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 <linux/kvm_host.h>
23 #include <linux/types.h>
24 #include <linux/string.h>
26 #include <linux/highmem.h>
27 #include <linux/module.h>
28 #include <linux/swap.h>
29 #include <linux/hugetlb.h>
30 #include <linux/compiler.h>
33 #include <asm/cmpxchg.h>
38 * When setting this variable to true it enables Two-Dimensional-Paging
39 * where the hardware walks 2 page tables:
40 * 1. the guest-virtual to guest-physical
41 * 2. while doing 1. it walks guest-physical to host-physical
42 * If the hardware supports that we don't need to do shadow paging.
44 bool tdp_enabled
= false;
51 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
);
53 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
) {}
58 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
59 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
63 #define pgprintk(x...) do { } while (0)
64 #define rmap_printk(x...) do { } while (0)
68 #if defined(MMU_DEBUG) || defined(AUDIT)
70 module_param(dbg
, bool, 0644);
73 static int oos_shadow
= 1;
74 module_param(oos_shadow
, bool, 0644);
77 #define ASSERT(x) do { } while (0)
81 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
82 __FILE__, __LINE__, #x); \
86 #define PT_FIRST_AVAIL_BITS_SHIFT 9
87 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
89 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
91 #define PT64_LEVEL_BITS 9
93 #define PT64_LEVEL_SHIFT(level) \
94 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
96 #define PT64_LEVEL_MASK(level) \
97 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
99 #define PT64_INDEX(address, level)\
100 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
103 #define PT32_LEVEL_BITS 10
105 #define PT32_LEVEL_SHIFT(level) \
106 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
108 #define PT32_LEVEL_MASK(level) \
109 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
111 #define PT32_INDEX(address, level)\
112 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
115 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
116 #define PT64_DIR_BASE_ADDR_MASK \
117 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
119 #define PT32_BASE_ADDR_MASK PAGE_MASK
120 #define PT32_DIR_BASE_ADDR_MASK \
121 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
123 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
126 #define PFERR_PRESENT_MASK (1U << 0)
127 #define PFERR_WRITE_MASK (1U << 1)
128 #define PFERR_USER_MASK (1U << 2)
129 #define PFERR_RSVD_MASK (1U << 3)
130 #define PFERR_FETCH_MASK (1U << 4)
132 #define PT_DIRECTORY_LEVEL 2
133 #define PT_PAGE_TABLE_LEVEL 1
137 #define ACC_EXEC_MASK 1
138 #define ACC_WRITE_MASK PT_WRITABLE_MASK
139 #define ACC_USER_MASK PT_USER_MASK
140 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
142 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
144 struct kvm_rmap_desc
{
145 u64
*shadow_ptes
[RMAP_EXT
];
146 struct kvm_rmap_desc
*more
;
149 struct kvm_shadow_walk_iterator
{
157 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
158 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
159 shadow_walk_okay(&(_walker)); \
160 shadow_walk_next(&(_walker)))
163 struct kvm_unsync_walk
{
164 int (*entry
) (struct kvm_mmu_page
*sp
, struct kvm_unsync_walk
*walk
);
167 typedef int (*mmu_parent_walk_fn
) (struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
);
169 static struct kmem_cache
*pte_chain_cache
;
170 static struct kmem_cache
*rmap_desc_cache
;
171 static struct kmem_cache
*mmu_page_header_cache
;
173 static u64 __read_mostly shadow_trap_nonpresent_pte
;
174 static u64 __read_mostly shadow_notrap_nonpresent_pte
;
175 static u64 __read_mostly shadow_base_present_pte
;
176 static u64 __read_mostly shadow_nx_mask
;
177 static u64 __read_mostly shadow_x_mask
; /* mutual exclusive with nx_mask */
178 static u64 __read_mostly shadow_user_mask
;
179 static u64 __read_mostly shadow_accessed_mask
;
180 static u64 __read_mostly shadow_dirty_mask
;
182 static inline u64
rsvd_bits(int s
, int e
)
184 return ((1ULL << (e
- s
+ 1)) - 1) << s
;
187 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte
, u64 notrap_pte
)
189 shadow_trap_nonpresent_pte
= trap_pte
;
190 shadow_notrap_nonpresent_pte
= notrap_pte
;
192 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes
);
194 void kvm_mmu_set_base_ptes(u64 base_pte
)
196 shadow_base_present_pte
= base_pte
;
198 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes
);
200 void kvm_mmu_set_mask_ptes(u64 user_mask
, u64 accessed_mask
,
201 u64 dirty_mask
, u64 nx_mask
, u64 x_mask
)
203 shadow_user_mask
= user_mask
;
204 shadow_accessed_mask
= accessed_mask
;
205 shadow_dirty_mask
= dirty_mask
;
206 shadow_nx_mask
= nx_mask
;
207 shadow_x_mask
= x_mask
;
209 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes
);
211 static int is_write_protection(struct kvm_vcpu
*vcpu
)
213 return vcpu
->arch
.cr0
& X86_CR0_WP
;
216 static int is_cpuid_PSE36(void)
221 static int is_nx(struct kvm_vcpu
*vcpu
)
223 return vcpu
->arch
.shadow_efer
& EFER_NX
;
226 static int is_shadow_present_pte(u64 pte
)
228 return pte
!= shadow_trap_nonpresent_pte
229 && pte
!= shadow_notrap_nonpresent_pte
;
232 static int is_large_pte(u64 pte
)
234 return pte
& PT_PAGE_SIZE_MASK
;
237 static int is_writeble_pte(unsigned long pte
)
239 return pte
& PT_WRITABLE_MASK
;
242 static int is_dirty_pte(unsigned long pte
)
244 return pte
& shadow_dirty_mask
;
247 static int is_rmap_pte(u64 pte
)
249 return is_shadow_present_pte(pte
);
252 static pfn_t
spte_to_pfn(u64 pte
)
254 return (pte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
257 static gfn_t
pse36_gfn_delta(u32 gpte
)
259 int shift
= 32 - PT32_DIR_PSE36_SHIFT
- PAGE_SHIFT
;
261 return (gpte
& PT32_DIR_PSE36_MASK
) << shift
;
264 static void set_shadow_pte(u64
*sptep
, u64 spte
)
267 set_64bit((unsigned long *)sptep
, spte
);
269 set_64bit((unsigned long long *)sptep
, spte
);
273 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
274 struct kmem_cache
*base_cache
, int min
)
278 if (cache
->nobjs
>= min
)
280 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
281 obj
= kmem_cache_zalloc(base_cache
, GFP_KERNEL
);
284 cache
->objects
[cache
->nobjs
++] = obj
;
289 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
292 kfree(mc
->objects
[--mc
->nobjs
]);
295 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache
*cache
,
300 if (cache
->nobjs
>= min
)
302 while (cache
->nobjs
< ARRAY_SIZE(cache
->objects
)) {
303 page
= alloc_page(GFP_KERNEL
);
306 set_page_private(page
, 0);
307 cache
->objects
[cache
->nobjs
++] = page_address(page
);
312 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache
*mc
)
315 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
318 static int mmu_topup_memory_caches(struct kvm_vcpu
*vcpu
)
322 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
,
326 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
,
330 r
= mmu_topup_memory_cache_page(&vcpu
->arch
.mmu_page_cache
, 8);
333 r
= mmu_topup_memory_cache(&vcpu
->arch
.mmu_page_header_cache
,
334 mmu_page_header_cache
, 4);
339 static void mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
341 mmu_free_memory_cache(&vcpu
->arch
.mmu_pte_chain_cache
);
342 mmu_free_memory_cache(&vcpu
->arch
.mmu_rmap_desc_cache
);
343 mmu_free_memory_cache_page(&vcpu
->arch
.mmu_page_cache
);
344 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_header_cache
);
347 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
,
353 p
= mc
->objects
[--mc
->nobjs
];
357 static struct kvm_pte_chain
*mmu_alloc_pte_chain(struct kvm_vcpu
*vcpu
)
359 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_pte_chain_cache
,
360 sizeof(struct kvm_pte_chain
));
363 static void mmu_free_pte_chain(struct kvm_pte_chain
*pc
)
368 static struct kvm_rmap_desc
*mmu_alloc_rmap_desc(struct kvm_vcpu
*vcpu
)
370 return mmu_memory_cache_alloc(&vcpu
->arch
.mmu_rmap_desc_cache
,
371 sizeof(struct kvm_rmap_desc
));
374 static void mmu_free_rmap_desc(struct kvm_rmap_desc
*rd
)
380 * Return the pointer to the largepage write count for a given
381 * gfn, handling slots that are not large page aligned.
383 static int *slot_largepage_idx(gfn_t gfn
, struct kvm_memory_slot
*slot
)
387 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
388 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
389 return &slot
->lpage_info
[idx
].write_count
;
392 static void account_shadowed(struct kvm
*kvm
, gfn_t gfn
)
396 gfn
= unalias_gfn(kvm
, gfn
);
397 write_count
= slot_largepage_idx(gfn
,
398 gfn_to_memslot_unaliased(kvm
, gfn
));
402 static void unaccount_shadowed(struct kvm
*kvm
, gfn_t gfn
)
406 gfn
= unalias_gfn(kvm
, gfn
);
407 write_count
= slot_largepage_idx(gfn
,
408 gfn_to_memslot_unaliased(kvm
, gfn
));
410 WARN_ON(*write_count
< 0);
413 static int has_wrprotected_page(struct kvm
*kvm
, gfn_t gfn
)
415 struct kvm_memory_slot
*slot
;
418 gfn
= unalias_gfn(kvm
, gfn
);
419 slot
= gfn_to_memslot_unaliased(kvm
, gfn
);
421 largepage_idx
= slot_largepage_idx(gfn
, slot
);
422 return *largepage_idx
;
428 static int host_largepage_backed(struct kvm
*kvm
, gfn_t gfn
)
430 struct vm_area_struct
*vma
;
434 addr
= gfn_to_hva(kvm
, gfn
);
435 if (kvm_is_error_hva(addr
))
438 down_read(¤t
->mm
->mmap_sem
);
439 vma
= find_vma(current
->mm
, addr
);
440 if (vma
&& is_vm_hugetlb_page(vma
))
442 up_read(¤t
->mm
->mmap_sem
);
447 static int is_largepage_backed(struct kvm_vcpu
*vcpu
, gfn_t large_gfn
)
449 struct kvm_memory_slot
*slot
;
451 if (has_wrprotected_page(vcpu
->kvm
, large_gfn
))
454 if (!host_largepage_backed(vcpu
->kvm
, large_gfn
))
457 slot
= gfn_to_memslot(vcpu
->kvm
, large_gfn
);
458 if (slot
&& slot
->dirty_bitmap
)
465 * Take gfn and return the reverse mapping to it.
466 * Note: gfn must be unaliased before this function get called
469 static unsigned long *gfn_to_rmap(struct kvm
*kvm
, gfn_t gfn
, int lpage
)
471 struct kvm_memory_slot
*slot
;
474 slot
= gfn_to_memslot(kvm
, gfn
);
476 return &slot
->rmap
[gfn
- slot
->base_gfn
];
478 idx
= (gfn
/ KVM_PAGES_PER_HPAGE
) -
479 (slot
->base_gfn
/ KVM_PAGES_PER_HPAGE
);
481 return &slot
->lpage_info
[idx
].rmap_pde
;
485 * Reverse mapping data structures:
487 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
488 * that points to page_address(page).
490 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
491 * containing more mappings.
