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>
31 #include <asm/cmpxchg.h>
38 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
40 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
45 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
46 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
50 #define pgprintk(x...) do { } while (0)
51 #define rmap_printk(x...) do { } while (0)
55 #if defined(MMU_DEBUG) || defined(AUDIT)
60 #define ASSERT(x) do { } while (0)
64 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
65 __FILE__, __LINE__, #x); \
69 #define PT64_PT_BITS 9
70 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
71 #define PT32_PT_BITS 10
72 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
74 #define PT_WRITABLE_SHIFT 1
76 #define PT_PRESENT_MASK (1ULL << 0)
77 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
78 #define PT_USER_MASK (1ULL << 2)
79 #define PT_PWT_MASK (1ULL << 3)
80 #define PT_PCD_MASK (1ULL << 4)
81 #define PT_ACCESSED_MASK (1ULL << 5)
82 #define PT_DIRTY_MASK (1ULL << 6)
83 #define PT_PAGE_SIZE_MASK (1ULL << 7)
84 #define PT_PAT_MASK (1ULL << 7)
85 #define PT_GLOBAL_MASK (1ULL << 8)
86 #define PT64_NX_MASK (1ULL << 63)
88 #define PT_PAT_SHIFT 7
89 #define PT_DIR_PAT_SHIFT 12
90 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
92 #define PT32_DIR_PSE36_SIZE 4
93 #define PT32_DIR_PSE36_SHIFT 13
94 #define PT32_DIR_PSE36_MASK \
95 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
98 #define PT_FIRST_AVAIL_BITS_SHIFT 9
99 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
101 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
103 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
105 #define PT64_LEVEL_BITS 9
107 #define PT64_LEVEL_SHIFT(level) \
108 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
110 #define PT64_LEVEL_MASK(level) \
111 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
113 #define PT64_INDEX(address, level)\
114 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
117 #define PT32_LEVEL_BITS 10
119 #define PT32_LEVEL_SHIFT(level) \
120 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
122 #define PT32_LEVEL_MASK(level) \
123 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
125 #define PT32_INDEX(address, level)\
126 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
129 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
130 #define PT64_DIR_BASE_ADDR_MASK \
131 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
133 #define PT32_BASE_ADDR_MASK PAGE_MASK
134 #define PT32_DIR_BASE_ADDR_MASK \
135 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
138 #define PFERR_PRESENT_MASK (1U << 0)
139 #define PFERR_WRITE_MASK (1U << 1)
140 #define PFERR_USER_MASK (1U << 2)
141 #define PFERR_FETCH_MASK (1U << 4)
143 #define PT64_ROOT_LEVEL 4
144 #define PT32_ROOT_LEVEL 2
145 #define PT32E_ROOT_LEVEL 3
147 #define PT_DIRECTORY_LEVEL 2
148 #define PT_PAGE_TABLE_LEVEL 1
152 struct kvm_rmap_desc
{
153 u64
*shadow_ptes
[RMAP_EXT
];
154 struct kvm_rmap_desc
*more
;
157 static struct kmem_cache
*pte_chain_cache
;
158 static struct kmem_cache
*rmap_desc_cache
;
159 static struct kmem_cache
*mmu_page_header_cache
;
161 static u64 __read_mostly shadow_trap_nonpresent_pte
;
162 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
164 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
166 shadow_trap_nonpresent_pte
= trap_pte
;
167 shadow_notrap_nonpresent_pte
= notrap_pte
;
169 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
171 static int is_write_protection(struct kvm_vcpu
*vcpu
)
173 return vcpu
->cr0
& X86_CR0_WP
;
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_shadow_present_pte(u64 pte
)
193 pte
&= ~PT_SHADOW_IO_MARK
;
194 return pte
!= shadow_trap_nonpresent_pte
195 && pte
!= shadow_notrap_nonpresent_pte
;
198 static int is_writeble_pte(unsigned long pte
)
200 return pte
& PT_WRITABLE_MASK
;
203 static int is_dirty_pte(unsigned long pte
)
205 return pte
& PT_DIRTY_MASK
;
208 static int is_io_pte(unsigned long pte
)
210 return pte
& PT_SHADOW_IO_MARK
;
213 static int is_rmap_pte(u64 pte
)
215 return pte
!= shadow_trap_nonpresent_pte
216 && pte
!= shadow_notrap_nonpresent_pte
;
219 static void set_shadow_pte(u64
*sptep
, u64 spte
)
222 set_64bit((unsigned long *)sptep
, spte
);
224 set_64bit((unsigned long long *)sptep
, spte
);
228 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
229 struct kmem_cache
*base_cache
, int min
)
233 if (cache
->nobjs
>= min
)
235 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
236 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
239 cache
->objects
[cache
->nobjs
++] = obj
;
244 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
247 kfree(mc
->objects
[--mc
->nobjs
]);
250 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
255 if (cache
->nobjs
>= min
)
257 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
258 page
= alloc_page(GFP_KERNEL
);
261 set_page_private(page
