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.
19 #include <linux/types.h>
20 #include <linux/string.h>
23 #include <linux/highmem.h>
24 #include <linux/module.h>
34 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
36 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
41 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
42 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
46 #define pgprintk(x...) do { } while (0)
47 #define rmap_printk(x...) do { } while (0)
51 #if defined(MMU_DEBUG) || defined(AUDIT)
56 #define ASSERT(x) do { } while (0)
60 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
61 __FILE__, __LINE__, #x); \
65 #define PT64_PT_BITS 9
66 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
67 #define PT32_PT_BITS 10
68 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
70 #define PT_WRITABLE_SHIFT 1
72 #define PT_PRESENT_MASK (1ULL << 0)
73 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
74 #define PT_USER_MASK (1ULL << 2)
75 #define PT_PWT_MASK (1ULL << 3)
76 #define PT_PCD_MASK (1ULL << 4)
77 #define PT_ACCESSED_MASK (1ULL << 5)
78 #define PT_DIRTY_MASK (1ULL << 6)
79 #define PT_PAGE_SIZE_MASK (1ULL << 7)
80 #define PT_PAT_MASK (1ULL << 7)
81 #define PT_GLOBAL_MASK (1ULL << 8)
82 #define PT64_NX_MASK (1ULL << 63)
84 #define PT_PAT_SHIFT 7
85 #define PT_DIR_PAT_SHIFT 12
86 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
88 #define PT32_DIR_PSE36_SIZE 4
89 #define PT32_DIR_PSE36_SHIFT 13
90 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
93 #define PT32_PTE_COPY_MASK \
94 (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK)
96 #define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK)
98 #define PT_FIRST_AVAIL_BITS_SHIFT 9
99 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
101 #define PT_SHADOW_PS_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
102 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
104 #define PT_SHADOW_WRITABLE_SHIFT (PT_FIRST_AVAIL_BITS_SHIFT + 1)
105 #define PT_SHADOW_WRITABLE_MASK (1ULL << PT_SHADOW_WRITABLE_SHIFT)
107 #define PT_SHADOW_USER_SHIFT (PT_SHADOW_WRITABLE_SHIFT + 1)
108 #define PT_SHADOW_USER_MASK (1ULL << (PT_SHADOW_USER_SHIFT))
110 #define PT_SHADOW_BITS_OFFSET (PT_SHADOW_WRITABLE_SHIFT - PT_WRITABLE_SHIFT)
112 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
114 #define PT64_LEVEL_BITS 9
116 #define PT64_LEVEL_SHIFT(level) \
117 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
119 #define PT64_LEVEL_MASK(level) \
120 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
122 #define PT64_INDEX(address, level)\
123 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
126 #define PT32_LEVEL_BITS 10
128 #define PT32_LEVEL_SHIFT(level) \
129 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
131 #define PT32_LEVEL_MASK(level) \
132 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
134 #define PT32_INDEX(address, level)\
135 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
138 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
139 #define PT64_DIR_BASE_ADDR_MASK \
140 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
142 #define PT32_BASE_ADDR_MASK PAGE_MASK
143 #define PT32_DIR_BASE_ADDR_MASK \
144 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
147 #define PFERR_PRESENT_MASK (1U << 0)
148 #define PFERR_WRITE_MASK (1U << 1)
149 #define PFERR_USER_MASK (1U << 2)
150 #define PFERR_FETCH_MASK (1U << 4)
152 #define PT64_ROOT_LEVEL 4
153 #define PT32_ROOT_LEVEL 2
154 #define PT32E_ROOT_LEVEL 3
156 #define PT_DIRECTORY_LEVEL 2
