2 * Kernel-based Virtual Machine driver for Linux
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
9 * Copyright (C) 2006 Qumranet, Inc.
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
22 #include "kvm_cache_regs.h"
24 #include <linux/kvm_host.h>
25 #include <linux/types.h>
26 #include <linux/string.h>
28 #include <linux/highmem.h>
29 #include <linux/module.h>
30 #include <linux/swap.h>
31 #include <linux/hugetlb.h>
32 #include <linux/compiler.h>
33 #include <linux/srcu.h>
36 #include <asm/cmpxchg.h>
41 * When setting this variable to true it enables Two-Dimensional-Paging
42 * where the hardware walks 2 page tables:
43 * 1. the guest-virtual to guest-physical
44 * 2. while doing 1. it walks guest-physical to host-physical
45 * If the hardware supports that we don't need to do shadow paging.
47 bool tdp_enabled
= false;
54 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
56 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
61 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
62 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
66 #define pgprintk(x...) do { } while (0)
67 #define rmap_printk(x...) do { } while (0)
71 #if defined(MMU_DEBUG) || defined(AUDIT)
73 module_param(dbg
, bool, 0644);
76 static int oos_shadow
= 1;
77 module_param(oos_shadow
, bool, 0644);
80 #define ASSERT(x) do { } while (0)
84 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
85 __FILE__, __LINE__, #x); \
89 #define PT_FIRST_AVAIL_BITS_SHIFT 9
90 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
92 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
94 #define PT64_LEVEL_BITS 9
96 #define PT64_LEVEL_SHIFT(level) \
97 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
99 #define PT64_LEVEL_MASK(level) \
100 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
102 #define PT64_INDEX(address, level)\
103 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
106 #define PT32_LEVEL_BITS 10
108 #define PT32_LEVEL_SHIFT(level) \
109 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
111 #define PT32_LEVEL_MASK(level) \
112 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
113 #define PT32_LVL_OFFSET_MASK(level) \
114 (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
115 * PT32_LEVEL_BITS))) - 1))
117 #define PT32_INDEX(address, level)\
118 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
121 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
122 #define PT64_DIR_BASE_ADDR_MASK \
123 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
124 #define PT64_LVL_ADDR_MASK(level) \
125 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
126 * PT64_LEVEL_BITS))) - 1))
127 #define PT64_LVL_OFFSET_MASK(level) \
128 (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
129 * PT64_LEVEL_BITS))) - 1))
131 #define PT32_BASE_ADDR_MASK PAGE_MASK
132 #define PT32_DIR_BASE_ADDR_MASK \
133 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
134 #define PT32_LVL_ADDR_MASK(level) \
135 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
136 * PT32_LEVEL_BITS))) - 1))
138 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
143 #define ACC_EXEC_MASK 1
144 #define ACC_WRITE_MASK PT_WRITABLE_MASK
145 #define ACC_USER_MASK PT_USER_MASK
146 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
148 #include <trace/events/kvm.h>
150 #undef TRACE_INCLUDE_FILE
151 #define CREATE_TRACE_POINTS
152 #include "mmutrace.h"
154 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
156 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
158 struct kvm_rmap_desc
{
159 u64
*sptes
[RMAP_EXT
];
160 struct kvm_rmap_desc
*more
;
163 struct kvm_shadow_walk_iterator
{
171 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
172 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
173 shadow_walk_okay(&(_walker)); \
174 shadow_walk_next(&(_walker)))
177 struct kvm_unsync_walk
{
178 int (*entry
) (struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
);
181 typedef int (*mmu_parent_walk_fn
) (struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
);
183 static struct kmem_cache
*pte_chain_cache
;
184 static struct kmem_cache
*rmap_desc_cache
;
185 static struct kmem_cache
*mmu_page_header_cache
;
187 static u64 __read_mostly shadow_trap_nonpresent_pte
;
188 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
189 static u64 __read_mostly shadow_base_present_pte
;
190 static u64 __read_mostly shadow_nx_mask
;
191 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
192 static u64 __read_mostly shadow_user_mask
;
193 static u64 __read_mostly shadow_accessed_mask
;
194 static u64 __read_mostly shadow_dirty_mask
;
196 static inline u64
rsvd_bits(int s
, int e
)
198 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
201 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
203 shadow_trap_nonpresent_pte
= trap_pte
;
204 shadow_notrap_nonpresent_pte
= notrap_pte
;
206 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
208 void kvm_mmu_set_base_ptes(u64 base_pte
)
210 shadow_base_present_pte
= base_pte
;
212 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes
);
214 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
215 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
217 shadow_user_mask
= user_mask
;
218 shadow_accessed_mask
= accessed_mask
;
219 shadow_dirty_mask
= dirty_mask
;
220 shadow_nx_mask
= nx_mask
;
221 shadow_x_mask
= x_mask
;
223 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
225 static int is_write_protection(struct kvm_vcpu
*vcpu
)
227 return kvm_read_cr0_bits(vcpu
, X86_CR0_WP
);
230 static int is_cpuid_PSE36(void)
235 static int is_nx(struct kvm_vcpu
*vcpu
)
237 return vcpu
->arch
.efer
& EFER_NX
;
240 static int is_shadow_present_pte(u64 pte
)
242 return pte
!= shadow_trap_nonpresent_pte
243 && pte
!= shadow_notrap_nonpresent_pte
;
246 static int is_large_pte(u64 pte
)
248 return pte
& PT_PAGE_SIZE_MASK
;
251 static int is_writable_pte(unsigned long pte
)
253 return pte
& PT_WRITABLE_MASK
;
256 static int is_dirty_gpte(unsigned long pte
)
258 return pte
& PT_DIRTY_MASK
;
261 static int is_rmap_spte(u64 pte
)
263 return is_shadow_present_pte(pte
);
266 static int is_last_spte(u64 pte
, int level
)
268 if (level
== PT_PAGE_TABLE_LEVEL
)
270 if (is_large_pte(pte
))
275 static pfn_t
spte_to_pfn(u64 pte
)
277 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
280 static gfn_t
pse36_gfn_delta(u32 gpte
)
282 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
284 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
287 static void __set_spte(u64
*sptep
, u64 spte
)
290 set_64bit((unsigned long *)sptep
, spte
);
292 set_64bit((unsigned long long *)sptep
, spte
);
296 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
297 struct kmem_cache
*base_cache
, int min
)
301 if (cache
->nobjs
>= min
)
303 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
304 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
307 cache
->objects
[cache
->nobjs
++] = obj
;
312 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
315 kfree(mc
->objects
[--mc
->nobjs
]);
318 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
323 if (cache
->nobjs
>= min
)
325 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
326 page
= alloc_page(GFP_KERNEL
);
329 set_page_private(page
, 0);
330 cache
->objects
[cache
->nobjs
++] = page_address(page
);
335 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
338 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
341 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
345 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
349 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
353 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
356 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
357 mmu_page_header_cache
, 4);
362 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
364 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
365 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
366 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
367 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
370 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
376 p
= mc
->objects
[--mc
->nobjs
];
380 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
382 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
383 sizeof(struct kvm_pte_chain
));
386 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
391 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
393 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
394 sizeof(struct kvm_rmap_desc
));
397 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
403 * Return the pointer to the largepage write count for a given
404 * gfn, handling slots that are not large page aligned.
406 static int *slot_largepage_idx(gfn_t gfn
,
407 struct kvm_memory_slot
*slot
,
412 idx
= (gfn
/ KVM_PAGES_PER_HPAGE(level
)) -
413 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE(level
));
414 return &slot
->lpage_info
[level
- 2][idx
].write_count
;
417 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
419 struct kvm_memory_slot
*slot
;
423 gfn
= unalias_gfn(kvm
, gfn
);
425 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
426 for (i
= PT_DIRECTORY_LEVEL
;
427 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
428 write_count
= slot_largepage_idx(gfn
, slot
, i
);
433 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
435 struct kvm_memory_slot
*slot
;
439 gfn
= unalias_gfn(kvm
, gfn
);
440 for (i
= PT_DIRECTORY_LEVEL
;
441 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
442 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
443 write_count
= slot_largepage_idx(gfn
, slot
, i
);
445 WARN_ON(*write_count
< 0);
449 static int has_wrprotected_page(struct kvm
*kvm
,
453 struct kvm_memory_slot
*slot
;
456 gfn
= unalias_gfn(kvm
, gfn
);
457 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
459 largepage_idx
= slot_largepage_idx(gfn
, slot
, level
);
460 return *largepage_idx
;
466 static int host_mapping_level(struct kvm
*kvm
, gfn_t gfn
)
468 unsigned long page_size
;
471 page_size
= kvm_host_page_size(kvm
, gfn
);
473 for (i
= PT_PAGE_TABLE_LEVEL
;
474 i
< (PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
); ++i
) {
475 if (page_size
>= KVM_HPAGE_SIZE(i
))
484 static int mapping_level(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
486 struct kvm_memory_slot
*slot
;
487 int host_level
, level
, max_level
;
489 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
490 if (slot
&& slot
->dirty_bitmap
)
491 return PT_PAGE_TABLE_LEVEL
;
493 host_level
= host_mapping_level(vcpu
->kvm
, large_gfn
);
495 if (host_level
== PT_PAGE_TABLE_LEVEL
)
498 max_level
= kvm_x86_ops
->get_lpage_level() < host_level
?
499 kvm_x86_ops
->get_lpage_level() : host_level
;
501 for (level
= PT_DIRECTORY_LEVEL
; level
<= max_level
; ++level
)
502 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
, level
))
509 * Take gfn and return the reverse mapping to it.
