2 * Kernel-based Virtual Machine driver for Linux
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
9 * Copyright (C) 2006 Qumranet, Inc.
10 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13 * Yaniv Kamay <yaniv@qumranet.com>
14 * Avi Kivity <avi@qumranet.com>
16 * This work is licensed under the terms of the GNU GPL, version 2. See
17 * the COPYING file in the top-level directory.
24 #include "kvm_cache_regs.h"
26 #include <linux/kvm_host.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
30 #include <linux/highmem.h>
31 #include <linux/module.h>
32 #include <linux/swap.h>
33 #include <linux/hugetlb.h>
34 #include <linux/compiler.h>
35 #include <linux/srcu.h>
36 #include <linux/slab.h>
37 #include <linux/uaccess.h>
40 #include <asm/cmpxchg.h>
45 * When setting this variable to true it enables Two-Dimensional-Paging
46 * where the hardware walks 2 page tables:
47 * 1. the guest-virtual to guest-physical
48 * 2. while doing 1. it walks guest-physical to host-physical
49 * If the hardware supports that we don't need to do shadow paging.
51 bool tdp_enabled
= false;
55 AUDIT_POST_PAGE_FAULT
,
66 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
67 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
71 #define pgprintk(x...) do { } while (0)
72 #define rmap_printk(x...) do { } while (0)
78 module_param(dbg
, bool, 0644);
82 #define ASSERT(x) do { } while (0)
86 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
87 __FILE__, __LINE__, #x); \
91 #define PTE_PREFETCH_NUM 8
93 #define PT_FIRST_AVAIL_BITS_SHIFT 10
94 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
96 #define PT64_LEVEL_BITS 9
98 #define PT64_LEVEL_SHIFT(level) \
99 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
101 #define PT64_INDEX(address, level)\
102 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
105 #define PT32_LEVEL_BITS 10
107 #define PT32_LEVEL_SHIFT(level) \
108 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
110 #define PT32_LVL_OFFSET_MASK(level) \
111 (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
112 * PT32_LEVEL_BITS))) - 1))
114 #define PT32_INDEX(address, level)\
115 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
118 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
119 #define PT64_DIR_BASE_ADDR_MASK \
120 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
121 #define PT64_LVL_ADDR_MASK(level) \
122 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
123 * PT64_LEVEL_BITS))) - 1))
124 #define PT64_LVL_OFFSET_MASK(level) \
125 (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
126 * PT64_LEVEL_BITS))) - 1))
128 #define PT32_BASE_ADDR_MASK PAGE_MASK
129 #define PT32_DIR_BASE_ADDR_MASK \
130 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
131 #define PT32_LVL_ADDR_MASK(level) \
132 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
133 * PT32_LEVEL_BITS))) - 1))
135 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
138 #define ACC_EXEC_MASK 1
139 #define ACC_WRITE_MASK PT_WRITABLE_MASK
140 #define ACC_USER_MASK PT_USER_MASK
141 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
143 #include <trace/events/kvm.h>
145 #define CREATE_TRACE_POINTS
146 #include "mmutrace.h"
148 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
149 #define SPTE_MMU_WRITEABLE (1ULL << (PT_FIRST_AVAIL_BITS_SHIFT + 1))
151 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
153 /* make pte_list_desc fit well in cache line */
154 #define PTE_LIST_EXT 3
156 struct pte_list_desc
{
157 u64
*sptes
[PTE_LIST_EXT
];
158 struct pte_list_desc
*more
;
161 struct kvm_shadow_walk_iterator
{
169 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
170 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
171 shadow_walk_okay(&(_walker)); \
172 shadow_walk_next(&(_walker)))
174 #define for_each_shadow_entry_lockless(_vcpu, _addr, _walker, spte) \
175 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
176 shadow_walk_okay(&(_walker)) && \
177 ({ spte = mmu_spte_get_lockless(_walker.sptep); 1; }); \
178 __shadow_walk_next(&(_walker), spte))
180 static struct kmem_cache
*pte_list_desc_cache
;
181 static struct kmem_cache
*mmu_page_header_cache
;
182 static struct percpu_counter kvm_total_used_mmu_pages
;
184 static u64 __read_mostly shadow_nx_mask
;
185 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
186 static u64 __read_mostly shadow_user_mask
;
187 static u64 __read_mostly shadow_accessed_mask
;
188 static u64 __read_mostly shadow_dirty_mask
;
189 static u64 __read_mostly shadow_mmio_mask
;
191 static void mmu_spte_set(u64
*sptep
, u64 spte
);
192 static void mmu_free_roots(struct kvm_vcpu
*vcpu
);
194 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask
)
196 shadow_mmio_mask
= mmio_mask
;
198 EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask
);
200 static void mark_mmio_spte(u64
*sptep
, u64 gfn
, unsigned access
)
202 access
&= ACC_WRITE_MASK
| ACC_USER_MASK
;
204 trace_mark_mmio_spte(sptep
, gfn
, access
);
205 mmu_spte_set(sptep
, shadow_mmio_mask
| access
| gfn
<< PAGE_SHIFT
);
208 static bool is_mmio_spte(u64 spte
)
210 return (spte
& shadow_mmio_mask
) == shadow_mmio_mask
;
213 static gfn_t
get_mmio_spte_gfn(u64 spte
)
215 return (spte
& ~shadow_mmio_mask
) >> PAGE_SHIFT
;
218 static unsigned get_mmio_spte_access(u64 spte
)
220 return (spte
& ~shadow_mmio_mask
) & ~PAGE_MASK
;
223 static bool set_mmio_spte(u64
*sptep
, gfn_t gfn
, pfn_t pfn
, unsigned access
)
225 if (unlikely(is_noslot_pfn(pfn
))) {
226 mark_mmio_spte(sptep
, gfn
, access
);
233 static inline u64
rsvd_bits(int s
, int e
)
235 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
238 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
239 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
241 shadow_user_mask
= user_mask
;
242 shadow_accessed_mask
= accessed_mask
;
243 shadow_dirty_mask
= dirty_mask
;
244 shadow_nx_mask
= nx_mask
;
245 shadow_x_mask
= x_mask
;
247 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
249 static int is_cpuid_PSE36(void)
254 static int is_nx(struct kvm_vcpu
*vcpu
)
256 return vcpu
->arch
.efer
& EFER_NX
;
259 static int is_shadow_present_pte(u64 pte
)
261 return pte
& PT_PRESENT_MASK
&& !is_mmio_spte(pte
);
264 static int is_large_pte(u64 pte
)
266 return pte
& PT_PAGE_SIZE_MASK
;
269 static int is_dirty_gpte(unsigned long pte
)
271 return pte
& PT_DIRTY_MASK
;
274 static int is_rmap_spte(u64 pte
)
276 return is_shadow_present_pte(pte
);
279 static int is_last_spte(u64 pte
, int level
)
281 if (level
== PT_PAGE_TABLE_LEVEL
)
283 if (is_large_pte(pte
))
288 static pfn_t
spte_to_pfn(u64 pte
)
290 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
293 static gfn_t
pse36_gfn_delta(u32 gpte
)
295 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
297 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
301 static void __set_spte(u64
*sptep
, u64 spte
)
306 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
311 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
313 return xchg(sptep
, spte
);
316 static u64
__get_spte_lockless(u64
*sptep
)
318 return ACCESS_ONCE(*sptep
);
321 static bool __check_direct_spte_mmio_pf(u64 spte
)
323 /* It is valid if the spte is zapped. */
335 static void count_spte_clear(u64
*sptep
, u64 spte
)
337 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
339 if (is_shadow_present_pte(spte
))
342 /* Ensure the spte is completely set before we increase the count */
344 sp
->clear_spte_count
++;
347 static void __set_spte(u64
*sptep
, u64 spte
)
349 union split_spte
*ssptep
, sspte
;
351 ssptep
= (union split_spte
*)sptep
;
352 sspte
= (union split_spte
)spte
;
354 ssptep
->spte_high
= sspte
.spte_high
;
357 * If we map the spte from nonpresent to present, We should store
358 * the high bits firstly, then set present bit, so cpu can not
359 * fetch this spte while we are setting the spte.
363 ssptep
->spte_low
= sspte
.spte_low
;
366 static void __update_clear_spte_fast(u64
*sptep
, u64 spte
)
368 union split_spte
*ssptep
, sspte
;
370 ssptep
= (union split_spte
*)sptep
;
371 sspte
= (union split_spte
)spte
;
373 ssptep
->spte_low
= sspte
.spte_low
;
376 * If we map the spte from present to nonpresent, we should clear
377 * present bit firstly to avoid vcpu fetch the old high bits.
381 ssptep
->spte_high
= sspte
.spte_high
;
382 count_spte_clear(sptep
, spte
);
385 static u64
__update_clear_spte_slow(u64
*sptep
, u64 spte
)
387 union split_spte
*ssptep
, sspte
, orig
;
389 ssptep
= (union split_spte
*)sptep
;
390 sspte
= (union split_spte
)spte
;
392 /* xchg acts as a barrier before the setting of the high bits */
393 orig
.spte_low
= xchg(&ssptep
->spte_low
, sspte
.spte_low
);
394 orig
.spte_high
= ssptep
->spte_high
;
395 ssptep
->spte_high
= sspte
.spte_high
;
396 count_spte_clear(sptep
, spte
);
402 * The idea using the light way get the spte on x86_32 guest is from
403 * gup_get_pte(arch/x86/mm/gup.c).
404 * The difference is we can not catch the spte tlb flush if we leave
405 * guest mode, so we emulate it by increase clear_spte_count when spte
408 static u64
__get_spte_lockless(u64
*sptep
)
410 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
411 union split_spte spte
, *orig
= (union split_spte
*)sptep
;
415 count
= sp
->clear_spte_count
;
418 spte
.spte_low
= orig
->spte_low
;
421 spte
.spte_high
= orig
->spte_high
;
424 if (unlikely(spte
.spte_low
!= orig
->spte_low
||
425 count
!= sp
->clear_spte_count
))
431 static bool __check_direct_spte_mmio_pf(u64 spte
)
433 union split_spte sspte
= (union split_spte
)spte
;
434 u32 high_mmio_mask
= shadow_mmio_mask
>> 32;
436 /* It is valid if the spte is zapped. */
440 /* It is valid if the spte is being zapped. */
441 if (sspte
.spte_low
== 0ull &&
442 (sspte
.spte_high
& high_mmio_mask
) == high_mmio_mask
)
449 static bool spte_is_locklessly_modifiable(u64 spte
)
451 return (spte
& (SPTE_HOST_WRITEABLE
| SPTE_MMU_WRITEABLE
)) ==
452 (SPTE_HOST_WRITEABLE
| SPTE_MMU_WRITEABLE
);
455 static bool spte_has_volatile_bits(u64 spte
)
458 * Always atomicly update spte if it can be updated
459 * out of mmu-lock, it can ensure dirty bit is not lost,
460 * also, it can help us to get a stable is_writable_pte()
461 * to ensure tlb flush is not missed.
463 if (spte_is_locklessly_modifiable(spte
))
466 if (!shadow_accessed_mask
)
469 if (!is_shadow_present_pte(spte
))
472 if ((spte
& shadow_accessed_mask
) &&
473 (!is_writable_pte(spte
) || (spte
& shadow_dirty_mask
)))
479 static bool spte_is_bit_cleared(u64 old_spte
, u64 new_spte
, u64 bit_mask
)
481 return (old_spte
& bit_mask
) && !(new_spte
& bit_mask
);
484 /* Rules for using mmu_spte_set:
485 * Set the sptep from nonpresent to present.
486 * Note: the sptep being assigned *must* be either not present
487 * or in a state where the hardware will not attempt to update
490 static void mmu_spte_set(u64
*sptep
, u64 new_spte
)
492 WARN_ON(is_shadow_present_pte(*sptep
));
493 __set_spte(sptep
, new_spte
);
496 /* Rules for using mmu_spte_update:
497 * Update the state bits, it means the mapped pfn is not changged.
499 * Whenever we overwrite a writable spte with a read-only one we
500 * should flush remote TLBs. Otherwise rmap_write_protect
501 * will find a read-only spte, even though the writable spte
502 * might be cached on a CPU's TLB, the return value indicates this
505 static bool mmu_spte_update(u64
*sptep
, u64 new_spte
)
507 u64 old_spte
= *sptep
;
510 WARN_ON(!is_rmap_spte(new_spte
));
512 if (!is_shadow_present_pte(old_spte
)) {
513 mmu_spte_set(sptep
, new_spte
);
517 if (!spte_has_volatile_bits(old_spte
))
518 __update_clear_spte_fast(sptep
, new_spte
);
520 old_spte
= __update_clear_spte_slow(sptep
, new_spte
);
523 * For the spte updated out of mmu-lock is safe, since
524 * we always atomicly update it, see the comments in
525 * spte_has_volatile_bits().
527 if (is_writable_pte(old_spte
) && !is_writable_pte(new_spte
))
530 if (!shadow_accessed_mask
)
533 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_accessed_mask
))
534 kvm_set_pfn_accessed(spte_to_pfn(old_spte
));
535 if (spte_is_bit_cleared(old_spte
, new_spte
, shadow_dirty_mask
))
536 kvm_set_pfn_dirty(spte_to_pfn(old_spte
));
542 * Rules for using mmu_spte_clear_track_bits:
543 * It sets the sptep from present to nonpresent, and track the
544 * state bits, it is used to clear the last level sptep.
546 static int mmu_spte_clear_track_bits(u64
*sptep
)
549 u64 old_spte
= *sptep
;
551 if (!spte_has_volatile_bits(old_spte
))
552 __update_clear_spte_fast(sptep
, 0ull);
554 old_spte
= __update_clear_spte_slow(sptep
, 0ull);
556 if (!is_rmap_spte(old_spte
))
559 pfn
= spte_to_pfn(old_spte
);
562 * KVM does not hold the refcount of the page used by
563 * kvm mmu, before reclaiming the page, we should
564 * unmap it from mmu first.
566 WARN_ON(!kvm_is_mmio_pfn(pfn
) && !page_count(pfn_to_page(pfn
)));
568 if (!shadow_accessed_mask
|| old_spte
& shadow_accessed_mask
)
569 kvm_set_pfn_accessed(pfn
);
570 if (!shadow_dirty_mask
|| (old_spte
& shadow_dirty_mask
))
571 kvm_set_pfn_dirty(pfn
);
576 * Rules for using mmu_spte_clear_no_track:
577 * Directly clear spte without caring the state bits of sptep,
578 * it is used to set the upper level spte.
