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.
21 #include "kvm_cache_regs.h"
23 #include <linux/kvm_host.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
27 #include <linux/highmem.h>
28 #include <linux/module.h>
29 #include <linux/swap.h>
30 #include <linux/hugetlb.h>
31 #include <linux/compiler.h>
32 #include <linux/srcu.h>
35 #include <asm/cmpxchg.h>
40 * When setting this variable to true it enables Two-Dimensional-Paging
41 * where the hardware walks 2 page tables:
42 * 1. the guest-virtual to guest-physical
43 * 2. while doing 1. it walks guest-physical to host-physical
44 * If the hardware supports that we don't need to do shadow paging.
46 bool tdp_enabled
= false;
53 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
55 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
60 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
61 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
65 #define pgprintk(x...) do { } while (0)
66 #define rmap_printk(x...) do { } while (0)
70 #if defined(MMU_DEBUG) || defined(AUDIT)
72 module_param(dbg
, bool, 0644);
75 static int oos_shadow
= 1;
76 module_param(oos_shadow
, bool, 0644);
79 #define ASSERT(x) do { } while (0)
83 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
84 __FILE__, __LINE__, #x); \
88 #define PT_FIRST_AVAIL_BITS_SHIFT 9
89 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
91 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
93 #define PT64_LEVEL_BITS 9
95 #define PT64_LEVEL_SHIFT(level) \
96 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
98 #define PT64_LEVEL_MASK(level) \
99 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
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_LEVEL_MASK(level) \
111 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
112 #define PT32_LVL_OFFSET_MASK(level) \
113 (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
114 * PT32_LEVEL_BITS))) - 1))
116 #define PT32_INDEX(address, level)\
117 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
120 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
121 #define PT64_DIR_BASE_ADDR_MASK \
122 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
123 #define PT64_LVL_ADDR_MASK(level) \
124 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
125 * PT64_LEVEL_BITS))) - 1))
126 #define PT64_LVL_OFFSET_MASK(level) \
127 (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
128 * PT64_LEVEL_BITS))) - 1))
130 #define PT32_BASE_ADDR_MASK PAGE_MASK
131 #define PT32_DIR_BASE_ADDR_MASK \
132 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
133 #define PT32_LVL_ADDR_MASK(level) \
134 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
135 * PT32_LEVEL_BITS))) - 1))
137 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
140 #define PFERR_PRESENT_MASK (1U << 0)
141 #define PFERR_WRITE_MASK (1U << 1)
142 #define PFERR_USER_MASK (1U << 2)
143 #define PFERR_RSVD_MASK (1U << 3)
144 #define PFERR_FETCH_MASK (1U << 4)
146 #define PT_PDPE_LEVEL 3
147 #define PT_DIRECTORY_LEVEL 2
148 #define PT_PAGE_TABLE_LEVEL 1
152 #define ACC_EXEC_MASK 1
153 #define ACC_WRITE_MASK PT_WRITABLE_MASK
154 #define ACC_USER_MASK PT_USER_MASK
155 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
157 #define CREATE_TRACE_POINTS
158 #include "mmutrace.h"
160 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
162 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
164 struct kvm_rmap_desc
{
165 u64
*sptes
[RMAP_EXT
];
166 struct kvm_rmap_desc
*more
;
169 struct kvm_shadow_walk_iterator
{
177 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
178 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
179 shadow_walk_okay(&(_walker)); \
180 shadow_walk_next(&(_walker)))
183 struct kvm_unsync_walk
{
184 int (*entry
) (struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
);
187 typedef int (*mmu_parent_walk_fn
) (struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
);
189 static struct kmem_cache
*pte_chain_cache
;
190 static struct kmem_cache
*rmap_desc_cache
;
191 static struct kmem_cache
*mmu_page_header_cache
;
193 static u64 __read_mostly shadow_trap_nonpresent_pte
;
194 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
195 static u64 __read_mostly shadow_base_present_pte
;
196 static u64 __read_mostly shadow_nx_mask
;
197 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
198 static u64 __read_mostly shadow_user_mask
;
199 static u64 __read_mostly shadow_accessed_mask
;
200 static u64 __read_mostly shadow_dirty_mask
;
202 static inline u64
rsvd_bits(int s
, int e
)
204 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
207 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
209 shadow_trap_nonpresent_pte
= trap_pte
;
210 shadow_notrap_nonpresent_pte
= notrap_pte
;
212 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
214 void kvm_mmu_set_base_ptes(u64 base_pte
)
216 shadow_base_present_pte
= base_pte
;
218 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes
);
220 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
221 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
223 shadow_user_mask
= user_mask
;
224 shadow_accessed_mask
= accessed_mask
;
225 shadow_dirty_mask
= dirty_mask
;
226 shadow_nx_mask
= nx_mask
;
227 shadow_x_mask
= x_mask
;
229 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
231 static int is_write_protection(struct kvm_vcpu
*vcpu
)
233 return vcpu
->arch
.cr0
& X86_CR0_WP
;
236 static int is_cpuid_PSE36(void)
241 static int is_nx(struct kvm_vcpu
*vcpu
)
243 return vcpu
->arch
.shadow_efer
& EFER_NX
;
246 static int is_shadow_present_pte(u64 pte
)
248 return pte
!= shadow_trap_nonpresent_pte
249 && pte
!= shadow_notrap_nonpresent_pte
;
252 static int is_large_pte(u64 pte
)
254 return pte
& PT_PAGE_SIZE_MASK
;
257 static int is_writeble_pte(unsigned long pte
)
259 return pte
& PT_WRITABLE_MASK
;
262 static int is_dirty_gpte(unsigned long pte
)
264 return pte
& PT_DIRTY_MASK
;
267 static int is_rmap_spte(u64 pte
)
269 return is_shadow_present_pte(pte
);
272 static int is_last_spte(u64 pte
, int level
)
274 if (level
== PT_PAGE_TABLE_LEVEL
)
276 if (is_large_pte(pte
))
281 static pfn_t
spte_to_pfn(u64 pte
)
283 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
286 static gfn_t
pse36_gfn_delta(u32 gpte
)
288 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
290 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
293 static void __set_spte(u64
*sptep
, u64 spte
)
296 set_64bit((unsigned long *)sptep
, spte
);
298 set_64bit((unsigned long long *)sptep
, spte
);
302 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
303 struct kmem_cache
*base_cache
, int min
)
307 if (cache
->nobjs
>= min
)
309 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
310 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
313 cache
->objects
[cache
->nobjs
++] = obj
;
318 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
321 kfree(mc
->objects
[--mc
->nobjs
]);
324 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
329 if (cache
->nobjs
>= min
)
331 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
332 page
= alloc_page(GFP_KERNEL
);
335 set_page_private(page
, 0);
336 cache
->objects
[cache
->nobjs
++] = page_address(page
);
341 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
344 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
347 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
351 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
355 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
359 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
362 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
363 mmu_page_header_cache
, 4);
368 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
370 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
371 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
372 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
373 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
376 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
382 p
= mc
->objects
[--mc
->nobjs
];
386 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
388 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
389 sizeof(struct kvm_pte_chain
));
392 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
397 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
399 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
400 sizeof(struct kvm_rmap_desc
));
403 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
409 * Return the pointer to the largepage write count for a given
410 * gfn, handling slots that are not large page aligned.
412 static int *slot_largepage_idx(gfn_t gfn
,
413 struct kvm_memory_slot
*slot
,
418 idx
= (gfn
/ KVM_PAGES_PER_HPAGE(level
)) -
419 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE(level
));
420 return &slot
->lpage_info
[level
- 2][idx
].write_count
;
423 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
425 struct kvm_memory_slot
*slot
;
429 gfn
= unalias_gfn(kvm
, gfn
);
431 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
432 for (i
= PT_DIRECTORY_LEVEL
;
433 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
434 write_count
= slot_largepage_idx(gfn
, slot
, i
);
439 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
441 struct kvm_memory_slot
*slot
;
445 gfn
= unalias_gfn(kvm
, gfn
);
446 for (i
= PT_DIRECTORY_LEVEL
;
447 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
448 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
449 write_count
= slot_largepage_idx(gfn
, slot
, i
);
451 WARN_ON(*write_count
< 0);
455 static int has_wrprotected_page(struct kvm
*kvm
,
459 struct kvm_memory_slot
*slot
;
462 gfn
= unalias_gfn(kvm
, gfn
);
463 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
465 largepage_idx
= slot_largepage_idx(gfn
, slot
, level
);
466 return *largepage_idx
;
472 static int host_mapping_level(struct kvm
*kvm
, gfn_t gfn
)
474 unsigned long page_size
= PAGE_SIZE
;
475 struct vm_area_struct
*vma
;
479 addr
= gfn_to_hva(kvm
, gfn
);
480 if (kvm_is_error_hva(addr
))
481 return PT_PAGE_TABLE_LEVEL
;
483 down_read(¤t
->mm
->mmap_sem
);
484 vma
= find_vma(current
->mm
, addr
);
488 page_size
= vma_kernel_pagesize(vma
);
491 up_read(¤t
->mm
->mmap_sem
);
493 for (i
= PT_PAGE_TABLE_LEVEL
;
494 i
< (PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
); ++i
) {
495 if (page_size
>= KVM_HPAGE_SIZE(i
))
504 static int mapping_level(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
506 struct kvm_memory_slot
*slot
;
508 int level
= PT_PAGE_TABLE_LEVEL
;
510 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
511 if (slot
&& slot
->dirty_bitmap
)
512 return PT_PAGE_TABLE_LEVEL
;
514 host_level
= host_mapping_level(vcpu
->kvm
, large_gfn
);
516 if (host_level
== PT_PAGE_TABLE_LEVEL
)
519 for (level
= PT_DIRECTORY_LEVEL
; level
<= host_level
; ++level
)
520 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
, level
))
527 * Take gfn and return the reverse mapping to it.
