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 9
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 PTE_LIST_EXT 4
140 #define ACC_EXEC_MASK 1
141 #define ACC_WRITE_MASK PT_WRITABLE_MASK
142 #define ACC_USER_MASK PT_USER_MASK
143 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
145 #include <trace/events/kvm.h>
147 #define CREATE_TRACE_POINTS
148 #include "mmutrace.h"
150 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
152 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
154 struct pte_list_desc
{
155 u64
*sptes
[PTE_LIST_EXT
];
156 struct pte_list_desc
*more
;
159 struct kvm_shadow_walk_iterator
{
167 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
168 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
169 shadow_walk_okay(&(_walker)); \
170 shadow_walk_next(&(_walker)))
172 #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \
173 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
174 shadow_walk_okay(&(_walker)) && \
175 ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \
176 __shadow_walk_next(&(_walker), spte))
178 static struct kmem_cache
*pte_list_desc_cache
;
179 static struct kmem_cache
*mmu_page_header_cache
;
180 static struct percpu_counter kvm_total_used_mmu_pages
;
182 static u64 __read_mostly shadow_nx_mask
;
183 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
184 static u64 __read_mostly shadow_user_mask
;
185 static u64 __read_mostly shadow_accessed_mask
;
186 static u64 __read_mostly shadow_dirty_mask
;
187 static u64 __read_mostly shadow_mmio_mask
;
189 static void mmu_spte_set(u64
*sptep
, u64 spte
);
191 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask
)
193 shadow_mmio_mask
= mmio_mask
;
195 EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask
);
197 static void mark_mmio_spte(u64
*sptep
, u64 gfn
, unsigned access
)
199 access
&= ACC_WRITE_MASK
| ACC_USER_MASK
;
201 trace_mark_mmio_spte(sptep
, gfn
, access
);
202 mmu_spte_set(sptep
, shadow_mmio_mask
| access
| gfn
<< PAGE_SHIFT
);
205 static bool is_mmio_spte(u64 spte
)
207 return (spte
& shadow_mmio_mask
) == shadow_mmio_mask
;
210 static gfn_t
get_mmio_spte_gfn(u64 spte
)
212 return (spte
& ~shadow_mmio_mask
) >> PAGE_SHIFT
;
215 static unsigned get_mmio_spte_access(u64 spte
)
217 return (spte
& ~shadow_mmio_mask
) & ~PAGE_MASK
;
220 static bool set_mmio_spte(u64
*sptep
, gfn_t gfn
, pfn_t pfn
, unsigned access
)
222 if (unlikely(is_noslot_pfn(pfn
))) {
223 mark_mmio_spte(sptep
, gfn
, access
);
230 static inline u64
rsvd_bits(int s
, int e
)
232 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
235 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
236 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
238 shadow_user_mask
= user_mask
;
239 shadow_accessed_mask
= accessed_mask
;
240 shadow_dirty_mask
= dirty_mask
;
241 shadow_nx_mask
= nx_mask
;
242 shadow_x_mask
= x_mask
;
244 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
246 static int is_cpuid_PSE36(void)
251 static int is_nx(struct kvm_vcpu
*vcpu
)
253 return vcpu
->arch
.efer
& EFER_NX
;
256 static int is_shadow_present_pte(u64 pte
)
258 return pte
& PT_PRESENT_MASK
&& !is_mmio_spte(pte
);
261 static int is_large_pte(u64 pte
)
263 return pte
& PT_PAGE_SIZE_MASK
;
266 static int is_dirty_gpte(unsigned long pte
)
268 return pte
& PT_DIRTY_MASK
;
271 static int is_rmap_spte(u64 pte
)
273 return is_shadow_present_pte(pte
);
276 static int is_last_spte(u64 pte
, int level
)
278 if (level
== PT_PAGE_TABLE_LEVEL
)
280 if (is_large_pte(pte
))
285 static pfn_t
spte_to_pfn(u64 pte
)
287 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
290 static gfn_t
pse36_gfn_delta(u32 gpte
)
292 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
294 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
298 static void __set_spte(u64
*sptep
, u64 spte
)
303 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
308 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
310 return xchg(sptep
, spte
);
313 static u64
__get_spte_lockless(u64
*sptep
)
315 return ACCESS_ONCE(*sptep
);
318 static bool __check_direct_spte_mmio_pf(u64 spte
)
320 /* It is valid if the spte is zapped. */
332 static void count_spte_clear(u64
*sptep
, u64 spte
)
334 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
336 if (is_shadow_present_pte(spte
))
339 /* Ensure the spte is completely set before we increase the count */
341 sp
->clear_spte_count
++;
344 static void __set_spte(u64
*sptep
, u64 spte
)
346 union split_spte
*ssptep
, sspte
;
348 ssptep
= (union split_spte
*)sptep
;
349 sspte
= (union split_spte
)spte
;
351 ssptep
->spte_high
= sspte
.spte_high
;
354 * If we map the spte from nonpresent to present, We should store
355 * the high bits firstly, then set present bit, so cpu can not
356 * fetch this spte while we are setting the spte.
360 ssptep
->spte_low
= sspte
.spte_low
;
363 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
365 union split_spte
*ssptep
, sspte
;
367 ssptep
= (union split_spte
*)sptep
;
368 sspte
= (union split_spte
)spte
;
370 ssptep
->spte_low
= sspte
.spte_low
;
373 * If we map the spte from present to nonpresent, we should clear
374 * present bit firstly to avoid vcpu fetch the old high bits.
378 ssptep
->spte_high
= sspte
.spte_high
;
379 count_spte_clear(sptep
, spte
);
382 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
384 union split_spte
*ssptep
, sspte
, orig
;
386 ssptep
= (union split_spte
*)sptep
;
387 sspte
= (union split_spte
)spte
;
389 /* xchg acts as a barrier before the setting of the high bits */
390 orig
.spte_low
= xchg(&ssptep
->spte_low
, sspte
.spte_low
);
391 orig
.spte_high
= ssptep
->spte_high
;
392 ssptep
->spte_high
= sspte
.spte_high
;
393 count_spte_clear(sptep
, spte
);
399 * The idea using the light way get the spte on x86_32 guest is from
400 * gup_get_pte(arch/x86/mm/gup.c).
401 * The difference is we can not catch the spte tlb flush if we leave
402 * guest mode, so we emulate it by increase clear_spte_count when spte
405 static u64
__get_spte_lockless(u64
*sptep
)
407 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
408 union split_spte spte
, *orig
= (union split_spte
*)sptep
;
412 count
= sp
->clear_spte_count
;
415 spte
.spte_low
= orig
->spte_low
;
418 spte
.spte_high
= orig
->spte_high
;
421 if (unlikely(spte
.spte_low
!= orig
->spte_low
||
422 count
!= sp
->clear_spte_count
))
428 static bool __check_direct_spte_mmio_pf(u64 spte
)
430 union split_spte sspte
= (union split_spte
)spte
;
431 u32 high_mmio_mask
= shadow_mmio_mask
>> 32;
433 /* It is valid if the spte is zapped. */
437 /* It is valid if the spte is being zapped. */
438 if (sspte
.spte_low
== 0ull &&
439 (sspte
.spte_high
& high_mmio_mask
) == high_mmio_mask
)
446 static bool spte_has_volatile_bits(u64 spte
)
448 if (!shadow_accessed_mask
)
451 if (!is_shadow_present_pte(spte
))
454 if ((spte
& shadow_accessed_mask
) &&
455 (!is_writable_pte(spte
) || (spte
& shadow_dirty_mask
)))
461 static bool spte_is_bit_cleared(u64 old_spte
, u64 new_spte
, u64 bit_mask
)
463 return (old_spte
& bit_mask
) && !(new_spte
& bit_mask
);
466 /* Rules for using mmu_spte_set:
467 * Set the sptep from nonpresent to present.
468 * Note: the sptep being assigned *must* be either not present
469 * or in a state where the hardware will not attempt to update
472 static void mmu_spte_set(u64
*sptep
, u64 new_spte
)
474 WARN_ON(is_shadow_present_pte(*sptep
));
475 __set_spte(sptep
, new_spte
);
478 /* Rules for using mmu_spte_update:
479 * Update the state bits, it means the mapped pfn is not changged.
481 static void mmu_spte_update(u64
*sptep
, u64 new_spte
)
483 u64 mask
, old_spte
= *sptep
;
485 WARN_ON(!is_rmap_spte(new_spte
));
487 if (!is_shadow_present_pte(old_spte
))
488 return mmu_spte_set(sptep
, new_spte
);
490 new_spte
|= old_spte
& shadow_dirty_mask
;
492 mask
= shadow_accessed_mask
;
493 if (is_writable_pte(old_spte
))
494 mask
|= shadow_dirty_mask
;
496 if (!spte_has_volatile_bits(old_spte
) || (new_spte
& mask
) == mask
)
497 __update_clear_spte_fast(sptep
, new_spte
);
499 old_spte
= __update_clear_spte_slow(sptep
, new_spte
);
501 if (!shadow_accessed_mask
)
504 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_accessed_mask
))
505 kvm_set_pfn_accessed(spte_to_pfn(old_spte
));
506 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_dirty_mask
))
507 kvm_set_pfn_dirty(spte_to_pfn(old_spte
));
511 * Rules for using mmu_spte_clear_track_bits:
512 * It sets the sptep from present to nonpresent, and track the
513 * state bits, it is used to clear the last level sptep.
515 static int mmu_spte_clear_track_bits(u64
*sptep
)
518 u64 old_spte
= *sptep
;
520 if (!spte_has_volatile_bits(old_spte
))
521 __update_clear_spte_fast(sptep
, 0ull);
523 old_spte
= __update_clear_spte_slow(sptep
, 0ull);
525 if (!is_rmap_spte(old_spte
))
528 pfn
= spte_to_pfn(old_spte
);
529 if (!shadow_accessed_mask
|| old_spte
& shadow_accessed_mask
)
530 kvm_set_pfn_accessed(pfn
);
531 if (!shadow_dirty_mask
|| (old_spte
& shadow_dirty_mask
))
532 kvm_set_pfn_dirty(pfn
);
537 * Rules for using mmu_spte_clear_no_track:
538 * Directly clear spte without caring the state bits of sptep,
539 * it is used to set the upper level spte.
541 static void mmu_spte_clear_no_track(u64
*sptep
)
543 __update_clear_spte_fast(sptep
, 0ull);
546 static u64
mmu_spte_get_lockless(u64
*sptep
)
548 return __get_spte_lockless(sptep
);
551 static void walk_shadow_page_lockless_begin(struct kvm_vcpu
*vcpu
)
554 atomic_inc(&vcpu
->kvm
->arch
.reader_counter
);
556 /* Increase the counter before walking shadow page table */
557 smp_mb__after_atomic_inc();
560 static void walk_shadow_page_lockless_end(struct kvm_vcpu
*vcpu
)
562 /* Decrease the counter after walking shadow page table finished */
563 smp_mb__before_atomic_dec();
564 atomic_dec(&vcpu
->kvm
->arch
.reader_counter
);
568 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
569 struct kmem_cache
*base_cache
, int min
)
573 if (cache
->nobjs
>= min
)
575 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
576 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
579 cache
->objects
[cache
->nobjs
++] = obj
;
584 static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache
*cache
)
589 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
,
590 struct kmem_cache
*cache
)
593 kmem_cache_free(cache
, mc
->objects
[--mc
->nobjs
]);
596 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
601 if (cache
->nobjs
>= min
)
603 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
604 page
= (void *)__get_free_page(GFP_KERNEL
);
607 cache
->objects
[cache
->nobjs
++] = page
;
612 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
615 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
618 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
622 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
623 pte_list_desc_cache
, 8 + PTE_PREFETCH_NUM
);
626 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
629 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
630 mmu_page_header_cache
, 4);
635 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
637 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
638 pte_list_desc_cache
);
639 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
640 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
641 mmu_page_header_cache
);
644 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
650 p
= mc
->objects
[--mc
->nobjs
];
654 static struct pte_list_desc
*mmu_alloc_pte_list_desc(struct kvm_vcpu
*vcpu
)
656 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_list_desc_cache
,
657 sizeof(struct pte_list_desc
));
660 static void mmu_free_pte_list_desc(struct pte_list_desc
*pte_list_desc
)
662 kmem_cache_free(pte_list_desc_cache
, pte_list_desc
);
665 static gfn_t
kvm_mmu_page_get_gfn(struct kvm_mmu_page
*sp
, int index
)
667 if (!sp
->role
.direct
)
668 return sp
->gfns
[index
];
670 return sp
->gfn
+ (index
<< ((sp
->role
.level
- 1) * PT64_LEVEL_BITS
));
673 static void kvm_mmu_page_set_gfn(struct kvm_mmu_page
*sp
, int index
, gfn_t gfn
)
676 BUG_ON(gfn
!= kvm_mmu_page_get_gfn(sp
, index
));
678 sp
->gfns
[index
] = gfn
;
682 * Return the pointer to the large page information for a given gfn,
683 * handling slots that are not large page aligned.