, 0);
262 cache
->objects
[cache
->nobjs
++] = page_address(page
);
267 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
270 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
273 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
277 kvm_mmu_free_some_pages(vcpu
);
278 r
= mmu_topup_memory_cache(&vcpu
->mmu_pte_chain_cache
,
282 r
= mmu_topup_memory_cache(&vcpu
->mmu_rmap_desc_cache
,
286 r
= mmu_topup_memory_cache_page(&vcpu
->mmu_page_cache
, 8);
289 r
= mmu_topup_memory_cache(&vcpu
->mmu_page_header_cache
,
290 mmu_page_header_cache
, 4);
295 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
297 mmu_free_memory_cache(&vcpu
->mmu_pte_chain_cache
);
298 mmu_free_memory_cache(&vcpu
->mmu_rmap_desc_cache
);
299 mmu_free_memory_cache_page(&vcpu
->mmu_page_cache
);
300 mmu_free_memory_cache(&vcpu
->mmu_page_header_cache
);
303 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
309 p
= mc
->objects
[--mc
->nobjs
];
314 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
316 return mmu_memory_cache_alloc(&vcpu
->mmu_pte_chain_cache
,
317 sizeof(struct kvm_pte_chain
));
320 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
325 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
327 return mmu_memory_cache_alloc(&vcpu
->mmu_rmap_desc_cache
,
328 sizeof(struct kvm_rmap_desc
));
331 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
337 * Take gfn and return the reverse mapping to it.
338 * Note: gfn must be unaliased before this function get called
341 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
)
343 struct kvm_memory_slot
*slot
;
345 slot
= gfn_to_memslot(kvm
, gfn
);
346 return &slot
->rmap
[gfn
- slot
->base_gfn
];
350 * Reverse mapping data structures:
352 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
353 * that points to page_address(page).
355 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
356 * containing more mappings.
358 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
360 struct kvm_mmu_page
*page
;
361 struct kvm_rmap_desc
*desc
;
362 unsigned long *rmapp
;
365 if (!is_rmap_pte(*spte
))
367 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
368 page
= page_header(__pa(spte
));
369 page
->gfns
[spte
- page
->spt
] = gfn
;
370 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
);
372 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
373 *rmapp
= (unsigned long)spte
;
374 } else if (!(*rmapp
& 1)) {
375 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
376 desc
= mmu_alloc_rmap_desc(vcpu
);
377 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
378 desc
->shadow_ptes
[1] = spte
;
379 *rmapp
= (unsigned long)desc
| 1;
381 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
382 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
383 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
385 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
386 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
389 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
391 desc
->shadow_ptes
[i
] = spte
;
395 static void rmap_desc_remove_entry(unsigned long *rmapp
,
396 struct kvm_rmap_desc
*desc
,
398 struct kvm_rmap_desc
*prev_desc
)
402 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
404 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
405 desc
->shadow_ptes
[j
] = NULL
;
408 if (!prev_desc
&& !desc
->more
)
409 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
412 prev_desc
->more
= desc
->more
;
414 *rmapp
= (unsigned long)desc
->more
| 1;
415 mmu_free_rmap_desc(desc
);
418 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
420 struct kvm_rmap_desc
*desc
;
421 struct kvm_rmap_desc
*prev_desc
;
422 struct kvm_mmu_page
*page
;
423 struct page
*release_page
;
424 unsigned long *rmapp
;
427 if (!is_rmap_pte(*spte
))
429 page
= page_header(__pa(spte
));
430 release_page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
431 if (is_writeble_pte(*spte
))
432 kvm_release_page_dirty(release_page
);
434 kvm_release_page_clean(release_page
);
435 rmapp
= gfn_to_rmap(kvm
, page
->gfns
[spte
- page
->spt
]);
437 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
439 } else if (!(*rmapp
& 1)) {
440 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
441 if ((u64
*)*rmapp
!= spte
) {
442 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
448 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
449 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
452 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
453 if (desc
->shadow_ptes
[i
] == spte
) {
454 rmap_desc_remove_entry(rmapp
,
466 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
468 struct kvm_rmap_desc
*desc
;
469 struct kvm_rmap_desc
*prev_desc
;
475 else if (!(*rmapp
& 1)) {
477 return (u64
*)*rmapp
;
480 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
484 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
485 if (prev_spte
== spte
)
486 return desc
->shadow_ptes
[i
];