510 * Note: gfn must be unaliased before this function get called
513 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int level
)
515 struct kvm_memory_slot
*slot
;
518 slot
= gfn_to_memslot(kvm
, gfn
);
519 if (likely(level
== PT_PAGE_TABLE_LEVEL
))
520 return &slot
->rmap
[gfn
- slot
->base_gfn
];
522 idx
= (gfn
/ KVM_PAGES_PER_HPAGE(level
)) -
523 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE(level
));
525 return &slot
->lpage_info
[level
- 2][idx
].rmap_pde
;
529 * Reverse mapping data structures:
531 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
532 * that points to page_address(page).
534 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
535 * containing more mappings.
537 * Returns the number of rmap entries before the spte was added or zero if
538 * the spte was not added.
541 static int rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
543 struct kvm_mmu_page
*sp
;
544 struct kvm_rmap_desc
*desc
;
545 unsigned long *rmapp
;
548 if (!is_rmap_spte(*spte
))
550 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
551 sp
= page_header(__pa(spte
));
552 sp
->gfns
[spte
- sp
->spt
] = gfn
;
553 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
555 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
556 *rmapp
= (unsigned long)spte
;
557 } else if (!(*rmapp
& 1)) {
558 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
559 desc
= mmu_alloc_rmap_desc(vcpu
);
560 desc
->sptes
[0] = (u64
*)*rmapp
;
561 desc
->sptes
[1] = spte
;
562 *rmapp
= (unsigned long)desc
| 1;
564 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
565 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
566 while (desc
->sptes
[RMAP_EXT
-1] && desc
->more
) {
570 if (desc
->sptes
[RMAP_EXT
-1]) {
571 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
574 for (i
= 0; desc
->sptes
[i
]; ++i
)
576 desc
->sptes
[i
] = spte
;
581 static void rmap_desc_remove_entry(unsigned long *rmapp
,
582 struct kvm_rmap_desc
*desc
,
584 struct kvm_rmap_desc
*prev_desc
)
588 for (j
= RMAP_EXT
- 1; !desc
->sptes
[j
] && j
> i
; --j
)
590 desc
->sptes
[i
] = desc
->sptes
[j
];
591 desc
->sptes
[j
] = NULL
;
594 if (!prev_desc
&& !desc
->more
)
595 *rmapp
= (unsigned long)desc
->sptes
[0];
598 prev_desc
->more
= desc
->more
;
600 *rmapp
= (unsigned long)desc
->more
| 1;
601 mmu_free_rmap_desc(desc
);
604 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
606 struct kvm_rmap_desc
*desc
;
607 struct kvm_rmap_desc
*prev_desc
;
608 struct kvm_mmu_page
*sp
;
610 unsigned long *rmapp
;
613 if (!is_rmap_spte(*spte
))
615 sp
= page_header(__pa(spte
));
616 pfn
= spte_to_pfn(*spte
);
617 if (*spte
& shadow_accessed_mask
)
618 kvm_set_pfn_accessed(pfn
);
619 if (is_writable_pte(*spte
))
620 kvm_set_pfn_dirty(pfn
);
621 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], sp
->role
.level
);
623 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
625 } else if (!(*rmapp
& 1)) {
626 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
627 if ((u64
*)*rmapp
!= spte
) {
628 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
634 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
635 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
638 for (i
= 0; i
< RMAP_EXT
&& desc
->sptes
[i
]; ++i
)
639 if (desc
->sptes
[i
] == spte
) {
640 rmap_desc_remove_entry(rmapp
,
648 pr_err("rmap_remove: %p %llx many->many\n", spte
, *spte
);
653 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
655 struct kvm_rmap_desc
*desc
;
656 struct kvm_rmap_desc
*prev_desc
;
662 else if (!(*rmapp
& 1)) {
664 return (u64
*)*rmapp
;
667 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
671 for (i
= 0; i
< RMAP_EXT
&& desc
->sptes
[i
]; ++i
) {
672 if (prev_spte
== spte
)
673 return desc
->sptes
[i
];
674 prev_spte
= desc
->sptes
[i
];
681 static int rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
683 unsigned long *rmapp
;
685 int i
, write_protected
= 0;
687 gfn
= unalias_gfn(kvm
, gfn
);
688 rmapp
= gfn_to_rmap(kvm
, gfn
, PT_PAGE_TABLE_LEVEL
);
690 spte
= rmap_next(kvm
, rmapp
, NULL
);
693 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
694 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
695 if (is_writable_pte(*spte
)) {
696 __set_spte(spte
, *spte
& ~PT_WRITABLE_MASK
);
699 spte
= rmap_next(kvm
, rmapp
, spte
);
701 if (write_protected
) {
704 spte
= rmap_next(kvm
, rmapp
, NULL
);
705 pfn
= spte_to_pfn(*spte
);
706 kvm_set_pfn_dirty(pfn
);
709 /* check for huge page mappings */
710 for (i
= PT_DIRECTORY_LEVEL
;
711 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
712 rmapp
= gfn_to_rmap(kvm
, gfn
, i
);
713 spte
= rmap_next(kvm
, rmapp
, NULL
);
716 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
717 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
718 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
719 if (is_writable_pte(*spte
)) {
720 rmap_remove(kvm
, spte
);
722 __set_spte(spte
, shadow_trap_nonpresent_pte
);
726 spte
= rmap_next(kvm
, rmapp
, spte
);
730 return write_protected
;
733 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
737 int need_tlb_flush
= 0;
739 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
740 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
741 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
742 rmap_remove(kvm
, spte
);
743 __set_spte(spte
, shadow_trap_nonpresent_pte
);
746 return need_tlb_flush
;
749 static int kvm_set_pte_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
754 pte_t
*ptep
= (pte_t
*)data
;
757 WARN_ON(pte_huge(*ptep
));
758 new_pfn
= pte_pfn(*ptep
);
759 spte
= rmap_next(kvm
, rmapp
, NULL
);
761 BUG_ON(!is_shadow_present_pte(*spte
));
762 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte
, *spte
);
764 if (pte_write(*ptep
)) {
765 rmap_remove(kvm
, spte
);
766 __set_spte(spte
, shadow_trap_nonpresent_pte
);
767 spte
= rmap_next(kvm
, rmapp
, NULL
);
769 new_spte
= *spte
&~ (PT64_BASE_ADDR_MASK
);
770 new_spte
|= (u64
)new_pfn
<< PAGE_SHIFT
;
772 new_spte
&= ~PT_WRITABLE_MASK
;
773 new_spte
&= ~SPTE_HOST_WRITEABLE
;
774 if (is_writable_pte(*spte
))
775 kvm_set_pfn_dirty(spte_to_pfn(*spte
));
776 __set_spte(spte
, new_spte
);
777 spte
= rmap_next(kvm
, rmapp
, spte
);
781 kvm_flush_remote_tlbs(kvm
);
786 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
788 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
,
794 struct kvm_memslots
*slots
;
796 slots
= rcu_dereference(kvm
->memslots
);
798 for (i
= 0; i
< slots
->nmemslots
; i
++) {
799 struct kvm_memory_slot
*memslot
= &slots
->memslots
[i
];
800 unsigned long start
= memslot
->userspace_addr
;
803 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
804 if (hva
>= start
&& hva
< end
) {
805 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
807 ret
= handler(kvm
, &memslot
->rmap
[gfn_offset
], data
);
809 for (j
= 0; j
< KVM_NR_PAGE_SIZES
- 1; ++j
) {
810 int idx
= gfn_offset
;
811 idx
/= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL
+ j
);
813 &memslot
->lpage_info
[j
][idx
].rmap_pde
,
816 trace_kvm_age_page(hva
, memslot
, ret
);
824 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
826 return kvm_handle_hva(kvm
, hva
, 0, kvm_unmap_rmapp
);
829 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
831 kvm_handle_hva(kvm
, hva
, (unsigned long)&pte
, kvm_set_pte_rmapp
);
834 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
841 * Emulate the accessed bit for EPT, by checking if this page has
842 * an EPT mapping, and clearing it if it does. On the next access,
843 * a new EPT mapping will be established.
844 * This has some overhead, but not as much as the cost of swapping
845 * out actively used pages or breaking up actively used hugepages.
