]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/kvm/mmu.c
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 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
96 #define PT_FIRST_AVAIL_BITS_SHIFT 9
97 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
99 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
101 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
103 #define PT64_LEVEL_BITS 9
105 #define PT64_LEVEL_SHIFT(level) \
106 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
108 #define PT64_LEVEL_MASK(level) \
109 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
111 #define PT64_INDEX(address, level)\
112 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
115 #define PT32_LEVEL_BITS 10
117 #define PT32_LEVEL_SHIFT(level) \
118 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
120 #define PT32_LEVEL_MASK(level) \
121 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
123 #define PT32_INDEX(address, level)\
124 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
127 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
128 #define PT64_DIR_BASE_ADDR_MASK \
129 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
131 #define PT32_BASE_ADDR_MASK PAGE_MASK
132 #define PT32_DIR_BASE_ADDR_MASK \
133 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
136 #define PFERR_PRESENT_MASK (1U << 0)
137 #define PFERR_WRITE_MASK (1U << 1)
138 #define PFERR_USER_MASK (1U << 2)
139 #define PFERR_FETCH_MASK (1U << 4)
141 #define PT64_ROOT_LEVEL 4
142 #define PT32_ROOT_LEVEL 2
143 #define PT32E_ROOT_LEVEL 3
145 #define PT_DIRECTORY_LEVEL 2
146 #define PT_PAGE_TABLE_LEVEL 1
150 struct kvm_rmap_desc
{
151 u64
*shadow_ptes
[RMAP_EXT
];
152 struct kvm_rmap_desc
*more
;
155 static struct kmem_cache
*pte_chain_cache
;
156 static struct kmem_cache
*rmap_desc_cache
;
157 static struct kmem_cache
*mmu_page_header_cache
;
159 static int is_write_protection(struct kvm_vcpu
*vcpu
)
161 return vcpu
->cr0
& CR0_WP_MASK
;
164 static int is_cpuid_PSE36(void)
169 static int is_nx(struct kvm_vcpu
*vcpu
)
171 return vcpu
->shadow_efer
& EFER_NX
;
174 static int is_present_pte(unsigned long pte
)
176 return pte
& PT_PRESENT_MASK
;
179 static int is_writeble_pte(unsigned long pte
)
181 return pte
& PT_WRITABLE_MASK
;
184 static int is_io_pte(unsigned long pte
)
186 return pte
& PT_SHADOW_IO_MARK
;
189 static int is_rmap_pte(u64 pte
)
191 return (pte
& (PT_WRITABLE_MASK
| PT_PRESENT_MASK
))
192 == (PT_WRITABLE_MASK
| PT_PRESENT_MASK
);
195 static void set_shadow_pte(u64
*sptep
, u64 spte
)
198 set_64bit((unsigned long *)sptep
, spte
);
200 set_64bit((unsigned long long *)sptep
, spte
);
204 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
205 struct kmem_cache
*base_cache
, int min
,
210 if (cache
->nobjs
>= min
)
212 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
213 obj
= kmem_cache_zalloc(base_cache
, gfp_flags
);
216 cache
->objects
[cache
->nobjs
++] = obj
;
221 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
224 kfree(mc
->objects
[--mc
->nobjs
]);
227 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
228 int min
, gfp_t gfp_flags
)
232 if (cache
->nobjs
>= min
)
234 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
235 page
= alloc_page(gfp_flags
);
238 set_page_private(page
, 0);
239 cache
->objects
[cache
->nobjs
++] = page_address(page
);
244 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
247 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
250 static int __mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
, gfp_t gfp_flags
)
254 r
= mmu_topup_memory_cache(&vcpu
->mmu_pte_chain_cache
,
255 pte_chain_cache
, 4, gfp_flags
);
258 r
= mmu_topup_memory_cache(&vcpu
->mmu_rmap_desc_cache
,
259 rmap_desc_cache
, 1, gfp_flags
);
262 r
= mmu_topup_memory_cache_page(&vcpu
->mmu_page_cache
, 4, gfp_flags
);
265 r
= mmu_topup_memory_cache(&vcpu
->mmu_page_header_cache
,
266 mmu_page_header_cache
, 4, gfp_flags
);
271 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
275 r
= __mmu_topup_memory_caches(vcpu
, GFP_NOWAIT
);
277 spin_unlock(&vcpu
->kvm
->lock
);
278 kvm_arch_ops
->vcpu_put(vcpu
);
279 r
= __mmu_topup_memory_caches(vcpu
, GFP_KERNEL