487 prev_spte
= desc
->shadow_ptes
[i
];
494 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
496 unsigned long *rmapp
;
499 gfn
= unalias_gfn(kvm
, gfn
);
500 rmapp
= gfn_to_rmap(kvm
, gfn
);
502 spte
= rmap_next(kvm
, rmapp
, NULL
);
505 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
506 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
507 if (is_writeble_pte(*spte
))
508 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
509 kvm_flush_remote_tlbs(kvm
);
510 spte
= rmap_next(kvm
, rmapp
, spte
);
515 static int is_empty_shadow_page(u64
*spt
)
520 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
521 if ((*pos
& ~PT_SHADOW_IO_MARK
) != shadow_trap_nonpresent_pte
) {
522 printk(KERN_ERR
"%s: %p %llx\n", __FUNCTION__
,
530 static void kvm_mmu_free_page(struct kvm
*kvm
,
531 struct kvm_mmu_page
*page_head
)
533 ASSERT(is_empty_shadow_page(page_head
->spt
));
534 list_del(&page_head
->link
);
535 __free_page(virt_to_page(page_head
->spt
));
536 __free_page(virt_to_page(page_head
->gfns
));
538 ++kvm
->n_free_mmu_pages
;
541 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
546 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
549 struct kvm_mmu_page
*page
;
551 if (!vcpu
->kvm
->n_free_mmu_pages
)
554 page
= mmu_memory_cache_alloc(&vcpu
->mmu_page_header_cache
,
556 page
->spt
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
557 page
->gfns
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
558 set_page_private(virt_to_page(page
->spt
), (unsigned long)page
);
559 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
560 ASSERT(is_empty_shadow_page(page
->spt
));
561 page
->slot_bitmap
= 0;
562 page
->multimapped
= 0;
563 page
->parent_pte
= parent_pte
;
564 --vcpu
->kvm
->n_free_mmu_pages
;
568 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
569 struct kvm_mmu_page
*page
, u64
*parent_pte
)
571 struct kvm_pte_chain
*pte_chain
;
572 struct hlist_node
*node
;
577 if (!page
->multimapped
) {
578 u64
*old
= page
->parent_pte
;
581 page
->parent_pte
= parent_pte
;
584 page
->multimapped
= 1;
585 pte_chain
= mmu_alloc_pte_chain(vcpu
);
586 INIT_HLIST_HEAD(&page
->parent_ptes
);
587 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
588 pte_chain
->parent_ptes
[0] = old
;
590 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
) {
591 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
593 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
594 if (!pte_chain
->parent_ptes
[i
]) {
595 pte_chain
->parent_ptes
[i
] = parent_pte
;
599 pte_chain
= mmu_alloc_pte_chain(vcpu
);
601 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
602 pte_chain
->parent_ptes
[0] = parent_pte
;
605 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*page
,
608 struct kvm_pte_chain
*pte_chain
;
609 struct hlist_node
*node
;
612 if (!page
->multimapped
) {
613 BUG_ON(page
->parent_pte
!= parent_pte
);
614 page
->parent_pte
= NULL
;
617 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
)
618 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
619 if (!pte_chain
->parent_ptes
[i
])
621 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
623 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
624 && pte_chain
->parent_ptes
[i
+ 1]) {
625 pte_chain
->parent_ptes
[i
]
626 = pte_chain
->parent_ptes
[i
+ 1];
629 pte_chain
->parent_ptes
[i
] = NULL
;
631 hlist_del(&pte_chain
->link
);
632 mmu_free_pte_chain(pte_chain
);
633 if (hlist_empty(&page
->parent_ptes
)) {
634 page
->multimapped
= 0;
635 page
->parent_pte
= NULL
;
643 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
,
647 struct hlist_head
*bucket
;
648 struct kvm_mmu_page
*page
;
649 struct hlist_node
*node
;
651 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
652 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
653 bucket
= &kvm
->mmu_page_hash
[index
];
654 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
655 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
656 pgprintk("%s: found role %x\n",
657 __FUNCTION__
, page
->role
.word
);
663 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
668 unsigned hugepage_access
,
671 union kvm_mmu_page_role role
;
674 struct hlist_head
*bucket
;
675 struct kvm_mmu_page
*page
;
676 struct hlist_node
*node
;
679 role
.glevels
= vcpu
->mmu
.root_level
;
681 role
.metaphysical
= metaphysical
;
682 role
.hugepage_access
= hugepage_access
;
683 if (vcpu
->mmu
.root_level
<= PT32_ROOT_LEVEL
) {
684 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
685 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
686 role
.quadrant
= quadrant
;
688 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__
,
690 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
691 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
692 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
693 if (page
->gfn
== gfn
&& page
->role
.word
== role
.word
) {
694 mmu_page_add_parent_pte(vcpu
, page
, parent_pte
);
