior to actually deleting/moving the memslot to allow vCPUs to
1839 * continue running by ensuring there are no mappings or shadow pages
1840 * for the memslot when it is deleted/moved. Without pre-invalidation
1841 * (and without a lock), a window would exist between effecting the
1842 * delete/move and committing the changes in arch code where KVM or a
1843 * guest could access a non-existent memslot.
1844 *
1845 * Modifications are done on a temporary, unreachable slot. The old
1846 * slot needs to be preserved in case a later step fails and the
1847 * invalidation needs to be reverted.
1848 */
1849 if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
1850 invalid_slot = kzalloc(sizeof(*invalid_slot), GFP_KERNEL_ACCOUNT);
1851 if (!invalid_slot) {
1852 mutex_unlock(&kvm->slots_arch_lock);
1853 return -ENOMEM;
1854 }
1855 kvm_invalidate_memslot(kvm, old, invalid_slot);
1856 }
1857
1858 r = kvm_prepare_memory_region(kvm, old, new, change);
1859 if (r) {
1860 /*
1861 * For DELETE/MOVE, revert the above INVALID change. No
1862 * modifications required since the original slot was preserved
1863 * in the inactive slots. Changing the active memslots also
1864 * release slots_arch_lock.
1865 */
1866 if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
1867 kvm_activate_memslot(kvm, invalid_slot, old);
1868 kfree(invalid_slot);
1869 } else {
1870 mutex_unlock(&kvm->slots_arch_lock);
1871 }
1872 return r;
1873 }
1874
1875 /*
1876 * For DELETE and MOVE, the working slot is now active as the INVALID
1877 * version of the old slot. MOVE is particularly special as it reuses
1878 * the old slot and returns a copy of the old slot (in working_slot).
1879 * For CREATE, there is no old slot. For DELETE and FLAGS_ONLY, the
1880 * old slot is detached but otherwise preserved.
1881 */
1882 if (change == KVM_MR_CREATE)
1883 kvm_create_memslot(kvm, new);
1884 else if (change == KVM_MR_DELETE)
1885 kvm_delete_memslot(kvm, old, invalid_slot);
1886 else if (change == KVM_MR_MOVE)
1887 kvm_move_memslot(kvm, old, new, invalid_slot);
1888 else if (change == KVM_MR_FLAGS_ONLY)
1889 kvm_update_flags_memslot(kvm, old, new);
1890 else
1891 BUG();
1892
1893 /* Free the temporary INVALID slot used for DELETE and MOVE. */
1894 if (change == KVM_MR_DELETE || change == KVM_MR_MOVE)
1895 kfree(invalid_slot);
1896
1897 /*
1898 * No need to refresh new->arch, changes after dropping slots_arch_lock
1899 * will directly hit the final, active memslot. Architectures are
1900 * responsible for knowing that new->arch may be stale.
1901 */
1902 kvm_commit_memory_region(kvm, old, new, change);
1903
1904 return 0;
1905}
1906
1907static bool kvm_check_memslot_overlap(struct kvm_memslots *slots, int id,
1908 gfn_t start, gfn_t end)
1909{
1910 struct kvm_memslot_iter iter;
1911
1912 kvm_for_each_memslot_in_gfn_range(&iter, slots, start, end) {
1913 if (iter.slot->id != id)
1914 return true;
1915 }
1916
1917 return false;
1918}
1919
1920/*
1921 * Allocate some memory and give it an address in the guest physical address
1922 * space.
1923 *
1924 * Discontiguous memory is allowed, mostly for framebuffers.
1925 *
1926 * Must be called holding kvm->slots_lock for write.
1927 */
1928int __kvm_set_memory_region(struct kvm *kvm,
1929 const struct kvm_userspace_memory_region *mem)
1930{
1931 struct kvm_memory_slot *old, *new;
1932 struct kvm_memslots *slots;
1933 enum kvm_mr_change change;
1934 unsigned long npages;
1935 gfn_t base_gfn;
1936 int as_id, id;
1937 int r;
1938
1939 r = check_memory_region_flags(mem);
1940 if (r)
1941 return r;
1942
1943 as_id = mem->slot >> 16;
1944 id = (u16)mem->slot;
1945
1946 /* General sanity checks */
1947 if ((mem->memory_size & (PAGE_SIZE - 1)) ||
1948 (mem->memory_size != (unsigned long)mem->memory_size))
1949 return -EINVAL;
1950 if (mem->guest_phys_addr & (PAGE_SIZE - 1))
1951 return -EINVAL;
1952 /* We can read the guest memory with __xxx_user() later on. */
1953 if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
1954 (mem->userspace_addr != untagged_addr(mem->userspace_addr)) ||
1955 !access_ok((void __user *)(unsigned long)mem->userspace_addr,
1956 mem->memory_size))
1957 return -EINVAL;
1958 if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
1959 return -EINVAL;
1960 if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
1961 return -EINVAL;
1962 if ((mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES)
1963 return -EINVAL;
1964
1965 slots = __kvm_memslots(kvm, as_id);
1966
1967 /*
1968 * Note, the old memslot (and the pointer itself!) may be invalidated
1969 * and/or destroyed by kvm_set_memslot().
1970 */
1971 old = id_to_memslot(slots, id);
1972
1973 if (!mem->memory_size) {
1974 if (!old || !old->npages)
1975 return -EINVAL;
1976
1977 if (WARN_ON_ONCE(kvm->nr_memslot_pages < old->npages))
1978 return -EIO;
1979
1980 return kvm_set_memslot(kvm, old, NULL, KVM_MR_DELETE);
1981 }
1982
1983 base_gfn = (mem->guest_phys_addr >> PAGE_SHIFT);
1984 npages = (mem->memory_size >> PAGE_SHIFT);
1985
1986 if (!old || !old->npages) {
1987 change = KVM_MR_CREATE;
1988
1989 /*
1990 * To simplify KVM internals, the total number of pages across
1991 * all memslots must fit in an unsigned long.
1992 */
1993 if ((kvm->nr_memslot_pages + npages) < kvm->nr_memslot_pages)
1994 return -EINVAL;
1995 } else { /* Modify an existing slot. */
1996 if ((mem->userspace_addr != old->userspace_addr) ||
1997 (npages != old->npages) ||
1998 ((mem->flags ^ old->flags) & KVM_MEM_READONLY))
1999 return -EINVAL;
2000
2001 if (base_gfn != old->base_gfn)
2002 change = KVM_MR_MOVE;
2003 else if (mem->flags != old->flags)
2004 change = KVM_MR_FLAGS_ONLY;
2005 else /* Nothing to change. */
2006 return 0;
2007 }
2008
2009 if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) &&
2010 kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages))
2011 return -EEXIST;
2012
2013 /* Allocate a slot that will persist in the memslot. */
2014 new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT);
2015 if (!new)
2016 return -ENOMEM;
2017
2018 new->as_id = as_id;
2019 new->id = id;
2020 new->base_gfn = base_gfn;
2021 new->npages = npages;
2022 new->flags = mem->flags;
2023 new->userspace_addr = mem->userspace_addr;
2024
2025 r = kvm_set_memslot(kvm, old, new, change);
2026 if (r)
2027 kfree(new);
2028 return r;
2029}
2030EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
2031
2032int kvm_set_memory_region(struct kvm *kvm,
2033 const struct kvm_userspace_memory_region *mem)
2034{
2035 int r;
2036
2037 mutex_lock(&kvm->slots_lock);
2038 r = __kvm_set_memory_region(kvm, mem);
2039 mutex_unlock(&kvm->slots_lock);
2040 return r;
2041}
2042EXPORT_SYMBOL_GPL(kvm_set_memory_region);
2043
2044static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
2045 struct kvm_userspace_memory_region *mem)
2046{
2047 if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
2048 return -EINVAL;
2049
2050 return kvm_set_memory_region(kvm, mem);
2051}
2052
2053#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
2054/**
2055 * kvm_get_dirty_log - get a snapshot of dirty pages
2056 * @kvm: pointer to kvm instance
2057 * @log: slot id and address to which we copy the log
2058 * @is_dirty: set to '1' if any dirty pages were found
2059 * @memslot: set to the associated memslot, always valid on success
2060 */
2061int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
2062 int *is_dirty, struct kvm_memory_slot **memslot)
2063{
2064 struct kvm_memslots *slots;
2065 int i, as_id, id;
2066 unsigned long n;
2067 unsigned long any = 0;
2068
2069 /* Dirty ring tracking may be exclusive to dirty log tracking */
2070 if (!kvm_use_dirty_bitmap(kvm))
2071 return -ENXIO;
2072
2073 *memslot = NULL;
2074 *is_dirty = 0;
2075
2076 as_id = log->slot >> 16;
2077 id = (u16)log->slot;
2078 if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
2079 return -EINVAL;
2080
2081 slots = __kvm_memslots(kvm, as_id);
2082 *memslot = id_to_memslot(slots, id);
2083 if (!(*memslot) || !(*memslot)->dirty_bitmap)
2084 return -ENOENT;
2085
2086 kvm_arch_sync_dirty_log(kvm, *memslot);
2087
2088 n = kvm_dirty_bitmap_bytes(*memslot);
2089
2090 for (i = 0; !any && i < n/sizeof(long); ++i)
2091 any = (*memslot)->dirty_bitmap[i];
2092
2093 if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
2094 return -EFAULT;
2095
2096 if (any)
2097 *is_dirty = 1;
2098 return 0;
2099}
2100EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
2101
2102#else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2103/**
2104 * kvm_get_dirty_log_protect - get a snapshot of dirty pages
2105 * and reenable dirty page tracking for the corresponding pages.
2106 * @kvm: pointer to kvm instance
2107 * @log: slot id and address to which we copy the log
2108 *
2109 * We need to keep it in mind that VCPU threads can write to the bitmap
2110 * concurrently. So, to avoid losing track of dirty pages we keep the
2111 * following order:
2112 *
2113 * 1. Take a snapshot of the bit and clear it if needed.
2114 * 2. Write protect the corresponding page.
2115 * 3. Copy the snapshot to the userspace.
2116 * 4. Upon return caller flushes TLB's if needed.
2117 *
2118 * Between 2 and 4, the guest may write to the page using the remaining TLB
2119 * entry. This is not a problem because the page is reported dirty using
2120 * the snapshot taken before and step 4 ensures that writes done after
2121 * exiting to userspace will be logged for the next call.
2122 *
2123 */
2124static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log)
2125{
2126 struct kvm_memslots *slots;
2127 struct kvm_memory_slot *memslot;
2128 int i, as_id, id;
2129 unsigned long n;
2130 unsigned long *dirty_bitmap;
2131 unsigned long *dirty_bitmap_buffer;
2132 bool flush;
2133
2134 /* Dirty ring tracking may be exclusive to dirty log tracking */
2135 if (!kvm_use_dirty_bitmap(kvm))
2136 return -ENXIO;
2137
2138 as_id = log->slot >> 16;
2139 id = (u16)log->slot;
2140 if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
2141 return -EINVAL;
2142
2143 slots = __kvm_memslots(kvm, as_id);
2144 memslot = id_to_memslot(slots, id);
2145 if (!memslot || !memslot->dirty_bitmap)
2146 return -ENOENT;
2147
2148 dirty_bitmap = memslot->dirty_bitmap;
2149
2150 kvm_arch_sync_dirty_log(kvm, memslot);
2151
2152 n = kvm_dirty_bitmap_bytes(memslot);
2153 flush = false;
2154 if (kvm->manual_dirty_log_protect) {
2155 /*
2156 * Unlike kvm_get_dirty_log, we always return false in *flush,
2157 * because no flush is needed until KVM_CLEAR_DIRTY_LOG. There
2158 * is some code duplication between this function and
2159 * kvm_get_dirty_log, but hopefully all architecture
2160 * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
2161 * can be eliminated.
2162 */
2163 dirty_bitmap_buffer = dirty_bitmap;
2164 } else {
2165 dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
2166 memset(dirty_bitmap_buffer, 0, n);
2167
2168 KVM_MMU_LOCK(kvm);
2169 for (i = 0; i < n / sizeof(long); i++) {
2170 unsigned long mask;
2171 gfn_t offset;
2172
2173 if (!dirty_bitmap[i])
2174 continue;
2175
2176 flush = true;
2177 mask = xchg(&dirty_bitmap[i], 0);
2178 dirty_bitmap_buffer[i] = mask;
2179
2180 offset = i * BITS_PER_LONG;
2181 kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
2182 offset, mask);
2183 }
2184 KVM_MMU_UNLOCK(kvm);
2185 }
2186
2187 if (flush)
2188 kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
2189
2190 if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
2191 return -EFAULT;
2192 return 0;
2193}
2194
2195
2196/**
2197 * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
2198 * @kvm: kvm instance
2199 * @log: slot id and address to which we copy the log
2200 *
2201 * Steps 1-4 below provide general overview of dirty page logging. See
2202 * kvm_get_dirty_log_protect() function description for additional details.
2203 *
2204 * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
2205 * always flush the TLB (step 4) even if previous step failed and the dirty
2206 * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
2207 * does not preclude user space subsequent dirty log read. Flushing TLB ensures
2208 * writes will be marked dirty for next log read.
2209 *
2210 * 1. Take a snapshot of the bit and clear it if needed.
2211 * 2. Write protect the corresponding page.
2212 * 3. Copy the snapshot to the userspace.
2213 * 4. Flush TLB's if needed.
2214 */
2215static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
2216 struct kvm_dirty_log *log)
2217{
2218 int r;
2219
2220 mutex_lock(&kvm->slots_lock);
2221
2222 r = kvm_get_dirty_log_protect(kvm, log);
2223
2224 mutex_unlock(&kvm->slots_lock);
2225 return r;
2226}
2227
2228/**
2229 * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
2230 * and reenable dirty page tracking for the corresponding pages.
2231 * @kvm: pointer to kvm instance
2232 * @log: slot id and address from which to fetch the bitmap of dirty pages
2233 */
2234static int kvm_clear_dirty_log_protect(struct kvm *kvm,
2235 struct kvm_clear_dirty_log *log)
2236{
2237 struct kvm_memslots *slots;
2238 struct kvm_memory_slot *memslot;
2239 int as_id, id;
2240 gfn_t offset;
2241 unsigned long i, n;
2242 unsigned long *dirty_bitmap;
2243 unsigned long *dirty_bitmap_buffer;
2244 bool flush;
2245
2246 /* Dirty ring tracking may be exclusive to dirty log tracking */
2247 if (!kvm_use_dirty_bitmap(kvm))
2248 return -ENXIO;
2249
2250 as_id = log->slot >> 16;
2251 id = (u16)log->slot;
2252 if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
2253 return -EINVAL;
2254
2255 if (log->first_page & 63)
2256 return -EINVAL;
2257
2258 slots = __kvm_memslots(kvm, as_id);
2259 memslot = id_to_memslot(slots, id);
2260 if (!memslot || !memslot->dirty_bitmap)
2261 return -ENOENT;
2262
2263 dirty_bitmap = memslot->dirty_bitmap;
2264
2265 n = ALIGN(log->num_pages, BITS_PER_LONG) / 8;
2266
2267 if (log->first_page > memslot->npages ||
2268 log->num_pages > memslot->npages - log->first_page ||
2269 (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63)))
2270 return -EINVAL;
2271
2272 kvm_arch_sync_dirty_log(kvm, memslot);
2273
2274 flush = false;
2275 dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
2276 if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n))
2277 return -EFAULT;
2278
2279 KVM_MMU_LOCK(kvm);
2280 for (offset = log->first_page, i = offset / BITS_PER_LONG,
2281 n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--;
2282 i++, offset += BITS_PER_LONG) {
2283 unsigned long mask = *dirty_bitmap_buffer++;
2284 atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
2285 if (!mask)
2286 continue;
2287
2288 mask &= atomic_long_fetch_andnot(mask, p);
2289
2290 /*
2291 * mask contains the bits that really have been cleared. This
2292 * never includes any bits beyond the length of the memslot (if
2293 * the length is not aligned to 64 pages), therefore it is not
2294 * a problem if userspace sets them in log->dirty_bitmap.
