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.
23 #include <linux/types.h>
24 #include <linux/string.h>
26 #include <linux/highmem.h>
27 #include <linux/module.h>
30 #include <asm/cmpxchg.h>
37 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
39 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
44 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
45 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
49 #define pgprintk(x...) do { } while (0)
50 #define rmap_printk(x...) do { } while (0)
54 #if defined(MMU_DEBUG) || defined(AUDIT)
59 #define ASSERT(x) do { } while (0)
63 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
64 __FILE__, __LINE__, #x); \
68 #define PT64_PT_BITS 9
69 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
70 #define PT32_PT_BITS 10
71 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
73 #define PT_WRITABLE_SHIFT 1
75 #define PT_PRESENT_MASK (1ULL << 0)
76 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
77 #define PT_USER_MASK (1ULL << 2)
78 #define PT_PWT_MASK (1ULL << 3)
79 #define PT_PCD_MASK (1ULL << 4)
80 #define PT_ACCESSED_MASK (1ULL << 5)
81 #define PT_DIRTY_MASK (1ULL << 6)
82 #define PT_PAGE_SIZE_MASK (1ULL << 7)
83 #define PT_PAT_MASK (1ULL << 7)
84 #define PT_GLOBAL_MASK (1ULL << 8)
85 #define PT64_NX_MASK (1ULL << 63)
87 #define PT_PAT_SHIFT 7
88 #define PT_DIR_PAT_SHIFT 12
89 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
91 #define PT32_DIR_PSE36_SIZE 4
92 #define PT32_DIR_PSE36_SHIFT 13
93 #define PT32_DIR_PSE36_MASK \
94 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
97 #define PT_FIRST_AVAIL_BITS_SHIFT 9
98 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
100 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
102 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
104 #define PT64_LEVEL_BITS 9
106 #define PT64_LEVEL_SHIFT(level) \
107 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
109 #define PT64_LEVEL_MASK(level) \
110 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
112 #define PT64_INDEX(address, level)\
113 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
116 #define PT32_LEVEL_BITS 10
118 #define PT32_LEVEL_SHIFT(level) \
119 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
121 #define PT32_LEVEL_MASK(level) \
122 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
124 #define PT32_INDEX(address, level)\
125 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
128 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
129 #define PT64_DIR_BASE_ADDR_MASK \
130 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
132 #define PT32_BASE_ADDR_MASK PAGE_MASK
133 #define PT32_DIR_BASE_ADDR_MASK \
134 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
137 #define PFERR_PRESENT_MASK (1U << 0)
138 #define PFERR_WRITE_MASK (1U << 1)
139 #define PFERR_USER_MASK (1U << 2)
140 #define PFERR_FETCH_MASK (1U << 4)
142 #define PT64_ROOT_LEVEL 4
143 #define PT32_ROOT_LEVEL 2
144 #define PT32E_ROOT_LEVEL 3
146 #define PT_DIRECTORY_LEVEL 2
147 #define PT_PAGE_TABLE_LEVEL 1
151 struct kvm_rmap_desc
{
152 u64
*shadow_ptes
[RMAP_EXT
];
153 struct kvm_rmap_desc
*more
;
156 static struct kmem_cache
*pte_chain_cache
;
157 static struct kmem_cache
*rmap_desc_cache
;
158 static struct kmem_cache
*mmu_page_header_cache
;
160 static u64 __read_mostly shadow_trap_nonpresent_pte
;
161 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
163 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
165 shadow_trap_nonpresent_pte
= trap_pte
;
166 shadow_notrap_nonpresent_pte
= notrap_pte
;
168 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
170 static int is_write_protection(struct kvm_vcpu
*vcpu
)
172 return vcpu
->cr0
& X86_CR0_WP
;
175 static int is_cpuid_PSE36(void)
180 static int is_nx(struct kvm_vcpu
*vcpu
)
182 return vcpu
->shadow_efer
& EFER_NX
;
185 static int is_present_pte(unsigned long pte
)
187 return pte
& PT_PRESENT_MASK
;
190 static int is_shadow_present_pte(u64 pte
)
192 pte
&= ~PT_SHADOW_IO_MARK
;
193 return pte
!= shadow_trap_nonpresent_pte
194 && pte
!= shadow_notrap_nonpresent_pte
;
197 static int is_writeble_pte(unsigned long pte
)
199 return pte
& PT_WRITABLE_MASK
;
202 static int is_dirty_pte(unsigned long pte
)
204 return pte
& PT_DIRTY_MASK
;
207 static int is_io_pte(unsigned long pte
)
209 return pte
& PT_SHADOW_IO_MARK
;
212 static int is_rmap_pte(u64 pte
)
214 return pte
!= shadow_trap_nonpresent_pte
215 && pte
!= shadow_notrap_nonpresent_pte