695 pgprintk("%s: found\n", __FUNCTION__
);
698 page
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
701 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__
, gfn
, role
.word
);
704 hlist_add_head(&page
->hash_link
, bucket
);
705 vcpu
->mmu
.prefetch_page(vcpu
, page
);
707 rmap_write_protect(vcpu
->kvm
, gfn
);
711 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
712 struct kvm_mmu_page
*page
)
720 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
721 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
722 if (is_shadow_present_pte(pt
[i
]))
723 rmap_remove(kvm
, &pt
[i
]);
724 pt
[i
] = shadow_trap_nonpresent_pte
;
726 kvm_flush_remote_tlbs(kvm
);
730 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
733 pt
[i
] = shadow_trap_nonpresent_pte
;
734 if (!is_shadow_present_pte(ent
))
736 ent
&= PT64_BASE_ADDR_MASK
;
737 mmu_page_remove_parent_pte(page_header(ent
), &pt
[i
]);
739 kvm_flush_remote_tlbs(kvm
);
742 static void kvm_mmu_put_page(struct kvm_mmu_page
*page
,
745 mmu_page_remove_parent_pte(page
, parent_pte
);
748 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
752 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
754 kvm
->vcpus
[i
]->last_pte_updated
= NULL
;
757 static void kvm_mmu_zap_page(struct kvm
*kvm
,
758 struct kvm_mmu_page
*page
)
762 ++kvm
->stat
.mmu_shadow_zapped
;
763 while (page
->multimapped
|| page
->parent_pte
) {
764 if (!page
->multimapped
)
765 parent_pte
= page
->parent_pte
;
767 struct kvm_pte_chain
*chain
;
769 chain
= container_of(page
->parent_ptes
.first
,
770 struct kvm_pte_chain
, link
);
771 parent_pte
= chain
->parent_ptes
[0];
774 kvm_mmu_put_page(page
, parent_pte
);
775 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
777 kvm_mmu_page_unlink_children(kvm
, page
);
778 if (!page
->root_count
) {
779 hlist_del(&page
->hash_link
);
780 kvm_mmu_free_page(kvm
, page
);
782 list_move(&page
->link
, &kvm
->active_mmu_pages
);
783 kvm_mmu_reset_last_pte_updated(kvm
);
787 * Changing the number of mmu pages allocated to the vm
788 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
790 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
793 * If we set the number of mmu pages to be smaller be than the
794 * number of actived pages , we must to free some mmu pages before we
798 if ((kvm
->n_alloc_mmu_pages
- kvm
->n_free_mmu_pages
) >
800 int n_used_mmu_pages
= kvm
->n_alloc_mmu_pages
801 - kvm
->n_free_mmu_pages
;
803 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
804 struct kvm_mmu_page
*page
;
806 page
= container_of(kvm
->active_mmu_pages
.prev
,
807 struct kvm_mmu_page
, link
);
808 kvm_mmu_zap_page(kvm
, page
);
811 kvm
->n_free_mmu_pages
= 0;
814 kvm
->n_free_mmu_pages
+= kvm_nr_mmu_pages
815 - kvm
->n_alloc_mmu_pages
;
817 kvm
->n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
820 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
823 struct hlist_head
*bucket
;
824 struct kvm_mmu_page
*page
;
825 struct hlist_node
*node
, *n
;
828 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
830 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
831 bucket
= &kvm
->mmu_page_hash
[index
];
832 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
)
833 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
834 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__
, gfn
,
836 kvm_mmu_zap_page(kvm
, page
);
842 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
844 struct kvm_mmu_page
*page
;
846 while ((page
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
847 pgprintk("%s: zap %lx %x\n",
848 __FUNCTION__
, gfn
, page
->role
.word
);
849 kvm_mmu_zap_page(kvm
, page
);
853 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gpa_t gpa
)
855 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gpa
>> PAGE_SHIFT
));
856 struct kvm_mmu_page
*page_head
= page_header(__pa(pte
));
858 __set_bit(slot
, &page_head
->slot_bitmap
);
861 hpa_t
gpa_to_hpa(struct kvm
*kvm
, gpa_t gpa
)
866 ASSERT((gpa
& HPA_ERR_MASK
) == 0);
867 page
= gfn_to_page(kvm
, gpa
>> PAGE_SHIFT
);
868 hpa
= ((hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
) | (gpa
& (PAGE_SIZE
-1));
869 if (is_error_page(page
))
870 return hpa
| HPA_ERR_MASK
;
874 hpa_t
gva_to_hpa(struct kvm_vcpu
*vcpu
, gva_t gva
)
876 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
878 if (gpa
== UNMAPPED_GVA
)
880 return gpa_to_hpa(vcpu
->kvm
, gpa
);
883 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
885 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
887 if (gpa
== UNMAPPED_GVA
)
889 return pfn_to_page(gpa_to_hpa(vcpu
->kvm
, gpa
) >> PAGE_SHIFT
);
892 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
896 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, hpa_t p
)
898 int level
= PT32E_ROOT_LEVEL
;
899 hpa_t table_addr
= vcpu
->mmu
.root_hpa
;
902 page
= pfn_to_page(p
>> PAGE_SHIFT
);
904 u32 index
= PT64_INDEX(v
, level
);
908 ASSERT(VALID_PAGE(table_addr
));
909 table