);
280 kvm_arch_ops
->vcpu_load(vcpu
);
281 spin_lock(&vcpu
->kvm
->lock
);
286 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
288 mmu_free_memory_cache(&vcpu
->mmu_pte_chain_cache
);
289 mmu_free_memory_cache(&vcpu
->mmu_rmap_desc_cache
);
290 mmu_free_memory_cache_page(&vcpu
->mmu_page_cache
);
291 mmu_free_memory_cache(&vcpu
->mmu_page_header_cache
);
294 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
300 p
= mc
->objects
[--mc
->nobjs
];
305 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
307 return mmu_memory_cache_alloc(&vcpu
->mmu_pte_chain_cache
,
308 sizeof(struct kvm_pte_chain
));
311 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
316 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
318 return mmu_memory_cache_alloc(&vcpu
->mmu_rmap_desc_cache
,
319 sizeof(struct kvm_rmap_desc
));
322 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
328 * Reverse mapping data structures:
330 * If page->private bit zero is zero, then page->private points to the
331 * shadow page table entry that points to page_address(page).
333 * If page->private bit zero is one, (then page->private & ~1) points
334 * to a struct kvm_rmap_desc containing more mappings.
336 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
)
339 struct kvm_rmap_desc
*desc
;
342 if (!is_rmap_pte(*spte
))
344 page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
345 if (!page_private(page
)) {
346 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
347 set_page_private(page
,(unsigned long)spte
);
348 } else if (!(page_private(page
) & 1)) {
349 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
350 desc
= mmu_alloc_rmap_desc(vcpu
);
351 desc
->shadow_ptes
[0] = (u64
*)page_private(page
);
352 desc
->shadow_ptes
[1] = spte
;
353 set_page_private(page
,(unsigned long)desc
| 1);
355 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
356 desc
= (struct kvm_rmap_desc
*)(page_private(page
) & ~1ul);
357 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
359 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
360 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
363 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
365 desc
->shadow_ptes
[i
] = spte
;
369 static void rmap_desc_remove_entry(struct page
*page
,
370 struct kvm_rmap_desc
*desc
,
372 struct kvm_rmap_desc
*prev_desc
)
376 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
378 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
379 desc
->shadow_ptes
[j
] = NULL
;
382 if (!prev_desc
&& !desc
->more
)
383 set_page_private(page
,(unsigned long)desc
->shadow_ptes
[0]);
386 prev_desc
->more
= desc
->more
;
388 set_page_private(page
,(unsigned long)desc
->more
| 1);
389 mmu_free_rmap_desc(desc
);
392 static void rmap_remove(u64
*spte
)
395 struct kvm_rmap_desc
*desc
;
396 struct kvm_rmap_desc
*prev_desc
;
399 if (!is_rmap_pte(*spte
))
401 page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
402 if (!page_private(page
)) {
403 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
405 } else if (!(page_private(page
) & 1)) {
406 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
407 if ((u64
*)page_private(page
) != spte
) {
408 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
412 set_page_private(page
,0);
414 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
415 desc
= (struct kvm_rmap_desc
*)(page_private(page
) & ~1ul);
418 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
419 if (desc
->shadow_ptes
[i
] == spte
) {
420 rmap_desc_remove_entry(page
,
432 static void rmap_write_protect(struct kvm_vcpu
*vcpu
, u64 gfn
)
434 struct kvm
*kvm
= vcpu
->kvm
;
436 struct kvm_rmap_desc
*desc
;
439 page
= gfn_to_page(kvm
, gfn
);
442 while (page_private(page
)) {
443 if (!(page_private(page
) & 1))
444 spte
= (u64
*)page_private(page
);
446 desc
= (struct kvm_rmap_desc
*)(page_private(page
) & ~1ul);
447 spte
= desc
->shadow_ptes
[0];
450 BUG_ON((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
451 != page_to_pfn(page
));
452 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
453 BUG_ON(!(*spte
& PT_WRITABLE_MASK
));
454 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