;
218 static void set_shadow_pte(u64
*sptep
, u64 spte
)
221 set_64bit((unsigned long *)sptep
, spte
);
223 set_64bit((unsigned long long *)sptep
, spte
);
227 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
228 struct kmem_cache
*base_cache
, int min
)
232 if (cache
->nobjs
>= min
)
234 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
235 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
238 cache
->objects
[cache
->nobjs
++] = obj
;
243 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
246 kfree(mc
->objects
[--mc
->nobjs
]);
249 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
254 if (cache
->nobjs
>= min
)
256 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
257 page
= alloc_page(GFP_KERNEL
);
260 set_page_private(page
, 0);
261 cache
->objects
[cache
->nobjs
++] = page_address(page
);
266 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
269 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
272 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
276 kvm_mmu_free_some_pages(vcpu
);
277 r
= mmu_topup_memory_cache(&vcpu
->mmu_pte_chain_cache
,
281 r
= mmu_topup_memory_cache(&vcpu
->mmu_rmap_desc_cache
,
285 r
= mmu_topup_memory_cache_page(&vcpu
->mmu_page_cache
, 8);
288 r
= mmu_topup_memory_cache(&vcpu
->mmu_page_header_cache
,
289 mmu_page_header_cache
, 4);
294 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
296 mmu_free_memory_cache(&vcpu
->mmu_pte_chain_cache
);
297 mmu_free_memory_cache(&vcpu
->mmu_rmap_desc_cache
);
298 mmu_free_memory_cache_page(&vcpu
->mmu_page_cache
);
299 mmu_free_memory_cache(&vcpu
->mmu_page_header_cache
);
302 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
308 p
= mc
->objects
[--mc
->nobjs
];
313 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
315 return mmu_memory_cache_alloc(&vcpu
->mmu_pte_chain_cache
,
316 sizeof(struct kvm_pte_chain
));
319 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
324 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
326 return mmu_memory_cache_alloc(&vcpu
->mmu_rmap_desc_cache
,
327 sizeof(struct kvm_rmap_desc
));
330 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
336 * Take gfn and return the reverse mapping to it.
337 * Note: gfn must be unaliased before this function get called
340 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
)
342 struct kvm_memory_slot
*slot
;
344 slot
= gfn_to_memslot(kvm
, gfn
);
345 return &slot
->rmap
[gfn
- slot
->base_gfn
];
349 * Reverse mapping data structures:
351 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
352 * that points to page_address(page).
354 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
355 * containing more mappings.
357 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
359 struct kvm_mmu_page
*page
;
360 struct kvm_rmap_desc
*desc
;
361 unsigned long *rmapp
;
364 if (!is_rmap_pte(*spte
))
366 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
367 page
= page_header(__pa(spte
));
368 page
->gfns
[spte
- page
->spt
] = gfn
;
369 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
);
371 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
372 *rmapp
= (unsigned long)spte
;
373 } else if (!(*rmapp
& 1)) {
374 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
375 desc
= mmu_alloc_rmap_desc(vcpu
);
376 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
377 desc
->shadow_ptes
[1] = spte
;
378 *rmapp
= (unsigned long)desc
| 1;
380 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
381 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
382 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
384 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
385 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
388 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
390 desc
->shadow_ptes
[i
] = spte
;
394 static void rmap_desc_remove_entry(unsigned long *rmapp
,
395 struct kvm_rmap_desc
*desc
,
397 struct kvm_rmap_desc
*prev_desc
)
401 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
403 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
404 desc
->shadow_ptes
[j
] = NULL
;
407 if (!prev_desc
&& !desc
->more
)
408 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
411 prev_desc
->more
= desc
->more
;
413 *rmapp
= (unsigned long)desc
->more
| 1;
414 mmu_free_rmap_desc(desc
);
417 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
419 struct kvm_rmap_desc
*desc
;
420 struct kvm_rmap_desc
*prev_desc
;
421 struct kvm_mmu_page
*page
;