685 static struct kvm_lpage_info
*lpage_info_slot(gfn_t gfn
,
686 struct kvm_memory_slot
*slot
,
691 idx
= (gfn
>> KVM_HPAGE_GFN_SHIFT(level
)) -
692 (slot
->base_gfn
>> KVM_HPAGE_GFN_SHIFT(level
));
693 return &slot
->lpage_info
[level
- 2][idx
];
696 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
698 struct kvm_memory_slot
*slot
;
699 struct kvm_lpage_info
*linfo
;
702 slot
= gfn_to_memslot(kvm
, gfn
);
703 for (i
= PT_DIRECTORY_LEVEL
;
704 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
705 linfo
= lpage_info_slot(gfn
, slot
, i
);
706 linfo
->write_count
+= 1;
708 kvm
->arch
.indirect_shadow_pages
++;
711 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
713 struct kvm_memory_slot
*slot
;
714 struct kvm_lpage_info
*linfo
;
717 slot
= gfn_to_memslot(kvm
, gfn
);
718 for (i
= PT_DIRECTORY_LEVEL
;
719 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
720 linfo
= lpage_info_slot(gfn
, slot
, i
);
721 linfo
->write_count
-= 1;
722 WARN_ON(linfo
->write_count
< 0);
724 kvm
->arch
.indirect_shadow_pages
--;
727 static int has_wrprotected_page(struct kvm
*kvm
,
731 struct kvm_memory_slot
*slot
;
732 struct kvm_lpage_info
*linfo
;
734 slot
= gfn_to_memslot(kvm
, gfn
);
736 linfo
= lpage_info_slot(gfn
, slot
, level
);
737 return linfo
->write_count
;
743 static int host_mapping_level(struct kvm
*kvm
, gfn_t gfn
)
745 unsigned long page_size
;
748 page_size
= kvm_host_page_size(kvm
, gfn
);
750 for (i
= PT_PAGE_TABLE_LEVEL
;
751 i
< (PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
); ++i
) {
752 if (page_size
>= KVM_HPAGE_SIZE(i
))
761 static struct kvm_memory_slot
*
762 gfn_to_memslot_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
765 struct kvm_memory_slot
*slot
;
767 slot
= gfn_to_memslot(vcpu
->kvm
, gfn
);
768 if (!slot
|| slot
->flags
& KVM_MEMSLOT_INVALID
||
769 (no_dirty_log
&& slot
->dirty_bitmap
))
775 static bool mapping_level_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
777 return !gfn_to_memslot_dirty_bitmap(vcpu
, large_gfn
, true);
780 static int mapping_level(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
782 int host_level
, level
, max_level
;
784 host_level
= host_mapping_level(vcpu
->kvm
, large_gfn
);
786 if (host_level
== PT_PAGE_TABLE_LEVEL
)
789 max_level
= kvm_x86_ops
->get_lpage_level() < host_level
?
790 kvm_x86_ops
->get_lpage_level() : host_level
;
792 for (level
= PT_DIRECTORY_LEVEL
; level
<= max_level
; ++level
)
793 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
, level
))
800 * Pte mapping structures:
802 * If pte_list bit zero is zero, then pte_list point to the spte.
804 * If pte_list bit zero is one, (then pte_list & ~1) points to a struct
805 * pte_list_desc containing more mappings.
807 * Returns the number of pte entries before the spte was added or zero if
808 * the spte was not added.
811 static int pte_list_add(struct kvm_vcpu
*vcpu
, u64
*spte
,
812 unsigned long *pte_list
)
814 struct pte_list_desc
*desc
;
818 rmap_printk("pte_list_add: %p %llx 0->1\n", spte
, *spte
);
819 *pte_list
= (unsigned long)spte
;
820 } else if (!(*pte_list
& 1)) {
821 rmap_printk("pte_list_add: %p %llx 1->many\n", spte
, *spte
);
822 desc
= mmu_alloc_pte_list_desc(vcpu
);
823 desc
->sptes
[0] = (u64
*)*pte_list
;
824 desc
->sptes
[1] = spte
;
825 *pte_list
= (unsigned long)desc
| 1;
828 rmap_printk("pte_list_add: %p %llx many->many\n", spte
, *spte
);
829 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
830 while (desc
->sptes
[PTE_LIST_EXT
-1] && desc
->more
) {
832 count
+= PTE_LIST_EXT
;
834 if (desc
->sptes
[PTE_LIST_EXT
-1]) {
835 desc
->more
= mmu_alloc_pte_list_desc(vcpu
);
838 for (i
= 0; desc
->sptes
[i
]; ++i
)
840 desc
->sptes
[i
] = spte
;
845 static u64
*pte_list_next(unsigned long *pte_list
, u64
*spte
)
847 struct pte_list_desc
*desc
;
853 else if (!(*pte_list
& 1)) {
855 return (u64
*)*pte_list
;
858 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
861 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
) {
862 if (prev_spte
== spte
)
863 return desc
->sptes
[i
];
864 prev_spte
= desc
->sptes
[i
];
872 pte_list_desc_remove_entry(unsigned long *pte_list
, struct pte_list_desc
*desc
,
873 int i
, struct pte_list_desc
*prev_desc
)
877 for (j
= PTE_LIST_EXT
- 1; !desc
->sptes
[j
] && j
> i
; --j
)
879 desc
->sptes
[i
] = desc
->sptes
[j
];
880 desc
->sptes
[j
] = NULL
;
883 if (!prev_desc
&& !desc
->more
)
884 *pte_list
= (unsigned long)desc
->sptes
[0];
887 prev_desc
->more
= desc
->more
;
889 *pte_list
= (unsigned long)desc
->more
| 1;
890 mmu_free_pte_list_desc(desc
);
893 static void pte_list_remove(u64
*spte
, unsigned long *pte_list
)
895 struct pte_list_desc
*desc
;
896 struct pte_list_desc
*prev_desc
;
900 printk(KERN_ERR
"pte_list_remove: %p 0->BUG\n", spte
);
902 } else if (!(*pte_list
& 1)) {
903 rmap_printk("pte_list_remove: %p 1->0\n", spte
);
904 if ((u64
*)*pte_list
!= spte
) {
905 printk(KERN_ERR
"pte_list_remove: %p 1->BUG\n", spte
);
910 rmap_printk("pte_list_remove: %p many->many\n", spte
);
911 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
914 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
915 if (desc
->sptes
[i
] == spte
) {
916 pte_list_desc_remove_entry(pte_list
,
924 pr_err("pte_list_remove: %p many->many\n", spte
);
929 typedef void (*pte_list_walk_fn
) (u64
*spte
);
930 static void pte_list_walk(unsigned long *pte_list
, pte_list_walk_fn fn
)
932 struct pte_list_desc
*desc
;
938 if (!(*pte_list
& 1))
939 return fn((u64
*)*pte_list
);
941 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
943 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
949 static unsigned long *__gfn_to_rmap(gfn_t gfn
, int level
,
950 struct kvm_memory_slot
*slot
)
952 struct kvm_lpage_info
*linfo
;
954 if (likely(level
== PT_PAGE_TABLE_LEVEL
))
955 return &slot
->rmap
[gfn
- slot
->base_gfn
];
957 linfo
= lpage_info_slot(gfn
, slot
, level
);
958 return &linfo
->rmap_pde
;
962 * Take gfn and return the reverse mapping to it.
964 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int level
)
966 struct kvm_memory_slot
*slot
;
968 slot
= gfn_to_memslot(kvm
, gfn
);
969 return __gfn_to_rmap(gfn
, level
, slot
);
972 static bool rmap_can_add(struct kvm_vcpu
*vcpu
)
974 struct kvm_mmu_memory_cache
*cache
;
976 cache
= &vcpu
->arch
.mmu_pte_list_desc_cache
;
977 return mmu_memory_cache_free_objects(cache
);
980 static int rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
982 struct kvm_mmu_page
*sp
;
983 unsigned long *rmapp
;
985 sp
= page_header(__pa(spte
));
986 kvm_mmu_page_set_gfn(sp
, spte
- sp
->spt
, gfn
);
987 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
988 return pte_list_add(vcpu
, spte
, rmapp
);
991 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
993 return pte_list_next(rmapp
, spte
);
996 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
998 struct kvm_mmu_page
*sp
;
1000 unsigned long *rmapp
;
1002 sp
= page_header(__pa(spte
));
1003 gfn
= kvm_mmu_page_get_gfn(sp
, spte
- sp
->spt
);
1004 rmapp
= gfn_to_rmap(kvm
, gfn
, sp
->role
.level
);
1005 pte_list_remove(spte
, rmapp
);
1008 static void drop_spte(struct kvm
*kvm
, u64
*sptep
)
1010 if (mmu_spte_clear_track_bits(sptep
))
1011 rmap_remove(kvm
, sptep
);
1014 int kvm_mmu_rmap_write_protect(struct kvm
*kvm
, u64 gfn
,
1015 struct kvm_memory_slot
*slot
)
1017 unsigned long *rmapp
;
1019 int i
, write_protected
= 0;
1021 rmapp
= __gfn_to_rmap(gfn
, PT_PAGE_TABLE_LEVEL
, slot
);
1022 spte
= rmap_next(kvm
, rmapp
, NULL
);
1024 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
1025 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
1026 if (is_writable_pte(*spte
)) {
1027 mmu_spte_update(spte
, *spte
& ~PT_WRITABLE_MASK
);
1028 write_protected
= 1;
1030 spte
= rmap_next(kvm
, rmapp
, spte
);
1033 /* check for huge page mappings */
1034 for (i
= PT_DIRECTORY_LEVEL
;
1035 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
1036 rmapp
= __gfn_to_rmap(gfn
, i
, slot
);
1037 spte
= rmap_next(kvm
, rmapp
, NULL
);
1039 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
1040 BUG_ON(!is_large_pte(*spte
));
1041 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
1042 if (is_writable_pte(*spte
)) {
1043 drop_spte(kvm
, spte
);
1046 write_protected
= 1;
1048 spte
= rmap_next(kvm
, rmapp
, spte
);
1052 return write_protected
;
1055 static int rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
1057 struct kvm_memory_slot
*slot
;
1059 slot
= gfn_to_memslot(kvm
, gfn
);
1060 return kvm_mmu_rmap_write_protect(kvm
, gfn
, slot
);
1063 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1067 int need_tlb_flush
= 0;
1069 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
1070 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
1071 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
1072 drop_spte(kvm
, spte
);
1075 return need_tlb_flush
;
1078 static int kvm_set_pte_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1082 u64
*spte
, new_spte
;
1083 pte_t
*ptep
= (pte_t
*)data
;
1086 WARN_ON(pte_huge(*ptep
));
1087 new_pfn
= pte_pfn(*ptep
);
1088 spte
= rmap_next(kvm
, rmapp
, NULL
);
1090 BUG_ON(!is_shadow_present_pte(*spte
));
1091 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte
, *spte
);
1093 if (pte_write(*ptep
)) {
1094 drop_spte(kvm
, spte
);
1095 spte
= rmap_next(kvm
, rmapp
, NULL
);
1097 new_spte
= *spte
&~ (PT64_BASE_ADDR_MASK
);
1098 new_spte
|= (u64
)new_pfn
<< PAGE_SHIFT
;
1100 new_spte
&= ~PT_WRITABLE_MASK
;
1101 new_spte
&= ~SPTE_HOST_WRITEABLE
;
1102 new_spte
&= ~shadow_accessed_mask
;
1103 mmu_spte_clear_track_bits(spte
);
1104 mmu_spte_set(spte
, new_spte
);
1105 spte
= rmap_next(kvm
, rmapp
, spte
);
1109 kvm_flush_remote_tlbs(kvm
);
1114 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
1116 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
,
1117 unsigned long data
))
1122 struct kvm_memslots
*slots
;
1123 struct kvm_memory_slot
*memslot
;
1125 slots
= kvm_memslots(kvm
);
1127 kvm_for_each_memslot(memslot
, slots
) {
1128 unsigned long start
= memslot
->userspace_addr
;
1131 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
1132 if (hva
>= start
&& hva
< end
) {
1133 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
1134 gfn_t gfn
= memslot
->base_gfn
+ gfn_offset
;
1136 ret
= handler(kvm
, &memslot
->rmap
[gfn_offset
], data
);
1138 for (j
= 0; j
< KVM_NR_PAGE_SIZES
- 1; ++j
) {
1139 struct kvm_lpage_info
*linfo
;
1141 linfo
= lpage_info_slot(gfn
, memslot
,
1142 PT_DIRECTORY_LEVEL
+ j
);
1143 ret
|= handler(kvm
, &linfo
->rmap_pde
, data
);
1145 trace_kvm_age_page(hva
, memslot
, ret
);
1153 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
1155 return kvm_handle_hva(kvm
, hva
, 0, kvm_unmap_rmapp
);
1158 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
1160 kvm_handle_hva(kvm
, hva
, (unsigned long)&pte
, kvm_set_pte_rmapp
);
1163 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1170 * Emulate the accessed bit for EPT, by checking if this page has
1171 * an EPT mapping, and clearing it if it does. On the next access,
1172 * a new EPT mapping will be established.
