Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * KVM guest address space mapping code
4 *
5 * Copyright IBM Corp. 2007, 2016, 2018
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 * David Hildenbrand <david@redhat.com>
8 * Janosch Frank <frankja@linux.vnet.ibm.com>
9 */
10
11#include <linux/kernel.h>
12#include <linux/pagewalk.h>
13#include <linux/swap.h>
14#include <linux/smp.h>
15#include <linux/spinlock.h>
16#include <linux/slab.h>
17#include <linux/swapops.h>
18#include <linux/ksm.h>
19#include <linux/mman.h>
20
21#include <asm/pgtable.h>
22#include <asm/pgalloc.h>
23#include <asm/gmap.h>
24#include <asm/tlb.h>
25
26#define GMAP_SHADOW_FAKE_TABLE 1ULL
27
28/**
29 * gmap_alloc - allocate and initialize a guest address space
30 * @mm: pointer to the parent mm_struct
31 * @limit: maximum address of the gmap address space
32 *
33 * Returns a guest address space structure.
34 */
35static struct gmap *gmap_alloc(unsigned long limit)
36{
37 struct gmap *gmap;
38 struct page *page;
39 unsigned long *table;
40 unsigned long etype, atype;
41
42 if (limit < _REGION3_SIZE) {
43 limit = _REGION3_SIZE - 1;
44 atype = _ASCE_TYPE_SEGMENT;
45 etype = _SEGMENT_ENTRY_EMPTY;
46 } else if (limit < _REGION2_SIZE) {
47 limit = _REGION2_SIZE - 1;
48 atype = _ASCE_TYPE_REGION3;
49 etype = _REGION3_ENTRY_EMPTY;
50 } else if (limit < _REGION1_SIZE) {
51 limit = _REGION1_SIZE - 1;
52 atype = _ASCE_TYPE_REGION2;
53 etype = _REGION2_ENTRY_EMPTY;
54 } else {
55 limit = -1UL;
56 atype = _ASCE_TYPE_REGION1;
57 etype = _REGION1_ENTRY_EMPTY;
58 }
59 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
60 if (!gmap)
61 goto out;
62 INIT_LIST_HEAD(&gmap->crst_list);
63 INIT_LIST_HEAD(&gmap->children);
64 INIT_LIST_HEAD(&gmap->pt_list);
65 INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
66 INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
67 INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC);
68 spin_lock_init(&gmap->guest_table_lock);
69 spin_lock_init(&gmap->shadow_lock);
70 refcount_set(&gmap->ref_count, 1);
71 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
72 if (!page)
73 goto out_free;
74 page->index = 0;
75 list_add(&page->lru, &gmap->crst_list);
76 table = (unsigned long *) page_to_phys(page);
77 crst_table_init(table, etype);
78 gmap->table = table;
79 gmap->asce = atype | _ASCE_TABLE_LENGTH |
80 _ASCE_USER_BITS | __pa(table);
81 gmap->asce_end = limit;
82 return gmap;
83
84out_free:
85 kfree(gmap);
86out:
87 return NULL;
88}
89
90/**
91 * gmap_create - create a guest address space
92 * @mm: pointer to the parent mm_struct
93 * @limit: maximum size of the gmap address space
94 *
95 * Returns a guest address space structure.
96 */
97struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
98{
99 struct gmap *gmap;
100 unsigned long gmap_asce;
101
102 gmap = gmap_alloc(limit);
103 if (!gmap)
104 return NULL;
105 gmap->mm = mm;
106 spin_lock(&mm->context.lock);
107 list_add_rcu(&gmap->list, &mm->context.gmap_list);
108 if (list_is_singular(&mm->context.gmap_list))
109 gmap_asce = gmap->asce;
110 else
111 gmap_asce = -1UL;
112 WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
113 spin_unlock(&mm->context.lock);
114 return gmap;
115}
116EXPORT_SYMBOL_GPL(gmap_create);
117
118static void gmap_flush_tlb(struct gmap *gmap)
119{
120 if (MACHINE_HAS_IDTE)
121 __tlb_flush_idte(gmap->asce);
122 else
123 __tlb_flush_global();
124}
125
126static void gmap_radix_tree_free(struct radix_tree_root *root)
127{
128 struct radix_tree_iter iter;
129 unsigned long indices[16];
130 unsigned long index;
131 void __rcu **slot;
132 int i, nr;
133
134 /* A radix tree is freed by deleting all of its entries */
135 index = 0;
136 do {
137 nr = 0;
138 radix_tree_for_each_slot(slot, root, &iter, index) {
139 indices[nr] = iter.index;
140 if (++nr == 16)
141 break;
142 }
143 for (i = 0; i < nr; i++) {
144 index = indices[i];
145 radix_tree_delete(root, index);
146 }
147 } while (nr > 0);
148}
149
150static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
151{
152 struct gmap_rmap *rmap, *rnext, *head;
153 struct radix_tree_iter iter;
154 unsigned long indices[16];
155 unsigned long index;
156 void __rcu **slot;
157 int i, nr;
158
159 /* A radix tree is freed by deleting all of its entries */
160 index = 0;
161 do {
162 nr = 0;
163 radix_tree_for_each_slot(slot, root, &iter, index) {
164 indices[nr] = iter.index;
165 if (++nr == 16)
166 break;
167 }
168 for (i = 0; i < nr; i++) {
169 index = indices[i];
170 head = radix_tree_delete(root, index);
171 gmap_for_each_rmap_safe(rmap, rnext, head)
172 kfree(rmap);
173 }
174 } while (nr > 0);
175}
176
177/**
178 * gmap_free - free a guest address space
179 * @gmap: pointer to the guest address space structure
180 *
181 * No locks required. There are no references to this gmap anymore.
182 */
183static void gmap_free(struct gmap *gmap)
184{
185 struct page *page, *next;
186
187 /* Flush tlb of all gmaps (if not already done for shadows) */
188 if (!(gmap_is_shadow(gmap) && gmap->removed))
189 gmap_flush_tlb(gmap);
190 /* Free all segment & region tables. */
191 list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
192 __free_pages(page, CRST_ALLOC_ORDER);
193 gmap_radix_tree_free(&gmap->guest_to_host);
194 gmap_radix_tree_free(&gmap->host_to_guest);
195
196 /* Free additional data for a shadow gmap */
197 if (gmap_is_shadow(gmap)) {
198 /* Free all page tables. */
199 list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
200 page_table_free_pgste(page);
201 gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
202 /* Release reference to the parent */
203 gmap_put(gmap->parent);
204 }
205
206 kfree(gmap);
207}
208
209/**
210 * gmap_get - increase reference counter for guest address space
211 * @gmap: pointer to the guest address space structure
212 *
213 * Returns the gmap pointer
214 */
215struct gmap *gmap_get(struct gmap *gmap)
216{
217 refcount_inc(&gmap->ref_count);
218 return gmap;
219}
220EXPORT_SYMBOL_GPL(gmap_get);
221
222/**
223 * gmap_put - decrease reference counter for guest address space
224 * @gmap: pointer to the guest address space structure
225 *
226 * If the reference counter reaches zero the guest address space is freed.
227 */
228void gmap_put(struct gmap *gmap)
229{
230 if (refcount_dec_and_test(&gmap->ref_count))
231 gmap_free(gmap);
232}
233EXPORT_SYMBOL_GPL(gmap_put);
234
235/**
236 * gmap_remove - remove a guest address space but do not free it yet
237 * @gmap: pointer to the guest address space structure
238 */
239void gmap_remove(struct gmap *gmap)
240{
241 struct gmap *sg, *next;
242 unsigned long gmap_asce;
243
244 /* Remove all shadow gmaps linked to this gmap */
245 if (!list_empty(&gmap->children)) {
246 spin_lock(&gmap->shadow_lock);
247 list_for_each_entry_safe(sg, next, &gmap->children, list) {
248 list_del(&sg->list);
249 gmap_put(sg);
250 }
251 spin_unlock(&gmap->shadow_lock);
252 }
253 /* Remove gmap from the pre-mm list */
254 spin_lock(&gmap->mm->context.lock);
255 list_del_rcu(&gmap->list);
256 if (list_empty(&gmap->mm->context.gmap_list))
257 gmap_asce = 0;
258 else if (list_is_singular(&gmap->mm->context.gmap_list))
259 gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
260 struct gmap, list)->asce;
261 else
262 gmap_asce = -1UL;
263 WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
264 spin_unlock(&gmap->mm->context.lock);
265 synchronize_rcu();
266 /* Put reference */
267 gmap_put(gmap);
268}
269EXPORT_SYMBOL_GPL(gmap_remove);
270
271/**
272 * gmap_enable - switch primary space to the guest address space
273 * @gmap: pointer to the guest address space structure
274 */
275void gmap_enable(struct gmap *gmap)
276{
277 S390_lowcore.gmap = (unsigned long) gmap;
278}
279EXPORT_SYMBOL_GPL(gmap_enable);
280
281/**
282 * gmap_disable - switch back to the standard primary address space
283 * @gmap: pointer to the guest address space structure
284 */
285void gmap_disable(struct gmap *gmap)
286{
287 S390_lowcore.gmap = 0UL;
288}
289EXPORT_SYMBOL_GPL(gmap_disable);
290
291/**
292 * gmap_get_enabled - get a pointer to the currently enabled gmap
293 *
294 * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
295 */
296struct gmap *gmap_get_enabled(void)
297{
298 return (struct gmap *) S390_lowcore.gmap;
299}
300EXPORT_SYMBOL_GPL(gmap_get_enabled);
301
302/*
303 * gmap_alloc_table is assumed to be called with mmap_sem held
304 */
305static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
306 unsigned long init, unsigned long gaddr)
307{
308 struct page *page;
309 unsigned long *new;
310
311 /* since we dont free the gmap table until gmap_free we can unlock */
312 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
313 if (!page)
314 return -ENOMEM;
315 new = (unsigned long *) page_to_phys(page);
316 crst_table_init(new, init);
317 spin_lock(&gmap->guest_table_lock);
318 if (*table & _REGION_ENTRY_INVALID) {
319 list_add(&page->lru, &gmap->crst_list);
320 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
321 (*table & _REGION_ENTRY_TYPE_MASK);
322 page->index = gaddr;
323 page = NULL;
324 }
325 spin_unlock(&gmap->guest_table_lock);
326 if (page)
327 __free_pages(page, CRST_ALLOC_ORDER);
328 return 0;
329}
330
331/**
332 * __gmap_segment_gaddr - find virtual address from segment pointer
333 * @entry: pointer to a segment table entry in the guest address space
334 *
335 * Returns the virtual address in the guest address space for the segment
336 */
337static unsigned long __gmap_segment_gaddr(unsigned long *entry)
338{
339 struct page *page;
340 unsigned long offset, mask;
341
342 offset = (unsigned long) entry / sizeof(unsigned long);
343 offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
344 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
345 page = virt_to_page((void *)((unsigned long) entry & mask));
346 return page->index + offset;
347}
348
349/**
350 * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
351 * @gmap: pointer to the guest address space structure
352 * @vmaddr: address in the host process address space
353 *
354 * Returns 1 if a TLB flush is required
355 */
356static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
357{
358 unsigned long *entry;
359 int flush = 0;
360
361 BUG_ON(gmap_is_shadow(gmap));
362 spin_lock(&gmap->guest_table_lock);
363 entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
364 if (entry) {
365 flush = (*entry != _SEGMENT_ENTRY_EMPTY);
366 *entry = _SEGMENT_ENTRY_EMPTY;
367 }
368 spin_unlock(&gmap->guest_table_lock);
369 return flush;
370}
371
372/**
373 * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
374 * @gmap: pointer to the guest address space structure
375 * @gaddr: address in the guest address space
376 *
377 * Returns 1 if a TLB flush is required
378 */
379static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
380{
381 unsigned long vmaddr;
382
383 vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
384 gaddr >> PMD_SHIFT);
385 return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
386}
387
388/**
389 * gmap_unmap_segment - unmap segment from the guest address space
390 * @gmap: pointer to the guest address space structure
391 * @to: address in the guest address space
392 * @len: length of the memory area to unmap
393 *
394 * Returns 0 if the unmap succeeded, -EINVAL if not.
