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>
39 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
41 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
46 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
47 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
51 #define pgprintk(x...) do { } while (0)
52 #define rmap_printk(x...) do { } while (0)
56 #if defined(MMU_DEBUG) || defined(AUDIT)
61 #define ASSERT(x) do { } while (0)
65 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
66 __FILE__, __LINE__, #x); \
70 #define PT64_PT_BITS 9
71 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
72 #define PT32_PT_BITS 10
73 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
75 #define PT_WRITABLE_SHIFT 1
77 #define PT_PRESENT_MASK (1ULL << 0)
78 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
79 #define PT_USER_MASK (1ULL << 2)
80 #define PT_PWT_MASK (1ULL << 3)
81 #define PT_PCD_MASK (1ULL << 4)
82 #define PT_ACCESSED_MASK (1ULL << 5)
83 #define PT_DIRTY_MASK (1ULL << 6)
84 #define PT_PAGE_SIZE_MASK (1ULL << 7)
85 #define PT_PAT_MASK (1ULL << 7)
86 #define PT_GLOBAL_MASK (1ULL << 8)
87 #define PT64_NX_MASK (1ULL << 63)
89 #define PT_PAT_SHIFT 7
90 #define PT_DIR_PAT_SHIFT 12
91 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
93 #define PT32_DIR_PSE36_SIZE 4
94 #define PT32_DIR_PSE36_SHIFT 13
95 #define PT32_DIR_PSE36_MASK \
96 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
99 #define PT_FIRST_AVAIL_BITS_SHIFT 9
100 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
102 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
104 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
106 #define PT64_LEVEL_BITS 9
108 #define PT64_LEVEL_SHIFT(level) \
109 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
111 #define PT64_LEVEL_MASK(level) \
112 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
114 #define PT64_INDEX(address, level)\
115 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
118 #define PT32_LEVEL_BITS 10
120 #define PT32_LEVEL_SHIFT(level) \
121 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
123 #define PT32_LEVEL_MASK(level) \
124 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
126 #define PT32_INDEX(address, level)\
127 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
130 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
131 #define PT64_DIR_BASE_ADDR_MASK \
132 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
134 #define PT32_BASE_ADDR_MASK PAGE_MASK
135 #define PT32_DIR_BASE_ADDR_MASK \
136 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
138 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
141 #define PFERR_PRESENT_MASK (1U << 0)
142 #define PFERR_WRITE_MASK (1U << 1)
143 #define PFERR_USER_MASK (1U << 2)
144 #define PFERR_FETCH_MASK (1U << 4)
146 #define PT64_ROOT_LEVEL 4
147 #define PT32_ROOT_LEVEL 2
148 #define PT32E_ROOT_LEVEL 3
150 #define PT_DIRECTORY_LEVEL 2
151 #define PT_PAGE_TABLE_LEVEL 1
155 struct kvm_rmap_desc
{
156 u64
*shadow_ptes
[RMAP_EXT
];
157 struct kvm_rmap_desc
*more
;
160 static struct kmem_cache
*pte_chain_cache
;
161 static struct kmem_cache
*rmap_desc_cache
;
162 static struct kmem_cache
*mmu_page_header_cache
;
164 static u64 __read_mostly shadow_trap_nonpresent_pte
;
165 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
167 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
169 shadow_trap_nonpresent_pte
= trap_pte
;
170 shadow_notrap_nonpresent_pte
= notrap_pte
;
172 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
174 static int is_write_protection(struct kvm_vcpu
*vcpu
)
176 return vcpu
->cr0
& X86_CR0_WP
;
179 static int is_cpuid_PSE36(void)
184 static int is_nx(struct kvm_vcpu
*vcpu
)
186 return vcpu
->shadow_efer
& EFER_NX
;
189 static int is_present_pte(unsigned long pte
)
191 return pte
& PT_PRESENT_MASK
;
194 static int is_shadow_present_pte(u64 pte
)
196 pte
&= ~PT_SHADOW_IO_MARK
;
197 return pte
!= shadow_trap_nonpresent_pte
198 && pte
!= shadow_notrap_nonpresent_pte
;
201 static int is_writeble_pte(unsigned long pte
)
203 return pte
& PT_WRITABLE_MASK
;
206 static int is_dirty_pte(unsigned long pte
)
208 return pte
& PT_DIRTY_MASK
;
211 static int is_io_pte(unsigned long pte
)
213 return pte
& PT_SHADOW_IO_MARK
;
216 static int is_rmap_pte(u64 pte
)
218 return pte
!= shadow_trap_nonpresent_pte
219 && pte
!= shadow_notrap_nonpresent_pte
;
222 static gfn_t
pse36_gfn_delta(u32 gpte
)
224 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
226 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
229 static void set_shadow_pte(u64
*sptep
, u64 spte
)
232 set_64bit((unsigned long *)sptep
, spte
);
234 set_64bit((unsigned long long *)sptep
, spte
);
238 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
239 struct kmem_cache
*base_cache
, int min
)
243 if (cache
->nobjs
>= min
)
245 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
246 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
249 cache
->objects
[cache
->nobjs
++] = obj
;
254 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
257 kfree(mc
