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>
31 #include <linux/compiler.h>
34 #include <asm/cmpxchg.h>
38 * When setting this variable to true it enables Two-Dimensional-Paging
39 * where the hardware walks 2 page tables:
40 * 1. the guest-virtual to guest-physical
41 * 2. while doing 1. it walks guest-physical to host-physical
42 * If the hardware supports that we don't need to do shadow paging.
44 bool tdp_enabled
= false;
51 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
53 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
58 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
59 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
63 #define pgprintk(x...) do { } while (0)
64 #define rmap_printk(x...) do { } while (0)
68 #if defined(MMU_DEBUG) || defined(AUDIT)
70 module_param(dbg
, bool, 0644);
74 #define ASSERT(x) do { } while (0)
78 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
79 __FILE__, __LINE__, #x); \
83 #define PT_FIRST_AVAIL_BITS_SHIFT 9
84 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
86 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
88 #define PT64_LEVEL_BITS 9
90 #define PT64_LEVEL_SHIFT(level) \
91 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
93 #define PT64_LEVEL_MASK(level) \
94 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
96 #define PT64_INDEX(address, level)\
97 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
100 #define PT32_LEVEL_BITS 10
102 #define PT32_LEVEL_SHIFT(level) \
103 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
105 #define PT32_LEVEL_MASK(level) \
106 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
108 #define PT32_INDEX(address, level)\
109 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
112 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
113 #define PT64_DIR_BASE_ADDR_MASK \
114 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
116 #define PT32_BASE_ADDR_MASK PAGE_MASK
117 #define PT32_DIR_BASE_ADDR_MASK \
118 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
120 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
123 #define PFERR_PRESENT_MASK (1U << 0)
124 #define PFERR_WRITE_MASK (1U << 1)
125 #define PFERR_USER_MASK (1U << 2)
126 #define PFERR_FETCH_MASK (1U << 4)
128 #define PT_DIRECTORY_LEVEL 2
129 #define PT_PAGE_TABLE_LEVEL 1
133 #define ACC_EXEC_MASK 1
134 #define ACC_WRITE_MASK PT_WRITABLE_MASK
135 #define ACC_USER_MASK PT_USER_MASK
136 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
138 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
140 struct kvm_rmap_desc
{
141 u64
*shadow_ptes
[RMAP_EXT
];
142 struct kvm_rmap_desc
*more
;
145 struct kvm_shadow_walk
{
146 int (*entry
)(struct kvm_shadow_walk
*walk
, struct kvm_vcpu
*vcpu
,
147 u64 addr
, u64
*spte
, int level
);
150 struct kvm_unsync_walk
{
151 int (*entry
) (struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
);
154 typedef int (*mmu_parent_walk_fn
) (struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
);
156 static struct kmem_cache
*pte_chain_cache
;
157 static struct kmem_cache
*rmap_desc_cache
;
158 static struct kmem_cache
*mmu_page_header_cache
;
160 static u64 __read_mostly shadow_trap_nonpresent_pte
;
161 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
162 static u64 __read_mostly shadow_base_present_pte
;
163 static u64 __read_mostly shadow_nx_mask
;
164 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
165 static u64 __read_mostly shadow_user_mask
;
166 static u64 __read_mostly shadow_accessed_mask
;
167 static u64 __read_mostly shadow_dirty_mask
;
169 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
171 shadow_trap_nonpresent_pte
= trap_pte
;
172 shadow_notrap_nonpresent_pte
= notrap_pte
;
174 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
176 void kvm_mmu_set_base_ptes(u64 base_pte
)
178 shadow_base_present_pte
= base_pte
;
180 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes
);
182 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
183 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
185 shadow_user_mask
= user_mask
;
186 shadow_accessed_mask
= accessed_mask
;
187 shadow_dirty_mask
= dirty_mask
;
188 shadow_nx_mask
= nx_mask
;
189 shadow_x_mask
= x_mask
;
191 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
193 static int is_write_protection(struct kvm_vcpu
*vcpu
)
195 return vcpu
->arch
.cr0
& X86_CR0_WP
;
198 static int is_cpuid_PSE36(void)
203 static int is_nx(struct kvm_vcpu
*vcpu
)
205 return vcpu
->arch
.shadow_efer
& EFER_NX
;
208 static int is_present_pte(unsigned long pte
)
210 return pte
& PT_PRESENT_MASK
;
213 static int is_shadow_present_pte(u64 pte
)
215 return pte
!= shadow_trap_nonpresent_pte
216 && pte
!= shadow_notrap_nonpresent_pte
;
219 static int is_large_pte(u64 pte
)
221 return pte
& PT_PAGE_SIZE_MASK
;
224 static int is_writeble_pte(unsigned long pte
)
226 return pte
& PT_WRITABLE_MASK
;
229 static int is_dirty_pte(unsigned long pte
)
231 return pte
& shadow_dirty_mask
;
234 static int is_rmap_pte(u64 pte
)
236 return is_shadow_present_pte(pte
);
239 static pfn_t
spte_to_pfn(u64 pte
)
241 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
244 static gfn_t
pse36_gfn_delta(u32 gpte
)
246 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
248 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
251 static void set_shadow_pte(u64
*sptep
, u64 spte
)
254 set_64bit((unsigned long *)sptep
, spte
);
256 set_64bit((unsigned long long *)sptep
, spte
);
260 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
261 struct kmem_cache
*base_cache
, int min
)
265 if (cache
->nobjs
>= min
)
267 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
268 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
271 cache
->objects
[cache
->nobjs
++] = obj
;
276 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
279 kfree(mc
->objects
[--mc
->nobjs
]);
282 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
287 if (cache
->nobjs
>= min
)
289 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
290 page
= alloc_page(GFP_KERNEL
);
293 set_page_private(page
, 0);
294 cache
->objects
[cache
->nobjs
++] = page_address(page
);
299 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
302 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
305 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
309 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
313 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
317 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
320 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
321 mmu_page_header_cache
, 4);
326 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
328 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
329 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
330 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
331 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
334 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
340 p
= mc
->objects
[--mc
->nobjs
];
345 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
347 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
348 sizeof(struct kvm_pte_chain
));
351 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
356 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
358 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
359 sizeof(struct kvm_rmap_desc
));
362 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
368 * Return the pointer to the largepage write count for a given
369 * gfn, handling slots that are not large page aligned.
371 static int *slot_largepage_idx(gfn_t gfn
, struct kvm_memory_slot
*slot
)
375 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
376 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
377 return &slot
->lpage_info
[idx
].write_count
;
380 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
384 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
388 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
392 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
394 WARN_ON(*write_count
< 0);
397 static int has_wrprotected_page(struct kvm
*kvm
, gfn_t gfn
)
399 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
403 largepage_idx
= slot_largepage_idx(gfn
, slot
);
404 return *largepage_idx
;
410 static int host_largepage_backed(struct kvm
*kvm
, gfn_t gfn
)
412 struct vm_area_struct
*vma
;
416 addr
= gfn_to_hva(kvm
, gfn
);
417 if (kvm_is_error_hva(addr
))
420 down_read(¤t
->mm
->mmap_sem
);
421 vma
= find_vma(current
->mm
, addr
);
422 if (vma
&& is_vm_hugetlb_page(vma
))
424 up_read(¤t
->mm
->mmap_sem
);
429 static int is_largepage_backed(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
431 struct kvm_memory_slot
*slot
;
433 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
))
436 if (!host_largepage_backed(vcpu
->kvm
, large_gfn
))
439 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
440 if (slot
&& slot
->dirty_bitmap
)
447 * Take gfn and return the reverse mapping to it.