528 * Note: gfn must be unaliased before this function get called
531 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int level
)
533 struct kvm_memory_slot
*slot
;
536 slot
= gfn_to_memslot(kvm
, gfn
);
537 if (likely(level
== PT_PAGE_TABLE_LEVEL
))
538 return &slot
->rmap
[gfn
- slot
->base_gfn
];
540 idx
= (gfn
/ KVM_PAGES_PER_HPAGE(level
)) -
541 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE(level
));
543 return &slot
->lpage_info
[level
- 2][idx
].rmap_pde
;
547 * Reverse mapping data structures:
549 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
550 * that points to page_address(page).
552 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
553 * containing more mappings.
555 * Returns the number of rmap entries before the spte was added or zero if
556 * the spte was not added.
559 static int rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
561 struct kvm_mmu_page
*sp
;
562 struct kvm_rmap_desc
*desc
;
563 unsigned long *rmapp
;
566 if (!is_rmap_spte(*spte
))
568 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
569 sp
= page_header(__pa(spte
));
570 sp
->gfns
[spte
- sp
->spt
] = gfn
;
571 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
573 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
574 *rmapp
= (unsigned long)spte
;
575 } else if (!(*rmapp
& 1)) {
576 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
577 desc
= mmu_alloc_rmap_desc(vcpu
);
578 desc
->sptes
[0] = (u64
*)*rmapp
;
579 desc
->sptes
[1] = spte
;
580 *rmapp
= (unsigned long)desc
| 1;
582 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
583 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
584 while (desc
->sptes
[RMAP_EXT
-1] && desc
->more
) {
588 if (desc
->sptes
[RMAP_EXT
-1]) {
589 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
592 for (i
= 0; desc
->sptes
[i
]; ++i
)
594 desc
->sptes
[i
] = spte
;
599 static void rmap_desc_remove_entry(unsigned long *rmapp
,
600 struct kvm_rmap_desc
*desc
,
602 struct kvm_rmap_desc
*prev_desc
)
606 for (j
= RMAP_EXT
- 1; !desc
->sptes
[j
] && j
> i
; --j
)
608 desc
->sptes
[i
] = desc
->sptes
[j
];
609 desc
->sptes
[j
] = NULL
;
612 if (!prev_desc
&& !desc
->more
)
613 *rmapp
= (unsigned long)desc
->sptes
[0];
616 prev_desc
->more
= desc
->more
;
618 *rmapp
= (unsigned long)desc
->more
| 1;
619 mmu_free_rmap_desc(desc
);
622 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
624 struct kvm_rmap_desc
*desc
;
625 struct kvm_rmap_desc
*prev_desc
;
626 struct kvm_mmu_page
*sp
;
628 unsigned long *rmapp
;
631 if (!is_rmap_spte(*spte
))
633 sp
= page_header(__pa(spte
));
634 pfn
= spte_to_pfn(*spte
);
635 if (*spte
& shadow_accessed_mask
)
636 kvm_set_pfn_accessed(pfn
);
637 if (is_writeble_pte(*spte
))
638 kvm_set_pfn_dirty(pfn
);
639 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], sp
->role
.level
);
641 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
643 } else if (!(*rmapp
& 1)) {
644 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
645 if ((u64
*)*rmapp
!= spte
) {
646 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
652 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
653 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
656 for (i
= 0; i
< RMAP_EXT
&& desc
->sptes
[i
]; ++i
)
657 if (desc
->sptes
[i
] == spte
) {
658 rmap_desc_remove_entry(rmapp
,
666 pr_err("rmap_remove: %p %llx many->many\n", spte
, *spte
);
671 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
673 struct kvm_rmap_desc
*desc
;
674 struct kvm_rmap_desc
*prev_desc
;
680 else if (!(*rmapp
& 1)) {
682 return (u64
*)*rmapp
;
685 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
689 for (i
= 0; i
< RMAP_EXT
&& desc
->sptes
[i
]; ++i
) {
690 if (prev_spte
== spte
)
691 return desc
->sptes
[i
];
692 prev_spte
= desc
->sptes
[i
];
699 static int rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
701 unsigned long *rmapp
;
703 int i
, write_protected
= 0;
705 gfn
= unalias_gfn(kvm
, gfn
);
706 rmapp
= gfn_to_rmap(kvm
, gfn
, PT_PAGE_TABLE_LEVEL
);
708 spte
= rmap_next(kvm
, rmapp
, NULL
);
711 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
712 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
713 if (is_writeble_pte(*spte
)) {
714 __set_spte(spte
, *spte
& ~PT_WRITABLE_MASK
);
717 spte
= rmap_next(kvm
, rmapp
, spte
);
719 if (write_protected
) {
722 spte
= rmap_next(kvm
, rmapp
, NULL
);
723 pfn
= spte_to_pfn(*spte
);
724 kvm_set_pfn_dirty(pfn
);
727 /* check for huge page mappings */
728 for (i
= PT_DIRECTORY_LEVEL
;
729 i
< PT_PAGE_TABLE_LEVEL
+ KVM_NR_PAGE_SIZES
; ++i
) {
730 rmapp
= gfn_to_rmap(kvm
, gfn
, i
);
731 spte
= rmap_next(kvm
, rmapp
, NULL
);
734 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
735 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
736 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
737 if (is_writeble_pte(*spte
)) {
738 rmap_remove(kvm
, spte
);
740 __set_spte(spte
, shadow_trap_nonpresent_pte
);
744 spte
= rmap_next(kvm
, rmapp
, spte
);
748 return write_protected
;
751 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
755 int need_tlb_flush
= 0;
757 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
758 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
759 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
760 rmap_remove(kvm
, spte
);
761 __set_spte(spte
, shadow_trap_nonpresent_pte
);
764 return need_tlb_flush
;
767 static int kvm_set_pte_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
772 pte_t
*ptep
= (pte_t
*)data
;
775 WARN_ON(pte_huge(*ptep
));
776 new_pfn
= pte_pfn(*ptep
);
777 spte
= rmap_next(kvm
, rmapp
, NULL
);
779 BUG_ON(!is_shadow_present_pte(*spte
));
780 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte
, *spte
);
782 if (pte_write(*ptep
)) {
783 rmap_remove(kvm
, spte
);
784 __set_spte(spte
, shadow_trap_nonpresent_pte
);
785 spte
= rmap_next(kvm
, rmapp
, NULL
);
787 new_spte
= *spte
&~ (PT64_BASE_ADDR_MASK
);
788 new_spte
|= (u64
)new_pfn
<< PAGE_SHIFT
;
790 new_spte
&= ~PT_WRITABLE_MASK
;
791 new_spte
&= ~SPTE_HOST_WRITEABLE
;
792 if (is_writeble_pte(*spte
))
793 kvm_set_pfn_dirty(spte_to_pfn(*spte
));
794 __set_spte(spte
, new_spte
);
795 spte
= rmap_next(kvm
, rmapp
, spte
);
799 kvm_flush_remote_tlbs(kvm
);
804 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
806 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
,
811 struct kvm_memslots
*slots
;
813 slots
= rcu_dereference(kvm
->memslots
);
815 for (i
= 0; i
< slots
->nmemslots
; i
++) {
816 struct kvm_memory_slot
*memslot
= &slots
->memslots
[i
];
817 unsigned long start
= memslot
->userspace_addr
;
820 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
821 if (hva
>= start
&& hva
< end
) {
822 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
824 retval
|= handler(kvm
, &memslot
->rmap
[gfn_offset
],
827 for (j
= 0; j
< KVM_NR_PAGE_SIZES
- 1; ++j
) {
828 int idx
= gfn_offset
;
829 idx
/= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL
+ j
);
830 retval
|= handler(kvm
,
831 &memslot
->lpage_info
[j
][idx
].rmap_pde
,
840 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
842 return kvm_handle_hva(kvm
, hva
, 0, kvm_unmap_rmapp
);
845 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
847 kvm_handle_hva(kvm
, hva
, (unsigned long)&pte
, kvm_set_pte_rmapp
);
850 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
,
856 /* always return old for EPT */
857 if (!shadow_accessed_mask
)
860 spte
= rmap_next(kvm
, rmapp
, NULL
);
864 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
865 _young
= _spte
& PT_ACCESSED_MASK
;
868 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
870 spte
= rmap_next(kvm
, rmapp
, spte
);
875 #define RMAP_RECYCLE_THRESHOLD 1000
877 static void rmap_recycle(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
)
879 unsigned long *rmapp
;
880 struct kvm_mmu_page
*sp
;
882 sp
= page_header(__pa(spte
));
884 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
885 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, sp
->role
.level
);
887 kvm_unmap_rmapp(vcpu
->kvm
, rmapp
, 0);
888 kvm_flush_remote_tlbs(vcpu
->kvm
);
891 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
893 return kvm_handle_hva(kvm
, hva
, 0, kvm_age_rmapp
);
897 static int is_empty_shadow_page(u64
*spt
)
902 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
903 if (is_shadow_present_pte(*pos
)) {
904 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
912 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
914 ASSERT(is_empty_shadow_page(sp
->spt
));
916 __free_page(virt_to_page(sp
->spt
));
917 __free_page(virt_to_page(sp
->gfns
));
919 ++kvm
->arch
.n_free_mmu_pages
;
922 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
924 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
927 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
930 struct kvm_mmu_page
*sp
;
932 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
933 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
934 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
935 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
936 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
937 INIT_LIST_HEAD(&sp
->oos_link
);
938 bitmap_zero(sp
->slot_bitmap
, KVM_MEMORY_SLOTS
+ KVM_PRIVATE_MEM_SLOTS
);
940 sp
->parent_pte
= parent_pte
;
941 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
945 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
946 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
948 struct kvm_pte_chain
*pte_chain
;
949 struct hlist_node
*node
;
954 if (!sp
->multimapped
) {
955 u64
*old
= sp
->parent_pte
;
958 sp
->parent_pte
= parent_pte
;
962 pte_chain
= mmu_alloc_pte_chain(vcpu
);
963 INIT_HLIST_HEAD(&sp
->parent_ptes
);
964 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
965 pte_chain
->parent_ptes
[0] = old
;
967 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
968 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
970 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
971 if (!pte_chain
->parent_ptes
[i
]) {
972 pte_chain
->parent_ptes
[i
] = parent_pte
;
976 pte_chain
= mmu_alloc_pte_chain(vcpu
);
978 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
979 pte_chain
->parent_ptes