->objects
[--mc
->nobjs
]);
260 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
265 if (cache
->nobjs
>= min
)
267 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
268 page
= alloc_page(GFP_KERNEL
);
271 set_page_private(page
, 0);
272 cache
->objects
[cache
->nobjs
++] = page_address(page
);
277 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
280 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
283 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
287 kvm_mmu_free_some_pages(vcpu
);
288 r
= mmu_topup_memory_cache(&vcpu
->mmu_pte_chain_cache
,
292 r
= mmu_topup_memory_cache(&vcpu
->mmu_rmap_desc_cache
,
296 r
= mmu_topup_memory_cache_page(&vcpu
->mmu_page_cache
, 8);
299 r
= mmu_topup_memory_cache(&vcpu
->mmu_page_header_cache
,
300 mmu_page_header_cache
, 4);
305 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
307 mmu_free_memory_cache(&vcpu
->mmu_pte_chain_cache
);
308 mmu_free_memory_cache(&vcpu
->mmu_rmap_desc_cache
);
309 mmu_free_memory_cache_page(&vcpu
->mmu_page_cache
);
310 mmu_free_memory_cache(&vcpu
->mmu_page_header_cache
);
313 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
319 p
= mc
->objects
[--mc
->nobjs
];
324 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
326 return mmu_memory_cache_alloc(&vcpu
->mmu_pte_chain_cache
,
327 sizeof(struct kvm_pte_chain
));
330 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
335 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
337 return mmu_memory_cache_alloc(&vcpu
->mmu_rmap_desc_cache
,
338 sizeof(struct kvm_rmap_desc
));
341 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
347 * Take gfn and return the reverse mapping to it.
348 * Note: gfn must be unaliased before this function get called
351 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
)
353 struct kvm_memory_slot
*slot
;
355 slot
= gfn_to_memslot(kvm
, gfn
);
356 return &slot
->rmap
[gfn
- slot
->base_gfn
];
360 * Reverse mapping data structures:
362 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
363 * that points to page_address(page).
365 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
366 * containing more mappings.
368 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
370 struct kvm_mmu_page
*page
;
371 struct kvm_rmap_desc
*desc
;
372 unsigned long *rmapp
;
375 if (!is_rmap_pte(*spte
))
377 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
378 page
= page_header(__pa(spte
));
379 page
->gfns
[spte
- page
->spt
] = gfn
;
380 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
);
382 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
383 *rmapp
= (unsigned long)spte
;
384 } else if (!(*rmapp
& 1)) {
385 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
386 desc
= mmu_alloc_rmap_desc(vcpu
);
387 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
388 desc
->shadow_ptes
[1] = spte
;
389 *rmapp
= (unsigned long)desc
| 1;
391 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
392 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
393 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
395 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
396 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
399 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
401 desc
->shadow_ptes
[i
] = spte
;
405 static void rmap_desc_remove_entry(unsigned long *rmapp
,
406 struct kvm_rmap_desc
*desc
,
408 struct kvm_rmap_desc
*prev_desc
)
412 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
414 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
415 desc
->shadow_ptes
[j
] = NULL
;
418 if (!prev_desc
&& !desc
->more
)
419 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
422 prev_desc
->more
= desc
->more
;
424 *rmapp
= (unsigned long)desc
->more
| 1;
425 mmu_free_rmap_desc(desc
);
428 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
430 struct kvm_rmap_desc
*desc
;
431 struct kvm_rmap_desc
*prev_desc
;
432 struct kvm_mmu_page
*page
;
433 struct page
*release_page
;
434 unsigned long *rmapp
;
437 if (!is_rmap_pte(*spte
))
439 page
= page_header(__pa(spte
));
440 release_page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
441 if (is_writeble_pte(*spte
))
442 kvm_release_page_dirty(release_page
);
444 kvm_release_page_clean(release_page
);
445 rmapp
= gfn_to_rmap(kvm
, page
->gfns
[spte
- page
->spt
]);
447 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
449 } else if (!(*rmapp
& 1)) {
450 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
451 if ((u64
*)*rmapp
!= spte
) {
452 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
458 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
459 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
462 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
463 if (desc
->shadow_ptes
[i
] == spte
) {
464 rmap_desc_remove_entry(rmapp
,
476 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
478 struct kvm_rmap_desc
*desc
;
479 struct kvm_rmap_desc
*prev_desc
;
485 else if (!(*rmapp
& 1)) {
487 return (u64
*)*rmapp
;
490 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