456 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
457 kvm_flush_remote_tlbs(vcpu
->kvm
);
462 static int is_empty_shadow_page(u64
*spt
)
467 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
469 printk(KERN_ERR
"%s: %p %llx\n", __FUNCTION__
,
477 static void kvm_mmu_free_page(struct kvm
*kvm
,
478 struct kvm_mmu_page
*page_head
)
480 ASSERT(is_empty_shadow_page(page_head
->spt
));
481 list_del(&page_head
->link
);
482 __free_page(virt_to_page(page_head
->spt
));
484 ++kvm
->n_free_mmu_pages
;
487 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
492 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
495 struct kvm_mmu_page
*page
;
497 if (!vcpu
->kvm
->n_free_mmu_pages
)
500 page
= mmu_memory_cache_alloc(&vcpu
->mmu_page_header_cache
,
502 page
->spt
= mmu_memory_cache_alloc(&vcpu
->mmu_page_cache
, PAGE_SIZE
);
503 set_page_private(virt_to_page(page
->spt
), (unsigned long)page
);
504 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
505 ASSERT(is_empty_shadow_page(page
->spt
));
506 page
->slot_bitmap
= 0;
507 page
->multimapped
= 0;
508 page
->parent_pte
= parent_pte
;
509 --vcpu
->kvm
->n_free_mmu_pages
;
513 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
514 struct kvm_mmu_page
*page
, u64
*parent_pte
)
516 struct kvm_pte_chain
*pte_chain
;
517 struct hlist_node
*node
;
522 if (!page
->multimapped
) {
523 u64
*old
= page
->parent_pte
;
526 page
->parent_pte
= parent_pte
;
529 page
->multimapped
= 1;
530 pte_chain
= mmu_alloc_pte_chain(vcpu
);
531 INIT_HLIST_HEAD(&page
->parent_ptes
);
532 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
533 pte_chain
->parent_ptes
[0] = old
;
535 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
) {
536 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
538 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
539 if (!pte_chain
->parent_ptes
[i
]) {
540 pte_chain
->parent_ptes
[i
] = parent_pte
;
544 pte_chain
= mmu_alloc_pte_chain(vcpu
);
546 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
547 pte_chain
->parent_ptes
[0] = parent_pte
;
550 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*page
,
553 struct kvm_pte_chain
*pte_chain
;
554 struct hlist_node
*node
;
557 if (!page
->multimapped
) {
558 BUG_ON(page
->parent_pte
!= parent_pte
);
559 page
->parent_pte
= NULL
;
562 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
)
563 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
564 if (!pte_chain
->parent_ptes
[i
])
566 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
568 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
569 && pte_chain
->parent_ptes
[i
+ 1]) {
570 pte_chain
->parent_ptes
[i
]
571 = pte_chain
->parent_ptes
[i
+ 1];
574 pte_chain
->parent_ptes
[i
] = NULL
;
576 hlist_del(&pte_chain
->link
);
577 mmu_free_pte_chain(pte_chain
);
578 if (hlist_empty(&page
->parent_ptes
)) {
579 page
->multimapped
= 0;
580 page
->parent_pte
= NULL
;
588 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm_vcpu
*vcpu
,
592 struct hlist_head
*bucket
;
593 struct kvm_mmu_page
*page
;
594 struct hlist_node
*node
;
596 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
597 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
598 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
599 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
600 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
601 pgprintk("%s: found role %x\n",
602 __FUNCTION__
, page
->role
.word
);
608 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
613 unsigned hugepage_access
,
616 union kvm_mmu_page_role role
;
619 struct hlist_head
*bucket
;
620 struct kvm_mmu_page
*page
;
621 struct hlist_node
*node
;
624 role
.glevels
= vcpu
->mmu
.root_level
;
626 role
.metaphysical
= metaphysical
;
627 role
.hugepage_access
= hugepage_access
;
628 if (vcpu
->mmu
.root_level
<= PT32_ROOT_LEVEL
) {
629 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
630 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
631 role
.quadrant
= quadrant
;
633 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__
,
635 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
636 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