157 #define PT_PAGE_TABLE_LEVEL 1
161 struct kvm_rmap_desc {
162 u64 *shadow_ptes[RMAP_EXT];
163 struct kvm_rmap_desc *more;
166 static struct kmem_cache *pte_chain_cache;
167 static struct kmem_cache *rmap_desc_cache;
168 static struct kmem_cache *mmu_page_cache;
169 static struct kmem_cache *mmu_page_header_cache;
171 static int is_write_protection(struct kvm_vcpu *vcpu)
173 return vcpu->cr0 & CR0_WP_MASK;
176 static int is_cpuid_PSE36(void)
181 static int is_nx(struct kvm_vcpu *vcpu)
183 return vcpu->shadow_efer & EFER_NX;
186 static int is_present_pte(unsigned long pte)
188 return pte & PT_PRESENT_MASK;
191 static int is_writeble_pte(unsigned long pte)
193 return pte & PT_WRITABLE_MASK;
196 static int is_io_pte(unsigned long pte)
198 return pte & PT_SHADOW_IO_MARK;
201 static int is_rmap_pte(u64 pte)
203 return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
204 == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
207 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
208 struct kmem_cache *base_cache, int min,
213 if (cache->nobjs >= min)
215 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
216 obj = kmem_cache_zalloc(base_cache, gfp_flags);
219 cache->objects[cache->nobjs++] = obj;
224 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
227 kfree(mc->objects[--mc->nobjs]);
230 static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags)
234 r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
235 pte_chain_cache, 4, gfp_flags);
238 r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
239 rmap_desc_cache, 1, gfp_flags);
242 r = mmu_topup_memory_cache(&vcpu->mmu_page_cache,
243 mmu_page_cache, 4, gfp_flags);
246 r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
247 mmu_page_header_cache, 4, gfp_flags);
252 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
256 r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
258 spin_unlock(&vcpu->kvm->lock);
259 kvm_arch_ops->vcpu_put(vcpu);
260 r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
261 kvm_arch_ops->vcpu_load(vcpu);
262 spin_lock(&vcpu->kvm->lock);
267 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
269 mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
270 mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
271 mmu_free_memory_cache(&vcpu->mmu_page_cache);
272 mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
275 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
281 p = mc->objects[--mc->nobjs];
286 static void mmu_memory_cache_free(struct kvm_mmu_memory_cache *mc, void *obj)
288 if (mc->nobjs < KVM_NR_MEM_OBJS)
289 mc->objects[mc->nobjs++] = obj;
294 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
296 return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
297 sizeof(struct kvm_pte_chain));
300 static void mmu_free_pte_chain(struct kvm_vcpu *vcpu,
301 struct kvm_pte_chain *pc)
303 mmu_memory_cache_free(&vcpu->mmu_pte_chain_cache, pc);
306 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
308 return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
309 sizeof(struct kvm_rmap_desc));
312 static void mmu_free_rmap_desc(struct kvm_vcpu *vcpu,
313 struct kvm_rmap_desc *rd)
315 mmu_memory_cache_free(&vcpu->mmu_rmap_desc_cache, rd);
319 * Reverse mapping data structures:
321 * If page->private bit zero is zero, then page->private points to the
322 * shadow page table entry that points to page_address(page).
324 * If page->private bit zero is one, (then page->private & ~1) points
325 * to a struct kvm_rmap_desc containing more mappings.