494 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
495 if (prev_spte
== spte
)
496 return desc
->shadow_ptes
[i
];
497 prev_spte
= desc
->shadow_ptes
[i
];
504 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
506 unsigned long *rmapp
;
509 gfn
= unalias_gfn(kvm
, gfn
);
510 rmapp
= gfn_to_rmap(kvm
, gfn
);
512 spte
= rmap_next(kvm
, rmapp
, NULL
);
515 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
516 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
517 if (is_writeble_pte(*spte
))
518 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
519 kvm_flush_remote_tlbs(kvm
);
520 spte
= rmap_next(kvm
, rmapp
, spte
);
525 static int is_empty_shadow_page(u64
*spt
)
530 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
531 if ((*pos
& ~PT_SHADOW_IO_MARK
) != shadow_trap_nonpresent_pte
) {
532 printk(KERN_ERR
"%s: %p %llx\n", __FUNCTION__
,
540 static void kvm_mmu_free_page(struct kvm
*kvm
,
541 struct kvm_mmu_page
*page_head
)
543 ASSERT(is_empty_shadow_page(page_head
->spt
));
544 list_del(&page_head
->link
);
545 __free_page(virt_to_page(page_head
->spt
));
546 __free_page(virt_to_page(page_head
->gfns
));
548 ++kvm
->n_free_mmu_pages
;
551 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
556 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
559 struct kvm_mmu_page
*page
;
561 if (!vcpu
->kvm
->n_free_mmu_pages
)
564 page
= mmu_memory_cache_alloc(&vcpu
->mmu_page_header_cache
,
566 page
->spt
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
567 page
->gfns
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
568 set_page_private(virt_to_page(page
->spt
), (unsigned long)page
);
569 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
570 ASSERT(is_empty_shadow_page(page
->spt
));
571 page
->slot_bitmap
= 0;
572 page
->multimapped
= 0;
573 page
->parent_pte
= parent_pte
;
574 --vcpu
->kvm
->n_free_mmu_pages
;
578 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
579 struct kvm_mmu_page
*page
, u64
*parent_pte
)
581 struct kvm_pte_chain
*pte_chain
;
582 struct hlist_node
*node
;
587 if (!page
->multimapped
) {
588 u64
*old
= page
->parent_pte
;
591 page
->parent_pte
= parent_pte
;
594 page
->multimapped
= 1;
595 pte_chain
= mmu_alloc_pte_chain(vcpu
);
596 INIT_HLIST_HEAD(&page
->parent_ptes
);
597 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
598 pte_chain
->parent_ptes
[0] = old
;
600 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
) {
601 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
603 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
604 if (!pte_chain
->parent_ptes
[i
]) {
605 pte_chain
->parent_ptes
[i
] = parent_pte
;
609 pte_chain
= mmu_alloc_pte_chain(vcpu
);
611 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
612 pte_chain
->parent_ptes
[0] = parent_pte
;
615 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*page
,
618 struct kvm_pte_chain
*pte_chain
;
619 struct hlist_node
*node
;
622 if (!page
->multimapped
) {
623 BUG_ON(page
->parent_pte
!= parent_pte
);
624 page
->parent_pte
= NULL
;
627 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
)
628 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
629 if (!pte_chain
->parent_ptes
[i
])
631 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
633 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
634 && pte_chain
->parent_ptes
[i
+ 1]) {
635 pte_chain
->parent_ptes
[i
]
636 = pte_chain
->parent_ptes
[i
+ 1];
639 pte_chain
->parent_ptes
[i
] = NULL
;
641 hlist_del(&pte_chain
->link
);
642 mmu_free_pte_chain(pte_chain
);
643 if (hlist_empty(&page
->parent_ptes
)) {
644 page
->multimapped
= 0;
645 page
->parent_pte
= NULL
;
653 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
,
657 struct hlist_head
*bucket
;
658 struct kvm_mmu_page
*page
;
659 struct hlist_node
*node
;
661 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
662 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
663 bucket
= &kvm
->mmu_page_hash
[index
];
664 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
665 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
666 pgprintk("%s: found role %x\n",
667 __FUNCTION__
, page
->role
.word
);
673 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
678 unsigned hugepage_access
,
681 union kvm_mmu_page_role role
;
684 struct hlist_head
*bucket
;
685 struct kvm_mmu_page
*page
;
686 struct hlist_node
*node
;
689 role
.glevels
= vcpu
->mmu
.root_level
;
691 role
.metaphysical
= metaphysical
;
692 role
.hugepage_access
= hugepage_access
;
693 if (vcpu
->mmu
.root_level
<= PT32_ROOT_LEVEL
) {
694 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
695 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
696 role
.quadrant
= quadrant
;
698 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__
,
700 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
701 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
702 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
703 if (page
->gfn
== gfn
&& page
->role
.word
== role
.word
) {
704 mmu_page_add_parent_pte(vcpu
, page
, parent_pte
);
705 pgprintk("%s: found\n", __FUNCTION__