448 * Note: gfn must be unaliased before this function get called
451 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int lpage
)
453 struct kvm_memory_slot
*slot
;
456 slot
= gfn_to_memslot(kvm
, gfn
);
458 return &slot
->rmap
[gfn
- slot
->base_gfn
];
460 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
461 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
463 return &slot
->lpage_info
[idx
].rmap_pde
;
467 * Reverse mapping data structures:
469 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
470 * that points to page_address(page).
472 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
473 * containing more mappings.
475 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
, int lpage
)
477 struct kvm_mmu_page
*sp
;
478 struct kvm_rmap_desc
*desc
;
479 unsigned long *rmapp
;
482 if (!is_rmap_pte(*spte
))
484 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
485 sp
= page_header(__pa(spte
));
486 sp
->gfns
[spte
- sp
->spt
] = gfn
;
487 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, lpage
);
489 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
490 *rmapp
= (unsigned long)spte
;
491 } else if (!(*rmapp
& 1)) {
492 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
493 desc
= mmu_alloc_rmap_desc(vcpu
);
494 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
495 desc
->shadow_ptes
[1] = spte
;
496 *rmapp
= (unsigned long)desc
| 1;
498 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
499 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
500 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
502 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
503 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
506 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
508 desc
->shadow_ptes
[i
] = spte
;
512 static void rmap_desc_remove_entry(unsigned long *rmapp
,
513 struct kvm_rmap_desc
*desc
,
515 struct kvm_rmap_desc
*prev_desc
)
519 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
521 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
522 desc
->shadow_ptes
[j
] = NULL
;
525 if (!prev_desc
&& !desc
->more
)
526 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
529 prev_desc
->more
= desc
->more
;
531 *rmapp
= (unsigned long)desc
->more
| 1;
532 mmu_free_rmap_desc(desc
);
535 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
537 struct kvm_rmap_desc
*desc
;
538 struct kvm_rmap_desc
*prev_desc
;
539 struct kvm_mmu_page
*sp
;
541 unsigned long *rmapp
;
544 if (!is_rmap_pte(*spte
))
546 sp
= page_header(__pa(spte
));
547 pfn
= spte_to_pfn(*spte
);
548 if (*spte
& shadow_accessed_mask
)
549 kvm_set_pfn_accessed(pfn
);
550 if (is_writeble_pte(*spte
))
551 kvm_release_pfn_dirty(pfn
);
553 kvm_release_pfn_clean(pfn
);
554 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], is_large_pte(*spte
));
556 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
558 } else if (!(*rmapp
& 1)) {
559 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
560 if ((u64
*)*rmapp
!= spte
) {
561 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
567 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
568 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
571 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
572 if (desc
->shadow_ptes
[i
] == spte
) {
573 rmap_desc_remove_entry(rmapp
,
585 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
587 struct kvm_rmap_desc
*desc
;
588 struct kvm_rmap_desc
*prev_desc
;
594 else if (!(*rmapp
& 1)) {
596 return (u64
*)*rmapp
;
599 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
603 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
604 if (prev_spte
== spte
)
605 return desc
->shadow_ptes
[i
];
606 prev_spte
= desc
->shadow_ptes
[i
];
613 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
615 unsigned long *rmapp
;
617 int write_protected
= 0;
619 gfn
= unalias_gfn(kvm
, gfn
);
620 rmapp
= gfn_to_rmap(kvm
, gfn
, 0);
622 spte
= rmap_next(kvm
, rmapp
, NULL
);
625 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
626 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
627 if (is_writeble_pte(*spte
)) {
628 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
631 spte
= rmap_next(kvm
, rmapp
, spte
);
633 if (write_protected
) {
636 spte
= rmap_next(kvm
, rmapp
, NULL
);
637 pfn
= spte_to_pfn(*spte
);
638 kvm_set_pfn_dirty(pfn
);
641 /* check for huge page mappings */
642 rmapp
= gfn_to_rmap(kvm
, gfn
, 1);
643 spte
= rmap_next(kvm
, rmapp
, NULL
);
646 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
647 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
648 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
649 if (is_writeble_pte(*spte
)) {
650 rmap_remove(kvm
, spte
);
652 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
656 spte
= rmap_next(kvm
, rmapp
, spte
);
660 kvm_flush_remote_tlbs(kvm
);
663 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
666 int need_tlb_flush
= 0;
668 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
669 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
670 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
671 rmap_remove(kvm
, spte
);
672 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
675 return need_tlb_flush
;
678 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
679 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
))
685 * If mmap_sem isn't taken, we can look the memslots with only
686 * the mmu_lock by skipping over the slots with userspace_addr == 0.
688 for (i
= 0; i
< kvm
->nmemslots
; i
++) {
689 struct kvm_memory_slot
*memslot
= &kvm
->memslots
[i
];
690 unsigned long start
= memslot
->userspace_addr
;
693 /* mmu_lock protects userspace_addr */
697 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
698 if (hva
>= start
&& hva
< end
) {
699 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
700 retval
|= handler(kvm
, &memslot
->rmap
[gfn_offset
]);
701 retval
|= handler(kvm
,
702 &memslot
->lpage_info
[
704 KVM_PAGES_PER_HPAGE
].rmap_pde
);
711 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
713 return kvm_handle_hva(kvm
, hva
, kvm_unmap_rmapp
);
716 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
721 /* always return old for EPT */
722 if (!shadow_accessed_mask
)
725 spte
= rmap_next(kvm
, rmapp
, NULL
);
729 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
730 _young
= _spte
& PT_ACCESSED_MASK
;
733 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
735 spte
= rmap_next(kvm
, rmapp
, spte
);
740 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
742 return kvm_handle_hva(kvm
, hva
, kvm_age_rmapp
);
746 static int is_empty_shadow_page(u64
*spt
)
751 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
752 if (is_shadow_present_pte(*pos
)) {
753 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
761 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
763 ASSERT(is_empty_shadow_page(sp
->spt
));
765 __free_page(virt_to_page(sp
->spt
));
766 __free_page(virt_to_page(sp
->gfns
));
768 ++kvm
->arch
.n_free_mmu_pages
;
771 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
773 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
776 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
779 struct kvm_mmu_page
*sp
;
781 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
782 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
783 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
784 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
785 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
786 ASSERT(is_empty_shadow_page(sp
->spt
));
789 sp
->parent_pte
= parent_pte
;
790 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
