2 * Kernel-based Virtual Machine driver for Linux
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
9 * Copyright (C) 2006 Qumranet, Inc.
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
24 #include <linux/types.h>
25 #include <linux/string.h>
27 #include <linux/highmem.h>
28 #include <linux/module.h>
29 #include <linux/swap.h>
32 #include <asm/cmpxchg.h>
40 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
42 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
47 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
48 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
52 #define pgprintk(x...) do { } while (0)
53 #define rmap_printk(x...) do { } while (0)
57 #if defined(MMU_DEBUG) || defined(AUDIT)
62 #define ASSERT(x) do { } while (0)
66 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
67 __FILE__, __LINE__, #x); \
71 #define PT64_PT_BITS 9
72 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
73 #define PT32_PT_BITS 10
74 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
76 #define PT_WRITABLE_SHIFT 1
78 #define PT_PRESENT_MASK (1ULL << 0)
79 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
80 #define PT_USER_MASK (1ULL << 2)
81 #define PT_PWT_MASK (1ULL << 3)
82 #define PT_PCD_MASK (1ULL << 4)
83 #define PT_ACCESSED_MASK (1ULL << 5)
84 #define PT_DIRTY_MASK (1ULL << 6)
85 #define PT_PAGE_SIZE_MASK (1ULL << 7)
86 #define PT_PAT_MASK (1ULL << 7)
87 #define PT_GLOBAL_MASK (1ULL << 8)
88 #define PT64_NX_SHIFT 63
89 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
91 #define PT_PAT_SHIFT 7
92 #define PT_DIR_PAT_SHIFT 12
93 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
95 #define PT32_DIR_PSE36_SIZE 4
96 #define PT32_DIR_PSE36_SHIFT 13
97 #define PT32_DIR_PSE36_MASK \
98 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
101 #define PT_FIRST_AVAIL_BITS_SHIFT 9
102 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
104 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
106 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
108 #define PT64_LEVEL_BITS 9
110 #define PT64_LEVEL_SHIFT(level) \
111 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
113 #define PT64_LEVEL_MASK(level) \
114 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
116 #define PT64_INDEX(address, level)\
117 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
120 #define PT32_LEVEL_BITS 10
122 #define PT32_LEVEL_SHIFT(level) \
123 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
125 #define PT32_LEVEL_MASK(level) \
126 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
128 #define PT32_INDEX(address, level)\
129 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
132 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
133 #define PT64_DIR_BASE_ADDR_MASK \
134 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
136 #define PT32_BASE_ADDR_MASK PAGE_MASK
137 #define PT32_DIR_BASE_ADDR_MASK \
138 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
140 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
143 #define PFERR_PRESENT_MASK (1U << 0)
144 #define PFERR_WRITE_MASK (1U << 1)
145 #define PFERR_USER_MASK (1U << 2)
146 #define PFERR_FETCH_MASK (1U << 4)
148 #define PT64_ROOT_LEVEL 4
149 #define PT32_ROOT_LEVEL 2
150 #define PT32E_ROOT_LEVEL 3
152 #define PT_DIRECTORY_LEVEL 2
153 #define PT_PAGE_TABLE_LEVEL 1
157 #define ACC_EXEC_MASK 1
158 #define ACC_WRITE_MASK PT_WRITABLE_MASK
159 #define ACC_USER_MASK PT_USER_MASK
160 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
162 struct kvm_rmap_desc {
163 u64 *shadow_ptes[RMAP_EXT];
164 struct kvm_rmap_desc *more;
167 static struct kmem_cache *pte_chain_cache;
168 static struct kmem_cache *rmap_desc_cache;
169 static struct kmem_cache *mmu_page_header_cache;
171 static u64 __read_mostly shadow_trap_nonpresent_pte;
172 static u64 __read_mostly shadow_notrap_nonpresent_pte;
174 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
176 shadow_trap_nonpresent_pte = trap_pte;
177 shadow_notrap_nonpresent_pte = notrap_pte;
179 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
181 static int is_write_protection(struct kvm_vcpu *vcpu)
183 return vcpu->cr0 & X86_CR0_WP;
186 static int is_cpuid_PSE36(void)
191 static int is_nx(struct kvm_vcpu *vcpu)
193 return vcpu->shadow_efer & EFER_NX;
196 static int is_present_pte(unsigned long pte)
198 return pte & PT_PRESENT_MASK;
201 static int is_shadow_present_pte(u64 pte)
203 pte &= ~PT_SHADOW_IO_MARK;
204 return pte != shadow_trap_nonpresent_pte
205 && pte != shadow_notrap_nonpresent_pte;
208 static int is_writeble_pte(unsigned long pte)
210 return pte & PT_WRITABLE_MASK;
213 static int is_dirty_pte(unsigned long pte)
215 return pte & PT_DIRTY_MASK;
218 static int is_io_pte(unsigned long pte)
220 return pte & PT_SHADOW_IO_MARK;
223 static int is_rmap_pte(u64 pte)
225 return pte != shadow_trap_nonpresent_pte
226 && pte != shadow_notrap_nonpresent_pte;
229 static gfn_t pse36_gfn_delta(u32 gpte)
231 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
233 return (gpte & PT32_DIR_PSE36_MASK) << shift;
236 static void set_shadow_pte(u64 *sptep, u64 spte)