[0] = parent_pte
;
982 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
985 struct kvm_pte_chain
*pte_chain
;
986 struct hlist_node
*node
;
989 if (!sp
->multimapped
) {
990 BUG_ON(sp
->parent_pte
!= parent_pte
);
991 sp
->parent_pte
= NULL
;
994 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
995 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
996 if (!pte_chain
->parent_ptes
[i
])
998 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
1000 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
1001 && pte_chain
->parent_ptes
[i
+ 1]) {
1002 pte_chain
->parent_ptes
[i
]
1003 = pte_chain
->parent_ptes
[i
+ 1];
1006 pte_chain
->parent_ptes
[i
] = NULL
;
1008 hlist_del(&pte_chain
->link
);
1009 mmu_free_pte_chain(pte_chain
);
1010 if (hlist_empty(&sp
->parent_ptes
)) {
1011 sp
->multimapped
= 0;
1012 sp
->parent_pte
= NULL
;
1021 static void mmu_parent_walk(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
1022 mmu_parent_walk_fn fn
)
1024 struct kvm_pte_chain
*pte_chain
;
1025 struct hlist_node
*node
;
1026 struct kvm_mmu_page
*parent_sp
;
1029 if (!sp
->multimapped
&& sp
->parent_pte
) {
1030 parent_sp
= page_header(__pa(sp
->parent_pte
));
1031 fn(vcpu
, parent_sp
);
1032 mmu_parent_walk(vcpu
, parent_sp
, fn
);
1035 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
1036 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
1037 if (!pte_chain
->parent_ptes
[i
])
1039 parent_sp
= page_header(__pa(pte_chain
->parent_ptes
[i
]));
1040 fn(vcpu
, parent_sp
);
1041 mmu_parent_walk(vcpu
, parent_sp
, fn
);
1045 static void kvm_mmu_update_unsync_bitmap(u64
*spte
)
1048 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
1050 index
= spte
- sp
->spt
;
1051 if (!__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
1052 sp
->unsync_children
++;
1053 WARN_ON(!sp
->unsync_children
);
1056 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page
*sp
)
1058 struct kvm_pte_chain
*pte_chain
;
1059 struct hlist_node
*node
;
1062 if (!sp
->parent_pte
)
1065 if (!sp
->multimapped
) {
1066 kvm_mmu_update_unsync_bitmap(sp
->parent_pte
);
1070 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
1071 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
1072 if (!pte_chain
->parent_ptes
[i
])
1074 kvm_mmu_update_unsync_bitmap(pte_chain
->parent_ptes
[i
]);
1078 static int unsync_walk_fn(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1080 kvm_mmu_update_parents_unsync(sp
);
1084 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu
*vcpu
,
1085 struct kvm_mmu_page
*sp
)
1087 mmu_parent_walk(vcpu
, sp
, unsync_walk_fn
);
1088 kvm_mmu_update_parents_unsync(sp
);
1091 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
1092 struct kvm_mmu_page
*sp
)
1096 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
1097 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
1100 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
1101 struct kvm_mmu_page
*sp
)
1106 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
1110 #define KVM_PAGE_ARRAY_NR 16
1112 struct kvm_mmu_pages
{
1113 struct mmu_page_and_offset
{
1114 struct kvm_mmu_page
*sp
;
1116 } page
[KVM_PAGE_ARRAY_NR
];
1120 #define for_each_unsync_children(bitmap, idx) \
1121 for (idx = find_first_bit(bitmap, 512); \
1123 idx = find_next_bit(bitmap, 512, idx+1))
1125 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
1131 for (i
=0; i
< pvec
->nr
; i
++)
1132 if (pvec
->page
[i
].sp
== sp
)
1135 pvec
->page
[pvec
->nr
].sp
= sp
;
1136 pvec
->page
[pvec
->nr
].idx
= idx
;
1138 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1141 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1142 struct kvm_mmu_pages
*pvec
)
1144 int i
, ret
, nr_unsync_leaf
= 0;
1146 for_each_unsync_children(sp
->unsync_child_bitmap
, i
) {
1147 u64 ent
= sp
->spt
[i
];
1149 if (is_shadow_present_pte(ent
) && !is_large_pte(ent
)) {
1150 struct kvm_mmu_page
*child
;
1151 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1153 if (child
->unsync_children
) {
1154 if (mmu_pages_add(pvec
, child
, i
))
1157 ret
= __mmu_unsync_walk(child
, pvec
);
1159 __clear_bit(i
, sp
->unsync_child_bitmap
);
1161 nr_unsync_leaf
+= ret
;
1166 if (child
->unsync
) {
1168 if (mmu_pages_add(pvec
, child
, i
))
1174 if (find_first_bit(sp
->unsync_child_bitmap
, 512) == 512)
1175 sp
->unsync_children
= 0;
1177 return nr_unsync_leaf
;
1180 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1181 struct kvm_mmu_pages
*pvec
)
1183 if (!sp
->unsync_children
)
1186 mmu_pages_add(pvec
, sp
, 0);
1187 return __mmu_unsync_walk(sp
, pvec
);
1190 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
1193 struct hlist_head
*bucket
;
1194 struct kvm_mmu_page
*sp
;
1195 struct hlist_node
*node
;
1197 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1198 index
= kvm_page_table_hashfn(gfn
);
1199 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1200 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
1201 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1202 && !sp
->role
.invalid
) {
1203 pgprintk("%s: found role %x\n",
1204 __func__
, sp
->role
.word
);
1210 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1212 WARN_ON(!sp
->unsync
);
1214 --kvm
->stat
.mmu_unsync
;
1217 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
);
1219 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1221 if (sp
->role
.glevels
!= vcpu
->arch
.mmu
.root_level
) {
1222 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1226 trace_kvm_mmu_sync_page(sp
);
1227 if (rmap_write_protect(vcpu
->kvm
, sp
->gfn
))
1228 kvm_flush_remote_tlbs(vcpu
->kvm
);
1229 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1230 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1231 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1235 kvm_mmu_flush_tlb(vcpu
);
1239 struct mmu_page_path
{
1240 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1241 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1244 #define for_each_sp(pvec, sp, parents, i) \
1245 for (i = mmu_pages_next(&pvec, &parents, -1), \
1246 sp = pvec.page[i].sp; \
1247 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1248 i = mmu_pages_next(&pvec, &parents, i))
1250 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1251 struct mmu_page_path
*parents
,
1256 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1257 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1259 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1260 parents
->idx
[0] = pvec
->page
[n
].idx
;
1264 parents
->parent
[sp
->role
.level
-2] = sp
;
1265 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1271 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1273 struct kvm_mmu_page
*sp
;
1274 unsigned int level
= 0;
1277 unsigned int idx
= parents
->idx
[level
];
1279 sp
= parents
->parent
[level
];
1283 --sp
->unsync_children
;
1284 WARN_ON((int)sp
->unsync_children
< 0);
1285 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1287 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1290 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1291 struct mmu_page_path
*parents
,
1292 struct kvm_mmu_pages
*pvec
)
1294 parents
->parent
[parent
->role
.level
-1] = NULL
;
1298 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1299 struct kvm_mmu_page
*parent
)
1302 struct kvm_mmu_page
*sp
;
1303 struct mmu_page_path parents
;
1304 struct kvm_mmu_pages pages
;
1306 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1307 while (mmu_unsync_walk(parent
, &pages
)) {
1310 for_each_sp(pages
, sp
, parents
, i
)
1311 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1314 kvm_flush_remote_tlbs(vcpu
->kvm
);
1316 for_each_sp(pages
, sp
, parents
, i
) {
1317 kvm_sync_page(vcpu
, sp
);
1318 mmu_pages_clear_parents(&parents
);
1320 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1321 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1325 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1333 union kvm_mmu_page_role role
;
1336 struct hlist_head
*bucket
;
1337 struct kvm_mmu_page
*sp
;
1338 struct hlist_node
*node
, *tmp
;
1340 role
= vcpu
->arch
.mmu
.base_role
;
1342 role
.direct
= direct
;
1343 role
.access
= access
;
1344 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1345 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1346 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1347 role
.quadrant
= quadrant
;
1349 index
= kvm_page_table_hashfn(gfn
);
1350 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1351 hlist_for_each_entry_safe(sp
, node
, tmp
, bucket
, hash_link
)
1352 if (sp
->gfn
== gfn
) {
1354 if (kvm_sync_page(vcpu
, sp
))
1357 if (sp
->role
.word
!= role
.word
)
1360 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1361 if (sp
->unsync_children
) {
1362 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
1363 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1365 trace_kvm_mmu_get_page(sp
, false);
1368 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1369 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
1374 hlist_add_head(&sp
->hash_link
, bucket
);
1376 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1377 kvm_flush_remote_tlbs(vcpu
->kvm
);
1378 account_shadowed(vcpu
->kvm
, gfn
);
1380 if (shadow_trap_nonpresent_pte
!= shadow_notrap_nonpresent_pte
)
1381 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
1383 nonpaging_prefetch_page(vcpu
, sp
);
1384 trace_kvm_mmu_get_page(sp
, true);
1388 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1389 struct kvm_vcpu
*vcpu
, u64 addr
)
1391 iterator
->addr
= addr
;
1392 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1393 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1394 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1395 iterator
->shadow_addr
1396 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1397 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1399 if (!iterator
->shadow_addr
)
1400 iterator
->level
= 0;
1404 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1406 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1409 if (iterator
->level
== PT_PAGE_TABLE_LEVEL
)
1410 if (is_large_pte(*iterator
->sptep
))