= __va(table_addr
);
915 was_rmapped
= is_rmap_pte(pte
);
916 if (is_shadow_present_pte(pte
) && is_writeble_pte(pte
)) {
917 kvm_release_page_clean(page
);
920 mark_page_dirty(vcpu
->kvm
, v
>> PAGE_SHIFT
);
921 page_header_update_slot(vcpu
->kvm
, table
, v
);
922 table
[index
] = p
| PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
925 rmap_add(vcpu
, &table
[index
], v
>> PAGE_SHIFT
);
927 kvm_release_page_clean(page
);
932 if (table
[index
] == shadow_trap_nonpresent_pte
) {
933 struct kvm_mmu_page
*new_table
;
936 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
938 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
940 1, 3, &table
[index
]);
942 pgprintk("nonpaging_map: ENOMEM\n");
943 kvm_release_page_clean(page
);
947 table
[index
] = __pa(new_table
->spt
) | PT_PRESENT_MASK
948 | PT_WRITABLE_MASK
| PT_USER_MASK
;
950 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
954 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
955 struct kvm_mmu_page
*sp
)
959 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
960 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
963 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
966 struct kvm_mmu_page
*page
;
968 if (!VALID_PAGE(vcpu
->mmu
.root_hpa
))
971 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
972 hpa_t root
= vcpu
->mmu
.root_hpa
;
974 page
= page_header(root
);
976 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
980 for (i
= 0; i
< 4; ++i
) {
981 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
984 root
&= PT64_BASE_ADDR_MASK
;
985 page
= page_header(root
);
988 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
990 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
993 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
997 struct kvm_mmu_page
*page
;
999 root_gfn
= vcpu
->cr3
>> PAGE_SHIFT
;
1001 #ifdef CONFIG_X86_64
1002 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1003 hpa_t root
= vcpu
->mmu
.root_hpa
;
1005 ASSERT(!VALID_PAGE(root
));
1006 page
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1007 PT64_ROOT_LEVEL
, 0, 0, NULL
);
1008 root
= __pa(page
->spt
);
1010 vcpu
->mmu
.root_hpa
= root
;
1014 for (i
= 0; i
< 4; ++i
) {
1015 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
1017 ASSERT(!VALID_PAGE(root
));
1018 if (vcpu
->mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1019 if (!is_present_pte(vcpu
->pdptrs
[i
])) {
1020 vcpu
->mmu
.pae_root
[i
] = 0;
1023 root_gfn
= vcpu
->pdptrs
[i
] >> PAGE_SHIFT
;
1024 } else if (vcpu
->mmu
.root_level
== 0)
1026 page
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1027 PT32_ROOT_LEVEL
, !is_paging(vcpu
),
1029 root
= __pa(page
->spt
);
1031 vcpu
->mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1033 vcpu
->mmu
.root_hpa
= __pa(vcpu
->mmu
.pae_root
);
1036 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1041 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1048 r
= mmu_topup_memory_caches(vcpu
);
1053 ASSERT(VALID_PAGE(vcpu
->mmu
.root_hpa
));
1056 paddr
= gpa_to_hpa(vcpu
->kvm
, addr
& PT64_BASE_ADDR_MASK
);
1058 if (is_error_hpa(paddr
)) {
1059 kvm_release_page_clean(pfn_to_page((paddr
& PT64_BASE_ADDR_MASK
)
1064 return nonpaging_map(vcpu
, addr
& PAGE_MASK
, paddr
);
1067 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1069 mmu_free_roots(vcpu
);
1072 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1074 struct kvm_mmu
*context
= &vcpu
->mmu
;
1076 context
->new_cr3
= nonpaging_new_cr3
;
1077 context
->page_fault
= nonpaging_page_fault
;
1078 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1079 context
->free
= nonpaging_free
;
1080 context
->prefetch_page
= nonpaging_prefetch_page
;
1081 context
->root_level
= 0;
1082 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1083 context
->root_hpa
= INVALID_PAGE
;
1087 static void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1089 ++vcpu
->stat
.tlb_flush
;
1090 kvm_x86_ops
->tlb_flush(vcpu
);
1093 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1095 pgprintk("%s: cr3 %lx\n", __FUNCTION__
, vcpu
->cr3
);
1096 mmu_free_roots(vcpu
);
1099 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1103 kvm_x86_ops
->inject_page_fault(vcpu
, addr
, err_code
);
1106 static void paging_free(struct kvm_vcpu
*vcpu
)
1108 nonpaging_free(vcpu
);
1112 #include "paging_tmpl.h"
1116 #include "paging_tmpl.h"
1119 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1121 struct kvm_mmu
*context
= &vcpu
->mmu
;
1123 ASSERT(is_pae(vcpu
));
1124 context
->new_cr3
= paging_new_cr3
;
1125 context
->page_fault
= paging64_page_fault
;
1126 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1127 context
->prefetch_page
= paging64_prefetch_page
;
1128 context
->free
= paging_free
;
1129 context
->root_level
= level
;
1130 context
->shadow_root_level
= level
;
1131 context
->root_hpa
= INVALID_PAGE
;
