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/kvm_host.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
27 #include <linux/highmem.h>
28 #include <linux/module.h>
29 #include <linux/swap.h>
30 #include <linux/hugetlb.h>
33 #include <asm/cmpxchg.h>
37 * When setting this variable to true it enables Two-Dimensional-Paging
38 * where the hardware walks 2 page tables:
39 * 1. the guest-virtual to guest-physical
40 * 2. while doing 1. it walks guest-physical to host-physical
41 * If the hardware supports that we don't need to do shadow paging.
43 static bool tdp_enabled
= false;
50 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
52 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
57 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
58 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
62 #define pgprintk(x...) do { } while (0)
63 #define rmap_printk(x...) do { } while (0)
67 #if defined(MMU_DEBUG) || defined(AUDIT)
72 #define ASSERT(x) do { } while (0)
76 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
77 __FILE__, __LINE__, #x); \
81 #define PT64_PT_BITS 9
82 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
83 #define PT32_PT_BITS 10
84 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
86 #define PT_WRITABLE_SHIFT 1
88 #define PT_PRESENT_MASK (1ULL << 0)
89 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
90 #define PT_USER_MASK (1ULL << 2)
91 #define PT_PWT_MASK (1ULL << 3)
92 #define PT_PCD_MASK (1ULL << 4)
93 #define PT_ACCESSED_MASK (1ULL << 5)
94 #define PT_DIRTY_MASK (1ULL << 6)
95 #define PT_PAGE_SIZE_MASK (1ULL << 7)
96 #define PT_PAT_MASK (1ULL << 7)
97 #define PT_GLOBAL_MASK (1ULL << 8)
98 #define PT64_NX_SHIFT 63
99 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
101 #define PT_PAT_SHIFT 7
102 #define PT_DIR_PAT_SHIFT 12
103 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
105 #define PT32_DIR_PSE36_SIZE 4
106 #define PT32_DIR_PSE36_SHIFT 13
107 #define PT32_DIR_PSE36_MASK \
108 (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
111 #define PT_FIRST_AVAIL_BITS_SHIFT 9
112 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
114 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
116 #define PT64_LEVEL_BITS 9
118 #define PT64_LEVEL_SHIFT(level) \
119 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
121 #define PT64_LEVEL_MASK(level) \
122 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
124 #define PT64_INDEX(address, level)\
125 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
128 #define PT32_LEVEL_BITS 10
130 #define PT32_LEVEL_SHIFT(level) \
131 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
133 #define PT32_LEVEL_MASK(level) \
134 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
136 #define PT32_INDEX(address, level)\
137 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
140 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
141 #define PT64_DIR_BASE_ADDR_MASK \
142 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
144 #define PT32_BASE_ADDR_MASK PAGE_MASK
145 #define PT32_DIR_BASE_ADDR_MASK \
146 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
148 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
151 #define PFERR_PRESENT_MASK (1U << 0)
152 #define PFERR_WRITE_MASK (1U << 1)
153 #define PFERR_USER_MASK (1U << 2)
154 #define PFERR_FETCH_MASK (1U << 4)
156 #define PT64_ROOT_LEVEL 4
157 #define PT32_ROOT_LEVEL 2
158 #define PT32E_ROOT_LEVEL 3
160 #define PT_DIRECTORY_LEVEL 2
161 #define PT_PAGE_TABLE_LEVEL 1
165 #define ACC_EXEC_MASK 1
166 #define ACC_WRITE_MASK PT_WRITABLE_MASK
167 #define ACC_USER_MASK PT_USER_MASK
168 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
170 struct kvm_rmap_desc
{
171 u64
*shadow_ptes
[RMAP_EXT
];
172 struct kvm_rmap_desc
*more
;
175 static struct kmem_cache
*pte_chain_cache
;
176 static struct kmem_cache
*rmap_desc_cache
;
177 static struct kmem_cache
*mmu_page_header_cache
;
179 static u64 __read_mostly shadow_trap_nonpresent_pte
;
180 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
182 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
184 shadow_trap_nonpresent_pte
= trap_pte
;
185 shadow_notrap_nonpresent_pte
= notrap_pte
;
187 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
189 static int is_write_protection(struct kvm_vcpu
*vcpu
)
191 return vcpu
->arch
.cr0
& X86_CR0_WP
;
194 static int is_cpuid_PSE36(void)
199 static int is_nx(struct kvm_vcpu
*vcpu
)
201 return vcpu
->arch
.shadow_efer
& EFER_NX
;
204 static int is_present_pte(unsigned long pte
)
206 return pte
& PT_PRESENT_MASK
;
209 static int is_shadow_present_pte(u64 pte
)
211 return pte
!= shadow_trap_nonpresent_pte
212 && pte
!= shadow_notrap_nonpresent_pte
;
215 static int is_large_pte(u64 pte
)
217 return pte
& PT_PAGE_SIZE_MASK
;
220 static int is_writeble_pte(unsigned long pte
)
222 return pte
& PT_WRITABLE_MASK
;
225 static int is_dirty_pte(unsigned long pte
)
227 return pte
& PT_DIRTY_MASK
;
230 static int is_rmap_pte(u64 pte
)
232 return is_shadow_present_pte(pte
);
235 static gfn_t
pse36_gfn_delta(u32 gpte
)
237 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
239 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
242 static void set_shadow_pte(u64
*sptep
, u64 spte
)
245 set_64bit((unsigned long *)sptep
, spte
);
247 set_64bit((unsigned long long *)sptep
, spte
);
251 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
252 struct kmem_cache
*base_cache
, int min
)
256 if (cache
->nobjs
>= min
)
258 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
259 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
262 cache
->objects
[cache
->nobjs
++] = obj
;
267 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
270 kfree(mc
->objects
[--mc
->nobjs
]);
273 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
278 if (cache
->nobjs
>= min
)
280 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
281 page
= alloc_page(GFP_KERNEL
);
284 set_page_private(page
, 0);
285 cache
->objects
[cache
->nobjs
++] = page_address(page
);
290 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
293 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
296 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
300 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
304 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
308 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
311 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
312 mmu_page_header_cache
, 4);
317 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
319 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
320 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
321 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
322 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
325 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
331 p
= mc
->objects
[--mc
->nobjs
];
336 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
338 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
339 sizeof(struct kvm_pte_chain
));
342 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
347 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
349 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
350 sizeof(struct kvm_rmap_desc
));
353 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
359 * Return the pointer to the largepage write count for a given
360 * gfn, handling slots that are not large page aligned.