493 static void rmap_add(struct kvm_vcpu
*vcpu
, u64
*spte
, gfn_t gfn
, int lpage
)
495 struct kvm_mmu_page
*sp
;
496 struct kvm_rmap_desc
*desc
;
497 unsigned long *rmapp
;
500 if (!is_rmap_pte(*spte
))
502 gfn
= unalias_gfn(vcpu
->kvm
, gfn
);
503 sp
= page_header(__pa(spte
));
504 sp
->gfns
[spte
- sp
->spt
] = gfn
;
505 rmapp
= gfn_to_rmap(vcpu
->kvm
, gfn
, lpage
);
507 rmap_printk("rmap_add: %p %llx 0->1\n", spte
, *spte
);
508 *rmapp
= (unsigned long)spte
;
509 } else if (!(*rmapp
& 1)) {
510 rmap_printk("rmap_add: %p %llx 1->many\n", spte
, *spte
);
511 desc
= mmu_alloc_rmap_desc(vcpu
);
512 desc
->shadow_ptes
[0] = (u64
*)*rmapp
;
513 desc
->shadow_ptes
[1] = spte
;
514 *rmapp
= (unsigned long)desc
| 1;
516 rmap_printk("rmap_add: %p %llx many->many\n", spte
, *spte
);
517 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
518 while (desc
->shadow_ptes
[RMAP_EXT
-1] && desc
->more
)
520 if (desc
->shadow_ptes
[RMAP_EXT
-1]) {
521 desc
->more
= mmu_alloc_rmap_desc(vcpu
);
524 for (i
= 0; desc
->shadow_ptes
[i
]; ++i
)
526 desc
->shadow_ptes
[i
] = spte
;
530 static void rmap_desc_remove_entry(unsigned long *rmapp
,
531 struct kvm_rmap_desc
*desc
,
533 struct kvm_rmap_desc
*prev_desc
)
537 for (j
= RMAP_EXT
- 1; !desc
->shadow_ptes
[j
] && j
> i
; --j
)
539 desc
->shadow_ptes
[i
] = desc
->shadow_ptes
[j
];
540 desc
->shadow_ptes
[j
] = NULL
;
543 if (!prev_desc
&& !desc
->more
)
544 *rmapp
= (unsigned long)desc
->shadow_ptes
[0];
547 prev_desc
->more
= desc
->more
;
549 *rmapp
= (unsigned long)desc
->more
| 1;
550 mmu_free_rmap_desc(desc
);
553 static void rmap_remove(struct kvm
*kvm
, u64
*spte
)
555 struct kvm_rmap_desc
*desc
;
556 struct kvm_rmap_desc
*prev_desc
;
557 struct kvm_mmu_page
*sp
;
559 unsigned long *rmapp
;
562 if (!is_rmap_pte(*spte
))
564 sp
= page_header(__pa(spte
));
565 pfn
= spte_to_pfn(*spte
);
566 if (*spte
& shadow_accessed_mask
)
567 kvm_set_pfn_accessed(pfn
);
568 if (is_writeble_pte(*spte
))
569 kvm_release_pfn_dirty(pfn
);
571 kvm_release_pfn_clean(pfn
);
572 rmapp
= gfn_to_rmap(kvm
, sp
->gfns
[spte
- sp
->spt
], is_large_pte(*spte
));
574 printk(KERN_ERR
"rmap_remove: %p %llx 0->BUG\n", spte
, *spte
);
576 } else if (!(*rmapp
& 1)) {
577 rmap_printk("rmap_remove: %p %llx 1->0\n", spte
, *spte
);
578 if ((u64
*)*rmapp
!= spte
) {
579 printk(KERN_ERR
"rmap_remove: %p %llx 1->BUG\n",
585 rmap_printk("rmap_remove: %p %llx many->many\n", spte
, *spte
);
586 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
589 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
)
590 if (desc
->shadow_ptes
[i
] == spte
) {
591 rmap_desc_remove_entry(rmapp
,
603 static u64
*rmap_next(struct kvm
*kvm
, unsigned long *rmapp
, u64
*spte
)
605 struct kvm_rmap_desc
*desc
;
606 struct kvm_rmap_desc
*prev_desc
;
612 else if (!(*rmapp
& 1)) {
614 return (u64
*)*rmapp
;
617 desc
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
621 for (i
= 0; i
< RMAP_EXT
&& desc
->shadow_ptes
[i
]; ++i
) {
622 if (prev_spte
== spte
)
623 return desc
->shadow_ptes
[i
];
624 prev_spte
= desc
->shadow_ptes
[i
];
631 static int rmap_write_protect(struct kvm
*kvm
, u64 gfn
)
633 unsigned long *rmapp
;
635 int write_protected
= 0;
637 gfn
= unalias_gfn(kvm
, gfn
);
638 rmapp
= gfn_to_rmap(kvm
, gfn
, 0);
640 spte
= rmap_next(kvm
, rmapp
, NULL
);
643 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
644 rmap_printk("rmap_write_protect: spte %p %llx\n", spte
, *spte
);
645 if (is_writeble_pte(*spte
)) {
646 set_shadow_pte(spte
, *spte
& ~PT_WRITABLE_MASK
);
649 spte
= rmap_next(kvm
, rmapp
, spte
);
651 if (write_protected
) {
654 spte
= rmap_next(kvm
, rmapp
, NULL
);
655 pfn
= spte_to_pfn(*spte
);
656 kvm_set_pfn_dirty(pfn
);
659 /* check for huge page mappings */
660 rmapp
= gfn_to_rmap(kvm
, gfn
, 1);
661 spte
= rmap_next(kvm
, rmapp
, NULL
);
664 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
665 BUG_ON((*spte
& (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
)) != (PT_PAGE_SIZE_MASK
|PT_PRESENT_MASK
));
666 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte
, *spte
, gfn
);
667 if (is_writeble_pte(*spte
)) {
668 rmap_remove(kvm
, spte
);
670 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
674 spte
= rmap_next(kvm
, rmapp
, spte
);
677 return write_protected
;
680 static int kvm_unmap_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
683 int need_tlb_flush
= 0;
685 while ((spte
= rmap_next(kvm
, rmapp
, NULL
))) {
686 BUG_ON(!(*spte
& PT_PRESENT_MASK
));
687 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte
, *spte
);
688 rmap_remove(kvm
, spte
);
689 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
692 return need_tlb_flush
;
695 static int kvm_handle_hva(struct kvm
*kvm
, unsigned long hva
,
696 int (*handler
)(struct kvm
*kvm
, unsigned long *rmapp
))
702 * If mmap_sem isn't taken, we can look the memslots with only
703 * the mmu_lock by skipping over the slots with userspace_addr == 0.
705 for (i
= 0; i
< kvm
->nmemslots
; i
++) {
706 struct kvm_memory_slot
*memslot
= &kvm
->memslots
[i
];
707 unsigned long start
= memslot
->userspace_addr
;
710 /* mmu_lock protects userspace_addr */
714 end
= start
+ (memslot
->npages
<< PAGE_SHIFT
);
715 if (hva
>= start
&& hva
< end
) {
716 gfn_t gfn_offset
= (hva
- start
) >> PAGE_SHIFT
;
717 retval
|= handler(kvm
, &memslot
->rmap
[gfn_offset
]);
718 retval
|= handler(kvm
,
719 &memslot
->lpage_info
[
721 KVM_PAGES_PER_HPAGE
].rmap_pde
);
728 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
730 return kvm_handle_hva(kvm
, hva
, kvm_unmap_rmapp
);
733 static int kvm_age_rmapp(struct kvm
*kvm
, unsigned long *rmapp
)
738 /* always return old for EPT */
739 if (!shadow_accessed_mask
)
742 spte
= rmap_next(kvm
, rmapp
, NULL
);
746 BUG_ON(!(_spte
& PT_PRESENT_MASK
));
747 _young
= _spte
& PT_ACCESSED_MASK
;
750 clear_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
752 spte
= rmap_next(kvm
, rmapp
, spte
);
757 int kvm_age_hva(struct kvm
*kvm
, unsigned long hva
)
759 return kvm_handle_hva(kvm
, hva
, kvm_age_rmapp
);
763 static int is_empty_shadow_page(u64
*spt
)
768 for (pos
= spt
, end
= pos
+ PAGE_SIZE
/ sizeof(u64
); pos
!= end
; pos
++)
769 if (is_shadow_present_pte(*pos
)) {
770 printk(KERN_ERR
"%s: %p %llx\n", __func__
,
778 static void kvm_mmu_free_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
780 ASSERT(is_empty_shadow_page(sp
->spt
));
782 __free_page(virt_to_page(sp
->spt
));
783 __free_page(virt_to_page(sp
->gfns
));
785 ++kvm
->arch
.n_free_mmu_pages
;
788 static unsigned kvm_page_table_hashfn(gfn_t gfn
)
790 return gfn
& ((1 << KVM_MMU_HASH_SHIFT
) - 1);
793 static struct kvm_mmu_page
*kvm_mmu_alloc_page(struct kvm_vcpu
*vcpu
,
796 struct kvm_mmu_page
*sp
;
798 sp
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_header_cache
, sizeof *sp
);
799 sp
->spt
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
800 sp
->gfns
= mmu_memory_cache_alloc(&vcpu
->arch
.mmu_page_cache
, PAGE_SIZE
);
801 set_page_private(virt_to_page(sp
->spt
), (unsigned long)sp
);
802 list_add(&sp
->link
, &vcpu
->kvm
->arch
.active_mmu_pages
);
803 INIT_LIST_HEAD(&sp
->oos_link
);
804 bitmap_zero(sp
->slot_bitmap
, KVM_MEMORY_SLOTS
+ KVM_PRIVATE_MEM_SLOTS
);
806 sp
->parent_pte
= parent_pte
;
807 --vcpu
->kvm
->arch
.n_free_mmu_pages
;
811 static void mmu_page_add_parent_pte(struct kvm_vcpu
*vcpu
,
812 struct kvm_mmu_page
*sp
, u64
*parent_pte
)
814 struct kvm_pte_chain
*pte_chain
;
815 struct hlist_node
*node
;
820 if (!sp
->multimapped
) {
821 u64
*old
= sp
->parent_pte
;
824 sp
->parent_pte
= parent_pte
;
828 pte_chain
= mmu_alloc_pte_chain(vcpu
);
829 INIT_HLIST_HEAD(&sp
->parent_ptes
);
830 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
831 pte_chain
->parent_ptes
[0] = old
;
833 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
) {
834 if (pte_chain
->parent_ptes
[NR_PTE_CHAIN_ENTRIES
-1])
836 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
)
837 if (!pte_chain
->parent_ptes
[i
]) {
838 pte_chain
->parent_ptes
[i
] = parent_pte
;
842 pte_chain
= mmu_alloc_pte_chain(vcpu
);
844 hlist_add_head(&pte_chain
->link
, &sp
->parent_ptes
);
845 pte_chain
->parent_ptes
[0] = parent_pte
;
848 static void mmu_page_remove_parent_pte(struct kvm_mmu_page
*sp
,
851 struct kvm_pte_chain
*pte_chain
;
852 struct hlist_node
*node
;
855 if (!sp
->multimapped
) {
856 BUG_ON(sp
->parent_pte
!= parent_pte
);
857 sp
->parent_pte
= NULL
;
860 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
861 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
862 if (!pte_chain
->parent_ptes
[i
])
864 if (pte_chain
->parent_ptes
[i
] != parent_pte
)
866 while (i
+ 1 < NR_PTE_CHAIN_ENTRIES
867 && pte_chain
->parent_ptes
[i
+ 1]) {
868 pte_chain
->parent_ptes
[i
]
869 = pte_chain
->parent_ptes
[i
+ 1];
872 pte_chain
->parent_ptes
[i
] = NULL
;
874 hlist_del(&pte_chain
->link
);
875 mmu_free_pte_chain(pte_chain
);
