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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * KVM guest address space mapping code
4 *
5 * Copyright IBM Corp. 2007, 2016
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 */
8
9#include <linux/kernel.h>
10#include <linux/mm.h>
11#include <linux/swap.h>
12#include <linux/smp.h>
13#include <linux/spinlock.h>
14#include <linux/slab.h>
15#include <linux/swapops.h>
16#include <linux/ksm.h>
17#include <linux/mman.h>
18
19#include <asm/pgtable.h>
20#include <asm/pgalloc.h>
21#include <asm/gmap.h>
22#include <asm/tlb.h>
23
24#define GMAP_SHADOW_FAKE_TABLE 1ULL
25
26/**
27 * gmap_alloc - allocate and initialize a guest address space
28 * @mm: pointer to the parent mm_struct
29 * @limit: maximum address of the gmap address space
30 *
31 * Returns a guest address space structure.
32 */
33static struct gmap *gmap_alloc(unsigned long limit)
34{
35 struct gmap *gmap;
36 struct page *page;
37 unsigned long *table;
38 unsigned long etype, atype;
39
40 if (limit < _REGION3_SIZE) {
41 limit = _REGION3_SIZE - 1;
42 atype = _ASCE_TYPE_SEGMENT;
43 etype = _SEGMENT_ENTRY_EMPTY;
44 } else if (limit < _REGION2_SIZE) {
45 limit = _REGION2_SIZE - 1;
46 atype = _ASCE_TYPE_REGION3;
47 etype = _REGION3_ENTRY_EMPTY;
48 } else if (limit < _REGION1_SIZE) {
49 limit = _REGION1_SIZE - 1;
50 atype = _ASCE_TYPE_REGION2;
51 etype = _REGION2_ENTRY_EMPTY;
52 } else {
53 limit = -1UL;
54 atype = _ASCE_TYPE_REGION1;
55 etype = _REGION1_ENTRY_EMPTY;
56 }
57 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
58 if (!gmap)
59 goto out;
60 INIT_LIST_HEAD(&gmap->crst_list);
61 INIT_LIST_HEAD(&gmap->children);
62 INIT_LIST_HEAD(&gmap->pt_list);
63 INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
64 INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
65 INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC);
66 spin_lock_init(&gmap->guest_table_lock);
67 spin_lock_init(&gmap->shadow_lock);
68 atomic_set(&gmap->ref_count, 1);
69 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
70 if (!page)
71 goto out_free;
72 page->index = 0;
73 list_add(&page->lru, &gmap->crst_list);
74 table = (unsigned long *) page_to_phys(page);
75 crst_table_init(table, etype);
76 gmap->table = table;
77 gmap->asce = atype | _ASCE_TABLE_LENGTH |
78 _ASCE_USER_BITS | __pa(table);
79 gmap->asce_end = limit;
80 return gmap;
81
82out_free:
83 kfree(gmap);
84out:
85 return NULL;
86}
87
88/**
89 * gmap_create - create a guest address space
90 * @mm: pointer to the parent mm_struct
91 * @limit: maximum size of the gmap address space
92 *
93 * Returns a guest address space structure.
94 */
95struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
96{
97 struct gmap *gmap;
98 unsigned long gmap_asce;
99
100 gmap = gmap_alloc(limit);
101 if (!gmap)
102 return NULL;
103 gmap->mm = mm;
104 spin_lock(&mm->context.lock);
105 list_add_rcu(&gmap->list, &mm->context.gmap_list);
106 if (list_is_singular(&mm->context.gmap_list))
107 gmap_asce = gmap->asce;
108 else
109 gmap_asce = -1UL;
110 WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
111 spin_unlock(&mm->context.lock);
112 return gmap;
113}
114EXPORT_SYMBOL_GPL(gmap_create);
115
116static void gmap_flush_tlb(struct gmap *gmap)
117{
118 if (MACHINE_HAS_IDTE)
119 __tlb_flush_idte(gmap->asce);
120 else
121 __tlb_flush_global();
122}
123
124static void gmap_radix_tree_free(struct radix_tree_root *root)
125{
126 struct radix_tree_iter iter;
127 unsigned long indices[16];
128 unsigned long index;
129 void __rcu **slot;
130 int i, nr;
131
132 /* A radix tree is freed by deleting all of its entries */
133 index = 0;
134 do {
135 nr = 0;
136 radix_tree_for_each_slot(slot, root, &iter, index) {
137 indices[nr] = iter.index;
138 if (++nr == 16)
139 break;
140 }
141 for (i = 0; i < nr; i++) {
142 index = indices[i];
143 radix_tree_delete(root, index);
144 }
145 } while (nr > 0);
146}
147
148static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
149{
150 struct gmap_rmap *rmap, *rnext, *head;
151 struct radix_tree_iter iter;
152 unsigned long indices[16];
153 unsigned long index;
154 void __rcu **slot;
155 int i, nr;
156
157 /* A radix tree is freed by deleting all of its entries */
158 index = 0;
159 do {
160 nr = 0;
161 radix_tree_for_each_slot(slot, root, &iter, index) {
162 indices[nr] = iter.index;
163 if (++nr == 16)
164 break;
165 }
166 for (i = 0; i < nr; i++) {
167 index = indices[i];
168 head = radix_tree_delete(root, index);
169 gmap_for_each_rmap_safe(rmap, rnext, head)
170 kfree(rmap);
171 }
172 } while (nr > 0);
173}
174
175/**
176 * gmap_free - free a guest address space
177 * @gmap: pointer to the guest address space structure
178 *
179 * No locks required. There are no references to this gmap anymore.
180 */
181static void gmap_free(struct gmap *gmap)
182{
183 struct page *page, *next;
184
185 /* Flush tlb of all gmaps (if not already done for shadows) */
186 if (!(gmap_is_shadow(gmap) && gmap->removed))
187 gmap_flush_tlb(gmap);
188 /* Free all segment & region tables. */
189 list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
190 __free_pages(page, CRST_ALLOC_ORDER);
191 gmap_radix_tree_free(&gmap->guest_to_host);
192 gmap_radix_tree_free(&gmap->host_to_guest);
193
194 /* Free additional data for a shadow gmap */
195 if (gmap_is_shadow(gmap)) {
196 /* Free all page tables. */
197 list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
198 page_table_free_pgste(page);
199 gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
200 /* Release reference to the parent */
201 gmap_put(gmap->parent);
202 }
203
204 kfree(gmap);
205}
206
207/**
208 * gmap_get - increase reference counter for guest address space
209 * @gmap: pointer to the guest address space structure
210 *
211 * Returns the gmap pointer
212 */
213struct gmap *gmap_get(struct gmap *gmap)
214{
215 atomic_inc(&gmap->ref_count);
216 return gmap;
217}
218EXPORT_SYMBOL_GPL(gmap_get);
219
220/**
221 * gmap_put - decrease reference counter for guest address space
222 * @gmap: pointer to the guest address space structure
223 *
224 * If the reference counter reaches zero the guest address space is freed.