847 if (!shadow_accessed_mask
)
848 return kvm_unmap_rmapp(kvm
, rmapp
, data
);
850 spte
= rmap_next(kvm
, rmapp
, NULL
);
854 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
855 _young
= _spte
& PT_ACCESSED_MASK
;
858 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
860 spte
= rmap_next(kvm
, rmapp
, spte
);
865 #define RMAP_RECYCLE_THRESHOLD 1000
867 static void rmap_recycle(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
869 unsigned long *rmapp
;
870 struct kvm_mmu_page
*sp
;
872 sp
= page_header(__pa(spte
));
874 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
875 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
877 kvm_unmap_rmapp(vcpu
->kvm
, rmapp
, 0);
878 kvm_flush_remote_tlbs(vcpu
->kvm
);
881 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
883 return kvm_handle_hva(kvm
, hva
, 0, kvm_age_rmapp
);
887 static int is_empty_shadow_page(u64
*spt
)
892 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
893 if (is_shadow_present_pte(*pos
)) {
894 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
902 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
904 ASSERT(is_empty_shadow_page(sp
->spt
));
906 __free_page(virt_to_page(sp
->spt
));
907 __free_page(virt_to_page(sp
->gfns
));
909 ++kvm
->arch
.n_free_mmu_pages
;
912 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
914 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
917 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
920 struct kvm_mmu_page
*sp
;
922 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
923 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
924 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
925 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
926 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
927 INIT_LIST_HEAD(&sp
->oos_link
);
928 bitmap_zero(sp
->slot_bitmap
, KVM_MEMORY_SLOTS
+ KVM_PRIVATE_MEM_SLOTS
);
930 sp
->parent_pte
= parent_pte
;
931 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
935 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
936 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
938 struct kvm_pte_chain
*pte_chain
;
939 struct hlist_node
*node
;
944 if (!sp
->multimapped
) {
945 u64
*old
= sp
->parent_pte
;
948 sp
->parent_pte
= parent_pte
;
952 pte_chain
= mmu_alloc_pte_chain(vcpu
);
953 INIT_HLIST_HEAD(&sp
->parent_ptes
);
954 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
955 pte_chain
->parent_ptes
[0] = old
;
957 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
958 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
960 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
961 if (!pte_chain
->parent_ptes
[i
]) {
962 pte_chain
->parent_ptes
[i
] = parent_pte
;
966 pte_chain
= mmu_alloc_pte_chain(vcpu
);
968 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
969 pte_chain
->parent_ptes
[0] = parent_pte
;
972 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
975 struct kvm_pte_chain
*pte_chain
;
976 struct hlist_node
*node
;
979 if (!sp
->multimapped
) {
980 BUG_ON(sp
->parent_pte
!= parent_pte
);
981 sp
->parent_pte
= NULL
;
984 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
985 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
986 if (!pte_chain
->parent_ptes
[i
])
988 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
990 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
991 && pte_chain
->parent_ptes
[i
+ 1]) {
992 pte_chain
->parent_ptes
[i
]
993 = pte_chain
->parent_ptes
[i
+ 1];
996 pte_chain
->parent_ptes
[i
] = NULL
;
998 hlist_del(&pte_chain
->link
);
999 mmu_free_pte_chain(pte_chain
);
1000 if (hlist_empty(&sp
->parent_ptes
)) {
1001 sp
->multimapped
= 0;
1002 sp
->parent_pte
= NULL
;
1011 static void mmu_parent_walk(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1012 mmu_parent_walk_fn fn
)
1014 struct kvm_pte_chain
*pte_chain
;
1015 struct hlist_node
*node
;
1016 struct kvm_mmu_page
*parent_sp
;
1019 if (!sp
->multimapped
&& sp
->parent_pte
) {
1020 parent_sp
= page_header(__pa(sp
->parent_pte
));
1021 fn(vcpu
, parent_sp
);
1022 mmu_parent_walk(vcpu
, parent_sp
, fn
);
1025 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
1026 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
1027 if (!pte_chain
->parent_ptes
[i
])
1029 parent_sp
= page_header(__pa(pte_chain
->parent_ptes
[i
]));
1030 fn(vcpu
, parent_sp
);
1031 mmu_parent_walk(vcpu
, parent_sp
, fn
);
1035 static void kvm_mmu_update_unsync_bitmap(u64
*spte
)
1038 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
1040 index
= spte
- sp
->spt
;
1041 if (!__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
1042 sp
->unsync_children
++;
1043 WARN_ON(!sp
->unsync_children
);
1046 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page
*sp
)
1048 struct kvm_pte_chain
*pte_chain
;
1049 struct hlist_node
*node
;
1052 if (!sp
->parent_pte
)
1055 if (!sp
->multimapped
) {
1056 kvm_mmu_update_unsync_bitmap(sp
->parent_pte
);
1060 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
1061 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
1062 if (!pte_chain
->parent_ptes
[i
])
1064 kvm_mmu_update_unsync_bitmap(pte_chain
->parent_ptes
[i
]);
1068 static int unsync_walk_fn(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1070 kvm_mmu_update_parents_unsync(sp
);
1074 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu
*vcpu
,
1075 struct kvm_mmu_page
*sp
)
1077 mmu_parent_walk(vcpu
, sp
, unsync_walk_fn
);
1078 kvm_mmu_update_parents_unsync(sp
);
1081 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
1082 struct kvm_mmu_page
*sp
)
1086 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1087 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
1090 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
1091 struct kvm_mmu_page
*sp
)
1096 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
1100 #define KVM_PAGE_ARRAY_NR 16
1102 struct kvm_mmu_pages
{
1103 struct mmu_page_and_offset
{
1104 struct kvm_mmu_page
*sp
;
1106 } page
[KVM_PAGE_ARRAY_NR
];
1110 #define for_each_unsync_children(bitmap, idx) \
1111 for (idx = find_first_bit(bitmap, 512); \
1113 idx = find_next_bit(bitmap, 512, idx+1))
1115 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
1121 for (i
=0; i
< pvec
->nr
; i
++)
1122 if (pvec
->page
[i
].sp
== sp
)
1125 pvec
->page
[pvec
->nr
].sp
= sp
;
1126 pvec
->page
[pvec
->nr
].idx
= idx
;
1128 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1131 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1132 struct kvm_mmu_pages
*pvec
)
1134 int i
, ret
, nr_unsync_leaf
= 0;
1136 for_each_unsync_children(sp
->unsync_child_bitmap
, i
) {
1137 u64 ent
= sp
->spt
[i
];
1139 if (is_shadow_present_pte(ent
) && !is_large_pte(ent
)) {
1140 struct kvm_mmu_page
*child
;
1141 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1143 if (child
->unsync_children
) {
1144 if (mmu_pages_add(pvec
, child
, i
))
1147 ret
= __mmu_unsync_walk(child
, pvec
);
1149 __clear_bit(i
, sp
->unsync_child_bitmap
);
1151 nr_unsync_leaf
+= ret
;
1156 if (child
->unsync
) {
1158 if (mmu_pages_add(pvec
, child
, i
))
1164 if (find_first_bit(sp
->unsync_child_bitmap
, 512) == 512)
1165 sp
->unsync_children
= 0;
1167 return nr_unsync_leaf
;
1170 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1171 struct kvm_mmu_pages
*pvec
)
1173 if (!sp
->unsync_children
)
1176 mmu_pages_add(pvec
, sp
, 0);
1177 return __mmu_unsync_walk(sp
, pvec
);
1180 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
1183 struct hlist_head
*bucket
;
1184 struct kvm_mmu_page
*sp
;
1185 struct hlist_node
*node
;
1187 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1188 index
= kvm_page_table_hashfn(gfn
);
1189 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1190 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
1191 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1192 && !sp
->role
.invalid
) {
1193 pgprintk("%s: found role %x\n",
1194 __func__
, sp
->role
.word
);
1200 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1202 WARN_ON(!sp
->unsync
);
1204 --kvm
->stat
.mmu_unsync
;
1207 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
);
1209 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1211 if (sp
->role
.glevels
!= vcpu
->arch
.mmu
.root_level
) {
1212 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1216 trace_kvm_mmu_sync_page(sp
);
1217 if (rmap_write_protect(vcpu
->kvm
, sp
->gfn
))
1218 kvm_flush_remote_tlbs(vcpu
->kvm
);
1219 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1220 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1221 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1225 kvm_mmu_flush_tlb(vcpu
);
1229 struct mmu_page_path
{
1230 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1231 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1234 #define for_each_sp(pvec, sp, parents, i) \
1235 for (i = mmu_pages_next(&pvec, &parents, -1), \
1236 sp = pvec.page[i].sp; \
1237 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1238 i = mmu_pages_next(&pvec, &parents, i))
1240 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1241 struct mmu_page_path
*parents
,
1246 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1247 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1249 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1250 parents
->idx
[0] = pvec
->page
[n
].idx
;
1254 parents
->parent
[sp
->role
.level
-2] = sp
;
1255 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1261 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1263 struct kvm_mmu_page
*sp
;
1264 unsigned int level
= 0;
1267 unsigned int idx
= parents
->idx
[level
];
1269 sp
= parents
->parent
[level
];
1273 --sp
->unsync_children
;
1274 WARN_ON((int)sp
->unsync_children
< 0);
1275 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1277 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1280 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1281 struct mmu_page_path
*parents
,
1282 struct kvm_mmu_pages
*pvec
)
1284 parents
->parent
[parent
->role
.level
-1] = NULL
;
1288 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1289 struct kvm_mmu_page
*parent
)
1292 struct kvm_mmu_page
*sp
;
1293 struct mmu_page_path parents
;
1294 struct kvm_mmu_pages pages
;
1296 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1297 while (mmu_unsync_walk(parent
, &pages
)) {
1300 for_each_sp(pages
, sp
, parents
, i
)
1301 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1304 kvm_flush_remote_tlbs(vcpu
->kvm
);
1306 for_each_sp(pages
, sp
, parents
, i
) {
1307 kvm_sync_page(vcpu
, sp
);
1308 mmu_pages_clear_parents(&parents
);
1310 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1311 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1315 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1323 union kvm_mmu_page_role role
;
1326 struct hlist_head
*bucket
;
1327 struct kvm_mmu_page
*sp
;
1328 struct hlist_node
*node
, *tmp
;
1330 role
= vcpu
->arch
.mmu
.base_role
;
1332 role
.direct
= direct
;
1333 role
.access
= access
;
1334 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1335 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1336 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1337 role
.quadrant
= quadrant
;
1339 index
= kvm_page_table_hashfn(gfn
);
1340 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1341 hlist_for_each_entry_safe(sp
, node
, tmp
, bucket
, hash_link
)
1342 if (sp
->gfn
== gfn
) {
1344 if (kvm_sync_page(vcpu
, sp
))
1347 if (sp
->role
.word
!= role
.word
)
1350 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1351 if (sp
->unsync_children
) {
1352 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
