2fc252813927d328591cd343aca80ee32060d94c
2 * Kernel-based Virtual Machine driver for Linux
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
9 * Copyright (C) 2006 Qumranet, Inc.
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
19 #include <linux/types.h>
20 #include <linux/string.h>
23 #include <linux/highmem.h>
24 #include <linux/module.h>
29 #define pgprintk(x...) do { printk(x); } while (0)
30 #define rmap_printk(x...) do { printk(x); } while (0)
34 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
35 __FILE__, __LINE__, #x); \
38 #define PT64_PT_BITS 9
39 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
40 #define PT32_PT_BITS 10
41 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
43 #define PT_WRITABLE_SHIFT 1
45 #define PT_PRESENT_MASK (1ULL << 0)
46 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
47 #define PT_USER_MASK (1ULL << 2)
48 #define PT_PWT_MASK (1ULL << 3)
49 #define PT_PCD_MASK (1ULL << 4)
50 #define PT_ACCESSED_MASK (1ULL << 5)
51 #define PT_DIRTY_MASK (1ULL << 6)
52 #define PT_PAGE_SIZE_MASK (1ULL << 7)
53 #define PT_PAT_MASK (1ULL << 7)
54 #define PT_GLOBAL_MASK (1ULL << 8)
55 #define PT64_NX_MASK (1ULL << 63)
57 #define PT_PAT_SHIFT 7
58 #define PT_DIR_PAT_SHIFT 12
59 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
61 #define PT32_DIR_PSE36_SIZE 4
62 #define PT32_DIR_PSE36_SHIFT 13
63 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
66 #define PT32_PTE_COPY_MASK \
67 (PT_PRESENT_MASK | PT_ACCESSED_MASK | PT_DIRTY_MASK | PT_GLOBAL_MASK)
69 #define PT64_PTE_COPY_MASK (PT64_NX_MASK | PT32_PTE_COPY_MASK)
71 #define PT_FIRST_AVAIL_BITS_SHIFT 9
72 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
74 #define PT_SHADOW_PS_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
75 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
77 #define PT_SHADOW_WRITABLE_SHIFT (PT_FIRST_AVAIL_BITS_SHIFT + 1)
78 #define PT_SHADOW_WRITABLE_MASK (1ULL << PT_SHADOW_WRITABLE_SHIFT)
80 #define PT_SHADOW_USER_SHIFT (PT_SHADOW_WRITABLE_SHIFT + 1)
81 #define PT_SHADOW_USER_MASK (1ULL << (PT_SHADOW_USER_SHIFT))
83 #define PT_SHADOW_BITS_OFFSET (PT_SHADOW_WRITABLE_SHIFT - PT_WRITABLE_SHIFT)
85 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
87 #define PT64_LEVEL_BITS 9
89 #define PT64_LEVEL_SHIFT(level) \
90 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
92 #define PT64_LEVEL_MASK(level) \
93 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
95 #define PT64_INDEX(address, level)\
96 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
99 #define PT32_LEVEL_BITS 10
101 #define PT32_LEVEL_SHIFT(level) \
102 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
104 #define PT32_LEVEL_MASK(level) \
105 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
107 #define PT32_INDEX(address, level)\
108 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
111 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & PAGE_MASK)
112 #define PT64_DIR_BASE_ADDR_MASK \
113 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
