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.
10 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13 * Yaniv Kamay <yaniv@qumranet.com>
14 * Avi Kivity <avi@qumranet.com>
16 * This work is licensed under the terms of the GNU GPL, version 2. See
17 * the COPYING file in the top-level directory.
24 #include "kvm_cache_regs.h"
26 #include <linux/kvm_host.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
30 #include <linux/highmem.h>
31 #include <linux/module.h>
32 #include <linux/swap.h>
33 #include <linux/hugetlb.h>
34 #include <linux/compiler.h>
35 #include <linux/srcu.h>
36 #include <linux/slab.h>
37 #include <linux/uaccess.h>
40 #include <asm/cmpxchg.h>
45 * When setting this variable to true it enables Two-Dimensional-Paging
46 * where the hardware walks 2 page tables:
47 * 1. the guest-virtual to guest-physical
48 * 2. while doing 1. it walks guest-physical to host-physical
49 * If the hardware supports that we don't need to do shadow paging.
51 bool tdp_enabled
= false;
55 AUDIT_POST_PAGE_FAULT
,
66 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
67 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
71 #define pgprintk(x...) do { } while (0)
72 #define rmap_printk(x...) do { } while (0)
78 module_param(dbg
, bool, 0644);
82 #define ASSERT(x) do { } while (0)
86 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
87 __FILE__, __LINE__, #x); \
91 #define PTE_PREFETCH_NUM 8
93 #define PT_FIRST_AVAIL_BITS_SHIFT 10
94 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
96 #define PT64_LEVEL_BITS 9
98 #define PT64_LEVEL_SHIFT(level) \
99 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
101 #define PT64_INDEX(address, level)\
102 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
105 #define PT32_LEVEL_BITS 10
107 #define PT32_LEVEL_SHIFT(level) \
108 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
110 #define PT32_LVL_OFFSET_MASK(level) \
111 (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
112 * PT32_LEVEL_BITS))) - 1))
114 #define PT32_INDEX(address, level)\
115 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
118 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
119 #define PT64_DIR_BASE_ADDR_MASK \
120 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
121 #define PT64_LVL_ADDR_MASK(level) \
122 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
123 * PT64_LEVEL_BITS))) - 1))
124 #define PT64_LVL_OFFSET_MASK(level) \
125 (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
126 * PT64_LEVEL_BITS))) - 1))
128 #define PT32_BASE_ADDR_MASK PAGE_MASK
129 #define PT32_DIR_BASE_ADDR_MASK \
130 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
131 #define PT32_LVL_ADDR_MASK(level) \
132 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
133 * PT32_LEVEL_BITS))) - 1))
135 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
138 #define ACC_EXEC_MASK 1
139 #define ACC_WRITE_MASK PT_WRITABLE_MASK
140 #define ACC_USER_MASK PT_USER_MASK
141 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
143 #include <trace/events/kvm.h>
145 #define CREATE_TRACE_POINTS
146 #include "mmutrace.h"
148 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
149 #define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
151 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
153 /* make pte_list_desc fit well in cache line */
154 #define PTE_LIST_EXT 3
156 struct pte_list_desc
{
157 u64
*sptes
[PTE_LIST_EXT
];
158 struct pte_list_desc
*more
;
161 struct kvm_shadow_walk_iterator
{
169 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
170 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
171 shadow_walk_okay(&(_walker)); \
172 shadow_walk_next(&(_walker)))
174 #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \
175 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
176 shadow_walk_okay(&(_walker)) && \
177 ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \
178 __shadow_walk_next(&(_walker), spte))
180 static struct kmem_cache
*pte_list_desc_cache
;
181 static struct kmem_cache
*mmu_page_header_cache
;
182 static struct percpu_counter kvm_total_used_mmu_pages
;
184 static u64 __read_mostly shadow_nx_mask
;
185 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
186 static u64 __read_mostly shadow_user_mask
;
187 static u64 __read_mostly shadow_accessed_mask
;
188 static u64 __read_mostly shadow_dirty_mask
;
189 static u64 __read_mostly shadow_mmio_mask
;
191 static void mmu_spte_set(u64
*sptep
, u64 spte
);
192 static void mmu_free_roots(struct kvm_vcpu
*vcpu
);
194 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask
)
196 shadow_mmio_mask
= mmio_mask
;
198 EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask
);
200 static void mark_mmio_spte(u64
*sptep
, u64 gfn
, unsigned access
)
202 access
&= ACC_WRITE_MASK
| ACC_USER_MASK
;
204 trace_mark_mmio_spte(sptep
, gfn
, access
);
205 mmu_spte_set(sptep
, shadow_mmio_mask
| access
| gfn
<< PAGE_SHIFT
);
208 static bool is_mmio_spte(u64 spte
)
210 return (spte
& shadow_mmio_mask
) == shadow_mmio_mask
;
213 static gfn_t
get_mmio_spte_gfn(u64 spte
)
215 return (spte
& ~shadow_mmio_mask
) >> PAGE_SHIFT
;
218 static unsigned get_mmio_spte_access(u64 spte
)
220 return (spte
& ~shadow_mmio_mask
) & ~PAGE_MASK
;
223 static bool set_mmio_spte(u64
*sptep
, gfn_t gfn
, pfn_t pfn
, unsigned access
)
225 if (unlikely(is_noslot_pfn(pfn
))) {
226 mark_mmio_spte(sptep
, gfn
, access
);
233 static inline u64
rsvd_bits(int s
, int e
)
235 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
238 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
239 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
241 shadow_user_mask
= user_mask
;
242 shadow_accessed_mask
= accessed_mask
;
243 shadow_dirty_mask
= dirty_mask
;
244 shadow_nx_mask
= nx_mask
;
245 shadow_x_mask
= x_mask
;
247 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
249 static int is_cpuid_PSE36(void)
254 static int is_nx(struct kvm_vcpu
*vcpu
)
256 return vcpu
->arch
.efer
& EFER_NX
;
259 static int is_shadow_present_pte(u64 pte
)
261 return pte
& PT_PRESENT_MASK
&& !is_mmio_spte(pte
);
264 static int is_large_pte(u64 pte
)
266 return pte
& PT_PAGE_SIZE_MASK
;
269 static int is_dirty_gpte(unsigned long pte
)
271 return pte
& PT_DIRTY_MASK
;
274 static int is_rmap_spte(u64 pte
)
276 return is_shadow_present_pte(pte
);
279 static int is_last_spte(u64 pte
, int level
)
281 if (level
== PT_PAGE_TABLE_LEVEL
)
283 if (is_large_pte(pte
))
288 static pfn_t
spte_to_pfn(u64 pte
)
290 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
293 static gfn_t
pse36_gfn_delta(u32 gpte
)
295 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
297 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
301 static void __set_spte(u64
*sptep
, u64 spte
)
306 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
311 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
313 return xchg(sptep
, spte
);
316 static u64
__get_spte_lockless(u64
*sptep
)
318 return ACCESS_ONCE(*sptep
);
321 static bool __check_direct_spte_mmio_pf(u64 spte
)
323 /* It is valid if the spte is zapped. */
335 static void count_spte_clear(u64
*sptep
, u64 spte
)
337 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
339 if (is_shadow_present_pte(spte
))
342 /* Ensure the spte is completely set before we increase the count */
344 sp
->clear_spte_count
++;
347 static void __set_spte(u64
*sptep
, u64 spte
)
349 union split_spte
*ssptep
, sspte
;
351 ssptep
= (union split_spte
*)sptep
;
352 sspte
= (union split_spte
)spte
;
354 ssptep
->spte_high
= sspte
.spte_high
;
357 * If we map the spte from nonpresent to present, We should store
358 * the high bits firstly, then set present bit, so cpu can not
359 * fetch this spte while we are setting the spte.
363 ssptep
->spte_low
= sspte
.spte_low
;
366 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
368 union split_spte
*ssptep
, sspte
;
370 ssptep
= (union split_spte
*)sptep
;
371 sspte
= (union split_spte
)spte
;
373 ssptep
->spte_low
= sspte
.spte_low
;
376 * If we map the spte from present to nonpresent, we should clear
377 * present bit firstly to avoid vcpu fetch the old high bits.
381 ssptep
->spte_high
= sspte
.spte_high
;
382 count_spte_clear(sptep
, spte
);
385 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
387 union split_spte
*ssptep
, sspte
, orig
;
389 ssptep
= (union split_spte
*)sptep
;
390 sspte
= (union split_spte
)spte
;
392 /* xchg acts as a barrier before the setting of the high bits */
393 orig
.spte_low
= xchg(&ssptep
->spte_low
, sspte
.spte_low
);
394 orig
.spte_high
= ssptep
->spte_high
;
395 ssptep
->spte_high
= sspte
.spte_high
;
396 count_spte_clear(sptep
, spte
);
402 * The idea using the light way get the spte on x86_32 guest is from
403 * gup_get_pte(arch/x86/mm/gup.c).
404 * The difference is we can not catch the spte tlb flush if we leave
405 * guest mode, so we emulate it by increase clear_spte_count when spte
408 static u64
__get_spte_lockless(u64
*sptep
)
410 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
411 union split_spte spte
, *orig
= (union split_spte
*)sptep
;
415 count
= sp
->clear_spte_count
;
418 spte
.spte_low
= orig
->spte_low
;
421 spte
.spte_high
= orig
->spte_high
;
424 if (unlikely(spte
.spte_low
!= orig
->spte_low
||
425 count
!= sp
->clear_spte_count
))
431 static bool __check_direct_spte_mmio_pf(u64 spte
)
433 union split_spte sspte
= (union split_spte
)spte
;
434 u32 high_mmio_mask
= shadow_mmio_mask
>> 32;
436 /* It is valid if the spte is zapped. */
440 /* It is valid if the spte is being zapped. */
441 if (sspte
.spte_low
== 0ull &&
442 (sspte
.spte_high
& high_mmio_mask
) == high_mmio_mask
)
449 static bool spte_is_locklessly_modifiable(u64 spte
)
451 return !(~spte
& (SPTE_HOST_WRITEABLE
| SPTE_MMU_WRITEABLE
));
454 static bool spte_has_volatile_bits(u64 spte
)
457 * Always atomicly update spte if it can be updated
458 * out of mmu-lock, it can ensure dirty bit is not lost,
459 * also, it can help us to get a stable is_writable_pte()
460 * to ensure tlb flush is not missed.
462 if (spte_is_locklessly_modifiable(spte
))
465 if (!shadow_accessed_mask
)
468 if (!is_shadow_present_pte(spte
))
471 if ((spte
& shadow_accessed_mask
) &&
472 (!is_writable_pte(spte
) || (spte
& shadow_dirty_mask
)))
478 static bool spte_is_bit_cleared(u64 old_spte
, u64 new_spte
, u64 bit_mask
)
480 return (old_spte
& bit_mask
) && !(new_spte
& bit_mask
);
483 /* Rules for using mmu_spte_set:
484 * Set the sptep from nonpresent to present.
485 * Note: the sptep being assigned *must* be either not present
486 * or in a state where the hardware will not attempt to update
489 static void mmu_spte_set(u64
*sptep
, u64 new_spte
)
491 WARN_ON(is_shadow_present_pte(*sptep
));
492 __set_spte(sptep
, new_spte
);
495 /* Rules for using mmu_spte_update:
496 * Update the state bits, it means the mapped pfn is not changged.
498 * Whenever we overwrite a writable spte with a read-only one we
499 * should flush remote TLBs. Otherwise rmap_write_protect
500 * will find a read-only spte, even though the writable spte
501 * might be cached on a CPU's TLB, the return value indicates this
504 static bool mmu_spte_update(u64
*sptep
, u64 new_spte
)
506 u64 old_spte
= *sptep
;
509 WARN_ON(!is_rmap_spte(new_spte
));
511 if (!is_shadow_present_pte(old_spte
)) {
512 mmu_spte_set(sptep
, new_spte
);
516 if (!spte_has_volatile_bits(old_spte
))
517 __update_clear_spte_fast(sptep
, new_spte
);
519 old_spte
= __update_clear_spte_slow(sptep
, new_spte
);
522 * For the spte updated out of mmu-lock is safe, since
523 * we always atomicly update it, see the comments in
524 * spte_has_volatile_bits().
526 if (is_writable_pte(old_spte
) && !is_writable_pte(new_spte
))
529 if (!shadow_accessed_mask
)
532 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_accessed_mask
))
533 kvm_set_pfn_accessed(spte_to_pfn(old_spte
));
534 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_dirty_mask
))
535 kvm_set_pfn_dirty(spte_to_pfn(old_spte
));
541 * Rules for using mmu_spte_clear_track_bits:
542 * It sets the sptep from present to nonpresent, and track the
543 * state bits, it is used to clear the last level sptep.
545 static int mmu_spte_clear_track_bits(u64
*sptep
)
548 u64 old_spte
= *sptep
;
550 if (!spte_has_volatile_bits(old_spte
))
551 __update_clear_spte_fast(sptep
, 0ull);
553 old_spte
= __update_clear_spte_slow(sptep
, 0ull);
555 if (!is_rmap_spte(old_spte
))
558 pfn
= spte_to_pfn(old_spte
);
561 * KVM does not hold the refcount of the page used by
562 * kvm mmu, before reclaiming the page, we should
563 * unmap it from mmu first.
565 WARN_ON(!kvm_is_mmio_pfn(pfn
) && !page_count(pfn_to_page(pfn
)));
567 if (!shadow_accessed_mask
|| old_spte
& shadow_accessed_mask
)
568 kvm_set_pfn_accessed(pfn
);
569 if (!shadow_dirty_mask
|| (old_spte
& shadow_dirty_mask
))
570 kvm_set_pfn_dirty(pfn
);
575 * Rules for using mmu_spte_clear_no_track:
576 * Directly clear spte without caring the state bits of sptep,
577 * it is used to set the upper level spte.
579 static void mmu_spte_clear_no_track(u64
*sptep
)
581 __update_clear_spte_fast(sptep
, 0ull);
584 static u64
mmu_spte_get_lockless(u64
*sptep
)
586 return __get_spte_lockless(sptep
);
589 static void walk_shadow_page_lockless_begin(struct kvm_vcpu
*vcpu
)
592 * Prevent page table teardown by making any free-er wait during
593 * kvm_flush_remote_tlbs() IPI to all active vcpus.