1353 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1355 trace_kvm_mmu_get_page(sp
, false);
1358 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1359 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
1364 hlist_add_head(&sp
->hash_link
, bucket
);
1366 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1367 kvm_flush_remote_tlbs(vcpu
->kvm
);
1368 account_shadowed(vcpu
->kvm
, gfn
);
1370 if (shadow_trap_nonpresent_pte
!= shadow_notrap_nonpresent_pte
)
1371 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
1373 nonpaging_prefetch_page(vcpu
, sp
);
1374 trace_kvm_mmu_get_page(sp
, true);
1378 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1379 struct kvm_vcpu
*vcpu
, u64 addr
)
1381 iterator
->addr
= addr
;
1382 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1383 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1384 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1385 iterator
->shadow_addr
1386 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1387 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1389 if (!iterator
->shadow_addr
)
1390 iterator
->level
= 0;
1394 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1396 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1399 if (iterator
->level
== PT_PAGE_TABLE_LEVEL
)
1400 if (is_large_pte(*iterator
->sptep
))
1403 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1404 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1408 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1410 iterator
->shadow_addr
= *iterator
->sptep
& PT64_BASE_ADDR_MASK
;
1414 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1415 struct kvm_mmu_page
*sp
)
1423 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1426 if (is_shadow_present_pte(ent
)) {
1427 if (!is_last_spte(ent
, sp
->role
.level
)) {
1428 ent
&= PT64_BASE_ADDR_MASK
;
1429 mmu_page_remove_parent_pte(page_header(ent
),
1432 if (is_large_pte(ent
))
1434 rmap_remove(kvm
, &pt
[i
]);
1437 pt
[i
] = shadow_trap_nonpresent_pte
;
1441 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1443 mmu_page_remove_parent_pte(sp
, parent_pte
);
1446 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
1449 struct kvm_vcpu
*vcpu
;
1451 kvm_for_each_vcpu(i
, vcpu
, kvm
)
1452 vcpu
->arch
.last_pte_updated
= NULL
;
1455 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1459 while (sp
->multimapped
|| sp
->parent_pte
) {
1460 if (!sp
->multimapped
)
1461 parent_pte
= sp
->parent_pte
;
1463 struct kvm_pte_chain
*chain
;
1465 chain
= container_of(sp
->parent_ptes
.first
,
1466 struct kvm_pte_chain
, link
);
1467 parent_pte
= chain
->parent_ptes
[0];
1469 BUG_ON(!parent_pte
);
1470 kvm_mmu_put_page(sp
, parent_pte
);
1471 __set_spte(parent_pte
, shadow_trap_nonpresent_pte
);
1475 static int mmu_zap_unsync_children(struct kvm
*kvm
,
1476 struct kvm_mmu_page
*parent
)
1479 struct mmu_page_path parents
;
1480 struct kvm_mmu_pages pages
;
1482 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1485 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1486 while (mmu_unsync_walk(parent
, &pages
)) {
1487 struct kvm_mmu_page
*sp
;
1489 for_each_sp(pages
, sp
, parents
, i
) {
1490 kvm_mmu_zap_page(kvm
, sp
);
1491 mmu_pages_clear_parents(&parents
);
1494 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1500 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1504 trace_kvm_mmu_zap_page(sp
);
1505 ++kvm
->stat
.mmu_shadow_zapped
;
1506 ret
= mmu_zap_unsync_children(kvm
, sp
);
1507 kvm_mmu_page_unlink_children(kvm
, sp
);
1508 kvm_mmu_unlink_parents(kvm
, sp
);
1509 kvm_flush_remote_tlbs(kvm
);
1510 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
1511 unaccount_shadowed(kvm
, sp
->gfn
);
1513 kvm_unlink_unsync_page(kvm
, sp
);
1514 if (!sp
->root_count
) {
1515 hlist_del(&sp
->hash_link
);
1516 kvm_mmu_free_page(kvm
, sp
);
1518 sp
->role
.invalid
= 1;
1519 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1520 kvm_reload_remote_mmus(kvm
);
1522 kvm_mmu_reset_last_pte_updated(kvm
);
1527 * Changing the number of mmu pages allocated to the vm
1528 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1530 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
1534 used_pages
= kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
;
1535 used_pages
= max(0, used_pages
);
1538 * If we set the number of mmu pages to be smaller be than the
1539 * number of actived pages , we must to free some mmu pages before we
1543 if (used_pages
> kvm_nr_mmu_pages
) {
1544 while (used_pages
> kvm_nr_mmu_pages
) {
1545 struct kvm_mmu_page
*page
;
1547 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
1548 struct kvm_mmu_page
, link
);
1549 kvm_mmu_zap_page(kvm
, page
);
1552 kvm
->arch
.n_free_mmu_pages
= 0;
1555 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
1556 - kvm
->arch
.n_alloc_mmu_pages
;
1558 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
1561 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
1564 struct hlist_head
*bucket
;
1565 struct kvm_mmu_page
*sp
;
1566 struct hlist_node
*node
, *n
;
1569 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1571 index
= kvm_page_table_hashfn(gfn
);
1572 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1573 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
1574 if (sp
->gfn
== gfn
&& !sp
->role
.direct
) {
1575 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
1578 if (kvm_mmu_zap_page(kvm
, sp
))
1584 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
1587 struct hlist_head
*bucket
;
1588 struct kvm_mmu_page
*sp
;
1589 struct hlist_node
*node
, *nn
;
1591 index
= kvm_page_table_hashfn(gfn
);
1592 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1593 hlist_for_each_entry_safe(sp
, node
, nn
, bucket
, hash_link
) {
1594 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1595 && !sp
->role
.invalid
) {
1596 pgprintk("%s: zap %lx %x\n",
1597 __func__
, gfn
, sp
->role
.word
);
1598 kvm_mmu_zap_page(kvm
, sp
);
1603 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
1605 int slot
= memslot_id(kvm
, gfn
);
1606 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
1608 __set_bit(slot
, sp
->slot_bitmap
);
1611 static void mmu_convert_notrap(struct kvm_mmu_page
*sp
)
1616 if (shadow_trap_nonpresent_pte
== shadow_notrap_nonpresent_pte
)
1619 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1620 if (pt
[i
] == shadow_notrap_nonpresent_pte
)
1621 __set_spte(&pt
[i
], shadow_trap_nonpresent_pte
);
1625 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
1629 gpa_t gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, gva
, NULL
);
1631 if (gpa
== UNMAPPED_GVA
)
1634 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1640 * The function is based on mtrr_type_lookup() in
1641 * arch/x86/kernel/cpu/mtrr/generic.c
1643 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
1648 u8 prev_match
, curr_match
;
1649 int num_var_ranges
= KVM_NR_VAR_MTRR
;
1651 if (!mtrr_state
->enabled
)
1654 /* Make end inclusive end, instead of exclusive */
1657 /* Look in fixed ranges. Just return the type as per start */
1658 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
1661 if (start
< 0x80000) {
1663 idx
+= (start
>> 16);
1664 return mtrr_state
->fixed_ranges
[idx
];
1665 } else if (start
< 0xC0000) {
1667 idx
+= ((start
- 0x80000) >> 14);
1668 return mtrr_state
->fixed_ranges
[idx
];
1669 } else if (start
< 0x1000000) {
1671 idx
+= ((start
- 0xC0000) >> 12);
1672 return mtrr_state
->fixed_ranges
[idx
];
1677 * Look in variable ranges
1678 * Look of multiple ranges matching this address and pick type
1679 * as per MTRR precedence
1681 if (!(mtrr_state
->enabled
& 2))
1682 return mtrr_state
->def_type
;
1685 for (i
= 0; i
< num_var_ranges
; ++i
) {
1686 unsigned short start_state
, end_state
;
1688 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
1691 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
1692 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
1693 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
1694 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
1696 start_state
= ((start
& mask
) == (base
& mask
));
1697 end_state
= ((end
& mask
) == (base
& mask
));
1698 if (start_state
!= end_state
)
1701 if ((start
& mask
) != (base
& mask
))
1704 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
1705 if (prev_match
== 0xFF) {
1706 prev_match
= curr_match
;
1710 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
1711 curr_match
== MTRR_TYPE_UNCACHABLE
)
1712 return MTRR_TYPE_UNCACHABLE
;
1714 if ((prev_match
== MTRR_TYPE_WRBACK
&&
1715 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
1716 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
1717 curr_match
== MTRR_TYPE_WRBACK
)) {
1718 prev_match
= MTRR_TYPE_WRTHROUGH
;
1719 curr_match
= MTRR_TYPE_WRTHROUGH
;
1722 if (prev_match
!= curr_match
)
1723 return MTRR_TYPE_UNCACHABLE
;
1726 if (prev_match
!= 0xFF)
1729 return mtrr_state
->def_type
;
1732 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1736 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
1737 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
1738 if (mtrr
== 0xfe || mtrr
== 0xff)
1739 mtrr
= MTRR_TYPE_WRBACK
;
1742 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
1744 static int kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1747 struct hlist_head
*bucket
;
1748 struct kvm_mmu_page
*s
;
1749 struct hlist_node
*node
, *n
;
1751 trace_kvm_mmu_unsync_page(sp
);
1752 index
= kvm_page_table_hashfn(sp
->gfn
);
1753 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1754 /* don't unsync if pagetable is shadowed with multiple roles */
1755 hlist_for_each_entry_safe(s
, node
, n
, bucket
, hash_link
) {
1756 if (s
->gfn
!= sp
->gfn
|| s
->role
.direct
)
1758 if (s
->role
.word
!= sp
->role
.word
)
1761 ++vcpu
->kvm
->stat
.mmu_unsync
;
1764 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1766 mmu_convert_notrap(sp
);
1770 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
1773 struct kvm_mmu_page
*shadow
;
1775 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1777 if (shadow
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1781 if (can_unsync
&& oos_shadow
)
1782 return kvm_unsync_page(vcpu
, shadow
);
1788 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1789 unsigned pte_access
, int user_fault
,
1790 int write_fault
, int dirty
, int level
,
1791 gfn_t gfn
, pfn_t pfn
, bool speculative
,
1792 bool can_unsync
, bool reset_host_protection
)
1798 * We don't set the accessed bit, since we sometimes want to see
1799 * whether the guest actually used the pte (in order to detect
1802 spte
= shadow_base_present_pte
| shadow_dirty_mask
;
1804 spte
|= shadow_accessed_mask
;
1806 pte_access
&= ~ACC_WRITE_MASK
;
1807 if (pte_access
& ACC_EXEC_MASK
)
1808 spte
|= shadow_x_mask
;
1810 spte
|= shadow_nx_mask
;
1811 if (pte_access
& ACC_USER_MASK
)
1812 spte
|= shadow_user_mask
;
1813 if (level
> PT_PAGE_TABLE_LEVEL
)
1814 spte
|= PT_PAGE_SIZE_MASK
;
1816 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
1817 kvm_is_mmio_pfn(pfn
));
1819 if (reset_host_protection
)
1820 spte
|= SPTE_HOST_WRITEABLE
;
1822 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
1824 if ((pte_access
& ACC_WRITE_MASK
)
1825 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1827 if (level
> PT_PAGE_TABLE_LEVEL
&&
1828 has_wrprotected_page(vcpu
->kvm
, gfn
, level
)) {
1830 spte
= shadow_trap_nonpresent_pte
;
1834 spte
|= PT_WRITABLE_MASK
;
1837 * Optimization: for pte sync, if spte was writable the hash
1838 * lookup is unnecessary (and expensive). Write protection
1839 * is responsibility of mmu_get_page / kvm_sync_page.