327 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
330 struct kvm_rmap_desc *desc;
333 if (!is_rmap_pte(*spte))
335 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
336 if (!page_private(page)) {
337 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
338 set_page_private(page,(unsigned long)spte);
339 } else if (!(page_private(page) & 1)) {
340 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
341 desc = mmu_alloc_rmap_desc(vcpu);
342 desc->shadow_ptes[0] = (u64 *)page_private(page);
343 desc->shadow_ptes[1] = spte;
344 set_page_private(page,(unsigned long)desc | 1);
346 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
347 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
348 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
350 if (desc->shadow_ptes[RMAP_EXT-1]) {
351 desc->more = mmu_alloc_rmap_desc(vcpu);
354 for (i = 0; desc->shadow_ptes[i]; ++i)
356 desc->shadow_ptes[i] = spte;
360 static void rmap_desc_remove_entry(struct kvm_vcpu *vcpu,
362 struct kvm_rmap_desc *desc,
364 struct kvm_rmap_desc *prev_desc)
368 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
370 desc->shadow_ptes[i] = desc->shadow_ptes[j];
371 desc->shadow_ptes[j] = NULL;
374 if (!prev_desc && !desc->more)
375 set_page_private(page,(unsigned long)desc->shadow_ptes[0]);
378 prev_desc->more = desc->more;
380 set_page_private(page,(unsigned long)desc->more | 1);
381 mmu_free_rmap_desc(vcpu, desc);
384 static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte)
387 struct kvm_rmap_desc *desc;
388 struct kvm_rmap_desc *prev_desc;
391 if (!is_rmap_pte(*spte))
393 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
394 if (!page_private(page)) {
395 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
397 } else if (!(page_private(page) & 1)) {
398 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
399 if ((u64 *)page_private(page) != spte) {
400 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
404 set_page_private(page,0);
406 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
407 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
410 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
411 if (desc->shadow_ptes[i] == spte) {
412 rmap_desc_remove_entry(vcpu, page,
424 static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
426 struct kvm *kvm = vcpu->kvm;
428 struct kvm_rmap_desc *desc;
431 page = gfn_to_page(kvm, gfn);
434 while (page_private(page)) {
435 if (!(page_private(page) & 1))
436 spte = (u64 *)page_private(page);
438 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
439 spte = desc->shadow_ptes[0];
442 BUG_ON((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT
443 != page_to_pfn(page));
444 BUG_ON(!(*spte & PT_PRESENT_MASK));
445 BUG_ON(!(*spte & PT_WRITABLE_MASK));
446 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
447 rmap_remove(vcpu, spte);
448 kvm_arch_ops->tlb_flush(vcpu);
449 *spte &= ~(u64)PT_WRITABLE_MASK;
454 static int is_empty_shadow_page(u64 *spt)
459 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
461 printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
469 static void kvm_mmu_free_page(struct kvm_vcpu *vcpu,
470 struct kvm_mmu_page *page_head)
472 ASSERT(is_empty_shadow_page(page_head->spt));
473 list_del(&page_head->link);
474 mmu_memory_cache_free(&vcpu->mmu_page_cache, page_head->spt);
475 mmu_memory_cache_free(&vcpu->mmu_page_header_cache, page_head);
476 ++vcpu->kvm->n_free_mmu_pages;
479 static unsigned kvm_page_table_hashfn(gfn_t gfn)
484 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
487 struct kvm_mmu_page *page;
489 if (!vcpu->kvm->n_free_mmu_pages)
492 page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache,
494 page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
495 set_page_private(virt_to_page(page->spt), (unsigned long)page);
496 list_add(&page->link, &vcpu->kvm->active_mmu_pages);
497 ASSERT(is_empty_shadow_page(page->spt));
498 page->slot_bitmap = 0;
499 page->multimapped = 0;
500 page->parent_pte = parent_pte;
501 --vcpu->kvm->n_free_mmu_pages;
505 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