362 static int *slot_largepage_idx(gfn_t gfn
, struct kvm_memory_slot
*slot
)
366 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
367 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
368 return &slot
->lpage_info
[idx
].write_count
;
371 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
375 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
377 WARN_ON(*write_count
> KVM_PAGES_PER_HPAGE
);
380 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
384 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
386 WARN_ON(*write_count
< 0);
389 static int has_wrprotected_page(struct kvm
*kvm
, gfn_t gfn
)
391 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
395 largepage_idx
= slot_largepage_idx(gfn
, slot
);
396 return *largepage_idx
;
402 static int host_largepage_backed(struct kvm
*kvm
, gfn_t gfn
)
404 struct vm_area_struct
*vma
;
407 addr
= gfn_to_hva(kvm
, gfn
);
408 if (kvm_is_error_hva(addr
))
411 vma
= find_vma(current
->mm
, addr
);
412 if (vma
&& is_vm_hugetlb_page(vma
))
418 static int is_largepage_backed(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
420 struct kvm_memory_slot
*slot
;
422 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
))
425 if (!host_largepage_backed(vcpu
->kvm
, large_gfn
))
428 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
429 if (slot
&& slot
->dirty_bitmap
)
436 * Take gfn and return the reverse mapping to it.
437 * Note: gfn must be unaliased before this function get called
440 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int lpage
)
442 struct kvm_memory_slot
*slot
;
445 slot
= gfn_to_memslot(kvm
, gfn
);
447 return &slot
->rmap
[gfn
- slot
->base_gfn
];
449 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
450 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
452 return &slot
->lpage_info
[idx
].rmap_pde
;
456 * Reverse mapping data structures:
458 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
459 * that points to page_address(page).
461 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
462 * containing more mappings.
464 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
, int lpage
)
466 struct kvm_mmu_page
*sp
;
467 struct kvm_rmap_desc
*desc
;
468 unsigned long *rmapp
;
471 if (!is_rmap_pte(*spte
))
473 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
474 sp
= page_header(__pa(spte
));
475 sp
->gfns
[spte
- sp
->spt
] = gfn
;
476 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, lpage
);
478 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
479 *rmapp
= (unsigned long)spte
;
480 } else if (!(*rmapp
& 1)) {
481 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
482 desc
= mmu_alloc_rmap_desc(vcpu
);
483 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
484 desc
->shadow_ptes
[1] = spte
;
485 *rmapp
= (unsigned long)desc
| 1;
487 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
488 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
489 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
491 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
492 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
495 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
497 desc
->shadow_ptes
[i
] = spte
;
501 static void rmap_desc_remove_entry(unsigned long *rmapp
,
502 struct kvm_rmap_desc
*desc
,
504 struct kvm_rmap_desc
*prev_desc
)
508 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
510 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
511 desc
->shadow_ptes
[j
] = NULL
;
514 if (!prev_desc
&& !desc
->more
)
515 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
518 prev_desc
->more
= desc
->more
;
520 *rmapp
= (unsigned long)desc
->more
| 1;
521 mmu_free_rmap_desc(desc
);
524 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
526 struct kvm_rmap_desc
*desc
;
527 struct kvm_rmap_desc
*prev_desc
;
528 struct kvm_mmu_page
*sp
;
530 unsigned long *rmapp
;
533 if (!is_rmap_pte(*spte
))
535 sp
= page_header(__pa(spte
));
536 page
= pfn_to_page((*spte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
);
537 mark_page_accessed(page
);
538 if (is_writeble_pte(*spte
))
539 kvm_release_page_dirty(page
);
541 kvm_release_page_clean(page
);
542 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], is_large_pte(*spte
));
544 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
546 } else if (!(*rmapp
& 1)) {
547 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
548 if ((u64
*)*rmapp
!= spte
) {
549 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
555 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
556 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
559 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
560 if (desc
->shadow_ptes
[i
] == spte
) {
561 rmap_desc_remove_entry(rmapp
,
573 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
575 struct kvm_rmap_desc
*desc
;
576 struct kvm_rmap_desc
*prev_desc
;
582 else if (!(*rmapp
& 1)) {
584 return (u64
*)*rmapp
;
587 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
591 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
592 if (prev_spte
== spte
)
593 return desc
->shadow_ptes
[i
];
594 prev_spte
= desc
->shadow_ptes
[i
];
601 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
603 unsigned long *rmapp
;
605 int write_protected
= 0;
607 gfn
= unalias_gfn(kvm
, gfn
);
608 rmapp
= gfn_to_rmap(kvm
, gfn
, 0);
610 spte
= rmap_next(kvm
, rmapp
, NULL
);
613 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
614 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
615 if (is_writeble_pte(*spte
)) {
616 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
619 spte
= rmap_next(kvm
, rmapp
, spte
);
621 /* check for huge page mappings */
622 rmapp
= gfn_to_rmap(kvm
, gfn
, 1);
623 spte
= rmap_next(kvm
, rmapp
, NULL
);
626 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
627 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
628 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