580 static void mmu_spte_clear_no_track(u64
*sptep
)
582 __update_clear_spte_fast(sptep
, 0ull);
585 static u64
mmu_spte_get_lockless(u64
*sptep
)
587 return __get_spte_lockless(sptep
);
590 static void walk_shadow_page_lockless_begin(struct kvm_vcpu
*vcpu
)
593 * Prevent page table teardown by making any free-er wait during
594 * kvm_flush_remote_tlbs() IPI to all active vcpus.
597 vcpu
->mode
= READING_SHADOW_PAGE_TABLES
;
599 * Make sure a following spte read is not reordered ahead of the write
605 static void walk_shadow_page_lockless_end(struct kvm_vcpu
*vcpu
)
608 * Make sure the write to vcpu->mode is not reordered in front of
609 * reads to sptes. If it does, kvm_commit_zap_page() can see us
610 * OUTSIDE_GUEST_MODE and proceed to free the shadow page table.
613 vcpu
->mode
= OUTSIDE_GUEST_MODE
;
617 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
618 struct kmem_cache
*base_cache
, int min
)
622 if (cache
->nobjs
>= min
)
624 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
625 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
628 cache
->objects
[cache
->nobjs
++] = obj
;
633 static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache
*cache
)
638 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
,
639 struct kmem_cache
*cache
)
642 kmem_cache_free(cache
, mc
->objects
[--mc
->nobjs
]);
645 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
650 if (cache
->nobjs
>= min
)
652 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
653 page
= (void *)__get_free_page(GFP_KERNEL
);
656 cache
->objects
[cache
->nobjs
++] = page
;
661 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
664 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
667 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
671 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
672 pte_list_desc_cache
, 8 + PTE_PREFETCH_NUM
);
675 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
678 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
679 mmu_page_header_cache
, 4);
684 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
686 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_list_desc_cache
,
687 pte_list_desc_cache
);
688 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
689 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
690 mmu_page_header_cache
);
693 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
)
698 p
= mc
->objects
[--mc
->nobjs
];
702 static struct pte_list_desc
*mmu_alloc_pte_list_desc(struct kvm_vcpu
*vcpu
)
704 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_list_desc_cache
);
707 static void mmu_free_pte_list_desc(struct pte_list_desc
*pte_list_desc
)
709 kmem_cache_free(pte_list_desc_cache
, pte_list_desc
);
712 static gfn_t
kvm_mmu_page_get_gfn(struct kvm_mmu_page
*sp
, int index
)
714 if (!sp
->role
.direct
)
715 return sp
->gfns
[index
];
717 return sp
->gfn
+ (index
<< ((sp
->role
.level
- 1) * PT64_LEVEL_BITS
));
720 static void kvm_mmu_page_set_gfn(struct kvm_mmu_page
*sp
, int index
, gfn_t gfn
)
723 BUG_ON(gfn
!= kvm_mmu_page_get_gfn(sp
, index
));
725 sp
->gfns
[index
] = gfn
;
729 * Return the pointer to the large page information for a given gfn,
730 * handling slots that are not large page aligned.
732 static struct kvm_lpage_info
*lpage_info_slot(gfn_t gfn
,
733 struct kvm_memory_slot
*slot
,
738 idx
= gfn_to_index(gfn
, slot
->base_gfn
, level
);
739 return &slot
->arch
.lpage_info
[level
- 2][idx
];
742 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
744 struct kvm_memory_slot
*slot
;
745 struct kvm_lpage_info
*linfo
;
748 slot
= gfn_to_memslot(kvm
, gfn
);
749 for (i
= PT_DIRECTORY_LEVEL
;
750 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
751 linfo
= lpage_info_slot(gfn
, slot
, i
);
752 linfo
->write_count
+= 1;
754 kvm
->arch
.indirect_shadow_pages
++;
757 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
759 struct kvm_memory_slot
*slot
;
760 struct kvm_lpage_info
*linfo
;
763 slot
= gfn_to_memslot(kvm
, gfn
);
764 for (i
= PT_DIRECTORY_LEVEL
;
765 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
766 linfo
= lpage_info_slot(gfn
, slot
, i
);
767 linfo
->write_count
-= 1;
768 WARN_ON(linfo
->write_count
< 0);
770 kvm
->arch
.indirect_shadow_pages
--;
773 static int has_wrprotected_page(struct kvm
*kvm
,
777 struct kvm_memory_slot
*slot
;
778 struct kvm_lpage_info
*linfo
;
780 slot
= gfn_to_memslot(kvm
, gfn
);
782 linfo
= lpage_info_slot(gfn
, slot
, level
);
783 return linfo
->write_count
;
789 static int host_mapping_level(struct kvm
*kvm
, gfn_t gfn
)
791 unsigned long page_size
;
794 page_size
= kvm_host_page_size(kvm
, gfn
);
796 for (i
= PT_PAGE_TABLE_LEVEL
;
797 i
< (PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
); ++i
) {
798 if (page_size
>= KVM_HPAGE_SIZE(i
))
807 static struct kvm_memory_slot
*
808 gfn_to_memslot_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
811 struct kvm_memory_slot
*slot
;
813 slot
= gfn_to_memslot(vcpu
->kvm
, gfn
);
814 if (!slot
|| slot
->flags
& KVM_MEMSLOT_INVALID
||
815 (no_dirty_log
&& slot
->dirty_bitmap
))
821 static bool mapping_level_dirty_bitmap(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
823 return !gfn_to_memslot_dirty_bitmap(vcpu
, large_gfn
, true);
826 static int mapping_level(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
828 int host_level
, level
, max_level
;
830 host_level
= host_mapping_level(vcpu
->kvm
, large_gfn
);
832 if (host_level
== PT_PAGE_TABLE_LEVEL
)
835 max_level
= min(kvm_x86_ops
->get_lpage_level(), host_level
);
837 for (level
= PT_DIRECTORY_LEVEL
; level
<= max_level
; ++level
)
838 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
, level
))
845 * Pte mapping structures:
847 * If pte_list bit zero is zero, then pte_list point to the spte.
849 * If pte_list bit zero is one, (then pte_list & ~1) points to a struct
850 * pte_list_desc containing more mappings.
852 * Returns the number of pte entries before the spte was added or zero if
853 * the spte was not added.
856 static int pte_list_add(struct kvm_vcpu
*vcpu
, u64
*spte
,
857 unsigned long *pte_list
)
859 struct pte_list_desc
*desc
;
863 rmap_printk("pte_list_add: %p %llx 0->1\n", spte
, *spte
);
864 *pte_list
= (unsigned long)spte
;
865 } else if (!(*pte_list
& 1)) {
866 rmap_printk("pte_list_add: %p %llx 1->many\n", spte
, *spte
);
867 desc
= mmu_alloc_pte_list_desc(vcpu
);
868 desc
->sptes
[0] = (u64
*)*pte_list
;
869 desc
->sptes
[1] = spte
;
870 *pte_list
= (unsigned long)desc
| 1;
873 rmap_printk("pte_list_add: %p %llx many->many\n", spte
, *spte
);
874 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
875 while (desc
->sptes
[PTE_LIST_EXT
-1] && desc
->more
) {
877 count
+= PTE_LIST_EXT
;
879 if (desc
->sptes
[PTE_LIST_EXT
-1]) {
880 desc
->more
= mmu_alloc_pte_list_desc(vcpu
);
883 for (i
= 0; desc
->sptes
[i
]; ++i
)
885 desc
->sptes
[i
] = spte
;
891 pte_list_desc_remove_entry(unsigned long *pte_list
, struct pte_list_desc
*desc
,
892 int i
, struct pte_list_desc
*prev_desc
)
896 for (j
= PTE_LIST_EXT
- 1; !desc
->sptes
[j
] && j
> i
; --j
)
898 desc
->sptes
[i
] = desc
->sptes
[j
];
899 desc
->sptes
[j
] = NULL
;
902 if (!prev_desc
&& !desc
->more
)
903 *pte_list
= (unsigned long)desc
->sptes
[0];
906 prev_desc
->more
= desc
->more
;
908 *pte_list
= (unsigned long)desc
->more
| 1;
909 mmu_free_pte_list_desc(desc
);
912 static void pte_list_remove(u64
*spte
, unsigned long *pte_list
)
914 struct pte_list_desc
*desc
;
915 struct pte_list_desc
*prev_desc
;
919 printk(KERN_ERR
"pte_list_remove: %p 0->BUG\n", spte
);
921 } else if (!(*pte_list
& 1)) {
922 rmap_printk("pte_list_remove: %p 1->0\n", spte
);
923 if ((u64
*)*pte_list
!= spte
) {
924 printk(KERN_ERR
"pte_list_remove: %p 1->BUG\n", spte
);
929 rmap_printk("pte_list_remove: %p many->many\n", spte
);
930 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
933 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
934 if (desc
->sptes
[i
] == spte
) {
935 pte_list_desc_remove_entry(pte_list
,
943 pr_err("pte_list_remove: %p many->many\n", spte
);
948 typedef void (*pte_list_walk_fn
) (u64
*spte
);
949 static void pte_list_walk(unsigned long *pte_list
, pte_list_walk_fn fn
)
951 struct pte_list_desc
*desc
;
957 if (!(*pte_list
& 1))
958 return fn((u64
*)*pte_list
);
960 desc
= (struct pte_list_desc
*)(*pte_list
& ~1ul);
962 for (i
= 0; i
< PTE_LIST_EXT
&& desc
->sptes
[i
]; ++i
)
968 static unsigned long *__gfn_to_rmap(gfn_t gfn
, int level
,
969 struct kvm_memory_slot
*slot
)
973 idx
= gfn_to_index(gfn
, slot
->base_gfn
, level
);
974 return &slot
->arch
.rmap
[level
- PT_PAGE_TABLE_LEVEL
][idx
];
978 * Take gfn and return the reverse mapping to it.
980 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int level
)
982 struct kvm_memory_slot
*slot
;
984 slot
= gfn_to_memslot(kvm
, gfn
);
985 return __gfn_to_rmap(gfn
, level
, slot
);
988 static bool rmap_can_add(struct kvm_vcpu
*vcpu
)
990 struct kvm_mmu_memory_cache
*cache
;
992 cache
= &vcpu
->arch
.mmu_pte_list_desc_cache
;
993 return mmu_memory_cache_free_objects(cache
);
996 static int rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
998 struct kvm_mmu_page
*sp
;
999 unsigned long *rmapp
;
1001 sp
= page_header(__pa(spte
));
1002 kvm_mmu_page_set_gfn(sp
, spte
- sp
->spt
, gfn
);
1003 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
1004 return pte_list_add(vcpu
, spte
, rmapp
);
1007 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
1009 struct kvm_mmu_page
*sp
;
1011 unsigned long *rmapp
;
1013 sp
= page_header(__pa(spte
));
1014 gfn
= kvm_mmu_page_get_gfn(sp
, spte
- sp
->spt
);
1015 rmapp
= gfn_to_rmap(kvm
, gfn
, sp
->role
.level
);
1016 pte_list_remove(spte
, rmapp
);
1020 * Used by the following functions to iterate through the sptes linked by a
1021 * rmap. All fields are private and not assumed to be used outside.
1023 struct rmap_iterator
{
1024 /* private fields */
1025 struct pte_list_desc
*desc
; /* holds the sptep if not NULL */
1026 int pos
; /* index of the sptep */
1030 * Iteration must be started by this function. This should also be used after
1031 * removing/dropping sptes from the rmap link because in such cases the
1032 * information in the itererator may not be valid.
1034 * Returns sptep if found, NULL otherwise.
1036 static u64
*rmap_get_first(unsigned long rmap
, struct rmap_iterator
*iter
)
1046 iter
->desc
= (struct pte_list_desc
*)(rmap
& ~1ul);
1048 return iter
->desc
->sptes
[iter
->pos
];
1052 * Must be used with a valid iterator: e.g. after rmap_get_first().
1054 * Returns sptep if found, NULL otherwise.
1056 static u64
*rmap_get_next(struct rmap_iterator
*iter
)
1059 if (iter
->pos
< PTE_LIST_EXT
- 1) {
1063 sptep
= iter
->desc
->sptes
[iter
->pos
];
1068 iter
->desc
= iter
->desc
->more
;
1072 /* desc->sptes[0] cannot be NULL */
1073 return iter
->desc
->sptes
[iter
->pos
];
1080 static void drop_spte(struct kvm
*kvm
, u64
*sptep
)
1082 if (mmu_spte_clear_track_bits(sptep
))
1083 rmap_remove(kvm
, sptep
);
1087 static bool __drop_large_spte(struct kvm
*kvm
, u64
*sptep
)
1089 if (is_large_pte(*sptep
)) {
1090 WARN_ON(page_header(__pa(sptep
))->role
.level
==
1091 PT_PAGE_TABLE_LEVEL
);
1092 drop_spte(kvm
, sptep
);
1100 static void drop_large_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
)
1102 if (__drop_large_spte(vcpu
->kvm
, sptep
))
1103 kvm_flush_remote_tlbs(vcpu
->kvm
);
1107 * Write-protect on the specified @sptep, @pt_protect indicates whether
1108 * spte writ-protection is caused by protecting shadow page table.
1109 * @flush indicates whether tlb need be flushed.
1111 * Note: write protection is difference between drity logging and spte
1113 * - for dirty logging, the spte can be set to writable at anytime if
1114 * its dirty bitmap is properly set.
1115 * - for spte protection, the spte can be writable only after unsync-ing
1118 * Return true if the spte is dropped.
1121 spte_write_protect(struct kvm
*kvm
, u64
*sptep
, bool *flush
, bool pt_protect
)
1125 if (!is_writable_pte(spte
) &&
1126 !(pt_protect
&& spte_is_locklessly_modifiable(spte
)))
1129 rmap_printk("rmap_write_protect: spte %p %llx\n", sptep
, *sptep
);
1131 if (__drop_large_spte(kvm
, sptep
)) {
1137 spte
&= ~SPTE_MMU_WRITEABLE
;
1138 spte
= spte
& ~PT_WRITABLE_MASK
;
1140 *flush
|= mmu_spte_update(sptep
, spte
);
1144 static bool __rmap_write_protect(struct kvm
*kvm
, unsigned long *rmapp
,
1148 struct rmap_iterator iter
;
1151 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;) {
1152 BUG_ON(!(*sptep
& PT_PRESENT_MASK
));
1153 if (spte_write_protect(kvm
, sptep
, &flush
, pt_protect
)) {
1154 sptep
= rmap_get_first(*rmapp
, &iter
);
1158 sptep
= rmap_get_next(&iter
);
1165 * kvm_mmu_write_protect_pt_masked - write protect selected PT level pages
1166 * @kvm: kvm instance
1167 * @slot: slot to protect
1168 * @gfn_offset: start of the BITS_PER_LONG pages we care about
1169 * @mask: indicates which pages we should protect
1171 * Used when we do not need to care about huge page mappings: e.g. during dirty
1172 * logging we do not have any such mappings.