395 */
396int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
397{
398 unsigned long off;
399 int flush;
400
401 BUG_ON(gmap_is_shadow(gmap));
402 if ((to | len) & (PMD_SIZE - 1))
403 return -EINVAL;
404 if (len == 0 || to + len < to)
405 return -EINVAL;
406
407 flush = 0;
408 down_write(&gmap->mm->mmap_sem);
409 for (off = 0; off < len; off += PMD_SIZE)
410 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
411 up_write(&gmap->mm->mmap_sem);
412 if (flush)
413 gmap_flush_tlb(gmap);
414 return 0;
415}
416EXPORT_SYMBOL_GPL(gmap_unmap_segment);
417
418/**
419 * gmap_map_segment - map a segment to the guest address space
420 * @gmap: pointer to the guest address space structure
421 * @from: source address in the parent address space
422 * @to: target address in the guest address space
423 * @len: length of the memory area to map
424 *
425 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
426 */
427int gmap_map_segment(struct gmap *gmap, unsigned long from,
428 unsigned long to, unsigned long len)
429{
430 unsigned long off;
431 int flush;
432
433 BUG_ON(gmap_is_shadow(gmap));
434 if ((from | to | len) & (PMD_SIZE - 1))
435 return -EINVAL;
436 if (len == 0 || from + len < from || to + len < to ||
437 from + len - 1 > TASK_SIZE_MAX || to + len - 1 > gmap->asce_end)
438 return -EINVAL;
439
440 flush = 0;
441 down_write(&gmap->mm->mmap_sem);
442 for (off = 0; off < len; off += PMD_SIZE) {
443 /* Remove old translation */
444 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
445 /* Store new translation */
446 if (radix_tree_insert(&gmap->guest_to_host,
447 (to + off) >> PMD_SHIFT,
448 (void *) from + off))
449 break;
450 }
451 up_write(&gmap->mm->mmap_sem);
452 if (flush)
453 gmap_flush_tlb(gmap);
454 if (off >= len)
455 return 0;
456 gmap_unmap_segment(gmap, to, len);
457 return -ENOMEM;
458}
459EXPORT_SYMBOL_GPL(gmap_map_segment);
460
461/**
462 * __gmap_translate - translate a guest address to a user space address
463 * @gmap: pointer to guest mapping meta data structure
464 * @gaddr: guest address
465 *
466 * Returns user space address which corresponds to the guest address or
467 * -EFAULT if no such mapping exists.
468 * This function does not establish potentially missing page table entries.
469 * The mmap_sem of the mm that belongs to the address space must be held
470 * when this function gets called.
471 *
472 * Note: Can also be called for shadow gmaps.
473 */
474unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
475{
476 unsigned long vmaddr;
477
478 vmaddr = (unsigned long)
479 radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
480 /* Note: guest_to_host is empty for a shadow gmap */
481 return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
482}
483EXPORT_SYMBOL_GPL(__gmap_translate);
484
485/**
486 * gmap_translate - translate a guest address to a user space address
487 * @gmap: pointer to guest mapping meta data structure
488 * @gaddr: guest address
489 *
490 * Returns user space address which corresponds to the guest address or
491 * -EFAULT if no such mapping exists.
492 * This function does not establish potentially missing page table entries.
493 */
494unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
495{
496 unsigned long rc;
497
498 down_read(&gmap->mm->mmap_sem);
499 rc = __gmap_translate(gmap, gaddr);
500 up_read(&gmap->mm->mmap_sem);
501 return rc;
502}
503EXPORT_SYMBOL_GPL(gmap_translate);
504
505/**
506 * gmap_unlink - disconnect a page table from the gmap shadow tables
507 * @gmap: pointer to guest mapping meta data structure
508 * @table: pointer to the host page table
509 * @vmaddr: vm address associated with the host page table
510 */
511void gmap_unlink(struct mm_struct *mm, unsigned long *table,
512 unsigned long vmaddr)
513{
514 struct gmap *gmap;
515 int flush;
516
517 rcu_read_lock();
518 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
519 flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
520 if (flush)
521 gmap_flush_tlb(gmap);
522 }
523 rcu_read_unlock();
524}
525
526static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *old, pmd_t new,
527 unsigned long gaddr);
528
529/**
530 * gmap_link - set up shadow page tables to connect a host to a guest address
531 * @gmap: pointer to guest mapping meta data structure
532 * @gaddr: guest address
533 * @vmaddr: vm address
534 *
535 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
536 * if the vm address is already mapped to a different guest segment.
537 * The mmap_sem of the mm that belongs to the address space must be held
538 * when this function gets called.
539 */
540int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
541{
542 struct mm_struct *mm;
543 unsigned long *table;
544 spinlock_t *ptl;
545 pgd_t *pgd;
546 p4d_t *p4d;
547 pud_t *pud;
548 pmd_t *pmd;
549 u64 unprot;
550 int rc;
551
552 BUG_ON(gmap_is_shadow(gmap));
553 /* Create higher level tables in the gmap page table */
554 table = gmap->table;
555 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
556 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
557 if ((*table & _REGION_ENTRY_INVALID) &&
558 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
559 gaddr & _REGION1_MASK))
560 return -ENOMEM;
561 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
562 }
563 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
564 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
565 if ((*table & _REGION_ENTRY_INVALID) &&
566 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
567 gaddr & _REGION2_MASK))
568 return -ENOMEM;
569 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
570 }
571 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
572 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
573 if ((*table & _REGION_ENTRY_INVALID) &&
574 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
575 gaddr & _REGION3_MASK))
576 return -ENOMEM;
577 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
578 }
579 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
580 /* Walk the parent mm page table */
581 mm = gmap->mm;
582 pgd = pgd_offset(mm, vmaddr);
583 VM_BUG_ON(pgd_none(*pgd));
584 p4d = p4d_offset(pgd, vmaddr);
585 VM_BUG_ON(p4d_none(*p4d));
586 pud = pud_offset(p4d, vmaddr);
587 VM_BUG_ON(pud_none(*pud));
588 /* large puds cannot yet be handled */
589 if (pud_large(*pud))
590 return -EFAULT;
591 pmd = pmd_offset(pud, vmaddr);
592 VM_BUG_ON(pmd_none(*pmd));
593 /* Are we allowed to use huge pages? */
594 if (pmd_large(*pmd) && !gmap->mm->context.allow_gmap_hpage_1m)
595 return -EFAULT;
596 /* Link gmap segment table entry location to page table. */
597 rc = radix_tree_preload(GFP_KERNEL);
598 if (rc)
599 return rc;
600 ptl = pmd_lock(mm, pmd);
601 spin_lock(&gmap->guest_table_lock);
602 if (*table == _SEGMENT_ENTRY_EMPTY) {
603 rc = radix_tree_insert(&gmap->host_to_guest,
604 vmaddr >> PMD_SHIFT, table);
605 if (!rc) {
606 if (pmd_large(*pmd)) {
607 *table = (pmd_val(*pmd) &
608 _SEGMENT_ENTRY_HARDWARE_BITS_LARGE)
609 | _SEGMENT_ENTRY_GMAP_UC;
610 } else
611 *table = pmd_val(*pmd) &
612 _SEGMENT_ENTRY_HARDWARE_BITS;
613 }
614 } else if (*table & _SEGMENT_ENTRY_PROTECT &&
615 !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
616 unprot = (u64)*table;
617 unprot &= ~_SEGMENT_ENTRY_PROTECT;
618 unprot |= _SEGMENT_ENTRY_GMAP_UC;
619 gmap_pmdp_xchg(gmap, (pmd_t *)table, __pmd(unprot), gaddr);
620 }
621 spin_unlock(&gmap->guest_table_lock);
622 spin_unlock(ptl);
623 radix_tree_preload_end();
624 return rc;
625}
626
627/**
628 * gmap_fault - resolve a fault on a guest address
629 * @gmap: pointer to guest mapping meta data structure
630 * @gaddr: guest address
631 * @fault_flags: flags to pass down to handle_mm_fault()
632 *
633 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
634 * if the vm address is already mapped to a different guest segment.
635 */
636int gmap_fault(struct gmap *gmap, unsigned long gaddr,
637 unsigned int fault_flags)
638{
639 unsigned long vmaddr;
640 int rc;
641 bool unlocked;
642
643 down_read(&gmap->mm->mmap_sem);
644
645retry:
646 unlocked = false;
647 vmaddr = __gmap_translate(gmap, gaddr);
648 if (IS_ERR_VALUE(vmaddr)) {
649 rc = vmaddr;
650 goto out_up;
651 }
652 if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
653 &unlocked)) {
654 rc = -EFAULT;
655 goto out_up;
656 }
657 /*
658 * In the case that fixup_user_fault unlocked the mmap_sem during
659 * faultin redo __gmap_translate to not race with a map/unmap_segment.
660 */
661 if (unlocked)
662 goto retry;
663
664 rc = __gmap_link(gmap, gaddr, vmaddr);
665out_up:
666 up_read(&gmap->mm->mmap_sem);
667 return rc;
668}
669EXPORT_SYMBOL_GPL(gmap_fault);
670
671/*
672 * this function is assumed to be called with mmap_sem held
673 */
674void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
675{
676 unsigned long vmaddr;
677 spinlock_t *ptl;
678 pte_t *ptep;
679
680 /* Find the vm address for the guest address */
681 vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
682 gaddr >> PMD_SHIFT);
683 if (vmaddr) {
684 vmaddr |= gaddr & ~PMD_MASK;
685 /* Get pointer to the page table entry */
686 ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
687 if (likely(ptep))
688 ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
689 pte_unmap_unlock(ptep, ptl);
690 }
691}
692EXPORT_SYMBOL_GPL(__gmap_zap);
693
694void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
695{
696 unsigned long gaddr, vmaddr, size;
697 struct vm_area_struct *vma;
698
699 down_read(&gmap->mm->mmap_sem);
700 for (gaddr = from; gaddr < to;
701 gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
702 /* Find the vm address for the guest address */
703 vmaddr = (unsigned long)
704 radix_tree_lookup(&gmap->guest_to_host,
705 gaddr >> PMD_SHIFT);
706 if (!vmaddr)
707 continue;
708 vmaddr |= gaddr & ~PMD_MASK;
709 /* Find vma in the parent mm */
710 vma = find_vma(gmap->mm, vmaddr);
711 if (!vma)
712 continue;
713 /*
714 * We do not discard pages that are backed by
715 * hugetlbfs, so we don't have to refault them.
