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);
73 static int oos_shadow
= 1;
74 module_param(oos_shadow
, bool, 0644);
77 #define ASSERT(x) do { } while (0)
81 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
82 __FILE__, __LINE__, #x); \
86 #define PT_FIRST_AVAIL_BITS_SHIFT 9
87 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
89 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
91 #define PT64_LEVEL_BITS 9
93 #define PT64_LEVEL_SHIFT(level) \
94 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
96 #define PT64_LEVEL_MASK(level) \
97 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
99 #define PT64_INDEX(address, level)\
100 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
103 #define PT32_LEVEL_BITS 10
105 #define PT32_LEVEL_SHIFT(level) \
106 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
108 #define PT32_LEVEL_MASK(level) \
109 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
111 #define PT32_INDEX(address, level)\
112 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
115 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
116 #define PT64_DIR_BASE_ADDR_MASK \
117 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
119 #define PT32_BASE_ADDR_MASK PAGE_MASK
120 #define PT32_DIR_BASE_ADDR_MASK \
121 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
123 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
126 #define PFERR_PRESENT_MASK (1U << 0)
127 #define PFERR_WRITE_MASK (1U << 1)
128 #define PFERR_USER_MASK (1U << 2)
129 #define PFERR_FETCH_MASK (1U << 4)
131 #define PT_DIRECTORY_LEVEL 2
132 #define PT_PAGE_TABLE_LEVEL 1
136 #define ACC_EXEC_MASK 1
137 #define ACC_WRITE_MASK PT_WRITABLE_MASK
138 #define ACC_USER_MASK PT_USER_MASK
139 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
141 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
143 struct kvm_rmap_desc
{
144 u64
*shadow_ptes
[RMAP_EXT
];
145 struct kvm_rmap_desc
*more
;
148 struct kvm_shadow_walk
{
149 int (*entry
)(struct kvm_shadow_walk
*walk
, struct kvm_vcpu
*vcpu
,
150 u64 addr
, u64
*spte
, int level
);
153 struct kvm_unsync_walk
{
154 int (*entry
) (struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
);
157 typedef int (*mmu_parent_walk_fn
) (struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
);
159 static struct kmem_cache
*pte_chain_cache
;
160 static struct kmem_cache
*rmap_desc_cache
;
161 static struct kmem_cache
*mmu_page_header_cache
;
163 static u64 __read_mostly shadow_trap_nonpresent_pte
;
164 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
165 static u64 __read_mostly shadow_base_present_pte
;
166 static u64 __read_mostly shadow_nx_mask
;
167 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
168 static u64 __read_mostly shadow_user_mask
;
169 static u64 __read_mostly shadow_accessed_mask
;
170 static u64 __read_mostly shadow_dirty_mask
;
172 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
174 shadow_trap_nonpresent_pte
= trap_pte
;
175 shadow_notrap_nonpresent_pte
= notrap_pte
;
177 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
179 void kvm_mmu_set_base_ptes(u64 base_pte
)
181 shadow_base_present_pte
= base_pte
;
183 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes
);
185 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
186 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
188 shadow_user_mask
= user_mask
;
189 shadow_accessed_mask
= accessed_mask
;
190 shadow_dirty_mask
= dirty_mask
;
191 shadow_nx_mask
= nx_mask
;
192 shadow_x_mask
= x_mask
;
194 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
196 static int is_write_protection(struct kvm_vcpu
*vcpu
)
198 return vcpu
->arch
.cr0
& X86_CR0_WP
;
201 static int is_cpuid_PSE36(void)
206 static int is_nx(struct kvm_vcpu
*vcpu
)
208 return vcpu
->arch
.shadow_efer
& EFER_NX
;
211 static int is_present_pte(unsigned long pte
)
213 return pte
& PT_PRESENT_MASK
;
216 static int is_shadow_present_pte(u64 pte
)
218 return pte
!= shadow_trap_nonpresent_pte
219 && pte
!= shadow_notrap_nonpresent_pte
;
222 static int is_large_pte(u64 pte
)
224 return pte
& PT_PAGE_SIZE_MASK
;
227 static int is_writeble_pte(unsigned long pte
)
229 return pte
& PT_WRITABLE_MASK
;
232 static int is_dirty_pte(unsigned long pte
)
234 return pte
& shadow_dirty_mask
;
237 static int is_rmap_pte(u64 pte
)
239 return is_shadow_present_pte(pte
);
242 static pfn_t
spte_to_pfn(u64 pte
)
244 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
247 static gfn_t
pse36_gfn_delta(u32 gpte
)
249 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
251 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
254 static void set_shadow_pte(u64
*sptep
, u64 spte
)
257 set_64bit((unsigned long *)sptep
, spte
);
259 set_64bit((unsigned long long *)sptep
, spte
);
263 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
264 struct kmem_cache
*base_cache
, int min
)
268 if (cache
->nobjs
>= min
)
270 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
271 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
274 cache
->objects
[cache
->nobjs
++] = obj
;
279 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
282 kfree(mc
->objects
[--mc
->nobjs
]);
285 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
290 if (cache
->nobjs
>= min
)
292 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
293 page
= alloc_page(GFP_KERNEL
);
296 set_page_private(page
, 0);
297 cache
->objects
[cache
->nobjs
++] = page_address(page
);
302 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
305 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
308 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
312 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
316 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
320 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
323 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
324 mmu_page_header_cache
, 4);
329 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
331 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
332 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
333 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
334 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
337 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
343 p
= mc
->objects
[--mc
->nobjs
];
348 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
350 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
351 sizeof(struct kvm_pte_chain
));
354 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
359 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
361 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
362 sizeof(struct kvm_rmap_desc
));
365 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
371 * Return the pointer to the largepage write count for a given
372 * gfn, handling slots that are not large page aligned.
374 static int *slot_largepage_idx(gfn_t gfn
, struct kvm_memory_slot
*slot
)
378 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
379 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
380 return &slot
->lpage_info
[idx
].write_count
;
383 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
387 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
391 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
395 write_count
= slot_largepage_idx(gfn
, gfn_to_memslot(kvm
, gfn
));
397 WARN_ON(*write_count
< 0);
400 static int has_wrprotected_page(struct kvm
*kvm
, gfn_t gfn
)
402 struct kvm_memory_slot
*slot
= gfn_to_memslot(kvm
, gfn
);
406 largepage_idx
= slot_largepage_idx(gfn
, slot
);
407 return *largepage_idx
;
413 static int host_largepage_backed(struct kvm
*kvm
, gfn_t gfn
)
415 struct vm_area_struct
*vma
;
419 addr
= gfn_to_hva(kvm
, gfn
);
420 if (kvm_is_error_hva(addr
))
423 down_read(¤t
->mm
->mmap_sem
);
424 vma
= find_vma(current
->mm
, addr
);
425 if (vma
&& is_vm_hugetlb_page(vma
))
427 up_read(¤t
->mm
->mmap_sem
);
432 static int is_largepage_backed(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
434 struct kvm_memory_slot
*slot
;
436 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
))
439 if (!host_largepage_backed(vcpu
->kvm
, large_gfn
))
442 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
443 if (slot
&& slot
->dirty_bitmap
)
450 * Take gfn and return the reverse mapping to it.
451 * Note: gfn must be unaliased before this function get called
454 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int lpage
)
456 struct kvm_memory_slot
*slot
;
459 slot
= gfn_to_memslot(kvm
, gfn
);
461 return &slot
->rmap
[gfn
- slot
->base_gfn
];
463 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
464 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
466 return &slot
->lpage_info
[idx
].rmap_pde
;
470 * Reverse mapping data structures:
472 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
473 * that points to page_address(page).