422 unsigned long *rmapp
;
425 if (!is_rmap_pte(*spte
))
427 page
= page_header(__pa(spte
));
428 kvm_release_page(pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >>
430 rmapp
= gfn_to_rmap(kvm
, page
->gfns
[spte
- page
->spt
]);
432 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
434 } else if (!(*rmapp
& 1)) {
435 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
436 if ((u64
*)*rmapp
!= spte
) {
437 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
443 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
444 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
447 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
448 if (desc
->shadow_ptes
[i
] == spte
) {
449 rmap_desc_remove_entry(rmapp
,
461 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
463 struct kvm_rmap_desc
*desc
;
464 struct kvm_rmap_desc
*prev_desc
;
470 else if (!(*rmapp
& 1)) {
472 return (u64
*)*rmapp
;
475 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
479 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
480 if (prev_spte
== spte
)
481 return desc
->shadow_ptes
[i
];
482 prev_spte
= desc
->shadow_ptes
[i
];
489 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
491 unsigned long *rmapp
;
494 gfn
= unalias_gfn(kvm
, gfn
);
495 rmapp
= gfn_to_rmap(kvm
, gfn
);
497 spte
= rmap_next(kvm
, rmapp
, NULL
);
500 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
501 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
502 if (is_writeble_pte(*spte
))
503 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
504 kvm_flush_remote_tlbs(kvm
);
505 spte
= rmap_next(kvm
, rmapp
, spte
);
510 static int is_empty_shadow_page(u64
*spt
)
515 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
516 if ((*pos
& ~PT_SHADOW_IO_MARK
) != shadow_trap_nonpresent_pte
) {
517 printk(KERN_ERR
"%s: %p %llx\n", __FUNCTION__
,
525 static void kvm_mmu_free_page(struct kvm
*kvm
,
526 struct kvm_mmu_page
*page_head
)
528 ASSERT(is_empty_shadow_page(page_head
->spt
));
529 list_del(&page_head
->link
);
530 __free_page(virt_to_page(page_head
->spt
));
531 __free_page(virt_to_page(page_head
->gfns
));
533 ++kvm
->n_free_mmu_pages
;
536 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
541 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
544 struct kvm_mmu_page
*page
;
546 if (!vcpu
->kvm
->n_free_mmu_pages
)
549 page
= mmu_memory_cache_alloc(&vcpu
->mmu_page_header_cache
,
551 page
->spt
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
552 page
->gfns
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
553 set_page_private(virt_to_page(page
->spt
), (unsigned long)page
);
554 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
555 ASSERT(is_empty_shadow_page(page
->spt
));
556 page
->slot_bitmap
= 0;
557 page
->multimapped
= 0;
558 page
->parent_pte
= parent_pte
;
559 --vcpu
->kvm
->n_free_mmu_pages
;
563 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
564 struct kvm_mmu_page
*page
, u64
*parent_pte
)
566 struct kvm_pte_chain
*pte_chain
;
567 struct hlist_node
*node
;
572 if (!page
->multimapped
) {
573 u64
*old
= page
->parent_pte
;
576 page
->parent_pte
= parent_pte
;
579 page
->multimapped
= 1;
580 pte_chain
= mmu_alloc_pte_chain(vcpu
);
581 INIT_HLIST_HEAD(&page
->parent_ptes
);
582 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
583 pte_chain
->parent_ptes
[0] = old
;
585 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
) {
586 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
588 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
589 if (!pte_chain
->parent_ptes
[i
]) {
590 pte_chain
->parent_ptes
[i
] = parent_pte
;
594 pte_chain
= mmu_alloc_pte_chain(vcpu
);
596 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
597 pte_chain
->parent_ptes
[0] = parent_pte
;
600 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*page
,
603 struct kvm_pte_chain
*pte_chain
;
604 struct hlist_node
*node
;
607 if (!page
->multimapped
) {
608 BUG_ON(page
->parent_pte
!= parent_pte
);
609 page
->parent_pte
= NULL
;
612 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
)
613 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
614 if (!pte_chain
->parent_ptes
[i
])
616 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
618 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
619 && pte_chain
->parent_ptes
[i
+ 1]) {
620 pte_chain
->parent_ptes
[i
]
621 = pte_chain
->parent_ptes
[i
+ 1];
624 pte_chain
->parent_ptes
[i
] = NULL
;
626 hlist_del(&pte_chain