637 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
638 if (page
->gfn
== gfn
&& page
->role
.word
== role
.word
) {
639 mmu_page_add_parent_pte(vcpu
, page
, parent_pte
);
640 pgprintk("%s: found\n", __FUNCTION__
);
643 page
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
646 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__
, gfn
, role
.word
);
649 hlist_add_head(&page
->hash_link
, bucket
);
651 rmap_write_protect(vcpu
, gfn
);
655 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
656 struct kvm_mmu_page
*page
)
664 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
665 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
666 if (pt
[i
] & PT_PRESENT_MASK
)
670 kvm_flush_remote_tlbs(kvm
);
674 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
678 if (!(ent
& PT_PRESENT_MASK
))
680 ent
&= PT64_BASE_ADDR_MASK
;
681 mmu_page_remove_parent_pte(page_header(ent
), &pt
[i
]);
683 kvm_flush_remote_tlbs(kvm
);
686 static void kvm_mmu_put_page(struct kvm_mmu_page
*page
,
689 mmu_page_remove_parent_pte(page
, parent_pte
);
692 static void kvm_mmu_zap_page(struct kvm
*kvm
,
693 struct kvm_mmu_page
*page
)
697 while (page
->multimapped
|| page
->parent_pte
) {
698 if (!page
->multimapped
)
699 parent_pte
= page
->parent_pte
;
701 struct kvm_pte_chain
*chain
;
703 chain
= container_of(page
->parent_ptes
.first
,
704 struct kvm_pte_chain
, link
);
705 parent_pte
= chain
->parent_ptes
[0];
708 kvm_mmu_put_page(page
, parent_pte
);
709 set_shadow_pte(parent_pte
, 0);
711 kvm_mmu_page_unlink_children(kvm
, page
);
712 if (!page
->root_count
) {
713 hlist_del(&page
->hash_link
);
714 kvm_mmu_free_page(kvm
, page
);
716 list_move(&page
->link
, &kvm
->active_mmu_pages
);
719 static int kvm_mmu_unprotect_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
722 struct hlist_head
*bucket
;
723 struct kvm_mmu_page
*page
;
724 struct hlist_node
*node
, *n
;
727 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
729 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
730 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
731 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
)
732 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
733 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__
, gfn
,
735 kvm_mmu_zap_page(vcpu
->kvm
, page
);
741 static void mmu_unshadow(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
743 struct kvm_mmu_page
*page
;
745 while ((page
= kvm_mmu_lookup_page(vcpu
, gfn
)) != NULL
) {
746 pgprintk("%s: zap %lx %x\n",
747 __FUNCTION__
, gfn
, page
->role
.word
);
748 kvm_mmu_zap_page(vcpu
->kvm
, page
);
752 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gpa_t gpa
)
754 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gpa
>> PAGE_SHIFT
));
755 struct kvm_mmu_page
*page_head
= page_header(__pa(pte
));
757 __set_bit(slot
, &page_head
->slot_bitmap
);
760 hpa_t
safe_gpa_to_hpa(struct kvm_vcpu
*vcpu
, gpa_t gpa
)
762 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
764 return is_error_hpa(hpa
) ? bad_page_address
| (gpa
& ~PAGE_MASK
): hpa
;
767 hpa_t
gpa_to_hpa(struct kvm_vcpu
*vcpu
, gpa_t gpa
)
771 ASSERT((gpa
& HPA_ERR_MASK
) == 0);
772 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
774 return gpa
| HPA_ERR_MASK
;
775 return ((hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
)
776 | (gpa
& (PAGE_SIZE
-1));
779 hpa_t
gva_to_hpa(struct kvm_vcpu
*vcpu
, gva_t gva
)
781 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
783 if (gpa
== UNMAPPED_GVA
)
785 return gpa_to_hpa(vcpu
, gpa
);
788 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
790 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
792 if (gpa
== UNMAPPED_GVA
)
794 return pfn_to_page(gpa_to_hpa(vcpu
, gpa
) >> PAGE_SHIFT
);
797 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
801 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, hpa_t p
)
803 int level
= PT32E_ROOT_LEVEL
;
804 hpa_t table_addr
= vcpu
->mmu
.root_hpa
;
807 u32 index
= PT64_INDEX(v
, level
);
811 ASSERT(VALID_PAGE(table_addr
));
812 table
= __va(table_addr
);
816 if (is_present_pte(pte
) && is_writeble_pte(pte
))
818 mark_page_dirty(vcpu
->kvm
, v
>> PAGE_SHIFT
);
819 page_header_update_slot(vcpu