2295 */
2296 if (mask) {
2297 flush = true;
2298 kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
2299 offset, mask);
2300 }
2301 }
2302 KVM_MMU_UNLOCK(kvm);
2303
2304 if (flush)
2305 kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
2306
2307 return 0;
2308}
2309
2310static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
2311 struct kvm_clear_dirty_log *log)
2312{
2313 int r;
2314
2315 mutex_lock(&kvm->slots_lock);
2316
2317 r = kvm_clear_dirty_log_protect(kvm, log);
2318
2319 mutex_unlock(&kvm->slots_lock);
2320 return r;
2321}
2322#endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
2323
2324struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
2325{
2326 return __gfn_to_memslot(kvm_memslots(kvm), gfn);
2327}
2328EXPORT_SYMBOL_GPL(gfn_to_memslot);
2329
2330struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
2331{
2332 struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
2333 u64 gen = slots->generation;
2334 struct kvm_memory_slot *slot;
2335
2336 /*
2337 * This also protects against using a memslot from a different address space,
2338 * since different address spaces have different generation numbers.
2339 */
2340 if (unlikely(gen != vcpu->last_used_slot_gen)) {
2341 vcpu->last_used_slot = NULL;
2342 vcpu->last_used_slot_gen = gen;
2343 }
2344
2345 slot = try_get_memslot(vcpu->last_used_slot, gfn);
2346 if (slot)
2347 return slot;
2348
2349 /*
2350 * Fall back to searching all memslots. We purposely use
2351 * search_memslots() instead of __gfn_to_memslot() to avoid
2352 * thrashing the VM-wide last_used_slot in kvm_memslots.
2353 */
2354 slot = search_memslots(slots, gfn, false);
2355 if (slot) {
2356 vcpu->last_used_slot = slot;
2357 return slot;
2358 }
2359
2360 return NULL;
2361}
2362
2363bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
2364{
2365 struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
2366
2367 return kvm_is_visible_memslot(memslot);
2368}
2369EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
2370
2371bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
2372{
2373 struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
2374
2375 return kvm_is_visible_memslot(memslot);
2376}
2377EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn);
2378
2379unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn)
2380{
2381 struct vm_area_struct *vma;
2382 unsigned long addr, size;
2383
2384 size = PAGE_SIZE;
2385
2386 addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL);
2387 if (kvm_is_error_hva(addr))
2388 return PAGE_SIZE;
2389
2390 mmap_read_lock(current->mm);
2391 vma = find_vma(current->mm, addr);
2392 if (!vma)
2393 goto out;
2394
2395 size = vma_kernel_pagesize(vma);
2396
2397out:
2398 mmap_read_unlock(current->mm);
2399
2400 return size;
2401}
2402
2403static bool memslot_is_readonly(const struct kvm_memory_slot *slot)
2404{
2405 return slot->flags & KVM_MEM_READONLY;
2406}
2407
2408static unsigned long __gfn_to_hva_many(const struct kvm_memory_slot *slot, gfn_t gfn,
2409 gfn_t *nr_pages, bool write)
2410{
2411 if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
2412 return KVM_HVA_ERR_BAD;
2413
2414 if (memslot_is_readonly(slot) && write)
2415 return KVM_HVA_ERR_RO_BAD;
2416
2417 if (nr_pages)
2418 *nr_pages = slot->npages - (gfn - slot->base_gfn);
2419
2420 return __gfn_to_hva_memslot(slot, gfn);
2421}
2422
2423static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
2424 gfn_t *nr_pages)
2425{
2426 return __gfn_to_hva_many(slot, gfn, nr_pages, true);
2427}
2428
2429unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
2430 gfn_t gfn)
2431{
2432 return gfn_to_hva_many(slot, gfn, NULL);
2433}
2434EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
2435
2436unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
2437{
2438 return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
2439}
2440EXPORT_SYMBOL_GPL(gfn_to_hva);
2441
2442unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
2443{
2444 return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
2445}
2446EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
2447
2448/*
2449 * Return the hva of a @gfn and the R/W attribute if possible.
2450 *
2451 * @slot: the kvm_memory_slot which contains @gfn
2452 * @gfn: the gfn to be translated
2453 * @writable: used to return the read/write attribute of the @slot if the hva
2454 * is valid and @writable is not NULL
2455 */
2456unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
2457 gfn_t gfn, bool *writable)
2458{
2459 unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
2460
2461 if (!kvm_is_error_hva(hva) && writable)
2462 *writable = !memslot_is_readonly(slot);
2463
2464 return hva;
2465}
2466
2467unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
2468{
2469 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
2470
2471 return gfn_to_hva_memslot_prot(slot, gfn, writable);
2472}
2473
2474unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
2475{
2476 struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
2477
2478 return gfn_to_hva_memslot_prot(slot, gfn, writable);
2479}
2480
2481static inline int check_user_page_hwpoison(unsigned long addr)
2482{
2483 int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
2484
2485 rc = get_user_pages(addr, 1, flags, NULL, NULL);
2486 return rc == -EHWPOISON;
2487}
2488
2489/*
2490 * The fast path to get the writable pfn which will be stored in @pfn,
2491 * true indicates success, otherwise false is returned. It's also the
2492 * only part that runs if we can in atomic context.
2493 */
2494static bool hva_to_pfn_fast(unsigned long addr, bool write_fault,
2495 bool *writable, kvm_pfn_t *pfn)
2496{
2497 struct page *page[1];
2498
2499 /*
2500 * Fast pin a writable pfn only if it is a write fault request
2501 * or the caller allows to map a writable pfn for a read fault
2502 * request.
2503 */
2504 if (!(write_fault || writable))
2505 return false;
2506
2507 if (get_user_page_fast_only(addr, FOLL_WRITE, page)) {
2508 *pfn = page_to_pfn(page[0]);
2509
2510 if (writable)
2511 *writable = true;
2512 return true;
2513 }
2514
2515 return false;
2516}
2517
2518/*
2519 * The slow path to get the pfn of the specified host virtual address,
2520 * 1 indicates success, -errno is returned if error is detected.
2521 */
2522static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
2523 bool interruptible, bool *writable, kvm_pfn_t *pfn)
2524{
2525 unsigned int flags = FOLL_HWPOISON;
2526 struct page *page;
2527 int npages;
2528
2529 might_sleep();
2530
2531 if (writable)
2532 *writable = write_fault;
2533
2534 if (write_fault)
2535 flags |= FOLL_WRITE;
2536 if (async)
2537 flags |= FOLL_NOWAIT;
2538 if (interruptible)
2539 flags |= FOLL_INTERRUPTIBLE;
2540
2541 npages = get_user_pages_unlocked(addr, 1, &page, flags);
2542 if (npages != 1)
2543 return npages;
2544
2545 /* map read fault as writable if possible */
2546 if (unlikely(!write_fault) && writable) {
2547 struct page *wpage;
2548
2549 if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) {
2550 *writable = true;
2551 put_page(page);
2552 page = wpage;
2553 }
2554 }
2555 *pfn = page_to_pfn(page);
2556 return npages;
2557}
2558
2559static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
2560{
2561 if (unlikely(!(vma->vm_flags & VM_READ)))
2562 return false;
2563
2564 if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
2565 return false;
2566
2567 return true;
2568}
2569
2570static int kvm_try_get_pfn(kvm_pfn_t pfn)
2571{
2572 struct page *page = kvm_pfn_to_refcounted_page(pfn);
2573
2574 if (!page)
2575 return 1;
2576
2577 return get_page_unless_zero(page);
2578}
2579
2580static int hva_to_pfn_remapped(struct vm_area_struct *vma,
2581 unsigned long addr, bool write_fault,
2582 bool *writable, kvm_pfn_t *p_pfn)
2583{
2584 kvm_pfn_t pfn;
2585 pte_t *ptep;
2586 spinlock_t *ptl;
2587 int r;
2588
2589 r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
2590 if (r) {
2591 /*
2592 * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
2593 * not call the fault handler, so do it here.
2594 */
2595 bool unlocked = false;
2596 r = fixup_user_fault(current->mm, addr,
2597 (write_fault ? FAULT_FLAG_WRITE : 0),
2598 &unlocked);
2599 if (unlocked)
2600 return -EAGAIN;
2601 if (r)
2602 return r;
2603
2604 r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
2605 if (r)
2606 return r;
2607 }
2608
2609 if (write_fault && !pte_write(*ptep)) {
2610 pfn = KVM_PFN_ERR_RO_FAULT;
2611 goto out;
2612 }
2613
2614 if (writable)
2615 *writable = pte_write(*ptep);
2616 pfn = pte_pfn(*ptep);
2617
2618 /*
2619 * Get a reference here because callers of *hva_to_pfn* and
2620 * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
2621 * returned pfn. This is only needed if the VMA has VM_MIXEDMAP
2622 * set, but the kvm_try_get_pfn/kvm_release_pfn_clean pair will
2623 * simply do nothing for reserved pfns.
2624 *
2625 * Whoever called remap_pfn_range is also going to call e.g.
2626 * unmap_mapping_range before the underlying pages are freed,
2627 * causing a call to our MMU notifier.
2628 *
2629 * Certain IO or PFNMAP mappings can be backed with valid
2630 * struct pages, but be allocated without refcounting e.g.,
2631 * tail pages of non-compound higher order allocations, which
2632 * would then underflow the refcount when the caller does the
2633 * required put_page. Don't allow those pages here.
2634 */
2635 if (!kvm_try_get_pfn(pfn))
2636 r = -EFAULT;
2637
2638out:
2639 pte_unmap_unlock(ptep, ptl);
2640 *p_pfn = pfn;
2641
2642 return r;
2643}
2644
2645/*
2646 * Pin guest page in memory and return its pfn.
2647 * @addr: host virtual address which maps memory to the guest
2648 * @atomic: whether this function can sleep
2649 * @interruptible: whether the process can be interrupted by non-fatal signals
2650 * @async: whether this function need to wait IO complete if the
2651 * host page is not in the memory
2652 * @write_fault: whether we should get a writable host page
2653 * @writable: whether it allows to map a writable host page for !@write_fault
2654 *
2655 * The function will map a writable host page for these two cases:
2656 * 1): @write_fault = true
2657 * 2): @write_fault = false && @writable, @writable will tell the caller
2658 * whether the mapping is writable.
2659 */
2660kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool interruptible,
2661 bool *async, bool write_fault, bool *writable)
2662{
2663 struct vm_area_struct *vma;
2664 kvm_pfn_t pfn;
2665 int npages, r;
2666
2667 /* we can do it either atomically or asynchronously, not both */
2668 BUG_ON(atomic && async);
2669
2670 if (hva_to_pfn_fast(addr, write_fault, writable, &pfn))
2671 return pfn;
2672
2673 if (atomic)
2674 return KVM_PFN_ERR_FAULT;
2675
2676 npages = hva_to_pfn_slow(addr, async, write_fault, interruptible,
2677 writable, &pfn);
2678 if (npages == 1)
2679 return pfn;
2680 if (npages == -EINTR)
2681 return KVM_PFN_ERR_SIGPENDING;
2682
2683 mmap_read_lock(current->mm);
2684 if (npages == -EHWPOISON ||
2685 (!async && check_user_page_hwpoison(addr))) {
2686 pfn = KVM_PFN_ERR_HWPOISON;
2687 goto exit;
2688 }
2689
2690retry:
2691 vma = vma_lookup(current->mm, addr);
2692
2693 if (vma == NULL)
2694 pfn = KVM_PFN_ERR_FAULT;
2695 else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
2696 r = hva_to_pfn_remapped(vma, addr, write_fault, writable, &pfn);
2697 if (r == -EAGAIN)
2698 goto retry;
2699 if (r < 0)
2700 pfn = KVM_PFN_ERR_FAULT;
2701 } else {
2702 if (async && vma_is_valid(vma, write_fault))
2703 *async = true;
2704 pfn = KVM_PFN_ERR_FAULT;
2705 }
2706exit:
2707 mmap_read_unlock(current->mm);
2708 return pfn;
2709}
2710
2711kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn,
2712 bool atomic, bool interruptible, bool *async,
2713 bool write_fault, bool *writable, hva_t *hva)
2714{
2715 unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
2716
2717 if (hva)
2718 *hva = addr;
2719
2720 if (addr == KVM_HVA_ERR_RO_BAD) {
2721 if (writable)
2722 *writable = false;
2723 return KVM_PFN_ERR_RO_FAULT;
2724 }
2725
2726 if (kvm_is_error_hva(addr)) {
2727 if (writable)
2728 *writable = false;
2729 return KVM_PFN_NOSLOT;
2730 }
2731
2732 /* Do not map writable pfn in the readonly memslot. */
2733 if (writable && memslot_is_readonly(slot)) {
2734 *writable = false;
2735 writable = NULL;
2736 }
2737
2738 return hva_to_pfn(addr, atomic, interruptible, async, write_fault,
2739 writable);
2740}
2741EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
2742
2743kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
2744 bool *writable)
2745{
2746 return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, false,
2747 NULL, write_fault, writable, NULL);
2748}
2749EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
2750
2751kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
2752{
2753 return __gfn_to_pfn_memslot(slot, gfn, false, false, NULL, true,
2754 NULL, NULL);
2755}
2756EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
2757
2758kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn)
2759{
2760 return __gfn_to_pfn_memslot(slot, gfn, true, false, NULL, true,
2761 NULL, NULL);
2762}
2763EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
2764
2765kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
2766{
2767 return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
2768}
2769EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
2770
2771kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
2772{
2773 return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
2774}
2775EXPORT_SYMBOL_GPL(gfn_to_pfn);
2776
2777kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
2778{
2779 return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
2780}
2781EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
2782
2783int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
2784 struct page **pages, int nr_pages)
2785{
2786 unsigned long addr;
2787 gfn_t entry = 0;
2788
2789 addr = gfn_to_hva_many(slot, gfn, &entry);
2790 if (kvm_is_error_hva(addr))
2791 return -1;
2792
2793 if (entry < nr_pages)
2794 return 0;
2795
2796 return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages);
2797}
2798EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
2799
2800/*
2801 * Do not use this helper unless you are absolutely certain the gfn _must_ be
2802 * backed by 'struct page'. A valid example is if the backing memslot is
2803 * controlled by KVM. Note, if the returned page is valid, it's refcount has
2804 * been elevated by gfn_to_pfn().
2805 */
2806struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
2807{
2808 struct page *page;
2809 kvm_pfn_t pfn;
2810
2811 pfn = gfn_to_pfn(kvm, gfn);
2812
2813 if (is_error_noslot_pfn(pfn))
2814 return KVM_ERR_PTR_BAD_PAGE;
2815
2816 page = kvm_pfn_to_refcounted_page(pfn);
2817 if (!page)
2818 return KVM_ERR_PTR_BAD_PAGE;
2819
2820 return page;
2821}
2822EXPORT_SYMBOL_GPL(gfn_to_page);
2823
2824void kvm_release_pfn(kvm_pfn_t pfn, bool dirty)
2825{
2826 if (dirty)
2827 kvm_release_pfn_dirty(pfn);
2828 else
2829 kvm_release_pfn_clean(pfn);
2830}
2831
2832int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map)
2833{
2834 kvm_pfn_t pfn;
2835 void *hva = NULL;
2836 struct page *page = KVM_UNMAPPED_PAGE;
2837
2838 if (!map)
2839 return -EINVAL;
2840
2841 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2842 if (is_error_noslot_pfn(pfn))
2843 return -EINVAL;
2844
2845 if (pfn_valid(pfn)) {
2846 page = pfn_to_page(pfn);
2847 hva = kmap(page);
2848#ifdef CONFIG_HAS_IOMEM
2849 } else {
2850 hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB);
2851#endif
2852 }
2853
2854 if (!hva)
2855 return -EFAULT;
2856
2857 map->page = page;
2858 map->hva = hva;
2859 map->pfn = pfn;
2860 map->gfn = gfn;
2861
2862 return 0;
2863}
2864EXPORT_SYMBOL_GPL(kvm_vcpu_map);
2865
2866void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty)
2867{
2868 if (!map)
2869 return;
2870
2871 if (!map->hva)
2872 return;
2873
2874 if (map->page != KVM_UNMAPPED_PAGE)
2875 kunmap(map->page);
2876#ifdef CONFIG_HAS_IOMEM
2877 else
2878 memunmap(map->hva);
2879#endif
2880
2881 if (dirty)
2882 kvm_vcpu_mark_page_dirty(vcpu, map->gfn);
2883
2884 kvm_release_pfn(map->pfn, dirty);
2885
2886 map->hva = NULL;
2887 map->page = NULL;
2888}
2889EXPORT_SYMBOL_GPL(kvm_vcpu_unmap);
2890
2891static bool kvm_is_ad_tracked_page(struct page *page)
2892{
2893 /*
2894 * Per page-flags.h, pages tagged PG_reserved "should in general not be
2895 * touched (e.g. set dirty) except by its owner".