629 if (is_writeble_pte(*spte
)) {
630 rmap_remove(kvm
, spte
);
632 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
635 spte
= rmap_next(kvm
, rmapp
, spte
);
639 kvm_flush_remote_tlbs(kvm
);
641 account_shadowed(kvm
, gfn
);
645 static int is_empty_shadow_page(u64
*spt
)
650 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
651 if (*pos
!= shadow_trap_nonpresent_pte
) {
652 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
660 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
662 ASSERT(is_empty_shadow_page(sp
->spt
));
664 __free_page(virt_to_page(sp
->spt
));
665 __free_page(virt_to_page(sp
->gfns
));
667 ++kvm
->arch
.n_free_mmu_pages
;
670 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
672 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
675 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
678 struct kvm_mmu_page
*sp
;
680 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
681 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
682 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
683 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
684 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
685 ASSERT(is_empty_shadow_page(sp
->spt
));
688 sp
->parent_pte
= parent_pte
;
689 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
693 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
694 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
696 struct kvm_pte_chain
*pte_chain
;
697 struct hlist_node
*node
;
702 if (!sp
->multimapped
) {
703 u64
*old
= sp
->parent_pte
;
706 sp
->parent_pte
= parent_pte
;
710 pte_chain
= mmu_alloc_pte_chain(vcpu
);
711 INIT_HLIST_HEAD(&sp
->parent_ptes
);
712 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
713 pte_chain
->parent_ptes
[0] = old
;
715 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
716 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
718 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
719 if (!pte_chain
->parent_ptes
[i
]) {
720 pte_chain
->parent_ptes
[i
] = parent_pte
;
724 pte_chain
= mmu_alloc_pte_chain(vcpu
);
726 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
727 pte_chain
->parent_ptes
[0] = parent_pte
;
730 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
733 struct kvm_pte_chain
*pte_chain
;
734 struct hlist_node
*node
;
737 if (!sp
->multimapped
) {
738 BUG_ON(sp
->parent_pte
!= parent_pte
);
739 sp
->parent_pte
= NULL
;
742 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
743 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
744 if (!pte_chain
->parent_ptes
[i
])
746 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
748 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
749 && pte_chain
->parent_ptes
[i
+ 1]) {
750 pte_chain
->parent_ptes
[i
]
751 = pte_chain
->parent_ptes
[i
+ 1];
754 pte_chain
->parent_ptes
[i
] = NULL
;
756 hlist_del(&pte_chain
->link
);
757 mmu_free_pte_chain(pte_chain
);
758 if (hlist_empty(&sp
->parent_ptes
)) {
760 sp
->parent_pte
= NULL
;
768 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
771 struct hlist_head
*bucket
;
772 struct kvm_mmu_page
*sp
;
773 struct hlist_node
*node
;
775 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
776 index
= kvm_page_table_hashfn(gfn
);
777 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
778 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
779 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
780 && !sp
->role
.invalid
) {
781 pgprintk("%s: found role %x\n",
782 __func__
, sp
->role
.word
);
788 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
796 union kvm_mmu_page_role role
;
799 struct hlist_head
*bucket
;
800 struct kvm_mmu_page
*sp
;
801 struct hlist_node
*node
;
804 role
.glevels
= vcpu
->arch
.mmu
.root_level
;
806 role
.metaphysical
= metaphysical
;
807 role
.access
= access
;
808 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
809 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
810 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
811 role
.quadrant
= quadrant
;
813 pgprintk("%s: looking gfn %lx role %x\n", __func__
,
815 index
= kvm_page_table_hashfn(gfn
);
816 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
817 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
818 if (sp
->gfn
== gfn
&& sp
->role
.word
== role
.word
) {
819 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
820 pgprintk("%s: found\n", __func__
);
823 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
824 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
827 pgprintk("%s: adding gfn %lx role %x\n", __func__
, gfn
, role
.word
);
830 hlist_add_head(&sp
->hash_link
, bucket
);
831 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
833 rmap_write_protect(vcpu
->kvm
, gfn
);
837 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
838 struct kvm_mmu_page
*sp
)
846 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
847 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
848 if (is_shadow_present_pte(pt
[i
]))
849 rmap_remove(kvm
, &pt
[i
]);
850 pt
[i
] = shadow_trap_nonpresent_pte
;
852 kvm_flush_remote_tlbs(kvm
);
856 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
859 if (is_shadow_present_pte(ent
)) {
860 if (!is_large_pte(ent
)) {
861 ent
&= PT64_BASE_ADDR_MASK
;
862 mmu_page_remove_parent_pte(page_header(ent
),
866 rmap_remove(kvm
, &pt
[i
]);
869 pt
[i
] = shadow_trap_nonpresent_pte
;
871 kvm_flush_remote_tlbs(kvm
);
874 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
876 mmu_page_remove_parent_pte(sp
, parent_pte
);
879 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
883 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
885 kvm
->vcpus
[i
]->arch
.last_pte_updated
= NULL
;
888 static void kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
892 ++kvm
->stat
.mmu_shadow_zapped
;
893 while (sp
->multimapped
|| sp
->parent_pte
) {
894 if (!sp
->multimapped
)
895 parent_pte
= sp
->parent_pte
;
897 struct kvm_pte_chain
*chain