475 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
476 * containing more mappings.
478 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
, int lpage
)
480 struct kvm_mmu_page
*sp
;
481 struct kvm_rmap_desc
*desc
;
482 unsigned long *rmapp
;
485 if (!is_rmap_pte(*spte
))
487 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
488 sp
= page_header(__pa(spte
));
489 sp
->gfns
[spte
- sp
->spt
] = gfn
;
490 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, lpage
);
492 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
493 *rmapp
= (unsigned long)spte
;
494 } else if (!(*rmapp
& 1)) {
495 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
496 desc
= mmu_alloc_rmap_desc(vcpu
);
497 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
498 desc
->shadow_ptes
[1] = spte
;
499 *rmapp
= (unsigned long)desc
| 1;
501 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
502 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
503 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
505 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
506 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
509 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
511 desc
->shadow_ptes
[i
] = spte
;
515 static void rmap_desc_remove_entry(unsigned long *rmapp
,
516 struct kvm_rmap_desc
*desc
,
518 struct kvm_rmap_desc
*prev_desc
)
522 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
524 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
525 desc
->shadow_ptes
[j
] = NULL
;
528 if (!prev_desc
&& !desc
->more
)
529 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
532 prev_desc
->more
= desc
->more
;
534 *rmapp
= (unsigned long)desc
->more
| 1;
535 mmu_free_rmap_desc(desc
);
538 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
540 struct kvm_rmap_desc
*desc
;
541 struct kvm_rmap_desc
*prev_desc
;
542 struct kvm_mmu_page
*sp
;
544 unsigned long *rmapp
;
547 if (!is_rmap_pte(*spte
))
549 sp
= page_header(__pa(spte
));
550 pfn
= spte_to_pfn(*spte
);
551 if (*spte
& shadow_accessed_mask
)
552 kvm_set_pfn_accessed(pfn
);
553 if (is_writeble_pte(*spte
))
554 kvm_release_pfn_dirty(pfn
);
556 kvm_release_pfn_clean(pfn
);
557 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], is_large_pte(*spte
));
559 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
561 } else if (!(*rmapp
& 1)) {
562 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
563 if ((u64
*)*rmapp
!= spte
) {
564 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
570 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
571 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
574 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
575 if (desc
->shadow_ptes
[i
] == spte
) {
576 rmap_desc_remove_entry(rmapp
,
588 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
590 struct kvm_rmap_desc
*desc
;
591 struct kvm_rmap_desc
*prev_desc
;
597 else if (!(*rmapp
& 1)) {
599 return (u64
*)*rmapp
;
602 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
606 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
607 if (prev_spte
== spte
)
608 return desc
->shadow_ptes
[i
];
609 prev_spte
= desc
->shadow_ptes
[i
];
616 static void rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
618 unsigned long *rmapp
;
620 int write_protected
= 0;
622 gfn
= unalias_gfn(kvm
, gfn
);
623 rmapp
= gfn_to_rmap(kvm
, gfn
, 0);
625 spte
= rmap_next(kvm
, rmapp
, NULL
);
628 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
629 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
630 if (is_writeble_pte(*spte
)) {
631 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
634 spte
= rmap_next(kvm
, rmapp
, spte
);
636 if (write_protected
) {
639 spte
= rmap_next(kvm
, rmapp
, NULL
);
640 pfn
= spte_to_pfn(*spte
);
641 kvm_set_pfn_dirty(pfn
);
644 /* check for huge page mappings */
645 rmapp
= gfn_to_rmap(kvm
, gfn
, 1);
646 spte
= rmap_next(kvm
, rmapp
, NULL
);
649 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
650 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
651 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
652 if (is_writeble_pte(*spte
)) {
653 rmap_remove(kvm
, spte
);
655 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
659 spte
= rmap_next(kvm
, rmapp
, spte
);
663 kvm_flush_remote_tlbs(kvm
);
666 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
669 int need_tlb_flush
= 0;
671 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
672 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
673 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
674 rmap_remove(kvm
, spte
);
675 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
678 return need_tlb_flush
;
681 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
682 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
))
688 * If mmap_sem isn't taken, we can look the memslots with only
689 * the mmu_lock by skipping over the slots with userspace_addr == 0.
691 for (i
= 0; i
< kvm
->nmemslots
; i
++) {
692 struct kvm_memory_slot
*memslot
= &kvm
->memslots
[i
];
693 unsigned long start
= memslot
->userspace_addr
;
696 /* mmu_lock protects userspace_addr */
700 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
701 if (hva
>= start
&& hva
< end
) {
702 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
703 retval
|= handler(kvm
, &memslot
->rmap
[gfn_offset
]);
704 retval
|= handler(kvm
,
705 &memslot
->lpage_info
[
707 KVM_PAGES_PER_HPAGE
].rmap_pde
);
714 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
716 return kvm_handle_hva(kvm
, hva
, kvm_unmap_rmapp
);
719 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
724 /* always return old for EPT */
725 if (!shadow_accessed_mask
)
728 spte
= rmap_next(kvm
, rmapp
, NULL
);
732 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
733 _young
= _spte
& PT_ACCESSED_MASK
;
736 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
738 spte
= rmap_next(kvm
, rmapp
, spte
);
743 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
745 return kvm_handle_hva(kvm
, hva
, kvm_age_rmapp
);
749 static int is_empty_shadow_page(u64
*spt
)
754 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
755 if (is_shadow_present_pte(*pos
)) {
756 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
764 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
766 ASSERT(is_empty_shadow_page(sp
->spt
));
768 __free_page(virt_to_page(sp
->spt
));
769 __free_page(virt_to_page(sp
->gfns
));
771 ++kvm
->arch
.n_free_mmu_pages
;
774 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
776 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
779 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
782 struct kvm_mmu_page
*sp
;
784 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
785 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
786 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
787 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
788 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
789 ASSERT(is_empty_shadow_page(sp
->spt
));
792 sp
->parent_pte
= parent_pte
;
793 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
797 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
798 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
800 struct kvm_pte_chain
*pte_chain
;
801 struct hlist_node
*node
;
806 if (!sp
->multimapped
) {
807 u64
*old
= sp
->parent_pte
;
810 sp
->parent_pte
= parent_pte
;
814 pte_chain
= mmu_alloc_pte_chain(vcpu
);
815 INIT_HLIST_HEAD(&sp
->parent_ptes
);
816 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
817 pte_chain
->parent_ptes
[0] = old
;
819 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
820 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
822 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
823 if (!pte_chain
->parent_ptes
[i
]) {
824 pte_chain
->parent_ptes
[i
] = parent_pte
;
828 pte_chain
= mmu_alloc_pte_chain(vcpu
);