225 */
226void gmap_put(struct gmap *gmap)
227{
228 if (atomic_dec_return(&gmap->ref_count) == 0)
229 gmap_free(gmap);
230}
231EXPORT_SYMBOL_GPL(gmap_put);
232
233/**
234 * gmap_remove - remove a guest address space but do not free it yet
235 * @gmap: pointer to the guest address space structure
236 */
237void gmap_remove(struct gmap *gmap)
238{
239 struct gmap *sg, *next;
240 unsigned long gmap_asce;
241
242 /* Remove all shadow gmaps linked to this gmap */
243 if (!list_empty(&gmap->children)) {
244 spin_lock(&gmap->shadow_lock);
245 list_for_each_entry_safe(sg, next, &gmap->children, list) {
246 list_del(&sg->list);
247 gmap_put(sg);
248 }
249 spin_unlock(&gmap->shadow_lock);
250 }
251 /* Remove gmap from the pre-mm list */
252 spin_lock(&gmap->mm->context.lock);
253 list_del_rcu(&gmap->list);
254 if (list_empty(&gmap->mm->context.gmap_list))
255 gmap_asce = 0;
256 else if (list_is_singular(&gmap->mm->context.gmap_list))
257 gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
258 struct gmap, list)->asce;
259 else
260 gmap_asce = -1UL;
261 WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
262 spin_unlock(&gmap->mm->context.lock);
263 synchronize_rcu();
264 /* Put reference */
265 gmap_put(gmap);
266}
267EXPORT_SYMBOL_GPL(gmap_remove);
268
269/**
270 * gmap_enable - switch primary space to the guest address space
271 * @gmap: pointer to the guest address space structure
272 */
273void gmap_enable(struct gmap *gmap)
274{
275 S390_lowcore.gmap = (unsigned long) gmap;
276}
277EXPORT_SYMBOL_GPL(gmap_enable);
278
279/**
280 * gmap_disable - switch back to the standard primary address space
281 * @gmap: pointer to the guest address space structure
282 */
283void gmap_disable(struct gmap *gmap)
284{
285 S390_lowcore.gmap = 0UL;
286}
287EXPORT_SYMBOL_GPL(gmap_disable);
288
289/**
290 * gmap_get_enabled - get a pointer to the currently enabled gmap
291 *
292 * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
293 */
294struct gmap *gmap_get_enabled(void)
295{
296 return (struct gmap *) S390_lowcore.gmap;
297}
298EXPORT_SYMBOL_GPL(gmap_get_enabled);
299
300/*
301 * gmap_alloc_table is assumed to be called with mmap_sem held
302 */
303static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
304 unsigned long init, unsigned long gaddr)
305{
306 struct page *page;
307 unsigned long *new;
308
309 /* since we dont free the gmap table until gmap_free we can unlock */
310 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
311 if (!page)
312 return -ENOMEM;
313 new = (unsigned long *) page_to_phys(page);
314 crst_table_init(new, init);
315 spin_lock(&gmap->guest_table_lock);
316 if (*table & _REGION_ENTRY_INVALID) {
317 list_add(&page->lru, &gmap->crst_list);
318 *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
319 (*table & _REGION_ENTRY_TYPE_MASK);
320 page->index = gaddr;
321 page = NULL;
322 }
323 spin_unlock(&gmap->guest_table_lock);
324 if (page)
325 __free_pages(page, CRST_ALLOC_ORDER);
326 return 0;
327}
328
329/**
330 * __gmap_segment_gaddr - find virtual address from segment pointer
331 * @entry: pointer to a segment table entry in the guest address space
332 *
333 * Returns the virtual address in the guest address space for the segment
334 */
335static unsigned long __gmap_segment_gaddr(unsigned long *entry)
336{
337 struct page *page;
338 unsigned long offset, mask;
339
340 offset = (unsigned long) entry / sizeof(unsigned long);
341 offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
342 mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
343 page = virt_to_page((void *)((unsigned long) entry & mask));
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 down_write(&gmap->mm->mmap_sem);
407 for (off = 0; off < len; off += PMD_SIZE)
408 flush |= __gmap_unmap_by_gaddr(gmap, to + off);
409 up_write(&gmap->mm->mmap_sem);
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 down_write(&gmap->mm->mmap_sem);
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 up_write(&gmap->mm->mmap_sem);
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_sem 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 down_read(&gmap->mm->mmap_sem);
497 rc = __gmap_translate(gmap, gaddr);
498 up_read(&gmap->mm->mmap_sem);
499 return rc;
500}
501EXPORT_SYMBOL_GPL(gmap_translate);
502
503/**
504 * gmap_unlink - disconnect a page table from the gmap shadow tables
505 * @gmap: pointer to guest mapping meta data structure
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
524/**
525 * gmap_link - set up shadow page tables to connect a host to a guest address
526 * @gmap: pointer to guest mapping meta data structure
527 * @gaddr: guest address
528 * @vmaddr: vm address
529 *
530 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
531 * if the vm address is already mapped to a different guest segment.
532 * The mmap_sem of the mm that belongs to the address space must be held
533 * when this function gets called.
534 */
535int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
536{
537 struct mm_struct *mm;
538 unsigned long *table;
539 spinlock_t *ptl;
540 pgd_t *pgd;
541 p4d_t *p4d;
542 pud_t *pud;
543 pmd_t *pmd;
544 int rc;
545
546 BUG_ON(gmap_is_shadow(gmap));
547 /* Create higher level tables in the gmap page table */
548 table = gmap->table;
549 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
550 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
551 if ((*table & _REGION_ENTRY_INVALID) &&
552 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
553 gaddr & _REGION1_MASK))
554 return -ENOMEM;
555 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
556 }
557 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
558 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
559 if ((*table & _REGION_ENTRY_INVALID) &&
560 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
561 gaddr & _REGION2_MASK))
562 return -ENOMEM;
563 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
564 }
565 if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
566 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
567 if ((*table & _REGION_ENTRY_INVALID) &&
568 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
569 gaddr & _REGION3_MASK))
570 return -ENOMEM;
571 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
572 }
573 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
574 /* Walk the parent mm page table */
575 mm = gmap->mm;
576 pgd = pgd_offset(mm, vmaddr);
577 VM_BUG_ON(pgd_none(*pgd));
578 p4d = p4d_offset(pgd, vmaddr);
579 VM_BUG_ON(p4d_none(*p4d));
580 pud = pud_offset(p4d, vmaddr);
581 VM_BUG_ON(pud_none(*pud));
582 /* large puds cannot yet be handled */
583 if (pud_large(*pud))
584 return -EFAULT;
585 pmd = pmd_offset(pud, vmaddr);
586 VM_BUG_ON(pmd_none(*pmd));
587 /* large pmds cannot yet be handled */
588 if (pmd_large(*pmd))
589 return -EFAULT;
590 /* Link gmap segment table entry location to page table. */
591 rc = radix_tree_preload(GFP_KERNEL);
592 if (rc)
593 return rc;
594 ptl = pmd_lock(mm, pmd);
595 spin_lock(&gmap->guest_table_lock);
596 if (*table == _SEGMENT_ENTRY_EMPTY) {
597 rc = radix_tree_insert(&gmap->host_to_guest,
598 vmaddr >> PMD_SHIFT, table);
599 if (!rc)
600 *table = pmd_val(*pmd);
601 } else
602 rc = 0;
603 spin_unlock(&gmap->guest_table_lock);
604 spin_unlock(ptl);
605 radix_tree_preload_end();
606 return rc;
607}
608
609/**
610 * gmap_fault - resolve a fault on a guest address
611 * @gmap: pointer to guest mapping meta data structure
612 * @gaddr: guest address
613 * @fault_flags: flags to pass down to handle_mm_fault()
614 *
615 * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
616 * if the vm address is already mapped to a different guest segment.
617 */
618int gmap_fault(struct gmap *gmap, unsigned long gaddr,
619 unsigned int fault_flags)
620{
621 unsigned long vmaddr;
622 int rc;
623 bool unlocked;
624
625 down_read(&gmap->mm->mmap_sem);
626
627retry:
628 unlocked = false;
629 vmaddr = __gmap_translate(gmap, gaddr);
630 if (IS_ERR_VALUE(vmaddr)) {
631 rc = vmaddr;
632 goto out_up;
633 }
634 if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
635 &unlocked)) {
636 rc = -EFAULT;
637 goto out_up;
638 }
639 /*
640 * In the case that fixup_user_fault unlocked the mmap_sem during
641 * faultin redo __gmap_translate to not race with a map/unmap_segment.
642 */
643 if (unlocked)
644 goto retry;
645
646 rc = __gmap_link(gmap, gaddr, vmaddr);
647out_up:
648 up_read(&gmap->mm->mmap_sem);
649 return rc;
650}
651EXPORT_SYMBOL_GPL(gmap_fault);
652
653/*
654 * this function is assumed to be called with mmap_sem held
655 */
656void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
657{
658 unsigned long vmaddr;
659 spinlock_t *ptl;
660 pte_t *ptep;
661
662 /* Find the vm address for the guest address */
663 vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
664 gaddr >> PMD_SHIFT);
665 if (vmaddr) {
666 vmaddr |= gaddr & ~PMD_MASK;
667 /* Get pointer to the page table entry */
668 ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
669 if (likely(ptep))
670 ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
671 pte_unmap_unlock(ptep, ptl);
672 }
673}
674EXPORT_SYMBOL_GPL(__gmap_zap);
675
676void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
677{
678 unsigned long gaddr, vmaddr, size;
679 struct vm_area_struct *vma;
680
681 down_read(&gmap->mm->mmap_sem);
682 for (gaddr = from; gaddr < to;
683 gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
684 /* Find the vm address for the guest address */
685 vmaddr = (unsigned long)
686 radix_tree_lookup(&gmap->guest_to_host,
687 gaddr >> PMD_SHIFT);
688 if (!vmaddr)
689 continue;
690 vmaddr |= gaddr & ~PMD_MASK;
691 /* Find vma in the parent mm */
692 vma = find_vma(gmap->mm, vmaddr);
693 size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
694 zap_page_range(vma, vmaddr, size);
695 }
696 up_read(&gmap->mm->mmap_sem);
697}
698EXPORT_SYMBOL_GPL(gmap_discard);
699
700static LIST_HEAD(gmap_notifier_list);
701static DEFINE_SPINLOCK(gmap_notifier_lock);
702
703/**
704 * gmap_register_pte_notifier - register a pte invalidation callback
705 * @nb: pointer to the gmap notifier block
706 */
707void gmap_register_pte_notifier(struct gmap_notifier *nb)
708{
709 spin_lock(&gmap_notifier_lock);
710 list_add_rcu(&nb->list, &gmap_notifier_list);
711 spin_unlock(&gmap_notifier_lock);
712}
713EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
714
715/**
716 * gmap_unregister_pte_notifier - remove a pte invalidation callback
717 * @nb: pointer to the gmap notifier block
718 */
719void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
720{
721 spin_lock(&gmap_notifier_lock);
722 list_del_rcu(&nb->list);
723 spin_unlock(&gmap_notifier_lock);
724 synchronize_rcu();
725}
726EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
727
728/**
729 * gmap_call_notifier - call all registered invalidation callbacks
730 * @gmap: pointer to guest mapping meta data structure
731 * @start: start virtual address in the guest address space
732 * @end: end virtual address in the guest address space
733 */
734static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
735 unsigned long end)
736{
737 struct gmap_notifier *nb;
738
739 list_for_each_entry(nb, &gmap_notifier_list, list)
740 nb->notifier_call(gmap, start, end);
741}
742
743/**
744 * gmap_table_walk - walk the gmap page tables
745 * @gmap: pointer to guest mapping meta data structure
746 * @gaddr: virtual address in the guest address space
747 * @level: page table level to stop at
748 *
749 * Returns a table entry pointer for the given guest address and @level
750 * @level=0 : returns a pointer to a page table table entry (or NULL)
751 * @level=1 : returns a pointer to a segment table entry (or NULL)
752 * @level=2 : returns a pointer to a region-3 table entry (or NULL)
753 * @level=3 : returns a pointer to a region-2 table entry (or NULL)
754 * @level=4 : returns a pointer to a region-1 table entry (or NULL)
755 *
756 * Returns NULL if the gmap page tables could not be walked to the
757 * requested level.