1840 * Same reasoning can be applied to dirty page accounting.
1842 if (!can_unsync
&& is_writable_pte(*sptep
))
1845 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
1846 pgprintk("%s: found shadow page for %lx, marking ro\n",
1849 pte_access
&= ~ACC_WRITE_MASK
;
1850 if (is_writable_pte(spte
))
1851 spte
&= ~PT_WRITABLE_MASK
;
1855 if (pte_access
& ACC_WRITE_MASK
)
1856 mark_page_dirty(vcpu
->kvm
, gfn
);
1859 __set_spte(sptep
, spte
);
1863 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1864 unsigned pt_access
, unsigned pte_access
,
1865 int user_fault
, int write_fault
, int dirty
,
1866 int *ptwrite
, int level
, gfn_t gfn
,
1867 pfn_t pfn
, bool speculative
,
1868 bool reset_host_protection
)
1870 int was_rmapped
= 0;
1871 int was_writable
= is_writable_pte(*sptep
);
1874 pgprintk("%s: spte %llx access %x write_fault %d"
1875 " user_fault %d gfn %lx\n",
1876 __func__
, *sptep
, pt_access
,
1877 write_fault
, user_fault
, gfn
);
1879 if (is_rmap_spte(*sptep
)) {
1881 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1882 * the parent of the now unreachable PTE.
1884 if (level
> PT_PAGE_TABLE_LEVEL
&&
1885 !is_large_pte(*sptep
)) {
1886 struct kvm_mmu_page
*child
;
1889 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1890 mmu_page_remove_parent_pte(child
, sptep
);
1891 } else if (pfn
!= spte_to_pfn(*sptep
)) {
1892 pgprintk("hfn old %lx new %lx\n",
1893 spte_to_pfn(*sptep
), pfn
);
1894 rmap_remove(vcpu
->kvm
, sptep
);
1899 if (set_spte(vcpu
, sptep
, pte_access
, user_fault
, write_fault
,
1900 dirty
, level
, gfn
, pfn
, speculative
, true,
1901 reset_host_protection
)) {
1904 kvm_x86_ops
->tlb_flush(vcpu
);
1907 pgprintk("%s: setting spte %llx\n", __func__
, *sptep
);
1908 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1909 is_large_pte(*sptep
)? "2MB" : "4kB",
1910 *sptep
& PT_PRESENT_MASK
?"RW":"R", gfn
,
1912 if (!was_rmapped
&& is_large_pte(*sptep
))
1913 ++vcpu
->kvm
->stat
.lpages
;
1915 page_header_update_slot(vcpu
->kvm
, sptep
, gfn
);
1917 rmap_count
= rmap_add(vcpu
, sptep
, gfn
);
1918 kvm_release_pfn_clean(pfn
);
1919 if (rmap_count
> RMAP_RECYCLE_THRESHOLD
)
1920 rmap_recycle(vcpu
, sptep
, gfn
);
1923 kvm_release_pfn_dirty(pfn
);
1925 kvm_release_pfn_clean(pfn
);
1928 vcpu
->arch
.last_pte_updated
= sptep
;
1929 vcpu
->arch
.last_pte_gfn
= gfn
;
1933 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1937 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1938 int level
, gfn_t gfn
, pfn_t pfn
)
1940 struct kvm_shadow_walk_iterator iterator
;
1941 struct kvm_mmu_page
*sp
;
1945 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
1946 if (iterator
.level
== level
) {
1947 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
, ACC_ALL
,
1948 0, write
, 1, &pt_write
,
1949 level
, gfn
, pfn
, false, true);
1950 ++vcpu
->stat
.pf_fixed
;
1954 if (*iterator
.sptep
== shadow_trap_nonpresent_pte
) {
1955 pseudo_gfn
= (iterator
.addr
& PT64_DIR_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1956 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
1958 1, ACC_ALL
, iterator
.sptep
);
1960 pgprintk("nonpaging_map: ENOMEM\n");
1961 kvm_release_pfn_clean(pfn
);
1965 __set_spte(iterator
.sptep
,
1967 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
1968 | shadow_user_mask
| shadow_x_mask
);
1974 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1979 unsigned long mmu_seq
;
1981 level
= mapping_level(vcpu
, gfn
);
1984 * This path builds a PAE pagetable - so we can map 2mb pages at
1985 * maximum. Therefore check if the level is larger than that.
1987 if (level
> PT_DIRECTORY_LEVEL
)
1988 level
= PT_DIRECTORY_LEVEL
;
1990 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
1992 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1994 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1997 if (is_error_pfn(pfn
)) {
1998 kvm_release_pfn_clean(pfn
);
2002 spin_lock(&vcpu
->kvm
->mmu_lock
);
2003 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2005 kvm_mmu_free_some_pages(vcpu
);
2006 r
= __direct_map(vcpu
, v
, write
, level
, gfn
, pfn
);
2007 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2013 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2014 kvm_release_pfn_clean(pfn
);
2019 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
2022 struct kvm_mmu_page
*sp
;
2024 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2026 spin_lock(&vcpu
->kvm
->mmu_lock
);
2027 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2028 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2030 sp
= page_header(root
);
2032 if (!sp
->root_count
&& sp
->role
.invalid
)
2033 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2034 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2035 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2038 for (i
= 0; i
< 4; ++i
) {
2039 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2042 root
&= PT64_BASE_ADDR_MASK
;
2043 sp
= page_header(root
);
2045 if (!sp
->root_count
&& sp
->role
.invalid
)
2046 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2048 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2050 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2051 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2054 static int mmu_check_root(struct kvm_vcpu
*vcpu
, gfn_t root_gfn
)
2058 if (!kvm_is_visible_gfn(vcpu
->kvm
, root_gfn
)) {
2059 set_bit(KVM_REQ_TRIPLE_FAULT
, &vcpu
->requests
);
2066 static int mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
2070 struct kvm_mmu_page
*sp
;
2074 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
2076 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2077 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2079 ASSERT(!VALID_PAGE(root
));
2082 if (mmu_check_root(vcpu
, root_gfn
))
2084 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
2085 PT64_ROOT_LEVEL
, direct
,
2087 root
= __pa(sp
->spt
);
2089 vcpu
->arch
.mmu
.root_hpa
= root
;
2092 direct
= !is_paging(vcpu
);
2095 for (i
= 0; i
< 4; ++i
) {
2096 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2098 ASSERT(!VALID_PAGE(root
));
2099 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
2100 pdptr
= kvm_pdptr_read(vcpu
, i
);
2101 if (!is_present_gpte(pdptr
)) {
2102 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
2105 root_gfn
= pdptr
>> PAGE_SHIFT
;
2106 } else if (vcpu
->arch
.mmu
.root_level
== 0)
2108 if (mmu_check_root(vcpu
, root_gfn
))
2110 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
2111 PT32_ROOT_LEVEL
, direct
,
2113 root
= __pa(sp
->spt
);
2115 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
2117 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2121 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2124 struct kvm_mmu_page
*sp
;
2126 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2128 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2129 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2130 sp
= page_header(root
);
2131 mmu_sync_children(vcpu
, sp
);
2134 for (i
= 0; i
< 4; ++i
) {
2135 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2137 if (root
&& VALID_PAGE(root
)) {
2138 root
&= PT64_BASE_ADDR_MASK
;
2139 sp
= page_header(root
);
2140 mmu_sync_children(vcpu
, sp
);
2145 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2147 spin_lock(&vcpu
->kvm
->mmu_lock
);
2148 mmu_sync_roots(vcpu
);
2149 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2152 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
,
2153 u32 access
, u32
*error
)
2160 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
2166 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
2167 r
= mmu_topup_memory_caches(vcpu
);
2172 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2174 gfn
= gva
>> PAGE_SHIFT
;
2176 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
2177 error_code
& PFERR_WRITE_MASK
, gfn
);
2180 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
2186 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2187 unsigned long mmu_seq
;
2190 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2192 r
= mmu_topup_memory_caches(vcpu
);
2196 level
= mapping_level(vcpu
, gfn
);
2198 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2200 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2202 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2203 if (is_error_pfn(pfn
)) {
2204 kvm_release_pfn_clean(pfn
);
2207 spin_lock(&vcpu
->kvm
->mmu_lock
);
2208 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2210 kvm_mmu_free_some_pages(vcpu
);
2211 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
2213 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2218 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2219 kvm_release_pfn_clean(pfn
);
2223 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
2225 mmu_free_roots(vcpu
);
2228 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
2230 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2232 context
->new_cr3
= nonpaging_new_cr3
;
2233 context
->page_fault
= nonpaging_page_fault
;
2234 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2235 context
->free
= nonpaging_free
;
2236 context
->prefetch_page
= nonpaging_prefetch_page
;
2237 context
->sync_page
= nonpaging_sync_page
;
2238 context
->invlpg
= nonpaging_invlpg
;
2239 context
->root_level
= 0;
2240 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2241 context
->root_hpa
= INVALID_PAGE
;
2245 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2247 ++vcpu
->stat
.tlb_flush
;
2248 kvm_x86_ops
->tlb_flush(vcpu
);
2251 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
2253 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
2254 mmu_free_roots(vcpu
);
2257 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
2261 kvm_inject_page_fault(vcpu
, addr
, err_code
);
2264 static void paging_free(struct kvm_vcpu
*vcpu
)
2266 nonpaging_free(vcpu
);
2269 static bool is_rsvd_bits_set(struct kvm_vcpu
*vcpu
, u64 gpte
, int level
)
2273 bit7
= (gpte
>> 7) & 1;
2274 return (gpte
& vcpu
->arch
.mmu
.rsvd_bits_mask
[bit7
][level
-1]) != 0;
2278 #include "paging_tmpl.h"
2282 #include "paging_tmpl.h"
2285 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
, int level
)
2287 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2288 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
2289 u64 exb_bit_rsvd
= 0;
2292 exb_bit_rsvd
= rsvd_bits(63, 63);
2294 case PT32_ROOT_LEVEL
:
2295 /* no rsvd bits for 2 level 4K page table entries */
2296 context
->rsvd_bits_mask
[0][1] = 0;
2297 context
->rsvd_bits_mask
[0][0] = 0;
2298 if (is_cpuid_PSE36())
2299 /* 36bits PSE 4MB page */
2300 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
2302 /* 32 bits PSE 4MB page */
2303 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
2304 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2306 case PT32E_ROOT_LEVEL
:
2307 context
->rsvd_bits_mask