1174 void kvm_mmu_write_protect_pt_masked(struct kvm
*kvm
,
1175 struct kvm_memory_slot
*slot
,
1176 gfn_t gfn_offset
, unsigned long mask
)
1178 unsigned long *rmapp
;
1181 rmapp
= __gfn_to_rmap(slot
->base_gfn
+ gfn_offset
+ __ffs(mask
),
1182 PT_PAGE_TABLE_LEVEL
, slot
);
1183 __rmap_write_protect(kvm
, rmapp
, false);
1185 /* clear the first set bit */
1190 static bool rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
1192 struct kvm_memory_slot
*slot
;
1193 unsigned long *rmapp
;
1195 bool write_protected
= false;
1197 slot
= gfn_to_memslot(kvm
, gfn
);
1199 for (i
= PT_PAGE_TABLE_LEVEL
;
1200 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
1201 rmapp
= __gfn_to_rmap(gfn
, i
, slot
);
1202 write_protected
|= __rmap_write_protect(kvm
, rmapp
, true);
1205 return write_protected
;
1208 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1209 struct kvm_memory_slot
*slot
, unsigned long data
)
1212 struct rmap_iterator iter
;
1213 int need_tlb_flush
= 0;
1215 while ((sptep
= rmap_get_first(*rmapp
, &iter
))) {
1216 BUG_ON(!(*sptep
& PT_PRESENT_MASK
));
1217 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", sptep
, *sptep
);
1219 drop_spte(kvm
, sptep
);
1223 return need_tlb_flush
;
1226 static int kvm_set_pte_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1227 struct kvm_memory_slot
*slot
, unsigned long data
)
1230 struct rmap_iterator iter
;
1233 pte_t
*ptep
= (pte_t
*)data
;
1236 WARN_ON(pte_huge(*ptep
));
1237 new_pfn
= pte_pfn(*ptep
);
1239 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;) {
1240 BUG_ON(!is_shadow_present_pte(*sptep
));
1241 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", sptep
, *sptep
);
1245 if (pte_write(*ptep
)) {
1246 drop_spte(kvm
, sptep
);
1247 sptep
= rmap_get_first(*rmapp
, &iter
);
1249 new_spte
= *sptep
& ~PT64_BASE_ADDR_MASK
;
1250 new_spte
|= (u64
)new_pfn
<< PAGE_SHIFT
;
1252 new_spte
&= ~PT_WRITABLE_MASK
;
1253 new_spte
&= ~SPTE_HOST_WRITEABLE
;
1254 new_spte
&= ~shadow_accessed_mask
;
1256 mmu_spte_clear_track_bits(sptep
);
1257 mmu_spte_set(sptep
, new_spte
);
1258 sptep
= rmap_get_next(&iter
);
1263 kvm_flush_remote_tlbs(kvm
);
1268 static int kvm_handle_hva_range(struct kvm
*kvm
,
1269 unsigned long start
,
1272 int (*handler
)(struct kvm
*kvm
,
1273 unsigned long *rmapp
,
1274 struct kvm_memory_slot
*slot
,
1275 unsigned long data
))
1279 struct kvm_memslots
*slots
;
1280 struct kvm_memory_slot
*memslot
;
1282 slots
= kvm_memslots(kvm
);
1284 kvm_for_each_memslot(memslot
, slots
) {
1285 unsigned long hva_start
, hva_end
;
1286 gfn_t gfn_start
, gfn_end
;
1288 hva_start
= max(start
, memslot
->userspace_addr
);
1289 hva_end
= min(end
, memslot
->userspace_addr
+
1290 (memslot
->npages
<< PAGE_SHIFT
));
1291 if (hva_start
>= hva_end
)
1294 * {gfn(page) | page intersects with [hva_start, hva_end)} =
1295 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1297 gfn_start
= hva_to_gfn_memslot(hva_start
, memslot
);
1298 gfn_end
= hva_to_gfn_memslot(hva_end
+ PAGE_SIZE
- 1, memslot
);
1300 for (j
= PT_PAGE_TABLE_LEVEL
;
1301 j
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++j
) {
1302 unsigned long idx
, idx_end
;
1303 unsigned long *rmapp
;
1306 * {idx(page_j) | page_j intersects with
1307 * [hva_start, hva_end)} = {idx, idx+1, ..., idx_end}.
1309 idx
= gfn_to_index(gfn_start
, memslot
->base_gfn
, j
);
1310 idx_end
= gfn_to_index(gfn_end
- 1, memslot
->base_gfn
, j
);
1312 rmapp
= __gfn_to_rmap(gfn_start
, j
, memslot
);
1314 for (; idx
<= idx_end
; ++idx
)
1315 ret
|= handler(kvm
, rmapp
++, memslot
, data
);
1322 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
1324 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
,
1325 struct kvm_memory_slot
*slot
,
1326 unsigned long data
))
1328 return kvm_handle_hva_range(kvm
, hva
, hva
+ 1, data
, handler
);
1331 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
1333 return kvm_handle_hva(kvm
, hva
, 0, kvm_unmap_rmapp
);
1336 int kvm_unmap_hva_range(struct kvm
*kvm
, unsigned long start
, unsigned long end
)
1338 return kvm_handle_hva_range(kvm
, start
, end
, 0, kvm_unmap_rmapp
);
1341 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
1343 kvm_handle_hva(kvm
, hva
, (unsigned long)&pte
, kvm_set_pte_rmapp
);
1346 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1347 struct kvm_memory_slot
*slot
, unsigned long data
)
1350 struct rmap_iterator
uninitialized_var(iter
);
1354 * In case of absence of EPT Access and Dirty Bits supports,
1355 * emulate the accessed bit for EPT, by checking if this page has
1356 * an EPT mapping, and clearing it if it does. On the next access,
1357 * a new EPT mapping will be established.
1358 * This has some overhead, but not as much as the cost of swapping
1359 * out actively used pages or breaking up actively used hugepages.
1361 if (!shadow_accessed_mask
) {
1362 young
= kvm_unmap_rmapp(kvm
, rmapp
, slot
, data
);
1366 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;
1367 sptep
= rmap_get_next(&iter
)) {
1368 BUG_ON(!is_shadow_present_pte(*sptep
));
1370 if (*sptep
& shadow_accessed_mask
) {
1372 clear_bit((ffs(shadow_accessed_mask
) - 1),
1373 (unsigned long *)sptep
);
1377 /* @data has hva passed to kvm_age_hva(). */
1378 trace_kvm_age_page(data
, slot
, young
);
1382 static int kvm_test_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
1383 struct kvm_memory_slot
*slot
, unsigned long data
)
1386 struct rmap_iterator iter
;
1390 * If there's no access bit in the secondary pte set by the
1391 * hardware it's up to gup-fast/gup to set the access bit in
1392 * the primary pte or in the page structure.
1394 if (!shadow_accessed_mask
)
1397 for (sptep
= rmap_get_first(*rmapp
, &iter
); sptep
;
1398 sptep
= rmap_get_next(&iter
)) {
1399 BUG_ON(!is_shadow_present_pte(*sptep
));
1401 if (*sptep
& shadow_accessed_mask
) {
1410 #define RMAP_RECYCLE_THRESHOLD 1000
1412 static void rmap_recycle(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
1414 unsigned long *rmapp
;
1415 struct kvm_mmu_page
*sp
;
1417 sp
= page_header(__pa(spte
));
1419 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
1421 kvm_unmap_rmapp(vcpu
->kvm
, rmapp
, NULL
, 0);
1422 kvm_flush_remote_tlbs(vcpu
->kvm
);
1425 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
1427 return kvm_handle_hva(kvm
, hva
, hva
, kvm_age_rmapp
);
1430 int kvm_test_age_hva(struct kvm
*kvm
, unsigned long hva
)
1432 return kvm_handle_hva(kvm
, hva
, 0, kvm_test_age_rmapp
);
1436 static int is_empty_shadow_page(u64
*spt
)
1441 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
1442 if (is_shadow_present_pte(*pos
)) {
1443 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
1452 * This value is the sum of all of the kvm instances's
1453 * kvm->arch.n_used_mmu_pages values. We need a global,
1454 * aggregate version in order to make the slab shrinker
1457 static inline void kvm_mod_used_mmu_pages(struct kvm
*kvm
, int nr
)
1459 kvm
->arch
.n_used_mmu_pages
+= nr
;
1460 percpu_counter_add(&kvm_total_used_mmu_pages
, nr
);
1463 static void kvm_mmu_free_page(struct kvm_mmu_page
*sp
)
1465 ASSERT(is_empty_shadow_page(sp
->spt
));
1466 hlist_del(&sp
->hash_link
);
1467 list_del(&sp
->link
);
1468 free_page((unsigned long)sp
->spt
);
1469 if (!sp
->role
.direct
)
1470 free_page((unsigned long)sp
->gfns
);
1471 kmem_cache_free(mmu_page_header_cache
, sp
);
1474 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
1476 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
1479 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
1480 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1485 pte_list_add(vcpu
, parent_pte
, &sp
->parent_ptes
);
1488 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
1491 pte_list_remove(parent_pte
, &sp
->parent_ptes
);
1494 static void drop_parent_pte(struct kvm_mmu_page
*sp
,
1497 mmu_page_remove_parent_pte(sp
, parent_pte
);
1498 mmu_spte_clear_no_track(parent_pte
);
1501 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
1502 u64
*parent_pte
, int direct
)
1504 struct kvm_mmu_page
*sp
;
1505 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
);
1506 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
);
1508 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
);
1509 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
1510 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
1511 sp
->parent_ptes
= 0;
1512 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1513 kvm_mod_used_mmu_pages(vcpu
->kvm
, +1);
1517 static void mark_unsync(u64
*spte
);
1518 static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page
*sp
)
1520 pte_list_walk(&sp
->parent_ptes
, mark_unsync
);
1523 static void mark_unsync(u64
*spte
)
1525 struct kvm_mmu_page
*sp
;
1528 sp
= page_header(__pa(spte
));
1529 index
= spte
- sp
->spt
;
1530 if (__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
1532 if (sp
->unsync_children
++)
1534 kvm_mmu_mark_parents_unsync(sp
);
1537 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
1538 struct kvm_mmu_page
*sp
)
1543 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
1547 static void nonpaging_update_pte(struct kvm_vcpu
*vcpu
,
1548 struct kvm_mmu_page
*sp
, u64
*spte
,
1554 #define KVM_PAGE_ARRAY_NR 16
1556 struct kvm_mmu_pages
{
1557 struct mmu_page_and_offset
{
1558 struct kvm_mmu_page
*sp
;
1560 } page
[KVM_PAGE_ARRAY_NR
];
1564 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
1570 for (i
=0; i
< pvec
->nr
; i
++)
1571 if (pvec
->page
[i
].sp
== sp
)
1574 pvec
->page
[pvec
->nr
].sp
= sp
;
1575 pvec
->page
[pvec
->nr
].idx
= idx
;
1577 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1580 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1581 struct kvm_mmu_pages
*pvec
)
1583 int i
, ret
, nr_unsync_leaf
= 0;
1585 for_each_set_bit(i
, sp
->unsync_child_bitmap
, 512) {
1586 struct kvm_mmu_page
*child
;
1587 u64 ent
= sp
->spt
[i
];
1589 if (!is_shadow_present_pte(ent
) || is_large_pte(ent
))
1590 goto clear_child_bitmap
;
1592 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1594 if (child
->unsync_children
) {
1595 if (mmu_pages_add(pvec
, child
, i
))
1598 ret
= __mmu_unsync_walk(child
, pvec
);
1600 goto clear_child_bitmap
;
1602 nr_unsync_leaf
+= ret
;
1605 } else if (child
->unsync
) {
1607 if (mmu_pages_add(pvec
, child
, i
))
1610 goto clear_child_bitmap
;
1615 __clear_bit(i
, sp
->unsync_child_bitmap
);
1616 sp
->unsync_children
--;
1617 WARN_ON((int)sp
->unsync_children
< 0);
1621 return nr_unsync_leaf
;
1624 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1625 struct kvm_mmu_pages
*pvec
)
1627 if (!sp
->unsync_children
)
1630 mmu_pages_add(pvec
, sp
, 0);
1631 return __mmu_unsync_walk(sp
, pvec
);
1634 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1636 WARN_ON(!sp
->unsync
);
1637 trace_kvm_mmu_sync_page(sp
);
1639 --kvm
->stat
.mmu_unsync
;
1642 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1643 struct list_head
*invalid_list
);
1644 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
1645 struct list_head
*invalid_list
);
1647 #define for_each_gfn_sp(kvm, sp, gfn, pos) \
1648 hlist_for_each_entry(sp, pos, \
1649 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1650 if ((sp)->gfn != (gfn)) {} else
1652 #define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos) \
1653 hlist_for_each_entry(sp, pos, \
1654 &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link) \
1655 if ((sp)->gfn != (gfn) || (sp)->role.direct || \
1656 (sp)->role.invalid) {} else
1658 /* @sp->gfn should be write-protected at the call site */
1659 static int __kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1660 struct list_head
*invalid_list
, bool clear_unsync
)
1662 if (sp
->role
.cr4_pae
!= !!is_pae(vcpu
)) {
1663 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1668 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1670 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1671 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, invalid_list
);
1675 kvm_mmu_flush_tlb(vcpu
);
1679 static int kvm_sync_page_transient(struct kvm_vcpu
*vcpu
,
1680 struct kvm_mmu_page
*sp
)
1682 LIST_HEAD(invalid_list
);
1685 ret
= __kvm_sync_page(vcpu
, sp
, &invalid_list
, false);
1687 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1692 #ifdef CONFIG_KVM_MMU_AUDIT
1693 #include "mmu_audit.c"
1695 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, int point
) { }
1696 static void mmu_audit_disable(void) { }
1699 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1700 struct list_head
*invalid_list
)
1702 return __kvm_sync_page(vcpu
, sp
, invalid_list
, true);
1705 /* @gfn should be write-protected at the call site */
1706 static void kvm_sync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1708 struct kvm_mmu_page
*s
;
1709 struct hlist_node
*node
;
1710 LIST_HEAD(invalid_list
);
1713 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
1717 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
1718 kvm_unlink_unsync_page(vcpu
->kvm
, s
);
1719 if ((s
->role
.cr4_pae
!= !!is_pae(vcpu
)) ||
1720 (vcpu
->arch
.mmu
.sync_page(vcpu
, s
))) {
1721 kvm_mmu_prepare_zap_page(vcpu
->kvm
, s
, &invalid_list
);
1727 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1729 kvm_mmu_flush_tlb(vcpu
);
1732 struct mmu_page_path
{
1733 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1734 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1737 #define for_each_sp(pvec, sp, parents, i) \
1738 for (i = mmu_pages_next(&pvec, &parents, -1), \
1739 sp = pvec.page[i].sp; \
1740 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1741 i = mmu_pages_next(&pvec, &parents, i))
1743 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1744 struct mmu_page_path
*parents
,
1749 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1750 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1752 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1753 parents
->idx
[0] = pvec
->page
[n
].idx
;
1757 parents
->parent
[sp
->role
.level
-2] = sp
;
1758 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1764 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1766 struct kvm_mmu_page
*sp
;
1767 unsigned int level
= 0;
1770 unsigned int idx
= parents
->idx