239 set_64bit((unsigned long *)sptep, spte);
241 set_64bit((unsigned long long *)sptep, spte);
245 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
246 struct kmem_cache *base_cache, int min)
250 if (cache->nobjs >= min)
252 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
253 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
256 cache->objects[cache->nobjs++] = obj;
261 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
264 kfree(mc->objects[--mc->nobjs]);
267 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
272 if (cache->nobjs >= min)
274 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
275 page = alloc_page(GFP_KERNEL);
278 set_page_private(page, 0);
279 cache->objects[cache->nobjs++] = page_address(page);
284 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
287 free_page((unsigned long)mc->objects[--mc->nobjs]);
290 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
294 kvm_mmu_free_some_pages(vcpu);
295 r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
299 r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
303 r = mmu_topup_memory_cache_page(&vcpu->mmu_page_cache, 8);
306 r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
307 mmu_page_header_cache, 4);
312 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
314 mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
315 mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
316 mmu_free_memory_cache_page(&vcpu->mmu_page_cache);
317 mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
320 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
326 p = mc->objects[--mc->nobjs];
331 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
333 return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
334 sizeof(struct kvm_pte_chain));
337 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
342 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
344 return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
345 sizeof(struct kvm_rmap_desc));
348 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
354 * Take gfn and return the reverse mapping to it.
355 * Note: gfn must be unaliased before this function get called
358 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
360 struct kvm_memory_slot *slot;
362 slot = gfn_to_memslot(kvm, gfn);
363 return &slot->rmap[gfn - slot->base_gfn];
367 * Reverse mapping data structures:
369 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
370 * that points to page_address(page).
372 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
373 * containing more mappings.
375 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
377 struct kvm_mmu_page *sp;
378 struct kvm_rmap_desc *desc;
379 unsigned long *rmapp;
382 if (!is_rmap_pte(*spte))
384 gfn = unalias_gfn(vcpu->kvm, gfn);
385 sp = page_header(__pa(spte));
386 sp->gfns[spte - sp->spt] = gfn;
387 rmapp = gfn_to_rmap(vcpu->kvm, gfn);
389 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
390 *rmapp = (unsigned long)spte;
391 } else if (!(*rmapp & 1)) {
392 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
393 desc = mmu_alloc_rmap_desc(vcpu);
394 desc->shadow_ptes[0] = (u64 *)*rmapp;
395 desc->shadow_ptes[1] = spte;
396 *rmapp = (unsigned long)desc | 1;
398 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
399 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
400 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
402 if (desc->shadow_ptes[RMAP_EXT-1]) {
403 desc->more = mmu_alloc_rmap_desc(vcpu);
406 for (i = 0; desc->shadow_ptes[i]; ++i)
408 desc->shadow_ptes[i] = spte;
412 static void rmap_desc_remove_entry(unsigned long *rmapp,
413 struct kvm_rmap_desc *desc,
415 struct kvm_rmap_desc *prev_desc)
419 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
421 desc->shadow_ptes[i] = desc->shadow_ptes[j];
422 desc->shadow_ptes[j] = NULL;
425 if (!prev_desc && !desc->more)
426 *rmapp = (unsigned long)desc->shadow_ptes[0];
429 prev_desc->more = desc->more;
431 *rmapp = (unsigned long)desc->more | 1;
432 mmu_free_rmap_desc(desc);
435 static void rmap_remove(struct kvm *kvm, u64 *spte)
437 struct kvm_rmap_desc *desc;
438 struct kvm_rmap_desc *prev_desc;
439 struct kvm_mmu_page *sp;
441 unsigned long *rmapp;
444 if (!is_rmap_pte(*spte))
446 sp = page_header(__pa(spte));
447 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
448 mark_page_accessed(page);
449 if (is_writeble_pte(*spte))
450 kvm_release_page_dirty(page);
452 kvm_release_page_clean(page);
453 rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]);
455 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
457 } else if (!(*rmapp & 1)) {
458 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
459 if ((u64 *)*rmapp != spte) {
460 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
466 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
467 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
470 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
471 if (desc->shadow_ptes[i] == spte) {
472 rmap_desc_remove_entry(rmapp,
484 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
486 struct kvm_rmap_desc *desc;
487 struct kvm_rmap_desc *prev_desc;