758 *
759 * Note: Can also be called for shadow gmaps.
760 */
761static inline unsigned long *gmap_table_walk(struct gmap *gmap,
762 unsigned long gaddr, int level)
763{
764 unsigned long *table;
765
766 if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
767 return NULL;
768 if (gmap_is_shadow(gmap) && gmap->removed)
769 return NULL;
770 if (gaddr & (-1UL << (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11)))
771 return NULL;
772 table = gmap->table;
773 switch (gmap->asce & _ASCE_TYPE_MASK) {
774 case _ASCE_TYPE_REGION1:
775 table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
776 if (level == 4)
777 break;
778 if (*table & _REGION_ENTRY_INVALID)
779 return NULL;
780 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
781 /* Fallthrough */
782 case _ASCE_TYPE_REGION2:
783 table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
784 if (level == 3)
785 break;
786 if (*table & _REGION_ENTRY_INVALID)
787 return NULL;
788 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
789 /* Fallthrough */
790 case _ASCE_TYPE_REGION3:
791 table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
792 if (level == 2)
793 break;
794 if (*table & _REGION_ENTRY_INVALID)
795 return NULL;
796 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
797 /* Fallthrough */
798 case _ASCE_TYPE_SEGMENT:
799 table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
800 if (level == 1)
801 break;
802 if (*table & _REGION_ENTRY_INVALID)
803 return NULL;
804 table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
805 table += (gaddr & _PAGE_INDEX) >> _PAGE_SHIFT;
806 }
807 return table;
808}
809
810/**
811 * gmap_pte_op_walk - walk the gmap page table, get the page table lock
812 * and return the pte pointer
813 * @gmap: pointer to guest mapping meta data structure
814 * @gaddr: virtual address in the guest address space
815 * @ptl: pointer to the spinlock pointer
816 *
817 * Returns a pointer to the locked pte for a guest address, or NULL
818 */
819static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
820 spinlock_t **ptl)
821{
822 unsigned long *table;
823
824 BUG_ON(gmap_is_shadow(gmap));
825 /* Walk the gmap page table, lock and get pte pointer */
826 table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
827 if (!table || *table & _SEGMENT_ENTRY_INVALID)
828 return NULL;
829 return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
830}
831
832/**
833 * gmap_pte_op_fixup - force a page in and connect the gmap page table
834 * @gmap: pointer to guest mapping meta data structure
835 * @gaddr: virtual address in the guest address space
836 * @vmaddr: address in the host process address space
837 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
838 *
839 * Returns 0 if the caller can retry __gmap_translate (might fail again),
840 * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
841 * up or connecting the gmap page table.
842 */
843static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
844 unsigned long vmaddr, int prot)
845{
846 struct mm_struct *mm = gmap->mm;
847 unsigned int fault_flags;
848 bool unlocked = false;
849
850 BUG_ON(gmap_is_shadow(gmap));
851 fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
852 if (fixup_user_fault(current, mm, vmaddr, fault_flags, &unlocked))
853 return -EFAULT;
854 if (unlocked)
855 /* lost mmap_sem, caller has to retry __gmap_translate */
856 return 0;
857 /* Connect the page tables */
858 return __gmap_link(gmap, gaddr, vmaddr);
859}
860
861/**
862 * gmap_pte_op_end - release the page table lock
863 * @ptl: pointer to the spinlock pointer
864 */
865static void gmap_pte_op_end(spinlock_t *ptl)
866{
867 spin_unlock(ptl);
868}
869
870/*
871 * gmap_protect_range - remove access rights to memory and set pgste bits
872 * @gmap: pointer to guest mapping meta data structure
873 * @gaddr: virtual address in the guest address space
874 * @len: size of area
875 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
876 * @bits: pgste notification bits to set
877 *
878 * Returns 0 if successfully protected, -ENOMEM if out of memory and
879 * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
880 *
881 * Called with sg->mm->mmap_sem in read.
882 */
883static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
884 unsigned long len, int prot, unsigned long bits)
885{
886 unsigned long vmaddr;
887 spinlock_t *ptl;
888 pte_t *ptep;
889 int rc;
890
891 BUG_ON(gmap_is_shadow(gmap));
892 while (len) {
893 rc = -EAGAIN;
894 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
895 if (ptep) {
896 rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits);
897 gmap_pte_op_end(ptl);
898 }
899 if (rc) {
900 vmaddr = __gmap_translate(gmap, gaddr);
901 if (IS_ERR_VALUE(vmaddr))
902 return vmaddr;
903 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
904 if (rc)
905 return rc;
906 continue;
907 }
908 gaddr += PAGE_SIZE;
909 len -= PAGE_SIZE;
910 }
911 return 0;
912}
913
914/**
915 * gmap_mprotect_notify - change access rights for a range of ptes and
916 * call the notifier if any pte changes again
917 * @gmap: pointer to guest mapping meta data structure
918 * @gaddr: virtual address in the guest address space
919 * @len: size of area
920 * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
921 *
922 * Returns 0 if for each page in the given range a gmap mapping exists,
923 * the new access rights could be set and the notifier could be armed.
924 * If the gmap mapping is missing for one or more pages -EFAULT is
925 * returned. If no memory could be allocated -ENOMEM is returned.
926 * This function establishes missing page table entries.
927 */
928int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
929 unsigned long len, int prot)
930{
931 int rc;
932
933 if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
934 return -EINVAL;
935 if (!MACHINE_HAS_ESOP && prot == PROT_READ)
936 return -EINVAL;
937 down_read(&gmap->mm->mmap_sem);
938 rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT);
939 up_read(&gmap->mm->mmap_sem);
940 return rc;
941}
942EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
943
944/**
945 * gmap_read_table - get an unsigned long value from a guest page table using
946 * absolute addressing, without marking the page referenced.
947 * @gmap: pointer to guest mapping meta data structure
948 * @gaddr: virtual address in the guest address space
949 * @val: pointer to the unsigned long value to return
950 *
951 * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
952 * if reading using the virtual address failed. -EINVAL if called on a gmap
953 * shadow.
954 *
955 * Called with gmap->mm->mmap_sem in read.
956 */
957int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
958{
959 unsigned long address, vmaddr;
960 spinlock_t *ptl;
961 pte_t *ptep, pte;
962 int rc;
963
964 if (gmap_is_shadow(gmap))
965 return -EINVAL;
966
967 while (1) {
968 rc = -EAGAIN;
969 ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
970 if (ptep) {
971 pte = *ptep;
972 if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
973 address = pte_val(pte) & PAGE_MASK;
974 address += gaddr & ~PAGE_MASK;
975 *val = *(unsigned long *) address;
976 pte_val(*ptep) |= _PAGE_YOUNG;
977 /* Do *NOT* clear the _PAGE_INVALID bit! */
978 rc = 0;
979 }
980 gmap_pte_op_end(ptl);
981 }
982 if (!rc)
983 break;
984 vmaddr = __gmap_translate(gmap, gaddr);
985 if (IS_ERR_VALUE(vmaddr)) {
986 rc = vmaddr;
987 break;
988 }
989 rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
990 if (rc)
991 break;
992 }
993 return rc;
994}
995EXPORT_SYMBOL_GPL(gmap_read_table);
996
997/**
998 * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
999 * @sg: pointer to the shadow guest address space structure
1000 * @vmaddr: vm address associated with the rmap
1001 * @rmap: pointer to the rmap structure
1002 *
1003 * Called with the sg->guest_table_lock
1004 */
1005static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
1006 struct gmap_rmap *rmap)
1007{
1008 void __rcu **slot;
1009
1010 BUG_ON(!gmap_is_shadow(sg));
1011 slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
1012 if (slot) {
1013 rmap->next = radix_tree_deref_slot_protected(slot,
1014 &sg->guest_table_lock);
1015 radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
1016 } else {
1017 rmap->next = NULL;
1018 radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
1019 rmap);
1020 }
1021}
1022
1023/**
1024 * gmap_protect_rmap - restrict access rights to memory (RO) and create an rmap
1025 * @sg: pointer to the shadow guest address space structure
1026 * @raddr: rmap address in the shadow gmap
1027 * @paddr: address in the parent guest address space
1028 * @len: length of the memory area to protect
1029 *
1030 * Returns 0 if successfully protected and the rmap was created, -ENOMEM
1031 * if out of memory and -EFAULT if paddr is invalid.