->link
);
627 mmu_free_pte_chain(pte_chain
);
628 if (hlist_empty(&page
->parent_ptes
)) {
629 page
->multimapped
= 0;
630 page
->parent_pte
= NULL
;
638 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
,
642 struct hlist_head
*bucket
;
643 struct kvm_mmu_page
*page
;
644 struct hlist_node
*node
;
646 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
647 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
648 bucket
= &kvm
->mmu_page_hash
[index
];
649 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
650 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
651 pgprintk("%s: found role %x\n",
652 __FUNCTION__
, page
->role
.word
);
658 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
663 unsigned hugepage_access
,
666 union kvm_mmu_page_role role
;
669 struct hlist_head
*bucket
;
670 struct kvm_mmu_page
*page
;
671 struct hlist_node
*node
;
674 role
.glevels
= vcpu
->mmu
.root_level
;
676 role
.metaphysical
= metaphysical
;
677 role
.hugepage_access
= hugepage_access
;
678 if (vcpu
->mmu
.root_level
<= PT32_ROOT_LEVEL
) {
679 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
680 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
681 role
.quadrant
= quadrant
;
683 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__
,
685 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
686 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
687 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
688 if (page
->gfn
== gfn
&& page
->role
.word
== role
.word
) {
689 mmu_page_add_parent_pte(vcpu
, page
, parent_pte
);
690 pgprintk("%s: found\n", __FUNCTION__
);
693 page
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
696 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__
, gfn
, role
.word
);
699 hlist_add_head(&page
->hash_link
, bucket
);
700 vcpu
->mmu
.prefetch_page(vcpu
, page
);
702 rmap_write_protect(vcpu
->kvm
, gfn
);
706 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
707 struct kvm_mmu_page
*page
)
715 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
716 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
717 if (is_shadow_present_pte(pt
[i
]))
718 rmap_remove(kvm
, &pt
[i
]);
719 pt
[i
] = shadow_trap_nonpresent_pte
;
721 kvm_flush_remote_tlbs(kvm
);
725 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
728 pt
[i
] = shadow_trap_nonpresent_pte
;
729 if (!is_shadow_present_pte(ent
))
731 ent
&= PT64_BASE_ADDR_MASK
;
732 mmu_page_remove_parent_pte(page_header(ent
), &pt
[i
]);
734 kvm_flush_remote_tlbs(kvm
);
737 static void kvm_mmu_put_page(struct kvm_mmu_page
*page
,
740 mmu_page_remove_parent_pte(page
, parent_pte
);
743 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
747 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
749 kvm
->vcpus
[i
]->last_pte_updated
= NULL
;
752 static void kvm_mmu_zap_page(struct kvm
*kvm
,
753 struct kvm_mmu_page
*page
)
757 while (page
->multimapped
|| page
->parent_pte
) {
758 if (!page
->multimapped
)
759 parent_pte
= page
->parent_pte
;
761 struct kvm_pte_chain
*chain
;
763 chain
= container_of(page
->parent_ptes
.first
,
764 struct kvm_pte_chain
, link
);
765 parent_pte
= chain
->parent_ptes
[0];
768 kvm_mmu_put_page(page
, parent_pte
);
769 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
771 kvm_mmu_page_unlink_children(kvm
, page
);
772 if (!page
->root_count
) {
773 hlist_del(&page
->hash_link
);
774 kvm_mmu_free_page(kvm
, page
);
776 list_move(&page
->link
, &kvm
->active_mmu_pages
);
777 kvm_mmu_reset_last_pte_updated(kvm
);
781 * Changing the number of mmu pages allocated to the vm
782 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
784 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
787 * If we set the number of mmu pages to be smaller be than the
788 * number of actived pages , we must to free some mmu pages before we
792 if ((kvm
->n_alloc_mmu_pages
- kvm
->n_free_mmu_pages
) >
794 int n_used_mmu_pages
= kvm
->n_alloc_mmu_pages
795 - kvm
->n_free_mmu_pages
;
797 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
798 struct kvm_mmu_page
*page
;
800 page
= container_of(kvm
->active_mmu_pages
.prev
,
801 struct kvm_mmu_page
, link
);
802 kvm_mmu_zap_page(kvm
, page
);
805 kvm
->n_free_mmu_pages
= 0;
808 kvm
->n_free_mmu_pages
+= kvm_nr_mmu_pages
809 - kvm
->n_alloc_mmu_pages
;
811 kvm
->n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
814 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
817 struct hlist_head
*bucket
;