716 */
717 if (is_vm_hugetlb_page(vma))
718 continue;
719 size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
720 zap_page_range(vma, vmaddr, size);
721 }
722 up_read(&gmap->mm->mmap_sem);
723}
724EXPORT_SYMBOL_GPL(gmap_discard);
725
726static LIST_HEAD(gmap_notifier_list);
727static DEFINE_SPINLOCK(gmap_notifier_lock);
728
729/**
730 * gmap_register_pte_notifier - register a pte invalidation callback
731 * @nb: pointer to the gmap notifier block
732 */
733void gmap_register_pte_notifier(struct gmap_notifier *nb)
734{
735 spin_lock(&gmap_notifier_lock);
736 list_add_rcu(&nb->list, &gmap_notifier_list);
737 spin_unlock(&gmap_notifier_lock);
738}
739EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
740
741/**
742 * gmap_unregister_pte_notifier - remove a pte invalidation callback
743 * @nb: pointer to the gmap notifier block
744 */
745void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
746{
747 spin_lock(&gmap_notifier_lock);
748 list_del_rcu(&nb->list);
749 spin_unlock(&gmap_notifier_lock);
750 synchronize_rcu();
751}
752EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
753
754/**
755 * gmap_call_notifier - call all registered invalidation callbacks
756 * @gmap: pointer to guest mapping meta data structure
757 * @start: start virtual address in the guest address space
758 * @end: end virtual address in the guest address space
759 */
760static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
761 unsigned long end)
762{
763 struct gmap_notifier *nb;
764
765 list_for_each_entry(nb, &gmap_notifier_list, list)
766 nb->notifier_call(gmap, start, end);
767}
768
769/**
770 * gmap_table_walk - walk the gmap page tables
771 * @gmap: pointer to guest mapping meta data structure
772 * @gaddr: virtual address in the guest address space
773 * @level: page table level to stop at
774 *
775 * Returns a table entry pointer for the given guest address and @level
776 * @level=0 : returns a pointer to a page table table entry (or NULL)
777 * @level=1 : returns a pointer to a segment table entry (or NULL)
778 * @level=2 : returns a pointer to a region-3 table entry (or NULL)
779 * @level=3 : returns a pointer to a region-2 table entry (or NULL)
780 * @level=4 : returns a pointer to a region-1 table entry (or NULL)
781 *
782 * Returns NULL if the gmap page tables could not be walked to the
783 * requested level.
784 *
785 * Note: Can also be called for shadow gmaps.
786 */
787static inline unsigned long *gmap_table_walk(struct gmap *gmap,
788 unsigned long gaddr, int level)
789{
790 unsigned long *table;
791
792 if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
793 return NULL;
794 if (gmap_is_shadow(gmap) && gmap->removed)
795 return NULL;
796 if (gaddr & (-1UL << (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11)))
797 return NULL;
798 table = gmap->table;
799 switch (gmap->asce & _ASCE_TYPE_MASK) {
800 case _ASCE_TYPE_REGION1:
801 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
802 if (level == 4)
803 break;
804 if (*table & _REGION_ENTRY_INVALID)
805 return NULL;
806 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
807 /* Fallthrough */
808 case _ASCE_TYPE_REGION2:
809 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
810 if (level == 3)
811 break;
812 if (*table & _REGION_ENTRY_INVALID)
813 return NULL;
814 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
815 /* Fallthrough */
816 case _ASCE_TYPE_REGION3:
817 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
818 if (level == 2)
819 break;
820 if (*table & _REGION_ENTRY_INVALID)
821 return NULL;
822 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
823 /* Fallthrough */
824 case _ASCE_TYPE_SEGMENT:
825 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
826 if (level == 1)
827 break;
828 if (*table & _REGION_ENTRY_INVALID)
829 return NULL;
830 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
831 table += (gaddr & _PAGE_INDEX) >> _PAGE_SHIFT;
832 }
833 return table;
834}
835
836/**
837 * gmap_pte_op_walk - walk the gmap page table, get the page table lock
838 * and return the pte pointer
839 * @gmap: pointer to guest mapping meta data structure
840 * @gaddr: virtual address in the guest address space
841 * @ptl: pointer to the spinlock pointer
842 *
843 * Returns a pointer to the locked pte for a guest address, or NULL
844 */
845static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
846 spinlock_t **ptl)
847{
848 unsigned long *table;
849
850 BUG_ON(gmap_is_shadow(gmap));
851 /* Walk the gmap page table, lock and get pte pointer */
852 table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
853 if (!table || *table & _SEGMENT_ENTRY_INVALID)
854 return NULL;
855 return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
856}
857
858/**
859 * gmap_pte_op_fixup - force a page in and connect the gmap page table
860 * @gmap: pointer to guest mapping meta data structure
861 * @gaddr: virtual address in the guest address space
862 * @vmaddr: address in the host process address space
863 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
864 *
865 * Returns 0 if the caller can retry __gmap_translate (might fail again),
866 * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
867 * up or connecting the gmap page table.
868 */
869static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
870 unsigned long vmaddr, int prot)
871{
872 struct mm_struct *mm = gmap->mm;
873 unsigned int fault_flags;
874 bool unlocked = false;
875
876 BUG_ON(gmap_is_shadow(gmap));
877 fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
878 if (fixup_user_fault(current, mm, vmaddr, fault_flags, &unlocked))
879 return -EFAULT;
880 if (unlocked)
881 /* lost mmap_sem, caller has to retry __gmap_translate */
882 return 0;
883 /* Connect the page tables */
884 return __gmap_link(gmap, gaddr, vmaddr);
885}
886
887/**
888 * gmap_pte_op_end - release the page table lock
889 * @ptl: pointer to the spinlock pointer
890 */
891static void gmap_pte_op_end(spinlock_t *ptl)
892{
893 if (ptl)
894 spin_unlock(ptl);
895}
896
897/**
898 * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock
899 * and return the pmd pointer
900 * @gmap: pointer to guest mapping meta data structure
901 * @gaddr: virtual address in the guest address space
902 *
903 * Returns a pointer to the pmd for a guest address, or NULL
904 */
905static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
906{
907 pmd_t *pmdp;
908
909 BUG_ON(gmap_is_shadow(gmap));
910 pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
911 if (!pmdp)
912 return NULL;
913
914 /* without huge pages, there is no need to take the table lock */
915 if (!gmap->mm->context.allow_gmap_hpage_1m)
916 return pmd_none(*pmdp) ? NULL : pmdp;
917
918 spin_lock(&gmap->guest_table_lock);
919 if (pmd_none(*pmdp)) {
920 spin_unlock(&gmap->guest_table_lock);
921 return NULL;
922 }
923
924 /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */
925 if (!pmd_large(*pmdp))
926 spin_unlock(&gmap->guest_table_lock);
927 return pmdp;
928}
929
930/**
931 * gmap_pmd_op_end - release the guest_table_lock if needed
932 * @gmap: pointer to the guest mapping meta data structure
933 * @pmdp: pointer to the pmd
934 */
935static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
936{
937 if (pmd_large(*pmdp))
938 spin_unlock(&gmap->guest_table_lock);
939}
940
941/*
942 * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
943 * @pmdp: pointer to the pmd to be protected
944 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
945 * @bits: notification bits to set
946 *
947 * Returns:
948 * 0 if successfully protected
949 * -EAGAIN if a fixup is needed
950 * -EINVAL if unsupported notifier bits have been specified
951 *
952 * Expected to be called with sg->mm->mmap_sem in read and
953 * guest_table_lock held.
954 */
955static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
956 pmd_t *pmdp, int prot, unsigned long bits)
957{
958 int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
959 int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
960 pmd_t new = *pmdp;
961
962 /* Fixup needed */
963 if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
964 return -EAGAIN;
965
966 if (prot == PROT_NONE && !pmd_i) {
967 pmd_val(new) |= _SEGMENT_ENTRY_INVALID;
968 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
969 }
970
971 if (prot == PROT_READ && !pmd_p) {
972 pmd_val(new) &= ~_SEGMENT_ENTRY_INVALID;
973 pmd_val(new) |= _SEGMENT_ENTRY_PROTECT;
974 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
975 }
976
977 if (bits & GMAP_NOTIFY_MPROT)
978 pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN;
979
980 /* Shadow GMAP protection needs split PMDs */
981 if (bits & GMAP_NOTIFY_SHADOW)
982 return -EINVAL;
983
984 return 0;
985}
986
987/*
988 * gmap_protect_pte - remove access rights to memory and set pgste bits
989 * @gmap: pointer to guest mapping meta data structure
990 * @gaddr: virtual address in the guest address space
991 * @pmdp: pointer to the pmd associated with the pte
992 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
993 * @bits: notification bits to set
994 *
995 * Returns 0 if successfully protected, -ENOMEM if out of memory and
996 * -EAGAIN if a fixup is needed.
997 *
998 * Expected to be called with sg->mm->mmap_sem in read
999 */
1000static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
1001 pmd_t *pmdp, int prot, unsigned long bits)
1002{
1003 int rc;
1004 pte_t *ptep;
1005 spinlock_t *ptl = NULL;
1006 unsigned long pbits = 0;
1007
1008 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
1009 return -EAGAIN;
1010
1011 ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl);
1012 if (!ptep)
1013 return -ENOMEM;
1014
1015 pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
1016 pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
1017 /* Protect and unlock. */
1018 rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
1019 gmap_pte_op_end(ptl);
1020 return rc;
1021}
1022
1023/*
1024 * gmap_protect_range - remove access rights to memory and set pgste bits
1025 * @gmap: pointer to guest mapping meta data structure
1026 * @gaddr: virtual address in the guest address space
1027 * @len: size of area
1028 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1029 * @bits: pgste notification bits to set
1030 *
1031 * Returns 0 if successfully protected, -ENOMEM if out of memory and
1032 * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
1033 *
1034 * Called with sg->mm->mmap_sem in read.
1035 */
1036static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
1037 unsigned long len, int prot, unsigned long bits)
1038{
1039 unsigned long vmaddr, dist;
1040 pmd_t *pmdp;
1041 int rc;
1042
1043 BUG_ON(gmap_is_shadow(gmap));
1044 while (len) {
1045 rc = -EAGAIN;
1046 pmdp = gmap_pmd_op_walk(gmap, gaddr);
1047 if (pmdp) {
1048 if (!pmd_large(*pmdp)) {
1049 rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
1050 bits);
1051 if (!rc) {
1052 len -= PAGE_SIZE;
1053 gaddr += PAGE_SIZE;
1054 }
1055 } else {
1056 rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
1057 bits);
1058 if (!rc) {
1059 dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
1060 len = len < dist ? 0 : len - dist;
1061 gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
1062 }
1063 }
1064 gmap_pmd_op_end(gmap, pmdp);
1065 }
1066 if (rc) {
1067 if (rc == -EINVAL)
1068 return rc;
1069
1070 /* -EAGAIN, fixup of userspace mm and gmap */
1071 vmaddr = __gmap_translate(gmap, gaddr);
1072 if (IS_ERR_VALUE(vmaddr))
1073 return vmaddr;
1074 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
1075 if (rc)
1076 return rc;
1077 }
1078 }
1079 return 0;
1080}
1081
1082/**
1083 * gmap_mprotect_notify - change access rights for a range of ptes and
1084 * call the notifier if any pte changes again
1085 * @gmap: pointer to guest mapping meta data structure
1086 * @gaddr: virtual address in the guest address space
1087 * @len: size of area
1088 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1089 *
1090 * Returns 0 if for each page in the given range a gmap mapping exists,
1091 * the new access rights could be set and the notifier could be armed.