493 else if (!(*rmapp & 1)) {
495 return (u64 *)*rmapp;
498 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
502 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
503 if (prev_spte == spte)
504 return desc->shadow_ptes[i];
505 prev_spte = desc->shadow_ptes[i];
512 static void rmap_write_protect(struct kvm *kvm, u64 gfn)
514 unsigned long *rmapp;
517 gfn = unalias_gfn(kvm, gfn);
518 rmapp = gfn_to_rmap(kvm, gfn);
520 spte = rmap_next(kvm, rmapp, NULL);
523 BUG_ON(!(*spte & PT_PRESENT_MASK));
524 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
525 if (is_writeble_pte(*spte))
526 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
527 kvm_flush_remote_tlbs(kvm);
528 spte = rmap_next(kvm, rmapp, spte);
533 static int is_empty_shadow_page(u64 *spt)
538 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
539 if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
540 printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
548 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
550 ASSERT(is_empty_shadow_page(sp->spt));
552 __free_page(virt_to_page(sp->spt));
553 __free_page(virt_to_page(sp->gfns));
555 ++kvm->n_free_mmu_pages;
558 static unsigned kvm_page_table_hashfn(gfn_t gfn)
563 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
566 struct kvm_mmu_page *sp;
568 if (!vcpu->kvm->n_free_mmu_pages)
571 sp = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache, sizeof *sp);
572 sp->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
573 sp->gfns = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
574 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
575 list_add(&sp->link, &vcpu->kvm->active_mmu_pages);
576 ASSERT(is_empty_shadow_page(sp->spt));
579 sp->parent_pte = parent_pte;
580 --vcpu->kvm->n_free_mmu_pages;
584 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
585 struct kvm_mmu_page *sp, u64 *parent_pte)
587 struct kvm_pte_chain *pte_chain;
588 struct hlist_node *node;
593 if (!sp->multimapped) {
594 u64 *old = sp->parent_pte;
597 sp->parent_pte = parent_pte;
601 pte_chain = mmu_alloc_pte_chain(vcpu);
602 INIT_HLIST_HEAD(&sp->parent_ptes);
603 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
604 pte_chain->parent_ptes[0] = old;
606 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
607 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
609 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
610 if (!pte_chain->parent_ptes[i]) {
611 pte_chain->parent_ptes[i] = parent_pte;
615 pte_chain = mmu_alloc_pte_chain(vcpu);
617 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
618 pte_chain->parent_ptes[0] = parent_pte;
621 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
624 struct kvm_pte_chain *pte_chain;
625 struct hlist_node *node;
628 if (!sp->multimapped) {
629 BUG_ON(sp->parent_pte != parent_pte);
630 sp->parent_pte = NULL;
633 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
634 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
635 if (!pte_chain->parent_ptes[i])
637 if (pte_chain->parent_ptes[i] != parent_pte)
639 while (i + 1 < NR_PTE_CHAIN_ENTRIES
640 && pte_chain->parent_ptes[i + 1]) {
641 pte_chain->parent_ptes[i]
642 = pte_chain->parent_ptes[i + 1];
645 pte_chain->parent_ptes[i] = NULL;
647 hlist_del(&pte_chain->link);
648 mmu_free_pte_chain(pte_chain);
649 if (hlist_empty(&sp->parent_ptes)) {
651 sp->parent_pte = NULL;
659 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
662 struct hlist_head *bucket;
663 struct kvm_mmu_page *sp;
664 struct hlist_node *node;
666 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
667 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
668 bucket = &kvm->mmu_page_hash[index];
669 hlist_for_each_entry(sp, node, bucket, hash_link)
670 if (sp->gfn == gfn && !sp->role.metaphysical) {
671 pgprintk("%s: found role %x\n",
672 __FUNCTION__, sp->role.word);
678 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
686 union kvm_mmu_page_role role;
689 struct hlist_head *bucket;
690 struct kvm_mmu_page *sp;
691 struct hlist_node *node;
694 role.glevels = vcpu->mmu.root_level;
696 role.metaphysical = metaphysical;
697 role.access = access;
698 if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
699 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
700 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
701 role.quadrant = quadrant;
703 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
705 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
706 bucket = &vcpu->kvm->mmu_page_hash[index];
707 hlist_for_each_entry(sp, node, bucket, hash_link)
708 if (sp->gfn == gfn && sp->role.word == role.word) {
709 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
710 pgprintk("%s: found\n", __FUNCTION__);
713 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
716 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
719 hlist_add_head(&sp->hash_link, bucket);
720 vcpu->mmu.prefetch_page(vcpu, sp);
722 rmap_write_protect(vcpu->kvm, gfn);
726 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
727 struct kvm_mmu_page *sp)
735 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