2896 */
2897 return !PageReserved(page);
2898}
2899
2900static void kvm_set_page_dirty(struct page *page)
2901{
2902 if (kvm_is_ad_tracked_page(page))
2903 SetPageDirty(page);
2904}
2905
2906static void kvm_set_page_accessed(struct page *page)
2907{
2908 if (kvm_is_ad_tracked_page(page))
2909 mark_page_accessed(page);
2910}
2911
2912void kvm_release_page_clean(struct page *page)
2913{
2914 WARN_ON(is_error_page(page));
2915
2916 kvm_set_page_accessed(page);
2917 put_page(page);
2918}
2919EXPORT_SYMBOL_GPL(kvm_release_page_clean);
2920
2921void kvm_release_pfn_clean(kvm_pfn_t pfn)
2922{
2923 struct page *page;
2924
2925 if (is_error_noslot_pfn(pfn))
2926 return;
2927
2928 page = kvm_pfn_to_refcounted_page(pfn);
2929 if (!page)
2930 return;
2931
2932 kvm_release_page_clean(page);
2933}
2934EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
2935
2936void kvm_release_page_dirty(struct page *page)
2937{
2938 WARN_ON(is_error_page(page));
2939
2940 kvm_set_page_dirty(page);
2941 kvm_release_page_clean(page);
2942}
2943EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
2944
2945void kvm_release_pfn_dirty(kvm_pfn_t pfn)
2946{
2947 struct page *page;
2948
2949 if (is_error_noslot_pfn(pfn))
2950 return;
2951
2952 page = kvm_pfn_to_refcounted_page(pfn);
2953 if (!page)
2954 return;
2955
2956 kvm_release_page_dirty(page);
2957}
2958EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
2959
2960/*
2961 * Note, checking for an error/noslot pfn is the caller's responsibility when
2962 * directly marking a page dirty/accessed. Unlike the "release" helpers, the
2963 * "set" helpers are not to be used when the pfn might point at garbage.
2964 */
2965void kvm_set_pfn_dirty(kvm_pfn_t pfn)
2966{
2967 if (WARN_ON(is_error_noslot_pfn(pfn)))
2968 return;
2969
2970 if (pfn_valid(pfn))
2971 kvm_set_page_dirty(pfn_to_page(pfn));
2972}
2973EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
2974
2975void kvm_set_pfn_accessed(kvm_pfn_t pfn)
2976{
2977 if (WARN_ON(is_error_noslot_pfn(pfn)))
2978 return;
2979
2980 if (pfn_valid(pfn))
2981 kvm_set_page_accessed(pfn_to_page(pfn));
2982}
2983EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
2984
2985static int next_segment(unsigned long len, int offset)
2986{
2987 if (len > PAGE_SIZE - offset)
2988 return PAGE_SIZE - offset;
2989 else
2990 return len;
2991}
2992
2993static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
2994 void *data, int offset, int len)
2995{
2996 int r;
2997 unsigned long addr;
2998
2999 addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
3000 if (kvm_is_error_hva(addr))
3001 return -EFAULT;
3002 r = __copy_from_user(data, (void __user *)addr + offset, len);
3003 if (r)
3004 return -EFAULT;
3005 return 0;
3006}
3007
3008int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
3009 int len)
3010{
3011 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
3012
3013 return __kvm_read_guest_page(slot, gfn, data, offset, len);
3014}
3015EXPORT_SYMBOL_GPL(kvm_read_guest_page);
3016
3017int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
3018 int offset, int len)
3019{
3020 struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3021
3022 return __kvm_read_guest_page(slot, gfn, data, offset, len);
3023}
3024EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
3025
3026int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
3027{
3028 gfn_t gfn = gpa >> PAGE_SHIFT;
3029 int seg;
3030 int offset = offset_in_page(gpa);
3031 int ret;
3032
3033 while ((seg = next_segment(len, offset)) != 0) {
3034 ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
3035 if (ret < 0)
3036 return ret;
3037 offset = 0;
3038 len -= seg;
3039 data += seg;
3040 ++gfn;
3041 }
3042 return 0;
3043}
3044EXPORT_SYMBOL_GPL(kvm_read_guest);
3045
3046int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
3047{
3048 gfn_t gfn = gpa >> PAGE_SHIFT;
3049 int seg;
3050 int offset = offset_in_page(gpa);
3051 int ret;
3052
3053 while ((seg = next_segment(len, offset)) != 0) {
3054 ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
3055 if (ret < 0)
3056 return ret;
3057 offset = 0;
3058 len -= seg;
3059 data += seg;
3060 ++gfn;
3061 }
3062 return 0;
3063}
3064EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
3065
3066static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
3067 void *data, int offset, unsigned long len)
3068{
3069 int r;
3070 unsigned long addr;
3071
3072 addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
3073 if (kvm_is_error_hva(addr))
3074 return -EFAULT;
3075 pagefault_disable();
3076 r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
3077 pagefault_enable();
3078 if (r)
3079 return -EFAULT;
3080 return 0;
3081}
3082
3083int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
3084 void *data, unsigned long len)
3085{
3086 gfn_t gfn = gpa >> PAGE_SHIFT;
3087 struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3088 int offset = offset_in_page(gpa);
3089
3090 return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
3091}
3092EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
3093
3094static int __kvm_write_guest_page(struct kvm *kvm,
3095 struct kvm_memory_slot *memslot, gfn_t gfn,
3096 const void *data, int offset, int len)
3097{
3098 int r;
3099 unsigned long addr;
3100
3101 addr = gfn_to_hva_memslot(memslot, gfn);
3102 if (kvm_is_error_hva(addr))
3103 return -EFAULT;
3104 r = __copy_to_user((void __user *)addr + offset, data, len);
3105 if (r)
3106 return -EFAULT;
3107 mark_page_dirty_in_slot(kvm, memslot, gfn);
3108 return 0;
3109}
3110
3111int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
3112 const void *data, int offset, int len)
3113{
3114 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
3115
3116 return __kvm_write_guest_page(kvm, slot, gfn, data, offset, len);
3117}
3118EXPORT_SYMBOL_GPL(kvm_write_guest_page);
3119
3120int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
3121 const void *data, int offset, int len)
3122{
3123 struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3124
3125 return __kvm_write_guest_page(vcpu->kvm, slot, gfn, data, offset, len);
3126}
3127EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
3128
3129int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
3130 unsigned long len)
3131{
3132 gfn_t gfn = gpa >> PAGE_SHIFT;
3133 int seg;
3134 int offset = offset_in_page(gpa);
3135 int ret;
3136
3137 while ((seg = next_segment(len, offset)) != 0) {
3138 ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
3139 if (ret < 0)
3140 return ret;
3141 offset = 0;
3142 len -= seg;
3143 data += seg;
3144 ++gfn;
3145 }
3146 return 0;
3147}
3148EXPORT_SYMBOL_GPL(kvm_write_guest);
3149
3150int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
3151 unsigned long len)
3152{
3153 gfn_t gfn = gpa >> PAGE_SHIFT;
3154 int seg;
3155 int offset = offset_in_page(gpa);
3156 int ret;
3157
3158 while ((seg = next_segment(len, offset)) != 0) {
3159 ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
3160 if (ret < 0)
3161 return ret;
3162 offset = 0;
3163 len -= seg;
3164 data += seg;
3165 ++gfn;
3166 }
3167 return 0;
3168}
3169EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
3170
3171static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
3172 struct gfn_to_hva_cache *ghc,
3173 gpa_t gpa, unsigned long len)
3174{
3175 int offset = offset_in_page(gpa);
3176 gfn_t start_gfn = gpa >> PAGE_SHIFT;
3177 gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
3178 gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
3179 gfn_t nr_pages_avail;
3180
3181 /* Update ghc->generation before performing any error checks. */
3182 ghc->generation = slots->generation;
3183
3184 if (start_gfn > end_gfn) {
3185 ghc->hva = KVM_HVA_ERR_BAD;
3186 return -EINVAL;
3187 }
3188
3189 /*
3190 * If the requested region crosses two memslots, we still
3191 * verify that the entire region is valid here.
3192 */
3193 for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) {
3194 ghc->memslot = __gfn_to_memslot(slots, start_gfn);
3195 ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
3196 &nr_pages_avail);
3197 if (kvm_is_error_hva(ghc->hva))
3198 return -EFAULT;
3199 }
3200
3201 /* Use the slow path for cross page reads and writes. */
3202 if (nr_pages_needed == 1)
3203 ghc->hva += offset;
3204 else
3205 ghc->memslot = NULL;
3206
3207 ghc->gpa = gpa;
3208 ghc->len = len;
3209 return 0;
3210}
3211
3212int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3213 gpa_t gpa, unsigned long len)
3214{
3215 struct kvm_memslots *slots = kvm_memslots(kvm);
3216 return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
3217}
3218EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
3219
3220int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3221 void *data, unsigned int offset,
3222 unsigned long len)
3223{
3224 struct kvm_memslots *slots = kvm_memslots(kvm);
3225 int r;
3226 gpa_t gpa = ghc->gpa + offset;
3227
3228 if (WARN_ON_ONCE(len + offset > ghc->len))
3229 return -EINVAL;
3230
3231 if (slots->generation != ghc->generation) {
3232 if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
3233 return -EFAULT;
3234 }
3235
3236 if (kvm_is_error_hva(ghc->hva))
3237 return -EFAULT;
3238
3239 if (unlikely(!ghc->memslot))
3240 return kvm_write_guest(kvm, gpa, data, len);
3241
3242 r = __copy_to_user((void __user *)ghc->hva + offset, data, len);
3243 if (r)
3244 return -EFAULT;
3245 mark_page_dirty_in_slot(kvm, ghc->memslot, gpa >> PAGE_SHIFT);
3246
3247 return 0;
3248}
3249EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
3250
3251int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3252 void *data, unsigned long len)
3253{
3254 return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
3255}
3256EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
3257
3258int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3259 void *data, unsigned int offset,
3260 unsigned long len)
3261{
3262 struct kvm_memslots *slots = kvm_memslots(kvm);
3263 int r;
3264 gpa_t gpa = ghc->gpa + offset;
3265
3266 if (WARN_ON_ONCE(len + offset > ghc->len))
3267 return -EINVAL;
3268
3269 if (slots->generation != ghc->generation) {
3270 if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
3271 return -EFAULT;
3272 }
3273
3274 if (kvm_is_error_hva(ghc->hva))
3275 return -EFAULT;
3276
3277 if (unlikely(!ghc->memslot))
3278 return kvm_read_guest(kvm, gpa, data, len);
3279
3280 r = __copy_from_user(data, (void __user *)ghc->hva + offset, len);
3281 if (r)
3282 return -EFAULT;
3283
3284 return 0;
3285}
3286EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached);
3287
3288int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
3289 void *data, unsigned long len)
3290{
3291 return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len);
3292}
3293EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
3294
3295int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
3296{
3297 const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
3298 gfn_t gfn = gpa >> PAGE_SHIFT;
3299 int seg;
3300 int offset = offset_in_page(gpa);
3301 int ret;
3302
3303 while ((seg = next_segment(len, offset)) != 0) {
3304 ret = kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
3305 if (ret < 0)
3306 return ret;
3307 offset = 0;
3308 len -= seg;
3309 ++gfn;
3310 }
3311 return 0;
3312}
3313EXPORT_SYMBOL_GPL(kvm_clear_guest);
3314
3315void mark_page_dirty_in_slot(struct kvm *kvm,
3316 const struct kvm_memory_slot *memslot,
3317 gfn_t gfn)
3318{
3319 struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
3320
3321#ifdef CONFIG_HAVE_KVM_DIRTY_RING
3322 if (WARN_ON_ONCE(vcpu && vcpu->kvm != kvm))
3323 return;
3324
3325 WARN_ON_ONCE(!vcpu && !kvm_arch_allow_write_without_running_vcpu(kvm));
3326#endif
3327
3328 if (memslot && kvm_slot_dirty_track_enabled(memslot)) {
3329 unsigned long rel_gfn = gfn - memslot->base_gfn;
3330 u32 slot = (memslot->as_id << 16) | memslot->id;
3331
3332 if (kvm->dirty_ring_size && vcpu)
3333 kvm_dirty_ring_push(vcpu, slot, rel_gfn);
3334 else if (memslot->dirty_bitmap)
3335 set_bit_le(rel_gfn, memslot->dirty_bitmap);
3336 }
3337}
3338EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot);
3339
3340void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
3341{
3342 struct kvm_memory_slot *memslot;
3343
3344 memslot = gfn_to_memslot(kvm, gfn);
3345 mark_page_dirty_in_slot(kvm, memslot, gfn);
3346}
3347EXPORT_SYMBOL_GPL(mark_page_dirty);
3348
3349void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
3350{
3351 struct kvm_memory_slot *memslot;
3352
3353 memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
3354 mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn);
3355}
3356EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
3357
3358void kvm_sigset_activate(struct kvm_vcpu *vcpu)
3359{
3360 if (!vcpu->sigset_active)
3361 return;
3362
3363 /*
3364 * This does a lockless modification of ->real_blocked, which is fine
3365 * because, only current can change ->real_blocked and all readers of
3366 * ->real_blocked don't care as long ->real_blocked is always a subset
3367 * of ->blocked.
3368 */
3369 sigprocmask(SIG_SETMASK, &vcpu->sigset, ¤t->real_blocked);
3370}
3371
3372void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
3373{
3374 if (!vcpu->sigset_active)
3375 return;
3376
3377 sigprocmask(SIG_SETMASK, ¤t->real_blocked, NULL);
3378 sigemptyset(¤t->real_blocked);
3379}
3380
3381static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
3382{
3383 unsigned int old, val, grow, grow_start;
3384
3385 old = val = vcpu->halt_poll_ns;
3386 grow_start = READ_ONCE(halt_poll_ns_grow_start);
3387 grow = READ_ONCE(halt_poll_ns_grow);
3388 if (!grow)
3389 goto out;
3390
3391 val *= grow;
3392 if (val < grow_start)
3393 val = grow_start;
3394
3395 vcpu->halt_poll_ns = val;
3396out:
3397 trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
3398}
3399
3400static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
3401{
3402 unsigned int old, val, shrink, grow_start;
3403
3404 old = val = vcpu->halt_poll_ns;
3405 shrink = READ_ONCE(halt_poll_ns_shrink);
3406 grow_start = READ_ONCE(halt_poll_ns_grow_start);
3407 if (shrink == 0)
3408 val = 0;
3409 else
3410 val /= shrink;
3411
3412 if (val < grow_start)
3413 val = 0;
3414
3415 vcpu->halt_poll_ns = val;
3416 trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
3417}
3418
3419static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
3420{
3421 int ret = -EINTR;
3422 int idx = srcu_read_lock(&vcpu->kvm->srcu);
3423
3424 if (kvm_arch_vcpu_runnable(vcpu))
3425 goto out;
3426 if (kvm_cpu_has_pending_timer(vcpu))
3427 goto out;
3428 if (signal_pending(current))
3429 goto out;
3430 if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu))
3431 goto out;
3432
3433 ret = 0;
3434out:
3435 srcu_read_unlock(&vcpu->kvm->srcu, idx);
3436 return ret;
3437}
3438
3439/*
3440 * Block the vCPU until the vCPU is runnable, an event arrives, or a signal is
3441 * pending. This is mostly used when halting a vCPU, but may also be used
3442 * directly for other vCPU non-runnable states, e.g. x86's Wait-For-SIPI.
3443 */
3444bool kvm_vcpu_block(struct kvm_vcpu *vcpu)
3445{
3446 struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
3447 bool waited = false;
3448
3449 vcpu->stat.generic.blocking = 1;
3450
3451 preempt_disable();
3452 kvm_arch_vcpu_blocking(vcpu);
3453 prepare_to_rcuwait(wait);
3454 preempt_enable();
3455
3456 for (;;) {
3457 set_current_state(TASK_INTERRUPTIBLE);
3458
3459 if (kvm_vcpu_check_block(vcpu) < 0)
3460 break;
3461
3462 waited = true;
3463 schedule();
3464 }
3465
3466 preempt_disable();
3467 finish_rcuwait(wait);
3468 kvm_arch_vcpu_unblocking(vcpu);
3469 preempt_enable();
3470
3471 vcpu->stat.generic.blocking = 0;
3472
3473 return waited;
3474}
3475
3476static inline void update_halt_poll_stats(struct kvm_vcpu *vcpu, ktime_t start,
3477 ktime_t end, bool success)
3478{
3479 struct kvm_vcpu_stat_generic *stats = &vcpu->stat.generic;
3480 u64 poll_ns = ktime_to_ns(ktime_sub(end, start));
3481
3482 ++vcpu->stat.generic.halt_attempted_poll;
3483
3484 if (success) {
3485 ++vcpu->stat.generic.halt_successful_poll;
3486
3487 if (!vcpu_valid_wakeup(vcpu))
3488 ++vcpu->stat.generic.halt_poll_invalid;
3489
3490 stats->halt_poll_success_ns += poll_ns;
3491 KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_success_hist, poll_ns);
3492 } else {
3493 stats->halt_poll_fail_ns += poll_ns;
3494 KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_fail_hist, poll_ns);
3495 }
3496}
3497
3498static unsigned int kvm_vcpu_max_halt_poll_ns(struct kvm_vcpu *vcpu)
3499{
3500 struct kvm *kvm = vcpu->kvm;
3501
3502 if (kvm->override_halt_poll_ns) {
3503 /*
3504 * Ensure kvm->max_halt_poll_ns is not read before
3505 * kvm->override_halt_poll_ns.
