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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * KVM guest address space mapping code
4 *
5 * Copyright IBM Corp. 2007, 2020
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#include <linux/pgtable.h>
21
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 * @limit: maximum address of the gmap address space
31 *
32 * Returns a guest address space structure.
33 */
34static struct gmap *gmap_alloc(unsigned long limit)
35{
36 struct gmap *gmap;
37 struct page *page;
38 unsigned long *table;
39 unsigned long etype, atype;
40
41 if (limit < _REGION3_SIZE) {
42 limit = _REGION3_SIZE - 1;
43 atype = _ASCE_TYPE_SEGMENT;
44 etype = _SEGMENT_ENTRY_EMPTY;
45 } else if (limit < _REGION2_SIZE) {
46 limit = _REGION2_SIZE - 1;
47 atype = _ASCE_TYPE_REGION3;
48 etype = _REGION3_ENTRY_EMPTY;
49 } else if (limit < _REGION1_SIZE) {
50 limit = _REGION1_SIZE - 1;
51 atype = _ASCE_TYPE_REGION2;
52 etype = _REGION2_ENTRY_EMPTY;
53 } else {
54 limit = -1UL;
55 atype = _ASCE_TYPE_REGION1;
56 etype = _REGION1_ENTRY_EMPTY;
57 }
58 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL_ACCOUNT);
59 if (!gmap)
60 goto out;
61 INIT_LIST_HEAD(&gmap->crst_list);
62 INIT_LIST_HEAD(&gmap->children);
63 INIT_LIST_HEAD(&gmap->pt_list);
64 INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL_ACCOUNT);
65 INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC | __GFP_ACCOUNT);
66 INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC | __GFP_ACCOUNT);
67 spin_lock_init(&gmap->guest_table_lock);
68 spin_lock_init(&gmap->shadow_lock);
69 refcount_set(&gmap->ref_count, 1);
70 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
71 if (!page)
72 goto out_free;
73 page->index = 0;
74 list_add(&page->lru, &gmap->crst_list);
75 table = page_to_virt(page);
76 crst_table_init(table, etype);
77 gmap->table = table;
78 gmap->asce = atype | _ASCE_TABLE_LENGTH |
79 _ASCE_USER_BITS | __pa(table);
80 gmap->asce_end = limit;
81 return gmap;
82
83out_free:
84 kfree(gmap);
85out:
86 return NULL;
87}
88
89/**
90 * gmap_create - create a guest address space
91 * @mm: pointer to the parent mm_struct
92 * @limit: maximum size of the gmap address space
93 *
94 * Returns a guest address space structure.
95 */
96struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
97{
98 struct gmap *gmap;
99 unsigned long gmap_asce;
100
101 gmap = gmap_alloc(limit);
102 if (!gmap)
103 return NULL;
104 gmap->mm = mm;
105 spin_lock(&mm->context.lock);
106 list_add_rcu(&gmap->list, &mm->context.gmap_list);
107 if (list_is_singular(&mm->context.gmap_list))
108 gmap_asce = gmap->asce;
109 else
110 gmap_asce = -1UL;
111 WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
112 spin_unlock(&mm->context.lock);
113 return gmap;
114}
115EXPORT_SYMBOL_GPL(gmap_create);
116
117static void gmap_flush_tlb(struct gmap *gmap)
118{
119 if (MACHINE_HAS_IDTE)
120 __tlb_flush_idte(gmap->asce);
121 else
122 __tlb_flush_global();
123}
124
125static void gmap_radix_tree_free(struct radix_tree_root *root)
126{
127 struct radix_tree_iter iter;
128 unsigned long indices[16];
129 unsigned long index;
130 void __rcu **slot;
131 int i, nr;
132
133 /* A radix tree is freed by deleting all of its entries */
134 index = 0;
135 do {
136 nr = 0;
137 radix_tree_for_each_slot(slot, root, &iter, index) {
138 indices[nr] = iter.index;
139 if (++nr == 16)
140 break;
141 }
142 for (i = 0; i < nr; i++) {
143 index = indices[i];
144 radix_tree_delete(root, index);
145 }
146 } while (nr > 0);
147}
148
149static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
150{
151 struct gmap_rmap *rmap, *rnext, *head;
152 struct radix_tree_iter iter;
153 unsigned long indices[16];
154 unsigned long index;
155 void __rcu **slot;
156 int i, nr;
157
158 /* A radix tree is freed by deleting all of its entries */
159 index = 0;
160 do {
161 nr = 0;
162 radix_tree_for_each_slot(slot, root, &iter, index) {
163 indices[nr] = iter.index;
164 if (++nr == 16)
165 break;
166 }
167 for (i = 0; i < nr; i++) {
168 index = indices[i];
169 head = radix_tree_delete(root, index);
170 gmap_for_each_rmap_safe(rmap, rnext, head)
171 kfree(rmap);
172 }
173 } while (nr > 0);
174}
175
176/**
177 * gmap_free - free a guest address space
178 * @gmap: pointer to the guest address space structure
179 *
180 * No locks required. There are no references to this gmap anymore.
181 */
182static void gmap_free(struct gmap *gmap)
183{
184 struct page *page, *next;
185
186 /* Flush tlb of all gmaps (if not already done for shadows) */
187 if (!(gmap_is_shadow(gmap) && gmap->removed))
188 gmap_flush_tlb(gmap);
189 /* Free all segment & region tables. */
190 list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
191 __free_pages(page, CRST_ALLOC_ORDER);
192 gmap_radix_tree_free(&gmap->guest_to_host);
193 gmap_radix_tree_free(&gmap->host_to_guest);
194
195 /* Free additional data for a shadow gmap */
196 if (gmap_is_shadow(gmap)) {
197 /* Free all page tables. */
198 list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
199 page_table_free_pgste(page);
200 gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
201 /* Release reference to the parent */
202 gmap_put(gmap->parent);
203 }
204
205 kfree(gmap);
206}
207
208/**
209 * gmap_get - increase reference counter for guest address space
210 * @gmap: pointer to the guest address space structure
211 *
212 * Returns the gmap pointer
213 */
214struct gmap *gmap_get(struct gmap *gmap)
215{
216 refcount_inc(&gmap->ref_count);
217 return gmap;
218}
219EXPORT_SYMBOL_GPL(gmap_get);
220
221/**
222 * gmap_put - decrease reference counter for guest address space
223 * @gmap: pointer to the guest address space structure
224 *
225 * If the reference counter reaches zero the guest address space is freed.
226 */
227void gmap_put(struct gmap *gmap)
228{
229 if (refcount_dec_and_test(&gmap->ref_count))
230 gmap_free(gmap);
231}
232EXPORT_SYMBOL_GPL(gmap_put);
233
234/**
235 * gmap_remove - remove a guest address space but do not free it yet
236 * @gmap: pointer to the guest address space structure
237 */
238void gmap_remove(struct gmap *gmap)
239{
240 struct gmap *sg, *next;
241 unsigned long gmap_asce;
242
243 /* Remove all shadow gmaps linked to this gmap */
244 if (!list_empty(&gmap->children)) {
245 spin_lock(&gmap->shadow_lock);
246 list_for_each_entry_safe(sg, next, &gmap->children, list) {
247 list_del(&sg->list);
248 gmap_put(sg);
249 }
250 spin_unlock(&gmap->shadow_lock);
251 }
252 /* Remove gmap from the pre-mm list */
253 spin_lock(&gmap->mm->context.lock);
254 list_del_rcu(&gmap->list);
255 if (list_empty(&gmap->mm->context.gmap_list))
256 gmap_asce = 0;
257 else if (list_is_singular(&gmap->mm->context.gmap_list))
258 gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
259 struct gmap, list)->asce;
260 else
261 gmap_asce = -1UL;
262 WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
263 spin_unlock(&gmap->mm->context.lock);
264 synchronize_rcu();
265 /* Put reference */
266 gmap_put(gmap);
267}
268EXPORT_SYMBOL_GPL(gmap_remove);
269
270/**
271 * gmap_enable - switch primary space to the guest address space
272 * @gmap: pointer to the guest address space structure
273 */
274void gmap_enable(struct gmap *gmap)
275{
276 S390_lowcore.gmap = (unsigned long) gmap;
277}
278EXPORT_SYMBOL_GPL(gmap_enable);
279
280/**
281 * gmap_disable - switch back to the standard primary address space
282 * @gmap: pointer to the guest address space structure
283 */
284void gmap_disable(struct gmap *gmap)
285{
286 S390_lowcore.gmap = 0UL;
287}
288EXPORT_SYMBOL_GPL(gmap_disable);
289
290/**
291 * gmap_get_enabled - get a pointer to the currently enabled gmap
292 *
293 * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
294 */
295struct gmap *gmap_get_enabled(void)
296{
297 return (struct gmap *) S390_lowcore.gmap;
298}
299EXPORT_SYMBOL_GPL(gmap_get_enabled);
300
301/*
302 * gmap_alloc_table is assumed to be called with mmap_lock held
303 */
304static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
305 unsigned long init, unsigned long gaddr)
306{
307 struct page *page;
308 unsigned long *new;
309
310 /* since we dont free the gmap table until gmap_free we can unlock */
311 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
312 if (!page)
313 return -ENOMEM;
314 new = page_to_virt(page);
315 crst_table_init(new, init);
316 spin_lock(&gmap->guest_table_lock);
317 if (*table & _REGION_ENTRY_INVALID) {
318 list_add(&page->lru, &gmap->crst_list);
319 *table = __pa(new) | _REGION_ENTRY_LENGTH |
320 (*table & _REGION_ENTRY_TYPE_MASK);
321 page->index = gaddr;
322 page = NULL;
323 }
324 spin_unlock(&gmap->guest_table_lock);
325 if (page)
326 __free_pages(page, CRST_ALLOC_ORDER);
327 return 0;
328}
329
330/**
331 * __gmap_segment_gaddr - find virtual address from segment pointer
332 * @entry: pointer to a segment table entry in the guest address space
333 *
334 * Returns the virtual address in the guest address space for the segment
335 */
336static unsigned long __gmap_segment_gaddr(unsigned long *entry)
337{
338 struct page *page;
339 unsigned long offset;
340
341 offset = (unsigned long) entry / sizeof(unsigned long);
342 offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
343 page = pmd_pgtable_page((pmd_t *) entry);
344 return page->index + offset;
345}
346
347/**
348 * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
349 * @gmap: pointer to the guest address space structure
350 * @vmaddr: address in the host process address space
351 *
352 * Returns 1 if a TLB flush is required
353 */
354static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
355{
356 unsigned long *entry;
357 int flush = 0;
358
359 BUG_ON(gmap_is_shadow(gmap));
360 spin_lock(&gmap->guest_table_lock);
361 entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
362 if (entry) {
363 flush = (*entry != _SEGMENT_ENTRY_EMPTY);
364 *entry = _SEGMENT_ENTRY_EMPTY;
365 }
366 spin_unlock(&gmap->guest_table_lock);
367 return flush;
368}
369
370/**
371 * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
372 * @gmap: pointer to the guest address space structure
373 * @gaddr: address in the guest address space
374 *
375 * Returns 1 if a TLB flush is required
376 */
377static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
378{
379 unsigned long vmaddr;
380
381 vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
382 gaddr >> PMD_SHIFT);
383 return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
384}
385
386/**
387 * gmap_unmap_segment - unmap segment from the guest address space
388 * @gmap: pointer to the guest address space structure
389 * @to: address in the guest address space
390 * @len: length of the memory area to unmap
391 *
392 * Returns 0 if the unmap succeeded, -EINVAL if not.
393 */
394int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
395{
396 unsigned long off;
397 int flush;
398
399 BUG_ON(gmap_is_shadow(gmap));
400 if ((to | len) & (PMD_SIZE - 1))
401 return -EINVAL;
402 if (len == 0 || to + len < to)
403 return -EINVAL;
404
405 flush = 0;
406 mmap_write_lock(gmap->mm);
407 for (off = 0; off < len; off += PMD_SIZE)
408 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
409 mmap_write_unlock(gmap->mm);
410 if (flush)
411 gmap_flush_tlb(gmap);
412 return 0;
413}
414EXPORT_SYMBOL_GPL(gmap_unmap_segment);
415
416/**
417 * gmap_map_segment - map a segment to the guest address space
418 * @gmap: pointer to the guest address space structure
419 * @from: source address in the parent address space
420 * @to: target address in the guest address space
421 * @len: length of the memory area to map
422 *
423 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
424 */
425int gmap_map_segment(struct gmap *gmap, unsigned long from,
426 unsigned long to, unsigned long len)
427{
428 unsigned long off;
429 int flush;
430
431 BUG_ON(gmap_is_shadow(gmap));
432 if ((from | to | len) & (PMD_SIZE - 1))
433 return -EINVAL;
434 if (len == 0 || from + len < from || to + len < to ||
435 from + len - 1 > TASK_SIZE_MAX || to + len - 1 > gmap->asce_end)
436 return -EINVAL;
437
438 flush = 0;
439 mmap_write_lock(gmap->mm);
440 for (off = 0; off < len; off += PMD_SIZE) {
441 /* Remove old translation */
442 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
443 /* Store new translation */
444 if (radix_tree_insert(&gmap->guest_to_host,
445 (to + off) >> PMD_SHIFT,
446 (void *) from + off))
447 break;
448 }
449 mmap_write_unlock(gmap->mm);
450 if (flush)
451 gmap_flush_tlb(gmap);
452 if (off >= len)
453 return 0;
454 gmap_unmap_segment(gmap, to, len);
455 return -ENOMEM;
456}
457EXPORT_SYMBOL_GPL(gmap_map_segment);
458
459/**
460 * __gmap_translate - translate a guest address to a user space address
461 * @gmap: pointer to guest mapping meta data structure
462 * @gaddr: guest address
463 *
464 * Returns user space address which corresponds to the guest address or
465 * -EFAULT if no such mapping exists.
466 * This function does not establish potentially missing page table entries.
467 * The mmap_lock of the mm that belongs to the address space must be held
468 * when this function gets called.
469 *
470 * Note: Can also be called for shadow gmaps.
471 */
472unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
473{
474 unsigned long vmaddr;
475
476 vmaddr = (unsigned long)
477 radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
478 /* Note: guest_to_host is empty for a shadow gmap */
479 return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
480}
481EXPORT_SYMBOL_GPL(__gmap_translate);
482
483/**
484 * gmap_translate - translate a guest address to a user space address
485 * @gmap: pointer to guest mapping meta data structure
486 * @gaddr: guest address
487 *
488 * Returns user space address which corresponds to the guest address or
489 * -EFAULT if no such mapping exists.
490 * This function does not establish potentially missing page table entries.
491 */
492unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
493{
494 unsigned long rc;
495
496 mmap_read_lock(gmap->mm);
497 rc = __gmap_translate(gmap, gaddr);
498 mmap_read_unlock(gmap->mm);
499 return rc;
500}
501EXPORT_SYMBOL_GPL(gmap_translate);
502
503/**
504 * gmap_unlink - disconnect a page table from the gmap shadow tables
505 * @mm: pointer to the parent mm_struct
506 * @table: pointer to the host page table
507 * @vmaddr: vm address associated with the host page table
508 */
509void gmap_unlink(struct mm_struct *mm, unsigned long *table,
510 unsigned long vmaddr)
511{
512 struct gmap *gmap;
513 int flush;
514
515 rcu_read_lock();
516 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
517 flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
518 if (flush)
519 gmap_flush_tlb(gmap);
520 }
521 rcu_read_unlock();
522}
523
524static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *old, pmd_t new,
525 unsigned long gaddr);
526
527/**
528 * __gmap_link - set up shadow page tables to connect a host to a guest address
529 * @gmap: pointer to guest mapping meta data structure
530 * @gaddr: guest address
531 * @vmaddr: vm address
532 *
533 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
534 * if the vm address is already mapped to a different guest segment.
535 * The mmap_lock of the mm that belongs to the address space must be held
536 * when this function gets called.
537 */
538int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
539{
540 struct mm_struct *mm;
541 unsigned long *table;
542 spinlock_t *ptl;
543 pgd_t *pgd;
544 p4d_t *p4d;
545 pud_t *pud;
546 pmd_t *pmd;
547 u64 unprot;
548 int rc;
549
550 BUG_ON(gmap_is_shadow(gmap));
551 /* Create higher level tables in the gmap page table */
552 table = gmap->table;
553 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
554 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
555 if ((*table & _REGION_ENTRY_INVALID) &&
556 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
557 gaddr & _REGION1_MASK))
558 return -ENOMEM;
559 table = __va(*table & _REGION_ENTRY_ORIGIN);
560 }
561 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
562 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
563 if ((*table & _REGION_ENTRY_INVALID) &&
564 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
565 gaddr & _REGION2_MASK))
566 return -ENOMEM;
567 table = __va(*table & _REGION_ENTRY_ORIGIN);
568 }
569 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
570 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
571 if ((*table & _REGION_ENTRY_INVALID) &&
572 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
573 gaddr & _REGION3_MASK))
574 return -ENOMEM;
575 table = __va(*table & _REGION_ENTRY_ORIGIN);
576 }
577 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
578 /* Walk the parent mm page table */
579 mm = gmap->mm;
580 pgd = pgd_offset(mm, vmaddr);
581 VM_BUG_ON(pgd_none(*pgd));
582 p4d = p4d_offset(pgd, vmaddr);
583 VM_BUG_ON(p4d_none(*p4d));
584 pud = pud_offset(p4d, vmaddr);
585 VM_BUG_ON(pud_none(*pud));
586 /* large puds cannot yet be handled */
587 if (pud_large(*pud))
588 return -EFAULT;
589 pmd = pmd_offset(pud, vmaddr);
590 VM_BUG_ON(pmd_none(*pmd));
591 /* Are we allowed to use huge pages? */
592 if (pmd_large(*pmd) && !gmap->mm->context.allow_gmap_hpage_1m)
593 return -EFAULT;
594 /* Link gmap segment table entry location to page table. */
595 rc = radix_tree_preload(GFP_KERNEL_ACCOUNT);
596 if (rc)
597 return rc;
598 ptl = pmd_lock(mm, pmd);
599 spin_lock(&gmap->guest_table_lock);
600 if (*table == _SEGMENT_ENTRY_EMPTY) {
601 rc = radix_tree_insert(&gmap->host_to_guest,
602 vmaddr >> PMD_SHIFT, table);
603 if (!rc) {
604 if (pmd_large(*pmd)) {
605 *table = (pmd_val(*pmd) &
606 _SEGMENT_ENTRY_HARDWARE_BITS_LARGE)
607 | _SEGMENT_ENTRY_GMAP_UC;
608 } else
609 *table = pmd_val(*pmd) &
610 _SEGMENT_ENTRY_HARDWARE_BITS;
611 }
612 } else if (*table & _SEGMENT_ENTRY_PROTECT &&
613 !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
614 unprot = (u64)*table;
615 unprot &= ~_SEGMENT_ENTRY_PROTECT;
616 unprot |= _SEGMENT_ENTRY_GMAP_UC;
617 gmap_pmdp_xchg(gmap, (pmd_t *)table, __pmd(unprot), gaddr);
618 }
619 spin_unlock(&gmap->guest_table_lock);
620 spin_unlock(ptl);
621 radix_tree_preload_end();
622 return rc;
623}
624
625/**
626 * gmap_fault - resolve a fault on a guest address
627 * @gmap: pointer to guest mapping meta data structure
628 * @gaddr: guest address
629 * @fault_flags: flags to pass down to handle_mm_fault()
630 *
631 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
632 * if the vm address is already mapped to a different guest segment.
633 */
634int gmap_fault(struct gmap *gmap, unsigned long gaddr,
635 unsigned int fault_flags)
636{
637 unsigned long vmaddr;
638 int rc;
639 bool unlocked;
640
641 mmap_read_lock(gmap->mm);
642
643retry:
644 unlocked = false;
645 vmaddr = __gmap_translate(gmap, gaddr);
646 if (IS_ERR_VALUE(vmaddr)) {
647 rc = vmaddr;
648 goto out_up;
649 }
650 if (fixup_user_fault(gmap->mm, vmaddr, fault_flags,
651 &unlocked)) {
652 rc = -EFAULT;
653 goto out_up;
654 }
655 /*
656 * In the case that fixup_user_fault unlocked the mmap_lock during
657 * faultin redo __gmap_translate to not race with a map/unmap_segment.
658 */
659 if (unlocked)
660 goto retry;
661
662 rc = __gmap_link(gmap, gaddr, vmaddr);
663out_up:
664 mmap_read_unlock(gmap->mm);
665 return rc;
666}
667EXPORT_SYMBOL_GPL(gmap_fault);
668
669/*
670 * this function is assumed to be called with mmap_lock held
671 */
672void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
673{
674 struct vm_area_struct *vma;
675 unsigned long vmaddr;
676 spinlock_t *ptl;
677 pte_t *ptep;
678
679 /* Find the vm address for the guest address */
680 vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
681 gaddr >> PMD_SHIFT);
682 if (vmaddr) {
683 vmaddr |= gaddr & ~PMD_MASK;
684
685 vma = vma_lookup(gmap->mm, vmaddr);
686 if (!vma || is_vm_hugetlb_page(vma))
687 return;
688
689 /* Get pointer to the page table entry */
690 ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
691 if (likely(ptep)) {
692 ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
693 pte_unmap_unlock(ptep, ptl);
694 }
695 }
696}
697EXPORT_SYMBOL_GPL(__gmap_zap);
698
699void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
700{
701 unsigned long gaddr, vmaddr, size;
702 struct vm_area_struct *vma;
703
704 mmap_read_lock(gmap->mm);
705 for (gaddr = from; gaddr < to;
706 gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
707 /* Find the vm address for the guest address */
708 vmaddr = (unsigned long)
709 radix_tree_lookup(&gmap->guest_to_host,
710 gaddr >> PMD_SHIFT);
711 if (!vmaddr)
712 continue;
713 vmaddr |= gaddr & ~PMD_MASK;
714 /* Find vma in the parent mm */
715 vma = find_vma(gmap->mm, vmaddr);
716 if (!vma)
717 continue;
718 /*
719 * We do not discard pages that are backed by
720 * hugetlbfs, so we don't have to refault them.