1032 */
1033static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
1034 unsigned long paddr, unsigned long len)
1035{
1036 struct gmap *parent;
1037 struct gmap_rmap *rmap;
1038 unsigned long vmaddr;
1039 spinlock_t *ptl;
1040 pte_t *ptep;
1041 int rc;
1042
1043 BUG_ON(!gmap_is_shadow(sg));
1044 parent = sg->parent;
1045 while (len) {
1046 vmaddr = __gmap_translate(parent, paddr);
1047 if (IS_ERR_VALUE(vmaddr))
1048 return vmaddr;
1049 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1050 if (!rmap)
1051 return -ENOMEM;
1052 rmap->raddr = raddr;
1053 rc = radix_tree_preload(GFP_KERNEL);
1054 if (rc) {
1055 kfree(rmap);
1056 return rc;
1057 }
1058 rc = -EAGAIN;
1059 ptep = gmap_pte_op_walk(parent, paddr, &ptl);
1060 if (ptep) {
1061 spin_lock(&sg->guest_table_lock);
1062 rc = ptep_force_prot(parent->mm, paddr, ptep, PROT_READ,
1063 PGSTE_VSIE_BIT);
1064 if (!rc)
1065 gmap_insert_rmap(sg, vmaddr, rmap);
1066 spin_unlock(&sg->guest_table_lock);
1067 gmap_pte_op_end(ptl);
1068 }
1069 radix_tree_preload_end();
1070 if (rc) {
1071 kfree(rmap);
1072 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, PROT_READ);
1073 if (rc)
1074 return rc;
1075 continue;
1076 }
1077 paddr += PAGE_SIZE;
1078 len -= PAGE_SIZE;
1079 }
1080 return 0;
1081}
1082
1083#define _SHADOW_RMAP_MASK 0x7
1084#define _SHADOW_RMAP_REGION1 0x5
1085#define _SHADOW_RMAP_REGION2 0x4
1086#define _SHADOW_RMAP_REGION3 0x3
1087#define _SHADOW_RMAP_SEGMENT 0x2
1088#define _SHADOW_RMAP_PGTABLE 0x1
1089
1090/**
1091 * gmap_idte_one - invalidate a single region or segment table entry
1092 * @asce: region or segment table *origin* + table-type bits
1093 * @vaddr: virtual address to identify the table entry to flush
1094 *
1095 * The invalid bit of a single region or segment table entry is set
1096 * and the associated TLB entries depending on the entry are flushed.
1097 * The table-type of the @asce identifies the portion of the @vaddr
1098 * that is used as the invalidation index.
1099 */
1100static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
1101{
1102 asm volatile(
1103 " .insn rrf,0xb98e0000,%0,%1,0,0"
1104 : : "a" (asce), "a" (vaddr) : "cc", "memory");
1105}
1106
1107/**
1108 * gmap_unshadow_page - remove a page from a shadow page table
1109 * @sg: pointer to the shadow guest address space structure
1110 * @raddr: rmap address in the shadow guest address space
1111 *
1112 * Called with the sg->guest_table_lock
1113 */
1114static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
1115{
1116 unsigned long *table;
1117
1118 BUG_ON(!gmap_is_shadow(sg));
1119 table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
1120 if (!table || *table & _PAGE_INVALID)
1121 return;
1122 gmap_call_notifier(sg, raddr, raddr + _PAGE_SIZE - 1);
1123 ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
1124}
1125
1126/**
1127 * __gmap_unshadow_pgt - remove all entries from a shadow page table
1128 * @sg: pointer to the shadow guest address space structure
1129 * @raddr: rmap address in the shadow guest address space
1130 * @pgt: pointer to the start of a shadow page table
1131 *
1132 * Called with the sg->guest_table_lock
1133 */
1134static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
1135 unsigned long *pgt)
1136{
1137 int i;
1138
1139 BUG_ON(!gmap_is_shadow(sg));
1140 for (i = 0; i < _PAGE_ENTRIES; i++, raddr += _PAGE_SIZE)
1141 pgt[i] = _PAGE_INVALID;
1142}
1143
1144/**
1145 * gmap_unshadow_pgt - remove a shadow page table from a segment entry
1146 * @sg: pointer to the shadow guest address space structure
1147 * @raddr: address in the shadow guest address space
1148 *
1149 * Called with the sg->guest_table_lock
1150 */
1151static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
1152{
1153 unsigned long sto, *ste, *pgt;
1154 struct page *page;
1155
1156 BUG_ON(!gmap_is_shadow(sg));
1157 ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
1158 if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
1159 return;
1160 gmap_call_notifier(sg, raddr, raddr + _SEGMENT_SIZE - 1);
1161 sto = (unsigned long) (ste - ((raddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT));
1162 gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
1163 pgt = (unsigned long *)(*ste & _SEGMENT_ENTRY_ORIGIN);
1164 *ste = _SEGMENT_ENTRY_EMPTY;
1165 __gmap_unshadow_pgt(sg, raddr, pgt);
1166 /* Free page table */
1167 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1168 list_del(&page->lru);
1169 page_table_free_pgste(page);
1170}
1171
1172/**
1173 * __gmap_unshadow_sgt - remove all entries from a shadow segment table
1174 * @sg: pointer to the shadow guest address space structure
1175 * @raddr: rmap address in the shadow guest address space
1176 * @sgt: pointer to the start of a shadow segment table
1177 *
1178 * Called with the sg->guest_table_lock
1179 */
1180static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
1181 unsigned long *sgt)
1182{
1183 unsigned long *pgt;
1184 struct page *page;
1185 int i;
1186
1187 BUG_ON(!gmap_is_shadow(sg));
1188 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
1189 if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
1190 continue;
1191 pgt = (unsigned long *)(sgt[i] & _REGION_ENTRY_ORIGIN);
1192 sgt[i] = _SEGMENT_ENTRY_EMPTY;
1193 __gmap_unshadow_pgt(sg, raddr, pgt);
1194 /* Free page table */
1195 page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
1196 list_del(&page->lru);
1197 page_table_free_pgste(page);
1198 }
1199}
1200
1201/**
1202 * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
1203 * @sg: pointer to the shadow guest address space structure
1204 * @raddr: rmap address in the shadow guest address space
1205 *
1206 * Called with the shadow->guest_table_lock
1207 */
1208static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
1209{
1210 unsigned long r3o, *r3e, *sgt;
1211 struct page *page;
1212
1213 BUG_ON(!gmap_is_shadow(sg));
1214 r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
1215 if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
1216 return;
1217 gmap_call_notifier(sg, raddr, raddr + _REGION3_SIZE - 1);
1218 r3o = (unsigned long) (r3e - ((raddr & _REGION3_INDEX) >> _REGION3_SHIFT));
1219 gmap_idte_one(r3o | _ASCE_TYPE_REGION3, raddr);
1220 sgt = (unsigned long *)(*r3e & _REGION_ENTRY_ORIGIN);
1221 *r3e = _REGION3_ENTRY_EMPTY;
1222 __gmap_unshadow_sgt(sg, raddr, sgt);
1223 /* Free segment table */
1224 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1225 list_del(&page->lru);
1226 __free_pages(page, CRST_ALLOC_ORDER);
1227}
1228
1229/**
1230 * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
1231 * @sg: pointer to the shadow guest address space structure
1232 * @raddr: address in the shadow guest address space
1233 * @r3t: pointer to the start of a shadow region-3 table
1234 *
1235 * Called with the sg->guest_table_lock
1236 */
1237static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
1238 unsigned long *r3t)
1239{
1240 unsigned long *sgt;
1241 struct page *page;
1242 int i;
1243
1244 BUG_ON(!gmap_is_shadow(sg));
1245 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
1246 if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
1247 continue;
1248 sgt = (unsigned long *)(r3t[i] & _REGION_ENTRY_ORIGIN);
1249 r3t[i] = _REGION3_ENTRY_EMPTY;
1250 __gmap_unshadow_sgt(sg, raddr, sgt);
1251 /* Free segment table */
1252 page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
1253 list_del(&page->lru);
1254 __free_pages(page, CRST_ALLOC_ORDER);