1135 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1137 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1140 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1142 struct kvm_mmu
*context
= &vcpu
->mmu
;
1144 context
->new_cr3
= paging_new_cr3
;
1145 context
->page_fault
= paging32_page_fault
;
1146 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1147 context
->free
= paging_free
;
1148 context
->prefetch_page
= paging32_prefetch_page
;
1149 context
->root_level
= PT32_ROOT_LEVEL
;
1150 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1151 context
->root_hpa
= INVALID_PAGE
;
1155 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1157 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1160 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1163 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1165 if (!is_paging(vcpu
))
1166 return nonpaging_init_context(vcpu
);
1167 else if (is_long_mode(vcpu
))
1168 return paging64_init_context(vcpu
);
1169 else if (is_pae(vcpu
))
1170 return paging32E_init_context(vcpu
);
1172 return paging32_init_context(vcpu
);
1175 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1178 if (VALID_PAGE(vcpu
->mmu
.root_hpa
)) {
1179 vcpu
->mmu
.free(vcpu
);
1180 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
1184 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1186 destroy_kvm_mmu(vcpu
);
1187 return init_kvm_mmu(vcpu
);
1189 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
1191 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1195 mutex_lock(&vcpu
->kvm
->lock
);
1196 r
= mmu_topup_memory_caches(vcpu
);
1199 mmu_alloc_roots(vcpu
);
1200 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->mmu
.root_hpa
);
1201 kvm_mmu_flush_tlb(vcpu
);
1203 mutex_unlock(&vcpu
->kvm
->lock
);
1206 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1208 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1210 mmu_free_roots(vcpu
);
1213 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1214 struct kvm_mmu_page
*page
,
1218 struct kvm_mmu_page
*child
;
1221 if (is_shadow_present_pte(pte
)) {
1222 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1223 rmap_remove(vcpu
->kvm
, spte
);
1225 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1226 mmu_page_remove_parent_pte(child
, spte
);
1229 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
1230 kvm_flush_remote_tlbs(vcpu
->kvm
);
1233 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
1234 struct kvm_mmu_page
*page
,
1236 const void *new, int bytes
,
1239 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
1240 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
1244 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
1245 if (page
->role
.glevels
== PT32_ROOT_LEVEL
)
1246 paging32_update_pte(vcpu
, page
, spte
, new, bytes
,
1249 paging64_update_pte(vcpu
, page
, spte
, new, bytes
,
1253 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
1255 u64
*spte
= vcpu
->last_pte_updated
;
1257 return !!(spte
&& (*spte
& PT_ACCESSED_MASK
));
1260 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1261 const u8
*new, int bytes
)
1263 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1264 struct kvm_mmu_page
*page
;
1265 struct hlist_node
*node
, *n
;
1266 struct hlist_head
*bucket
;
1269 unsigned offset
= offset_in_page(gpa
);
1271 unsigned page_offset
;
1272 unsigned misaligned
;
1278 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__
, gpa
, bytes
);
1279 ++vcpu
->kvm
->stat
.mmu_pte_write
;
1280 kvm_mmu_audit(vcpu
, "pre pte write");
1281 if (gfn
== vcpu
->last_pt_write_gfn
1282 && !last_updated_pte_accessed(vcpu
)) {
1283 ++vcpu
->last_pt_write_count
;
1284 if (vcpu
->last_pt_write_count
>= 3)
1287 vcpu
->last_pt_write_gfn
= gfn
;
1288 vcpu
->last_pt_write_count
= 1;
1289 vcpu
->last_pte_updated
= NULL
;
1291 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
1292 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
1293 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
) {
1294 if (page
->gfn
!= gfn
|| page
->role
.metaphysical
)
1296 pte_size
= page
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1297 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1298 misaligned
|= bytes
< 4;
1299 if (misaligned
|| flooded
) {
1301 * Misaligned accesses are too much trouble to fix
1302 * up; also, they usually indicate a page is not used
1305 * If we're seeing too many writes to a page,
1306 * it may no longer be a page table, or we may be
1307 * forking, in which case it is better to unmap the
1310 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1311 gpa
, bytes
, page
->role
.word
);
1312 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1313 ++vcpu
->kvm
->stat
.mmu_flooded
;
1316 page_offset
= offset
;
1317 level
= page
->role
.level
;
1319 if (page
->role
.glevels
== PT32_ROOT_LEVEL
) {
1320 page_offset
<<= 1; /* 32->64 */
1322 * A 32-bit pde maps 4MB while the shadow pdes map
1323 * only 2MB. So we need to double the offset again
1324 * and zap two pdes instead of one.