721 */
722 if (is_vm_hugetlb_page(vma))
723 continue;
724 size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
725 zap_page_range(vma, vmaddr, size);
726 }
727 mmap_read_unlock(gmap->mm);
728}
729EXPORT_SYMBOL_GPL(gmap_discard);
730
731static LIST_HEAD(gmap_notifier_list);
732static DEFINE_SPINLOCK(gmap_notifier_lock);
733
734/**
735 * gmap_register_pte_notifier - register a pte invalidation callback
736 * @nb: pointer to the gmap notifier block
737 */
738void gmap_register_pte_notifier(struct gmap_notifier *nb)
739{
740 spin_lock(&gmap_notifier_lock);
741 list_add_rcu(&nb->list, &gmap_notifier_list);
742 spin_unlock(&gmap_notifier_lock);
743}
744EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
745
746/**
747 * gmap_unregister_pte_notifier - remove a pte invalidation callback
748 * @nb: pointer to the gmap notifier block
749 */
750void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
751{
752 spin_lock(&gmap_notifier_lock);
753 list_del_rcu(&nb->list);
754 spin_unlock(&gmap_notifier_lock);
755 synchronize_rcu();
756}
757EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
758
759/**
760 * gmap_call_notifier - call all registered invalidation callbacks
761 * @gmap: pointer to guest mapping meta data structure
762 * @start: start virtual address in the guest address space
763 * @end: end virtual address in the guest address space
764 */
765static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
766 unsigned long end)
767{
768 struct gmap_notifier *nb;
769
770 list_for_each_entry(nb, &gmap_notifier_list, list)
771 nb->notifier_call(gmap, start, end);
772}
773
774/**
775 * gmap_table_walk - walk the gmap page tables
776 * @gmap: pointer to guest mapping meta data structure
777 * @gaddr: virtual address in the guest address space
778 * @level: page table level to stop at
779 *
780 * Returns a table entry pointer for the given guest address and @level
781 * @level=0 : returns a pointer to a page table table entry (or NULL)
782 * @level=1 : returns a pointer to a segment table entry (or NULL)
783 * @level=2 : returns a pointer to a region-3 table entry (or NULL)
784 * @level=3 : returns a pointer to a region-2 table entry (or NULL)
785 * @level=4 : returns a pointer to a region-1 table entry (or NULL)
786 *
787 * Returns NULL if the gmap page tables could not be walked to the
788 * requested level.
789 *
790 * Note: Can also be called for shadow gmaps.
791 */
792static inline unsigned long *gmap_table_walk(struct gmap *gmap,
793 unsigned long gaddr, int level)
794{
795 const int asce_type = gmap->asce & _ASCE_TYPE_MASK;
796 unsigned long *table = gmap->table;
797
798 if (gmap_is_shadow(gmap) && gmap->removed)
799 return NULL;
800
801 if (WARN_ON_ONCE(level > (asce_type >> 2) + 1))
802 return NULL;
803
804 if (asce_type != _ASCE_TYPE_REGION1 &&
805 gaddr & (-1UL << (31 + (asce_type >> 2) * 11)))
806 return NULL;
807
808 switch (asce_type) {
809 case _ASCE_TYPE_REGION1:
810 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
811 if (level == 4)
812 break;
813 if (*table & _REGION_ENTRY_INVALID)
814 return NULL;
815 table = __va(*table & _REGION_ENTRY_ORIGIN);
816 fallthrough;
817 case _ASCE_TYPE_REGION2:
818 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
819 if (level == 3)
820 break;
821 if (*table & _REGION_ENTRY_INVALID)
822 return NULL;
823 table = __va(*table & _REGION_ENTRY_ORIGIN);
824 fallthrough;
825 case _ASCE_TYPE_REGION3:
826 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
827 if (level == 2)
828 break;
829 if (*table & _REGION_ENTRY_INVALID)
830 return NULL;
831 table = __va(*table & _REGION_ENTRY_ORIGIN);
832 fallthrough;
833 case _ASCE_TYPE_SEGMENT:
834 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
835 if (level == 1)
836 break;
837 if (*table & _REGION_ENTRY_INVALID)
838 return NULL;
839 table = __va(*table & _SEGMENT_ENTRY_ORIGIN);
840 table += (gaddr & _PAGE_INDEX) >> _PAGE_SHIFT;
841 }
842 return table;
843}
844
845/**
846 * gmap_pte_op_walk - walk the gmap page table, get the page table lock
847 * and return the pte pointer
848 * @gmap: pointer to guest mapping meta data structure
849 * @gaddr: virtual address in the guest address space
850 * @ptl: pointer to the spinlock pointer
851 *
852 * Returns a pointer to the locked pte for a guest address, or NULL
853 */
854static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
855 spinlock_t **ptl)
856{
857 unsigned long *table;
858
859 BUG_ON(gmap_is_shadow(gmap));
860 /* Walk the gmap page table, lock and get pte pointer */
861 table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
862 if (!table || *table & _SEGMENT_ENTRY_INVALID)
863 return NULL;
864 return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
865}
866
867/**
868 * gmap_pte_op_fixup - force a page in and connect the gmap page table
869 * @gmap: pointer to guest mapping meta data structure
870 * @gaddr: virtual address in the guest address space
871 * @vmaddr: address in the host process address space
872 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
873 *
874 * Returns 0 if the caller can retry __gmap_translate (might fail again),
875 * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
876 * up or connecting the gmap page table.
877 */
878static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
879 unsigned long vmaddr, int prot)
880{
881 struct mm_struct *mm = gmap->mm;
882 unsigned int fault_flags;
883 bool unlocked = false;
884
885 BUG_ON(gmap_is_shadow(gmap));
886 fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
887 if (fixup_user_fault(mm, vmaddr, fault_flags, &unlocked))
888 return -EFAULT;
889 if (unlocked)
890 /* lost mmap_lock, caller has to retry __gmap_translate */
891 return 0;
892 /* Connect the page tables */
893 return __gmap_link(gmap, gaddr, vmaddr);
894}
895
896/**
897 * gmap_pte_op_end - release the page table lock
898 * @ptl: pointer to the spinlock pointer
899 */
900static void gmap_pte_op_end(spinlock_t *ptl)
901{
902 if (ptl)
903 spin_unlock(ptl);
904}
905
906/**
907 * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock
908 * and return the pmd pointer
909 * @gmap: pointer to guest mapping meta data structure
910 * @gaddr: virtual address in the guest address space
911 *
912 * Returns a pointer to the pmd for a guest address, or NULL
913 */
914static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
915{
916 pmd_t *pmdp;
917
918 BUG_ON(gmap_is_shadow(gmap));
919 pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
920 if (!pmdp)
921 return NULL;
922
923 /* without huge pages, there is no need to take the table lock */
924 if (!gmap->mm->context.allow_gmap_hpage_1m)
925 return pmd_none(*pmdp) ? NULL : pmdp;
926
927 spin_lock(&gmap->guest_table_lock);
928 if (pmd_none(*pmdp)) {
929 spin_unlock(&gmap->guest_table_lock);
930 return NULL;
931 }
932
933 /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */
934 if (!pmd_large(*pmdp))
935 spin_unlock(&gmap->guest_table_lock);
936 return pmdp;
937}
938
939/**
940 * gmap_pmd_op_end - release the guest_table_lock if needed
941 * @gmap: pointer to the guest mapping meta data structure
942 * @pmdp: pointer to the pmd
943 */
944static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
945{
946 if (pmd_large(*pmdp))
947 spin_unlock(&gmap->guest_table_lock);
948}
949
950/*
951 * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
952 * @pmdp: pointer to the pmd to be protected
953 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
954 * @bits: notification bits to set
955 *
956 * Returns:
957 * 0 if successfully protected
958 * -EAGAIN if a fixup is needed
959 * -EINVAL if unsupported notifier bits have been specified
960 *
961 * Expected to be called with sg->mm->mmap_lock in read and
962 * guest_table_lock held.
963 */
964static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
965 pmd_t *pmdp, int prot, unsigned long bits)
966{
967 int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
968 int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
969 pmd_t new = *pmdp;
970
971 /* Fixup needed */
972 if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
973 return -EAGAIN;
974
975 if (prot == PROT_NONE && !pmd_i) {
976 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));
977 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
978 }
979
980 if (prot == PROT_READ && !pmd_p) {
981 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_INVALID));
982 new = set_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_PROTECT));
983 gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
984 }
985
986 if (bits & GMAP_NOTIFY_MPROT)
987 set_pmd(pmdp, set_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_GMAP_IN)));
988
989 /* Shadow GMAP protection needs split PMDs */
990 if (bits & GMAP_NOTIFY_SHADOW)
991 return -EINVAL;
992
993 return 0;
994}
995
996/*
997 * gmap_protect_pte - remove access rights to memory and set pgste bits
998 * @gmap: pointer to guest mapping meta data structure
999 * @gaddr: virtual address in the guest address space
1000 * @pmdp: pointer to the pmd associated with the pte
1001 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1002 * @bits: notification bits to set
1003 *
1004 * Returns 0 if successfully protected, -ENOMEM if out of memory and
1005 * -EAGAIN if a fixup is needed.
1006 *
1007 * Expected to be called with sg->mm->mmap_lock in read
1008 */
1009static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
1010 pmd_t *pmdp, int prot, unsigned long bits)
1011{
1012 int rc;
1013 pte_t *ptep;
1014 spinlock_t *ptl = NULL;
1015 unsigned long pbits = 0;
1016
1017 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
1018 return -EAGAIN;
1019
1020 ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl);
1021 if (!ptep)
1022 return -ENOMEM;
1023
1024 pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
1025 pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
1026 /* Protect and unlock. */
1027 rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
1028 gmap_pte_op_end(ptl);
1029 return rc;
1030}
1031
1032/*
1033 * gmap_protect_range - remove access rights to memory and set pgste bits
1034 * @gmap: pointer to guest mapping meta data structure
1035 * @gaddr: virtual address in the guest address space
1036 * @len: size of area
1037 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1038 * @bits: pgste notification bits to set
1039 *
1040 * Returns 0 if successfully protected, -ENOMEM if out of memory and
1041 * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
1042 *
1043 * Called with sg->mm->mmap_lock in read.
1044 */
1045static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
1046 unsigned long len, int prot, unsigned long bits)
1047{
1048 unsigned long vmaddr, dist;
1049 pmd_t *pmdp;
1050 int rc;
1051
1052 BUG_ON(gmap_is_shadow(gmap));
1053 while (len) {
1054 rc = -EAGAIN;
1055 pmdp = gmap_pmd_op_walk(gmap, gaddr);
1056 if (pmdp) {
1057 if (!pmd_large(*pmdp)) {
1058 rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
1059 bits);
1060 if (!rc) {
1061 len -= PAGE_SIZE;
1062 gaddr += PAGE_SIZE;
1063 }
1064 } else {
1065 rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
1066 bits);
1067 if (!rc) {
1068 dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
1069 len = len < dist ? 0 : len - dist;
1070 gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
1071 }
1072 }
1073 gmap_pmd_op_end(gmap, pmdp);
1074 }
1075 if (rc) {
1076 if (rc == -EINVAL)
1077 return rc;
1078
1079 /* -EAGAIN, fixup of userspace mm and gmap */
1080 vmaddr = __gmap_translate(gmap, gaddr);
1081 if (IS_ERR_VALUE(vmaddr))
1082 return vmaddr;
1083 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
1084 if (rc)
1085 return rc;
1086 }
1087 }
1088 return 0;
1089}
1090
1091/**
1092 * gmap_mprotect_notify - change access rights for a range of ptes and
1093 * call the notifier if any pte changes again
1094 * @gmap: pointer to guest mapping meta data structure
1095 * @gaddr: virtual address in the guest address space
1096 * @len: size of area
1097 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
1098 *
1099 * Returns 0 if for each page in the given range a gmap mapping exists,
1100 * the new access rights could be set and the notifier could be armed.
1101 * If the gmap mapping is missing for one or more pages -EFAULT is
1102 * returned. If no memory could be allocated -ENOMEM is returned.
1103 * This function establishes missing page table entries.
1104 */
1105int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
1106 unsigned long len, int prot)
1107{
1108 int rc;
1109
1110 if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
1111 return -EINVAL;
1112 if (!MACHINE_HAS_ESOP && prot == PROT_READ)
1113 return -EINVAL;
1114 mmap_read_lock(gmap->mm);
1115 rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
1116 mmap_read_unlock(gmap->mm);
1117 return rc;
1118}
1119EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
1120
1121/**
1122 * gmap_read_table - get an unsigned long value from a guest page table using
1123 * absolute addressing, without marking the page referenced.
1124 * @gmap: pointer to guest mapping meta data structure
1125 * @gaddr: virtual address in the guest address space
1126 * @val: pointer to the unsigned long value to return
1127 *
1128 * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
1129 * if reading using the virtual address failed. -EINVAL if called on a gmap
1130 * shadow.
1131 *
1132 * Called with gmap->mm->mmap_lock in read.
1133 */
1134int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
1135{
1136 unsigned long address, vmaddr;
1137 spinlock_t *ptl;
1138 pte_t *ptep, pte;
1139 int rc;
1140
1141 if (gmap_is_shadow(gmap))
1142 return -EINVAL;
1143
1144 while (1) {
1145 rc = -EAGAIN;
1146 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
1147 if (ptep) {
1148 pte = *ptep;
1149 if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
1150 address = pte_val(pte) & PAGE_MASK;
1151 address += gaddr & ~PAGE_MASK;
1152 *val = *(unsigned long *)__va(address);
1153 set_pte(ptep, set_pte_bit(*ptep, __pgprot(_PAGE_YOUNG)));
1154 /* Do *NOT* clear the _PAGE_INVALID bit! */
1155 rc = 0;
1156 }
1157 gmap_pte_op_end(ptl);
1158 }
1159 if (!rc)
1160 break;
1161 vmaddr = __gmap_translate(gmap, gaddr);
1162 if (IS_ERR_VALUE(vmaddr)) {
1163 rc = vmaddr;
1164 break;
1165 }
1166 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
1167 if (rc)
1168 break;
1169 }
1170 return rc;
1171}
1172EXPORT_SYMBOL_GPL(gmap_read_table);
1173
1174/**
1175 * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
1176 * @sg: pointer to the shadow guest address space structure
1177 * @vmaddr: vm address associated with the rmap
1178 * @rmap: pointer to the rmap structure
1179 *
1180 * Called with the sg->guest_table_lock
1181 */
1182static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
1183 struct gmap_rmap *rmap)
1184{
1185 struct gmap_rmap *temp;
1186 void __rcu **slot;
1187
1188 BUG_ON(!gmap_is_shadow(sg));
1189 slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
1190 if (slot) {
1191 rmap->next = radix_tree_deref_slot_protected(slot,
1192 &sg->guest_table_lock);
1193 for (temp = rmap->next; temp; temp = temp->next) {
1194 if (temp->raddr == rmap->raddr) {
1195 kfree(rmap);
1196 return;
1197 }
1198 }
1199 radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
1200 } else {
1201 rmap->next = NULL;
1202 radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
1203 rmap);
1204 }
1205}
1206
1207/**
1208 * gmap_protect_rmap - restrict access rights to memory (RO) and create an rmap
1209 * @sg: pointer to the shadow guest address space structure
1210 * @raddr: rmap address in the shadow gmap
1211 * @paddr: address in the parent guest address space
1212 * @len: length of the memory area to protect
1213 *
1214 * Returns 0 if successfully protected and the rmap was created, -ENOMEM
1215 * if out of memory and -EFAULT if paddr is invalid.
1216 */
1217static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
1218 unsigned long paddr, unsigned long len)
1219{
1220 struct gmap *parent;
1221 struct gmap_rmap *rmap;
1222 unsigned long vmaddr;
1223 spinlock_t *ptl;
1224 pte_t *ptep;
1225 int rc;
1226
1227 BUG_ON(!gmap_is_shadow(sg));
1228 parent = sg->parent;
1229 while (len) {
1230 vmaddr = __gmap_translate(parent, paddr);
1231 if (IS_ERR_VALUE(vmaddr))
1232 return vmaddr;
1233 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL_ACCOUNT);
1234 if (!rmap)
1235 return -ENOMEM;
1236 rmap->raddr = raddr;
1237 rc = radix_tree_preload(GFP_KERNEL_ACCOUNT);
1238 if (rc) {
1239 kfree(rmap);
1240 return rc;
1241 }
1242 rc = -EAGAIN;
1243 ptep = gmap_pte_op_walk(parent, paddr, &ptl);
1244 if (ptep) {
1245 spin_lock(&sg->guest_table_lock);
1246 rc = ptep_force_prot(parent->mm, paddr, ptep, PROT_READ,
1247 PGSTE_VSIE_BIT);
1248 if (!rc)
1249 gmap_insert_rmap(sg, vmaddr, rmap);
1250 spin_unlock(&sg->guest_table_lock);
1251 gmap_pte_op_end(ptl);
1252 }
1253 radix_tree_preload_end();
1254 if (rc) {
1255 kfree(rmap);
1256 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, PROT_READ);
1257 if (rc)
1258 return rc;
1259 continue;
1260 }
1261 paddr += PAGE_SIZE;
1262 len -= PAGE_SIZE;
1263 }
1264 return 0;
1265}
1266
1267#define _SHADOW_RMAP_MASK 0x7
1268#define _SHADOW_RMAP_REGION1 0x5
1269#define _SHADOW_RMAP_REGION2 0x4
1270#define _SHADOW_RMAP_REGION3 0x3
1271#define _SHADOW_RMAP_SEGMENT 0x2
1272#define _SHADOW_RMAP_PGTABLE 0x1
1273
1274/**
1275 * gmap_idte_one - invalidate a single region or segment table entry
1276 * @asce: region or segment table *origin* + table-type bits
1277 * @vaddr: virtual address to identify the table entry to flush
1278 *
1279 * The invalid bit of a single region or segment table entry is set
1280 * and the associated TLB entries depending on the entry are flushed.
1281 * The table-type of the @asce identifies the portion of the @vaddr
1282 * that is used as the invalidation index.