736 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
737 if (is_shadow_present_pte(pt[i]))
738 rmap_remove(kvm, &pt[i]);
739 pt[i] = shadow_trap_nonpresent_pte;
741 kvm_flush_remote_tlbs(kvm);
745 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
748 pt[i] = shadow_trap_nonpresent_pte;
749 if (!is_shadow_present_pte(ent))
751 ent &= PT64_BASE_ADDR_MASK;
752 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
754 kvm_flush_remote_tlbs(kvm);
757 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
759 mmu_page_remove_parent_pte(sp, parent_pte);
762 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
766 for (i = 0; i < KVM_MAX_VCPUS; ++i)
768 kvm->vcpus[i]->last_pte_updated = NULL;
771 static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
775 ++kvm->stat.mmu_shadow_zapped;
776 while (sp->multimapped || sp->parent_pte) {
777 if (!sp->multimapped)
778 parent_pte = sp->parent_pte;
780 struct kvm_pte_chain *chain;
782 chain = container_of(sp->parent_ptes.first,
783 struct kvm_pte_chain, link);
784 parent_pte = chain->parent_ptes[0];
787 kvm_mmu_put_page(sp, parent_pte);
788 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
790 kvm_mmu_page_unlink_children(kvm, sp);
791 if (!sp->root_count) {
792 hlist_del(&sp->hash_link);
793 kvm_mmu_free_page(kvm, sp);
795 list_move(&sp->link, &kvm->active_mmu_pages);
796 kvm_mmu_reset_last_pte_updated(kvm);
800 * Changing the number of mmu pages allocated to the vm
801 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
803 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
806 * If we set the number of mmu pages to be smaller be than the
807 * number of actived pages , we must to free some mmu pages before we
811 if ((kvm->n_alloc_mmu_pages - kvm->n_free_mmu_pages) >
813 int n_used_mmu_pages = kvm->n_alloc_mmu_pages
814 - kvm->n_free_mmu_pages;
816 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
817 struct kvm_mmu_page *page;
819 page = container_of(kvm->active_mmu_pages.prev,
820 struct kvm_mmu_page, link);
821 kvm_mmu_zap_page(kvm, page);
824 kvm->n_free_mmu_pages = 0;
827 kvm->n_free_mmu_pages += kvm_nr_mmu_pages
828 - kvm->n_alloc_mmu_pages;
830 kvm->n_alloc_mmu_pages = kvm_nr_mmu_pages;
833 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
836 struct hlist_head *bucket;
837 struct kvm_mmu_page *sp;
838 struct hlist_node *node, *n;
841 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
843 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
844 bucket = &kvm->mmu_page_hash[index];
845 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
846 if (sp->gfn == gfn && !sp->role.metaphysical) {
847 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
849 kvm_mmu_zap_page(kvm, sp);
855 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
857 struct kvm_mmu_page *sp;
859 while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
860 pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word);
861 kvm_mmu_zap_page(kvm, sp);
865 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
867 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
868 struct kvm_mmu_page *sp = page_header(__pa(pte));
870 __set_bit(slot, &sp->slot_bitmap);
873 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
875 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
877 if (gpa == UNMAPPED_GVA)
879 return gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
882 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
883 unsigned pt_access, unsigned pte_access,
884 int user_fault, int write_fault, int dirty,
885 int *ptwrite, gfn_t gfn)
888 int was_rmapped = is_rmap_pte(*shadow_pte);
891 pgprintk("%s: spte %llx gpte %llx access %x write_fault %d"
892 " user_fault %d gfn %lx\n",
893 __FUNCTION__, *shadow_pte, (u64)gpte, pt_access,
894 write_fault, user_fault, gfn);
897 * We don't set the accessed bit, since we sometimes want to see
898 * whether the guest actually used the pte (in order to detect
901 spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
903 pte_access &= ~ACC_WRITE_MASK;
904 if (!(pte_access & ACC_EXEC_MASK))
905 spte |= PT64_NX_MASK;
907 page = gfn_to_page(vcpu->kvm, gfn);
909 spte |= PT_PRESENT_MASK;
910 if (pte_access & ACC_USER_MASK)
911 spte |= PT_USER_MASK;
913 if (is_error_page(page)) {
914 set_shadow_pte(shadow_pte,
915 shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
916 kvm_release_page_clean(page);
920 spte |= page_to_phys(page);
922 if ((pte_access & ACC_WRITE_MASK)
923 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
924 struct kvm_mmu_page *shadow;
926 spte |= PT_WRITABLE_MASK;
928 mmu_unshadow(vcpu->kvm, gfn);
932 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
934 pgprintk("%s: found shadow page for %lx, marking ro\n",
936 pte_access &= ~ACC_WRITE_MASK;
937 if (is_writeble_pte(spte)) {
938 spte &= ~PT_WRITABLE_MASK;
939 kvm_x86_ops->tlb_flush(vcpu);
948 if (pte_access & ACC_WRITE_MASK)
949 mark_page_dirty(vcpu->kvm, gfn);
951 pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
952 set_shadow_pte(shadow_pte, spte);
953 page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
955 rmap_add(vcpu, shadow_pte, gfn);