794 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
795 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
797 struct kvm_pte_chain
*pte_chain
;
798 struct hlist_node
*node
;
803 if (!sp
->multimapped
) {
804 u64
*old
= sp
->parent_pte
;
807 sp
->parent_pte
= parent_pte
;
811 pte_chain
= mmu_alloc_pte_chain(vcpu
);
812 INIT_HLIST_HEAD(&sp
->parent_ptes
);
813 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
814 pte_chain
->parent_ptes
[0] = old
;
816 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
817 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
819 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
820 if (!pte_chain
->parent_ptes
[i
]) {
821 pte_chain
->parent_ptes
[i
] = parent_pte
;
825 pte_chain
= mmu_alloc_pte_chain(vcpu
);
827 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
828 pte_chain
->parent_ptes
[0] = parent_pte
;
831 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
834 struct kvm_pte_chain
*pte_chain
;
835 struct hlist_node
*node
;
838 if (!sp
->multimapped
) {
839 BUG_ON(sp
->parent_pte
!= parent_pte
);
840 sp
->parent_pte
= NULL
;
843 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
844 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
845 if (!pte_chain
->parent_ptes
[i
])
847 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
849 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
850 && pte_chain
->parent_ptes
[i
+ 1]) {
851 pte_chain
->parent_ptes
[i
]
852 = pte_chain
->parent_ptes
[i
+ 1];
855 pte_chain
->parent_ptes
[i
] = NULL
;
857 hlist_del(&pte_chain
->link
);
858 mmu_free_pte_chain(pte_chain
);
859 if (hlist_empty(&sp
->parent_ptes
)) {
861 sp
->parent_pte
= NULL
;
870 static void mmu_parent_walk(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
871 mmu_parent_walk_fn fn
)
873 struct kvm_pte_chain
*pte_chain
;
874 struct hlist_node
*node
;
875 struct kvm_mmu_page
*parent_sp
;
878 if (!sp
->multimapped
&& sp
->parent_pte
) {
879 parent_sp
= page_header(__pa(sp
->parent_pte
));
881 mmu_parent_walk(vcpu
, parent_sp
, fn
);
884 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
885 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
886 if (!pte_chain
->parent_ptes
[i
])
888 parent_sp
= page_header(__pa(pte_chain
->parent_ptes
[i
]));
890 mmu_parent_walk(vcpu
, parent_sp
, fn
);
894 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
895 struct kvm_mmu_page
*sp
)
899 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
900 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
903 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
904 struct kvm_mmu_page
*sp
)
909 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
913 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
914 struct kvm_unsync_walk
*walker
)
918 if (!sp
->unsync_children
)
921 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
922 u64 ent
= sp
->spt
[i
];
924 if (is_shadow_present_pte(ent
)) {
925 struct kvm_mmu_page
*child
;
926 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
928 if (child
->unsync_children
) {
929 ret
= mmu_unsync_walk(child
, walker
);
935 ret
= walker
->entry(child
, walker
);
942 if (i
== PT64_ENT_PER_PAGE
)
943 sp
->unsync_children
= 0;
948 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
951 struct hlist_head
*bucket
;
952 struct kvm_mmu_page
*sp
;
953 struct hlist_node
*node
;
955 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
956 index
= kvm_page_table_hashfn(gfn
);
957 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
958 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
959 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
960 && !sp
->role
.invalid
) {
961 pgprintk("%s: found role %x\n",
962 __func__
, sp
->role
.word
);
968 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
970 WARN_ON(!sp
->unsync
);
972 --kvm
->stat
.mmu_unsync
;
975 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
);
977 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
979 if (sp
->role
.glevels
!= vcpu
->arch
.mmu
.root_level
) {
980 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
984 rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
985 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
986 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
990 kvm_mmu_flush_tlb(vcpu
);
991 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
996 struct kvm_vcpu
*vcpu
;
997 struct kvm_unsync_walk walker
;
1000 static int mmu_sync_fn(struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
)
1002 struct sync_walker
*sync_walk
= container_of(walk
, struct sync_walker
,
1004 struct kvm_vcpu
*vcpu
= sync_walk
->vcpu
;
1006 kvm_sync_page(vcpu
, sp
);
1007 return (need_resched() || spin_needbreak(&vcpu
->kvm
->mmu_lock
));
1010 static void mmu_sync_children(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1012 struct sync_walker walker
= {
1013 .walker
= { .entry
= mmu_sync_fn
, },
1017 while (mmu_unsync_walk(sp
, &walker
.walker
))
1018 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1021 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1029 union kvm_mmu_page_role role
;
1032 struct hlist_head
*bucket
;
1033 struct kvm_mmu_page
*sp
;
1034 struct hlist_node
*node
, *tmp
;
1037 role
.glevels
= vcpu
->arch
.mmu
.root_level
;
1039 role
.metaphysical
= metaphysical
;
1040 role
.access
= access
;
1041 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1042 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1043 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1044 role
.quadrant
= quadrant
;
1046 pgprintk("%s: looking gfn %lx role %x\n", __func__
,
1048 index
= kvm_page_table_hashfn(gfn
);
1049 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1050 hlist_for_each_entry_safe(sp
, node
, tmp
, bucket
, hash_link
)
1051 if (sp
->gfn
== gfn
) {
1053 if (kvm_sync_page(vcpu
, sp
))
1056 if (sp
->role
.word
!= role
.word
)
1059 if (sp
->unsync_children
)
1060 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
1062 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1063 pgprintk("%s: found\n", __func__
);
1066 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1067 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
1070 pgprintk("%s: adding gfn %lx role %x\n", __func__
, gfn
, role
.word
);
1073 hlist_add_head(&sp
->hash_link
, bucket
);
1074 if (!metaphysical
) {
1075 rmap_write_protect(vcpu
->kvm
, gfn
);
1076 account_shadowed(vcpu
->kvm
, gfn
);
1078 if (shadow_trap_nonpresent_pte
!= shadow_notrap_nonpresent_pte
)
1079 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
1081 nonpaging_prefetch_page(vcpu
, sp
);
1085 static int walk_shadow(struct kvm_shadow_walk
*walker
,
1086 struct kvm_vcpu
*vcpu
, u64 addr
)
1094 shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1095 level
= vcpu
->arch
.mmu
.shadow_root_level
;
1096 if (level
== PT32E_ROOT_LEVEL
) {
1097 shadow_addr
= vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1098 shadow_addr
&= PT64_BASE_ADDR_MASK
;
1102 while (level
>= PT_PAGE_TABLE_LEVEL
) {
1103 index
= SHADOW_PT_INDEX(addr
, level
);
1104 sptep
= ((u64
*)__va(shadow_addr
)) + index
;
1105 r
= walker
->entry(walker
, vcpu
, addr
, sptep
, level
);
1108 shadow_addr
= *sptep
& PT64_BASE_ADDR_MASK
;
1114 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1115 struct kvm_mmu_page
*sp
)
1123 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1124 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1125 if (is_shadow_present_pte(pt
[i
]))
1126 rmap_remove(kvm
, &pt
[i
]);
1127 pt
[i
] = shadow_trap_nonpresent_pte
;
1132 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1135 if (is_shadow_present_pte(ent