115 #define PT32_BASE_ADDR_MASK PAGE_MASK
116 #define PT32_DIR_BASE_ADDR_MASK \
117 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
120 #define PFERR_PRESENT_MASK (1U << 0)
121 #define PFERR_WRITE_MASK (1U << 1)
122 #define PFERR_USER_MASK (1U << 2)
124 #define PT64_ROOT_LEVEL 4
125 #define PT32_ROOT_LEVEL 2
126 #define PT32E_ROOT_LEVEL 3
128 #define PT_DIRECTORY_LEVEL 2
129 #define PT_PAGE_TABLE_LEVEL 1
133 struct kvm_rmap_desc
{
134 u64
*shadow_ptes
[RMAP_EXT
];
135 struct kvm_rmap_desc
*more
;
138 static int is_write_protection(struct kvm_vcpu
*vcpu
)
140 return vcpu
->cr0
& CR0_WP_MASK
;
143 static int is_cpuid_PSE36(void)
148 static int is_present_pte(unsigned long pte
)
150 return pte
& PT_PRESENT_MASK
;
153 static int is_writeble_pte(unsigned long pte
)
155 return pte
& PT_WRITABLE_MASK
;
158 static int is_io_pte(unsigned long pte
)
160 return pte
& PT_SHADOW_IO_MARK
;
163 static int is_rmap_pte(u64 pte
)
165 return (pte
& (PT_WRITABLE_MASK
| PT_PRESENT_MASK
))
166 == (PT_WRITABLE_MASK
| PT_PRESENT_MASK
);
169 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
170 size_t objsize
, int min
)
174 if (cache
->nobjs
>= min
)
176 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
177 obj
= kzalloc(objsize
, GFP_NOWAIT
);
180 cache
->objects
[cache
->nobjs
++] = obj
;
185 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
188 kfree(mc
->objects
[--mc
->nobjs
]);
191 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
195 r
= mmu_topup_memory_cache(&vcpu
->mmu_pte_chain_cache
,
196 sizeof(struct kvm_pte_chain
), 4);
199 r
= mmu_topup_memory_cache(&vcpu
->mmu_rmap_desc_cache
,
200 sizeof(struct kvm_rmap_desc
), 1);
205 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
207 mmu_free_memory_cache(&vcpu
->mmu_pte_chain_cache
);
208 mmu_free_memory_cache(&vcpu
->mmu_rmap_desc_cache
);
211 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
217 p
= mc
->objects
[--mc
->nobjs
];
222 static void mmu_memory_cache_free(struct kvm_mmu_memory_cache
*mc
, void *obj
)
224 if (mc
->nobjs
< KVM_NR_MEM_OBJS
)
225 mc
->objects
[mc
->nobjs
++] = obj
;
230 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
232 return mmu_memory_cache_alloc(&vcpu
->mmu_pte_chain_cache
,
233 sizeof(struct kvm_pte_chain
));
236 static void mmu_free_pte_chain(struct kvm_vcpu
*vcpu
,
237 struct kvm_pte_chain
*pc
)
239 mmu_memory_cache_free(&vcpu
->mmu_pte_chain_cache
, pc
);
242 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
244 return mmu_memory_cache_alloc(&vcpu
->mmu_rmap_desc_cache
,
245 sizeof(struct kvm_rmap_desc
));
248 static void mmu_free_rmap_desc(struct kvm_vcpu
*vcpu
,
249 struct kvm_rmap_desc
*rd
)
251 mmu_memory_cache_free(&vcpu
->mmu_rmap_desc_cache
, rd
);
255 * Reverse mapping data structures:
257 * If page->private bit zero is zero, then page->private points to the
258 * shadow page table entry that points to page_address(page).
260 * If page->private bit zero is one, (then page->private & ~1) points
261 * to a struct kvm_rmap_desc containing more mappings.