);
708 page
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
711 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__
, gfn
, role
.word
);
714 hlist_add_head(&page
->hash_link
, bucket
);
715 vcpu
->mmu
.prefetch_page(vcpu
, page
);
717 rmap_write_protect(vcpu
->kvm
, gfn
);
721 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
722 struct kvm_mmu_page
*page
)
730 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
731 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
732 if (is_shadow_present_pte(pt
[i
]))
733 rmap_remove(kvm
, &pt
[i
]);
734 pt
[i
] = shadow_trap_nonpresent_pte
;
736 kvm_flush_remote_tlbs(kvm
);
740 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
743 pt
[i
] = shadow_trap_nonpresent_pte
;
744 if (!is_shadow_present_pte(ent
))
746 ent
&= PT64_BASE_ADDR_MASK
;
747 mmu_page_remove_parent_pte(page_header(ent
), &pt
[i
]);
749 kvm_flush_remote_tlbs(kvm
);
752 static void kvm_mmu_put_page(struct kvm_mmu_page
*page
,
755 mmu_page_remove_parent_pte(page
, parent_pte
);
758 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
762 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
764 kvm
->vcpus
[i
]->last_pte_updated
= NULL
;
767 static void kvm_mmu_zap_page(struct kvm
*kvm
,
768 struct kvm_mmu_page
*page
)
772 ++kvm
->stat
.mmu_shadow_zapped
;
773 while (page
->multimapped
|| page
->parent_pte
) {
774 if (!page
->multimapped
)
775 parent_pte
= page
->parent_pte
;
777 struct kvm_pte_chain
*chain
;
779 chain
= container_of(page
->parent_ptes
.first
,
780 struct kvm_pte_chain
, link
);
781 parent_pte
= chain
->parent_ptes
[0];
784 kvm_mmu_put_page(page
, parent_pte
);
785 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
787 kvm_mmu_page_unlink_children(kvm
, page
);
788 if (!page
->root_count
) {
789 hlist_del(&page
->hash_link
);
790 kvm_mmu_free_page(kvm
, page
);
792 list_move(&page
->link
, &kvm
->active_mmu_pages
);
793 kvm_mmu_reset_last_pte_updated(kvm
);
797 * Changing the number of mmu pages allocated to the vm
798 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
800 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
803 * If we set the number of mmu pages to be smaller be than the
804 * number of actived pages , we must to free some mmu pages before we
808 if ((kvm
->n_alloc_mmu_pages
- kvm
->n_free_mmu_pages
) >
810 int n_used_mmu_pages
= kvm
->n_alloc_mmu_pages
811 - kvm
->n_free_mmu_pages
;
813 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
814 struct kvm_mmu_page
*page
;
816 page
= container_of(kvm
->active_mmu_pages
.prev
,
817 struct kvm_mmu_page
, link
);
818 kvm_mmu_zap_page(kvm
, page
);
821 kvm
->n_free_mmu_pages
= 0;
824 kvm
->n_free_mmu_pages
+= kvm_nr_mmu_pages
825 - kvm
->n_alloc_mmu_pages
;
827 kvm
->n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
830 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
833 struct hlist_head
*bucket
;
834 struct kvm_mmu_page
*page
;
835 struct hlist_node
*node
, *n
;
838 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
840 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
841 bucket
= &kvm
->mmu_page_hash
[index
];
842 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
)
843 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
844 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__
, gfn
,
846 kvm_mmu_zap_page(kvm
, page
);
852 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
854 struct kvm_mmu_page
*page
;
856 while ((page
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
857 pgprintk("%s: zap %lx %x\n",
858 __FUNCTION__
, gfn
, page
->role
.word
);
859 kvm_mmu_zap_page(kvm
, page
);
863 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gpa_t gpa
)
865 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gpa
>> PAGE_SHIFT
));
866 struct kvm_mmu_page
*page_head
= page_header(__pa(pte
));
868 __set_bit(slot
, &page_head
->slot_bitmap
);
871 hpa_t
gpa_to_hpa(struct kvm
*kvm
, gpa_t gpa
)
876 ASSERT((gpa
& HPA_ERR_MASK
) == 0);
877 page
= gfn_to_page(kvm
, gpa
>> PAGE_SHIFT
);
878 hpa
= ((hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
) | (gpa
& (PAGE_SIZE
-1));
879 if (is_error_page(page
))
880 return hpa
| HPA_ERR_MASK
;
884 hpa_t
gva_to_hpa(struct kvm_vcpu
*vcpu
, gva_t gva
)
886 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
888 if (gpa
== UNMAPPED_GVA
)
890 return gpa_to_hpa(vcpu
->kvm
, gpa
);
893 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
895 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
897 if (gpa
== UNMAPPED_GVA
)
899 return pfn_to_page(gpa_to_hpa(vcpu
->kvm
, gpa
) >> PAGE_SHIFT
);
902 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
906 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, hpa_t p
)
908 int level
= PT32E_ROOT_LEVEL
;
909 hpa_t table_addr
= vcpu
->mmu
.root_hpa
;
912 page
= pfn_to_page(p
>> PAGE_SHIFT
);
914 u32 index
= PT64_INDEX(v
, level
);
918 ASSERT(VALID_PAGE(table_addr
));
919 table
= __va(table_addr
);
925 was_rmapped
= is_rmap_pte(pte
);
926 if (is_shadow_present_pte(pte
) && is_writeble_pte(pte
)) {
927 kvm_release_page_clean(page