)) {
1136 if (!is_large_pte(ent
)) {
1137 ent
&= PT64_BASE_ADDR_MASK
;
1138 mmu_page_remove_parent_pte(page_header(ent
),
1142 rmap_remove(kvm
, &pt
[i
]);
1145 pt
[i
] = shadow_trap_nonpresent_pte
;
1149 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1151 mmu_page_remove_parent_pte(sp
, parent_pte
);
1154 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
1158 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
1160 kvm
->vcpus
[i
]->arch
.last_pte_updated
= NULL
;
1163 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1167 while (sp
->multimapped
|| sp
->parent_pte
) {
1168 if (!sp
->multimapped
)
1169 parent_pte
= sp
->parent_pte
;
1171 struct kvm_pte_chain
*chain
;
1173 chain
= container_of(sp
->parent_ptes
.first
,
1174 struct kvm_pte_chain
, link
);
1175 parent_pte
= chain
->parent_ptes
[0];
1177 BUG_ON(!parent_pte
);
1178 kvm_mmu_put_page(sp
, parent_pte
);
1179 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
1184 struct kvm_unsync_walk walker
;
1189 static int mmu_zap_fn(struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
)
1191 struct zap_walker
*zap_walk
= container_of(walk
, struct zap_walker
,
1193 kvm_mmu_zap_page(zap_walk
->kvm
, sp
);
1194 zap_walk
->zapped
= 1;
1198 static int mmu_zap_unsync_children(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1200 struct zap_walker walker
= {
1201 .walker
= { .entry
= mmu_zap_fn
, },
1206 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1208 mmu_unsync_walk(sp
, &walker
.walker
);
1209 return walker
.zapped
;
1212 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1215 ++kvm
->stat
.mmu_shadow_zapped
;
1216 ret
= mmu_zap_unsync_children(kvm
, sp
);
1217 kvm_mmu_page_unlink_children(kvm
, sp
);
1218 kvm_mmu_unlink_parents(kvm
, sp
);
1219 kvm_flush_remote_tlbs(kvm
);
1220 if (!sp
->role
.invalid
&& !sp
->role
.metaphysical
)
1221 unaccount_shadowed(kvm
, sp
->gfn
);
1223 kvm_unlink_unsync_page(kvm
, sp
);
1224 if (!sp
->root_count
) {
1225 hlist_del(&sp
->hash_link
);
1226 kvm_mmu_free_page(kvm
, sp
);
1228 sp
->role
.invalid
= 1;
1229 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1230 kvm_reload_remote_mmus(kvm
);
1232 kvm_mmu_reset_last_pte_updated(kvm
);
1237 * Changing the number of mmu pages allocated to the vm
1238 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1240 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
1243 * If we set the number of mmu pages to be smaller be than the
1244 * number of actived pages , we must to free some mmu pages before we
1248 if ((kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
) >
1250 int n_used_mmu_pages
= kvm
->arch
.n_alloc_mmu_pages
1251 - kvm
->arch
.n_free_mmu_pages
;
1253 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
1254 struct kvm_mmu_page
*page
;
1256 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
1257 struct kvm_mmu_page
, link
);
1258 kvm_mmu_zap_page(kvm
, page
);
1261 kvm
->arch
.n_free_mmu_pages
= 0;
1264 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
1265 - kvm
->arch
.n_alloc_mmu_pages
;
1267 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
1270 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
1273 struct hlist_head
*bucket
;
1274 struct kvm_mmu_page
*sp
;
1275 struct hlist_node
*node
, *n
;
1278 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1280 index
= kvm_page_table_hashfn(gfn
);
1281 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1282 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
1283 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
) {
1284 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
1287 if (kvm_mmu_zap_page(kvm
, sp
))
1293 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
1295 struct kvm_mmu_page
*sp
;
1297 while ((sp
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
1298 pgprintk("%s: zap %lx %x\n", __func__
, gfn
, sp
->role
.word
);
1299 kvm_mmu_zap_page(kvm
, sp
);
1303 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
1305 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gfn
));
1306 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
1308 __set_bit(slot
, &sp
->slot_bitmap
);
1311 static void mmu_convert_notrap(struct kvm_mmu_page
*sp
)
1316 if (shadow_trap_nonpresent_pte
== shadow_notrap_nonpresent_pte
)
1319 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1320 if (pt
[i
] == shadow_notrap_nonpresent_pte
)
1321 set_shadow_pte(&pt
[i
], shadow_trap_nonpresent_pte
);
1325 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
1329 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1331 if (gpa
== UNMAPPED_GVA
)
1334 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1339 static int unsync_walk_fn(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1341 sp
->unsync_children
= 1;
1345 static int kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1348 struct hlist_head
*bucket
;
1349 struct kvm_mmu_page
*s
;
1350 struct hlist_node
*node
, *n
;
1352 index
= kvm_page_table_hashfn(sp
->gfn
);
1353 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1354 /* don't unsync if pagetable is shadowed with multiple roles */
1355 hlist_for_each_entry_safe(s
, node
, n
, bucket
, hash_link
) {
1356 if (s
->gfn
!= sp
->gfn
|| s
->role
.metaphysical
)
1358 if (s
->role
.word
!= sp
->role
.word
)
1361 mmu_parent_walk(vcpu
, sp
, unsync_walk_fn
);
1362 ++vcpu
->kvm
->stat
.mmu_unsync
;
1364 mmu_convert_notrap(sp
);
1368 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
1371 struct kvm_mmu_page
*shadow
;
1373 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1375 if (shadow
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1380 return kvm_unsync_page(vcpu
, shadow
);
1386 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1387 unsigned pte_access
, int user_fault
,
1388 int write_fault
, int dirty
, int largepage
,
1389 gfn_t gfn
, pfn_t pfn
, bool speculative
,
1395 * We don't set the accessed bit, since we sometimes want to see
1396 * whether the guest actually used the pte (in order to detect
1399 spte
= shadow_base_present_pte
| shadow_dirty_mask
;
1401 spte
|= shadow_accessed_mask
;
1403 pte_access
&= ~ACC_WRITE_MASK
;
1404 if (pte_access
& ACC_EXEC_MASK
)
1405 spte
|= shadow_x_mask
;
1407 spte
|= shadow_nx_mask
;
1408 if (pte_access
& ACC_USER_MASK
)
1409 spte
|= shadow_user_mask
;
1411 spte
|= PT_PAGE_SIZE_MASK
;
1413 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
1415 if ((pte_access
& ACC_WRITE_MASK
)
1416 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1418 if (largepage
&& has_wrprotected_page(vcpu
->kvm
, gfn
)) {
1420 spte
= shadow_trap_nonpresent_pte
;
1424 spte
|= PT_WRITABLE_MASK
;
1426 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
1427 pgprintk("%s: found shadow page for %lx, marking ro\n",
1430 pte_access
&= ~ACC_WRITE_MASK
;
1431 if (is_writeble_pte(spte
))
1432 spte
&= ~PT_WRITABLE_MASK
;
1436 if (pte_access
& ACC_WRITE_MASK
)
1437 mark_page_dirty(vcpu
->kvm
, gfn
);
1440 set_shadow_pte(shadow_pte
, spte
);
1444 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1445 unsigned pt_access
, unsigned pte_access
,
1446 int user_fault
, int write_fault
, int dirty
,
1447 int *ptwrite
, int largepage
, gfn_t gfn
,
1448 pfn_t pfn
, bool speculative
)
1450 int was_rmapped
= 0;
1451 int was_writeble
= is_writeble_pte(*shadow_pte
);
1453 pgprintk("%s: spte %llx access %x write_fault %d"
1454 " user_fault %d gfn %lx\n",
1455 __func__
, *shadow_pte
, pt_access
,
1456 write_fault
, user_fault
, gfn
);
1458 if (is_rmap_pte(*shadow_pte
)) {
1460 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1461 * the parent of the now unreachable PTE.