263 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
)
266 struct kvm_rmap_desc
*desc
;
269 if (!is_rmap_pte(*spte
))
271 page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
272 if (!page
->private) {
273 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
274 page
->private = (unsigned long)spte
;
275 } else if (!(page
->private & 1)) {
276 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
277 desc
= mmu_alloc_rmap_desc(vcpu
);
278 desc
->shadow_ptes
[0] = (u64
*)page
->private;
279 desc
->shadow_ptes
[1] = spte
;
280 page
->private = (unsigned long)desc
| 1;
282 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
283 desc
= (struct kvm_rmap_desc
*)(page
->private & ~1ul);
284 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
286 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
287 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
290 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
292 desc
->shadow_ptes
[i
] = spte
;
296 static void rmap_desc_remove_entry(struct kvm_vcpu
*vcpu
,
298 struct kvm_rmap_desc
*desc
,
300 struct kvm_rmap_desc
*prev_desc
)
304 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
306 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
307 desc
->shadow_ptes
[j
] = 0;
310 if (!prev_desc
&& !desc
->more
)
311 page
->private = (unsigned long)desc
->shadow_ptes
[0];
314 prev_desc
->more
= desc
->more
;
316 page
->private = (unsigned long)desc
->more
| 1;
317 mmu_free_rmap_desc(vcpu
, desc
);
320 static void rmap_remove(struct kvm_vcpu
*vcpu
, u64
*spte
)
323 struct kvm_rmap_desc
*desc
;
324 struct kvm_rmap_desc
*prev_desc
;
327 if (!is_rmap_pte(*spte
))
329 page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
330 if (!page
->private) {
331 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
333 } else if (!(page
->private & 1)) {
334 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
335 if ((u64
*)page
->private != spte
) {
336 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
342 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
343 desc
= (struct kvm_rmap_desc
*)(page
->private & ~1ul);
346 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
347 if (desc
->shadow_ptes
[i
] == spte
) {
348 rmap_desc_remove_entry(vcpu
, page
,
360 static void rmap_write_protect(struct kvm_vcpu
*vcpu
, u64 gfn
)
362 struct kvm
*kvm
= vcpu
->kvm
;
364 struct kvm_memory_slot
*slot
;
365 struct kvm_rmap_desc
*desc
;
368 slot
= gfn_to_memslot(kvm
, gfn
);
370 page
= gfn_to_page(slot
, gfn
);
372 while (page
->private) {
373 if (!(page
->private & 1))
374 spte
= (u64
*)page
->private;
376 desc
= (struct kvm_rmap_desc
*)(page
->private & ~1ul);
377 spte
= desc
->shadow_ptes
[0];
380 BUG_ON((*spte
& PT64_BASE_ADDR_MASK
) !=
381 page_to_pfn(page
) << PAGE_SHIFT
);
382 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
383 BUG_ON(!(*spte
& PT_WRITABLE_MASK
));
384 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
385 rmap_remove(vcpu
, spte
);
386 kvm_arch_ops
->tlb_flush(vcpu
);
387 *spte
&= ~(u64
)PT_WRITABLE_MASK
;
391 static int is_empty_shadow_page(hpa_t page_hpa
)
396 for (pos
= __va(page_hpa
), end
= pos
+ PAGE_SIZE
/ sizeof(u64
);
399 printk(KERN_ERR
"%s: %p %llx\n", __FUNCTION__
,
406 static void kvm_mmu_free_page(struct kvm_vcpu
*vcpu
, hpa_t page_hpa
)
408 struct kvm_mmu_page
*page_head
= page_header(page_hpa
);
410 ASSERT(is_empty_shadow_page(page_hpa
));
411 list_del(&page_head
->link
);
412 page_head
->page_hpa
= page_hpa
;
413 list_add(&page_head
->link
, &vcpu
->free_pages
);
414 ++vcpu
->kvm
->n_free_mmu_pages
;
417 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
422 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
425 struct kvm_mmu_page
*page
;
427 if (list_empty(&vcpu
->free_pages
))
430 page
= list_entry(vcpu
->free_pages
.next
, struct kvm_mmu_page
, link
);
431 list_del(&page
->link
);
432 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
433 ASSERT(is_empty_shadow_page(page
->page_hpa
));
434 page
->slot_bitmap