1173 * This has some overhead, but not as much as the cost of swapping
1174 * out actively used pages or breaking up actively used hugepages.
1176 if (!shadow_accessed_mask
)
1177 return kvm_unmap_rmapp(kvm
, rmapp
, data
);
1179 spte
= rmap_next(kvm
, rmapp
, NULL
);
1183 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
1184 _young
= _spte
& PT_ACCESSED_MASK
;
1187 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
1189 spte
= rmap_next(kvm
, rmapp
, spte
);
1194 static int kvm_test_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1201 * If there's no access bit in the secondary pte set by the
1202 * hardware it's up to gup-fast/gup to set the access bit in
1203 * the primary pte or in the page structure.
1205 if (!shadow_accessed_mask
)
1208 spte
= rmap_next(kvm
, rmapp
, NULL
);
1211 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
1212 young
= _spte
& PT_ACCESSED_MASK
;
1217 spte
= rmap_next(kvm
, rmapp
, spte
);
1223 #define RMAP_RECYCLE_THRESHOLD 1000
1225 static void rmap_recycle(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
1227 unsigned long *rmapp
;
1228 struct kvm_mmu_page
*sp
;
1230 sp
= page_header(__pa(spte
));
1232 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
1234 kvm_unmap_rmapp(vcpu
->kvm
, rmapp
, 0);
1235 kvm_flush_remote_tlbs(vcpu
->kvm
);
1238 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
1240 return kvm_handle_hva(kvm
, hva
, 0, kvm_age_rmapp
);
1243 int kvm_test_age_hva(struct kvm
*kvm
, unsigned long hva
)
1245 return kvm_handle_hva(kvm
, hva
, 0, kvm_test_age_rmapp
);
1249 static int is_empty_shadow_page(u64
*spt
)
1254 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
1255 if (is_shadow_present_pte(*pos
)) {
1256 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
1265 * This value is the sum of all of the kvm instances's
1266 * kvm->arch.n_used_mmu_pages values. We need a global,
1267 * aggregate version in order to make the slab shrinker
1270 static inline void kvm_mod_used_mmu_pages(struct kvm
*kvm
, int nr
)
1272 kvm
->arch
.n_used_mmu_pages
+= nr
;
1273 percpu_counter_add(&kvm_total_used_mmu_pages
, nr
);
1277 * Remove the sp from shadow page cache, after call it,
1278 * we can not find this sp from the cache, and the shadow
1279 * page table is still valid.
1280 * It should be under the protection of mmu lock.
1282 static void kvm_mmu_isolate_page(struct kvm_mmu_page
*sp
)
1284 ASSERT(is_empty_shadow_page(sp
->spt
));
1285 hlist_del(&sp
->hash_link
);
1286 if (!sp
->role
.direct
)
1287 free_page((unsigned long)sp
->gfns
);
1291 * Free the shadow page table and the sp, we can do it
1292 * out of the protection of mmu lock.
1294 static void kvm_mmu_free_page(struct kvm_mmu_page
*sp
)
1296 list_del(&sp
->link
);
1297 free_page((unsigned long)sp
->spt
);
1298 kmem_cache_free(mmu_page_header_cache
, sp
);
1301 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
1303 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
1306 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
1307 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1312 pte_list_add(vcpu
, parent_pte
, &sp
->parent_ptes
);
1315 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
1318 pte_list_remove(parent_pte
, &sp
->parent_ptes
);
1321 static void drop_parent_pte(struct kvm_mmu_page
*sp
,
1324 mmu_page_remove_parent_pte(sp
, parent_pte
);
1325 mmu_spte_clear_no_track(parent_pte
);
1328 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
1329 u64
*parent_pte
, int direct
)
1331 struct kvm_mmu_page
*sp
;
1332 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
,
1334 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
1336 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
,
1338 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
1339 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
1340 bitmap_zero(sp
->slot_bitmap
, KVM_MEM_SLOTS_NUM
);
1341 sp
->parent_ptes
= 0;
1342 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1343 kvm_mod_used_mmu_pages(vcpu
->kvm
, +1);
1347 static void mark_unsync(u64
*spte
);
1348 static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page
*sp
)
1350 pte_list_walk(&sp
->parent_ptes
, mark_unsync
);
1353 static void mark_unsync(u64
*spte
)
1355 struct kvm_mmu_page
*sp
;
1358 sp
= page_header(__pa(spte
));
1359 index
= spte
- sp
->spt
;
1360 if (__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
1362 if (sp
->unsync_children
++)
1364 kvm_mmu_mark_parents_unsync(sp
);
1367 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
1368 struct kvm_mmu_page
*sp
)
1373 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
1377 static void nonpaging_update_pte(struct kvm_vcpu
*vcpu
,
1378 struct kvm_mmu_page
*sp
, u64
*spte
,
1384 #define KVM_PAGE_ARRAY_NR 16
1386 struct kvm_mmu_pages
{
1387 struct mmu_page_and_offset
{
1388 struct kvm_mmu_page
*sp
;
1390 } page
[KVM_PAGE_ARRAY_NR
];
1394 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
1400 for (i
=0; i
< pvec
->nr
; i
++)
1401 if (pvec
->page
[i
].sp
== sp
)
1404 pvec
->page
[pvec
->nr
].sp
= sp
;
1405 pvec
->page
[pvec
->nr
].idx
= idx
;
1407 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1410 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1411 struct kvm_mmu_pages
*pvec
)
1413 int i
, ret
, nr_unsync_leaf
= 0;
1415 for_each_set_bit(i
, sp
->unsync_child_bitmap
, 512) {
1416 struct kvm_mmu_page
*child
;
1417 u64 ent
= sp
->spt
[i
];
1419 if (!is_shadow_present_pte(ent
) || is_large_pte(ent
))
1420 goto clear_child_bitmap
;
1422 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1424 if (child
->unsync_children
) {
1425 if (mmu_pages_add(pvec
, child
, i
))
1428 ret
= __mmu_unsync_walk(child
, pvec
);
1430 goto clear_child_bitmap
;
1432 nr_unsync_leaf
+= ret
;
1435 } else if (child
->unsync
) {
1437 if (mmu_pages_add(pvec
, child
, i
))
1440 goto clear_child_bitmap
;
1445 __clear_bit(i
, sp
->unsync_child_bitmap
);
1446 sp
->unsync_children
--;
1447 WARN_ON((int)sp
->unsync_children
< 0);
1451 return nr_unsync_leaf
;
1454 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1455 struct kvm_mmu_pages
*pvec
)
1457 if (!sp
->unsync_children
)
1460 mmu_pages_add(pvec
, sp
, 0);
1461 return __mmu_unsync_walk(sp
, pvec
);
1464 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1466 WARN_ON(!sp
->unsync
);
1467 trace_kvm_mmu_sync_page(sp
);
1469 --kvm
->stat
.mmu_unsync
;
1472 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1473 struct list_head
*invalid_list
);
1474 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
1475 struct list_head
*invalid_list
);
1477 #define for_each_gfn_sp(kvm, sp, gfn, pos) \
1478 hlist_for_each_entry(sp, pos, \
1479 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1480 if ((sp)->gfn != (gfn)) {} else
1482 #define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos) \
1483 hlist_for_each_entry(sp, pos, \
1484 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1485 if ((sp)->gfn != (gfn) || (sp)->role.direct || \
1486 (sp)->role.invalid) {} else
1488 /* @sp->gfn should be write-protected at the call site */
1489 static int __kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1490 struct list_head
*invalid_list
, bool clear_unsync
)
1492 if (sp
->role
.cr4_pae
!= !!is_pae(vcpu
)) {
1493 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1498 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1500 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1501 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1505 kvm_mmu_flush_tlb(vcpu
);
1509 static int kvm_sync_page_transient(struct kvm_vcpu
*vcpu
,
1510 struct kvm_mmu_page
*sp
)
1512 LIST_HEAD(invalid_list
);
1515 ret
= __kvm_sync_page(vcpu
, sp
, &invalid_list
, false);
1517 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1522 #ifdef CONFIG_KVM_MMU_AUDIT
1523 #include "mmu_audit.c"
1525 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, int point
) { }
1526 static void mmu_audit_disable(void) { }
1529 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1530 struct list_head
*invalid_list
)
1532 return __kvm_sync_page(vcpu
, sp
, invalid_list
, true);
1535 /* @gfn should be write-protected at the call site */
1536 static void kvm_sync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1538 struct kvm_mmu_page
*s
;
1539 struct hlist_node
*node
;
1540 LIST_HEAD(invalid_list
);
1543 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
1547 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
1548 kvm_unlink_unsync_page(vcpu
->kvm
, s
);
1549 if ((s
->role
.cr4_pae
!= !!is_pae(vcpu
)) ||
1550 (vcpu
->arch
.mmu
.sync_page(vcpu
, s
))) {
1551 kvm_mmu_prepare_zap_page(vcpu
->kvm
, s
, &invalid_list
);
1557 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1559 kvm_mmu_flush_tlb(vcpu
);
1562 struct mmu_page_path
{
1563 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1564 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1567 #define for_each_sp(pvec, sp, parents, i) \
1568 for (i = mmu_pages_next(&pvec, &parents, -1), \
1569 sp = pvec.page[i].sp; \
1570 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1571 i = mmu_pages_next(&pvec, &parents, i))
1573 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1574 struct mmu_page_path
*parents
,
1579 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1580 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1582 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1583 parents
->idx
[0] = pvec
->page
[n
].idx
;
1587 parents
->parent
[sp
->role
.level
-2] = sp
;
1588 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1594 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1596 struct kvm_mmu_page
*sp
;
1597 unsigned int level
= 0;
1600 unsigned int idx
= parents
->idx
[level
];
1602 sp
= parents
->parent
[level
];
1606 --sp
->unsync_children
;
1607 WARN_ON((int)sp
->unsync_children
< 0);
1608 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1610 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1613 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1614 struct mmu_page_path
*parents
,
1615 struct kvm_mmu_pages
*pvec
)
1617 parents
->parent
[parent
->role
.level
-1] = NULL
;
1621 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1622 struct kvm_mmu_page
*parent
)
1625 struct kvm_mmu_page
*sp
;
1626 struct mmu_page_path parents
;
1627 struct kvm_mmu_pages pages
;
1628 LIST_HEAD(invalid_list
);
1630 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1631 while (mmu_unsync_walk(parent
, &pages
)) {
1634 for_each_sp(pages
, sp
, parents
, i
)
1635 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1638 kvm_flush_remote_tlbs(vcpu
->kvm
);
1640 for_each_sp(pages
, sp
, parents
, i
) {
1641 kvm_sync_page(vcpu
, sp
, &invalid_list
);
1642 mmu_pages_clear_parents(&parents
);
1644 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1645 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1646 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1650 static void init_shadow_page_table(struct kvm_mmu_page
*sp
)
1654 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1658 static void __clear_sp_write_flooding_count(struct kvm_mmu_page
*sp
)
1660 sp
->write_flooding_count
= 0;
1663 static void clear_sp_write_flooding_count(u64
*spte
)
1665 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
1667 __clear_sp_write_flooding_count(sp
);
1670 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1678 union kvm_mmu_page_role role
;
1680 struct kvm_mmu_page
*sp
;
1681 struct hlist_node
*node
;
1682 bool need_sync
= false;
1684 role
= vcpu
->arch
.mmu
.base_role
;
1686 role
.direct
= direct
;
1689 role
.access
= access
;
1690 if (!vcpu
->arch
.mmu
.direct_map
1691 && vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1692 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1693 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1694 role
.quadrant
= quadrant
;
1696 for_each_gfn_sp(vcpu
->kvm
, sp
, gfn
, node
) {
1697 if (!need_sync
&& sp
->unsync
)
1700 if (sp
->role
.word
!= role
.word
)
1703 if (sp
->unsync
&& kvm_sync_page_transient(vcpu
, sp
))
1706 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1707 if (sp
->unsync_children
) {
1708 kvm_make_request(KVM_REQ_MMU_SYNC
, vcpu
);
1709 kvm_mmu_mark_parents_unsync(sp
);
1710 } else if (sp
->unsync
)
1711 kvm_mmu_mark_parents_unsync(sp
);
1713 __clear_sp_write_flooding_count(sp
);
1714 trace_kvm_mmu_get_page(sp
, false);
1717 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1718 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
, direct
);
1723 hlist_add_head(&sp
->hash_link
,
1724 &vcpu
->kvm
->arch
.mmu_page_hash
[kvm_page_table_hashfn(gfn
)]);
1726 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1727 kvm_flush_remote_tlbs(vcpu
->kvm
);
1728 if (level
> PT_PAGE_TABLE_LEVEL
&& need_sync
)
1729 kvm_sync_pages(vcpu
, gfn
);
1731 account_shadowed(vcpu
->kvm
, gfn
);
1733 init_shadow_page_table(sp
);
1734 trace_kvm_mmu_get_page(sp
, true);
1738 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1739 struct kvm_vcpu
*vcpu
, u64 addr
)
1741 iterator
->addr
= addr
;
1742 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1743 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1745 if (iterator
->level
== PT64_ROOT_LEVEL
&&
1746 vcpu
->arch
.mmu
.root_level
< PT64_ROOT_LEVEL
&&
1747 !vcpu
->arch
.mmu
.direct_map
)
1750 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1751 iterator
->shadow_addr
1752 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1753 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1755 if (!iterator
->shadow_addr
)
1756 iterator
->level
= 0;
1760 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1762 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1765 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1766 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1770 static void __shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
,
1773 if (is_last_spte(spte
, iterator
->level
)) {
1774 iterator
->level
= 0;
1778 iterator
->shadow_addr
= spte
& PT64_BASE_ADDR_MASK
;
1782 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1784 return __shadow_walk_next(iterator
, *iterator
->sptep
);
1787 static void link_shadow_page(u64
*sptep
, struct kvm_mmu_page
*sp
)
1791 spte
= __pa(sp
->spt
)
1792 | PT_PRESENT_MASK
| PT_ACCESSED_MASK
1793 | PT_WRITABLE_MASK
| PT_USER_MASK
;
1794 mmu_spte_set(sptep
, spte
);
1797 static void drop_large_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
)
1799 if (is_large_pte(*sptep
)) {
1800 drop_spte(vcpu
->kvm
, sptep
);
1801 --vcpu
->kvm
->stat
.lpages
;
1802 kvm_flush_remote_tlbs(vcpu
->kvm
);
1806 static void validate_direct_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1807 unsigned direct_access
)
1809 if (is_shadow_present_pte(*sptep
) && !is_large_pte(*sptep
)) {
1810 struct kvm_mmu_page
*child
;
1813 * For the direct sp, if the guest pte's dirty bit
1814 * changed form clean to dirty, it will corrupt the
1815 * sp's access: allow writable in the read-only sp,
1816 * so we should update the spte at this point to get
1817 * a new sp with the correct access.