1463 if (largepage
&& !is_large_pte(*shadow_pte
)) {
1464 struct kvm_mmu_page
*child
;
1465 u64 pte
= *shadow_pte
;
1467 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1468 mmu_page_remove_parent_pte(child
, shadow_pte
);
1469 } else if (pfn
!= spte_to_pfn(*shadow_pte
)) {
1470 pgprintk("hfn old %lx new %lx\n",
1471 spte_to_pfn(*shadow_pte
), pfn
);
1472 rmap_remove(vcpu
->kvm
, shadow_pte
);
1475 was_rmapped
= is_large_pte(*shadow_pte
);
1480 if (set_spte(vcpu
, shadow_pte
, pte_access
, user_fault
, write_fault
,
1481 dirty
, largepage
, gfn
, pfn
, speculative
, true)) {
1484 kvm_x86_ops
->tlb_flush(vcpu
);
1487 pgprintk("%s: setting spte %llx\n", __func__
, *shadow_pte
);
1488 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1489 is_large_pte(*shadow_pte
)? "2MB" : "4kB",
1490 is_present_pte(*shadow_pte
)?"RW":"R", gfn
,
1491 *shadow_pte
, shadow_pte
);
1492 if (!was_rmapped
&& is_large_pte(*shadow_pte
))
1493 ++vcpu
->kvm
->stat
.lpages
;
1495 page_header_update_slot(vcpu
->kvm
, shadow_pte
, gfn
);
1497 rmap_add(vcpu
, shadow_pte
, gfn
, largepage
);
1498 if (!is_rmap_pte(*shadow_pte
))
1499 kvm_release_pfn_clean(pfn
);
1502 kvm_release_pfn_dirty(pfn
);
1504 kvm_release_pfn_clean(pfn
);
1507 vcpu
->arch
.last_pte_updated
= shadow_pte
;
1508 vcpu
->arch
.last_pte_gfn
= gfn
;
1512 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1516 struct direct_shadow_walk
{
1517 struct kvm_shadow_walk walker
;
1524 static int direct_map_entry(struct kvm_shadow_walk
*_walk
,
1525 struct kvm_vcpu
*vcpu
,
1526 u64 addr
, u64
*sptep
, int level
)
1528 struct direct_shadow_walk
*walk
=
1529 container_of(_walk
, struct direct_shadow_walk
, walker
);
1530 struct kvm_mmu_page
*sp
;
1532 gfn_t gfn
= addr
>> PAGE_SHIFT
;
1534 if (level
== PT_PAGE_TABLE_LEVEL
1535 || (walk
->largepage
&& level
== PT_DIRECTORY_LEVEL
)) {
1536 mmu_set_spte(vcpu
, sptep
, ACC_ALL
, ACC_ALL
,
1537 0, walk
->write
, 1, &walk
->pt_write
,
1538 walk
->largepage
, gfn
, walk
->pfn
, false);
1539 ++vcpu
->stat
.pf_fixed
;
1543 if (*sptep
== shadow_trap_nonpresent_pte
) {
1544 pseudo_gfn
= (addr
& PT64_DIR_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1545 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, (gva_t
)addr
, level
- 1,
1548 pgprintk("nonpaging_map: ENOMEM\n");
1549 kvm_release_pfn_clean(walk
->pfn
);
1553 set_shadow_pte(sptep
,
1555 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
1556 | shadow_user_mask
| shadow_x_mask
);
1561 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1562 int largepage
, gfn_t gfn
, pfn_t pfn
)
1565 struct direct_shadow_walk walker
= {
1566 .walker
= { .entry
= direct_map_entry
, },
1568 .largepage
= largepage
,
1573 r
= walk_shadow(&walker
.walker
, vcpu
, gfn
<< PAGE_SHIFT
);
1576 return walker
.pt_write
;
1579 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1584 unsigned long mmu_seq
;
1586 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1587 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1591 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1593 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1596 if (is_error_pfn(pfn
)) {
1597 kvm_release_pfn_clean(pfn
);
1601 spin_lock(&vcpu
->kvm
->mmu_lock
);
1602 if (mmu_notifier_retry(vcpu
, mmu_seq
))
1604 kvm_mmu_free_some_pages(vcpu
);
1605 r
= __direct_map(vcpu
, v
, write
, largepage
, gfn
, pfn
);
1606 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1612 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1613 kvm_release_pfn_clean(pfn
);
1618 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
1621 struct kvm_mmu_page
*sp
;
1623 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1625 spin_lock(&vcpu
->kvm
->mmu_lock
);
1626 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1627 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1629 sp
= page_header(root
);
1631 if (!sp
->root_count
&& sp
->role
.invalid
)
1632 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1633 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1634 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1637 for (i
= 0; i
< 4; ++i
) {
1638 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1641 root
&= PT64_BASE_ADDR_MASK
;
1642 sp
= page_header(root
);
1644 if (!sp
->root_count
&& sp
->role
.invalid
)
1645 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1647 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
1649 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1650 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1653 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
1657 struct kvm_mmu_page
*sp
;
1658 int metaphysical
= 0;
1660 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
1662 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1663 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1665 ASSERT(!VALID_PAGE(root
));
1668 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1669 PT64_ROOT_LEVEL
, metaphysical
,
1671 root
= __pa(sp
->spt
);
1673 vcpu
->arch
.mmu
.root_hpa
= root
;
1676 metaphysical
= !is_paging(vcpu
);
1679 for (i
= 0; i
< 4; ++i
) {
1680 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1682 ASSERT(!VALID_PAGE(root
));
1683 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1684 if (!is_present_pte(vcpu
->arch
.pdptrs
[i
])) {
1685 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
1688 root_gfn
= vcpu
->arch
.pdptrs
[i
] >> PAGE_SHIFT
;
1689 } else if (vcpu
->arch
.mmu
.root_level
== 0)
1691 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1692 PT32_ROOT_LEVEL
, metaphysical
,
1694 root
= __pa(sp
->spt
);
1696 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1698 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
1701 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1704 struct kvm_mmu_page
*sp
;
1706 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1708 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1709 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1710 sp
= page_header(root
);
1711 mmu_sync_children(vcpu
, sp
);
1714 for (i
= 0; i
< 4; ++i
) {
1715 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1718 root
&= PT64_BASE_ADDR_MASK
;
1719 sp
= page_header(root
);
1720 mmu_sync_children(vcpu
, sp
);
1725 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1727 spin_lock(&vcpu
->kvm
->mmu_lock
);
1728 mmu_sync_roots(vcpu
);
1729 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1732 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1737 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1743 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
1744 r
= mmu_topup_memory_caches(vcpu
);
1749 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1751 gfn
= gva
>> PAGE_SHIFT
;
1753 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
1754 error_code
& PFERR_WRITE_MASK
, gfn
);
1757 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
1763 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1764 unsigned long mmu_seq
;
1767 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1769 r
= mmu_topup_memory_caches(vcpu
);
1773 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1774 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1777 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1779 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1780 if (is_error_pfn(pfn
)) {
1781 kvm_release_pfn_clean(pfn
);
1784 spin_lock(&vcpu
->kvm
->mmu_lock
);
1785 if (mmu_notifier_retry(vcpu
, mmu_seq
))
1787 kvm_mmu_free_some_pages(vcpu
);
1788 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
1789 largepage
, gfn
, pfn
);
1790 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1795 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1796 kvm_release_pfn_clean(pfn
);
1800 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1802 mmu_free_roots(vcpu
);
1805 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1807 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1809 context
->new_cr3
= nonpaging_new_cr3
;
1810 context
->page_fault
= nonpaging_page_fault
;
1811 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1812 context
->free
= nonpaging_free
;
1813 context
->prefetch_page
= nonpaging_prefetch_page
;
1814 context
->sync_page
= nonpaging_sync_page
;
1815 context
->invlpg
= nonpaging_invlpg
;
1816 context
->root_level
= 0;
1817 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1818 context
->root_hpa
= INVALID_PAGE
;
1822 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1824 ++vcpu
->stat
.tlb_flush
;
1825 kvm_x86_ops
->tlb_flush(vcpu
);
1828 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1830 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
1831 mmu_free_roots(vcpu
);
1834 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1838 kvm_inject_page_fault(vcpu
, addr
, err_code
);
1841 static void paging_free(struct kvm_vcpu
*vcpu
)
1843 nonpaging_free(vcpu
);
1847 #include "paging_tmpl.h"
1851 #include "paging_tmpl.h"
1854 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1856 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1858 ASSERT(is_pae(vcpu
));
1859 context
->new_cr3
= paging_new_cr3
;
1860 context
->page_fault
= paging64_page_fault
;
