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KVM: MMU: mmu_parent_walk
[deliverable/linux.git] / arch / x86 / kvm / mmu.c
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1/*
2 * Kernel-based Virtual Machine driver for Linux
3 *
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
6 *
7 * MMU support
8 *
9 * Copyright (C) 2006 Qumranet, Inc.
10 *
11 * Authors:
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
14 *
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
17 *
18 */
19
20#include "vmx.h"
21#include "mmu.h"
22
23#include <linux/kvm_host.h>
24#include <linux/types.h>
25#include <linux/string.h>
26#include <linux/mm.h>
27#include <linux/highmem.h>
28#include <linux/module.h>
29#include <linux/swap.h>
30#include <linux/hugetlb.h>
31#include <linux/compiler.h>
32
33#include <asm/page.h>
34#include <asm/cmpxchg.h>
35#include <asm/io.h>
36
37/*
38 * When setting this variable to true it enables Two-Dimensional-Paging
39 * where the hardware walks 2 page tables:
40 * 1. the guest-virtual to guest-physical
41 * 2. while doing 1. it walks guest-physical to host-physical
42 * If the hardware supports that we don't need to do shadow paging.
43 */
44bool tdp_enabled = false;
45
46#undef MMU_DEBUG
47
48#undef AUDIT
49
50#ifdef AUDIT
51static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
52#else
53static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
54#endif
55
56#ifdef MMU_DEBUG
57
58#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
59#define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
60
61#else
62
63#define pgprintk(x...) do { } while (0)
64#define rmap_printk(x...) do { } while (0)
65
66#endif
67
68#if defined(MMU_DEBUG) || defined(AUDIT)
69static int dbg = 0;
70module_param(dbg, bool, 0644);
71#endif
72
73#ifndef MMU_DEBUG
74#define ASSERT(x) do { } while (0)
75#else
76#define ASSERT(x) \
77 if (!(x)) { \
78 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
79 __FILE__, __LINE__, #x); \
80 }
81#endif
82
83#define PT_FIRST_AVAIL_BITS_SHIFT 9
84#define PT64_SECOND_AVAIL_BITS_SHIFT 52
85
86#define VALID_PAGE(x) ((x) != INVALID_PAGE)
87
88#define PT64_LEVEL_BITS 9
89
90#define PT64_LEVEL_SHIFT(level) \
91 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
92
93#define PT64_LEVEL_MASK(level) \
94 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
95
96#define PT64_INDEX(address, level)\
97 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
98
99
100#define PT32_LEVEL_BITS 10
101
102#define PT32_LEVEL_SHIFT(level) \
103 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
104
105#define PT32_LEVEL_MASK(level) \
106 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
107
108#define PT32_INDEX(address, level)\
109 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
110
111
112#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
113#define PT64_DIR_BASE_ADDR_MASK \
114 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
115
116#define PT32_BASE_ADDR_MASK PAGE_MASK
117#define PT32_DIR_BASE_ADDR_MASK \
118 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
119
120#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
121 | PT64_NX_MASK)
122
123#define PFERR_PRESENT_MASK (1U << 0)
124#define PFERR_WRITE_MASK (1U << 1)
125#define PFERR_USER_MASK (1U << 2)
126#define PFERR_FETCH_MASK (1U << 4)
127
128#define PT_DIRECTORY_LEVEL 2
129#define PT_PAGE_TABLE_LEVEL 1
130
131#define RMAP_EXT 4
132
133#define ACC_EXEC_MASK 1
134#define ACC_WRITE_MASK PT_WRITABLE_MASK
135#define ACC_USER_MASK PT_USER_MASK
136#define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
137
138#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
139
140struct kvm_rmap_desc {
141 u64 *shadow_ptes[RMAP_EXT];
142 struct kvm_rmap_desc *more;
143};
144
145struct kvm_shadow_walk {
146 int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu,
147 u64 addr, u64 *spte, int level);
148};
149
150typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
151
152static struct kmem_cache *pte_chain_cache;
153static struct kmem_cache *rmap_desc_cache;
154static struct kmem_cache *mmu_page_header_cache;
155
156static u64 __read_mostly shadow_trap_nonpresent_pte;
157static u64 __read_mostly shadow_notrap_nonpresent_pte;
158static u64 __read_mostly shadow_base_present_pte;
159static u64 __read_mostly shadow_nx_mask;
160static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
161static u64 __read_mostly shadow_user_mask;
162static u64 __read_mostly shadow_accessed_mask;
163static u64 __read_mostly shadow_dirty_mask;
164
165void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
166{
167 shadow_trap_nonpresent_pte = trap_pte;
168 shadow_notrap_nonpresent_pte = notrap_pte;
169}
170EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
171
172void kvm_mmu_set_base_ptes(u64 base_pte)
173{
174 shadow_base_present_pte = base_pte;
175}
176EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
177
178void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
179 u64 dirty_mask, u64 nx_mask, u64 x_mask)
180{
181 shadow_user_mask = user_mask;
182 shadow_accessed_mask = accessed_mask;
183 shadow_dirty_mask = dirty_mask;
184 shadow_nx_mask = nx_mask;
185 shadow_x_mask = x_mask;
186}
187EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
188
189static int is_write_protection(struct kvm_vcpu *vcpu)
190{
191 return vcpu->arch.cr0 & X86_CR0_WP;
192}
193
194static int is_cpuid_PSE36(void)
195{
196 return 1;
197}
198
199static int is_nx(struct kvm_vcpu *vcpu)
200{
201 return vcpu->arch.shadow_efer & EFER_NX;
202}
203
204static int is_present_pte(unsigned long pte)
205{
206 return pte & PT_PRESENT_MASK;
207}
208
209static int is_shadow_present_pte(u64 pte)
210{
211 return pte != shadow_trap_nonpresent_pte
212 && pte != shadow_notrap_nonpresent_pte;
213}
214
215static int is_large_pte(u64 pte)
216{
217 return pte & PT_PAGE_SIZE_MASK;
218}
219
220static int is_writeble_pte(unsigned long pte)
221{
222 return pte & PT_WRITABLE_MASK;
223}
224
225static int is_dirty_pte(unsigned long pte)
226{
227 return pte & shadow_dirty_mask;
228}
229
230static int is_rmap_pte(u64 pte)
231{
232 return is_shadow_present_pte(pte);
233}
234
235static pfn_t spte_to_pfn(u64 pte)
236{
237 return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
238}
239
240static gfn_t pse36_gfn_delta(u32 gpte)
241{
242 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
243
244 return (gpte & PT32_DIR_PSE36_MASK) << shift;
245}
246
247static void set_shadow_pte(u64 *sptep, u64 spte)
248{
249#ifdef CONFIG_X86_64
250 set_64bit((unsigned long *)sptep, spte);
251#else
252 set_64bit((unsigned long long *)sptep, spte);
253#endif
254}
255
256static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
257 struct kmem_cache *base_cache, int min)
258{
259 void *obj;
260
261 if (cache->nobjs >= min)
262 return 0;
263 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
264 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
265 if (!obj)
266 return -ENOMEM;
267 cache->objects[cache->nobjs++] = obj;
268 }
269 return 0;
270}
271
272static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
273{
274 while (mc->nobjs)
275 kfree(mc->objects[--mc->nobjs]);
276}
277
278static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
279 int min)
280{
281 struct page *page;
282
283 if (cache->nobjs >= min)
284 return 0;
285 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
286 page = alloc_page(GFP_KERNEL);
287 if (!page)
288 return -ENOMEM;
289 set_page_private(page, 0);
290 cache->objects[cache->nobjs++] = page_address(page);
291 }
292 return 0;
293}
294
295static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
296{
297 while (mc->nobjs)
298 free_page((unsigned long)mc->objects[--mc->nobjs]);
299}
300
301static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
302{
303 int r;
304
305 r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
306 pte_chain_cache, 4);
307 if (r)
308 goto out;
309 r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
310 rmap_desc_cache, 1);
311 if (r)
312 goto out;
313 r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
314 if (r)
315 goto out;
316 r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
317 mmu_page_header_cache, 4);
318out:
319 return r;
320}
321
322static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
323{
324 mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
325 mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
326 mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
327 mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
328}
329
330static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
331 size_t size)
332{
333 void *p;
334
335 BUG_ON(!mc->nobjs);
336 p = mc->objects[--mc->nobjs];
337 memset(p, 0, size);
338 return p;
339}
340
341static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
342{
343 return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
344 sizeof(struct kvm_pte_chain));
345}
346
347static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
348{
349 kfree(pc);
350}
351
352static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
353{
354 return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
355 sizeof(struct kvm_rmap_desc));
356}
357
358static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
359{
360 kfree(rd);
361}
362
363/*
364 * Return the pointer to the largepage write count for a given
365 * gfn, handling slots that are not large page aligned.