596 vcpu
->mode
= READING_SHADOW_PAGE_TABLES
;
598 * Make sure a following spte read is not reordered ahead of the write
604 static void walk_shadow_page_lockless_end(struct kvm_vcpu
*vcpu
)
607 * Make sure the write to vcpu->mode is not reordered in front of
608 * reads to sptes. If it does, kvm_commit_zap_page() can see us
609 * OUTSIDE_GUEST_MODE and proceed to free the shadow page table.
612 vcpu
->mode
= OUTSIDE_GUEST_MODE
;
616 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
617 struct kmem_cache
*base_cache
, int min
)
621 if (cache
->nobjs
>= min
)
623 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
624 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
627 cache
->objects
[cache
->nobjs
++] = obj
;
632 static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache
*cache
)
637 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
,
638 struct kmem_cache
*cache
)
641 kmem_cache_free(cache
, mc
->objects
[--mc
->nobjs
]);
644 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
649 if (cache
->nobjs
>= min
)
651 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
652 page
= (void *)__get_free_page(GFP_KERNEL
);
655 cache
->objects
[cache
->nobjs
++] = page
;
660 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
663 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
666 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
670 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
671 pte_list_desc_cache
, 8 + PTE_PREFETCH_NUM
);
674 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
677 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
678 mmu_page_header_cache
, 4);
683 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
685 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
686 pte_list_desc_cache
);
687 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
688 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
689 mmu_page_header_cache
);
692 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
)
697 p
= mc
->objects
[--mc
->nobjs
];
701 static struct pte_list_desc
*mmu_alloc_pte_list_desc(struct kvm_vcpu
*vcpu
)
703 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_list_desc_cache
);
706 static void mmu_free_pte_list_desc(struct pte_list_desc
*pte_list_desc
)
708 kmem_cache_free(pte_list_desc_cache
, pte_list_desc
);
711 static gfn_t
kvm_mmu_page_get_gfn(struct kvm_mmu_page
*sp
, int index
)
713 if (!sp
->role
.direct
)
714 return sp
->gfns
[index
];
716 return sp
->gfn
+ (index
<< ((sp
->role
.level
- 1) * PT64_LEVEL_BITS
));
719 static void kvm_mmu_page_set_gfn(struct kvm_mmu_page
*sp
, int index
, gfn_t gfn
)
722 BUG_ON(gfn
!= kvm_mmu_page_get_gfn(sp
, index
));
724 sp
->gfns
[index
] = gfn
;
728 * Return the pointer to the large page information for a given gfn,
729 * handling slots that are not large page aligned.
731 static struct kvm_lpage_info
*lpage_info_slot(gfn_t gfn
,
732 struct kvm_memory_slot
*slot
,
737 idx
= gfn_to_index(gfn
, slot
->base_gfn
, level
);
738 return &slot
->arch
.lpage_info
[level
- 2][idx
];
741 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
743 struct kvm_memory_slot
*slot
;
744 struct kvm_lpage_info
*linfo
;
747 slot
= gfn_to_memslot(kvm
, gfn
);
748 for (i
= PT_DIRECTORY_LEVEL
;
749 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
750 linfo
= lpage_info_slot(gfn
, slot
, i
);
751 linfo
->write_count
+= 1;
753 kvm
->arch
.indirect_shadow_pages
++;
756 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
758 struct kvm_memory_slot
*slot
;
759 struct kvm_lpage_info
*linfo
;
762 slot
= gfn_to_memslot(kvm
, gfn
);
763 for (i
= PT_DIRECTORY_LEVEL
;
764 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
765 linfo
= lpage_info_slot(gfn
, slot
, i
);
766 linfo
->write_count
-= 1;
767 WARN_ON(linfo
->write_count
< 0);
769 kvm
->arch
.indirect_shadow_pages
--;
772 static int has_wrprotected_page(struct kvm
*kvm
,
776 struct kvm_memory_slot
*slot
;
777 struct kvm_lpage_info
*linfo
;
779 slot
= gfn_to_memslot(kvm
, gfn
);
781 linfo
= lpage_info_slot(gfn
, slot
, level
);
782 return linfo
->write_count
;
788 static int host_mapping_level(struct kvm
*kvm
, gfn_t gfn
)
790 unsigned long page_size
;
793 page_size
= kvm_host_page_size(kvm
, gfn
);
795 for (i
= PT_PAGE_TABLE_LEVEL
;
796 i
< (PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
); ++i
) {
797 if (page_size
>= KVM_HPAGE_SIZE(i
))
806 static struct kvm_memory_slot
*
807 gfn_to_memslot_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
810 struct kvm_memory_slot
*slot
;
812 slot
= gfn_to_memslot(vcpu
->kvm
, gfn
);
813 if (!slot
|| slot
->flags
& KVM_MEMSLOT_INVALID
||
814 (no_dirty_log
&& slot
->dirty_bitmap
))
820 static bool mapping_level_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
822 return !gfn_to_memslot_dirty_bitmap(vcpu
, large_gfn
, true);
825 static int mapping_level(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
827 int host_level
, level
, max_level
;
829 host_level
= host_mapping_level(vcpu
->kvm
, large_gfn
);
831 if (host_level
== PT_PAGE_TABLE_LEVEL
)
834 max_level
= kvm_x86_ops
->get_lpage_level() < host_level
?
835 kvm_x86_ops
->get_lpage_level() : host_level
;
837 for (level
= PT_DIRECTORY_LEVEL
; level
<= max_level
; ++level
)
838 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
, level
))
845 * Pte mapping structures:
847 * If pte_list bit zero is zero, then pte_list point to the spte.
849 * If pte_list bit zero is one, (then pte_list & ~1) points to a struct
850 * pte_list_desc containing more mappings.
852 * Returns the number of pte entries before the spte was added or zero if
853 * the spte was not added.
856 static int pte_list_add(struct kvm_vcpu
*vcpu
, u64
*spte
,
857 unsigned long *pte_list
)
859 struct pte_list_desc
*desc
;
863 rmap_printk("pte_list_add: %p %llx 0->1\n", spte
, *spte
);
864 *pte_list
= (unsigned long)spte
;
865 } else if (!(*pte_list
& 1)) {
866 rmap_printk("pte_list_add: %p %llx 1->many\n", spte
, *spte
);
867 desc
= mmu_alloc_pte_list_desc(vcpu
);
868 desc
->sptes
[0] = (u64
*)*pte_list
;
869 desc
->sptes
[1] = spte
;
870 *pte_list
= (unsigned long)desc
| 1;
873 rmap_printk("pte_list_add: %p %llx many->many\n", spte
, *spte
);
874 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
875 while (desc
->sptes
[PTE_LIST_EXT
-1] && desc
->more
) {
877 count
+= PTE_LIST_EXT
;
879 if (desc
->sptes
[PTE_LIST_EXT
-1]) {
880 desc
->more
= mmu_alloc_pte_list_desc(vcpu
);
883 for (i
= 0; desc
->sptes
[i
]; ++i
)
885 desc
->sptes
[i
] = spte
;
891 pte_list_desc_remove_entry(unsigned long *pte_list
, struct pte_list_desc
*desc
,
892 int i
, struct pte_list_desc
*prev_desc
)
896 for (j
= PTE_LIST_EXT
- 1; !desc
->sptes
[j
] && j
> i
; --j
)
898 desc
->sptes
[i
] = desc
->sptes
[j
];
899 desc
->sptes
[j
] = NULL
;
902 if (!prev_desc
&& !desc
->more
)
903 *pte_list
= (unsigned long)desc
->sptes
[0];
906 prev_desc
->more
= desc
->more
;
908 *pte_list
= (unsigned long)desc
->more
| 1;
909 mmu_free_pte_list_desc(desc
);
912 static void pte_list_remove(u64
*spte
, unsigned long *pte_list
)
914 struct pte_list_desc
*desc
;
915 struct pte_list_desc
*prev_desc
;
919 printk(KERN_ERR
"pte_list_remove: %p 0->BUG\n", spte
);
921 } else if (!(*pte_list
& 1)) {
922 rmap_printk("pte_list_remove: %p 1->0\n", spte
);
923 if ((u64
*)*pte_list
!= spte
) {
924 printk(KERN_ERR
"pte_list_remove: %p 1->BUG\n", spte
);
929 rmap_printk("pte_list_remove: %p many->many\n", spte
);
930 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
933 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
934 if (desc
->sptes
[i
] == spte
) {
935 pte_list_desc_remove_entry(pte_list
,
943 pr_err("pte_list_remove: %p many->many\n", spte
);
948 typedef void (*pte_list_walk_fn
) (u64
*spte
);
949 static void pte_list_walk(unsigned long *pte_list
, pte_list_walk_fn fn
)
951 struct pte_list_desc
*desc
;
957 if (!(*pte_list
& 1))
958 return fn((u64
*)*pte_list
);
960 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
962 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
968 static unsigned long *__gfn_to_rmap(gfn_t gfn
, int level
,
969 struct kvm_memory_slot
*slot
)
973 idx
= gfn_to_index(gfn
, slot
->base_gfn
, level
);
974 return &slot
->arch
.rmap
[level
- PT_PAGE_TABLE_LEVEL
][idx
];
978 * Take gfn and return the reverse mapping to it.
980 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int level
)
982 struct kvm_memory_slot
*slot
;
984 slot
= gfn_to_memslot(kvm
, gfn
);
985 return __gfn_to_rmap(gfn
, level
, slot
);
988 static bool rmap_can_add(struct kvm_vcpu
*vcpu
)
990 struct kvm_mmu_memory_cache
*cache
;
992 cache
= &vcpu
->arch
.mmu_pte_list_desc_cache
;
993 return mmu_memory_cache_free_objects(cache
);
996 static int rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
998 struct kvm_mmu_page
*sp
;
999 unsigned long *rmapp
;
1001 sp
= page_header(__pa(spte
));
1002 kvm_mmu_page_set_gfn(sp
, spte
- sp
->spt
, gfn
);
1003 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
1004 return pte_list_add(vcpu
, spte
, rmapp
);
1007 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
1009 struct kvm_mmu_page
*sp
;
1011 unsigned long *rmapp
;
1013 sp
= page_header(__pa(spte
));
1014 gfn
= kvm_mmu_page_get_gfn(sp
, spte
- sp
->spt
);
1015 rmapp
= gfn_to_rmap(kvm
, gfn
, sp
->role
.level
);
1016 pte_list_remove(spte
, rmapp
);
1020 * Used by the following functions to iterate through the sptes linked by a
1021 * rmap. All fields are private and not assumed to be used outside.
1023 struct rmap_iterator
{
1024 /* private fields */
1025 struct pte_list_desc
*desc
; /* holds the sptep if not NULL */
1026 int pos
; /* index of the sptep */
1030 * Iteration must be started by this function. This should also be used after
1031 * removing/dropping sptes from the rmap link because in such cases the
1032 * information in the itererator may not be valid.
1034 * Returns sptep if found, NULL otherwise.
1036 static u64
*rmap_get_first(unsigned long rmap
, struct rmap_iterator
*iter
)
1046 iter
->desc
= (struct pte_list_desc
*)(rmap
& ~1ul);
1048 return iter
->desc
->sptes
[iter
->pos
];
1052 * Must be used with a valid iterator: e.g. after rmap_get_first().
1054 * Returns sptep if found, NULL otherwise.
1056 static u64
*rmap_get_next(struct rmap_iterator
*iter
)
1059 if (iter
->pos
< PTE_LIST_EXT
- 1) {
1063 sptep
= iter
->desc
->sptes
[iter
->pos
];
1068 iter
->desc
= iter
->desc
->more
;
1072 /* desc->sptes[0] cannot be NULL */
1073 return iter
->desc
->sptes
[iter
->pos
];
1080 static void drop_spte(struct kvm
*kvm
, u64
*sptep
)
1082 if (mmu_spte_clear_track_bits(sptep
))
1083 rmap_remove(kvm
, sptep
);
1087 static bool __drop_large_spte(struct kvm
*kvm
, u64
*sptep
)
1089 if (is_large_pte(*sptep
)) {
1090 WARN_ON(page_header(__pa(sptep
))->role
.level
==
1091 PT_PAGE_TABLE_LEVEL
);
1092 drop_spte(kvm
, sptep
);
1100 static void drop_large_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
)
1102 if (__drop_large_spte(vcpu
->kvm
, sptep
))
1103 kvm_flush_remote_tlbs(vcpu
->kvm
);
1107 * Write-protect on the specified @sptep, @pt_protect indicates whether
1108 * spte writ-protection is caused by protecting shadow page table.
1109 * @flush indicates whether tlb need be flushed.
1111 * Note: write protection is difference between drity logging and spte
1113 * - for dirty logging, the spte can be set to writable at anytime if
1114 * its dirty bitmap is properly set.
1115 * - for spte protection, the spte can be writable only after unsync-ing
1118 * Return true if the spte is dropped.
1121 spte_write_protect(struct kvm
*kvm
, u64
*sptep
, bool *flush
, bool pt_protect
)
1125 if (!is_writable_pte(spte
) &&
1126 !(pt_protect
&& spte_is_locklessly_modifiable(spte
)))
1129 rmap_printk("rmap_write_protect: spte %p %llx\n", sptep
, *sptep
);
1131 if (__drop_large_spte(kvm
, sptep
)) {
1137 spte
&= ~SPTE_MMU_WRITEABLE
;
1138 spte
= spte
& ~PT_WRITABLE_MASK
;
1140 *flush
|= mmu_spte_update(sptep
, spte
);
1144 static bool __rmap_write_protect(struct kvm
*kvm
, unsigned long *rmapp
,
1148 struct rmap_iterator iter
;
1151 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;) {
1152 BUG_ON(!(*sptep
& PT_PRESENT_MASK
));
1153 if (spte_write_protect(kvm
, sptep
, &flush
, pt_protect
)) {
1154 sptep
= rmap_get_first(*rmapp
, &iter
);
1158 sptep
= rmap_get_next(&iter
);
1165 * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages
1166 * @kvm: kvm instance
1167 * @slot: slot to protect
1168 * @gfn_offset: start of the BITS_PER_LONG pages we care about
1169 * @mask: indicates which pages we should protect
1171 * Used when we do not need to care about huge page mappings: e.g. during dirty
1172 * logging we do not have any such mappings.