[0][2] =
2308 rsvd_bits(maxphyaddr
, 63) |
2309 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
2310 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2311 rsvd_bits(maxphyaddr
, 62); /* PDE */
2312 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2313 rsvd_bits(maxphyaddr
, 62); /* PTE */
2314 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2315 rsvd_bits(maxphyaddr
, 62) |
2316 rsvd_bits(13, 20); /* large page */
2317 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2319 case PT64_ROOT_LEVEL
:
2320 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
2321 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2322 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
2323 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2324 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2325 rsvd_bits(maxphyaddr
, 51);
2326 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2327 rsvd_bits(maxphyaddr
, 51);
2328 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
2329 context
->rsvd_bits_mask
[1][2] = exb_bit_rsvd
|
2330 rsvd_bits(maxphyaddr
, 51) |
2332 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2333 rsvd_bits(maxphyaddr
, 51) |
2334 rsvd_bits(13, 20); /* large page */
2335 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2340 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
2342 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2344 ASSERT(is_pae(vcpu
));
2345 context
->new_cr3
= paging_new_cr3
;
2346 context
->page_fault
= paging64_page_fault
;
2347 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2348 context
->prefetch_page
= paging64_prefetch_page
;
2349 context
->sync_page
= paging64_sync_page
;
2350 context
->invlpg
= paging64_invlpg
;
2351 context
->free
= paging_free
;
2352 context
->root_level
= level
;
2353 context
->shadow_root_level
= level
;
2354 context
->root_hpa
= INVALID_PAGE
;
2358 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
2360 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2361 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
2364 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
2366 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2368 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2369 context
->new_cr3
= paging_new_cr3
;
2370 context
->page_fault
= paging32_page_fault
;
2371 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2372 context
->free
= paging_free
;
2373 context
->prefetch_page
= paging32_prefetch_page
;
2374 context
->sync_page
= paging32_sync_page
;
2375 context
->invlpg
= paging32_invlpg
;
2376 context
->root_level
= PT32_ROOT_LEVEL
;
2377 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2378 context
->root_hpa
= INVALID_PAGE
;
2382 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
2384 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2385 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
2388 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
2390 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2392 context
->new_cr3
= nonpaging_new_cr3
;
2393 context
->page_fault
= tdp_page_fault
;
2394 context
->free
= nonpaging_free
;
2395 context
->prefetch_page
= nonpaging_prefetch_page
;
2396 context
->sync_page
= nonpaging_sync_page
;
2397 context
->invlpg
= nonpaging_invlpg
;
2398 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
2399 context
->root_hpa
= INVALID_PAGE
;
2401 if (!is_paging(vcpu
)) {
2402 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2403 context
->root_level
= 0;
2404 } else if (is_long_mode(vcpu
)) {
2405 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2406 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2407 context
->root_level
= PT64_ROOT_LEVEL
;
2408 } else if (is_pae(vcpu
)) {
2409 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2410 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2411 context
->root_level
= PT32E_ROOT_LEVEL
;
2413 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2414 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2415 context
->root_level
= PT32_ROOT_LEVEL
;
2421 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
2426 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2428 if (!is_paging(vcpu
))
2429 r
= nonpaging_init_context(vcpu
);
2430 else if (is_long_mode(vcpu
))
2431 r
= paging64_init_context(vcpu
);
2432 else if (is_pae(vcpu
))
2433 r
= paging32E_init_context(vcpu
);
2435 r
= paging32_init_context(vcpu
);
2437 vcpu
->arch
.mmu
.base_role
.glevels
= vcpu
->arch
.mmu
.root_level
;
2442 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
2444 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2447 return init_kvm_tdp_mmu(vcpu
);
2449 return init_kvm_softmmu(vcpu
);
2452 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
2455 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
2456 vcpu
->arch
.mmu
.free(vcpu
);
2457 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2461 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
2463 destroy_kvm_mmu(vcpu
);
2464 return init_kvm_mmu(vcpu
);
2466 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
2468 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
2472 r
= mmu_topup_memory_caches(vcpu
);
2475 spin_lock(&vcpu
->kvm
->mmu_lock
);
2476 kvm_mmu_free_some_pages(vcpu
);
2477 r
= mmu_alloc_roots(vcpu
);
2478 mmu_sync_roots(vcpu
);
2479 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2482 /* set_cr3() should ensure TLB has been flushed */
2483 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
2487 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
2489 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
2491 mmu_free_roots(vcpu
);
2494 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
2495 struct kvm_mmu_page
*sp
,
2499 struct kvm_mmu_page
*child
;
2502 if (is_shadow_present_pte(pte
)) {
2503 if (is_last_spte(pte
, sp
->role
.level
))
2504 rmap_remove(vcpu
->kvm
, spte
);
2506 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2507 mmu_page_remove_parent_pte(child
, spte
);
2510 __set_spte(spte
, shadow_trap_nonpresent_pte
);
2511 if (is_large_pte(pte
))
2512 --vcpu
->kvm
->stat
.lpages
;
2515 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
2516 struct kvm_mmu_page
*sp
,
2520 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
2521 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
2525 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
2526 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
2527 paging32_update_pte(vcpu
, sp
, spte
, new);
2529 paging64_update_pte(vcpu
, sp
, spte
, new);
2532 static bool need_remote_flush(u64 old
, u64
new)
2534 if (!is_shadow_present_pte(old
))
2536 if (!is_shadow_present_pte(new))
2538 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
2540 old
^= PT64_NX_MASK
;
2541 new ^= PT64_NX_MASK
;
2542 return (old
& ~new & PT64_PERM_MASK
) != 0;
2545 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
2547 if (need_remote_flush(old
, new))
2548 kvm_flush_remote_tlbs(vcpu
->kvm
);
2550 kvm_mmu_flush_tlb(vcpu
);
2553 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
2555 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2557 return !!(spte
&& (*spte
& shadow_accessed_mask
));
2560 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2561 const u8
*new, int bytes
)
2568 if (bytes
!= 4 && bytes
!= 8)
2572 * Assume that the pte write on a page table of the same type
2573 * as the current vcpu paging mode. This is nearly always true
2574 * (might be false while changing modes). Note it is verified later
2578 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2579 if ((bytes
== 4) && (gpa
% 4 == 0)) {
2580 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
2583 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
2584 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
2585 memcpy((void *)&gpte
, new, 8);
2588 if ((bytes
== 4) && (gpa
% 4 == 0))
2589 memcpy((void *)&gpte
, new, 4);
2591 if (!is_present_gpte(gpte
))
2593 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
2595 vcpu
->arch
.update_pte
.mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2597 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2599 if (is_error_pfn(pfn
)) {
2600 kvm_release_pfn_clean(pfn
);
2603 vcpu
->arch
.update_pte
.gfn
= gfn
;
2604 vcpu
->arch
.update_pte
.pfn
= pfn
;
2607 static void kvm_mmu_access_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2609 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2612 && vcpu
->arch
.last_pte_gfn
== gfn
2613 && shadow_accessed_mask
2614 && !(*spte
& shadow_accessed_mask
)
2615 && is_shadow_present_pte(*spte
))
2616 set_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
2619 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2620 const u8
*new, int bytes
,
2621 bool guest_initiated
)
2623 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2624 struct kvm_mmu_page
*sp
;
2625 struct hlist_node
*node
, *n
;
2626 struct hlist_head
*bucket
;
2630 unsigned offset
= offset_in_page(gpa
);
2632 unsigned page_offset
;
2633 unsigned misaligned
;
2640 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
2641 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
2642 spin_lock(&vcpu
->kvm
->mmu_lock
);
2643 kvm_mmu_access_page(vcpu
, gfn
);
2644 kvm_mmu_free_some_pages(vcpu
);
2645 ++vcpu
->kvm
->stat
.mmu_pte_write
;
2646 kvm_mmu_audit(vcpu
, "pre pte write");
2647 if (guest_initiated
) {
2648 if (gfn
== vcpu
->arch
.last_pt_write_gfn
2649 && !last_updated_pte_accessed(vcpu
)) {
2650 ++vcpu
->arch
.last_pt_write_count
;
2651 if (vcpu
->arch
.last_pt_write_count
>= 3)
2654 vcpu
->arch
.last_pt_write_gfn
= gfn
;
2655 vcpu
->arch
.last_pt_write_count
= 1;
2656 vcpu
->arch
.last_pte_updated
= NULL
;
2659 index
= kvm_page_table_hashfn(gfn
);
2660 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
2661 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
2662 if (sp
->gfn
!= gfn
|| sp
->role
.direct
|| sp
->role
.invalid
)
2664 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
2665 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
2666 misaligned
|= bytes
< 4;
2667 if (misaligned
|| flooded
) {
2669 * Misaligned accesses are too much trouble to fix
2670 * up; also, they usually indicate a page is not used
2673 * If we're seeing too many writes to a page,
2674 * it may no longer be a page table, or we may be
2675 * forking, in which case it is better to unmap the
2678 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2679 gpa
, bytes
, sp
->role
.word
);
2680 if (kvm_mmu_zap_page(vcpu
->kvm
, sp
))
2682 ++vcpu
->kvm
->stat
.mmu_flooded
;
2685 page_offset
= offset
;
2686 level
= sp
->role
.level
;
2688 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2689 page_offset
<<= 1; /* 32->64 */
2691 * A 32-bit pde maps 4MB while the shadow pdes map
2692 * only 2MB. So we need to double the offset again
2693 * and zap two pdes instead of one.