= 0;
436 page
->multimapped
= 0;
437 page
->parent_pte
= parent_pte
;
438 --vcpu
->kvm
->n_free_mmu_pages
;
442 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
443 struct kvm_mmu_page
*page
, u64
*parent_pte
)
445 struct kvm_pte_chain
*pte_chain
;
446 struct hlist_node
*node
;
451 if (!page
->multimapped
) {
452 u64
*old
= page
->parent_pte
;
455 page
->parent_pte
= parent_pte
;
458 page
->multimapped
= 1;
459 pte_chain
= mmu_alloc_pte_chain(vcpu
);
460 INIT_HLIST_HEAD(&page
->parent_ptes
);
461 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
462 pte_chain
->parent_ptes
[0] = old
;
464 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
) {
465 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
467 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
468 if (!pte_chain
->parent_ptes
[i
]) {
469 pte_chain
->parent_ptes
[i
] = parent_pte
;
473 pte_chain
= mmu_alloc_pte_chain(vcpu
);
475 hlist_add_head(&pte_chain
->link
, &page
->parent_ptes
);
476 pte_chain
->parent_ptes
[0] = parent_pte
;
479 static void mmu_page_remove_parent_pte(struct kvm_vcpu
*vcpu
,
480 struct kvm_mmu_page
*page
,
483 struct kvm_pte_chain
*pte_chain
;
484 struct hlist_node
*node
;
487 if (!page
->multimapped
) {
488 BUG_ON(page
->parent_pte
!= parent_pte
);
489 page
->parent_pte
= NULL
;
492 hlist_for_each_entry(pte_chain
, node
, &page
->parent_ptes
, link
)
493 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
494 if (!pte_chain
->parent_ptes
[i
])
496 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
498 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
499 && pte_chain
->parent_ptes
[i
+ 1]) {
500 pte_chain
->parent_ptes
[i
]
501 = pte_chain
->parent_ptes
[i
+ 1];
504 pte_chain
->parent_ptes
[i
] = NULL
;
506 hlist_del(&pte_chain
->link
);
507 mmu_free_pte_chain(vcpu
, pte_chain
);
508 if (hlist_empty(&page
->parent_ptes
)) {
509 page
->multimapped
= 0;
510 page
->parent_pte
= NULL
;
518 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm_vcpu
*vcpu
,
522 struct hlist_head
*bucket
;
523 struct kvm_mmu_page
*page
;
524 struct hlist_node
*node
;
526 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
527 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
528 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
529 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
530 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
531 pgprintk("%s: found role %x\n",
532 __FUNCTION__
, page
->role
.word
);
538 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
545 union kvm_mmu_page_role role
;
548 struct hlist_head
*bucket
;
549 struct kvm_mmu_page
*page
;
550 struct hlist_node
*node
;
553 role
.glevels
= vcpu
->mmu
.root_level
;
555 role
.metaphysical
= metaphysical
;
556 if (vcpu
->mmu
.root_level
<= PT32_ROOT_LEVEL
) {
557 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
558 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
559 role
.quadrant
= quadrant
;
561 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__
,
563 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
564 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
565 hlist_for_each_entry(page
, node
, bucket
, hash_link
)
566 if (page
->gfn
== gfn
&& page
->role
.word
== role
.word
) {
567 mmu_page_add_parent_pte(vcpu
, page
, parent_pte
);
568 pgprintk("%s: found\n", __FUNCTION__
);
571 page
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
574 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__
, gfn
, role
.word
);
577 hlist_add_head(&page
->hash_link
, bucket
);
579 rmap_write_protect(vcpu
, gfn
);
583 static void kvm_mmu_page_unlink_children(struct kvm_vcpu
*vcpu
,
584 struct kvm_mmu_page
*page
)
590 pt
= __va(page
->page_hpa
);
592 if (page
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
593 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
594 if (pt
[i
] & PT_PRESENT_MASK
)
595 rmap_remove(vcpu
, &pt
[i
]);
598 kvm_arch_ops
->tlb_flush(vcpu
);
602 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