[level
];
1772 sp
= parents
->parent
[level
];
1776 --sp
->unsync_children
;
1777 WARN_ON((int)sp
->unsync_children
< 0);
1778 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1780 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1783 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1784 struct mmu_page_path
*parents
,
1785 struct kvm_mmu_pages
*pvec
)
1787 parents
->parent
[parent
->role
.level
-1] = NULL
;
1791 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1792 struct kvm_mmu_page
*parent
)
1795 struct kvm_mmu_page
*sp
;
1796 struct mmu_page_path parents
;
1797 struct kvm_mmu_pages pages
;
1798 LIST_HEAD(invalid_list
);
1800 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1801 while (mmu_unsync_walk(parent
, &pages
)) {
1802 bool protected = false;
1804 for_each_sp(pages
, sp
, parents
, i
)
1805 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1808 kvm_flush_remote_tlbs(vcpu
->kvm
);
1810 for_each_sp(pages
, sp
, parents
, i
) {
1811 kvm_sync_page(vcpu
, sp
, &invalid_list
);
1812 mmu_pages_clear_parents(&parents
);
1814 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
1815 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1816 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1820 static void init_shadow_page_table(struct kvm_mmu_page
*sp
)
1824 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1828 static void __clear_sp_write_flooding_count(struct kvm_mmu_page
*sp
)
1830 sp
->write_flooding_count
= 0;
1833 static void clear_sp_write_flooding_count(u64
*spte
)
1835 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
1837 __clear_sp_write_flooding_count(sp
);
1840 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1848 union kvm_mmu_page_role role
;
1850 struct kvm_mmu_page
*sp
;
1851 struct hlist_node
*node
;
1852 bool need_sync
= false;
1854 role
= vcpu
->arch
.mmu
.base_role
;
1856 role
.direct
= direct
;
1859 role
.access
= access
;
1860 if (!vcpu
->arch
.mmu
.direct_map
1861 && vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1862 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1863 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1864 role
.quadrant
= quadrant
;
1866 for_each_gfn_sp(vcpu
->kvm
, sp
, gfn
, node
) {
1867 if (!need_sync
&& sp
->unsync
)
1870 if (sp
->role
.word
!= role
.word
)
1873 if (sp
->unsync
&& kvm_sync_page_transient(vcpu
, sp
))
1876 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1877 if (sp
->unsync_children
) {
1878 kvm_make_request(KVM_REQ_MMU_SYNC
, vcpu
);
1879 kvm_mmu_mark_parents_unsync(sp
);
1880 } else if (sp
->unsync
)
1881 kvm_mmu_mark_parents_unsync(sp
);
1883 __clear_sp_write_flooding_count(sp
);
1884 trace_kvm_mmu_get_page(sp
, false);
1887 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1888 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
, direct
);
1893 hlist_add_head(&sp
->hash_link
,
1894 &vcpu
->kvm
->arch
.mmu_page_hash
[kvm_page_table_hashfn(gfn
)]);
1896 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1897 kvm_flush_remote_tlbs(vcpu
->kvm
);
1898 if (level
> PT_PAGE_TABLE_LEVEL
&& need_sync
)
1899 kvm_sync_pages(vcpu
, gfn
);
1901 account_shadowed(vcpu
->kvm
, gfn
);
1903 init_shadow_page_table(sp
);
1904 trace_kvm_mmu_get_page(sp
, true);
1908 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1909 struct kvm_vcpu
*vcpu
, u64 addr
)
1911 iterator
->addr
= addr
;
1912 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1913 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1915 if (iterator
->level
== PT64_ROOT_LEVEL
&&
1916 vcpu
->arch
.mmu
.root_level
< PT64_ROOT_LEVEL
&&
1917 !vcpu
->arch
.mmu
.direct_map
)
1920 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1921 iterator
->shadow_addr
1922 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1923 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1925 if (!iterator
->shadow_addr
)
1926 iterator
->level
= 0;
1930 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1932 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1935 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1936 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1940 static void __shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
,
1943 if (is_last_spte(spte
, iterator
->level
)) {
1944 iterator
->level
= 0;
1948 iterator
->shadow_addr
= spte
& PT64_BASE_ADDR_MASK
;
1952 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1954 return __shadow_walk_next(iterator
, *iterator
->sptep
);
1957 static void link_shadow_page(u64
*sptep
, struct kvm_mmu_page
*sp
)
1961 spte
= __pa(sp
->spt
) | PT_PRESENT_MASK
| PT_WRITABLE_MASK
|
1962 shadow_user_mask
| shadow_x_mask
| shadow_accessed_mask
;
1964 mmu_spte_set(sptep
, spte
);
1967 static void validate_direct_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1968 unsigned direct_access
)
1970 if (is_shadow_present_pte(*sptep
) && !is_large_pte(*sptep
)) {
1971 struct kvm_mmu_page
*child
;
1974 * For the direct sp, if the guest pte's dirty bit
1975 * changed form clean to dirty, it will corrupt the
1976 * sp's access: allow writable in the read-only sp,
1977 * so we should update the spte at this point to get
1978 * a new sp with the correct access.
1980 child
= page_header(*sptep
& PT64_BASE_ADDR_MASK
);
1981 if (child
->role
.access
== direct_access
)
1984 drop_parent_pte(child
, sptep
);
1985 kvm_flush_remote_tlbs(vcpu
->kvm
);
1989 static bool mmu_page_zap_pte(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
1993 struct kvm_mmu_page
*child
;
1996 if (is_shadow_present_pte(pte
)) {
1997 if (is_last_spte(pte
, sp
->role
.level
)) {
1998 drop_spte(kvm
, spte
);
1999 if (is_large_pte(pte
))
2002 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2003 drop_parent_pte(child
, spte
);
2008 if (is_mmio_spte(pte
))
2009 mmu_spte_clear_no_track(spte
);
2014 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
2015 struct kvm_mmu_page
*sp
)
2019 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2020 mmu_page_zap_pte(kvm
, sp
, sp
->spt
+ i
);
2023 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
2025 mmu_page_remove_parent_pte(sp
, parent_pte
);
2028 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
2031 struct rmap_iterator iter
;
2033 while ((sptep
= rmap_get_first(sp
->parent_ptes
, &iter
)))
2034 drop_parent_pte(sp
, sptep
);
2037 static int mmu_zap_unsync_children(struct kvm
*kvm
,
2038 struct kvm_mmu_page
*parent
,
2039 struct list_head
*invalid_list
)
2042 struct mmu_page_path parents
;
2043 struct kvm_mmu_pages pages
;
2045 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
2048 kvm_mmu_pages_init(parent
, &parents
, &pages
);
2049 while (mmu_unsync_walk(parent
, &pages
)) {
2050 struct kvm_mmu_page
*sp
;
2052 for_each_sp(pages
, sp
, parents
, i
) {
2053 kvm_mmu_prepare_zap_page(kvm
, sp
, invalid_list
);
2054 mmu_pages_clear_parents(&parents
);
2057 kvm_mmu_pages_init(parent
, &parents
, &pages
);
2063 static int kvm_mmu_prepare_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
2064 struct list_head
*invalid_list
)
2068 trace_kvm_mmu_prepare_zap_page(sp
);
2069 ++kvm
->stat
.mmu_shadow_zapped
;
2070 ret
= mmu_zap_unsync_children(kvm
, sp
, invalid_list
);
2071 kvm_mmu_page_unlink_children(kvm
, sp
);
2072 kvm_mmu_unlink_parents(kvm
, sp
);
2073 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
2074 unaccount_shadowed(kvm
, sp
->gfn
);
2076 kvm_unlink_unsync_page(kvm
, sp
);
2077 if (!sp
->root_count
) {
2080 list_move(&sp
->link
, invalid_list
);
2081 kvm_mod_used_mmu_pages(kvm
, -1);
2083 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
2084 kvm_reload_remote_mmus(kvm
);
2087 sp
->role
.invalid
= 1;
2091 static void kvm_mmu_commit_zap_page(struct kvm
*kvm
,
2092 struct list_head
*invalid_list
)
2094 struct kvm_mmu_page
*sp
;
2096 if (list_empty(invalid_list
))
2100 * wmb: make sure everyone sees our modifications to the page tables
2101 * rmb: make sure we see changes to vcpu->mode
2106 * Wait for all vcpus to exit guest mode and/or lockless shadow
2109 kvm_flush_remote_tlbs(kvm
);
2112 sp
= list_first_entry(invalid_list
, struct kvm_mmu_page
, link
);
2113 WARN_ON(!sp
->role
.invalid
|| sp
->root_count
);
2114 kvm_mmu_free_page(sp
);
2115 } while (!list_empty(invalid_list
));
2119 * Changing the number of mmu pages allocated to the vm
2120 * Note: if goal_nr_mmu_pages is too small, you will get dead lock
2122 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int goal_nr_mmu_pages
)
2124 LIST_HEAD(invalid_list
);
2126 * If we set the number of mmu pages to be smaller be than the
2127 * number of actived pages , we must to free some mmu pages before we
2131 spin_lock(&kvm
->mmu_lock
);
2133 if (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
) {
2134 while (kvm
->arch
.n_used_mmu_pages
> goal_nr_mmu_pages
&&
2135 !list_empty(&kvm
->arch
.active_mmu_pages
)) {
2136 struct kvm_mmu_page
*page
;
2138 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2139 struct kvm_mmu_page
, link
);
2140 kvm_mmu_prepare_zap_page(kvm
, page
, &invalid_list
);
2142 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2143 goal_nr_mmu_pages
= kvm
->arch
.n_used_mmu_pages
;
2146 kvm
->arch
.n_max_mmu_pages
= goal_nr_mmu_pages
;
2148 spin_unlock(&kvm
->mmu_lock
);
2151 int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
2153 struct kvm_mmu_page
*sp
;
2154 struct hlist_node
*node
;
2155 LIST_HEAD(invalid_list
);
2158 pgprintk("%s: looking for gfn %llx\n", __func__
, gfn
);
2160 spin_lock(&kvm
->mmu_lock
);
2161 for_each_gfn_indirect_valid_sp(kvm
, sp
, gfn
, node
) {
2162 pgprintk("%s: gfn %llx role %x\n", __func__
, gfn
,
2165 kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
);
2167 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
2168 spin_unlock(&kvm
->mmu_lock
);
2172 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page
);
2175 * The function is based on mtrr_type_lookup() in
2176 * arch/x86/kernel/cpu/mtrr/generic.c
2178 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
2183 u8 prev_match
, curr_match
;
2184 int num_var_ranges
= KVM_NR_VAR_MTRR
;
2186 if (!mtrr_state
->enabled
)
2189 /* Make end inclusive end, instead of exclusive */
2192 /* Look in fixed ranges. Just return the type as per start */
2193 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
2196 if (start
< 0x80000) {
2198 idx
+= (start
>> 16);
2199 return mtrr_state
->fixed_ranges
[idx
];
2200 } else if (start
< 0xC0000) {
2202 idx
+= ((start
- 0x80000) >> 14);
2203 return mtrr_state
->fixed_ranges
[idx
];
2204 } else if (start
< 0x1000000) {
2206 idx
+= ((start
- 0xC0000) >> 12);
2207 return mtrr_state
->fixed_ranges
[idx
];
2212 * Look in variable ranges
2213 * Look of multiple ranges matching this address and pick type
2214 * as per MTRR precedence
2216 if (!(mtrr_state
->enabled
& 2))
2217 return mtrr_state
->def_type
;
2220 for (i
= 0; i
< num_var_ranges
; ++i
) {
2221 unsigned short start_state
, end_state
;
2223 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
2226 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
2227 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
2228 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
2229 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
2231 start_state
= ((start
& mask
) == (base
& mask
));
2232 end_state
= ((end
& mask
) == (base
& mask
));
2233 if (start_state
!= end_state
)
2236 if ((start
& mask
) != (base
& mask
))
2239 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
2240 if (prev_match
== 0xFF) {
2241 prev_match
= curr_match
;
2245 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
2246 curr_match
== MTRR_TYPE_UNCACHABLE
)
2247 return MTRR_TYPE_UNCACHABLE
;
2249 if ((prev_match
== MTRR_TYPE_WRBACK
&&
2250 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
2251 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
2252 curr_match
== MTRR_TYPE_WRBACK
)) {
2253 prev_match
= MTRR_TYPE_WRTHROUGH
;
2254 curr_match
= MTRR_TYPE_WRTHROUGH
;
2257 if (prev_match
!= curr_match
)
2258 return MTRR_TYPE_UNCACHABLE
;
2261 if (prev_match
!= 0xFF)
2264 return mtrr_state
->def_type
;
2267 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2271 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
2272 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
2273 if (mtrr
== 0xfe || mtrr
== 0xff)
2274 mtrr
= MTRR_TYPE_WRBACK
;
2277 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
2279 static void __kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
2281 trace_kvm_mmu_unsync_page(sp
);
2282 ++vcpu
->kvm
->stat
.mmu_unsync
;
2285 kvm_mmu_mark_parents_unsync(sp
);
2288 static void kvm_unsync_pages(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2290 struct kvm_mmu_page
*s
;
2291 struct hlist_node
*node
;
2293 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2296 WARN_ON(s
->role
.level
!= PT_PAGE_TABLE_LEVEL
);
2297 __kvm_unsync_page(vcpu
, s
);
2301 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2304 struct kvm_mmu_page
*s
;
2305 struct hlist_node
*node
;
2306 bool need_unsync
= false;
2308 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, s
, gfn
, node
) {
2312 if (s
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
2319 kvm_unsync_pages(vcpu
, gfn
);
2323 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2324 unsigned pte_access
, int level
,
2325 gfn_t gfn
, pfn_t pfn
, bool speculative
,
2326 bool can_unsync
, bool host_writable
)
2331 if (set_mmio_spte(sptep
, gfn
, pfn
, pte_access
))
2334 spte
= PT_PRESENT_MASK
;
2336 spte
|= shadow_accessed_mask
;
2338 if (pte_access
& ACC_EXEC_MASK
)
2339 spte
|= shadow_x_mask
;
2341 spte
|= shadow_nx_mask
;
2343 if (pte_access
& ACC_USER_MASK
)
2344 spte
|= shadow_user_mask
;
2346 if (level
> PT_PAGE_TABLE_LEVEL
)
2347 spte
|= PT_PAGE_SIZE_MASK
;
2349 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
2350 kvm_is_mmio_pfn(pfn
));
2353 spte
|= SPTE_HOST_WRITEABLE
;
2355 pte_access
&= ~ACC_WRITE_MASK
;
2357 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
2359 if (pte_access
& ACC_WRITE_MASK
) {
2362 * Other vcpu creates new sp in the window between
2363 * mapping_level() and acquiring mmu-lock. We can
2364 * allow guest to retry the access, the mapping can
2365 * be fixed if guest refault.