1255 }
1256}
1257
1258/**
1259 * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
1260 * @sg: pointer to the shadow guest address space structure
1261 * @raddr: rmap address in the shadow guest address space
1262 *
1263 * Called with the sg->guest_table_lock
1264 */
1265static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
1266{
1267 unsigned long r2o, *r2e, *r3t;
1268 struct page *page;
1269
1270 BUG_ON(!gmap_is_shadow(sg));
1271 r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
1272 if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
1273 return;
1274 gmap_call_notifier(sg, raddr, raddr + _REGION2_SIZE - 1);
1275 r2o = (unsigned long) (r2e - ((raddr & _REGION2_INDEX) >> _REGION2_SHIFT));
1276 gmap_idte_one(r2o | _ASCE_TYPE_REGION2, raddr);
1277 r3t = (unsigned long *)(*r2e & _REGION_ENTRY_ORIGIN);
1278 *r2e = _REGION2_ENTRY_EMPTY;
1279 __gmap_unshadow_r3t(sg, raddr, r3t);
1280 /* Free region 3 table */
1281 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1282 list_del(&page->lru);
1283 __free_pages(page, CRST_ALLOC_ORDER);
1284}
1285
1286/**
1287 * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
1288 * @sg: pointer to the shadow guest address space structure
1289 * @raddr: rmap address in the shadow guest address space
1290 * @r2t: pointer to the start of a shadow region-2 table
1291 *
1292 * Called with the sg->guest_table_lock
1293 */
1294static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
1295 unsigned long *r2t)
1296{
1297 unsigned long *r3t;
1298 struct page *page;
1299 int i;
1300
1301 BUG_ON(!gmap_is_shadow(sg));
1302 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
1303 if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
1304 continue;
1305 r3t = (unsigned long *)(r2t[i] & _REGION_ENTRY_ORIGIN);
1306 r2t[i] = _REGION2_ENTRY_EMPTY;
1307 __gmap_unshadow_r3t(sg, raddr, r3t);
1308 /* Free region 3 table */
1309 page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
1310 list_del(&page->lru);
1311 __free_pages(page, CRST_ALLOC_ORDER);
1312 }
1313}
1314
1315/**
1316 * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
1317 * @sg: pointer to the shadow guest address space structure
1318 * @raddr: rmap address in the shadow guest address space
1319 *
1320 * Called with the sg->guest_table_lock
1321 */
1322static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
1323{
1324 unsigned long r1o, *r1e, *r2t;
1325 struct page *page;
1326
1327 BUG_ON(!gmap_is_shadow(sg));
1328 r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
1329 if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
1330 return;
1331 gmap_call_notifier(sg, raddr, raddr + _REGION1_SIZE - 1);
1332 r1o = (unsigned long) (r1e - ((raddr & _REGION1_INDEX) >> _REGION1_SHIFT));
1333 gmap_idte_one(r1o | _ASCE_TYPE_REGION1, raddr);
1334 r2t = (unsigned long *)(*r1e & _REGION_ENTRY_ORIGIN);
1335 *r1e = _REGION1_ENTRY_EMPTY;
1336 __gmap_unshadow_r2t(sg, raddr, r2t);
1337 /* Free region 2 table */
1338 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1339 list_del(&page->lru);
1340 __free_pages(page, CRST_ALLOC_ORDER);
1341}
1342
1343/**
1344 * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
1345 * @sg: pointer to the shadow guest address space structure
1346 * @raddr: rmap address in the shadow guest address space
1347 * @r1t: pointer to the start of a shadow region-1 table
1348 *
1349 * Called with the shadow->guest_table_lock
1350 */
1351static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
1352 unsigned long *r1t)
1353{
1354 unsigned long asce, *r2t;
1355 struct page *page;
1356 int i;
1357
1358 BUG_ON(!gmap_is_shadow(sg));
1359 asce = (unsigned long) r1t | _ASCE_TYPE_REGION1;
1360 for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION1_SIZE) {
1361 if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
1362 continue;
1363 r2t = (unsigned long *)(r1t[i] & _REGION_ENTRY_ORIGIN);
1364 __gmap_unshadow_r2t(sg, raddr, r2t);
1365 /* Clear entry and flush translation r1t -> r2t */
1366 gmap_idte_one(asce, raddr);
1367 r1t[i] = _REGION1_ENTRY_EMPTY;
1368 /* Free region 2 table */
1369 page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
1370 list_del(&page->lru);
1371 __free_pages(page, CRST_ALLOC_ORDER);
1372 }
1373}
1374
1375/**
1376 * gmap_unshadow - remove a shadow page table completely
1377 * @sg: pointer to the shadow guest address space structure
1378 *
1379 * Called with sg->guest_table_lock
1380 */
1381static void gmap_unshadow(struct gmap *sg)
1382{
1383 unsigned long *table;
1384
1385 BUG_ON(!gmap_is_shadow(sg));
1386 if (sg->removed)
1387 return;
1388 sg->removed = 1;
1389 gmap_call_notifier(sg, 0, -1UL);
1390 gmap_flush_tlb(sg);
1391 table = (unsigned long *)(sg->asce & _ASCE_ORIGIN);
1392 switch (sg->asce & _ASCE_TYPE_MASK) {
1393 case _ASCE_TYPE_REGION1:
1394 __gmap_unshadow_r1t(sg, 0, table);
1395 break;
1396 case _ASCE_TYPE_REGION2:
1397 __gmap_unshadow_r2t(sg, 0, table);
1398 break;
1399 case _ASCE_TYPE_REGION3:
1400 __gmap_unshadow_r3t(sg, 0, table);
1401 break;
1402 case _ASCE_TYPE_SEGMENT:
1403 __gmap_unshadow_sgt(sg, 0, table);
1404 break;
1405 }
1406}
1407
1408/**
1409 * gmap_find_shadow - find a specific asce in the list of shadow tables
1410 * @parent: pointer to the parent gmap
1411 * @asce: ASCE for which the shadow table is created
1412 * @edat_level: edat level to be used for the shadow translation
1413 *
1414 * Returns the pointer to a gmap if a shadow table with the given asce is
1415 * already available, ERR_PTR(-EAGAIN) if another one is just being created,
1416 * otherwise NULL
1417 */
1418static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
1419 int edat_level)
1420{
1421 struct gmap *sg;
1422
1423 list_for_each_entry(sg, &parent->children, list) {
1424 if (sg->orig_asce != asce || sg->edat_level != edat_level ||
1425 sg->removed)
1426 continue;
1427 if (!sg->initialized)
1428 return ERR_PTR(-EAGAIN);
1429 atomic_inc(&sg->ref_count);
1430 return sg;
1431 }
1432 return NULL;
1433}
1434
1435/**
1436 * gmap_shadow_valid - check if a shadow guest address space matches the
1437 * given properties and is still valid
1438 * @sg: pointer to the shadow guest address space structure
1439 * @asce: ASCE for which the shadow table is requested
1440 * @edat_level: edat level to be used for the shadow translation
1441 *
1442 * Returns 1 if the gmap shadow is still valid and matches the given
1443 * properties, the caller can continue using it. Returns 0 otherwise, the
1444 * caller has to request a new shadow gmap in this case.
1445 *
1446 */
1447int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
1448{
1449 if (sg->removed)
1450 return 0;
1451 return sg->orig_asce == asce && sg->edat_level == edat_level;
1452}
1453EXPORT_SYMBOL_GPL(gmap_shadow_valid);
1454
1455/**
1456 * gmap_shadow - create/find a shadow guest address space
1457 * @parent: pointer to the parent gmap
1458 * @asce: ASCE for which the shadow table is created
1459 * @edat_level: edat level to be used for the shadow translation
1460 *
1461 * The pages of the top level page table referred by the asce parameter
1462 * will be set to read-only and marked in the PGSTEs of the kvm process.
1463 * The shadow table will be removed automatically on any change to the
1464 * PTE mapping for the source table.
1465 *
1466 * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
1467 * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
1468 * parent gmap table could not be protected.