956 if (!is_rmap_pte(*shadow_pte))
957 kvm_release_page_clean(page);
960 kvm_release_page_clean(page);
961 if (!ptwrite || !*ptwrite)
962 vcpu->last_pte_updated = shadow_pte;
965 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
969 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, struct page *page)
971 int level = PT32E_ROOT_LEVEL;
972 hpa_t table_addr = vcpu->mmu.root_hpa;
975 u32 index = PT64_INDEX(v, level);
979 ASSERT(VALID_PAGE(table_addr));
980 table = __va(table_addr);
986 was_rmapped = is_rmap_pte(pte);
987 if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {
988 kvm_release_page_clean(page);
991 mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
992 page_header_update_slot(vcpu->kvm, table,
994 table[index] = page_to_phys(page)
995 | PT_PRESENT_MASK | PT_WRITABLE_MASK
998 rmap_add(vcpu, &table[index], v >> PAGE_SHIFT);
1000 kvm_release_page_clean(page);
1005 if (table[index] == shadow_trap_nonpresent_pte) {
1006 struct kvm_mmu_page *new_table;
1009 pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
1011 new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
1013 1, ACC_ALL, &table[index]);
1015 pgprintk("nonpaging_map: ENOMEM\n");
1016 kvm_release_page_clean(page);
1020 table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
1021 | PT_WRITABLE_MASK | PT_USER_MASK;
1023 table_addr = table[index] & PT64_BASE_ADDR_MASK;
1027 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1028 struct kvm_mmu_page *sp)
1032 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1033 sp->spt[i] = shadow_trap_nonpresent_pte;
1036 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1039 struct kvm_mmu_page *sp;
1041 if (!VALID_PAGE(vcpu->mmu.root_hpa))
1043 #ifdef CONFIG_X86_64
1044 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1045 hpa_t root = vcpu->mmu.root_hpa;
1047 sp = page_header(root);
1049 vcpu->mmu.root_hpa = INVALID_PAGE;
1053 for (i = 0; i < 4; ++i) {
1054 hpa_t root = vcpu->mmu.pae_root[i];
1057 root &= PT64_BASE_ADDR_MASK;
1058 sp = page_header(root);
1061 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1063 vcpu->mmu.root_hpa = INVALID_PAGE;
1066 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1070 struct kvm_mmu_page *sp;
1072 root_gfn = vcpu->cr3 >> PAGE_SHIFT;
1074 #ifdef CONFIG_X86_64
1075 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1076 hpa_t root = vcpu->mmu.root_hpa;
1078 ASSERT(!VALID_PAGE(root));
1079 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1080 PT64_ROOT_LEVEL, 0, ACC_ALL, NULL);
1081 root = __pa(sp->spt);
1083 vcpu->mmu.root_hpa = root;
1087 for (i = 0; i < 4; ++i) {
1088 hpa_t root = vcpu->mmu.pae_root[i];
1090 ASSERT(!VALID_PAGE(root));
1091 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
1092 if (!is_present_pte(vcpu->pdptrs[i])) {
1093 vcpu->mmu.pae_root[i] = 0;
1096 root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
1097 } else if (vcpu->mmu.root_level == 0)
1099 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1100 PT32_ROOT_LEVEL, !is_paging(vcpu),
1102 root = __pa(sp->spt);
1104 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
1106 vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
1109 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1114 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1120 r = mmu_topup_memory_caches(vcpu);
1125 ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
1127 page = gfn_to_page(vcpu->kvm, gva >> PAGE_SHIFT);
1129 if (is_error_page(page)) {
1130 kvm_release_page_clean(page);
1134 return nonpaging_map(vcpu, gva & PAGE_MASK, page);
1137 static void nonpaging_free(struct kvm_vcpu *vcpu)
1139 mmu_free_roots(vcpu);
1142 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1144 struct kvm_mmu *context = &vcpu->mmu;
1146 context->new_cr3 = nonpaging_new_cr3;
1147 context->page_fault = nonpaging_page_fault;
1148 context->gva_to_gpa = nonpaging_gva_to_gpa;
1149 context->free = nonpaging_free;
1150 context->prefetch_page = nonpaging_prefetch_page;
1151 context->root_level = 0;
1152 context->shadow_root_level = PT32E_ROOT_LEVEL;
1153 context->root_hpa = INVALID_PAGE;
1157 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1159 ++vcpu->stat.tlb_flush;
1160 kvm_x86_ops->tlb_flush(vcpu);
1163 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1165 pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
1166 mmu_free_roots(vcpu);
1169 static void inject_page_fault(struct kvm_vcpu *vcpu,
1173 kvm_inject_page_fault(vcpu, addr, err_code);
1176 static void paging_free(struct kvm_vcpu *vcpu)
1178 nonpaging_free(vcpu);
1182 #include "paging_tmpl.h"
1186 #include "paging_tmpl.h"
1189 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1191 struct kvm_mmu *context = &vcpu->mmu;
1193 ASSERT(is_pae(vcpu));
1194 context->new_cr3 = paging_new_cr3;
1195 context->page_fault = paging64_page_fault;
1196 context->gva_to_gpa = paging64_gva_to_gpa;
1197 context->prefetch_page = paging64_prefetch_page;
1198 context->free = paging_free;
1199 context->root_level = level;
1200 context->shadow_root_level = level;
1201 context->root_hpa = INVALID_PAGE;
1205 static int paging64_init_context(struct kvm_vcpu *vcpu)