366 */
367static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
368{
369 unsigned long idx;
370
371 idx = (gfn / KVM_PAGES_PER_HPAGE) -
372 (slot->base_gfn / KVM_PAGES_PER_HPAGE);
373 return &slot->lpage_info[idx].write_count;
374}
375
376static void account_shadowed(struct kvm *kvm, gfn_t gfn)
377{
378 int *write_count;
379
380 write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
381 *write_count += 1;
382}
383
384static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
385{
386 int *write_count;
387
388 write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
389 *write_count -= 1;
390 WARN_ON(*write_count < 0);
391}
392
393static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
394{
395 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
396 int *largepage_idx;
397
398 if (slot) {
399 largepage_idx = slot_largepage_idx(gfn, slot);
400 return *largepage_idx;
401 }
402
403 return 1;
404}
405
406static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
407{
408 struct vm_area_struct *vma;
409 unsigned long addr;
410 int ret = 0;
411
412 addr = gfn_to_hva(kvm, gfn);
413 if (kvm_is_error_hva(addr))
414 return ret;
415
416 down_read(&current->mm->mmap_sem);
417 vma = find_vma(current->mm, addr);
418 if (vma && is_vm_hugetlb_page(vma))
419 ret = 1;
420 up_read(&current->mm->mmap_sem);
421
422 return ret;
423}
424
425static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
426{
427 struct kvm_memory_slot *slot;
428
429 if (has_wrprotected_page(vcpu->kvm, large_gfn))
430 return 0;
431
432 if (!host_largepage_backed(vcpu->kvm, large_gfn))
433 return 0;
434
435 slot = gfn_to_memslot(vcpu->kvm, large_gfn);
436 if (slot && slot->dirty_bitmap)
437 return 0;
438
439 return 1;
440}
441
442/*
443 * Take gfn and return the reverse mapping to it.
444 * Note: gfn must be unaliased before this function get called
445 */
446
447static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
448{
449 struct kvm_memory_slot *slot;
450 unsigned long idx;
451
452 slot = gfn_to_memslot(kvm, gfn);
453 if (!lpage)
454 return &slot->rmap[gfn - slot->base_gfn];
455
456 idx = (gfn / KVM_PAGES_PER_HPAGE) -
457 (slot->base_gfn / KVM_PAGES_PER_HPAGE);
458
459 return &slot->lpage_info[idx].rmap_pde;
460}
461
462/*
463 * Reverse mapping data structures:
464 *
465 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
466 * that points to page_address(page).
467 *
468 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
469 * containing more mappings.
470 */
471static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
472{
473 struct kvm_mmu_page *sp;
474 struct kvm_rmap_desc *desc;
475 unsigned long *rmapp;
476 int i;
477
478 if (!is_rmap_pte(*spte))
479 return;
480 gfn = unalias_gfn(vcpu->kvm, gfn);
481 sp = page_header(__pa(spte));
482 sp->gfns[spte - sp->spt] = gfn;
483 rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
484 if (!*rmapp) {
485 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
486 *rmapp = (unsigned long)spte;
487 } else if (!(*rmapp & 1)) {
488 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
489 desc = mmu_alloc_rmap_desc(vcpu);
490 desc->shadow_ptes[0] = (u64 *)*rmapp;
491 desc->shadow_ptes[1] = spte;
492 *rmapp = (unsigned long)desc | 1;
493 } else {
494 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
495 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
496 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
497 desc = desc->more;
498 if (desc->shadow_ptes[RMAP_EXT-1]) {
499 desc->more = mmu_alloc_rmap_desc(vcpu);
500 desc = desc->more;
501 }
502 for (i = 0; desc->shadow_ptes[i]; ++i)
503 ;
504 desc->shadow_ptes[i] = spte;
505 }
506}
507
508static void rmap_desc_remove_entry(unsigned long *rmapp,
509 struct kvm_rmap_desc *desc,
510 int i,
511 struct kvm_rmap_desc *prev_desc)
512{
513 int j;
514
515 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
516 ;
517 desc->shadow_ptes[i] = desc->shadow_ptes[j];
518 desc->shadow_ptes[j] = NULL;
519 if (j != 0)
520 return;
521 if (!prev_desc && !desc->more)
522 *rmapp = (unsigned long)desc->shadow_ptes[0];
523 else
524 if (prev_desc)
525 prev_desc->more = desc->more;
526 else
527 *rmapp = (unsigned long)desc->more | 1;
528 mmu_free_rmap_desc(desc);
529}
530
531static void rmap_remove(struct kvm *kvm, u64 *spte)
532{
533 struct kvm_rmap_desc *desc;
534 struct kvm_rmap_desc *prev_desc;
535 struct kvm_mmu_page *sp;
536 pfn_t pfn;
537 unsigned long *rmapp;
538 int i;
539
540 if (!is_rmap_pte(*spte))
541 return;
542 sp = page_header(__pa(spte));
543 pfn = spte_to_pfn(*spte);
544 if (*spte & shadow_accessed_mask)
545 kvm_set_pfn_accessed(pfn);
546 if (is_writeble_pte(*spte))
547 kvm_release_pfn_dirty(pfn);
548 else
549 kvm_release_pfn_clean(pfn);
550 rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
551 if (!*rmapp) {
552 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
553 BUG();
554 } else if (!(*rmapp & 1)) {
555 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
556 if ((u64 *)*rmapp != spte) {
557 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
558 spte, *spte);
559 BUG();
560 }
561 *rmapp = 0;
562 } else {
563 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
564 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
565 prev_desc = NULL;
566 while (desc) {
567 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
568 if (desc->shadow_ptes[i] == spte) {
569 rmap_desc_remove_entry(rmapp,
570 desc, i,
571 prev_desc);
572 return;
573 }
574 prev_desc = desc;
575 desc = desc->more;
576 }
577 BUG();
578 }
579}
580
581static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
582{
583 struct kvm_rmap_desc *desc;
584 struct kvm_rmap_desc *prev_desc;
585 u64 *prev_spte;
586 int i;
587
588 if (!*rmapp)
589 return NULL;
590 else if (!(*rmapp & 1)) {
591 if (!spte)
592 return (u64 *)*rmapp;
593 return NULL;
594 }
595 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
596 prev_desc = NULL;
597 prev_spte = NULL;
598 while (desc) {
599 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
600 if (prev_spte == spte)
601 return desc->shadow_ptes[i];
602 prev_spte = desc->shadow_ptes[i];
603 }
604 desc = desc->more;
605 }
606 return NULL;
607}
608
609static void rmap_write_protect(struct kvm *kvm, u64 gfn)
610{
611 unsigned long *rmapp;
612 u64 *spte;
613 int write_protected = 0;
614
615 gfn = unalias_gfn(kvm, gfn);
616 rmapp = gfn_to_rmap(kvm, gfn, 0);
617
618 spte = rmap_next(kvm, rmapp, NULL);
619 while (spte) {
620 BUG_ON(!spte);
621 BUG_ON(!(*spte & PT_PRESENT_MASK));
622 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
623 if (is_writeble_pte(*spte)) {
624 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
625 write_protected = 1;
626 }
627 spte = rmap_next(kvm, rmapp, spte);
628 }
629 if (write_protected) {
630 pfn_t pfn;
631
632 spte = rmap_next(kvm, rmapp, NULL);
633 pfn = spte_to_pfn(*spte);
634 kvm_set_pfn_dirty(pfn);
635 }
636
637 /* check for huge page mappings */
638 rmapp = gfn_to_rmap(kvm, gfn, 1);
639 spte = rmap_next(kvm, rmapp, NULL);
640 while (spte) {
641 BUG_ON(!spte);
642 BUG_ON(!(*spte & PT_PRESENT_MASK));
643 BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
644 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
645 if (is_writeble_pte(*spte)) {
646 rmap_remove(kvm, spte);
647 --kvm->stat.lpages;
648 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
649 spte = NULL;
650 write_protected = 1;
651 }
652 spte = rmap_next(kvm, rmapp, spte);
653 }
654
655 if (write_protected)
656 kvm_flush_remote_tlbs(kvm);
657
658 account_shadowed(kvm, gfn);
659}
660
661static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
662{
663 u64 *spte;
664 int need_tlb_flush = 0;
665
666 while ((spte = rmap_next(kvm, rmapp, NULL))) {
667 BUG_ON(!(*spte & PT_PRESENT_MASK));
668 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
669 rmap_remove(kvm, spte);
670 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
671 need_tlb_flush = 1;
672 }
673 return need_tlb_flush;
674}
675
676static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
677 int (*handler)(struct kvm *kvm, unsigned long *rmapp))
678{
679 int i;
680 int retval = 0;
681
682 /*
683 * If mmap_sem isn't taken, we can look the memslots with only
684 * the mmu_lock by skipping over the slots with userspace_addr == 0.