1283 */
1284static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
1285{
1286 asm volatile(
1287 " idte %0,0,%1"
1288 : : "a" (asce), "a" (vaddr) : "cc", "memory");
1289}
1290
1291/**
1292 * gmap_unshadow_page - remove a page from a shadow page table
1293 * @sg: pointer to the shadow guest address space structure
1294 * @raddr: rmap address in the shadow guest address space
1295 *
1296 * Called with the sg->guest_table_lock
1297 */
1298static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
1299{
1300 unsigned long *table;
1301
1302 BUG_ON(!gmap_is_shadow(sg));
1303 table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
1304 if (!table || *table & _PAGE_INVALID)
1305 return;
1306 gmap_call_notifier(sg, raddr, raddr + _PAGE_SIZE - 1);
1307 ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
1308}
1309
1310/**
1311 * __gmap_unshadow_pgt - remove all entries from a shadow page table
1312 * @sg: pointer to the shadow guest address space structure
1313 * @raddr: rmap address in the shadow guest address space
1314 * @pgt: pointer to the start of a shadow page table
1315 *
1316 * Called with the sg->guest_table_lock
1317 */
1318static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
1319 unsigned long *pgt)
1320{
1321 int i;
1322
1323 BUG_ON(!gmap_is_shadow(sg));
1324 for (i = 0; i < _PAGE_ENTRIES; i++, raddr += _PAGE_SIZE)
1325 pgt[i] = _PAGE_INVALID;
1326}
1327
1328/**
1329 * gmap_unshadow_pgt - remove a shadow page table from a segment entry
1330 * @sg: pointer to the shadow guest address space structure
1331 * @raddr: address in the shadow guest address space
1332 *
1333 * Called with the sg->guest_table_lock
1334 */
1335static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
1336{
1337 unsigned long *ste;
1338 phys_addr_t sto, pgt;
1339 struct page *page;
1340
1341 BUG_ON(!gmap_is_shadow(sg));
1342 ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
1343 if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
1344 return;
1345 gmap_call_notifier(sg, raddr, raddr + _SEGMENT_SIZE - 1);
1346 sto = __pa(ste - ((raddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT));
1347 gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
1348 pgt = *ste & _SEGMENT_ENTRY_ORIGIN;
1349 *ste = _SEGMENT_ENTRY_EMPTY;
1350 __gmap_unshadow_pgt(sg, raddr, __va(pgt));
1351 /* Free page table */
1352 page = phys_to_page(pgt);
1353 list_del(&page->lru);
1354 page_table_free_pgste(page);
1355}
1356
1357/**
1358 * __gmap_unshadow_sgt - remove all entries from a shadow segment table
1359 * @sg: pointer to the shadow guest address space structure
1360 * @raddr: rmap address in the shadow guest address space
1361 * @sgt: pointer to the start of a shadow segment table
1362 *
1363 * Called with the sg->guest_table_lock
1364 */
1365static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
1366 unsigned long *sgt)
1367{
1368 struct page *page;
1369 phys_addr_t pgt;
1370 int i;
1371
1372 BUG_ON(!gmap_is_shadow(sg));
1373 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
1374 if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
1375 continue;
1376 pgt = sgt[i] & _REGION_ENTRY_ORIGIN;
1377 sgt[i] = _SEGMENT_ENTRY_EMPTY;
1378 __gmap_unshadow_pgt(sg, raddr, __va(pgt));
1379 /* Free page table */
1380 page = phys_to_page(pgt);
1381 list_del(&page->lru);
1382 page_table_free_pgste(page);
1383 }
1384}
1385
1386/**
1387 * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
1388 * @sg: pointer to the shadow guest address space structure
1389 * @raddr: rmap address in the shadow guest address space
1390 *
1391 * Called with the shadow->guest_table_lock
1392 */
1393static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
1394{
1395 unsigned long r3o, *r3e;
1396 phys_addr_t sgt;
1397 struct page *page;
1398
1399 BUG_ON(!gmap_is_shadow(sg));
1400 r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
1401 if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
1402 return;
1403 gmap_call_notifier(sg, raddr, raddr + _REGION3_SIZE - 1);
1404 r3o = (unsigned long) (r3e - ((raddr & _REGION3_INDEX) >> _REGION3_SHIFT));
1405 gmap_idte_one(__pa(r3o) | _ASCE_TYPE_REGION3, raddr);
1406 sgt = *r3e & _REGION_ENTRY_ORIGIN;
1407 *r3e = _REGION3_ENTRY_EMPTY;
1408 __gmap_unshadow_sgt(sg, raddr, __va(sgt));
1409 /* Free segment table */
1410 page = phys_to_page(sgt);
1411 list_del(&page->lru);
1412 __free_pages(page, CRST_ALLOC_ORDER);
1413}
1414
1415/**
1416 * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
1417 * @sg: pointer to the shadow guest address space structure
1418 * @raddr: address in the shadow guest address space
1419 * @r3t: pointer to the start of a shadow region-3 table
1420 *
1421 * Called with the sg->guest_table_lock
1422 */
1423static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
1424 unsigned long *r3t)
1425{
1426 struct page *page;
1427 phys_addr_t sgt;
1428 int i;
1429
1430 BUG_ON(!gmap_is_shadow(sg));
1431 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
1432 if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
1433 continue;
1434 sgt = r3t[i] & _REGION_ENTRY_ORIGIN;
1435 r3t[i] = _REGION3_ENTRY_EMPTY;
1436 __gmap_unshadow_sgt(sg, raddr, __va(sgt));
1437 /* Free segment table */
1438 page = phys_to_page(sgt);
1439 list_del(&page->lru);
1440 __free_pages(page, CRST_ALLOC_ORDER);
1441 }
1442}
1443
1444/**
1445 * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
1446 * @sg: pointer to the shadow guest address space structure
1447 * @raddr: rmap address in the shadow guest address space
1448 *
1449 * Called with the sg->guest_table_lock
1450 */
1451static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
1452{
1453 unsigned long r2o, *r2e;
1454 phys_addr_t r3t;
1455 struct page *page;
1456
1457 BUG_ON(!gmap_is_shadow(sg));
1458 r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
1459 if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
1460 return;
1461 gmap_call_notifier(sg, raddr, raddr + _REGION2_SIZE - 1);
1462 r2o = (unsigned long) (r2e - ((raddr & _REGION2_INDEX) >> _REGION2_SHIFT));
1463 gmap_idte_one(__pa(r2o) | _ASCE_TYPE_REGION2, raddr);
1464 r3t = *r2e & _REGION_ENTRY_ORIGIN;
1465 *r2e = _REGION2_ENTRY_EMPTY;
1466 __gmap_unshadow_r3t(sg, raddr, __va(r3t));
1467 /* Free region 3 table */
1468 page = phys_to_page(r3t);
1469 list_del(&page->lru);
1470 __free_pages(page, CRST_ALLOC_ORDER);
1471}
1472
1473/**
1474 * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
1475 * @sg: pointer to the shadow guest address space structure
1476 * @raddr: rmap address in the shadow guest address space
1477 * @r2t: pointer to the start of a shadow region-2 table
1478 *
1479 * Called with the sg->guest_table_lock
1480 */
1481static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
1482 unsigned long *r2t)
1483{
1484 phys_addr_t r3t;
1485 struct page *page;
1486 int i;
1487
1488 BUG_ON(!gmap_is_shadow(sg));
1489 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
1490 if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
1491 continue;
1492 r3t = r2t[i] & _REGION_ENTRY_ORIGIN;
1493 r2t[i] = _REGION2_ENTRY_EMPTY;
1494 __gmap_unshadow_r3t(sg, raddr, __va(r3t));
1495 /* Free region 3 table */
1496 page = phys_to_page(r3t);
1497 list_del(&page->lru);
1498 __free_pages(page, CRST_ALLOC_ORDER);
1499 }
1500}
1501
1502/**
1503 * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
1504 * @sg: pointer to the shadow guest address space structure
1505 * @raddr: rmap address in the shadow guest address space
1506 *
1507 * Called with the sg->guest_table_lock
1508 */
1509static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
1510{
1511 unsigned long r1o, *r1e;
1512 struct page *page;
1513 phys_addr_t r2t;
1514
1515 BUG_ON(!gmap_is_shadow(sg));
1516 r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
1517 if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
1518 return;
1519 gmap_call_notifier(sg, raddr, raddr + _REGION1_SIZE - 1);
1520 r1o = (unsigned long) (r1e - ((raddr & _REGION1_INDEX) >> _REGION1_SHIFT));
1521 gmap_idte_one(__pa(r1o) | _ASCE_TYPE_REGION1, raddr);
1522 r2t = *r1e & _REGION_ENTRY_ORIGIN;
1523 *r1e = _REGION1_ENTRY_EMPTY;
1524 __gmap_unshadow_r2t(sg, raddr, __va(r2t));
1525 /* Free region 2 table */
1526 page = phys_to_page(r2t);
1527 list_del(&page->lru);
1528 __free_pages(page, CRST_ALLOC_ORDER);
1529}
1530
1531/**
1532 * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
1533 * @sg: pointer to the shadow guest address space structure
1534 * @raddr: rmap address in the shadow guest address space
1535 * @r1t: pointer to the start of a shadow region-1 table
1536 *
1537 * Called with the shadow->guest_table_lock
1538 */
1539static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
1540 unsigned long *r1t)
1541{
1542 unsigned long asce;
1543 struct page *page;
1544 phys_addr_t r2t;
1545 int i;
1546
1547 BUG_ON(!gmap_is_shadow(sg));
1548 asce = __pa(r1t) | _ASCE_TYPE_REGION1;
1549 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION1_SIZE) {
1550 if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
1551 continue;
1552 r2t = r1t[i] & _REGION_ENTRY_ORIGIN;
1553 __gmap_unshadow_r2t(sg, raddr, __va(r2t));
1554 /* Clear entry and flush translation r1t -> r2t */
1555 gmap_idte_one(asce, raddr);
1556 r1t[i] = _REGION1_ENTRY_EMPTY;
1557 /* Free region 2 table */
1558 page = phys_to_page(r2t);
1559 list_del(&page->lru);
1560 __free_pages(page, CRST_ALLOC_ORDER);
1561 }
1562}
1563
1564/**
1565 * gmap_unshadow - remove a shadow page table completely
1566 * @sg: pointer to the shadow guest address space structure
1567 *
1568 * Called with sg->guest_table_lock
1569 */
1570static void gmap_unshadow(struct gmap *sg)
1571{
1572 unsigned long *table;
1573
1574 BUG_ON(!gmap_is_shadow(sg));
1575 if (sg->removed)
1576 return;
1577 sg->removed = 1;
1578 gmap_call_notifier(sg, 0, -1UL);
1579 gmap_flush_tlb(sg);
1580 table = __va(sg->asce & _ASCE_ORIGIN);
1581 switch (sg->asce & _ASCE_TYPE_MASK) {
1582 case _ASCE_TYPE_REGION1:
1583 __gmap_unshadow_r1t(sg, 0, table);
1584 break;
1585 case _ASCE_TYPE_REGION2:
1586 __gmap_unshadow_r2t(sg, 0, table);
1587 break;
1588 case _ASCE_TYPE_REGION3:
1589 __gmap_unshadow_r3t(sg, 0, table);
1590 break;
1591 case _ASCE_TYPE_SEGMENT:
1592 __gmap_unshadow_sgt(sg, 0, table);
1593 break;
1594 }
1595}
1596
1597/**
1598 * gmap_find_shadow - find a specific asce in the list of shadow tables
1599 * @parent: pointer to the parent gmap
1600 * @asce: ASCE for which the shadow table is created
1601 * @edat_level: edat level to be used for the shadow translation
1602 *
1603 * Returns the pointer to a gmap if a shadow table with the given asce is
1604 * already available, ERR_PTR(-EAGAIN) if another one is just being created,
1605 * otherwise NULL
1606 */
1607static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
1608 int edat_level)
1609{
1610 struct gmap *sg;
1611
1612 list_for_each_entry(sg, &parent->children, list) {
1613 if (sg->orig_asce != asce || sg->edat_level != edat_level ||
1614 sg->removed)
1615 continue;
1616 if (!sg->initialized)
1617 return ERR_PTR(-EAGAIN);
1618 refcount_inc(&sg->ref_count);
1619 return sg;
1620 }
1621 return NULL;
1622}
1623
1624/**
1625 * gmap_shadow_valid - check if a shadow guest address space matches the
1626 * given properties and is still valid
1627 * @sg: pointer to the shadow guest address space structure
1628 * @asce: ASCE for which the shadow table is requested
1629 * @edat_level: edat level to be used for the shadow translation
1630 *
1631 * Returns 1 if the gmap shadow is still valid and matches the given
1632 * properties, the caller can continue using it. Returns 0 otherwise, the
1633 * caller has to request a new shadow gmap in this case.
1634 *
1635 */
1636int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
1637{
1638 if (sg->removed)
1639 return 0;
1640 return sg->orig_asce == asce && sg->edat_level == edat_level;
1641}
1642EXPORT_SYMBOL_GPL(gmap_shadow_valid);
1643
1644/**
1645 * gmap_shadow - create/find a shadow guest address space
1646 * @parent: pointer to the parent gmap
1647 * @asce: ASCE for which the shadow table is created
1648 * @edat_level: edat level to be used for the shadow translation
1649 *
1650 * The pages of the top level page table referred by the asce parameter
1651 * will be set to read-only and marked in the PGSTEs of the kvm process.
1652 * The shadow table will be removed automatically on any change to the
1653 * PTE mapping for the source table.
1654 *
1655 * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
1656 * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
1657 * parent gmap table could not be protected.
1658 */
1659struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
1660 int edat_level)
1661{
1662 struct gmap *sg, *new;
1663 unsigned long limit;
1664 int rc;
1665
1666 BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
1667 BUG_ON(gmap_is_shadow(parent));
1668 spin_lock(&parent->shadow_lock);
1669 sg = gmap_find_shadow(parent, asce, edat_level);
1670 spin_unlock(&parent->shadow_lock);
1671 if (sg)
1672 return sg;
1673 /* Create a new shadow gmap */
1674 limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
1675 if (asce & _ASCE_REAL_SPACE)
1676 limit = -1UL;
1677 new = gmap_alloc(limit);
1678 if (!new)
1679 return ERR_PTR(-ENOMEM);
1680 new->mm = parent->mm;
1681 new->parent = gmap_get(parent);
1682 new->orig_asce = asce;
1683 new->edat_level = edat_level;
1684 new->initialized = false;
1685 spin_lock(&parent->shadow_lock);
1686 /* Recheck if another CPU created the same shadow */
1687 sg = gmap_find_shadow(parent, asce, edat_level);
1688 if (sg) {
1689 spin_unlock(&parent->shadow_lock);
1690 gmap_free(new);
1691 return sg;
1692 }
1693 if (asce & _ASCE_REAL_SPACE) {
1694 /* only allow one real-space gmap shadow */
1695 list_for_each_entry(sg, &parent->children, list) {
1696 if (sg->orig_asce & _ASCE_REAL_SPACE) {
1697 spin_lock(&sg->guest_table_lock);
1698 gmap_unshadow(sg);
1699 spin_unlock(&sg->guest_table_lock);
1700 list_del(&sg->list);
1701 gmap_put(sg);
1702 break;
1703 }
1704 }
1705 }
1706 refcount_set(&new->ref_count, 2);
1707 list_add(&new->list, &parent->children);
1708 if (asce & _ASCE_REAL_SPACE) {
1709 /* nothing to protect, return right away */
1710 new->initialized = true;
1711 spin_unlock(&parent->shadow_lock);
1712 return new;
1713 }
1714 spin_unlock(&parent->shadow_lock);
1715 /* protect after insertion, so it will get properly invalidated */
1716 mmap_read_lock(parent->mm);
1717 rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
1718 ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
1719 PROT_READ, GMAP_NOTIFY_SHADOW);
1720 mmap_read_unlock(parent->mm);
1721 spin_lock(&parent->shadow_lock);
1722 new->initialized = true;
1723 if (rc) {
1724 list_del(&new->list);
1725 gmap_free(new);
1726 new = ERR_PTR(rc);
1727 }
1728 spin_unlock(&parent->shadow_lock);
1729 return new;
1730}
1731EXPORT_SYMBOL_GPL(gmap_shadow);
1732
1733/**
1734 * gmap_shadow_r2t - create an empty shadow region 2 table
1735 * @sg: pointer to the shadow guest address space structure
1736 * @saddr: faulting address in the shadow gmap
1737 * @r2t: parent gmap address of the region 2 table to get shadowed
1738 * @fake: r2t references contiguous guest memory block, not a r2t
1739 *
1740 * The r2t parameter specifies the address of the source table. The
1741 * four pages of the source table are made read-only in the parent gmap
1742 * address space. A write to the source table area @r2t will automatically
1743 * remove the shadow r2 table and all of its decendents.
1744 *
1745 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1746 * shadow table structure is incomplete, -ENOMEM if out of memory and
1747 * -EFAULT if an address in the parent gmap could not be resolved.
1748 *
1749 * Called with sg->mm->mmap_lock in read.
1750 */
1751int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
1752 int fake)
1753{
1754 unsigned long raddr, origin, offset, len;
1755 unsigned long *table;
1756 phys_addr_t s_r2t;
1757 struct page *page;
1758 int rc;
1759
1760 BUG_ON(!gmap_is_shadow(sg));
1761 /* Allocate a shadow region second table */
1762 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
1763 if (!page)
1764 return -ENOMEM;
1765 page->index = r2t & _REGION_ENTRY_ORIGIN;
1766 if (fake)
1767 page->index |= GMAP_SHADOW_FAKE_TABLE;
1768 s_r2t = page_to_phys(page);
1769 /* Install shadow region second table */
1770 spin_lock(&sg->guest_table_lock);
1771 table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
1772 if (!table) {
1773 rc = -EAGAIN; /* Race with unshadow */
1774 goto out_free;
1775 }
1776 if (!(*table & _REGION_ENTRY_INVALID)) {
1777 rc = 0; /* Already established */
1778 goto out_free;
1779 } else if (*table & _REGION_ENTRY_ORIGIN) {
1780 rc = -EAGAIN; /* Race with shadow */
1781 goto out_free;
1782 }
1783 crst_table_init(__va(s_r2t), _REGION2_ENTRY_EMPTY);
1784 /* mark as invalid as long as the parent table is not protected */
1785 *table = s_r2t | _REGION_ENTRY_LENGTH |
1786 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
1787 if (sg->edat_level >= 1)
1788 *table |= (r2t & _REGION_ENTRY_PROTECT);
1789 list_add(&page->lru, &sg->crst_list);
1790 if (fake) {
1791 /* nothing to protect for fake tables */
1792 *table &= ~_REGION_ENTRY_INVALID;
1793 spin_unlock(&sg->guest_table_lock);
1794 return 0;
1795 }
1796 spin_unlock(&sg->guest_table_lock);
1797 /* Make r2t read-only in parent gmap page table */
1798 raddr = (saddr & _REGION1_MASK) | _SHADOW_RMAP_REGION1;
1799 origin = r2t & _REGION_ENTRY_ORIGIN;
1800 offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1801 len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1802 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1803 spin_lock(&sg->guest_table_lock);
1804 if (!rc) {
1805 table = gmap_table_walk(sg, saddr, 4);
1806 if (!table || (*table & _REGION_ENTRY_ORIGIN) != s_r2t)
1807 rc = -EAGAIN; /* Race with unshadow */
1808 else
1809 *table &= ~_REGION_ENTRY_INVALID;
1810 } else {
1811 gmap_unshadow_r2t(sg, raddr);
1812 }
1813 spin_unlock(&sg->guest_table_lock);
1814 return rc;
1815out_free:
1816 spin_unlock(&sg->guest_table_lock);
1817 __free_pages(page, CRST_ALLOC_ORDER);
1818 return rc;
1819}
1820EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
1821
1822/**
1823 * gmap_shadow_r3t - create a shadow region 3 table
1824 * @sg: pointer to the shadow guest address space structure
1825 * @saddr: faulting address in the shadow gmap
1826 * @r3t: parent gmap address of the region 3 table to get shadowed
1827 * @fake: r3t references contiguous guest memory block, not a r3t
1828 *
1829 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1830 * shadow table structure is incomplete, -ENOMEM if out of memory and
1831 * -EFAULT if an address in the parent gmap could not be resolved.
1832 *
1833 * Called with sg->mm->mmap_lock in read.
1834 */
1835int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
1836 int fake)
1837{
1838 unsigned long raddr, origin, offset, len;
1839 unsigned long *table;
1840 phys_addr_t s_r3t;
1841 struct page *page;
1842 int rc;
1843
1844 BUG_ON(!gmap_is_shadow(sg));
1845 /* Allocate a shadow region second table */
1846 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
1847 if (!page)
1848 return -ENOMEM;
1849 page->index = r3t & _REGION_ENTRY_ORIGIN;
1850 if (fake)
1851 page->index |= GMAP_SHADOW_FAKE_TABLE;
1852 s_r3t = page_to_phys(page);
1853 /* Install shadow region second table */
1854 spin_lock(&sg->guest_table_lock);
1855 table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
1856 if (!table) {
1857 rc = -EAGAIN; /* Race with unshadow */
1858 goto out_free;
1859 }
1860 if (!(*table & _REGION_ENTRY_INVALID)) {
1861 rc = 0; /* Already established */
1862 goto out_free;
1863 } else if (*table & _REGION_ENTRY_ORIGIN) {
1864 rc = -EAGAIN; /* Race with shadow */
1865 goto out_free;
1866 }
1867 crst_table_init(__va(s_r3t), _REGION3_ENTRY_EMPTY);
1868 /* mark as invalid as long as the parent table is not protected */
1869 *table = s_r3t | _REGION_ENTRY_LENGTH |
1870 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
1871 if (sg->edat_level >= 1)
1872 *table |= (r3t & _REGION_ENTRY_PROTECT);
1873 list_add(&page->lru, &sg->crst_list);
1874 if (fake) {
1875 /* nothing to protect for fake tables */
1876 *table &= ~_REGION_ENTRY_INVALID;
1877 spin_unlock(&sg->guest_table_lock);
1878 return 0;
1879 }
1880 spin_unlock(&sg->guest_table_lock);
1881 /* Make r3t read-only in parent gmap page table */
1882 raddr = (saddr & _REGION2_MASK) | _SHADOW_RMAP_REGION2;
1883 origin = r3t & _REGION_ENTRY_ORIGIN;
1884 offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1885 len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1886 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1887 spin_lock(&sg->guest_table_lock);
1888 if (!rc) {
1889 table = gmap_table_walk(sg, saddr, 3);
1890 if (!table || (*table & _REGION_ENTRY_ORIGIN) != s_r3t)
1891 rc = -EAGAIN; /* Race with unshadow */
1892 else
1893 *table &= ~_REGION_ENTRY_INVALID;
1894 } else {
1895 gmap_unshadow_r3t(sg, raddr);
1896 }
1897 spin_unlock(&sg->guest_table_lock);
1898 return rc;
1899out_free:
1900 spin_unlock(&sg->guest_table_lock);
1901 __free_pages(page, CRST_ALLOC_ORDER);
1902 return rc;
1903}
1904EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
1905
1906/**
1907 * gmap_shadow_sgt - create a shadow segment table
1908 * @sg: pointer to the shadow guest address space structure
1909 * @saddr: faulting address in the shadow gmap
1910 * @sgt: parent gmap address of the segment table to get shadowed
1911 * @fake: sgt references contiguous guest memory block, not a sgt
1912 *
1913 * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
1914 * shadow table structure is incomplete, -ENOMEM if out of memory and
1915 * -EFAULT if an address in the parent gmap could not be resolved.
1916 *
1917 * Called with sg->mm->mmap_lock in read.