3506 *
3507 * Pairs with the smp_wmb() when enabling KVM_CAP_HALT_POLL.
3508 */
3509 smp_rmb();
3510 return READ_ONCE(kvm->max_halt_poll_ns);
3511 }
3512
3513 return READ_ONCE(halt_poll_ns);
3514}
3515
3516/*
3517 * Emulate a vCPU halt condition, e.g. HLT on x86, WFI on arm, etc... If halt
3518 * polling is enabled, busy wait for a short time before blocking to avoid the
3519 * expensive block+unblock sequence if a wake event arrives soon after the vCPU
3520 * is halted.
3521 */
3522void kvm_vcpu_halt(struct kvm_vcpu *vcpu)
3523{
3524 unsigned int max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu);
3525 bool halt_poll_allowed = !kvm_arch_no_poll(vcpu);
3526 ktime_t start, cur, poll_end;
3527 bool waited = false;
3528 bool do_halt_poll;
3529 u64 halt_ns;
3530
3531 if (vcpu->halt_poll_ns > max_halt_poll_ns)
3532 vcpu->halt_poll_ns = max_halt_poll_ns;
3533
3534 do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns;
3535
3536 start = cur = poll_end = ktime_get();
3537 if (do_halt_poll) {
3538 ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns);
3539
3540 do {
3541 if (kvm_vcpu_check_block(vcpu) < 0)
3542 goto out;
3543 cpu_relax();
3544 poll_end = cur = ktime_get();
3545 } while (kvm_vcpu_can_poll(cur, stop));
3546 }
3547
3548 waited = kvm_vcpu_block(vcpu);
3549
3550 cur = ktime_get();
3551 if (waited) {
3552 vcpu->stat.generic.halt_wait_ns +=
3553 ktime_to_ns(cur) - ktime_to_ns(poll_end);
3554 KVM_STATS_LOG_HIST_UPDATE(vcpu->stat.generic.halt_wait_hist,
3555 ktime_to_ns(cur) - ktime_to_ns(poll_end));
3556 }
3557out:
3558 /* The total time the vCPU was "halted", including polling time. */
3559 halt_ns = ktime_to_ns(cur) - ktime_to_ns(start);
3560
3561 /*
3562 * Note, halt-polling is considered successful so long as the vCPU was
3563 * never actually scheduled out, i.e. even if the wake event arrived
3564 * after of the halt-polling loop itself, but before the full wait.
3565 */
3566 if (do_halt_poll)
3567 update_halt_poll_stats(vcpu, start, poll_end, !waited);
3568
3569 if (halt_poll_allowed) {
3570 /* Recompute the max halt poll time in case it changed. */
3571 max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu);
3572
3573 if (!vcpu_valid_wakeup(vcpu)) {
3574 shrink_halt_poll_ns(vcpu);
3575 } else if (max_halt_poll_ns) {
3576 if (halt_ns <= vcpu->halt_poll_ns)
3577 ;
3578 /* we had a long block, shrink polling */
3579 else if (vcpu->halt_poll_ns &&
3580 halt_ns > max_halt_poll_ns)
3581 shrink_halt_poll_ns(vcpu);
3582 /* we had a short halt and our poll time is too small */
3583 else if (vcpu->halt_poll_ns < max_halt_poll_ns &&
3584 halt_ns < max_halt_poll_ns)
3585 grow_halt_poll_ns(vcpu);
3586 } else {
3587 vcpu->halt_poll_ns = 0;
3588 }
3589 }
3590
3591 trace_kvm_vcpu_wakeup(halt_ns, waited, vcpu_valid_wakeup(vcpu));
3592}
3593EXPORT_SYMBOL_GPL(kvm_vcpu_halt);
3594
3595bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
3596{
3597 if (__kvm_vcpu_wake_up(vcpu)) {
3598 WRITE_ONCE(vcpu->ready, true);
3599 ++vcpu->stat.generic.halt_wakeup;
3600 return true;
3601 }
3602
3603 return false;
3604}
3605EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up);
3606
3607#ifndef CONFIG_S390
3608/*
3609 * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
3610 */
3611void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
3612{
3613 int me, cpu;
3614
3615 if (kvm_vcpu_wake_up(vcpu))
3616 return;
3617
3618 me = get_cpu();
3619 /*
3620 * The only state change done outside the vcpu mutex is IN_GUEST_MODE
3621 * to EXITING_GUEST_MODE. Therefore the moderately expensive "should
3622 * kick" check does not need atomic operations if kvm_vcpu_kick is used
3623 * within the vCPU thread itself.
3624 */
3625 if (vcpu == __this_cpu_read(kvm_running_vcpu)) {
3626 if (vcpu->mode == IN_GUEST_MODE)
3627 WRITE_ONCE(vcpu->mode, EXITING_GUEST_MODE);
3628 goto out;
3629 }
3630
3631 /*
3632 * Note, the vCPU could get migrated to a different pCPU at any point
3633 * after kvm_arch_vcpu_should_kick(), which could result in sending an
3634 * IPI to the previous pCPU. But, that's ok because the purpose of the
3635 * IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the
3636 * vCPU also requires it to leave IN_GUEST_MODE.
3637 */
3638 if (kvm_arch_vcpu_should_kick(vcpu)) {
3639 cpu = READ_ONCE(vcpu->cpu);
3640 if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
3641 smp_send_reschedule(cpu);
3642 }
3643out:
3644 put_cpu();
3645}
3646EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
3647#endif /* !CONFIG_S390 */
3648
3649int kvm_vcpu_yield_to(struct kvm_vcpu *target)
3650{
3651 struct pid *pid;
3652 struct task_struct *task = NULL;
3653 int ret = 0;
3654
3655 rcu_read_lock();
3656 pid = rcu_dereference(target->pid);
3657 if (pid)
3658 task = get_pid_task(pid, PIDTYPE_PID);
3659 rcu_read_unlock();
3660 if (!task)
3661 return ret;
3662 ret = yield_to(task, 1);
3663 put_task_struct(task);
3664
3665 return ret;
3666}
3667EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
3668
3669/*
3670 * Helper that checks whether a VCPU is eligible for directed yield.
3671 * Most eligible candidate to yield is decided by following heuristics:
3672 *
3673 * (a) VCPU which has not done pl-exit or cpu relax intercepted recently
3674 * (preempted lock holder), indicated by @in_spin_loop.
3675 * Set at the beginning and cleared at the end of interception/PLE handler.
3676 *
3677 * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
3678 * chance last time (mostly it has become eligible now since we have probably
3679 * yielded to lockholder in last iteration. This is done by toggling
3680 * @dy_eligible each time a VCPU checked for eligibility.)
3681 *
3682 * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
3683 * to preempted lock-holder could result in wrong VCPU selection and CPU
3684 * burning. Giving priority for a potential lock-holder increases lock
3685 * progress.
3686 *
3687 * Since algorithm is based on heuristics, accessing another VCPU data without
3688 * locking does not harm. It may result in trying to yield to same VCPU, fail
3689 * and continue with next VCPU and so on.
3690 */
3691static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
3692{
3693#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
3694 bool eligible;
3695
3696 eligible = !vcpu->spin_loop.in_spin_loop ||
3697 vcpu->spin_loop.dy_eligible;
3698
3699 if (vcpu->spin_loop.in_spin_loop)
3700 kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
3701
3702 return eligible;
3703#else
3704 return true;
3705#endif
3706}
3707
3708/*
3709 * Unlike kvm_arch_vcpu_runnable, this function is called outside
3710 * a vcpu_load/vcpu_put pair. However, for most architectures
3711 * kvm_arch_vcpu_runnable does not require vcpu_load.
3712 */
3713bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu)
3714{
3715 return kvm_arch_vcpu_runnable(vcpu);
3716}
3717
3718static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu)
3719{
3720 if (kvm_arch_dy_runnable(vcpu))
3721 return true;
3722
3723#ifdef CONFIG_KVM_ASYNC_PF
3724 if (!list_empty_careful(&vcpu->async_pf.done))
3725 return true;
3726#endif
3727
3728 return false;
3729}
3730
3731bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
3732{
3733 return false;
3734}
3735
3736void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
3737{
3738 struct kvm *kvm = me->kvm;
3739 struct kvm_vcpu *vcpu;
3740 int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
3741 unsigned long i;
3742 int yielded = 0;
3743 int try = 3;
3744 int pass;
3745
3746 kvm_vcpu_set_in_spin_loop(me, true);
3747 /*
3748 * We boost the priority of a VCPU that is runnable but not
3749 * currently running, because it got preempted by something
3750 * else and called schedule in __vcpu_run. Hopefully that
3751 * VCPU is holding the lock that we need and will release it.
3752 * We approximate round-robin by starting at the last boosted VCPU.
3753 */
3754 for (pass = 0; pass < 2 && !yielded && try; pass++) {
3755 kvm_for_each_vcpu(i, vcpu, kvm) {
3756 if (!pass && i <= last_boosted_vcpu) {
3757 i = last_boosted_vcpu;
3758 continue;
3759 } else if (pass && i > last_boosted_vcpu)
3760 break;
3761 if (!READ_ONCE(vcpu->ready))
3762 continue;
3763 if (vcpu == me)
3764 continue;
3765 if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu))
3766 continue;
3767 if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode &&
3768 !kvm_arch_dy_has_pending_interrupt(vcpu) &&
3769 !kvm_arch_vcpu_in_kernel(vcpu))
3770 continue;
3771 if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
3772 continue;
3773
3774 yielded = kvm_vcpu_yield_to(vcpu);
3775 if (yielded > 0) {
3776 kvm->last_boosted_vcpu = i;
3777 break;
3778 } else if (yielded < 0) {
3779 try--;
3780 if (!try)
3781 break;
3782 }
3783 }
3784 }
3785 kvm_vcpu_set_in_spin_loop(me, false);
3786
3787 /* Ensure vcpu is not eligible during next spinloop */
3788 kvm_vcpu_set_dy_eligible(me, false);
3789}
3790EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
3791
3792static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff)
3793{
3794#ifdef CONFIG_HAVE_KVM_DIRTY_RING
3795 return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) &&
3796 (pgoff < KVM_DIRTY_LOG_PAGE_OFFSET +
3797 kvm->dirty_ring_size / PAGE_SIZE);
3798#else
3799 return false;
3800#endif
3801}
3802
3803static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
3804{
3805 struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data;
3806 struct page *page;
3807
3808 if (vmf->pgoff == 0)
3809 page = virt_to_page(vcpu->run);
3810#ifdef CONFIG_X86
3811 else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
3812 page = virt_to_page(vcpu->arch.pio_data);
3813#endif
3814#ifdef CONFIG_KVM_MMIO
3815 else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
3816 page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
3817#endif
3818 else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff))
3819 page = kvm_dirty_ring_get_page(
3820 &vcpu->dirty_ring,
3821 vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET);
3822 else
3823 return kvm_arch_vcpu_fault(vcpu, vmf);
3824 get_page(page);
3825 vmf->page = page;
3826 return 0;
3827}
3828
3829static const struct vm_operations_struct kvm_vcpu_vm_ops = {
3830 .fault = kvm_vcpu_fault,
3831};
3832
3833static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
3834{
3835 struct kvm_vcpu *vcpu = file->private_data;
3836 unsigned long pages = vma_pages(vma);
3837
3838 if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) ||
3839 kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) &&
3840 ((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED)))
3841 return -EINVAL;
3842
3843 vma->vm_ops = &kvm_vcpu_vm_ops;
3844 return 0;
3845}
3846
3847static int kvm_vcpu_release(struct inode *inode, struct file *filp)
3848{
3849 struct kvm_vcpu *vcpu = filp->private_data;
3850
3851 kvm_put_kvm(vcpu->kvm);
3852 return 0;
3853}
3854
3855static const struct file_operations kvm_vcpu_fops = {
3856 .release = kvm_vcpu_release,
3857 .unlocked_ioctl = kvm_vcpu_ioctl,
3858 .mmap = kvm_vcpu_mmap,
3859 .llseek = noop_llseek,
3860 KVM_COMPAT(kvm_vcpu_compat_ioctl),
3861};
3862
3863/*
3864 * Allocates an inode for the vcpu.
3865 */
3866static int create_vcpu_fd(struct kvm_vcpu *vcpu)
3867{
3868 char name[8 + 1 + ITOA_MAX_LEN + 1];
3869
3870 snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id);
3871 return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
3872}
3873
3874#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
3875static int vcpu_get_pid(void *data, u64 *val)
3876{
3877 struct kvm_vcpu *vcpu = (struct kvm_vcpu *) data;
3878 *val = pid_nr(rcu_access_pointer(vcpu->pid));
3879 return 0;
3880}
3881
3882DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops, vcpu_get_pid, NULL, "%llu\n");
3883
3884static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
3885{
3886 struct dentry *debugfs_dentry;
3887 char dir_name[ITOA_MAX_LEN * 2];
3888
3889 if (!debugfs_initialized())
3890 return;
3891
3892 snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
3893 debugfs_dentry = debugfs_create_dir(dir_name,
3894 vcpu->kvm->debugfs_dentry);
3895 debugfs_create_file("pid", 0444, debugfs_dentry, vcpu,
3896 &vcpu_get_pid_fops);
3897
3898 kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry);
3899}
3900#endif
3901
3902/*
3903 * Creates some virtual cpus. Good luck creating more than one.
3904 */
3905static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
3906{
3907 int r;
3908 struct kvm_vcpu *vcpu;
3909 struct page *page;
3910
3911 if (id >= KVM_MAX_VCPU_IDS)
3912 return -EINVAL;
3913
3914 mutex_lock(&kvm->lock);
3915 if (kvm->created_vcpus >= kvm->max_vcpus) {
3916 mutex_unlock(&kvm->lock);
3917 return -EINVAL;
3918 }
3919
3920 r = kvm_arch_vcpu_precreate(kvm, id);
3921 if (r) {
3922 mutex_unlock(&kvm->lock);
3923 return r;
3924 }
3925
3926 kvm->created_vcpus++;
3927 mutex_unlock(&kvm->lock);
3928
3929 vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT);
3930 if (!vcpu) {
3931 r = -ENOMEM;
3932 goto vcpu_decrement;
3933 }
3934
3935 BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE);
3936 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
3937 if (!page) {
3938 r = -ENOMEM;
3939 goto vcpu_free;
3940 }
3941 vcpu->run = page_address(page);
3942
3943 kvm_vcpu_init(vcpu, kvm, id);
3944
3945 r = kvm_arch_vcpu_create(vcpu);
3946 if (r)
3947 goto vcpu_free_run_page;
3948
3949 if (kvm->dirty_ring_size) {
3950 r = kvm_dirty_ring_alloc(&vcpu->dirty_ring,
3951 id, kvm->dirty_ring_size);
3952 if (r)
3953 goto arch_vcpu_destroy;
3954 }
3955
3956 mutex_lock(&kvm->lock);
3957
3958#ifdef CONFIG_LOCKDEP
3959 /* Ensure that lockdep knows vcpu->mutex is taken *inside* kvm->lock */
3960 mutex_lock(&vcpu->mutex);
3961 mutex_unlock(&vcpu->mutex);
3962#endif
3963
3964 if (kvm_get_vcpu_by_id(kvm, id)) {
3965 r = -EEXIST;
3966 goto unlock_vcpu_destroy;
3967 }
3968
3969 vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
3970 r = xa_insert(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, GFP_KERNEL_ACCOUNT);
3971 BUG_ON(r == -EBUSY);
3972 if (r)
3973 goto unlock_vcpu_destroy;
3974
3975 /* Now it's all set up, let userspace reach it */
3976 kvm_get_kvm(kvm);
3977 r = create_vcpu_fd(vcpu);
3978 if (r < 0) {
3979 xa_erase(&kvm->vcpu_array, vcpu->vcpu_idx);
3980 kvm_put_kvm_no_destroy(kvm);
3981 goto unlock_vcpu_destroy;
3982 }
3983
3984 /*
3985 * Pairs with smp_rmb() in kvm_get_vcpu. Store the vcpu
3986 * pointer before kvm->online_vcpu's incremented value.