1819 child
= page_header(*sptep
& PT64_BASE_ADDR_MASK
);
1820 if (child
->role
.access
== direct_access
)
1823 drop_parent_pte(child
, sptep
);
1824 kvm_flush_remote_tlbs(vcpu
->kvm
);
1828 static bool mmu_page_zap_pte(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1832 struct kvm_mmu_page
*child
;
1835 if (is_shadow_present_pte(pte
)) {
1836 if (is_last_spte(pte
, sp
->role
.level
)) {
1837 drop_spte(kvm
, spte
);
1838 if (is_large_pte(pte
))
1841 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1842 drop_parent_pte(child
, spte
);
1847 if (is_mmio_spte(pte
))
1848 mmu_spte_clear_no_track(spte
);
1853 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1854 struct kvm_mmu_page
*sp
)
1858 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1859 mmu_page_zap_pte(kvm
, sp
, sp
->spt
+ i
);
1862 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1864 mmu_page_remove_parent_pte(sp
, parent_pte
);
1867 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1871 while ((parent_pte
= pte_list_next(&sp
->parent_ptes
, NULL
)))
1872 drop_parent_pte(sp
, parent_pte
);
1875 static int mmu_zap_unsync_children(struct kvm
*kvm
,
1876 struct kvm_mmu_page
*parent
,
1877 struct list_head
*invalid_list
)
1880 struct mmu_page_path parents
;
1881 struct kvm_mmu_pages pages
;
1883 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1886 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1887 while (mmu_unsync_walk(parent
, &pages
)) {
1888 struct kvm_mmu_page
*sp
;
1890 for_each_sp(pages
, sp
, parents
, i
) {
1891 kvm_mmu_prepare_zap_page(kvm
, sp
, invalid_list
);
1892 mmu_pages_clear_parents(&parents
);
1895 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1901 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1902 struct list_head
*invalid_list
)
1906 trace_kvm_mmu_prepare_zap_page(sp
);
1907 ++kvm
->stat
.mmu_shadow_zapped
;
1908 ret
= mmu_zap_unsync_children(kvm
, sp
, invalid_list
);
1909 kvm_mmu_page_unlink_children(kvm
, sp
);
1910 kvm_mmu_unlink_parents(kvm
, sp
);
1911 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
1912 unaccount_shadowed(kvm
, sp
->gfn
);
1914 kvm_unlink_unsync_page(kvm
, sp
);
1915 if (!sp
->root_count
) {
1918 list_move(&sp
->link
, invalid_list
);
1919 kvm_mod_used_mmu_pages(kvm
, -1);
1921 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1922 kvm_reload_remote_mmus(kvm
);
1925 sp
->role
.invalid
= 1;
1929 static void kvm_mmu_isolate_pages(struct list_head
*invalid_list
)
1931 struct kvm_mmu_page
*sp
;
1933 list_for_each_entry(sp
, invalid_list
, link
)
1934 kvm_mmu_isolate_page(sp
);
1937 static void free_pages_rcu(struct rcu_head
*head
)
1939 struct kvm_mmu_page
*next
, *sp
;
1941 sp
= container_of(head
, struct kvm_mmu_page
, rcu
);
1943 if (!list_empty(&sp
->link
))
1944 next
= list_first_entry(&sp
->link
,
1945 struct kvm_mmu_page
, link
);
1948 kvm_mmu_free_page(sp
);
1953 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
1954 struct list_head
*invalid_list
)
1956 struct kvm_mmu_page
*sp
;
1958 if (list_empty(invalid_list
))
1961 kvm_flush_remote_tlbs(kvm
);
1963 if (atomic_read(&kvm
->arch
.reader_counter
)) {
1964 kvm_mmu_isolate_pages(invalid_list
);
1965 sp
= list_first_entry(invalid_list
, struct kvm_mmu_page
, link
);
1966 list_del_init(invalid_list
);
1968 trace_kvm_mmu_delay_free_pages(sp
);
1969 call_rcu(&sp
->rcu
, free_pages_rcu
);
1974 sp
= list_first_entry(invalid_list
, struct kvm_mmu_page
, link
);
1975 WARN_ON(!sp
->role
.invalid
|| sp
->root_count
);
1976 kvm_mmu_isolate_page(sp
);
1977 kvm_mmu_free_page(sp
);
1978 } while (!list_empty(invalid_list
));
1983 * Changing the number of mmu pages allocated to the vm
1984 * Note: if goal_nr_mmu_pages is too small, you will get dead lock
1986 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int goal_nr_mmu_pages
)
1988 LIST_HEAD(invalid_list
);
1990 * If we set the number of mmu pages to be smaller be than the
1991 * number of actived pages , we must to free some mmu pages before we
1995 if (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
) {
1996 while (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
&&
1997 !list_empty(&kvm
->arch
.active_mmu_pages
)) {
1998 struct kvm_mmu_page
*page
;
2000 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2001 struct kvm_mmu_page
, link
);
2002 kvm_mmu_prepare_zap_page(kvm
, page
, &invalid_list
);
2004 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2005 goal_nr_mmu_pages
= kvm
->arch
.n_used_mmu_pages
;
2008 kvm
->arch
.n_max_mmu_pages
= goal_nr_mmu_pages
;
2011 int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
2013 struct kvm_mmu_page
*sp
;
2014 struct hlist_node
*node
;
2015 LIST_HEAD(invalid_list
);
2018 pgprintk("%s: looking for gfn %llx\n", __func__
, gfn
);
2020 spin_lock(&kvm
->mmu_lock
);
2021 for_each_gfn_indirect_valid_sp(kvm
, sp
, gfn
, node
) {
2022 pgprintk("%s: gfn %llx role %x\n", __func__
, gfn
,
2025 kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
);
2027 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2028 spin_unlock(&kvm
->mmu_lock
);
2032 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page
);
2034 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
2036 int slot
= memslot_id(kvm
, gfn
);
2037 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
2039 __set_bit(slot
, sp
->slot_bitmap
);
2043 * The function is based on mtrr_type_lookup() in
2044 * arch/x86/kernel/cpu/mtrr/generic.c
2046 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
2051 u8 prev_match
, curr_match
;
2052 int num_var_ranges
= KVM_NR_VAR_MTRR
;
2054 if (!mtrr_state
->enabled
)
2057 /* Make end inclusive end, instead of exclusive */
2060 /* Look in fixed ranges. Just return the type as per start */
2061 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
2064 if (start
< 0x80000) {
2066 idx
+= (start
>> 16);
2067 return mtrr_state
->fixed_ranges
[idx
];
2068 } else if (start
< 0xC0000) {
2070 idx
+= ((start
- 0x80000) >> 14);
2071 return mtrr_state
->fixed_ranges
[idx
];
2072 } else if (start
< 0x1000000) {
2074 idx
+= ((start
- 0xC0000) >> 12);
2075 return mtrr_state
->fixed_ranges
[idx
];
2080 * Look in variable ranges
2081 * Look of multiple ranges matching this address and pick type
2082 * as per MTRR precedence
2084 if (!(mtrr_state
->enabled
& 2))
2085 return mtrr_state
->def_type
;
2088 for (i
= 0; i
< num_var_ranges
; ++i
) {
2089 unsigned short start_state
, end_state
;
2091 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
2094 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
2095 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
2096 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
2097 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
2099 start_state
= ((start
& mask
) == (base
& mask
));
2100 end_state
= ((end
& mask
) == (base
& mask
));
2101 if (start_state
!= end_state
)
2104 if ((start
& mask
) != (base
& mask
))
2107 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
2108 if (prev_match
== 0xFF) {
2109 prev_match
= curr_match
;
2113 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
2114 curr_match
== MTRR_TYPE_UNCACHABLE
)
2115 return MTRR_TYPE_UNCACHABLE
;
2117 if ((prev_match
== MTRR_TYPE_WRBACK
&&
2118 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
2119 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
2120 curr_match
== MTRR_TYPE_WRBACK
)) {
2121 prev_match
= MTRR_TYPE_WRTHROUGH
;
2122 curr_match
= MTRR_TYPE_WRTHROUGH
;
2125 if (prev_match
!= curr_match
)
2126 return MTRR_TYPE_UNCACHABLE
;
2129 if (prev_match
!= 0xFF)
2132 return mtrr_state
->def_type
;
2135 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2139 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
2140 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
2141 if (mtrr
== 0xfe || mtrr
== 0xff)
2142 mtrr
= MTRR_TYPE_WRBACK
;
2145 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
2147 static void __kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
2149 trace_kvm_mmu_unsync_page(sp
);
2150 ++vcpu
->kvm
->stat
.mmu_unsync
;
2153 kvm_mmu_mark_parents_unsync(sp
);
2156 static void kvm_unsync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2158 struct kvm_mmu_page
*s
;
2159 struct hlist_node
*node
;
2161 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2164 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
2165 __kvm_unsync_page(vcpu
, s
);
2169 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2172 struct kvm_mmu_page
*s
;
2173 struct hlist_node
*node
;
2174 bool need_unsync
= false;
2176 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2180 if (s
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2183 if (!need_unsync
&& !s
->unsync
) {
2188 kvm_unsync_pages(vcpu
, gfn
);
2192 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2193 unsigned pte_access
, int user_fault
,
2194 int write_fault
, int level
,
2195 gfn_t gfn
, pfn_t pfn
, bool speculative
,
2196 bool can_unsync
, bool host_writable
)
2198 u64 spte
, entry
= *sptep
;
2201 if (set_mmio_spte(sptep
, gfn
, pfn
, pte_access
))
2204 spte
= PT_PRESENT_MASK
;
2206 spte
|= shadow_accessed_mask
;
2208 if (pte_access
& ACC_EXEC_MASK
)
2209 spte
|= shadow_x_mask
;
2211 spte
|= shadow_nx_mask
;
2212 if (pte_access
& ACC_USER_MASK
)
2213 spte
|= shadow_user_mask
;
2214 if (level
> PT_PAGE_TABLE_LEVEL
)
2215 spte
|= PT_PAGE_SIZE_MASK
;
2217 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
2218 kvm_is_mmio_pfn(pfn
));
2221 spte
|= SPTE_HOST_WRITEABLE
;
2223 pte_access
&= ~ACC_WRITE_MASK
;
2225 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
2227 if ((pte_access
& ACC_WRITE_MASK
)
2228 || (!vcpu
->arch
.mmu
.direct_map
&& write_fault
2229 && !is_write_protection(vcpu
) && !user_fault
)) {
2231 if (level
> PT_PAGE_TABLE_LEVEL
&&
2232 has_wrprotected_page(vcpu
->kvm
, gfn
, level
)) {
2234 drop_spte(vcpu
->kvm
, sptep
);
2238 spte
|= PT_WRITABLE_MASK
;
2240 if (!vcpu
->arch
.mmu
.direct_map
2241 && !(pte_access
& ACC_WRITE_MASK
)) {
2242 spte
&= ~PT_USER_MASK
;
2244 * If we converted a user page to a kernel page,
2245 * so that the kernel can write to it when cr0.wp=0,
2246 * then we should prevent the kernel from executing it
2247 * if SMEP is enabled.