830 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
831 pte_chain
->parent_ptes
[0] = parent_pte
;
834 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
837 struct kvm_pte_chain
*pte_chain
;
838 struct hlist_node
*node
;
841 if (!sp
->multimapped
) {
842 BUG_ON(sp
->parent_pte
!= parent_pte
);
843 sp
->parent_pte
= NULL
;
846 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
847 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
848 if (!pte_chain
->parent_ptes
[i
])
850 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
852 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
853 && pte_chain
->parent_ptes
[i
+ 1]) {
854 pte_chain
->parent_ptes
[i
]
855 = pte_chain
->parent_ptes
[i
+ 1];
858 pte_chain
->parent_ptes
[i
] = NULL
;
860 hlist_del(&pte_chain
->link
);
861 mmu_free_pte_chain(pte_chain
);
862 if (hlist_empty(&sp
->parent_ptes
)) {
864 sp
->parent_pte
= NULL
;
873 static void mmu_parent_walk(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
874 mmu_parent_walk_fn fn
)
876 struct kvm_pte_chain
*pte_chain
;
877 struct hlist_node
*node
;
878 struct kvm_mmu_page
*parent_sp
;
881 if (!sp
->multimapped
&& sp
->parent_pte
) {
882 parent_sp
= page_header(__pa(sp
->parent_pte
));
884 mmu_parent_walk(vcpu
, parent_sp
, fn
);
887 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
888 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
889 if (!pte_chain
->parent_ptes
[i
])
891 parent_sp
= page_header(__pa(pte_chain
->parent_ptes
[i
]));
893 mmu_parent_walk(vcpu
, parent_sp
, fn
);
897 static void kvm_mmu_update_unsync_bitmap(u64
*spte
)
900 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
902 index
= spte
- sp
->spt
;
903 __set_bit(index
, sp
->unsync_child_bitmap
);
904 sp
->unsync_children
= 1;
907 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page
*sp
)
909 struct kvm_pte_chain
*pte_chain
;
910 struct hlist_node
*node
;
916 if (!sp
->multimapped
) {
917 kvm_mmu_update_unsync_bitmap(sp
->parent_pte
);
921 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
922 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
923 if (!pte_chain
->parent_ptes
[i
])
925 kvm_mmu_update_unsync_bitmap(pte_chain
->parent_ptes
[i
]);
929 static int unsync_walk_fn(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
931 sp
->unsync_children
= 1;
932 kvm_mmu_update_parents_unsync(sp
);
936 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu
*vcpu
,
937 struct kvm_mmu_page
*sp
)
939 mmu_parent_walk(vcpu
, sp
, unsync_walk_fn
);
940 kvm_mmu_update_parents_unsync(sp
);
943 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
944 struct kvm_mmu_page
*sp
)
948 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
949 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
952 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
953 struct kvm_mmu_page
*sp
)
958 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
962 #define for_each_unsync_children(bitmap, idx) \
963 for (idx = find_first_bit(bitmap, 512); \
965 idx = find_next_bit(bitmap, 512, idx+1))
967 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
968 struct kvm_unsync_walk
*walker
)
972 if (!sp
->unsync_children
)
975 for_each_unsync_children(sp
->unsync_child_bitmap
, i
) {
976 u64 ent
= sp
->spt
[i
];
978 if (is_shadow_present_pte(ent
)) {
979 struct kvm_mmu_page
*child
;
980 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
982 if (child
->unsync_children
) {
983 ret
= mmu_unsync_walk(child
, walker
);
986 __clear_bit(i
, sp
->unsync_child_bitmap
);
990 ret
= walker
->entry(child
, walker
);
991 __clear_bit(i
, sp
->unsync_child_bitmap
);
998 if (find_first_bit(sp
->unsync_child_bitmap
, 512) == 512)
999 sp
->unsync_children
= 0;
1004 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
1007 struct hlist_head
*bucket
;
1008 struct kvm_mmu_page
*sp
;
1009 struct hlist_node
*node
;
1011 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1012 index
= kvm_page_table_hashfn(gfn
);
1013 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1014 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
1015 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
1016 && !sp
->role
.invalid
) {
1017 pgprintk("%s: found role %x\n",
1018 __func__
, sp
->role
.word
);
1024 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1026 WARN_ON(!sp
->unsync
);
1028 --kvm
->stat
.mmu_unsync
;
1031 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
);
1033 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1035 if (sp
->role
.glevels
!= vcpu
->arch
.mmu
.root_level
) {
1036 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1040 rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1041 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1042 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1043 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1047 kvm_mmu_flush_tlb(vcpu
);
1051 struct sync_walker
{
1052 struct kvm_vcpu
*vcpu
;
1053 struct kvm_unsync_walk walker
;
1056 static int mmu_sync_fn(struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
)
1058 struct sync_walker
*sync_walk
= container_of(walk
, struct sync_walker
,
1060 struct kvm_vcpu
*vcpu
= sync_walk
->vcpu
;
1062 kvm_sync_page(vcpu
, sp
);
1063 return (need_resched() || spin_needbreak(&vcpu
->kvm
->mmu_lock
));
1066 static void mmu_sync_children(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1068 struct sync_walker walker
= {
1069 .walker
= { .entry
= mmu_sync_fn
, },
1073 while (mmu_unsync_walk(sp
, &walker
.walker
))
1074 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1077 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1085 union kvm_mmu_page_role role
;
1088 struct hlist_head
*bucket
;
1089 struct kvm_mmu_page
*sp
;
1090 struct hlist_node
*node
, *tmp
;
1093 role
.glevels
= vcpu
->arch
.mmu
.root_level
;
1095 role
.metaphysical
= metaphysical
;
1096 role
.access
= access
;
1097 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1098 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1099 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1100 role
.quadrant
= quadrant
;
1102 pgprintk("%s: looking gfn %lx role %x\n", __func__
,
1104 index
= kvm_page_table_hashfn(gfn
);
1105 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1106 hlist_for_each_entry_safe(sp
, node
, tmp
, bucket
, hash_link
)
1107 if (sp
->gfn
== gfn
) {
1109 if (kvm_sync_page(vcpu
, sp
))
1112 if (sp
->role
.word
!= role
.word
)
1115 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1116 if (sp
->unsync_children
) {
1117 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
1118 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1120 pgprintk("%s: found\n", __func__
);
1123 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1124 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
1127 pgprintk("%s: adding gfn %lx role %x\n", __func__
, gfn
, role
.word
);
1130 hlist_add_head(&sp
->hash_link
, bucket
);
1131 if (!metaphysical
) {
1132 rmap_write_protect(vcpu
->kvm
, gfn
);
1133 account_shadowed(vcpu
->kvm
, gfn
);
1135 if (shadow_trap_nonpresent_pte
!= shadow_notrap_nonpresent_pte
)
1136 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
1138 nonpaging_prefetch_page(vcpu
, sp
);
1142 static int walk_shadow(struct kvm_shadow_walk
*walker
,
1143 struct kvm_vcpu
*vcpu
, u64 addr
)
1151 shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1152 level
= vcpu
->arch
.mmu
.shadow_root_level
;
1153 if (level
== PT32E_ROOT_LEVEL
) {
1154 shadow_addr
= vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1155 shadow_addr
&= PT64_BASE_ADDR_MASK
;
1159 while (level
>= PT_PAGE_TABLE_LEVEL
) {
1160 index
= SHADOW_PT_INDEX(addr
, level
);
1161 sptep
= ((u64
*)__va(shadow_addr
)) + index
;
1162 r
= walker
->entry(walker
, vcpu
, addr
, sptep
, level
);
1165 shadow_addr
= *sptep
& PT64_BASE_ADDR_MASK
;
1171 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1172 struct kvm_mmu_page