3987 */
3988 smp_wmb();
3989 atomic_inc(&kvm->online_vcpus);
3990
3991 mutex_unlock(&kvm->lock);
3992 kvm_arch_vcpu_postcreate(vcpu);
3993 kvm_create_vcpu_debugfs(vcpu);
3994 return r;
3995
3996unlock_vcpu_destroy:
3997 mutex_unlock(&kvm->lock);
3998 kvm_dirty_ring_free(&vcpu->dirty_ring);
3999arch_vcpu_destroy:
4000 kvm_arch_vcpu_destroy(vcpu);
4001vcpu_free_run_page:
4002 free_page((unsigned long)vcpu->run);
4003vcpu_free:
4004 kmem_cache_free(kvm_vcpu_cache, vcpu);
4005vcpu_decrement:
4006 mutex_lock(&kvm->lock);
4007 kvm->created_vcpus--;
4008 mutex_unlock(&kvm->lock);
4009 return r;
4010}
4011
4012static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
4013{
4014 if (sigset) {
4015 sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
4016 vcpu->sigset_active = 1;
4017 vcpu->sigset = *sigset;
4018 } else
4019 vcpu->sigset_active = 0;
4020 return 0;
4021}
4022
4023static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer,
4024 size_t size, loff_t *offset)
4025{
4026 struct kvm_vcpu *vcpu = file->private_data;
4027
4028 return kvm_stats_read(vcpu->stats_id, &kvm_vcpu_stats_header,
4029 &kvm_vcpu_stats_desc[0], &vcpu->stat,
4030 sizeof(vcpu->stat), user_buffer, size, offset);
4031}
4032
4033static const struct file_operations kvm_vcpu_stats_fops = {
4034 .read = kvm_vcpu_stats_read,
4035 .llseek = noop_llseek,
4036};
4037
4038static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu)
4039{
4040 int fd;
4041 struct file *file;
4042 char name[15 + ITOA_MAX_LEN + 1];
4043
4044 snprintf(name, sizeof(name), "kvm-vcpu-stats:%d", vcpu->vcpu_id);
4045
4046 fd = get_unused_fd_flags(O_CLOEXEC);
4047 if (fd < 0)
4048 return fd;
4049
4050 file = anon_inode_getfile(name, &kvm_vcpu_stats_fops, vcpu, O_RDONLY);
4051 if (IS_ERR(file)) {
4052 put_unused_fd(fd);
4053 return PTR_ERR(file);
4054 }
4055 file->f_mode |= FMODE_PREAD;
4056 fd_install(fd, file);
4057
4058 return fd;
4059}
4060
4061static long kvm_vcpu_ioctl(struct file *filp,
4062 unsigned int ioctl, unsigned long arg)
4063{
4064 struct kvm_vcpu *vcpu = filp->private_data;
4065 void __user *argp = (void __user *)arg;
4066 int r;
4067 struct kvm_fpu *fpu = NULL;
4068 struct kvm_sregs *kvm_sregs = NULL;
4069
4070 if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead)
4071 return -EIO;
4072
4073 if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
4074 return -EINVAL;
4075
4076 /*
4077 * Some architectures have vcpu ioctls that are asynchronous to vcpu
4078 * execution; mutex_lock() would break them.
4079 */
4080 r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
4081 if (r != -ENOIOCTLCMD)
4082 return r;
4083
4084 if (mutex_lock_killable(&vcpu->mutex))
4085 return -EINTR;
4086 switch (ioctl) {
4087 case KVM_RUN: {
4088 struct pid *oldpid;
4089 r = -EINVAL;
4090 if (arg)
4091 goto out;
4092 oldpid = rcu_access_pointer(vcpu->pid);
4093 if (unlikely(oldpid != task_pid(current))) {
4094 /* The thread running this VCPU changed. */
4095 struct pid *newpid;
4096
4097 r = kvm_arch_vcpu_run_pid_change(vcpu);
4098 if (r)
4099 break;
4100
4101 newpid = get_task_pid(current, PIDTYPE_PID);
4102 rcu_assign_pointer(vcpu->pid, newpid);
4103 if (oldpid)
4104 synchronize_rcu();
4105 put_pid(oldpid);
4106 }
4107 r = kvm_arch_vcpu_ioctl_run(vcpu);
4108 trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
4109 break;
4110 }
4111 case KVM_GET_REGS: {
4112 struct kvm_regs *kvm_regs;
4113
4114 r = -ENOMEM;
4115 kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL_ACCOUNT);
4116 if (!kvm_regs)
4117 goto out;
4118 r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
4119 if (r)
4120 goto out_free1;
4121 r = -EFAULT;
4122 if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
4123 goto out_free1;
4124 r = 0;
4125out_free1:
4126 kfree(kvm_regs);
4127 break;
4128 }
4129 case KVM_SET_REGS: {
4130 struct kvm_regs *kvm_regs;
4131
4132 kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
4133 if (IS_ERR(kvm_regs)) {
4134 r = PTR_ERR(kvm_regs);
4135 goto out;
4136 }
4137 r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
4138 kfree(kvm_regs);
4139 break;
4140 }
4141 case KVM_GET_SREGS: {
4142 kvm_sregs = kzalloc(sizeof(struct kvm_sregs),
4143 GFP_KERNEL_ACCOUNT);
4144 r = -ENOMEM;
4145 if (!kvm_sregs)
4146 goto out;
4147 r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
4148 if (r)
4149 goto out;
4150 r = -EFAULT;
4151 if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
4152 goto out;
4153 r = 0;
4154 break;
4155 }
4156 case KVM_SET_SREGS: {
4157 kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
4158 if (IS_ERR(kvm_sregs)) {
4159 r = PTR_ERR(kvm_sregs);
4160 kvm_sregs = NULL;
4161 goto out;
4162 }
4163 r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
4164 break;
4165 }
4166 case KVM_GET_MP_STATE: {
4167 struct kvm_mp_state mp_state;
4168
4169 r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
4170 if (r)
4171 goto out;
4172 r = -EFAULT;
4173 if (copy_to_user(argp, &mp_state, sizeof(mp_state)))
4174 goto out;
4175 r = 0;
4176 break;
4177 }
4178 case KVM_SET_MP_STATE: {
4179 struct kvm_mp_state mp_state;
4180
4181 r = -EFAULT;
4182 if (copy_from_user(&mp_state, argp, sizeof(mp_state)))
4183 goto out;
4184 r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
4185 break;
4186 }
4187 case KVM_TRANSLATE: {
4188 struct kvm_translation tr;
4189
4190 r = -EFAULT;
4191 if (copy_from_user(&tr, argp, sizeof(tr)))
4192 goto out;
4193 r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
4194 if (r)
4195 goto out;
4196 r = -EFAULT;
4197 if (copy_to_user(argp, &tr, sizeof(tr)))
4198 goto out;
4199 r = 0;
4200 break;
4201 }
4202 case KVM_SET_GUEST_DEBUG: {
4203 struct kvm_guest_debug dbg;
4204
4205 r = -EFAULT;
4206 if (copy_from_user(&dbg, argp, sizeof(dbg)))
4207 goto out;
4208 r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
4209 break;
4210 }
4211 case KVM_SET_SIGNAL_MASK: {
4212 struct kvm_signal_mask __user *sigmask_arg = argp;
4213 struct kvm_signal_mask kvm_sigmask;
4214 sigset_t sigset, *p;
4215
4216 p = NULL;
4217 if (argp) {
4218 r = -EFAULT;
4219 if (copy_from_user(&kvm_sigmask, argp,
4220 sizeof(kvm_sigmask)))
4221 goto out;
4222 r = -EINVAL;
4223 if (kvm_sigmask.len != sizeof(sigset))
4224 goto out;
4225 r = -EFAULT;
4226 if (copy_from_user(&sigset, sigmask_arg->sigset,
4227 sizeof(sigset)))
4228 goto out;
4229 p = &sigset;
4230 }
4231 r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
4232 break;
4233 }
4234 case KVM_GET_FPU: {
4235 fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL_ACCOUNT);
4236 r = -ENOMEM;
4237 if (!fpu)
4238 goto out;
4239 r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
4240 if (r)
4241 goto out;
4242 r = -EFAULT;
4243 if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
4244 goto out;
4245 r = 0;
4246 break;
4247 }
4248 case KVM_SET_FPU: {
4249 fpu = memdup_user(argp, sizeof(*fpu));
4250 if (IS_ERR(fpu)) {
4251 r = PTR_ERR(fpu);
4252 fpu = NULL;
4253 goto out;
4254 }
4255 r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
4256 break;
4257 }
4258 case KVM_GET_STATS_FD: {
4259 r = kvm_vcpu_ioctl_get_stats_fd(vcpu);
4260 break;
4261 }
4262 default:
4263 r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
4264 }
4265out:
4266 mutex_unlock(&vcpu->mutex);
4267 kfree(fpu);
4268 kfree(kvm_sregs);
4269 return r;
4270}
4271
4272#ifdef CONFIG_KVM_COMPAT
4273static long kvm_vcpu_compat_ioctl(struct file *filp,
4274 unsigned int ioctl, unsigned long arg)
4275{
4276 struct kvm_vcpu *vcpu = filp->private_data;
4277 void __user *argp = compat_ptr(arg);
4278 int r;
4279
4280 if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead)
4281 return -EIO;
4282
4283 switch (ioctl) {
4284 case KVM_SET_SIGNAL_MASK: {
4285 struct kvm_signal_mask __user *sigmask_arg = argp;
4286 struct kvm_signal_mask kvm_sigmask;
4287 sigset_t sigset;
4288
4289 if (argp) {
4290 r = -EFAULT;
4291 if (copy_from_user(&kvm_sigmask, argp,
4292 sizeof(kvm_sigmask)))
4293 goto out;
4294 r = -EINVAL;
4295 if (kvm_sigmask.len != sizeof(compat_sigset_t))
4296 goto out;
4297 r = -EFAULT;
4298 if (get_compat_sigset(&sigset,
4299 (compat_sigset_t __user *)sigmask_arg->sigset))
4300 goto out;
4301 r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
4302 } else
4303 r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
4304 break;
4305 }
4306 default:
4307 r = kvm_vcpu_ioctl(filp, ioctl, arg);
4308 }
4309
4310out:
4311 return r;
4312}
4313#endif
4314
4315static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma)
4316{
4317 struct kvm_device *dev = filp->private_data;
4318
4319 if (dev->ops->mmap)
4320 return dev->ops->mmap(dev, vma);
4321
4322 return -ENODEV;
4323}
4324
4325static int kvm_device_ioctl_attr(struct kvm_device *dev,
4326 int (*accessor)(struct kvm_device *dev,
4327 struct kvm_device_attr *attr),
4328 unsigned long arg)
4329{
4330 struct kvm_device_attr attr;
4331
4332 if (!accessor)
4333 return -EPERM;
4334
4335 if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
4336 return -EFAULT;
4337
4338 return accessor(dev, &attr);
4339}
4340
4341static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
4342 unsigned long arg)
4343{
4344 struct kvm_device *dev = filp->private_data;
4345
4346 if (dev->kvm->mm != current->mm || dev->kvm->vm_dead)
4347 return -EIO;
4348
4349 switch (ioctl) {
4350 case KVM_SET_DEVICE_ATTR:
4351 return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg);
4352 case KVM_GET_DEVICE_ATTR:
4353 return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg);
4354 case KVM_HAS_DEVICE_ATTR:
4355 return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg);
4356 default:
4357 if (dev->ops->ioctl)
4358 return dev->ops->ioctl(dev, ioctl, arg);
4359
4360 return -ENOTTY;
4361 }
4362}
4363
4364static int kvm_device_release(struct inode *inode, struct file *filp)
4365{
4366 struct kvm_device *dev = filp->private_data;
4367 struct kvm *kvm = dev->kvm;
4368
4369 if (dev->ops->release) {
4370 mutex_lock(&kvm->lock);
4371 list_del(&dev->vm_node);
4372 dev->ops->release(dev);
4373 mutex_unlock(&kvm->lock);
4374 }
4375
4376 kvm_put_kvm(kvm);
4377 return 0;
4378}
4379
4380static const struct file_operations kvm_device_fops = {
4381 .unlocked_ioctl = kvm_device_ioctl,
4382 .release = kvm_device_release,
4383 KVM_COMPAT(kvm_device_ioctl),
4384 .mmap = kvm_device_mmap,
4385};
4386
4387struct kvm_device *kvm_device_from_filp(struct file *filp)
4388{
4389 if (filp->f_op != &kvm_device_fops)
4390 return NULL;
4391
4392 return filp->private_data;
4393}
4394
4395static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
4396#ifdef CONFIG_KVM_MPIC
4397 [KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops,
4398 [KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops,
4399#endif
4400};
4401
4402int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type)
4403{
4404 if (type >= ARRAY_SIZE(kvm_device_ops_table))
4405 return -ENOSPC;
4406
4407 if (kvm_device_ops_table[type] != NULL)
4408 return -EEXIST;
4409
4410 kvm_device_ops_table[type] = ops;
4411 return 0;
4412}
4413
4414void kvm_unregister_device_ops(u32 type)
4415{
4416 if (kvm_device_ops_table[type] != NULL)
4417 kvm_device_ops_table[type] = NULL;
4418}
4419
4420static int kvm_ioctl_create_device(struct kvm *kvm,
4421 struct kvm_create_device *cd)
4422{
4423 const struct kvm_device_ops *ops;
4424 struct kvm_device *dev;
4425 bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
4426 int type;
4427 int ret;
4428
4429 if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
4430 return -ENODEV;
4431
4432 type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table));
4433 ops = kvm_device_ops_table[type];
4434 if (ops == NULL)
4435 return -ENODEV;
4436
4437 if (test)
4438 return 0;
4439
4440 dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT);
4441 if (!dev)
4442 return -ENOMEM;
4443
4444 dev->ops = ops;
4445 dev->kvm = kvm;
4446
4447 mutex_lock(&kvm->lock);
4448 ret = ops->create(dev, type);
4449 if (ret < 0) {
4450 mutex_unlock(&kvm->lock);
4451 kfree(dev);
4452 return ret;
4453 }
4454 list_add(&dev->vm_node, &kvm->devices);
4455 mutex_unlock(&kvm->lock);
4456
4457 if (ops->init)
4458 ops->init(dev);
4459
4460 kvm_get_kvm(kvm);
4461 ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
4462 if (ret < 0) {
4463 kvm_put_kvm_no_destroy(kvm);
4464 mutex_lock(&kvm->lock);
4465 list_del(&dev->vm_node);
4466 if (ops->release)
4467 ops->release(dev);
4468 mutex_unlock(&kvm->lock);
4469 if (ops->destroy)
4470 ops->destroy(dev);
4471 return ret;
4472 }
4473
4474 cd->fd = ret;
4475 return 0;
4476}
4477
4478static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
4479{
4480 switch (arg) {
4481 case KVM_CAP_USER_MEMORY:
4482 case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
4483 case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
4484 case KVM_CAP_INTERNAL_ERROR_DATA:
4485#ifdef CONFIG_HAVE_KVM_MSI
4486 case KVM_CAP_SIGNAL_MSI:
4487#endif
4488#ifdef CONFIG_HAVE_KVM_IRQFD
4489 case KVM_CAP_IRQFD:
4490 case KVM_CAP_IRQFD_RESAMPLE:
4491#endif
4492 case KVM_CAP_IOEVENTFD_ANY_LENGTH:
4493 case KVM_CAP_CHECK_EXTENSION_VM:
4494 case KVM_CAP_ENABLE_CAP_VM:
4495 case KVM_CAP_HALT_POLL:
4496 return 1;
4497#ifdef CONFIG_KVM_MMIO
4498 case KVM_CAP_COALESCED_MMIO:
4499 return KVM_COALESCED_MMIO_PAGE_OFFSET;
4500 case KVM_CAP_COALESCED_PIO:
4501 return 1;
4502#endif
4503#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4504 case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2:
4505 return KVM_DIRTY_LOG_MANUAL_CAPS;
4506#endif
4507#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
4508 case KVM_CAP_IRQ_ROUTING:
4509 return KVM_MAX_IRQ_ROUTES;
4510#endif
4511#if KVM_ADDRESS_SPACE_NUM > 1
4512 case KVM_CAP_MULTI_ADDRESS_SPACE:
4513 return KVM_ADDRESS_SPACE_NUM;
4514#endif
4515 case KVM_CAP_NR_MEMSLOTS:
4516 return KVM_USER_MEM_SLOTS;
4517 case KVM_CAP_DIRTY_LOG_RING:
4518#ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO
4519 return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
4520#else
4521 return 0;
4522#endif
4523 case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
4524#ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL
4525 return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
4526#else
4527 return 0;
4528#endif
4529#ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP
4530 case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP:
4531#endif
4532 case KVM_CAP_BINARY_STATS_FD:
4533 case KVM_CAP_SYSTEM_EVENT_DATA:
4534 return 1;
4535 default:
4536 break;
4537 }
4538 return kvm_vm_ioctl_check_extension(kvm, arg);
4539}
4540
4541static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size)
4542{
4543 int r;
4544
4545 if (!KVM_DIRTY_LOG_PAGE_OFFSET)
4546 return -EINVAL;
4547
4548 /* the size should be power of 2 */
4549 if (!size || (size & (size - 1)))
4550 return -EINVAL;
4551
4552 /* Should be bigger to keep the reserved entries, or a page */
4553 if (size < kvm_dirty_ring_get_rsvd_entries() *
4554 sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE)
4555 return -EINVAL;
4556
4557 if (size > KVM_DIRTY_RING_MAX_ENTRIES *
4558 sizeof(struct kvm_dirty_gfn))
4559 return -E2BIG;
4560
4561 /* We only allow it to set once */
4562 if (kvm->dirty_ring_size)
4563 return -EINVAL;
4564
4565 mutex_lock(&kvm->lock);
4566
4567 if (kvm->created_vcpus) {
4568 /* We don't allow to change this value after vcpu created */
4569 r = -EINVAL;
4570 } else {
4571 kvm->dirty_ring_size = size;
4572 r = 0;
4573 }
4574
4575 mutex_unlock(&kvm->lock);
4576 return r;
4577}
4578
4579static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm)
4580{
4581 unsigned long i;
4582 struct kvm_vcpu *vcpu;
4583 int cleared = 0;
4584
4585 if (!kvm->dirty_ring_size)
4586 return -EINVAL;
4587
4588 mutex_lock(&kvm->slots_lock);
4589
4590 kvm_for_each_vcpu(i, vcpu, kvm)
4591 cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring);
4592
4593 mutex_unlock(&kvm->slots_lock);
4594
4595 if (cleared)
4596 kvm_flush_remote_tlbs(kvm);
4597
4598 return cleared;
4599}
4600
4601int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
4602 struct kvm_enable_cap *cap)
4603{
4604 return -EINVAL;
4605}
4606
4607static bool kvm_are_all_memslots_empty(struct kvm *kvm)
4608{
4609 int i;
4610
4611 lockdep_assert_held(&kvm->slots_lock);
4612
4613 for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
4614 if (!kvm_memslots_empty(__kvm_memslots(kvm, i)))
4615 return false;
4616 }
4617
4618 return true;
4619}
4620
4621static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
4622 struct kvm_enable_cap *cap)
4623{
4624 switch (cap->cap) {
4625#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4626 case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: {
4627 u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE;
4628
4629 if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE)
4630 allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS;
4631
4632 if (cap->flags || (cap->args[0] & ~allowed_options))
4633 return -EINVAL;
4634 kvm->manual_dirty_log_protect = cap->args[0];
4635 return 0;
4636 }
4637#endif
4638 case KVM_CAP_HALT_POLL: {
4639 if (cap->flags || cap->args[0] != (unsigned int)cap->args[0])
4640 return -EINVAL;
4641
4642 kvm->max_halt_poll_ns = cap->args[0];
4643
4644 /*
4645 * Ensure kvm->override_halt_poll_ns does not become visible
4646 * before kvm->max_halt_poll_ns.