1469 */
1470struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
1471 int edat_level)
1472{
1473 struct gmap *sg, *new;
1474 unsigned long limit;
1475 int rc;
1476
1477 BUG_ON(gmap_is_shadow(parent));
1478 spin_lock(&parent->shadow_lock);
1479 sg = gmap_find_shadow(parent, asce, edat_level);
1480 spin_unlock(&parent->shadow_lock);
1481 if (sg)
1482 return sg;
1483 /* Create a new shadow gmap */
1484 limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
1485 if (asce & _ASCE_REAL_SPACE)
1486 limit = -1UL;
1487 new = gmap_alloc(limit);
1488 if (!new)
1489 return ERR_PTR(-ENOMEM);
1490 new->mm = parent->mm;
1491 new->parent = gmap_get(parent);
1492 new->orig_asce = asce;
1493 new->edat_level = edat_level;
1494 new->initialized = false;
1495 spin_lock(&parent->shadow_lock);
1496 /* Recheck if another CPU created the same shadow */
1497 sg = gmap_find_shadow(parent, asce, edat_level);
1498 if (sg) {
1499 spin_unlock(&parent->shadow_lock);
1500 gmap_free(new);
1501 return sg;
1502 }
1503 if (asce & _ASCE_REAL_SPACE) {
1504 /* only allow one real-space gmap shadow */
1505 list_for_each_entry(sg, &parent->children, list) {
1506 if (sg->orig_asce & _ASCE_REAL_SPACE) {
1507 spin_lock(&sg->guest_table_lock);
1508 gmap_unshadow(sg);
1509 spin_unlock(&sg->guest_table_lock);
1510 list_del(&sg->list);
1511 gmap_put(sg);
1512 break;
1513 }
1514 }
1515 }
1516 atomic_set(&new->ref_count, 2);
1517 list_add(&new->list, &parent->children);
1518 if (asce & _ASCE_REAL_SPACE) {
1519 /* nothing to protect, return right away */
1520 new->initialized = true;
1521 spin_unlock(&parent->shadow_lock);
1522 return new;
1523 }
1524 spin_unlock(&parent->shadow_lock);
1525 /* protect after insertion, so it will get properly invalidated */
1526 down_read(&parent->mm->mmap_sem);
1527 rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
1528 ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
1529 PROT_READ, PGSTE_VSIE_BIT);
1530 up_read(&parent->mm->mmap_sem);
1531 spin_lock(&parent->shadow_lock);
1532 new->initialized = true;
1533 if (rc) {
1534 list_del(&new->list);
1535 gmap_free(new);
1536 new = ERR_PTR(rc);
1537 }
1538 spin_unlock(&parent->shadow_lock);
1539 return new;
1540}
1541EXPORT_SYMBOL_GPL(gmap_shadow);
1542
1543/**
1544 * gmap_shadow_r2t - create an empty shadow region 2 table
1545 * @sg: pointer to the shadow guest address space structure
1546 * @saddr: faulting address in the shadow gmap
1547 * @r2t: parent gmap address of the region 2 table to get shadowed
1548 * @fake: r2t references contiguous guest memory block, not a r2t
1549 *
1550 * The r2t parameter specifies the address of the source table. The
1551 * four pages of the source table are made read-only in the parent gmap
1552 * address space. A write to the source table area @r2t will automatically
1553 * remove the shadow r2 table and all of its decendents.
1554 *
1555 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1556 * shadow table structure is incomplete, -ENOMEM if out of memory and
1557 * -EFAULT if an address in the parent gmap could not be resolved.
1558 *
1559 * Called with sg->mm->mmap_sem in read.
1560 */
1561int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
1562 int fake)
1563{
1564 unsigned long raddr, origin, offset, len;
1565 unsigned long *s_r2t, *table;
1566 struct page *page;
1567 int rc;
1568
1569 BUG_ON(!gmap_is_shadow(sg));
1570 /* Allocate a shadow region second table */
1571 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1572 if (!page)
1573 return -ENOMEM;
1574 page->index = r2t & _REGION_ENTRY_ORIGIN;
1575 if (fake)
1576 page->index |= GMAP_SHADOW_FAKE_TABLE;
1577 s_r2t = (unsigned long *) page_to_phys(page);
1578 /* Install shadow region second table */
1579 spin_lock(&sg->guest_table_lock);
1580 table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
1581 if (!table) {
1582 rc = -EAGAIN; /* Race with unshadow */
1583 goto out_free;
1584 }
1585 if (!(*table & _REGION_ENTRY_INVALID)) {
1586 rc = 0; /* Already established */
1587 goto out_free;
1588 } else if (*table & _REGION_ENTRY_ORIGIN) {
1589 rc = -EAGAIN; /* Race with shadow */
1590 goto out_free;
1591 }
1592 crst_table_init(s_r2t, _REGION2_ENTRY_EMPTY);
1593 /* mark as invalid as long as the parent table is not protected */
1594 *table = (unsigned long) s_r2t | _REGION_ENTRY_LENGTH |
1595 _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
1596 if (sg->edat_level >= 1)
1597 *table |= (r2t & _REGION_ENTRY_PROTECT);
1598 list_add(&page->lru, &sg->crst_list);
1599 if (fake) {
1600 /* nothing to protect for fake tables */
1601 *table &= ~_REGION_ENTRY_INVALID;
1602 spin_unlock(&sg->guest_table_lock);
1603 return 0;
1604 }
1605 spin_unlock(&sg->guest_table_lock);
1606 /* Make r2t read-only in parent gmap page table */
1607 raddr = (saddr & _REGION1_MASK) | _SHADOW_RMAP_REGION1;
1608 origin = r2t & _REGION_ENTRY_ORIGIN;
1609 offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1610 len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1611 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1612 spin_lock(&sg->guest_table_lock);
1613 if (!rc) {
1614 table = gmap_table_walk(sg, saddr, 4);
1615 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1616 (unsigned long) s_r2t)
1617 rc = -EAGAIN; /* Race with unshadow */
1618 else
1619 *table &= ~_REGION_ENTRY_INVALID;
1620 } else {
1621 gmap_unshadow_r2t(sg, raddr);
1622 }
1623 spin_unlock(&sg->guest_table_lock);
1624 return rc;
1625out_free:
1626 spin_unlock(&sg->guest_table_lock);
1627 __free_pages(page, CRST_ALLOC_ORDER);
1628 return rc;
1629}
1630EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
1631
1632/**
1633 * gmap_shadow_r3t - create a shadow region 3 table
1634 * @sg: pointer to the shadow guest address space structure
1635 * @saddr: faulting address in the shadow gmap
1636 * @r3t: parent gmap address of the region 3 table to get shadowed
1637 * @fake: r3t references contiguous guest memory block, not a r3t
1638 *
1639 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1640 * shadow table structure is incomplete, -ENOMEM if out of memory and
1641 * -EFAULT if an address in the parent gmap could not be resolved.
1642 *
1643 * Called with sg->mm->mmap_sem in read.
1644 */
1645int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
1646 int fake)
1647{
1648 unsigned long raddr, origin, offset, len;
1649 unsigned long *s_r3t, *table;
1650 struct page *page;
1651 int rc;
1652
1653 BUG_ON(!gmap_is_shadow(sg));
1654 /* Allocate a shadow region second table */
1655 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1656 if (!page)
1657 return -ENOMEM;
1658 page->index = r3t & _REGION_ENTRY_ORIGIN;
1659 if (fake)
1660 page->index |= GMAP_SHADOW_FAKE_TABLE;
1661 s_r3t = (unsigned long *) page_to_phys(page);
1662 /* Install shadow region second table */
1663 spin_lock(&sg->guest_table_lock);
1664 table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
1665 if (!table) {
1666 rc = -EAGAIN; /* Race with unshadow */
1667 goto out_free;
1668 }
1669 if (!(*table & _REGION_ENTRY_INVALID)) {
1670 rc = 0; /* Already established */
1671 goto out_free;
1672 } else if (*table & _REGION_ENTRY_ORIGIN) {
1673 rc = -EAGAIN; /* Race with shadow */
1674 }
1675 crst_table_init(s_r3t, _REGION3_ENTRY_EMPTY);
1676 /* mark as invalid as long as the parent table is not protected */
1677 *table = (unsigned long) s_r3t | _REGION_ENTRY_LENGTH |
1678 _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
1679 if (sg->edat_level >= 1)
1680 *table |= (r3t & _REGION_ENTRY_PROTECT);
1681 list_add(&page->lru, &sg->crst_list);
1682 if (fake) {
1683 /* nothing to protect for fake tables */
1684 *table &= ~_REGION_ENTRY_INVALID;
1685 spin_unlock(&sg->guest_table_lock);
1686 return 0;
1687 }
1688 spin_unlock(&sg->guest_table_lock);
1689 /* Make r3t read-only in parent gmap page table */
1690 raddr = (saddr & _REGION2_MASK) | _SHADOW_RMAP_REGION2;
1691 origin = r3t & _REGION_ENTRY_ORIGIN;
1692 offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1693 len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1694 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1695 spin_lock(&sg->guest_table_lock);
1696 if (!rc) {
1697 table = gmap_table_walk(sg, saddr, 3);
1698 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1699 (unsigned long) s_r3t)
1700 rc = -EAGAIN; /* Race with unshadow */
1701 else
1702 *table &= ~_REGION_ENTRY_INVALID;
1703 } else {
1704 gmap_unshadow_r3t(sg, raddr);
1705 }
1706 spin_unlock(&sg->guest_table_lock);
1707 return rc;
1708out_free:
1709 spin_unlock(&sg->guest_table_lock);
1710 __free_pages(page, CRST_ALLOC_ORDER);
1711 return rc;
1712}
1713EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
1714
1715/**
1716 * gmap_shadow_sgt - create a shadow segment table
1717 * @sg: pointer to the shadow guest address space structure
1718 * @saddr: faulting address in the shadow gmap
1719 * @sgt: parent gmap address of the segment table to get shadowed
1720 * @fake: sgt references contiguous guest memory block, not a sgt
1721 *
1722 * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
1723 * shadow table structure is incomplete, -ENOMEM if out of memory and
1724 * -EFAULT if an address in the parent gmap could not be resolved.