818 struct kvm_mmu_page
*page
;
819 struct hlist_node
*node
, *n
;
822 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
824 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
825 bucket
= &kvm
->mmu_page_hash
[index
];
826 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
)
827 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
828 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__
, gfn
,
830 kvm_mmu_zap_page(kvm
, page
);
836 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
838 struct kvm_mmu_page
*page
;
840 while ((page
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
841 pgprintk("%s: zap %lx %x\n",
842 __FUNCTION__
, gfn
, page
->role
.word
);
843 kvm_mmu_zap_page(kvm
, page
);
847 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gpa_t gpa
)
849 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gpa
>> PAGE_SHIFT
));
850 struct kvm_mmu_page
*page_head
= page_header(__pa(pte
));
852 __set_bit(slot
, &page_head
->slot_bitmap
);
855 hpa_t
gpa_to_hpa(struct kvm
*kvm
, gpa_t gpa
)
860 ASSERT((gpa
& HPA_ERR_MASK
) == 0);
861 page
= gfn_to_page(kvm
, gpa
>> PAGE_SHIFT
);
862 hpa
= ((hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
) | (gpa
& (PAGE_SIZE
-1));
863 if (is_error_page(page
))
864 return hpa
| HPA_ERR_MASK
;
868 hpa_t
gva_to_hpa(struct kvm_vcpu
*vcpu
, gva_t gva
)
870 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
872 if (gpa
== UNMAPPED_GVA
)
874 return gpa_to_hpa(vcpu
->kvm
, gpa
);
877 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
879 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
881 if (gpa
== UNMAPPED_GVA
)
883 return pfn_to_page(gpa_to_hpa(vcpu
->kvm
, gpa
) >> PAGE_SHIFT
);
886 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
890 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, hpa_t p
)
892 int level
= PT32E_ROOT_LEVEL
;
893 hpa_t table_addr
= vcpu
->mmu
.root_hpa
;
896 u32 index
= PT64_INDEX(v
, level
);
900 ASSERT(VALID_PAGE(table_addr
));
901 table
= __va(table_addr
);
907 was_rmapped
= is_rmap_pte(pte
);
908 if (is_shadow_present_pte(pte
) && is_writeble_pte(pte
))
910 mark_page_dirty(vcpu
->kvm
, v
>> PAGE_SHIFT
);
911 page_header_update_slot(vcpu
->kvm
, table
, v
);
912 table
[index
] = p
| PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
915 rmap_add(vcpu
, &table
[index
], v
>> PAGE_SHIFT
);
917 kvm_release_page(pfn_to_page(p
>> PAGE_SHIFT
));
921 if (table
[index
] == shadow_trap_nonpresent_pte
) {
922 struct kvm_mmu_page
*new_table
;
925 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
927 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
929 1, 3, &table
[index
]);
931 pgprintk("nonpaging_map: ENOMEM\n");
932 kvm_release_page(pfn_to_page(p
>> PAGE_SHIFT
));
936 table
[index
] = __pa(new_table
->spt
) | PT_PRESENT_MASK
937 | PT_WRITABLE_MASK
| PT_USER_MASK
;
939 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
943 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
944 struct kvm_mmu_page
*sp
)
948 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
949 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
952 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
955 struct kvm_mmu_page
*page
;
957 if (!VALID_PAGE(vcpu
->mmu
.root_hpa
))
960 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
961 hpa_t root
= vcpu
->mmu
.root_hpa
;
963 page
= page_header(root
);
965 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
969 for (i
= 0; i
< 4; ++i
) {
970 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
973 root
&= PT64_BASE_ADDR_MASK
;
974 page
= page_header(root
);
977 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
979 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
982 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
986 struct kvm_mmu_page
*page
;
988 root_gfn
= vcpu
->cr3
>> PAGE_SHIFT
;
991 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
992 hpa_t root
= vcpu
->mmu
.root_hpa
;
994 ASSERT(!VALID_PAGE(root
));
995 page
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
996 PT64_ROOT_LEVEL
, 0, 0, NULL
);
997 root
= __pa(page
->spt
);
999 vcpu
->mmu
.root_hpa
= root
;
1003 for (i
= 0; i
< 4; ++i
) {
1004 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
1006 ASSERT(!VALID_PAGE(root
));
1007 if (vcpu
->mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1008 if (!is_present_pte(vcpu
->pdptrs
[i
])) {
1009 vcpu
->mmu
.pae_root
[i
] = 0;
1012 root_gfn
= vcpu
->pdptrs
[i
] >> PAGE_SHIFT
;
1013 } else if (vcpu
->mmu