606 if (!(ent
& PT_PRESENT_MASK
))
608 ent
&= PT64_BASE_ADDR_MASK
;
609 mmu_page_remove_parent_pte(vcpu
, page_header(ent
), &pt
[i
]);
613 static void kvm_mmu_put_page(struct kvm_vcpu
*vcpu
,
614 struct kvm_mmu_page
*page
,
617 mmu_page_remove_parent_pte(vcpu
, page
, parent_pte
);
620 static void kvm_mmu_zap_page(struct kvm_vcpu
*vcpu
,
621 struct kvm_mmu_page
*page
)
625 while (page
->multimapped
|| page
->parent_pte
) {
626 if (!page
->multimapped
)
627 parent_pte
= page
->parent_pte
;
629 struct kvm_pte_chain
*chain
;
631 chain
= container_of(page
->parent_ptes
.first
,
632 struct kvm_pte_chain
, link
);
633 parent_pte
= chain
->parent_ptes
[0];
636 kvm_mmu_put_page(vcpu
, page
, parent_pte
);
639 kvm_mmu_page_unlink_children(vcpu
, page
);
640 if (!page
->root_count
) {
641 hlist_del(&page
->hash_link
);
642 kvm_mmu_free_page(vcpu
, page
->page_hpa
);
644 list_del(&page
->link
);
645 list_add(&page
->link
, &vcpu
->kvm
->active_mmu_pages
);
649 static int kvm_mmu_unprotect_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
652 struct hlist_head
*bucket
;
653 struct kvm_mmu_page
*page
;
654 struct hlist_node
*node
, *n
;
657 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__
, gfn
);
659 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
660 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
661 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
)
662 if (page
->gfn
== gfn
&& !page
->role
.metaphysical
) {
663 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__
, gfn
,
665 kvm_mmu_zap_page(vcpu
, page
);
671 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gpa_t gpa
)
673 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gpa
>> PAGE_SHIFT
));
674 struct kvm_mmu_page
*page_head
= page_header(__pa(pte
));
676 __set_bit(slot
, &page_head
->slot_bitmap
);
679 hpa_t
safe_gpa_to_hpa(struct kvm_vcpu
*vcpu
, gpa_t gpa
)
681 hpa_t hpa
= gpa_to_hpa(vcpu
, gpa
);
683 return is_error_hpa(hpa
) ? bad_page_address
| (gpa
& ~PAGE_MASK
): hpa
;
686 hpa_t
gpa_to_hpa(struct kvm_vcpu
*vcpu
, gpa_t gpa
)
688 struct kvm_memory_slot
*slot
;
691 ASSERT((gpa
& HPA_ERR_MASK
) == 0);
692 slot
= gfn_to_memslot(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
694 return gpa
| HPA_ERR_MASK
;
695 page
= gfn_to_page(slot
, gpa
>> PAGE_SHIFT
);
696 return ((hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
)
697 | (gpa
& (PAGE_SIZE
-1));
700 hpa_t
gva_to_hpa(struct kvm_vcpu
*vcpu
, gva_t gva
)
702 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
704 if (gpa
== UNMAPPED_GVA
)
706 return gpa_to_hpa(vcpu
, gpa
);
709 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
713 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, hpa_t p
)
715 int level
= PT32E_ROOT_LEVEL
;
716 hpa_t table_addr
= vcpu
->mmu
.root_hpa
;
719 u32 index
= PT64_INDEX(v
, level
);
723 ASSERT(VALID_PAGE(table_addr
));
724 table
= __va(table_addr
);
728 if (is_present_pte(pte
) && is_writeble_pte(pte
))
730 mark_page_dirty(vcpu
->kvm
, v
>> PAGE_SHIFT
);
731 page_header_update_slot(vcpu
->kvm
, table
, v
);
732 table
[index
] = p
| PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
734 rmap_add(vcpu
, &table
[index
]);
738 if (table
[index
] == 0) {
739 struct kvm_mmu_page
*new_table
;
742 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
744 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
748 pgprintk("nonpaging_map: ENOMEM\n");
752 table
[index
] = new_table
->page_hpa
| PT_PRESENT_MASK
753 | PT_WRITABLE_MASK
| PT_USER_MASK
;
755 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
759 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
762 struct kvm_mmu_page
*page
;
765 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
766 hpa_t root
= vcpu
->mmu
.root_hpa
;
768 ASSERT(VALID_PAGE(root
));
769 page
= page_header(root
);
771 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
775 for (i
= 0; i
< 4; ++i
) {
776 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
778 ASSERT(VALID_PAGE(root
));