685 */
686 for (i = 0; i < kvm->nmemslots; i++) {
687 struct kvm_memory_slot *memslot = &kvm->memslots[i];
688 unsigned long start = memslot->userspace_addr;
689 unsigned long end;
690
691 /* mmu_lock protects userspace_addr */
692 if (!start)
693 continue;
694
695 end = start + (memslot->npages << PAGE_SHIFT);
696 if (hva >= start && hva < end) {
697 gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
698 retval |= handler(kvm, &memslot->rmap[gfn_offset]);
699 retval |= handler(kvm,
700 &memslot->lpage_info[
701 gfn_offset /
702 KVM_PAGES_PER_HPAGE].rmap_pde);
703 }
704 }
705
706 return retval;
707}
708
709int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
710{
711 return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
712}
713
714static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
715{
716 u64 *spte;
717 int young = 0;
718
719 /* always return old for EPT */
720 if (!shadow_accessed_mask)
721 return 0;
722
723 spte = rmap_next(kvm, rmapp, NULL);
724 while (spte) {
725 int _young;
726 u64 _spte = *spte;
727 BUG_ON(!(_spte & PT_PRESENT_MASK));
728 _young = _spte & PT_ACCESSED_MASK;
729 if (_young) {
730 young = 1;
731 clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
732 }
733 spte = rmap_next(kvm, rmapp, spte);
734 }
735 return young;
736}
737
738int kvm_age_hva(struct kvm *kvm, unsigned long hva)
739{
740 return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
741}
742
743#ifdef MMU_DEBUG
744static int is_empty_shadow_page(u64 *spt)
745{
746 u64 *pos;
747 u64 *end;
748
749 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
750 if (is_shadow_present_pte(*pos)) {
751 printk(KERN_ERR "%s: %p %llx\n", __func__,
752 pos, *pos);
753 return 0;
754 }
755 return 1;
756}
757#endif
758
759static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
760{
761 ASSERT(is_empty_shadow_page(sp->spt));
762 list_del(&sp->link);
763 __free_page(virt_to_page(sp->spt));
764 __free_page(virt_to_page(sp->gfns));
765 kfree(sp);
766 ++kvm->arch.n_free_mmu_pages;
767}
768
769static unsigned kvm_page_table_hashfn(gfn_t gfn)
770{
771 return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
772}
773
774static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
775 u64 *parent_pte)
776{
777 struct kvm_mmu_page *sp;
778
779 sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
780 sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
781 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
782 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
783 list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
784 ASSERT(is_empty_shadow_page(sp->spt));
785 sp->slot_bitmap = 0;
786 sp->multimapped = 0;
787 sp->parent_pte = parent_pte;
788 --vcpu->kvm->arch.n_free_mmu_pages;
789 return sp;
790}
791
792static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
793 struct kvm_mmu_page *sp, u64 *parent_pte)
794{
795 struct kvm_pte_chain *pte_chain;
796 struct hlist_node *node;
797 int i;
798
799 if (!parent_pte)
800 return;
801 if (!sp->multimapped) {
802 u64 *old = sp->parent_pte;
803
804 if (!old) {
805 sp->parent_pte = parent_pte;
806 return;
807 }
808 sp->multimapped = 1;
809 pte_chain = mmu_alloc_pte_chain(vcpu);
810 INIT_HLIST_HEAD(&sp->parent_ptes);
811 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
812 pte_chain->parent_ptes[0] = old;
813 }
814 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
815 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
816 continue;
817 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
818 if (!pte_chain->parent_ptes[i]) {
819 pte_chain->parent_ptes[i] = parent_pte;
820 return;
821 }
822 }
823 pte_chain = mmu_alloc_pte_chain(vcpu);
824 BUG_ON(!pte_chain);
825 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
826 pte_chain->parent_ptes[0] = parent_pte;
827}
828
829static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
830 u64 *parent_pte)
831{
832 struct kvm_pte_chain *pte_chain;
833 struct hlist_node *node;
834 int i;
835
836 if (!sp->multimapped) {
837 BUG_ON(sp->parent_pte != parent_pte);
838 sp->parent_pte = NULL;
839 return;
840 }
841 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
842 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
843 if (!pte_chain->parent_ptes[i])
844 break;
845 if (pte_chain->parent_ptes[i] != parent_pte)
846 continue;
847 while (i + 1 < NR_PTE_CHAIN_ENTRIES
848 && pte_chain->parent_ptes[i + 1]) {
849 pte_chain->parent_ptes[i]
850 = pte_chain->parent_ptes[i + 1];
851 ++i;
852 }
853 pte_chain->parent_ptes[i] = NULL;
854 if (i == 0) {
855 hlist_del(&pte_chain->link);
856 mmu_free_pte_chain(pte_chain);
857 if (hlist_empty(&sp->parent_ptes)) {
858 sp->multimapped = 0;
859 sp->parent_pte = NULL;
860 }
861 }
862 return;
863 }
864 BUG();
865}
866
867
868static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
869 mmu_parent_walk_fn fn)
870{
871 struct kvm_pte_chain *pte_chain;
872 struct hlist_node *node;
873 struct kvm_mmu_page *parent_sp;
874 int i;
875
876 if (!sp->multimapped && sp->parent_pte) {
877 parent_sp = page_header(__pa(sp->parent_pte));
878 fn(vcpu, parent_sp);
879 mmu_parent_walk(vcpu, parent_sp, fn);
880 return;
881 }
882 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
883 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
884 if (!pte_chain->parent_ptes[i])
885 break;
886 parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
887 fn(vcpu, parent_sp);
888 mmu_parent_walk(vcpu, parent_sp, fn);
889 }
890}
891
892static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
893 struct kvm_mmu_page *sp)
894{
895 int i;
896
897 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
898 sp->spt[i] = shadow_trap_nonpresent_pte;
899}
900
901static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
902 struct kvm_mmu_page *sp)
903{
904 return 1;
905}
906
907static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
908{
909}
910
911static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
912{
913 unsigned index;
914 struct hlist_head *bucket;
915 struct kvm_mmu_page *sp;
916 struct hlist_node *node;
917
918 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
919 index = kvm_page_table_hashfn(gfn);
920 bucket = &kvm->arch.mmu_page_hash[index];
921 hlist_for_each_entry(sp, node, bucket, hash_link)
922 if (sp->gfn == gfn && !sp->role.metaphysical
923 && !sp->role.invalid) {
924 pgprintk("%s: found role %x\n",
925 __func__, sp->role.word);
926 return sp;
927 }
928 return NULL;
929}
930
931static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
932 gfn_t gfn,
933 gva_t gaddr,
934 unsigned level,
935 int metaphysical,
936 unsigned access,
937 u64 *parent_pte)
938{
939 union kvm_mmu_page_role role;
940 unsigned index;
941 unsigned quadrant;
942 struct hlist_head *bucket;
943 struct kvm_mmu_page *sp;
944 struct hlist_node *node;
945
946 role.word = 0;
947 role.glevels = vcpu->arch.mmu.root_level;
948 role.level = level;
949 role.metaphysical = metaphysical;
950 role.access = access;
951 if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
952 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
953 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
954 role.quadrant = quadrant;
955 }
956 pgprintk("%s: looking gfn %lx role %x\n", __func__,
957 gfn, role.word);
958 index = kvm_page_table_hashfn(gfn);
959 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
960 hlist_for_each_entry(sp, node, bucket, hash_link)
961 if (sp->gfn == gfn && sp->role.word == role.word) {
962 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
963 pgprintk("%s: found\n", __func__);
964 return sp;
965 }
966 ++vcpu->kvm->stat.mmu_cache_miss;
967 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
968 if (!sp)
969 return sp;
970 pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
971 sp->gfn = gfn;
972 sp->role = role;
973 hlist_add_head(&sp->hash_link, bucket);
974 if (!metaphysical)
975 rmap_write_protect(vcpu->kvm, gfn);
976 if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
977 vcpu->arch.mmu.prefetch_page(vcpu, sp);
978 else
979 nonpaging_prefetch_page(vcpu, sp);
980 return sp;
981}
982
983static int walk_shadow(struct kvm_shadow_walk *walker,
984 struct kvm_vcpu *vcpu, u64 addr)
985{
986 hpa_t shadow_addr;
987 int level;
988 int r;
989 u64 *sptep;
990 unsigned index;
991
992 shadow_addr = vcpu->arch.mmu.root_hpa;
993 level = vcpu->arch.mmu.shadow_root_level;
994 if (level == PT32E_ROOT_LEVEL) {
995 shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
996 shadow_addr &= PT64_BASE_ADDR_MASK;
997 --level;
998 }
999
1000 while (level >= PT_PAGE_TABLE_LEVEL) {
1001 index = SHADOW_PT_INDEX(addr, level);
1002 sptep = ((u64 *)__va(shadow_addr)) + index;
1003 r = walker->entry(walker, vcpu, addr, sptep, level);
1004 if (r)
1005 return r;
1006 shadow_addr = *sptep & PT64_BASE_ADDR_MASK;
1007 --level;
1008 }
1009 return 0;
1010}
1011
1012static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1013 struct kvm_mmu_page *sp)
1014{
1015 unsigned i;
1016 u64 *pt;
1017 u64 ent;
1018
1019 pt = sp->spt;
1020