->kvm
, table
, v
);
820 table
[index
] = p
| PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
822 rmap_add(vcpu
, &table
[index
]);
826 if (table
[index
] == 0) {
827 struct kvm_mmu_page
*new_table
;
830 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
832 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
834 1, 0, &table
[index
]);
836 pgprintk("nonpaging_map: ENOMEM\n");
840 table
[index
] = __pa(new_table
->spt
) | PT_PRESENT_MASK
841 | PT_WRITABLE_MASK
| PT_USER_MASK
;
843 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
847 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
850 struct kvm_mmu_page
*page
;
852 if (!VALID_PAGE(vcpu
->mmu
.root_hpa
))
855 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
856 hpa_t root
= vcpu
->mmu
.root_hpa
;
858 page
= page_header(root
);
860 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
864 for (i
= 0; i
< 4; ++i
) {
865 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
868 root
&= PT64_BASE_ADDR_MASK
;
869 page
= page_header(root
);
872 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
874 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
877 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
881 struct kvm_mmu_page
*page
;
883 root_gfn
= vcpu
->cr3
>> PAGE_SHIFT
;
886 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
887 hpa_t root
= vcpu
->mmu
.root_hpa
;
889 ASSERT(!VALID_PAGE(root
));
890 page
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
891 PT64_ROOT_LEVEL
, 0, 0, NULL
);
892 root
= __pa(page
->spt
);
894 vcpu
->mmu
.root_hpa
= root
;
898 for (i
= 0; i
< 4; ++i
) {
899 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
901 ASSERT(!VALID_PAGE(root
));
902 if (vcpu
->mmu
.root_level
== PT32E_ROOT_LEVEL
) {
903 if (!is_present_pte(vcpu
->pdptrs
[i
])) {
904 vcpu
->mmu
.pae_root
[i
] = 0;
907 root_gfn
= vcpu
->pdptrs
[i
] >> PAGE_SHIFT
;
908 } else if (vcpu
->mmu
.root_level
== 0)
910 page
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
911 PT32_ROOT_LEVEL
, !is_paging(vcpu
),
913 root
= __pa(page
->spt
);
915 vcpu
->mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
917 vcpu
->mmu
.root_hpa
= __pa(vcpu
->mmu
.pae_root
);
920 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
925 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
932 r
= mmu_topup_memory_caches(vcpu
);
937 ASSERT(VALID_PAGE(vcpu
->mmu
.root_hpa
));
940 paddr
= gpa_to_hpa(vcpu
, addr
& PT64_BASE_ADDR_MASK
);
942 if (is_error_hpa(paddr
))
945 return nonpaging_map(vcpu
, addr
& PAGE_MASK
, paddr
);
948 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
950 mmu_free_roots(vcpu
);
953 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
955 struct kvm_mmu
*context
= &vcpu
->mmu
;
957 context
->new_cr3
= nonpaging_new_cr3
;
958 context
->page_fault
= nonpaging_page_fault
;
959 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
960 context
->free
= nonpaging_free
;
961 context
->root_level
= 0;
962 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
963 context
->root_hpa
= INVALID_PAGE
;
967 static void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
969 ++vcpu
->stat
.tlb_flush
;
970 kvm_arch_ops
->tlb_flush(vcpu
);
973 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
975 pgprintk("%s: cr3 %lx\n", __FUNCTION__
, vcpu
->cr3
);
976 mmu_free_roots(vcpu
);
979 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
983 kvm_arch_ops
->inject_page_fault(vcpu
, addr
, err_code
);
986 static void paging_free(struct kvm_vcpu
*vcpu
)
988 nonpaging_free(vcpu
);
992 #include "paging_tmpl.h"
996 #include "paging_tmpl.h"
999 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1001 struct kvm_mmu
*context
= &vcpu
->mmu
;
1003 ASSERT(is_pae(vcpu
));
1004 context
->new_cr3
= paging_new_cr3
;
1005 context
->page_fault
= paging64_page_fault
;
1006 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1007 context
->free
= paging_free
;
1008 context
->root_level
= level
;
1009 context
->shadow_root_level
= level
;
1010 context
->root_hpa
= INVALID_PAGE
;
1014 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1016 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1019 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1021 struct kvm_mmu