1918 */
1919int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
1920 int fake)
1921{
1922 unsigned long raddr, origin, offset, len;
1923 unsigned long *table;
1924 phys_addr_t s_sgt;
1925 struct page *page;
1926 int rc;
1927
1928 BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
1929 /* Allocate a shadow segment table */
1930 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
1931 if (!page)
1932 return -ENOMEM;
1933 page->index = sgt & _REGION_ENTRY_ORIGIN;
1934 if (fake)
1935 page->index |= GMAP_SHADOW_FAKE_TABLE;
1936 s_sgt = page_to_phys(page);
1937 /* Install shadow region second table */
1938 spin_lock(&sg->guest_table_lock);
1939 table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
1940 if (!table) {
1941 rc = -EAGAIN; /* Race with unshadow */
1942 goto out_free;
1943 }
1944 if (!(*table & _REGION_ENTRY_INVALID)) {
1945 rc = 0; /* Already established */
1946 goto out_free;
1947 } else if (*table & _REGION_ENTRY_ORIGIN) {
1948 rc = -EAGAIN; /* Race with shadow */
1949 goto out_free;
1950 }
1951 crst_table_init(__va(s_sgt), _SEGMENT_ENTRY_EMPTY);
1952 /* mark as invalid as long as the parent table is not protected */
1953 *table = s_sgt | _REGION_ENTRY_LENGTH |
1954 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
1955 if (sg->edat_level >= 1)
1956 *table |= sgt & _REGION_ENTRY_PROTECT;
1957 list_add(&page->lru, &sg->crst_list);
1958 if (fake) {
1959 /* nothing to protect for fake tables */
1960 *table &= ~_REGION_ENTRY_INVALID;
1961 spin_unlock(&sg->guest_table_lock);
1962 return 0;
1963 }
1964 spin_unlock(&sg->guest_table_lock);
1965 /* Make sgt read-only in parent gmap page table */
1966 raddr = (saddr & _REGION3_MASK) | _SHADOW_RMAP_REGION3;
1967 origin = sgt & _REGION_ENTRY_ORIGIN;
1968 offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1969 len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1970 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1971 spin_lock(&sg->guest_table_lock);
1972 if (!rc) {
1973 table = gmap_table_walk(sg, saddr, 2);
1974 if (!table || (*table & _REGION_ENTRY_ORIGIN) != s_sgt)
1975 rc = -EAGAIN; /* Race with unshadow */
1976 else
1977 *table &= ~_REGION_ENTRY_INVALID;
1978 } else {
1979 gmap_unshadow_sgt(sg, raddr);
1980 }
1981 spin_unlock(&sg->guest_table_lock);
1982 return rc;
1983out_free:
1984 spin_unlock(&sg->guest_table_lock);
1985 __free_pages(page, CRST_ALLOC_ORDER);
1986 return rc;
1987}
1988EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
1989
1990/**
1991 * gmap_shadow_pgt_lookup - find a shadow page table
1992 * @sg: pointer to the shadow guest address space structure
1993 * @saddr: the address in the shadow aguest address space
1994 * @pgt: parent gmap address of the page table to get shadowed
1995 * @dat_protection: if the pgtable is marked as protected by dat
1996 * @fake: pgt references contiguous guest memory block, not a pgtable
1997 *
1998 * Returns 0 if the shadow page table was found and -EAGAIN if the page
1999 * table was not found.
2000 *
2001 * Called with sg->mm->mmap_lock in read.
2002 */
2003int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
2004 unsigned long *pgt, int *dat_protection,
2005 int *fake)
2006{
2007 unsigned long *table;
2008 struct page *page;
2009 int rc;
2010
2011 BUG_ON(!gmap_is_shadow(sg));
2012 spin_lock(&sg->guest_table_lock);
2013 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
2014 if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
2015 /* Shadow page tables are full pages (pte+pgste) */
2016 page = pfn_to_page(*table >> PAGE_SHIFT);
2017 *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
2018 *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
2019 *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
2020 rc = 0;
2021 } else {
2022 rc = -EAGAIN;
2023 }
2024 spin_unlock(&sg->guest_table_lock);
2025 return rc;
2026
2027}
2028EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
2029
2030/**
2031 * gmap_shadow_pgt - instantiate a shadow page table
2032 * @sg: pointer to the shadow guest address space structure
2033 * @saddr: faulting address in the shadow gmap
2034 * @pgt: parent gmap address of the page table to get shadowed
2035 * @fake: pgt references contiguous guest memory block, not a pgtable
2036 *
2037 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2038 * shadow table structure is incomplete, -ENOMEM if out of memory,
2039 * -EFAULT if an address in the parent gmap could not be resolved and
2040 *
2041 * Called with gmap->mm->mmap_lock in read
2042 */
2043int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
2044 int fake)
2045{
2046 unsigned long raddr, origin;
2047 unsigned long *table;
2048 struct page *page;
2049 phys_addr_t s_pgt;
2050 int rc;
2051
2052 BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
2053 /* Allocate a shadow page table */
2054 page = page_table_alloc_pgste(sg->mm);
2055 if (!page)
2056 return -ENOMEM;
2057 page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
2058 if (fake)
2059 page->index |= GMAP_SHADOW_FAKE_TABLE;
2060 s_pgt = page_to_phys(page);
2061 /* Install shadow page table */
2062 spin_lock(&sg->guest_table_lock);
2063 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
2064 if (!table) {
2065 rc = -EAGAIN; /* Race with unshadow */
2066 goto out_free;
2067 }
2068 if (!(*table & _SEGMENT_ENTRY_INVALID)) {
2069 rc = 0; /* Already established */
2070 goto out_free;
2071 } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
2072 rc = -EAGAIN; /* Race with shadow */
2073 goto out_free;
2074 }
2075 /* mark as invalid as long as the parent table is not protected */
2076 *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
2077 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
2078 list_add(&page->lru, &sg->pt_list);
2079 if (fake) {
2080 /* nothing to protect for fake tables */
2081 *table &= ~_SEGMENT_ENTRY_INVALID;
2082 spin_unlock(&sg->guest_table_lock);
2083 return 0;
2084 }
2085 spin_unlock(&sg->guest_table_lock);
2086 /* Make pgt read-only in parent gmap page table (not the pgste) */
2087 raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
2088 origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
2089 rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
2090 spin_lock(&sg->guest_table_lock);
2091 if (!rc) {
2092 table = gmap_table_walk(sg, saddr, 1);
2093 if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) != s_pgt)
2094 rc = -EAGAIN; /* Race with unshadow */
2095 else
2096 *table &= ~_SEGMENT_ENTRY_INVALID;
2097 } else {
2098 gmap_unshadow_pgt(sg, raddr);
2099 }
2100 spin_unlock(&sg->guest_table_lock);
2101 return rc;
2102out_free:
2103 spin_unlock(&sg->guest_table_lock);
2104 page_table_free_pgste(page);
2105 return rc;
2106
2107}
2108EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
2109
2110/**
2111 * gmap_shadow_page - create a shadow page mapping
2112 * @sg: pointer to the shadow guest address space structure
2113 * @saddr: faulting address in the shadow gmap
2114 * @pte: pte in parent gmap address space to get shadowed
2115 *
2116 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
2117 * shadow table structure is incomplete, -ENOMEM if out of memory and
2118 * -EFAULT if an address in the parent gmap could not be resolved.
2119 *
2120 * Called with sg->mm->mmap_lock in read.
2121 */
2122int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
2123{
2124 struct gmap *parent;
2125 struct gmap_rmap *rmap;
2126 unsigned long vmaddr, paddr;
2127 spinlock_t *ptl;
2128 pte_t *sptep, *tptep;
2129 int prot;
2130 int rc;
2131
2132 BUG_ON(!gmap_is_shadow(sg));
2133 parent = sg->parent;
2134 prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
2135
2136 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL_ACCOUNT);
2137 if (!rmap)
2138 return -ENOMEM;
2139 rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
2140
2141 while (1) {
2142 paddr = pte_val(pte) & PAGE_MASK;
2143 vmaddr = __gmap_translate(parent, paddr);
2144 if (IS_ERR_VALUE(vmaddr)) {
2145 rc = vmaddr;
2146 break;
2147 }
2148 rc = radix_tree_preload(GFP_KERNEL_ACCOUNT);
2149 if (rc)
2150 break;
2151 rc = -EAGAIN;
2152 sptep = gmap_pte_op_walk(parent, paddr, &ptl);
2153 if (sptep) {
2154 spin_lock(&sg->guest_table_lock);
2155 /* Get page table pointer */
2156 tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
2157 if (!tptep) {
2158 spin_unlock(&sg->guest_table_lock);
2159 gmap_pte_op_end(ptl);
2160 radix_tree_preload_end();
2161 break;
2162 }
2163 rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
2164 if (rc > 0) {
2165 /* Success and a new mapping */
2166 gmap_insert_rmap(sg, vmaddr, rmap);
2167 rmap = NULL;
2168 rc = 0;
2169 }
2170 gmap_pte_op_end(ptl);
2171 spin_unlock(&sg->guest_table_lock);
2172 }
2173 radix_tree_preload_end();
2174 if (!rc)
2175 break;
2176 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
2177 if (rc)
2178 break;
2179 }
2180 kfree(rmap);
2181 return rc;
2182}
2183EXPORT_SYMBOL_GPL(gmap_shadow_page);
2184
2185/*
2186 * gmap_shadow_notify - handle notifications for shadow gmap
2187 *
2188 * Called with sg->parent->shadow_lock.
2189 */
2190static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
2191 unsigned long gaddr)
2192{
2193 struct gmap_rmap *rmap, *rnext, *head;
2194 unsigned long start, end, bits, raddr;
2195
2196 BUG_ON(!gmap_is_shadow(sg));
2197
2198 spin_lock(&sg->guest_table_lock);
2199 if (sg->removed) {
2200 spin_unlock(&sg->guest_table_lock);
2201 return;
2202 }
2203 /* Check for top level table */
2204 start = sg->orig_asce & _ASCE_ORIGIN;
2205 end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE;
2206 if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
2207 gaddr < end) {
2208 /* The complete shadow table has to go */
2209 gmap_unshadow(sg);
2210 spin_unlock(&sg->guest_table_lock);
2211 list_del(&sg->list);
2212 gmap_put(sg);
2213 return;
2214 }
2215 /* Remove the page table tree from on specific entry */
2216 head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
2217 gmap_for_each_rmap_safe(rmap, rnext, head) {
2218 bits = rmap->raddr & _SHADOW_RMAP_MASK;
2219 raddr = rmap->raddr ^ bits;
2220 switch (bits) {
2221 case _SHADOW_RMAP_REGION1:
2222 gmap_unshadow_r2t(sg, raddr);
2223 break;
2224 case _SHADOW_RMAP_REGION2:
2225 gmap_unshadow_r3t(sg, raddr);
2226 break;
2227 case _SHADOW_RMAP_REGION3:
2228 gmap_unshadow_sgt(sg, raddr);
2229 break;
2230 case _SHADOW_RMAP_SEGMENT:
2231 gmap_unshadow_pgt(sg, raddr);
2232 break;
2233 case _SHADOW_RMAP_PGTABLE:
2234 gmap_unshadow_page(sg, raddr);
2235 break;
2236 }
2237 kfree(rmap);
2238 }
2239 spin_unlock(&sg->guest_table_lock);
2240}
2241
2242/**
2243 * ptep_notify - call all invalidation callbacks for a specific pte.
2244 * @mm: pointer to the process mm_struct
2245 * @vmaddr: virtual address in the process address space
2246 * @pte: pointer to the page table entry
2247 * @bits: bits from the pgste that caused the notify call
2248 *
2249 * This function is assumed to be called with the page table lock held
2250 * for the pte to notify.
2251 */
2252void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
2253 pte_t *pte, unsigned long bits)
2254{
2255 unsigned long offset, gaddr = 0;
2256 unsigned long *table;
2257 struct gmap *gmap, *sg, *next;
2258
2259 offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
2260 offset = offset * (PAGE_SIZE / sizeof(pte_t));
2261 rcu_read_lock();
2262 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2263 spin_lock(&gmap->guest_table_lock);
2264 table = radix_tree_lookup(&gmap->host_to_guest,
2265 vmaddr >> PMD_SHIFT);
2266 if (table)
2267 gaddr = __gmap_segment_gaddr(table) + offset;
2268 spin_unlock(&gmap->guest_table_lock);
2269 if (!table)
2270 continue;
2271
2272 if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
2273 spin_lock(&gmap->shadow_lock);
2274 list_for_each_entry_safe(sg, next,
2275 &gmap->children, list)
2276 gmap_shadow_notify(sg, vmaddr, gaddr);
2277 spin_unlock(&gmap->shadow_lock);
2278 }
2279 if (bits & PGSTE_IN_BIT)
2280 gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
2281 }
2282 rcu_read_unlock();
2283}
2284EXPORT_SYMBOL_GPL(ptep_notify);
2285
2286static void pmdp_notify_gmap(struct gmap *gmap, pmd_t *pmdp,
2287 unsigned long gaddr)
2288{
2289 set_pmd(pmdp, clear_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_GMAP_IN)));
2290 gmap_call_notifier(gmap, gaddr, gaddr + HPAGE_SIZE - 1);
2291}
2292
2293/**
2294 * gmap_pmdp_xchg - exchange a gmap pmd with another
2295 * @gmap: pointer to the guest address space structure
2296 * @pmdp: pointer to the pmd entry
2297 * @new: replacement entry
2298 * @gaddr: the affected guest address
2299 *
2300 * This function is assumed to be called with the guest_table_lock
2301 * held.
2302 */
2303static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *pmdp, pmd_t new,
2304 unsigned long gaddr)
2305{
2306 gaddr &= HPAGE_MASK;
2307 pmdp_notify_gmap(gmap, pmdp, gaddr);
2308 new = clear_pmd_bit(new, __pgprot(_SEGMENT_ENTRY_GMAP_IN));
2309 if (MACHINE_HAS_TLB_GUEST)
2310 __pmdp_idte(gaddr, (pmd_t *)pmdp, IDTE_GUEST_ASCE, gmap->asce,
2311 IDTE_GLOBAL);
2312 else if (MACHINE_HAS_IDTE)
2313 __pmdp_idte(gaddr, (pmd_t *)pmdp, 0, 0, IDTE_GLOBAL);
2314 else
2315 __pmdp_csp(pmdp);
2316 set_pmd(pmdp, new);
2317}
2318
2319static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
2320 int purge)
2321{
2322 pmd_t *pmdp;
2323 struct gmap *gmap;
2324 unsigned long gaddr;
2325
2326 rcu_read_lock();
2327 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2328 spin_lock(&gmap->guest_table_lock);
2329 pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
2330 vmaddr >> PMD_SHIFT);
2331 if (pmdp) {
2332 gaddr = __gmap_segment_gaddr((unsigned long *)pmdp);
2333 pmdp_notify_gmap(gmap, pmdp, gaddr);
2334 WARN_ON(pmd_val(*pmdp) & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2335 _SEGMENT_ENTRY_GMAP_UC));
2336 if (purge)
2337 __pmdp_csp(pmdp);
2338 set_pmd(pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
2339 }
2340 spin_unlock(&gmap->guest_table_lock);
2341 }
2342 rcu_read_unlock();
2343}
2344
2345/**
2346 * gmap_pmdp_invalidate - invalidate all affected guest pmd entries without
2347 * flushing
2348 * @mm: pointer to the process mm_struct
2349 * @vmaddr: virtual address in the process address space
2350 */
2351void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr)
2352{
2353 gmap_pmdp_clear(mm, vmaddr, 0);
2354}
2355EXPORT_SYMBOL_GPL(gmap_pmdp_invalidate);
2356
2357/**
2358 * gmap_pmdp_csp - csp all affected guest pmd entries
2359 * @mm: pointer to the process mm_struct
2360 * @vmaddr: virtual address in the process address space
2361 */
2362void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr)
2363{
2364 gmap_pmdp_clear(mm, vmaddr, 1);
2365}
2366EXPORT_SYMBOL_GPL(gmap_pmdp_csp);
2367
2368/**
2369 * gmap_pmdp_idte_local - invalidate and clear a guest pmd entry
2370 * @mm: pointer to the process mm_struct
2371 * @vmaddr: virtual address in the process address space
2372 */
2373void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
2374{
2375 unsigned long *entry, gaddr;
2376 struct gmap *gmap;
2377 pmd_t *pmdp;
2378
2379 rcu_read_lock();
2380 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2381 spin_lock(&gmap->guest_table_lock);
2382 entry = radix_tree_delete(&gmap->host_to_guest,
2383 vmaddr >> PMD_SHIFT);
2384 if (entry) {
2385 pmdp = (pmd_t *)entry;
2386 gaddr = __gmap_segment_gaddr(entry);
2387 pmdp_notify_gmap(gmap, pmdp, gaddr);
2388 WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2389 _SEGMENT_ENTRY_GMAP_UC));
2390 if (MACHINE_HAS_TLB_GUEST)
2391 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2392 gmap->asce, IDTE_LOCAL);
2393 else if (MACHINE_HAS_IDTE)
2394 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_LOCAL);
2395 *entry = _SEGMENT_ENTRY_EMPTY;
2396 }
2397 spin_unlock(&gmap->guest_table_lock);
2398 }
2399 rcu_read_unlock();
2400}
2401EXPORT_SYMBOL_GPL(gmap_pmdp_idte_local);
2402
2403/**
2404 * gmap_pmdp_idte_global - invalidate and clear a guest pmd entry
2405 * @mm: pointer to the process mm_struct
2406 * @vmaddr: virtual address in the process address space
2407 */
2408void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
2409{
2410 unsigned long *entry, gaddr;
2411 struct gmap *gmap;
2412 pmd_t *pmdp;
2413
2414 rcu_read_lock();
2415 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2416 spin_lock(&gmap->guest_table_lock);
2417 entry = radix_tree_delete(&gmap->host_to_guest,
2418 vmaddr >> PMD_SHIFT);
2419 if (entry) {
2420 pmdp = (pmd_t *)entry;
2421 gaddr = __gmap_segment_gaddr(entry);
2422 pmdp_notify_gmap(gmap, pmdp, gaddr);
2423 WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
2424 _SEGMENT_ENTRY_GMAP_UC));
2425 if (MACHINE_HAS_TLB_GUEST)
2426 __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
2427 gmap->asce, IDTE_GLOBAL);
2428 else if (MACHINE_HAS_IDTE)
2429 __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_GLOBAL);
2430 else
2431 __pmdp_csp(pmdp);
2432 *entry = _SEGMENT_ENTRY_EMPTY;
2433 }
2434 spin_unlock(&gmap->guest_table_lock);
2435 }
2436 rcu_read_unlock();
2437}
2438EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global);
2439
2440/**
2441 * gmap_test_and_clear_dirty_pmd - test and reset segment dirty status
2442 * @gmap: pointer to guest address space
2443 * @pmdp: pointer to the pmd to be tested
2444 * @gaddr: virtual address in the guest address space
2445 *
2446 * This function is assumed to be called with the guest_table_lock
2447 * held.
2448 */
2449static bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp,
2450 unsigned long gaddr)
2451{
2452 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
2453 return false;
2454
2455 /* Already protected memory, which did not change is clean */
2456 if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT &&
2457 !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
2458 return false;
2459
2460 /* Clear UC indication and reset protection */
2461 set_pmd(pmdp, clear_pmd_bit(*pmdp, __pgprot(_SEGMENT_ENTRY_GMAP_UC)));
2462 gmap_protect_pmd(gmap, gaddr, pmdp, PROT_READ, 0);
2463 return true;
2464}
2465
2466/**
2467 * gmap_sync_dirty_log_pmd - set bitmap based on dirty status of segment
2468 * @gmap: pointer to guest address space
2469 * @bitmap: dirty bitmap for this pmd
2470 * @gaddr: virtual address in the guest address space
2471 * @vmaddr: virtual address in the host address space
2472 *
2473 * This function is assumed to be called with the guest_table_lock
2474 * held.
2475 */
2476void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
2477 unsigned long gaddr, unsigned long vmaddr)
2478{
2479 int i;
2480 pmd_t *pmdp;
2481 pte_t *ptep;
2482 spinlock_t *ptl;
2483
2484 pmdp = gmap_pmd_op_walk(gmap, gaddr);
2485 if (!pmdp)
2486 return;
2487
2488 if (pmd_large(*pmdp)) {
2489 if (gmap_test_and_clear_dirty_pmd(gmap, pmdp, gaddr))
2490 bitmap_fill(bitmap, _PAGE_ENTRIES);
2491 } else {
2492 for (i = 0; i < _PAGE_ENTRIES; i++, vmaddr += PAGE_SIZE) {
2493 ptep = pte_alloc_map_lock(gmap->mm, pmdp, vmaddr, &ptl);
2494 if (!ptep)
2495 continue;
2496 if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep))
2497 set_bit(i, bitmap);
2498 spin_unlock(ptl);
2499 }
2500 }
2501 gmap_pmd_op_end(gmap, pmdp);
2502}
2503EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
2504
2505#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2506static int thp_split_walk_pmd_entry(pmd_t *pmd, unsigned long addr,
2507 unsigned long end, struct mm_walk *walk)
2508{
2509 struct vm_area_struct *vma = walk->vma;
2510
2511 split_huge_pmd(vma, pmd, addr);
2512 return 0;
2513}
2514
2515static const struct mm_walk_ops thp_split_walk_ops = {
2516 .pmd_entry = thp_split_walk_pmd_entry,
2517};
2518
2519static inline void thp_split_mm(struct mm_struct *mm)
2520{
2521 struct vm_area_struct *vma;
2522 VMA_ITERATOR(vmi, mm, 0);
2523
2524 for_each_vma(vmi, vma) {
2525 vma->vm_flags &= ~VM_HUGEPAGE;
2526 vma->vm_flags |= VM_NOHUGEPAGE;
2527 walk_page_vma(vma, &thp_split_walk_ops, NULL);
2528 }
2529 mm->def_flags |= VM_NOHUGEPAGE;
2530}
2531#else
2532static inline void thp_split_mm(struct mm_struct *mm)
2533{
2534}
2535#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
2536
2537/*
2538 * Remove all empty zero pages from the mapping for lazy refaulting
2539 * - This must be called after mm->context.has_pgste is set, to avoid
2540 * future creation of zero pages
2541 * - This must be called after THP was enabled
2542 */
2543static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
2544 unsigned long end, struct mm_walk *walk)
2545{
2546 unsigned long addr;
2547
2548 for (addr = start; addr != end; addr += PAGE_SIZE) {
2549 pte_t *ptep;
2550 spinlock_t *ptl;
2551
2552 ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
2553 if (is_zero_pfn(pte_pfn(*ptep)))
2554 ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID));
2555 pte_unmap_unlock(ptep, ptl);
2556 }
2557 return 0;
2558}
2559
2560static const struct mm_walk_ops zap_zero_walk_ops = {
2561 .pmd_entry = __zap_zero_pages,
2562};
2563
2564/*
2565 * switch on pgstes for its userspace process (for kvm)
2566 */
2567int s390_enable_sie(void)
2568{
2569 struct mm_struct *mm = current->mm;
2570
2571 /* Do we have pgstes? if yes, we are done */
2572 if (mm_has_pgste(mm))
2573 return 0;
2574 /* Fail if the page tables are 2K */
2575 if (!mm_alloc_pgste(mm))
2576 return -EINVAL;
2577 mmap_write_lock(mm);
2578 mm->context.has_pgste = 1;
2579 /* split thp mappings and disable thp for future mappings */
2580 thp_split_mm(mm);
2581 walk_page_range(mm, 0, TASK_SIZE, &zap_zero_walk_ops, NULL);
2582 mmap_write_unlock(mm);
2583 return 0;
2584}
2585EXPORT_SYMBOL_GPL(s390_enable_sie);
2586
2587int gmap_mark_unmergeable(void)
2588{
2589 struct mm_struct *mm = current->mm;
2590 struct vm_area_struct *vma;
2591 int ret;
2592 VMA_ITERATOR(vmi, mm, 0);
2593
2594 for_each_vma(vmi, vma) {
2595 ret = ksm_madvise(vma, vma->vm_start, vma->vm_end,
2596 MADV_UNMERGEABLE, &vma->vm_flags);
2597 if (ret)
2598 return ret;
2599 }
2600 mm->def_flags &= ~VM_MERGEABLE;
2601 return 0;
2602}
2603EXPORT_SYMBOL_GPL(gmap_mark_unmergeable);
2604
2605/*
2606 * Enable storage key handling from now on and initialize the storage
2607 * keys with the default key.