1207 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1210 static int paging32_init_context(struct kvm_vcpu *vcpu)
1212 struct kvm_mmu *context = &vcpu->mmu;
1214 context->new_cr3 = paging_new_cr3;
1215 context->page_fault = paging32_page_fault;
1216 context->gva_to_gpa = paging32_gva_to_gpa;
1217 context->free = paging_free;
1218 context->prefetch_page = paging32_prefetch_page;
1219 context->root_level = PT32_ROOT_LEVEL;
1220 context->shadow_root_level = PT32E_ROOT_LEVEL;
1221 context->root_hpa = INVALID_PAGE;
1225 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1227 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1230 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1233 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1235 if (!is_paging(vcpu))
1236 return nonpaging_init_context(vcpu);
1237 else if (is_long_mode(vcpu))
1238 return paging64_init_context(vcpu);
1239 else if (is_pae(vcpu))
1240 return paging32E_init_context(vcpu);
1242 return paging32_init_context(vcpu);
1245 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1248 if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1249 vcpu->mmu.free(vcpu);
1250 vcpu->mmu.root_hpa = INVALID_PAGE;
1254 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1256 destroy_kvm_mmu(vcpu);
1257 return init_kvm_mmu(vcpu);
1259 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1261 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1265 mutex_lock(&vcpu->kvm->lock);
1266 r = mmu_topup_memory_caches(vcpu);
1269 mmu_alloc_roots(vcpu);
1270 kvm_x86_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
1271 kvm_mmu_flush_tlb(vcpu);
1273 mutex_unlock(&vcpu->kvm->lock);
1276 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1278 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1280 mmu_free_roots(vcpu);
1283 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1284 struct kvm_mmu_page *sp,
1288 struct kvm_mmu_page *child;
1291 if (is_shadow_present_pte(pte)) {
1292 if (sp->role.level == PT_PAGE_TABLE_LEVEL)
1293 rmap_remove(vcpu->kvm, spte);
1295 child = page_header(pte & PT64_BASE_ADDR_MASK);
1296 mmu_page_remove_parent_pte(child, spte);
1299 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1302 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1303 struct kvm_mmu_page *sp,
1305 const void *new, int bytes,
1308 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1309 ++vcpu->kvm->stat.mmu_pde_zapped;
1313 ++vcpu->kvm->stat.mmu_pte_updated;
1314 if (sp->role.glevels == PT32_ROOT_LEVEL)
1315 paging32_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1317 paging64_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1320 static bool need_remote_flush(u64 old, u64 new)
1322 if (!is_shadow_present_pte(old))
1324 if (!is_shadow_present_pte(new))
1326 if ((old ^ new) & PT64_BASE_ADDR_MASK)
1328 old ^= PT64_NX_MASK;
1329 new ^= PT64_NX_MASK;
1330 return (old & ~new & PT64_PERM_MASK) != 0;
1333 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1335 if (need_remote_flush(old, new))
1336 kvm_flush_remote_tlbs(vcpu->kvm);
1338 kvm_mmu_flush_tlb(vcpu);
1341 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1343 u64 *spte = vcpu->last_pte_updated;
1345 return !!(spte && (*spte & PT_ACCESSED_MASK));
1348 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1349 const u8 *new, int bytes)
1351 gfn_t gfn = gpa >> PAGE_SHIFT;
1352 struct kvm_mmu_page *sp;
1353 struct hlist_node *node, *n;
1354 struct hlist_head *bucket;
1358 unsigned offset = offset_in_page(gpa);
1360 unsigned page_offset;
1361 unsigned misaligned;
1367 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1368 ++vcpu->kvm->stat.mmu_pte_write;
1369 kvm_mmu_audit(vcpu, "pre pte write");
1370 if (gfn == vcpu->last_pt_write_gfn
1371 && !last_updated_pte_accessed(vcpu)) {
1372 ++vcpu->last_pt_write_count;
1373 if (vcpu->last_pt_write_count >= 3)
1376 vcpu->last_pt_write_gfn = gfn;
1377 vcpu->last_pt_write_count = 1;
1378 vcpu->last_pte_updated = NULL;
1380 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1381 bucket = &vcpu->kvm->mmu_page_hash[index];
1382 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1383 if (sp->gfn != gfn || sp->role.metaphysical)
1385 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1386 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1387 misaligned |= bytes < 4;
1388 if (misaligned || flooded) {
1390 * Misaligned accesses are too much trouble to fix
1391 * up; also, they usually indicate a page is not used
1394 * If we're seeing too many writes to a page,
1395 * it may no longer be a page table, or we may be
1396 * forking, in which case it is better to unmap the
1399 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1400 gpa, bytes, sp->role.word);
1401 kvm_mmu_zap_page(vcpu->kvm, sp);
1402 ++vcpu->kvm->stat.mmu_flooded;
1405 page_offset = offset;
1406 level = sp->role.level;
1408 if (sp->role.glevels == PT32_ROOT_LEVEL) {
1409 page_offset <<= 1; /* 32->64 */
1411 * A 32-bit pde maps 4MB while the shadow pdes map
1412 * only 2MB. So we need to double the offset again
1413 * and zap two pdes instead of one.