1174 void kvm_mmu_write_protect_pt_masked(struct kvm
*kvm
,
1175 struct kvm_memory_slot
*slot
,
1176 gfn_t gfn_offset
, unsigned long mask
)
1178 unsigned long *rmapp
;
1181 rmapp
= __gfn_to_rmap(slot
->base_gfn
+ gfn_offset
+ __ffs(mask
),
1182 PT_PAGE_TABLE_LEVEL
, slot
);
1183 __rmap_write_protect(kvm
, rmapp
, false);
1185 /* clear the first set bit */
1190 static bool rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
1192 struct kvm_memory_slot
*slot
;
1193 unsigned long *rmapp
;
1195 bool write_protected
= false;
1197 slot
= gfn_to_memslot(kvm
, gfn
);
1199 for (i
= PT_PAGE_TABLE_LEVEL
;
1200 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
1201 rmapp
= __gfn_to_rmap(gfn
, i
, slot
);
1202 write_protected
|= __rmap_write_protect(kvm
, rmapp
, true);
1205 return write_protected
;
1208 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1209 struct kvm_memory_slot
*slot
, unsigned long data
)
1212 struct rmap_iterator iter
;
1213 int need_tlb_flush
= 0;
1215 while ((sptep
= rmap_get_first(*rmapp
, &iter
))) {
1216 BUG_ON(!(*sptep
& PT_PRESENT_MASK
));
1217 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", sptep
, *sptep
);
1219 drop_spte(kvm
, sptep
);
1223 return need_tlb_flush
;
1226 static int kvm_set_pte_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1227 struct kvm_memory_slot
*slot
, unsigned long data
)
1230 struct rmap_iterator iter
;
1233 pte_t
*ptep
= (pte_t
*)data
;
1236 WARN_ON(pte_huge(*ptep
));
1237 new_pfn
= pte_pfn(*ptep
);
1239 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;) {
1240 BUG_ON(!is_shadow_present_pte(*sptep
));
1241 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", sptep
, *sptep
);
1245 if (pte_write(*ptep
)) {
1246 drop_spte(kvm
, sptep
);
1247 sptep
= rmap_get_first(*rmapp
, &iter
);
1249 new_spte
= *sptep
& ~PT64_BASE_ADDR_MASK
;
1250 new_spte
|= (u64
)new_pfn
<< PAGE_SHIFT
;
1252 new_spte
&= ~PT_WRITABLE_MASK
;
1253 new_spte
&= ~SPTE_HOST_WRITEABLE
;
1254 new_spte
&= ~shadow_accessed_mask
;
1256 mmu_spte_clear_track_bits(sptep
);
1257 mmu_spte_set(sptep
, new_spte
);
1258 sptep
= rmap_get_next(&iter
);
1263 kvm_flush_remote_tlbs(kvm
);
1268 static int kvm_handle_hva_range(struct kvm
*kvm
,
1269 unsigned long start
,
1272 int (*handler
)(struct kvm
*kvm
,
1273 unsigned long *rmapp
,
1274 struct kvm_memory_slot
*slot
,
1275 unsigned long data
))
1279 struct kvm_memslots
*slots
;
1280 struct kvm_memory_slot
*memslot
;
1282 slots
= kvm_memslots(kvm
);
1284 kvm_for_each_memslot(memslot
, slots
) {
1285 unsigned long hva_start
, hva_end
;
1286 gfn_t gfn_start
, gfn_end
;
1288 hva_start
= max(start
, memslot
->userspace_addr
);
1289 hva_end
= min(end
, memslot
->userspace_addr
+
1290 (memslot
->npages
<< PAGE_SHIFT
));
1291 if (hva_start
>= hva_end
)
1294 * {gfn(page) | page intersects with [hva_start, hva_end)} =
1295 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1297 gfn_start
= hva_to_gfn_memslot(hva_start
, memslot
);
1298 gfn_end
= hva_to_gfn_memslot(hva_end
+ PAGE_SIZE
- 1, memslot
);
1300 for (j
= PT_PAGE_TABLE_LEVEL
;
1301 j
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++j
) {
1302 unsigned long idx
, idx_end
;
1303 unsigned long *rmapp
;
1306 * {idx(page_j) | page_j intersects with
1307 * [hva_start, hva_end)} = {idx, idx+1, ..., idx_end}.
1309 idx
= gfn_to_index(gfn_start
, memslot
->base_gfn
, j
);
1310 idx_end
= gfn_to_index(gfn_end
- 1, memslot
->base_gfn
, j
);
1312 rmapp
= __gfn_to_rmap(gfn_start
, j
, memslot
);
1314 for (; idx
<= idx_end
; ++idx
)
1315 ret
|= handler(kvm
, rmapp
++, memslot
, data
);
1322 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
1324 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
,
1325 struct kvm_memory_slot
*slot
,
1326 unsigned long data
))
1328 return kvm_handle_hva_range(kvm
, hva
, hva
+ 1, data
, handler
);
1331 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
1333 return kvm_handle_hva(kvm
, hva
, 0, kvm_unmap_rmapp
);
1336 int kvm_unmap_hva_range(struct kvm
*kvm
, unsigned long start
, unsigned long end
)
1338 return kvm_handle_hva_range(kvm
, start
, end
, 0, kvm_unmap_rmapp
);
1341 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
1343 kvm_handle_hva(kvm
, hva
, (unsigned long)&pte
, kvm_set_pte_rmapp
);
1346 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1347 struct kvm_memory_slot
*slot
, unsigned long data
)
1350 struct rmap_iterator
uninitialized_var(iter
);
1354 * In case of absence of EPT Access and Dirty Bits supports,
1355 * emulate the accessed bit for EPT, by checking if this page has
1356 * an EPT mapping, and clearing it if it does. On the next access,
1357 * a new EPT mapping will be established.
1358 * This has some overhead, but not as much as the cost of swapping
1359 * out actively used pages or breaking up actively used hugepages.
1361 if (!shadow_accessed_mask
) {
1362 young
= kvm_unmap_rmapp(kvm
, rmapp
, slot
, data
);
1366 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;
1367 sptep
= rmap_get_next(&iter
)) {
1368 BUG_ON(!is_shadow_present_pte(*sptep
));
1370 if (*sptep
& shadow_accessed_mask
) {
1372 clear_bit((ffs(shadow_accessed_mask
) - 1),
1373 (unsigned long *)sptep
);
1377 /* @data has hva passed to kvm_age_hva(). */
1378 trace_kvm_age_page(data
, slot
, young
);
1382 static int kvm_test_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1383 struct kvm_memory_slot
*slot
, unsigned long data
)
1386 struct rmap_iterator iter
;
1390 * If there's no access bit in the secondary pte set by the
1391 * hardware it's up to gup-fast/gup to set the access bit in
1392 * the primary pte or in the page structure.
1394 if (!shadow_accessed_mask
)
1397 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;
1398 sptep
= rmap_get_next(&iter
)) {
1399 BUG_ON(!is_shadow_present_pte(*sptep
));
1401 if (*sptep
& shadow_accessed_mask
) {
1410 #define RMAP_RECYCLE_THRESHOLD 1000
1412 static void rmap_recycle(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
1414 unsigned long *rmapp
;
1415 struct kvm_mmu_page
*sp
;
1417 sp
= page_header(__pa(spte
));
1419 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
1421 kvm_unmap_rmapp(vcpu
->kvm
, rmapp
, NULL
, 0);
1422 kvm_flush_remote_tlbs(vcpu
->kvm
);
1425 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
1427 return kvm_handle_hva(kvm
, hva
, hva
, kvm_age_rmapp
);
1430 int kvm_test_age_hva(struct kvm
*kvm
, unsigned long hva
)
1432 return kvm_handle_hva(kvm
, hva
, 0, kvm_test_age_rmapp
);
1436 static int is_empty_shadow_page(u64
*spt
)
1441 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
1442 if (is_shadow_present_pte(*pos
)) {
1443 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
1452 * This value is the sum of all of the kvm instances's
1453 * kvm->arch.n_used_mmu_pages values. We need a global,
1454 * aggregate version in order to make the slab shrinker
1457 static inline void kvm_mod_used_mmu_pages(struct kvm
*kvm
, int nr
)
1459 kvm
->arch
.n_used_mmu_pages
+= nr
;
1460 percpu_counter_add(&kvm_total_used_mmu_pages
, nr
);
1464 * Remove the sp from shadow page cache, after call it,
1465 * we can not find this sp from the cache, and the shadow
1466 * page table is still valid.
1467 * It should be under the protection of mmu lock.
1469 static void kvm_mmu_isolate_page(struct kvm_mmu_page
*sp
)
1471 ASSERT(is_empty_shadow_page(sp
->spt
));
1472 hlist_del(&sp
->hash_link
);
1473 if (!sp
->role
.direct
)
1474 free_page((unsigned long)sp
->gfns
);
1478 * Free the shadow page table and the sp, we can do it
1479 * out of the protection of mmu lock.
1481 static void kvm_mmu_free_page(struct kvm_mmu_page
*sp
)
1483 list_del(&sp
->link
);
1484 free_page((unsigned long)sp
->spt
);
1485 kmem_cache_free(mmu_page_header_cache
, sp
);
1488 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
1490 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
1493 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
1494 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1499 pte_list_add(vcpu
, parent_pte
, &sp
->parent_ptes
);
1502 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
1505 pte_list_remove(parent_pte
, &sp
->parent_ptes
);
1508 static void drop_parent_pte(struct kvm_mmu_page
*sp
,
1511 mmu_page_remove_parent_pte(sp
, parent_pte
);
1512 mmu_spte_clear_no_track(parent_pte
);
1515 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
1516 u64
*parent_pte
, int direct
)
1518 struct kvm_mmu_page
*sp
;
1519 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
);
1520 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
);
1522 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
);
1523 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
1524 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
1525 sp
->parent_ptes
= 0;
1526 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1527 kvm_mod_used_mmu_pages(vcpu
->kvm
, +1);
1531 static void mark_unsync(u64
*spte
);
1532 static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page
*sp
)
1534 pte_list_walk(&sp
->parent_ptes
, mark_unsync
);
1537 static void mark_unsync(u64
*spte
)
1539 struct kvm_mmu_page
*sp
;
1542 sp
= page_header(__pa(spte
));
1543 index
= spte
- sp
->spt
;
1544 if (__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
1546 if (sp
->unsync_children
++)
1548 kvm_mmu_mark_parents_unsync(sp
);
1551 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
1552 struct kvm_mmu_page
*sp
)
1557 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
1561 static void nonpaging_update_pte(struct kvm_vcpu
*vcpu
,
1562 struct kvm_mmu_page
*sp
, u64
*spte
,
1568 #define KVM_PAGE_ARRAY_NR 16
1570 struct kvm_mmu_pages
{
1571 struct mmu_page_and_offset
{
1572 struct kvm_mmu_page
*sp
;
1574 } page
[KVM_PAGE_ARRAY_NR
];
1578 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
1584 for (i
=0; i
< pvec
->nr
; i
++)
1585 if (pvec
->page
[i
].sp
== sp
)
1588 pvec
->page
[pvec
->nr
].sp
= sp
;
1589 pvec
->page
[pvec
->nr
].idx
= idx
;
1591 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1594 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1595 struct kvm_mmu_pages
*pvec
)
1597 int i
, ret
, nr_unsync_leaf
= 0;
1599 for_each_set_bit(i
, sp
->unsync_child_bitmap
, 512) {
1600 struct kvm_mmu_page
*child
;
1601 u64 ent
= sp
->spt
[i
];
1603 if (!is_shadow_present_pte(ent
) || is_large_pte(ent
))
1604 goto clear_child_bitmap
;
1606 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1608 if (child
->unsync_children
) {
1609 if (mmu_pages_add(pvec
, child
, i
))
1612 ret
= __mmu_unsync_walk(child
, pvec
);
1614 goto clear_child_bitmap
;
1616 nr_unsync_leaf
+= ret
;
1619 } else if (child
->unsync
) {
1621 if (mmu_pages_add(pvec
, child
, i
))
1624 goto clear_child_bitmap
;
1629 __clear_bit(i
, sp
->unsync_child_bitmap
);
1630 sp
->unsync_children
--;
1631 WARN_ON((int)sp
->unsync_children
< 0);
1635 return nr_unsync_leaf
;
1638 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1639 struct kvm_mmu_pages
*pvec
)
1641 if (!sp
->unsync_children
)
1644 mmu_pages_add(pvec
, sp
, 0);
1645 return __mmu_unsync_walk(sp
, pvec
);
1648 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1650 WARN_ON(!sp
->unsync
);
1651 trace_kvm_mmu_sync_page(sp
);
1653 --kvm
->stat
.mmu_unsync
;
1656 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1657 struct list_head
*invalid_list
);
1658 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
1659 struct list_head
*invalid_list
);
1661 #define for_each_gfn_sp(kvm, sp, gfn, pos) \
1662 hlist_for_each_entry(sp, pos, \
1663 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1664 if ((sp)->gfn != (gfn)) {} else
1666 #define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos) \
1667 hlist_for_each_entry(sp, pos, \
1668 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1669 if ((sp)->gfn != (gfn) || (sp)->role.direct || \
1670 (sp)->role.invalid) {} else
1672 /* @sp->gfn should be write-protected at the call site */
1673 static int __kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1674 struct list_head
*invalid_list
, bool clear_unsync
)
1676 if (sp
->role
.cr4_pae
!= !!is_pae(vcpu
)) {
1677 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1682 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1684 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1685 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1689 kvm_mmu_flush_tlb(vcpu
);
1693 static int kvm_sync_page_transient(struct kvm_vcpu
*vcpu
,
1694 struct kvm_mmu_page
*sp
)
1696 LIST_HEAD(invalid_list
);
1699 ret
= __kvm_sync_page(vcpu
, sp
, &invalid_list
, false);
1701 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1706 #ifdef CONFIG_KVM_MMU_AUDIT
1707 #include "mmu_audit.c"
1709 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, int point
) { }
1710 static void mmu_audit_disable(void) { }
1713 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1714 struct list_head
*invalid_list
)
1716 return __kvm_sync_page(vcpu
, sp
, invalid_list
, true);
1719 /* @gfn should be write-protected at the call site */
1720 static void kvm_sync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1722 struct kvm_mmu_page
*s
;
1723 struct hlist_node
*node
;
1724 LIST_HEAD(invalid_list
);
1727 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
1731 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
1732 kvm_unlink_unsync_page(vcpu
->kvm
, s
);
1733 if ((s
->role
.cr4_pae
!= !!is_pae(vcpu
)) ||
1734 (vcpu
->arch
.mmu
.sync_page(vcpu
, s
))) {
1735 kvm_mmu_prepare_zap_page(vcpu
->kvm
, s
, &invalid_list
);
1741 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1743 kvm_mmu_flush_tlb(vcpu
);
1746 struct mmu_page_path
{
1747 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1748 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1751 #define for_each_sp(pvec, sp, parents, i) \
1752 for (i = mmu_pages_next(&pvec, &parents, -1), \
1753 sp = pvec.page[i].sp; \
1754 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1755 i = mmu_pages_next(&pvec, &parents, i))
1757 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1758 struct mmu_page_path
*parents
,
1763 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1764 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1766 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1767 parents
->idx
[0] = pvec
->page
[n
].idx
;
1771 parents
->parent
[sp
->role
.level
-2] = sp
;