;
899 chain
= container_of(sp
->parent_ptes
.first
,
900 struct kvm_pte_chain
, link
);
901 parent_pte
= chain
->parent_ptes
[0];
904 kvm_mmu_put_page(sp
, parent_pte
);
905 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
907 kvm_mmu_page_unlink_children(kvm
, sp
);
908 if (!sp
->root_count
) {
909 if (!sp
->role
.metaphysical
)
910 unaccount_shadowed(kvm
, sp
->gfn
);
911 hlist_del(&sp
->hash_link
);
912 kvm_mmu_free_page(kvm
, sp
);
914 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
915 sp
->role
.invalid
= 1;
916 kvm_reload_remote_mmus(kvm
);
918 kvm_mmu_reset_last_pte_updated(kvm
);
922 * Changing the number of mmu pages allocated to the vm
923 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
925 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
928 * If we set the number of mmu pages to be smaller be than the
929 * number of actived pages , we must to free some mmu pages before we
933 if ((kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
) >
935 int n_used_mmu_pages
= kvm
->arch
.n_alloc_mmu_pages
936 - kvm
->arch
.n_free_mmu_pages
;
938 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
939 struct kvm_mmu_page
*page
;
941 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
942 struct kvm_mmu_page
, link
);
943 kvm_mmu_zap_page(kvm
, page
);
946 kvm
->arch
.n_free_mmu_pages
= 0;
949 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
950 - kvm
->arch
.n_alloc_mmu_pages
;
952 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
955 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
958 struct hlist_head
*bucket
;
959 struct kvm_mmu_page
*sp
;
960 struct hlist_node
*node
, *n
;
963 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
965 index
= kvm_page_table_hashfn(gfn
);
966 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
967 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
968 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
) {
969 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
971 kvm_mmu_zap_page(kvm
, sp
);
977 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
979 struct kvm_mmu_page
*sp
;
981 while ((sp
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
982 pgprintk("%s: zap %lx %x\n", __func__
, gfn
, sp
->role
.word
);
983 kvm_mmu_zap_page(kvm
, sp
);
987 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
989 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gfn
));
990 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
992 __set_bit(slot
, &sp
->slot_bitmap
);
995 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
999 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1001 if (gpa
== UNMAPPED_GVA
)
1004 down_read(¤t
->mm
->mmap_sem
);
1005 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1006 up_read(¤t
->mm
->mmap_sem
);
1011 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1012 unsigned pt_access
, unsigned pte_access
,
1013 int user_fault
, int write_fault
, int dirty
,
1014 int *ptwrite
, int largepage
, gfn_t gfn
,
1018 int was_rmapped
= 0;
1019 int was_writeble
= is_writeble_pte(*shadow_pte
);
1020 hfn_t host_pfn
= (*shadow_pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1022 pgprintk("%s: spte %llx access %x write_fault %d"
1023 " user_fault %d gfn %lx\n",
1024 __func__
, *shadow_pte
, pt_access
,
1025 write_fault
, user_fault
, gfn
);
1027 if (is_rmap_pte(*shadow_pte
)) {
1029 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1030 * the parent of the now unreachable PTE.
1032 if (largepage
&& !is_large_pte(*shadow_pte
)) {
1033 struct kvm_mmu_page
*child
;
1034 u64 pte
= *shadow_pte
;
1036 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1037 mmu_page_remove_parent_pte(child
, shadow_pte
);
1038 } else if (host_pfn
!= page_to_pfn(page
)) {
1039 pgprintk("hfn old %lx new %lx\n",
1040 host_pfn
, page_to_pfn(page
));
1041 rmap_remove(vcpu
->kvm
, shadow_pte
);
1044 was_rmapped
= is_large_pte(*shadow_pte
);
1051 * We don't set the accessed bit, since we sometimes want to see
1052 * whether the guest actually used the pte (in order to detect
1055 spte
= PT_PRESENT_MASK
| PT_DIRTY_MASK
;
1057 pte_access
&= ~ACC_WRITE_MASK
;
1058 if (!(pte_access
& ACC_EXEC_MASK
))
1059 spte
|= PT64_NX_MASK
;
1061 spte
|= PT_PRESENT_MASK
;
1062 if (pte_access
& ACC_USER_MASK
)
1063 spte
|= PT_USER_MASK
;
1065 spte
|= PT_PAGE_SIZE_MASK
;
1067 spte
|= page_to_phys(page
);
1069 if ((pte_access
& ACC_WRITE_MASK
)
1070 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1071 struct kvm_mmu_page
*shadow
;
1073 spte
|= PT_WRITABLE_MASK
;
1075 mmu_unshadow(vcpu
->kvm
, gfn
);
1079 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1081 (largepage
&& has_wrprotected_page(vcpu
->kvm
, gfn
))) {
1082 pgprintk("%s: found shadow page for %lx, marking ro\n",
1084 pte_access
&= ~ACC_WRITE_MASK
;
1085 if (is_writeble_pte(spte
)) {
1086 spte
&= ~PT_WRITABLE_MASK
;
1087 kvm_x86_ops
->tlb_flush(vcpu
);
1096 if (pte_access
& ACC_WRITE_MASK
)
1097 mark_page_dirty(vcpu
->kvm
, gfn
);
1099 pgprintk("%s: setting spte %llx\n", __func__
, spte
);
1100 pgprintk("instantiating %s PTE (%s) at %d (%llx) addr %llx\n",
1101 (spte
&PT_PAGE_SIZE_MASK
)? "2MB" : "4kB",
1102 (spte
&PT_WRITABLE_MASK
)?"RW":"R", gfn
, spte
, shadow_pte
);
1103 set_shadow_pte(shadow_pte
, spte
);
1104 if (!was_rmapped
&& (spte
& PT_PAGE_SIZE_MASK
)
1105 && (spte
& PT_PRESENT_MASK
))
1106 ++vcpu
->kvm
->stat
.lpages
;
1108 page_header_update_slot(vcpu
->kvm
, shadow_pte
, gfn
);
1110 rmap_add(vcpu
, shadow_pte
, gfn
, largepage
);
1111 if (!is_rmap_pte(*shadow_pte
))
1112 kvm_release_page_clean(page
);
1115 kvm_release_page_dirty(page
);
1117 kvm_release_page_clean(page
);
1119 if (!ptwrite
|| !*ptwrite
)
1120 vcpu
->arch
.last_pte_updated
= shadow_pte
;
1123 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1127 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1128 int largepage
, gfn_t gfn
, struct page
*page
,
1131 hpa_t table_addr
= vcpu
->arch
.mmu