506 struct kvm_mmu_page *page, u64 *parent_pte)
508 struct kvm_pte_chain *pte_chain;
509 struct hlist_node *node;
514 if (!page->multimapped) {
515 u64 *old = page->parent_pte;
518 page->parent_pte = parent_pte;
521 page->multimapped = 1;
522 pte_chain = mmu_alloc_pte_chain(vcpu);
523 INIT_HLIST_HEAD(&page->parent_ptes);
524 hlist_add_head(&pte_chain->link, &page->parent_ptes);
525 pte_chain->parent_ptes[0] = old;
527 hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
528 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
530 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
531 if (!pte_chain->parent_ptes[i]) {
532 pte_chain->parent_ptes[i] = parent_pte;
536 pte_chain = mmu_alloc_pte_chain(vcpu);
538 hlist_add_head(&pte_chain->link, &page->parent_ptes);
539 pte_chain->parent_ptes[0] = parent_pte;
542 static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu,
543 struct kvm_mmu_page *page,
546 struct kvm_pte_chain *pte_chain;
547 struct hlist_node *node;
550 if (!page->multimapped) {
551 BUG_ON(page->parent_pte != parent_pte);
552 page->parent_pte = NULL;
555 hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
556 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
557 if (!pte_chain->parent_ptes[i])
559 if (pte_chain->parent_ptes[i] != parent_pte)
561 while (i + 1 < NR_PTE_CHAIN_ENTRIES
562 && pte_chain->parent_ptes[i + 1]) {
563 pte_chain->parent_ptes[i]
564 = pte_chain->parent_ptes[i + 1];
567 pte_chain->parent_ptes[i] = NULL;
569 hlist_del(&pte_chain->link);
570 mmu_free_pte_chain(vcpu, pte_chain);
571 if (hlist_empty(&page->parent_ptes)) {
572 page->multimapped = 0;
573 page->parent_pte = NULL;
581 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
585 struct hlist_head *bucket;
586 struct kvm_mmu_page *page;
587 struct hlist_node *node;
589 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
590 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
591 bucket = &vcpu->kvm->mmu_page_hash[index];
592 hlist_for_each_entry(page, node, bucket, hash_link)
593 if (page->gfn == gfn && !page->role.metaphysical) {
594 pgprintk("%s: found role %x\n",
595 __FUNCTION__, page->role.word);
601 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
606 unsigned hugepage_access,
609 union kvm_mmu_page_role role;
612 struct hlist_head *bucket;
613 struct kvm_mmu_page *page;
614 struct hlist_node *node;
617 role.glevels = vcpu->mmu.root_level;
619 role.metaphysical = metaphysical;
620 role.hugepage_access = hugepage_access;
621 if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
622 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
623 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
624 role.quadrant = quadrant;
626 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
628 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
629 bucket = &vcpu->kvm->mmu_page_hash[index];
630 hlist_for_each_entry(page, node, bucket, hash_link)
631 if (page->gfn == gfn && page->role.word == role.word) {
632 mmu_page_add_parent_pte(vcpu, page, parent_pte);
633 pgprintk("%s: found\n", __FUNCTION__);
636 page = kvm_mmu_alloc_page(vcpu, parent_pte);
639 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
642 hlist_add_head(&page->hash_link, bucket);
644 rmap_write_protect(vcpu, gfn);
648 static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
649 struct kvm_mmu_page *page)
657 if (page->role.level == PT_PAGE_TABLE_LEVEL) {
658 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
659 if (pt[i] & PT_PRESENT_MASK)
660 rmap_remove(vcpu, &pt[i]);
663 kvm_arch_ops->tlb_flush(vcpu);
667 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
671 if (!(ent & PT_PRESENT_MASK))
673 ent &= PT64_BASE_ADDR_MASK;
674 mmu_page_remove_parent_pte(vcpu, page_header(ent), &pt[i]);
678 static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
679 struct kvm_mmu_page *page,
682 mmu_page_remove_parent_pte(vcpu, page, parent_pte);
685 static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
686 struct kvm_mmu_page *page)
690 while (page->multimapped || page->parent_pte) {
691 if (!page->multimapped)
692 parent_pte = page->parent_pte;
694 struct kvm_pte_chain *chain;