*sp
)
1180 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1181 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1182 if (is_shadow_present_pte(pt
[i
]))
1183 rmap_remove(kvm
, &pt
[i
]);
1184 pt
[i
] = shadow_trap_nonpresent_pte
;
1189 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1192 if (is_shadow_present_pte(ent
)) {
1193 if (!is_large_pte(ent
)) {
1194 ent
&= PT64_BASE_ADDR_MASK
;
1195 mmu_page_remove_parent_pte(page_header(ent
),
1199 rmap_remove(kvm
, &pt
[i
]);
1202 pt
[i
] = shadow_trap_nonpresent_pte
;
1206 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1208 mmu_page_remove_parent_pte(sp
, parent_pte
);
1211 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
1215 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
1217 kvm
->vcpus
[i
]->arch
.last_pte_updated
= NULL
;
1220 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1224 while (sp
->multimapped
|| sp
->parent_pte
) {
1225 if (!sp
->multimapped
)
1226 parent_pte
= sp
->parent_pte
;
1228 struct kvm_pte_chain
*chain
;
1230 chain
= container_of(sp
->parent_ptes
.first
,
1231 struct kvm_pte_chain
, link
);
1232 parent_pte
= chain
->parent_ptes
[0];
1234 BUG_ON(!parent_pte
);
1235 kvm_mmu_put_page(sp
, parent_pte
);
1236 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
1241 struct kvm_unsync_walk walker
;
1246 static int mmu_zap_fn(struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
)
1248 struct zap_walker
*zap_walk
= container_of(walk
, struct zap_walker
,
1250 kvm_mmu_zap_page(zap_walk
->kvm
, sp
);
1251 zap_walk
->zapped
= 1;
1255 static int mmu_zap_unsync_children(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1257 struct zap_walker walker
= {
1258 .walker
= { .entry
= mmu_zap_fn
, },
1263 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1265 mmu_unsync_walk(sp
, &walker
.walker
);
1266 return walker
.zapped
;
1269 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1272 ++kvm
->stat
.mmu_shadow_zapped
;
1273 ret
= mmu_zap_unsync_children(kvm
, sp
);
1274 kvm_mmu_page_unlink_children(kvm
, sp
);
1275 kvm_mmu_unlink_parents(kvm
, sp
);
1276 kvm_flush_remote_tlbs(kvm
);
1277 if (!sp
->role
.invalid
&& !sp
->role
.metaphysical
)
1278 unaccount_shadowed(kvm
, sp
->gfn
);
1280 kvm_unlink_unsync_page(kvm
, sp
);
1281 if (!sp
->root_count
) {
1282 hlist_del(&sp
->hash_link
);
1283 kvm_mmu_free_page(kvm
, sp
);
1285 sp
->role
.invalid
= 1;
1286 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1287 kvm_reload_remote_mmus(kvm
);
1289 kvm_mmu_reset_last_pte_updated(kvm
);
1294 * Changing the number of mmu pages allocated to the vm
1295 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1297 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
1300 * If we set the number of mmu pages to be smaller be than the
1301 * number of actived pages , we must to free some mmu pages before we
1305 if ((kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
) >
1307 int n_used_mmu_pages
= kvm
->arch
.n_alloc_mmu_pages
1308 - kvm
->arch
.n_free_mmu_pages
;
1310 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
1311 struct kvm_mmu_page
*page
;
1313 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
1314 struct kvm_mmu_page
, link
);
1315 kvm_mmu_zap_page(kvm
, page
);
1318 kvm
->arch
.n_free_mmu_pages
= 0;
1321 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
1322 - kvm
->arch
.n_alloc_mmu_pages
;
1324 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
1327 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
1330 struct hlist_head
*bucket
;
1331 struct kvm_mmu_page
*sp
;
1332 struct hlist_node
*node
, *n
;
1335 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1337 index
= kvm_page_table_hashfn(gfn
);
1338 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1339 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
1340 if (sp
->gfn
== gfn
&& !sp
->role
.metaphysical
) {
1341 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
1344 if (kvm_mmu_zap_page(kvm
, sp
))
1350 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
1352 struct kvm_mmu_page
*sp
;
1354 while ((sp
= kvm_mmu_lookup_page(kvm
, gfn
)) != NULL
) {
1355 pgprintk("%s: zap %lx %x\n", __func__
, gfn
, sp
->role
.word
);
1356 kvm_mmu_zap_page(kvm
, sp
);
1360 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
1362 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gfn
));
1363 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
1365 __set_bit(slot
, &sp
->slot_bitmap
);
1368 static void mmu_convert_notrap(struct kvm_mmu_page
*sp
)
1373 if (shadow_trap_nonpresent_pte
== shadow_notrap_nonpresent_pte
)
1376 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1377 if (pt
[i
] == shadow_notrap_nonpresent_pte
)
1378 set_shadow_pte(&pt
[i
], shadow_trap_nonpresent_pte
);
1382 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
1386 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1388 if (gpa
== UNMAPPED_GVA
)
1391 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1396 static int kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1399 struct hlist_head
*bucket
;
1400 struct kvm_mmu_page
*s
;
1401 struct hlist_node
*node
, *n
;
1403 index
= kvm_page_table_hashfn(sp
->gfn
);
1404 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1405 /* don't unsync if pagetable is shadowed with multiple roles */
1406 hlist_for_each_entry_safe(s
, node
, n
, bucket
, hash_link
) {
1407 if (s
->gfn
!= sp
->gfn
|| s
->role
.metaphysical
)
1409 if (s
->role
.word
!= sp
->role
.word
)
1412 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1413 ++vcpu
->kvm
->stat
.mmu_unsync
;
1415 mmu_convert_notrap(sp
);
1419 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
1422 struct kvm_mmu_page
*shadow
;
1424 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1426 if (shadow
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1430 if (can_unsync
&& oos_shadow
)
1431 return kvm_unsync_page(vcpu
, shadow
);
1437 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1438 unsigned pte_access
, int user_fault
,
1439 int write_fault
, int dirty
, int largepage
,
1440 gfn_t gfn
, pfn_t pfn
, bool speculative
,
1446 * We don't set the accessed bit, since we sometimes want to see
1447 * whether the guest actually used the pte (in order to detect
1450 spte
= shadow_base_present_pte
| shadow_dirty_mask
;
1452 spte
|= shadow_accessed_mask
;
1454 pte_access
&= ~ACC_WRITE_MASK
;
1455 if (pte_access
& ACC_EXEC_MASK
)
1456 spte
|= shadow_x_mask
;
1458 spte
|= shadow_nx_mask
;
1459 if (pte_access
& ACC_USER_MASK
)
1460 spte
|= shadow_user_mask
;
1462 spte
|= PT_PAGE_SIZE_MASK
;
1464 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
1466 if ((pte_access
& ACC_WRITE_MASK
)
1467 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1469 if (largepage
&& has_wrprotected_page(vcpu
->kvm
, gfn
)) {
1471 spte
= shadow_trap_nonpresent_pte
;
1475 spte
|= PT_WRITABLE_MASK
;
1477 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
1478 pgprintk("%s: found shadow page for %lx, marking ro\n",
1481 pte_access
&= ~ACC_WRITE_MASK
;
1482 if (is_writeble_pte(spte
))
1483 spte
&= ~PT_WRITABLE_MASK
;
1487 if (pte_access
& ACC_WRITE_MASK
)
1488 mark_page_dirty(vcpu
->kvm
, gfn
);
1491 set_shadow_pte(shadow_pte
, spte
);
1495 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1496 unsigned pt_access
, unsigned pte_access
,
1497 int user_fault
, int write_fault
, int dirty
,
1498 int *ptwrite
, int largepage
, gfn_t gfn
,
1499 pfn_t pfn
, bool speculative
)
1501 int was_rmapped
= 0;
1502 int was_writeble
= is_writeble_pte(*shadow_pte
);
1504 pgprintk("%s: spte %llx access %x write_fault %d"
1505 " user_fault %d gfn %lx\n",
1506 __func__
, *shadow_pte
, pt_access
,
1507 write_fault
, user_fault
, gfn
);
1509 if (is_rmap_pte(*shadow_pte
)) {
1511 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1512 * the parent of the now unreachable PTE.