2695 if (level
== PT32_ROOT_LEVEL
) {
2696 page_offset
&= ~7; /* kill rounding error */
2700 quadrant
= page_offset
>> PAGE_SHIFT
;
2701 page_offset
&= ~PAGE_MASK
;
2702 if (quadrant
!= sp
->role
.quadrant
)
2705 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
2706 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
2708 r
= kvm_read_guest_atomic(vcpu
->kvm
,
2709 gpa
& ~(u64
)(pte_size
- 1),
2711 new = (const void *)&gentry
;
2717 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
2719 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
2720 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
2724 kvm_mmu_audit(vcpu
, "post pte write");
2725 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2726 if (!is_error_pfn(vcpu
->arch
.update_pte
.pfn
)) {
2727 kvm_release_pfn_clean(vcpu
->arch
.update_pte
.pfn
);
2728 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2732 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
2740 gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, gva
, NULL
);
2742 spin_lock(&vcpu
->kvm
->mmu_lock
);
2743 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
2744 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2747 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
2749 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
2751 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
&&
2752 !list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
2753 struct kvm_mmu_page
*sp
;
2755 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
2756 struct kvm_mmu_page
, link
);
2757 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2758 ++vcpu
->kvm
->stat
.mmu_recycled
;
2762 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
2765 enum emulation_result er
;
2767 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
2776 r
= mmu_topup_memory_caches(vcpu
);
2780 er
= emulate_instruction(vcpu
, cr2
, error_code
, 0);
2785 case EMULATE_DO_MMIO
:
2786 ++vcpu
->stat
.mmio_exits
;
2789 vcpu
->run
->exit_reason
= KVM_EXIT_INTERNAL_ERROR
;
2790 vcpu
->run
->internal
.suberror
= KVM_INTERNAL_ERROR_EMULATION
;
2791 vcpu
->run
->internal
.ndata
= 0;
2799 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
2801 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
2803 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
2804 kvm_mmu_flush_tlb(vcpu
);
2805 ++vcpu
->stat
.invlpg
;
2807 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
2809 void kvm_enable_tdp(void)
2813 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
2815 void kvm_disable_tdp(void)
2817 tdp_enabled
= false;
2819 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
2821 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
2823 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
2826 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
2834 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2835 * Therefore we need to allocate shadow page tables in the first
2836 * 4GB of memory, which happens to fit the DMA32 zone.
2838 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
2842 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
2843 for (i
= 0; i
< 4; ++i
)
2844 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2849 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
2852 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2854 return alloc_mmu_pages(vcpu
);
2857 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
2860 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2862 return init_kvm_mmu(vcpu
);
2865 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
2869 destroy_kvm_mmu(vcpu
);
2870 free_mmu_pages(vcpu
);
2871 mmu_free_memory_caches(vcpu
);
2874 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
2876 struct kvm_mmu_page
*sp
;
2878 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
2882 if (!test_bit(slot
, sp
->slot_bitmap
))
2886 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2888 if (pt
[i
] & PT_WRITABLE_MASK
)
2889 pt
[i
] &= ~PT_WRITABLE_MASK
;
2891 kvm_flush_remote_tlbs(kvm
);
2894 void kvm_mmu_zap_all(struct kvm
*kvm
)
2896 struct kvm_mmu_page
*sp
, *node
;
2898 spin_lock(&kvm
->mmu_lock
);
2899 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
2900 if (kvm_mmu_zap_page(kvm
, sp
))
2901 node
= container_of(kvm
->arch
.active_mmu_pages
.next
,
2902 struct kvm_mmu_page
, link
);
2903 spin_unlock(&kvm
->mmu_lock
);
2905 kvm_flush_remote_tlbs(kvm
);
2908 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm
*kvm
)
2910 struct kvm_mmu_page
*page
;
2912 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2913 struct kvm_mmu_page
, link
);
2914 kvm_mmu_zap_page(kvm
, page
);
2917 static int mmu_shrink(int nr_to_scan
, gfp_t gfp_mask
)
2920 struct kvm
*kvm_freed
= NULL
;
2921 int cache_count
= 0;
2923 spin_lock(&kvm_lock
);
2925 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
2928 idx
= srcu_read_lock(&kvm
->srcu
);
2929 spin_lock(&kvm
->mmu_lock
);
2930 npages
= kvm
->arch
.n_alloc_mmu_pages
-
2931 kvm
->arch
.n_free_mmu_pages
;
2932 cache_count
+= npages
;
2933 if (!kvm_freed
&& nr_to_scan
> 0 && npages
> 0) {
2934 kvm_mmu_remove_one_alloc_mmu_page(kvm
);
2940 spin_unlock(&kvm
->mmu_lock
);
2941 srcu_read_unlock(&kvm
->srcu
, idx
);
2944 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
2946 spin_unlock(&kvm_lock
);
2951 static struct shrinker mmu_shrinker
= {
2952 .shrink
= mmu_shrink
,
2953 .seeks
= DEFAULT_SEEKS
* 10,
2956 static void mmu_destroy_caches(void)
2958 if (pte_chain_cache
)
2959 kmem_cache_destroy(pte_chain_cache
);
2960 if (rmap_desc_cache
)
2961 kmem_cache_destroy(rmap_desc_cache
);
2962 if (mmu_page_header_cache
)
2963 kmem_cache_destroy(mmu_page_header_cache
);
2966 void kvm_mmu_module_exit(void)
2968 mmu_destroy_caches();
2969 unregister_shrinker(&mmu_shrinker
);
2972 int kvm_mmu_module_init(void)
2974 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
2975 sizeof(struct kvm_pte_chain
),
2977 if (!pte_chain_cache
)
2979 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
2980 sizeof(struct kvm_rmap_desc
),
2982 if (!rmap_desc_cache
)
2985 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
2986 sizeof(struct kvm_mmu_page
),
2988 if (!mmu_page_header_cache
)
2991 register_shrinker(&mmu_shrinker
);
2996 mmu_destroy_caches();
3001 * Caculate mmu pages needed for kvm.