);
930 mark_page_dirty(vcpu
->kvm
, v
>> PAGE_SHIFT
);
931 page_header_update_slot(vcpu
->kvm
, table
, v
);
932 table
[index
] = p
| PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
935 rmap_add(vcpu
, &table
[index
], v
>> PAGE_SHIFT
);
937 kvm_release_page_clean(page
);
942 if (table
[index
] == shadow_trap_nonpresent_pte
) {
943 struct kvm_mmu_page
*new_table
;
946 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
948 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
950 1, 3, &table
[index
]);
952 pgprintk("nonpaging_map: ENOMEM\n");
953 kvm_release_page_clean(page
);
957 table
[index
] = __pa(new_table
->spt
) | PT_PRESENT_MASK
958 | PT_WRITABLE_MASK
| PT_USER_MASK
;
960 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
964 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
965 struct kvm_mmu_page
*sp
)
969 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
970 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
973 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
976 struct kvm_mmu_page
*page
;
978 if (!VALID_PAGE(vcpu
->mmu
.root_hpa
))
981 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
982 hpa_t root
= vcpu
->mmu
.root_hpa
;
984 page
= page_header(root
);
986 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
990 for (i
= 0; i
< 4; ++i
) {
991 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
994 root
&= PT64_BASE_ADDR_MASK
;
995 page
= page_header(root
);
998 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1000 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
1003 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
1007 struct kvm_mmu_page
*page
;
1009 root_gfn
= vcpu
->cr3
>> PAGE_SHIFT
;
1011 #ifdef CONFIG_X86_64
1012 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1013 hpa_t root
= vcpu
->mmu
.root_hpa
;
1015 ASSERT(!VALID_PAGE(root
));
1016 page
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1017 PT64_ROOT_LEVEL
, 0, 0, NULL
);
1018 root
= __pa(page
->spt
);
1020 vcpu
->mmu
.root_hpa
= root
;
1024 for (i
= 0; i
< 4; ++i
) {
1025 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
1027 ASSERT(!VALID_PAGE(root
));
1028 if (vcpu
->mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1029 if (!is_present_pte(vcpu
->pdptrs
[i
])) {
1030 vcpu
->mmu
.pae_root
[i
] = 0;
1033 root_gfn
= vcpu
->pdptrs
[i
] >> PAGE_SHIFT
;
1034 } else if (vcpu
->mmu
.root_level
== 0)
1036 page
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1037 PT32_ROOT_LEVEL
, !is_paging(vcpu
),
1039 root
= __pa(page
->spt
);
1041 vcpu
->mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1043 vcpu
->mmu
.root_hpa
= __pa(vcpu
->mmu
.pae_root
);
1046 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1051 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1058 r
= mmu_topup_memory_caches(vcpu
);
1063 ASSERT(VALID_PAGE(vcpu
->mmu
.root_hpa
));
1066 paddr
= gpa_to_hpa(vcpu
->kvm
, addr
& PT64_BASE_ADDR_MASK
);
1068 if (is_error_hpa(paddr
)) {
1069 kvm_release_page_clean(pfn_to_page((paddr
& PT64_BASE_ADDR_MASK
)
1074 return nonpaging_map(vcpu
, addr
& PAGE_MASK
, paddr
);
1077 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1079 mmu_free_roots(vcpu
);
1082 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1084 struct kvm_mmu
*context
= &vcpu
->mmu
;
1086 context
->new_cr3
= nonpaging_new_cr3
;
1087 context
->page_fault
= nonpaging_page_fault
;
1088 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1089 context
->free
= nonpaging_free
;
1090 context
->prefetch_page
= nonpaging_prefetch_page
;
1091 context
->root_level
= 0;
1092 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1093 context
->root_hpa
= INVALID_PAGE
;
1097 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1099 ++vcpu
->stat
.tlb_flush
;
1100 kvm_x86_ops
->tlb_flush(vcpu
);
1103 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1105 pgprintk("%s: cr3 %lx\n", __FUNCTION__
, vcpu
->cr3
);
1106 mmu_free_roots(vcpu
);
1109 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1113 kvm_x86_ops
->inject_page_fault(vcpu
, addr
, err_code
);
1116 static void paging_free(struct kvm_vcpu
*vcpu
)
1118 nonpaging_free(vcpu
);
1122 #include "paging_tmpl.h"
1126 #include "paging_tmpl.h"
1129 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1131 struct kvm_mmu
*context
= &vcpu
->mmu
;
1133 ASSERT(is_pae(vcpu
));
1134 context
->new_cr3
= paging_new_cr3
;
1135 context
->page_fault
= paging64_page_fault
;
1136 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1137 context
->prefetch_page
= paging64_prefetch_page
;
1138 context
->free
= paging_free
;
1139 context
->root_level
= level
;
1140 context
->shadow_root_level
= level
;
1141 context
->root_hpa
= INVALID_PAGE
;
1145 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1147 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1150 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1152 struct kvm_mmu
*context
= &vcpu
->mmu
;
1154 context
->new_cr3
= paging_new_cr3
;
1155 context
->page_fault
= paging32_page_fault
;
1156 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1157 context