.root_hpa
;
1135 u32 index
= PT64_INDEX(v
, level
);
1138 ASSERT(VALID_PAGE(table_addr
));
1139 table
= __va(table_addr
);
1142 mmu_set_spte(vcpu
, &table
[index
], ACC_ALL
, ACC_ALL
,
1143 0, write
, 1, &pt_write
, 0, gfn
, page
);
1147 if (largepage
&& level
== 2) {
1148 mmu_set_spte(vcpu
, &table
[index
], ACC_ALL
, ACC_ALL
,
1149 0, write
, 1, &pt_write
, 1, gfn
, page
);
1153 if (table
[index
] == shadow_trap_nonpresent_pte
) {
1154 struct kvm_mmu_page
*new_table
;
1157 pseudo_gfn
= (v
& PT64_DIR_BASE_ADDR_MASK
)
1159 new_table
= kvm_mmu_get_page(vcpu
, pseudo_gfn
,
1161 1, ACC_ALL
, &table
[index
]);
1163 pgprintk("nonpaging_map: ENOMEM\n");
1164 kvm_release_page_clean(page
);
1168 table
[index
] = __pa(new_table
->spt
) | PT_PRESENT_MASK
1169 | PT_WRITABLE_MASK
| PT_USER_MASK
;
1171 table_addr
= table
[index
] & PT64_BASE_ADDR_MASK
;
1175 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1182 down_read(&vcpu
->kvm
->slots_lock
);
1184 down_read(¤t
->mm
->mmap_sem
);
1185 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1186 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1190 page
= gfn_to_page(vcpu
->kvm
, gfn
);
1191 up_read(¤t
->mm
->mmap_sem
);
1194 if (is_error_page(page
)) {
1195 kvm_release_page_clean(page
);
1196 up_read(&vcpu
->kvm
->slots_lock
);
1200 spin_lock(&vcpu
->kvm
->mmu_lock
);
1201 kvm_mmu_free_some_pages(vcpu
);
1202 r
= __direct_map(vcpu
, v
, write
, largepage
, gfn
, page
,
1204 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1206 up_read(&vcpu
->kvm
->slots_lock
);
1212 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
1213 struct kvm_mmu_page
*sp
)
1217 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1218 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
1221 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
1224 struct kvm_mmu_page
*sp
;
1226 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1228 spin_lock(&vcpu
->kvm
->mmu_lock
);
1229 #ifdef CONFIG_X86_64
1230 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1231 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1233 sp
= page_header(root
);
1235 if (!sp
->root_count
&& sp
->role
.invalid
)
1236 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1237 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1238 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1242 for (i
= 0; i
< 4; ++i
) {
1243 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1246 root
&= PT64_BASE_ADDR_MASK
;
1247 sp
= page_header(root
);
1249 if (!sp
->root_count
&& sp
->role
.invalid
)
1250 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1252 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
1254 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1255 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1258 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
1262 struct kvm_mmu_page
*sp
;
1263 int metaphysical
= 0;
1265 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
1267 #ifdef CONFIG_X86_64
1268 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1269 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1271 ASSERT(!VALID_PAGE(root
));
1274 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1275 PT64_ROOT_LEVEL
, metaphysical
,
1277 root
= __pa(sp
->spt
);
1279 vcpu
->arch
.mmu
.root_hpa
= root
;
1283 metaphysical
= !is_paging(vcpu
);
1286 for (i
= 0; i
< 4; ++i
) {
1287 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1289 ASSERT(!VALID_PAGE(root
));
1290 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1291 if (!is_present_pte(vcpu
->arch
.pdptrs
[i
])) {
1292 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
1295 root_gfn
= vcpu
->arch
.pdptrs
[i
] >> PAGE_SHIFT
;
1296 } else if (vcpu
->arch
.mmu
.root_level
== 0)
1298 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1299 PT32_ROOT_LEVEL
, metaphysical
,
1301 root
= __pa(sp
->spt
);
1303 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1305 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
1308 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1313 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1319 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
1320 r
= mmu_topup_memory_caches(vcpu
);
1325 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1327 gfn
= gva
>> PAGE_SHIFT
;
1329 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
1330 error_code
& PFERR_WRITE_MASK
, gfn
);
1333 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
1339 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1342 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1344 r
= mmu_topup_memory_caches(vcpu
);
1348 down_read(¤t
->mm
->mmap_sem
);
1349 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1350 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1353 page
= gfn_to_page(vcpu
->kvm
, gfn
);
1354 if (is_error_page(page
)) {
1355 kvm_release_page_clean(page
);
1356 up_read(¤t
->mm
->mmap_sem
);
1359 spin_lock(&vcpu
->kvm
->mmu_lock
);
1360 kvm_mmu_free_some_pages(vcpu
);
1361 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
1362 largepage
, gfn
, page
, TDP_ROOT_LEVEL
);
1363 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1364 up_read(¤t
->mm
->mmap_sem
);
1369 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1371 mmu_free_roots(vcpu
);
1374 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1376 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1378 context
->new_cr3
= nonpaging_new_cr3
;
1379 context
->page_fault
= nonpaging_page_fault
;
1380 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1381 context
->free
= nonpaging_free
;
1382 context
->prefetch_page
= nonpaging_prefetch_page
;
1383 context
->root_level
= 0;
1384 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1385 context
->root_hpa
= INVALID_PAGE
;
1389 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1391 ++vcpu
->stat
.tlb_flush
;
1392 kvm_x86_ops
->tlb_flush(vcpu
);