2249 if (kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
))
2250 spte
|= PT64_NX_MASK
;
2254 * Optimization: for pte sync, if spte was writable the hash
2255 * lookup is unnecessary (and expensive). Write protection
2256 * is responsibility of mmu_get_page / kvm_sync_page.
2257 * Same reasoning can be applied to dirty page accounting.
2259 if (!can_unsync
&& is_writable_pte(*sptep
))
2262 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
2263 pgprintk("%s: found shadow page for %llx, marking ro\n",
2266 pte_access
&= ~ACC_WRITE_MASK
;
2267 if (is_writable_pte(spte
))
2268 spte
&= ~PT_WRITABLE_MASK
;
2272 if (pte_access
& ACC_WRITE_MASK
)
2273 mark_page_dirty(vcpu
->kvm
, gfn
);
2276 mmu_spte_update(sptep
, spte
);
2278 * If we overwrite a writable spte with a read-only one we
2279 * should flush remote TLBs. Otherwise rmap_write_protect
2280 * will find a read-only spte, even though the writable spte
2281 * might be cached on a CPU's TLB.
2283 if (is_writable_pte(entry
) && !is_writable_pte(*sptep
))
2284 kvm_flush_remote_tlbs(vcpu
->kvm
);
2289 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2290 unsigned pt_access
, unsigned pte_access
,
2291 int user_fault
, int write_fault
,
2292 int *emulate
, int level
, gfn_t gfn
,
2293 pfn_t pfn
, bool speculative
,
2296 int was_rmapped
= 0;
2299 pgprintk("%s: spte %llx access %x write_fault %d"
2300 " user_fault %d gfn %llx\n",
2301 __func__
, *sptep
, pt_access
,
2302 write_fault
, user_fault
, gfn
);
2304 if (is_rmap_spte(*sptep
)) {
2306 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
2307 * the parent of the now unreachable PTE.
2309 if (level
> PT_PAGE_TABLE_LEVEL
&&
2310 !is_large_pte(*sptep
)) {
2311 struct kvm_mmu_page
*child
;
2314 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2315 drop_parent_pte(child
, sptep
);
2316 kvm_flush_remote_tlbs(vcpu
->kvm
);
2317 } else if (pfn
!= spte_to_pfn(*sptep
)) {
2318 pgprintk("hfn old %llx new %llx\n",
2319 spte_to_pfn(*sptep
), pfn
);
2320 drop_spte(vcpu
->kvm
, sptep
);
2321 kvm_flush_remote_tlbs(vcpu
->kvm
);
2326 if (set_spte(vcpu
, sptep
, pte_access
, user_fault
, write_fault
,
2327 level
, gfn
, pfn
, speculative
, true,
2331 kvm_mmu_flush_tlb(vcpu
);
2334 if (unlikely(is_mmio_spte(*sptep
) && emulate
))
2337 pgprintk("%s: setting spte %llx\n", __func__
, *sptep
);
2338 pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
2339 is_large_pte(*sptep
)? "2MB" : "4kB",
2340 *sptep
& PT_PRESENT_MASK
?"RW":"R", gfn
,
2342 if (!was_rmapped
&& is_large_pte(*sptep
))
2343 ++vcpu
->kvm
->stat
.lpages
;
2345 if (is_shadow_present_pte(*sptep
)) {
2346 page_header_update_slot(vcpu
->kvm
, sptep
, gfn
);
2348 rmap_count
= rmap_add(vcpu
, sptep
, gfn
);
2349 if (rmap_count
> RMAP_RECYCLE_THRESHOLD
)
2350 rmap_recycle(vcpu
, sptep
, gfn
);
2353 kvm_release_pfn_clean(pfn
);
2356 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
2360 static pfn_t
pte_prefetch_gfn_to_pfn(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2363 struct kvm_memory_slot
*slot
;
2366 slot
= gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, no_dirty_log
);
2368 get_page(fault_page
);
2369 return page_to_pfn(fault_page
);
2372 hva
= gfn_to_hva_memslot(slot
, gfn
);
2374 return hva_to_pfn_atomic(vcpu
->kvm
, hva
);
2377 static int direct_pte_prefetch_many(struct kvm_vcpu
*vcpu
,
2378 struct kvm_mmu_page
*sp
,
2379 u64
*start
, u64
*end
)
2381 struct page
*pages
[PTE_PREFETCH_NUM
];
2382 unsigned access
= sp
->role
.access
;
2386 gfn
= kvm_mmu_page_get_gfn(sp
, start
- sp
->spt
);
2387 if (!gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, access
& ACC_WRITE_MASK
))
2390 ret
= gfn_to_page_many_atomic(vcpu
->kvm
, gfn
, pages
, end
- start
);
2394 for (i
= 0; i
< ret
; i
++, gfn
++, start
++)
2395 mmu_set_spte(vcpu
, start
, ACC_ALL
,
2397 sp
->role
.level
, gfn
,
2398 page_to_pfn(pages
[i
]), true, true);
2403 static void __direct_pte_prefetch(struct kvm_vcpu
*vcpu
,
2404 struct kvm_mmu_page
*sp
, u64
*sptep
)
2406 u64
*spte
, *start
= NULL
;
2409 WARN_ON(!sp
->role
.direct
);
2411 i
= (sptep
- sp
->spt
) & ~(PTE_PREFETCH_NUM
- 1);
2414 for (i
= 0; i
< PTE_PREFETCH_NUM
; i
++, spte
++) {
2415 if (is_shadow_present_pte(*spte
) || spte
== sptep
) {
2418 if (direct_pte_prefetch_many(vcpu
, sp
, start
, spte
) < 0)
2426 static void direct_pte_prefetch(struct kvm_vcpu
*vcpu
, u64
*sptep
)
2428 struct kvm_mmu_page
*sp
;
2431 * Since it's no accessed bit on EPT, it's no way to
2432 * distinguish between actually accessed translations
2433 * and prefetched, so disable pte prefetch if EPT is
2436 if (!shadow_accessed_mask
)
2439 sp
= page_header(__pa(sptep
));
2440 if (sp
->role
.level
> PT_PAGE_TABLE_LEVEL
)
2443 __direct_pte_prefetch(vcpu
, sp
, sptep
);
2446 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
2447 int map_writable
, int level
, gfn_t gfn
, pfn_t pfn
,
2450 struct kvm_shadow_walk_iterator iterator
;
2451 struct kvm_mmu_page
*sp
;
2455 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
2456 if (iterator
.level
== level
) {
2457 unsigned pte_access
= ACC_ALL
;
2459 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
, pte_access
,
2461 level
, gfn
, pfn
, prefault
, map_writable
);
2462 direct_pte_prefetch(vcpu
, iterator
.sptep
);
2463 ++vcpu
->stat
.pf_fixed
;
2467 if (!is_shadow_present_pte(*iterator
.sptep
)) {
2468 u64 base_addr
= iterator
.addr
;
2470 base_addr
&= PT64_LVL_ADDR_MASK(iterator
.level
);
2471 pseudo_gfn
= base_addr
>> PAGE_SHIFT
;
2472 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
2474 1, ACC_ALL
, iterator
.sptep
);
2476 pgprintk("nonpaging_map: ENOMEM\n");
2477 kvm_release_pfn_clean(pfn
);
2481 mmu_spte_set(iterator
.sptep
,
2483 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
2484 | shadow_user_mask
| shadow_x_mask
2485 | shadow_accessed_mask
);
2491 static void kvm_send_hwpoison_signal(unsigned long address
, struct task_struct
*tsk
)
2495 info
.si_signo
= SIGBUS
;
2497 info
.si_code
= BUS_MCEERR_AR
;
2498 info
.si_addr
= (void __user
*)address
;
2499 info
.si_addr_lsb
= PAGE_SHIFT
;
2501 send_sig_info(SIGBUS
, &info
, tsk
);
2504 static int kvm_handle_bad_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
, pfn_t pfn
)
2506 kvm_release_pfn_clean(pfn
);
2507 if (is_hwpoison_pfn(pfn
)) {
2508 kvm_send_hwpoison_signal(gfn_to_hva(vcpu
->kvm
, gfn
), current
);
2515 static void transparent_hugepage_adjust(struct kvm_vcpu
*vcpu
,
2516 gfn_t
*gfnp
, pfn_t
*pfnp
, int *levelp
)
2520 int level
= *levelp
;
2523 * Check if it's a transparent hugepage. If this would be an
2524 * hugetlbfs page, level wouldn't be set to
2525 * PT_PAGE_TABLE_LEVEL and there would be no adjustment done
2528 if (!is_error_pfn(pfn
) && !kvm_is_mmio_pfn(pfn
) &&
2529 level
== PT_PAGE_TABLE_LEVEL
&&
2530 PageTransCompound(pfn_to_page(pfn
)) &&
2531 !has_wrprotected_page(vcpu
->kvm
, gfn
, PT_DIRECTORY_LEVEL
)) {
2534 * mmu_notifier_retry was successful and we hold the
2535 * mmu_lock here, so the pmd can't become splitting
2536 * from under us, and in turn
2537 * __split_huge_page_refcount() can't run from under
2538 * us and we can safely transfer the refcount from
2539 * PG_tail to PG_head as we switch the pfn to tail to
2542 *levelp
= level
= PT_DIRECTORY_LEVEL
;
2543 mask
= KVM_PAGES_PER_HPAGE(level
) - 1;
2544 VM_BUG_ON((gfn
& mask
) != (pfn
& mask
));
2548 kvm_release_pfn_clean(pfn
);
2550 if (!get_page_unless_zero(pfn_to_page(pfn
)))
2557 static bool mmu_invalid_pfn(pfn_t pfn
)
2559 return unlikely(is_invalid_pfn(pfn
));
2562 static bool handle_abnormal_pfn(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
,
2563 pfn_t pfn
, unsigned access
, int *ret_val
)
2567 /* The pfn is invalid, report the error! */
2568 if (unlikely(is_invalid_pfn(pfn
))) {
2569 *ret_val
= kvm_handle_bad_page(vcpu
, gfn
, pfn
);
2573 if (unlikely(is_noslot_pfn(pfn
)))
2574 vcpu_cache_mmio_info(vcpu
, gva
, gfn
, access
);
2581 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
2582 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
);
2584 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
,
2591 unsigned long mmu_seq
;
2594 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
2595 if (likely(!force_pt_level
)) {
2596 level
= mapping_level(vcpu
, gfn
);
2598 * This path builds a PAE pagetable - so we can map
2599 * 2mb pages at maximum. Therefore check if the level
2600 * is larger than that.