1772 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1778 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1780 struct kvm_mmu_page
*sp
;
1781 unsigned int level
= 0;
1784 unsigned int idx
= parents
->idx
[level
];
1786 sp
= parents
->parent
[level
];
1790 --sp
->unsync_children
;
1791 WARN_ON((int)sp
->unsync_children
< 0);
1792 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1794 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1797 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1798 struct mmu_page_path
*parents
,
1799 struct kvm_mmu_pages
*pvec
)
1801 parents
->parent
[parent
->role
.level
-1] = NULL
;
1805 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1806 struct kvm_mmu_page
*parent
)
1809 struct kvm_mmu_page
*sp
;
1810 struct mmu_page_path parents
;
1811 struct kvm_mmu_pages pages
;
1812 LIST_HEAD(invalid_list
);
1814 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1815 while (mmu_unsync_walk(parent
, &pages
)) {
1816 bool protected = false;
1818 for_each_sp(pages
, sp
, parents
, i
)
1819 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1822 kvm_flush_remote_tlbs(vcpu
->kvm
);
1824 for_each_sp(pages
, sp
, parents
, i
) {
1825 kvm_sync_page(vcpu
, sp
, &invalid_list
);
1826 mmu_pages_clear_parents(&parents
);
1828 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1829 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1830 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1834 static void init_shadow_page_table(struct kvm_mmu_page
*sp
)
1838 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1842 static void __clear_sp_write_flooding_count(struct kvm_mmu_page
*sp
)
1844 sp
->write_flooding_count
= 0;
1847 static void clear_sp_write_flooding_count(u64
*spte
)
1849 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
1851 __clear_sp_write_flooding_count(sp
);
1854 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1862 union kvm_mmu_page_role role
;
1864 struct kvm_mmu_page
*sp
;
1865 struct hlist_node
*node
;
1866 bool need_sync
= false;
1868 role
= vcpu
->arch
.mmu
.base_role
;
1870 role
.direct
= direct
;
1873 role
.access
= access
;
1874 if (!vcpu
->arch
.mmu
.direct_map
1875 && vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1876 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1877 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1878 role
.quadrant
= quadrant
;
1880 for_each_gfn_sp(vcpu
->kvm
, sp
, gfn
, node
) {
1881 if (!need_sync
&& sp
->unsync
)
1884 if (sp
->role
.word
!= role
.word
)
1887 if (sp
->unsync
&& kvm_sync_page_transient(vcpu
, sp
))
1890 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1891 if (sp
->unsync_children
) {
1892 kvm_make_request(KVM_REQ_MMU_SYNC
, vcpu
);
1893 kvm_mmu_mark_parents_unsync(sp
);
1894 } else if (sp
->unsync
)
1895 kvm_mmu_mark_parents_unsync(sp
);
1897 __clear_sp_write_flooding_count(sp
);
1898 trace_kvm_mmu_get_page(sp
, false);
1901 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1902 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
, direct
);
1907 hlist_add_head(&sp
->hash_link
,
1908 &vcpu
->kvm
->arch
.mmu_page_hash
[kvm_page_table_hashfn(gfn
)]);
1910 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1911 kvm_flush_remote_tlbs(vcpu
->kvm
);
1912 if (level
> PT_PAGE_TABLE_LEVEL
&& need_sync
)
1913 kvm_sync_pages(vcpu
, gfn
);
1915 account_shadowed(vcpu
->kvm
, gfn
);
1917 init_shadow_page_table(sp
);
1918 trace_kvm_mmu_get_page(sp
, true);
1922 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1923 struct kvm_vcpu
*vcpu
, u64 addr
)
1925 iterator
->addr
= addr
;
1926 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1927 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1929 if (iterator
->level
== PT64_ROOT_LEVEL
&&
1930 vcpu
->arch
.mmu
.root_level
< PT64_ROOT_LEVEL
&&
1931 !vcpu
->arch
.mmu
.direct_map
)
1934 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1935 iterator
->shadow_addr
1936 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1937 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1939 if (!iterator
->shadow_addr
)
1940 iterator
->level
= 0;
1944 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1946 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1949 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1950 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1954 static void __shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
,
1957 if (is_last_spte(spte
, iterator
->level
)) {
1958 iterator
->level
= 0;
1962 iterator
->shadow_addr
= spte
& PT64_BASE_ADDR_MASK
;
1966 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1968 return __shadow_walk_next(iterator
, *iterator
->sptep
);
1971 static void link_shadow_page(u64
*sptep
, struct kvm_mmu_page
*sp
)
1975 spte
= __pa(sp
->spt
)
1976 | PT_PRESENT_MASK
| PT_ACCESSED_MASK
1977 | PT_WRITABLE_MASK
| PT_USER_MASK
;
1978 mmu_spte_set(sptep
, spte
);
1981 static void validate_direct_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1982 unsigned direct_access
)
1984 if (is_shadow_present_pte(*sptep
) && !is_large_pte(*sptep
)) {
1985 struct kvm_mmu_page
*child
;
1988 * For the direct sp, if the guest pte's dirty bit
1989 * changed form clean to dirty, it will corrupt the
1990 * sp's access: allow writable in the read-only sp,
1991 * so we should update the spte at this point to get
1992 * a new sp with the correct access.
1994 child
= page_header(*sptep
& PT64_BASE_ADDR_MASK
);
1995 if (child
->role
.access
== direct_access
)
1998 drop_parent_pte(child
, sptep
);
1999 kvm_flush_remote_tlbs(vcpu
->kvm
);
2003 static bool mmu_page_zap_pte(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
2007 struct kvm_mmu_page
*child
;
2010 if (is_shadow_present_pte(pte
)) {
2011 if (is_last_spte(pte
, sp
->role
.level
)) {
2012 drop_spte(kvm
, spte
);
2013 if (is_large_pte(pte
))
2016 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2017 drop_parent_pte(child
, spte
);
2022 if (is_mmio_spte(pte
))
2023 mmu_spte_clear_no_track(spte
);
2028 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
2029 struct kvm_mmu_page
*sp
)
2033 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2034 mmu_page_zap_pte(kvm
, sp
, sp
->spt
+ i
);
2037 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
2039 mmu_page_remove_parent_pte(sp
, parent_pte
);
2042 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
2045 struct rmap_iterator iter
;
2047 while ((sptep
= rmap_get_first(sp
->parent_ptes
, &iter
)))
2048 drop_parent_pte(sp
, sptep
);
2051 static int mmu_zap_unsync_children(struct kvm
*kvm
,
2052 struct kvm_mmu_page
*parent
,
2053 struct list_head
*invalid_list
)
2056 struct mmu_page_path parents
;
2057 struct kvm_mmu_pages pages
;
2059 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
2062 kvm_mmu_pages_init(parent
, &parents
, &pages
);
2063 while (mmu_unsync_walk(parent
, &pages
)) {
2064 struct kvm_mmu_page
*sp
;
2066 for_each_sp(pages
, sp
, parents
, i
) {
2067 kvm_mmu_prepare_zap_page(kvm
, sp
, invalid_list
);
2068 mmu_pages_clear_parents(&parents
);
2071 kvm_mmu_pages_init(parent
, &parents
, &pages
);
2077 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
2078 struct list_head
*invalid_list
)
2082 trace_kvm_mmu_prepare_zap_page(sp
);
2083 ++kvm
->stat
.mmu_shadow_zapped
;
2084 ret
= mmu_zap_unsync_children(kvm
, sp
, invalid_list
);
2085 kvm_mmu_page_unlink_children(kvm
, sp
);
2086 kvm_mmu_unlink_parents(kvm
, sp
);
2087 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
2088 unaccount_shadowed(kvm
, sp
->gfn
);
2090 kvm_unlink_unsync_page(kvm
, sp
);
2091 if (!sp
->root_count
) {
2094 list_move(&sp
->link
, invalid_list
);
2095 kvm_mod_used_mmu_pages(kvm
, -1);
2097 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
2098 kvm_reload_remote_mmus(kvm
);
2101 sp
->role
.invalid
= 1;
2105 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
2106 struct list_head
*invalid_list
)
2108 struct kvm_mmu_page
*sp
;
2110 if (list_empty(invalid_list
))
2114 * wmb: make sure everyone sees our modifications to the page tables
2115 * rmb: make sure we see changes to vcpu->mode
2120 * Wait for all vcpus to exit guest mode and/or lockless shadow
2123 kvm_flush_remote_tlbs(kvm
);
2126 sp
= list_first_entry(invalid_list
, struct kvm_mmu_page
, link
);
2127 WARN_ON(!sp
->role
.invalid
|| sp
->root_count
);
2128 kvm_mmu_isolate_page(sp
);
2129 kvm_mmu_free_page(sp
);
2130 } while (!list_empty(invalid_list
));
2134 * Changing the number of mmu pages allocated to the vm
2135 * Note: if goal_nr_mmu_pages is too small, you will get dead lock
2137 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int goal_nr_mmu_pages
)
2139 LIST_HEAD(invalid_list
);
2141 * If we set the number of mmu pages to be smaller be than the
2142 * number of actived pages , we must to free some mmu pages before we
2146 spin_lock(&kvm
->mmu_lock
);
2148 if (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
) {
2149 while (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
&&
2150 !list_empty(&kvm
->arch
.active_mmu_pages
)) {
2151 struct kvm_mmu_page
*page
;
2153 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2154 struct kvm_mmu_page
, link
);
2155 kvm_mmu_prepare_zap_page(kvm
, page
, &invalid_list
);
2157 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2158 goal_nr_mmu_pages
= kvm
->arch
.n_used_mmu_pages
;
2161 kvm
->arch
.n_max_mmu_pages
= goal_nr_mmu_pages
;
2163 spin_unlock(&kvm
->mmu_lock
);
2166 int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
2168 struct kvm_mmu_page
*sp
;
2169 struct hlist_node
*node
;
2170 LIST_HEAD(invalid_list
);
2173 pgprintk("%s: looking for gfn %llx\n", __func__
, gfn
);
2175 spin_lock(&kvm
->mmu_lock
);
2176 for_each_gfn_indirect_valid_sp(kvm
, sp
, gfn
, node
) {
2177 pgprintk("%s: gfn %llx role %x\n", __func__
, gfn
,
2180 kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
);
2182 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2183 spin_unlock(&kvm
->mmu_lock
);
2187 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page
);
2190 * The function is based on mtrr_type_lookup() in
2191 * arch/x86/kernel/cpu/mtrr/generic.c
2193 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
2198 u8 prev_match
, curr_match
;
2199 int num_var_ranges
= KVM_NR_VAR_MTRR
;
2201 if (!mtrr_state
->enabled
)
2204 /* Make end inclusive end, instead of exclusive */
2207 /* Look in fixed ranges. Just return the type as per start */
2208 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
2211 if (start
< 0x80000) {
2213 idx
+= (start
>> 16);
2214 return mtrr_state
->fixed_ranges
[idx
];
2215 } else if (start
< 0xC0000) {
2217 idx
+= ((start
- 0x80000) >> 14);
2218 return mtrr_state
->fixed_ranges
[idx
];
2219 } else if (start
< 0x1000000) {
2221 idx
+= ((start
- 0xC0000) >> 12);
2222 return mtrr_state
->fixed_ranges
[idx
];
2227 * Look in variable ranges
2228 * Look of multiple ranges matching this address and pick type
2229 * as per MTRR precedence
2231 if (!(mtrr_state
->enabled
& 2))
2232 return mtrr_state
->def_type
;
2235 for (i
= 0; i
< num_var_ranges
; ++i
) {
2236 unsigned short start_state
, end_state
;
2238 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
2241 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
2242 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
2243 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
2244 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
2246 start_state
= ((start
& mask
) == (base
& mask
));
2247 end_state
= ((end
& mask
) == (base
& mask
));
2248 if (start_state
!= end_state
)
2251 if ((start
& mask
) != (base
& mask
))
2254 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
2255 if (prev_match
== 0xFF) {
2256 prev_match
= curr_match
;
2260 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
2261 curr_match
== MTRR_TYPE_UNCACHABLE
)
2262 return MTRR_TYPE_UNCACHABLE
;
2264 if ((prev_match
== MTRR_TYPE_WRBACK
&&
2265 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
2266 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
2267 curr_match
== MTRR_TYPE_WRBACK
)) {
2268 prev_match
= MTRR_TYPE_WRTHROUGH
;
2269 curr_match
= MTRR_TYPE_WRTHROUGH
;
2272 if (prev_match
!= curr_match
)
2273 return MTRR_TYPE_UNCACHABLE
;
2276 if (prev_match
!= 0xFF)
2279 return mtrr_state
->def_type
;
2282 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2286 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
2287 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
2288 if (mtrr
== 0xfe || mtrr
== 0xff)
2289 mtrr
= MTRR_TYPE_WRBACK
;
2292 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
2294 static void __kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
2296 trace_kvm_mmu_unsync_page(sp
);
2297 ++vcpu
->kvm
->stat
.mmu_unsync
;
2300 kvm_mmu_mark_parents_unsync(sp
);
2303 static void kvm_unsync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2305 struct kvm_mmu_page
*s
;
2306 struct hlist_node
*node
;
2308 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2311 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
2312 __kvm_unsync_page(vcpu
, s
);
2316 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2319 struct kvm_mmu_page
*s
;
2320 struct hlist_node
*node
;
2321 bool need_unsync
= false;
2323 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2327 if (s
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2330 if (!need_unsync
&& !s
->unsync
) {
2335 kvm_unsync_pages(vcpu
, gfn
);
2339 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2340 unsigned pte_access
, int level
,
2341 gfn_t gfn
, pfn_t pfn
, bool speculative
,
2342 bool can_unsync
, bool host_writable
)
2347 if (set_mmio_spte(sptep
, gfn
, pfn
, pte_access
))
2350 spte
= PT_PRESENT_MASK
;
2352 spte
|= shadow_accessed_mask
;
2354 if (pte_access
& ACC_EXEC_MASK
)
2355 spte
|= shadow_x_mask
;
2357 spte
|= shadow_nx_mask
;
2359 if (pte_access
& ACC_USER_MASK
)
2360 spte
|= shadow_user_mask
;
2362 if (level
> PT_PAGE_TABLE_LEVEL
)
2363 spte
|= PT_PAGE_SIZE_MASK
;
2365 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
2366 kvm_is_mmio_pfn(pfn
));
2369 spte
|= SPTE_HOST_WRITEABLE
;
2371 pte_access
&= ~ACC_WRITE_MASK
;
2373 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
2375 if (pte_access
& ACC_WRITE_MASK
) {
2378 * Other vcpu creates new sp in the window between
2379 * mapping_level() and acquiring mmu-lock. We can
2380 * allow guest to retry the access, the mapping can
2381 * be fixed if guest refault.