2608 */
2609static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
2610 unsigned long next, struct mm_walk *walk)
2611{
2612 /* Clear storage key */
2613 ptep_zap_key(walk->mm, addr, pte);
2614 return 0;
2615}
2616
2617/*
2618 * Give a chance to schedule after setting a key to 256 pages.
2619 * We only hold the mm lock, which is a rwsem and the kvm srcu.
2620 * Both can sleep.
2621 */
2622static int __s390_enable_skey_pmd(pmd_t *pmd, unsigned long addr,
2623 unsigned long next, struct mm_walk *walk)
2624{
2625 cond_resched();
2626 return 0;
2627}
2628
2629static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
2630 unsigned long hmask, unsigned long next,
2631 struct mm_walk *walk)
2632{
2633 pmd_t *pmd = (pmd_t *)pte;
2634 unsigned long start, end;
2635 struct page *page = pmd_page(*pmd);
2636
2637 /*
2638 * The write check makes sure we do not set a key on shared
2639 * memory. This is needed as the walker does not differentiate
2640 * between actual guest memory and the process executable or
2641 * shared libraries.
2642 */
2643 if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
2644 !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
2645 return 0;
2646
2647 start = pmd_val(*pmd) & HPAGE_MASK;
2648 end = start + HPAGE_SIZE - 1;
2649 __storage_key_init_range(start, end);
2650 set_bit(PG_arch_1, &page->flags);
2651 cond_resched();
2652 return 0;
2653}
2654
2655static const struct mm_walk_ops enable_skey_walk_ops = {
2656 .hugetlb_entry = __s390_enable_skey_hugetlb,
2657 .pte_entry = __s390_enable_skey_pte,
2658 .pmd_entry = __s390_enable_skey_pmd,
2659};
2660
2661int s390_enable_skey(void)
2662{
2663 struct mm_struct *mm = current->mm;
2664 int rc = 0;
2665
2666 mmap_write_lock(mm);
2667 if (mm_uses_skeys(mm))
2668 goto out_up;
2669
2670 mm->context.uses_skeys = 1;
2671 rc = gmap_mark_unmergeable();
2672 if (rc) {
2673 mm->context.uses_skeys = 0;
2674 goto out_up;
2675 }
2676 walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL);
2677
2678out_up:
2679 mmap_write_unlock(mm);
2680 return rc;
2681}
2682EXPORT_SYMBOL_GPL(s390_enable_skey);
2683
2684/*
2685 * Reset CMMA state, make all pages stable again.
2686 */
2687static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
2688 unsigned long next, struct mm_walk *walk)
2689{
2690 ptep_zap_unused(walk->mm, addr, pte, 1);
2691 return 0;
2692}
2693
2694static const struct mm_walk_ops reset_cmma_walk_ops = {
2695 .pte_entry = __s390_reset_cmma,
2696};
2697
2698void s390_reset_cmma(struct mm_struct *mm)
2699{
2700 mmap_write_lock(mm);
2701 walk_page_range(mm, 0, TASK_SIZE, &reset_cmma_walk_ops, NULL);
2702 mmap_write_unlock(mm);
2703}
2704EXPORT_SYMBOL_GPL(s390_reset_cmma);
2705
2706#define GATHER_GET_PAGES 32
2707
2708struct reset_walk_state {
2709 unsigned long next;
2710 unsigned long count;
2711 unsigned long pfns[GATHER_GET_PAGES];
2712};
2713
2714static int s390_gather_pages(pte_t *ptep, unsigned long addr,
2715 unsigned long next, struct mm_walk *walk)
2716{
2717 struct reset_walk_state *p = walk->private;
2718 pte_t pte = READ_ONCE(*ptep);
2719
2720 if (pte_present(pte)) {
2721 /* we have a reference from the mapping, take an extra one */
2722 get_page(phys_to_page(pte_val(pte)));
2723 p->pfns[p->count] = phys_to_pfn(pte_val(pte));
2724 p->next = next;
2725 p->count++;
2726 }
2727 return p->count >= GATHER_GET_PAGES;
2728}
2729
2730static const struct mm_walk_ops gather_pages_ops = {
2731 .pte_entry = s390_gather_pages,
2732};
2733
2734/*
2735 * Call the Destroy secure page UVC on each page in the given array of PFNs.
2736 * Each page needs to have an extra reference, which will be released here.
2737 */
2738void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns)
2739{
2740 unsigned long i;
2741
2742 for (i = 0; i < count; i++) {
2743 /* we always have an extra reference */
2744 uv_destroy_owned_page(pfn_to_phys(pfns[i]));
2745 /* get rid of the extra reference */
2746 put_page(pfn_to_page(pfns[i]));
2747 cond_resched();
2748 }
2749}
2750EXPORT_SYMBOL_GPL(s390_uv_destroy_pfns);
2751
2752/**
2753 * __s390_uv_destroy_range - Call the destroy secure page UVC on each page
2754 * in the given range of the given address space.
2755 * @mm: the mm to operate on
2756 * @start: the start of the range
2757 * @end: the end of the range
2758 * @interruptible: if not 0, stop when a fatal signal is received
2759 *
2760 * Walk the given range of the given address space and call the destroy
2761 * secure page UVC on each page. Optionally exit early if a fatal signal is
2762 * pending.
2763 *
2764 * Return: 0 on success, -EINTR if the function stopped before completing
2765 */
2766int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
2767 unsigned long end, bool interruptible)
2768{
2769 struct reset_walk_state state = { .next = start };
2770 int r = 1;
2771
2772 while (r > 0) {
2773 state.count = 0;
2774 mmap_read_lock(mm);
2775 r = walk_page_range(mm, state.next, end, &gather_pages_ops, &state);
2776 mmap_read_unlock(mm);
2777 cond_resched();
2778 s390_uv_destroy_pfns(state.count, state.pfns);
2779 if (interruptible && fatal_signal_pending(current))
2780 return -EINTR;
2781 }
2782 return 0;
2783}
2784EXPORT_SYMBOL_GPL(__s390_uv_destroy_range);
2785
2786/**
2787 * s390_unlist_old_asce - Remove the topmost level of page tables from the
2788 * list of page tables of the gmap.
2789 * @gmap: the gmap whose table is to be removed
2790 *
2791 * On s390x, KVM keeps a list of all pages containing the page tables of the
2792 * gmap (the CRST list). This list is used at tear down time to free all
2793 * pages that are now not needed anymore.
2794 *
2795 * This function removes the topmost page of the tree (the one pointed to by
2796 * the ASCE) from the CRST list.
2797 *
2798 * This means that it will not be freed when the VM is torn down, and needs
2799 * to be handled separately by the caller, unless a leak is actually
2800 * intended. Notice that this function will only remove the page from the
2801 * list, the page will still be used as a top level page table (and ASCE).
2802 */
2803void s390_unlist_old_asce(struct gmap *gmap)
2804{
2805 struct page *old;
2806
2807 old = virt_to_page(gmap->table);
2808 spin_lock(&gmap->guest_table_lock);
2809 list_del(&old->lru);
2810 /*
2811 * Sometimes the topmost page might need to be "removed" multiple
2812 * times, for example if the VM is rebooted into secure mode several
2813 * times concurrently, or if s390_replace_asce fails after calling
2814 * s390_remove_old_asce and is attempted again later. In that case
2815 * the old asce has been removed from the list, and therefore it
2816 * will not be freed when the VM terminates, but the ASCE is still
2817 * in use and still pointed to.
2818 * A subsequent call to replace_asce will follow the pointer and try
2819 * to remove the same page from the list again.
2820 * Therefore it's necessary that the page of the ASCE has valid
2821 * pointers, so list_del can work (and do nothing) without
2822 * dereferencing stale or invalid pointers.
2823 */
2824 INIT_LIST_HEAD(&old->lru);
2825 spin_unlock(&gmap->guest_table_lock);
2826}
2827EXPORT_SYMBOL_GPL(s390_unlist_old_asce);
2828
2829/**
2830 * s390_replace_asce - Try to replace the current ASCE of a gmap with a copy
2831 * @gmap: the gmap whose ASCE needs to be replaced
2832 *
2833 * If the allocation of the new top level page table fails, the ASCE is not
2834 * replaced.
2835 * In any case, the old ASCE is always removed from the gmap CRST list.
2836 * Therefore the caller has to make sure to save a pointer to it
2837 * beforehand, unless a leak is actually intended.
2838 */
2839int s390_replace_asce(struct gmap *gmap)
2840{
2841 unsigned long asce;
2842 struct page *page;
2843 void *table;
2844
2845 s390_unlist_old_asce(gmap);
2846
2847 page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER);
2848 if (!page)
2849 return -ENOMEM;
2850 table = page_to_virt(page);
2851 memcpy(table, gmap->table, 1UL << (CRST_ALLOC_ORDER + PAGE_SHIFT));
2852
2853 /*
2854 * The caller has to deal with the old ASCE, but here we make sure
2855 * the new one is properly added to the CRST list, so that
2856 * it will be freed when the VM is torn down.
2857 */
2858 spin_lock(&gmap->guest_table_lock);
2859 list_add(&page->lru, &gmap->crst_list);
2860 spin_unlock(&gmap->guest_table_lock);
2861
2862 /* Set new table origin while preserving existing ASCE control bits */
2863 asce = (gmap->asce & ~_ASCE_ORIGIN) | __pa(table);
2864 WRITE_ONCE(gmap->asce, asce);
2865 WRITE_ONCE(gmap->mm->context.gmap_asce, asce);
2866 WRITE_ONCE(gmap->table, table);
2867
2868 return 0;
2869}
2870EXPORT_SYMBOL_GPL(s390_replace_asce);
1/*
2 * KVM guest address space mapping code
3 *
4 * Copyright IBM Corp. 2007, 2016
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6 */
7
8#include <linux/kernel.h>
9#include <linux/mm.h>
10#include <linux/swap.h>
11#include <linux/smp.h>
12#include <linux/spinlock.h>
13#include <linux/slab.h>
14#include <linux/swapops.h>
15#include <linux/ksm.h>
16#include <linux/mman.h>
17
18#include <asm/pgtable.h>
19#include <asm/pgalloc.h>
20#include <asm/gmap.h>
21#include <asm/tlb.h>
22
23#define GMAP_SHADOW_FAKE_TABLE 1ULL
24
25/**
26 * gmap_alloc - allocate and initialize a guest address space
27 * @mm: pointer to the parent mm_struct
28 * @limit: maximum address of the gmap address space
29 *
30 * Returns a guest address space structure.
31 */
32static struct gmap *gmap_alloc(unsigned long limit)
33{
34 struct gmap *gmap;
35 struct page *page;
36 unsigned long *table;
37 unsigned long etype, atype;
38
39 if (limit < (1UL << 31)) {
40 limit = (1UL << 31) - 1;
41 atype = _ASCE_TYPE_SEGMENT;
42 etype = _SEGMENT_ENTRY_EMPTY;
43 } else if (limit < (1UL << 42)) {
44 limit = (1UL << 42) - 1;
45 atype = _ASCE_TYPE_REGION3;
46 etype = _REGION3_ENTRY_EMPTY;
47 } else if (limit < (1UL << 53)) {
48 limit = (1UL << 53) - 1;
49 atype = _ASCE_TYPE_REGION2;
50 etype = _REGION2_ENTRY_EMPTY;
51 } else {
52 limit = -1UL;
53 atype = _ASCE_TYPE_REGION1;
54 etype = _REGION1_ENTRY_EMPTY;
55 }
56 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
57 if (!gmap)
58 goto out;
59 INIT_LIST_HEAD(&gmap->crst_list);
60 INIT_LIST_HEAD(&gmap->children);
61 INIT_LIST_HEAD(&gmap->pt_list);
62 INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
63 INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
64 INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC);
65 spin_lock_init(&gmap->guest_table_lock);
66 spin_lock_init(&gmap->shadow_lock);
67 atomic_set(&gmap->ref_count, 1);
68 page = alloc_pages(GFP_KERNEL, 2);
69 if (!page)
70 goto out_free;
71 page->index = 0;
72 list_add(&page->lru, &gmap->crst_list);
73 table = (unsigned long *) page_to_phys(page);
74 crst_table_init(table, etype);
75 gmap->table = table;
76 gmap->asce = atype | _ASCE_TABLE_LENGTH |
77 _ASCE_USER_BITS | __pa(table);
78 gmap->asce_end = limit;
79 return gmap;
80
81out_free:
82 kfree(gmap);
83out:
84 return NULL;
85}
86
87/**
88 * gmap_create - create a guest address space
89 * @mm: pointer to the parent mm_struct
90 * @limit: maximum size of the gmap address space
91 *
92 * Returns a guest address space structure.
93 */
94struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
95{
96 struct gmap *gmap;
97 unsigned long gmap_asce;
98
99 gmap = gmap_alloc(limit);
100 if (!gmap)
101 return NULL;
102 gmap->mm = mm;
103 spin_lock(&mm->context.gmap_lock);
104 list_add_rcu(&gmap->list, &mm->context.gmap_list);
105 if (list_is_singular(&mm->context.gmap_list))
106 gmap_asce = gmap->asce;
107 else
108 gmap_asce = -1UL;
109 WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
110 spin_unlock(&mm->context.gmap_lock);
111 return gmap;
112}
113EXPORT_SYMBOL_GPL(gmap_create);
114
115static void gmap_flush_tlb(struct gmap *gmap)
116{
117 if (MACHINE_HAS_IDTE)
118 __tlb_flush_idte(gmap->asce);
119 else
120 __tlb_flush_global();
121}
122
123static void gmap_radix_tree_free(struct radix_tree_root *root)
124{
125 struct radix_tree_iter iter;
126 unsigned long indices[16];
127 unsigned long index;
128 void **slot;
129 int i, nr;
130
131 /* A radix tree is freed by deleting all of its entries */
132 index = 0;
133 do {
134 nr = 0;
135 radix_tree_for_each_slot(slot, root, &iter, index) {
136 indices[nr] = iter.index;
137 if (++nr == 16)
138 break;
139 }
140 for (i = 0; i < nr; i++) {
141 index = indices[i];
142 radix_tree_delete(root, index);
143 }
144 } while (nr > 0);
145}
146
147static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
148{
149 struct gmap_rmap *rmap, *rnext, *head;
150 struct radix_tree_iter iter;
151 unsigned long indices[16];
152 unsigned long index;
153 void **slot;
154 int i, nr;
155
156 /* A radix tree is freed by deleting all of its entries */
157 index = 0;
158 do {
159 nr = 0;
160 radix_tree_for_each_slot(slot, root, &iter, index) {
161 indices[nr] = iter.index;
162 if (++nr == 16)
163 break;
164 }
165 for (i = 0; i < nr; i++) {
166 index = indices[i];
167 head = radix_tree_delete(root, index);
168 gmap_for_each_rmap_safe(rmap, rnext, head)
169 kfree(rmap);
170 }
171 } while (nr > 0);
172}
173
174/**
175 * gmap_free - free a guest address space
176 * @gmap: pointer to the guest address space structure
177 *
178 * No locks required. There are no references to this gmap anymore.
179 */
180static void gmap_free(struct gmap *gmap)
181{
182 struct page *page, *next;
183
184 /* Flush tlb of all gmaps (if not already done for shadows) */
185 if (!(gmap_is_shadow(gmap) && gmap->removed))
186 gmap_flush_tlb(gmap);
187 /* Free all segment & region tables. */
188 list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
189 __free_pages(page, 2);
190 gmap_radix_tree_free(&gmap->guest_to_host);
191 gmap_radix_tree_free(&gmap->host_to_guest);
192
193 /* Free additional data for a shadow gmap */
194 if (gmap_is_shadow(gmap)) {
195 /* Free all page tables. */
196 list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
197 page_table_free_pgste(page);
198 gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
199 /* Release reference to the parent */
200 gmap_put(gmap->parent);
201 }
202
203 kfree(gmap);
204}
205
206/**
207 * gmap_get - increase reference counter for guest address space
208 * @gmap: pointer to the guest address space structure
209 *
210 * Returns the gmap pointer
211 */
212struct gmap *gmap_get(struct gmap *gmap)
213{
214 atomic_inc(&gmap->ref_count);
215 return gmap;
216}
217EXPORT_SYMBOL_GPL(gmap_get);
218
219/**
220 * gmap_put - decrease reference counter for guest address space
221 * @gmap: pointer to the guest address space structure
222 *
223 * If the reference counter reaches zero the guest address space is freed.
224 */
225void gmap_put(struct gmap *gmap)
226{
227 if (atomic_dec_return(&gmap->ref_count) == 0)
228 gmap_free(gmap);
229}
230EXPORT_SYMBOL_GPL(gmap_put);
231
232/**
233 * gmap_remove - remove a guest address space but do not free it yet
234 * @gmap: pointer to the guest address space structure
235 */
236void gmap_remove(struct gmap *gmap)
237{
238 struct gmap *sg, *next;
239 unsigned long gmap_asce;
240
241 /* Remove all shadow gmaps linked to this gmap */
242 if (!list_empty(&gmap->children)) {
243 spin_lock(&gmap->shadow_lock);
244 list_for_each_entry_safe(sg, next, &gmap->children, list) {
245 list_del(&sg->list);
246 gmap_put(sg);
247 }
248 spin_unlock(&gmap->shadow_lock);
249 }
250 /* Remove gmap from the pre-mm list */
251 spin_lock(&gmap->mm->context.gmap_lock);
252 list_del_rcu(&gmap->list);
253 if (list_empty(&gmap->mm->context.gmap_list))
254 gmap_asce = 0;
255 else if (list_is_singular(&gmap->mm->context.gmap_list))
256 gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
257 struct gmap, list)->asce;
258 else
259 gmap_asce = -1UL;
260 WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
261 spin_unlock(&gmap->mm->context.gmap_lock);
262 synchronize_rcu();
263 /* Put reference */
264 gmap_put(gmap);
265}
266EXPORT_SYMBOL_GPL(gmap_remove);
267
268/**
269 * gmap_enable - switch primary space to the guest address space
270 * @gmap: pointer to the guest address space structure
271 */
272void gmap_enable(struct gmap *gmap)
273{
274 S390_lowcore.gmap = (unsigned long) gmap;
275}
276EXPORT_SYMBOL_GPL(gmap_enable);
277
278/**
279 * gmap_disable - switch back to the standard primary address space
280 * @gmap: pointer to the guest address space structure
281 */
282void gmap_disable(struct gmap *gmap)
283{
284 S390_lowcore.gmap = 0UL;
285}
286EXPORT_SYMBOL_GPL(gmap_disable);
287
288/**
289 * gmap_get_enabled - get a pointer to the currently enabled gmap
290 *
291 * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
292 */
293struct gmap *gmap_get_enabled(void)
294{
295 return (struct gmap *) S390_lowcore.gmap;
296}
297EXPORT_SYMBOL_GPL(gmap_get_enabled);
298
299/*
300 * gmap_alloc_table is assumed to be called with mmap_sem held
301 */
302static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
303 unsigned long init, unsigned long gaddr)
304{
305 struct page *page;
306 unsigned long *new;
307
308 /* since we dont free the gmap table until gmap_free we can unlock */
309 page = alloc_pages(GFP_KERNEL, 2);
310 if (!page)
311 return -ENOMEM;
312 new = (unsigned long *) page_to_phys(page);
313 crst_table_init(new, init);
314 spin_lock(&gmap->guest_table_lock);
315 if (*table & _REGION_ENTRY_INVALID) {
316 list_add(&page->lru, &gmap->crst_list);
317 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
318 (*table & _REGION_ENTRY_TYPE_MASK);
319 page->index = gaddr;
320 page = NULL;
321 }
322 spin_unlock(&gmap->guest_table_lock);
323 if (page)
324 __free_pages(page, 2);
325 return 0;
326}
327
328/**
329 * __gmap_segment_gaddr - find virtual address from segment pointer
330 * @entry: pointer to a segment table entry in the guest address space
331 *
332 * Returns the virtual address in the guest address space for the segment
333 */
334static unsigned long __gmap_segment_gaddr(unsigned long *entry)
335{
336 struct page *page;
337 unsigned long offset, mask;
338
339 offset = (unsigned long) entry / sizeof(unsigned long);
340 offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
341 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
342 page = virt_to_page((void *)((unsigned long) entry & mask));
343 return page->index + offset;
344}
345
346/**
347 * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
348 * @gmap: pointer to the guest address space structure
349 * @vmaddr: address in the host process address space
350 *
351 * Returns 1 if a TLB flush is required
352 */
353static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
354{
355 unsigned long *entry;
356 int flush = 0;
357
358 BUG_ON(gmap_is_shadow(gmap));
359 spin_lock(&gmap->guest_table_lock);
360 entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
361 if (entry) {
362 flush = (*entry != _SEGMENT_ENTRY_INVALID);
363 *entry = _SEGMENT_ENTRY_INVALID;
364 }
365 spin_unlock(&gmap->guest_table_lock);
366 return flush;
367}
368
369/**
370 * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
371 * @gmap: pointer to the guest address space structure
372 * @gaddr: address in the guest address space
373 *
374 * Returns 1 if a TLB flush is required
375 */
376static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
377{
378 unsigned long vmaddr;
379
380 vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
381 gaddr >> PMD_SHIFT);
382 return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
383}
384
385/**
386 * gmap_unmap_segment - unmap segment from the guest address space
387 * @gmap: pointer to the guest address space structure
388 * @to: address in the guest address space
389 * @len: length of the memory area to unmap
390 *
391 * Returns 0 if the unmap succeeded, -EINVAL if not.