3003 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
3006 unsigned int nr_mmu_pages
;
3007 unsigned int nr_pages
= 0;
3008 struct kvm_memslots
*slots
;
3010 slots
= rcu_dereference(kvm
->memslots
);
3011 for (i
= 0; i
< slots
->nmemslots
; i
++)
3012 nr_pages
+= slots
->memslots
[i
].npages
;
3014 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
3015 nr_mmu_pages
= max(nr_mmu_pages
,
3016 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
3018 return nr_mmu_pages
;
3021 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
3024 if (len
> buffer
->len
)
3029 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
3034 ret
= pv_mmu_peek_buffer(buffer
, len
);
3039 buffer
->processed
+= len
;
3043 static int kvm_pv_mmu_write(struct kvm_vcpu
*vcpu
,
3044 gpa_t addr
, gpa_t value
)
3049 if (!is_long_mode(vcpu
) && !is_pae(vcpu
))
3052 r
= mmu_topup_memory_caches(vcpu
);
3056 if (!emulator_write_phys(vcpu
, addr
, &value
, bytes
))
3062 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
3064 kvm_set_cr3(vcpu
, vcpu
->arch
.cr3
);
3068 static int kvm_pv_mmu_release_pt(struct kvm_vcpu
*vcpu
, gpa_t addr
)
3070 spin_lock(&vcpu
->kvm
->mmu_lock
);
3071 mmu_unshadow(vcpu
->kvm
, addr
>> PAGE_SHIFT
);
3072 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3076 static int kvm_pv_mmu_op_one(struct kvm_vcpu
*vcpu
,
3077 struct kvm_pv_mmu_op_buffer
*buffer
)
3079 struct kvm_mmu_op_header
*header
;
3081 header
= pv_mmu_peek_buffer(buffer
, sizeof *header
);
3084 switch (header
->op
) {
3085 case KVM_MMU_OP_WRITE_PTE
: {
3086 struct kvm_mmu_op_write_pte
*wpte
;
3088 wpte
= pv_mmu_read_buffer(buffer
, sizeof *wpte
);
3091 return kvm_pv_mmu_write(vcpu
, wpte
->pte_phys
,
3094 case KVM_MMU_OP_FLUSH_TLB
: {
3095 struct kvm_mmu_op_flush_tlb
*ftlb
;
3097 ftlb
= pv_mmu_read_buffer(buffer
, sizeof *ftlb
);
3100 return kvm_pv_mmu_flush_tlb(vcpu
);
3102 case KVM_MMU_OP_RELEASE_PT
: {
3103 struct kvm_mmu_op_release_pt
*rpt
;
3105 rpt
= pv_mmu_read_buffer(buffer
, sizeof *rpt
);
3108 return kvm_pv_mmu_release_pt(vcpu
, rpt
->pt_phys
);
3114 int kvm_pv_mmu_op(struct kvm_vcpu
*vcpu
, unsigned long bytes
,
3115 gpa_t addr
, unsigned long *ret
)
3118 struct kvm_pv_mmu_op_buffer
*buffer
= &vcpu
->arch
.mmu_op_buffer
;
3120 buffer
->ptr
= buffer
->buf
;
3121 buffer
->len
= min_t(unsigned long, bytes
, sizeof buffer
->buf
);
3122 buffer
->processed
= 0;
3124 r
= kvm_read_guest(vcpu
->kvm
, addr
, buffer
->buf
, buffer
->len
);
3128 while (buffer
->len
) {
3129 r
= kvm_pv_mmu_op_one(vcpu
, buffer
);
3138 *ret
= buffer
->processed
;
3142 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu
*vcpu
, u64 addr
, u64 sptes
[4])
3144 struct kvm_shadow_walk_iterator iterator
;
3147 spin_lock(&vcpu
->kvm
->mmu_lock
);
3148 for_each_shadow_entry(vcpu
, addr
, iterator
) {
3149 sptes
[iterator
.level
-1] = *iterator
.sptep
;
3151 if (!is_shadow_present_pte(*iterator
.sptep
))
3154 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3158 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy
);
3162 static const char *audit_msg
;
3164 static gva_t
canonicalize(gva_t gva
)
3166 #ifdef CONFIG_X86_64
3167 gva
= (long long)(gva
<< 16) >> 16;
3173 typedef void (*inspect_spte_fn
) (struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
3176 static void __mmu_spte_walk(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
3181 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3182 u64 ent
= sp
->spt
[i
];
3184 if (is_shadow_present_pte(ent
)) {
3185 if (!is_last_spte(ent
, sp
->role
.level
)) {
3186 struct kvm_mmu_page
*child
;
3187 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
3188 __mmu_spte_walk(kvm
, child
, fn
);
3190 fn(kvm
, sp
, &sp
->spt
[i
]);
3195 static void mmu_spte_walk(struct kvm_vcpu
*vcpu
, inspect_spte_fn fn
)
3198 struct kvm_mmu_page
*sp
;
3200 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3202 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
3203 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
3204 sp
= page_header(root
);
3205 __mmu_spte_walk(vcpu
->kvm
, sp
, fn
);
3208 for (i
= 0; i
< 4; ++i
) {
3209 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
3211 if (root
&& VALID_PAGE(root
)) {
3212 root
&= PT64_BASE_ADDR_MASK
;
3213 sp
= page_header(root
);
3214 __mmu_spte_walk(vcpu
->kvm
, sp
, fn
);
3220 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
3221 gva_t va
, int level
)
3223 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
3225 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
3227 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
3230 if (ent
== shadow_trap_nonpresent_pte
)
3233 va
= canonicalize(va
);
3234 if (is_shadow_present_pte(ent
) && !is_last_spte(ent
, level
))
3235 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
3237 gpa_t gpa
= kvm_mmu_gva_to_gpa_read(vcpu
, va
, NULL
);
3238 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3239 pfn_t pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
3240 hpa_t hpa
= (hpa_t
)pfn
<< PAGE_SHIFT
;
3242 if (is_error_pfn(pfn
)) {
3243 kvm_release_pfn_clean(pfn
);
3247 if (is_shadow_present_pte(ent
)
3248 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
3249 printk(KERN_ERR
"xx audit error: (%s) levels %d"
3250 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3251 audit_msg
, vcpu
->arch
.mmu
.root_level
,
3253 is_shadow_present_pte(ent
));
3254 else if (ent
== shadow_notrap_nonpresent_pte
3255 && !is_error_hpa(hpa
))
3256 printk(KERN_ERR
"audit: (%s) notrap shadow,"
3257 " valid guest gva %lx\n", audit_msg
, va
);
3258 kvm_release_pfn_clean(pfn
);
3264 static void audit_mappings(struct kvm_vcpu
*vcpu
)
3268 if (vcpu
->arch
.mmu
.root_level
== 4)
3269 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
3271 for (i
= 0; i
< 4; ++i
)
3272 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
3273 audit_mappings_page(vcpu
,
3274 vcpu
->arch
.mmu
.pae_root
[i
],
3279 static int count_rmaps(struct kvm_vcpu
*vcpu
)
3284 idx
= srcu_read_lock(&kvm
->srcu
);
3285 slots
= rcu_dereference(kvm
->memslots
);
3286 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
3287 struct kvm_memory_slot
*m
= &slots
->memslots
[i
];
3288 struct kvm_rmap_desc
*d
;
3290 for (j
= 0; j
< m
->npages
; ++j
) {
3291 unsigned long *rmapp
= &m
->rmap
[j
];
3295 if (!(*rmapp
& 1)) {
3299 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
3301 for (k
= 0; k
< RMAP_EXT
; ++k
)
3310 srcu_read_unlock(&kvm
->srcu
, idx
);
3314 void inspect_spte_has_rmap(struct kvm
*kvm
, struct kvm_mmu_page
*sp
, u64
*sptep
)
3316 unsigned long *rmapp
;
3317 struct kvm_mmu_page
*rev_sp
;
3320 if (*sptep
& PT_WRITABLE_MASK
) {
3321 rev_sp
= page_header(__pa(sptep
));
3322 gfn
= rev_sp
->gfns
[sptep
- rev_sp
->spt
];
3324 if (!gfn_to_memslot(kvm
, gfn
)) {
3325 if (!printk_ratelimit())
3327 printk(KERN_ERR
"%s: no memslot for gfn %ld\n",
3329 printk(KERN_ERR
"%s: index %ld of sp (gfn=%lx)\n",
3330 audit_msg
, sptep
- rev_sp
->spt
,
3336 rmapp
= gfn_to_rmap(kvm
, rev_sp
->gfns
[sptep
- rev_sp
->spt
],
3337 is_large_pte(*sptep
));
3339 if (!printk_ratelimit())
3341 printk(KERN_ERR
"%s: no rmap for writable spte %llx\n",
3349 void audit_writable_sptes_have_rmaps(struct kvm_vcpu
*vcpu
)
3351 mmu_spte_walk(vcpu
, inspect_spte_has_rmap
);
3354 static void check_writable_mappings_rmap(struct kvm_vcpu
*vcpu
)
3356 struct kvm_mmu_page
*sp
;
3359 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3362 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
3365 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3368 if (!(ent
& PT_PRESENT_MASK
))
3370 if (!(ent
& PT_WRITABLE_MASK
))
3372 inspect_spte_has_rmap(vcpu
->kvm
, sp
, &pt
[i
]);
3378 static void audit_rmap(struct kvm_vcpu
*vcpu
)
3380 check_writable_mappings_rmap(vcpu
);
3384 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
3386 struct kvm_mmu_page
*sp
;
3387 struct kvm_memory_slot
*slot
;
3388 unsigned long *rmapp
;
3392 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3393 if (sp
->role
.direct
)
3398 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
3399 slot
= gfn_to_memslot_unaliased(vcpu
->kvm
, sp
->gfn
);
3400 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
3402 spte
= rmap_next(vcpu
->kvm
, rmapp
, NULL
);
3404 if (*spte
& PT_WRITABLE_MASK
)
3405 printk(KERN_ERR
"%s: (%s) shadow page has "
3406 "writable mappings: gfn %lx role %x\n",
3407 __func__
, audit_msg
, sp
->gfn
,
3409 spte
= rmap_next(vcpu
->kvm
, rmapp
, spte
);
3414 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
3421 audit_write_protection(vcpu
);
3422 if (strcmp("pre pte write", audit_msg
) != 0)
3423 audit_mappings(vcpu
);
3424 audit_writable_sptes_have_rmaps(vcpu
);