.root_level
== 0)
1015 page
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1016 PT32_ROOT_LEVEL
, !is_paging(vcpu
),
1018 root
= __pa(page
->spt
);
1020 vcpu
->mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1022 vcpu
->mmu
.root_hpa
= __pa(vcpu
->mmu
.pae_root
);
1025 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1030 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1037 r
= mmu_topup_memory_caches(vcpu
);
1042 ASSERT(VALID_PAGE(vcpu
->mmu
.root_hpa
));
1045 paddr
= gpa_to_hpa(vcpu
->kvm
, addr
& PT64_BASE_ADDR_MASK
);
1047 if (is_error_hpa(paddr
)) {
1048 kvm_release_page(pfn_to_page((paddr
& PT64_BASE_ADDR_MASK
)
1053 return nonpaging_map(vcpu
, addr
& PAGE_MASK
, paddr
);
1056 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1058 mmu_free_roots(vcpu
);
1061 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1063 struct kvm_mmu
*context
= &vcpu
->mmu
;
1065 context
->new_cr3
= nonpaging_new_cr3
;
1066 context
->page_fault
= nonpaging_page_fault
;
1067 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1068 context
->free
= nonpaging_free
;
1069 context
->prefetch_page
= nonpaging_prefetch_page
;
1070 context
->root_level
= 0;
1071 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1072 context
->root_hpa
= INVALID_PAGE
;
1076 static void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1078 ++vcpu
->stat
.tlb_flush
;
1079 kvm_x86_ops
->tlb_flush(vcpu
);
1082 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1084 pgprintk("%s: cr3 %lx\n", __FUNCTION__
, vcpu
->cr3
);
1085 mmu_free_roots(vcpu
);
1088 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1092 kvm_x86_ops
->inject_page_fault(vcpu
, addr
, err_code
);
1095 static void paging_free(struct kvm_vcpu
*vcpu
)
1097 nonpaging_free(vcpu
);
1101 #include "paging_tmpl.h"
1105 #include "paging_tmpl.h"
1108 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1110 struct kvm_mmu
*context
= &vcpu
->mmu
;
1112 ASSERT(is_pae(vcpu
));
1113 context
->new_cr3
= paging_new_cr3
;
1114 context
->page_fault
= paging64_page_fault
;
1115 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1116 context
->prefetch_page
= paging64_prefetch_page
;
1117 context
->free
= paging_free
;
1118 context
->root_level
= level
;
1119 context
->shadow_root_level
= level
;
1120 context
->root_hpa
= INVALID_PAGE
;
1124 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1126 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1129 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1131 struct kvm_mmu
*context
= &vcpu
->mmu
;
1133 context
->new_cr3
= paging_new_cr3
;
1134 context
->page_fault
= paging32_page_fault
;
1135 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1136 context
->free
= paging_free
;
1137 context
->prefetch_page
= paging32_prefetch_page
;
1138 context
->root_level
= PT32_ROOT_LEVEL
;
1139 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1140 context
->root_hpa
= INVALID_PAGE
;
1144 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1146 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1149 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1152 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1154 if (!is_paging(vcpu
))
1155 return nonpaging_init_context(vcpu
);
1156 else if (is_long_mode(vcpu
))
1157 return paging64_init_context(vcpu
);
1158 else if (is_pae(vcpu
))
1159 return paging32E_init_context(vcpu
);
1161 return paging32_init_context(vcpu
);
1164 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1167 if (VALID_PAGE(vcpu
->mmu
.root_hpa
)) {
1168 vcpu
->mmu
.free(vcpu
);
1169 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
1173 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1175 destroy_kvm_mmu(vcpu
);
1176 return init_kvm_mmu(vcpu
);
1178 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
1180 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1184 mutex_lock(&vcpu
->kvm
->lock
);
1185 r
= mmu_topup_memory_caches(vcpu
);
1188 mmu_alloc_roots(vcpu
);
1189 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->mmu
.root_hpa
);
1190 kvm_mmu_flush_tlb(vcpu
);
1192 mutex_unlock(&vcpu
->kvm
->lock
);
1195 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1197 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1199 mmu_free_roots(vcpu
);
1202 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1203 struct kvm_mmu_page
*page
,
1207 struct kvm_mmu_page
*child
;
1210 if (is_shadow_present_pte(pte
)) {
1211 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1212 rmap_remove(vcpu