1415 if (level == PT32_ROOT_LEVEL) {
1416 page_offset &= ~7; /* kill rounding error */
1420 quadrant = page_offset >> PAGE_SHIFT;
1421 page_offset &= ~PAGE_MASK;
1422 if (quadrant != sp->role.quadrant)
1425 spte = &sp->spt[page_offset / sizeof(*spte)];
1428 mmu_pte_write_zap_pte(vcpu, sp, spte);
1429 mmu_pte_write_new_pte(vcpu, sp, spte, new, bytes,
1430 page_offset & (pte_size - 1));
1431 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
1435 kvm_mmu_audit(vcpu, "post pte write");
1438 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1440 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1442 return kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1445 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1447 while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1448 struct kvm_mmu_page *sp;
1450 sp = container_of(vcpu->kvm->active_mmu_pages.prev,
1451 struct kvm_mmu_page, link);
1452 kvm_mmu_zap_page(vcpu->kvm, sp);
1453 ++vcpu->kvm->stat.mmu_recycled;
1457 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
1460 enum emulation_result er;
1462 mutex_lock(&vcpu->kvm->lock);
1463 r = vcpu->mmu.page_fault(vcpu, cr2, error_code);
1472 r = mmu_topup_memory_caches(vcpu);
1476 er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
1477 mutex_unlock(&vcpu->kvm->lock);
1482 case EMULATE_DO_MMIO:
1483 ++vcpu->stat.mmio_exits;
1486 kvm_report_emulation_failure(vcpu, "pagetable");
1492 mutex_unlock(&vcpu->kvm->lock);
1495 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
1497 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1499 struct kvm_mmu_page *sp;
1501 while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1502 sp = container_of(vcpu->kvm->active_mmu_pages.next,
1503 struct kvm_mmu_page, link);
1504 kvm_mmu_zap_page(vcpu->kvm, sp);
1506 free_page((unsigned long)vcpu->mmu.pae_root);
1509 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1516 if (vcpu->kvm->n_requested_mmu_pages)
1517 vcpu->kvm->n_free_mmu_pages = vcpu->kvm->n_requested_mmu_pages;
1519 vcpu->kvm->n_free_mmu_pages = vcpu->kvm->n_alloc_mmu_pages;
1521 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1522 * Therefore we need to allocate shadow page tables in the first
1523 * 4GB of memory, which happens to fit the DMA32 zone.
1525 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1528 vcpu->mmu.pae_root = page_address(page);
1529 for (i = 0; i < 4; ++i)
1530 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1535 free_mmu_pages(vcpu);
1539 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1542 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1544 return alloc_mmu_pages(vcpu);
1547 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1550 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1552 return init_kvm_mmu(vcpu);
1555 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1559 destroy_kvm_mmu(vcpu);
1560 free_mmu_pages(vcpu);
1561 mmu_free_memory_caches(vcpu);
1564 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1566 struct kvm_mmu_page *sp;
1568 list_for_each_entry(sp, &kvm->active_mmu_pages, link) {
1572 if (!test_bit(slot, &sp->slot_bitmap))
1576 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1578 if (pt[i] & PT_WRITABLE_MASK)
1579 pt[i] &= ~PT_WRITABLE_MASK;
1583 void kvm_mmu_zap_all(struct kvm *kvm)
1585 struct kvm_mmu_page *sp, *node;
1587 list_for_each_entry_safe(sp, node, &kvm->active_mmu_pages, link)
1588 kvm_mmu_zap_page(kvm, sp);
1590 kvm_flush_remote_tlbs(kvm);
1593 void kvm_mmu_module_exit(void)
1595 if (pte_chain_cache)
1596 kmem_cache_destroy(pte_chain_cache);
1597 if (rmap_desc_cache)
1598 kmem_cache_destroy(rmap_desc_cache);
1599 if (mmu_page_header_cache)
1600 kmem_cache_destroy(mmu_page_header_cache);
1603 int kvm_mmu_module_init(void)
1605 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1606 sizeof(struct kvm_pte_chain),
1608 if (!pte_chain_cache)
1610 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1611 sizeof(struct kvm_rmap_desc),
1613 if (!rmap_desc_cache)
1616 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1617 sizeof(struct kvm_mmu_page),
1619 if (!mmu_page_header_cache)
1625 kvm_mmu_module_exit();
1630 * Caculate mmu pages needed for kvm.