1861 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1862 context
->prefetch_page
= paging64_prefetch_page
;
1863 context
->sync_page
= paging64_sync_page
;
1864 context
->invlpg
= paging64_invlpg
;
1865 context
->free
= paging_free
;
1866 context
->root_level
= level
;
1867 context
->shadow_root_level
= level
;
1868 context
->root_hpa
= INVALID_PAGE
;
1872 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1874 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1877 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1879 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1881 context
->new_cr3
= paging_new_cr3
;
1882 context
->page_fault
= paging32_page_fault
;
1883 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1884 context
->free
= paging_free
;
1885 context
->prefetch_page
= paging32_prefetch_page
;
1886 context
->sync_page
= paging32_sync_page
;
1887 context
->invlpg
= paging32_invlpg
;
1888 context
->root_level
= PT32_ROOT_LEVEL
;
1889 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1890 context
->root_hpa
= INVALID_PAGE
;
1894 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1896 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1899 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
1901 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1903 context
->new_cr3
= nonpaging_new_cr3
;
1904 context
->page_fault
= tdp_page_fault
;
1905 context
->free
= nonpaging_free
;
1906 context
->prefetch_page
= nonpaging_prefetch_page
;
1907 context
->sync_page
= nonpaging_sync_page
;
1908 context
->invlpg
= nonpaging_invlpg
;
1909 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
1910 context
->root_hpa
= INVALID_PAGE
;
1912 if (!is_paging(vcpu
)) {
1913 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1914 context
->root_level
= 0;
1915 } else if (is_long_mode(vcpu
)) {
1916 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1917 context
->root_level
= PT64_ROOT_LEVEL
;
1918 } else if (is_pae(vcpu
)) {
1919 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1920 context
->root_level
= PT32E_ROOT_LEVEL
;
1922 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1923 context
->root_level
= PT32_ROOT_LEVEL
;
1929 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
1932 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1934 if (!is_paging(vcpu
))
1935 return nonpaging_init_context(vcpu
);
1936 else if (is_long_mode(vcpu
))
1937 return paging64_init_context(vcpu
);
1938 else if (is_pae(vcpu
))
1939 return paging32E_init_context(vcpu
);
1941 return paging32_init_context(vcpu
);
1944 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1946 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
1949 return init_kvm_tdp_mmu(vcpu
);
1951 return init_kvm_softmmu(vcpu
);
1954 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
1957 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
1958 vcpu
->arch
.mmu
.free(vcpu
);
1959 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1963 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
1965 destroy_kvm_mmu(vcpu
);
1966 return init_kvm_mmu(vcpu
);
1968 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
1970 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
1974 r
= mmu_topup_memory_caches(vcpu
);
1977 spin_lock(&vcpu
->kvm
->mmu_lock
);
1978 kvm_mmu_free_some_pages(vcpu
);
1979 mmu_alloc_roots(vcpu
);
1980 mmu_sync_roots(vcpu
);
1981 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1982 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
1983 kvm_mmu_flush_tlb(vcpu
);
1987 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
1989 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
1991 mmu_free_roots(vcpu
);
1994 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
1995 struct kvm_mmu_page
*sp
,
1999 struct kvm_mmu_page
*child
;
2002 if (is_shadow_present_pte(pte
)) {
2003 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
||
2005 rmap_remove(vcpu
->kvm
, spte
);
2007 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2008 mmu_page_remove_parent_pte(child
, spte
);
2011 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
2012 if (is_large_pte(pte
))
2013 --vcpu
->kvm
->stat
.lpages
;
2016 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
2017 struct kvm_mmu_page
*sp
,
2021 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
2022 if (!vcpu
->arch
.update_pte
.largepage
||
2023 sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2024 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
2029 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
2030 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
2031 paging32_update_pte(vcpu
, sp
, spte
, new);
2033 paging64_update_pte(vcpu
, sp
, spte
, new);
2036 static bool need_remote_flush(u64 old
, u64
new)
2038 if (!is_shadow_present_pte(old
))
2040 if (!is_shadow_present_pte(new))
2042 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
2044 old
^= PT64_NX_MASK
;
2045 new ^= PT64_NX_MASK
;
2046 return (old
& ~new & PT64_PERM_MASK
) != 0;
2049 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
2051 if (need_remote_flush(old
, new))
2052 kvm_flush_remote_tlbs(vcpu
->kvm
);
2054 kvm_mmu_flush_tlb(vcpu
);
2057 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
2059 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2061 return !!(spte
&& (*spte
& shadow_accessed_mask
));
2064 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2065 const u8
*new, int bytes
)
2072 vcpu
->arch
.update_pte
.largepage
= 0;
2074 if (bytes
!= 4 && bytes
!= 8)
2078 * Assume that the pte write on a page table of the same type
2079 * as the current vcpu paging mode. This is nearly always true
2080 * (might be false while changing modes). Note it is verified later
2084 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2085 if ((bytes
== 4) && (gpa
% 4 == 0)) {
2086 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
2089 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
2090 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
2091 memcpy((void *)&gpte
, new, 8);
2094 if ((bytes
== 4) && (gpa
% 4 == 0))
2095 memcpy((void *)&gpte
, new, 4);
2097 if (!is_present_pte(gpte
))
2099 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
2101 if (is_large_pte(gpte
) && is_largepage_backed(vcpu
, gfn
)) {
2102 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
2103 vcpu
->arch
.update_pte
.largepage
= 1;
2105 vcpu
->arch
.update_pte
.mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2107 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2109 if (is_error_pfn(pfn
)) {
2110 kvm_release_pfn_clean(pfn
);
2113 vcpu
->arch
.update_pte
.gfn
= gfn
;
2114 vcpu
->arch
.update_pte
.pfn
= pfn
;
2117 static void kvm_mmu_access_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2119 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2122 && vcpu
->arch
.last_pte_gfn
== gfn
2123 && shadow_accessed_mask
2124 && !(*spte
& shadow_accessed_mask
)
2125 && is_shadow_present_pte(*spte
))
2126 set_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
2129 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2130 const u8
*new, int bytes
)
2132 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2133 struct kvm_mmu_page
*sp
;
2134 struct hlist_node
*node
, *n
;
2135 struct hlist_head
*bucket
;
2139 unsigned offset
= offset_in_page(gpa
);
2141 unsigned page_offset
;
2142 unsigned misaligned
;
2149 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
2150 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
2151 spin_lock(&vcpu
->kvm
->mmu_lock
);
2152 kvm_mmu_access_page(vcpu
, gfn
);
2153 kvm_mmu_free_some_pages(vcpu
);
2154 ++vcpu
->kvm
->stat
.mmu_pte_write
;
2155 kvm_mmu_audit(vcpu
, "pre pte write");
2156 if (gfn
== vcpu
->arch
.last_pt_write_gfn
2157 && !last_updated_pte_accessed(vcpu
)) {
2158 ++vcpu
->arch
.last_pt_write_count
;
2159 if (vcpu
->arch
.last_pt_write_count
>= 3)
2162 vcpu
->arch
.last_pt_write_gfn
= gfn
;
2163 vcpu
->arch
.last_pt_write_count
= 1;
2164 vcpu
->arch
.last_pte_updated
= NULL
;
2166 index
= kvm_page_table_hashfn(gfn
);
2167 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
2168 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
2169 if (sp
->gfn
!= gfn
|| sp
->role
.metaphysical
|| sp
->role
.invalid
)
2171 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
2172 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
2173 misaligned
|= bytes
< 4;
2174 if (misaligned
|| flooded
) {
2176 * Misaligned accesses are too much trouble to fix
2177 * up; also, they usually indicate a page is not used
2180 * If we're seeing too many writes to a page,
2181 * it may no longer be a page table, or we may be
2182 * forking, in which case it is better to unmap the
2185 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2186 gpa
, bytes
, sp
->role
.word
);
2187 if (kvm_mmu_zap_page(vcpu
->kvm
, sp
))
2189 ++vcpu
->kvm
->stat
.mmu_flooded
;
2192 page_offset
= offset
;
2193 level
= sp
->role
.level
;
2195 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2196 page_offset
<<= 1; /* 32->64 */
2198 * A 32-bit pde maps 4MB while the shadow pdes map
2199 * only 2MB. So we need to double the offset again
2200 * and zap two pdes instead of one.