1092 * If the gmap mapping is missing for one or more pages -EFAULT is
1093 * returned. If no memory could be allocated -ENOMEM is returned.
1094 * This function establishes missing page table entries.
1095 */
1096int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
1097 unsigned long len, int prot)
1098{
1099 int rc;
1100
1101 if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
1102 return -EINVAL;
1103 if (!MACHINE_HAS_ESOP && prot == PROT_READ)
1104 return -EINVAL;
1105 down_read(&gmap->mm->mmap_sem);
1106 rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
1107 up_read(&gmap->mm->mmap_sem);
1108 return rc;
1109}
1110EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
1111
1112/**
1113 * gmap_read_table - get an unsigned long value from a guest page table using
1114 * absolute addressing, without marking the page referenced.
1115 * @gmap: pointer to guest mapping meta data structure
1116 * @gaddr: virtual address in the guest address space
1117 * @val: pointer to the unsigned long value to return
1118 *
1119 * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
1120 * if reading using the virtual address failed. -EINVAL if called on a gmap
1121 * shadow.
1122 *
1123 * Called with gmap->mm->mmap_sem in read.
1124 */
1125int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
1126{
1127 unsigned long address, vmaddr;
1128 spinlock_t *ptl;
1129 pte_t *ptep, pte;
1130 int rc;
1131
1132 if (gmap_is_shadow(gmap))
1133 return -EINVAL;
1134
1135 while (1) {
1136 rc = -EAGAIN;
1137 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
1138 if (ptep) {
1139 pte = *ptep;
1140 if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
1141 address = pte_val(pte) & PAGE_MASK;
1142 address += gaddr & ~PAGE_MASK;
1143 *val = *(unsigned long *) address;
1144 pte_val(*ptep) |= _PAGE_YOUNG;
1145 /* Do *NOT* clear the _PAGE_INVALID bit! */
1146 rc = 0;
1147 }
1148 gmap_pte_op_end(ptl);
1149 }
1150 if (!rc)
1151 break;
1152 vmaddr = __gmap_translate(gmap, gaddr);
1153 if (IS_ERR_VALUE(vmaddr)) {
1154 rc = vmaddr;
1155 break;
1156 }
1157 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
1158 if (rc)
1159 break;
1160 }
1161 return rc;
1162}
1163EXPORT_SYMBOL_GPL(gmap_read_table);
1164
1165/**
1166 * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
1167 * @sg: pointer to the shadow guest address space structure
1168 * @vmaddr: vm address associated with the rmap
1169 * @rmap: pointer to the rmap structure
1170 *
1171 * Called with the sg->guest_table_lock
1172 */
1173static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
1174 struct gmap_rmap *rmap)
1175{
1176 void __rcu **slot;
1177
1178 BUG_ON(!gmap_is_shadow(sg));
1179 slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
1180 if (slot) {
1181 rmap->next = radix_tree_deref_slot_protected(slot,
1182 &sg->guest_table_lock);
1183 radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
1184 } else {
1185 rmap->next = NULL;
1186 radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
1187 rmap);
1188 }
1189}
1190
1191/**
1192 * gmap_protect_rmap - restrict access rights to memory (RO) and create an rmap
1193 * @sg: pointer to the shadow guest address space structure
1194 * @raddr: rmap address in the shadow gmap
1195 * @paddr: address in the parent guest address space
1196 * @len: length of the memory area to protect
1197 *
1198 * Returns 0 if successfully protected and the rmap was created, -ENOMEM
1199 * if out of memory and -EFAULT if paddr is invalid.
1200 */
1201static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
1202 unsigned long paddr, unsigned long len)
1203{
1204 struct gmap *parent;
1205 struct gmap_rmap *rmap;
1206 unsigned long vmaddr;
1207 spinlock_t *ptl;
1208 pte_t *ptep;
1209 int rc;
1210
1211 BUG_ON(!gmap_is_shadow(sg));
1212 parent = sg->parent;
1213 while (len) {
1214 vmaddr = __gmap_translate(parent, paddr);
1215 if (IS_ERR_VALUE(vmaddr))
1216 return vmaddr;
1217 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1218 if (!rmap)
1219 return -ENOMEM;
1220 rmap->raddr = raddr;
1221 rc = radix_tree_preload(GFP_KERNEL);
1222 if (rc) {
1223 kfree(rmap);
1224 return rc;
1225 }
1226 rc = -EAGAIN;
1227 ptep = gmap_pte_op_walk(parent, paddr, &ptl);
1228 if (ptep) {
1229 spin_lock(&sg->guest_table_lock);
1230 rc = ptep_force_prot(parent->mm, paddr, ptep, PROT_READ,
1231 PGSTE_VSIE_BIT);
1232 if (!rc)
1233 gmap_insert_rmap(sg, vmaddr, rmap);
1234 spin_unlock(&sg->guest_table_lock);
1235 gmap_pte_op_end(ptl);
1236 }
1237 radix_tree_preload_end();
1238 if (rc) {
1239 kfree(rmap);
1240 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, PROT_READ);
1241 if (rc)
1242 return rc;
1243 continue;
1244 }
1245 paddr += PAGE_SIZE;
1246 len -= PAGE_SIZE;
1247 }
1248 return 0;
1249}
1250
1251#define _SHADOW_RMAP_MASK 0x7
1252#define _SHADOW_RMAP_REGION1 0x5
1253#define _SHADOW_RMAP_REGION2 0x4
1254#define _SHADOW_RMAP_REGION3 0x3
1255#define _SHADOW_RMAP_SEGMENT 0x2
1256#define _SHADOW_RMAP_PGTABLE 0x1
1257
1258/**
1259 * gmap_idte_one - invalidate a single region or segment table entry
1260 * @asce: region or segment table *origin* + table-type bits
1261 * @vaddr: virtual address to identify the table entry to flush
1262 *
1263 * The invalid bit of a single region or segment table entry is set
1264 * and the associated TLB entries depending on the entry are flushed.
1265 * The table-type of the @asce identifies the portion of the @vaddr
1266 * that is used as the invalidation index.
1267 */
1268static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
1269{
1270 asm volatile(
1271 " .insn rrf,0xb98e0000,%0,%1,0,0"
1272 : : "a" (asce), "a" (vaddr) : "cc", "memory");
1273}
1274
1275/**
1276 * gmap_unshadow_page - remove a page from a shadow page table
1277 * @sg: pointer to the shadow guest address space structure
1278 * @raddr: rmap address in the shadow guest address space
1279 *
1280 * Called with the sg->guest_table_lock
1281 */
1282static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
1283{
1284 unsigned long *table;
1285
1286 BUG_ON(!gmap_is_shadow(sg));
1287 table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
1288 if (!table || *table & _PAGE_INVALID)
1289 return;
1290 gmap_call_notifier(sg, raddr, raddr + _PAGE_SIZE - 1);
1291 ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
1292}
1293
1294/**
1295 * __gmap_unshadow_pgt - remove all entries from a shadow page table
1296 * @sg: pointer to the shadow guest address space structure
1297 * @raddr: rmap address in the shadow guest address space
1298 * @pgt: pointer to the start of a shadow page table
1299 *
1300 * Called with the sg->guest_table_lock
1301 */
1302static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
1303 unsigned long *pgt)
1304{
1305 int i;
1306
1307 BUG_ON(!gmap_is_shadow(sg));
1308 for (i = 0; i < _PAGE_ENTRIES; i++, raddr += _PAGE_SIZE)
1309 pgt[i] = _PAGE_INVALID;
1310}
1311
1312/**
1313 * gmap_unshadow_pgt - remove a shadow page table from a segment entry
1314 * @sg: pointer to the shadow guest address space structure
1315 * @raddr: address in the shadow guest address space
1316 *
1317 * Called with the sg->guest_table_lock
1318 */
1319static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
1320{
1321 unsigned long sto, *ste, *pgt;
1322 struct page *page;
1323
1324 BUG_ON(!gmap_is_shadow(sg));
1325 ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
1326 if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
1327 return;
1328 gmap_call_notifier(sg, raddr, raddr + _SEGMENT_SIZE - 1);
1329 sto = (unsigned long) (ste - ((raddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT));
1330 gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
1331 pgt = (unsigned long *)(*ste & _SEGMENT_ENTRY_ORIGIN);
1332 *ste = _SEGMENT_ENTRY_EMPTY;
1333 __gmap_unshadow_pgt(sg, raddr, pgt);
1334 /* Free page table */
1335 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1336 list_del(&page->lru);
1337 page_table_free_pgste(page);
1338}
1339
1340/**
1341 * __gmap_unshadow_sgt - remove all entries from a shadow segment table
1342 * @sg: pointer to the shadow guest address space structure
1343 * @raddr: rmap address in the shadow guest address space
1344 * @sgt: pointer to the start of a shadow segment table
1345 *
1346 * Called with the sg->guest_table_lock
1347 */
1348static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
1349 unsigned long *sgt)
1350{
1351 unsigned long *pgt;
1352 struct page *page;
1353 int i;
1354
1355 BUG_ON(!gmap_is_shadow(sg));
1356 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
1357 if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
1358 continue;
1359 pgt = (unsigned long *)(sgt[i] & _REGION_ENTRY_ORIGIN);
1360 sgt[i] = _SEGMENT_ENTRY_EMPTY;
1361 __gmap_unshadow_pgt(sg, raddr, pgt);
1362 /* Free page table */
1363 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1364 list_del(&page->lru);
1365 page_table_free_pgste(page);
1366 }
1367}
1368
1369/**
1370 * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
1371 * @sg: pointer to the shadow guest address space structure
1372 * @raddr: rmap address in the shadow guest address space
1373 *
1374 * Called with the shadow->guest_table_lock
1375 */
1376static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
1377{
1378 unsigned long r3o, *r3e, *sgt;
1379 struct page *page;
1380
1381 BUG_ON(!gmap_is_shadow(sg));
1382 r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
1383 if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
1384 return;
1385 gmap_call_notifier(sg, raddr, raddr + _REGION3_SIZE - 1);
1386 r3o = (unsigned long) (r3e - ((raddr & _REGION3_INDEX) >> _REGION3_SHIFT));
1387 gmap_idte_one(r3o | _ASCE_TYPE_REGION3, raddr);
1388 sgt = (unsigned long *)(*r3e & _REGION_ENTRY_ORIGIN);
1389 *r3e = _REGION3_ENTRY_EMPTY;
1390 __gmap_unshadow_sgt(sg, raddr, sgt);
1391 /* Free segment table */
1392 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1393 list_del(&page->lru);
1394 __free_pages(page, CRST_ALLOC_ORDER);
1395}
1396
1397/**
1398 * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
1399 * @sg: pointer to the shadow guest address space structure
1400 * @raddr: address in the shadow guest address space
1401 * @r3t: pointer to the start of a shadow region-3 table
1402 *
1403 * Called with the sg->guest_table_lock
1404 */
1405static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
1406 unsigned long *r3t)
1407{
1408 unsigned long *sgt;
1409 struct page *page;
1410 int i;
1411
1412 BUG_ON(!gmap_is_shadow(sg));
1413 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
1414 if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
1415 continue;