779 root
&= PT64_BASE_ADDR_MASK
;
780 page
= page_header(root
);
782 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
784 vcpu
->mmu
.root_hpa
= INVALID_PAGE
;
787 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
791 struct kvm_mmu_page
*page
;
793 root_gfn
= vcpu
->cr3
>> PAGE_SHIFT
;
796 if (vcpu
->mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
797 hpa_t root
= vcpu
->mmu
.root_hpa
;
799 ASSERT(!VALID_PAGE(root
));
800 root
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
801 PT64_ROOT_LEVEL
, 0, NULL
)->page_hpa
;
802 page
= page_header(root
);
804 vcpu
->mmu
.root_hpa
= root
;
808 for (i
= 0; i
< 4; ++i
) {
809 hpa_t root
= vcpu
->mmu
.pae_root
[i
];
811 ASSERT(!VALID_PAGE(root
));
812 if (vcpu
->mmu
.root_level
== PT32E_ROOT_LEVEL
)
813 root_gfn
= vcpu
->pdptrs
[i
] >> PAGE_SHIFT
;
814 else if (vcpu
->mmu
.root_level
== 0)
816 root
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
817 PT32_ROOT_LEVEL
, !is_paging(vcpu
),
819 page
= page_header(root
);
821 vcpu
->mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
823 vcpu
->mmu
.root_hpa
= __pa(vcpu
->mmu
.pae_root
);
826 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
831 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
838 r
= mmu_topup_memory_caches(vcpu
);
843 ASSERT(VALID_PAGE(vcpu
->mmu
.root_hpa
));
846 paddr
= gpa_to_hpa(vcpu
, addr
& PT64_BASE_ADDR_MASK
);
848 if (is_error_hpa(paddr
))
851 return nonpaging_map(vcpu
, addr
& PAGE_MASK
, paddr
);
854 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
856 mmu_free_roots(vcpu
);
859 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
861 struct kvm_mmu
*context
= &vcpu
->mmu
;
863 context
->new_cr3
= nonpaging_new_cr3
;
864 context
->page_fault
= nonpaging_page_fault
;
865 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
866 context
->free
= nonpaging_free
;
867 context
->root_level
= 0;
868 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
869 mmu_alloc_roots(vcpu
);
870 ASSERT(VALID_PAGE(context
->root_hpa
));
871 kvm_arch_ops
->set_cr3(vcpu
, context
->root_hpa
);
875 static void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
877 ++kvm_stat
.tlb_flush
;
878 kvm_arch_ops
->tlb_flush(vcpu
);
881 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
883 pgprintk("%s: cr3 %lx\n", __FUNCTION__
, vcpu
->cr3
);
884 mmu_free_roots(vcpu
);
885 mmu_alloc_roots(vcpu
);
886 kvm_mmu_flush_tlb(vcpu
);
887 kvm_arch_ops
->set_cr3(vcpu
, vcpu
->mmu
.root_hpa
);
890 static void mark_pagetable_nonglobal(void *shadow_pte
)
892 page_header(__pa(shadow_pte
))->global
= 0;
895 static inline void set_pte_common(struct kvm_vcpu
*vcpu
,
904 *shadow_pte
|= access_bits
<< PT_SHADOW_BITS_OFFSET
;
906 access_bits
&= ~PT_WRITABLE_MASK
;
908 paddr
= gpa_to_hpa(vcpu
, gaddr
& PT64_BASE_ADDR_MASK
);
910 *shadow_pte
|= access_bits
;
912 if (!(*shadow_pte
& PT_GLOBAL_MASK
))
913 mark_pagetable_nonglobal(shadow_pte
);
915 if (is_error_hpa(paddr
)) {
916 *shadow_pte
|= gaddr
;
917 *shadow_pte
|= PT_SHADOW_IO_MARK
;
918 *shadow_pte
&= ~PT_PRESENT_MASK
;
922 *shadow_pte
|= paddr
;
924 if (access_bits
& PT_WRITABLE_MASK
) {
925 struct kvm_mmu_page
*shadow
;
927 shadow
= kvm_mmu_lookup_page(vcpu
, gfn
);
929 pgprintk("%s: found shadow page for %lx, marking ro\n",
931 access_bits
&= ~PT_WRITABLE_MASK
;
932 if (is_writeble_pte(*shadow_pte
)) {
933 *shadow_pte
&= ~PT_WRITABLE_MASK
;
934 kvm_arch_ops
->tlb_flush(vcpu
);
939 if (access_bits
& PT_WRITABLE_MASK
)
940 mark_page_dirty(vcpu
->kvm
, gaddr
>> PAGE_SHIFT
);
942 page_header_update_slot(vcpu
->kvm
, shadow_pte
, gaddr
);
943 rmap_add(vcpu
, shadow_pte
);
946 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
950 kvm_arch_ops
->inject_page_fault(vcpu
, addr
, err_code
);
953 static inline int fix_read_pf(u64
*shadow_ent
)
955 if ((*shadow_ent
& PT_SHADOW_USER_MASK
) &&
956 !(*shadow_ent
& PT_USER_MASK
)) {
958 * If supervisor write protect is disabled, we shadow kernel
959 * pages as user pages so we can trap the write access.