696 chain = container_of(page->parent_ptes.first,
697 struct kvm_pte_chain, link);
698 parent_pte = chain->parent_ptes[0];
701 kvm_mmu_put_page(vcpu, page, parent_pte);
704 kvm_mmu_page_unlink_children(vcpu, page);
705 if (!page->root_count) {
706 hlist_del(&page->hash_link);
707 kvm_mmu_free_page(vcpu, page);
709 list_move(&page->link, &vcpu->kvm->active_mmu_pages);
712 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
715 struct hlist_head *bucket;
716 struct kvm_mmu_page *page;
717 struct hlist_node *node, *n;
720 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
722 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
723 bucket = &vcpu->kvm->mmu_page_hash[index];
724 hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
725 if (page->gfn == gfn && !page->role.metaphysical) {
726 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
728 kvm_mmu_zap_page(vcpu, page);
734 static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
736 struct kvm_mmu_page *page;
738 while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
739 pgprintk("%s: zap %lx %x\n",
740 __FUNCTION__, gfn, page->role.word);
741 kvm_mmu_zap_page(vcpu, page);
745 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
747 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
748 struct kvm_mmu_page *page_head = page_header(__pa(pte));
750 __set_bit(slot, &page_head->slot_bitmap);
753 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
755 hpa_t hpa = gpa_to_hpa(vcpu, gpa);
757 return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
760 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
764 ASSERT((gpa & HPA_ERR_MASK) == 0);
765 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
767 return gpa | HPA_ERR_MASK;
768 return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
769 | (gpa & (PAGE_SIZE-1));
772 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
774 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
776 if (gpa == UNMAPPED_GVA)
778 return gpa_to_hpa(vcpu, gpa);
781 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
783 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
785 if (gpa == UNMAPPED_GVA)
787 return pfn_to_page(gpa_to_hpa(vcpu, gpa) >> PAGE_SHIFT);
790 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
794 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
796 int level = PT32E_ROOT_LEVEL;
797 hpa_t table_addr = vcpu->mmu.root_hpa;
800 u32 index = PT64_INDEX(v, level);
804 ASSERT(VALID_PAGE(table_addr));
805 table = __va(table_addr);
809 if (is_present_pte(pte) && is_writeble_pte(pte))
811 mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
812 page_header_update_slot(vcpu->kvm, table, v);
813 table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
815 rmap_add(vcpu, &table[index]);
819 if (table[index] == 0) {
820 struct kvm_mmu_page *new_table;
823 pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
825 new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
827 1, 0, &table[index]);
829 pgprintk("nonpaging_map: ENOMEM\n");
833 table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
834 | PT_WRITABLE_MASK | PT_USER_MASK;
836 table_addr = table[index] & PT64_BASE_ADDR_MASK;
840 static void mmu_free_roots(struct kvm_vcpu *vcpu)
843 struct kvm_mmu_page *page;
846 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
847 hpa_t root = vcpu->mmu.root_hpa;
849 ASSERT(VALID_PAGE(root));
850 page = page_header(root);
852 vcpu->mmu.root_hpa = INVALID_PAGE;
856 for (i = 0; i < 4; ++i) {
857 hpa_t root = vcpu->mmu.pae_root[i];
860 ASSERT(VALID_PAGE(root));
861 root &= PT64_BASE_ADDR_MASK;
862 page = page_header(root);
865 vcpu->mmu.pae_root[i] = INVALID_PAGE;
867 vcpu->mmu.root_hpa = INVALID_PAGE;
870 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
874 struct kvm_mmu_page *page;
876 root_gfn = vcpu->cr3 >> PAGE_SHIFT;
879 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
880 hpa_t root = vcpu->mmu.root_hpa;
882 ASSERT(!VALID_PAGE(root));
883 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
884 PT64_ROOT_LEVEL, 0, 0, NULL);
885 root = __pa(page->spt);
887 vcpu->mmu.root_hpa = root;