1416 sgt = (unsigned long *)(r3t[i] & _REGION_ENTRY_ORIGIN);
1417 r3t[i] = _REGION3_ENTRY_EMPTY;
1418 __gmap_unshadow_sgt(sg, raddr, sgt);
1419 /* Free segment table */
1420 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1421 list_del(&page->lru);
1422 __free_pages(page, CRST_ALLOC_ORDER);
1423 }
1424}
1425
1426/**
1427 * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
1428 * @sg: pointer to the shadow guest address space structure
1429 * @raddr: rmap address in the shadow guest address space
1430 *
1431 * Called with the sg->guest_table_lock
1432 */
1433static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
1434{
1435 unsigned long r2o, *r2e, *r3t;
1436 struct page *page;
1437
1438 BUG_ON(!gmap_is_shadow(sg));
1439 r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
1440 if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
1441 return;
1442 gmap_call_notifier(sg, raddr, raddr + _REGION2_SIZE - 1);
1443 r2o = (unsigned long) (r2e - ((raddr & _REGION2_INDEX) >> _REGION2_SHIFT));
1444 gmap_idte_one(r2o | _ASCE_TYPE_REGION2, raddr);
1445 r3t = (unsigned long *)(*r2e & _REGION_ENTRY_ORIGIN);
1446 *r2e = _REGION2_ENTRY_EMPTY;
1447 __gmap_unshadow_r3t(sg, raddr, r3t);
1448 /* Free region 3 table */
1449 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1450 list_del(&page->lru);
1451 __free_pages(page, CRST_ALLOC_ORDER);
1452}
1453
1454/**
1455 * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
1456 * @sg: pointer to the shadow guest address space structure
1457 * @raddr: rmap address in the shadow guest address space
1458 * @r2t: pointer to the start of a shadow region-2 table
1459 *
1460 * Called with the sg->guest_table_lock
1461 */
1462static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
1463 unsigned long *r2t)
1464{
1465 unsigned long *r3t;
1466 struct page *page;
1467 int i;
1468
1469 BUG_ON(!gmap_is_shadow(sg));
1470 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
1471 if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
1472 continue;
1473 r3t = (unsigned long *)(r2t[i] & _REGION_ENTRY_ORIGIN);
1474 r2t[i] = _REGION2_ENTRY_EMPTY;
1475 __gmap_unshadow_r3t(sg, raddr, r3t);
1476 /* Free region 3 table */
1477 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1478 list_del(&page->lru);
1479 __free_pages(page, CRST_ALLOC_ORDER);
1480 }
1481}
1482
1483/**
1484 * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
1485 * @sg: pointer to the shadow guest address space structure
1486 * @raddr: rmap address in the shadow guest address space
1487 *
1488 * Called with the sg->guest_table_lock
1489 */
1490static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
1491{
1492 unsigned long r1o, *r1e, *r2t;
1493 struct page *page;
1494
1495 BUG_ON(!gmap_is_shadow(sg));
1496 r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
1497 if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
1498 return;
1499 gmap_call_notifier(sg, raddr, raddr + _REGION1_SIZE - 1);
1500 r1o = (unsigned long) (r1e - ((raddr & _REGION1_INDEX) >> _REGION1_SHIFT));
1501 gmap_idte_one(r1o | _ASCE_TYPE_REGION1, raddr);
1502 r2t = (unsigned long *)(*r1e & _REGION_ENTRY_ORIGIN);
1503 *r1e = _REGION1_ENTRY_EMPTY;
1504 __gmap_unshadow_r2t(sg, raddr, r2t);
1505 /* Free region 2 table */
1506 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1507 list_del(&page->lru);
1508 __free_pages(page, CRST_ALLOC_ORDER);
1509}
1510
1511/**
1512 * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
1513 * @sg: pointer to the shadow guest address space structure
1514 * @raddr: rmap address in the shadow guest address space
1515 * @r1t: pointer to the start of a shadow region-1 table
1516 *
1517 * Called with the shadow->guest_table_lock
1518 */
1519static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
1520 unsigned long *r1t)
1521{
1522 unsigned long asce, *r2t;
1523 struct page *page;
1524 int i;
1525
1526 BUG_ON(!gmap_is_shadow(sg));
1527 asce = (unsigned long) r1t | _ASCE_TYPE_REGION1;
1528 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION1_SIZE) {
1529 if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
1530 continue;
1531 r2t = (unsigned long *)(r1t[i] & _REGION_ENTRY_ORIGIN);
1532 __gmap_unshadow_r2t(sg, raddr, r2t);
1533 /* Clear entry and flush translation r1t -> r2t */
1534 gmap_idte_one(asce, raddr);
1535 r1t[i] = _REGION1_ENTRY_EMPTY;
1536 /* Free region 2 table */
1537 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1538 list_del(&page->lru);
1539 __free_pages(page, CRST_ALLOC_ORDER);
1540 }
1541}
1542
1543/**
1544 * gmap_unshadow - remove a shadow page table completely
1545 * @sg: pointer to the shadow guest address space structure
1546 *
1547 * Called with sg->guest_table_lock
1548 */
1549static void gmap_unshadow(struct gmap *sg)
1550{
1551 unsigned long *table;
1552
1553 BUG_ON(!gmap_is_shadow(sg));
1554 if (sg->removed)
1555 return;
1556 sg->removed = 1;
1557 gmap_call_notifier(sg, 0, -1UL);
1558 gmap_flush_tlb(sg);
1559 table = (unsigned long *)(sg->asce & _ASCE_ORIGIN);
1560 switch (sg->asce & _ASCE_TYPE_MASK) {
1561 case _ASCE_TYPE_REGION1:
1562 __gmap_unshadow_r1t(sg, 0, table);
1563 break;
1564 case _ASCE_TYPE_REGION2:
1565 __gmap_unshadow_r2t(sg, 0, table);
1566 break;
1567 case _ASCE_TYPE_REGION3:
1568 __gmap_unshadow_r3t(sg, 0, table);
1569 break;
1570 case _ASCE_TYPE_SEGMENT:
1571 __gmap_unshadow_sgt(sg, 0, table);
1572 break;
1573 }
1574}
1575
1576/**
1577 * gmap_find_shadow - find a specific asce in the list of shadow tables
1578 * @parent: pointer to the parent gmap
1579 * @asce: ASCE for which the shadow table is created
1580 * @edat_level: edat level to be used for the shadow translation
1581 *
1582 * Returns the pointer to a gmap if a shadow table with the given asce is
1583 * already available, ERR_PTR(-EAGAIN) if another one is just being created,
1584 * otherwise NULL
1585 */
1586static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
1587 int edat_level)
1588{
1589 struct gmap *sg;
1590
1591 list_for_each_entry(sg, &parent->children, list) {
1592 if (sg->orig_asce != asce || sg->edat_level != edat_level ||
1593 sg->removed)
1594 continue;
1595 if (!sg->initialized)
1596 return ERR_PTR(-EAGAIN);
1597 refcount_inc(&sg->ref_count);
1598 return sg;
1599 }
1600 return NULL;
1601}
1602
1603/**
1604 * gmap_shadow_valid - check if a shadow guest address space matches the
1605 * given properties and is still valid
1606 * @sg: pointer to the shadow guest address space structure
1607 * @asce: ASCE for which the shadow table is requested
1608 * @edat_level: edat level to be used for the shadow translation
1609 *
1610 * Returns 1 if the gmap shadow is still valid and matches the given
1611 * properties, the caller can continue using it. Returns 0 otherwise, the
1612 * caller has to request a new shadow gmap in this case.
1613 *
1614 */
1615int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
1616{
1617 if (sg->removed)
1618 return 0;
1619 return sg->orig_asce == asce && sg->edat_level == edat_level;
1620}
1621EXPORT_SYMBOL_GPL(gmap_shadow_valid);
1622
1623/**
1624 * gmap_shadow - create/find a shadow guest address space
1625 * @parent: pointer to the parent gmap
1626 * @asce: ASCE for which the shadow table is created
1627 * @edat_level: edat level to be used for the shadow translation
1628 *
1629 * The pages of the top level page table referred by the asce parameter
1630 * will be set to read-only and marked in the PGSTEs of the kvm process.
1631 * The shadow table will be removed automatically on any change to the
1632 * PTE mapping for the source table.
1633 *
1634 * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
1635 * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
1636 * parent gmap table could not be protected.
1637 */
1638struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
1639 int edat_level)
1640{
1641 struct gmap *sg, *new;
1642 unsigned long limit;
1643 int rc;
1644
1645 BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
1646 BUG_ON(gmap_is_shadow(parent));
1647 spin_lock(&parent->shadow_lock);
1648 sg = gmap_find_shadow(parent, asce, edat_level);
1649 spin_unlock(&parent->shadow_lock);
1650 if (sg)
1651 return sg;
1652 /* Create a new shadow gmap */
1653 limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
1654 if (asce & _ASCE_REAL_SPACE)
1655 limit = -1UL;
1656 new = gmap_alloc(limit);
1657 if (!new)
1658 return ERR_PTR(-ENOMEM);
1659 new->mm = parent->mm;
1660 new->parent = gmap_get(parent);
1661 new->orig_asce = asce;
1662 new->edat_level = edat_level;
1663 new->initialized = false;
1664 spin_lock(&parent->shadow_lock);
1665 /* Recheck if another CPU created the same shadow */
1666 sg = gmap_find_shadow(parent, asce, edat_level);
1667 if (sg) {
1668 spin_unlock(&parent->shadow_lock);
1669 gmap_free(new);
1670 return sg;
1671 }
1672 if (asce & _ASCE_REAL_SPACE) {
1673 /* only allow one real-space gmap shadow */
1674 list_for_each_entry(sg, &parent->children, list) {
1675 if (sg->orig_asce & _ASCE_REAL_SPACE) {
1676 spin_lock(&sg->guest_table_lock);
1677 gmap_unshadow(sg);
1678 spin_unlock(&sg->guest_table_lock);
1679 list_del(&sg->list);
1680 gmap_put(sg);
1681 break;
1682 }
1683 }
1684 }
1685 refcount_set(&new->ref_count, 2);
1686 list_add(&new->list, &parent->children);
1687 if (asce & _ASCE_REAL_SPACE) {
1688 /* nothing to protect, return right away */
1689 new->initialized = true;
1690 spin_unlock(&parent->shadow_lock);
1691 return new;
1692 }
1693 spin_unlock(&parent->shadow_lock);
1694 /* protect after insertion, so it will get properly invalidated */
1695 down_read(&parent->mm->mmap_sem);
1696 rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
1697 ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
1698 PROT_READ, GMAP_NOTIFY_SHADOW);
1699 up_read(&parent->mm->mmap_sem);
1700 spin_lock(&parent->shadow_lock);
1701 new->initialized = true;
1702 if (rc) {
1703 list_del(&new->list);
1704 gmap_free(new);
1705 new = ERR_PTR(rc);
1706 }
1707 spin_unlock(&parent->shadow_lock);
1708 return new;
1709}
1710EXPORT_SYMBOL_GPL(gmap_shadow);
1711
1712/**
1713 * gmap_shadow_r2t - create an empty shadow region 2 table
1714 * @sg: pointer to the shadow guest address space structure
1715 * @saddr: faulting address in the shadow gmap
1716 * @r2t: parent gmap address of the region 2 table to get shadowed
1717 * @fake: r2t references contiguous guest memory block, not a r2t
1718 *
1719 * The r2t parameter specifies the address of the source table. The
1720 * four pages of the source table are made read-only in the parent gmap
1721 * address space. A write to the source table area @r2t will automatically
1722 * remove the shadow r2 table and all of its decendents.