1021 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1022 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1023 if (is_shadow_present_pte(pt[i]))
1024 rmap_remove(kvm, &pt[i]);
1025 pt[i] = shadow_trap_nonpresent_pte;
1026 }
1027 return;
1028 }
1029
1030 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1031 ent = pt[i];
1032
1033 if (is_shadow_present_pte(ent)) {
1034 if (!is_large_pte(ent)) {
1035 ent &= PT64_BASE_ADDR_MASK;
1036 mmu_page_remove_parent_pte(page_header(ent),
1037 &pt[i]);
1038 } else {
1039 --kvm->stat.lpages;
1040 rmap_remove(kvm, &pt[i]);
1041 }
1042 }
1043 pt[i] = shadow_trap_nonpresent_pte;
1044 }
1045}
1046
1047static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1048{
1049 mmu_page_remove_parent_pte(sp, parent_pte);
1050}
1051
1052static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1053{
1054 int i;
1055
1056 for (i = 0; i < KVM_MAX_VCPUS; ++i)
1057 if (kvm->vcpus[i])
1058 kvm->vcpus[i]->arch.last_pte_updated = NULL;
1059}
1060
1061static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1062{
1063 u64 *parent_pte;
1064
1065 while (sp->multimapped || sp->parent_pte) {
1066 if (!sp->multimapped)
1067 parent_pte = sp->parent_pte;
1068 else {
1069 struct kvm_pte_chain *chain;
1070
1071 chain = container_of(sp->parent_ptes.first,
1072 struct kvm_pte_chain, link);
1073 parent_pte = chain->parent_ptes[0];
1074 }
1075 BUG_ON(!parent_pte);
1076 kvm_mmu_put_page(sp, parent_pte);
1077 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
1078 }
1079}
1080
1081static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1082{
1083 ++kvm->stat.mmu_shadow_zapped;
1084 kvm_mmu_page_unlink_children(kvm, sp);
1085 kvm_mmu_unlink_parents(kvm, sp);
1086 kvm_flush_remote_tlbs(kvm);
1087 if (!sp->role.invalid && !sp->role.metaphysical)
1088 unaccount_shadowed(kvm, sp->gfn);
1089 if (!sp->root_count) {
1090 hlist_del(&sp->hash_link);
1091 kvm_mmu_free_page(kvm, sp);
1092 } else {
1093 sp->role.invalid = 1;
1094 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1095 kvm_reload_remote_mmus(kvm);
1096 }
1097 kvm_mmu_reset_last_pte_updated(kvm);
1098}
1099
1100/*
1101 * Changing the number of mmu pages allocated to the vm
1102 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1103 */
1104void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1105{
1106 /*
1107 * If we set the number of mmu pages to be smaller be than the
1108 * number of actived pages , we must to free some mmu pages before we
1109 * change the value
1110 */
1111
1112 if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
1113 kvm_nr_mmu_pages) {
1114 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
1115 - kvm->arch.n_free_mmu_pages;
1116
1117 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
1118 struct kvm_mmu_page *page;
1119
1120 page = container_of(kvm->arch.active_mmu_pages.prev,
1121 struct kvm_mmu_page, link);
1122 kvm_mmu_zap_page(kvm, page);
1123 n_used_mmu_pages--;
1124 }
1125 kvm->arch.n_free_mmu_pages = 0;
1126 }
1127 else
1128 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1129 - kvm->arch.n_alloc_mmu_pages;
1130
1131 kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1132}
1133
1134static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1135{
1136 unsigned index;
1137 struct hlist_head *bucket;
1138 struct kvm_mmu_page *sp;
1139 struct hlist_node *node, *n;
1140 int r;
1141
1142 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1143 r = 0;
1144 index = kvm_page_table_hashfn(gfn);
1145 bucket = &kvm->arch.mmu_page_hash[index];
1146 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1147 if (sp->gfn == gfn && !sp->role.metaphysical) {
1148 pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1149 sp->role.word);
1150 kvm_mmu_zap_page(kvm, sp);
1151 r = 1;
1152 }
1153 return r;
1154}
1155
1156static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1157{
1158 struct kvm_mmu_page *sp;
1159
1160 while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
1161 pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
1162 kvm_mmu_zap_page(kvm, sp);
1163 }
1164}
1165
1166static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1167{
1168 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1169 struct kvm_mmu_page *sp = page_header(__pa(pte));
1170
1171 __set_bit(slot, &sp->slot_bitmap);
1172}
1173
1174struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1175{
1176 struct page *page;
1177
1178 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1179
1180 if (gpa == UNMAPPED_GVA)
1181 return NULL;
1182
1183 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1184
1185 return page;
1186}
1187
1188static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1189 unsigned pte_access, int user_fault,
1190 int write_fault, int dirty, int largepage,
1191 gfn_t gfn, pfn_t pfn, bool speculative)
1192{
1193 u64 spte;
1194 int ret = 0;
1195 /*
1196 * We don't set the accessed bit, since we sometimes want to see
1197 * whether the guest actually used the pte (in order to detect
1198 * demand paging).
1199 */
1200 spte = shadow_base_present_pte | shadow_dirty_mask;
1201 if (!speculative)
1202 spte |= shadow_accessed_mask;
1203 if (!dirty)
1204 pte_access &= ~ACC_WRITE_MASK;
1205 if (pte_access & ACC_EXEC_MASK)
1206 spte |= shadow_x_mask;
1207 else
1208 spte |= shadow_nx_mask;
1209 if (pte_access & ACC_USER_MASK)
1210 spte |= shadow_user_mask;
1211 if (largepage)
1212 spte |= PT_PAGE_SIZE_MASK;
1213
1214 spte |= (u64)pfn << PAGE_SHIFT;
1215
1216 if ((pte_access & ACC_WRITE_MASK)
1217 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1218 struct kvm_mmu_page *shadow;
1219
1220 if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) {
1221 ret = 1;
1222 spte = shadow_trap_nonpresent_pte;
1223 goto set_pte;
1224 }
1225
1226 spte |= PT_WRITABLE_MASK;
1227
1228 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1229 if (shadow) {
1230 pgprintk("%s: found shadow page for %lx, marking ro\n",
1231 __func__, gfn);
1232 ret = 1;
1233 pte_access &= ~ACC_WRITE_MASK;
1234 if (is_writeble_pte(spte))
1235 spte &= ~PT_WRITABLE_MASK;
1236 }
1237 }
1238
1239 if (pte_access & ACC_WRITE_MASK)
1240 mark_page_dirty(vcpu->kvm, gfn);
1241
1242set_pte:
1243 set_shadow_pte(shadow_pte, spte);
1244 return ret;
1245}
1246
1247
1248static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1249 unsigned pt_access, unsigned pte_access,
1250 int user_fault, int write_fault, int dirty,
1251 int *ptwrite, int largepage, gfn_t gfn,
1252 pfn_t pfn, bool speculative)
1253{
1254 int was_rmapped = 0;
1255 int was_writeble = is_writeble_pte(*shadow_pte);
1256
1257 pgprintk("%s: spte %llx access %x write_fault %d"
1258 " user_fault %d gfn %lx\n",
1259 __func__, *shadow_pte, pt_access,
1260 write_fault, user_fault, gfn);
1261
1262 if (is_rmap_pte(*shadow_pte)) {
1263 /*
1264 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1265 * the parent of the now unreachable PTE.
1266 */
1267 if (largepage && !is_large_pte(*shadow_pte)) {
1268 struct kvm_mmu_page *child;
1269 u64 pte = *shadow_pte;
1270
1271 child = page_header(pte & PT64_BASE_ADDR_MASK);
1272 mmu_page_remove_parent_pte(child, shadow_pte);
1273 } else if (pfn != spte_to_pfn(*shadow_pte)) {
1274 pgprintk("hfn old %lx new %lx\n",
1275 spte_to_pfn(*shadow_pte), pfn);
1276 rmap_remove(vcpu->kvm, shadow_pte);
1277 } else {
1278 if (largepage)
1279 was_rmapped = is_large_pte(*shadow_pte);
1280 else
1281 was_rmapped = 1;
1282 }
1283 }
1284 if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
1285 dirty, largepage, gfn, pfn, speculative)) {
1286 if (write_fault)
1287 *ptwrite = 1;
1288 kvm_x86_ops->tlb_flush(vcpu);
1289 }
1290
1291 pgprintk("%s: setting spte %llx\n", __func__, *shadow_pte);
1292 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1293 is_large_pte(*shadow_pte)? "2MB" : "4kB",
1294 is_present_pte(*shadow_pte)?"RW":"R", gfn,
1295 *shadow_pte, shadow_pte);
1296 if (!was_rmapped && is_large_pte(*shadow_pte))
1297 ++vcpu->kvm->stat.lpages;
1298
1299 page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
1300 if (!was_rmapped) {
1301 rmap_add(vcpu, shadow_pte, gfn, largepage);
1302 if (!is_rmap_pte(*shadow_pte))
1303 kvm_release_pfn_clean(pfn);
1304 } else {
1305 if (was_writeble)
1306 kvm_release_pfn_dirty(pfn);
1307 else
1308 kvm_release_pfn_clean(pfn);
1309 }
1310 if (speculative) {
1311 vcpu->arch.last_pte_updated = shadow_pte;
1312 vcpu->arch.last_pte_gfn = gfn;
1313 }
1314}
1315
1316static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1317{
1318}
1319
1320struct direct_shadow_walk {
1321 struct kvm_shadow_walk walker;
1322 pfn_t pfn;
1323 int write;
1324 int largepage;
1325 int pt_write;
1326};
1327
1328static int direct_map_entry(struct kvm_shadow_walk *_walk,
1329 struct kvm_vcpu *vcpu,
1330 u64 addr, u64 *sptep, int level)
1331{
1332 struct direct_shadow_walk *walk =
1333 container_of(_walk, struct direct_shadow_walk, walker);
1334 struct kvm_mmu_page *sp;
1335 gfn_t pseudo_gfn;
1336 gfn_t gfn = addr >> PAGE_SHIFT;
1337
1338 if (level == PT_PAGE_TABLE_LEVEL
1339 || (walk->largepage && level == PT_DIRECTORY_LEVEL)) {
1340 mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL,