961 *shadow_ent
|= PT_USER_MASK
;
962 *shadow_ent
&= ~PT_WRITABLE_MASK
;
970 static int may_access(u64 pte
, int write
, int user
)
973 if (user
&& !(pte
& PT_USER_MASK
))
975 if (write
&& !(pte
& PT_WRITABLE_MASK
))
980 static void paging_free(struct kvm_vcpu
*vcpu
)
982 nonpaging_free(vcpu
);
986 #include "paging_tmpl.h"
990 #include "paging_tmpl.h"
993 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
995 struct kvm_mmu
*context
= &vcpu
->mmu
;
997 ASSERT(is_pae(vcpu
));
998 context
->new_cr3
= paging_new_cr3
;
999 context
->page_fault
= paging64_page_fault
;
1000 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1001 context
->free
= paging_free
;
1002 context
->root_level
= level
;
1003 context
->shadow_root_level
= level
;
1004 mmu_alloc_roots(vcpu
);
1005 ASSERT(VALID_PAGE(context
->root_hpa
));
1006 kvm_arch_ops
->set_cr3(vcpu
, context
->root_hpa
|
1007 (vcpu
->cr3
& (CR3_PCD_MASK
| CR3_WPT_MASK
)));
1011 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1013 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1016 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1018 struct kvm_mmu
*context
= &vcpu
->mmu
;
1020 context
->new_cr3
= paging_new_cr3
;
1021 context
->page_fault
= paging32_page_fault
;
1022 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1023 context
->free
= paging_free
;
1024 context
->root_level
= PT32_ROOT_LEVEL
;
1025 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1026 mmu_alloc_roots(vcpu
);
1027 ASSERT(VALID_PAGE(context
->root_hpa
));
1028 kvm_arch_ops
->set_cr3(vcpu
, context
->root_hpa
|
1029 (vcpu
->cr3
& (CR3_PCD_MASK
| CR3_WPT_MASK
)));
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
)
1066 destroy_kvm_mmu(vcpu
);
1067 r
= init_kvm_mmu(vcpu
);
1070 r
= mmu_topup_memory_caches(vcpu
);
1075 void kvm_mmu_pre_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
, int bytes
)
1077 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1078 struct kvm_mmu_page
*page
;
1079 struct kvm_mmu_page
*child
;
1080 struct hlist_node
*node
, *n
;
1081 struct hlist_head
*bucket
;
1085 unsigned offset
= offset_in_page(gpa
);
1087 unsigned page_offset
;
1088 unsigned misaligned
;
1092 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__
, gpa
, bytes
);
1093 if (gfn
== vcpu
->last_pt_write_gfn
) {
1094 ++vcpu
->last_pt_write_count
;
1095 if (vcpu
->last_pt_write_count
>= 3)
1098 vcpu
->last_pt_write_gfn
= gfn
;
1099 vcpu
->last_pt_write_count
= 1;
1101 index
= kvm_page_table_hashfn(gfn
) % KVM_NUM_MMU_PAGES
;
1102 bucket
= &vcpu
->kvm
->mmu_page_hash
[index
];
1103 hlist_for_each_entry_safe(page
, node
, n
, bucket
, hash_link
) {
1104 if (page
->gfn
!= gfn
|| page
->role
.metaphysical
)
1106 pte_size
= page
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1107 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1108 if (misaligned
|| flooded
) {
1110 * Misaligned accesses are too much trouble to fix
1111 * up; also, they usually indicate a page is not used
1114 * If we're seeing too many writes to a page,
1115 * it may no longer be a page table, or we may be
1116 * forking, in which case it is better to unmap the
1119 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1120 gpa
, bytes
, page
->role
.word
);
1121 kvm_mmu_zap_page(vcpu
, page
);
1124 page_offset
= offset
;
1125 level
= page
->role
.level
;
1126 if (page
->role
.glevels
== PT32_ROOT_LEVEL
) {
1127 page_offset
<<= 1; /* 32->64 */
1128 page_offset
&= ~PAGE_MASK
;
1130 spte
= __va(page
->page_hpa
);
1131 spte