2602 if (level
> PT_DIRECTORY_LEVEL
)
2603 level
= PT_DIRECTORY_LEVEL
;
2605 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2607 level
= PT_PAGE_TABLE_LEVEL
;
2609 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2612 if (try_async_pf(vcpu
, prefault
, gfn
, v
, &pfn
, write
, &map_writable
))
2615 if (handle_abnormal_pfn(vcpu
, v
, gfn
, pfn
, ACC_ALL
, &r
))
2618 spin_lock(&vcpu
->kvm
->mmu_lock
);
2619 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2621 kvm_mmu_free_some_pages(vcpu
);
2622 if (likely(!force_pt_level
))
2623 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
2624 r
= __direct_map(vcpu
, v
, write
, map_writable
, level
, gfn
, pfn
,
2626 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2632 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2633 kvm_release_pfn_clean(pfn
);
2638 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
2641 struct kvm_mmu_page
*sp
;
2642 LIST_HEAD(invalid_list
);
2644 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2646 spin_lock(&vcpu
->kvm
->mmu_lock
);
2647 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
&&
2648 (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
||
2649 vcpu
->arch
.mmu
.direct_map
)) {
2650 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2652 sp
= page_header(root
);
2654 if (!sp
->root_count
&& sp
->role
.invalid
) {
2655 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
2656 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2658 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2659 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2662 for (i
= 0; i
< 4; ++i
) {
2663 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2666 root
&= PT64_BASE_ADDR_MASK
;
2667 sp
= page_header(root
);
2669 if (!sp
->root_count
&& sp
->role
.invalid
)
2670 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
2673 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2675 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2676 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2677 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2680 static int mmu_check_root(struct kvm_vcpu
*vcpu
, gfn_t root_gfn
)
2684 if (!kvm_is_visible_gfn(vcpu
->kvm
, root_gfn
)) {
2685 kvm_make_request(KVM_REQ_TRIPLE_FAULT
, vcpu
);
2692 static int mmu_alloc_direct_roots(struct kvm_vcpu
*vcpu
)
2694 struct kvm_mmu_page
*sp
;
2697 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2698 spin_lock(&vcpu
->kvm
->mmu_lock
);
2699 kvm_mmu_free_some_pages(vcpu
);
2700 sp
= kvm_mmu_get_page(vcpu
, 0, 0, PT64_ROOT_LEVEL
,
2703 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2704 vcpu
->arch
.mmu
.root_hpa
= __pa(sp
->spt
);
2705 } else if (vcpu
->arch
.mmu
.shadow_root_level
== PT32E_ROOT_LEVEL
) {
2706 for (i
= 0; i
< 4; ++i
) {
2707 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2709 ASSERT(!VALID_PAGE(root
));
2710 spin_lock(&vcpu
->kvm
->mmu_lock
);
2711 kvm_mmu_free_some_pages(vcpu
);
2712 sp
= kvm_mmu_get_page(vcpu
, i
<< (30 - PAGE_SHIFT
),
2714 PT32_ROOT_LEVEL
, 1, ACC_ALL
,
2716 root
= __pa(sp
->spt
);
2718 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2719 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
2721 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2728 static int mmu_alloc_shadow_roots(struct kvm_vcpu
*vcpu
)
2730 struct kvm_mmu_page
*sp
;
2735 root_gfn
= vcpu
->arch
.mmu
.get_cr3(vcpu
) >> PAGE_SHIFT
;
2737 if (mmu_check_root(vcpu
, root_gfn
))
2741 * Do we shadow a long mode page table? If so we need to
2742 * write-protect the guests page table root.
2744 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
2745 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2747 ASSERT(!VALID_PAGE(root
));
2749 spin_lock(&vcpu
->kvm
->mmu_lock
);
2750 kvm_mmu_free_some_pages(vcpu
);
2751 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0, PT64_ROOT_LEVEL
,
2753 root
= __pa(sp
->spt
);
2755 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2756 vcpu
->arch
.mmu
.root_hpa
= root
;
2761 * We shadow a 32 bit page table. This may be a legacy 2-level
2762 * or a PAE 3-level page table. In either case we need to be aware that
2763 * the shadow page table may be a PAE or a long mode page table.
2765 pm_mask
= PT_PRESENT_MASK
;
2766 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
)
2767 pm_mask
|= PT_ACCESSED_MASK
| PT_WRITABLE_MASK
| PT_USER_MASK
;
2769 for (i
= 0; i
< 4; ++i
) {
2770 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2772 ASSERT(!VALID_PAGE(root
));
2773 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
2774 pdptr
= vcpu
->arch
.mmu
.get_pdptr(vcpu
, i
);
2775 if (!is_present_gpte(pdptr
)) {
2776 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
2779 root_gfn
= pdptr
>> PAGE_SHIFT
;
2780 if (mmu_check_root(vcpu
, root_gfn
))
2783 spin_lock(&vcpu
->kvm
->mmu_lock
);
2784 kvm_mmu_free_some_pages(vcpu
);
2785 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
2788 root
= __pa(sp
->spt
);
2790 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2792 vcpu
->arch
.mmu
.pae_root
[i
] = root
| pm_mask
;
2794 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2797 * If we shadow a 32 bit page table with a long mode page
2798 * table we enter this path.
2800 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2801 if (vcpu
->arch
.mmu
.lm_root
== NULL
) {
2803 * The additional page necessary for this is only
2804 * allocated on demand.
2809 lm_root
= (void*)get_zeroed_page(GFP_KERNEL
);
2810 if (lm_root
== NULL
)
2813 lm_root
[0] = __pa(vcpu
->arch
.mmu
.pae_root
) | pm_mask
;
2815 vcpu
->arch
.mmu
.lm_root
= lm_root
;
2818 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.lm_root
);
2824 static int mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
2826 if (vcpu
->arch
.mmu
.direct_map
)
2827 return mmu_alloc_direct_roots(vcpu
);
2829 return mmu_alloc_shadow_roots(vcpu
);
2832 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2835 struct kvm_mmu_page
*sp
;
2837 if (vcpu
->arch
.mmu
.direct_map
)
2840 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2843 vcpu_clear_mmio_info(vcpu
, ~0ul);
2844 kvm_mmu_audit(vcpu
, AUDIT_PRE_SYNC
);
2845 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
2846 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2847 sp
= page_header(root
);
2848 mmu_sync_children(vcpu
, sp
);
2849 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
2852 for (i
= 0; i
< 4; ++i
) {
2853 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2855 if (root
&& VALID_PAGE(root
)) {
2856 root
&= PT64_BASE_ADDR_MASK
;
2857 sp
= page_header(root
);
2858 mmu_sync_children(vcpu
, sp
);
2861 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
2864 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2866 spin_lock(&vcpu
->kvm
->mmu_lock
);
2867 mmu_sync_roots(vcpu
);
2868 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2871 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
2872 u32 access
, struct x86_exception
*exception
)
2875 exception
->error_code
= 0;
2879 static gpa_t
nonpaging_gva_to_gpa_nested(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
2881 struct x86_exception
*exception
)
2884 exception
->error_code
= 0;
2885 return vcpu
->arch
.nested_mmu
.translate_gpa(vcpu
, vaddr
, access
);
2888 static bool quickly_check_mmio_pf(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
2891 return vcpu_match_mmio_gpa(vcpu
, addr
);
2893 return vcpu_match_mmio_gva(vcpu
, addr
);
2898 * On direct hosts, the last spte is only allows two states
2899 * for mmio page fault:
2900 * - It is the mmio spte
2901 * - It is zapped or it is being zapped.
2903 * This function completely checks the spte when the last spte
2904 * is not the mmio spte.
2906 static bool check_direct_spte_mmio_pf(u64 spte
)
2908 return __check_direct_spte_mmio_pf(spte
);
2911 static u64
walk_shadow_page_get_mmio_spte(struct kvm_vcpu
*vcpu
, u64 addr
)
2913 struct kvm_shadow_walk_iterator iterator
;
2916 walk_shadow_page_lockless_begin(vcpu
);
2917 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
)
2918 if (!is_shadow_present_pte(spte
))
2920 walk_shadow_page_lockless_end(vcpu
);
2926 * If it is a real mmio page fault, return 1 and emulat the instruction
2927 * directly, return 0 to let CPU fault again on the address, -1 is
2928 * returned if bug is detected.
2930 int handle_mmio_page_fault_common(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
2934 if (quickly_check_mmio_pf(vcpu
, addr
, direct
))
2937 spte
= walk_shadow_page_get_mmio_spte(vcpu
, addr
);
2939 if (is_mmio_spte(spte
)) {
2940 gfn_t gfn
= get_mmio_spte_gfn(spte
);
2941 unsigned access
= get_mmio_spte_access(spte
);
2946 trace_handle_mmio_page_fault(addr
, gfn
, access
);
2947 vcpu_cache_mmio_info(vcpu
, addr
, gfn
, access
);
2952 * It's ok if the gva is remapped by other cpus on shadow guest,
2953 * it's a BUG if the gfn is not a mmio page.
2955 if (direct
&& !check_direct_spte_mmio_pf(spte
))
2959 * If the page table is zapped by other cpus, let CPU fault again on
2964 EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common
);
2966 static int handle_mmio_page_fault(struct kvm_vcpu
*vcpu
, u64 addr
,
2967 u32 error_code
, bool direct
)
2971 ret
= handle_mmio_page_fault_common(vcpu
, addr
, direct
);
2976 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
2977 u32 error_code
, bool prefault
)
2982 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
2984 if (unlikely(error_code
& PFERR_RSVD_MASK
))
2985 return handle_mmio_page_fault(vcpu
, gva
, error_code
, true);
2987 r
= mmu_topup_memory_caches(vcpu
);
2992 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2994 gfn
= gva
>> PAGE_SHIFT
;
2996 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
2997 error_code
& PFERR_WRITE_MASK
, gfn
, prefault
);
3000 static int kvm_arch_setup_async_pf(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
)
3002 struct kvm_arch_async_pf arch
;
3004 arch
.token
= (vcpu
->arch
.apf
.id
++ << 12) | vcpu
->vcpu_id
;
3006 arch
.direct_map
= vcpu
->arch
.mmu
.direct_map
;
3007 arch
.cr3
= vcpu
->arch
.mmu
.get_cr3(vcpu
);
3009 return kvm_setup_async_pf(vcpu
, gva
, gfn
, &arch
);
3012 static bool can_do_async_pf(struct kvm_vcpu
*vcpu
)
3014 if (unlikely(!irqchip_in_kernel(vcpu
->kvm
) ||
3015 kvm_event_needs_reinjection(vcpu
)))
3018 return kvm_x86_ops
->interrupt_allowed(vcpu
);
3021 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
3022 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
)
3026 *pfn
= gfn_to_pfn_async(vcpu
->kvm
, gfn
, &async
, write
, writable
);
3029 return false; /* *pfn has correct page already */
3031 put_page(pfn_to_page(*pfn
));
3033 if (!prefault
&& can_do_async_pf(vcpu
)) {
3034 trace_kvm_try_async_get_page(gva
, gfn
);
3035 if (kvm_find_async_pf_gfn(vcpu
, gfn
)) {
3036 trace_kvm_async_pf_doublefault(gva
, gfn
);
3037 kvm_make_request(KVM_REQ_APF_HALT
, vcpu
);
3039 } else if (kvm_arch_setup_async_pf(vcpu
, gva
, gfn
))
3043 *pfn
= gfn_to_pfn_prot(vcpu
->kvm
, gfn
, write
, writable
);
3048 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
, u32 error_code
,
3055 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3056 unsigned long mmu_seq
;
3057 int write
= error_code
& PFERR_WRITE_MASK
;
3061 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3063 if (unlikely(error_code
& PFERR_RSVD_MASK
))
3064 return handle_mmio_page_fault(vcpu
, gpa
, error_code
, true);
3066 r
= mmu_topup_memory_caches(vcpu
);
3070 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
3071 if (likely(!force_pt_level
)) {
3072 level
= mapping_level(vcpu
, gfn
);
3073 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
3075 level
= PT_PAGE_TABLE_LEVEL
;
3077 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
3080 if (try_async_pf(vcpu
, prefault
, gfn
, gpa
, &pfn
, write
, &map_writable
))
3083 if (handle_abnormal_pfn(vcpu
, 0, gfn
, pfn
, ACC_ALL
, &r
))
3086 spin_lock(&vcpu
->kvm
->mmu_lock
);
3087 if (mmu_notifier_retry(vcpu
, mmu_seq
))
3089 kvm_mmu_free_some_pages(vcpu
);
3090 if (likely(!force_pt_level
))
3091 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
3092 r
= __direct_map(vcpu
, gpa
, write
, map_writable
,
3093 level
, gfn
, pfn
, prefault
);