1413 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1414 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1418 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1420 iterator
->shadow_addr
= *iterator
->sptep
& PT64_BASE_ADDR_MASK
;
1424 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1425 struct kvm_mmu_page
*sp
)
1433 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1436 if (is_shadow_present_pte(ent
)) {
1437 if (!is_last_spte(ent
, sp
->role
.level
)) {
1438 ent
&= PT64_BASE_ADDR_MASK
;
1439 mmu_page_remove_parent_pte(page_header(ent
),
1442 if (is_large_pte(ent
))
1444 rmap_remove(kvm
, &pt
[i
]);
1447 pt
[i
] = shadow_trap_nonpresent_pte
;
1451 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1453 mmu_page_remove_parent_pte(sp
, parent_pte
);
1456 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
1459 struct kvm_vcpu
*vcpu
;
1461 kvm_for_each_vcpu(i
, vcpu
, kvm
)
1462 vcpu
->arch
.last_pte_updated
= NULL
;
1465 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1469 while (sp
->multimapped
|| sp
->parent_pte
) {
1470 if (!sp
->multimapped
)
1471 parent_pte
= sp
->parent_pte
;
1473 struct kvm_pte_chain
*chain
;
1475 chain
= container_of(sp
->parent_ptes
.first
,
1476 struct kvm_pte_chain
, link
);
1477 parent_pte
= chain
->parent_ptes
[0];
1479 BUG_ON(!parent_pte
);
1480 kvm_mmu_put_page(sp
, parent_pte
);
1481 __set_spte(parent_pte
, shadow_trap_nonpresent_pte
);
1485 static int mmu_zap_unsync_children(struct kvm
*kvm
,
1486 struct kvm_mmu_page
*parent
)
1489 struct mmu_page_path parents
;
1490 struct kvm_mmu_pages pages
;
1492 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1495 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1496 while (mmu_unsync_walk(parent
, &pages
)) {
1497 struct kvm_mmu_page
*sp
;
1499 for_each_sp(pages
, sp
, parents
, i
) {
1500 kvm_mmu_zap_page(kvm
, sp
);
1501 mmu_pages_clear_parents(&parents
);
1504 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1510 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1514 trace_kvm_mmu_zap_page(sp
);
1515 ++kvm
->stat
.mmu_shadow_zapped
;
1516 ret
= mmu_zap_unsync_children(kvm
, sp
);
1517 kvm_mmu_page_unlink_children(kvm
, sp
);
1518 kvm_mmu_unlink_parents(kvm
, sp
);
1519 kvm_flush_remote_tlbs(kvm
);
1520 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
1521 unaccount_shadowed(kvm
, sp
->gfn
);
1523 kvm_unlink_unsync_page(kvm
, sp
);
1524 if (!sp
->root_count
) {
1525 hlist_del(&sp
->hash_link
);
1526 kvm_mmu_free_page(kvm
, sp
);
1528 sp
->role
.invalid
= 1;
1529 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1530 kvm_reload_remote_mmus(kvm
);
1532 kvm_mmu_reset_last_pte_updated(kvm
);
1537 * Changing the number of mmu pages allocated to the vm
1538 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1540 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
1544 used_pages
= kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
;
1545 used_pages
= max(0, used_pages
);
1548 * If we set the number of mmu pages to be smaller be than the
1549 * number of actived pages , we must to free some mmu pages before we
1553 if (used_pages
> kvm_nr_mmu_pages
) {
1554 while (used_pages
> kvm_nr_mmu_pages
) {
1555 struct kvm_mmu_page
*page
;
1557 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
1558 struct kvm_mmu_page
, link
);
1559 kvm_mmu_zap_page(kvm
, page
);
1562 kvm
->arch
.n_free_mmu_pages
= 0;
1565 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
1566 - kvm
->arch
.n_alloc_mmu_pages
;
1568 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
1571 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
1574 struct hlist_head
*bucket
;
1575 struct kvm_mmu_page
*sp
;
1576 struct hlist_node
*node
, *n
;
1579 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1581 index
= kvm_page_table_hashfn(gfn
);
1582 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1583 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
1584 if (sp
->gfn
== gfn
&& !sp
->role
.direct
) {
1585 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
1588 if (kvm_mmu_zap_page(kvm
, sp
))
1594 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
1597 struct hlist_head
*bucket
;
1598 struct kvm_mmu_page
*sp
;
1599 struct hlist_node
*node
, *nn
;
1601 index
= kvm_page_table_hashfn(gfn
);
1602 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1603 hlist_for_each_entry_safe(sp
, node
, nn
, bucket
, hash_link
) {
1604 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1605 && !sp
->role
.invalid
) {
1606 pgprintk("%s: zap %lx %x\n",
1607 __func__
, gfn
, sp
->role
.word
);
1608 kvm_mmu_zap_page(kvm
, sp
);
1613 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
1615 int slot
= memslot_id(kvm
, gfn
);
1616 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
1618 __set_bit(slot
, sp
->slot_bitmap
);
1621 static void mmu_convert_notrap(struct kvm_mmu_page
*sp
)
1626 if (shadow_trap_nonpresent_pte
== shadow_notrap_nonpresent_pte
)
1629 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1630 if (pt
[i
] == shadow_notrap_nonpresent_pte
)
1631 __set_spte(&pt
[i
], shadow_trap_nonpresent_pte
);
1635 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
1639 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1641 if (gpa
== UNMAPPED_GVA
)
1644 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1650 * The function is based on mtrr_type_lookup() in
1651 * arch/x86/kernel/cpu/mtrr/generic.c
1653 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
1658 u8 prev_match
, curr_match
;
1659 int num_var_ranges
= KVM_NR_VAR_MTRR
;
1661 if (!mtrr_state
->enabled
)
1664 /* Make end inclusive end, instead of exclusive */
1667 /* Look in fixed ranges. Just return the type as per start */
1668 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
1671 if (start
< 0x80000) {
1673 idx
+= (start
>> 16);
1674 return mtrr_state
->fixed_ranges
[idx
];
1675 } else if (start
< 0xC0000) {
1677 idx
+= ((start
- 0x80000) >> 14);
1678 return mtrr_state
->fixed_ranges
[idx
];
1679 } else if (start
< 0x1000000) {
1681 idx
+= ((start
- 0xC0000) >> 12);
1682 return mtrr_state
->fixed_ranges
[idx
];
1687 * Look in variable ranges
1688 * Look of multiple ranges matching this address and pick type
1689 * as per MTRR precedence
1691 if (!(mtrr_state
->enabled
& 2))
1692 return mtrr_state
->def_type
;
1695 for (i
= 0; i
< num_var_ranges
; ++i
) {
1696 unsigned short start_state
, end_state
;
1698 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
1701 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
1702 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
1703 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
1704 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
1706 start_state
= ((start
& mask
) == (base
& mask
));
1707 end_state
= ((end
& mask
) == (base
& mask
));
1708 if (start_state
!= end_state
)
1711 if ((start
& mask
) != (base
& mask
))
1714 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
1715 if (prev_match
== 0xFF) {
1716 prev_match
= curr_match
;
1720 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
1721 curr_match
== MTRR_TYPE_UNCACHABLE
)
1722 return MTRR_TYPE_UNCACHABLE
;
1724 if ((prev_match
== MTRR_TYPE_WRBACK
&&
1725 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
1726 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
1727 curr_match
== MTRR_TYPE_WRBACK
)) {
1728 prev_match
= MTRR_TYPE_WRTHROUGH
;
1729 curr_match
= MTRR_TYPE_WRTHROUGH
;
1732 if (prev_match
!= curr_match
)
1733 return MTRR_TYPE_UNCACHABLE
;
1736 if (prev_match
!= 0xFF)
1739 return mtrr_state
->def_type
;
1742 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1746 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
1747 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
1748 if (mtrr
== 0xfe || mtrr
== 0xff)
1749 mtrr
= MTRR_TYPE_WRBACK
;
1752 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
1754 static int kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1757 struct hlist_head
*bucket
;
1758 struct kvm_mmu_page
*s
;
1759 struct hlist_node
*node
, *n
;
1761 trace_kvm_mmu_unsync_page(sp
);
1762 index
= kvm_page_table_hashfn(sp
->gfn
);
1763 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1764 /* don't unsync if pagetable is shadowed with multiple roles */
1765 hlist_for_each_entry_safe(s
, node
, n
, bucket
, hash_link
) {
1766 if (s
->gfn
!= sp
->gfn
|| s
->role
.direct
)
1768 if (s
->role
.word
!= sp
->role
.word
)
1771 ++vcpu
->kvm
->stat
.mmu_unsync
;
1774 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1776 mmu_convert_notrap(sp
);
1780 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
1783 struct kvm_mmu_page
*shadow
;
1785 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1787 if (shadow
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1791 if (can_unsync
&& oos_shadow
)
1792 return kvm_unsync_page(vcpu
, shadow
);
1798 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1799 unsigned pte_access
, int user_fault
,
1800 int write_fault
, int dirty
, int level
,
1801 gfn_t gfn
, pfn_t pfn
, bool speculative
,
1802 bool can_unsync
, bool reset_host_protection
)
1808 * We don't set the accessed bit, since we sometimes want to see
1809 * whether the guest actually used the pte (in order to detect
1812 spte
= shadow_base_present_pte
| shadow_dirty_mask
;
1814 spte
|= shadow_accessed_mask
;
1816 pte_access
&= ~ACC_WRITE_MASK
;
1817 if (pte_access
& ACC_EXEC_MASK
)
1818 spte
|= shadow_x_mask
;
1820 spte
|= shadow_nx_mask
;
1821 if (pte_access
& ACC_USER_MASK
)
1822 spte
|= shadow_user_mask
;
1823 if (level
> PT_PAGE_TABLE_LEVEL
)
1824 spte
|= PT_PAGE_SIZE_MASK
;
1826 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
1827 kvm_is_mmio_pfn(pfn
));
1829 if (reset_host_protection
)
1830 spte
|= SPTE_HOST_WRITEABLE
;
1832 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
1834 if ((pte_access
& ACC_WRITE_MASK
)
1835 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1837 if (level
> PT_PAGE_TABLE_LEVEL
&&
1838 has_wrprotected_page(vcpu
->kvm
, gfn
, level
)) {
1840 spte
= shadow_trap_nonpresent_pte
;
1844 spte
|= PT_WRITABLE_MASK
;
1847 * Optimization: for pte sync, if spte was writable the hash
1848 * lookup is unnecessary (and expensive). Write protection
1849 * is responsibility of mmu_get_page / kvm_sync_page.