1395 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1397 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
1398 mmu_free_roots(vcpu
);
1401 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1405 kvm_inject_page_fault(vcpu
, addr
, err_code
);
1408 static void paging_free(struct kvm_vcpu
*vcpu
)
1410 nonpaging_free(vcpu
);
1414 #include "paging_tmpl.h"
1418 #include "paging_tmpl.h"
1421 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1423 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1425 ASSERT(is_pae(vcpu
));
1426 context
->new_cr3
= paging_new_cr3
;
1427 context
->page_fault
= paging64_page_fault
;
1428 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1429 context
->prefetch_page
= paging64_prefetch_page
;
1430 context
->free
= paging_free
;
1431 context
->root_level
= level
;
1432 context
->shadow_root_level
= level
;
1433 context
->root_hpa
= INVALID_PAGE
;
1437 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1439 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1442 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1444 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1446 context
->new_cr3
= paging_new_cr3
;
1447 context
->page_fault
= paging32_page_fault
;
1448 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1449 context
->free
= paging_free
;
1450 context
->prefetch_page
= paging32_prefetch_page
;
1451 context
->root_level
= PT32_ROOT_LEVEL
;
1452 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1453 context
->root_hpa
= INVALID_PAGE
;
1457 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1459 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1462 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
1464 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1466 context
->new_cr3
= nonpaging_new_cr3
;
1467 context
->page_fault
= tdp_page_fault
;
1468 context
->free
= nonpaging_free
;
1469 context
->prefetch_page
= nonpaging_prefetch_page
;
1470 context
->shadow_root_level
= TDP_ROOT_LEVEL
;
1471 context
->root_hpa
= INVALID_PAGE
;
1473 if (!is_paging(vcpu
)) {
1474 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1475 context
->root_level
= 0;
1476 } else if (is_long_mode(vcpu
)) {
1477 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1478 context
->root_level
= PT64_ROOT_LEVEL
;
1479 } else if (is_pae(vcpu
)) {
1480 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1481 context
->root_level
= PT32E_ROOT_LEVEL
;
1483 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1484 context
->root_level
= PT32_ROOT_LEVEL
;
1490 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
1493 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1495 if (!is_paging(vcpu
))
1496 return nonpaging_init_context(vcpu
);
1497 else if (is_long_mode(vcpu
))
1498 return paging64_init_context(vcpu
);
1499 else if (is_pae(vcpu
))
1500 return paging32E_init_context(vcpu
);
1502 return paging32_init_context(vcpu
);
1505 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1508 return init_kvm_tdp_mmu(vcpu
);
1510 return init_kvm_softmmu(vcpu
);
1513 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1516 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
1517 vcpu
->arch
.mmu
.free(vcpu
);
1518 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1522 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1524 destroy_kvm_mmu(vcpu
);
1525 return init_kvm_mmu(vcpu
);
1527 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
1529 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1533 r
= mmu_topup_memory_caches(vcpu
);
1536 spin_lock(&vcpu
->kvm
->mmu_lock
);
1537 kvm_mmu_free_some_pages(vcpu
);
1538 mmu_alloc_roots(vcpu
);
1539 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1540 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
1541 kvm_mmu_flush_tlb(vcpu
);
1545 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1547 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1549 mmu_free_roots(vcpu
);
1552 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1553 struct kvm_mmu_page
*sp
,
1557 struct kvm_mmu_page
*child
;
1560 if (is_shadow_present_pte(pte
)) {
1561 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
||
1563 rmap_remove(vcpu
->kvm
, spte
);
1565 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1566 mmu_page_remove_parent_pte(child
, spte
);
1569 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
1570 if (is_large_pte(pte
))
1571 --vcpu
->kvm
->stat
.lpages
;
1574 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
1575 struct kvm_mmu_page
*sp
,
1579 if ((sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1580 && !vcpu
->arch
.update_pte
.largepage
) {
1581 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
1585 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
1586 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
1587 paging32_update_pte(vcpu
, sp
, spte
, new);
1589 paging64_update_pte(vcpu
, sp
, spte
, new);
1592 static bool need_remote_flush(u64 old
, u64
new)
1594 if (!is_shadow_present_pte(old
))
1596 if (!is_shadow_present_pte(new))
1598 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
1600 old
^= PT64_NX_MASK
;
1601 new ^= PT64_NX_MASK
;
1602 return (old
& ~new & PT64_PERM_MASK
) != 0;
1605 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
1607 if (need_remote_flush(old
, new))
1608 kvm_flush_remote_tlbs(vcpu
->kvm
);
1610 kvm_mmu_flush_tlb(vcpu
);
1613 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
1615 u64
*spte
= vcpu
->arch
.last_pte_updated
;
1617 return !!(spte
&& (*spte
& PT_ACCESSED_MASK
));
1620 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1621 const u8
*new, int bytes
)
1628 vcpu
->arch
.update_pte
.largepage
= 0;
1630 if (bytes
!= 4 && bytes
!= 8)
1634 * Assume that the pte write on a page table of the same type
1635 * as the current vcpu paging mode. This is nearly always true
1636 * (might be false while changing modes). Note it is verified later
1640 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1641 if ((bytes