*context
= &vcpu
->mmu
;
1023 context
->new_cr3
= paging_new_cr3
;
1024 context
->page_fault
= paging32_page_fault
;
1025 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1026 context
->free
= paging_free
;
1027 context
->root_level
= PT32_ROOT_LEVEL
;
1028 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1029 context
->root_hpa
= INVALID_PAGE
;
1033 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1035 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1038 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1041 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1043 if (!is_paging(vcpu
))
1044 return nonpaging_init_context(vcpu
);
1045 else if (is_long_mode(vcpu
))
1046 return paging64_init_context(vcpu
);
1047 else if (is_pae(vcpu
))
1048 return paging32E_init_context(vcpu
);
1050 return paging32_init_context(vcpu
);
1053 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1056 if (VALID_PAGE(vcpu
->mmu
.root_hpa
)) {
1057 vcpu
->mmu
.free(vcpu
);
1058 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
1062 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1064 destroy_kvm_mmu(vcpu
);
1065 return init_kvm_mmu(vcpu
);
1068 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1072 spin_lock(&vcpu
->kvm
->lock
);
1073 r
= mmu_topup_memory_caches(vcpu
);
1076 mmu_alloc_roots(vcpu
);
1077 kvm_arch_ops
->set_cr3(vcpu
, vcpu
->mmu
.root_hpa
);
1078 kvm_mmu_flush_tlb(vcpu
);
1080 spin_unlock(&vcpu
->kvm
->lock
);
1083 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1085 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1087 mmu_free_roots(vcpu
);
1090 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1091 struct kvm_mmu_page
*page
,
1095 struct kvm_mmu_page
*child
;
1098 if (is_present_pte(pte
)) {
1099 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1102 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1103 mmu_page_remove_parent_pte(child
, spte
);
1107 kvm_flush_remote_tlbs(vcpu
->kvm
);
1110 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
1111 struct kvm_mmu_page
*page
,
1113 const void *new, int bytes
)
1115 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1118 if (page
->role
.glevels
== PT32_ROOT_LEVEL
)
1119 paging32_update_pte(vcpu
, page
, spte
, new, bytes
);
1121 paging64_update_pte(vcpu
, page
, spte
, new, bytes
);
1124 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1125 const u8
*old
, const u8
*new, int bytes
)
1127 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1128 struct kvm_mmu_page
*page
;
1129 struct hlist_node
*node
, *n
;
1130 struct hlist_head
*bucket
;
1133 unsigned offset
= offset_in_page(gpa
);
1135 unsigned page_offset
;
1136 unsigned misaligned
;
1142 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__
, gpa
, bytes
);
1143 if (gfn
== vcpu
->last_pt_write_gfn
) {
1144 ++vcpu
->last_pt_write_count
;
1145 if (vcpu
->last_pt_write_count
>= 3)
1148 vcpu
->last_pt_write_gfn
= gfn
;
1149 vcpu
->last_pt_write_count
= 1;
1151 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
1152 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
1153 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
) {
1154 if (page
->gfn
!= gfn
|| page
->role
.metaphysical
)
1156 pte_size
= page
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1157 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1158 misaligned
|= bytes
< 4;
1159 if (misaligned
|| flooded
) {
1161 * Misaligned accesses are too much trouble to fix
1162 * up; also, they usually indicate a page is not used
1165 * If we're seeing too many writes to a page,
1166 * it may no longer be a page table, or we may be
1167 * forking, in which case it is better to unmap the
1170 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1171 gpa
, bytes
, page
->role
.word
);
1172 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1175 page_offset
= offset
;
1176 level
= page
->role
.level
;
1178 if (page
->role
.glevels
== PT32_ROOT_LEVEL
) {
1179 page_offset
<<= 1; /* 32->64 */
1181 * A 32-bit pde maps 4MB while the shadow pdes map
1182 * only 2MB. So we need to double the offset again
1183 * and zap two pdes instead of one.