1341 0, walk->write, 1, &walk->pt_write,
1342 walk->largepage, gfn, walk->pfn, false);
1343 ++vcpu->stat.pf_fixed;
1344 return 1;
1345 }
1346
1347 if (*sptep == shadow_trap_nonpresent_pte) {
1348 pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1349 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1,
1350 1, ACC_ALL, sptep);
1351 if (!sp) {
1352 pgprintk("nonpaging_map: ENOMEM\n");
1353 kvm_release_pfn_clean(walk->pfn);
1354 return -ENOMEM;
1355 }
1356
1357 set_shadow_pte(sptep,
1358 __pa(sp->spt)
1359 | PT_PRESENT_MASK | PT_WRITABLE_MASK
1360 | shadow_user_mask | shadow_x_mask);
1361 }
1362 return 0;
1363}
1364
1365static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1366 int largepage, gfn_t gfn, pfn_t pfn)
1367{
1368 int r;
1369 struct direct_shadow_walk walker = {
1370 .walker = { .entry = direct_map_entry, },
1371 .pfn = pfn,
1372 .largepage = largepage,
1373 .write = write,
1374 .pt_write = 0,
1375 };
1376
1377 r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT);
1378 if (r < 0)
1379 return r;
1380 return walker.pt_write;
1381}
1382
1383static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1384{
1385 int r;
1386 int largepage = 0;
1387 pfn_t pfn;
1388 unsigned long mmu_seq;
1389
1390 if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1391 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1392 largepage = 1;
1393 }
1394
1395 mmu_seq = vcpu->kvm->mmu_notifier_seq;
1396 smp_rmb();
1397 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1398
1399 /* mmio */
1400 if (is_error_pfn(pfn)) {
1401 kvm_release_pfn_clean(pfn);
1402 return 1;
1403 }
1404
1405 spin_lock(&vcpu->kvm->mmu_lock);
1406 if (mmu_notifier_retry(vcpu, mmu_seq))
1407 goto out_unlock;
1408 kvm_mmu_free_some_pages(vcpu);
1409 r = __direct_map(vcpu, v, write, largepage, gfn, pfn);
1410 spin_unlock(&vcpu->kvm->mmu_lock);
1411
1412
1413 return r;
1414
1415out_unlock:
1416 spin_unlock(&vcpu->kvm->mmu_lock);
1417 kvm_release_pfn_clean(pfn);
1418 return 0;
1419}
1420
1421
1422static void mmu_free_roots(struct kvm_vcpu *vcpu)
1423{
1424 int i;
1425 struct kvm_mmu_page *sp;
1426
1427 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1428 return;
1429 spin_lock(&vcpu->kvm->mmu_lock);
1430 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1431 hpa_t root = vcpu->arch.mmu.root_hpa;
1432
1433 sp = page_header(root);
1434 --sp->root_count;
1435 if (!sp->root_count && sp->role.invalid)
1436 kvm_mmu_zap_page(vcpu->kvm, sp);
1437 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1438 spin_unlock(&vcpu->kvm->mmu_lock);
1439 return;
1440 }
1441 for (i = 0; i < 4; ++i) {
1442 hpa_t root = vcpu->arch.mmu.pae_root[i];
1443
1444 if (root) {
1445 root &= PT64_BASE_ADDR_MASK;
1446 sp = page_header(root);
1447 --sp->root_count;
1448 if (!sp->root_count && sp->role.invalid)
1449 kvm_mmu_zap_page(vcpu->kvm, sp);
1450 }
1451 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1452 }
1453 spin_unlock(&vcpu->kvm->mmu_lock);
1454 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1455}
1456
1457static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1458{
1459 int i;
1460 gfn_t root_gfn;
1461 struct kvm_mmu_page *sp;
1462 int metaphysical = 0;
1463
1464 root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1465
1466 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1467 hpa_t root = vcpu->arch.mmu.root_hpa;
1468
1469 ASSERT(!VALID_PAGE(root));
1470 if (tdp_enabled)
1471 metaphysical = 1;
1472 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1473 PT64_ROOT_LEVEL, metaphysical,
1474 ACC_ALL, NULL);
1475 root = __pa(sp->spt);
1476 ++sp->root_count;
1477 vcpu->arch.mmu.root_hpa = root;
1478 return;
1479 }
1480 metaphysical = !is_paging(vcpu);
1481 if (tdp_enabled)
1482 metaphysical = 1;
1483 for (i = 0; i < 4; ++i) {
1484 hpa_t root = vcpu->arch.mmu.pae_root[i];
1485
1486 ASSERT(!VALID_PAGE(root));
1487 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1488 if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1489 vcpu->arch.mmu.pae_root[i] = 0;
1490 continue;
1491 }
1492 root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1493 } else if (vcpu->arch.mmu.root_level == 0)
1494 root_gfn = 0;
1495 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1496 PT32_ROOT_LEVEL, metaphysical,
1497 ACC_ALL, NULL);
1498 root = __pa(sp->spt);
1499 ++sp->root_count;
1500 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1501 }
1502 vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1503}
1504
1505static void mmu_sync_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1506{
1507}
1508
1509static void mmu_sync_roots(struct kvm_vcpu *vcpu)
1510{
1511 int i;
1512 struct kvm_mmu_page *sp;
1513
1514 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1515 return;
1516 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1517 hpa_t root = vcpu->arch.mmu.root_hpa;
1518 sp = page_header(root);
1519 mmu_sync_children(vcpu, sp);
1520 return;
1521 }
1522 for (i = 0; i < 4; ++i) {
1523 hpa_t root = vcpu->arch.mmu.pae_root[i];
1524
1525 if (root) {
1526 root &= PT64_BASE_ADDR_MASK;
1527 sp = page_header(root);
1528 mmu_sync_children(vcpu, sp);
1529 }
1530 }
1531}
1532
1533void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
1534{
1535 spin_lock(&vcpu->kvm->mmu_lock);
1536 mmu_sync_roots(vcpu);
1537 spin_unlock(&vcpu->kvm->mmu_lock);
1538}
1539
1540static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1541{
1542 return vaddr;
1543}
1544
1545static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1546 u32 error_code)
1547{
1548 gfn_t gfn;
1549 int r;
1550
1551 pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
1552 r = mmu_topup_memory_caches(vcpu);
1553 if (r)
1554 return r;
1555
1556 ASSERT(vcpu);
1557 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1558
1559 gfn = gva >> PAGE_SHIFT;
1560
1561 return nonpaging_map(vcpu, gva & PAGE_MASK,
1562 error_code & PFERR_WRITE_MASK, gfn);
1563}
1564
1565static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
1566 u32 error_code)
1567{
1568 pfn_t pfn;
1569 int r;
1570 int largepage = 0;
1571 gfn_t gfn = gpa >> PAGE_SHIFT;
1572 unsigned long mmu_seq;
1573
1574 ASSERT(vcpu);
1575 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1576
1577 r = mmu_topup_memory_caches(vcpu);
1578 if (r)
1579 return r;
1580
1581 if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1582 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1583 largepage = 1;
1584 }
1585 mmu_seq = vcpu->kvm->mmu_notifier_seq;
1586 smp_rmb();
1587 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1588 if (is_error_pfn(pfn)) {
1589 kvm_release_pfn_clean(pfn);
1590 return 1;
1591 }
1592 spin_lock(&vcpu->kvm->mmu_lock);
1593 if (mmu_notifier_retry(vcpu, mmu_seq))
1594 goto out_unlock;
1595 kvm_mmu_free_some_pages(vcpu);
1596 r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
1597 largepage, gfn, pfn);
1598 spin_unlock(&vcpu->kvm->mmu_lock);
1599
1600 return r;
1601
1602out_unlock:
1603 spin_unlock(&vcpu->kvm->mmu_lock);
1604 kvm_release_pfn_clean(pfn);
1605 return 0;
1606}
1607
1608static void nonpaging_free(struct kvm_vcpu *vcpu)
1609{
1610 mmu_free_roots(vcpu);
1611}
1612
1613static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1614{
1615 struct kvm_mmu *context = &vcpu->arch.mmu;
1616
1617 context->new_cr3 = nonpaging_new_cr3;
1618 context->page_fault = nonpaging_page_fault;
1619 context->gva_to_gpa = nonpaging_gva_to_gpa;
1620 context->free = nonpaging_free;
1621 context->prefetch_page = nonpaging_prefetch_page;
1622 context->sync_page = nonpaging_sync_page;
1623 context->invlpg = nonpaging_invlpg;
1624 context->root_level = 0;
1625 context->shadow_root_level = PT32E_ROOT_LEVEL;
1626 context->root_hpa = INVALID_PAGE;
1627 return 0;
1628}
1629
1630void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1631{
1632 ++vcpu->stat.tlb_flush;
1633 kvm_x86_ops->tlb_flush(vcpu);
1634}
1635
1636static void paging_new_cr3(struct kvm_vcpu *vcpu)
1637{
1638 pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
1639 mmu_free_roots(vcpu);
1640}
1641
1642static void inject_page_fault(struct kvm_vcpu *vcpu,
1643 u64 addr,
1644 u32 err_code)
1645{
1646 kvm_inject_page_fault(vcpu, addr, err_code);
1647}
1648
1649static void paging_free(struct kvm_vcpu *vcpu)
1650{
1651 nonpaging_free(vcpu);
1652}
1653
1654#define PTTYPE 64
1655#include "paging_tmpl.h"
1656#undef PTTYPE
1657
1658#define PTTYPE 32
1659#include "paging_tmpl.h"
1660#undef PTTYPE
1661
1662static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1663{
1664 struct kvm_mmu *context = &vcpu->arch.mmu;
1665
1666 ASSERT(is_pae(vcpu));
1667 context->new_cr3 = paging_new_cr3;
1668 context->page_fault = paging64_page_fault;
1669 context->gva_to_gpa = paging64_gva_to_gpa;
1670 context->prefetch_page = paging64_prefetch_page;
1671 context->sync_page = paging64_sync_page;
1672 context->invlpg = paging64_invlpg;
1673 context->free = paging_free;
1674 context->root_level = level;
1675 context->shadow_root_level = level;
1676 context->root_hpa = INVALID_PAGE;
1677 return 0;
1678}
1679