1850 * Same reasoning can be applied to dirty page accounting.
1852 if (!can_unsync
&& is_writeble_pte(*sptep
))
1855 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
1856 pgprintk("%s: found shadow page for %lx, marking ro\n",
1859 pte_access
&= ~ACC_WRITE_MASK
;
1860 if (is_writeble_pte(spte
))
1861 spte
&= ~PT_WRITABLE_MASK
;
1865 if (pte_access
& ACC_WRITE_MASK
)
1866 mark_page_dirty(vcpu
->kvm
, gfn
);
1869 __set_spte(sptep
, spte
);
1873 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*sptep
,
1874 unsigned pt_access
, unsigned pte_access
,
1875 int user_fault
, int write_fault
, int dirty
,
1876 int *ptwrite
, int level
, gfn_t gfn
,
1877 pfn_t pfn
, bool speculative
,
1878 bool reset_host_protection
)
1880 int was_rmapped
= 0;
1881 int was_writeble
= is_writeble_pte(*sptep
);
1884 pgprintk("%s: spte %llx access %x write_fault %d"
1885 " user_fault %d gfn %lx\n",
1886 __func__
, *sptep
, pt_access
,
1887 write_fault
, user_fault
, gfn
);
1889 if (is_rmap_spte(*sptep
)) {
1891 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1892 * the parent of the now unreachable PTE.
1894 if (level
> PT_PAGE_TABLE_LEVEL
&&
1895 !is_large_pte(*sptep
)) {
1896 struct kvm_mmu_page
*child
;
1899 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1900 mmu_page_remove_parent_pte(child
, sptep
);
1901 } else if (pfn
!= spte_to_pfn(*sptep
)) {
1902 pgprintk("hfn old %lx new %lx\n",
1903 spte_to_pfn(*sptep
), pfn
);
1904 rmap_remove(vcpu
->kvm
, sptep
);
1909 if (set_spte(vcpu
, sptep
, pte_access
, user_fault
, write_fault
,
1910 dirty
, level
, gfn
, pfn
, speculative
, true,
1911 reset_host_protection
)) {
1914 kvm_x86_ops
->tlb_flush(vcpu
);
1917 pgprintk("%s: setting spte %llx\n", __func__
, *sptep
);
1918 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1919 is_large_pte(*sptep
)? "2MB" : "4kB",
1920 *sptep
& PT_PRESENT_MASK
?"RW":"R", gfn
,
1922 if (!was_rmapped
&& is_large_pte(*sptep
))
1923 ++vcpu
->kvm
->stat
.lpages
;
1925 page_header_update_slot(vcpu
->kvm
, sptep
, gfn
);
1927 rmap_count
= rmap_add(vcpu
, sptep
, gfn
);
1928 kvm_release_pfn_clean(pfn
);
1929 if (rmap_count
> RMAP_RECYCLE_THRESHOLD
)
1930 rmap_recycle(vcpu
, sptep
, gfn
);
1933 kvm_release_pfn_dirty(pfn
);
1935 kvm_release_pfn_clean(pfn
);
1938 vcpu
->arch
.last_pte_updated
= sptep
;
1939 vcpu
->arch
.last_pte_gfn
= gfn
;
1943 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1947 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1948 int level
, gfn_t gfn
, pfn_t pfn
)
1950 struct kvm_shadow_walk_iterator iterator
;
1951 struct kvm_mmu_page
*sp
;
1955 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
1956 if (iterator
.level
== level
) {
1957 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
, ACC_ALL
,
1958 0, write
, 1, &pt_write
,
1959 level
, gfn
, pfn
, false, true);
1960 ++vcpu
->stat
.pf_fixed
;
1964 if (*iterator
.sptep
== shadow_trap_nonpresent_pte
) {
1965 pseudo_gfn
= (iterator
.addr
& PT64_DIR_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1966 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
1968 1, ACC_ALL
, iterator
.sptep
);
1970 pgprintk("nonpaging_map: ENOMEM\n");
1971 kvm_release_pfn_clean(pfn
);
1975 __set_spte(iterator
.sptep
,
1977 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
1978 | shadow_user_mask
| shadow_x_mask
);
1984 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1989 unsigned long mmu_seq
;
1991 level
= mapping_level(vcpu
, gfn
);
1994 * This path builds a PAE pagetable - so we can map 2mb pages at
1995 * maximum. Therefore check if the level is larger than that.
1997 if (level
> PT_DIRECTORY_LEVEL
)
1998 level
= PT_DIRECTORY_LEVEL
;
2000 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2002 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2004 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2007 if (is_error_pfn(pfn
)) {
2008 kvm_release_pfn_clean(pfn
);
2012 spin_lock(&vcpu
->kvm
->mmu_lock
);
2013 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2015 kvm_mmu_free_some_pages(vcpu
);
2016 r
= __direct_map(vcpu
, v
, write
, level
, gfn
, pfn
);
2017 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2023 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2024 kvm_release_pfn_clean(pfn
);
2029 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
2032 struct kvm_mmu_page
*sp
;
2034 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2036 spin_lock(&vcpu
->kvm
->mmu_lock
);
2037 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2038 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2040 sp
= page_header(root
);
2042 if (!sp
->root_count
&& sp
->role
.invalid
)
2043 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2044 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2045 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2048 for (i
= 0; i
< 4; ++i
) {
2049 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2052 root
&= PT64_BASE_ADDR_MASK
;
2053 sp
= page_header(root
);
2055 if (!sp
->root_count
&& sp
->role
.invalid
)
2056 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2058 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2060 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2061 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2064 static int mmu_check_root(struct kvm_vcpu
*vcpu
, gfn_t root_gfn
)
2068 if (!kvm_is_visible_gfn(vcpu
->kvm
, root_gfn
)) {
2069 set_bit(KVM_REQ_TRIPLE_FAULT
, &vcpu
->requests
);
2076 static int mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
2080 struct kvm_mmu_page
*sp
;
2084 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
2086 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2087 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2089 ASSERT(!VALID_PAGE(root
));
2092 if (mmu_check_root(vcpu
, root_gfn
))
2094 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
2095 PT64_ROOT_LEVEL
, direct
,
2097 root
= __pa(sp
->spt
);
2099 vcpu
->arch
.mmu
.root_hpa
= root
;
2102 direct
= !is_paging(vcpu
);
2105 for (i
= 0; i
< 4; ++i
) {
2106 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2108 ASSERT(!VALID_PAGE(root
));
2109 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
2110 pdptr
= kvm_pdptr_read(vcpu
, i
);
2111 if (!is_present_gpte(pdptr
)) {
2112 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
2115 root_gfn
= pdptr
>> PAGE_SHIFT
;
2116 } else if (vcpu
->arch
.mmu
.root_level
== 0)
2118 if (mmu_check_root(vcpu
, root_gfn
))
2120 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
2121 PT32_ROOT_LEVEL
, direct
,
2123 root
= __pa(sp
->spt
);
2125 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
2127 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
2131 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2134 struct kvm_mmu_page
*sp
;
2136 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
2138 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
2139 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
2140 sp
= page_header(root
);
2141 mmu_sync_children(vcpu
, sp
);
2144 for (i
= 0; i
< 4; ++i
) {
2145 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
2147 if (root
&& VALID_PAGE(root
)) {
2148 root
&= PT64_BASE_ADDR_MASK
;
2149 sp
= page_header(root
);
2150 mmu_sync_children(vcpu
, sp
);
2155 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
2157 spin_lock(&vcpu
->kvm
->mmu_lock
);
2158 mmu_sync_roots(vcpu
);
2159 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2162 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
2167 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
2173 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
2174 r
= mmu_topup_memory_caches(vcpu
);
2179 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2181 gfn
= gva
>> PAGE_SHIFT
;
2183 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
2184 error_code
& PFERR_WRITE_MASK
, gfn
);
2187 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
2193 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2194 unsigned long mmu_seq
;
2197 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2199 r
= mmu_topup_memory_caches(vcpu
);
2203 level
= mapping_level(vcpu
, gfn
);
2205 gfn
&= ~(KVM_PAGES_PER_HPAGE(level
) - 1);
2207 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2209 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2210 if (is_error_pfn(pfn
)) {
2211 kvm_release_pfn_clean(pfn
);
2214 spin_lock(&vcpu
->kvm
->mmu_lock
);
2215 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2217 kvm_mmu_free_some_pages(vcpu
);
2218 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
2220 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2225 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2226 kvm_release_pfn_clean(pfn
);
2230 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
2232 mmu_free_roots(vcpu
);
2235 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
2237 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2239 context
->new_cr3
= nonpaging_new_cr3
;
2240 context
->page_fault
= nonpaging_page_fault
;
2241 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2242 context
->free
= nonpaging_free
;
2243 context
->prefetch_page
= nonpaging_prefetch_page
;
2244 context
->sync_page
= nonpaging_sync_page
;
2245 context
->invlpg
= nonpaging_invlpg
;
2246 context
->root_level
= 0;
2247 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2248 context
->root_hpa
= INVALID_PAGE
;
2252 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2254 ++vcpu
->stat
.tlb_flush
;
2255 kvm_x86_ops
->tlb_flush(vcpu
);
2258 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
2260 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
2261 mmu_free_roots(vcpu
);
2264 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
2268 kvm_inject_page_fault(vcpu
, addr
, err_code
);
2271 static void paging_free(struct kvm_vcpu
*vcpu
)
2273 nonpaging_free(vcpu
);
2276 static bool is_rsvd_bits_set(struct kvm_vcpu
*vcpu
, u64 gpte
, int level
)
2280 bit7
= (gpte
>> 7) & 1;
2281 return (gpte
& vcpu
->arch
.mmu
.rsvd_bits_mask
[bit7
][level
-1]) != 0;
2285 #include "paging_tmpl.h"
2289 #include "paging_tmpl.h"
2292 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
, int level
)
2294 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2295 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
2296 u64 exb_bit_rsvd
= 0;
2299 exb_bit_rsvd
= rsvd_bits(63, 63);
2301 case PT32_ROOT_LEVEL
:
2302 /* no rsvd bits for 2 level 4K page table entries */
2303 context
->rsvd_bits_mask
[0][1] = 0;
2304 context
->rsvd_bits_mask
[0][0] = 0;
2305 if (is_cpuid_PSE36())
2306 /* 36bits PSE 4MB page */
2307 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
2309 /* 32 bits PSE 4MB page */
2310 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
2311 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2313 case PT32E_ROOT_LEVEL
:
2314 context
->rsvd_bits_mask
[0][2] =
2315 rsvd_bits(maxphyaddr