891 for (i = 0; i < 4; ++i) {
892 hpa_t root = vcpu->mmu.pae_root[i];
894 ASSERT(!VALID_PAGE(root));
895 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
896 if (!is_present_pte(vcpu->pdptrs[i])) {
897 vcpu->mmu.pae_root[i] = 0;
900 root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
901 } else if (vcpu->mmu.root_level == 0)
903 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
904 PT32_ROOT_LEVEL, !is_paging(vcpu),
906 root = __pa(page->spt);
908 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
910 vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
913 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
918 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
925 r = mmu_topup_memory_caches(vcpu);
930 ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
933 paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
935 if (is_error_hpa(paddr))
938 return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
941 static void nonpaging_free(struct kvm_vcpu *vcpu)
943 mmu_free_roots(vcpu);
946 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
948 struct kvm_mmu *context = &vcpu->mmu;
950 context->new_cr3 = nonpaging_new_cr3;
951 context->page_fault = nonpaging_page_fault;
952 context->gva_to_gpa = nonpaging_gva_to_gpa;
953 context->free = nonpaging_free;
954 context->root_level = 0;
955 context->shadow_root_level = PT32E_ROOT_LEVEL;
956 mmu_alloc_roots(vcpu);
957 ASSERT(VALID_PAGE(context->root_hpa));
958 kvm_arch_ops->set_cr3(vcpu, context->root_hpa);
962 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
964 ++vcpu->stat.tlb_flush;
965 kvm_arch_ops->tlb_flush(vcpu);
968 static void paging_new_cr3(struct kvm_vcpu *vcpu)
970 pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
971 mmu_free_roots(vcpu);
972 if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES))
973 kvm_mmu_free_some_pages(vcpu);
974 mmu_alloc_roots(vcpu);
975 kvm_mmu_flush_tlb(vcpu);
976 kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
979 static void inject_page_fault(struct kvm_vcpu *vcpu,
983 kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
986 static void paging_free(struct kvm_vcpu *vcpu)
988 nonpaging_free(vcpu);
992 #include "paging_tmpl.h"
996 #include "paging_tmpl.h"
999 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1001 struct kvm_mmu *context = &vcpu->mmu;
1003 ASSERT(is_pae(vcpu));
1004 context->new_cr3 = paging_new_cr3;
1005 context->page_fault = paging64_page_fault;
1006 context->gva_to_gpa = paging64_gva_to_gpa;
1007 context->free = paging_free;
1008 context->root_level = level;
1009 context->shadow_root_level = level;
1010 mmu_alloc_roots(vcpu);
1011 ASSERT(VALID_PAGE(context->root_hpa));
1012 kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
1013 (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
1017 static int paging64_init_context(struct kvm_vcpu *vcpu)
1019 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1022 static int paging32_init_context(struct kvm_vcpu *vcpu)
1024 struct kvm_mmu *context = &vcpu->mmu;
1026 context->new_cr3 = paging_new_cr3;
1027 context->page_fault = paging32_page_fault;
1028 context->gva_to_gpa = paging32_gva_to_gpa;
1029 context->free = paging_free;
1030 context->root_level = PT32_ROOT_LEVEL;
1031 context->shadow_root_level = PT32E_ROOT_LEVEL;
1032 mmu_alloc_roots(vcpu);
1033 ASSERT(VALID_PAGE(context->root_hpa));
1034 kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
1035 (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
1039 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1041 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1044 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1047 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1049 mmu_topup_memory_caches(vcpu);
1050 if (!is_paging(vcpu))
1051 return nonpaging_init_context(vcpu);
1052 else if (is_long_mode(vcpu))
1053 return paging64_init_context(vcpu);
1054 else if (is_pae(vcpu))
1055 return paging32E_init_context(vcpu);
1057 return paging32_init_context(vcpu);
1060 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1063 if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1064 vcpu->mmu.free(vcpu);