1725 *
1726 * Called with sg->mm->mmap_sem in read.
1727 */
1728int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
1729 int fake)
1730{
1731 unsigned long raddr, origin, offset, len;
1732 unsigned long *s_sgt, *table;
1733 struct page *page;
1734 int rc;
1735
1736 BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
1737 /* Allocate a shadow segment table */
1738 page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
1739 if (!page)
1740 return -ENOMEM;
1741 page->index = sgt & _REGION_ENTRY_ORIGIN;
1742 if (fake)
1743 page->index |= GMAP_SHADOW_FAKE_TABLE;
1744 s_sgt = (unsigned long *) page_to_phys(page);
1745 /* Install shadow region second table */
1746 spin_lock(&sg->guest_table_lock);
1747 table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
1748 if (!table) {
1749 rc = -EAGAIN; /* Race with unshadow */
1750 goto out_free;
1751 }
1752 if (!(*table & _REGION_ENTRY_INVALID)) {
1753 rc = 0; /* Already established */
1754 goto out_free;
1755 } else if (*table & _REGION_ENTRY_ORIGIN) {
1756 rc = -EAGAIN; /* Race with shadow */
1757 goto out_free;
1758 }
1759 crst_table_init(s_sgt, _SEGMENT_ENTRY_EMPTY);
1760 /* mark as invalid as long as the parent table is not protected */
1761 *table = (unsigned long) s_sgt | _REGION_ENTRY_LENGTH |
1762 _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
1763 if (sg->edat_level >= 1)
1764 *table |= sgt & _REGION_ENTRY_PROTECT;
1765 list_add(&page->lru, &sg->crst_list);
1766 if (fake) {
1767 /* nothing to protect for fake tables */
1768 *table &= ~_REGION_ENTRY_INVALID;
1769 spin_unlock(&sg->guest_table_lock);
1770 return 0;
1771 }
1772 spin_unlock(&sg->guest_table_lock);
1773 /* Make sgt read-only in parent gmap page table */
1774 raddr = (saddr & _REGION3_MASK) | _SHADOW_RMAP_REGION3;
1775 origin = sgt & _REGION_ENTRY_ORIGIN;
1776 offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
1777 len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
1778 rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
1779 spin_lock(&sg->guest_table_lock);
1780 if (!rc) {
1781 table = gmap_table_walk(sg, saddr, 2);
1782 if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
1783 (unsigned long) s_sgt)
1784 rc = -EAGAIN; /* Race with unshadow */
1785 else
1786 *table &= ~_REGION_ENTRY_INVALID;
1787 } else {
1788 gmap_unshadow_sgt(sg, raddr);
1789 }
1790 spin_unlock(&sg->guest_table_lock);
1791 return rc;
1792out_free:
1793 spin_unlock(&sg->guest_table_lock);
1794 __free_pages(page, CRST_ALLOC_ORDER);
1795 return rc;
1796}
1797EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
1798
1799/**
1800 * gmap_shadow_lookup_pgtable - find a shadow page table
1801 * @sg: pointer to the shadow guest address space structure
1802 * @saddr: the address in the shadow aguest address space
1803 * @pgt: parent gmap address of the page table to get shadowed
1804 * @dat_protection: if the pgtable is marked as protected by dat
1805 * @fake: pgt references contiguous guest memory block, not a pgtable
1806 *
1807 * Returns 0 if the shadow page table was found and -EAGAIN if the page
1808 * table was not found.
1809 *
1810 * Called with sg->mm->mmap_sem in read.
1811 */
1812int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
1813 unsigned long *pgt, int *dat_protection,
1814 int *fake)
1815{
1816 unsigned long *table;
1817 struct page *page;
1818 int rc;
1819
1820 BUG_ON(!gmap_is_shadow(sg));
1821 spin_lock(&sg->guest_table_lock);
1822 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1823 if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
1824 /* Shadow page tables are full pages (pte+pgste) */
1825 page = pfn_to_page(*table >> PAGE_SHIFT);
1826 *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
1827 *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
1828 *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
1829 rc = 0;
1830 } else {
1831 rc = -EAGAIN;
1832 }
1833 spin_unlock(&sg->guest_table_lock);
1834 return rc;
1835
1836}
1837EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
1838
1839/**
1840 * gmap_shadow_pgt - instantiate a shadow page table
1841 * @sg: pointer to the shadow guest address space structure
1842 * @saddr: faulting address in the shadow gmap
1843 * @pgt: parent gmap address of the page table to get shadowed
1844 * @fake: pgt references contiguous guest memory block, not a pgtable
1845 *
1846 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1847 * shadow table structure is incomplete, -ENOMEM if out of memory,
1848 * -EFAULT if an address in the parent gmap could not be resolved and
1849 *
1850 * Called with gmap->mm->mmap_sem in read
1851 */
1852int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
1853 int fake)
1854{
1855 unsigned long raddr, origin;
1856 unsigned long *s_pgt, *table;
1857 struct page *page;
1858 int rc;
1859
1860 BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
1861 /* Allocate a shadow page table */
1862 page = page_table_alloc_pgste(sg->mm);
1863 if (!page)
1864 return -ENOMEM;
1865 page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
1866 if (fake)
1867 page->index |= GMAP_SHADOW_FAKE_TABLE;
1868 s_pgt = (unsigned long *) page_to_phys(page);
1869 /* Install shadow page table */
1870 spin_lock(&sg->guest_table_lock);
1871 table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
1872 if (!table) {
1873 rc = -EAGAIN; /* Race with unshadow */
1874 goto out_free;
1875 }
1876 if (!(*table & _SEGMENT_ENTRY_INVALID)) {
1877 rc = 0; /* Already established */
1878 goto out_free;
1879 } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
1880 rc = -EAGAIN; /* Race with shadow */
1881 goto out_free;
1882 }
1883 /* mark as invalid as long as the parent table is not protected */
1884 *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
1885 (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
1886 list_add(&page->lru, &sg->pt_list);
1887 if (fake) {
1888 /* nothing to protect for fake tables */
1889 *table &= ~_SEGMENT_ENTRY_INVALID;
1890 spin_unlock(&sg->guest_table_lock);
1891 return 0;
1892 }
1893 spin_unlock(&sg->guest_table_lock);
1894 /* Make pgt read-only in parent gmap page table (not the pgste) */
1895 raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
1896 origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
1897 rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
1898 spin_lock(&sg->guest_table_lock);
1899 if (!rc) {
1900 table = gmap_table_walk(sg, saddr, 1);
1901 if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
1902 (unsigned long) s_pgt)
1903 rc = -EAGAIN; /* Race with unshadow */
1904 else
1905 *table &= ~_SEGMENT_ENTRY_INVALID;
1906 } else {
1907 gmap_unshadow_pgt(sg, raddr);
1908 }
1909 spin_unlock(&sg->guest_table_lock);
1910 return rc;
1911out_free:
1912 spin_unlock(&sg->guest_table_lock);
1913 page_table_free_pgste(page);
1914 return rc;
1915
1916}
1917EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
1918
1919/**
1920 * gmap_shadow_page - create a shadow page mapping
1921 * @sg: pointer to the shadow guest address space structure
1922 * @saddr: faulting address in the shadow gmap
1923 * @pte: pte in parent gmap address space to get shadowed
1924 *
1925 * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
1926 * shadow table structure is incomplete, -ENOMEM if out of memory and
1927 * -EFAULT if an address in the parent gmap could not be resolved.
1928 *
1929 * Called with sg->mm->mmap_sem in read.
1930 */
1931int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
1932{
1933 struct gmap *parent;
1934 struct gmap_rmap *rmap;
1935 unsigned long vmaddr, paddr;
1936 spinlock_t *ptl;
1937 pte_t *sptep, *tptep;
1938 int prot;
1939 int rc;
1940
1941 BUG_ON(!gmap_is_shadow(sg));
1942 parent = sg->parent;
1943 prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
1944
1945 rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
1946 if (!rmap)
1947 return -ENOMEM;
1948 rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
1949
1950 while (1) {
1951 paddr = pte_val(pte) & PAGE_MASK;
1952 vmaddr = __gmap_translate(parent, paddr);
1953 if (IS_ERR_VALUE(vmaddr)) {
1954 rc = vmaddr;
1955 break;
1956 }
1957 rc = radix_tree_preload(GFP_KERNEL);
1958 if (rc)
1959 break;
1960 rc = -EAGAIN;
1961 sptep = gmap_pte_op_walk(parent, paddr, &ptl);
1962 if (sptep) {
1963 spin_lock(&sg->guest_table_lock);
1964 /* Get page table pointer */
1965 tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
1966 if (!tptep) {
1967 spin_unlock(&sg->guest_table_lock);
1968 gmap_pte_op_end(ptl);
1969 radix_tree_preload_end();
1970 break;
1971 }
1972 rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
1973 if (rc > 0) {
1974 /* Success and a new mapping */
1975 gmap_insert_rmap(sg, vmaddr, rmap);
1976 rmap = NULL;
1977 rc = 0;
1978 }
1979 gmap_pte_op_end(ptl);
1980 spin_unlock(&sg->guest_table_lock);
1981 }
1982 radix_tree_preload_end();
1983 if (!rc)
1984 break;
1985 rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
1986 if (rc)
1987 break;
1988 }
1989 kfree(rmap);
1990 return rc;
1991}
1992EXPORT_SYMBOL_GPL(gmap_shadow_page);
1993
1994/**
1995 * gmap_shadow_notify - handle notifications for shadow gmap
1996 *
1997 * Called with sg->parent->shadow_lock.