876 if (hlist_empty(&sp
->parent_ptes
)) {
878 sp
->parent_pte
= NULL
;
887 static void mmu_parent_walk(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
,
888 mmu_parent_walk_fn fn
)
890 struct kvm_pte_chain
*pte_chain
;
891 struct hlist_node
*node
;
892 struct kvm_mmu_page
*parent_sp
;
895 if (!sp
->multimapped
&& sp
->parent_pte
) {
896 parent_sp
= page_header(__pa(sp
->parent_pte
));
898 mmu_parent_walk(vcpu
, parent_sp
, fn
);
901 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
902 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
903 if (!pte_chain
->parent_ptes
[i
])
905 parent_sp
= page_header(__pa(pte_chain
->parent_ptes
[i
]));
907 mmu_parent_walk(vcpu
, parent_sp
, fn
);
911 static void kvm_mmu_update_unsync_bitmap(u64
*spte
)
914 struct kvm_mmu_page
*sp
= page_header(__pa(spte
));
916 index
= spte
- sp
->spt
;
917 if (!__test_and_set_bit(index
, sp
->unsync_child_bitmap
))
918 sp
->unsync_children
++;
919 WARN_ON(!sp
->unsync_children
);
922 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page
*sp
)
924 struct kvm_pte_chain
*pte_chain
;
925 struct hlist_node
*node
;
931 if (!sp
->multimapped
) {
932 kvm_mmu_update_unsync_bitmap(sp
->parent_pte
);
936 hlist_for_each_entry(pte_chain
, node
, &sp
->parent_ptes
, link
)
937 for (i
= 0; i
< NR_PTE_CHAIN_ENTRIES
; ++i
) {
938 if (!pte_chain
->parent_ptes
[i
])
940 kvm_mmu_update_unsync_bitmap(pte_chain
->parent_ptes
[i
]);
944 static int unsync_walk_fn(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
946 kvm_mmu_update_parents_unsync(sp
);
950 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu
*vcpu
,
951 struct kvm_mmu_page
*sp
)
953 mmu_parent_walk(vcpu
, sp
, unsync_walk_fn
);
954 kvm_mmu_update_parents_unsync(sp
);
957 static void nonpaging_prefetch_page(struct kvm_vcpu
*vcpu
,
958 struct kvm_mmu_page
*sp
)
962 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
963 sp
->spt
[i
] = shadow_trap_nonpresent_pte
;
966 static int nonpaging_sync_page(struct kvm_vcpu
*vcpu
,
967 struct kvm_mmu_page
*sp
)
972 static void nonpaging_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
976 #define KVM_PAGE_ARRAY_NR 16
978 struct kvm_mmu_pages
{
979 struct mmu_page_and_offset
{
980 struct kvm_mmu_page
*sp
;
982 } page
[KVM_PAGE_ARRAY_NR
];
986 #define for_each_unsync_children(bitmap, idx) \
987 for (idx = find_first_bit(bitmap, 512); \
989 idx = find_next_bit(bitmap, 512, idx+1))
991 static int mmu_pages_add(struct kvm_mmu_pages
*pvec
, struct kvm_mmu_page
*sp
,
997 for (i
=0; i
< pvec
->nr
; i
++)
998 if (pvec
->page
[i
].sp
== sp
)
1001 pvec
->page
[pvec
->nr
].sp
= sp
;
1002 pvec
->page
[pvec
->nr
].idx
= idx
;
1004 return (pvec
->nr
== KVM_PAGE_ARRAY_NR
);
1007 static int __mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1008 struct kvm_mmu_pages
*pvec
)
1010 int i
, ret
, nr_unsync_leaf
= 0;
1012 for_each_unsync_children(sp
->unsync_child_bitmap
, i
) {
1013 u64 ent
= sp
->spt
[i
];
1015 if (is_shadow_present_pte(ent
) && !is_large_pte(ent
)) {
1016 struct kvm_mmu_page
*child
;
1017 child
= page_header(ent
& PT64_BASE_ADDR_MASK
);
1019 if (child
->unsync_children
) {
1020 if (mmu_pages_add(pvec
, child
, i
))
1023 ret
= __mmu_unsync_walk(child
, pvec
);
1025 __clear_bit(i
, sp
->unsync_child_bitmap
);
1027 nr_unsync_leaf
+= ret
;
1032 if (child
->unsync
) {
1034 if (mmu_pages_add(pvec
, child
, i
))
1040 if (find_first_bit(sp
->unsync_child_bitmap
, 512) == 512)
1041 sp
->unsync_children
= 0;
1043 return nr_unsync_leaf
;
1046 static int mmu_unsync_walk(struct kvm_mmu_page
*sp
,
1047 struct kvm_mmu_pages
*pvec
)
1049 if (!sp
->unsync_children
)
1052 mmu_pages_add(pvec
, sp
, 0);
1053 return __mmu_unsync_walk(sp
, pvec
);
1056 static struct kvm_mmu_page
*kvm_mmu_lookup_page(struct kvm
*kvm
, gfn_t gfn
)
1059 struct hlist_head
*bucket
;
1060 struct kvm_mmu_page
*sp
;
1061 struct hlist_node
*node
;
1063 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1064 index
= kvm_page_table_hashfn(gfn
);
1065 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1066 hlist_for_each_entry(sp
, node
, bucket
, hash_link
)
1067 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1068 && !sp
->role
.invalid
) {
1069 pgprintk("%s: found role %x\n",
1070 __func__
, sp
->role
.word
);
1076 static void kvm_unlink_unsync_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1078 WARN_ON(!sp
->unsync
);
1080 --kvm
->stat
.mmu_unsync
;
1083 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
);
1085 static int kvm_sync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1087 if (sp
->role
.glevels
!= vcpu
->arch
.mmu
.root_level
) {
1088 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1092 if (rmap_write_protect(vcpu
->kvm
, sp
->gfn
))
1093 kvm_flush_remote_tlbs(vcpu
->kvm
);
1094 kvm_unlink_unsync_page(vcpu
->kvm
, sp
);
1095 if (vcpu
->arch
.mmu
.sync_page(vcpu
, sp
)) {
1096 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1100 kvm_mmu_flush_tlb(vcpu
);
1104 struct mmu_page_path
{
1105 struct kvm_mmu_page
*parent
[PT64_ROOT_LEVEL
-1];
1106 unsigned int idx
[PT64_ROOT_LEVEL
-1];
1109 #define for_each_sp(pvec, sp, parents, i) \
1110 for (i = mmu_pages_next(&pvec, &parents, -1), \
1111 sp = pvec.page[i].sp; \
1112 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1113 i = mmu_pages_next(&pvec, &parents, i))
1115 static int mmu_pages_next(struct kvm_mmu_pages
*pvec
,
1116 struct mmu_page_path
*parents
,
1121 for (n
= i
+1; n
< pvec
->nr
; n
++) {
1122 struct kvm_mmu_page
*sp
= pvec
->page
[n
].sp
;
1124 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1125 parents
->idx
[0] = pvec
->page
[n
].idx
;
1129 parents
->parent
[sp
->role
.level
-2] = sp
;
1130 parents
->idx
[sp
->role
.level
-1] = pvec
->page
[n
].idx
;
1136 static void mmu_pages_clear_parents(struct mmu_page_path
*parents
)
1138 struct kvm_mmu_page
*sp
;
1139 unsigned int level
= 0;
1142 unsigned int idx
= parents
->idx
[level
];
1144 sp
= parents
->parent
[level
];
1148 --sp
->unsync_children
;
1149 WARN_ON((int)sp
->unsync_children
< 0);
1150 __clear_bit(idx
, sp
->unsync_child_bitmap
);
1152 } while (level
< PT64_ROOT_LEVEL
-1 && !sp
->unsync_children
);
1155 static void kvm_mmu_pages_init(struct kvm_mmu_page
*parent
,
1156 struct mmu_page_path
*parents
,
1157 struct kvm_mmu_pages
*pvec
)
1159 parents
->parent
[parent
->role
.level
-1] = NULL
;
1163 static void mmu_sync_children(struct kvm_vcpu
*vcpu
,
1164 struct kvm_mmu_page
*parent
)
1167 struct kvm_mmu_page
*sp
;
1168 struct mmu_page_path parents
;
1169 struct kvm_mmu_pages pages
;
1171 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1172 while (mmu_unsync_walk(parent
, &pages
)) {
1175 for_each_sp(pages
, sp
, parents
, i
)
1176 protected |= rmap_write_protect(vcpu
->kvm
, sp
->gfn
);
1179 kvm_flush_remote_tlbs(vcpu
->kvm
);
1181 for_each_sp(pages
, sp
, parents
, i
) {
1182 kvm_sync_page(vcpu
, sp
);
1183 mmu_pages_clear_parents(&parents
);
1185 cond_resched_lock(&vcpu
->kvm
->mmu_lock
);
1186 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1190 static struct kvm_mmu_page
*kvm_mmu_get_page(struct kvm_vcpu
*vcpu
,
1198 union kvm_mmu_page_role role
;
1201 struct hlist_head
*bucket
;
1202 struct kvm_mmu_page
*sp
;
1203 struct hlist_node
*node
, *tmp
;
1205 role
= vcpu
->arch
.mmu
.base_role
;
1207 role
.direct
= direct
;
1208 role
.access
= access
;
1209 if (vcpu
->arch
.mmu
.root_level
<= PT32_ROOT_LEVEL
) {
1210 quadrant
= gaddr
>> (PAGE_SHIFT
+ (PT64_PT_BITS
* level
));
1211 quadrant
&= (1 << ((PT32_PT_BITS
- PT64_PT_BITS
) * level
)) - 1;
1212 role
.quadrant
= quadrant
;
1214 pgprintk("%s: looking gfn %lx role %x\n", __func__
,
1216 index
= kvm_page_table_hashfn(gfn
);
1217 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1218 hlist_for_each_entry_safe(sp
, node
, tmp
, bucket
, hash_link
)
1219 if (sp
->gfn
== gfn
) {
1221 if (kvm_sync_page(vcpu
, sp
))
1224 if (sp
->role
.word
!= role
.word
)
1227 mmu_page_add_parent_pte(vcpu
, sp
, parent_pte
);
1228 if (sp
->unsync_children
) {
1229 set_bit(KVM_REQ_MMU_SYNC
, &vcpu
->requests
);
1230 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1232 pgprintk("%s: found\n", __func__
);
1235 ++vcpu
->kvm
->stat
.mmu_cache_miss
;
1236 sp
= kvm_mmu_alloc_page(vcpu
, parent_pte
);
1239 pgprintk("%s: adding gfn %lx role %x\n", __func__
, gfn
, role
.word
);
1242 hlist_add_head(&sp
->hash_link
, bucket
);
1244 if (rmap_write_protect(vcpu
->kvm
, gfn
))
1245 kvm_flush_remote_tlbs(vcpu
->kvm
);
1246 account_shadowed(vcpu
->kvm
, gfn
);
1248 if (shadow_trap_nonpresent_pte
!= shadow_notrap_nonpresent_pte
)
1249 vcpu
->arch
.mmu
.prefetch_page(vcpu
, sp
);
1251 nonpaging_prefetch_page(vcpu
, sp
);
1255 static void shadow_walk_init(struct kvm_shadow_walk_iterator
*iterator
,
1256 struct kvm_vcpu
*vcpu
, u64 addr
)
1258 iterator
->addr
= addr
;
1259 iterator
->shadow_addr
= vcpu
->arch
.mmu
.root_hpa
;
1260 iterator
->level
= vcpu
->arch
.mmu
.shadow_root_level