1632 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
1635 unsigned int nr_mmu_pages;
1636 unsigned int nr_pages = 0;
1638 for (i = 0; i < kvm->nmemslots; i++)
1639 nr_pages += kvm->memslots[i].npages;
1641 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
1642 nr_mmu_pages = max(nr_mmu_pages,
1643 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
1645 return nr_mmu_pages;
1650 static const char *audit_msg;
1652 static gva_t canonicalize(gva_t gva)
1654 #ifdef CONFIG_X86_64
1655 gva = (long long)(gva << 16) >> 16;
1660 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1661 gva_t va, int level)
1663 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1665 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1667 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1670 if (ent == shadow_trap_nonpresent_pte)
1673 va = canonicalize(va);
1675 if (ent == shadow_notrap_nonpresent_pte)
1676 printk(KERN_ERR "audit: (%s) nontrapping pte"
1677 " in nonleaf level: levels %d gva %lx"
1678 " level %d pte %llx\n", audit_msg,
1679 vcpu->mmu.root_level, va, level, ent);
1681 audit_mappings_page(vcpu, ent, va, level - 1);
1683 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1684 struct page *page = gpa_to_page(vcpu, gpa);
1685 hpa_t hpa = page_to_phys(page);
1687 if (is_shadow_present_pte(ent)
1688 && (ent & PT64_BASE_ADDR_MASK) != hpa)
1689 printk(KERN_ERR "xx audit error: (%s) levels %d"
1690 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1691 audit_msg, vcpu->mmu.root_level,
1693 is_shadow_present_pte(ent));
1694 else if (ent == shadow_notrap_nonpresent_pte
1695 && !is_error_hpa(hpa))
1696 printk(KERN_ERR "audit: (%s) notrap shadow,"
1697 " valid guest gva %lx\n", audit_msg, va);
1698 kvm_release_page_clean(page);
1704 static void audit_mappings(struct kvm_vcpu *vcpu)
1708 if (vcpu->mmu.root_level == 4)
1709 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1711 for (i = 0; i < 4; ++i)
1712 if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1713 audit_mappings_page(vcpu,
1714 vcpu->mmu.pae_root[i],
1719 static int count_rmaps(struct kvm_vcpu *vcpu)
1724 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1725 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1726 struct kvm_rmap_desc *d;
1728 for (j = 0; j < m->npages; ++j) {
1729 unsigned long *rmapp = &m->rmap[j];
1733 if (!(*rmapp & 1)) {
1737 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
1739 for (k = 0; k < RMAP_EXT; ++k)
1740 if (d->shadow_ptes[k])
1751 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1754 struct kvm_mmu_page *sp;
1757 list_for_each_entry(sp, &vcpu->kvm->active_mmu_pages, link) {
1760 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
1763 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1766 if (!(ent & PT_PRESENT_MASK))
1768 if (!(ent & PT_WRITABLE_MASK))
1776 static void audit_rmap(struct kvm_vcpu *vcpu)
1778 int n_rmap = count_rmaps(vcpu);
1779 int n_actual = count_writable_mappings(vcpu);
1781 if (n_rmap != n_actual)
1782 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1783 __FUNCTION__, audit_msg, n_rmap, n_actual);
1786 static void audit_write_protection(struct kvm_vcpu *vcpu)
1788 struct kvm_mmu_page *sp;
1789 struct kvm_memory_slot *slot;
1790 unsigned long *rmapp;
1793 list_for_each_entry(sp, &vcpu->kvm->active_mmu_pages, link) {
1794 if (sp->role.metaphysical)
1797 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
1798 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
1799 rmapp = &slot->rmap[gfn - slot->base_gfn];
1801 printk(KERN_ERR "%s: (%s) shadow page has writable"
1802 " mappings: gfn %lx role %x\n",
1803 __FUNCTION__, audit_msg, sp->gfn,
1808 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1815 audit_write_protection(vcpu);
1816 audit_mappings(vcpu);