4647 *
4648 * Pairs with the smp_rmb() in kvm_vcpu_max_halt_poll_ns().
4649 */
4650 smp_wmb();
4651 kvm->override_halt_poll_ns = true;
4652
4653 return 0;
4654 }
4655 case KVM_CAP_DIRTY_LOG_RING:
4656 case KVM_CAP_DIRTY_LOG_RING_ACQ_REL:
4657 if (!kvm_vm_ioctl_check_extension_generic(kvm, cap->cap))
4658 return -EINVAL;
4659
4660 return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]);
4661 case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: {
4662 int r = -EINVAL;
4663
4664 if (!IS_ENABLED(CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP) ||
4665 !kvm->dirty_ring_size || cap->flags)
4666 return r;
4667
4668 mutex_lock(&kvm->slots_lock);
4669
4670 /*
4671 * For simplicity, allow enabling ring+bitmap if and only if
4672 * there are no memslots, e.g. to ensure all memslots allocate
4673 * a bitmap after the capability is enabled.
4674 */
4675 if (kvm_are_all_memslots_empty(kvm)) {
4676 kvm->dirty_ring_with_bitmap = true;
4677 r = 0;
4678 }
4679
4680 mutex_unlock(&kvm->slots_lock);
4681
4682 return r;
4683 }
4684 default:
4685 return kvm_vm_ioctl_enable_cap(kvm, cap);
4686 }
4687}
4688
4689static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
4690 size_t size, loff_t *offset)
4691{
4692 struct kvm *kvm = file->private_data;
4693
4694 return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header,
4695 &kvm_vm_stats_desc[0], &kvm->stat,
4696 sizeof(kvm->stat), user_buffer, size, offset);
4697}
4698
4699static const struct file_operations kvm_vm_stats_fops = {
4700 .read = kvm_vm_stats_read,
4701 .llseek = noop_llseek,
4702};
4703
4704static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
4705{
4706 int fd;
4707 struct file *file;
4708
4709 fd = get_unused_fd_flags(O_CLOEXEC);
4710 if (fd < 0)
4711 return fd;
4712
4713 file = anon_inode_getfile("kvm-vm-stats",
4714 &kvm_vm_stats_fops, kvm, O_RDONLY);
4715 if (IS_ERR(file)) {
4716 put_unused_fd(fd);
4717 return PTR_ERR(file);
4718 }
4719 file->f_mode |= FMODE_PREAD;
4720 fd_install(fd, file);
4721
4722 return fd;
4723}
4724
4725static long kvm_vm_ioctl(struct file *filp,
4726 unsigned int ioctl, unsigned long arg)
4727{
4728 struct kvm *kvm = filp->private_data;
4729 void __user *argp = (void __user *)arg;
4730 int r;
4731
4732 if (kvm->mm != current->mm || kvm->vm_dead)
4733 return -EIO;
4734 switch (ioctl) {
4735 case KVM_CREATE_VCPU:
4736 r = kvm_vm_ioctl_create_vcpu(kvm, arg);
4737 break;
4738 case KVM_ENABLE_CAP: {
4739 struct kvm_enable_cap cap;
4740
4741 r = -EFAULT;
4742 if (copy_from_user(&cap, argp, sizeof(cap)))
4743 goto out;
4744 r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap);
4745 break;
4746 }
4747 case KVM_SET_USER_MEMORY_REGION: {
4748 struct kvm_userspace_memory_region kvm_userspace_mem;
4749
4750 r = -EFAULT;
4751 if (copy_from_user(&kvm_userspace_mem, argp,
4752 sizeof(kvm_userspace_mem)))
4753 goto out;
4754
4755 r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
4756 break;
4757 }
4758 case KVM_GET_DIRTY_LOG: {
4759 struct kvm_dirty_log log;
4760
4761 r = -EFAULT;
4762 if (copy_from_user(&log, argp, sizeof(log)))
4763 goto out;
4764 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
4765 break;
4766 }
4767#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4768 case KVM_CLEAR_DIRTY_LOG: {
4769 struct kvm_clear_dirty_log log;
4770
4771 r = -EFAULT;
4772 if (copy_from_user(&log, argp, sizeof(log)))
4773 goto out;
4774 r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
4775 break;
4776 }
4777#endif
4778#ifdef CONFIG_KVM_MMIO
4779 case KVM_REGISTER_COALESCED_MMIO: {
4780 struct kvm_coalesced_mmio_zone zone;
4781
4782 r = -EFAULT;
4783 if (copy_from_user(&zone, argp, sizeof(zone)))
4784 goto out;
4785 r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
4786 break;
4787 }
4788 case KVM_UNREGISTER_COALESCED_MMIO: {
4789 struct kvm_coalesced_mmio_zone zone;
4790
4791 r = -EFAULT;
4792 if (copy_from_user(&zone, argp, sizeof(zone)))
4793 goto out;
4794 r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
4795 break;
4796 }
4797#endif
4798 case KVM_IRQFD: {
4799 struct kvm_irqfd data;
4800
4801 r = -EFAULT;
4802 if (copy_from_user(&data, argp, sizeof(data)))
4803 goto out;
4804 r = kvm_irqfd(kvm, &data);
4805 break;
4806 }
4807 case KVM_IOEVENTFD: {
4808 struct kvm_ioeventfd data;
4809
4810 r = -EFAULT;
4811 if (copy_from_user(&data, argp, sizeof(data)))
4812 goto out;
4813 r = kvm_ioeventfd(kvm, &data);
4814 break;
4815 }
4816#ifdef CONFIG_HAVE_KVM_MSI
4817 case KVM_SIGNAL_MSI: {
4818 struct kvm_msi msi;
4819
4820 r = -EFAULT;
4821 if (copy_from_user(&msi, argp, sizeof(msi)))
4822 goto out;
4823 r = kvm_send_userspace_msi(kvm, &msi);
4824 break;
4825 }
4826#endif
4827#ifdef __KVM_HAVE_IRQ_LINE
4828 case KVM_IRQ_LINE_STATUS:
4829 case KVM_IRQ_LINE: {
4830 struct kvm_irq_level irq_event;
4831
4832 r = -EFAULT;
4833 if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
4834 goto out;
4835
4836 r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
4837 ioctl == KVM_IRQ_LINE_STATUS);
4838 if (r)
4839 goto out;
4840
4841 r = -EFAULT;
4842 if (ioctl == KVM_IRQ_LINE_STATUS) {
4843 if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
4844 goto out;
4845 }
4846
4847 r = 0;
4848 break;
4849 }
4850#endif
4851#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
4852 case KVM_SET_GSI_ROUTING: {
4853 struct kvm_irq_routing routing;
4854 struct kvm_irq_routing __user *urouting;
4855 struct kvm_irq_routing_entry *entries = NULL;
4856
4857 r = -EFAULT;
4858 if (copy_from_user(&routing, argp, sizeof(routing)))
4859 goto out;
4860 r = -EINVAL;
4861 if (!kvm_arch_can_set_irq_routing(kvm))
4862 goto out;
4863 if (routing.nr > KVM_MAX_IRQ_ROUTES)
4864 goto out;
4865 if (routing.flags)
4866 goto out;
4867 if (routing.nr) {
4868 urouting = argp;
4869 entries = vmemdup_user(urouting->entries,
4870 array_size(sizeof(*entries),
4871 routing.nr));
4872 if (IS_ERR(entries)) {
4873 r = PTR_ERR(entries);
4874 goto out;
4875 }
4876 }
4877 r = kvm_set_irq_routing(kvm, entries, routing.nr,
4878 routing.flags);
4879 kvfree(entries);
4880 break;
4881 }
4882#endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
4883 case KVM_CREATE_DEVICE: {
4884 struct kvm_create_device cd;
4885
4886 r = -EFAULT;
4887 if (copy_from_user(&cd, argp, sizeof(cd)))
4888 goto out;
4889
4890 r = kvm_ioctl_create_device(kvm, &cd);
4891 if (r)
4892 goto out;
4893
4894 r = -EFAULT;
4895 if (copy_to_user(argp, &cd, sizeof(cd)))
4896 goto out;
4897
4898 r = 0;
4899 break;
4900 }
4901 case KVM_CHECK_EXTENSION:
4902 r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
4903 break;
4904 case KVM_RESET_DIRTY_RINGS:
4905 r = kvm_vm_ioctl_reset_dirty_pages(kvm);
4906 break;
4907 case KVM_GET_STATS_FD:
4908 r = kvm_vm_ioctl_get_stats_fd(kvm);
4909 break;
4910 default:
4911 r = kvm_arch_vm_ioctl(filp, ioctl, arg);
4912 }
4913out:
4914 return r;
4915}
4916
4917#ifdef CONFIG_KVM_COMPAT
4918struct compat_kvm_dirty_log {
4919 __u32 slot;
4920 __u32 padding1;
4921 union {
4922 compat_uptr_t dirty_bitmap; /* one bit per page */
4923 __u64 padding2;
4924 };
4925};
4926
4927struct compat_kvm_clear_dirty_log {
4928 __u32 slot;
4929 __u32 num_pages;
4930 __u64 first_page;
4931 union {
4932 compat_uptr_t dirty_bitmap; /* one bit per page */
4933 __u64 padding2;
4934 };
4935};
4936
4937long __weak kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl,
4938 unsigned long arg)
4939{
4940 return -ENOTTY;
4941}
4942
4943static long kvm_vm_compat_ioctl(struct file *filp,
4944 unsigned int ioctl, unsigned long arg)
4945{
4946 struct kvm *kvm = filp->private_data;
4947 int r;
4948
4949 if (kvm->mm != current->mm || kvm->vm_dead)
4950 return -EIO;
4951
4952 r = kvm_arch_vm_compat_ioctl(filp, ioctl, arg);
4953 if (r != -ENOTTY)
4954 return r;
4955
4956 switch (ioctl) {
4957#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
4958 case KVM_CLEAR_DIRTY_LOG: {
4959 struct compat_kvm_clear_dirty_log compat_log;
4960 struct kvm_clear_dirty_log log;
4961
4962 if (copy_from_user(&compat_log, (void __user *)arg,
4963 sizeof(compat_log)))
4964 return -EFAULT;
4965 log.slot = compat_log.slot;
4966 log.num_pages = compat_log.num_pages;
4967 log.first_page = compat_log.first_page;
4968 log.padding2 = compat_log.padding2;
4969 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
4970
4971 r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
4972 break;
4973 }
4974#endif
4975 case KVM_GET_DIRTY_LOG: {
4976 struct compat_kvm_dirty_log compat_log;
4977 struct kvm_dirty_log log;
4978
4979 if (copy_from_user(&compat_log, (void __user *)arg,
4980 sizeof(compat_log)))
4981 return -EFAULT;
4982 log.slot = compat_log.slot;
4983 log.padding1 = compat_log.padding1;
4984 log.padding2 = compat_log.padding2;
4985 log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
4986
4987 r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
4988 break;
4989 }
4990 default:
4991 r = kvm_vm_ioctl(filp, ioctl, arg);
4992 }
4993 return r;
4994}
4995#endif
4996
4997static const struct file_operations kvm_vm_fops = {
4998 .release = kvm_vm_release,
4999 .unlocked_ioctl = kvm_vm_ioctl,
5000 .llseek = noop_llseek,
5001 KVM_COMPAT(kvm_vm_compat_ioctl),
5002};
5003
5004bool file_is_kvm(struct file *file)
5005{
5006 return file && file->f_op == &kvm_vm_fops;
5007}
5008EXPORT_SYMBOL_GPL(file_is_kvm);
5009
5010static int kvm_dev_ioctl_create_vm(unsigned long type)
5011{
5012 char fdname[ITOA_MAX_LEN + 1];
5013 int r, fd;
5014 struct kvm *kvm;
5015 struct file *file;
5016
5017 fd = get_unused_fd_flags(O_CLOEXEC);
5018 if (fd < 0)
5019 return fd;
5020
5021 snprintf(fdname, sizeof(fdname), "%d", fd);
5022
5023 kvm = kvm_create_vm(type, fdname);
5024 if (IS_ERR(kvm)) {
5025 r = PTR_ERR(kvm);
5026 goto put_fd;
5027 }
5028
5029 file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
5030 if (IS_ERR(file)) {
5031 r = PTR_ERR(file);
5032 goto put_kvm;
5033 }
5034
5035 /*
5036 * Don't call kvm_put_kvm anymore at this point; file->f_op is
5037 * already set, with ->release() being kvm_vm_release(). In error
5038 * cases it will be called by the final fput(file) and will take
5039 * care of doing kvm_put_kvm(kvm).