;
1261 if (iterator
->level
== PT32E_ROOT_LEVEL
) {
1262 iterator
->shadow_addr
1263 = vcpu
->arch
.mmu
.pae_root
[(addr
>> 30) & 3];
1264 iterator
->shadow_addr
&= PT64_BASE_ADDR_MASK
;
1266 if (!iterator
->shadow_addr
)
1267 iterator
->level
= 0;
1271 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator
*iterator
)
1273 if (iterator
->level
< PT_PAGE_TABLE_LEVEL
)
1275 iterator
->index
= SHADOW_PT_INDEX(iterator
->addr
, iterator
->level
);
1276 iterator
->sptep
= ((u64
*)__va(iterator
->shadow_addr
)) + iterator
->index
;
1280 static void shadow_walk_next(struct kvm_shadow_walk_iterator
*iterator
)
1282 iterator
->shadow_addr
= *iterator
->sptep
& PT64_BASE_ADDR_MASK
;
1286 static void kvm_mmu_page_unlink_children(struct kvm
*kvm
,
1287 struct kvm_mmu_page
*sp
)
1295 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
) {
1296 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1297 if (is_shadow_present_pte(pt
[i
]))
1298 rmap_remove(kvm
, &pt
[i
]);
1299 pt
[i
] = shadow_trap_nonpresent_pte
;
1304 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1307 if (is_shadow_present_pte(ent
)) {
1308 if (!is_large_pte(ent
)) {
1309 ent
&= PT64_BASE_ADDR_MASK
;
1310 mmu_page_remove_parent_pte(page_header(ent
),
1314 rmap_remove(kvm
, &pt
[i
]);
1317 pt
[i
] = shadow_trap_nonpresent_pte
;
1321 static void kvm_mmu_put_page(struct kvm_mmu_page
*sp
, u64
*parent_pte
)
1323 mmu_page_remove_parent_pte(sp
, parent_pte
);
1326 static void kvm_mmu_reset_last_pte_updated(struct kvm
*kvm
)
1330 for (i
= 0; i
< KVM_MAX_VCPUS
; ++i
)
1332 kvm
->vcpus
[i
]->arch
.last_pte_updated
= NULL
;
1335 static void kvm_mmu_unlink_parents(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1339 while (sp
->multimapped
|| sp
->parent_pte
) {
1340 if (!sp
->multimapped
)
1341 parent_pte
= sp
->parent_pte
;
1343 struct kvm_pte_chain
*chain
;
1345 chain
= container_of(sp
->parent_ptes
.first
,
1346 struct kvm_pte_chain
, link
);
1347 parent_pte
= chain
->parent_ptes
[0];
1349 BUG_ON(!parent_pte
);
1350 kvm_mmu_put_page(sp
, parent_pte
);
1351 set_shadow_pte(parent_pte
, shadow_trap_nonpresent_pte
);
1355 static int mmu_zap_unsync_children(struct kvm
*kvm
,
1356 struct kvm_mmu_page
*parent
)
1359 struct mmu_page_path parents
;
1360 struct kvm_mmu_pages pages
;
1362 if (parent
->role
.level
== PT_PAGE_TABLE_LEVEL
)
1365 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1366 while (mmu_unsync_walk(parent
, &pages
)) {
1367 struct kvm_mmu_page
*sp
;
1369 for_each_sp(pages
, sp
, parents
, i
) {
1370 kvm_mmu_zap_page(kvm
, sp
);
1371 mmu_pages_clear_parents(&parents
);
1374 kvm_mmu_pages_init(parent
, &parents
, &pages
);
1380 static int kvm_mmu_zap_page(struct kvm
*kvm
, struct kvm_mmu_page
*sp
)
1383 ++kvm
->stat
.mmu_shadow_zapped
;
1384 ret
= mmu_zap_unsync_children(kvm
, sp
);
1385 kvm_mmu_page_unlink_children(kvm
, sp
);
1386 kvm_mmu_unlink_parents(kvm
, sp
);
1387 kvm_flush_remote_tlbs(kvm
);
1388 if (!sp
->role
.invalid
&& !sp
->role
.direct
)
1389 unaccount_shadowed(kvm
, sp
->gfn
);
1391 kvm_unlink_unsync_page(kvm
, sp
);
1392 if (!sp
->root_count
) {
1393 hlist_del(&sp
->hash_link
);
1394 kvm_mmu_free_page(kvm
, sp
);
1396 sp
->role
.invalid
= 1;
1397 list_move(&sp
->link
, &kvm
->arch
.active_mmu_pages
);
1398 kvm_reload_remote_mmus(kvm
);
1400 kvm_mmu_reset_last_pte_updated(kvm
);
1405 * Changing the number of mmu pages allocated to the vm
1406 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1408 void kvm_mmu_change_mmu_pages(struct kvm
*kvm
, unsigned int kvm_nr_mmu_pages
)
1411 * If we set the number of mmu pages to be smaller be than the
1412 * number of actived pages , we must to free some mmu pages before we
1416 if ((kvm
->arch
.n_alloc_mmu_pages
- kvm
->arch
.n_free_mmu_pages
) >
1418 int n_used_mmu_pages
= kvm
->arch
.n_alloc_mmu_pages
1419 - kvm
->arch
.n_free_mmu_pages
;
1421 while (n_used_mmu_pages
> kvm_nr_mmu_pages
) {
1422 struct kvm_mmu_page
*page
;
1424 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
1425 struct kvm_mmu_page
, link
);
1426 kvm_mmu_zap_page(kvm
, page
);
1429 kvm
->arch
.n_free_mmu_pages
= 0;
1432 kvm
->arch
.n_free_mmu_pages
+= kvm_nr_mmu_pages
1433 - kvm
->arch
.n_alloc_mmu_pages
;
1435 kvm
->arch
.n_alloc_mmu_pages
= kvm_nr_mmu_pages
;
1438 static int kvm_mmu_unprotect_page(struct kvm
*kvm
, gfn_t gfn
)
1441 struct hlist_head
*bucket
;
1442 struct kvm_mmu_page
*sp
;
1443 struct hlist_node
*node
, *n
;
1446 pgprintk("%s: looking for gfn %lx\n", __func__
, gfn
);
1448 index
= kvm_page_table_hashfn(gfn
);
1449 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1450 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
)
1451 if (sp
->gfn
== gfn
&& !sp
->role
.direct
) {
1452 pgprintk("%s: gfn %lx role %x\n", __func__
, gfn
,
1455 if (kvm_mmu_zap_page(kvm
, sp
))
1461 static void mmu_unshadow(struct kvm
*kvm
, gfn_t gfn
)
1464 struct hlist_head
*bucket
;
1465 struct kvm_mmu_page
*sp
;
1466 struct hlist_node
*node
, *nn
;
1468 index
= kvm_page_table_hashfn(gfn
);
1469 bucket
= &kvm
->arch
.mmu_page_hash
[index
];
1470 hlist_for_each_entry_safe(sp
, node
, nn
, bucket
, hash_link
) {
1471 if (sp
->gfn
== gfn
&& !sp
->role
.direct
1472 && !sp
->role
.invalid
) {
1473 pgprintk("%s: zap %lx %x\n",
1474 __func__
, gfn
, sp
->role
.word
);
1475 kvm_mmu_zap_page(kvm
, sp
);
1480 static void page_header_update_slot(struct kvm
*kvm
, void *pte
, gfn_t gfn
)
1482 int slot
= memslot_id(kvm
, gfn_to_memslot(kvm
, gfn
));
1483 struct kvm_mmu_page
*sp
= page_header(__pa(pte
));
1485 __set_bit(slot
, sp
->slot_bitmap
);
1488 static void mmu_convert_notrap(struct kvm_mmu_page
*sp
)
1493 if (shadow_trap_nonpresent_pte
== shadow_notrap_nonpresent_pte
)
1496 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
1497 if (pt
[i
] == shadow_notrap_nonpresent_pte
)
1498 set_shadow_pte(&pt
[i
], shadow_trap_nonpresent_pte
);
1502 struct page
*gva_to_page(struct kvm_vcpu
*vcpu
, gva_t gva
)
1506 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
1508 if (gpa
== UNMAPPED_GVA
)
1511 page
= gfn_to_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
1517 * The function is based on mtrr_type_lookup() in
1518 * arch/x86/kernel/cpu/mtrr/generic.c
1520 static int get_mtrr_type(struct mtrr_state_type
*mtrr_state
,
1525 u8 prev_match
, curr_match
;
1526 int num_var_ranges
= KVM_NR_VAR_MTRR
;
1528 if (!mtrr_state
->enabled
)
1531 /* Make end inclusive end, instead of exclusive */
1534 /* Look in fixed ranges. Just return the type as per start */
1535 if (mtrr_state
->have_fixed
&& (start
< 0x100000)) {
1538 if (start
< 0x80000) {
1540 idx
+= (start
>> 16);
1541 return mtrr_state
->fixed_ranges
[idx
];
1542 } else if (start
< 0xC0000) {
1544 idx
+= ((start
- 0x80000) >> 14);
1545 return mtrr_state
->fixed_ranges
[idx
];
1546 } else if (start
< 0x1000000) {
1548 idx
+= ((start
- 0xC0000) >> 12);
1549 return mtrr_state
->fixed_ranges
[idx
];
1554 * Look in variable ranges
1555 * Look of multiple ranges matching this address and pick type
1556 * as per MTRR precedence
1558 if (!(mtrr_state
->enabled
& 2))
1559 return mtrr_state
->def_type
;
1562 for (i
= 0; i
< num_var_ranges
; ++i
) {
1563 unsigned short start_state
, end_state
;
1565 if (!(mtrr_state
->var_ranges
[i
].mask_lo
& (1 << 11)))
1568 base
= (((u64
)mtrr_state
->var_ranges
[i
].base_hi
) << 32) +
1569 (mtrr_state
->var_ranges
[i
].base_lo
& PAGE_MASK
);
1570 mask
= (((u64
)mtrr_state
->var_ranges
[i
].mask_hi
) << 32) +
1571 (mtrr_state
->var_ranges
[i
].mask_lo
& PAGE_MASK
);
1573 start_state
= ((start
& mask
) == (base
& mask
));
1574 end_state
= ((end
& mask
) == (base
& mask
));
1575 if (start_state
!= end_state
)
1578 if ((start
& mask
) != (base
& mask
))
1581 curr_match
= mtrr_state
->var_ranges
[i
].base_lo
& 0xff;
1582 if (prev_match
== 0xFF) {
1583 prev_match
= curr_match
;
1587 if (prev_match
== MTRR_TYPE_UNCACHABLE
||
1588 curr_match
== MTRR_TYPE_UNCACHABLE
)
1589 return MTRR_TYPE_UNCACHABLE
;
1591 if ((prev_match
== MTRR_TYPE_WRBACK
&&
1592 curr_match
== MTRR_TYPE_WRTHROUGH
) ||
1593 (prev_match
== MTRR_TYPE_WRTHROUGH
&&
1594 curr_match
== MTRR_TYPE_WRBACK
)) {
1595 prev_match
= MTRR_TYPE_WRTHROUGH
;
1596 curr_match
= MTRR_TYPE_WRTHROUGH
;
1599 if (prev_match
!= curr_match
)
1600 return MTRR_TYPE_UNCACHABLE
;
1603 if (prev_match
!= 0xFF)
1606 return mtrr_state
->def_type
;
1609 u8
kvm_get_guest_memory_type(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
1613 mtrr
= get_mtrr_type(&vcpu
->arch
.mtrr_state
, gfn
<< PAGE_SHIFT
,
1614 (gfn
<< PAGE_SHIFT
) + PAGE_SIZE
);
1615 if (mtrr
== 0xfe || mtrr
== 0xff)
1616 mtrr
= MTRR_TYPE_WRBACK
;
1619 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type
);
1621 static int kvm_unsync_page(struct kvm_vcpu
*vcpu
, struct kvm_mmu_page
*sp
)
1624 struct hlist_head
*bucket
;
1625 struct kvm_mmu_page
*s
;
1626 struct hlist_node
*node
, *n
;
1628 index
= kvm_page_table_hashfn(sp
->gfn
);