1514 if (largepage
&& !is_large_pte(*shadow_pte
)) {
1515 struct kvm_mmu_page
*child
;
1516 u64 pte
= *shadow_pte
;
1518 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1519 mmu_page_remove_parent_pte(child
, shadow_pte
);
1520 } else if (pfn
!= spte_to_pfn(*shadow_pte
)) {
1521 pgprintk("hfn old %lx new %lx\n",
1522 spte_to_pfn(*shadow_pte
), pfn
);
1523 rmap_remove(vcpu
->kvm
, shadow_pte
);
1526 was_rmapped
= is_large_pte(*shadow_pte
);
1531 if (set_spte(vcpu
, shadow_pte
, pte_access
, user_fault
, write_fault
,
1532 dirty
, largepage
, gfn
, pfn
, speculative
, true)) {
1535 kvm_x86_ops
->tlb_flush(vcpu
);
1538 pgprintk("%s: setting spte %llx\n", __func__
, *shadow_pte
);
1539 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1540 is_large_pte(*shadow_pte
)? "2MB" : "4kB",
1541 is_present_pte(*shadow_pte
)?"RW":"R", gfn
,
1542 *shadow_pte
, shadow_pte
);
1543 if (!was_rmapped
&& is_large_pte(*shadow_pte
))
1544 ++vcpu
->kvm
->stat
.lpages
;
1546 page_header_update_slot(vcpu
->kvm
, shadow_pte
, gfn
);
1548 rmap_add(vcpu
, shadow_pte
, gfn
, largepage
);
1549 if (!is_rmap_pte(*shadow_pte
))
1550 kvm_release_pfn_clean(pfn
);
1553 kvm_release_pfn_dirty(pfn
);
1555 kvm_release_pfn_clean(pfn
);
1558 vcpu
->arch
.last_pte_updated
= shadow_pte
;
1559 vcpu
->arch
.last_pte_gfn
= gfn
;
1563 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1567 struct direct_shadow_walk
{
1568 struct kvm_shadow_walk walker
;
1575 static int direct_map_entry(struct kvm_shadow_walk
*_walk
,
1576 struct kvm_vcpu
*vcpu
,
1577 u64 addr
, u64
*sptep
, int level
)
1579 struct direct_shadow_walk
*walk
=
1580 container_of(_walk
, struct direct_shadow_walk
, walker
);
1581 struct kvm_mmu_page
*sp
;
1583 gfn_t gfn
= addr
>> PAGE_SHIFT
;
1585 if (level
== PT_PAGE_TABLE_LEVEL
1586 || (walk
->largepage
&& level
== PT_DIRECTORY_LEVEL
)) {
1587 mmu_set_spte(vcpu
, sptep
, ACC_ALL
, ACC_ALL
,
1588 0, walk
->write
, 1, &walk
->pt_write
,
1589 walk
->largepage
, gfn
, walk
->pfn
, false);
1590 ++vcpu
->stat
.pf_fixed
;
1594 if (*sptep
== shadow_trap_nonpresent_pte
) {
1595 pseudo_gfn
= (addr
& PT64_DIR_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1596 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, (gva_t
)addr
, level
- 1,
1599 pgprintk("nonpaging_map: ENOMEM\n");
1600 kvm_release_pfn_clean(walk
->pfn
);
1604 set_shadow_pte(sptep
,
1606 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
1607 | shadow_user_mask
| shadow_x_mask
);
1612 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1613 int largepage
, gfn_t gfn
, pfn_t pfn
)
1616 struct direct_shadow_walk walker
= {
1617 .walker
= { .entry
= direct_map_entry
, },
1619 .largepage
= largepage
,
1624 r
= walk_shadow(&walker
.walker
, vcpu
, gfn
<< PAGE_SHIFT
);
1627 return walker
.pt_write
;
1630 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1635 unsigned long mmu_seq
;
1637 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1638 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1642 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1644 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1647 if (is_error_pfn(pfn
)) {
1648 kvm_release_pfn_clean(pfn
);
1652 spin_lock(&vcpu
->kvm
->mmu_lock
);
1653 if (mmu_notifier_retry(vcpu
, mmu_seq
))
1655 kvm_mmu_free_some_pages(vcpu
);
1656 r
= __direct_map(vcpu
, v
, write
, largepage
, gfn
, pfn
);
1657 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1663 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1664 kvm_release_pfn_clean(pfn
);
1669 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
1672 struct kvm_mmu_page
*sp
;
1674 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1676 spin_lock(&vcpu
->kvm
->mmu_lock
);
1677 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1678 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1680 sp
= page_header(root
);
1682 if (!sp
->root_count
&& sp
->role
.invalid
)
1683 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1684 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1685 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1688 for (i
= 0; i
< 4; ++i
) {
1689 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1692 root
&= PT64_BASE_ADDR_MASK
;
1693 sp
= page_header(root
);
1695 if (!sp
->root_count
&& sp
->role
.invalid
)
1696 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1698 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
1700 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1701 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1704 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
1708 struct kvm_mmu_page
*sp
;
1709 int metaphysical
= 0;
1711 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
1713 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1714 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1716 ASSERT(!VALID_PAGE(root
));
1719 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1720 PT64_ROOT_LEVEL
, metaphysical
,
1722 root
= __pa(sp
->spt
);
1724 vcpu
->arch
.mmu
.root_hpa
= root
;
1727 metaphysical
= !is_paging(vcpu
);
1730 for (i
= 0; i
< 4; ++i
) {
1731 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1733 ASSERT(!VALID_PAGE(root
));
1734 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1735 if (!is_present_pte(vcpu
->arch
.pdptrs
[i
])) {
1736 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
1739 root_gfn
= vcpu
->arch
.pdptrs
[i
] >> PAGE_SHIFT
;
1740 } else if (vcpu
->arch
.mmu
.root_level
== 0)
1742 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1743 PT32_ROOT_LEVEL
, metaphysical
,
1745 root
= __pa(sp
->spt
);
1747 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1749 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
1752 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1755 struct kvm_mmu_page
*sp
;
1757 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1759 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1760 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1761 sp
= page_header(root
);
1762 mmu_sync_children(vcpu
, sp
);
1765 for (i
= 0; i
< 4; ++i
) {
1766 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1769 root
&= PT64_BASE_ADDR_MASK
;
1770 sp
= page_header(root
);
1771 mmu_sync_children(vcpu
, sp
);
1776 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1778 spin_lock(&vcpu
->kvm
->mmu_lock
);
1779 mmu_sync_roots(vcpu
);
1780 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1783 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1788 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
1794 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
1795 r
= mmu_topup_memory_caches(vcpu
);
1800 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1802 gfn
= gva
>> PAGE_SHIFT
;
1804 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
1805 error_code
& PFERR_WRITE_MASK
, gfn
);
1808 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
1814 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
1815 unsigned long mmu_seq
;
1818 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1820 r
= mmu_topup_memory_caches(vcpu
);
1824 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1825 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1828 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1830 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1831 if (is_error_pfn(pfn
)) {
1832 kvm_release_pfn_clean(pfn
);
1835 spin_lock(&vcpu
->kvm
->mmu_lock
);
1836 if (mmu_notifier_retry(vcpu
, mmu_seq
))
1838 kvm_mmu_free_some_pages(vcpu
);
1839 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
1840 largepage
, gfn
, pfn
);
1841 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1846 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1847 kvm_release_pfn_clean(pfn
);
1851 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
1853 mmu_free_roots(vcpu
);
1856 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
1858 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1860 context
->new_cr3
= nonpaging_new_cr3
;
1861 context
->page_fault
= nonpaging_page_fault
;
1862 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1863 context
->free
= nonpaging_free
;
1864 context
->prefetch_page
= nonpaging_prefetch_page
;
1865 context
->sync_page
= nonpaging_sync_page
;
1866 context
->invlpg
= nonpaging_invlpg
;
1867 context
->root_level
= 0;
1868 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1869 context
->root_hpa
= INVALID_PAGE
;
1873 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
1875 ++vcpu
->stat
.tlb_flush
;
1876 kvm_x86_ops
->tlb_flush(vcpu
);
1879 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
1881 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
1882 mmu_free_roots(vcpu
);
1885 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
1889 kvm_inject_page_fault(vcpu
, addr
, err_code
);
1892 static void paging_free(struct kvm_vcpu
*vcpu
)
1894 nonpaging_free(vcpu
);
1898 #include "paging_tmpl.h"
1902 #include "paging_tmpl.h"
1905 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
1907 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1909 ASSERT(is_pae(vcpu
));
1910 context
->new_cr3
= paging_new_cr3
;
1911 context
->page_fault
= paging64_page_fault
;