->free
= paging_free
;
1158 context
->prefetch_page
= paging32_prefetch_page
;
1159 context
->root_level
= PT32_ROOT_LEVEL
;
1160 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1161 context
->root_hpa
= INVALID_PAGE
;
1165 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1167 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1170 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1173 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1175 if (!is_paging(vcpu
))
1176 return nonpaging_init_context(vcpu
);
1177 else if (is_long_mode(vcpu
))
1178 return paging64_init_context(vcpu
);
1179 else if (is_pae(vcpu
))
1180 return paging32E_init_context(vcpu
);
1182 return paging32_init_context(vcpu
);
1185 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1188 if (VALID_PAGE(vcpu
->mmu
.root_hpa
)) {
1189 vcpu
->mmu
.free(vcpu
);
1190 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
1194 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1196 destroy_kvm_mmu(vcpu
);
1197 return init_kvm_mmu(vcpu
);
1199 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
1201 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1205 mutex_lock(&vcpu
->kvm
->lock
);
1206 r
= mmu_topup_memory_caches(vcpu
);
1209 mmu_alloc_roots(vcpu
);
1210 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->mmu
.root_hpa
);
1211 kvm_mmu_flush_tlb(vcpu
);
1213 mutex_unlock(&vcpu
->kvm
->lock
);
1216 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1218 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1220 mmu_free_roots(vcpu
);
1223 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1224 struct kvm_mmu_page
*page
,
1228 struct kvm_mmu_page
*child
;
1231 if (is_shadow_present_pte(pte
)) {
1232 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1233 rmap_remove(vcpu
->kvm
, spte
);
1235 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1236 mmu_page_remove_parent_pte(child
, spte
);
1239 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
1242 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
1243 struct kvm_mmu_page
*page
,
1245 const void *new, int bytes
,
1248 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
1249 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
1253 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
1254 if (page
->role
.glevels
== PT32_ROOT_LEVEL
)
1255 paging32_update_pte(vcpu
, page
, spte
, new, bytes
,
1258 paging64_update_pte(vcpu
, page
, spte
, new, bytes
,
1262 static bool need_remote_flush(u64 old
, u64
new)
1264 if (!is_shadow_present_pte(old
))
1266 if (!is_shadow_present_pte(new))
1268 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
1270 old
^= PT64_NX_MASK
;
1271 new ^= PT64_NX_MASK
;
1272 return (old
& ~new & PT64_PERM_MASK
) != 0;
1275 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
1277 if (need_remote_flush(old
, new))
1278 kvm_flush_remote_tlbs(vcpu
->kvm
);
1280 kvm_mmu_flush_tlb(vcpu
);
1283 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
1285 u64
*spte
= vcpu
->last_pte_updated
;
1287 return !!(spte
&& (*spte
& PT_ACCESSED_MASK
));
1290 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1291 const u8
*new, int bytes
)
1293 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1294 struct kvm_mmu_page
*page
;
1295 struct hlist_node
*node
, *n
;
1296 struct hlist_head
*bucket
;
1300 unsigned offset
= offset_in_page(gpa
);
1302 unsigned page_offset
;
1303 unsigned misaligned
;
1309 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__
, gpa
, bytes
);
1310 ++vcpu
->kvm
->stat
.mmu_pte_write
;
1311 kvm_mmu_audit(vcpu
, "pre pte write");
1312 if (gfn
== vcpu
->last_pt_write_gfn
1313 && !last_updated_pte_accessed(vcpu
)) {
1314 ++vcpu
->last_pt_write_count
;
1315 if (vcpu
->last_pt_write_count
>= 3)
1318 vcpu
->last_pt_write_gfn
= gfn
;
1319 vcpu
->last_pt_write_count
= 1;
1320 vcpu
->last_pte_updated
= NULL
;
1322 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
1323 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
1324 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
) {
1325 if (page
->gfn
!= gfn
|| page
->role
.metaphysical
)
1327 pte_size
= page
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1328 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1329 misaligned
|= bytes
< 4;
1330 if (misaligned
|| flooded
) {
1332 * Misaligned accesses are too much trouble to fix
1333 * up; also, they usually indicate a page is not used
1336 * If we're seeing too many writes to a page,
1337 * it may no longer be a page table, or we may be
1338 * forking, in which case it is better to unmap the
1341 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1342 gpa
, bytes
, page
->role
.word
);
1343 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1344 ++vcpu
->kvm
->stat
.mmu_flooded
;
1347 page_offset
= offset
;
1348 level
= page
->role
.level
;
1350 if (page
->role
.glevels
== PT32_ROOT_LEVEL
) {
1351 page_offset
<<= 1; /* 32->64 */
1353 * A 32-bit pde maps 4MB while the shadow pdes map
1354 * only 2MB. So we need to double the offset again
1355 * and zap two pdes instead of one.