, 63) |
2316 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
2317 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2318 rsvd_bits(maxphyaddr
, 62); /* PDE */
2319 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2320 rsvd_bits(maxphyaddr
, 62); /* PTE */
2321 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2322 rsvd_bits(maxphyaddr
, 62) |
2323 rsvd_bits(13, 20); /* large page */
2324 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2326 case PT64_ROOT_LEVEL
:
2327 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
2328 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2329 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
2330 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2331 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2332 rsvd_bits(maxphyaddr
, 51);
2333 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2334 rsvd_bits(maxphyaddr
, 51);
2335 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
2336 context
->rsvd_bits_mask
[1][2] = exb_bit_rsvd
|
2337 rsvd_bits(maxphyaddr
, 51) |
2339 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2340 rsvd_bits(maxphyaddr
, 51) |
2341 rsvd_bits(13, 20); /* large page */
2342 context
->rsvd_bits_mask
[1][0] = context
->rsvd_bits_mask
[1][0];
2347 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
2349 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2351 ASSERT(is_pae(vcpu
));
2352 context
->new_cr3
= paging_new_cr3
;
2353 context
->page_fault
= paging64_page_fault
;
2354 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2355 context
->prefetch_page
= paging64_prefetch_page
;
2356 context
->sync_page
= paging64_sync_page
;
2357 context
->invlpg
= paging64_invlpg
;
2358 context
->free
= paging_free
;
2359 context
->root_level
= level
;
2360 context
->shadow_root_level
= level
;
2361 context
->root_hpa
= INVALID_PAGE
;
2365 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
2367 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2368 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
2371 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
2373 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2375 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2376 context
->new_cr3
= paging_new_cr3
;
2377 context
->page_fault
= paging32_page_fault
;
2378 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2379 context
->free
= paging_free
;
2380 context
->prefetch_page
= paging32_prefetch_page
;
2381 context
->sync_page
= paging32_sync_page
;
2382 context
->invlpg
= paging32_invlpg
;
2383 context
->root_level
= PT32_ROOT_LEVEL
;
2384 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2385 context
->root_hpa
= INVALID_PAGE
;
2389 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
2391 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2392 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
2395 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
2397 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2399 context
->new_cr3
= nonpaging_new_cr3
;
2400 context
->page_fault
= tdp_page_fault
;
2401 context
->free
= nonpaging_free
;
2402 context
->prefetch_page
= nonpaging_prefetch_page
;
2403 context
->sync_page
= nonpaging_sync_page
;
2404 context
->invlpg
= nonpaging_invlpg
;
2405 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
2406 context
->root_hpa
= INVALID_PAGE
;
2408 if (!is_paging(vcpu
)) {
2409 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2410 context
->root_level
= 0;
2411 } else if (is_long_mode(vcpu
)) {
2412 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2413 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2414 context
->root_level
= PT64_ROOT_LEVEL
;
2415 } else if (is_pae(vcpu
)) {
2416 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2417 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2418 context
->root_level
= PT32E_ROOT_LEVEL
;
2420 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2421 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2422 context
->root_level
= PT32_ROOT_LEVEL
;
2428 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
2433 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2435 if (!is_paging(vcpu
))
2436 r
= nonpaging_init_context(vcpu
);
2437 else if (is_long_mode(vcpu
))
2438 r
= paging64_init_context(vcpu
);
2439 else if (is_pae(vcpu
))
2440 r
= paging32E_init_context(vcpu
);
2442 r
= paging32_init_context(vcpu
);
2444 vcpu
->arch
.mmu
.base_role
.glevels
= vcpu
->arch
.mmu
.root_level
;
2449 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
2451 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2454 return init_kvm_tdp_mmu(vcpu
);
2456 return init_kvm_softmmu(vcpu
);
2459 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
2462 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
2463 vcpu
->arch
.mmu
.free(vcpu
);
2464 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2468 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
2470 destroy_kvm_mmu(vcpu
);
2471 return init_kvm_mmu(vcpu
);
2473 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
2475 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
2479 r
= mmu_topup_memory_caches(vcpu
);
2482 spin_lock(&vcpu
->kvm
->mmu_lock
);
2483 kvm_mmu_free_some_pages(vcpu
);
2484 r
= mmu_alloc_roots(vcpu
);
2485 mmu_sync_roots(vcpu
);
2486 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2489 /* set_cr3() should ensure TLB has been flushed */
2490 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
2494 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
2496 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
2498 mmu_free_roots(vcpu
);
2501 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
2502 struct kvm_mmu_page
*sp
,
2506 struct kvm_mmu_page
*child
;
2509 if (is_shadow_present_pte(pte
)) {
2510 if (is_last_spte(pte
, sp
->role
.level
))
2511 rmap_remove(vcpu
->kvm
, spte
);
2513 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2514 mmu_page_remove_parent_pte(child
, spte
);
2517 __set_spte(spte
, shadow_trap_nonpresent_pte
);
2518 if (is_large_pte(pte
))
2519 --vcpu
->kvm
->stat
.lpages
;
2522 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
2523 struct kvm_mmu_page
*sp
,
2527 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
2528 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
2532 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
2533 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
2534 paging32_update_pte(vcpu
, sp
, spte
, new);
2536 paging64_update_pte(vcpu
, sp
, spte
, new);
2539 static bool need_remote_flush(u64 old
, u64
new)
2541 if (!is_shadow_present_pte(old
))
2543 if (!is_shadow_present_pte(new))
2545 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
2547 old
^= PT64_NX_MASK
;
2548 new ^= PT64_NX_MASK
;
2549 return (old
& ~new & PT64_PERM_MASK
) != 0;
2552 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
2554 if (need_remote_flush(old
, new))
2555 kvm_flush_remote_tlbs(vcpu
->kvm
);
2557 kvm_mmu_flush_tlb(vcpu
);
2560 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
2562 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2564 return !!(spte
&& (*spte
& shadow_accessed_mask
));
2567 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2568 const u8
*new, int bytes
)
2575 if (bytes
!= 4 && bytes
!= 8)
2579 * Assume that the pte write on a page table of the same type
2580 * as the current vcpu paging mode. This is nearly always true
2581 * (might be false while changing modes). Note it is verified later
2585 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2586 if ((bytes
== 4) && (gpa
% 4 == 0)) {
2587 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
2590 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
2591 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
2592 memcpy((void *)&gpte
, new, 8);
2595 if ((bytes
== 4) && (gpa
% 4 == 0))
2596 memcpy((void *)&gpte
, new, 4);
2598 if (!is_present_gpte(gpte
))
2600 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
2602 vcpu
->arch
.update_pte
.mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2604 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2606 if (is_error_pfn(pfn
)) {
2607 kvm_release_pfn_clean(pfn
);
2610 vcpu
->arch
.update_pte
.gfn
= gfn
;
2611 vcpu
->arch
.update_pte
.pfn
= pfn
;
2614 static void kvm_mmu_access_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2616 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2619 && vcpu
->arch
.last_pte_gfn
== gfn
2620 && shadow_accessed_mask
2621 && !(*spte
& shadow_accessed_mask
)
2622 && is_shadow_present_pte(*spte
))
2623 set_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
2626 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2627 const u8
*new, int bytes
,
2628 bool guest_initiated
)
2630 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2631 struct kvm_mmu_page
*sp
;
2632 struct hlist_node
*node
, *n
;
2633 struct hlist_head
*bucket
;
2637 unsigned offset
= offset_in_page(gpa
);
2639 unsigned page_offset
;
2640 unsigned misaligned
;
2647 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
2648 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
2649 spin_lock(&vcpu
->kvm
->mmu_lock
);
2650 kvm_mmu_access_page(vcpu
, gfn
);
2651 kvm_mmu_free_some_pages(vcpu
);
2652 ++vcpu
->kvm
->stat
.mmu_pte_write
;
2653 kvm_mmu_audit(vcpu
, "pre pte write");
2654 if (guest_initiated
) {
2655 if (gfn
== vcpu
->arch
.last_pt_write_gfn
2656 && !last_updated_pte_accessed(vcpu
)) {
2657 ++vcpu
->arch
.last_pt_write_count
;
2658 if (vcpu
->arch
.last_pt_write_count
>= 3)
2661 vcpu
->arch
.last_pt_write_gfn
= gfn
;
2662 vcpu
->arch
.last_pt_write_count
= 1;
2663 vcpu
->arch
.last_pte_updated
= NULL
;
2666 index
= kvm_page_table_hashfn(gfn
);
2667 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
2668 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
2669 if (sp
->gfn
!= gfn
|| sp
->role
.direct
|| sp
->role
.invalid
)
2671 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
2672 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
2673 misaligned
|= bytes
< 4;
2674 if (misaligned
|| flooded
) {
2676 * Misaligned accesses are too much trouble to fix
2677 * up; also, they usually indicate a page is not used
2680 * If we're seeing too many writes to a page,
2681 * it may no longer be a page table, or we may be
2682 * forking, in which case it is better to unmap the
2685 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2686 gpa
, bytes
, sp
->role
.word
);
2687 if (kvm_mmu_zap_page(vcpu
->kvm
, sp
))
2689 ++vcpu
->kvm
->stat
.mmu_flooded
;
2692 page_offset
= offset
;
2693 level
= sp
->role
.level
;
2695 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2696 page_offset
<<= 1; /* 32->64 */
2698 * A 32-bit pde maps 4MB while the shadow pdes map
2699 * only 2MB. So we need to double the offset again
2700 * and zap two pdes instead of one.