2367 if (level
> PT_PAGE_TABLE_LEVEL
&&
2368 has_wrprotected_page(vcpu
->kvm
, gfn
, level
))
2371 spte
|= PT_WRITABLE_MASK
| SPTE_MMU_WRITEABLE
;
2374 * Optimization: for pte sync, if spte was writable the hash
2375 * lookup is unnecessary (and expensive). Write protection
2376 * is responsibility of mmu_get_page / kvm_sync_page.
2377 * Same reasoning can be applied to dirty page accounting.
2379 if (!can_unsync
&& is_writable_pte(*sptep
))
2382 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
2383 pgprintk("%s: found shadow page for %llx, marking ro\n",
2386 pte_access
&= ~ACC_WRITE_MASK
;
2387 spte
&= ~(PT_WRITABLE_MASK
| SPTE_MMU_WRITEABLE
);
2391 if (pte_access
& ACC_WRITE_MASK
)
2392 mark_page_dirty(vcpu
->kvm
, gfn
);
2395 if (mmu_spte_update(sptep
, spte
))
2396 kvm_flush_remote_tlbs(vcpu
->kvm
);
2401 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
2402 unsigned pte_access
, int write_fault
, int *emulate
,
2403 int level
, gfn_t gfn
, pfn_t pfn
, bool speculative
,
2406 int was_rmapped
= 0;
2409 pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__
,
2410 *sptep
, write_fault
, gfn
);
2412 if (is_rmap_spte(*sptep
)) {
2414 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
2415 * the parent of the now unreachable PTE.
2417 if (level
> PT_PAGE_TABLE_LEVEL
&&
2418 !is_large_pte(*sptep
)) {
2419 struct kvm_mmu_page
*child
;
2422 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2423 drop_parent_pte(child
, sptep
);
2424 kvm_flush_remote_tlbs(vcpu
->kvm
);
2425 } else if (pfn
!= spte_to_pfn(*sptep
)) {
2426 pgprintk("hfn old %llx new %llx\n",
2427 spte_to_pfn(*sptep
), pfn
);
2428 drop_spte(vcpu
->kvm
, sptep
);
2429 kvm_flush_remote_tlbs(vcpu
->kvm
);
2434 if (set_spte(vcpu
, sptep
, pte_access
, level
, gfn
, pfn
, speculative
,
2435 true, host_writable
)) {
2438 kvm_mmu_flush_tlb(vcpu
);
2441 if (unlikely(is_mmio_spte(*sptep
) && emulate
))
2444 pgprintk("%s: setting spte %llx\n", __func__
, *sptep
);
2445 pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n",
2446 is_large_pte(*sptep
)? "2MB" : "4kB",
2447 *sptep
& PT_PRESENT_MASK
?"RW":"R", gfn
,
2449 if (!was_rmapped
&& is_large_pte(*sptep
))
2450 ++vcpu
->kvm
->stat
.lpages
;
2452 if (is_shadow_present_pte(*sptep
)) {
2454 rmap_count
= rmap_add(vcpu
, sptep
, gfn
);
2455 if (rmap_count
> RMAP_RECYCLE_THRESHOLD
)
2456 rmap_recycle(vcpu
, sptep
, gfn
);
2460 kvm_release_pfn_clean(pfn
);
2463 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
2465 mmu_free_roots(vcpu
);
2468 static bool is_rsvd_bits_set(struct kvm_mmu
*mmu
, u64 gpte
, int level
)
2472 bit7
= (gpte
>> 7) & 1;
2473 return (gpte
& mmu
->rsvd_bits_mask
[bit7
][level
-1]) != 0;
2476 static pfn_t
pte_prefetch_gfn_to_pfn(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
2479 struct kvm_memory_slot
*slot
;
2481 slot
= gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, no_dirty_log
);
2483 return KVM_PFN_ERR_FAULT
;
2485 return gfn_to_pfn_memslot_atomic(slot
, gfn
);
2488 static bool prefetch_invalid_gpte(struct kvm_vcpu
*vcpu
,
2489 struct kvm_mmu_page
*sp
, u64
*spte
,
2492 if (is_rsvd_bits_set(&vcpu
->arch
.mmu
, gpte
, PT_PAGE_TABLE_LEVEL
))
2495 if (!is_present_gpte(gpte
))
2498 if (!(gpte
& PT_ACCESSED_MASK
))
2504 drop_spte(vcpu
->kvm
, spte
);
2508 static int direct_pte_prefetch_many(struct kvm_vcpu
*vcpu
,
2509 struct kvm_mmu_page
*sp
,
2510 u64
*start
, u64
*end
)
2512 struct page
*pages
[PTE_PREFETCH_NUM
];
2513 unsigned access
= sp
->role
.access
;
2517 gfn
= kvm_mmu_page_get_gfn(sp
, start
- sp
->spt
);
2518 if (!gfn_to_memslot_dirty_bitmap(vcpu
, gfn
, access
& ACC_WRITE_MASK
))
2521 ret
= gfn_to_page_many_atomic(vcpu
->kvm
, gfn
, pages
, end
- start
);
2525 for (i
= 0; i
< ret
; i
++, gfn
++, start
++)
2526 mmu_set_spte(vcpu
, start
, access
, 0, NULL
,
2527 sp
->role
.level
, gfn
, page_to_pfn(pages
[i
]),
2533 static void __direct_pte_prefetch(struct kvm_vcpu
*vcpu
,
2534 struct kvm_mmu_page
*sp
, u64
*sptep
)
2536 u64
*spte
, *start
= NULL
;
2539 WARN_ON(!sp
->role
.direct
);
2541 i
= (sptep
- sp
->spt
) & ~(PTE_PREFETCH_NUM
- 1);
2544 for (i
= 0; i
< PTE_PREFETCH_NUM
; i
++, spte
++) {
2545 if (is_shadow_present_pte(*spte
) || spte
== sptep
) {
2548 if (direct_pte_prefetch_many(vcpu
, sp
, start
, spte
) < 0)
2556 static void direct_pte_prefetch(struct kvm_vcpu
*vcpu
, u64
*sptep
)
2558 struct kvm_mmu_page
*sp
;
2561 * Since it's no accessed bit on EPT, it's no way to
2562 * distinguish between actually accessed translations
2563 * and prefetched, so disable pte prefetch if EPT is
2566 if (!shadow_accessed_mask
)
2569 sp
= page_header(__pa(sptep
));
2570 if (sp
->role
.level
> PT_PAGE_TABLE_LEVEL
)
2573 __direct_pte_prefetch(vcpu
, sp
, sptep
);
2576 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
2577 int map_writable
, int level
, gfn_t gfn
, pfn_t pfn
,
2580 struct kvm_shadow_walk_iterator iterator
;
2581 struct kvm_mmu_page
*sp
;
2585 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
2586 if (iterator
.level
== level
) {
2587 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
,
2588 write
, &emulate
, level
, gfn
, pfn
,
2589 prefault
, map_writable
);
2590 direct_pte_prefetch(vcpu
, iterator
.sptep
);
2591 ++vcpu
->stat
.pf_fixed
;
2595 if (!is_shadow_present_pte(*iterator
.sptep
)) {
2596 u64 base_addr
= iterator
.addr
;
2598 base_addr
&= PT64_LVL_ADDR_MASK(iterator
.level
);
2599 pseudo_gfn
= base_addr
>> PAGE_SHIFT
;
2600 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
2602 1, ACC_ALL
, iterator
.sptep
);
2604 link_shadow_page(iterator
.sptep
, sp
);
2610 static void kvm_send_hwpoison_signal(unsigned long address
, struct task_struct
*tsk
)
2614 info
.si_signo
= SIGBUS
;
2616 info
.si_code
= BUS_MCEERR_AR
;
2617 info
.si_addr
= (void __user
*)address
;
2618 info
.si_addr_lsb
= PAGE_SHIFT
;
2620 send_sig_info(SIGBUS
, &info
, tsk
);
2623 static int kvm_handle_bad_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
, pfn_t pfn
)
2626 * Do not cache the mmio info caused by writing the readonly gfn
2627 * into the spte otherwise read access on readonly gfn also can
2628 * caused mmio page fault and treat it as mmio access.
2629 * Return 1 to tell kvm to emulate it.
2631 if (pfn
== KVM_PFN_ERR_RO_FAULT
)
2634 if (pfn
== KVM_PFN_ERR_HWPOISON
) {
2635 kvm_send_hwpoison_signal(gfn_to_hva(vcpu
->kvm
, gfn
), current
);
2642 static void transparent_hugepage_adjust(struct kvm_vcpu
*vcpu
,
2643 gfn_t
*gfnp
, pfn_t
*pfnp
, int *levelp
)
2647 int level
= *levelp
;
2650 * Check if it's a transparent hugepage. If this would be an
2651 * hugetlbfs page, level wouldn't be set to
2652 * PT_PAGE_TABLE_LEVEL and there would be no adjustment done
2655 if (!is_error_noslot_pfn(pfn
) && !kvm_is_mmio_pfn(pfn
) &&
2656 level
== PT_PAGE_TABLE_LEVEL
&&
2657 PageTransCompound(pfn_to_page(pfn
)) &&
2658 !has_wrprotected_page(vcpu
->kvm
, gfn
, PT_DIRECTORY_LEVEL
)) {
2661 * mmu_notifier_retry was successful and we hold the
2662 * mmu_lock here, so the pmd can't become splitting
2663 * from under us, and in turn
2664 * __split_huge_page_refcount() can't run from under
2665 * us and we can safely transfer the refcount from
2666 * PG_tail to PG_head as we switch the pfn to tail to
2669 *levelp
= level
= PT_DIRECTORY_LEVEL
;
2670 mask
= KVM_PAGES_PER_HPAGE(level
) - 1;
2671 VM_BUG_ON((gfn
& mask
) != (pfn
& mask
));
2675 kvm_release_pfn_clean(pfn
);
2683 static bool handle_abnormal_pfn(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
,
2684 pfn_t pfn
, unsigned access
, int *ret_val
)
2688 /* The pfn is invalid, report the error! */
2689 if (unlikely(is_error_pfn(pfn
))) {
2690 *ret_val
= kvm_handle_bad_page(vcpu
, gfn
, pfn
);
2694 if (unlikely(is_noslot_pfn(pfn
)))
2695 vcpu_cache_mmio_info(vcpu
, gva
, gfn
, access
);
2702 static bool page_fault_can_be_fast(struct kvm_vcpu
*vcpu
, u32 error_code
)
2705 * #PF can be fast only if the shadow page table is present and it
2706 * is caused by write-protect, that means we just need change the
2707 * W bit of the spte which can be done out of mmu-lock.
2709 if (!(error_code
& PFERR_PRESENT_MASK
) ||
2710 !(error_code
& PFERR_WRITE_MASK
))
2717 fast_pf_fix_direct_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
, u64 spte
)
2719 struct kvm_mmu_page
*sp
= page_header(__pa(sptep
));
2722 WARN_ON(!sp
->role
.direct
);
2725 * The gfn of direct spte is stable since it is calculated
2728 gfn
= kvm_mmu_page_get_gfn(sp
, sptep
- sp
->spt
);
2730 if (cmpxchg64(sptep
, spte
, spte
| PT_WRITABLE_MASK
) == spte
)
2731 mark_page_dirty(vcpu
->kvm
, gfn
);
2738 * - true: let the vcpu to access on the same address again.
2739 * - false: let the real page fault path to fix it.
2741 static bool fast_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
, int level
,
2744 struct kvm_shadow_walk_iterator iterator
;
2748 if (!page_fault_can_be_fast(vcpu
, error_code
))
2751 walk_shadow_page_lockless_begin(vcpu
);
2752 for_each_shadow_entry_lockless(vcpu
, gva
, iterator
, spte
)
2753 if (!is_shadow_present_pte(spte
) || iterator
.level
< level
)
2757 * If the mapping has been changed, let the vcpu fault on the
2758 * same address again.
2760 if (!is_rmap_spte(spte
)) {
2765 if (!is_last_spte(spte
, level
))
2769 * Check if it is a spurious fault caused by TLB lazily flushed.
2771 * Need not check the access of upper level table entries since
2772 * they are always ACC_ALL.
2774 if (is_writable_pte(spte
)) {
2780 * Currently, to simplify the code, only the spte write-protected
2781 * by dirty-log can be fast fixed.
2783 if (!spte_is_locklessly_modifiable(spte
))
2787 * Currently, fast page fault only works for direct mapping since
2788 * the gfn is not stable for indirect shadow page.
2789 * See Documentation/virtual/kvm/locking.txt to get more detail.
2791 ret
= fast_pf_fix_direct_spte(vcpu
, iterator
.sptep
, spte
);
2793 trace_fast_page_fault(vcpu
, gva
, error_code
, iterator
.sptep
,
2795 walk_shadow_page_lockless_end(vcpu
);
2800 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
2801 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
);
2803 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, u32 error_code
,
2804 gfn_t gfn
, bool prefault
)
2810 unsigned long mmu_seq
;
2811 bool map_writable
, write
= error_code
& PFERR_WRITE_MASK
;
2813 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
2814 if (likely(!force_pt_level
)) {
2815 level
= mapping_level(vcpu
, gfn
);
2817 * This path builds a PAE pagetable - so we can map
2818 * 2mb pages at maximum. Therefore check if the level
2819 * is larger than that.