+= page_offset
/ sizeof(*spte
);
1133 if (is_present_pte(pte
)) {
1134 if (level
== PT_PAGE_TABLE_LEVEL
)
1135 rmap_remove(vcpu
, spte
);
1137 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1138 mmu_page_remove_parent_pte(vcpu
, child
, spte
);
1145 void kvm_mmu_post_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
, int bytes
)
1149 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1151 gpa_t gpa
= vcpu
->mmu
.gva_to_gpa(vcpu
, gva
);
1153 return kvm_mmu_unprotect_page(vcpu
, gpa
>> PAGE_SHIFT
);
1156 void kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1158 while (vcpu
->kvm
->n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1159 struct kvm_mmu_page
*page
;
1161 page
= container_of(vcpu
->kvm
->active_mmu_pages
.prev
,
1162 struct kvm_mmu_page
, link
);
1163 kvm_mmu_zap_page(vcpu
, page
);
1166 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages
);
1168 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1170 struct kvm_mmu_page
*page
;
1172 while (!list_empty(&vcpu
->kvm
->active_mmu_pages
)) {
1173 page
= container_of(vcpu
->kvm
->active_mmu_pages
.next
,
1174 struct kvm_mmu_page
, link
);
1175 kvm_mmu_zap_page(vcpu
, page
);
1177 while (!list_empty(&vcpu
->free_pages
)) {
1178 page
= list_entry(vcpu
->free_pages
.next
,
1179 struct kvm_mmu_page
, link
);
1180 list_del(&page
->link
);
1181 __free_page(pfn_to_page(page
->page_hpa
>> PAGE_SHIFT
));
1182 page
->page_hpa
= INVALID_PAGE
;
1184 free_page((unsigned long)vcpu
->mmu
.pae_root
);
1187 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1194 for (i
= 0; i
< KVM_NUM_MMU_PAGES
; i
++) {
1195 struct kvm_mmu_page
*page_header
= &vcpu
->page_header_buf
[i
];
1197 INIT_LIST_HEAD(&page_header
->link
);
1198 if ((page
= alloc_page(GFP_KERNEL
)) == NULL
)
1200 page
->private = (unsigned long)page_header
;
1201 page_header
->page_hpa
= (hpa_t
)page_to_pfn(page
) << PAGE_SHIFT
;
1202 memset(__va(page_header
->page_hpa
), 0, PAGE_SIZE
);
1203 list_add(&page_header
->link
, &vcpu
->free_pages
);
1204 ++vcpu
->kvm
->n_free_mmu_pages
;
1208 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1209 * Therefore we need to allocate shadow page tables in the first
1210 * 4GB of memory, which happens to fit the DMA32 zone.
1212 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1215 vcpu
->mmu
.pae_root
= page_address(page
);
1216 for (i
= 0; i
< 4; ++i
)
1217 vcpu
->mmu
.pae_root
[i
] = INVALID_PAGE
;
1222 free_mmu_pages(vcpu
);
1226 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1229 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1230 ASSERT(list_empty(&vcpu
->free_pages
));
1232 return alloc_mmu_pages(vcpu
);
1235 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1238 ASSERT(!VALID_PAGE(vcpu
->mmu
.root_hpa
));
1239 ASSERT(!list_empty(&vcpu
->free_pages
));
1241 return init_kvm_mmu(vcpu
);
1244 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1248 destroy_kvm_mmu(vcpu
);
1249 free_mmu_pages(vcpu
);
1250 mmu_free_memory_caches(vcpu
);
1253 void kvm_mmu_slot_remove_write_access(struct kvm_vcpu
*vcpu
, int slot
)
1255 struct kvm
*kvm
= vcpu
->kvm
;
1256 struct kvm_mmu_page
*page
;
1258 list_for_each_entry(page
, &kvm
->active_mmu_pages
, link
) {
1262 if (!test_bit(slot
, &page
->slot_bitmap
))
1265 pt
= __va(page
->page_hpa
);
1266 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1268 if (pt
[i
] & PT_WRITABLE_MASK
) {
1269 rmap_remove(vcpu
, &pt
[i
]);
1270 pt
[i
] &= ~PT_WRITABLE_MASK
;
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