2702 if (level
== PT32_ROOT_LEVEL
) {
2703 page_offset
&= ~7; /* kill rounding error */
2707 quadrant
= page_offset
>> PAGE_SHIFT
;
2708 page_offset
&= ~PAGE_MASK
;
2709 if (quadrant
!= sp
->role
.quadrant
)
2712 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
2713 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
2715 r
= kvm_read_guest_atomic(vcpu
->kvm
,
2716 gpa
& ~(u64
)(pte_size
- 1),
2718 new = (const void *)&gentry
;
2724 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
2726 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
2727 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
2731 kvm_mmu_audit(vcpu
, "post pte write");
2732 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2733 if (!is_error_pfn(vcpu
->arch
.update_pte
.pfn
)) {
2734 kvm_release_pfn_clean(vcpu
->arch
.update_pte
.pfn
);
2735 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2739 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
2747 gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
2749 spin_lock(&vcpu
->kvm
->mmu_lock
);
2750 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
2751 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2754 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
2756 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
2758 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
&&
2759 !list_empty(&vcpu
->kvm
->arch
.active_mmu_pages
)) {
2760 struct kvm_mmu_page
*sp
;
2762 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
2763 struct kvm_mmu_page
, link
);
2764 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2765 ++vcpu
->kvm
->stat
.mmu_recycled
;
2769 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
2772 enum emulation_result er
;
2774 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
2783 r
= mmu_topup_memory_caches(vcpu
);
2787 er
= emulate_instruction(vcpu
, cr2
, error_code
, 0);
2792 case EMULATE_DO_MMIO
:
2793 ++vcpu
->stat
.mmio_exits
;
2796 vcpu
->run
->exit_reason
= KVM_EXIT_INTERNAL_ERROR
;
2797 vcpu
->run
->internal
.suberror
= KVM_INTERNAL_ERROR_EMULATION
;
2798 vcpu
->run
->internal
.ndata
= 0;
2806 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
2808 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
2810 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
2811 kvm_mmu_flush_tlb(vcpu
);
2812 ++vcpu
->stat
.invlpg
;
2814 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
2816 void kvm_enable_tdp(void)
2820 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
2822 void kvm_disable_tdp(void)
2824 tdp_enabled
= false;
2826 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
2828 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
2830 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
2833 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
2841 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2842 * Therefore we need to allocate shadow page tables in the first
2843 * 4GB of memory, which happens to fit the DMA32 zone.
2845 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
2848 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
2849 for (i
= 0; i
< 4; ++i
)
2850 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2855 free_mmu_pages(vcpu
);
2859 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
2862 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2864 return alloc_mmu_pages(vcpu
);
2867 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
2870 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2872 return init_kvm_mmu(vcpu
);
2875 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
2879 destroy_kvm_mmu(vcpu
);
2880 free_mmu_pages(vcpu
);
2881 mmu_free_memory_caches(vcpu
);
2884 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
2886 struct kvm_mmu_page
*sp
;
2888 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
2892 if (!test_bit(slot
, sp
->slot_bitmap
))
2896 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2898 if (pt
[i
] & PT_WRITABLE_MASK
)
2899 pt
[i
] &= ~PT_WRITABLE_MASK
;
2901 kvm_flush_remote_tlbs(kvm
);
2904 void kvm_mmu_zap_all(struct kvm
*kvm
)
2906 struct kvm_mmu_page
*sp
, *node
;
2908 spin_lock(&kvm
->mmu_lock
);
2909 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
2910 if (kvm_mmu_zap_page(kvm
, sp
))
2911 node
= container_of(kvm
->arch
.active_mmu_pages
.next
,
2912 struct kvm_mmu_page
, link
);
2913 spin_unlock(&kvm
->mmu_lock
);
2915 kvm_flush_remote_tlbs(kvm
);
2918 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm
*kvm
)
2920 struct kvm_mmu_page
*page
;
2922 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2923 struct kvm_mmu_page
, link
);
2924 kvm_mmu_zap_page(kvm
, page
);
2927 static int mmu_shrink(int nr_to_scan
, gfp_t gfp_mask
)
2930 struct kvm
*kvm_freed
= NULL
;
2931 int cache_count
= 0;
2933 spin_lock(&kvm_lock
);
2935 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
2938 idx
= srcu_read_lock(&kvm
->srcu
);
2939 spin_lock(&kvm
->mmu_lock
);
2940 npages
= kvm
->arch
.n_alloc_mmu_pages
-
2941 kvm
->arch
.n_free_mmu_pages
;
2942 cache_count
+= npages
;
2943 if (!kvm_freed
&& nr_to_scan
> 0 && npages
> 0) {
2944 kvm_mmu_remove_one_alloc_mmu_page(kvm
);
2950 spin_unlock(&kvm
->mmu_lock
);
2951 srcu_read_unlock(&kvm
->srcu
, idx
);
2954 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
2956 spin_unlock(&kvm_lock
);
2961 static struct shrinker mmu_shrinker
= {
2962 .shrink
= mmu_shrink
,
2963 .seeks
= DEFAULT_SEEKS
* 10,
2966 static void mmu_destroy_caches(void)
2968 if (pte_chain_cache
)
2969 kmem_cache_destroy(pte_chain_cache
);
2970 if (rmap_desc_cache
)
2971 kmem_cache_destroy(rmap_desc_cache
);
2972 if (mmu_page_header_cache
)
2973 kmem_cache_destroy(mmu_page_header_cache
);
2976 void kvm_mmu_module_exit(void)
2978 mmu_destroy_caches();
2979 unregister_shrinker(&mmu_shrinker
);
2982 int kvm_mmu_module_init(void)
2984 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
2985 sizeof(struct kvm_pte_chain
),
2987 if (!pte_chain_cache
)
2989 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
2990 sizeof(struct kvm_rmap_desc
),
2992 if (!rmap_desc_cache
)
2995 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
2996 sizeof(struct kvm_mmu_page
),
2998 if (!mmu_page_header_cache
)
3001 register_shrinker(&mmu_shrinker
);
3006 mmu_destroy_caches();
3011 * Caculate mmu pages needed for kvm.