1723 *
1724 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1725 * shadow table structure is incomplete, -ENOMEM if out of memory and
1726 * -EFAULT if an address in the parent gmap could not be resolved.
1727 *
1728 * Called with sg->mm->mmap_sem in read.
1729 */
1730int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
1731 int fake)
1732{
1733 unsigned long raddr, origin, offset, len;
1734 unsigned long *s_r2t, *table;
1735 struct page *page;
1736 int rc;
1737
1738 BUG_ON(!gmap_is_shadow(sg));
1739 /* Allocate a shadow region second table */
1740 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1741 if (!page)
1742 return -ENOMEM;
1743 page->index = r2t & _REGION_ENTRY_ORIGIN;
1744 if (fake)
1745 page->index |= GMAP_SHADOW_FAKE_TABLE;
1746 s_r2t = (unsigned long *) page_to_phys(page);
1747 /* Install shadow region second table */
1748 spin_lock(&sg->guest_table_lock);
1749 table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
1750 if (!table) {
1751 rc = -EAGAIN; /* Race with unshadow */
1752 goto out_free;
1753 }
1754 if (!(*table & _REGION_ENTRY_INVALID)) {
1755 rc = 0; /* Already established */
1756 goto out_free;
1757 } else if (*table & _REGION_ENTRY_ORIGIN) {
1758 rc = -EAGAIN; /* Race with shadow */
1759 goto out_free;
1760 }
1761 crst_table_init(s_r2t, _REGION2_ENTRY_EMPTY);
1762 /* mark as invalid as long as the parent table is not protected */
1763 *table = (unsigned long) s_r2t | _REGION_ENTRY_LENGTH |
1764 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
1765 if (sg->edat_level >= 1)
1766 *table |= (r2t & _REGION_ENTRY_PROTECT);
1767 list_add(&page->lru, &sg->crst_list);
1768 if (fake) {
1769 /* nothing to protect for fake tables */
1770 *table &= ~_REGION_ENTRY_INVALID;
1771 spin_unlock(&sg->guest_table_lock);
1772 return 0;
1773 }
1774 spin_unlock(&sg->guest_table_lock);
1775 /* Make r2t read-only in parent gmap page table */
1776 raddr = (saddr & _REGION1_MASK) | _SHADOW_RMAP_REGION1;
1777 origin = r2t & _REGION_ENTRY_ORIGIN;
1778 offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1779 len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1780 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1781 spin_lock(&sg->guest_table_lock);
1782 if (!rc) {
1783 table = gmap_table_walk(sg, saddr, 4);
1784 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1785 (unsigned long) s_r2t)
1786 rc = -EAGAIN; /* Race with unshadow */
1787 else
1788 *table &= ~_REGION_ENTRY_INVALID;
1789 } else {
1790 gmap_unshadow_r2t(sg, raddr);
1791 }
1792 spin_unlock(&sg->guest_table_lock);
1793 return rc;
1794out_free:
1795 spin_unlock(&sg->guest_table_lock);
1796 __free_pages(page, CRST_ALLOC_ORDER);
1797 return rc;
1798}
1799EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
1800
1801/**
1802 * gmap_shadow_r3t - create a shadow region 3 table
1803 * @sg: pointer to the shadow guest address space structure
1804 * @saddr: faulting address in the shadow gmap
1805 * @r3t: parent gmap address of the region 3 table to get shadowed
1806 * @fake: r3t references contiguous guest memory block, not a r3t
1807 *
1808 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1809 * shadow table structure is incomplete, -ENOMEM if out of memory and
1810 * -EFAULT if an address in the parent gmap could not be resolved.
1811 *
1812 * Called with sg->mm->mmap_sem in read.
1813 */
1814int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
1815 int fake)
1816{
1817 unsigned long raddr, origin, offset, len;
1818 unsigned long *s_r3t, *table;
1819 struct page *page;
1820 int rc;
1821
1822 BUG_ON(!gmap_is_shadow(sg));
1823 /* Allocate a shadow region second table */
1824 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1825 if (!page)
1826 return -ENOMEM;
1827 page->index = r3t & _REGION_ENTRY_ORIGIN;
1828 if (fake)
1829 page->index |= GMAP_SHADOW_FAKE_TABLE;
1830 s_r3t = (unsigned long *) page_to_phys(page);
1831 /* Install shadow region second table */
1832 spin_lock(&sg->guest_table_lock);
1833 table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
1834 if (!table) {
1835 rc = -EAGAIN; /* Race with unshadow */
1836 goto out_free;
1837 }
1838 if (!(*table & _REGION_ENTRY_INVALID)) {
1839 rc = 0; /* Already established */
1840 goto out_free;
1841 } else if (*table & _REGION_ENTRY_ORIGIN) {
1842 rc = -EAGAIN; /* Race with shadow */
1843 }
1844 crst_table_init(s_r3t, _REGION3_ENTRY_EMPTY);
1845 /* mark as invalid as long as the parent table is not protected */
1846 *table = (unsigned long) s_r3t | _REGION_ENTRY_LENGTH |
1847 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
1848 if (sg->edat_level >= 1)
1849 *table |= (r3t & _REGION_ENTRY_PROTECT);
1850 list_add(&page->lru, &sg->crst_list);
1851 if (fake) {
1852 /* nothing to protect for fake tables */
1853 *table &= ~_REGION_ENTRY_INVALID;
1854 spin_unlock(&sg->guest_table_lock);
1855 return 0;
1856 }
1857 spin_unlock(&sg->guest_table_lock);
1858 /* Make r3t read-only in parent gmap page table */
1859 raddr = (saddr & _REGION2_MASK) | _SHADOW_RMAP_REGION2;
1860 origin = r3t & _REGION_ENTRY_ORIGIN;
1861 offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1862 len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1863 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1864 spin_lock(&sg->guest_table_lock);
1865 if (!rc) {
1866 table = gmap_table_walk(sg, saddr, 3);
1867 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1868 (unsigned long) s_r3t)
1869 rc = -EAGAIN; /* Race with unshadow */
1870 else
1871 *table &= ~_REGION_ENTRY_INVALID;
1872 } else {
1873 gmap_unshadow_r3t(sg, raddr);
1874 }
1875 spin_unlock(&sg->guest_table_lock);
1876 return rc;
1877out_free:
1878 spin_unlock(&sg->guest_table_lock);
1879 __free_pages(page, CRST_ALLOC_ORDER);
1880 return rc;
1881}
1882EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
1883
1884/**
1885 * gmap_shadow_sgt - create a shadow segment table
1886 * @sg: pointer to the shadow guest address space structure
1887 * @saddr: faulting address in the shadow gmap
1888 * @sgt: parent gmap address of the segment table to get shadowed
1889 * @fake: sgt references contiguous guest memory block, not a sgt
1890 *
1891 * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
1892 * shadow table structure is incomplete, -ENOMEM if out of memory and
1893 * -EFAULT if an address in the parent gmap could not be resolved.
1894 *
1895 * Called with sg->mm->mmap_sem in read.
1896 */
1897int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
1898 int fake)
1899{
1900 unsigned long raddr, origin, offset, len;
1901 unsigned long *s_sgt, *table;
1902 struct page *page;
1903 int rc;
1904
1905 BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
1906 /* Allocate a shadow segment table */
1907 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1908 if (!page)
1909 return -ENOMEM;
1910 page->index = sgt & _REGION_ENTRY_ORIGIN;
1911 if (fake)
1912 page->index |= GMAP_SHADOW_FAKE_TABLE;
1913 s_sgt = (unsigned long *) page_to_phys(page);
1914 /* Install shadow region second table */
1915 spin_lock(&sg->guest_table_lock);
1916 table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
1917 if (!table) {
1918 rc = -EAGAIN; /* Race with unshadow */
1919 goto out_free;
1920 }
1921 if (!(*table & _REGION_ENTRY_INVALID)) {
1922 rc = 0; /* Already established */
1923 goto out_free;
1924 } else if (*table & _REGION_ENTRY_ORIGIN) {
1925 rc = -EAGAIN; /* Race with shadow */
1926 goto out_free;
1927 }
1928 crst_table_init(s_sgt, _SEGMENT_ENTRY_EMPTY);
1929 /* mark as invalid as long as the parent table is not protected */
1930 *table = (unsigned long) s_sgt | _REGION_ENTRY_LENGTH |
1931 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
1932 if (sg->edat_level >= 1)
1933 *table |= sgt & _REGION_ENTRY_PROTECT;
1934 list_add(&page->lru, &sg->crst_list);
1935 if (fake) {
1936 /* nothing to protect for fake tables */
1937 *table &= ~_REGION_ENTRY_INVALID;
1938 spin_unlock(&sg->guest_table_lock);
1939 return 0;
1940 }
1941 spin_unlock(&sg->guest_table_lock);
1942 /* Make sgt read-only in parent gmap page table */
1943 raddr = (saddr & _REGION3_MASK) | _SHADOW_RMAP_REGION3;
1944 origin = sgt & _REGION_ENTRY_ORIGIN;
1945 offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1946 len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1947 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1948 spin_lock(&sg->guest_table_lock);
1949 if (!rc) {
1950 table = gmap_table_walk(sg, saddr, 2);
1951 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1952 (unsigned long) s_sgt)
1953 rc = -EAGAIN; /* Race with unshadow */
1954 else
1955 *table &= ~_REGION_ENTRY_INVALID;
1956 } else {
1957 gmap_unshadow_sgt(sg, raddr);
1958 }
1959 spin_unlock(&sg->guest_table_lock);
1960 return rc;
1961out_free:
1962 spin_unlock(&sg->guest_table_lock);
1963 __free_pages(page, CRST_ALLOC_ORDER);
1964 return rc;
1965}
1966EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
1967
1968/**
1969 * gmap_shadow_lookup_pgtable - find a shadow page table
1970 * @sg: pointer to the shadow guest address space structure
1971 * @saddr: the address in the shadow aguest address space
1972 * @pgt: parent gmap address of the page table to get shadowed
1973 * @dat_protection: if the pgtable is marked as protected by dat
1974 * @fake: pgt references contiguous guest memory block, not a pgtable
1975 *
1976 * Returns 0 if the shadow page table was found and -EAGAIN if the page
1977 * table was not found.
1978 *
1979 * Called with sg->mm->mmap_sem in read.