2821 if (level
> PT_DIRECTORY_LEVEL
)
2822 level
= PT_DIRECTORY_LEVEL
;
2824 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2826 level
= PT_PAGE_TABLE_LEVEL
;
2828 if (fast_page_fault(vcpu
, v
, level
, error_code
))
2831 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2834 if (try_async_pf(vcpu
, prefault
, gfn
, v
, &pfn
, write
, &map_writable
))
2837 if (handle_abnormal_pfn(vcpu
, v
, gfn
, pfn
, ACC_ALL
, &r
))
2840 spin_lock(&vcpu
->kvm
->mmu_lock
);
2841 if (mmu_notifier_retry(vcpu
->kvm
, mmu_seq
))
2843 kvm_mmu_free_some_pages(vcpu
);
2844 if (likely(!force_pt_level
))
2845 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
2846 r
= __direct_map(vcpu
, v
, write
, map_writable
, level
, gfn
, pfn
,
2848 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2854 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2855 kvm_release_pfn_clean(pfn
);
2860 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
2863 struct kvm_mmu_page
*sp
;
2864 LIST_HEAD(invalid_list
);
2866 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2868 spin_lock(&vcpu
->kvm
->mmu_lock
);
2869 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
&&
2870 (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
||
2871 vcpu
->arch
.mmu
.direct_map
)) {
2872 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2874 sp
= page_header(root
);
2876 if (!sp
->root_count
&& sp
->role
.invalid
) {
2877 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
2878 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2880 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2881 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2884 for (i
= 0; i
< 4; ++i
) {
2885 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2888 root
&= PT64_BASE_ADDR_MASK
;
2889 sp
= page_header(root
);
2891 if (!sp
->root_count
&& sp
->role
.invalid
)
2892 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
2895 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2897 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
2898 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2899 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2902 static int mmu_check_root(struct kvm_vcpu
*vcpu
, gfn_t root_gfn
)
2906 if (!kvm_is_visible_gfn(vcpu
->kvm
, root_gfn
)) {
2907 kvm_make_request(KVM_REQ_TRIPLE_FAULT
, vcpu
);
2914 static int mmu_alloc_direct_roots(struct kvm_vcpu
*vcpu
)
2916 struct kvm_mmu_page
*sp
;
2919 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2920 spin_lock(&vcpu
->kvm
->mmu_lock
);
2921 kvm_mmu_free_some_pages(vcpu
);
2922 sp
= kvm_mmu_get_page(vcpu
, 0, 0, PT64_ROOT_LEVEL
,
2925 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2926 vcpu
->arch
.mmu
.root_hpa
= __pa(sp
->spt
);
2927 } else if (vcpu
->arch
.mmu
.shadow_root_level
== PT32E_ROOT_LEVEL
) {
2928 for (i
= 0; i
< 4; ++i
) {
2929 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2931 ASSERT(!VALID_PAGE(root
));
2932 spin_lock(&vcpu
->kvm
->mmu_lock
);
2933 kvm_mmu_free_some_pages(vcpu
);
2934 sp
= kvm_mmu_get_page(vcpu
, i
<< (30 - PAGE_SHIFT
),
2936 PT32_ROOT_LEVEL
, 1, ACC_ALL
,
2938 root
= __pa(sp
->spt
);
2940 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2941 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
2943 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2950 static int mmu_alloc_shadow_roots(struct kvm_vcpu
*vcpu
)
2952 struct kvm_mmu_page
*sp
;
2957 root_gfn
= vcpu
->arch
.mmu
.get_cr3(vcpu
) >> PAGE_SHIFT
;
2959 if (mmu_check_root(vcpu
, root_gfn
))
2963 * Do we shadow a long mode page table? If so we need to
2964 * write-protect the guests page table root.
2966 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
2967 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2969 ASSERT(!VALID_PAGE(root
));
2971 spin_lock(&vcpu
->kvm
->mmu_lock
);
2972 kvm_mmu_free_some_pages(vcpu
);
2973 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0, PT64_ROOT_LEVEL
,
2975 root
= __pa(sp
->spt
);
2977 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2978 vcpu
->arch
.mmu
.root_hpa
= root
;
2983 * We shadow a 32 bit page table. This may be a legacy 2-level
2984 * or a PAE 3-level page table. In either case we need to be aware that
2985 * the shadow page table may be a PAE or a long mode page table.
2987 pm_mask
= PT_PRESENT_MASK
;
2988 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
)
2989 pm_mask
|= PT_ACCESSED_MASK
| PT_WRITABLE_MASK
| PT_USER_MASK
;
2991 for (i
= 0; i
< 4; ++i
) {
2992 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2994 ASSERT(!VALID_PAGE(root
));
2995 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
2996 pdptr
= vcpu
->arch
.mmu
.get_pdptr(vcpu
, i
);
2997 if (!is_present_gpte(pdptr
)) {
2998 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
3001 root_gfn
= pdptr
>> PAGE_SHIFT
;
3002 if (mmu_check_root(vcpu
, root_gfn
))
3005 spin_lock(&vcpu
->kvm
->mmu_lock
);
3006 kvm_mmu_free_some_pages(vcpu
);
3007 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
3010 root
= __pa(sp
->spt
);
3012 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3014 vcpu
->arch
.mmu
.pae_root
[i
] = root
| pm_mask
;
3016 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
3019 * If we shadow a 32 bit page table with a long mode page
3020 * table we enter this path.
3022 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
3023 if (vcpu
->arch
.mmu
.lm_root
== NULL
) {
3025 * The additional page necessary for this is only
3026 * allocated on demand.
3031 lm_root
= (void*)get_zeroed_page(GFP_KERNEL
);
3032 if (lm_root
== NULL
)
3035 lm_root
[0] = __pa(vcpu
->arch
.mmu
.pae_root
) | pm_mask
;
3037 vcpu
->arch
.mmu
.lm_root
= lm_root
;
3040 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.lm_root
);
3046 static int mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
3048 if (vcpu
->arch
.mmu
.direct_map
)
3049 return mmu_alloc_direct_roots(vcpu
);
3051 return mmu_alloc_shadow_roots(vcpu
);
3054 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
3057 struct kvm_mmu_page
*sp
;
3059 if (vcpu
->arch
.mmu
.direct_map
)
3062 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3065 vcpu_clear_mmio_info(vcpu
, ~0ul);
3066 kvm_mmu_audit(vcpu
, AUDIT_PRE_SYNC
);
3067 if (vcpu
->arch
.mmu
.root_level
== PT64_ROOT_LEVEL
) {
3068 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
3069 sp
= page_header(root
);
3070 mmu_sync_children(vcpu
, sp
);
3071 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
3074 for (i
= 0; i
< 4; ++i
) {
3075 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
3077 if (root
&& VALID_PAGE(root
)) {
3078 root
&= PT64_BASE_ADDR_MASK
;
3079 sp
= page_header(root
);
3080 mmu_sync_children(vcpu
, sp
);
3083 kvm_mmu_audit(vcpu
, AUDIT_POST_SYNC
);
3086 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
3088 spin_lock(&vcpu
->kvm
->mmu_lock
);
3089 mmu_sync_roots(vcpu
);
3090 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3093 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
3094 u32 access
, struct x86_exception
*exception
)
3097 exception
->error_code
= 0;
3101 static gpa_t
nonpaging_gva_to_gpa_nested(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
3103 struct x86_exception
*exception
)
3106 exception
->error_code
= 0;
3107 return vcpu
->arch
.nested_mmu
.translate_gpa(vcpu
, vaddr
, access
);
3110 static bool quickly_check_mmio_pf(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
3113 return vcpu_match_mmio_gpa(vcpu
, addr
);
3115 return vcpu_match_mmio_gva(vcpu
, addr
);
3120 * On direct hosts, the last spte is only allows two states
3121 * for mmio page fault:
3122 * - It is the mmio spte
3123 * - It is zapped or it is being zapped.
3125 * This function completely checks the spte when the last spte
3126 * is not the mmio spte.
3128 static bool check_direct_spte_mmio_pf(u64 spte
)
3130 return __check_direct_spte_mmio_pf(spte
);
3133 static u64
walk_shadow_page_get_mmio_spte(struct kvm_vcpu
*vcpu
, u64 addr
)
3135 struct kvm_shadow_walk_iterator iterator
;
3138 walk_shadow_page_lockless_begin(vcpu
);
3139 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
)
3140 if (!is_shadow_present_pte(spte
))
3142 walk_shadow_page_lockless_end(vcpu
);
3148 * If it is a real mmio page fault, return 1 and emulat the instruction
3149 * directly, return 0 to let CPU fault again on the address, -1 is
3150 * returned if bug is detected.
3152 int handle_mmio_page_fault_common(struct kvm_vcpu
*vcpu
, u64 addr
, bool direct
)
3156 if (quickly_check_mmio_pf(vcpu
, addr
, direct
))
3159 spte
= walk_shadow_page_get_mmio_spte(vcpu
, addr
);
3161 if (is_mmio_spte(spte
)) {
3162 gfn_t gfn
= get_mmio_spte_gfn(spte
);
3163 unsigned access
= get_mmio_spte_access(spte
);
3168 trace_handle_mmio_page_fault(addr
, gfn
, access
);
3169 vcpu_cache_mmio_info(vcpu
, addr
, gfn
, access
);
3174 * It's ok if the gva is remapped by other cpus on shadow guest,
3175 * it's a BUG if the gfn is not a mmio page.
3177 if (direct
&& !check_direct_spte_mmio_pf(spte
))
3181 * If the page table is zapped by other cpus, let CPU fault again on
3186 EXPORT_SYMBOL_GPL(handle_mmio_page_fault_common
);
3188 static int handle_mmio_page_fault(struct kvm_vcpu
*vcpu
, u64 addr
,
3189 u32 error_code
, bool direct
)
3193 ret
= handle_mmio_page_fault_common(vcpu
, addr
, direct
);
3198 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
3199 u32 error_code
, bool prefault
)
3204 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
3206 if (unlikely(error_code
& PFERR_RSVD_MASK
))
3207 return handle_mmio_page_fault(vcpu
, gva
, error_code
, true);
3209 r
= mmu_topup_memory_caches(vcpu
);
3214 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3216 gfn
= gva
>> PAGE_SHIFT
;
3218 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
3219 error_code
, gfn
, prefault
);
3222 static int kvm_arch_setup_async_pf(struct kvm_vcpu
*vcpu
, gva_t gva
, gfn_t gfn
)
3224 struct kvm_arch_async_pf arch
;
3226 arch
.token
= (vcpu
->arch
.apf
.id
++ << 12) | vcpu
->vcpu_id
;
3228 arch
.direct_map
= vcpu
->arch
.mmu
.direct_map
;
3229 arch
.cr3
= vcpu
->arch
.mmu
.get_cr3(vcpu
);
3231 return kvm_setup_async_pf(vcpu
, gva
, gfn
, &arch
);
3234 static bool can_do_async_pf(struct kvm_vcpu
*vcpu
)
3236 if (unlikely(!irqchip_in_kernel(vcpu
->kvm
) ||
3237 kvm_event_needs_reinjection(vcpu
)))
3240 return kvm_x86_ops
->interrupt_allowed(vcpu
);
3243 static bool try_async_pf(struct kvm_vcpu
*vcpu
, bool prefault
, gfn_t gfn
,
3244 gva_t gva
, pfn_t
*pfn
, bool write
, bool *writable
)
3248 *pfn
= gfn_to_pfn_async(vcpu
->kvm
, gfn
, &async
, write
, writable
);
3251 return false; /* *pfn has correct page already */
3253 if (!prefault
&& can_do_async_pf(vcpu
)) {
3254 trace_kvm_try_async_get_page(gva
, gfn
);
3255 if (kvm_find_async_pf_gfn(vcpu
, gfn
)) {
3256 trace_kvm_async_pf_doublefault(gva
, gfn
);
3257 kvm_make_request(KVM_REQ_APF_HALT
, vcpu
);
3259 } else if (kvm_arch_setup_async_pf(vcpu
, gva
, gfn
))
3263 *pfn
= gfn_to_pfn_prot(vcpu
->kvm
, gfn
, write
, writable
);
3268 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
, u32 error_code
,
3275 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3276 unsigned long mmu_seq
;
3277 int write
= error_code
& PFERR_WRITE_MASK
;
3281 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3283 if (unlikely(error_code
& PFERR_RSVD_MASK
))
3284 return handle_mmio_page_fault(vcpu
, gpa
, error_code
, true);
3286 r
= mmu_topup_memory_caches(vcpu
);
3290 force_pt_level
= mapping_level_dirty_bitmap(vcpu
, gfn
);
3291 if (likely(!force_pt_level
)) {
3292 level
= mapping_level(vcpu
, gfn
);
3293 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
3295 level
= PT_PAGE_TABLE_LEVEL
;
3297 if (fast_page_fault(vcpu
, gpa
, level
, error_code
))
3300 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
3303 if (try_async_pf(vcpu
, prefault
, gfn
, gpa
, &pfn
, write
, &map_writable
))
3306 if (handle_abnormal_pfn(vcpu
, 0, gfn
, pfn
, ACC_ALL
, &r
))
3309 spin_lock(&vcpu
->kvm
->mmu_lock
);
3310 if (mmu_notifier_retry(vcpu
->kvm
, mmu_seq
))
3312 kvm_mmu_free_some_pages(vcpu
);
3313 if (likely(!force_pt_level
))
3314 transparent_hugepage_adjust(vcpu
, &gfn
, &pfn
, &level
);
3315 r
= __direct_map(vcpu
, gpa
, write
, map_writable
,
3316 level
, gfn
, pfn
, prefault
);
3317 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3322 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3323 kvm_release_pfn_clean(pfn
);
3327 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
3329 mmu_free_roots(vcpu
);
3332 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
,
3333 struct kvm_mmu
*context
)
3335 context
->new_cr3
= nonpaging_new_cr3
;
3336 context
->page_fault
= nonpaging_page_fault
;
3337 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3338 context
->free
= nonpaging_free
;
3339 context
->sync_page
= nonpaging_sync_page
;
3340 context
->invlpg
= nonpaging_invlpg
;
3341 context
->update_pte
= nonpaging_update_pte
;
3342 context
->root_level
= 0;
3343 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3344 context
->root_hpa
= INVALID_PAGE
;
3345 context
->direct_map
= true;
3346 context
->nx
= false;
3350 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
3352 ++vcpu
->stat
.tlb_flush
;
3353 kvm_make_request(KVM_REQ_TLB_FLUSH
, vcpu
);
3356 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
3358 pgprintk("%s: cr3 %lx\n", __func__
, kvm_read_cr3(vcpu
));
3359 mmu_free_roots(vcpu
);
3362 static unsigned long get_cr3(struct kvm_vcpu