3094 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3099 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3100 kvm_release_pfn_clean(pfn
);
3104 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
3106 mmu_free_roots(vcpu
);
3109 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
,
3110 struct kvm_mmu
*context
)
3112 context
->new_cr3
= nonpaging_new_cr3
;
3113 context
->page_fault
= nonpaging_page_fault
;
3114 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3115 context
->free
= nonpaging_free
;
3116 context
->sync_page
= nonpaging_sync_page
;
3117 context
->invlpg
= nonpaging_invlpg
;
3118 context
->update_pte
= nonpaging_update_pte
;
3119 context
->root_level
= 0;
3120 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3121 context
->root_hpa
= INVALID_PAGE
;
3122 context
->direct_map
= true;
3123 context
->nx
= false;
3127 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
3129 ++vcpu
->stat
.tlb_flush
;
3130 kvm_make_request(KVM_REQ_TLB_FLUSH
, vcpu
);
3133 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
3135 pgprintk("%s: cr3 %lx\n", __func__
, kvm_read_cr3(vcpu
));
3136 mmu_free_roots(vcpu
);
3139 static unsigned long get_cr3(struct kvm_vcpu
*vcpu
)
3141 return kvm_read_cr3(vcpu
);
3144 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
3145 struct x86_exception
*fault
)
3147 vcpu
->arch
.mmu
.inject_page_fault(vcpu
, fault
);
3150 static void paging_free(struct kvm_vcpu
*vcpu
)
3152 nonpaging_free(vcpu
);
3155 static bool is_rsvd_bits_set(struct kvm_mmu
*mmu
, u64 gpte
, int level
)
3159 bit7
= (gpte
>> 7) & 1;
3160 return (gpte
& mmu
->rsvd_bits_mask
[bit7
][level
-1]) != 0;
3163 static bool sync_mmio_spte(u64
*sptep
, gfn_t gfn
, unsigned access
,
3166 if (unlikely(is_mmio_spte(*sptep
))) {
3167 if (gfn
!= get_mmio_spte_gfn(*sptep
)) {
3168 mmu_spte_clear_no_track(sptep
);
3173 mark_mmio_spte(sptep
, gfn
, access
);
3181 #include "paging_tmpl.h"
3185 #include "paging_tmpl.h"
3188 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
,
3189 struct kvm_mmu
*context
,
3192 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
3193 u64 exb_bit_rsvd
= 0;
3196 exb_bit_rsvd
= rsvd_bits(63, 63);
3198 case PT32_ROOT_LEVEL
:
3199 /* no rsvd bits for 2 level 4K page table entries */
3200 context
->rsvd_bits_mask
[0][1] = 0;
3201 context
->rsvd_bits_mask
[0][0] = 0;
3202 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3204 if (!is_pse(vcpu
)) {
3205 context
->rsvd_bits_mask
[1][1] = 0;
3209 if (is_cpuid_PSE36())
3210 /* 36bits PSE 4MB page */
3211 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
3213 /* 32 bits PSE 4MB page */
3214 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
3216 case PT32E_ROOT_LEVEL
:
3217 context
->rsvd_bits_mask
[0][2] =
3218 rsvd_bits(maxphyaddr
, 63) |
3219 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
3220 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3221 rsvd_bits(maxphyaddr
, 62); /* PDE */
3222 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3223 rsvd_bits(maxphyaddr
, 62); /* PTE */
3224 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3225 rsvd_bits(maxphyaddr
, 62) |
3226 rsvd_bits(13, 20); /* large page */
3227 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3229 case PT64_ROOT_LEVEL
:
3230 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
3231 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3232 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
3233 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3234 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3235 rsvd_bits(maxphyaddr
, 51);
3236 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3237 rsvd_bits(maxphyaddr
, 51);
3238 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
3239 context
->rsvd_bits_mask
[1][2] = exb_bit_rsvd
|
3240 rsvd_bits(maxphyaddr
, 51) |
3242 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3243 rsvd_bits(maxphyaddr
, 51) |
3244 rsvd_bits(13, 20); /* large page */
3245 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3250 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
,
3251 struct kvm_mmu
*context
,
3254 context
->nx
= is_nx(vcpu
);
3256 reset_rsvds_bits_mask(vcpu
, context
, level
);
3258 ASSERT(is_pae(vcpu
));
3259 context
->new_cr3
= paging_new_cr3
;
3260 context
->page_fault
= paging64_page_fault
;
3261 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3262 context
->sync_page
= paging64_sync_page
;
3263 context
->invlpg
= paging64_invlpg
;
3264 context
->update_pte
= paging64_update_pte
;
3265 context
->free
= paging_free
;
3266 context
->root_level
= level
;
3267 context
->shadow_root_level
= level
;
3268 context
->root_hpa
= INVALID_PAGE
;
3269 context
->direct_map
= false;
3273 static int paging64_init_context(struct kvm_vcpu
*vcpu
,
3274 struct kvm_mmu
*context
)
3276 return paging64_init_context_common(vcpu
, context
, PT64_ROOT_LEVEL
);
3279 static int paging32_init_context(struct kvm_vcpu
*vcpu
,
3280 struct kvm_mmu
*context
)
3282 context
->nx
= false;
3284 reset_rsvds_bits_mask(vcpu
, context
, PT32_ROOT_LEVEL
);
3286 context
->new_cr3
= paging_new_cr3
;
3287 context
->page_fault
= paging32_page_fault
;
3288 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3289 context
->free
= paging_free
;
3290 context
->sync_page
= paging32_sync_page
;
3291 context
->invlpg
= paging32_invlpg
;
3292 context
->update_pte
= paging32_update_pte
;
3293 context
->root_level
= PT32_ROOT_LEVEL
;
3294 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3295 context
->root_hpa
= INVALID_PAGE
;
3296 context
->direct_map
= false;
3300 static int paging32E_init_context(struct kvm_vcpu
*vcpu
,
3301 struct kvm_mmu
*context
)
3303 return paging64_init_context_common(vcpu
, context
, PT32E_ROOT_LEVEL
);
3306 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
3308 struct kvm_mmu
*context
= vcpu
->arch
.walk_mmu
;
3310 context
->base_role
.word
= 0;
3311 context
->new_cr3
= nonpaging_new_cr3
;
3312 context
->page_fault
= tdp_page_fault
;
3313 context
->free
= nonpaging_free
;
3314 context
->sync_page
= nonpaging_sync_page
;
3315 context
->invlpg
= nonpaging_invlpg
;
3316 context
->update_pte
= nonpaging_update_pte
;
3317 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
3318 context
->root_hpa
= INVALID_PAGE
;
3319 context
->direct_map
= true;
3320 context
->set_cr3
= kvm_x86_ops
->set_tdp_cr3
;
3321 context
->get_cr3
= get_cr3
;
3322 context
->get_pdptr
= kvm_pdptr_read
;
3323 context
->inject_page_fault
= kvm_inject_page_fault
;
3325 if (!is_paging(vcpu
)) {
3326 context
->nx
= false;
3327 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3328 context
->root_level
= 0;
3329 } else if (is_long_mode(vcpu
)) {
3330 context
->nx
= is_nx(vcpu
);
3331 reset_rsvds_bits_mask(vcpu
, context
, PT64_ROOT_LEVEL
);
3332 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3333 context
->root_level
= PT64_ROOT_LEVEL
;
3334 } else if (is_pae(vcpu
)) {
3335 context
->nx
= is_nx(vcpu
);
3336 reset_rsvds_bits_mask(vcpu
, context
, PT32E_ROOT_LEVEL
);
3337 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3338 context
->root_level
= PT32E_ROOT_LEVEL
;
3340 context
->nx
= false;
3341 reset_rsvds_bits_mask(vcpu
, context
, PT32_ROOT_LEVEL
);
3342 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3343 context
->root_level
= PT32_ROOT_LEVEL
;
3349 int kvm_init_shadow_mmu(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*context
)
3352 bool smep
= kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
);
3354 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3356 if (!is_paging(vcpu
))
3357 r
= nonpaging_init_context(vcpu
, context
);
3358 else if (is_long_mode(vcpu
))
3359 r
= paging64_init_context(vcpu
, context
);
3360 else if (is_pae(vcpu
))
3361 r
= paging32E_init_context(vcpu
, context
);
3363 r
= paging32_init_context(vcpu
, context
);
3365 vcpu
->arch
.mmu
.base_role
.cr4_pae
= !!is_pae(vcpu
);
3366 vcpu
->arch
.mmu
.base_role
.cr0_wp
= is_write_protection(vcpu
);
3367 vcpu
->arch
.mmu
.base_role
.smep_andnot_wp
3368 = smep
&& !is_write_protection(vcpu
);
3372 EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu
);
3374 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
3376 int r
= kvm_init_shadow_mmu(vcpu
, vcpu
->arch
.walk_mmu
);
3378 vcpu
->arch
.walk_mmu
->set_cr3
= kvm_x86_ops
->set_cr3
;
3379 vcpu
->arch
.walk_mmu
->get_cr3
= get_cr3
;
3380 vcpu
->arch
.walk_mmu
->get_pdptr
= kvm_pdptr_read
;
3381 vcpu
->arch
.walk_mmu
->inject_page_fault
= kvm_inject_page_fault
;
3386 static int init_kvm_nested_mmu(struct kvm_vcpu
*vcpu
)
3388 struct kvm_mmu
*g_context
= &vcpu
->arch
.nested_mmu
;
3390 g_context
->get_cr3
= get_cr3
;
3391 g_context
->get_pdptr
= kvm_pdptr_read
;
3392 g_context
->inject_page_fault
= kvm_inject_page_fault
;
3395 * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
3396 * translation of l2_gpa to l1_gpa addresses is done using the
3397 * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa
3398 * functions between mmu and nested_mmu are swapped.
3400 if (!is_paging(vcpu
)) {
3401 g_context
->nx
= false;
3402 g_context
->root_level
= 0;
3403 g_context
->gva_to_gpa
= nonpaging_gva_to_gpa_nested
;
3404 } else if (is_long_mode(vcpu
)) {
3405 g_context
->nx
= is_nx(vcpu
);
3406 reset_rsvds_bits_mask(vcpu
, g_context
, PT64_ROOT_LEVEL
);
3407 g_context
->root_level
= PT64_ROOT_LEVEL
;
3408 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3409 } else if (is_pae(vcpu
)) {
3410 g_context
->nx
= is_nx(vcpu
);
3411 reset_rsvds_bits_mask(vcpu
, g_context
, PT32E_ROOT_LEVEL
);
3412 g_context
->root_level
= PT32E_ROOT_LEVEL
;
3413 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3415 g_context
->nx
= false;
3416 reset_rsvds_bits_mask(vcpu
, g_context
, PT32_ROOT_LEVEL
);
3417 g_context
->root_level
= PT32_ROOT_LEVEL
;
3418 g_context
->gva_to_gpa
= paging32_gva_to_gpa_nested
;
3424 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
3426 if (mmu_is_nested(vcpu
))
3427 return init_kvm_nested_mmu(vcpu
);
3428 else if (tdp_enabled
)
3429 return init_kvm_tdp_mmu(vcpu
);
3431 return init_kvm_softmmu(vcpu
);
3434 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
3437 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3438 /* mmu.free() should set root_hpa = INVALID_PAGE */
3439 vcpu
->arch
.mmu
.free(vcpu
);
3442 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
3444 destroy_kvm_mmu(vcpu
);
3445 return init_kvm_mmu(vcpu
);
3447 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
3449 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
3453 r
= mmu_topup_memory_caches(vcpu
);
3456 r
= mmu_alloc_roots(vcpu
);
3457 spin_lock(&vcpu
->kvm
->mmu_lock
);
3458 mmu_sync_roots(vcpu
);
3459 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3462 /* set_cr3() should ensure TLB has been flushed */
3463 vcpu
->arch
.mmu
.set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
3467 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
3469 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
3471 mmu_free_roots(vcpu
);
3473 EXPORT_SYMBOL_GPL(kvm_mmu_unload
);
3475 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
3476 struct kvm_mmu_page
*sp
, u64
*spte
,
3479 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
3480 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
3484 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
3485 vcpu
->arch
.mmu
.update_pte(vcpu
, sp
, spte
, new);
3488 static bool need_remote_flush(u64 old
, u64
new)
3490 if (!is_shadow_present_pte(old
))
3492 if (!is_shadow_present_pte(new))
3494 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
3496 old
^= PT64_NX_MASK
;
3497 new ^= PT64_NX_MASK
;
3498 return (old
& ~new & PT64_PERM_MASK
) != 0;
3501 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, bool zap_page
,
3502 bool remote_flush
, bool local_flush
)
3508 kvm_flush_remote_tlbs(vcpu
->kvm
);
3509 else if (local_flush
)
3510 kvm_mmu_flush_tlb(vcpu
);
3513 static u64
mmu_pte_write_fetch_gpte(struct kvm_vcpu
*vcpu
, gpa_t
*gpa
,
3514 const u8
*new, int *bytes
)
3520 * Assume that the pte write on a page table of the same type
3521 * as the current vcpu paging mode since we update the sptes only
3522 * when they have the same mode.