== 4) && (gpa
% 4 == 0)) {
1642 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
1645 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
1646 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
1647 memcpy((void *)&gpte
, new, 8);
1650 if ((bytes
== 4) && (gpa
% 4 == 0))
1651 memcpy((void *)&gpte
, new, 4);
1653 if (!is_present_pte(gpte
))
1655 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1657 down_read(¤t
->mm
->mmap_sem
);
1658 if (is_large_pte(gpte
) && is_largepage_backed(vcpu
, gfn
)) {
1659 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1660 vcpu
->arch
.update_pte
.largepage
= 1;
1662 page
= gfn_to_page(vcpu
->kvm
, gfn
);
1663 up_read(¤t
->mm
->mmap_sem
);
1665 if (is_error_page(page
)) {
1666 kvm_release_page_clean(page
);
1669 vcpu
->arch
.update_pte
.gfn
= gfn
;
1670 vcpu
->arch
.update_pte
.page
= page
;
1673 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
1674 const u8
*new, int bytes
)
1676 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1677 struct kvm_mmu_page
*sp
;
1678 struct hlist_node
*node
, *n
;
1679 struct hlist_head
*bucket
;
1683 unsigned offset
= offset_in_page(gpa
);
1685 unsigned page_offset
;
1686 unsigned misaligned
;
1693 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
1694 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
1695 spin_lock(&vcpu
->kvm
->mmu_lock
);
1696 kvm_mmu_free_some_pages(vcpu
);
1697 ++vcpu
->kvm
->stat
.mmu_pte_write
;
1698 kvm_mmu_audit(vcpu
, "pre pte write");
1699 if (gfn
== vcpu
->arch
.last_pt_write_gfn
1700 && !last_updated_pte_accessed(vcpu
)) {
1701 ++vcpu
->arch
.last_pt_write_count
;
1702 if (vcpu
->arch
.last_pt_write_count
>= 3)
1705 vcpu
->arch
.last_pt_write_gfn
= gfn
;
1706 vcpu
->arch
.last_pt_write_count
= 1;
1707 vcpu
->arch
.last_pte_updated
= NULL
;
1709 index
= kvm_page_table_hashfn(gfn
);
1710 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1711 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
1712 if (sp
->gfn
!= gfn
|| sp
->role
.metaphysical
)
1714 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
1715 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
1716 misaligned
|= bytes
< 4;
1717 if (misaligned
|| flooded
) {
1719 * Misaligned accesses are too much trouble to fix
1720 * up; also, they usually indicate a page is not used
1723 * If we're seeing too many writes to a page,
1724 * it may no longer be a page table, or we may be
1725 * forking, in which case it is better to unmap the
1728 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1729 gpa
, bytes
, sp
->role
.word
);
1730 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1731 ++vcpu
->kvm
->stat
.mmu_flooded
;
1734 page_offset
= offset
;
1735 level
= sp
->role
.level
;
1737 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
1738 page_offset
<<= 1; /* 32->64 */
1740 * A 32-bit pde maps 4MB while the shadow pdes map
1741 * only 2MB. So we need to double the offset again
1742 * and zap two pdes instead of one.
1744 if (level
== PT32_ROOT_LEVEL
) {
1745 page_offset
&= ~7; /* kill rounding error */
1749 quadrant
= page_offset
>> PAGE_SHIFT
;
1750 page_offset
&= ~PAGE_MASK
;
1751 if (quadrant
!= sp
->role
.quadrant
)
1754 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
1755 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
1757 r
= kvm_read_guest_atomic(vcpu
->kvm
,
1758 gpa
& ~(u64
)(pte_size
- 1),
1760 new = (const void *)&gentry
;
1766 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
1768 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
1769 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
1773 kvm_mmu_audit(vcpu
, "post pte write");
1774 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1775 if (vcpu
->arch
.update_pte
.page
) {
1776 kvm_release_page_clean(vcpu
->arch
.update_pte
.page
);
1777 vcpu
->arch
.update_pte
.page
= NULL
;
1781 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
1786 down_read(&vcpu
->kvm
->slots_lock
);
1787 gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1788 up_read(&vcpu
->kvm
->slots_lock
);
1790 spin_lock(&vcpu
->kvm
->mmu_lock
);
1791 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1792 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1796 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
1798 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
) {
1799 struct kvm_mmu_page
*sp
;
1801 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
1802 struct kvm_mmu_page
, link
);
1803 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1804 ++vcpu
->kvm
->stat
.mmu_recycled
;
1808 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
1811 enum emulation_result er
;
1813 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
1822 r
= mmu_topup_memory_caches(vcpu
);
1826 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
1831 case EMULATE_DO_MMIO
:
1832 ++vcpu
->stat
.mmio_exits
;
1835 kvm_report_emulation_failure(vcpu
, "pagetable");
1843 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
1845 void kvm_enable_tdp(void)
1849 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
1851 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
1853 struct kvm_mmu_page
*sp
;
1855 while (!list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
1856 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.next
,
1857 struct kvm_mmu_page
, link
);
1858 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1860 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
1863 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
1870 if (vcpu
->kvm
->arch
.n_requested_mmu_pages
)
1871 vcpu
->kvm
->arch
.n_free_mmu_pages
=
1872 vcpu
->kvm
->arch
.n_requested_mmu_pages
;
1874 vcpu
->kvm
->arch
.n_free_mmu_pages
=
1875 vcpu
->kvm
->arch
.n_alloc_mmu_pages
;
1877 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1878 * Therefore we need to allocate shadow page tables in the first
1879 * 4GB of memory, which happens to fit the DMA32 zone.