*vcpu
)
3364 return kvm_read_cr3(vcpu
);
3367 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
3368 struct x86_exception
*fault
)
3370 vcpu
->arch
.mmu
.inject_page_fault(vcpu
, fault
);
3373 static void paging_free(struct kvm_vcpu
*vcpu
)
3375 nonpaging_free(vcpu
);
3378 static inline void protect_clean_gpte(unsigned *access
, unsigned gpte
)
3382 BUILD_BUG_ON(PT_WRITABLE_MASK
!= ACC_WRITE_MASK
);
3384 mask
= (unsigned)~ACC_WRITE_MASK
;
3385 /* Allow write access to dirty gptes */
3386 mask
|= (gpte
>> (PT_DIRTY_SHIFT
- PT_WRITABLE_SHIFT
)) & PT_WRITABLE_MASK
;
3390 static bool sync_mmio_spte(u64
*sptep
, gfn_t gfn
, unsigned access
,
3393 if (unlikely(is_mmio_spte(*sptep
))) {
3394 if (gfn
!= get_mmio_spte_gfn(*sptep
)) {
3395 mmu_spte_clear_no_track(sptep
);
3400 mark_mmio_spte(sptep
, gfn
, access
);
3407 static inline unsigned gpte_access(struct kvm_vcpu
*vcpu
, u64 gpte
)
3411 access
= (gpte
& (PT_WRITABLE_MASK
| PT_USER_MASK
)) | ACC_EXEC_MASK
;
3412 access
&= ~(gpte
>> PT64_NX_SHIFT
);
3417 static inline bool is_last_gpte(struct kvm_mmu
*mmu
, unsigned level
, unsigned gpte
)
3422 index
|= (gpte
& PT_PAGE_SIZE_MASK
) >> (PT_PAGE_SIZE_SHIFT
- 2);
3423 return mmu
->last_pte_bitmap
& (1 << index
);
3427 #include "paging_tmpl.h"
3431 #include "paging_tmpl.h"
3434 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
,
3435 struct kvm_mmu
*context
)
3437 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
3438 u64 exb_bit_rsvd
= 0;
3441 exb_bit_rsvd
= rsvd_bits(63, 63);
3442 switch (context
->root_level
) {
3443 case PT32_ROOT_LEVEL
:
3444 /* no rsvd bits for 2 level 4K page table entries */
3445 context
->rsvd_bits_mask
[0][1] = 0;
3446 context
->rsvd_bits_mask
[0][0] = 0;
3447 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3449 if (!is_pse(vcpu
)) {
3450 context
->rsvd_bits_mask
[1][1] = 0;
3454 if (is_cpuid_PSE36())
3455 /* 36bits PSE 4MB page */
3456 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
3458 /* 32 bits PSE 4MB page */
3459 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
3461 case PT32E_ROOT_LEVEL
:
3462 context
->rsvd_bits_mask
[0][2] =
3463 rsvd_bits(maxphyaddr
, 63) |
3464 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
3465 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3466 rsvd_bits(maxphyaddr
, 62); /* PDE */
3467 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3468 rsvd_bits(maxphyaddr
, 62); /* PTE */
3469 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3470 rsvd_bits(maxphyaddr
, 62) |
3471 rsvd_bits(13, 20); /* large page */
3472 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3474 case PT64_ROOT_LEVEL
:
3475 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
3476 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3477 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
3478 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
3479 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
3480 rsvd_bits(maxphyaddr
, 51);
3481 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
3482 rsvd_bits(maxphyaddr
, 51);
3483 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
3484 context
->rsvd_bits_mask
[1][2] = exb_bit_rsvd
|
3485 rsvd_bits(maxphyaddr
, 51) |
3487 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
3488 rsvd_bits(maxphyaddr
, 51) |
3489 rsvd_bits(13, 20); /* large page */
3490 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[0][0];
3495 static void update_permission_bitmask(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*mmu
)
3497 unsigned bit
, byte
, pfec
;
3499 bool fault
, x
, w
, u
, wf
, uf
, ff
, smep
;
3501 smep
= kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
);
3502 for (byte
= 0; byte
< ARRAY_SIZE(mmu
->permissions
); ++byte
) {
3505 wf
= pfec
& PFERR_WRITE_MASK
;
3506 uf
= pfec
& PFERR_USER_MASK
;
3507 ff
= pfec
& PFERR_FETCH_MASK
;
3508 for (bit
= 0; bit
< 8; ++bit
) {
3509 x
= bit
& ACC_EXEC_MASK
;
3510 w
= bit
& ACC_WRITE_MASK
;
3511 u
= bit
& ACC_USER_MASK
;
3513 /* Not really needed: !nx will cause pte.nx to fault */
3515 /* Allow supervisor writes if !cr0.wp */
3516 w
|= !is_write_protection(vcpu
) && !uf
;
3517 /* Disallow supervisor fetches of user code if cr4.smep */
3518 x
&= !(smep
&& u
&& !uf
);
3520 fault
= (ff
&& !x
) || (uf
&& !u
) || (wf
&& !w
);
3521 map
|= fault
<< bit
;
3523 mmu
->permissions
[byte
] = map
;
3527 static void update_last_pte_bitmap(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*mmu
)
3530 unsigned level
, root_level
= mmu
->root_level
;
3531 const unsigned ps_set_index
= 1 << 2; /* bit 2 of index: ps */
3533 if (root_level
== PT32E_ROOT_LEVEL
)
3535 /* PT_PAGE_TABLE_LEVEL always terminates */
3536 map
= 1 | (1 << ps_set_index
);
3537 for (level
= PT_DIRECTORY_LEVEL
; level
<= root_level
; ++level
) {
3538 if (level
<= PT_PDPE_LEVEL
3539 && (mmu
->root_level
>= PT32E_ROOT_LEVEL
|| is_pse(vcpu
)))
3540 map
|= 1 << (ps_set_index
| (level
- 1));
3542 mmu
->last_pte_bitmap
= map
;
3545 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
,
3546 struct kvm_mmu
*context
,
3549 context
->nx
= is_nx(vcpu
);
3550 context
->root_level
= level
;
3552 reset_rsvds_bits_mask(vcpu
, context
);
3553 update_permission_bitmask(vcpu
, context
);
3554 update_last_pte_bitmap(vcpu
, context
);
3556 ASSERT(is_pae(vcpu
));
3557 context
->new_cr3
= paging_new_cr3
;
3558 context
->page_fault
= paging64_page_fault
;
3559 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3560 context
->sync_page
= paging64_sync_page
;
3561 context
->invlpg
= paging64_invlpg
;
3562 context
->update_pte
= paging64_update_pte
;
3563 context
->free
= paging_free
;
3564 context
->shadow_root_level
= level
;
3565 context
->root_hpa
= INVALID_PAGE
;
3566 context
->direct_map
= false;
3570 static int paging64_init_context(struct kvm_vcpu
*vcpu
,
3571 struct kvm_mmu
*context
)
3573 return paging64_init_context_common(vcpu
, context
, PT64_ROOT_LEVEL
);
3576 static int paging32_init_context(struct kvm_vcpu
*vcpu
,
3577 struct kvm_mmu
*context
)
3579 context
->nx
= false;
3580 context
->root_level
= PT32_ROOT_LEVEL
;
3582 reset_rsvds_bits_mask(vcpu
, context
);
3583 update_permission_bitmask(vcpu
, context
);
3584 update_last_pte_bitmap(vcpu
, context
);
3586 context
->new_cr3
= paging_new_cr3
;
3587 context
->page_fault
= paging32_page_fault
;
3588 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3589 context
->free
= paging_free
;
3590 context
->sync_page
= paging32_sync_page
;
3591 context
->invlpg
= paging32_invlpg
;
3592 context
->update_pte
= paging32_update_pte
;
3593 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
3594 context
->root_hpa
= INVALID_PAGE
;
3595 context
->direct_map
= false;
3599 static int paging32E_init_context(struct kvm_vcpu
*vcpu
,
3600 struct kvm_mmu
*context
)
3602 return paging64_init_context_common(vcpu
, context
, PT32E_ROOT_LEVEL
);
3605 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
3607 struct kvm_mmu
*context
= vcpu
->arch
.walk_mmu
;
3609 context
->base_role
.word
= 0;
3610 context
->new_cr3
= nonpaging_new_cr3
;
3611 context
->page_fault
= tdp_page_fault
;
3612 context
->free
= nonpaging_free
;
3613 context
->sync_page
= nonpaging_sync_page
;
3614 context
->invlpg
= nonpaging_invlpg
;
3615 context
->update_pte
= nonpaging_update_pte
;
3616 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
3617 context
->root_hpa
= INVALID_PAGE
;
3618 context
->direct_map
= true;
3619 context
->set_cr3
= kvm_x86_ops
->set_tdp_cr3
;
3620 context
->get_cr3
= get_cr3
;
3621 context
->get_pdptr
= kvm_pdptr_read
;
3622 context
->inject_page_fault
= kvm_inject_page_fault
;
3624 if (!is_paging(vcpu
)) {
3625 context
->nx
= false;
3626 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
3627 context
->root_level
= 0;
3628 } else if (is_long_mode(vcpu
)) {
3629 context
->nx
= is_nx(vcpu
);
3630 context
->root_level
= PT64_ROOT_LEVEL
;
3631 reset_rsvds_bits_mask(vcpu
, context
);
3632 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3633 } else if (is_pae(vcpu
)) {
3634 context
->nx
= is_nx(vcpu
);
3635 context
->root_level
= PT32E_ROOT_LEVEL
;
3636 reset_rsvds_bits_mask(vcpu
, context
);
3637 context
->gva_to_gpa
= paging64_gva_to_gpa
;
3639 context
->nx
= false;
3640 context
->root_level
= PT32_ROOT_LEVEL
;
3641 reset_rsvds_bits_mask(vcpu
, context
);
3642 context
->gva_to_gpa
= paging32_gva_to_gpa
;
3645 update_permission_bitmask(vcpu
, context
);
3646 update_last_pte_bitmap(vcpu
, context
);
3651 int kvm_init_shadow_mmu(struct kvm_vcpu
*vcpu
, struct kvm_mmu
*context
)
3654 bool smep
= kvm_read_cr4_bits(vcpu
, X86_CR4_SMEP
);
3656 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
3658 if (!is_paging(vcpu
))
3659 r
= nonpaging_init_context(vcpu
, context
);
3660 else if (is_long_mode(vcpu
))
3661 r
= paging64_init_context(vcpu
, context
);
3662 else if (is_pae(vcpu
))
3663 r
= paging32E_init_context(vcpu
, context
);
3665 r
= paging32_init_context(vcpu
, context
);
3667 vcpu
->arch
.mmu
.base_role
.nxe
= is_nx(vcpu
);
3668 vcpu
->arch
.mmu
.base_role
.cr4_pae
= !!is_pae(vcpu
);
3669 vcpu
->arch
.mmu
.base_role
.cr0_wp
= is_write_protection(vcpu
);
3670 vcpu
->arch
.mmu
.base_role
.smep_andnot_wp
3671 = smep
&& !is_write_protection(vcpu
);
3675 EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu
);
3677 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
3679 int r
= kvm_init_shadow_mmu(vcpu
, vcpu
->arch
.walk_mmu
);
3681 vcpu
->arch
.walk_mmu
->set_cr3
= kvm_x86_ops
->set_cr3
;
3682 vcpu
->arch
.walk_mmu
->get_cr3
= get_cr3
;
3683 vcpu
->arch
.walk_mmu
->get_pdptr
= kvm_pdptr_read
;
3684 vcpu
->arch
.walk_mmu
->inject_page_fault
= kvm_inject_page_fault
;
3689 static int init_kvm_nested_mmu(struct kvm_vcpu
*vcpu
)
3691 struct kvm_mmu
*g_context
= &vcpu
->arch
.nested_mmu
;
3693 g_context
->get_cr3
= get_cr3
;
3694 g_context
->get_pdptr
= kvm_pdptr_read
;
3695 g_context
->inject_page_fault
= kvm_inject_page_fault
;
3698 * Note that arch.mmu.gva_to_gpa translates l2_gva to l1_gpa. The
3699 * translation of l2_gpa to l1_gpa addresses is done using the
3700 * arch.nested_mmu.gva_to_gpa function. Basically the gva_to_gpa
3701 * functions between mmu and nested_mmu are swapped.
3703 if (!is_paging(vcpu
)) {
3704 g_context
->nx
= false;
3705 g_context
->root_level
= 0;
3706 g_context
->gva_to_gpa
= nonpaging_gva_to_gpa_nested
;
3707 } else if (is_long_mode(vcpu
)) {
3708 g_context
->nx
= is_nx(vcpu
);
3709 g_context
->root_level
= PT64_ROOT_LEVEL
;
3710 reset_rsvds_bits_mask(vcpu
, g_context
);
3711 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3712 } else if (is_pae(vcpu
)) {
3713 g_context
->nx
= is_nx(vcpu
);
3714 g_context
->root_level
= PT32E_ROOT_LEVEL
;
3715 reset_rsvds_bits_mask(vcpu
, g_context
);
3716 g_context
->gva_to_gpa
= paging64_gva_to_gpa_nested
;
3718 g_context
->nx
= false;
3719 g_context
->root_level
= PT32_ROOT_LEVEL
;
3720 reset_rsvds_bits_mask(vcpu
, g_context
);
3721 g_context
->gva_to_gpa
= paging32_gva_to_gpa_nested
;
3724 update_permission_bitmask(vcpu
, g_context
);
3725 update_last_pte_bitmap(vcpu
, g_context
);
3730 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
3732 if (mmu_is_nested(vcpu
))
3733 return init_kvm_nested_mmu(vcpu
);
3734 else if (tdp_enabled
)
3735 return init_kvm_tdp_mmu(vcpu
);
3737 return init_kvm_softmmu(vcpu
);
3740 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
3743 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3744 /* mmu.free() should set root_hpa = INVALID_PAGE */
3745 vcpu
->arch
.mmu
.free(vcpu
);
3748 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
3750 destroy_kvm_mmu(vcpu
);
3751 return init_kvm_mmu(vcpu
);
3753 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
3755 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
3759 r
= mmu_topup_memory_caches(vcpu
);
3762 r
= mmu_alloc_roots(vcpu
);
3763 spin_lock(&vcpu
->kvm
->mmu_lock
);
3764 mmu_sync_roots(vcpu
);
3765 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3768 /* set_cr3() should ensure TLB has been flushed */
3769 vcpu
->arch
.mmu
.set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
3773 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
3775 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
3777 mmu_free_roots(vcpu
);
3779 EXPORT_SYMBOL_GPL(kvm_mmu_unload
);
3781 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
3782 struct kvm_mmu_page
*sp
, u64
*spte
,
3785 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
3786 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
3790 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
3791 vcpu
->arch
.mmu
.update_pte(vcpu
, sp
, spte
, new);
3794 static bool need_remote_flush(u64 old
, u64
new)
3796 if (!is_shadow_present_pte(old
))
3798 if (!is_shadow_present_pte(new))
3800 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
3802 old
^= PT64_NX_MASK
;
3803 new ^= PT64_NX_MASK
;
3804 return (old
& ~new & PT64_PERM_MASK
) != 0;
3807 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, bool zap_page
,
3808 bool remote_flush
, bool local_flush
)
3814 kvm_flush_remote_tlbs(vcpu
->kvm
);
3815 else if (local_flush
)
3816 kvm_mmu_flush_tlb(vcpu
);
3819 static u64
mmu_pte_write_fetch_gpte(struct kvm_vcpu
*vcpu
, gpa_t
*gpa
,
3820 const u8
*new, int *bytes
)
3826 * Assume that the pte write on a page table of the same type
3827 * as the current vcpu paging mode since we update the sptes only
3828 * when they have the same mode.