1185 if (level
== PT32_ROOT_LEVEL
) {
1186 page_offset
&= ~7; /* kill rounding error */
1190 quadrant
= page_offset
>> PAGE_SHIFT
;
1191 page_offset
&= ~PAGE_MASK
;
1192 if (quadrant
!= page
->role
.quadrant
)
1195 spte
= &page
->spt
[page_offset
/ sizeof(*spte
)];
1197 mmu_pte_write_zap_pte(vcpu
, page
, spte
);
1198 mmu_pte_write_new_pte(vcpu
, page
, spte
, new, bytes
);
1204 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1206 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
1208 return kvm_mmu_unprotect_page(vcpu
, gpa
>> PAGE_SHIFT
);
1211 void kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1213 while (vcpu
->kvm
->n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1214 struct kvm_mmu_page
*page
;
1216 page
= container_of(vcpu
->kvm
->active_mmu_pages
.prev
,
1217 struct kvm_mmu_page
, link
);
1218 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1221 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages
);
1223 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1225 struct kvm_mmu_page
*page
;
1227 while (!list_empty(&vcpu
->kvm
->active_mmu_pages
)) {
1228 page
= container_of(vcpu
->kvm
->active_mmu_pages
.next
,
1229 struct kvm_mmu_page
, link
);
1230 kvm_mmu_zap_page(vcpu
->kvm
, page
);
1232 free_page((unsigned long)vcpu
->mmu
.pae_root
);
1235 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1242 vcpu
->kvm
->n_free_mmu_pages
= KVM_NUM_MMU_PAGES
;
1245 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1246 * Therefore we need to allocate shadow page tables in the first
1247 * 4GB of memory, which happens to fit the DMA32 zone.