1357 if (level
== PT32_ROOT_LEVEL
) {
1358 page_offset
&= ~7; /* kill rounding error */
1362 quadrant
= page_offset
>> PAGE_SHIFT
;
1363 page_offset
&= ~PAGE_MASK
;
1364 if (quadrant
!= page
->role
.quadrant
)
1367 spte
= &page
->spt
[page_offset
/ sizeof(*spte
)];
1370 mmu_pte_write_zap_pte(vcpu
, page
, spte
);
1371 mmu_pte_write_new_pte(vcpu
, page
, spte
, new, bytes
,
1372 page_offset
& (pte_size
- 1));
1373 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
1377 kvm_mmu_audit(vcpu
, "post pte write");
1380 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1382 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
1384 return kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1387 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1389 while (vcpu
->kvm
->n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1390 struct kvm_mmu_page
*page
;
1392 page
= container_of(vcpu
->kvm
->active_mmu_pages
.prev
,
1393 struct kvm_mmu_page
, link
);
1394 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1395 ++vcpu
->kvm
->stat
.mmu_recycled
;
1399 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
1402 enum emulation_result er
;
1404 mutex_lock(&vcpu
->kvm
->lock
);
1405 r
= vcpu
->mmu
.page_fault(vcpu
, cr2
, error_code
);
1414 r
= mmu_topup_memory_caches(vcpu
);
1418 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
1419 mutex_unlock(&vcpu
->kvm
->lock
);
1424 case EMULATE_DO_MMIO
:
1425 ++vcpu
->stat
.mmio_exits
;
1428 kvm_report_emulation_failure(vcpu
, "pagetable");
1434 mutex_unlock(&vcpu
->kvm
->lock
);
1437 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
1439 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1441 struct kvm_mmu_page
*page
;
1443 while (!list_empty(&vcpu
->kvm
->active_mmu_pages
)) {
1444 page
= container_of(vcpu
->kvm
->active_mmu_pages
.next
,
1445 struct kvm_mmu_page
, link
);
1446 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1448 free_page((unsigned long)vcpu
->mmu
.pae_root
);
1451 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1458 if (vcpu
->kvm
->n_requested_mmu_pages
)
1459 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_requested_mmu_pages
;
1461 vcpu
->kvm
->n_free_mmu_pages
= vcpu
->kvm
->n_alloc_mmu_pages
;
1463 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1464 * Therefore we need to allocate shadow page tables in the first
1465 * 4GB of memory, which happens to fit the DMA32 zone.
1467 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1470 vcpu
->mmu
.pae_root
= page_address(page
);
1471 for (i
= 0; i
< 4; ++i
)
1472 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1477 free_mmu_pages(vcpu
);
1481 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1484 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1486 return alloc_mmu_pages(vcpu
);
1489 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1492 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1494 return init_kvm_mmu(vcpu
);
1497 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1501 destroy_kvm_mmu(vcpu
);
1502 free_mmu_pages(vcpu
);
1503 mmu_free_memory_caches(vcpu
);
1506 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
1508 struct kvm_mmu_page
*page
;
1510 list_for_each_entry(page
, &kvm
->active_mmu_pages
, link
) {
1514 if (!test_bit(slot
, &page
->slot_bitmap
))
1518 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1520 if (pt
[i
] & PT_WRITABLE_MASK
)
1521 pt
[i
] &= ~PT_WRITABLE_MASK
;
1525 void kvm_mmu_zap_all(struct kvm
*kvm
)
1527 struct kvm_mmu_page
*page
, *node
;
1529 list_for_each_entry_safe(page
, node
, &kvm
->active_mmu_pages
, link
)
1530 kvm_mmu_zap_page(kvm
, page
);
1532 kvm_flush_remote_tlbs(kvm
);
1535 void kvm_mmu_module_exit(void)
1537 if (pte_chain_cache
)
1538 kmem_cache_destroy(pte_chain_cache
);
1539 if (rmap_desc_cache
)
1540 kmem_cache_destroy(rmap_desc_cache
);
1541 if (mmu_page_header_cache
)
1542 kmem_cache_destroy(mmu_page_header_cache
);
1545 int kvm_mmu_module_init(void)
1547 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
1548 sizeof(struct kvm_pte_chain
),
1550 if (!pte_chain_cache
)
1552 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
1553 sizeof(struct kvm_rmap_desc
),
1555 if (!rmap_desc_cache
)
1558 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
1559 sizeof(struct kvm_mmu_page
),
1561 if (!mmu_page_header_cache
)
1567 kvm_mmu_module_exit();
1572 * Caculate mmu pages needed for kvm.