1326 if (level
== PT32_ROOT_LEVEL
) {
1327 page_offset
&= ~7; /* kill rounding error */
1331 quadrant
= page_offset
>> PAGE_SHIFT
;
1332 page_offset
&= ~PAGE_MASK
;
1333 if (quadrant
!= page
->role
.quadrant
)
1336 spte
= &page
->spt
[page_offset
/ sizeof(*spte
)];
1338 mmu_pte_write_zap_pte(vcpu
, page
, spte
);
1339 mmu_pte_write_new_pte(vcpu
, page
, spte
, new, bytes
,
1340 page_offset
& (pte_size
- 1));
1344 kvm_mmu_audit(vcpu
, "post pte write");
1347 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1349 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
1351 return kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1354 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1356 while (vcpu
->kvm
->n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1357 struct kvm_mmu_page
*page
;
1359 page
= container_of(vcpu
->kvm
->active_mmu_pages
.prev
,
1360 struct kvm_mmu_page
, link
);
1361 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1362 ++vcpu
->kvm
->stat
.mmu_recycled
;
1366 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
1369 enum emulation_result er
;
1371 mutex_lock(&vcpu
->kvm
->lock
);
1372 r
= vcpu
->mmu
.page_fault(vcpu
, cr2
, error_code
);
1381 r
= mmu_topup_memory_caches(vcpu
);
1385 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
1386 mutex_unlock(&vcpu
->kvm
->lock
);
1391 case EMULATE_DO_MMIO
:
1392 ++vcpu
->stat
.mmio_exits
;
1395 kvm_report_emulation_failure(vcpu
, "pagetable");
1401 mutex_unlock(&vcpu
->kvm
->lock
);
1404 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
1406 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1408 struct kvm_mmu_page
*page
;
1410 while (!list_empty(&vcpu
->kvm
->active_mmu_pages
)) {
1411 page
= container_of(vcpu
->kvm
->active_mmu_pages
.next
,
1412 struct kvm_mmu_page
, link
);
1413 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1415 free_page((unsigned long)vcpu
->mmu
.pae_root
);
1418 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1425 if (vcpu
->kvm
->n_requested_mmu_pages
)
1426 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_requested_mmu_pages
;
1428 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_alloc_mmu_pages
;
1430 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1431 * Therefore we need to allocate shadow page tables in the first
1432 * 4GB of memory, which happens to fit the DMA32 zone.
1434 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1437 vcpu
->mmu
.pae_root
= page_address(page
);
1438 for (i
= 0; i
< 4; ++i
)
1439 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1444 free_mmu_pages(vcpu
);
1448 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1451 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1453 return alloc_mmu_pages(vcpu
);
1456 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1459 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1461 return init_kvm_mmu(vcpu
);
1464 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1468 destroy_kvm_mmu(vcpu
);
1469 free_mmu_pages(vcpu
);
1470 mmu_free_memory_caches(vcpu
);
1473 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
1475 struct kvm_mmu_page
*page
;
1477 list_for_each_entry(page
, &kvm
->active_mmu_pages
, link
) {
1481 if (!test_bit(slot
, &page
->slot_bitmap
))
1485 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1487 if (pt
[i
] & PT_WRITABLE_MASK
)
1488 pt
[i
] &= ~PT_WRITABLE_MASK
;
1492 void kvm_mmu_zap_all(struct kvm
*kvm
)
1494 struct kvm_mmu_page
*page
, *node
;
1496 list_for_each_entry_safe(page
, node
, &kvm
->active_mmu_pages
, link
)
1497 kvm_mmu_zap_page(kvm
, page
);
1499 kvm_flush_remote_tlbs(kvm
);
1502 void kvm_mmu_module_exit(void)
1504 if (pte_chain_cache
)
1505 kmem_cache_destroy(pte_chain_cache
);
1506 if (rmap_desc_cache
)
1507 kmem_cache_destroy(rmap_desc_cache
);
1508 if (mmu_page_header_cache
)
1509 kmem_cache_destroy(mmu_page_header_cache
);
1512 int kvm_mmu_module_init(void)
1514 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
1515 sizeof(struct kvm_pte_chain
),
1517 if (!pte_chain_cache
)
1519 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
1520 sizeof(struct kvm_rmap_desc
),
1522 if (!rmap_desc_cache
)
1525 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
1526 sizeof(struct kvm_mmu_page
),
1528 if (!mmu_page_header_cache
)
1534 kvm_mmu_module_exit();
1539 * Caculate mmu pages needed for kvm.