1680static int paging64_init_context(struct kvm_vcpu *vcpu)
1681{
1682 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1683}
1684
1685static int paging32_init_context(struct kvm_vcpu *vcpu)
1686{
1687 struct kvm_mmu *context = &vcpu->arch.mmu;
1688
1689 context->new_cr3 = paging_new_cr3;
1690 context->page_fault = paging32_page_fault;
1691 context->gva_to_gpa = paging32_gva_to_gpa;
1692 context->free = paging_free;
1693 context->prefetch_page = paging32_prefetch_page;
1694 context->sync_page = paging32_sync_page;
1695 context->invlpg = paging32_invlpg;
1696 context->root_level = PT32_ROOT_LEVEL;
1697 context->shadow_root_level = PT32E_ROOT_LEVEL;
1698 context->root_hpa = INVALID_PAGE;
1699 return 0;
1700}
1701
1702static int paging32E_init_context(struct kvm_vcpu *vcpu)
1703{
1704 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1705}
1706
1707static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
1708{
1709 struct kvm_mmu *context = &vcpu->arch.mmu;
1710
1711 context->new_cr3 = nonpaging_new_cr3;
1712 context->page_fault = tdp_page_fault;
1713 context->free = nonpaging_free;
1714 context->prefetch_page = nonpaging_prefetch_page;
1715 context->sync_page = nonpaging_sync_page;
1716 context->invlpg = nonpaging_invlpg;
1717 context->shadow_root_level = kvm_x86_ops->get_tdp_level();
1718 context->root_hpa = INVALID_PAGE;
1719
1720 if (!is_paging(vcpu)) {
1721 context->gva_to_gpa = nonpaging_gva_to_gpa;
1722 context->root_level = 0;
1723 } else if (is_long_mode(vcpu)) {
1724 context->gva_to_gpa = paging64_gva_to_gpa;
1725 context->root_level = PT64_ROOT_LEVEL;
1726 } else if (is_pae(vcpu)) {
1727 context->gva_to_gpa = paging64_gva_to_gpa;
1728 context->root_level = PT32E_ROOT_LEVEL;
1729 } else {
1730 context->gva_to_gpa = paging32_gva_to_gpa;
1731 context->root_level = PT32_ROOT_LEVEL;
1732 }
1733
1734 return 0;
1735}
1736
1737static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
1738{
1739 ASSERT(vcpu);
1740 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1741
1742 if (!is_paging(vcpu))
1743 return nonpaging_init_context(vcpu);
1744 else if (is_long_mode(vcpu))
1745 return paging64_init_context(vcpu);
1746 else if (is_pae(vcpu))
1747 return paging32E_init_context(vcpu);
1748 else
1749 return paging32_init_context(vcpu);
1750}
1751
1752static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1753{
1754 vcpu->arch.update_pte.pfn = bad_pfn;
1755
1756 if (tdp_enabled)
1757 return init_kvm_tdp_mmu(vcpu);
1758 else
1759 return init_kvm_softmmu(vcpu);
1760}
1761
1762static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1763{
1764 ASSERT(vcpu);
1765 if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1766 vcpu->arch.mmu.free(vcpu);
1767 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1768 }
1769}
1770
1771int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1772{
1773 destroy_kvm_mmu(vcpu);
1774 return init_kvm_mmu(vcpu);
1775}
1776EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1777
1778int kvm_mmu_load(struct kvm_vcpu *vcpu)
1779{
1780 int r;
1781
1782 r = mmu_topup_memory_caches(vcpu);
1783 if (r)
1784 goto out;
1785 spin_lock(&vcpu->kvm->mmu_lock);
1786 kvm_mmu_free_some_pages(vcpu);
1787 mmu_alloc_roots(vcpu);
1788 mmu_sync_roots(vcpu);
1789 spin_unlock(&vcpu->kvm->mmu_lock);
1790 kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1791 kvm_mmu_flush_tlb(vcpu);
1792out:
1793 return r;
1794}
1795EXPORT_SYMBOL_GPL(kvm_mmu_load);
1796
1797void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1798{
1799 mmu_free_roots(vcpu);
1800}
1801
1802static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1803 struct kvm_mmu_page *sp,
1804 u64 *spte)
1805{
1806 u64 pte;
1807 struct kvm_mmu_page *child;
1808
1809 pte = *spte;
1810 if (is_shadow_present_pte(pte)) {
1811 if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
1812 is_large_pte(pte))
1813 rmap_remove(vcpu->kvm, spte);
1814 else {
1815 child = page_header(pte & PT64_BASE_ADDR_MASK);
1816 mmu_page_remove_parent_pte(child, spte);
1817 }
1818 }
1819 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1820 if (is_large_pte(pte))
1821 --vcpu->kvm->stat.lpages;
1822}
1823
1824static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1825 struct kvm_mmu_page *sp,
1826 u64 *spte,
1827 const void *new)
1828{
1829 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1830 if (!vcpu->arch.update_pte.largepage ||
1831 sp->role.glevels == PT32_ROOT_LEVEL) {
1832 ++vcpu->kvm->stat.mmu_pde_zapped;
1833 return;
1834 }
1835 }
1836
1837 ++vcpu->kvm->stat.mmu_pte_updated;
1838 if (sp->role.glevels == PT32_ROOT_LEVEL)
1839 paging32_update_pte(vcpu, sp, spte, new);
1840 else
1841 paging64_update_pte(vcpu, sp, spte, new);
1842}
1843
1844static bool need_remote_flush(u64 old, u64 new)
1845{
1846 if (!is_shadow_present_pte(old))
1847 return false;
1848 if (!is_shadow_present_pte(new))
1849 return true;
1850 if ((old ^ new) & PT64_BASE_ADDR_MASK)
1851 return true;
1852 old ^= PT64_NX_MASK;
1853 new ^= PT64_NX_MASK;
1854 return (old & ~new & PT64_PERM_MASK) != 0;
1855}
1856
1857static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1858{
1859 if (need_remote_flush(old, new))
1860 kvm_flush_remote_tlbs(vcpu->kvm);
1861 else
1862 kvm_mmu_flush_tlb(vcpu);
1863}
1864
1865static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1866{
1867 u64 *spte = vcpu->arch.last_pte_updated;
1868
1869 return !!(spte && (*spte & shadow_accessed_mask));
1870}
1871
1872static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1873 const u8 *new, int bytes)
1874{
1875 gfn_t gfn;
1876 int r;
1877 u64 gpte = 0;
1878 pfn_t pfn;
1879
1880 vcpu->arch.update_pte.largepage = 0;
1881
1882 if (bytes != 4 && bytes != 8)
1883 return;
1884
1885 /*
1886 * Assume that the pte write on a page table of the same type
1887 * as the current vcpu paging mode. This is nearly always true
1888 * (might be false while changing modes). Note it is verified later
1889 * by update_pte().
1890 */
1891 if (is_pae(vcpu)) {
1892 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1893 if ((bytes == 4) && (gpa % 4 == 0)) {
1894 r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1895 if (r)
1896 return;
1897 memcpy((void *)&gpte + (gpa % 8), new, 4);
1898 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1899 memcpy((void *)&gpte, new, 8);
1900 }
1901 } else {
1902 if ((bytes == 4) && (gpa % 4 == 0))
1903 memcpy((void *)&gpte, new, 4);
1904 }
1905 if (!is_present_pte(gpte))
1906 return;
1907 gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1908
1909 if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
1910 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1911 vcpu->arch.update_pte.largepage = 1;
1912 }
1913 vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
1914 smp_rmb();
1915 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1916
1917 if (is_error_pfn(pfn)) {
1918 kvm_release_pfn_clean(pfn);
1919 return;
1920 }
1921 vcpu->arch.update_pte.gfn = gfn;
1922 vcpu->arch.update_pte.pfn = pfn;
1923}
1924
1925static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1926{
1927 u64 *spte = vcpu->arch.last_pte_updated;
1928
1929 if (spte
1930 && vcpu->arch.last_pte_gfn == gfn
1931 && shadow_accessed_mask
1932 && !(*spte & shadow_accessed_mask)
1933 && is_shadow_present_pte(*spte))
1934 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
1935}
1936
1937void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1938 const u8 *new, int bytes)
1939{
1940 gfn_t gfn = gpa >> PAGE_SHIFT;
1941 struct kvm_mmu_page *sp;
1942 struct hlist_node *node, *n;
1943 struct hlist_head *bucket;
1944 unsigned index;
1945 u64 entry, gentry;
1946 u64 *spte;
1947 unsigned offset = offset_in_page(gpa);
1948 unsigned pte_size;
1949 unsigned page_offset;
1950 unsigned misaligned;
1951 unsigned quadrant;
1952 int level;
1953 int flooded = 0;
1954 int npte;
1955 int r;
1956
1957 pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
1958 mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1959 spin_lock(&vcpu->kvm->mmu_lock);
1960 kvm_mmu_access_page(vcpu, gfn);
1961 kvm_mmu_free_some_pages(vcpu);
1962 ++vcpu->kvm->stat.mmu_pte_write;
1963 kvm_mmu_audit(vcpu, "pre pte write");
1964 if (gfn == vcpu->arch.last_pt_write_gfn
1965 && !last_updated_pte_accessed(vcpu)) {
1966 ++vcpu->arch.last_pt_write_count;
1967 if (vcpu->arch.last_pt_write_count >= 3)
1968 flooded = 1;
1969 } else {
1970 vcpu->arch.last_pt_write_gfn = gfn;
1971 vcpu->arch.last_pt_write_count = 1;
1972 vcpu->arch.last_pte_updated = NULL;
1973 }
1974 index = kvm_page_table_hashfn(gfn);
1975 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1976 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1977 if (sp->gfn != gfn || sp->role.metaphysical || sp->role.invalid)
1978 continue;
1979 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1980 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1981 misaligned |= bytes < 4;
1982 if (misaligned || flooded) {
1983 /*
1984 * Misaligned accesses are too much trouble to fix
1985 * up; also, they usually indicate a page is not used
1986 * as a page table.