3013 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
3016 unsigned int nr_mmu_pages
;
3017 unsigned int nr_pages
= 0;
3018 struct kvm_memslots
*slots
;
3020 slots
= rcu_dereference(kvm
->memslots
);
3021 for (i
= 0; i
< slots
->nmemslots
; i
++)
3022 nr_pages
+= slots
->memslots
[i
].npages
;
3024 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
3025 nr_mmu_pages
= max(nr_mmu_pages
,
3026 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
3028 return nr_mmu_pages
;
3031 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
3034 if (len
> buffer
->len
)
3039 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
3044 ret
= pv_mmu_peek_buffer(buffer
, len
);
3049 buffer
->processed
+= len
;
3053 static int kvm_pv_mmu_write(struct kvm_vcpu
*vcpu
,
3054 gpa_t addr
, gpa_t value
)
3059 if (!is_long_mode(vcpu
) && !is_pae(vcpu
))
3062 r
= mmu_topup_memory_caches(vcpu
);
3066 if (!emulator_write_phys(vcpu
, addr
, &value
, bytes
))
3072 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
3074 kvm_set_cr3(vcpu
, vcpu
->arch
.cr3
);
3078 static int kvm_pv_mmu_release_pt(struct kvm_vcpu
*vcpu
, gpa_t addr
)
3080 spin_lock(&vcpu
->kvm
->mmu_lock
);
3081 mmu_unshadow(vcpu
->kvm
, addr
>> PAGE_SHIFT
);
3082 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3086 static int kvm_pv_mmu_op_one(struct kvm_vcpu
*vcpu
,
3087 struct kvm_pv_mmu_op_buffer
*buffer
)
3089 struct kvm_mmu_op_header
*header
;
3091 header
= pv_mmu_peek_buffer(buffer
, sizeof *header
);
3094 switch (header
->op
) {
3095 case KVM_MMU_OP_WRITE_PTE
: {
3096 struct kvm_mmu_op_write_pte
*wpte
;
3098 wpte
= pv_mmu_read_buffer(buffer
, sizeof *wpte
);
3101 return kvm_pv_mmu_write(vcpu
, wpte
->pte_phys
,
3104 case KVM_MMU_OP_FLUSH_TLB
: {
3105 struct kvm_mmu_op_flush_tlb
*ftlb
;
3107 ftlb
= pv_mmu_read_buffer(buffer
, sizeof *ftlb
);
3110 return kvm_pv_mmu_flush_tlb(vcpu
);
3112 case KVM_MMU_OP_RELEASE_PT
: {
3113 struct kvm_mmu_op_release_pt
*rpt
;
3115 rpt
= pv_mmu_read_buffer(buffer
, sizeof *rpt
);
3118 return kvm_pv_mmu_release_pt(vcpu
, rpt
->pt_phys
);
3124 int kvm_pv_mmu_op(struct kvm_vcpu
*vcpu
, unsigned long bytes
,
3125 gpa_t addr
, unsigned long *ret
)
3128 struct kvm_pv_mmu_op_buffer
*buffer
= &vcpu
->arch
.mmu_op_buffer
;
3130 buffer
->ptr
= buffer
->buf
;
3131 buffer
->len
= min_t(unsigned long, bytes
, sizeof buffer
->buf
);
3132 buffer
->processed
= 0;
3134 r
= kvm_read_guest(vcpu
->kvm
, addr
, buffer
->buf
, buffer
->len
);
3138 while (buffer
->len
) {
3139 r
= kvm_pv_mmu_op_one(vcpu
, buffer
);
3148 *ret
= buffer
->processed
;
3152 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu
*vcpu
, u64 addr
, u64 sptes
[4])
3154 struct kvm_shadow_walk_iterator iterator
;
3157 spin_lock(&vcpu
->kvm
->mmu_lock
);
3158 for_each_shadow_entry(vcpu
, addr
, iterator
) {
3159 sptes
[iterator
.level
-1] = *iterator
.sptep
;
3161 if (!is_shadow_present_pte(*iterator
.sptep
))
3164 spin_unlock(&vcpu
->kvm
->mmu_lock
);
3168 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy
);
3172 static const char *audit_msg
;
3174 static gva_t
canonicalize(gva_t gva
)
3176 #ifdef CONFIG_X86_64
3177 gva
= (long long)(gva
<< 16) >> 16;
3183 typedef void (*inspect_spte_fn
) (struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
3186 static void __mmu_spte_walk(struct kvm
*kvm
, struct kvm_mmu_page
*sp
,
3191 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3192 u64 ent
= sp
->spt
[i
];
3194 if (is_shadow_present_pte(ent
)) {
3195 if (!is_last_spte(ent
, sp
->role
.level
)) {
3196 struct kvm_mmu_page
*child
;
3197 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
3198 __mmu_spte_walk(kvm
, child
, fn
);
3200 fn(kvm
, sp
, &sp
->spt
[i
]);
3205 static void mmu_spte_walk(struct kvm_vcpu
*vcpu
, inspect_spte_fn fn
)
3208 struct kvm_mmu_page
*sp
;
3210 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
3212 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
3213 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
3214 sp
= page_header(root
);
3215 __mmu_spte_walk(vcpu
->kvm
, sp
, fn
);
3218 for (i
= 0; i
< 4; ++i
) {
3219 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
3221 if (root
&& VALID_PAGE(root
)) {
3222 root
&= PT64_BASE_ADDR_MASK
;
3223 sp
= page_header(root
);
3224 __mmu_spte_walk(vcpu
->kvm
, sp
, fn
);
3230 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
3231 gva_t va
, int level
)
3233 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
3235 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
3237 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
3240 if (ent
== shadow_trap_nonpresent_pte
)
3243 va
= canonicalize(va
);
3244 if (is_shadow_present_pte(ent
) && !is_last_spte(ent
, level
))
3245 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
3247 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, va
);
3248 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3249 pfn_t pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
3250 hpa_t hpa
= (hpa_t
)pfn
<< PAGE_SHIFT
;
3252 if (is_error_pfn(pfn
)) {
3253 kvm_release_pfn_clean(pfn
);
3257 if (is_shadow_present_pte(ent
)
3258 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
3259 printk(KERN_ERR
"xx audit error: (%s) levels %d"
3260 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3261 audit_msg
, vcpu
->arch
.mmu
.root_level
,
3263 is_shadow_present_pte(ent
));
3264 else if (ent
== shadow_notrap_nonpresent_pte
3265 && !is_error_hpa(hpa
))
3266 printk(KERN_ERR
"audit: (%s) notrap shadow,"
3267 " valid guest gva %lx\n", audit_msg
, va
);
3268 kvm_release_pfn_clean(pfn
);
3274 static void audit_mappings(struct kvm_vcpu
*vcpu
)
3278 if (vcpu
->arch
.mmu
.root_level
== 4)
3279 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
3281 for (i
= 0; i
< 4; ++i
)
3282 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
3283 audit_mappings_page(vcpu
,
3284 vcpu
->arch
.mmu
.pae_root
[i
],
3289 static int count_rmaps(struct kvm_vcpu
*vcpu
)
3294 idx
= srcu_read_lock(&kvm
->srcu
);
3295 slots
= rcu_dereference(kvm
->memslots
);
3296 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
3297 struct kvm_memory_slot
*m
= &slots
->memslots
[i
];
3298 struct kvm_rmap_desc
*d
;
3300 for (j
= 0; j
< m
->npages
; ++j
) {
3301 unsigned long *rmapp
= &m
->rmap
[j
];
3305 if (!(*rmapp
& 1)) {
3309 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
3311 for (k
= 0; k
< RMAP_EXT
; ++k
)
3320 srcu_read_unlock(&kvm
->srcu
, idx
);
3324 void inspect_spte_has_rmap(struct kvm
*kvm
, struct kvm_mmu_page
*sp
, u64
*sptep
)
3326 unsigned long *rmapp
;
3327 struct kvm_mmu_page
*rev_sp
;
3330 if (*sptep
& PT_WRITABLE_MASK
) {
3331 rev_sp
= page_header(__pa(sptep
));
3332 gfn
= rev_sp
->gfns
[sptep
- rev_sp
->spt
];
3334 if (!gfn_to_memslot(kvm
, gfn
)) {
3335 if (!printk_ratelimit())
3337 printk(KERN_ERR
"%s: no memslot for gfn %ld\n",
3339 printk(KERN_ERR
"%s: index %ld of sp (gfn=%lx)\n",
3340 audit_msg
, sptep
- rev_sp
->spt
,
3346 rmapp
= gfn_to_rmap(kvm
, rev_sp
->gfns
[sptep
- rev_sp
->spt
],
3347 is_large_pte(*sptep
));
3349 if (!printk_ratelimit())
3351 printk(KERN_ERR
"%s: no rmap for writable spte %llx\n",
3359 void audit_writable_sptes_have_rmaps(struct kvm_vcpu
*vcpu
)
3361 mmu_spte_walk(vcpu
, inspect_spte_has_rmap
);
3364 static void check_writable_mappings_rmap(struct kvm_vcpu
*vcpu
)
3366 struct kvm_mmu_page
*sp
;
3369 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3372 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
3375 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3378 if (!(ent
& PT_PRESENT_MASK
))
3380 if (!(ent
& PT_WRITABLE_MASK
))
3382 inspect_spte_has_rmap(vcpu
->kvm
, sp
, &pt
[i
]);
3388 static void audit_rmap(struct kvm_vcpu
*vcpu
)
3390 check_writable_mappings_rmap(vcpu
);
3394 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
3396 struct kvm_mmu_page
*sp
;
3397 struct kvm_memory_slot
*slot
;
3398 unsigned long *rmapp
;
3402 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3403 if (sp
->role
.direct
)
3408 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
3409 slot
= gfn_to_memslot_unaliased(vcpu
->kvm
, sp
->gfn
);
3410 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
3412 spte
= rmap_next(vcpu
->kvm
, rmapp
, NULL
);
3414 if (*spte
& PT_WRITABLE_MASK
)
3415 printk(KERN_ERR
"%s: (%s) shadow page has "
3416 "writable mappings: gfn %lx role %x\n",
3417 __func__
, audit_msg
, sp
->gfn
,
3419 spte
= rmap_next(vcpu
->kvm
, rmapp
, spte
);
3424 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
3431 audit_write_protection(vcpu
);
3432 if (strcmp("pre pte write", audit_msg
) != 0)
3433 audit_mappings(vcpu
);
3434 audit_writable_sptes_have_rmaps(vcpu
);