1881 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
1884 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
1885 for (i
= 0; i
< 4; ++i
)
1886 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
1891 free_mmu_pages(vcpu
);
1895 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
1898 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1900 return alloc_mmu_pages(vcpu
);
1903 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
1906 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1908 return init_kvm_mmu(vcpu
);
1911 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
1915 destroy_kvm_mmu(vcpu
);
1916 free_mmu_pages(vcpu
);
1917 mmu_free_memory_caches(vcpu
);
1920 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
1922 struct kvm_mmu_page
*sp
;
1924 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
1928 if (!test_bit(slot
, &sp
->slot_bitmap
))
1932 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1934 if (pt
[i
] & PT_WRITABLE_MASK
)
1935 pt
[i
] &= ~PT_WRITABLE_MASK
;
1939 void kvm_mmu_zap_all(struct kvm
*kvm
)
1941 struct kvm_mmu_page
*sp
, *node
;
1943 spin_lock(&kvm
->mmu_lock
);
1944 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
1945 kvm_mmu_zap_page(kvm
, sp
);
1946 spin_unlock(&kvm
->mmu_lock
);
1948 kvm_flush_remote_tlbs(kvm
);
1951 void kvm_mmu_module_exit(void)
1953 if (pte_chain_cache
)
1954 kmem_cache_destroy(pte_chain_cache
);
1955 if (rmap_desc_cache
)
1956 kmem_cache_destroy(rmap_desc_cache
);
1957 if (mmu_page_header_cache
)
1958 kmem_cache_destroy(mmu_page_header_cache
);
1961 int kvm_mmu_module_init(void)
1963 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
1964 sizeof(struct kvm_pte_chain
),
1966 if (!pte_chain_cache
)
1968 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
1969 sizeof(struct kvm_rmap_desc
),
1971 if (!rmap_desc_cache
)
1974 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
1975 sizeof(struct kvm_mmu_page
),
1977 if (!mmu_page_header_cache
)
1983 kvm_mmu_module_exit();
1988 * Caculate mmu pages needed for kvm.
1990 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
1993 unsigned int nr_mmu_pages
;
1994 unsigned int nr_pages
= 0;
1996 for (i
= 0; i
< kvm
->nmemslots
; i
++)
1997 nr_pages
+= kvm
->memslots
[i
].npages
;
1999 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
2000 nr_mmu_pages
= max(nr_mmu_pages
,
2001 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
2003 return nr_mmu_pages
;
2008 static const char *audit_msg
;
2010 static gva_t
canonicalize(gva_t gva
)
2012 #ifdef CONFIG_X86_64
2013 gva
= (long long)(gva
<< 16) >> 16;
2018 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
2019 gva_t va
, int level
)
2021 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
2023 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
2025 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
2028 if (ent
== shadow_trap_nonpresent_pte
)
2031 va
= canonicalize(va
);
2033 if (ent
== shadow_notrap_nonpresent_pte
)
2034 printk(KERN_ERR
"audit: (%s) nontrapping pte"
2035 " in nonleaf level: levels %d gva %lx"
2036 " level %d pte %llx\n", audit_msg
,
2037 vcpu
->arch
.mmu
.root_level
, va
, level
, ent
);
2039 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
2041 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, va
);
2042 struct page
*page
= gpa_to_page(vcpu
, gpa
);
2043 hpa_t hpa
= page_to_phys(page
);
2045 if (is_shadow_present_pte(ent
)
2046 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
2047 printk(KERN_ERR
"xx audit error: (%s) levels %d"
2048 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2049 audit_msg
, vcpu
->arch
.mmu
.root_level
,
2051 is_shadow_present_pte(ent
));
2052 else if (ent
== shadow_notrap_nonpresent_pte
2053 && !is_error_hpa(hpa
))
2054 printk(KERN_ERR
"audit: (%s) notrap shadow,"
2055 " valid guest gva %lx\n", audit_msg
, va
);
2056 kvm_release_page_clean(page
);
2062 static void audit_mappings(struct kvm_vcpu
*vcpu
)
2066 if (vcpu
->arch
.mmu
.root_level
== 4)
2067 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
2069 for (i
= 0; i
< 4; ++i
)
2070 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
2071 audit_mappings_page(vcpu
,
2072 vcpu
->arch
.mmu
.pae_root
[i
],
2077 static int count_rmaps(struct kvm_vcpu
*vcpu
)
2082 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
2083 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
2084 struct kvm_rmap_desc
*d
;
2086 for (j
= 0; j
< m
->npages
; ++j
) {
2087 unsigned long *rmapp
= &m
->rmap
[j
];
2091 if (!(*rmapp
& 1)) {
2095 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
2097 for (k
= 0; k
< RMAP_EXT
; ++k
)
2098 if (d
->shadow_ptes
[k
])
2109 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
2112 struct kvm_mmu_page
*sp
;
2115 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2118 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2121 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
2124 if (!(ent
& PT_PRESENT_MASK
))
2126 if (!(ent
& PT_WRITABLE_MASK
))
2134 static void audit_rmap(struct kvm_vcpu
*vcpu
)
2136 int n_rmap
= count_rmaps(vcpu
);
2137 int n_actual
= count_writable_mappings(vcpu
);
2139 if (n_rmap
!= n_actual
)
2140 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
2141 __func__
, audit_msg
, n_rmap
, n_actual
);
2144 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
2146 struct kvm_mmu_page
*sp
;
2147 struct kvm_memory_slot
*slot
;
2148 unsigned long *rmapp
;
2151 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2152 if (sp
->role
.metaphysical
)
2155 slot
= gfn_to_memslot(vcpu
->kvm
, sp
->gfn
);
2156 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
2157 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
2159 printk(KERN_ERR
"%s: (%s) shadow page has writable"
2160 " mappings: gfn %lx role %x\n",
2161 __func__
, audit_msg
, sp
->gfn
,
2166 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
2173 audit_write_protection(vcpu
);
2174 audit_mappings(vcpu
);