1912 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1913 context
->prefetch_page
= paging64_prefetch_page
;
1914 context
->sync_page
= paging64_sync_page
;
1915 context
->invlpg
= paging64_invlpg
;
1916 context
->free
= paging_free
;
1917 context
->root_level
= level
;
1918 context
->shadow_root_level
= level
;
1919 context
->root_hpa
= INVALID_PAGE
;
1923 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
1925 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
1928 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
1930 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1932 context
->new_cr3
= paging_new_cr3
;
1933 context
->page_fault
= paging32_page_fault
;
1934 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1935 context
->free
= paging_free
;
1936 context
->prefetch_page
= paging32_prefetch_page
;
1937 context
->sync_page
= paging32_sync_page
;
1938 context
->invlpg
= paging32_invlpg
;
1939 context
->root_level
= PT32_ROOT_LEVEL
;
1940 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
1941 context
->root_hpa
= INVALID_PAGE
;
1945 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
1947 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
1950 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
1952 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
1954 context
->new_cr3
= nonpaging_new_cr3
;
1955 context
->page_fault
= tdp_page_fault
;
1956 context
->free
= nonpaging_free
;
1957 context
->prefetch_page
= nonpaging_prefetch_page
;
1958 context
->sync_page
= nonpaging_sync_page
;
1959 context
->invlpg
= nonpaging_invlpg
;
1960 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
1961 context
->root_hpa
= INVALID_PAGE
;
1963 if (!is_paging(vcpu
)) {
1964 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
1965 context
->root_level
= 0;
1966 } else if (is_long_mode(vcpu
)) {
1967 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1968 context
->root_level
= PT64_ROOT_LEVEL
;
1969 } else if (is_pae(vcpu
)) {
1970 context
->gva_to_gpa
= paging64_gva_to_gpa
;
1971 context
->root_level
= PT32E_ROOT_LEVEL
;
1973 context
->gva_to_gpa
= paging32_gva_to_gpa
;
1974 context
->root_level
= PT32_ROOT_LEVEL
;
1980 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
1983 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
1985 if (!is_paging(vcpu
))
1986 return nonpaging_init_context(vcpu
);
1987 else if (is_long_mode(vcpu
))
1988 return paging64_init_context(vcpu
);
1989 else if (is_pae(vcpu
))
1990 return paging32E_init_context(vcpu
);
1992 return paging32_init_context(vcpu
);
1995 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
1997 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2000 return init_kvm_tdp_mmu(vcpu
);
2002 return init_kvm_softmmu(vcpu
);
2005 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
2008 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
2009 vcpu
->arch
.mmu
.free(vcpu
);
2010 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2014 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
2016 destroy_kvm_mmu(vcpu
);
2017 return init_kvm_mmu(vcpu
);
2019 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
2021 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
2025 r
= mmu_topup_memory_caches(vcpu
);
2028 spin_lock(&vcpu
->kvm
->mmu_lock
);
2029 kvm_mmu_free_some_pages(vcpu
);
2030 mmu_alloc_roots(vcpu
);
2031 mmu_sync_roots(vcpu
);
2032 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2033 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
2034 kvm_mmu_flush_tlb(vcpu
);
2038 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
2040 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
2042 mmu_free_roots(vcpu
);
2045 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
2046 struct kvm_mmu_page
*sp
,
2050 struct kvm_mmu_page
*child
;
2053 if (is_shadow_present_pte(pte
)) {
2054 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
||
2056 rmap_remove(vcpu
->kvm
, spte
);
2058 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2059 mmu_page_remove_parent_pte(child
, spte
);
2062 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
2063 if (is_large_pte(pte
))
2064 --vcpu
->kvm
->stat
.lpages
;
2067 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
2068 struct kvm_mmu_page
*sp
,
2072 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
2073 if (!vcpu
->arch
.update_pte
.largepage
||
2074 sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2075 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
2080 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
2081 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
2082 paging32_update_pte(vcpu
, sp
, spte
, new);
2084 paging64_update_pte(vcpu
, sp
, spte
, new);
2087 static bool need_remote_flush(u64 old
, u64
new)
2089 if (!is_shadow_present_pte(old
))
2091 if (!is_shadow_present_pte(new))
2093 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
2095 old
^= PT64_NX_MASK
;
2096 new ^= PT64_NX_MASK
;
2097 return (old
& ~new & PT64_PERM_MASK
) != 0;
2100 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
2102 if (need_remote_flush(old
, new))
2103 kvm_flush_remote_tlbs(vcpu
->kvm
);
2105 kvm_mmu_flush_tlb(vcpu
);
2108 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
2110 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2112 return !!(spte
&& (*spte
& shadow_accessed_mask
));
2115 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2116 const u8
*new, int bytes
)
2123 vcpu
->arch
.update_pte
.largepage
= 0;
2125 if (bytes
!= 4 && bytes
!= 8)
2129 * Assume that the pte write on a page table of the same type
2130 * as the current vcpu paging mode. This is nearly always true
2131 * (might be false while changing modes). Note it is verified later
2135 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2136 if ((bytes
== 4) && (gpa
% 4 == 0)) {
2137 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
2140 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
2141 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
2142 memcpy((void *)&gpte
, new, 8);
2145 if ((bytes
== 4) && (gpa
% 4 == 0))
2146 memcpy((void *)&gpte
, new, 4);
2148 if (!is_present_pte(gpte
))
2150 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
2152 if (is_large_pte(gpte
) && is_largepage_backed(vcpu
, gfn
)) {
2153 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
2154 vcpu
->arch
.update_pte
.largepage
= 1;
2156 vcpu
->arch
.update_pte
.mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2158 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2160 if (is_error_pfn(pfn
)) {
2161 kvm_release_pfn_clean(pfn
);
2164 vcpu
->arch
.update_pte
.gfn
= gfn
;
2165 vcpu
->arch
.update_pte
.pfn
= pfn
;
2168 static void kvm_mmu_access_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2170 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2173 && vcpu
->arch
.last_pte_gfn
== gfn
2174 && shadow_accessed_mask
2175 && !(*spte
& shadow_accessed_mask
)
2176 && is_shadow_present_pte(*spte
))
2177 set_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
2180 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2181 const u8
*new, int bytes
)
2183 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2184 struct kvm_mmu_page
*sp
;
2185 struct hlist_node
*node
, *n
;
2186 struct hlist_head
*bucket
;
2190 unsigned offset
= offset_in_page(gpa
);
2192 unsigned page_offset
;
2193 unsigned misaligned
;
2200 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
2201 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
2202 spin_lock(&vcpu
->kvm
->mmu_lock
);
2203 kvm_mmu_access_page(vcpu
, gfn
);
2204 kvm_mmu_free_some_pages(vcpu
);
2205 ++vcpu
->kvm
->stat
.mmu_pte_write
;
2206 kvm_mmu_audit(vcpu
, "pre pte write");
2207 if (gfn
== vcpu
->arch
.last_pt_write_gfn
2208 && !last_updated_pte_accessed(vcpu
)) {
2209 ++vcpu
->arch
.last_pt_write_count
;
2210 if (vcpu
->arch
.last_pt_write_count
>= 3)
2213 vcpu
->arch
.last_pt_write_gfn
= gfn
;
2214 vcpu
->arch
.last_pt_write_count
= 1;
2215 vcpu
->arch
.last_pte_updated
= NULL
;
2217 index
= kvm_page_table_hashfn(gfn
);
2218 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
2219 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
2220 if (sp
->gfn
!= gfn
|| sp
->role
.metaphysical
|| sp
->role
.invalid
)
2222 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
2223 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
2224 misaligned
|= bytes
< 4;
2225 if (misaligned
|| flooded
) {
2227 * Misaligned accesses are too much trouble to fix
2228 * up; also, they usually indicate a page is not used
2231 * If we're seeing too many writes to a page,
2232 * it may no longer be a page table, or we may be
2233 * forking, in which case it is better to unmap the
2236 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2237 gpa
, bytes
, sp
->role
.word
);
2238 if (kvm_mmu_zap_page(vcpu
->kvm
, sp
))
2240 ++vcpu
->kvm
->stat
.mmu_flooded
;
2243 page_offset
= offset
;
2244 level
= sp
->role
.level
;
2246 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2247 page_offset
<<= 1; /* 32->64 */
2249 * A 32-bit pde maps 4MB while the shadow pdes map
2250 * only 2MB. So we need to double the offset again
2251 * and zap two pdes instead of one.