1987 *
1988 * If we're seeing too many writes to a page,
1989 * it may no longer be a page table, or we may be
1990 * forking, in which case it is better to unmap the
1991 * page.
1992 */
1993 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1994 gpa, bytes, sp->role.word);
1995 kvm_mmu_zap_page(vcpu->kvm, sp);
1996 ++vcpu->kvm->stat.mmu_flooded;
1997 continue;
1998 }
1999 page_offset = offset;
2000 level = sp->role.level;
2001 npte = 1;
2002 if (sp->role.glevels == PT32_ROOT_LEVEL) {
2003 page_offset <<= 1; /* 32->64 */
2004 /*
2005 * A 32-bit pde maps 4MB while the shadow pdes map
2006 * only 2MB. So we need to double the offset again
2007 * and zap two pdes instead of one.
2008 */
2009 if (level == PT32_ROOT_LEVEL) {
2010 page_offset &= ~7; /* kill rounding error */
2011 page_offset <<= 1;
2012 npte = 2;
2013 }
2014 quadrant = page_offset >> PAGE_SHIFT;
2015 page_offset &= ~PAGE_MASK;
2016 if (quadrant != sp->role.quadrant)
2017 continue;
2018 }
2019 spte = &sp->spt[page_offset / sizeof(*spte)];
2020 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
2021 gentry = 0;
2022 r = kvm_read_guest_atomic(vcpu->kvm,
2023 gpa & ~(u64)(pte_size - 1),
2024 &gentry, pte_size);
2025 new = (const void *)&gentry;
2026 if (r < 0)
2027 new = NULL;
2028 }
2029 while (npte--) {
2030 entry = *spte;
2031 mmu_pte_write_zap_pte(vcpu, sp, spte);
2032 if (new)
2033 mmu_pte_write_new_pte(vcpu, sp, spte, new);
2034 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
2035 ++spte;
2036 }
2037 }
2038 kvm_mmu_audit(vcpu, "post pte write");
2039 spin_unlock(&vcpu->kvm->mmu_lock);
2040 if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2041 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2042 vcpu->arch.update_pte.pfn = bad_pfn;
2043 }
2044}
2045
2046int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2047{
2048 gpa_t gpa;
2049 int r;
2050
2051 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
2052
2053 spin_lock(&vcpu->kvm->mmu_lock);
2054 r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2055 spin_unlock(&vcpu->kvm->mmu_lock);
2056 return r;
2057}
2058EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2059
2060void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2061{
2062 while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
2063 struct kvm_mmu_page *sp;
2064
2065 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2066 struct kvm_mmu_page, link);
2067 kvm_mmu_zap_page(vcpu->kvm, sp);
2068 ++vcpu->kvm->stat.mmu_recycled;
2069 }
2070}
2071
2072int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2073{
2074 int r;
2075 enum emulation_result er;
2076
2077 r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2078 if (r < 0)
2079 goto out;
2080
2081 if (!r) {
2082 r = 1;
2083 goto out;
2084 }
2085
2086 r = mmu_topup_memory_caches(vcpu);
2087 if (r)
2088 goto out;
2089
2090 er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
2091
2092 switch (er) {
2093 case EMULATE_DONE:
2094 return 1;
2095 case EMULATE_DO_MMIO:
2096 ++vcpu->stat.mmio_exits;
2097 return 0;
2098 case EMULATE_FAIL:
2099 kvm_report_emulation_failure(vcpu, "pagetable");
2100 return 1;
2101 default:
2102 BUG();
2103 }
2104out:
2105 return r;
2106}
2107EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2108
2109void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2110{
2111 spin_lock(&vcpu->kvm->mmu_lock);
2112 vcpu->arch.mmu.invlpg(vcpu, gva);
2113 spin_unlock(&vcpu->kvm->mmu_lock);
2114 kvm_mmu_flush_tlb(vcpu);
2115 ++vcpu->stat.invlpg;
2116}
2117EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2118
2119void kvm_enable_tdp(void)
2120{
2121 tdp_enabled = true;
2122}
2123EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2124
2125void kvm_disable_tdp(void)
2126{
2127 tdp_enabled = false;
2128}
2129EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2130
2131static void free_mmu_pages(struct kvm_vcpu *vcpu)
2132{
2133 struct kvm_mmu_page *sp;
2134
2135 while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2136 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
2137 struct kvm_mmu_page, link);
2138 kvm_mmu_zap_page(vcpu->kvm, sp);
2139 cond_resched();
2140 }
2141 free_page((unsigned long)vcpu->arch.mmu.pae_root);
2142}
2143
2144static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2145{
2146 struct page *page;
2147 int i;
2148
2149 ASSERT(vcpu);
2150
2151 if (vcpu->kvm->arch.n_requested_mmu_pages)
2152 vcpu->kvm->arch.n_free_mmu_pages =
2153 vcpu->kvm->arch.n_requested_mmu_pages;
2154 else
2155 vcpu->kvm->arch.n_free_mmu_pages =
2156 vcpu->kvm->arch.n_alloc_mmu_pages;
2157 /*
2158 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2159 * Therefore we need to allocate shadow page tables in the first
2160 * 4GB of memory, which happens to fit the DMA32 zone.
2161 */
2162 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2163 if (!page)
2164 goto error_1;
2165 vcpu->arch.mmu.pae_root = page_address(page);
2166 for (i = 0; i < 4; ++i)
2167 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2168
2169 return 0;
2170
2171error_1:
2172 free_mmu_pages(vcpu);
2173 return -ENOMEM;
2174}
2175
2176int kvm_mmu_create(struct kvm_vcpu *vcpu)
2177{
2178 ASSERT(vcpu);
2179 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2180
2181 return alloc_mmu_pages(vcpu);
2182}
2183
2184int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2185{
2186 ASSERT(vcpu);
2187 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2188
2189 return init_kvm_mmu(vcpu);
2190}
2191
2192void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2193{
2194 ASSERT(vcpu);
2195
2196 destroy_kvm_mmu(vcpu);
2197 free_mmu_pages(vcpu);
2198 mmu_free_memory_caches(vcpu);
2199}
2200
2201void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2202{
2203 struct kvm_mmu_page *sp;
2204
2205 spin_lock(&kvm->mmu_lock);
2206 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2207 int i;
2208 u64 *pt;
2209
2210 if (!test_bit(slot, &sp->slot_bitmap))
2211 continue;
2212
2213 pt = sp->spt;
2214 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2215 /* avoid RMW */
2216 if (pt[i] & PT_WRITABLE_MASK)
2217 pt[i] &= ~PT_WRITABLE_MASK;
2218 }
2219 kvm_flush_remote_tlbs(kvm);
2220 spin_unlock(&kvm->mmu_lock);
2221}
2222
2223void kvm_mmu_zap_all(struct kvm *kvm)
2224{
2225 struct kvm_mmu_page *sp, *node;
2226
2227 spin_lock(&kvm->mmu_lock);
2228 list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2229 kvm_mmu_zap_page(kvm, sp);
2230 spin_unlock(&kvm->mmu_lock);
2231
2232 kvm_flush_remote_tlbs(kvm);
2233}
2234
2235static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2236{
2237 struct kvm_mmu_page *page;
2238
2239 page = container_of(kvm->arch.active_mmu_pages.prev,
2240 struct kvm_mmu_page, link);
2241 kvm_mmu_zap_page(kvm, page);
2242}
2243
2244static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2245{
2246 struct kvm *kvm;
2247 struct kvm *kvm_freed = NULL;
2248 int cache_count = 0;
2249
2250 spin_lock(&kvm_lock);
2251
2252 list_for_each_entry(kvm, &vm_list, vm_list) {
2253 int npages;
2254
2255 if (!down_read_trylock(&kvm->slots_lock))
2256 continue;
2257 spin_lock(&kvm->mmu_lock);
2258 npages = kvm->arch.n_alloc_mmu_pages -
2259 kvm->arch.n_free_mmu_pages;
2260 cache_count += npages;
2261 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2262 kvm_mmu_remove_one_alloc_mmu_page(kvm);
2263 cache_count--;
2264 kvm_freed = kvm;
2265 }
2266 nr_to_scan--;
2267
2268 spin_unlock(&kvm->mmu_lock);
2269 up_read(&kvm->slots_lock);
2270 }
2271 if (kvm_freed)
2272 list_move_tail(&kvm_freed->vm_list, &vm_list);
2273
2274 spin_unlock(&kvm_lock);
2275
2276 return cache_count;
2277}
2278
2279static struct shrinker mmu_shrinker = {
2280 .shrink = mmu_shrink,
2281 .seeks = DEFAULT_SEEKS * 10,
2282};
2283
2284static void mmu_destroy_caches(void)
2285{
2286 if (pte_chain_cache)
2287 kmem_cache_destroy(pte_chain_cache);
2288 if (rmap_desc_cache)
2289 kmem_cache_destroy(rmap_desc_cache);
2290 if (mmu_page_header_cache)
2291 kmem_cache_destroy(mmu_page_header_cache);
2292}
2293
2294void kvm_mmu_module_exit(void)
2295{
2296 mmu_destroy_caches();
2297 unregister_shrinker(&mmu_shrinker);
2298}
2299
2300int kvm_mmu_module_init(void)
2301{
2302 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2303 sizeof(struct kvm_pte_chain),
2304 0, 0, NULL);
2305 if (!pte_chain_cache)
2306 goto nomem;
2307 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2308 sizeof(struct kvm_rmap_desc),
2309 0, 0, NULL);
2310 if (!rmap_desc_cache)
2311 goto nomem;
2312
2313 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2314 sizeof(struct kvm_mmu_page),
2315 0, 0, NULL);
2316 if (!mmu_page_header_cache)
2317 goto nomem;
2318
2319 register_shrinker(&mmu_shrinker);
2320
2321 return 0;
2322
2323nomem:
2324 mmu_destroy_caches();
2325 return -ENOMEM;
2326}
2327
2328/*
2329 * Caculate mmu pages needed for kvm.