1629 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
1630 /* don't unsync if pagetable is shadowed with multiple roles */
1631 hlist_for_each_entry_safe(s
, node
, n
, bucket
, hash_link
) {
1632 if (s
->gfn
!= sp
->gfn
|| s
->role
.direct
)
1634 if (s
->role
.word
!= sp
->role
.word
)
1637 ++vcpu
->kvm
->stat
.mmu_unsync
;
1640 kvm_mmu_mark_parents_unsync(vcpu
, sp
);
1642 mmu_convert_notrap(sp
);
1646 static int mmu_need_write_protect(struct kvm_vcpu
*vcpu
, gfn_t gfn
,
1649 struct kvm_mmu_page
*shadow
;
1651 shadow
= kvm_mmu_lookup_page(vcpu
->kvm
, gfn
);
1653 if (shadow
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
1657 if (can_unsync
&& oos_shadow
)
1658 return kvm_unsync_page(vcpu
, shadow
);
1664 static int set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1665 unsigned pte_access
, int user_fault
,
1666 int write_fault
, int dirty
, int largepage
,
1667 gfn_t gfn
, pfn_t pfn
, bool speculative
,
1674 * We don't set the accessed bit, since we sometimes want to see
1675 * whether the guest actually used the pte (in order to detect
1678 spte
= shadow_base_present_pte
| shadow_dirty_mask
;
1680 spte
|= shadow_accessed_mask
;
1682 pte_access
&= ~ACC_WRITE_MASK
;
1683 if (pte_access
& ACC_EXEC_MASK
)
1684 spte
|= shadow_x_mask
;
1686 spte
|= shadow_nx_mask
;
1687 if (pte_access
& ACC_USER_MASK
)
1688 spte
|= shadow_user_mask
;
1690 spte
|= PT_PAGE_SIZE_MASK
;
1692 spte
|= kvm_x86_ops
->get_mt_mask(vcpu
, gfn
,
1693 kvm_is_mmio_pfn(pfn
));
1695 spte
|= (u64
)pfn
<< PAGE_SHIFT
;
1697 if ((pte_access
& ACC_WRITE_MASK
)
1698 || (write_fault
&& !is_write_protection(vcpu
) && !user_fault
)) {
1700 if (largepage
&& has_wrprotected_page(vcpu
->kvm
, gfn
)) {
1702 spte
= shadow_trap_nonpresent_pte
;
1706 spte
|= PT_WRITABLE_MASK
;
1709 * Optimization: for pte sync, if spte was writable the hash
1710 * lookup is unnecessary (and expensive). Write protection
1711 * is responsibility of mmu_get_page / kvm_sync_page.
1712 * Same reasoning can be applied to dirty page accounting.
1714 if (!can_unsync
&& is_writeble_pte(*shadow_pte
))
1717 if (mmu_need_write_protect(vcpu
, gfn
, can_unsync
)) {
1718 pgprintk("%s: found shadow page for %lx, marking ro\n",
1721 pte_access
&= ~ACC_WRITE_MASK
;
1722 if (is_writeble_pte(spte
))
1723 spte
&= ~PT_WRITABLE_MASK
;
1727 if (pte_access
& ACC_WRITE_MASK
)
1728 mark_page_dirty(vcpu
->kvm
, gfn
);
1731 set_shadow_pte(shadow_pte
, spte
);
1735 static void mmu_set_spte(struct kvm_vcpu
*vcpu
, u64
*shadow_pte
,
1736 unsigned pt_access
, unsigned pte_access
,
1737 int user_fault
, int write_fault
, int dirty
,
1738 int *ptwrite
, int largepage
, gfn_t gfn
,
1739 pfn_t pfn
, bool speculative
)
1741 int was_rmapped
= 0;
1742 int was_writeble
= is_writeble_pte(*shadow_pte
);
1744 pgprintk("%s: spte %llx access %x write_fault %d"
1745 " user_fault %d gfn %lx\n",
1746 __func__
, *shadow_pte
, pt_access
,
1747 write_fault
, user_fault
, gfn
);
1749 if (is_rmap_pte(*shadow_pte
)) {
1751 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1752 * the parent of the now unreachable PTE.
1754 if (largepage
&& !is_large_pte(*shadow_pte
)) {
1755 struct kvm_mmu_page
*child
;
1756 u64 pte
= *shadow_pte
;
1758 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
1759 mmu_page_remove_parent_pte(child
, shadow_pte
);
1760 } else if (pfn
!= spte_to_pfn(*shadow_pte
)) {
1761 pgprintk("hfn old %lx new %lx\n",
1762 spte_to_pfn(*shadow_pte
), pfn
);
1763 rmap_remove(vcpu
->kvm
, shadow_pte
);
1767 if (set_spte(vcpu
, shadow_pte
, pte_access
, user_fault
, write_fault
,
1768 dirty
, largepage
, gfn
, pfn
, speculative
, true)) {
1771 kvm_x86_ops
->tlb_flush(vcpu
);
1774 pgprintk("%s: setting spte %llx\n", __func__
, *shadow_pte
);
1775 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1776 is_large_pte(*shadow_pte
)? "2MB" : "4kB",
1777 is_present_pte(*shadow_pte
)?"RW":"R", gfn
,
1778 *shadow_pte
, shadow_pte
);
1779 if (!was_rmapped
&& is_large_pte(*shadow_pte
))
1780 ++vcpu
->kvm
->stat
.lpages
;
1782 page_header_update_slot(vcpu
->kvm
, shadow_pte
, gfn
);
1784 rmap_add(vcpu
, shadow_pte
, gfn
, largepage
);
1785 if (!is_rmap_pte(*shadow_pte
))
1786 kvm_release_pfn_clean(pfn
);
1789 kvm_release_pfn_dirty(pfn
);
1791 kvm_release_pfn_clean(pfn
);
1794 vcpu
->arch
.last_pte_updated
= shadow_pte
;
1795 vcpu
->arch
.last_pte_gfn
= gfn
;
1799 static void nonpaging_new_cr3(struct kvm_vcpu
*vcpu
)
1803 static int __direct_map(struct kvm_vcpu
*vcpu
, gpa_t v
, int write
,
1804 int largepage
, gfn_t gfn
, pfn_t pfn
)
1806 struct kvm_shadow_walk_iterator iterator
;
1807 struct kvm_mmu_page
*sp
;
1811 for_each_shadow_entry(vcpu
, (u64
)gfn
<< PAGE_SHIFT
, iterator
) {
1812 if (iterator
.level
== PT_PAGE_TABLE_LEVEL
1813 || (largepage
&& iterator
.level
== PT_DIRECTORY_LEVEL
)) {
1814 mmu_set_spte(vcpu
, iterator
.sptep
, ACC_ALL
, ACC_ALL
,
1815 0, write
, 1, &pt_write
,
1816 largepage
, gfn
, pfn
, false);
1817 ++vcpu
->stat
.pf_fixed
;
1821 if (*iterator
.sptep
== shadow_trap_nonpresent_pte
) {
1822 pseudo_gfn
= (iterator
.addr
& PT64_DIR_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
1823 sp
= kvm_mmu_get_page(vcpu
, pseudo_gfn
, iterator
.addr
,
1825 1, ACC_ALL
, iterator
.sptep
);
1827 pgprintk("nonpaging_map: ENOMEM\n");
1828 kvm_release_pfn_clean(pfn
);
1832 set_shadow_pte(iterator
.sptep
,
1834 | PT_PRESENT_MASK
| PT_WRITABLE_MASK
1835 | shadow_user_mask
| shadow_x_mask
);
1841 static int nonpaging_map(struct kvm_vcpu
*vcpu
, gva_t v
, int write
, gfn_t gfn
)
1846 unsigned long mmu_seq
;
1848 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
1849 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
1853 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1855 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
1858 if (is_error_pfn(pfn
)) {
1859 kvm_release_pfn_clean(pfn
);
1863 spin_lock(&vcpu
->kvm
->mmu_lock
);
1864 if (mmu_notifier_retry(vcpu
, mmu_seq
))
1866 kvm_mmu_free_some_pages(vcpu
);
1867 r
= __direct_map(vcpu
, v
, write
, largepage
, gfn
, pfn
);
1868 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1874 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1875 kvm_release_pfn_clean(pfn
);
1880 static void mmu_free_roots(struct kvm_vcpu
*vcpu
)
1883 struct kvm_mmu_page
*sp
;
1885 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1887 spin_lock(&vcpu
->kvm
->mmu_lock
);
1888 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1889 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1891 sp
= page_header(root
);
1893 if (!sp
->root_count
&& sp
->role
.invalid
)
1894 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1895 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1896 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1899 for (i
= 0; i
< 4; ++i
) {
1900 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1903 root
&= PT64_BASE_ADDR_MASK
;
1904 sp
= page_header(root
);
1906 if (!sp
->root_count
&& sp
->role
.invalid
)
1907 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
1909 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
1911 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1912 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
1915 static void mmu_alloc_roots(struct kvm_vcpu
*vcpu
)
1919 struct kvm_mmu_page
*sp
;
1922 root_gfn
= vcpu
->arch
.cr3
>> PAGE_SHIFT
;
1924 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1925 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1927 ASSERT(!VALID_PAGE(root
));
1930 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, 0,
1931 PT64_ROOT_LEVEL
, direct
,
1933 root
= __pa(sp
->spt
);
1935 vcpu
->arch
.mmu
.root_hpa
= root
;
1938 direct
= !is_paging(vcpu
);
1941 for (i
= 0; i
< 4; ++i
) {
1942 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1944 ASSERT(!VALID_PAGE(root
));
1945 if (vcpu
->arch
.mmu
.root_level
== PT32E_ROOT_LEVEL
) {
1946 if (!is_present_pte(vcpu
->arch
.pdptrs
[i
])) {
1947 vcpu
->arch
.mmu
.pae_root
[i
] = 0;
1950 root_gfn
= vcpu
->arch
.pdptrs
[i
] >> PAGE_SHIFT
;
1951 } else if (vcpu
->arch
.mmu
.root_level
== 0)
1953 sp
= kvm_mmu_get_page(vcpu
, root_gfn
, i
<< 30,
1954 PT32_ROOT_LEVEL
, direct
,
1956 root
= __pa(sp
->spt
);
1958 vcpu
->arch
.mmu
.pae_root
[i
] = root
| PT_PRESENT_MASK
;
1960 vcpu
->arch
.mmu
.root_hpa
= __pa(vcpu
->arch
.mmu
.pae_root
);
1963 static void mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1966 struct kvm_mmu_page
*sp
;
1968 if (!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
))
1970 if (vcpu
->arch
.mmu
.shadow_root_level
== PT64_ROOT_LEVEL
) {
1971 hpa_t root
= vcpu
->arch
.mmu
.root_hpa
;
1972 sp
= page_header(root
);
1973 mmu_sync_children(vcpu
, sp
);
1976 for (i
= 0; i
< 4; ++i
) {
1977 hpa_t root
= vcpu
->arch
.mmu
.pae_root
[i
];
1980 root
&= PT64_BASE_ADDR_MASK
;
1981 sp
= page_header(root
);
1982 mmu_sync_children(vcpu
, sp
);
1987 void kvm_mmu_sync_roots(struct kvm_vcpu
*vcpu
)