->kvm
, spte
);
1214 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1215 mmu_page_remove_parent_pte(child
, spte
);
1218 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
1219 kvm_flush_remote_tlbs(vcpu
->kvm
);
1222 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
1223 struct kvm_mmu_page
*page
,
1225 const void *new, int bytes
,
1228 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1231 if (page
->role
.glevels
== PT32_ROOT_LEVEL
)
1232 paging32_update_pte(vcpu
, page
, spte
, new, bytes
,
1235 paging64_update_pte(vcpu
, page
, spte
, new, bytes
,
1239 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
1241 u64
*spte
= vcpu
->last_pte_updated
;
1243 return !!(spte
&& (*spte
& PT_ACCESSED_MASK
));
1246 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1247 const u8
*new, int bytes
)
1249 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1250 struct kvm_mmu_page
*page
;
1251 struct hlist_node
*node
, *n
;
1252 struct hlist_head
*bucket
;
1255 unsigned offset
= offset_in_page(gpa
);
1257 unsigned page_offset
;
1258 unsigned misaligned
;
1264 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__
, gpa
, bytes
);
1265 kvm_mmu_audit(vcpu
, "pre pte write");
1266 if (gfn
== vcpu
->last_pt_write_gfn
1267 && !last_updated_pte_accessed(vcpu
)) {
1268 ++vcpu
->last_pt_write_count
;
1269 if (vcpu
->last_pt_write_count
>= 3)
1272 vcpu
->last_pt_write_gfn
= gfn
;
1273 vcpu
->last_pt_write_count
= 1;
1274 vcpu
->last_pte_updated
= NULL
;
1276 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
1277 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
1278 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
) {
1279 if (page
->gfn
!= gfn
|| page
->role
.metaphysical
)
1281 pte_size
= page
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1282 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1283 misaligned
|= bytes
< 4;
1284 if (misaligned
|| flooded
) {
1286 * Misaligned accesses are too much trouble to fix
1287 * up; also, they usually indicate a page is not used
1290 * If we're seeing too many writes to a page,
1291 * it may no longer be a page table, or we may be
1292 * forking, in which case it is better to unmap the
1295 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1296 gpa
, bytes
, page
->role
.word
);
1297 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1300 page_offset
= offset
;
1301 level
= page
->role
.level
;
1303 if (page
->role
.glevels
== PT32_ROOT_LEVEL
) {
1304 page_offset
<<= 1; /* 32->64 */
1306 * A 32-bit pde maps 4MB while the shadow pdes map
1307 * only 2MB. So we need to double the offset again
1308 * and zap two pdes instead of one.
1310 if (level
== PT32_ROOT_LEVEL
) {
1311 page_offset
&= ~7; /* kill rounding error */
1315 quadrant
= page_offset
>> PAGE_SHIFT
;
1316 page_offset
&= ~PAGE_MASK
;
1317 if (quadrant
!= page
->role
.quadrant
)
1320 spte
= &page
->spt
[page_offset
/ sizeof(*spte
)];
1322 mmu_pte_write_zap_pte(vcpu
, page
, spte
);
1323 mmu_pte_write_new_pte(vcpu
, page
, spte
, new, bytes
,
1324 page_offset
& (pte_size
- 1));
1328 kvm_mmu_audit(vcpu
, "post pte write");
1331 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1333 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
1335 return kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1338 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1340 while (vcpu
->kvm
->n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1341 struct kvm_mmu_page
*page
;
1343 page
= container_of(vcpu
->kvm
->active_mmu_pages
.prev
,
1344 struct kvm_mmu_page
, link
);
1345 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1349 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1351 struct kvm_mmu_page
*page
;
1353 while (!list_empty(&vcpu
->kvm
->active_mmu_pages
)) {
1354 page
= container_of(vcpu
->kvm
->active_mmu_pages
.next
,
1355 struct kvm_mmu_page
, link
);
1356 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1358 free_page((unsigned long)vcpu
->mmu
.pae_root
);
1361 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1368 if (vcpu
->kvm
->n_requested_mmu_pages
)
1369 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_requested_mmu_pages
;
1371 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_alloc_mmu_pages
;
1373 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1374 * Therefore we need to allocate shadow page tables in the first
1375 * 4GB of memory, which happens to fit the DMA32 zone.