1065 vcpu->mmu.root_hpa = INVALID_PAGE;
1069 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1073 destroy_kvm_mmu(vcpu);
1074 r = init_kvm_mmu(vcpu);
1077 r = mmu_topup_memory_caches(vcpu);
1082 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1083 struct kvm_mmu_page *page,
1087 struct kvm_mmu_page *child;
1090 if (is_present_pte(pte)) {
1091 if (page->role.level == PT_PAGE_TABLE_LEVEL)
1092 rmap_remove(vcpu, spte);
1094 child = page_header(pte & PT64_BASE_ADDR_MASK);
1095 mmu_page_remove_parent_pte(vcpu, child, spte);
1101 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1102 struct kvm_mmu_page *page,
1104 const void *new, int bytes)
1106 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1109 if (page->role.glevels == PT32_ROOT_LEVEL)
1110 paging32_update_pte(vcpu, page, spte, new, bytes);
1112 paging64_update_pte(vcpu, page, spte, new, bytes);
1115 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1116 const u8 *old, const u8 *new, int bytes)
1118 gfn_t gfn = gpa >> PAGE_SHIFT;
1119 struct kvm_mmu_page *page;
1120 struct hlist_node *node, *n;
1121 struct hlist_head *bucket;
1124 unsigned offset = offset_in_page(gpa);
1126 unsigned page_offset;
1127 unsigned misaligned;
1133 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1134 if (gfn == vcpu->last_pt_write_gfn) {
1135 ++vcpu->last_pt_write_count;
1136 if (vcpu->last_pt_write_count >= 3)
1139 vcpu->last_pt_write_gfn = gfn;
1140 vcpu->last_pt_write_count = 1;
1142 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1143 bucket = &vcpu->kvm->mmu_page_hash[index];
1144 hlist_for_each_entry_safe(page, node, n, bucket, hash_link) {
1145 if (page->gfn != gfn || page->role.metaphysical)
1147 pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1148 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1149 misaligned |= bytes < 4;
1150 if (misaligned || flooded) {
1152 * Misaligned accesses are too much trouble to fix
1153 * up; also, they usually indicate a page is not used
1156 * If we're seeing too many writes to a page,
1157 * it may no longer be a page table, or we may be
1158 * forking, in which case it is better to unmap the
1161 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1162 gpa, bytes, page->role.word);
1163 kvm_mmu_zap_page(vcpu, page);
1166 page_offset = offset;
1167 level = page->role.level;
1169 if (page->role.glevels == PT32_ROOT_LEVEL) {
1170 page_offset <<= 1; /* 32->64 */
1172 * A 32-bit pde maps 4MB while the shadow pdes map
1173 * only 2MB. So we need to double the offset again
1174 * and zap two pdes instead of one.
1176 if (level == PT32_ROOT_LEVEL) {
1177 page_offset &= ~7; /* kill rounding error */
1181 quadrant = page_offset >> PAGE_SHIFT;
1182 page_offset &= ~PAGE_MASK;
1183 if (quadrant != page->role.quadrant)
1186 spte = &page->spt[page_offset / sizeof(*spte)];
1188 mmu_pte_write_zap_pte(vcpu, page, spte);
1189 mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
1195 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1197 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1199 return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
1202 void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1204 while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1205 struct kvm_mmu_page *page;
1207 page = container_of(vcpu->kvm->active_mmu_pages.prev,
1208 struct kvm_mmu_page, link);
1209 kvm_mmu_zap_page(vcpu, page);
1212 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
1214 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1216 struct kvm_mmu_page *page;
1218 while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1219 page = container_of(vcpu->kvm->active_mmu_pages.next,
1220 struct kvm_mmu_page, link);
1221 kvm_mmu_zap_page(vcpu, page);
1223 free_page((unsigned long)vcpu->mmu.pae_root);
1226 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1233 vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES;
1236 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1237 * Therefore we need to allocate shadow page tables in the first
1238 * 4GB of memory, which happens to fit the DMA32 zone.