1574 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
1577 unsigned int nr_mmu_pages
;
1578 unsigned int nr_pages
= 0;
1580 for (i
= 0; i
< kvm
->nmemslots
; i
++)
1581 nr_pages
+= kvm
->memslots
[i
].npages
;
1583 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
1584 nr_mmu_pages
= max(nr_mmu_pages
,
1585 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
1587 return nr_mmu_pages
;
1592 static const char *audit_msg
;
1594 static gva_t
canonicalize(gva_t gva
)
1596 #ifdef CONFIG_X86_64
1597 gva
= (long long)(gva
<< 16) >> 16;
1602 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
1603 gva_t va
, int level
)
1605 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
1607 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
1609 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
1612 if (ent
== shadow_trap_nonpresent_pte
)
1615 va
= canonicalize(va
);
1617 if (ent
== shadow_notrap_nonpresent_pte
)
1618 printk(KERN_ERR
"audit: (%s) nontrapping pte"
1619 " in nonleaf level: levels %d gva %lx"
1620 " level %d pte %llx\n", audit_msg
,
1621 vcpu
->mmu
.root_level
, va
, level
, ent
);
1623 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
1625 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, va
);
1626 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
1629 if (is_shadow_present_pte(ent
)
1630 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
1631 printk(KERN_ERR
"xx audit error: (%s) levels %d"
1632 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1633 audit_msg
, vcpu
->mmu
.root_level
,
1635 is_shadow_present_pte(ent
));
1636 else if (ent
== shadow_notrap_nonpresent_pte
1637 && !is_error_hpa(hpa
))
1638 printk(KERN_ERR
"audit: (%s) notrap shadow,"
1639 " valid guest gva %lx\n", audit_msg
, va
);
1640 page
= pfn_to_page((gpa
& PT64_BASE_ADDR_MASK
)
1642 kvm_release_page_clean(page
);
1648 static void audit_mappings(struct kvm_vcpu
*vcpu
)
1652 if (vcpu
->mmu
.root_level
== 4)
1653 audit_mappings_page(vcpu
, vcpu
->mmu
.root_hpa
, 0, 4);
1655 for (i
= 0; i
< 4; ++i
)
1656 if (vcpu
->mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
1657 audit_mappings_page(vcpu
,
1658 vcpu
->mmu
.pae_root
[i
],
1663 static int count_rmaps(struct kvm_vcpu
*vcpu
)
1668 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
1669 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
1670 struct kvm_rmap_desc
*d
;
1672 for (j
= 0; j
< m
->npages
; ++j
) {
1673 unsigned long *rmapp
= &m
->rmap
[j
];
1677 if (!(*rmapp
& 1)) {
1681 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
1683 for (k
= 0; k
< RMAP_EXT
; ++k
)
1684 if (d
->shadow_ptes
[k
])
1695 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
1698 struct kvm_mmu_page
*page
;
1701 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1702 u64
*pt
= page
->spt
;
1704 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1707 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1710 if (!(ent
& PT_PRESENT_MASK
))
1712 if (!(ent
& PT_WRITABLE_MASK
))
1720 static void audit_rmap(struct kvm_vcpu
*vcpu
)
1722 int n_rmap
= count_rmaps(vcpu
);
1723 int n_actual
= count_writable_mappings(vcpu
);
1725 if (n_rmap
!= n_actual
)
1726 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
1727 __FUNCTION__
, audit_msg
, n_rmap
, n_actual
);
1730 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
1732 struct kvm_mmu_page
*page
;
1733 struct kvm_memory_slot
*slot
;
1734 unsigned long *rmapp
;
1737 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1738 if (page
->role
.metaphysical
)
1741 slot
= gfn_to_memslot(vcpu
->kvm
, page
->gfn
);
1742 gfn
= unalias_gfn(vcpu
->kvm
, page
->gfn
);
1743 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
1745 printk(KERN_ERR
"%s: (%s) shadow page has writable"
1746 " mappings: gfn %lx role %x\n",
1747 __FUNCTION__
, audit_msg
, page
->gfn
,
1752 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
1759 audit_write_protection(vcpu
);
1760 audit_mappings(vcpu
);