2383 if (level
> PT_PAGE_TABLE_LEVEL
&&
2384 has_wrprotected_page(vcpu
->kvm
, gfn
, level
))
2387 spte
|= PT_WRITABLE_MASK
| SPTE_MMU_WRITEABLE
;
2390 * Optimization: for pte sync, if spte was writable the hash
2391 * lookup is unnecessary (and expensive). Write protection
2392 * is responsibility of mmu_get_page / kvm_sync_page.
2393 * Same reasoning can be applied to dirty page accounting.
2395 if (!can_unsync
&& is_writable_pte(*sptep
))
2398 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
2399 pgprintk("%s: found shadow page for %llx, marking ro\n",
2402 pte_access
&= ~ACC_WRITE_MASK
;
2403 spte
&= ~(PT_WRITABLE_MASK
| SPTE_MMU_WRITEABLE
);
2407 if (pte_access
& ACC_WRITE_MASK
)
2408 mark_page_dirty(vcpu
->kvm
, gfn
);
2411 if (mmu_spte_update(sptep
, spte
))
2412 kvm_flush_remote_tlbs(vcpu
->kvm
);
2417 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2418 unsigned pt_access
, unsigned pte_access
,
2419 int write_fault
, int *emulate
, int level
, gfn_t gfn
,
2420 pfn_t pfn
, bool speculative
, bool host_writable
)
2422 int was_rmapped
= 0;
2425 pgprintk("%s: spte %llx access %x write_fault %d gfn %llx\n",
2426 __func__
, *sptep
, pt_access
,
2429 if (is_rmap_spte(*sptep
)) {
2431 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
2432 * the parent of the now unreachable PTE.
2434 if (level
> PT_PAGE_TABLE_LEVEL
&&
2435 !is_large_pte(*sptep
)) {
2436 struct kvm_mmu_page
*child
;
2439 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2440 drop_parent_pte(child
, sptep
);
2441 kvm_flush_remote_tlbs(vcpu
->kvm
);
2442 } else if (pfn
!= spte_to_pfn(*sptep
)) {
2443 pgprintk("hfn old %llx new %llx\n",
2444 spte_to_pfn(*sptep
), pfn
);
2445 drop_spte(vcpu
->kvm
, sptep
);
2446 kvm_flush_remote_tlbs(vcpu
->kvm
);
2451 if (set_spte(vcpu
, sptep
, pte_access
, level
, gfn
, pfn
, speculative
,
2452 true, host_writable
)) {
2455 kvm_mmu_flush_tlb(vcpu
);
2458 if (unlikely(is_mmio_spte(*sptep
) && emulate
))
2461 pgprintk("%s: setting spte %llx\n", __func__
, *sptep
);
2462 pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
2463 is_large_pte(*sptep
)? "2MB" : "4kB",
2464 *sptep
& PT_PRESENT_MASK
?"RW":"R", gfn
,
2466 if (!was_rmapped
&& is_large_pte(*sptep
))
2467 ++vcpu
->kvm
->stat
.lpages
;
2469 if (is_shadow_present_pte(*sptep
)) {
2471 rmap_count
= rmap_add(vcpu
, sptep
, gfn
);
2472 if (rmap_count
> RMAP_RECYCLE_THRESHOLD
)
2473 rmap_recycle(vcpu
, sptep
, gfn
);
2477 kvm_release_pfn_clean(pfn
);
2480 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
2482 mmu_free_roots(vcpu
);
2485 static bool is_rsvd_bits_set(struct kvm_mmu
*mmu
, u64 gpte
, int level
)
2489 bit7
= (gpte
>> 7) & 1;
2490 return (gpte
& mmu
->rsvd_bits_mask
[bit7
][level
-1]) != 0;
2493 static pfn_t
pte_prefetch_gfn_to_pfn(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2496 struct kvm_memory_slot
*slot
;
2498 slot
= gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, no_dirty_log
);
2500 return KVM_PFN_ERR_FAULT
;
2502 return gfn_to_pfn_memslot_atomic(slot
, gfn
);
2505 static bool prefetch_invalid_gpte(struct kvm_vcpu
*vcpu
,
2506 struct kvm_mmu_page
*sp
, u64
*spte
,
2509 if (is_rsvd_bits_set(&vcpu
->arch
.mmu
, gpte
, PT_PAGE_TABLE_LEVEL
))
2512 if (!is_present_gpte(gpte
))
2515 if (!(gpte
& PT_ACCESSED_MASK
))
2521 drop_spte(vcpu
->kvm
, spte
);
2525 static int direct_pte_prefetch_many(struct kvm_vcpu
*vcpu
,
2526 struct kvm_mmu_page
*sp
,
2527 u64
*start
, u64
*end
)
2529 struct page
*pages
[PTE_PREFETCH_NUM
];
2530 unsigned access
= sp
->role
.access
;
2534 gfn
= kvm_mmu_page_get_gfn(sp
, start
- sp
->spt
);
2535 if (!gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, access
& ACC_WRITE_MASK
))
2538 ret
= gfn_to_page_many_atomic(vcpu
->kvm
, gfn
, pages
, end
- start
);
2542 for (i
= 0; i
< ret
; i
++, gfn
++, start
++)
2543 mmu_set_spte(vcpu
, start
, ACC_ALL
, access
, 0, NULL
,
2544 sp
->role
.level
, gfn
, page_to_pfn(pages
[i
]),
2550 static void __direct_pte_prefetch(struct kvm_vcpu
*vcpu
,
2551 struct kvm_mmu_page
*sp
, u64
*sptep
)
2553 u64
*spte
, *start
= NULL
;
2556 WARN_ON(!sp
->role
.direct
);
2558 i
= (sptep
- sp
->spt
) & ~(PTE_PREFETCH_NUM
- 1);
2561 for (i
= 0; i
< PTE_PREFETCH_NUM
; i
++, spte
++) {
2562 if (is_shadow_present_pte(*spte
) || spte
== sptep
) {
2565 if (direct_pte_prefetch_many(vcpu
, sp
, start
, spte
) < 0)
2573 static void direct_pte_prefetch(struct kvm_vcpu
*vcpu
, u64
*sptep
)
2575 struct kvm_mmu_page
*sp
;
2578 * Since it's no accessed bit on EPT, it's no way to
2579 * distinguish between actually accessed translations
2580 * and prefetched, so disable pte prefetch if EPT is
2583 if (!shadow_accessed_mask
)
2586 sp
= page_header(__pa(sptep
));
2587 if (sp
->role
.level
> PT_PAGE_TABLE_LEVEL
)
2590 __direct_pte_prefetch(vcpu
, sp
, sptep
);
2593 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
2594 int map_writable
, int level
, gfn_t gfn
, pfn_t pfn
,
2597 struct kvm_shadow_walk_iterator iterator
;
2598 struct kvm_mmu_page
*sp
;
2602 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
2603 if (iterator
.level
== level
) {
2604 unsigned pte_access
= ACC_ALL
;
2606 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
, pte_access
,
2607 write
, &emulate
, level
, gfn
, pfn
,
2608 prefault
, map_writable
);
2609 direct_pte_prefetch(vcpu
, iterator
.sptep
);
2610 ++vcpu
->stat
.pf_fixed
;
2614 if (!is_shadow_present_pte(*iterator
.sptep
)) {
2615 u64 base_addr
= iterator
.addr
;
2617 base_addr
&= PT64_LVL_ADDR_MASK(iterator
.level
);
2618 pseudo_gfn
= base_addr
>> PAGE_SHIFT
;
2619 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
2621 1, ACC_ALL
, iterator
.sptep
);
2623 mmu_spte_set(iterator
.sptep
,
2625 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
2626 | shadow_user_mask
| shadow_x_mask
2627 | shadow_accessed_mask
);
2633 static void kvm_send_hwpoison_signal(unsigned long address
, struct task_struct
*tsk
)
2637 info
.si_signo
= SIGBUS
;
2639 info
.si_code
= BUS_MCEERR_AR
;
2640 info
.si_addr
= (void __user
*)address
;
2641 info
.si_addr_lsb
= PAGE_SHIFT
;
2643 send_sig_info(SIGBUS
, &info
, tsk
);
2646 static int kvm_handle_bad_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
, pfn_t pfn
)
2649 * Do not cache the mmio info caused by writing the readonly gfn
2650 * into the spte otherwise read access on readonly gfn also can
2651 * caused mmio page fault and treat it as mmio access.
2652 * Return 1 to tell kvm to emulate it.
2654 if (pfn
== KVM_PFN_ERR_RO_FAULT
)
2657 if (pfn
== KVM_PFN_ERR_HWPOISON
) {
2658 kvm_send_hwpoison_signal(gfn_to_hva(vcpu
->kvm
, gfn
), current
);
2665 static void transparent_hugepage_adjust(struct kvm_vcpu
*vcpu
,
2666 gfn_t
*gfnp
, pfn_t
*pfnp
, int *levelp
)
2670 int level
= *levelp
;
2673 * Check if it's a transparent hugepage. If this would be an
2674 * hugetlbfs page, level wouldn't be set to
2675 * PT_PAGE_TABLE_LEVEL and there would be no adjustment done
2678 if (!is_error_noslot_pfn(pfn
) && !kvm_is_mmio_pfn(pfn
) &&
2679 level
== PT_PAGE_TABLE_LEVEL
&&
2680 PageTransCompound(pfn_to_page(pfn
)) &&
2681 !has_wrprotected_page(vcpu
->kvm
, gfn
, PT_DIRECTORY_LEVEL
)) {
2684 * mmu_notifier_retry was successful and we hold the
2685 * mmu_lock here, so the pmd can't become splitting
2686 * from under us, and in turn
2687 * __split_huge_page_refcount() can't run from under
2688 * us and we can safely transfer the refcount from
2689 * PG_tail to PG_head as we switch the pfn to tail to
2692 *levelp
= level
= PT_DIRECTORY_LEVEL
;
2693 mask
= KVM_PAGES_PER_HPAGE(level
) - 1;
2694 VM_BUG_ON((gfn
& mask
) != (pfn
& mask
));
2698 kvm_release_pfn_clean(pfn
);
2706 static bool handle_abnormal_pfn(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
,
2707 pfn_t pfn
, unsigned access
, int *ret_val
)
2711 /* The pfn is invalid, report the error! */
2712 if (unlikely(is_error_pfn(pfn
))) {
2713 *ret_val
= kvm_handle_bad_page(vcpu
, gfn
, pfn
);
2717 if (unlikely(is_noslot_pfn(pfn
)))
2718 vcpu_cache_mmio_info(vcpu
, gva
, gfn
, access
);
2725 static bool page_fault_can_be_fast(struct kvm_vcpu
*vcpu
, u32 error_code
)
2728 * #PF can be fast only if the shadow page table is present and it
2729 * is caused by write-protect, that means we just need change the
2730 * W bit of the spte which can be done out of mmu-lock.
2732 if (!(error_code
& PFERR_PRESENT_MASK
) ||
2733 !(error_code
& PFERR_WRITE_MASK
))
2740 fast_pf_fix_direct_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
, u64 spte
)
2742 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
2745 WARN_ON(!sp
->role
.direct
);
2748 * The gfn of direct spte is stable since it is calculated
2751 gfn
= kvm_mmu_page_get_gfn(sp
, sptep
- sp
->spt
);
2753 if (cmpxchg64(sptep
, spte
, spte
| PT_WRITABLE_MASK
) == spte
)
2754 mark_page_dirty(vcpu
->kvm
, gfn
);
2761 * - true: let the vcpu to access on the same address again.
2762 * - false: let the real page fault path to fix it.
2764 static bool fast_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
, int level
,
2767 struct kvm_shadow_walk_iterator iterator
;
2771 if (!page_fault_can_be_fast(vcpu
, error_code
))
2774 walk_shadow_page_lockless_begin(vcpu
);
2775 for_each_shadow_entry_lockless(vcpu
, gva
, iterator
, spte
)
2776 if (!is_shadow_present_pte(spte
) || iterator
.level
< level
)
2780 * If the mapping has been changed, let the vcpu fault on the
2781 * same address again.
2783 if (!is_rmap_spte(spte
)) {
2788 if (!is_last_spte(spte
, level
))
2792 * Check if it is a spurious fault caused by TLB lazily flushed.
2794 * Need not check the access of upper level table entries since
2795 * they are always ACC_ALL.
2797 if (is_writable_pte(spte
)) {
2803 * Currently, to simplify the code, only the spte write-protected
2804 * by dirty-log can be fast fixed.
2806 if (!spte_is_locklessly_modifiable(spte
))
2810 * Currently, fast page fault only works for direct mapping since
2811 * the gfn is not stable for indirect shadow page.
2812 * See Documentation/virtual/kvm/locking.txt to get more detail.