2202 if (level
== PT32_ROOT_LEVEL
) {
2203 page_offset
&= ~7; /* kill rounding error */
2207 quadrant
= page_offset
>> PAGE_SHIFT
;
2208 page_offset
&= ~PAGE_MASK
;
2209 if (quadrant
!= sp
->role
.quadrant
)
2212 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
2213 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
2215 r
= kvm_read_guest_atomic(vcpu
->kvm
,
2216 gpa
& ~(u64
)(pte_size
- 1),
2218 new = (const void *)&gentry
;
2224 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
2226 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
2227 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
2231 kvm_mmu_audit(vcpu
, "post pte write");
2232 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2233 if (!is_error_pfn(vcpu
->arch
.update_pte
.pfn
)) {
2234 kvm_release_pfn_clean(vcpu
->arch
.update_pte
.pfn
);
2235 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2239 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
2244 gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
2246 spin_lock(&vcpu
->kvm
->mmu_lock
);
2247 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
2248 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2251 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
2253 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
2255 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
) {
2256 struct kvm_mmu_page
*sp
;
2258 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
2259 struct kvm_mmu_page
, link
);
2260 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2261 ++vcpu
->kvm
->stat
.mmu_recycled
;
2265 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
2268 enum emulation_result er
;
2270 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
2279 r
= mmu_topup_memory_caches(vcpu
);
2283 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
2288 case EMULATE_DO_MMIO
:
2289 ++vcpu
->stat
.mmio_exits
;
2292 kvm_report_emulation_failure(vcpu
, "pagetable");
2300 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
2302 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
2304 spin_lock(&vcpu
->kvm
->mmu_lock
);
2305 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
2306 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2307 kvm_mmu_flush_tlb(vcpu
);
2308 ++vcpu
->stat
.invlpg
;
2310 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
2312 void kvm_enable_tdp(void)
2316 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
2318 void kvm_disable_tdp(void)
2320 tdp_enabled
= false;
2322 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
2324 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
2326 struct kvm_mmu_page
*sp
;
2328 while (!list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
2329 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.next
,
2330 struct kvm_mmu_page
, link
);
2331 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2334 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
2337 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
2344 if (vcpu
->kvm
->arch
.n_requested_mmu_pages
)
2345 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2346 vcpu
->kvm
->arch
.n_requested_mmu_pages
;
2348 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2349 vcpu
->kvm
->arch
.n_alloc_mmu_pages
;
2351 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2352 * Therefore we need to allocate shadow page tables in the first
2353 * 4GB of memory, which happens to fit the DMA32 zone.
2355 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
2358 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
2359 for (i
= 0; i
< 4; ++i
)
2360 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2365 free_mmu_pages(vcpu
);
2369 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
2372 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2374 return alloc_mmu_pages(vcpu
);
2377 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
2380 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2382 return init_kvm_mmu(vcpu
);
2385 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
2389 destroy_kvm_mmu(vcpu
);
2390 free_mmu_pages(vcpu
);
2391 mmu_free_memory_caches(vcpu
);
2394 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
2396 struct kvm_mmu_page
*sp
;
2398 spin_lock(&kvm
->mmu_lock
);
2399 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
2403 if (!test_bit(slot
, &sp
->slot_bitmap
))
2407 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2409 if (pt
[i
] & PT_WRITABLE_MASK
)
2410 pt
[i
] &= ~PT_WRITABLE_MASK
;
2412 kvm_flush_remote_tlbs(kvm
);
2413 spin_unlock(&kvm
->mmu_lock
);
2416 void kvm_mmu_zap_all(struct kvm
*kvm
)
2418 struct kvm_mmu_page
*sp
, *node
;
2420 spin_lock(&kvm
->mmu_lock
);
2421 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
2422 if (kvm_mmu_zap_page(kvm
, sp
))
2423 node
= container_of(kvm
->arch
.active_mmu_pages
.next
,
2424 struct kvm_mmu_page
, link
);
2425 spin_unlock(&kvm
->mmu_lock
);
2427 kvm_flush_remote_tlbs(kvm
);
2430 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm
*kvm
)
2432 struct kvm_mmu_page
*page
;
2434 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2435 struct kvm_mmu_page
, link
);
2436 kvm_mmu_zap_page(kvm
, page
);
2439 static int mmu_shrink(int nr_to_scan
, gfp_t gfp_mask
)
2442 struct kvm
*kvm_freed
= NULL
;
2443 int cache_count
= 0;
2445 spin_lock(&kvm_lock
);
2447 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
2450 if (!down_read_trylock(&kvm
->slots_lock
))
2452 spin_lock(&kvm
->mmu_lock
);
2453 npages
= kvm
->arch
.n_alloc_mmu_pages
-
2454 kvm
->arch
.n_free_mmu_pages
;
2455 cache_count
+= npages
;
2456 if (!kvm_freed
&& nr_to_scan
> 0 && npages
> 0) {
2457 kvm_mmu_remove_one_alloc_mmu_page(kvm
);
2463 spin_unlock(&kvm
->mmu_lock
);
2464 up_read(&kvm
->slots_lock
);
2467 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
2469 spin_unlock(&kvm_lock
);
2474 static struct shrinker mmu_shrinker
= {
2475 .shrink
= mmu_shrink
,
2476 .seeks
= DEFAULT_SEEKS
* 10,
2479 static void mmu_destroy_caches(void)
2481 if (pte_chain_cache
)
2482 kmem_cache_destroy(pte_chain_cache
);
2483 if (rmap_desc_cache
)
2484 kmem_cache_destroy(rmap_desc_cache
);
2485 if (mmu_page_header_cache
)
2486 kmem_cache_destroy(mmu_page_header_cache
);
2489 void kvm_mmu_module_exit(void)
2491 mmu_destroy_caches();
2492 unregister_shrinker(&mmu_shrinker
);
2495 int kvm_mmu_module_init(void)
2497 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
2498 sizeof(struct kvm_pte_chain
),
2500 if (!pte_chain_cache
)
2502 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
2503 sizeof(struct kvm_rmap_desc
),
2505 if (!rmap_desc_cache
)
2508 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
2509 sizeof(struct kvm_mmu_page
),
2511 if (!mmu_page_header_cache
)
2514 register_shrinker(&mmu_shrinker
);
2519 mmu_destroy_caches();
2524 * Caculate mmu pages needed for kvm.