1989 spin_lock(&vcpu
->kvm
->mmu_lock
);
1990 mmu_sync_roots(vcpu
);
1991 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1994 static gpa_t
nonpaging_gva_to_gpa(struct kvm_vcpu
*vcpu
, gva_t vaddr
)
1999 static int nonpaging_page_fault(struct kvm_vcpu
*vcpu
, gva_t gva
,
2005 pgprintk("%s: gva %lx error %x\n", __func__
, gva
, error_code
);
2006 r
= mmu_topup_memory_caches(vcpu
);
2011 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2013 gfn
= gva
>> PAGE_SHIFT
;
2015 return nonpaging_map(vcpu
, gva
& PAGE_MASK
,
2016 error_code
& PFERR_WRITE_MASK
, gfn
);
2019 static int tdp_page_fault(struct kvm_vcpu
*vcpu
, gva_t gpa
,
2025 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2026 unsigned long mmu_seq
;
2029 ASSERT(VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2031 r
= mmu_topup_memory_caches(vcpu
);
2035 if (is_largepage_backed(vcpu
, gfn
& ~(KVM_PAGES_PER_HPAGE
-1))) {
2036 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
2039 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2041 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2042 if (is_error_pfn(pfn
)) {
2043 kvm_release_pfn_clean(pfn
);
2046 spin_lock(&vcpu
->kvm
->mmu_lock
);
2047 if (mmu_notifier_retry(vcpu
, mmu_seq
))
2049 kvm_mmu_free_some_pages(vcpu
);
2050 r
= __direct_map(vcpu
, gpa
, error_code
& PFERR_WRITE_MASK
,
2051 largepage
, gfn
, pfn
);
2052 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2057 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2058 kvm_release_pfn_clean(pfn
);
2062 static void nonpaging_free(struct kvm_vcpu
*vcpu
)
2064 mmu_free_roots(vcpu
);
2067 static int nonpaging_init_context(struct kvm_vcpu
*vcpu
)
2069 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2071 context
->new_cr3
= nonpaging_new_cr3
;
2072 context
->page_fault
= nonpaging_page_fault
;
2073 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2074 context
->free
= nonpaging_free
;
2075 context
->prefetch_page
= nonpaging_prefetch_page
;
2076 context
->sync_page
= nonpaging_sync_page
;
2077 context
->invlpg
= nonpaging_invlpg
;
2078 context
->root_level
= 0;
2079 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2080 context
->root_hpa
= INVALID_PAGE
;
2084 void kvm_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2086 ++vcpu
->stat
.tlb_flush
;
2087 kvm_x86_ops
->tlb_flush(vcpu
);
2090 static void paging_new_cr3(struct kvm_vcpu
*vcpu
)
2092 pgprintk("%s: cr3 %lx\n", __func__
, vcpu
->arch
.cr3
);
2093 mmu_free_roots(vcpu
);
2096 static void inject_page_fault(struct kvm_vcpu
*vcpu
,
2100 kvm_inject_page_fault(vcpu
, addr
, err_code
);
2103 static void paging_free(struct kvm_vcpu
*vcpu
)
2105 nonpaging_free(vcpu
);
2108 static bool is_rsvd_bits_set(struct kvm_vcpu
*vcpu
, u64 gpte
, int level
)
2112 bit7
= (gpte
>> 7) & 1;
2113 return (gpte
& vcpu
->arch
.mmu
.rsvd_bits_mask
[bit7
][level
-1]) != 0;
2117 #include "paging_tmpl.h"
2121 #include "paging_tmpl.h"
2124 static void reset_rsvds_bits_mask(struct kvm_vcpu
*vcpu
, int level
)
2126 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2127 int maxphyaddr
= cpuid_maxphyaddr(vcpu
);
2128 u64 exb_bit_rsvd
= 0;
2131 exb_bit_rsvd
= rsvd_bits(63, 63);
2133 case PT32_ROOT_LEVEL
:
2134 /* no rsvd bits for 2 level 4K page table entries */
2135 context
->rsvd_bits_mask
[0][1] = 0;
2136 context
->rsvd_bits_mask
[0][0] = 0;
2137 if (is_cpuid_PSE36())
2138 /* 36bits PSE 4MB page */
2139 context
->rsvd_bits_mask
[1][1] = rsvd_bits(17, 21);
2141 /* 32 bits PSE 4MB page */
2142 context
->rsvd_bits_mask
[1][1] = rsvd_bits(13, 21);
2143 context
->rsvd_bits_mask
[1][0] = ~0ull;
2145 case PT32E_ROOT_LEVEL
:
2146 context
->rsvd_bits_mask
[0][2] =
2147 rsvd_bits(maxphyaddr
, 63) |
2148 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
2149 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2150 rsvd_bits(maxphyaddr
, 62); /* PDE */
2151 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2152 rsvd_bits(maxphyaddr
, 62); /* PTE */
2153 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2154 rsvd_bits(maxphyaddr
, 62) |
2155 rsvd_bits(13, 20); /* large page */
2156 context
->rsvd_bits_mask
[1][0] = ~0ull;
2158 case PT64_ROOT_LEVEL
:
2159 context
->rsvd_bits_mask
[0][3] = exb_bit_rsvd
|
2160 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2161 context
->rsvd_bits_mask
[0][2] = exb_bit_rsvd
|
2162 rsvd_bits(maxphyaddr
, 51) | rsvd_bits(7, 8);
2163 context
->rsvd_bits_mask
[0][1] = exb_bit_rsvd
|
2164 rsvd_bits(maxphyaddr
, 51);
2165 context
->rsvd_bits_mask
[0][0] = exb_bit_rsvd
|
2166 rsvd_bits(maxphyaddr
, 51);
2167 context
->rsvd_bits_mask
[1][3] = context
->rsvd_bits_mask
[0][3];
2168 context
->rsvd_bits_mask
[1][2] = context
->rsvd_bits_mask
[0][2];
2169 context
->rsvd_bits_mask
[1][1] = exb_bit_rsvd
|
2170 rsvd_bits(maxphyaddr
, 51) |
2171 rsvd_bits(13, 20); /* large page */
2172 context
->rsvd_bits_mask
[1][0] = ~0ull;
2177 static int paging64_init_context_common(struct kvm_vcpu
*vcpu
, int level
)
2179 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2181 ASSERT(is_pae(vcpu
));
2182 context
->new_cr3
= paging_new_cr3
;
2183 context
->page_fault
= paging64_page_fault
;
2184 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2185 context
->prefetch_page
= paging64_prefetch_page
;
2186 context
->sync_page
= paging64_sync_page
;
2187 context
->invlpg
= paging64_invlpg
;
2188 context
->free
= paging_free
;
2189 context
->root_level
= level
;
2190 context
->shadow_root_level
= level
;
2191 context
->root_hpa
= INVALID_PAGE
;
2195 static int paging64_init_context(struct kvm_vcpu
*vcpu
)
2197 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2198 return paging64_init_context_common(vcpu
, PT64_ROOT_LEVEL
);
2201 static int paging32_init_context(struct kvm_vcpu
*vcpu
)
2203 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2205 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2206 context
->new_cr3
= paging_new_cr3
;
2207 context
->page_fault
= paging32_page_fault
;
2208 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2209 context
->free
= paging_free
;
2210 context
->prefetch_page
= paging32_prefetch_page
;
2211 context
->sync_page
= paging32_sync_page
;
2212 context
->invlpg
= paging32_invlpg
;
2213 context
->root_level
= PT32_ROOT_LEVEL
;
2214 context
->shadow_root_level
= PT32E_ROOT_LEVEL
;
2215 context
->root_hpa
= INVALID_PAGE
;
2219 static int paging32E_init_context(struct kvm_vcpu
*vcpu
)
2221 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2222 return paging64_init_context_common(vcpu
, PT32E_ROOT_LEVEL
);
2225 static int init_kvm_tdp_mmu(struct kvm_vcpu
*vcpu
)
2227 struct kvm_mmu
*context
= &vcpu
->arch
.mmu
;
2229 context
->new_cr3
= nonpaging_new_cr3
;
2230 context
->page_fault
= tdp_page_fault
;
2231 context
->free
= nonpaging_free
;
2232 context
->prefetch_page
= nonpaging_prefetch_page
;
2233 context
->sync_page
= nonpaging_sync_page
;
2234 context
->invlpg
= nonpaging_invlpg
;
2235 context
->shadow_root_level
= kvm_x86_ops
->get_tdp_level();
2236 context
->root_hpa
= INVALID_PAGE
;
2238 if (!is_paging(vcpu
)) {
2239 context
->gva_to_gpa
= nonpaging_gva_to_gpa
;
2240 context
->root_level
= 0;
2241 } else if (is_long_mode(vcpu
)) {
2242 reset_rsvds_bits_mask(vcpu
, PT64_ROOT_LEVEL
);
2243 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2244 context
->root_level
= PT64_ROOT_LEVEL
;
2245 } else if (is_pae(vcpu
)) {
2246 reset_rsvds_bits_mask(vcpu
, PT32E_ROOT_LEVEL
);
2247 context
->gva_to_gpa
= paging64_gva_to_gpa
;
2248 context
->root_level
= PT32E_ROOT_LEVEL
;
2250 reset_rsvds_bits_mask(vcpu
, PT32_ROOT_LEVEL
);
2251 context
->gva_to_gpa
= paging32_gva_to_gpa
;
2252 context
->root_level
= PT32_ROOT_LEVEL
;
2258 static int init_kvm_softmmu(struct kvm_vcpu
*vcpu
)
2263 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2265 if (!is_paging(vcpu
))
2266 r
= nonpaging_init_context(vcpu
);
2267 else if (is_long_mode(vcpu
))
2268 r
= paging64_init_context(vcpu
);
2269 else if (is_pae(vcpu
))
2270 r
= paging32E_init_context(vcpu
);
2272 r
= paging32_init_context(vcpu
);
2274 vcpu
->arch
.mmu
.base_role
.glevels
= vcpu
->arch
.mmu
.root_level
;
2279 static int init_kvm_mmu(struct kvm_vcpu
*vcpu
)
2281 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2284 return init_kvm_tdp_mmu(vcpu
);
2286 return init_kvm_softmmu(vcpu
);
2289 static void destroy_kvm_mmu(struct kvm_vcpu
*vcpu
)
2292 if (VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
)) {
2293 vcpu
->arch
.mmu
.free(vcpu
);
2294 vcpu
->arch
.mmu
.root_hpa
= INVALID_PAGE
;
2298 int kvm_mmu_reset_context(struct kvm_vcpu
*vcpu
)
2300 destroy_kvm_mmu(vcpu
);
2301 return init_kvm_mmu(vcpu
);
2303 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context
);
2305 int kvm_mmu_load(struct kvm_vcpu
*vcpu
)
2309 r
= mmu_topup_memory_caches(vcpu
);
2312 spin_lock(&vcpu
->kvm
->mmu_lock
);
2313 kvm_mmu_free_some_pages(vcpu
);
2314 mmu_alloc_roots(vcpu
);
2315 mmu_sync_roots(vcpu