2814 ret
= fast_pf_fix_direct_spte(vcpu
, iterator
.sptep
, spte
);
2816 trace_fast_page_fault(vcpu
, gva
, error_code
, iterator
.sptep
,
2818 walk_shadow_page_lockless_end(vcpu
);
2823 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
2824 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
);
2826 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, u32 error_code
,
2827 gfn_t gfn
, bool prefault
)
2833 unsigned long mmu_seq
;
2834 bool map_writable
, write
= error_code
& PFERR_WRITE_MASK
;
2836 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
2837 if (likely(!force_pt_level
)) {
2838 level
= mapping_level(vcpu
, gfn
);
2840 * This path builds a PAE pagetable - so we can map
2841 * 2mb pages at maximum. Therefore check if the level
2842 * is larger than that.
2844 if (level
> PT_DIRECTORY_LEVEL
)
2845 level
= PT_DIRECTORY_LEVEL
;
2847 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2849 level
= PT_PAGE_TABLE_LEVEL
;
2851 if (fast_page_fault(vcpu
, v
, level
, error_code
))
2854 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2857 if (try_async_pf(vcpu
, prefault
, gfn
, v
, &pfn
, write
, &map_writable
))
2860 if (handle_abnormal_pfn(vcpu
, v
, gfn
, pfn
, ACC_ALL
, &r
))
2863 spin_lock(&vcpu
->kvm
->mmu_lock
);
2864 if (mmu_notifier_retry(vcpu
->kvm
, mmu_seq
))
2866 kvm_mmu_free_some_pages(vcpu
);
2867 if (likely(!force_pt_level
))
2868 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
2869 r
= __direct_map(vcpu
, v
, write
, map_writable
, level
, gfn
, pfn
,
2871 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2877 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2878 kvm_release_pfn_clean(pfn
);
2883 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
2886 struct kvm_mmu_page
*sp
;
2887 LIST_HEAD(invalid_list
);
2889 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2891 spin_lock(&vcpu
->kvm
->mmu_lock
);
2892 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
&&
2893 (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
||
2894 vcpu
->arch
.mmu
.direct_map
)) {
2895 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2897 sp
= page_header(root
);
2899 if (!sp
->root_count
&& sp
->role
.invalid
) {
2900 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
2901 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2903 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2904 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2907 for (i
= 0; i
< 4; ++i
) {
2908 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2911 root
&= PT64_BASE_ADDR_MASK
;
2912 sp
= page_header(root
);
2914 if (!sp
->root_count
&& sp
->role
.invalid
)
2915 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
2918 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2920 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2921 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2922 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2925 static int mmu_check_root(struct kvm_vcpu
*vcpu
, gfn_t root_gfn
)
2929 if (!kvm_is_visible_gfn(vcpu
->kvm
, root_gfn
)) {
2930 kvm_make_request(KVM_REQ_TRIPLE_FAULT
, vcpu
);
2937 static int mmu_alloc_direct_roots(struct kvm_vcpu
*vcpu
)
2939 struct kvm_mmu_page
*sp
;
2942 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2943 spin_lock(&vcpu
->kvm
->mmu_lock
);
2944 kvm_mmu_free_some_pages(vcpu
);
2945 sp
= kvm_mmu_get_page(vcpu
, 0, 0, PT64_ROOT_LEVEL
,
2948 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2949 vcpu
->arch
.mmu
.root_hpa
= __pa(sp
->spt
);
2950 } else if (vcpu
->arch
.mmu
.shadow_root_level
== PT32E_ROOT_LEVEL
) {
2951 for (i
= 0; i
< 4; ++i
) {
2952 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2954 ASSERT(!VALID_PAGE(root
));
2955 spin_lock(&vcpu
->kvm
->mmu_lock
);
2956 kvm_mmu_free_some_pages(vcpu
);
2957 sp
= kvm_mmu_get_page(vcpu
, i
<< (30 - PAGE_SHIFT
),
2959 PT32_ROOT_LEVEL
, 1, ACC_ALL
,
2961 root
= __pa(sp
->spt
);
2963 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2964 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
2966 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2973 static int mmu_alloc_shadow_roots(struct kvm_vcpu
*vcpu
)
2975 struct kvm_mmu_page
*sp
;
2980 root_gfn
= vcpu
->arch
.mmu
.get_cr3(vcpu
) >> PAGE_SHIFT
;
2982 if (mmu_check_root(vcpu
, root_gfn
))
2986 * Do we shadow a long mode page table? If so we need to
2987 * write-protect the guests page table root.
2989 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
2990 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2992 ASSERT(!VALID_PAGE(root
));
2994 spin_lock(&vcpu
->kvm
->mmu_lock
);
2995 kvm_mmu_free_some_pages(vcpu
);
2996 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0, PT64_ROOT_LEVEL
,
2998 root
= __pa(sp
->spt
);
3000 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3001 vcpu
->arch
.mmu
.root_hpa
= root
;
3006 * We shadow a 32 bit page table. This may be a legacy 2-level
3007 * or a PAE 3-level page table. In either case we need to be aware that
3008 * the shadow page table may be a PAE or a long mode page table.
3010 pm_mask
= PT_PRESENT_MASK
;
3011 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
)
3012 pm_mask
|= PT_ACCESSED_MASK
| PT_WRITABLE_MASK
| PT_USER_MASK
;
3014 for (i
= 0; i
< 4; ++i
) {
3015 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
3017 ASSERT(!VALID_PAGE(root
));
3018 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
3019 pdptr
= vcpu
->arch
.mmu
.get_pdptr(vcpu
, i
);
3020 if (!is_present_gpte(pdptr
)) {
3021 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
3024 root_gfn
= pdptr
>> PAGE_SHIFT
;
3025 if (mmu_check_root(vcpu
, root_gfn
))
3028 spin_lock(&vcpu
->kvm
->mmu_lock
);
3029 kvm_mmu_free_some_pages(vcpu
);
3030 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
3033 root
= __pa(sp
->spt
);
3035 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3037 vcpu
->arch
.mmu
.pae_root
[i
] = root
| pm_mask
;
3039 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
3042 * If we shadow a 32 bit page table with a long mode page
3043 * table we enter this path.
3045 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
3046 if (vcpu
->arch
.mmu
.lm_root
== NULL
) {
3048 * The additional page necessary for this is only
3049 * allocated on demand.
3054 lm_root
= (void*)get_zeroed_page(GFP_KERNEL
);
3055 if (lm_root
== NULL
)
3058 lm_root
[0] = __pa(vcpu
->arch
.mmu
.pae_root
) | pm_mask
;
3060 vcpu
->arch
.mmu
.lm_root
= lm_root
;
3063 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.lm_root
);
3069 static int mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
3071 if (vcpu
->arch
.mmu
.direct_map
)
3072 return mmu_alloc_direct_roots(vcpu
);
3074 return mmu_alloc_shadow_roots(vcpu
);
3077 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
3080 struct kvm_mmu_page
*sp
;
3082 if (vcpu
->arch
.mmu
.direct_map
)
3085 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3088 vcpu_clear_mmio_info(vcpu
, ~0ul);
3089 kvm_mmu_audit(vcpu
, AUDIT_PRE_SYNC
);
3090 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
3091 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
3092 sp
= page_header(root
);
3093 mmu_sync_children(vcpu
, sp
);
3094 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
3097 for (i
= 0; i
< 4; ++i
) {
3098 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
3100 if (root
&& VALID_PAGE(root
)) {
3101 root
&= PT64_BASE_ADDR_MASK
;
3102 sp
= page_header(root
);
3103 mmu_sync_children(vcpu
, sp
);
3106 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
3109 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
3111 spin_lock(&vcpu
->kvm
->mmu_lock
);
3112 mmu_sync_roots(vcpu
);
3113 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3116 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
3117 u32 access
, struct x86_exception
*exception
)
3120 exception
->error_code
= 0;
3124 static gpa_t
nonpaging_gva_to_gpa_nested(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
3126 struct x86_exception
*exception
)
3129 exception
->error_code
= 0;
3130 return vcpu
->arch
.nested_mmu
.translate_gpa(vcpu
, vaddr
, access
);
3133 static bool quickly_check_mmio_pf(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
3136 return vcpu_match_mmio_gpa(vcpu
, addr
);
3138 return vcpu_match_mmio_gva(vcpu
, addr
);
3143 * On direct hosts, the last spte is only allows two states
3144 * for mmio page fault:
3145 * - It is the mmio spte
3146 * - It is zapped or it is being zapped.
3148 * This function completely checks the spte when the last spte
3149 * is not the mmio spte.
3151 static bool check_direct_spte_mmio_pf(u64 spte
)
3153 return __check_direct_spte_mmio_pf(spte
);
3156 static u64
walk_shadow_page_get_mmio_spte(struct kvm_vcpu
*vcpu
, u64 addr
)
3158 struct kvm_shadow_walk_iterator iterator
;
3161 walk_shadow_page_lockless_begin(vcpu
);
3162 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
)
3163 if (!is_shadow_present_pte(spte
))
3165 walk_shadow_page_lockless_end(vcpu
);
3171 * If it is a real mmio page fault, return 1 and emulat the instruction
3172 * directly, return 0 to let CPU fault again on the address, -1 is
3173 * returned if bug is detected.
3175 int handle_mmio_page_fault_common(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
3179 if (quickly_check_mmio_pf(vcpu
, addr
, direct
))
3182 spte
= walk_shadow_page_get_mmio_spte(vcpu
, addr
);
3184 if (is_mmio_spte(spte
)) {
3185 gfn_t gfn
= get_mmio_spte_gfn(spte
);
3186 unsigned access
= get_mmio_spte_access(spte
);
3191 trace_handle_mmio_page_fault(addr
, gfn
, access
);
3192 vcpu_cache_mmio_info(vcpu
, addr
, gfn
, access
);
3197 * It's ok if the gva is remapped by other cpus on shadow guest,
3198 * it's a BUG if the gfn is not a mmio page.
3200 if (direct
&& !check_direct_spte_mmio_pf(spte
))
3204 * If the page table is zapped by other cpus, let CPU fault again on
3209 EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common
);
3211 static int handle_mmio_page_fault(struct kvm_vcpu
*vcpu
, u64 addr
,
3212 u32 error_code
, bool direct
)
3216 ret
= handle_mmio_page_fault_common(vcpu
, addr
, direct
);
3221 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
3222 u32 error_code
, bool prefault
)
3227 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
3229 if (unlikely(error_code
& PFERR_RSVD_MASK
))
3230 return handle_mmio_page_fault(vcpu
, gva
, error_code
, true);
3232 r
= mmu_topup_memory_caches(vcpu
);
3237 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3239 gfn
= gva
>> PAGE_SHIFT
;
3241 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
3242 error_code
, gfn
, prefault
);
3245 static int kvm_arch_setup_async_pf(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
)
3247 struct kvm_arch_async_pf arch
;
3249 arch
.token
= (vcpu
->arch
.apf
.id
++ << 12) | vcpu
->vcpu_id
;
3251 arch
.direct_map
= vcpu
->arch
.mmu
.direct_map
;
3252 arch
.cr3
= vcpu
->arch
.mmu
.get_cr3(vcpu
);
3254 return kvm_setup_async_pf(vcpu
, gva
, gfn
, &arch
);
3257 static bool can_do_async_pf(struct kvm_vcpu
*vcpu
)
3259 if (unlikely(!irqchip_in_kernel(vcpu
->kvm
) ||
3260 kvm_event_needs_reinjection(vcpu
)))
3263 return kvm_x86_ops
->interrupt_allowed(vcpu
);
3266 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
3267 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
)
3271 *pfn
= gfn_to_pfn_async(vcpu
->kvm
, gfn
, &async
, write
, writable
);
3274 return false; /* *pfn has correct page already */
3276 if (!prefault
&& can_do_async_pf(vcpu
)) {
3277 trace_kvm_try_async_get_page(gva
, gfn
);
3278 if (kvm_find_async_pf_gfn(vcpu
, gfn
)) {
3279 trace_kvm_async_pf_doublefault(gva
, gfn
);
3280 kvm_make_request(KVM_REQ_APF_HALT
, vcpu
);
3282 } else if (kvm_arch_setup_async_pf(vcpu
, gva
, gfn
))
3286 *pfn
= gfn_to_pfn_prot(vcpu
->kvm
, gfn
, write
, writable
);
3291 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
, u32 error_code
,
3298 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3299 unsigned long mmu_seq
;
3300 int write
= error_code
& PFERR_WRITE_MASK
;
3304 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3306 if (unlikely(error_code
& PFERR_RSVD_MASK
))
3307 return handle_mmio_page_fault(vcpu
, gpa
, error_code
, true);
3309 r
= mmu_topup_memory_caches(vcpu
);
3313 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
3314 if (likely(!force_pt_level
)) {
3315 level
= mapping_level(vcpu
, gfn
);
3316 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
3318 level
= PT_PAGE_TABLE_LEVEL
;
3320 if (fast_page_fault(vcpu
, gpa
, level
, error_code
))
3323 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
3326 if (try_async_pf(vcpu
, prefault
, gfn
, gpa
, &pfn
, write
, &map_writable
))
3329 if (handle_abnormal_pfn(vcpu
, 0, gfn
, pfn
, ACC_ALL
, &r
))
3332 spin_lock(&vcpu
->kvm
->mmu_lock
);
3333 if (mmu_notifier_retry(vcpu
->kvm
, mmu_seq
))
3335 kvm_mmu_free_some_pages(vcpu
);
3336 if (likely(!force_pt_level
))
3337 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
3338 r
= __direct_map(vcpu
, gpa
, write
, map_writable
,
3339 level
, gfn
, pfn
, prefault
);
3340 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3345 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3346 kvm_release_pfn_clean(pfn
);
3350 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
3352 mmu_free_roots(vcpu
);
3355 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
,
3356 struct kvm_mmu
*context
)
3358 context
->new_cr3
= nonpaging_new_cr3
;
3359 context
->page_fault
= nonpaging_page_fault
;
3360 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3361 context
->free
= nonpaging_free
;
3362 context
->sync_page
= nonpaging_sync_page
;
3363 context
->invlpg
= nonpaging_invlpg
;
3364 context
->update_pte
= nonpaging_update_pte
;
3365 context
->root_level
= 0;
3366 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3367 context