3830 if (is_pae(vcpu
) && *bytes
== 4) {
3831 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
3834 r
= kvm_read_guest(vcpu
->kvm
, *gpa
, &gentry
, 8);
3837 new = (const u8
*)&gentry
;
3842 gentry
= *(const u32
*)new;
3845 gentry
= *(const u64
*)new;
3856 * If we're seeing too many writes to a page, it may no longer be a page table,
3857 * or we may be forking, in which case it is better to unmap the page.
3859 static bool detect_write_flooding(struct kvm_mmu_page
*sp
)
3862 * Skip write-flooding detected for the sp whose level is 1, because
3863 * it can become unsync, then the guest page is not write-protected.
3865 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
)
3868 return ++sp
->write_flooding_count
>= 3;
3872 * Misaligned accesses are too much trouble to fix up; also, they usually
3873 * indicate a page is not used as a page table.
3875 static bool detect_write_misaligned(struct kvm_mmu_page
*sp
, gpa_t gpa
,
3878 unsigned offset
, pte_size
, misaligned
;
3880 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
3881 gpa
, bytes
, sp
->role
.word
);
3883 offset
= offset_in_page(gpa
);
3884 pte_size
= sp
->role
.cr4_pae
? 8 : 4;
3887 * Sometimes, the OS only writes the last one bytes to update status
3888 * bits, for example, in linux, andb instruction is used in clear_bit().
3890 if (!(offset
& (pte_size
- 1)) && bytes
== 1)
3893 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
3894 misaligned
|= bytes
< 4;
3899 static u64
*get_written_sptes(struct kvm_mmu_page
*sp
, gpa_t gpa
, int *nspte
)
3901 unsigned page_offset
, quadrant
;
3905 page_offset
= offset_in_page(gpa
);
3906 level
= sp
->role
.level
;
3908 if (!sp
->role
.cr4_pae
) {
3909 page_offset
<<= 1; /* 32->64 */
3911 * A 32-bit pde maps 4MB while the shadow pdes map
3912 * only 2MB. So we need to double the offset again
3913 * and zap two pdes instead of one.
3915 if (level
== PT32_ROOT_LEVEL
) {
3916 page_offset
&= ~7; /* kill rounding error */
3920 quadrant
= page_offset
>> PAGE_SHIFT
;
3921 page_offset
&= ~PAGE_MASK
;
3922 if (quadrant
!= sp
->role
.quadrant
)
3926 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
3930 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
3931 const u8
*new, int bytes
)
3933 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3934 union kvm_mmu_page_role mask
= { .word
= 0 };
3935 struct kvm_mmu_page
*sp
;
3936 struct hlist_node
*node
;
3937 LIST_HEAD(invalid_list
);
3938 u64 entry
, gentry
, *spte
;
3940 bool remote_flush
, local_flush
, zap_page
;
3943 * If we don't have indirect shadow pages, it means no page is
3944 * write-protected, so we can exit simply.
3946 if (!ACCESS_ONCE(vcpu
->kvm
->arch
.indirect_shadow_pages
))
3949 zap_page
= remote_flush
= local_flush
= false;
3951 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
3953 gentry
= mmu_pte_write_fetch_gpte(vcpu
, &gpa
, new, &bytes
);
3956 * No need to care whether allocation memory is successful
3957 * or not since pte prefetch is skiped if it does not have
3958 * enough objects in the cache.
3960 mmu_topup_memory_caches(vcpu
);
3962 spin_lock(&vcpu
->kvm
->mmu_lock
);
3963 ++vcpu
->kvm
->stat
.mmu_pte_write
;
3964 kvm_mmu_audit(vcpu
, AUDIT_PRE_PTE_WRITE
);
3966 mask
.cr0_wp
= mask
.cr4_pae
= mask
.nxe
= 1;
3967 for_each_gfn_indirect_valid_sp(vcpu
->kvm
, sp
, gfn
, node
) {
3968 if (detect_write_misaligned(sp
, gpa
, bytes
) ||
3969 detect_write_flooding(sp
)) {
3970 zap_page
|= !!kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
,
3972 ++vcpu
->kvm
->stat
.mmu_flooded
;
3976 spte
= get_written_sptes(sp
, gpa
, &npte
);
3983 mmu_page_zap_pte(vcpu
->kvm
, sp
, spte
);
3985 !((sp
->role
.word
^ vcpu
->arch
.mmu
.base_role
.word
)
3986 & mask
.word
) && rmap_can_add(vcpu
))
3987 mmu_pte_write_new_pte(vcpu
, sp
, spte
, &gentry
);
3988 if (need_remote_flush(entry
, *spte
))
3989 remote_flush
= true;
3993 mmu_pte_write_flush_tlb(vcpu
, zap_page
, remote_flush
, local_flush
);
3994 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
3995 kvm_mmu_audit(vcpu
, AUDIT_POST_PTE_WRITE
);
3996 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3999 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
4004 if (vcpu
->arch
.mmu
.direct_map
)
4007 gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, gva
, NULL
);
4009 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
4013 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
4015 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
4017 LIST_HEAD(invalid_list
);
4019 while (kvm_mmu_available_pages(vcpu
->kvm
) < KVM_REFILL_PAGES
&&
4020 !list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
4021 struct kvm_mmu_page
*sp
;
4023 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
4024 struct kvm_mmu_page
, link
);
4025 kvm_mmu_prepare_zap_page(vcpu
->kvm
, sp
, &invalid_list
);
4026 ++vcpu
->kvm
->stat
.mmu_recycled
;
4028 kvm_mmu_commit_zap_page(vcpu
->kvm
, &invalid_list
);
4031 static bool is_mmio_page_fault(struct kvm_vcpu
*vcpu
, gva_t addr
)
4033 if (vcpu
->arch
.mmu
.direct_map
|| mmu_is_nested(vcpu
))
4034 return vcpu_match_mmio_gpa(vcpu
, addr
);
4036 return vcpu_match_mmio_gva(vcpu
, addr
);
4039 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
,
4040 void *insn
, int insn_len
)
4042 int r
, emulation_type
= EMULTYPE_RETRY
;
4043 enum emulation_result er
;
4045 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
, false);
4054 if (is_mmio_page_fault(vcpu
, cr2
))
4057 er
= x86_emulate_instruction(vcpu
, cr2
, emulation_type
, insn
, insn_len
);
4062 case EMULATE_DO_MMIO
:
4063 ++vcpu
->stat
.mmio_exits
;
4073 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
4075 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
4077 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
4078 kvm_mmu_flush_tlb(vcpu
);
4079 ++vcpu
->stat
.invlpg
;
4081 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
4083 void kvm_enable_tdp(void)
4087 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
4089 void kvm_disable_tdp(void)
4091 tdp_enabled
= false;
4093 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
4095 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
4097 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
4098 if (vcpu
->arch
.mmu
.lm_root
!= NULL
)
4099 free_page((unsigned long)vcpu
->arch
.mmu
.lm_root
);
4102 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
4110 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
4111 * Therefore we need to allocate shadow page tables in the first
4112 * 4GB of memory, which happens to fit the DMA32 zone.
4114 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
4118 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
4119 for (i
= 0; i
< 4; ++i
)
4120 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
4125 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
4129 vcpu
->arch
.walk_mmu
= &vcpu
->arch
.mmu
;
4130 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
4131 vcpu
->arch
.mmu
.translate_gpa
= translate_gpa
;
4132 vcpu
->arch
.nested_mmu
.translate_gpa
= translate_nested_gpa
;
4134 return alloc_mmu_pages(vcpu
);
4137 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
4140 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
4142 return init_kvm_mmu(vcpu
);
4145 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
4147 struct kvm_memory_slot
*memslot
;
4151 memslot
= id_to_memslot(kvm
->memslots
, slot
);
4152 last_gfn
= memslot
->base_gfn
+ memslot
->npages
- 1;
4154 spin_lock(&kvm
->mmu_lock
);
4156 for (i
= PT_PAGE_TABLE_LEVEL
;
4157 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
4158 unsigned long *rmapp
;
4159 unsigned long last_index
, index
;
4161 rmapp
= memslot
->arch
.rmap
[i
- PT_PAGE_TABLE_LEVEL
];
4162 last_index
= gfn_to_index(last_gfn
, memslot
->base_gfn
, i
);
4164 for (index
= 0; index
<= last_index
; ++index
, ++rmapp
) {
4166 __rmap_write_protect(kvm
, rmapp
, false);
4168 if (need_resched() || spin_needbreak(&kvm
->mmu_lock
)) {
4169 kvm_flush_remote_tlbs(kvm
);
4170 cond_resched_lock(&kvm
->mmu_lock
);
4175 kvm_flush_remote_tlbs(kvm
);
4176 spin_unlock(&kvm
->mmu_lock
);
4179 void kvm_mmu_zap_all(struct kvm
*kvm
)
4181 struct kvm_mmu_page
*sp
, *node
;
4182 LIST_HEAD(invalid_list
);
4184 spin_lock(&kvm
->mmu_lock
);
4186 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
4187 if (kvm_mmu_prepare_zap_page(kvm
, sp
, &invalid_list
))
4190 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
4191 spin_unlock(&kvm
->mmu_lock
);
4194 static void kvm_mmu_remove_some_alloc_mmu_pages(struct kvm
*kvm
,
4195 struct list_head
*invalid_list
)
4197 struct kvm_mmu_page
*page
;
4199 if (list_empty(&kvm
->arch
.active_mmu_pages
))
4202 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
4203 struct kvm_mmu_page
, link
);
4204 kvm_mmu_prepare_zap_page(kvm
, page
, invalid_list
);
4207 static int mmu_shrink(struct shrinker
*shrink
, struct shrink_control
*sc
)
4210 int nr_to_scan
= sc
->nr_to_scan
;
4212 if (nr_to_scan
== 0)
4215 raw_spin_lock(&kvm_lock
);
4217 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
4219 LIST_HEAD(invalid_list
);
4222 * Never scan more than sc->nr_to_scan VM instances.
4223 * Will not hit this condition practically since we do not try
4224 * to shrink more than one VM and it is very unlikely to see
4225 * !n_used_mmu_pages so many times.
4230 * n_used_mmu_pages is accessed without holding kvm->mmu_lock
4231 * here. We may skip a VM instance errorneosly, but we do not
4232 * want to shrink a VM that only started to populate its MMU
4235 if (!kvm
->arch
.n_used_mmu_pages
)
4238 idx
= srcu_read_lock(&kvm
->srcu
);
4239 spin_lock(&kvm
->mmu_lock
);
4241 kvm_mmu_remove_some_alloc_mmu_pages(kvm
, &invalid_list
);
4242 kvm_mmu_commit_zap_page(kvm
, &invalid_list
);
4244 spin_unlock(&kvm
->mmu_lock
);
4245 srcu_read_unlock(&kvm
->srcu
, idx
);
4247 list_move_tail(&kvm
->vm_list
, &vm_list
);
4251 raw_spin_unlock(&kvm_lock
);
4254 return percpu_counter_read_positive(&kvm_total_used_mmu_pages
);
4257 static struct shrinker mmu_shrinker
= {
4258 .shrink
= mmu_shrink
,
4259 .seeks
= DEFAULT_SEEKS
* 10,
4262 static void mmu_destroy_caches(void)
4264 if (pte_list_desc_cache
)
4265 kmem_cache_destroy(pte_list_desc_cache
);
4266 if (mmu_page_header_cache
)
4267 kmem_cache_destroy(mmu_page_header_cache
);
4270 int kvm_mmu_module_init(void)
4272 pte_list_desc_cache
= kmem_cache_create("pte_list_desc",
4273 sizeof(struct pte_list_desc
),
4275 if (!pte_list_desc_cache
)
4278 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
4279 sizeof(struct kvm_mmu_page
),
4281 if (!mmu_page_header_cache
)
4284 if (percpu_counter_init(&kvm_total_used_mmu_pages
, 0))
4287 register_shrinker(&mmu_shrinker
);
4292 mmu_destroy_caches();
4297 * Caculate mmu pages needed for kvm.
4299 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
4301 unsigned int nr_mmu_pages
;
4302 unsigned int nr_pages
= 0;
4303 struct kvm_memslots
*slots
;
4304 struct kvm_memory_slot
*memslot
;
4306 slots
= kvm_memslots(kvm
);
4308 kvm_for_each_memslot(memslot
, slots
)
4309 nr_pages
+= memslot
->npages
;
4311 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
4312 nr_mmu_pages
= max(nr_mmu_pages
,
4313 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
4315 return nr_mmu_pages
;
4318 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu
*vcpu
, u64 addr
, u64 sptes
[4])
4320 struct kvm_shadow_walk_iterator iterator
;
4324 walk_shadow_page_lockless_begin(vcpu
);
4325 for_each_shadow_entry_lockless(vcpu
, addr
, iterator
, spte
) {
4326 sptes
[iterator
.level
-1] = spte
;
4328 if (!is_shadow_present_pte(spte
))
4331 walk_shadow_page_lockless_end(vcpu
);
4335 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy
);
4337 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
4341 destroy_kvm_mmu(vcpu
);
4342 free_mmu_pages(vcpu
);
4343 mmu_free_memory_caches(vcpu
);
4346 void kvm_mmu_module_exit(void)
4348 mmu_destroy_caches();
4349 percpu_counter_destroy(&kvm_total_used_mmu_pages
);
4350 unregister_shrinker(&mmu_shrinker
);
4351 mmu_audit_disable();