);
2316 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2317 kvm_x86_ops
->set_cr3(vcpu
, vcpu
->arch
.mmu
.root_hpa
);
2318 kvm_mmu_flush_tlb(vcpu
);
2322 EXPORT_SYMBOL_GPL(kvm_mmu_load
);
2324 void kvm_mmu_unload(struct kvm_vcpu
*vcpu
)
2326 mmu_free_roots(vcpu
);
2329 static void mmu_pte_write_zap_pte(struct kvm_vcpu
*vcpu
,
2330 struct kvm_mmu_page
*sp
,
2334 struct kvm_mmu_page
*child
;
2337 if (is_shadow_present_pte(pte
)) {
2338 if (sp
->role
.level
== PT_PAGE_TABLE_LEVEL
||
2340 rmap_remove(vcpu
->kvm
, spte
);
2342 child
= page_header(pte
& PT64_BASE_ADDR_MASK
);
2343 mmu_page_remove_parent_pte(child
, spte
);
2346 set_shadow_pte(spte
, shadow_trap_nonpresent_pte
);
2347 if (is_large_pte(pte
))
2348 --vcpu
->kvm
->stat
.lpages
;
2351 static void mmu_pte_write_new_pte(struct kvm_vcpu
*vcpu
,
2352 struct kvm_mmu_page
*sp
,
2356 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
) {
2357 if (!vcpu
->arch
.update_pte
.largepage
||
2358 sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2359 ++vcpu
->kvm
->stat
.mmu_pde_zapped
;
2364 ++vcpu
->kvm
->stat
.mmu_pte_updated
;
2365 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
)
2366 paging32_update_pte(vcpu
, sp
, spte
, new);
2368 paging64_update_pte(vcpu
, sp
, spte
, new);
2371 static bool need_remote_flush(u64 old
, u64
new)
2373 if (!is_shadow_present_pte(old
))
2375 if (!is_shadow_present_pte(new))
2377 if ((old
^ new) & PT64_BASE_ADDR_MASK
)
2379 old
^= PT64_NX_MASK
;
2380 new ^= PT64_NX_MASK
;
2381 return (old
& ~new & PT64_PERM_MASK
) != 0;
2384 static void mmu_pte_write_flush_tlb(struct kvm_vcpu
*vcpu
, u64 old
, u64
new)
2386 if (need_remote_flush(old
, new))
2387 kvm_flush_remote_tlbs(vcpu
->kvm
);
2389 kvm_mmu_flush_tlb(vcpu
);
2392 static bool last_updated_pte_accessed(struct kvm_vcpu
*vcpu
)
2394 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2396 return !!(spte
&& (*spte
& shadow_accessed_mask
));
2399 static void mmu_guess_page_from_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2400 const u8
*new, int bytes
)
2407 vcpu
->arch
.update_pte
.largepage
= 0;
2409 if (bytes
!= 4 && bytes
!= 8)
2413 * Assume that the pte write on a page table of the same type
2414 * as the current vcpu paging mode. This is nearly always true
2415 * (might be false while changing modes). Note it is verified later
2419 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2420 if ((bytes
== 4) && (gpa
% 4 == 0)) {
2421 r
= kvm_read_guest(vcpu
->kvm
, gpa
& ~(u64
)7, &gpte
, 8);
2424 memcpy((void *)&gpte
+ (gpa
% 8), new, 4);
2425 } else if ((bytes
== 8) && (gpa
% 8 == 0)) {
2426 memcpy((void *)&gpte
, new, 8);
2429 if ((bytes
== 4) && (gpa
% 4 == 0))
2430 memcpy((void *)&gpte
, new, 4);
2432 if (!is_present_pte(gpte
))
2434 gfn
= (gpte
& PT64_BASE_ADDR_MASK
) >> PAGE_SHIFT
;
2436 if (is_large_pte(gpte
) && is_largepage_backed(vcpu
, gfn
)) {
2437 gfn
&= ~(KVM_PAGES_PER_HPAGE
-1);
2438 vcpu
->arch
.update_pte
.largepage
= 1;
2440 vcpu
->arch
.update_pte
.mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
2442 pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
2444 if (is_error_pfn(pfn
)) {
2445 kvm_release_pfn_clean(pfn
);
2448 vcpu
->arch
.update_pte
.gfn
= gfn
;
2449 vcpu
->arch
.update_pte
.pfn
= pfn
;
2452 static void kvm_mmu_access_page(struct kvm_vcpu
*vcpu
, gfn_t gfn
)
2454 u64
*spte
= vcpu
->arch
.last_pte_updated
;
2457 && vcpu
->arch
.last_pte_gfn
== gfn
2458 && shadow_accessed_mask
2459 && !(*spte
& shadow_accessed_mask
)
2460 && is_shadow_present_pte(*spte
))
2461 set_bit(PT_ACCESSED_SHIFT
, (unsigned long *)spte
);
2464 void kvm_mmu_pte_write(struct kvm_vcpu
*vcpu
, gpa_t gpa
,
2465 const u8
*new, int bytes
,
2466 bool guest_initiated
)
2468 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
2469 struct kvm_mmu_page
*sp
;
2470 struct hlist_node
*node
, *n
;
2471 struct hlist_head
*bucket
;
2475 unsigned offset
= offset_in_page(gpa
);
2477 unsigned page_offset
;
2478 unsigned misaligned
;
2485 pgprintk("%s: gpa %llx bytes %d\n", __func__
, gpa
, bytes
);
2486 mmu_guess_page_from_pte_write(vcpu
, gpa
, new, bytes
);
2487 spin_lock(&vcpu
->kvm
->mmu_lock
);
2488 kvm_mmu_access_page(vcpu
, gfn
);
2489 kvm_mmu_free_some_pages(vcpu
);
2490 ++vcpu
->kvm
->stat
.mmu_pte_write
;
2491 kvm_mmu_audit(vcpu
, "pre pte write");
2492 if (guest_initiated
) {
2493 if (gfn
== vcpu
->arch
.last_pt_write_gfn
2494 && !last_updated_pte_accessed(vcpu
)) {
2495 ++vcpu
->arch
.last_pt_write_count
;
2496 if (vcpu
->arch
.last_pt_write_count
>= 3)
2499 vcpu
->arch
.last_pt_write_gfn
= gfn
;
2500 vcpu
->arch
.last_pt_write_count
= 1;
2501 vcpu
->arch
.last_pte_updated
= NULL
;
2504 index
= kvm_page_table_hashfn(gfn
);
2505 bucket
= &vcpu
->kvm
->arch
.mmu_page_hash
[index
];
2506 hlist_for_each_entry_safe(sp
, node
, n
, bucket
, hash_link
) {
2507 if (sp
->gfn
!= gfn
|| sp
->role
.direct
|| sp
->role
.invalid
)
2509 pte_size
= sp
->role
.glevels
== PT32_ROOT_LEVEL
? 4 : 8;
2510 misaligned
= (offset
^ (offset
+ bytes
- 1)) & ~(pte_size
- 1);
2511 misaligned
|= bytes
< 4;
2512 if (misaligned
|| flooded
) {
2514 * Misaligned accesses are too much trouble to fix
2515 * up; also, they usually indicate a page is not used
2518 * If we're seeing too many writes to a page,
2519 * it may no longer be a page table, or we may be
2520 * forking, in which case it is better to unmap the
2523 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2524 gpa
, bytes
, sp
->role
.word
);
2525 if (kvm_mmu_zap_page(vcpu
->kvm
, sp
))
2527 ++vcpu
->kvm
->stat
.mmu_flooded
;
2530 page_offset
= offset
;
2531 level
= sp
->role
.level
;
2533 if (sp
->role
.glevels
== PT32_ROOT_LEVEL
) {
2534 page_offset
<<= 1; /* 32->64 */
2536 * A 32-bit pde maps 4MB while the shadow pdes map
2537 * only 2MB. So we need to double the offset again
2538 * and zap two pdes instead of one.
2540 if (level
== PT32_ROOT_LEVEL
) {
2541 page_offset
&= ~7; /* kill rounding error */
2545 quadrant
= page_offset
>> PAGE_SHIFT
;
2546 page_offset
&= ~PAGE_MASK
;
2547 if (quadrant
!= sp
->role
.quadrant
)
2550 spte
= &sp
->spt
[page_offset
/ sizeof(*spte
)];
2551 if ((gpa
& (pte_size
- 1)) || (bytes
< pte_size
)) {
2553 r
= kvm_read_guest_atomic(vcpu
->kvm
,
2554 gpa
& ~(u64
)(pte_size
- 1),
2556 new = (const void *)&gentry
;
2562 mmu_pte_write_zap_pte(vcpu
, sp
, spte
);
2564 mmu_pte_write_new_pte(vcpu
, sp
, spte
, new);
2565 mmu_pte_write_flush_tlb(vcpu
, entry
, *spte
);
2569 kvm_mmu_audit(vcpu
, "post pte write");
2570 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2571 if (!is_error_pfn(vcpu
->arch
.update_pte
.pfn
)) {
2572 kvm_release_pfn_clean(vcpu
->arch
.update_pte
.pfn
);
2573 vcpu
->arch
.update_pte
.pfn
= bad_pfn
;
2577 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu
*vcpu
, gva_t gva
)
2582 gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, gva
);
2584 spin_lock(&vcpu
->kvm
->mmu_lock
);
2585 r
= kvm_mmu_unprotect_page(vcpu
->kvm
, gpa
>> PAGE_SHIFT
);
2586 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2589 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt
);
2591 void __kvm_mmu_free_some_pages(struct kvm_vcpu
*vcpu
)
2593 while (vcpu
->kvm
->arch
.n_free_mmu_pages
< KVM_REFILL_PAGES
) {
2594 struct kvm_mmu_page
*sp
;
2596 sp
= container_of(vcpu
->kvm
->arch
.active_mmu_pages
.prev
,
2597 struct kvm_mmu_page
, link
);
2598 kvm_mmu_zap_page(vcpu
->kvm
, sp
);
2599 ++vcpu
->kvm
->stat
.mmu_recycled
;
2603 int kvm_mmu_page_fault(struct kvm_vcpu
*vcpu
, gva_t cr2
, u32 error_code
)
2606 enum emulation_result er
;
2608 r
= vcpu
->arch
.mmu
.page_fault(vcpu
, cr2
, error_code
);
2617 r
= mmu_topup_memory_caches(vcpu
);
2621 er
= emulate_instruction(vcpu
, vcpu
->run
, cr2
, error_code
, 0);
2626 case EMULATE_DO_MMIO
:
2627 ++vcpu
->stat
.mmio_exits
;
2630 kvm_report_emulation_failure(vcpu
, "pagetable");
2638 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault
);
2640 void kvm_mmu_invlpg(struct kvm_vcpu
*vcpu
, gva_t gva
)
2642 vcpu
->arch
.mmu
.invlpg(vcpu
, gva
);
2643 kvm_mmu_flush_tlb(vcpu
);
2644 ++vcpu
->stat
.invlpg
;
2646 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg
);
2648 void kvm_enable_tdp(void)
2652 EXPORT_SYMBOL_GPL(kvm_enable_tdp
);
2654 void kvm_disable_tdp(void)
2656 tdp_enabled
= false;
2658 EXPORT_SYMBOL_GPL(kvm_disable_tdp
);
2660 static void free_mmu_pages(struct kvm_vcpu
*vcpu
)
2662 free_page((unsigned long)vcpu
->arch
.mmu
.pae_root
);
2665 static int alloc_mmu_pages(struct kvm_vcpu
*vcpu
)
2672 if (vcpu
->kvm
->arch
.n_requested_mmu_pages
)
2673 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2674 vcpu
->kvm
->arch
.n_requested_mmu_pages
;
2676 vcpu
->kvm
->arch
.n_free_mmu_pages
=
2677 vcpu
->kvm
->arch
.n_alloc_mmu_pages
;
2679 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2680 * Therefore we need to allocate shadow page tables in the first
2681 * 4GB of memory, which happens to fit the DMA32 zone.