5040 */
5041 kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
5042
5043 fd_install(fd, file);
5044 return fd;
5045
5046put_kvm:
5047 kvm_put_kvm(kvm);
5048put_fd:
5049 put_unused_fd(fd);
5050 return r;
5051}
5052
5053static long kvm_dev_ioctl(struct file *filp,
5054 unsigned int ioctl, unsigned long arg)
5055{
5056 long r = -EINVAL;
5057
5058 switch (ioctl) {
5059 case KVM_GET_API_VERSION:
5060 if (arg)
5061 goto out;
5062 r = KVM_API_VERSION;
5063 break;
5064 case KVM_CREATE_VM:
5065 r = kvm_dev_ioctl_create_vm(arg);
5066 break;
5067 case KVM_CHECK_EXTENSION:
5068 r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
5069 break;
5070 case KVM_GET_VCPU_MMAP_SIZE:
5071 if (arg)
5072 goto out;
5073 r = PAGE_SIZE; /* struct kvm_run */
5074#ifdef CONFIG_X86
5075 r += PAGE_SIZE; /* pio data page */
5076#endif
5077#ifdef CONFIG_KVM_MMIO
5078 r += PAGE_SIZE; /* coalesced mmio ring page */
5079#endif
5080 break;
5081 case KVM_TRACE_ENABLE:
5082 case KVM_TRACE_PAUSE:
5083 case KVM_TRACE_DISABLE:
5084 r = -EOPNOTSUPP;
5085 break;
5086 default:
5087 return kvm_arch_dev_ioctl(filp, ioctl, arg);
5088 }
5089out:
5090 return r;
5091}
5092
5093static struct file_operations kvm_chardev_ops = {
5094 .unlocked_ioctl = kvm_dev_ioctl,
5095 .llseek = noop_llseek,
5096 KVM_COMPAT(kvm_dev_ioctl),
5097};
5098
5099static struct miscdevice kvm_dev = {
5100 KVM_MINOR,
5101 "kvm",
5102 &kvm_chardev_ops,
5103};
5104
5105static void hardware_enable_nolock(void *junk)
5106{
5107 int cpu = raw_smp_processor_id();
5108 int r;
5109
5110 if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
5111 return;
5112
5113 cpumask_set_cpu(cpu, cpus_hardware_enabled);
5114
5115 r = kvm_arch_hardware_enable();
5116
5117 if (r) {
5118 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
5119 atomic_inc(&hardware_enable_failed);
5120 pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
5121 }
5122}
5123
5124static int kvm_starting_cpu(unsigned int cpu)
5125{
5126 raw_spin_lock(&kvm_count_lock);
5127 if (kvm_usage_count)
5128 hardware_enable_nolock(NULL);
5129 raw_spin_unlock(&kvm_count_lock);
5130 return 0;
5131}
5132
5133static void hardware_disable_nolock(void *junk)
5134{
5135 int cpu = raw_smp_processor_id();
5136
5137 if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
5138 return;
5139 cpumask_clear_cpu(cpu, cpus_hardware_enabled);
5140 kvm_arch_hardware_disable();
5141}
5142
5143static int kvm_dying_cpu(unsigned int cpu)
5144{
5145 raw_spin_lock(&kvm_count_lock);
5146 if (kvm_usage_count)
5147 hardware_disable_nolock(NULL);
5148 raw_spin_unlock(&kvm_count_lock);
5149 return 0;
5150}
5151
5152static void hardware_disable_all_nolock(void)
5153{
5154 BUG_ON(!kvm_usage_count);
5155
5156 kvm_usage_count--;
5157 if (!kvm_usage_count)
5158 on_each_cpu(hardware_disable_nolock, NULL, 1);
5159}
5160
5161static void hardware_disable_all(void)
5162{
5163 raw_spin_lock(&kvm_count_lock);
5164 hardware_disable_all_nolock();
5165 raw_spin_unlock(&kvm_count_lock);
5166}
5167
5168static int hardware_enable_all(void)
5169{
5170 int r = 0;
5171
5172 raw_spin_lock(&kvm_count_lock);
5173
5174 kvm_usage_count++;
5175 if (kvm_usage_count == 1) {
5176 atomic_set(&hardware_enable_failed, 0);
5177 on_each_cpu(hardware_enable_nolock, NULL, 1);
5178
5179 if (atomic_read(&hardware_enable_failed)) {
5180 hardware_disable_all_nolock();
5181 r = -EBUSY;
5182 }
5183 }
5184
5185 raw_spin_unlock(&kvm_count_lock);
5186
5187 return r;
5188}
5189
5190static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
5191 void *v)
5192{
5193 /*
5194 * Some (well, at least mine) BIOSes hang on reboot if
5195 * in vmx root mode.
5196 *
5197 * And Intel TXT required VMX off for all cpu when system shutdown.
5198 */
5199 pr_info("kvm: exiting hardware virtualization\n");
5200 kvm_rebooting = true;
5201 on_each_cpu(hardware_disable_nolock, NULL, 1);
5202 return NOTIFY_OK;
5203}
5204
5205static struct notifier_block kvm_reboot_notifier = {
5206 .notifier_call = kvm_reboot,
5207 .priority = 0,
5208};
5209
5210static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
5211{
5212 int i;
5213
5214 for (i = 0; i < bus->dev_count; i++) {
5215 struct kvm_io_device *pos = bus->range[i].dev;
5216
5217 kvm_iodevice_destructor(pos);
5218 }
5219 kfree(bus);
5220}
5221
5222static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
5223 const struct kvm_io_range *r2)
5224{
5225 gpa_t addr1 = r1->addr;
5226 gpa_t addr2 = r2->addr;
5227
5228 if (addr1 < addr2)
5229 return -1;
5230
5231 /* If r2->len == 0, match the exact address. If r2->len != 0,
5232 * accept any overlapping write. Any order is acceptable for
5233 * overlapping ranges, because kvm_io_bus_get_first_dev ensures
5234 * we process all of them.
5235 */
5236 if (r2->len) {
5237 addr1 += r1->len;
5238 addr2 += r2->len;
5239 }
5240
5241 if (addr1 > addr2)
5242 return 1;
5243
5244 return 0;
5245}
5246
5247static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
5248{
5249 return kvm_io_bus_cmp(p1, p2);
5250}
5251
5252static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
5253 gpa_t addr, int len)
5254{
5255 struct kvm_io_range *range, key;
5256 int off;
5257
5258 key = (struct kvm_io_range) {
5259 .addr = addr,
5260 .len = len,
5261 };
5262
5263 range = bsearch(&key, bus->range, bus->dev_count,
5264 sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
5265 if (range == NULL)
5266 return -ENOENT;
5267
5268 off = range - bus->range;
5269
5270 while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
5271 off--;
5272
5273 return off;
5274}
5275
5276static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
5277 struct kvm_io_range *range, const void *val)
5278{
5279 int idx;
5280
5281 idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
5282 if (idx < 0)
5283 return -EOPNOTSUPP;
5284
5285 while (idx < bus->dev_count &&
5286 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
5287 if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
5288 range->len, val))
5289 return idx;
5290 idx++;
5291 }
5292
5293 return -EOPNOTSUPP;
5294}
5295
5296/* kvm_io_bus_write - called under kvm->slots_lock */
5297int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
5298 int len, const void *val)
5299{
5300 struct kvm_io_bus *bus;
5301 struct kvm_io_range range;
5302 int r;
5303
5304 range = (struct kvm_io_range) {
5305 .addr = addr,
5306 .len = len,
5307 };
5308
5309 bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5310 if (!bus)
5311 return -ENOMEM;
5312 r = __kvm_io_bus_write(vcpu, bus, &range, val);
5313 return r < 0 ? r : 0;
5314}
5315EXPORT_SYMBOL_GPL(kvm_io_bus_write);
5316
5317/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
5318int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
5319 gpa_t addr, int len, const void *val, long cookie)
5320{
5321 struct kvm_io_bus *bus;
5322 struct kvm_io_range range;
5323
5324 range = (struct kvm_io_range) {
5325 .addr = addr,
5326 .len = len,
5327 };
5328
5329 bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5330 if (!bus)
5331 return -ENOMEM;
5332
5333 /* First try the device referenced by cookie. */
5334 if ((cookie >= 0) && (cookie < bus->dev_count) &&
5335 (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
5336 if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
5337 val))
5338 return cookie;
5339
5340 /*
5341 * cookie contained garbage; fall back to search and return the
5342 * correct cookie value.
5343 */
5344 return __kvm_io_bus_write(vcpu, bus, &range, val);
5345}
5346
5347static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
5348 struct kvm_io_range *range, void *val)
5349{
5350 int idx;
5351
5352 idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
5353 if (idx < 0)
5354 return -EOPNOTSUPP;
5355
5356 while (idx < bus->dev_count &&
5357 kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
5358 if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
5359 range->len, val))
5360 return idx;
5361 idx++;
5362 }
5363
5364 return -EOPNOTSUPP;
5365}
5366
5367/* kvm_io_bus_read - called under kvm->slots_lock */
5368int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
5369 int len, void *val)
5370{
5371 struct kvm_io_bus *bus;
5372 struct kvm_io_range range;
5373 int r;
5374
5375 range = (struct kvm_io_range) {
5376 .addr = addr,
5377 .len = len,
5378 };
5379
5380 bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
5381 if (!bus)
5382 return -ENOMEM;
5383 r = __kvm_io_bus_read(vcpu, bus, &range, val);
5384 return r < 0 ? r : 0;
5385}
5386
5387/* Caller must hold slots_lock. */
5388int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
5389 int len, struct kvm_io_device *dev)
5390{
5391 int i;
5392 struct kvm_io_bus *new_bus, *bus;
5393 struct kvm_io_range range;
5394
5395 bus = kvm_get_bus(kvm, bus_idx);
5396 if (!bus)
5397 return -ENOMEM;
5398
5399 /* exclude ioeventfd which is limited by maximum fd */
5400 if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
5401 return -ENOSPC;
5402
5403 new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1),
5404 GFP_KERNEL_ACCOUNT);
5405 if (!new_bus)
5406 return -ENOMEM;
5407
5408 range = (struct kvm_io_range) {
5409 .addr = addr,
5410 .len = len,
5411 .dev = dev,
5412 };
5413
5414 for (i = 0; i < bus->dev_count; i++)
5415 if (kvm_io_bus_cmp(&bus->range[i], &range) > 0)
5416 break;
5417
5418 memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
5419 new_bus->dev_count++;
5420 new_bus->range[i] = range;
5421 memcpy(new_bus->range + i + 1, bus->range + i,
5422 (bus->dev_count - i) * sizeof(struct kvm_io_range));
5423 rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
5424 synchronize_srcu_expedited(&kvm->srcu);
5425 kfree(bus);
5426
5427 return 0;
5428}
5429
5430int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
5431 struct kvm_io_device *dev)
5432{
5433 int i, j;
5434 struct kvm_io_bus *new_bus, *bus;
5435
5436 lockdep_assert_held(&kvm->slots_lock);
5437
5438 bus = kvm_get_bus(kvm, bus_idx);
5439 if (!bus)
5440 return 0;
5441
5442 for (i = 0; i < bus->dev_count; i++) {
5443 if (bus->range[i].dev == dev) {
5444 break;
5445 }
5446 }
5447
5448 if (i == bus->dev_count)
5449 return 0;
5450
5451 new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
5452 GFP_KERNEL_ACCOUNT);
5453 if (new_bus) {
5454 memcpy(new_bus, bus, struct_size(bus, range, i));
5455 new_bus->dev_count--;
5456 memcpy(new_bus->range + i, bus->range + i + 1,
5457 flex_array_size(new_bus, range, new_bus->dev_count - i));
5458 }
5459
5460 rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
5461 synchronize_srcu_expedited(&kvm->srcu);
5462
5463 /* Destroy the old bus _after_ installing the (null) bus. */
5464 if (!new_bus) {
5465 pr_err("kvm: failed to shrink bus, removing it completely\n");
5466 for (j = 0; j < bus->dev_count; j++) {
5467 if (j == i)
5468 continue;
5469 kvm_iodevice_destructor(bus->range[j].dev);
5470 }
5471 }
5472
5473 kfree(bus);
5474 return new_bus ? 0 : -ENOMEM;
5475}
5476
5477struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
5478 gpa_t addr)
5479{
5480 struct kvm_io_bus *bus;
5481 int dev_idx, srcu_idx;
5482 struct kvm_io_device *iodev = NULL;
5483
5484 srcu_idx = srcu_read_lock(&kvm->srcu);
5485
5486 bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
5487 if (!bus)
5488 goto out_unlock;
5489
5490 dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1);
5491 if (dev_idx < 0)
5492 goto out_unlock;
5493
5494 iodev = bus->range[dev_idx].dev;
5495
5496out_unlock:
5497 srcu_read_unlock(&kvm->srcu, srcu_idx);
5498
5499 return iodev;
5500}
5501EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);
5502
5503static int kvm_debugfs_open(struct inode *inode, struct file *file,
5504 int (*get)(void *, u64 *), int (*set)(void *, u64),
5505 const char *fmt)
5506{
5507 int ret;
5508 struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
5509 inode->i_private;
5510
5511 /*
5512 * The debugfs files are a reference to the kvm struct which
5513 * is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe
5514 * avoids the race between open and the removal of the debugfs directory.