392 */
393int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
394{
395 unsigned long off;
396 int flush;
397
398 BUG_ON(gmap_is_shadow(gmap));
399 if ((to | len) & (PMD_SIZE - 1))
400 return -EINVAL;
401 if (len == 0 || to + len < to)
402 return -EINVAL;
403
404 flush = 0;
405 down_write(&gmap->mm->mmap_sem);
406 for (off = 0; off < len; off += PMD_SIZE)
407 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
408 up_write(&gmap->mm->mmap_sem);
409 if (flush)
410 gmap_flush_tlb(gmap);
411 return 0;
412}
413EXPORT_SYMBOL_GPL(gmap_unmap_segment);
414
415/**
416 * gmap_map_segment - map a segment to the guest address space
417 * @gmap: pointer to the guest address space structure
418 * @from: source address in the parent address space
419 * @to: target address in the guest address space
420 * @len: length of the memory area to map
421 *
422 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
423 */
424int gmap_map_segment(struct gmap *gmap, unsigned long from,
425 unsigned long to, unsigned long len)
426{
427 unsigned long off;
428 int flush;
429
430 BUG_ON(gmap_is_shadow(gmap));
431 if ((from | to | len) & (PMD_SIZE - 1))
432 return -EINVAL;
433 if (len == 0 || from + len < from || to + len < to ||
434 from + len - 1 > TASK_MAX_SIZE || to + len - 1 > gmap->asce_end)
435 return -EINVAL;
436
437 flush = 0;
438 down_write(&gmap->mm->mmap_sem);
439 for (off = 0; off < len; off += PMD_SIZE) {
440 /* Remove old translation */
441 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
442 /* Store new translation */
443 if (radix_tree_insert(&gmap->guest_to_host,
444 (to + off) >> PMD_SHIFT,
445 (void *) from + off))
446 break;
447 }
448 up_write(&gmap->mm->mmap_sem);
449 if (flush)
450 gmap_flush_tlb(gmap);
451 if (off >= len)
452 return 0;
453 gmap_unmap_segment(gmap, to, len);
454 return -ENOMEM;
455}
456EXPORT_SYMBOL_GPL(gmap_map_segment);
457
458/**
459 * __gmap_translate - translate a guest address to a user space address
460 * @gmap: pointer to guest mapping meta data structure
461 * @gaddr: guest address
462 *
463 * Returns user space address which corresponds to the guest address or
464 * -EFAULT if no such mapping exists.
465 * This function does not establish potentially missing page table entries.
466 * The mmap_sem of the mm that belongs to the address space must be held
467 * when this function gets called.
468 *
469 * Note: Can also be called for shadow gmaps.
470 */
471unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
472{
473 unsigned long vmaddr;
474
475 vmaddr = (unsigned long)
476 radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
477 /* Note: guest_to_host is empty for a shadow gmap */
478 return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
479}
480EXPORT_SYMBOL_GPL(__gmap_translate);
481
482/**
483 * gmap_translate - translate a guest address to a user space address
484 * @gmap: pointer to guest mapping meta data structure
485 * @gaddr: guest address
486 *
487 * Returns user space address which corresponds to the guest address or
488 * -EFAULT if no such mapping exists.
489 * This function does not establish potentially missing page table entries.
490 */
491unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
492{
493 unsigned long rc;
494
495 down_read(&gmap->mm->mmap_sem);
496 rc = __gmap_translate(gmap, gaddr);
497 up_read(&gmap->mm->mmap_sem);
498 return rc;
499}
500EXPORT_SYMBOL_GPL(gmap_translate);
501
502/**
503 * gmap_unlink - disconnect a page table from the gmap shadow tables
504 * @gmap: pointer to guest mapping meta data structure
505 * @table: pointer to the host page table
506 * @vmaddr: vm address associated with the host page table
507 */
508void gmap_unlink(struct mm_struct *mm, unsigned long *table,
509 unsigned long vmaddr)
510{
511 struct gmap *gmap;
512 int flush;
513
514 rcu_read_lock();
515 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
516 flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
517 if (flush)
518 gmap_flush_tlb(gmap);
519 }
520 rcu_read_unlock();
521}
522
523/**
524 * gmap_link - set up shadow page tables to connect a host to a guest address
525 * @gmap: pointer to guest mapping meta data structure
526 * @gaddr: guest address
527 * @vmaddr: vm address
528 *
529 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
530 * if the vm address is already mapped to a different guest segment.
531 * The mmap_sem of the mm that belongs to the address space must be held
532 * when this function gets called.
533 */
534int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
535{
536 struct mm_struct *mm;
537 unsigned long *table;
538 spinlock_t *ptl;
539 pgd_t *pgd;
540 pud_t *pud;
541 pmd_t *pmd;
542 int rc;
543
544 BUG_ON(gmap_is_shadow(gmap));
545 /* Create higher level tables in the gmap page table */
546 table = gmap->table;
547 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
548 table += (gaddr >> 53) & 0x7ff;
549 if ((*table & _REGION_ENTRY_INVALID) &&
550 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
551 gaddr & 0xffe0000000000000UL))
552 return -ENOMEM;
553 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
554 }
555 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
556 table += (gaddr >> 42) & 0x7ff;
557 if ((*table & _REGION_ENTRY_INVALID) &&
558 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
559 gaddr & 0xfffffc0000000000UL))
560 return -ENOMEM;
561 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
562 }
563 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
564 table += (gaddr >> 31) & 0x7ff;
565 if ((*table & _REGION_ENTRY_INVALID) &&
566 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
567 gaddr & 0xffffffff80000000UL))
568 return -ENOMEM;
569 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
570 }
571 table += (gaddr >> 20) & 0x7ff;
572 /* Walk the parent mm page table */
573 mm = gmap->mm;
574 pgd = pgd_offset(mm, vmaddr);
575 VM_BUG_ON(pgd_none(*pgd));
576 pud = pud_offset(pgd, vmaddr);
577 VM_BUG_ON(pud_none(*pud));
578 /* large puds cannot yet be handled */
579 if (pud_large(*pud))
580 return -EFAULT;
581 pmd = pmd_offset(pud, vmaddr);
582 VM_BUG_ON(pmd_none(*pmd));
583 /* large pmds cannot yet be handled */
584 if (pmd_large(*pmd))
585 return -EFAULT;
586 /* Link gmap segment table entry location to page table. */
587 rc = radix_tree_preload(GFP_KERNEL);
588 if (rc)
589 return rc;
590 ptl = pmd_lock(mm, pmd);
591 spin_lock(&gmap->guest_table_lock);
592 if (*table == _SEGMENT_ENTRY_INVALID) {
593 rc = radix_tree_insert(&gmap->host_to_guest,
594 vmaddr >> PMD_SHIFT, table);
595 if (!rc)
596 *table = pmd_val(*pmd);
597 } else
598 rc = 0;
599 spin_unlock(&gmap->guest_table_lock);
600 spin_unlock(ptl);
601 radix_tree_preload_end();
602 return rc;
603}
604
605/**
606 * gmap_fault - resolve a fault on a guest address
607 * @gmap: pointer to guest mapping meta data structure
608 * @gaddr: guest address
609 * @fault_flags: flags to pass down to handle_mm_fault()
610 *
611 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
612 * if the vm address is already mapped to a different guest segment.
613 */
614int gmap_fault(struct gmap *gmap, unsigned long gaddr,
615 unsigned int fault_flags)
616{
617 unsigned long vmaddr;
618 int rc;
619 bool unlocked;
620
621 down_read(&gmap->mm->mmap_sem);
622
623retry:
624 unlocked = false;
625 vmaddr = __gmap_translate(gmap, gaddr);
626 if (IS_ERR_VALUE(vmaddr)) {
627 rc = vmaddr;
628 goto out_up;
629 }
630 if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
631 &unlocked)) {
632 rc = -EFAULT;
633 goto out_up;
634 }
635 /*
636 * In the case that fixup_user_fault unlocked the mmap_sem during
637 * faultin redo __gmap_translate to not race with a map/unmap_segment.
638 */
639 if (unlocked)
640 goto retry;
641
642 rc = __gmap_link(gmap, gaddr, vmaddr);
643out_up:
644 up_read(&gmap->mm->mmap_sem);
645 return rc;
646}
647EXPORT_SYMBOL_GPL(gmap_fault);
648
649/*
650 * this function is assumed to be called with mmap_sem held
651 */
652void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
653{
654 unsigned long vmaddr;
655 spinlock_t *ptl;
656 pte_t *ptep;
657
658 /* Find the vm address for the guest address */
659 vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
660 gaddr >> PMD_SHIFT);
661 if (vmaddr) {
662 vmaddr |= gaddr & ~PMD_MASK;
663 /* Get pointer to the page table entry */
664 ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
665 if (likely(ptep))
666 ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
667 pte_unmap_unlock(ptep, ptl);
668 }
669}
670EXPORT_SYMBOL_GPL(__gmap_zap);
671
672void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
673{
674 unsigned long gaddr, vmaddr, size;
675 struct vm_area_struct *vma;
676
677 down_read(&gmap->mm->mmap_sem);
678 for (gaddr = from; gaddr < to;
679 gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
680 /* Find the vm address for the guest address */
681 vmaddr = (unsigned long)
682 radix_tree_lookup(&gmap->guest_to_host,
683 gaddr >> PMD_SHIFT);
684 if (!vmaddr)
685 continue;
686 vmaddr |= gaddr & ~PMD_MASK;
687 /* Find vma in the parent mm */
688 vma = find_vma(gmap->mm, vmaddr);
689 size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
690 zap_page_range(vma, vmaddr, size, NULL);
691 }
692 up_read(&gmap->mm->mmap_sem);
693}
694EXPORT_SYMBOL_GPL(gmap_discard);
695
696static LIST_HEAD(gmap_notifier_list);
697static DEFINE_SPINLOCK(gmap_notifier_lock);
698
699/**
700 * gmap_register_pte_notifier - register a pte invalidation callback
701 * @nb: pointer to the gmap notifier block
702 */
703void gmap_register_pte_notifier(struct gmap_notifier *nb)
704{
705 spin_lock(&gmap_notifier_lock);
706 list_add_rcu(&nb->list, &gmap_notifier_list);
707 spin_unlock(&gmap_notifier_lock);
708}
709EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
710
711/**
712 * gmap_unregister_pte_notifier - remove a pte invalidation callback
713 * @nb: pointer to the gmap notifier block
714 */
715void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
716{
717 spin_lock(&gmap_notifier_lock);
718 list_del_rcu(&nb->list);
719 spin_unlock(&gmap_notifier_lock);
720 synchronize_rcu();
721}
722EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
723
724/**
725 * gmap_call_notifier - call all registered invalidation callbacks
726 * @gmap: pointer to guest mapping meta data structure
727 * @start: start virtual address in the guest address space
728 * @end: end virtual address in the guest address space
729 */
730static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
731 unsigned long end)
732{
733 struct gmap_notifier *nb;
734
735 list_for_each_entry(nb, &gmap_notifier_list, list)
736 nb->notifier_call(gmap, start, end);
737}
738
739/**
740 * gmap_table_walk - walk the gmap page tables
741 * @gmap: pointer to guest mapping meta data structure
742 * @gaddr: virtual address in the guest address space
743 * @level: page table level to stop at
744 *
745 * Returns a table entry pointer for the given guest address and @level
746 * @level=0 : returns a pointer to a page table table entry (or NULL)
747 * @level=1 : returns a pointer to a segment table entry (or NULL)
748 * @level=2 : returns a pointer to a region-3 table entry (or NULL)
749 * @level=3 : returns a pointer to a region-2 table entry (or NULL)
750 * @level=4 : returns a pointer to a region-1 table entry (or NULL)
751 *
752 * Returns NULL if the gmap page tables could not be walked to the
753 * requested level.
754 *
755 * Note: Can also be called for shadow gmaps.
756 */
757static inline unsigned long *gmap_table_walk(struct gmap *gmap,
758 unsigned long gaddr, int level)
759{
760 unsigned long *table;
761
762 if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
763 return NULL;
764 if (gmap_is_shadow(gmap) && gmap->removed)
765 return NULL;
766 if (gaddr & (-1UL << (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11)))
767 return NULL;
768 table = gmap->table;
769 switch (gmap->asce & _ASCE_TYPE_MASK) {
770 case _ASCE_TYPE_REGION1:
771 table += (gaddr >> 53) & 0x7ff;
772 if (level == 4)
773 break;
774 if (*table & _REGION_ENTRY_INVALID)
775 return NULL;
776 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
777 /* Fallthrough */
778 case _ASCE_TYPE_REGION2:
779 table += (gaddr >> 42) & 0x7ff;
780 if (level == 3)
781 break;
782 if (*table & _REGION_ENTRY_INVALID)
783 return NULL;
784 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
785 /* Fallthrough */
786 case _ASCE_TYPE_REGION3:
787 table += (gaddr >> 31) & 0x7ff;
788 if (level == 2)
789 break;
790 if (*table & _REGION_ENTRY_INVALID)
791 return NULL;
792 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
793 /* Fallthrough */
794 case _ASCE_TYPE_SEGMENT:
795 table += (gaddr >> 20) & 0x7ff;
796 if (level == 1)
797 break;
798 if (*table & _REGION_ENTRY_INVALID)
799 return NULL;
800 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
801 table += (gaddr >> 12) & 0xff;
802 }
803 return table;
804}
805
806/**
807 * gmap_pte_op_walk - walk the gmap page table, get the page table lock
808 * and return the pte pointer
809 * @gmap: pointer to guest mapping meta data structure
810 * @gaddr: virtual address in the guest address space
811 * @ptl: pointer to the spinlock pointer
812 *
813 * Returns a pointer to the locked pte for a guest address, or NULL
814 *
815 * Note: Can also be called for shadow gmaps.
816 */
817static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
818 spinlock_t **ptl)
819{
820 unsigned long *table;
821
822 if (gmap_is_shadow(gmap))
823 spin_lock(&gmap->guest_table_lock);
824 /* Walk the gmap page table, lock and get pte pointer */
825 table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
826 if (!table || *table & _SEGMENT_ENTRY_INVALID) {
827 if (gmap_is_shadow(gmap))
828 spin_unlock(&gmap->guest_table_lock);
829 return NULL;
830 }
831 if (gmap_is_shadow(gmap)) {
832 *ptl = &gmap->guest_table_lock;
833 return pte_offset_map((pmd_t *) table, gaddr);
834 }
835 return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
836}
837
838/**
839 * gmap_pte_op_fixup - force a page in and connect the gmap page table
840 * @gmap: pointer to guest mapping meta data structure
841 * @gaddr: virtual address in the guest address space
842 * @vmaddr: address in the host process address space
843 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
844 *
845 * Returns 0 if the caller can retry __gmap_translate (might fail again),
846 * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
847 * up or connecting the gmap page table.
848 */
849static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
850 unsigned long vmaddr, int prot)
851{
852 struct mm_struct *mm = gmap->mm;
853 unsigned int fault_flags;
854 bool unlocked = false;
855
856 BUG_ON(gmap_is_shadow(gmap));
857 fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
858 if (fixup_user_fault(current, mm, vmaddr, fault_flags, &unlocked))
859 return -EFAULT;
860 if (unlocked)
861 /* lost mmap_sem, caller has to retry __gmap_translate */
862 return 0;
863 /* Connect the page tables */
864 return __gmap_link(gmap, gaddr, vmaddr);
865}
866
867/**
868 * gmap_pte_op_end - release the page table lock
869 * @ptl: pointer to the spinlock pointer
870 */
871static void gmap_pte_op_end(spinlock_t *ptl)
872{
873 spin_unlock(ptl);
874}
875
876/*
877 * gmap_protect_range - remove access rights to memory and set pgste bits
878 * @gmap: pointer to guest mapping meta data structure
879 * @gaddr: virtual address in the guest address space
880 * @len: size of area
881 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
882 * @bits: pgste notification bits to set
883 *
884 * Returns 0 if successfully protected, -ENOMEM if out of memory and
885 * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
886 *
887 * Called with sg->mm->mmap_sem in read.
888 *
889 * Note: Can also be called for shadow gmaps.
890 */
891static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
892 unsigned long len, int prot, unsigned long bits)
893{
894 unsigned long vmaddr;
895 spinlock_t *ptl;
896 pte_t *ptep;
897 int rc;
898
899 while (len) {
900 rc = -EAGAIN;
901 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
902 if (ptep) {
903 rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits);
904 gmap_pte_op_end(ptl);
905 }
906 if (rc) {
907 vmaddr = __gmap_translate(gmap, gaddr);
908 if (IS_ERR_VALUE(vmaddr))
909 return vmaddr;
910 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
911 if (rc)
912 return rc;
913 continue;
914 }
915 gaddr += PAGE_SIZE;
916 len -= PAGE_SIZE;
917 }
918 return 0;
919}
920
921/**
922 * gmap_mprotect_notify - change access rights for a range of ptes and
923 * call the notifier if any pte changes again
924 * @gmap: pointer to guest mapping meta data structure
925 * @gaddr: virtual address in the guest address space
926 * @len: size of area
927 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
928 *
929 * Returns 0 if for each page in the given range a gmap mapping exists,
930 * the new access rights could be set and the notifier could be armed.
931 * If the gmap mapping is missing for one or more pages -EFAULT is
932 * returned. If no memory could be allocated -ENOMEM is returned.
933 * This function establishes missing page table entries.
934 */
935int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
936 unsigned long len, int prot)
937{
938 int rc;
939
940 if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
941 return -EINVAL;
942 if (!MACHINE_HAS_ESOP && prot == PROT_READ)
943 return -EINVAL;
944 down_read(&gmap->mm->mmap_sem);
945 rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT);
946 up_read(&gmap->mm->mmap_sem);
947 return rc;
948}
949EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
950
951/**
952 * gmap_read_table - get an unsigned long value from a guest page table using
953 * absolute addressing, without marking the page referenced.
954 * @gmap: pointer to guest mapping meta data structure
955 * @gaddr: virtual address in the guest address space
956 * @val: pointer to the unsigned long value to return
957 *
958 * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
959 * if reading using the virtual address failed.
960 *
961 * Called with gmap->mm->mmap_sem in read.
962 */
963int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
964{
965 unsigned long address, vmaddr;
966 spinlock_t *ptl;
967 pte_t *ptep, pte;
968 int rc;
969
970 while (1) {
971 rc = -EAGAIN;
972 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
973 if (ptep) {
974 pte = *ptep;
975 if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
976 address = pte_val(pte) & PAGE_MASK;
977 address += gaddr & ~PAGE_MASK;
978 *val = *(unsigned long *) address;
979 pte_val(*ptep) |= _PAGE_YOUNG;
980 /* Do *NOT* clear the _PAGE_INVALID bit! */
981 rc = 0;
982 }
983 gmap_pte_op_end(ptl);
984 }
985 if (!rc)
986 break;
987 vmaddr = __gmap_translate(gmap, gaddr);
988 if (IS_ERR_VALUE(vmaddr)) {
989 rc = vmaddr;
990 break;
991 }
992 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
993 if (rc)
994 break;
995 }
996 return rc;
997}
998EXPORT_SYMBOL_GPL(gmap_read_table);
999
1000/**
1001 * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
1002 * @sg: pointer to the shadow guest address space structure
1003 * @vmaddr: vm address associated with the rmap
1004 * @rmap: pointer to the rmap structure
1005 *
1006 * Called with the sg->guest_table_lock
1007 */
1008static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
1009 struct gmap_rmap *rmap)
1010{
1011 void **slot;
1012
1013 BUG_ON(!gmap_is_shadow(sg));
1014 slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
1015 if (slot) {
1016 rmap->next = radix_tree_deref_slot_protected(slot,
1017 &sg->guest_table_lock);
1018 radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
1019 } else {
1020 rmap->next = NULL;
1021 radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
1022 rmap);
1023 }
1024}
1025
1026/**
1027 * gmap_protect_rmap - modify access rights to memory and create an rmap
1028 * @sg: pointer to the shadow guest address space structure
1029 * @raddr: rmap address in the shadow gmap
1030 * @paddr: address in the parent guest address space
1031 * @len: length of the memory area to protect
1032 * @prot: indicates access rights: none, read-only or read-write
1033 *
1034 * Returns 0 if successfully protected and the rmap was created, -ENOMEM
1035 * if out of memory and -EFAULT if paddr is invalid.