->root_hpa
= INVALID_PAGE
;
3368 context
->direct_map
= true;
3369 context
->nx
= false;
3373 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
3375 ++vcpu
->stat
.tlb_flush
;
3376 kvm_make_request(KVM_REQ_TLB_FLUSH
, vcpu
);
3379 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
3381 pgprintk("%s: cr3 %lx\n", __func__
, kvm_read_cr3(vcpu
));
3382 mmu_free_roots(vcpu
);
3385 static unsigned long get_cr3(struct kvm_vcpu
*vcpu
)
3387 return kvm_read_cr3(vcpu
);
3390 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
3391 struct x86_exception
*fault
)
3393 vcpu
->arch
.mmu
.inject_page_fault(vcpu
, fault
);
3396 static void paging_free(struct kvm_vcpu
*vcpu
)
3398 nonpaging_free(vcpu
);
3401 static inline void protect_clean_gpte(unsigned *access
, unsigned gpte
)
3405 BUILD_BUG_ON(PT_WRITABLE_MASK
!= ACC_WRITE_MASK
);
3407 mask
= (unsigned)~ACC_WRITE_MASK
;
3408 /* Allow write access to dirty gptes */
3409 mask
|= (gpte
>> (PT_DIRTY_SHIFT
- PT_WRITABLE_SHIFT
)) & PT_WRITABLE_MASK
;
3413 static bool sync_mmio_spte(u64
*sptep
, gfn_t gfn
, unsigned access
,
3416 if (unlikely(is_mmio_spte(*sptep
))) {
3417 if (gfn
!= get_mmio_spte_gfn(*sptep
)) {
3418 mmu_spte_clear_no_track(sptep
);
3423 mark_mmio_spte(sptep
, gfn
, access
);
3430 static inline unsigned gpte_access(struct kvm_vcpu
*vcpu
, u64 gpte
)
3434 access
= (gpte
& (PT_WRITABLE_MASK
| PT_USER_MASK
)) | ACC_EXEC_MASK
;
3435 access
&= ~(gpte
>> PT64_NX_SHIFT
);
3440 static inline bool is_last_gpte(struct kvm_mmu
*mmu
, unsigned level
, unsigned gpte
)
3445 index
|= (gpte
& PT_PAGE_SIZE_MASK
) >> (PT_PAGE_SIZE_SHIFT
- 2);
3446 return mmu
->last_pte_bitmap
& (1 << index
);
3450 #include "paging_tmpl.h"
3454 #include "paging_tmpl.h"
3457 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
,
3458 struct kvm_mmu
*context
)
3460 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
3461 u64 exb_bit_rsvd
= 0;
3464 exb_bit_rsvd
= rsvd_bits(63, 63);
3465 switch (context
->root_level
) {
3466 case PT32_ROOT_LEVEL
:
3467 /* no rsvd bits for 2 level 4K page table entries */
3468 context
->rsvd_bits_mask
[0][1] = 0;
3469 context
->rsvd_bits_mask
[0][0] = 0;
3470 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3472 if (!is_pse(vcpu
)) {
3473 context
->rsvd_bits_mask
[1][1] = 0;
3477 if (is_cpuid_PSE36())
3478 /* 36bits PSE 4MB page */
3479 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
3481 /* 32 bits PSE 4MB page */
3482 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
3484 case PT32E_ROOT_LEVEL
:
3485 context
->rsvd_bits_mask
[0][2] =
3486 rsvd_bits(maxphyaddr
, 63) |
3487 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
3488 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3489 rsvd_bits(maxphyaddr
, 62); /* PDE */
3490 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3491 rsvd_bits(maxphyaddr
, 62); /* PTE */
3492 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3493 rsvd_bits(maxphyaddr
, 62) |
3494 rsvd_bits(13, 20); /* large page */
3495 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3497 case PT64_ROOT_LEVEL
:
3498 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
3499 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3500 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
3501 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3502 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3503 rsvd_bits(maxphyaddr
, 51);
3504 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3505 rsvd_bits(maxphyaddr
, 51);
3506 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
3507 context
->rsvd_bits_mask
[1][2] = exb_bit_rsvd
|
3508 rsvd_bits(maxphyaddr
, 51) |
3510 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3511 rsvd_bits(maxphyaddr
, 51) |
3512 rsvd_bits(13, 20); /* large page */
3513 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3518 static void update_permission_bitmask(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*mmu
)
3520 unsigned bit
, byte
, pfec
;
3522 bool fault
, x
, w
, u
, wf
, uf
, ff
, smep
;
3524 smep
= kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
);
3525 for (byte
= 0; byte
< ARRAY_SIZE(mmu
->permissions
); ++byte
) {
3528 wf
= pfec
& PFERR_WRITE_MASK
;
3529 uf
= pfec
& PFERR_USER_MASK
;
3530 ff
= pfec
& PFERR_FETCH_MASK
;
3531 for (bit
= 0; bit
< 8; ++bit
) {
3532 x
= bit
& ACC_EXEC_MASK
;
3533 w
= bit
& ACC_WRITE_MASK
;
3534 u
= bit
& ACC_USER_MASK
;
3536 /* Not really needed: !nx will cause pte.nx to fault */
3538 /* Allow supervisor writes if !cr0.wp */
3539 w
|= !is_write_protection(vcpu
) && !uf
;
3540 /* Disallow supervisor fetches of user code if cr4.smep */
3541 x
&= !(smep
&& u
&& !uf
);
3543 fault
= (ff
&& !x
) || (uf
&& !u
) || (wf
&& !w
);
3544 map
|= fault
<< bit
;
3546 mmu
->permissions
[byte
] = map
;
3550 static void update_last_pte_bitmap(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*mmu
)
3553 unsigned level
, root_level
= mmu
->root_level
;
3554 const unsigned ps_set_index
= 1 << 2; /* bit 2 of index: ps */
3556 if (root_level
== PT32E_ROOT_LEVEL
)
3558 /* PT_PAGE_TABLE_LEVEL always terminates */
3559 map
= 1 | (1 << ps_set_index
);
3560 for (level
= PT_DIRECTORY_LEVEL
; level
<= root_level
; ++level
) {
3561 if (level
<= PT_PDPE_LEVEL
3562 && (mmu
->root_level
>= PT32E_ROOT_LEVEL
|| is_pse(vcpu
)))
3563 map
|= 1 << (ps_set_index
| (level
- 1));
3565 mmu
->last_pte_bitmap
= map
;
3568 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
,
3569 struct kvm_mmu
*context
,
3572 context
->nx
= is_nx(vcpu
);
3573 context
->root_level
= level
;
3575 reset_rsvds_bits_mask(vcpu
, context
);
3576 update_permission_bitmask(vcpu
, context
);
3577 update_last_pte_bitmap(vcpu
, context
);
3579 ASSERT(is_pae(vcpu
));
3580 context
->new_cr3
= paging_new_cr3
;
3581 context
->page_fault
= paging64_page_fault
;
3582 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3583 context
->sync_page
= paging64_sync_page
;
3584 context
->invlpg
= paging64_invlpg
;
3585 context
->update_pte
= paging64_update_pte
;
3586 context
->free
= paging_free
;
3587 context
->shadow_root_level
= level
;
3588 context
->root_hpa
= INVALID_PAGE
;
3589 context
->direct_map
= false;
3593 static int paging64_init_context(struct kvm_vcpu
*vcpu
,
3594 struct kvm_mmu
*context
)
3596 return paging64_init_context_common(vcpu
, context
, PT64_ROOT_LEVEL
);
3599 static int paging32_init_context(struct kvm_vcpu
*vcpu
,
3600 struct kvm_mmu
*context
)
3602 context
->nx
= false;
3603 context
->root_level
= PT32_ROOT_LEVEL
;
3605 reset_rsvds_bits_mask(vcpu
, context
);
3606 update_permission_bitmask(vcpu
, context
);
3607 update_last_pte_bitmap(vcpu
, context
);
3609 context
->new_cr3
= paging_new_cr3
;
3610 context
->page_fault
= paging32_page_fault
;
3611 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3612 context
->free
= paging_free
;
3613 context
->sync_page
= paging32_sync_page
;
3614 context
->invlpg
= paging32_invlpg
;
3615 context
->update_pte
= paging32_update_pte
;
3616 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3617 context
->root_hpa
= INVALID_PAGE
;
3618 context
->direct_map
= false;
3622 static int paging32E_init_context(struct kvm_vcpu
*vcpu
,
3623 struct kvm_mmu
*context
)
3625 return paging64_init_context_common(vcpu
, context
, PT32E_ROOT_LEVEL
);
3628 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
3630 struct kvm_mmu
*context
= vcpu
->arch
.walk_mmu
;
3632 context
->base_role
.word
= 0;
3633 context
->new_cr3
= nonpaging_new_cr3
;
3634 context
->page_fault
= tdp_page_fault
;
3635 context
->free
= nonpaging_free
;
3636 context
->sync_page
= nonpaging_sync_page
;
3637 context
->invlpg
= nonpaging_invlpg
;
3638 context
->update_pte
= nonpaging_update_pte
;
3639 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
3640 context
->root_hpa
= INVALID_PAGE
;
3641 context
->direct_map
= true;
3642 context
->set_cr3
= kvm_x86_ops
->set_tdp_cr3
;
3643 context
->get_cr3
= get_cr3
;
3644 context
->get_pdptr
= kvm_pdptr_read
;
3645 context
->inject_page_fault
= kvm_inject_page_fault
;
3647 if (!is_paging(vcpu
)) {
3648 context
->nx
= false;
3649 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3650 context
->root_level
= 0;
3651 } else if (is_long_mode(vcpu
)) {
3652 context
->nx
= is_nx(vcpu
);
3653 context
->root_level
= PT64_ROOT_LEVEL
;
3654 reset_rsvds_bits_mask(vcpu
, context
);
3655 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3656 } else if (is_pae(vcpu
)) {
3657 context
->nx
= is_nx(vcpu
);
3658 context
->root_level
= PT32E_ROOT_LEVEL
;
3659 reset_rsvds_bits_mask(vcpu
, context
);
3660 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3662 context
->nx
= false;
3663 context
->root_level
= PT32_ROOT_LEVEL
;
3664 reset_rsvds_bits_mask(vcpu
, context
);
3665 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3668 update_permission_bitmask(vcpu
, context
);
3669 update_last_pte_bitmap(vcpu
, context
);
3674 int kvm_init_shadow_mmu(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*context
)
3677 bool smep
= kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
);
3679 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3681 if (!is_paging(vcpu
))
3682 r
= nonpaging_init_context(vcpu
, context
);
3683 else if (is_long_mode(vcpu
))
3684 r
= paging64_init_context(vcpu
, context
);
3685 else if (is_pae(vcpu
))
3686 r
= paging32E_init_context(vcpu
, context
);
3688 r
= paging32_init_context(vcpu
, context
);
3690 vcpu
->arch
.mmu
.base_role
.cr4_pae
= !!is_pae(vcpu
);
3691 vcpu
->arch
.mmu
.base_role
.cr0_wp
= is_write_protection(vcpu
);
3692 vcpu
->arch
.mmu
.base_role
.smep_andnot_wp
3693 = smep
&& !is_write_protection(vcpu
);
3697 EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu
);
3699 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
3701 int r
= kvm_init_shadow_mmu(vcpu
, vcpu
->arch
.walk_mmu
);
3703 vcpu
->arch
.walk_mmu
->set_cr3
= kvm_x86_ops
->set_cr3
;
3704 vcpu
->arch
.walk_mmu
->get_cr3
= get_cr3
;
3705 vcpu
->arch
.walk_mmu
->get_pdptr
= kvm_pdptr_read
;
3706 vcpu
->arch
.walk_mmu
->inject_page_fault
= kvm_inject_page_fault
;
3711 static int init_kvm_nested_mmu(struct kvm_vcpu
*vcpu
)
3713 struct kvm_mmu
*g_context
= &vcpu
->arch
.nested_mmu
;
3715 g_context
->get_cr3
= get_cr3
;
3716 g_context
->get_pdptr
= kvm_pdptr_read
;
3717 g_context
->inject_page_fault
= kvm_inject_page_fault
;
3720 * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
3721 * translation of l2_gpa to l1_gpa addresses is done using the
3722 * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa
3723 * functions between mmu and nested_mmu are swapped.
3725 if (!is_paging(vcpu
)) {
3726 g_context
->nx
= false;
3727 g_context
->root_level
= 0;
3728 g_context
->gva_to_gpa
= nonpaging_gva_to_gpa_nested
;
3729 } else if (is_long_mode(vcpu
)) {
3730 g_context
->nx
= is_nx(vcpu
);
3731 g_context
->root_level
= PT64_ROOT_LEVEL
;
3732 reset_rsvds_bits_mask(vcpu
, g_context
);
3733 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3734 } else if (is_pae(vcpu
)) {
3735 g_context
->nx
= is_nx(vcpu
);
3736 g_context
->root_level
= PT32E_ROOT_LEVEL
;
3737 reset_rsvds_bits_mask(vcpu
, g_context
);
3738 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3740 g_context
->nx
= false;
3741 g_context
->root_level
= PT32_ROOT_LEVEL
;
3742 reset_rsvds_bits_mask(vcpu
, g_context
);
3743 g_context
->gva_to_gpa
= paging32_gva_to_gpa_nested
;
3746 update_permission_bitmask(vcpu
, g_context
);
3747 update_last_pte_bitmap(vcpu
, g_context
);
3752 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
3754 if (mmu_is_nested(vcpu
))
3755 return init_kvm_nested_mmu(vcpu
);
3756 else if (tdp_enabled
)
3757 return init_kvm_tdp_mmu(vcpu
);
3759 return init_kvm_softmmu(vcpu
);
3762 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
3765 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3766 /* mmu.free() should set root_hpa = INVALID_PAGE */
3767 vcpu
->arch
.mmu
.free(vcpu
);
3770 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
3772 destroy_kvm_mmu(vcpu
);
3773 return init_kvm_mmu(vcpu
);
3775 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
3777 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
3781 r
= mmu_topup_memory_caches(vcpu
);
3784 r
= mmu_alloc_roots(vcpu
);
3785 spin_lock(&vcpu
->kvm
->mmu_lock
);
3786 mmu_sync_roots(vcpu
);
3787 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3790 /* set_cr3() should ensure TLB has been flushed */
3791 vcpu
->arch
.mmu
.set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
3795 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
3797 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
3799 mmu_free_roots(vcpu
);
3801 EXPORT_SYMBOL_GPL(kvm_mmu_unload
);
3803 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
3804 struct kvm_mmu_page
*sp
, u64
*spte
,
3807 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
3808 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
3812 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
3813 vcpu
->arch
.mmu
.update_pte(vcpu
, sp
, spte
, new);
3816 static bool need_remote_flush(u64 old
, u64
new)
3818 if (!is_shadow_present_pte(old
))
3820 if (!is_shadow_present_pte(new))
3822 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
3824 old
^= PT64_NX_MASK
;
3825 new ^= PT64_NX_MASK
;
3826 return (old
& ~new & PT64_PERM_MASK
) != 0;
3829 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, bool zap_page
,
3830 bool remote_flush
, bool local_flush
)
3836 kvm_flush_remote_tlbs(vcpu
->kvm
);
3837 else if (local_flush
)
3838 kvm_mmu_flush_tlb(vcpu
);
3841 static u64
mmu_pte_write_fetch_gpte(struct kvm_vcpu
*vcpu
, gpa_t
*gpa
,
3842 const u8
*new, int *bytes
)
3848 * Assume that the pte write on a page table of the same type
3849 * as the current vcpu paging mode since we update the sptes only
3850 * when they have the same mode.