3524 if (is_pae(vcpu
) && *bytes
== 4) {
3525 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
3528 r
= kvm_read_guest(vcpu
->kvm
, *gpa
, &gentry
, min(*bytes
, 8));
3531 new = (const u8
*)&gentry
;
3536 gentry
= *(const u32
*)new;
3539 gentry
= *(const u64
*)new;
3550 * If we're seeing too many writes to a page, it may no longer be a page table,
3551 * or we may be forking, in which case it is better to unmap the page.
3553 static bool detect_write_flooding(struct kvm_mmu_page
*sp
)
3556 * Skip write-flooding detected for the sp whose level is 1, because
3557 * it can become unsync, then the guest page is not write-protected.
3559 if (sp
->role
.level
== 1)
3562 return ++sp
->write_flooding_count
>= 3;
3566 * Misaligned accesses are too much trouble to fix up; also, they usually
3567 * indicate a page is not used as a page table.
3569 static bool detect_write_misaligned(struct kvm_mmu_page
*sp
, gpa_t gpa
,
3572 unsigned offset
, pte_size
, misaligned
;
3574 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
3575 gpa
, bytes
, sp
->role
.word
);
3577 offset
= offset_in_page(gpa
);
3578 pte_size
= sp
->role
.cr4_pae
? 8 : 4;
3581 * Sometimes, the OS only writes the last one bytes to update status
3582 * bits, for example, in linux, andb instruction is used in clear_bit().
3584 if (!(offset
& (pte_size
- 1)) && bytes
== 1)
3587 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
3588 misaligned
|= bytes
< 4;
3593 static u64
*get_written_sptes(struct kvm_mmu_page
*sp
, gpa_t gpa
, int *nspte
)
3595 unsigned page_offset
, quadrant
;
3599 page_offset
= offset_in_page(gpa
);
3600 level
= sp
->role
.level
;
3602 if (!sp
->role
.cr4_pae
) {
3603 page_offset
<<= 1; /* 32->64 */
3605 * A 32-bit pde maps 4MB while the shadow pdes map
3606 * only 2MB. So we need to double the offset again
3607 * and zap two pdes instead of one.
3609 if (level
== PT32_ROOT_LEVEL
) {
3610 page_offset
&= ~7; /* kill rounding error */
3614 quadrant
= page_offset
>> PAGE_SHIFT
;
3615 page_offset
&= ~PAGE_MASK
;
3616 if (quadrant
!= sp
->role
.quadrant
)
3620 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
3624 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
3625 const u8
*new, int bytes
)
3627 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3628 union kvm_mmu_page_role mask
= { .word
= 0 };
3629 struct kvm_mmu_page
*sp
;
3630 struct hlist_node
*node
;
3631 LIST_HEAD(invalid_list
);
3632 u64 entry
, gentry
, *spte
;
3634 bool remote_flush
, local_flush
, zap_page
;
3637 * If we don't have indirect shadow pages, it means no page is
3638 * write-protected, so we can exit simply.
3640 if (!ACCESS_ONCE(vcpu
->kvm
->arch
.indirect_shadow_pages
))
3643 zap_page
= remote_flush
= local_flush
= false;
3645 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
3647 gentry
= mmu_pte_write_fetch_gpte(vcpu
, &gpa
, new, &bytes
);
3650 * No need to care whether allocation memory is successful
3651 * or not since pte prefetch is skiped if it does not have
3652 * enough objects in the cache.
3654 mmu_topup_memory_caches(vcpu
);
3656 spin_lock(&vcpu
->kvm
->mmu_lock
);
3657 ++vcpu
->kvm
->stat
.mmu_pte_write
;
3658 kvm_mmu_audit(vcpu
, AUDIT_PRE_PTE_WRITE
);
3660 mask
.cr0_wp
= mask
.cr4_pae
= mask
.nxe
= 1;
3661 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, sp
, gfn
, node
) {
3662 if (detect_write_misaligned(sp
, gpa
, bytes
) ||
3663 detect_write_flooding(sp
)) {
3664 zap_page
|= !!kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
3666 ++vcpu
->kvm
->stat
.mmu_flooded
;
3670 spte
= get_written_sptes(sp
, gpa
, &npte
);
3677 mmu_page_zap_pte(vcpu
->kvm
, sp
, spte
);
3679 !((sp
->role
.word
^ vcpu
->arch
.mmu
.base_role
.word
)
3680 & mask
.word
) && rmap_can_add(vcpu
))
3681 mmu_pte_write_new_pte(vcpu
, sp
, spte
, &gentry
);
3682 if (!remote_flush
&& need_remote_flush(entry
, *spte
))
3683 remote_flush
= true;
3687 mmu_pte_write_flush_tlb(vcpu
, zap_page
, remote_flush
, local_flush
);
3688 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
3689 kvm_mmu_audit(vcpu
, AUDIT_POST_PTE_WRITE
);
3690 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3693 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
3698 if (vcpu
->arch
.mmu
.direct_map
)
3701 gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, gva
, NULL
);
3703 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
3707 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
3709 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
3711 LIST_HEAD(invalid_list
);
3713 while (kvm_mmu_available_pages(vcpu
->kvm
) < KVM_REFILL_PAGES
&&
3714 !list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
3715 struct kvm_mmu_page
*sp
;
3717 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
3718 struct kvm_mmu_page
, link
);
3719 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
3720 ++vcpu
->kvm
->stat
.mmu_recycled
;
3722 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
3725 static bool is_mmio_page_fault(struct kvm_vcpu
*vcpu
, gva_t addr
)
3727 if (vcpu
->arch
.mmu
.direct_map
|| mmu_is_nested(vcpu
))
3728 return vcpu_match_mmio_gpa(vcpu
, addr
);
3730 return vcpu_match_mmio_gva(vcpu
, addr
);
3733 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
,
3734 void *insn
, int insn_len
)
3736 int r
, emulation_type
= EMULTYPE_RETRY
;
3737 enum emulation_result er
;
3739 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
, false);
3748 if (is_mmio_page_fault(vcpu
, cr2
))
3751 er
= x86_emulate_instruction(vcpu
, cr2
, emulation_type
, insn
, insn_len
);
3756 case EMULATE_DO_MMIO
:
3757 ++vcpu
->stat
.mmio_exits
;
3767 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
3769 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
3771 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
3772 kvm_mmu_flush_tlb(vcpu
);
3773 ++vcpu
->stat
.invlpg
;
3775 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
3777 void kvm_enable_tdp(void)
3781 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
3783 void kvm_disable_tdp(void)
3785 tdp_enabled
= false;
3787 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
3789 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
3791 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
3792 if (vcpu
->arch
.mmu
.lm_root
!= NULL
)
3793 free_page((unsigned long)vcpu
->arch
.mmu
.lm_root
);
3796 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
3804 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
3805 * Therefore we need to allocate shadow page tables in the first
3806 * 4GB of memory, which happens to fit the DMA32 zone.
3808 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
3812 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
3813 for (i
= 0; i
< 4; ++i
)
3814 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
3819 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
3823 vcpu
->arch
.walk_mmu
= &vcpu
->arch
.mmu
;
3824 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
3825 vcpu
->arch
.mmu
.translate_gpa
= translate_gpa
;
3826 vcpu
->arch
.nested_mmu
.translate_gpa
= translate_nested_gpa
;
3828 return alloc_mmu_pages(vcpu
);
3831 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
3834 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3836 return init_kvm_mmu(vcpu
);
3839 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
3841 struct kvm_mmu_page
*sp
;
3843 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
3847 if (!test_bit(slot
, sp
->slot_bitmap
))
3851 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3852 if (!is_shadow_present_pte(pt
[i
]) ||
3853 !is_last_spte(pt
[i
], sp
->role
.level
))
3856 if (is_large_pte(pt
[i
])) {
3857 drop_spte(kvm
, &pt
[i
]);
3863 if (is_writable_pte(pt
[i
]))
3864 mmu_spte_update(&pt
[i
],
3865 pt
[i
] & ~PT_WRITABLE_MASK
);
3868 kvm_flush_remote_tlbs(kvm
);
3871 void kvm_mmu_zap_all(struct kvm
*kvm
)
3873 struct kvm_mmu_page
*sp
, *node
;
3874 LIST_HEAD(invalid_list
);
3876 spin_lock(&kvm
->mmu_lock
);
3878 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
3879 if (kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
))
3882 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
3883 spin_unlock(&kvm
->mmu_lock
);
3886 static void kvm_mmu_remove_some_alloc_mmu_pages(struct kvm
*kvm
,
3887 struct list_head
*invalid_list
)
3889 struct kvm_mmu_page
*page
;
3891 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
3892 struct kvm_mmu_page
, link
);
3893 kvm_mmu_prepare_zap_page(kvm
, page
, invalid_list
);
3896 static int mmu_shrink(struct shrinker
*shrink
, struct shrink_control
*sc
)
3899 struct kvm
*kvm_freed
= NULL
;
3900 int nr_to_scan
= sc
->nr_to_scan
;
3902 if (nr_to_scan
== 0)
3905 raw_spin_lock(&kvm_lock
);
3907 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
3909 LIST_HEAD(invalid_list
);
3911 idx
= srcu_read_lock(&kvm
->srcu
);
3912 spin_lock(&kvm
->mmu_lock
);
3913 if (!kvm_freed
&& nr_to_scan
> 0 &&
3914 kvm
->arch
.n_used_mmu_pages
> 0) {
3915 kvm_mmu_remove_some_alloc_mmu_pages(kvm
,
3921 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
3922 spin_unlock(&kvm
->mmu_lock
);
3923 srcu_read_unlock(&kvm
->srcu
, idx
);
3926 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
3928 raw_spin_unlock(&kvm_lock
);
3931 return percpu_counter_read_positive(&kvm_total_used_mmu_pages
);
3934 static struct shrinker mmu_shrinker
= {
3935 .shrink
= mmu_shrink
,
3936 .seeks
= DEFAULT_SEEKS
* 10,
3939 static void mmu_destroy_caches(void)
3941 if (pte_list_desc_cache
)
3942 kmem_cache_destroy(pte_list_desc_cache
);
3943 if (mmu_page_header_cache
)
3944 kmem_cache_destroy(mmu_page_header_cache
);
3947 int kvm_mmu_module_init(void)
3949 pte_list_desc_cache
= kmem_cache_create("pte_list_desc",
3950 sizeof(struct pte_list_desc
),
3952 if (!pte_list_desc_cache
)
3955 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
3956 sizeof(struct kvm_mmu_page
),
3958 if (!mmu_page_header_cache
)
3961 if (percpu_counter_init(&kvm_total_used_mmu_pages
, 0))
3964 register_shrinker(&mmu_shrinker
);
3969 mmu_destroy_caches();
3974 * Caculate mmu pages needed for kvm.
3976 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
3978 unsigned int nr_mmu_pages
;
3979 unsigned int nr_pages
= 0;
3980 struct kvm_memslots
*slots
;
3981 struct kvm_memory_slot
*memslot
;
3983 slots
= kvm_memslots(kvm
);
3985 kvm_for_each_memslot(memslot
, slots
)
3986 nr_pages
+= memslot
->npages
;
3988 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
3989 nr_mmu_pages
= max(nr_mmu_pages
,
3990 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
3992 return nr_mmu_pages
;
3995 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu
*vcpu
, u64 addr
, u64 sptes
[4])
3997 struct kvm_shadow_walk_iterator iterator
;
4001 walk_shadow_page_lockless_begin(vcpu
);
4002 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
) {
4003 sptes
[iterator
.level
-1] = spte
;
4005 if (!is_shadow_present_pte(spte
))
4008 walk_shadow_page_lockless_end(vcpu
);
4012 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy
);
4014 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
4018 destroy_kvm_mmu(vcpu
);
4019 free_mmu_pages(vcpu
);
4020 mmu_free_memory_caches(vcpu
);
4023 void kvm_mmu_module_exit(void)
4025 mmu_destroy_caches();
4026 percpu_counter_destroy(&kvm_total_used_mmu_pages
);
4027 unregister_shrinker(&mmu_shrinker
);
4028 mmu_audit_disable();