1036 */
1037static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
1038 unsigned long paddr, unsigned long len, int prot)
1039{
1040 struct gmap *parent;
1041 struct gmap_rmap *rmap;
1042 unsigned long vmaddr;
1043 spinlock_t *ptl;
1044 pte_t *ptep;
1045 int rc;
1046
1047 BUG_ON(!gmap_is_shadow(sg));
1048 parent = sg->parent;
1049 while (len) {
1050 vmaddr = __gmap_translate(parent, paddr);
1051 if (IS_ERR_VALUE(vmaddr))
1052 return vmaddr;
1053 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1054 if (!rmap)
1055 return -ENOMEM;
1056 rmap->raddr = raddr;
1057 rc = radix_tree_preload(GFP_KERNEL);
1058 if (rc) {
1059 kfree(rmap);
1060 return rc;
1061 }
1062 rc = -EAGAIN;
1063 ptep = gmap_pte_op_walk(parent, paddr, &ptl);
1064 if (ptep) {
1065 spin_lock(&sg->guest_table_lock);
1066 rc = ptep_force_prot(parent->mm, paddr, ptep, prot,
1067 PGSTE_VSIE_BIT);
1068 if (!rc)
1069 gmap_insert_rmap(sg, vmaddr, rmap);
1070 spin_unlock(&sg->guest_table_lock);
1071 gmap_pte_op_end(ptl);
1072 }
1073 radix_tree_preload_end();
1074 if (rc) {
1075 kfree(rmap);
1076 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
1077 if (rc)
1078 return rc;
1079 continue;
1080 }
1081 paddr += PAGE_SIZE;
1082 len -= PAGE_SIZE;
1083 }
1084 return 0;
1085}
1086
1087#define _SHADOW_RMAP_MASK 0x7
1088#define _SHADOW_RMAP_REGION1 0x5
1089#define _SHADOW_RMAP_REGION2 0x4
1090#define _SHADOW_RMAP_REGION3 0x3
1091#define _SHADOW_RMAP_SEGMENT 0x2
1092#define _SHADOW_RMAP_PGTABLE 0x1
1093
1094/**
1095 * gmap_idte_one - invalidate a single region or segment table entry
1096 * @asce: region or segment table *origin* + table-type bits
1097 * @vaddr: virtual address to identify the table entry to flush
1098 *
1099 * The invalid bit of a single region or segment table entry is set
1100 * and the associated TLB entries depending on the entry are flushed.
1101 * The table-type of the @asce identifies the portion of the @vaddr
1102 * that is used as the invalidation index.
1103 */
1104static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
1105{
1106 asm volatile(
1107 " .insn rrf,0xb98e0000,%0,%1,0,0"
1108 : : "a" (asce), "a" (vaddr) : "cc", "memory");
1109}
1110
1111/**
1112 * gmap_unshadow_page - remove a page from a shadow page table
1113 * @sg: pointer to the shadow guest address space structure
1114 * @raddr: rmap address in the shadow guest address space
1115 *
1116 * Called with the sg->guest_table_lock
1117 */
1118static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
1119{
1120 unsigned long *table;
1121
1122 BUG_ON(!gmap_is_shadow(sg));
1123 table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
1124 if (!table || *table & _PAGE_INVALID)
1125 return;
1126 gmap_call_notifier(sg, raddr, raddr + (1UL << 12) - 1);
1127 ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
1128}
1129
1130/**
1131 * __gmap_unshadow_pgt - remove all entries from a shadow page table
1132 * @sg: pointer to the shadow guest address space structure
1133 * @raddr: rmap address in the shadow guest address space
1134 * @pgt: pointer to the start of a shadow page table
1135 *
1136 * Called with the sg->guest_table_lock
1137 */
1138static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
1139 unsigned long *pgt)
1140{
1141 int i;
1142
1143 BUG_ON(!gmap_is_shadow(sg));
1144 for (i = 0; i < 256; i++, raddr += 1UL << 12)
1145 pgt[i] = _PAGE_INVALID;
1146}
1147
1148/**
1149 * gmap_unshadow_pgt - remove a shadow page table from a segment entry
1150 * @sg: pointer to the shadow guest address space structure
1151 * @raddr: address in the shadow guest address space
1152 *
1153 * Called with the sg->guest_table_lock
1154 */
1155static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
1156{
1157 unsigned long sto, *ste, *pgt;
1158 struct page *page;
1159
1160 BUG_ON(!gmap_is_shadow(sg));
1161 ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
1162 if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
1163 return;
1164 gmap_call_notifier(sg, raddr, raddr + (1UL << 20) - 1);
1165 sto = (unsigned long) (ste - ((raddr >> 20) & 0x7ff));
1166 gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
1167 pgt = (unsigned long *)(*ste & _SEGMENT_ENTRY_ORIGIN);
1168 *ste = _SEGMENT_ENTRY_EMPTY;
1169 __gmap_unshadow_pgt(sg, raddr, pgt);
1170 /* Free page table */
1171 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1172 list_del(&page->lru);
1173 page_table_free_pgste(page);
1174}
1175
1176/**
1177 * __gmap_unshadow_sgt - remove all entries from a shadow segment table
1178 * @sg: pointer to the shadow guest address space structure
1179 * @raddr: rmap address in the shadow guest address space
1180 * @sgt: pointer to the start of a shadow segment table
1181 *
1182 * Called with the sg->guest_table_lock
1183 */
1184static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
1185 unsigned long *sgt)
1186{
1187 unsigned long asce, *pgt;
1188 struct page *page;
1189 int i;
1190
1191 BUG_ON(!gmap_is_shadow(sg));
1192 asce = (unsigned long) sgt | _ASCE_TYPE_SEGMENT;
1193 for (i = 0; i < 2048; i++, raddr += 1UL << 20) {
1194 if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
1195 continue;
1196 pgt = (unsigned long *)(sgt[i] & _REGION_ENTRY_ORIGIN);
1197 sgt[i] = _SEGMENT_ENTRY_EMPTY;
1198 __gmap_unshadow_pgt(sg, raddr, pgt);
1199 /* Free page table */
1200 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1201 list_del(&page->lru);
1202 page_table_free_pgste(page);
1203 }
1204}
1205
1206/**
1207 * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
1208 * @sg: pointer to the shadow guest address space structure
1209 * @raddr: rmap address in the shadow guest address space
1210 *
1211 * Called with the shadow->guest_table_lock
1212 */
1213static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
1214{
1215 unsigned long r3o, *r3e, *sgt;
1216 struct page *page;
1217
1218 BUG_ON(!gmap_is_shadow(sg));
1219 r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
1220 if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
1221 return;
1222 gmap_call_notifier(sg, raddr, raddr + (1UL << 31) - 1);
1223 r3o = (unsigned long) (r3e - ((raddr >> 31) & 0x7ff));
1224 gmap_idte_one(r3o | _ASCE_TYPE_REGION3, raddr);
1225 sgt = (unsigned long *)(*r3e & _REGION_ENTRY_ORIGIN);
1226 *r3e = _REGION3_ENTRY_EMPTY;
1227 __gmap_unshadow_sgt(sg, raddr, sgt);
1228 /* Free segment table */
1229 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1230 list_del(&page->lru);
1231 __free_pages(page, 2);
1232}
1233
1234/**
1235 * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
1236 * @sg: pointer to the shadow guest address space structure
1237 * @raddr: address in the shadow guest address space
1238 * @r3t: pointer to the start of a shadow region-3 table
1239 *
1240 * Called with the sg->guest_table_lock
1241 */
1242static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
1243 unsigned long *r3t)
1244{
1245 unsigned long asce, *sgt;
1246 struct page *page;
1247 int i;
1248
1249 BUG_ON(!gmap_is_shadow(sg));
1250 asce = (unsigned long) r3t | _ASCE_TYPE_REGION3;
1251 for (i = 0; i < 2048; i++, raddr += 1UL << 31) {
1252 if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
1253 continue;
1254 sgt = (unsigned long *)(r3t[i] & _REGION_ENTRY_ORIGIN);
1255 r3t[i] = _REGION3_ENTRY_EMPTY;
1256 __gmap_unshadow_sgt(sg, raddr, sgt);
1257 /* Free segment table */
1258 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1259 list_del(&page->lru);
1260 __free_pages(page, 2);
1261 }
1262}
1263
1264/**
1265 * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
1266 * @sg: pointer to the shadow guest address space structure
1267 * @raddr: rmap address in the shadow guest address space
1268 *
1269 * Called with the sg->guest_table_lock
1270 */
1271static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
1272{
1273 unsigned long r2o, *r2e, *r3t;
1274 struct page *page;
1275
1276 BUG_ON(!gmap_is_shadow(sg));
1277 r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
1278 if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
1279 return;
1280 gmap_call_notifier(sg, raddr, raddr + (1UL << 42) - 1);
1281 r2o = (unsigned long) (r2e - ((raddr >> 42) & 0x7ff));
1282 gmap_idte_one(r2o | _ASCE_TYPE_REGION2, raddr);
1283 r3t = (unsigned long *)(*r2e & _REGION_ENTRY_ORIGIN);
1284 *r2e = _REGION2_ENTRY_EMPTY;
1285 __gmap_unshadow_r3t(sg, raddr, r3t);
1286 /* Free region 3 table */
1287 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1288 list_del(&page->lru);
1289 __free_pages(page, 2);
1290}
1291
1292/**
1293 * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
1294 * @sg: pointer to the shadow guest address space structure
1295 * @raddr: rmap address in the shadow guest address space
1296 * @r2t: pointer to the start of a shadow region-2 table
1297 *
1298 * Called with the sg->guest_table_lock
1299 */
1300static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
1301 unsigned long *r2t)
1302{
1303 unsigned long asce, *r3t;
1304 struct page *page;
1305 int i;
1306
1307 BUG_ON(!gmap_is_shadow(sg));
1308 asce = (unsigned long) r2t | _ASCE_TYPE_REGION2;
1309 for (i = 0; i < 2048; i++, raddr += 1UL << 42) {
1310 if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
1311 continue;
1312 r3t = (unsigned long *)(r2t[i] & _REGION_ENTRY_ORIGIN);
1313 r2t[i] = _REGION2_ENTRY_EMPTY;
1314 __gmap_unshadow_r3t(sg, raddr, r3t);
1315 /* Free region 3 table */
1316 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1317 list_del(&page->lru);
1318 __free_pages(page, 2);
1319 }
1320}
1321
1322/**
1323 * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
1324 * @sg: pointer to the shadow guest address space structure
1325 * @raddr: rmap address in the shadow guest address space
1326 *
1327 * Called with the sg->guest_table_lock
1328 */
1329static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
1330{
1331 unsigned long r1o, *r1e, *r2t;
1332 struct page *page;
1333
1334 BUG_ON(!gmap_is_shadow(sg));
1335 r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
1336 if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
1337 return;
1338 gmap_call_notifier(sg, raddr, raddr + (1UL << 53) - 1);
1339 r1o = (unsigned long) (r1e - ((raddr >> 53) & 0x7ff));
1340 gmap_idte_one(r1o | _ASCE_TYPE_REGION1, raddr);
1341 r2t = (unsigned long *)(*r1e & _REGION_ENTRY_ORIGIN);
1342 *r1e = _REGION1_ENTRY_EMPTY;
1343 __gmap_unshadow_r2t(sg, raddr, r2t);
1344 /* Free region 2 table */
1345 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1346 list_del(&page->lru);
1347 __free_pages(page, 2);
1348}
1349
1350/**
1351 * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
1352 * @sg: pointer to the shadow guest address space structure
1353 * @raddr: rmap address in the shadow guest address space
1354 * @r1t: pointer to the start of a shadow region-1 table
1355 *
1356 * Called with the shadow->guest_table_lock
1357 */
1358static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
1359 unsigned long *r1t)
1360{
1361 unsigned long asce, *r2t;
1362 struct page *page;
1363 int i;
1364
1365 BUG_ON(!gmap_is_shadow(sg));
1366 asce = (unsigned long) r1t | _ASCE_TYPE_REGION1;
1367 for (i = 0; i < 2048; i++, raddr += 1UL << 53) {
1368 if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
1369 continue;
1370 r2t = (unsigned long *)(r1t[i] & _REGION_ENTRY_ORIGIN);
1371 __gmap_unshadow_r2t(sg, raddr, r2t);
1372 /* Clear entry and flush translation r1t -> r2t */
1373 gmap_idte_one(asce, raddr);
1374 r1t[i] = _REGION1_ENTRY_EMPTY;
1375 /* Free region 2 table */
1376 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1377 list_del(&page->lru);
1378 __free_pages(page, 2);
1379 }
1380}
1381
1382/**
1383 * gmap_unshadow - remove a shadow page table completely
1384 * @sg: pointer to the shadow guest address space structure
1385 *
1386 * Called with sg->guest_table_lock
1387 */
1388static void gmap_unshadow(struct gmap *sg)
1389{
1390 unsigned long *table;
1391
1392 BUG_ON(!gmap_is_shadow(sg));
1393 if (sg->removed)
1394 return;
1395 sg->removed = 1;
1396 gmap_call_notifier(sg, 0, -1UL);
1397 gmap_flush_tlb(sg);
1398 table = (unsigned long *)(sg->asce & _ASCE_ORIGIN);
1399 switch (sg->asce & _ASCE_TYPE_MASK) {
1400 case _ASCE_TYPE_REGION1:
1401 __gmap_unshadow_r1t(sg, 0, table);
1402 break;
1403 case _ASCE_TYPE_REGION2:
1404 __gmap_unshadow_r2t(sg, 0, table);
1405 break;
1406 case _ASCE_TYPE_REGION3:
1407 __gmap_unshadow_r3t(sg, 0, table);
1408 break;
1409 case _ASCE_TYPE_SEGMENT:
1410 __gmap_unshadow_sgt(sg, 0, table);
1411 break;
1412 }
1413}
1414
1415/**
1416 * gmap_find_shadow - find a specific asce in the list of shadow tables
1417 * @parent: pointer to the parent gmap
1418 * @asce: ASCE for which the shadow table is created
1419 * @edat_level: edat level to be used for the shadow translation
1420 *
1421 * Returns the pointer to a gmap if a shadow table with the given asce is
1422 * already available, ERR_PTR(-EAGAIN) if another one is just being created,
1423 * otherwise NULL
1424 */
1425static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
1426 int edat_level)
1427{
1428 struct gmap *sg;
1429
1430 list_for_each_entry(sg, &parent->children, list) {
1431 if (sg->orig_asce != asce || sg->edat_level != edat_level ||
1432 sg->removed)
1433 continue;
1434 if (!sg->initialized)
1435 return ERR_PTR(-EAGAIN);
1436 atomic_inc(&sg->ref_count);
1437 return sg;
1438 }
1439 return NULL;
1440}
1441
1442/**
1443 * gmap_shadow_valid - check if a shadow guest address space matches the
1444 * given properties and is still valid
1445 * @sg: pointer to the shadow guest address space structure
1446 * @asce: ASCE for which the shadow table is requested
1447 * @edat_level: edat level to be used for the shadow translation
1448 *
1449 * Returns 1 if the gmap shadow is still valid and matches the given
1450 * properties, the caller can continue using it. Returns 0 otherwise, the
1451 * caller has to request a new shadow gmap in this case.
1452 *
1453 */
1454int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
1455{
1456 if (sg->removed)
1457 return 0;
1458 return sg->orig_asce == asce && sg->edat_level == edat_level;
1459}
1460EXPORT_SYMBOL_GPL(gmap_shadow_valid);
1461
1462/**
1463 * gmap_shadow - create/find a shadow guest address space
1464 * @parent: pointer to the parent gmap
1465 * @asce: ASCE for which the shadow table is created
1466 * @edat_level: edat level to be used for the shadow translation
1467 *
1468 * The pages of the top level page table referred by the asce parameter
1469 * will be set to read-only and marked in the PGSTEs of the kvm process.
1470 * The shadow table will be removed automatically on any change to the
1471 * PTE mapping for the source table.
1472 *
1473 * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
1474 * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
1475 * parent gmap table could not be protected.
1476 */
1477struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
1478 int edat_level)
1479{
1480 struct gmap *sg, *new;
1481 unsigned long limit;
1482 int rc;
1483
1484 BUG_ON(gmap_is_shadow(parent));
1485 spin_lock(&parent->shadow_lock);
1486 sg = gmap_find_shadow(parent, asce, edat_level);
1487 spin_unlock(&parent->shadow_lock);
1488 if (sg)
1489 return sg;
1490 /* Create a new shadow gmap */
1491 limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
1492 if (asce & _ASCE_REAL_SPACE)
1493 limit = -1UL;
1494 new = gmap_alloc(limit);
1495 if (!new)
1496 return ERR_PTR(-ENOMEM);
1497 new->mm = parent->mm;
1498 new->parent = gmap_get(parent);
1499 new->orig_asce = asce;
1500 new->edat_level = edat_level;
1501 new->initialized = false;
1502 spin_lock(&parent->shadow_lock);
1503 /* Recheck if another CPU created the same shadow */
1504 sg = gmap_find_shadow(parent, asce, edat_level);
1505 if (sg) {
1506 spin_unlock(&parent->shadow_lock);
1507 gmap_free(new);
1508 return sg;
1509 }
1510 if (asce & _ASCE_REAL_SPACE) {
1511 /* only allow one real-space gmap shadow */
1512 list_for_each_entry(sg, &parent->children, list) {
1513 if (sg->orig_asce & _ASCE_REAL_SPACE) {
1514 spin_lock(&sg->guest_table_lock);
1515 gmap_unshadow(sg);
1516 spin_unlock(&sg->guest_table_lock);
1517 list_del(&sg->list);
1518 gmap_put(sg);
1519 break;
1520 }
1521 }
1522 }
1523 atomic_set(&new->ref_count, 2);
1524 list_add(&new->list, &parent->children);
1525 if (asce & _ASCE_REAL_SPACE) {
1526 /* nothing to protect, return right away */
1527 new->initialized = true;
1528 spin_unlock(&parent->shadow_lock);
1529 return new;
1530 }
1531 spin_unlock(&parent->shadow_lock);
1532 /* protect after insertion, so it will get properly invalidated */
1533 down_read(&parent->mm->mmap_sem);
1534 rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
1535 ((asce & _ASCE_TABLE_LENGTH) + 1) * 4096,
1536 PROT_READ, PGSTE_VSIE_BIT);
1537 up_read(&parent->mm->mmap_sem);
1538 spin_lock(&parent->shadow_lock);
1539 new->initialized = true;
1540 if (rc) {
1541 list_del(&new->list);
1542 gmap_free(new);
1543 new = ERR_PTR(rc);
1544 }
1545 spin_unlock(&parent->shadow_lock);
1546 return new;
1547}
1548EXPORT_SYMBOL_GPL(gmap_shadow);
1549
1550/**
1551 * gmap_shadow_r2t - create an empty shadow region 2 table
1552 * @sg: pointer to the shadow guest address space structure
1553 * @saddr: faulting address in the shadow gmap
1554 * @r2t: parent gmap address of the region 2 table to get shadowed
1555 * @fake: r2t references contiguous guest memory block, not a r2t
1556 *
1557 * The r2t parameter specifies the address of the source table. The
1558 * four pages of the source table are made read-only in the parent gmap
1559 * address space. A write to the source table area @r2t will automatically
1560 * remove the shadow r2 table and all of its decendents.
1561 *
1562 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1563 * shadow table structure is incomplete, -ENOMEM if out of memory and
1564 * -EFAULT if an address in the parent gmap could not be resolved.
1565 *
1566 * Called with sg->mm->mmap_sem in read.
1567 */
1568int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
1569 int fake)
1570{
1571 unsigned long raddr, origin, offset, len;
1572 unsigned long *s_r2t, *table;
1573 struct page *page;
1574 int rc;
1575
1576 BUG_ON(!gmap_is_shadow(sg));
1577 /* Allocate a shadow region second table */
1578 page = alloc_pages(GFP_KERNEL, 2);
1579 if (!page)
1580 return -ENOMEM;
1581 page->index = r2t & _REGION_ENTRY_ORIGIN;
1582 if (fake)
1583 page->index |= GMAP_SHADOW_FAKE_TABLE;
1584 s_r2t = (unsigned long *) page_to_phys(page);
1585 /* Install shadow region second table */
1586 spin_lock(&sg->guest_table_lock);
1587 table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
1588 if (!table) {
1589 rc = -EAGAIN; /* Race with unshadow */
1590 goto out_free;
1591 }
1592 if (!(*table & _REGION_ENTRY_INVALID)) {
1593 rc = 0; /* Already established */
1594 goto out_free;
1595 } else if (*table & _REGION_ENTRY_ORIGIN) {
1596 rc = -EAGAIN; /* Race with shadow */
1597 goto out_free;
1598 }
1599 crst_table_init(s_r2t, _REGION2_ENTRY_EMPTY);
1600 /* mark as invalid as long as the parent table is not protected */
1601 *table = (unsigned long) s_r2t | _REGION_ENTRY_LENGTH |
1602 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
1603 if (sg->edat_level >= 1)
1604 *table |= (r2t & _REGION_ENTRY_PROTECT);
1605 list_add(&page->lru, &sg->crst_list);
1606 if (fake) {
1607 /* nothing to protect for fake tables */
1608 *table &= ~_REGION_ENTRY_INVALID;
1609 spin_unlock(&sg->guest_table_lock);
1610 return 0;
1611 }
1612 spin_unlock(&sg->guest_table_lock);
1613 /* Make r2t read-only in parent gmap page table */
1614 raddr = (saddr & 0xffe0000000000000UL) | _SHADOW_RMAP_REGION1;
1615 origin = r2t & _REGION_ENTRY_ORIGIN;
1616 offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * 4096;
1617 len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset;
1618 rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ);
1619 spin_lock(&sg->guest_table_lock);
1620 if (!rc) {
1621 table = gmap_table_walk(sg, saddr, 4);
1622 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1623 (unsigned long) s_r2t)
1624 rc = -EAGAIN; /* Race with unshadow */
1625 else
1626 *table &= ~_REGION_ENTRY_INVALID;
1627 } else {
1628 gmap_unshadow_r2t(sg, raddr);
1629 }
1630 spin_unlock(&sg->guest_table_lock);
1631 return rc;
1632out_free:
1633 spin_unlock(&sg->guest_table_lock);
1634 __free_pages(page, 2);
1635 return rc;
1636}
1637EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
1638
1639/**
1640 * gmap_shadow_r3t - create a shadow region 3 table
1641 * @sg: pointer to the shadow guest address space structure
1642 * @saddr: faulting address in the shadow gmap
1643 * @r3t: parent gmap address of the region 3 table to get shadowed
1644 * @fake: r3t references contiguous guest memory block, not a r3t
1645 *
1646 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1647 * shadow table structure is incomplete, -ENOMEM if out of memory and
1648 * -EFAULT if an address in the parent gmap could not be resolved.