1980 */
1981int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
1982 unsigned long *pgt, int *dat_protection,
1983 int *fake)
1984{
1985 unsigned long *table;
1986 struct page *page;
1987 int rc;
1988
1989 BUG_ON(!gmap_is_shadow(sg));
1990 spin_lock(&sg->guest_table_lock);
1991 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1992 if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
1993 /* Shadow page tables are full pages (pte+pgste) */
1994 page = pfn_to_page(*table >> PAGE_SHIFT);
1995 *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
1996 *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
1997 *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
1998 rc = 0;
1999 } else {
2000 rc = -EAGAIN;
2001 }
2002 spin_unlock(&sg->guest_table_lock);
2003 return rc;
2004
2005}
2006EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
2007
2008/**
2009 * gmap_shadow_pgt - instantiate a shadow page table
2010 * @sg: pointer to the shadow guest address space structure
2011 * @saddr: faulting address in the shadow gmap
2012 * @pgt: parent gmap address of the page table to get shadowed
2013 * @fake: pgt references contiguous guest memory block, not a pgtable
2014 *
2015 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2016 * shadow table structure is incomplete, -ENOMEM if out of memory,
2017 * -EFAULT if an address in the parent gmap could not be resolved and
2018 *
2019 * Called with gmap->mm->mmap_sem in read
2020 */
2021int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
2022 int fake)
2023{
2024 unsigned long raddr, origin;
2025 unsigned long *s_pgt, *table;
2026 struct page *page;
2027 int rc;
2028
2029 BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
2030 /* Allocate a shadow page table */
2031 page = page_table_alloc_pgste(sg->mm);
2032 if (!page)
2033 return -ENOMEM;
2034 page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
2035 if (fake)
2036 page->index |= GMAP_SHADOW_FAKE_TABLE;
2037 s_pgt = (unsigned long *) page_to_phys(page);
2038 /* Install shadow page table */
2039 spin_lock(&sg->guest_table_lock);
2040 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
2041 if (!table) {
2042 rc = -EAGAIN; /* Race with unshadow */
2043 goto out_free;
2044 }
2045 if (!(*table & _SEGMENT_ENTRY_INVALID)) {
2046 rc = 0; /* Already established */
2047 goto out_free;
2048 } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
2049 rc = -EAGAIN; /* Race with shadow */
2050 goto out_free;
2051 }
2052 /* mark as invalid as long as the parent table is not protected */
2053 *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
2054 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
2055 list_add(&page->lru, &sg->pt_list);
2056 if (fake) {
2057 /* nothing to protect for fake tables */
2058 *table &= ~_SEGMENT_ENTRY_INVALID;
2059 spin_unlock(&sg->guest_table_lock);
2060 return 0;
2061 }
2062 spin_unlock(&sg->guest_table_lock);
2063 /* Make pgt read-only in parent gmap page table (not the pgste) */
2064 raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
2065 origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
2066 rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
2067 spin_lock(&sg->guest_table_lock);
2068 if (!rc) {
2069 table = gmap_table_walk(sg, saddr, 1);
2070 if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
2071 (unsigned long) s_pgt)
2072 rc = -EAGAIN; /* Race with unshadow */
2073 else
2074 *table &= ~_SEGMENT_ENTRY_INVALID;
2075 } else {
2076 gmap_unshadow_pgt(sg, raddr);
2077 }
2078 spin_unlock(&sg->guest_table_lock);
2079 return rc;
2080out_free:
2081 spin_unlock(&sg->guest_table_lock);
2082 page_table_free_pgste(page);
2083 return rc;
2084
2085}
2086EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
2087
2088/**
2089 * gmap_shadow_page - create a shadow page mapping
2090 * @sg: pointer to the shadow guest address space structure
2091 * @saddr: faulting address in the shadow gmap
2092 * @pte: pte in parent gmap address space to get shadowed
2093 *
2094 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2095 * shadow table structure is incomplete, -ENOMEM if out of memory and
2096 * -EFAULT if an address in the parent gmap could not be resolved.
2097 *
2098 * Called with sg->mm->mmap_sem in read.
2099 */
2100int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
2101{
2102 struct gmap *parent;
2103 struct gmap_rmap *rmap;
2104 unsigned long vmaddr, paddr;
2105 spinlock_t *ptl;
2106 pte_t *sptep, *tptep;
2107 int prot;
2108 int rc;
2109
2110 BUG_ON(!gmap_is_shadow(sg));
2111 parent = sg->parent;
2112 prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
2113
2114 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
2115 if (!rmap)
2116 return -ENOMEM;
2117 rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
2118
2119 while (1) {
2120 paddr = pte_val(pte) & PAGE_MASK;
2121 vmaddr = __gmap_translate(parent, paddr);
2122 if (IS_ERR_VALUE(vmaddr)) {
2123 rc = vmaddr;
2124 break;
2125 }
2126 rc = radix_tree_preload(GFP_KERNEL);
2127 if (rc)
2128 break;
2129 rc = -EAGAIN;
2130 sptep = gmap_pte_op_walk(parent, paddr, &ptl);
2131 if (sptep) {
2132 spin_lock(&sg->guest_table_lock);
2133 /* Get page table pointer */
2134 tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
2135 if (!tptep) {
2136 spin_unlock(&sg->guest_table_lock);
2137 gmap_pte_op_end(ptl);
2138 radix_tree_preload_end();
2139 break;
2140 }
2141 rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
2142 if (rc > 0) {
2143 /* Success and a new mapping */
2144 gmap_insert_rmap(sg, vmaddr, rmap);
2145 rmap = NULL;
2146 rc = 0;
2147 }
2148 gmap_pte_op_end(ptl);
2149 spin_unlock(&sg->guest_table_lock);
2150 }
2151 radix_tree_preload_end();
2152 if (!rc)
2153 break;
2154 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
2155 if (rc)
2156 break;
2157 }
2158 kfree(rmap);
2159 return rc;
2160}
2161EXPORT_SYMBOL_GPL(gmap_shadow_page);
2162
2163/**
2164 * gmap_shadow_notify - handle notifications for shadow gmap
2165 *
2166 * Called with sg->parent->shadow_lock.
2167 */
2168static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
2169 unsigned long gaddr)
2170{
2171 struct gmap_rmap *rmap, *rnext, *head;
2172 unsigned long start, end, bits, raddr;
2173
2174 BUG_ON(!gmap_is_shadow(sg));
2175
2176 spin_lock(&sg->guest_table_lock);
2177 if (sg->removed) {
2178 spin_unlock(&sg->guest_table_lock);
2179 return;
2180 }
2181 /* Check for top level table */
2182 start = sg->orig_asce & _ASCE_ORIGIN;
2183 end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE;
2184 if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
2185 gaddr < end) {
2186 /* The complete shadow table has to go */
2187 gmap_unshadow(sg);
2188 spin_unlock(&sg->guest_table_lock);
2189 list_del(&sg->list);
2190 gmap_put(sg);
2191 return;
2192 }
2193 /* Remove the page table tree from on specific entry */
2194 head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
2195 gmap_for_each_rmap_safe(rmap, rnext, head) {
2196 bits = rmap->raddr & _SHADOW_RMAP_MASK;
2197 raddr = rmap->raddr ^ bits;
2198 switch (bits) {
2199 case _SHADOW_RMAP_REGION1:
2200 gmap_unshadow_r2t(sg, raddr);
2201 break;
2202 case _SHADOW_RMAP_REGION2:
2203 gmap_unshadow_r3t(sg, raddr);
2204 break;
2205 case _SHADOW_RMAP_REGION3:
2206 gmap_unshadow_sgt(sg, raddr);
2207 break;
2208 case _SHADOW_RMAP_SEGMENT:
2209 gmap_unshadow_pgt(sg, raddr);
2210 break;
2211 case _SHADOW_RMAP_PGTABLE:
2212 gmap_unshadow_page(sg, raddr);
2213 break;
2214 }
2215 kfree(rmap);
2216 }
2217 spin_unlock(&sg->guest_table_lock);
2218}
2219
2220/**
2221 * ptep_notify - call all invalidation callbacks for a specific pte.
2222 * @mm: pointer to the process mm_struct
2223 * @addr: virtual address in the process address space
2224 * @pte: pointer to the page table entry
2225 * @bits: bits from the pgste that caused the notify call
2226 *
2227 * This function is assumed to be called with the page table lock held
2228 * for the pte to notify.
2229 */
2230void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
2231 pte_t *pte, unsigned long bits)
2232{
2233 unsigned long offset, gaddr = 0;
2234 unsigned long *table;
2235 struct gmap *gmap, *sg, *next;
2236
2237 offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
2238 offset = offset * (PAGE_SIZE / sizeof(pte_t));
2239 rcu_read_lock();
2240 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2241 spin_lock(&gmap->guest_table_lock);
2242 table = radix_tree_lookup(&gmap->host_to_guest,
2243 vmaddr >> PMD_SHIFT);
2244 if (table)
2245 gaddr = __gmap_segment_gaddr(table) + offset;
2246 spin_unlock(&gmap->guest_table_lock);
2247 if (!table)
2248 continue;
2249
2250 if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
2251 spin_lock(&gmap->shadow_lock);
2252 list_for_each_entry_safe(sg, next,
2253 &gmap->children, list)
2254 gmap_shadow_notify(sg, vmaddr, gaddr);
2255 spin_unlock(&gmap->shadow_lock);
2256 }
2257 if (bits & PGSTE_IN_BIT)
2258 gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
2259 }
2260 rcu_read_unlock();
2261}
2262EXPORT_SYMBOL_GPL(ptep_notify);
2263
2264static void pmdp_notify_gmap(struct gmap *gmap, pmd_t *pmdp,
2265 unsigned long gaddr)
2266{
2267 pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_IN;
2268 gmap_call_notifier(gmap, gaddr, gaddr + HPAGE_SIZE - 1);
2269}
2270
2271/**
2272 * gmap_pmdp_xchg - exchange a gmap pmd with another
2273 * @gmap: pointer to the guest address space structure
2274 * @pmdp: pointer to the pmd entry
2275 * @new: replacement entry
2276 * @gaddr: the affected guest address
2277 *
2278 * This function is assumed to be called with the guest_table_lock
2279 * held.