1377 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1380 vcpu
->mmu
.pae_root
= page_address(page
);
1381 for (i
= 0; i
< 4; ++i
)
1382 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1387 free_mmu_pages(vcpu
);
1391 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1394 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1396 return alloc_mmu_pages(vcpu
);
1399 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1402 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1404 return init_kvm_mmu(vcpu
);
1407 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1411 destroy_kvm_mmu(vcpu
);
1412 free_mmu_pages(vcpu
);
1413 mmu_free_memory_caches(vcpu
);
1416 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
1418 struct kvm_mmu_page
*page
;
1420 list_for_each_entry(page
, &kvm
->active_mmu_pages
, link
) {
1424 if (!test_bit(slot
, &page
->slot_bitmap
))
1428 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1430 if (pt
[i
] & PT_WRITABLE_MASK
)
1431 pt
[i
] &= ~PT_WRITABLE_MASK
;
1435 void kvm_mmu_zap_all(struct kvm
*kvm
)
1437 struct kvm_mmu_page
*page
, *node
;
1439 list_for_each_entry_safe(page
, node
, &kvm
->active_mmu_pages
, link
)
1440 kvm_mmu_zap_page(kvm
, page
);
1442 kvm_flush_remote_tlbs(kvm
);
1445 void kvm_mmu_module_exit(void)
1447 if (pte_chain_cache
)
1448 kmem_cache_destroy(pte_chain_cache
);
1449 if (rmap_desc_cache
)
1450 kmem_cache_destroy(rmap_desc_cache
);
1451 if (mmu_page_header_cache
)
1452 kmem_cache_destroy(mmu_page_header_cache
);
1455 int kvm_mmu_module_init(void)
1457 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
1458 sizeof(struct kvm_pte_chain
),
1460 if (!pte_chain_cache
)
1462 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
1463 sizeof(struct kvm_rmap_desc
),
1465 if (!rmap_desc_cache
)
1468 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
1469 sizeof(struct kvm_mmu_page
),
1471 if (!mmu_page_header_cache
)
1477 kvm_mmu_module_exit();
1483 static const char *audit_msg
;
1485 static gva_t
canonicalize(gva_t gva
)
1487 #ifdef CONFIG_X86_64
1488 gva
= (long long)(gva
<< 16) >> 16;
1493 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
1494 gva_t va
, int level
)
1496 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
1498 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
1500 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
1503 if (ent
== shadow_trap_nonpresent_pte
)
1506 va
= canonicalize(va
);
1508 if (ent
== shadow_notrap_nonpresent_pte
)
1509 printk(KERN_ERR
"audit: (%s) nontrapping pte"
1510 " in nonleaf level: levels %d gva %lx"
1511 " level %d pte %llx\n", audit_msg
,
1512 vcpu
->mmu
.root_level
, va
, level
, ent
);
1514 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
1516 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, va
);
1517 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
1520 if (is_shadow_present_pte(ent
)
1521 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
1522 printk(KERN_ERR
"xx audit error: (%s) levels %d"
1523 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1524 audit_msg
, vcpu
->mmu
.root_level
,
1526 is_shadow_present_pte(ent
));
1527 else if (ent
== shadow_notrap_nonpresent_pte
1528 && !is_error_hpa(hpa
))
1529 printk(KERN_ERR
"audit: (%s) notrap shadow,"
1530 " valid guest gva %lx\n", audit_msg
, va
);
1531 page
= pfn_to_page((gpa
& PT64_BASE_ADDR_MASK
)
1533 kvm_release_page(page
);
1539 static void audit_mappings(struct kvm_vcpu
*vcpu
)
1543 if (vcpu
->mmu
.root_level
== 4)
1544 audit_mappings_page(vcpu
, vcpu
->mmu
.root_hpa
, 0, 4);
1546 for (i
= 0; i
< 4; ++i
)
1547 if (vcpu
->mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
1548 audit_mappings_page(vcpu
,
1549 vcpu
->mmu
.pae_root
[i
],
1554 static int count_rmaps(struct kvm_vcpu
*vcpu
)
1559 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
1560 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
1561 struct kvm_rmap_desc
*d
;
1563 for (j
= 0; j
< m
->npages
; ++j
) {
1564 unsigned long *rmapp
= &m
->rmap
[j
];
1568 if (!(*rmapp
& 1)) {
1572 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
1574 for (k
= 0; k
< RMAP_EXT
; ++k
)
1575 if (d
->shadow_ptes
[k
])
1586 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
1589 struct kvm_mmu_page
*page
;
1592 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1593 u64
*pt
= page
->spt
;
1595 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1598 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1601 if (!(ent
& PT_PRESENT_MASK
))
1603 if (!(ent
& PT_WRITABLE_MASK
))
1611 static void audit_rmap(struct kvm_vcpu
*vcpu
)
1613 int n_rmap
= count_rmaps(vcpu
);
1614 int n_actual
= count_writable_mappings(vcpu
);
1616 if (n_rmap
!= n_actual
)
1617 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
1618 __FUNCTION__
, audit_msg
, n_rmap
, n_actual
);
1621 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
1623 struct kvm_mmu_page
*page
;
1624 struct kvm_memory_slot
*slot
;
1625 unsigned long *rmapp
;
1628 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1629 if (page
->role
.metaphysical
)
1632 slot
= gfn_to_memslot(vcpu
->kvm
, page
->gfn
);
1633 gfn
= unalias_gfn(vcpu
->kvm
, page
->gfn
);
1634 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
1636 printk(KERN_ERR
"%s: (%s) shadow page has writable"
1637 " mappings: gfn %lx role %x\n",
1638 __FUNCTION__
, audit_msg
, page
->gfn
,
1643 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
1650 audit_write_protection(vcpu
);
1651 audit_mappings(vcpu
);