2253 if (level
== PT32_ROOT_LEVEL
) {
2254 page_offset
&= ~7; /* kill rounding error */
2258 quadrant
= page_offset
>> PAGE_SHIFT
;
2259 page_offset
&= ~PAGE_MASK
;
2260 if (quadrant
!= sp
->role
.quadrant
)
2263 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
2264 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
2266 r
= kvm_read_guest_atomic(vcpu
->kvm
,
2267 gpa
& ~(u64
)(pte_size
- 1),
2269 new = (const void *)&gentry
;
2275 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
2277 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
2278 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
2282 kvm_mmu_audit(vcpu
, "post pte write");
2283 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2284 if (!is_error_pfn(vcpu
->arch
.update_pte
.pfn
)) {
2285 kvm_release_pfn_clean(vcpu
->arch
.update_pte
.pfn
);
2286 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2290 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
2295 gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
2297 spin_lock(&vcpu
->kvm
->mmu_lock
);
2298 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
2299 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2302 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
2304 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
2306 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
) {
2307 struct kvm_mmu_page
*sp
;
2309 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
2310 struct kvm_mmu_page
, link
);
2311 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2312 ++vcpu
->kvm
->stat
.mmu_recycled
;
2316 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
2319 enum emulation_result er
;
2321 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
2330 r
= mmu_topup_memory_caches(vcpu
);
2334 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
2339 case EMULATE_DO_MMIO
:
2340 ++vcpu
->stat
.mmio_exits
;
2343 kvm_report_emulation_failure(vcpu
, "pagetable");
2351 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
2353 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
2355 spin_lock(&vcpu
->kvm
->mmu_lock
);
2356 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
2357 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2358 kvm_mmu_flush_tlb(vcpu
);
2359 ++vcpu
->stat
.invlpg
;
2361 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
2363 void kvm_enable_tdp(void)
2367 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
2369 void kvm_disable_tdp(void)
2371 tdp_enabled
= false;
2373 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
2375 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
2377 struct kvm_mmu_page
*sp
;
2379 while (!list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
2380 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.next
,
2381 struct kvm_mmu_page
, link
);
2382 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2385 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
2388 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
2395 if (vcpu
->kvm
->arch
.n_requested_mmu_pages
)
2396 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2397 vcpu
->kvm
->arch
.n_requested_mmu_pages
;
2399 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2400 vcpu
->kvm
->arch
.n_alloc_mmu_pages
;
2402 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2403 * Therefore we need to allocate shadow page tables in the first
2404 * 4GB of memory, which happens to fit the DMA32 zone.
2406 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
2409 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
2410 for (i
= 0; i
< 4; ++i
)
2411 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2416 free_mmu_pages(vcpu
);
2420 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
2423 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2425 return alloc_mmu_pages(vcpu
);
2428 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
2431 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2433 return init_kvm_mmu(vcpu
);
2436 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
2440 destroy_kvm_mmu(vcpu
);
2441 free_mmu_pages(vcpu
);
2442 mmu_free_memory_caches(vcpu
);
2445 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
2447 struct kvm_mmu_page
*sp
;
2449 spin_lock(&kvm
->mmu_lock
);
2450 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
2454 if (!test_bit(slot
, &sp
->slot_bitmap
))
2458 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2460 if (pt
[i
] & PT_WRITABLE_MASK
)
2461 pt
[i
] &= ~PT_WRITABLE_MASK
;
2463 kvm_flush_remote_tlbs(kvm
);
2464 spin_unlock(&kvm
->mmu_lock
);
2467 void kvm_mmu_zap_all(struct kvm
*kvm
)
2469 struct kvm_mmu_page
*sp
, *node
;
2471 spin_lock(&kvm
->mmu_lock
);
2472 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
2473 if (kvm_mmu_zap_page(kvm
, sp
))
2474 node
= container_of(kvm
->arch
.active_mmu_pages
.next
,
2475 struct kvm_mmu_page
, link
);
2476 spin_unlock(&kvm
->mmu_lock
);
2478 kvm_flush_remote_tlbs(kvm
);
2481 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm
*kvm
)
2483 struct kvm_mmu_page
*page
;
2485 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2486 struct kvm_mmu_page
, link
);
2487 kvm_mmu_zap_page(kvm
, page
);
2490 static int mmu_shrink(int nr_to_scan
, gfp_t gfp_mask
)
2493 struct kvm
*kvm_freed
= NULL
;
2494 int cache_count
= 0;
2496 spin_lock(&kvm_lock
);
2498 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
2501 if (!down_read_trylock(&kvm
->slots_lock
))
2503 spin_lock(&kvm
->mmu_lock
);
2504 npages
= kvm
->arch
.n_alloc_mmu_pages
-
2505 kvm
->arch
.n_free_mmu_pages
;
2506 cache_count
+= npages
;
2507 if (!kvm_freed
&& nr_to_scan
> 0 && npages
> 0) {
2508 kvm_mmu_remove_one_alloc_mmu_page(kvm
);
2514 spin_unlock(&kvm
->mmu_lock
);
2515 up_read(&kvm
->slots_lock
);
2518 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
2520 spin_unlock(&kvm_lock
);
2525 static struct shrinker mmu_shrinker
= {
2526 .shrink
= mmu_shrink
,
2527 .seeks
= DEFAULT_SEEKS
* 10,
2530 static void mmu_destroy_caches(void)
2532 if (pte_chain_cache
)
2533 kmem_cache_destroy(pte_chain_cache
);
2534 if (rmap_desc_cache
)
2535 kmem_cache_destroy(rmap_desc_cache
);
2536 if (mmu_page_header_cache
)
2537 kmem_cache_destroy(mmu_page_header_cache
);
2540 void kvm_mmu_module_exit(void)
2542 mmu_destroy_caches();
2543 unregister_shrinker(&mmu_shrinker
);
2546 int kvm_mmu_module_init(void)
2548 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
2549 sizeof(struct kvm_pte_chain
),
2551 if (!pte_chain_cache
)
2553 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
2554 sizeof(struct kvm_rmap_desc
),
2556 if (!rmap_desc_cache
)
2559 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
2560 sizeof(struct kvm_mmu_page
),
2562 if (!mmu_page_header_cache
)
2565 register_shrinker(&mmu_shrinker
);
2570 mmu_destroy_caches();
2575 * Caculate mmu pages needed for kvm.