2526 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
2529 unsigned int nr_mmu_pages
;
2530 unsigned int nr_pages
= 0;
2532 for (i
= 0; i
< kvm
->nmemslots
; i
++)
2533 nr_pages
+= kvm
->memslots
[i
].npages
;
2535 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
2536 nr_mmu_pages
= max(nr_mmu_pages
,
2537 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
2539 return nr_mmu_pages
;
2542 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2545 if (len
> buffer
->len
)
2550 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2555 ret
= pv_mmu_peek_buffer(buffer
, len
);
2560 buffer
->processed
+= len
;
2564 static int kvm_pv_mmu_write(struct kvm_vcpu
*vcpu
,
2565 gpa_t addr
, gpa_t value
)
2570 if (!is_long_mode(vcpu
) && !is_pae(vcpu
))
2573 r
= mmu_topup_memory_caches(vcpu
);
2577 if (!emulator_write_phys(vcpu
, addr
, &value
, bytes
))
2583 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2585 kvm_x86_ops
->tlb_flush(vcpu
);
2589 static int kvm_pv_mmu_release_pt(struct kvm_vcpu
*vcpu
, gpa_t addr
)
2591 spin_lock(&vcpu
->kvm
->mmu_lock
);
2592 mmu_unshadow(vcpu
->kvm
, addr
>> PAGE_SHIFT
);
2593 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2597 static int kvm_pv_mmu_op_one(struct kvm_vcpu
*vcpu
,
2598 struct kvm_pv_mmu_op_buffer
*buffer
)
2600 struct kvm_mmu_op_header
*header
;
2602 header
= pv_mmu_peek_buffer(buffer
, sizeof *header
);
2605 switch (header
->op
) {
2606 case KVM_MMU_OP_WRITE_PTE
: {
2607 struct kvm_mmu_op_write_pte
*wpte
;
2609 wpte
= pv_mmu_read_buffer(buffer
, sizeof *wpte
);
2612 return kvm_pv_mmu_write(vcpu
, wpte
->pte_phys
,
2615 case KVM_MMU_OP_FLUSH_TLB
: {
2616 struct kvm_mmu_op_flush_tlb
*ftlb
;
2618 ftlb
= pv_mmu_read_buffer(buffer
, sizeof *ftlb
);
2621 return kvm_pv_mmu_flush_tlb(vcpu
);
2623 case KVM_MMU_OP_RELEASE_PT
: {
2624 struct kvm_mmu_op_release_pt
*rpt
;
2626 rpt
= pv_mmu_read_buffer(buffer
, sizeof *rpt
);
2629 return kvm_pv_mmu_release_pt(vcpu
, rpt
->pt_phys
);
2635 int kvm_pv_mmu_op(struct kvm_vcpu
*vcpu
, unsigned long bytes
,
2636 gpa_t addr
, unsigned long *ret
)
2639 struct kvm_pv_mmu_op_buffer
*buffer
= &vcpu
->arch
.mmu_op_buffer
;
2641 buffer
->ptr
= buffer
->buf
;
2642 buffer
->len
= min_t(unsigned long, bytes
, sizeof buffer
->buf
);
2643 buffer
->processed
= 0;
2645 r
= kvm_read_guest(vcpu
->kvm
, addr
, buffer
->buf
, buffer
->len
);
2649 while (buffer
->len
) {
2650 r
= kvm_pv_mmu_op_one(vcpu
, buffer
);
2659 *ret
= buffer
->processed
;
2665 static const char *audit_msg
;
2667 static gva_t
canonicalize(gva_t gva
)
2669 #ifdef CONFIG_X86_64
2670 gva
= (long long)(gva
<< 16) >> 16;
2675 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
2676 gva_t va
, int level
)
2678 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
2680 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
2682 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
2685 if (ent
== shadow_trap_nonpresent_pte
)
2688 va
= canonicalize(va
);
2690 if (ent
== shadow_notrap_nonpresent_pte
)
2691 printk(KERN_ERR
"audit: (%s) nontrapping pte"
2692 " in nonleaf level: levels %d gva %lx"
2693 " level %d pte %llx\n", audit_msg
,
2694 vcpu
->arch
.mmu
.root_level
, va
, level
, ent
);
2696 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
2698 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, va
);
2699 hpa_t hpa
= (hpa_t
)gpa_to_pfn(vcpu
, gpa
) << PAGE_SHIFT
;
2701 if (is_shadow_present_pte(ent
)
2702 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
2703 printk(KERN_ERR
"xx audit error: (%s) levels %d"
2704 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2705 audit_msg
, vcpu
->arch
.mmu
.root_level
,
2707 is_shadow_present_pte(ent
));
2708 else if (ent
== shadow_notrap_nonpresent_pte
2709 && !is_error_hpa(hpa
))
2710 printk(KERN_ERR
"audit: (%s) notrap shadow,"
2711 " valid guest gva %lx\n", audit_msg
, va
);
2712 kvm_release_pfn_clean(pfn
);
2718 static void audit_mappings(struct kvm_vcpu
*vcpu
)
2722 if (vcpu
->arch
.mmu
.root_level
== 4)
2723 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
2725 for (i
= 0; i
< 4; ++i
)
2726 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
2727 audit_mappings_page(vcpu
,
2728 vcpu
->arch
.mmu
.pae_root
[i
],
2733 static int count_rmaps(struct kvm_vcpu
*vcpu
)
2738 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
2739 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
2740 struct kvm_rmap_desc
*d
;
2742 for (j
= 0; j
< m
->npages
; ++j
) {
2743 unsigned long *rmapp
= &m
->rmap
[j
];
2747 if (!(*rmapp
& 1)) {
2751 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
2753 for (k
= 0; k
< RMAP_EXT
; ++k
)
2754 if (d
->shadow_ptes
[k
])
2765 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
2768 struct kvm_mmu_page
*sp
;
2771 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2774 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2777 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
2780 if (!(ent
& PT_PRESENT_MASK
))
2782 if (!(ent
& PT_WRITABLE_MASK
))
2790 static void audit_rmap(struct kvm_vcpu
*vcpu
)
2792 int n_rmap
= count_rmaps(vcpu
);
2793 int n_actual
= count_writable_mappings(vcpu
);
2795 if (n_rmap
!= n_actual
)
2796 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
2797 __func__
, audit_msg
, n_rmap
, n_actual
);
2800 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
2802 struct kvm_mmu_page
*sp
;
2803 struct kvm_memory_slot
*slot
;
2804 unsigned long *rmapp
;
2807 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2808 if (sp
->role
.metaphysical
)
2811 slot
= gfn_to_memslot(vcpu
->kvm
, sp
->gfn
);
2812 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
2813 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
2815 printk(KERN_ERR
"%s: (%s) shadow page has writable"
2816 " mappings: gfn %lx role %x\n",
2817 __func__
, audit_msg
, sp
->gfn
,
2822 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
2829 audit_write_protection(vcpu
);
2830 audit_mappings(vcpu
);