3852 if (is_pae(vcpu
) && *bytes
== 4) {
3853 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
3856 r
= kvm_read_guest(vcpu
->kvm
, *gpa
, &gentry
, min(*bytes
, 8));
3859 new = (const u8
*)&gentry
;
3864 gentry
= *(const u32
*)new;
3867 gentry
= *(const u64
*)new;
3878 * If we're seeing too many writes to a page, it may no longer be a page table,
3879 * or we may be forking, in which case it is better to unmap the page.
3881 static bool detect_write_flooding(struct kvm_mmu_page
*sp
)
3884 * Skip write-flooding detected for the sp whose level is 1, because
3885 * it can become unsync, then the guest page is not write-protected.
3887 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
)
3890 return ++sp
->write_flooding_count
>= 3;
3894 * Misaligned accesses are too much trouble to fix up; also, they usually
3895 * indicate a page is not used as a page table.
3897 static bool detect_write_misaligned(struct kvm_mmu_page
*sp
, gpa_t gpa
,
3900 unsigned offset
, pte_size
, misaligned
;
3902 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
3903 gpa
, bytes
, sp
->role
.word
);
3905 offset
= offset_in_page(gpa
);
3906 pte_size
= sp
->role
.cr4_pae
? 8 : 4;
3909 * Sometimes, the OS only writes the last one bytes to update status
3910 * bits, for example, in linux, andb instruction is used in clear_bit().
3912 if (!(offset
& (pte_size
- 1)) && bytes
== 1)
3915 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
3916 misaligned
|= bytes
< 4;
3921 static u64
*get_written_sptes(struct kvm_mmu_page
*sp
, gpa_t gpa
, int *nspte
)
3923 unsigned page_offset
, quadrant
;
3927 page_offset
= offset_in_page(gpa
);
3928 level
= sp
->role
.level
;
3930 if (!sp
->role
.cr4_pae
) {
3931 page_offset
<<= 1; /* 32->64 */
3933 * A 32-bit pde maps 4MB while the shadow pdes map
3934 * only 2MB. So we need to double the offset again
3935 * and zap two pdes instead of one.
3937 if (level
== PT32_ROOT_LEVEL
) {
3938 page_offset
&= ~7; /* kill rounding error */
3942 quadrant
= page_offset
>> PAGE_SHIFT
;
3943 page_offset
&= ~PAGE_MASK
;
3944 if (quadrant
!= sp
->role
.quadrant
)
3948 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
3952 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
3953 const u8
*new, int bytes
)
3955 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3956 union kvm_mmu_page_role mask
= { .word
= 0 };
3957 struct kvm_mmu_page
*sp
;
3958 struct hlist_node
*node
;
3959 LIST_HEAD(invalid_list
);
3960 u64 entry
, gentry
, *spte
;
3962 bool remote_flush
, local_flush
, zap_page
;
3965 * If we don't have indirect shadow pages, it means no page is
3966 * write-protected, so we can exit simply.
3968 if (!ACCESS_ONCE(vcpu
->kvm
->arch
.indirect_shadow_pages
))
3971 zap_page
= remote_flush
= local_flush
= false;
3973 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
3975 gentry
= mmu_pte_write_fetch_gpte(vcpu
, &gpa
, new, &bytes
);
3978 * No need to care whether allocation memory is successful
3979 * or not since pte prefetch is skiped if it does not have
3980 * enough objects in the cache.
3982 mmu_topup_memory_caches(vcpu
);
3984 spin_lock(&vcpu
->kvm
->mmu_lock
);
3985 ++vcpu
->kvm
->stat
.mmu_pte_write
;
3986 kvm_mmu_audit(vcpu
, AUDIT_PRE_PTE_WRITE
);
3988 mask
.cr0_wp
= mask
.cr4_pae
= mask
.nxe
= 1;
3989 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, sp
, gfn
, node
) {
3990 if (detect_write_misaligned(sp
, gpa
, bytes
) ||
3991 detect_write_flooding(sp
)) {
3992 zap_page
|= !!kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
3994 ++vcpu
->kvm
->stat
.mmu_flooded
;
3998 spte
= get_written_sptes(sp
, gpa
, &npte
);
4005 mmu_page_zap_pte(vcpu
->kvm
, sp
, spte
);
4007 !((sp
->role
.word
^ vcpu
->arch
.mmu
.base_role
.word
)
4008 & mask
.word
) && rmap_can_add(vcpu
))
4009 mmu_pte_write_new_pte(vcpu
, sp
, spte
, &gentry
);
4010 if (!remote_flush
&& need_remote_flush(entry
, *spte
))
4011 remote_flush
= true;
4015 mmu_pte_write_flush_tlb(vcpu
, zap_page
, remote_flush
, local_flush
);
4016 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
4017 kvm_mmu_audit(vcpu
, AUDIT_POST_PTE_WRITE
);
4018 spin_unlock(&vcpu
->kvm
->mmu_lock
);
4021 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
4026 if (vcpu
->arch
.mmu
.direct_map
)
4029 gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, gva
, NULL
);
4031 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
4035 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
4037 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
4039 LIST_HEAD(invalid_list
);
4041 while (kvm_mmu_available_pages(vcpu
->kvm
) < KVM_REFILL_PAGES
&&
4042 !list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
4043 struct kvm_mmu_page
*sp
;
4045 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
4046 struct kvm_mmu_page
, link
);
4047 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
4048 ++vcpu
->kvm
->stat
.mmu_recycled
;
4050 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
4053 static bool is_mmio_page_fault(struct kvm_vcpu
*vcpu
, gva_t addr
)
4055 if (vcpu
->arch
.mmu
.direct_map
|| mmu_is_nested(vcpu
))
4056 return vcpu_match_mmio_gpa(vcpu
, addr
);
4058 return vcpu_match_mmio_gva(vcpu
, addr
);
4061 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
,
4062 void *insn
, int insn_len
)
4064 int r
, emulation_type
= EMULTYPE_RETRY
;
4065 enum emulation_result er
;
4067 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
, false);
4076 if (is_mmio_page_fault(vcpu
, cr2
))
4079 er
= x86_emulate_instruction(vcpu
, cr2
, emulation_type
, insn
, insn_len
);
4084 case EMULATE_DO_MMIO
:
4085 ++vcpu
->stat
.mmio_exits
;
4095 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
4097 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
4099 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
4100 kvm_mmu_flush_tlb(vcpu
);
4101 ++vcpu
->stat
.invlpg
;
4103 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
4105 void kvm_enable_tdp(void)
4109 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
4111 void kvm_disable_tdp(void)
4113 tdp_enabled
= false;
4115 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
4117 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
4119 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
4120 if (vcpu
->arch
.mmu
.lm_root
!= NULL
)
4121 free_page((unsigned long)vcpu
->arch
.mmu
.lm_root
);
4124 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
4132 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
4133 * Therefore we need to allocate shadow page tables in the first
4134 * 4GB of memory, which happens to fit the DMA32 zone.
4136 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
4140 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
4141 for (i
= 0; i
< 4; ++i
)
4142 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
4147 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
4151 vcpu
->arch
.walk_mmu
= &vcpu
->arch
.mmu
;
4152 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
4153 vcpu
->arch
.mmu
.translate_gpa
= translate_gpa
;
4154 vcpu
->arch
.nested_mmu
.translate_gpa
= translate_nested_gpa
;
4156 return alloc_mmu_pages(vcpu
);
4159 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
4162 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
4164 return init_kvm_mmu(vcpu
);
4167 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
4169 struct kvm_memory_slot
*memslot
;
4173 memslot
= id_to_memslot(kvm
->memslots
, slot
);
4174 last_gfn
= memslot
->base_gfn
+ memslot
->npages
- 1;
4176 spin_lock(&kvm
->mmu_lock
);
4178 for (i
= PT_PAGE_TABLE_LEVEL
;
4179 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
4180 unsigned long *rmapp
;
4181 unsigned long last_index
, index
;
4183 rmapp
= memslot
->arch
.rmap
[i
- PT_PAGE_TABLE_LEVEL
];
4184 last_index
= gfn_to_index(last_gfn
, memslot
->base_gfn
, i
);
4186 for (index
= 0; index
<= last_index
; ++index
, ++rmapp
) {
4188 __rmap_write_protect(kvm
, rmapp
, false);
4190 if (need_resched() || spin_needbreak(&kvm
->mmu_lock
)) {
4191 kvm_flush_remote_tlbs(kvm
);
4192 cond_resched_lock(&kvm
->mmu_lock
);
4197 kvm_flush_remote_tlbs(kvm
);
4198 spin_unlock(&kvm
->mmu_lock
);
4201 void kvm_mmu_zap_all(struct kvm
*kvm
)
4203 struct kvm_mmu_page
*sp
, *node
;
4204 LIST_HEAD(invalid_list
);
4206 spin_lock(&kvm
->mmu_lock
);
4208 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
4209 if (kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
))
4212 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
4213 spin_unlock(&kvm
->mmu_lock
);
4216 static void kvm_mmu_remove_some_alloc_mmu_pages(struct kvm
*kvm
,
4217 struct list_head
*invalid_list
)
4219 struct kvm_mmu_page
*page
;
4221 if (list_empty(&kvm
->arch
.active_mmu_pages
))
4224 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
4225 struct kvm_mmu_page
, link
);
4226 kvm_mmu_prepare_zap_page(kvm
, page
, invalid_list
);
4229 static int mmu_shrink(struct shrinker
*shrink
, struct shrink_control
*sc
)
4232 int nr_to_scan
= sc
->nr_to_scan
;
4234 if (nr_to_scan
== 0)
4237 raw_spin_lock(&kvm_lock
);
4239 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
4241 LIST_HEAD(invalid_list
);
4244 * Never scan more than sc->nr_to_scan VM instances.
4245 * Will not hit this condition practically since we do not try
4246 * to shrink more than one VM and it is very unlikely to see
4247 * !n_used_mmu_pages so many times.
4252 * n_used_mmu_pages is accessed without holding kvm->mmu_lock
4253 * here. We may skip a VM instance errorneosly, but we do not
4254 * want to shrink a VM that only started to populate its MMU
4257 if (!kvm
->arch
.n_used_mmu_pages
)
4260 idx
= srcu_read_lock(&kvm
->srcu
);
4261 spin_lock(&kvm
->mmu_lock
);
4263 kvm_mmu_remove_some_alloc_mmu_pages(kvm
, &invalid_list
);
4264 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
4266 spin_unlock(&kvm
->mmu_lock
);
4267 srcu_read_unlock(&kvm
->srcu
, idx
);
4269 list_move_tail(&kvm
->vm_list
, &vm_list
);
4273 raw_spin_unlock(&kvm_lock
);
4276 return percpu_counter_read_positive(&kvm_total_used_mmu_pages
);
4279 static struct shrinker mmu_shrinker
= {
4280 .shrink
= mmu_shrink
,
4281 .seeks
= DEFAULT_SEEKS
* 10,
4284 static void mmu_destroy_caches(void)
4286 if (pte_list_desc_cache
)
4287 kmem_cache_destroy(pte_list_desc_cache
);
4288 if (mmu_page_header_cache
)
4289 kmem_cache_destroy(mmu_page_header_cache
);
4292 int kvm_mmu_module_init(void)
4294 pte_list_desc_cache
= kmem_cache_create("pte_list_desc",
4295 sizeof(struct pte_list_desc
),
4297 if (!pte_list_desc_cache
)
4300 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
4301 sizeof(struct kvm_mmu_page
),
4303 if (!mmu_page_header_cache
)
4306 if (percpu_counter_init(&kvm_total_used_mmu_pages
, 0))
4309 register_shrinker(&mmu_shrinker
);
4314 mmu_destroy_caches();
4319 * Caculate mmu pages needed for kvm.
4321 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
4323 unsigned int nr_mmu_pages
;
4324 unsigned int nr_pages
= 0;
4325 struct kvm_memslots
*slots
;
4326 struct kvm_memory_slot
*memslot
;
4328 slots
= kvm_memslots(kvm
);
4330 kvm_for_each_memslot(memslot
, slots
)
4331 nr_pages
+= memslot
->npages
;
4333 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
4334 nr_mmu_pages
= max(nr_mmu_pages
,
4335 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
4337 return nr_mmu_pages
;
4340 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu
*vcpu
, u64 addr
, u64 sptes
[4])
4342 struct kvm_shadow_walk_iterator iterator
;
4346 walk_shadow_page_lockless_begin(vcpu
);
4347 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
) {
4348 sptes
[iterator
.level
-1] = spte
;
4350 if (!is_shadow_present_pte(spte
))
4353 walk_shadow_page_lockless_end(vcpu
);
4357 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy
);
4359 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
4363 destroy_kvm_mmu(vcpu
);
4364 free_mmu_pages(vcpu
);
4365 mmu_free_memory_caches(vcpu
);
4368 void kvm_mmu_module_exit(void)
4370 mmu_destroy_caches();
4371 percpu_counter_destroy(&kvm_total_used_mmu_pages
);
4372 unregister_shrinker(&mmu_shrinker
);
4373 mmu_audit_disable();