1240 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1243 vcpu->mmu.pae_root = page_address(page);
1244 for (i = 0; i < 4; ++i)
1245 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1250 free_mmu_pages(vcpu);
1254 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1257 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1259 return alloc_mmu_pages(vcpu);
1262 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1265 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1267 return init_kvm_mmu(vcpu);
1270 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1274 destroy_kvm_mmu(vcpu);
1275 free_mmu_pages(vcpu);
1276 mmu_free_memory_caches(vcpu);
1279 void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
1281 struct kvm *kvm = vcpu->kvm;
1282 struct kvm_mmu_page *page;
1284 list_for_each_entry(page, &kvm->active_mmu_pages, link) {
1288 if (!test_bit(slot, &page->slot_bitmap))
1292 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1294 if (pt[i] & PT_WRITABLE_MASK) {
1295 rmap_remove(vcpu, &pt[i]);
1296 pt[i] &= ~PT_WRITABLE_MASK;
1301 void kvm_mmu_zap_all(struct kvm_vcpu *vcpu)
1303 destroy_kvm_mmu(vcpu);
1305 while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1306 struct kvm_mmu_page *page;
1308 page = container_of(vcpu->kvm->active_mmu_pages.next,
1309 struct kvm_mmu_page, link);
1310 kvm_mmu_zap_page(vcpu, page);
1313 mmu_free_memory_caches(vcpu);
1314 kvm_arch_ops->tlb_flush(vcpu);
1318 void kvm_mmu_module_exit(void)
1320 if (pte_chain_cache)
1321 kmem_cache_destroy(pte_chain_cache);
1322 if (rmap_desc_cache)
1323 kmem_cache_destroy(rmap_desc_cache);
1325 kmem_cache_destroy(mmu_page_cache);
1326 if (mmu_page_header_cache)
1327 kmem_cache_destroy(mmu_page_header_cache);
1330 int kvm_mmu_module_init(void)
1332 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1333 sizeof(struct kvm_pte_chain),
1335 if (!pte_chain_cache)
1337 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1338 sizeof(struct kvm_rmap_desc),
1340 if (!rmap_desc_cache)
1343 mmu_page_cache = kmem_cache_create("kvm_mmu_page",
1345 PAGE_SIZE, 0, NULL, NULL);
1346 if (!mmu_page_cache)
1349 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1350 sizeof(struct kvm_mmu_page),
1352 if (!mmu_page_header_cache)
1358 kvm_mmu_module_exit();
1364 static const char *audit_msg;
1366 static gva_t canonicalize(gva_t gva)
1368 #ifdef CONFIG_X86_64
1369 gva = (long long)(gva << 16) >> 16;
1374 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1375 gva_t va, int level)
1377 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1379 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1381 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1384 if (!(ent & PT_PRESENT_MASK))
1387 va = canonicalize(va);
1389 audit_mappings_page(vcpu, ent, va, level - 1);
1391 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1392 hpa_t hpa = gpa_to_hpa(vcpu, gpa);
1394 if ((ent & PT_PRESENT_MASK)
1395 && (ent & PT64_BASE_ADDR_MASK) != hpa)
1396 printk(KERN_ERR "audit error: (%s) levels %d"
1397 " gva %lx gpa %llx hpa %llx ent %llx\n",
1398 audit_msg, vcpu->mmu.root_level,
1404 static void audit_mappings(struct kvm_vcpu *vcpu)
1408 if (vcpu->mmu.root_level == 4)
1409 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1411 for (i = 0; i < 4; ++i)
1412 if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1413 audit_mappings_page(vcpu,
1414 vcpu->mmu.pae_root[i],
1419 static int count_rmaps(struct kvm_vcpu *vcpu)
1424 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1425 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1426 struct kvm_rmap_desc *d;
1428 for (j = 0; j < m->npages; ++j) {
1429 struct page *page = m->phys_mem[j];
1433 if (!(page->private & 1)) {
1437 d = (struct kvm_rmap_desc *)(page->private & ~1ul);
1439 for (k = 0; k < RMAP_EXT; ++k)
1440 if (d->shadow_ptes[k])
1451 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1454 struct kvm_mmu_page *page;
1457 list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1458 u64 *pt = page->spt;
1460 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1463 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1466 if (!(ent & PT_PRESENT_MASK))
1468 if (!(ent & PT_WRITABLE_MASK))
1476 static void audit_rmap(struct kvm_vcpu *vcpu)
1478 int n_rmap = count_rmaps(vcpu);
1479 int n_actual = count_writable_mappings(vcpu);
1481 if (n_rmap != n_actual)
1482 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1483 __FUNCTION__, audit_msg, n_rmap, n_actual);
1486 static void audit_write_protection(struct kvm_vcpu *vcpu)
1488 struct kvm_mmu_page *page;
1490 list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1494 if (page->role.metaphysical)
1497 hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT)
1499 pg = pfn_to_page(hfn);
1501 printk(KERN_ERR "%s: (%s) shadow page has writable"
1502 " mappings: gfn %lx role %x\n",
1503 __FUNCTION__, audit_msg, page->gfn,
1508 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1515 audit_write_protection(vcpu);
1516 audit_mappings(vcpu);