2577 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
2580 unsigned int nr_mmu_pages
;
2581 unsigned int nr_pages
= 0;
2583 for (i
= 0; i
< kvm
->nmemslots
; i
++)
2584 nr_pages
+= kvm
->memslots
[i
].npages
;
2586 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
2587 nr_mmu_pages
= max(nr_mmu_pages
,
2588 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
2590 return nr_mmu_pages
;
2593 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2596 if (len
> buffer
->len
)
2601 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2606 ret
= pv_mmu_peek_buffer(buffer
, len
);
2611 buffer
->processed
+= len
;
2615 static int kvm_pv_mmu_write(struct kvm_vcpu
*vcpu
,
2616 gpa_t addr
, gpa_t value
)
2621 if (!is_long_mode(vcpu
) && !is_pae(vcpu
))
2624 r
= mmu_topup_memory_caches(vcpu
);
2628 if (!emulator_write_phys(vcpu
, addr
, &value
, bytes
))
2634 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2636 kvm_x86_ops
->tlb_flush(vcpu
);
2637 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
2641 static int kvm_pv_mmu_release_pt(struct kvm_vcpu
*vcpu
, gpa_t addr
)
2643 spin_lock(&vcpu
->kvm
->mmu_lock
);
2644 mmu_unshadow(vcpu
->kvm
, addr
>> PAGE_SHIFT
);
2645 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2649 static int kvm_pv_mmu_op_one(struct kvm_vcpu
*vcpu
,
2650 struct kvm_pv_mmu_op_buffer
*buffer
)
2652 struct kvm_mmu_op_header
*header
;
2654 header
= pv_mmu_peek_buffer(buffer
, sizeof *header
);
2657 switch (header
->op
) {
2658 case KVM_MMU_OP_WRITE_PTE
: {
2659 struct kvm_mmu_op_write_pte
*wpte
;
2661 wpte
= pv_mmu_read_buffer(buffer
, sizeof *wpte
);
2664 return kvm_pv_mmu_write(vcpu
, wpte
->pte_phys
,
2667 case KVM_MMU_OP_FLUSH_TLB
: {
2668 struct kvm_mmu_op_flush_tlb
*ftlb
;
2670 ftlb
= pv_mmu_read_buffer(buffer
, sizeof *ftlb
);
2673 return kvm_pv_mmu_flush_tlb(vcpu
);
2675 case KVM_MMU_OP_RELEASE_PT
: {
2676 struct kvm_mmu_op_release_pt
*rpt
;
2678 rpt
= pv_mmu_read_buffer(buffer
, sizeof *rpt
);
2681 return kvm_pv_mmu_release_pt(vcpu
, rpt
->pt_phys
);
2687 int kvm_pv_mmu_op(struct kvm_vcpu
*vcpu
, unsigned long bytes
,
2688 gpa_t addr
, unsigned long *ret
)
2691 struct kvm_pv_mmu_op_buffer
*buffer
= &vcpu
->arch
.mmu_op_buffer
;
2693 buffer
->ptr
= buffer
->buf
;
2694 buffer
->len
= min_t(unsigned long, bytes
, sizeof buffer
->buf
);
2695 buffer
->processed
= 0;
2697 r
= kvm_read_guest(vcpu
->kvm
, addr
, buffer
->buf
, buffer
->len
);
2701 while (buffer
->len
) {
2702 r
= kvm_pv_mmu_op_one(vcpu
, buffer
);
2711 *ret
= buffer
->processed
;
2717 static const char *audit_msg
;
2719 static gva_t
canonicalize(gva_t gva
)
2721 #ifdef CONFIG_X86_64
2722 gva
= (long long)(gva
<< 16) >> 16;
2727 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
2728 gva_t va
, int level
)
2730 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
2732 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
2734 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
2737 if (ent
== shadow_trap_nonpresent_pte
)
2740 va
= canonicalize(va
);
2742 if (ent
== shadow_notrap_nonpresent_pte
)
2743 printk(KERN_ERR
"audit: (%s) nontrapping pte"
2744 " in nonleaf level: levels %d gva %lx"
2745 " level %d pte %llx\n", audit_msg
,
2746 vcpu
->arch
.mmu
.root_level
, va
, level
, ent
);
2748 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
2750 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, va
);
2751 hpa_t hpa
= (hpa_t
)gpa_to_pfn(vcpu
, gpa
) << PAGE_SHIFT
;
2753 if (is_shadow_present_pte(ent
)
2754 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
2755 printk(KERN_ERR
"xx audit error: (%s) levels %d"
2756 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2757 audit_msg
, vcpu
->arch
.mmu
.root_level
,
2759 is_shadow_present_pte(ent
));
2760 else if (ent
== shadow_notrap_nonpresent_pte
2761 && !is_error_hpa(hpa
))
2762 printk(KERN_ERR
"audit: (%s) notrap shadow,"
2763 " valid guest gva %lx\n", audit_msg
, va
);
2764 kvm_release_pfn_clean(pfn
);
2770 static void audit_mappings(struct kvm_vcpu
*vcpu
)
2774 if (vcpu
->arch
.mmu
.root_level
== 4)
2775 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
2777 for (i
= 0; i
< 4; ++i
)
2778 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
2779 audit_mappings_page(vcpu
,
2780 vcpu
->arch
.mmu
.pae_root
[i
],
2785 static int count_rmaps(struct kvm_vcpu
*vcpu
)
2790 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
2791 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
2792 struct kvm_rmap_desc
*d
;
2794 for (j
= 0; j
< m
->npages
; ++j
) {
2795 unsigned long *rmapp
= &m
->rmap
[j
];
2799 if (!(*rmapp
& 1)) {
2803 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
2805 for (k
= 0; k
< RMAP_EXT
; ++k
)
2806 if (d
->shadow_ptes
[k
])
2817 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
2820 struct kvm_mmu_page
*sp
;
2823 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2826 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2829 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
2832 if (!(ent
& PT_PRESENT_MASK
))
2834 if (!(ent
& PT_WRITABLE_MASK
))
2842 static void audit_rmap(struct kvm_vcpu
*vcpu
)
2844 int n_rmap
= count_rmaps(vcpu
);
2845 int n_actual
= count_writable_mappings(vcpu
);
2847 if (n_rmap
!= n_actual
)
2848 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
2849 __func__
, audit_msg
, n_rmap
, n_actual
);
2852 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
2854 struct kvm_mmu_page
*sp
;
2855 struct kvm_memory_slot
*slot
;
2856 unsigned long *rmapp
;
2859 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
2860 if (sp
->role
.metaphysical
)
2863 slot
= gfn_to_memslot(vcpu
->kvm
, sp
->gfn
);
2864 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
2865 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
2867 printk(KERN_ERR
"%s: (%s) shadow page has writable"
2868 " mappings: gfn %lx role %x\n",
2869 __func__
, audit_msg
, sp
->gfn
,
2874 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
2881 audit_write_protection(vcpu
);
2882 audit_mappings(vcpu
);