5515 */
5516 if (!kvm_get_kvm_safe(stat_data->kvm))
5517 return -ENOENT;
5518
5519 ret = simple_attr_open(inode, file, get,
5520 kvm_stats_debugfs_mode(stat_data->desc) & 0222
5521 ? set : NULL, fmt);
5522 if (ret)
5523 kvm_put_kvm(stat_data->kvm);
5524
5525 return ret;
5526}
5527
5528static int kvm_debugfs_release(struct inode *inode, struct file *file)
5529{
5530 struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
5531 inode->i_private;
5532
5533 simple_attr_release(inode, file);
5534 kvm_put_kvm(stat_data->kvm);
5535
5536 return 0;
5537}
5538
5539static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
5540{
5541 *val = *(u64 *)((void *)(&kvm->stat) + offset);
5542
5543 return 0;
5544}
5545
5546static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
5547{
5548 *(u64 *)((void *)(&kvm->stat) + offset) = 0;
5549
5550 return 0;
5551}
5552
5553static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
5554{
5555 unsigned long i;
5556 struct kvm_vcpu *vcpu;
5557
5558 *val = 0;
5559
5560 kvm_for_each_vcpu(i, vcpu, kvm)
5561 *val += *(u64 *)((void *)(&vcpu->stat) + offset);
5562
5563 return 0;
5564}
5565
5566static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
5567{
5568 unsigned long i;
5569 struct kvm_vcpu *vcpu;
5570
5571 kvm_for_each_vcpu(i, vcpu, kvm)
5572 *(u64 *)((void *)(&vcpu->stat) + offset) = 0;
5573
5574 return 0;
5575}
5576
5577static int kvm_stat_data_get(void *data, u64 *val)
5578{
5579 int r = -EFAULT;
5580 struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
5581
5582 switch (stat_data->kind) {
5583 case KVM_STAT_VM:
5584 r = kvm_get_stat_per_vm(stat_data->kvm,
5585 stat_data->desc->desc.offset, val);
5586 break;
5587 case KVM_STAT_VCPU:
5588 r = kvm_get_stat_per_vcpu(stat_data->kvm,
5589 stat_data->desc->desc.offset, val);
5590 break;
5591 }
5592
5593 return r;
5594}
5595
5596static int kvm_stat_data_clear(void *data, u64 val)
5597{
5598 int r = -EFAULT;
5599 struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
5600
5601 if (val)
5602 return -EINVAL;
5603
5604 switch (stat_data->kind) {
5605 case KVM_STAT_VM:
5606 r = kvm_clear_stat_per_vm(stat_data->kvm,
5607 stat_data->desc->desc.offset);
5608 break;
5609 case KVM_STAT_VCPU:
5610 r = kvm_clear_stat_per_vcpu(stat_data->kvm,
5611 stat_data->desc->desc.offset);
5612 break;
5613 }
5614
5615 return r;
5616}
5617
5618static int kvm_stat_data_open(struct inode *inode, struct file *file)
5619{
5620 __simple_attr_check_format("%llu\n", 0ull);
5621 return kvm_debugfs_open(inode, file, kvm_stat_data_get,
5622 kvm_stat_data_clear, "%llu\n");
5623}
5624
5625static const struct file_operations stat_fops_per_vm = {
5626 .owner = THIS_MODULE,
5627 .open = kvm_stat_data_open,
5628 .release = kvm_debugfs_release,
5629 .read = simple_attr_read,
5630 .write = simple_attr_write,
5631 .llseek = no_llseek,
5632};
5633
5634static int vm_stat_get(void *_offset, u64 *val)
5635{
5636 unsigned offset = (long)_offset;
5637 struct kvm *kvm;
5638 u64 tmp_val;
5639
5640 *val = 0;
5641 mutex_lock(&kvm_lock);
5642 list_for_each_entry(kvm, &vm_list, vm_list) {
5643 kvm_get_stat_per_vm(kvm, offset, &tmp_val);
5644 *val += tmp_val;
5645 }
5646 mutex_unlock(&kvm_lock);
5647 return 0;
5648}
5649
5650static int vm_stat_clear(void *_offset, u64 val)
5651{
5652 unsigned offset = (long)_offset;
5653 struct kvm *kvm;
5654
5655 if (val)
5656 return -EINVAL;
5657
5658 mutex_lock(&kvm_lock);
5659 list_for_each_entry(kvm, &vm_list, vm_list) {
5660 kvm_clear_stat_per_vm(kvm, offset);
5661 }
5662 mutex_unlock(&kvm_lock);
5663
5664 return 0;
5665}
5666
5667DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
5668DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n");
5669
5670static int vcpu_stat_get(void *_offset, u64 *val)
5671{
5672 unsigned offset = (long)_offset;
5673 struct kvm *kvm;
5674 u64 tmp_val;
5675
5676 *val = 0;
5677 mutex_lock(&kvm_lock);
5678 list_for_each_entry(kvm, &vm_list, vm_list) {
5679 kvm_get_stat_per_vcpu(kvm, offset, &tmp_val);
5680 *val += tmp_val;
5681 }
5682 mutex_unlock(&kvm_lock);
5683 return 0;
5684}
5685
5686static int vcpu_stat_clear(void *_offset, u64 val)
5687{
5688 unsigned offset = (long)_offset;
5689 struct kvm *kvm;
5690
5691 if (val)
5692 return -EINVAL;
5693
5694 mutex_lock(&kvm_lock);
5695 list_for_each_entry(kvm, &vm_list, vm_list) {
5696 kvm_clear_stat_per_vcpu(kvm, offset);
5697 }
5698 mutex_unlock(&kvm_lock);
5699
5700 return 0;
5701}
5702
5703DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
5704 "%llu\n");
5705DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n");
5706
5707static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
5708{
5709 struct kobj_uevent_env *env;
5710 unsigned long long created, active;
5711
5712 if (!kvm_dev.this_device || !kvm)
5713 return;
5714
5715 mutex_lock(&kvm_lock);
5716 if (type == KVM_EVENT_CREATE_VM) {
5717 kvm_createvm_count++;
5718 kvm_active_vms++;
5719 } else if (type == KVM_EVENT_DESTROY_VM) {
5720 kvm_active_vms--;
5721 }
5722 created = kvm_createvm_count;
5723 active = kvm_active_vms;
5724 mutex_unlock(&kvm_lock);
5725
5726 env = kzalloc(sizeof(*env), GFP_KERNEL_ACCOUNT);
5727 if (!env)
5728 return;
5729
5730 add_uevent_var(env, "CREATED=%llu", created);
5731 add_uevent_var(env, "COUNT=%llu", active);
5732
5733 if (type == KVM_EVENT_CREATE_VM) {
5734 add_uevent_var(env, "EVENT=create");
5735 kvm->userspace_pid = task_pid_nr(current);
5736 } else if (type == KVM_EVENT_DESTROY_VM) {
5737 add_uevent_var(env, "EVENT=destroy");
5738 }
5739 add_uevent_var(env, "PID=%d", kvm->userspace_pid);
5740
5741 if (!IS_ERR(kvm->debugfs_dentry)) {
5742 char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
5743
5744 if (p) {
5745 tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
5746 if (!IS_ERR(tmp))
5747 add_uevent_var(env, "STATS_PATH=%s", tmp);
5748 kfree(p);
5749 }
5750 }
5751 /* no need for checks, since we are adding at most only 5 keys */
5752 env->envp[env->envp_idx++] = NULL;
5753 kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp);
5754 kfree(env);
5755}
5756
5757static void kvm_init_debug(void)
5758{
5759 const struct file_operations *fops;
5760 const struct _kvm_stats_desc *pdesc;
5761 int i;
5762
5763 kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
5764
5765 for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
5766 pdesc = &kvm_vm_stats_desc[i];
5767 if (kvm_stats_debugfs_mode(pdesc) & 0222)
5768 fops = &vm_stat_fops;
5769 else
5770 fops = &vm_stat_readonly_fops;
5771 debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
5772 kvm_debugfs_dir,
5773 (void *)(long)pdesc->desc.offset, fops);
5774 }
5775
5776 for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
5777 pdesc = &kvm_vcpu_stats_desc[i];
5778 if (kvm_stats_debugfs_mode(pdesc) & 0222)
5779 fops = &vcpu_stat_fops;
5780 else
5781 fops = &vcpu_stat_readonly_fops;
5782 debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
5783 kvm_debugfs_dir,
5784 (void *)(long)pdesc->desc.offset, fops);
5785 }
5786}
5787
5788static int kvm_suspend(void)
5789{
5790 if (kvm_usage_count)
5791 hardware_disable_nolock(NULL);
5792 return 0;
5793}
5794
5795static void kvm_resume(void)
5796{
5797 if (kvm_usage_count) {
5798 lockdep_assert_not_held(&kvm_count_lock);
5799 hardware_enable_nolock(NULL);
5800 }
5801}
5802
5803static struct syscore_ops kvm_syscore_ops = {
5804 .suspend = kvm_suspend,
5805 .resume = kvm_resume,
5806};
5807
5808static inline
5809struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
5810{
5811 return container_of(pn, struct kvm_vcpu, preempt_notifier);
5812}
5813
5814static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
5815{
5816 struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
5817
5818 WRITE_ONCE(vcpu->preempted, false);
5819 WRITE_ONCE(vcpu->ready, false);
5820
5821 __this_cpu_write(kvm_running_vcpu, vcpu);
5822 kvm_arch_sched_in(vcpu, cpu);
5823 kvm_arch_vcpu_load(vcpu, cpu);
5824}
5825
5826static void kvm_sched_out(struct preempt_notifier *pn,
5827 struct task_struct *next)
5828{
5829 struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
5830
5831 if (current->on_rq) {
5832 WRITE_ONCE(vcpu->preempted, true);
5833 WRITE_ONCE(vcpu->ready, true);
5834 }
5835 kvm_arch_vcpu_put(vcpu);
5836 __this_cpu_write(kvm_running_vcpu, NULL);
5837}
5838
5839/**
5840 * kvm_get_running_vcpu - get the vcpu running on the current CPU.
5841 *
5842 * We can disable preemption locally around accessing the per-CPU variable,
5843 * and use the resolved vcpu pointer after enabling preemption again,
5844 * because even if the current thread is migrated to another CPU, reading
5845 * the per-CPU value later will give us the same value as we update the
5846 * per-CPU variable in the preempt notifier handlers.
5847 */
5848struct kvm_vcpu *kvm_get_running_vcpu(void)
5849{
5850 struct kvm_vcpu *vcpu;
5851
5852 preempt_disable();
5853 vcpu = __this_cpu_read(kvm_running_vcpu);
5854 preempt_enable();
5855
5856 return vcpu;
5857}
5858EXPORT_SYMBOL_GPL(kvm_get_running_vcpu);
5859
5860/**
5861 * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus.
5862 */
5863struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
5864{
5865 return &kvm_running_vcpu;
5866}
5867
5868#ifdef CONFIG_GUEST_PERF_EVENTS
5869static unsigned int kvm_guest_state(void)
5870{
5871 struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
5872 unsigned int state;
5873
5874 if (!kvm_arch_pmi_in_guest(vcpu))
5875 return 0;
5876
5877 state = PERF_GUEST_ACTIVE;
5878 if (!kvm_arch_vcpu_in_kernel(vcpu))
5879 state |= PERF_GUEST_USER;
5880
5881 return state;
5882}
5883
5884static unsigned long kvm_guest_get_ip(void)
5885{
5886 struct kvm_vcpu *vcpu = kvm_get_running_vcpu();
5887
5888 /* Retrieving the IP must be guarded by a call to kvm_guest_state(). */
5889 if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu)))
5890 return 0;
5891
5892 return kvm_arch_vcpu_get_ip(vcpu);
5893}
5894
5895static struct perf_guest_info_callbacks kvm_guest_cbs = {
5896 .state = kvm_guest_state,
5897 .get_ip = kvm_guest_get_ip,
5898 .handle_intel_pt_intr = NULL,
5899};
5900
5901void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void))
5902{
5903 kvm_guest_cbs.handle_intel_pt_intr = pt_intr_handler;
5904 perf_register_guest_info_callbacks(&kvm_guest_cbs);
5905}
5906void kvm_unregister_perf_callbacks(void)
5907{
5908 perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
5909}
5910#endif
5911
5912struct kvm_cpu_compat_check {
5913 void *opaque;
5914 int *ret;
5915};
5916
5917static void check_processor_compat(void *data)
5918{
5919 struct kvm_cpu_compat_check *c = data;
5920
5921 *c->ret = kvm_arch_check_processor_compat(c->opaque);
5922}
5923
5924int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
5925 struct module *module)
5926{
5927 struct kvm_cpu_compat_check c;
5928 int r;
5929 int cpu;
5930
5931 r = kvm_arch_init(opaque);
5932 if (r)
5933 goto out_fail;
5934
5935 /*
5936 * kvm_arch_init makes sure there's at most one caller
5937 * for architectures that support multiple implementations,
5938 * like intel and amd on x86.
5939 * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
5940 * conflicts in case kvm is already setup for another implementation.
5941 */
5942 r = kvm_irqfd_init();
5943 if (r)
5944 goto out_irqfd;
5945
5946 if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
5947 r = -ENOMEM;
5948 goto out_free_0;
5949 }
5950
5951 r = kvm_arch_hardware_setup(opaque);
5952 if (r < 0)
5953 goto out_free_1;
5954
5955 c.ret = &r;
5956 c.opaque = opaque;
5957 for_each_online_cpu(cpu) {
5958 smp_call_function_single(cpu, check_processor_compat, &c, 1);
5959 if (r < 0)
5960 goto out_free_2;
5961 }
5962
5963 r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
5964 kvm_starting_cpu, kvm_dying_cpu);
5965 if (r)
5966 goto out_free_2;
5967 register_reboot_notifier(&kvm_reboot_notifier);
5968
5969 /* A kmem cache lets us meet the alignment requirements of fx_save. */
5970 if (!vcpu_align)
5971 vcpu_align = __alignof__(struct kvm_vcpu);
5972 kvm_vcpu_cache =
5973 kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
5974 SLAB_ACCOUNT,
5975 offsetof(struct kvm_vcpu, arch),
5976 offsetofend(struct kvm_vcpu, stats_id)
5977 - offsetof(struct kvm_vcpu, arch),
5978 NULL);
5979 if (!kvm_vcpu_cache) {
5980 r = -ENOMEM;
5981 goto out_free_3;
5982 }
5983
5984 for_each_possible_cpu(cpu) {
5985 if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu),
5986 GFP_KERNEL, cpu_to_node(cpu))) {
5987 r = -ENOMEM;
5988 goto out_free_4;
5989 }
5990 }
5991
5992 r = kvm_async_pf_init();
5993 if (r)
5994 goto out_free_4;
5995
5996 kvm_chardev_ops.owner = module;
5997
5998 r = misc_register(&kvm_dev);
5999 if (r) {
6000 pr_err("kvm: misc device register failed\n");
6001 goto out_unreg;
6002 }
6003
6004 register_syscore_ops(&kvm_syscore_ops);
6005
6006 kvm_preempt_ops.sched_in = kvm_sched_in;
6007 kvm_preempt_ops.sched_out = kvm_sched_out;
6008
6009 kvm_init_debug();
6010
6011 r = kvm_vfio_ops_init();
6012 WARN_ON(r);
6013
6014 return 0;
6015
6016out_unreg:
6017 kvm_async_pf_deinit();
6018out_free_4:
6019 for_each_possible_cpu(cpu)
6020 free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
6021 kmem_cache_destroy(kvm_vcpu_cache);
6022out_free_3:
6023 unregister_reboot_notifier(&kvm_reboot_notifier);
6024 cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
6025out_free_2:
6026 kvm_arch_hardware_unsetup();
6027out_free_1:
6028 free_cpumask_var(cpus_hardware_enabled);
6029out_free_0:
6030 kvm_irqfd_exit();
6031out_irqfd:
6032 kvm_arch_exit();
6033out_fail:
6034 return r;
6035}
6036EXPORT_SYMBOL_GPL(kvm_init);
6037
6038void kvm_exit(void)
6039{
6040 int cpu;
6041
6042 debugfs_remove_recursive(kvm_debugfs_dir);
6043 misc_deregister(&kvm_dev);
6044 for_each_possible_cpu(cpu)
6045 free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
6046 kmem_cache_destroy(kvm_vcpu_cache);
6047 kvm_async_pf_deinit();
6048 unregister_syscore_ops(&kvm_syscore_ops);
6049 unregister_reboot_notifier(&kvm_reboot_notifier);
6050 cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
6051 on_each_cpu(hardware_disable_nolock, NULL, 1);
6052 kvm_arch_hardware_unsetup();
6053 kvm_arch_exit();
6054 kvm_irqfd_exit();
6055 free_cpumask_var(cpus_hardware_enabled);
6056 kvm_vfio_ops_exit();
6057}
6058EXPORT_SYMBOL_GPL(kvm_exit);
6059
6060struct kvm_vm_worker_thread_context {
6061 struct kvm *kvm;
6062 struct task_struct *parent;
6063 struct completion init_done;
6064 kvm_vm_thread_fn_t thread_fn;
6065 uintptr_t data;
6066 int err;
6067};
6068
6069static int kvm_vm_worker_thread(void *context)
6070{
6071 /*
6072 * The init_context is allocated on the stack of the parent thread, so
6073 * we have to locally copy anything that is needed beyond initialization
6074 */
6075 struct kvm_vm_worker_thread_context *init_context = context;
6076 struct task_struct *parent;
6077 struct kvm *kvm = init_context->kvm;
6078 kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
6079 uintptr_t data = init_context->data;
6080 int err;
6081
6082 err = kthread_park(current);
6083 /* kthread_park(current) is never supposed to return an error */
6084 WARN_ON(err != 0);
6085 if (err)
6086 goto init_complete;
6087
6088 err = cgroup_attach_task_all(init_context->parent, current);
6089 if (err) {
6090 kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
6091 __func__, err);
6092 goto init_complete;
6093 }
6094
6095 set_user_nice(current, task_nice(init_context->parent));
6096
6097init_complete:
6098 init_context->err = err;
6099 complete(&init_context->init_done);
6100 init_context = NULL;
6101
6102 if (err)
6103 goto out;
6104
6105 /* Wait to be woken up by the spawner before proceeding. */
6106 kthread_parkme();
6107
6108 if (!kthread_should_stop())
6109 err = thread_fn(kvm, data);
6110
6111out:
6112 /*
6113 * Move kthread back to its original cgroup to prevent it lingering in
6114 * the cgroup of the VM process, after the latter finishes its
6115 * execution.
6116 *
6117 * kthread_stop() waits on the 'exited' completion condition which is
6118 * set in exit_mm(), via mm_release(), in do_exit(). However, the
6119 * kthread is removed from the cgroup in the cgroup_exit() which is
6120 * called after the exit_mm(). This causes the kthread_stop() to return
6121 * before the kthread actually quits the cgroup.
6122 */
6123 rcu_read_lock();
6124 parent = rcu_dereference(current->real_parent);
6125 get_task_struct(parent);
6126 rcu_read_unlock();
6127 cgroup_attach_task_all(parent, current);
6128 put_task_struct(parent);
6129
6130 return err;
6131}
6132
6133int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
6134 uintptr_t data, const char *name,
6135 struct task_struct **thread_ptr)
6136{
6137 struct kvm_vm_worker_thread_context init_context = {};
6138 struct task_struct *thread;
6139
6140 *thread_ptr = NULL;
6141 init_context.kvm = kvm;
6142 init_context.parent = current;
6143 init_context.thread_fn = thread_fn;
6144 init_context.data = data;
6145 init_completion(&init_context.init_done);
6146
6147 thread = kthread_run(kvm_vm_worker_thread, &init_context,
6148 "%s-%d", name, task_pid_nr(current));
6149 if (IS_ERR(thread))
6150 return PTR_ERR(thread);
6151
6152 /* kthread_run is never supposed to return NULL */
6153 WARN_ON(thread == NULL);
6154
6155 wait_for_completion(&init_context.init_done);
6156
6157 if (!init_context.err)
6158 *thread_ptr = thread;
6159
6160 return init_context.err;
6161}