2330 */
2331unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
2332{
2333 int i;
2334 unsigned int nr_mmu_pages;
2335 unsigned int nr_pages = 0;
2336
2337 for (i = 0; i < kvm->nmemslots; i++)
2338 nr_pages += kvm->memslots[i].npages;
2339
2340 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
2341 nr_mmu_pages = max(nr_mmu_pages,
2342 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
2343
2344 return nr_mmu_pages;
2345}
2346
2347static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2348 unsigned len)
2349{
2350 if (len > buffer->len)
2351 return NULL;
2352 return buffer->ptr;
2353}
2354
2355static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2356 unsigned len)
2357{
2358 void *ret;
2359
2360 ret = pv_mmu_peek_buffer(buffer, len);
2361 if (!ret)
2362 return ret;
2363 buffer->ptr += len;
2364 buffer->len -= len;
2365 buffer->processed += len;
2366 return ret;
2367}
2368
2369static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
2370 gpa_t addr, gpa_t value)
2371{
2372 int bytes = 8;
2373 int r;
2374
2375 if (!is_long_mode(vcpu) && !is_pae(vcpu))
2376 bytes = 4;
2377
2378 r = mmu_topup_memory_caches(vcpu);
2379 if (r)
2380 return r;
2381
2382 if (!emulator_write_phys(vcpu, addr, &value, bytes))
2383 return -EFAULT;
2384
2385 return 1;
2386}
2387
2388static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2389{
2390 kvm_x86_ops->tlb_flush(vcpu);
2391 return 1;
2392}
2393
2394static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
2395{
2396 spin_lock(&vcpu->kvm->mmu_lock);
2397 mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
2398 spin_unlock(&vcpu->kvm->mmu_lock);
2399 return 1;
2400}
2401
2402static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
2403 struct kvm_pv_mmu_op_buffer *buffer)
2404{
2405 struct kvm_mmu_op_header *header;
2406
2407 header = pv_mmu_peek_buffer(buffer, sizeof *header);
2408 if (!header)
2409 return 0;
2410 switch (header->op) {
2411 case KVM_MMU_OP_WRITE_PTE: {
2412 struct kvm_mmu_op_write_pte *wpte;
2413
2414 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
2415 if (!wpte)
2416 return 0;
2417 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
2418 wpte->pte_val);
2419 }
2420 case KVM_MMU_OP_FLUSH_TLB: {
2421 struct kvm_mmu_op_flush_tlb *ftlb;
2422
2423 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
2424 if (!ftlb)
2425 return 0;
2426 return kvm_pv_mmu_flush_tlb(vcpu);
2427 }
2428 case KVM_MMU_OP_RELEASE_PT: {
2429 struct kvm_mmu_op_release_pt *rpt;
2430
2431 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
2432 if (!rpt)
2433 return 0;
2434 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
2435 }
2436 default: return 0;
2437 }
2438}
2439
2440int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
2441 gpa_t addr, unsigned long *ret)
2442{
2443 int r;
2444 struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
2445
2446 buffer->ptr = buffer->buf;
2447 buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
2448 buffer->processed = 0;
2449
2450 r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
2451 if (r)
2452 goto out;
2453
2454 while (buffer->len) {
2455 r = kvm_pv_mmu_op_one(vcpu, buffer);
2456 if (r < 0)
2457 goto out;
2458 if (r == 0)
2459 break;
2460 }
2461
2462 r = 1;
2463out:
2464 *ret = buffer->processed;
2465 return r;
2466}
2467
2468#ifdef AUDIT
2469
2470static const char *audit_msg;
2471
2472static gva_t canonicalize(gva_t gva)
2473{
2474#ifdef CONFIG_X86_64
2475 gva = (long long)(gva << 16) >> 16;
2476#endif
2477 return gva;
2478}
2479
2480static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
2481 gva_t va, int level)
2482{
2483 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
2484 int i;
2485 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
2486
2487 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
2488 u64 ent = pt[i];
2489
2490 if (ent == shadow_trap_nonpresent_pte)
2491 continue;
2492
2493 va = canonicalize(va);
2494 if (level > 1) {
2495 if (ent == shadow_notrap_nonpresent_pte)
2496 printk(KERN_ERR "audit: (%s) nontrapping pte"
2497 " in nonleaf level: levels %d gva %lx"
2498 " level %d pte %llx\n", audit_msg,
2499 vcpu->arch.mmu.root_level, va, level, ent);
2500
2501 audit_mappings_page(vcpu, ent, va, level - 1);
2502 } else {
2503 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
2504 hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
2505
2506 if (is_shadow_present_pte(ent)
2507 && (ent & PT64_BASE_ADDR_MASK) != hpa)
2508 printk(KERN_ERR "xx audit error: (%s) levels %d"
2509 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2510 audit_msg, vcpu->arch.mmu.root_level,
2511 va, gpa, hpa, ent,
2512 is_shadow_present_pte(ent));
2513 else if (ent == shadow_notrap_nonpresent_pte
2514 && !is_error_hpa(hpa))
2515 printk(KERN_ERR "audit: (%s) notrap shadow,"
2516 " valid guest gva %lx\n", audit_msg, va);
2517 kvm_release_pfn_clean(pfn);
2518
2519 }
2520 }
2521}
2522
2523static void audit_mappings(struct kvm_vcpu *vcpu)
2524{
2525 unsigned i;
2526
2527 if (vcpu->arch.mmu.root_level == 4)
2528 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
2529 else
2530 for (i = 0; i < 4; ++i)
2531 if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
2532 audit_mappings_page(vcpu,
2533 vcpu->arch.mmu.pae_root[i],
2534 i << 30,
2535 2);
2536}
2537
2538static int count_rmaps(struct kvm_vcpu *vcpu)
2539{
2540 int nmaps = 0;
2541 int i, j, k;
2542
2543 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
2544 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
2545 struct kvm_rmap_desc *d;
2546
2547 for (j = 0; j < m->npages; ++j) {
2548 unsigned long *rmapp = &m->rmap[j];
2549
2550 if (!*rmapp)
2551 continue;
2552 if (!(*rmapp & 1)) {
2553 ++nmaps;
2554 continue;
2555 }
2556 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
2557 while (d) {
2558 for (k = 0; k < RMAP_EXT; ++k)
2559 if (d->shadow_ptes[k])
2560 ++nmaps;
2561 else
2562 break;
2563 d = d->more;
2564 }
2565 }
2566 }
2567 return nmaps;
2568}
2569
2570static int count_writable_mappings(struct kvm_vcpu *vcpu)
2571{
2572 int nmaps = 0;
2573 struct kvm_mmu_page *sp;
2574 int i;
2575
2576 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2577 u64 *pt = sp->spt;
2578
2579 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
2580 continue;
2581
2582 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
2583 u64 ent = pt[i];
2584
2585 if (!(ent & PT_PRESENT_MASK))
2586 continue;
2587 if (!(ent & PT_WRITABLE_MASK))
2588 continue;
2589 ++nmaps;
2590 }
2591 }
2592 return nmaps;
2593}
2594
2595static void audit_rmap(struct kvm_vcpu *vcpu)
2596{
2597 int n_rmap = count_rmaps(vcpu);
2598 int n_actual = count_writable_mappings(vcpu);
2599
2600 if (n_rmap != n_actual)
2601 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
2602 __func__, audit_msg, n_rmap, n_actual);
2603}
2604
2605static void audit_write_protection(struct kvm_vcpu *vcpu)
2606{
2607 struct kvm_mmu_page *sp;
2608 struct kvm_memory_slot *slot;
2609 unsigned long *rmapp;
2610 gfn_t gfn;
2611
2612 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2613 if (sp->role.metaphysical)
2614 continue;
2615
2616 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
2617 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
2618 rmapp = &slot->rmap[gfn - slot->base_gfn];
2619 if (*rmapp)
2620 printk(KERN_ERR "%s: (%s) shadow page has writable"
2621 " mappings: gfn %lx role %x\n",
2622 __func__, audit_msg, sp->gfn,
2623 sp->role.word);
2624 }
2625}
2626
2627static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
2628{
2629 int olddbg = dbg;
2630
2631 dbg = 0;
2632 audit_msg = msg;
2633 audit_rmap(vcpu);
2634 audit_write_protection(vcpu);
2635 audit_mappings(vcpu);
2636 dbg = olddbg;
2637}
2638
2639#endif
Linux kernel - Deliverables
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