1541 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
1544 unsigned int nr_mmu_pages
;
1545 unsigned int nr_pages
= 0;
1547 for (i
= 0; i
< kvm
->nmemslots
; i
++)
1548 nr_pages
+= kvm
->memslots
[i
].npages
;
1550 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
1551 nr_mmu_pages
= max(nr_mmu_pages
,
1552 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
1554 return nr_mmu_pages
;
1559 static const char *audit_msg
;
1561 static gva_t
canonicalize(gva_t gva
)
1563 #ifdef CONFIG_X86_64
1564 gva
= (long long)(gva
<< 16) >> 16;
1569 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
1570 gva_t va
, int level
)
1572 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
1574 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
1576 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
1579 if (ent
== shadow_trap_nonpresent_pte
)
1582 va
= canonicalize(va
);
1584 if (ent
== shadow_notrap_nonpresent_pte
)
1585 printk(KERN_ERR
"audit: (%s) nontrapping pte"
1586 " in nonleaf level: levels %d gva %lx"
1587 " level %d pte %llx\n", audit_msg
,
1588 vcpu
->mmu
.root_level
, va
, level
, ent
);
1590 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
1592 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, va
);
1593 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
1596 if (is_shadow_present_pte(ent
)
1597 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
1598 printk(KERN_ERR
"xx audit error: (%s) levels %d"
1599 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1600 audit_msg
, vcpu
->mmu
.root_level
,
1602 is_shadow_present_pte(ent
));
1603 else if (ent
== shadow_notrap_nonpresent_pte
1604 && !is_error_hpa(hpa
))
1605 printk(KERN_ERR
"audit: (%s) notrap shadow,"
1606 " valid guest gva %lx\n", audit_msg
, va
);
1607 page
= pfn_to_page((gpa
& PT64_BASE_ADDR_MASK
)
1609 kvm_release_page_clean(page
);
1615 static void audit_mappings(struct kvm_vcpu
*vcpu
)
1619 if (vcpu
->mmu
.root_level
== 4)
1620 audit_mappings_page(vcpu
, vcpu
->mmu
.root_hpa
, 0, 4);
1622 for (i
= 0; i
< 4; ++i
)
1623 if (vcpu
->mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
1624 audit_mappings_page(vcpu
,
1625 vcpu
->mmu
.pae_root
[i
],
1630 static int count_rmaps(struct kvm_vcpu
*vcpu
)
1635 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
1636 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
1637 struct kvm_rmap_desc
*d
;
1639 for (j
= 0; j
< m
->npages
; ++j
) {
1640 unsigned long *rmapp
= &m
->rmap
[j
];
1644 if (!(*rmapp
& 1)) {
1648 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
1650 for (k
= 0; k
< RMAP_EXT
; ++k
)
1651 if (d
->shadow_ptes
[k
])
1662 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
1665 struct kvm_mmu_page
*page
;
1668 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1669 u64
*pt
= page
->spt
;
1671 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1674 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1677 if (!(ent
& PT_PRESENT_MASK
))
1679 if (!(ent
& PT_WRITABLE_MASK
))
1687 static void audit_rmap(struct kvm_vcpu
*vcpu
)
1689 int n_rmap
= count_rmaps(vcpu
);
1690 int n_actual
= count_writable_mappings(vcpu
);
1692 if (n_rmap
!= n_actual
)
1693 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
1694 __FUNCTION__
, audit_msg
, n_rmap
, n_actual
);
1697 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
1699 struct kvm_mmu_page
*page
;
1700 struct kvm_memory_slot
*slot
;
1701 unsigned long *rmapp
;
1704 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1705 if (page
->role
.metaphysical
)
1708 slot
= gfn_to_memslot(vcpu
->kvm
, page
->gfn
);
1709 gfn
= unalias_gfn(vcpu
->kvm
, page
->gfn
);
1710 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
1712 printk(KERN_ERR
"%s: (%s) shadow page has writable"
1713 " mappings: gfn %lx role %x\n",
1714 __FUNCTION__
, audit_msg
, page
->gfn
,
1719 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
1726 audit_write_protection(vcpu
);
1727 audit_mappings(vcpu
);