1649 *
1650 * Called with sg->mm->mmap_sem in read.
1651 */
1652int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
1653 int fake)
1654{
1655 unsigned long raddr, origin, offset, len;
1656 unsigned long *s_r3t, *table;
1657 struct page *page;
1658 int rc;
1659
1660 BUG_ON(!gmap_is_shadow(sg));
1661 /* Allocate a shadow region second table */
1662 page = alloc_pages(GFP_KERNEL, 2);
1663 if (!page)
1664 return -ENOMEM;
1665 page->index = r3t & _REGION_ENTRY_ORIGIN;
1666 if (fake)
1667 page->index |= GMAP_SHADOW_FAKE_TABLE;
1668 s_r3t = (unsigned long *) page_to_phys(page);
1669 /* Install shadow region second table */
1670 spin_lock(&sg->guest_table_lock);
1671 table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
1672 if (!table) {
1673 rc = -EAGAIN; /* Race with unshadow */
1674 goto out_free;
1675 }
1676 if (!(*table & _REGION_ENTRY_INVALID)) {
1677 rc = 0; /* Already established */
1678 goto out_free;
1679 } else if (*table & _REGION_ENTRY_ORIGIN) {
1680 rc = -EAGAIN; /* Race with shadow */
1681 }
1682 crst_table_init(s_r3t, _REGION3_ENTRY_EMPTY);
1683 /* mark as invalid as long as the parent table is not protected */
1684 *table = (unsigned long) s_r3t | _REGION_ENTRY_LENGTH |
1685 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
1686 if (sg->edat_level >= 1)
1687 *table |= (r3t & _REGION_ENTRY_PROTECT);
1688 list_add(&page->lru, &sg->crst_list);
1689 if (fake) {
1690 /* nothing to protect for fake tables */
1691 *table &= ~_REGION_ENTRY_INVALID;
1692 spin_unlock(&sg->guest_table_lock);
1693 return 0;
1694 }
1695 spin_unlock(&sg->guest_table_lock);
1696 /* Make r3t read-only in parent gmap page table */
1697 raddr = (saddr & 0xfffffc0000000000UL) | _SHADOW_RMAP_REGION2;
1698 origin = r3t & _REGION_ENTRY_ORIGIN;
1699 offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * 4096;
1700 len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset;
1701 rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ);
1702 spin_lock(&sg->guest_table_lock);
1703 if (!rc) {
1704 table = gmap_table_walk(sg, saddr, 3);
1705 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1706 (unsigned long) s_r3t)
1707 rc = -EAGAIN; /* Race with unshadow */
1708 else
1709 *table &= ~_REGION_ENTRY_INVALID;
1710 } else {
1711 gmap_unshadow_r3t(sg, raddr);
1712 }
1713 spin_unlock(&sg->guest_table_lock);
1714 return rc;
1715out_free:
1716 spin_unlock(&sg->guest_table_lock);
1717 __free_pages(page, 2);
1718 return rc;
1719}
1720EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
1721
1722/**
1723 * gmap_shadow_sgt - create a shadow segment table
1724 * @sg: pointer to the shadow guest address space structure
1725 * @saddr: faulting address in the shadow gmap
1726 * @sgt: parent gmap address of the segment table to get shadowed
1727 * @fake: sgt references contiguous guest memory block, not a sgt
1728 *
1729 * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
1730 * shadow table structure is incomplete, -ENOMEM if out of memory and
1731 * -EFAULT if an address in the parent gmap could not be resolved.
1732 *
1733 * Called with sg->mm->mmap_sem in read.
1734 */
1735int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
1736 int fake)
1737{
1738 unsigned long raddr, origin, offset, len;
1739 unsigned long *s_sgt, *table;
1740 struct page *page;
1741 int rc;
1742
1743 BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
1744 /* Allocate a shadow segment table */
1745 page = alloc_pages(GFP_KERNEL, 2);
1746 if (!page)
1747 return -ENOMEM;
1748 page->index = sgt & _REGION_ENTRY_ORIGIN;
1749 if (fake)
1750 page->index |= GMAP_SHADOW_FAKE_TABLE;
1751 s_sgt = (unsigned long *) page_to_phys(page);
1752 /* Install shadow region second table */
1753 spin_lock(&sg->guest_table_lock);
1754 table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
1755 if (!table) {
1756 rc = -EAGAIN; /* Race with unshadow */
1757 goto out_free;
1758 }
1759 if (!(*table & _REGION_ENTRY_INVALID)) {
1760 rc = 0; /* Already established */
1761 goto out_free;
1762 } else if (*table & _REGION_ENTRY_ORIGIN) {
1763 rc = -EAGAIN; /* Race with shadow */
1764 goto out_free;
1765 }
1766 crst_table_init(s_sgt, _SEGMENT_ENTRY_EMPTY);
1767 /* mark as invalid as long as the parent table is not protected */
1768 *table = (unsigned long) s_sgt | _REGION_ENTRY_LENGTH |
1769 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
1770 if (sg->edat_level >= 1)
1771 *table |= sgt & _REGION_ENTRY_PROTECT;
1772 list_add(&page->lru, &sg->crst_list);
1773 if (fake) {
1774 /* nothing to protect for fake tables */
1775 *table &= ~_REGION_ENTRY_INVALID;
1776 spin_unlock(&sg->guest_table_lock);
1777 return 0;
1778 }
1779 spin_unlock(&sg->guest_table_lock);
1780 /* Make sgt read-only in parent gmap page table */
1781 raddr = (saddr & 0xffffffff80000000UL) | _SHADOW_RMAP_REGION3;
1782 origin = sgt & _REGION_ENTRY_ORIGIN;
1783 offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * 4096;
1784 len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset;
1785 rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ);
1786 spin_lock(&sg->guest_table_lock);
1787 if (!rc) {
1788 table = gmap_table_walk(sg, saddr, 2);
1789 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1790 (unsigned long) s_sgt)
1791 rc = -EAGAIN; /* Race with unshadow */
1792 else
1793 *table &= ~_REGION_ENTRY_INVALID;
1794 } else {
1795 gmap_unshadow_sgt(sg, raddr);
1796 }
1797 spin_unlock(&sg->guest_table_lock);
1798 return rc;
1799out_free:
1800 spin_unlock(&sg->guest_table_lock);
1801 __free_pages(page, 2);
1802 return rc;
1803}
1804EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
1805
1806/**
1807 * gmap_shadow_lookup_pgtable - find a shadow page table
1808 * @sg: pointer to the shadow guest address space structure
1809 * @saddr: the address in the shadow aguest address space
1810 * @pgt: parent gmap address of the page table to get shadowed
1811 * @dat_protection: if the pgtable is marked as protected by dat
1812 * @fake: pgt references contiguous guest memory block, not a pgtable
1813 *
1814 * Returns 0 if the shadow page table was found and -EAGAIN if the page
1815 * table was not found.
1816 *
1817 * Called with sg->mm->mmap_sem in read.
1818 */
1819int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
1820 unsigned long *pgt, int *dat_protection,
1821 int *fake)
1822{
1823 unsigned long *table;
1824 struct page *page;
1825 int rc;
1826
1827 BUG_ON(!gmap_is_shadow(sg));
1828 spin_lock(&sg->guest_table_lock);
1829 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1830 if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
1831 /* Shadow page tables are full pages (pte+pgste) */
1832 page = pfn_to_page(*table >> PAGE_SHIFT);
1833 *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
1834 *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
1835 *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
1836 rc = 0;
1837 } else {
1838 rc = -EAGAIN;
1839 }
1840 spin_unlock(&sg->guest_table_lock);
1841 return rc;
1842
1843}
1844EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
1845
1846/**
1847 * gmap_shadow_pgt - instantiate a shadow page table
1848 * @sg: pointer to the shadow guest address space structure
1849 * @saddr: faulting address in the shadow gmap
1850 * @pgt: parent gmap address of the page table to get shadowed
1851 * @fake: pgt references contiguous guest memory block, not a pgtable
1852 *
1853 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1854 * shadow table structure is incomplete, -ENOMEM if out of memory,
1855 * -EFAULT if an address in the parent gmap could not be resolved and
1856 *
1857 * Called with gmap->mm->mmap_sem in read
1858 */
1859int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
1860 int fake)
1861{
1862 unsigned long raddr, origin;
1863 unsigned long *s_pgt, *table;
1864 struct page *page;
1865 int rc;
1866
1867 BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
1868 /* Allocate a shadow page table */
1869 page = page_table_alloc_pgste(sg->mm);
1870 if (!page)
1871 return -ENOMEM;
1872 page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
1873 if (fake)
1874 page->index |= GMAP_SHADOW_FAKE_TABLE;
1875 s_pgt = (unsigned long *) page_to_phys(page);
1876 /* Install shadow page table */
1877 spin_lock(&sg->guest_table_lock);
1878 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1879 if (!table) {
1880 rc = -EAGAIN; /* Race with unshadow */
1881 goto out_free;
1882 }
1883 if (!(*table & _SEGMENT_ENTRY_INVALID)) {
1884 rc = 0; /* Already established */
1885 goto out_free;
1886 } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
1887 rc = -EAGAIN; /* Race with shadow */
1888 goto out_free;
1889 }
1890 /* mark as invalid as long as the parent table is not protected */
1891 *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
1892 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
1893 list_add(&page->lru, &sg->pt_list);
1894 if (fake) {
1895 /* nothing to protect for fake tables */
1896 *table &= ~_SEGMENT_ENTRY_INVALID;
1897 spin_unlock(&sg->guest_table_lock);
1898 return 0;
1899 }
1900 spin_unlock(&sg->guest_table_lock);
1901 /* Make pgt read-only in parent gmap page table (not the pgste) */
1902 raddr = (saddr & 0xfffffffffff00000UL) | _SHADOW_RMAP_SEGMENT;
1903 origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
1904 rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE, PROT_READ);
1905 spin_lock(&sg->guest_table_lock);
1906 if (!rc) {
1907 table = gmap_table_walk(sg, saddr, 1);
1908 if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
1909 (unsigned long) s_pgt)
1910 rc = -EAGAIN; /* Race with unshadow */
1911 else
1912 *table &= ~_SEGMENT_ENTRY_INVALID;
1913 } else {
1914 gmap_unshadow_pgt(sg, raddr);
1915 }
1916 spin_unlock(&sg->guest_table_lock);
1917 return rc;
1918out_free:
1919 spin_unlock(&sg->guest_table_lock);
1920 page_table_free_pgste(page);
1921 return rc;
1922
1923}
1924EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
1925
1926/**
1927 * gmap_shadow_page - create a shadow page mapping
1928 * @sg: pointer to the shadow guest address space structure
1929 * @saddr: faulting address in the shadow gmap
1930 * @pte: pte in parent gmap address space to get shadowed
1931 *
1932 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1933 * shadow table structure is incomplete, -ENOMEM if out of memory and
1934 * -EFAULT if an address in the parent gmap could not be resolved.
1935 *
1936 * Called with sg->mm->mmap_sem in read.
1937 */
1938int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
1939{
1940 struct gmap *parent;
1941 struct gmap_rmap *rmap;
1942 unsigned long vmaddr, paddr;
1943 spinlock_t *ptl;
1944 pte_t *sptep, *tptep;
1945 int prot;
1946 int rc;
1947
1948 BUG_ON(!gmap_is_shadow(sg));
1949 parent = sg->parent;
1950 prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
1951
1952 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1953 if (!rmap)
1954 return -ENOMEM;
1955 rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
1956
1957 while (1) {
1958 paddr = pte_val(pte) & PAGE_MASK;
1959 vmaddr = __gmap_translate(parent, paddr);
1960 if (IS_ERR_VALUE(vmaddr)) {
1961 rc = vmaddr;
1962 break;
1963 }
1964 rc = radix_tree_preload(GFP_KERNEL);
1965 if (rc)
1966 break;
1967 rc = -EAGAIN;
1968 sptep = gmap_pte_op_walk(parent, paddr, &ptl);
1969 if (sptep) {
1970 spin_lock(&sg->guest_table_lock);
1971 /* Get page table pointer */
1972 tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
1973 if (!tptep) {
1974 spin_unlock(&sg->guest_table_lock);
1975 gmap_pte_op_end(ptl);
1976 radix_tree_preload_end();
1977 break;
1978 }
1979 rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
1980 if (rc > 0) {
1981 /* Success and a new mapping */
1982 gmap_insert_rmap(sg, vmaddr, rmap);
1983 rmap = NULL;
1984 rc = 0;
1985 }
1986 gmap_pte_op_end(ptl);
1987 spin_unlock(&sg->guest_table_lock);
1988 }
1989 radix_tree_preload_end();
1990 if (!rc)
1991 break;
1992 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
1993 if (rc)
1994 break;
1995 }
1996 kfree(rmap);
1997 return rc;
1998}
1999EXPORT_SYMBOL_GPL(gmap_shadow_page);
2000
2001/**
2002 * gmap_shadow_notify - handle notifications for shadow gmap
2003 *
2004 * Called with sg->parent->shadow_lock.
2005 */
2006static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
2007 unsigned long offset, pte_t *pte)
2008{
2009 struct gmap_rmap *rmap, *rnext, *head;
2010 unsigned long gaddr, start, end, bits, raddr;
2011 unsigned long *table;
2012
2013 BUG_ON(!gmap_is_shadow(sg));
2014 spin_lock(&sg->parent->guest_table_lock);
2015 table = radix_tree_lookup(&sg->parent->host_to_guest,
2016 vmaddr >> PMD_SHIFT);
2017 gaddr = table ? __gmap_segment_gaddr(table) + offset : 0;
2018 spin_unlock(&sg->parent->guest_table_lock);
2019 if (!table)
2020 return;
2021
2022 spin_lock(&sg->guest_table_lock);
2023 if (sg->removed) {
2024 spin_unlock(&sg->guest_table_lock);
2025 return;
2026 }
2027 /* Check for top level table */
2028 start = sg->orig_asce & _ASCE_ORIGIN;
2029 end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * 4096;
2030 if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
2031 gaddr < end) {
2032 /* The complete shadow table has to go */
2033 gmap_unshadow(sg);
2034 spin_unlock(&sg->guest_table_lock);
2035 list_del(&sg->list);
2036 gmap_put(sg);
2037 return;
2038 }
2039 /* Remove the page table tree from on specific entry */
2040 head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> 12);
2041 gmap_for_each_rmap_safe(rmap, rnext, head) {
2042 bits = rmap->raddr & _SHADOW_RMAP_MASK;
2043 raddr = rmap->raddr ^ bits;
2044 switch (bits) {
2045 case _SHADOW_RMAP_REGION1:
2046 gmap_unshadow_r2t(sg, raddr);
2047 break;
2048 case _SHADOW_RMAP_REGION2:
2049 gmap_unshadow_r3t(sg, raddr);
2050 break;
2051 case _SHADOW_RMAP_REGION3:
2052 gmap_unshadow_sgt(sg, raddr);
2053 break;
2054 case _SHADOW_RMAP_SEGMENT:
2055 gmap_unshadow_pgt(sg, raddr);
2056 break;
2057 case _SHADOW_RMAP_PGTABLE:
2058 gmap_unshadow_page(sg, raddr);
2059 break;
2060 }
2061 kfree(rmap);
2062 }
2063 spin_unlock(&sg->guest_table_lock);
2064}
2065
2066/**
2067 * ptep_notify - call all invalidation callbacks for a specific pte.
2068 * @mm: pointer to the process mm_struct
2069 * @addr: virtual address in the process address space
2070 * @pte: pointer to the page table entry
2071 * @bits: bits from the pgste that caused the notify call
2072 *
2073 * This function is assumed to be called with the page table lock held
2074 * for the pte to notify.
2075 */
2076void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
2077 pte_t *pte, unsigned long bits)
2078{
2079 unsigned long offset, gaddr;
2080 unsigned long *table;
2081 struct gmap *gmap, *sg, *next;
2082
2083 offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
2084 offset = offset * (4096 / sizeof(pte_t));
2085 rcu_read_lock();
2086 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2087 if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
2088 spin_lock(&gmap->shadow_lock);
2089 list_for_each_entry_safe(sg, next,
2090 &gmap->children, list)
2091 gmap_shadow_notify(sg, vmaddr, offset, pte);
2092 spin_unlock(&gmap->shadow_lock);
2093 }
2094 if (!(bits & PGSTE_IN_BIT))
2095 continue;
2096 spin_lock(&gmap->guest_table_lock);
2097 table = radix_tree_lookup(&gmap->host_to_guest,
2098 vmaddr >> PMD_SHIFT);
2099 if (table)
2100 gaddr = __gmap_segment_gaddr(table) + offset;
2101 spin_unlock(&gmap->guest_table_lock);
2102 if (table)
2103 gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
2104 }
2105 rcu_read_unlock();
2106}
2107EXPORT_SYMBOL_GPL(ptep_notify);
2108
2109static inline void thp_split_mm(struct mm_struct *mm)
2110{
2111#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2112 struct vm_area_struct *vma;
2113 unsigned long addr;
2114
2115 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
2116 for (addr = vma->vm_start;
2117 addr < vma->vm_end;
2118 addr += PAGE_SIZE)
2119 follow_page(vma, addr, FOLL_SPLIT);
2120 vma->vm_flags &= ~VM_HUGEPAGE;
2121 vma->vm_flags |= VM_NOHUGEPAGE;
2122 }
2123 mm->def_flags |= VM_NOHUGEPAGE;
2124#endif
2125}
2126
2127/*
2128 * switch on pgstes for its userspace process (for kvm)
2129 */
2130int s390_enable_sie(void)
2131{
2132 struct mm_struct *mm = current->mm;
2133
2134 /* Do we have pgstes? if yes, we are done */
2135 if (mm_has_pgste(mm))
2136 return 0;
2137 /* Fail if the page tables are 2K */
2138 if (!mm_alloc_pgste(mm))
2139 return -EINVAL;
2140 down_write(&mm->mmap_sem);
2141 mm->context.has_pgste = 1;
2142 /* split thp mappings and disable thp for future mappings */
2143 thp_split_mm(mm);
2144 up_write(&mm->mmap_sem);
2145 return 0;
2146}
2147EXPORT_SYMBOL_GPL(s390_enable_sie);
2148
2149/*
2150 * Enable storage key handling from now on and initialize the storage
2151 * keys with the default key.
2152 */
2153static int __s390_enable_skey(pte_t *pte, unsigned long addr,
2154 unsigned long next, struct mm_walk *walk)
2155{
2156 /*
2157 * Remove all zero page mappings,
2158 * after establishing a policy to forbid zero page mappings
2159 * following faults for that page will get fresh anonymous pages
2160 */
2161 if (is_zero_pfn(pte_pfn(*pte)))
2162 ptep_xchg_direct(walk->mm, addr, pte, __pte(_PAGE_INVALID));
2163 /* Clear storage key */
2164 ptep_zap_key(walk->mm, addr, pte);
2165 return 0;
2166}
2167
2168int s390_enable_skey(void)
2169{
2170 struct mm_walk walk = { .pte_entry = __s390_enable_skey };
2171 struct mm_struct *mm = current->mm;
2172 struct vm_area_struct *vma;
2173 int rc = 0;
2174
2175 down_write(&mm->mmap_sem);
2176 if (mm_use_skey(mm))
2177 goto out_up;
2178
2179 mm->context.use_skey = 1;
2180 for (vma = mm->mmap; vma; vma = vma->vm_next) {
2181 if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
2182 MADV_UNMERGEABLE, &vma->vm_flags)) {
2183 mm->context.use_skey = 0;
2184 rc = -ENOMEM;
2185 goto out_up;
2186 }
2187 }
2188 mm->def_flags &= ~VM_MERGEABLE;
2189
2190 walk.mm = mm;
2191 walk_page_range(0, TASK_SIZE, &walk);
2192
2193out_up:
2194 up_write(&mm->mmap_sem);
2195 return rc;
2196}
2197EXPORT_SYMBOL_GPL(s390_enable_skey);
2198
2199/*
2200 * Reset CMMA state, make all pages stable again.
2201 */
2202static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
2203 unsigned long next, struct mm_walk *walk)
2204{
2205 ptep_zap_unused(walk->mm, addr, pte, 1);
2206 return 0;
2207}
2208
2209void s390_reset_cmma(struct mm_struct *mm)
2210{
2211 struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
2212
2213 down_write(&mm->mmap_sem);
2214 walk.mm = mm;
2215 walk_page_range(0, TASK_SIZE, &walk);
2216 up_write(&mm->mmap_sem);
2217}
2218EXPORT_SYMBOL_GPL(s390_reset_cmma);