1249 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1252 vcpu
->mmu
.pae_root
= page_address(page
);
1253 for (i
= 0; i
< 4; ++i
)
1254 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1259 free_mmu_pages(vcpu
);
1263 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1266 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1268 return alloc_mmu_pages(vcpu
);
1271 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1274 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1276 return init_kvm_mmu(vcpu
);
1279 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1283 destroy_kvm_mmu(vcpu
);
1284 free_mmu_pages(vcpu
);
1285 mmu_free_memory_caches(vcpu
);
1288 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
1290 struct kvm_mmu_page
*page
;
1292 list_for_each_entry(page
, &kvm
->active_mmu_pages
, link
) {
1296 if (!test_bit(slot
, &page
->slot_bitmap
))
1300 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1302 if (pt
[i
] & PT_WRITABLE_MASK
) {
1303 rmap_remove(&pt
[i
]);
1304 pt
[i
] &= ~PT_WRITABLE_MASK
;
1309 void kvm_mmu_zap_all(struct kvm
*kvm
)
1311 struct kvm_mmu_page
*page
, *node
;
1313 list_for_each_entry_safe(page
, node
, &kvm
->active_mmu_pages
, link
)
1314 kvm_mmu_zap_page(kvm
, page
);
1316 kvm_flush_remote_tlbs(kvm
);
1319 void kvm_mmu_module_exit(void)
1321 if (pte_chain_cache
)
1322 kmem_cache_destroy(pte_chain_cache
);
1323 if (rmap_desc_cache
)
1324 kmem_cache_destroy(rmap_desc_cache
);
1325 if (mmu_page_header_cache
)
1326 kmem_cache_destroy(mmu_page_header_cache
);
1329 int kvm_mmu_module_init(void)
1331 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
1332 sizeof(struct kvm_pte_chain
),
1334 if (!pte_chain_cache
)
1336 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
1337 sizeof(struct kvm_rmap_desc
),
1339 if (!rmap_desc_cache
)
1342 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
1343 sizeof(struct kvm_mmu_page
),
1345 if (!mmu_page_header_cache
)
1351 kvm_mmu_module_exit();
1357 static const char *audit_msg
;
1359 static gva_t
canonicalize(gva_t gva
)
1361 #ifdef CONFIG_X86_64
1362 gva
= (long long)(gva
<< 16) >> 16;
1367 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
1368 gva_t va
, int level
)
1370 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
1372 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
1374 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
1377 if (!(ent
& PT_PRESENT_MASK
))
1380 va
= canonicalize(va
);
1382 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
1384 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, va
);
1385 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
1387 if ((ent
& PT_PRESENT_MASK
)
1388 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
1389 printk(KERN_ERR
"audit error: (%s) levels %d"
1390 " gva %lx gpa %llx hpa %llx ent %llx\n",
1391 audit_msg
, vcpu
->mmu
.root_level
,
1397 static void audit_mappings(struct kvm_vcpu
*vcpu
)
1401 if (vcpu
->mmu
.root_level
== 4)
1402 audit_mappings_page(vcpu
, vcpu
->mmu
.root_hpa
, 0, 4);
1404 for (i
= 0; i
< 4; ++i
)
1405 if (vcpu
->mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
1406 audit_mappings_page(vcpu
,
1407 vcpu
->mmu
.pae_root
[i
],
1412 static int count_rmaps(struct kvm_vcpu
*vcpu
)
1417 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
1418 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
1419 struct kvm_rmap_desc
*d
;
1421 for (j
= 0; j
< m
->npages
; ++j
) {
1422 struct page
*page
= m
->phys_mem
[j
];
1426 if (!(page
->private & 1)) {
1430 d
= (struct kvm_rmap_desc
*)(page
->private & ~1ul);
1432 for (k
= 0; k
< RMAP_EXT
; ++k
)
1433 if (d
->shadow_ptes
[k
])
1444 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
1447 struct kvm_mmu_page
*page
;
1450 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1451 u64
*pt
= page
->spt
;
1453 if (page
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1456 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1459 if (!(ent
& PT_PRESENT_MASK
))
1461 if (!(ent
& PT_WRITABLE_MASK
))
1469 static void audit_rmap(struct kvm_vcpu
*vcpu
)
1471 int n_rmap
= count_rmaps(vcpu
);
1472 int n_actual
= count_writable_mappings(vcpu
);
1474 if (n_rmap
!= n_actual
)
1475 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
1476 __FUNCTION__
, audit_msg
, n_rmap
, n_actual
);
1479 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
1481 struct kvm_mmu_page
*page
;
1483 list_for_each_entry(page
, &vcpu
->kvm
->active_mmu_pages
, link
) {
1487 if (page
->role
.metaphysical
)
1490 hfn
= gpa_to_hpa(vcpu
, (gpa_t
)page
->gfn
<< PAGE_SHIFT
)
1492 pg
= pfn_to_page(hfn
);
1494 printk(KERN_ERR
"%s: (%s) shadow page has writable"
1495 " mappings: gfn %lx role %x\n",
1496 __FUNCTION__
, audit_msg
, page
->gfn
,
1501 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
1508 audit_write_protection(vcpu
);
1509 audit_mappings(vcpu
);