2280 */
2281static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *pmdp, pmd_t new,
2282 unsigned long gaddr)
2283{
2284 gaddr &= HPAGE_MASK;
2285 pmdp_notify_gmap(gmap, pmdp, gaddr);
2286 pmd_val(new) &= ~_SEGMENT_ENTRY_GMAP_IN;
2287 if (MACHINE_HAS_TLB_GUEST)
2288 __pmdp_idte(gaddr, (pmd_t *)pmdp, IDTE_GUEST_ASCE, gmap->asce,
2289 IDTE_GLOBAL);
2290 else if (MACHINE_HAS_IDTE)
2291 __pmdp_idte(gaddr, (pmd_t *)pmdp, 0, 0, IDTE_GLOBAL);
2292 else
2293 __pmdp_csp(pmdp);
2294 *pmdp = new;
2295}
2296
2297static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
2298 int purge)
2299{
2300 pmd_t *pmdp;
2301 struct gmap *gmap;
2302 unsigned long gaddr;
2303
2304 rcu_read_lock();
2305 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2306 spin_lock(&gmap->guest_table_lock);
2307 pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
2308 vmaddr >> PMD_SHIFT);
2309 if (pmdp) {
2310 gaddr = __gmap_segment_gaddr((unsigned long *)pmdp);
2311 pmdp_notify_gmap(gmap, pmdp, gaddr);
2312 WARN_ON(pmd_val(*pmdp) & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2313 _SEGMENT_ENTRY_GMAP_UC));
2314 if (purge)
2315 __pmdp_csp(pmdp);
2316 pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
2317 }
2318 spin_unlock(&gmap->guest_table_lock);
2319 }
2320 rcu_read_unlock();
2321}
2322
2323/**
2324 * gmap_pmdp_invalidate - invalidate all affected guest pmd entries without
2325 * flushing
2326 * @mm: pointer to the process mm_struct
2327 * @vmaddr: virtual address in the process address space
2328 */
2329void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr)
2330{
2331 gmap_pmdp_clear(mm, vmaddr, 0);
2332}
2333EXPORT_SYMBOL_GPL(gmap_pmdp_invalidate);
2334
2335/**
2336 * gmap_pmdp_csp - csp all affected guest pmd entries
2337 * @mm: pointer to the process mm_struct
2338 * @vmaddr: virtual address in the process address space
2339 */
2340void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr)
2341{
2342 gmap_pmdp_clear(mm, vmaddr, 1);
2343}
2344EXPORT_SYMBOL_GPL(gmap_pmdp_csp);
2345
2346/**
2347 * gmap_pmdp_idte_local - invalidate and clear a guest pmd entry
2348 * @mm: pointer to the process mm_struct
2349 * @vmaddr: virtual address in the process address space
2350 */
2351void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
2352{
2353 unsigned long *entry, gaddr;
2354 struct gmap *gmap;
2355 pmd_t *pmdp;
2356
2357 rcu_read_lock();
2358 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2359 spin_lock(&gmap->guest_table_lock);
2360 entry = radix_tree_delete(&gmap->host_to_guest,
2361 vmaddr >> PMD_SHIFT);
2362 if (entry) {
2363 pmdp = (pmd_t *)entry;
2364 gaddr = __gmap_segment_gaddr(entry);
2365 pmdp_notify_gmap(gmap, pmdp, gaddr);
2366 WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2367 _SEGMENT_ENTRY_GMAP_UC));
2368 if (MACHINE_HAS_TLB_GUEST)
2369 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2370 gmap->asce, IDTE_LOCAL);
2371 else if (MACHINE_HAS_IDTE)
2372 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_LOCAL);
2373 *entry = _SEGMENT_ENTRY_EMPTY;
2374 }
2375 spin_unlock(&gmap->guest_table_lock);
2376 }
2377 rcu_read_unlock();
2378}
2379EXPORT_SYMBOL_GPL(gmap_pmdp_idte_local);
2380
2381/**
2382 * gmap_pmdp_idte_global - invalidate and clear a guest pmd entry
2383 * @mm: pointer to the process mm_struct
2384 * @vmaddr: virtual address in the process address space
2385 */
2386void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
2387{
2388 unsigned long *entry, gaddr;
2389 struct gmap *gmap;
2390 pmd_t *pmdp;
2391
2392 rcu_read_lock();
2393 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2394 spin_lock(&gmap->guest_table_lock);
2395 entry = radix_tree_delete(&gmap->host_to_guest,
2396 vmaddr >> PMD_SHIFT);
2397 if (entry) {
2398 pmdp = (pmd_t *)entry;
2399 gaddr = __gmap_segment_gaddr(entry);
2400 pmdp_notify_gmap(gmap, pmdp, gaddr);
2401 WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2402 _SEGMENT_ENTRY_GMAP_UC));
2403 if (MACHINE_HAS_TLB_GUEST)
2404 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2405 gmap->asce, IDTE_GLOBAL);
2406 else if (MACHINE_HAS_IDTE)
2407 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_GLOBAL);
2408 else
2409 __pmdp_csp(pmdp);
2410 *entry = _SEGMENT_ENTRY_EMPTY;
2411 }
2412 spin_unlock(&gmap->guest_table_lock);
2413 }
2414 rcu_read_unlock();
2415}
2416EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global);
2417
2418/**
2419 * gmap_test_and_clear_dirty_pmd - test and reset segment dirty status
2420 * @gmap: pointer to guest address space
2421 * @pmdp: pointer to the pmd to be tested
2422 * @gaddr: virtual address in the guest address space
2423 *
2424 * This function is assumed to be called with the guest_table_lock
2425 * held.
2426 */
2427static bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp,
2428 unsigned long gaddr)
2429{
2430 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
2431 return false;
2432
2433 /* Already protected memory, which did not change is clean */
2434 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT &&
2435 !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
2436 return false;
2437
2438 /* Clear UC indication and reset protection */
2439 pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_UC;
2440 gmap_protect_pmd(gmap, gaddr, pmdp, PROT_READ, 0);
2441 return true;
2442}
2443
2444/**
2445 * gmap_sync_dirty_log_pmd - set bitmap based on dirty status of segment
2446 * @gmap: pointer to guest address space
2447 * @bitmap: dirty bitmap for this pmd
2448 * @gaddr: virtual address in the guest address space
2449 * @vmaddr: virtual address in the host address space
2450 *
2451 * This function is assumed to be called with the guest_table_lock
2452 * held.
2453 */
2454void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
2455 unsigned long gaddr, unsigned long vmaddr)
2456{
2457 int i;
2458 pmd_t *pmdp;
2459 pte_t *ptep;
2460 spinlock_t *ptl;
2461
2462 pmdp = gmap_pmd_op_walk(gmap, gaddr);
2463 if (!pmdp)
2464 return;
2465
2466 if (pmd_large(*pmdp)) {
2467 if (gmap_test_and_clear_dirty_pmd(gmap, pmdp, gaddr))
2468 bitmap_fill(bitmap, _PAGE_ENTRIES);
2469 } else {
2470 for (i = 0; i < _PAGE_ENTRIES; i++, vmaddr += PAGE_SIZE) {
2471 ptep = pte_alloc_map_lock(gmap->mm, pmdp, vmaddr, &ptl);
2472 if (!ptep)
2473 continue;
2474 if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep))
2475 set_bit(i, bitmap);
2476 spin_unlock(ptl);
2477 }
2478 }
2479 gmap_pmd_op_end(gmap, pmdp);
2480}
2481EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
2482
2483static inline void thp_split_mm(struct mm_struct *mm)
2484{
2485#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2486 struct vm_area_struct *vma;
2487 unsigned long addr;
2488
2489 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
2490 for (addr = vma->vm_start;
2491 addr < vma->vm_end;
2492 addr += PAGE_SIZE)
2493 follow_page(vma, addr, FOLL_SPLIT);
2494 vma->vm_flags &= ~VM_HUGEPAGE;
2495 vma->vm_flags |= VM_NOHUGEPAGE;
2496 }
2497 mm->def_flags |= VM_NOHUGEPAGE;
2498#endif
2499}
2500
2501/*
2502 * Remove all empty zero pages from the mapping for lazy refaulting
2503 * - This must be called after mm->context.has_pgste is set, to avoid
2504 * future creation of zero pages
2505 * - This must be called after THP was enabled
2506 */
2507static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
2508 unsigned long end, struct mm_walk *walk)
2509{
2510 unsigned long addr;
2511
2512 for (addr = start; addr != end; addr += PAGE_SIZE) {
2513 pte_t *ptep;
2514 spinlock_t *ptl;
2515
2516 ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
2517 if (is_zero_pfn(pte_pfn(*ptep)))
2518 ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID));
2519 pte_unmap_unlock(ptep, ptl);
2520 }
2521 return 0;
2522}
2523
2524static const struct mm_walk_ops zap_zero_walk_ops = {
2525 .pmd_entry = __zap_zero_pages,
2526};
2527
2528/*
2529 * switch on pgstes for its userspace process (for kvm)
2530 */
2531int s390_enable_sie(void)
2532{
2533 struct mm_struct *mm = current->mm;
2534
2535 /* Do we have pgstes? if yes, we are done */
2536 if (mm_has_pgste(mm))
2537 return 0;
2538 /* Fail if the page tables are 2K */
2539 if (!mm_alloc_pgste(mm))
2540 return -EINVAL;
2541 down_write(&mm->mmap_sem);
2542 mm->context.has_pgste = 1;
2543 /* split thp mappings and disable thp for future mappings */
2544 thp_split_mm(mm);
2545 walk_page_range(mm, 0, TASK_SIZE, &zap_zero_walk_ops, NULL);
2546 up_write(&mm->mmap_sem);
2547 return 0;
2548}
2549EXPORT_SYMBOL_GPL(s390_enable_sie);
2550
2551/*
2552 * Enable storage key handling from now on and initialize the storage
2553 * keys with the default key.
2554 */
2555static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
2556 unsigned long next, struct mm_walk *walk)
2557{
2558 /* Clear storage key */
2559 ptep_zap_key(walk->mm, addr, pte);
2560 return 0;
2561}
2562
2563static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
2564 unsigned long hmask, unsigned long next,
2565 struct mm_walk *walk)
2566{
2567 pmd_t *pmd = (pmd_t *)pte;
2568 unsigned long start, end;
2569 struct page *page = pmd_page(*pmd);
2570
2571 /*
2572 * The write check makes sure we do not set a key on shared
2573 * memory. This is needed as the walker does not differentiate
2574 * between actual guest memory and the process executable or
2575 * shared libraries.
2576 */
2577 if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
2578 !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
2579 return 0;
2580
2581 start = pmd_val(*pmd) & HPAGE_MASK;
2582 end = start + HPAGE_SIZE - 1;
2583 __storage_key_init_range(start, end);
2584 set_bit(PG_arch_1, &page->flags);
2585 return 0;
2586}
2587
2588static const struct mm_walk_ops enable_skey_walk_ops = {
2589 .hugetlb_entry = __s390_enable_skey_hugetlb,
2590 .pte_entry = __s390_enable_skey_pte,
2591};
2592
2593int s390_enable_skey(void)
2594{
2595 struct mm_struct *mm = current->mm;
2596 struct vm_area_struct *vma;
2597 int rc = 0;
2598
2599 down_write(&mm->mmap_sem);
2600 if (mm_uses_skeys(mm))
2601 goto out_up;
2602
2603 mm->context.uses_skeys = 1;
2604 for (vma = mm->mmap; vma; vma = vma->vm_next) {
2605 if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
2606 MADV_UNMERGEABLE, &vma->vm_flags)) {
2607 mm->context.uses_skeys = 0;
2608 rc = -ENOMEM;
2609 goto out_up;
2610 }
2611 }
2612 mm->def_flags &= ~VM_MERGEABLE;
2613
2614 walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL);
2615
2616out_up:
2617 up_write(&mm->mmap_sem);
2618 return rc;
2619}
2620EXPORT_SYMBOL_GPL(s390_enable_skey);
2621
2622/*
2623 * Reset CMMA state, make all pages stable again.
2624 */
2625static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
2626 unsigned long next, struct mm_walk *walk)
2627{
2628 ptep_zap_unused(walk->mm, addr, pte, 1);
2629 return 0;
2630}
2631
2632static const struct mm_walk_ops reset_cmma_walk_ops = {
2633 .pte_entry = __s390_reset_cmma,
2634};
2635
2636void s390_reset_cmma(struct mm_struct *mm)
2637{
2638 down_write(&mm->mmap_sem);
2639 walk_page_range(mm, 0, TASK_SIZE, &reset_cmma_walk_ops, NULL);
2640 up_write(&mm->mmap_sem);
2641}
2642EXPORT_SYMBOL_GPL(s390_reset_cmma);