1998 */
1999static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
2000 unsigned long gaddr)
2001{
2002 struct gmap_rmap *rmap, *rnext, *head;
2003 unsigned long start, end, bits, raddr;
2004
2005 BUG_ON(!gmap_is_shadow(sg));
2006
2007 spin_lock(&sg->guest_table_lock);
2008 if (sg->removed) {
2009 spin_unlock(&sg->guest_table_lock);
2010 return;
2011 }
2012 /* Check for top level table */
2013 start = sg->orig_asce & _ASCE_ORIGIN;
2014 end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE;
2015 if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
2016 gaddr < end) {
2017 /* The complete shadow table has to go */
2018 gmap_unshadow(sg);
2019 spin_unlock(&sg->guest_table_lock);
2020 list_del(&sg->list);
2021 gmap_put(sg);
2022 return;
2023 }
2024 /* Remove the page table tree from on specific entry */
2025 head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
2026 gmap_for_each_rmap_safe(rmap, rnext, head) {
2027 bits = rmap->raddr & _SHADOW_RMAP_MASK;
2028 raddr = rmap->raddr ^ bits;
2029 switch (bits) {
2030 case _SHADOW_RMAP_REGION1:
2031 gmap_unshadow_r2t(sg, raddr);
2032 break;
2033 case _SHADOW_RMAP_REGION2:
2034 gmap_unshadow_r3t(sg, raddr);
2035 break;
2036 case _SHADOW_RMAP_REGION3:
2037 gmap_unshadow_sgt(sg, raddr);
2038 break;
2039 case _SHADOW_RMAP_SEGMENT:
2040 gmap_unshadow_pgt(sg, raddr);
2041 break;
2042 case _SHADOW_RMAP_PGTABLE:
2043 gmap_unshadow_page(sg, raddr);
2044 break;
2045 }
2046 kfree(rmap);
2047 }
2048 spin_unlock(&sg->guest_table_lock);
2049}
2050
2051/**
2052 * ptep_notify - call all invalidation callbacks for a specific pte.
2053 * @mm: pointer to the process mm_struct
2054 * @addr: virtual address in the process address space
2055 * @pte: pointer to the page table entry
2056 * @bits: bits from the pgste that caused the notify call
2057 *
2058 * This function is assumed to be called with the page table lock held
2059 * for the pte to notify.
2060 */
2061void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
2062 pte_t *pte, unsigned long bits)
2063{
2064 unsigned long offset, gaddr = 0;
2065 unsigned long *table;
2066 struct gmap *gmap, *sg, *next;
2067
2068 offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
2069 offset = offset * (PAGE_SIZE / sizeof(pte_t));
2070 rcu_read_lock();
2071 list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
2072 spin_lock(&gmap->guest_table_lock);
2073 table = radix_tree_lookup(&gmap->host_to_guest,
2074 vmaddr >> PMD_SHIFT);
2075 if (table)
2076 gaddr = __gmap_segment_gaddr(table) + offset;
2077 spin_unlock(&gmap->guest_table_lock);
2078 if (!table)
2079 continue;
2080
2081 if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
2082 spin_lock(&gmap->shadow_lock);
2083 list_for_each_entry_safe(sg, next,
2084 &gmap->children, list)
2085 gmap_shadow_notify(sg, vmaddr, gaddr);
2086 spin_unlock(&gmap->shadow_lock);
2087 }
2088 if (bits & PGSTE_IN_BIT)
2089 gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
2090 }
2091 rcu_read_unlock();
2092}
2093EXPORT_SYMBOL_GPL(ptep_notify);
2094
2095static inline void thp_split_mm(struct mm_struct *mm)
2096{
2097#ifdef CONFIG_TRANSPARENT_HUGEPAGE
2098 struct vm_area_struct *vma;
2099 unsigned long addr;
2100
2101 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
2102 for (addr = vma->vm_start;
2103 addr < vma->vm_end;
2104 addr += PAGE_SIZE)
2105 follow_page(vma, addr, FOLL_SPLIT);
2106 vma->vm_flags &= ~VM_HUGEPAGE;
2107 vma->vm_flags |= VM_NOHUGEPAGE;
2108 }
2109 mm->def_flags |= VM_NOHUGEPAGE;
2110#endif
2111}
2112
2113/*
2114 * Remove all empty zero pages from the mapping for lazy refaulting
2115 * - This must be called after mm->context.has_pgste is set, to avoid
2116 * future creation of zero pages
2117 * - This must be called after THP was enabled
2118 */
2119static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
2120 unsigned long end, struct mm_walk *walk)
2121{
2122 unsigned long addr;
2123
2124 for (addr = start; addr != end; addr += PAGE_SIZE) {
2125 pte_t *ptep;
2126 spinlock_t *ptl;
2127
2128 ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
2129 if (is_zero_pfn(pte_pfn(*ptep)))
2130 ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID));
2131 pte_unmap_unlock(ptep, ptl);
2132 }
2133 return 0;
2134}
2135
2136static inline void zap_zero_pages(struct mm_struct *mm)
2137{
2138 struct mm_walk walk = { .pmd_entry = __zap_zero_pages };
2139
2140 walk.mm = mm;
2141 walk_page_range(0, TASK_SIZE, &walk);
2142}
2143
2144/*
2145 * switch on pgstes for its userspace process (for kvm)
2146 */
2147int s390_enable_sie(void)
2148{
2149 struct mm_struct *mm = current->mm;
2150
2151 /* Do we have pgstes? if yes, we are done */
2152 if (mm_has_pgste(mm))
2153 return 0;
2154 /* Fail if the page tables are 2K */
2155 if (!mm_alloc_pgste(mm))
2156 return -EINVAL;
2157 down_write(&mm->mmap_sem);
2158 mm->context.has_pgste = 1;
2159 /* split thp mappings and disable thp for future mappings */
2160 thp_split_mm(mm);
2161 zap_zero_pages(mm);
2162 up_write(&mm->mmap_sem);
2163 return 0;
2164}
2165EXPORT_SYMBOL_GPL(s390_enable_sie);
2166
2167/*
2168 * Enable storage key handling from now on and initialize the storage
2169 * keys with the default key.
2170 */
2171static int __s390_enable_skey(pte_t *pte, unsigned long addr,
2172 unsigned long next, struct mm_walk *walk)
2173{
2174 /* Clear storage key */
2175 ptep_zap_key(walk->mm, addr, pte);
2176 return 0;
2177}
2178
2179int s390_enable_skey(void)
2180{
2181 struct mm_walk walk = { .pte_entry = __s390_enable_skey };
2182 struct mm_struct *mm = current->mm;
2183 struct vm_area_struct *vma;
2184 int rc = 0;
2185
2186 down_write(&mm->mmap_sem);
2187 if (mm_use_skey(mm))
2188 goto out_up;
2189
2190 mm->context.use_skey = 1;
2191 for (vma = mm->mmap; vma; vma = vma->vm_next) {
2192 if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
2193 MADV_UNMERGEABLE, &vma->vm_flags)) {
2194 mm->context.use_skey = 0;
2195 rc = -ENOMEM;
2196 goto out_up;
2197 }
2198 }
2199 mm->def_flags &= ~VM_MERGEABLE;
2200
2201 walk.mm = mm;
2202 walk_page_range(0, TASK_SIZE, &walk);
2203
2204out_up:
2205 up_write(&mm->mmap_sem);
2206 return rc;
2207}
2208EXPORT_SYMBOL_GPL(s390_enable_skey);
2209
2210/*
2211 * Reset CMMA state, make all pages stable again.
2212 */
2213static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
2214 unsigned long next, struct mm_walk *walk)
2215{
2216 ptep_zap_unused(walk->mm, addr, pte, 1);
2217 return 0;
2218}
2219
2220void s390_reset_cmma(struct mm_struct *mm)
2221{
2222 struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
2223
2224 down_write(&mm->mmap_sem);
2225 walk.mm = mm;
2226 walk_page_range(0, TASK_SIZE, &walk);
2227 up_write(&mm->mmap_sem);
2228}
2229EXPORT_SYMBOL_GPL(s390_reset_cmma);