2683 page
= alloc_page(GFP_KERNEL
| __GFP_DMA32
);
2686 vcpu
->arch
.mmu
.pae_root
= page_address(page
);
2687 for (i
= 0; i
< 4; ++i
)
2688 vcpu
->arch
.mmu
.pae_root
[i
] = INVALID_PAGE
;
2693 free_mmu_pages(vcpu
);
2697 int kvm_mmu_create(struct kvm_vcpu
*vcpu
)
2700 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2702 return alloc_mmu_pages(vcpu
);
2705 int kvm_mmu_setup(struct kvm_vcpu
*vcpu
)
2708 ASSERT(!VALID_PAGE(vcpu
->arch
.mmu
.root_hpa
));
2710 return init_kvm_mmu(vcpu
);
2713 void kvm_mmu_destroy(struct kvm_vcpu
*vcpu
)
2717 destroy_kvm_mmu(vcpu
);
2718 free_mmu_pages(vcpu
);
2719 mmu_free_memory_caches(vcpu
);
2722 void kvm_mmu_slot_remove_write_access(struct kvm
*kvm
, int slot
)
2724 struct kvm_mmu_page
*sp
;
2726 spin_lock(&kvm
->mmu_lock
);
2727 list_for_each_entry(sp
, &kvm
->arch
.active_mmu_pages
, link
) {
2731 if (!test_bit(slot
, sp
->slot_bitmap
))
2735 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
)
2737 if (pt
[i
] & PT_WRITABLE_MASK
)
2738 pt
[i
] &= ~PT_WRITABLE_MASK
;
2740 kvm_flush_remote_tlbs(kvm
);
2741 spin_unlock(&kvm
->mmu_lock
);
2744 void kvm_mmu_zap_all(struct kvm
*kvm
)
2746 struct kvm_mmu_page
*sp
, *node
;
2748 spin_lock(&kvm
->mmu_lock
);
2749 list_for_each_entry_safe(sp
, node
, &kvm
->arch
.active_mmu_pages
, link
)
2750 if (kvm_mmu_zap_page(kvm
, sp
))
2751 node
= container_of(kvm
->arch
.active_mmu_pages
.next
,
2752 struct kvm_mmu_page
, link
);
2753 spin_unlock(&kvm
->mmu_lock
);
2755 kvm_flush_remote_tlbs(kvm
);
2758 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm
*kvm
)
2760 struct kvm_mmu_page
*page
;
2762 page
= container_of(kvm
->arch
.active_mmu_pages
.prev
,
2763 struct kvm_mmu_page
, link
);
2764 kvm_mmu_zap_page(kvm
, page
);
2767 static int mmu_shrink(int nr_to_scan
, gfp_t gfp_mask
)
2770 struct kvm
*kvm_freed
= NULL
;
2771 int cache_count
= 0;
2773 spin_lock(&kvm_lock
);
2775 list_for_each_entry(kvm
, &vm_list
, vm_list
) {
2778 if (!down_read_trylock(&kvm
->slots_lock
))
2780 spin_lock(&kvm
->mmu_lock
);
2781 npages
= kvm
->arch
.n_alloc_mmu_pages
-
2782 kvm
->arch
.n_free_mmu_pages
;
2783 cache_count
+= npages
;
2784 if (!kvm_freed
&& nr_to_scan
> 0 && npages
> 0) {
2785 kvm_mmu_remove_one_alloc_mmu_page(kvm
);
2791 spin_unlock(&kvm
->mmu_lock
);
2792 up_read(&kvm
->slots_lock
);
2795 list_move_tail(&kvm_freed
->vm_list
, &vm_list
);
2797 spin_unlock(&kvm_lock
);
2802 static struct shrinker mmu_shrinker
= {
2803 .shrink
= mmu_shrink
,
2804 .seeks
= DEFAULT_SEEKS
* 10,
2807 static void mmu_destroy_caches(void)
2809 if (pte_chain_cache
)
2810 kmem_cache_destroy(pte_chain_cache
);
2811 if (rmap_desc_cache
)
2812 kmem_cache_destroy(rmap_desc_cache
);
2813 if (mmu_page_header_cache
)
2814 kmem_cache_destroy(mmu_page_header_cache
);
2817 void kvm_mmu_module_exit(void)
2819 mmu_destroy_caches();
2820 unregister_shrinker(&mmu_shrinker
);
2823 int kvm_mmu_module_init(void)
2825 pte_chain_cache
= kmem_cache_create("kvm_pte_chain",
2826 sizeof(struct kvm_pte_chain
),
2828 if (!pte_chain_cache
)
2830 rmap_desc_cache
= kmem_cache_create("kvm_rmap_desc",
2831 sizeof(struct kvm_rmap_desc
),
2833 if (!rmap_desc_cache
)
2836 mmu_page_header_cache
= kmem_cache_create("kvm_mmu_page_header",
2837 sizeof(struct kvm_mmu_page
),
2839 if (!mmu_page_header_cache
)
2842 register_shrinker(&mmu_shrinker
);
2847 mmu_destroy_caches();
2852 * Caculate mmu pages needed for kvm.
2854 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm
*kvm
)
2857 unsigned int nr_mmu_pages
;
2858 unsigned int nr_pages
= 0;
2860 for (i
= 0; i
< kvm
->nmemslots
; i
++)
2861 nr_pages
+= kvm
->memslots
[i
].npages
;
2863 nr_mmu_pages
= nr_pages
* KVM_PERMILLE_MMU_PAGES
/ 1000;
2864 nr_mmu_pages
= max(nr_mmu_pages
,
2865 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES
);
2867 return nr_mmu_pages
;
2870 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2873 if (len
> buffer
->len
)
2878 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer
*buffer
,
2883 ret
= pv_mmu_peek_buffer(buffer
, len
);
2888 buffer
->processed
+= len
;
2892 static int kvm_pv_mmu_write(struct kvm_vcpu
*vcpu
,
2893 gpa_t addr
, gpa_t value
)
2898 if (!is_long_mode(vcpu
) && !is_pae(vcpu
))
2901 r
= mmu_topup_memory_caches(vcpu
);
2905 if (!emulator_write_phys(vcpu
, addr
, &value
, bytes
))
2911 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu
*vcpu
)
2913 kvm_set_cr3(vcpu
, vcpu
->arch
.cr3
);
2917 static int kvm_pv_mmu_release_pt(struct kvm_vcpu
*vcpu
, gpa_t addr
)
2919 spin_lock(&vcpu
->kvm
->mmu_lock
);
2920 mmu_unshadow(vcpu
->kvm
, addr
>> PAGE_SHIFT
);
2921 spin_unlock(&vcpu
->kvm
->mmu_lock
);
2925 static int kvm_pv_mmu_op_one(struct kvm_vcpu
*vcpu
,
2926 struct kvm_pv_mmu_op_buffer
*buffer
)
2928 struct kvm_mmu_op_header
*header
;
2930 header
= pv_mmu_peek_buffer(buffer
, sizeof *header
);
2933 switch (header
->op
) {
2934 case KVM_MMU_OP_WRITE_PTE
: {
2935 struct kvm_mmu_op_write_pte
*wpte
;
2937 wpte
= pv_mmu_read_buffer(buffer
, sizeof *wpte
);
2940 return kvm_pv_mmu_write(vcpu
, wpte
->pte_phys
,
2943 case KVM_MMU_OP_FLUSH_TLB
: {
2944 struct kvm_mmu_op_flush_tlb
*ftlb
;
2946 ftlb
= pv_mmu_read_buffer(buffer
, sizeof *ftlb
);
2949 return kvm_pv_mmu_flush_tlb(vcpu
);
2951 case KVM_MMU_OP_RELEASE_PT
: {
2952 struct kvm_mmu_op_release_pt
*rpt
;
2954 rpt
= pv_mmu_read_buffer(buffer
, sizeof *rpt
);
2957 return kvm_pv_mmu_release_pt(vcpu
, rpt
->pt_phys
);
2963 int kvm_pv_mmu_op(struct kvm_vcpu
*vcpu
, unsigned long bytes
,
2964 gpa_t addr
, unsigned long *ret
)
2967 struct kvm_pv_mmu_op_buffer
*buffer
= &vcpu
->arch
.mmu_op_buffer
;
2969 buffer
->ptr
= buffer
->buf
;
2970 buffer
->len
= min_t(unsigned long, bytes
, sizeof buffer
->buf
);
2971 buffer
->processed
= 0;
2973 r
= kvm_read_guest(vcpu
->kvm
, addr
, buffer
->buf
, buffer
->len
);
2977 while (buffer
->len
) {
2978 r
= kvm_pv_mmu_op_one(vcpu
, buffer
);
2987 *ret
= buffer
->processed
;
2993 static const char *audit_msg
;
2995 static gva_t
canonicalize(gva_t gva
)
2997 #ifdef CONFIG_X86_64
2998 gva
= (long long)(gva
<< 16) >> 16;
3003 static void audit_mappings_page(struct kvm_vcpu
*vcpu
, u64 page_pte
,
3004 gva_t va
, int level
)
3006 u64
*pt
= __va(page_pte
& PT64_BASE_ADDR_MASK
);
3008 gva_t va_delta
= 1ul << (PAGE_SHIFT
+ 9 * (level
- 1));
3010 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
, va
+= va_delta
) {
3013 if (ent
== shadow_trap_nonpresent_pte
)
3016 va
= canonicalize(va
);
3018 if (ent
== shadow_notrap_nonpresent_pte
)
3019 printk(KERN_ERR
"audit: (%s) nontrapping pte"
3020 " in nonleaf level: levels %d gva %lx"
3021 " level %d pte %llx\n", audit_msg
,
3022 vcpu
->arch
.mmu
.root_level
, va
, level
, ent
);
3024 audit_mappings_page(vcpu
, ent
, va
, level
- 1);
3026 gpa_t gpa
= vcpu
->arch
.mmu
.gva_to_gpa(vcpu
, va
);
3027 gfn_t gfn
= gpa
>> PAGE_SHIFT
;
3028 pfn_t pfn
= gfn_to_pfn(vcpu
->kvm
, gfn
);
3029 hpa_t hpa
= (hpa_t
)pfn
<< PAGE_SHIFT
;
3031 if (is_shadow_present_pte(ent
)
3032 && (ent
& PT64_BASE_ADDR_MASK
) != hpa
)
3033 printk(KERN_ERR
"xx audit error: (%s) levels %d"
3034 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3035 audit_msg
, vcpu
->arch
.mmu
.root_level
,
3037 is_shadow_present_pte(ent
));
3038 else if (ent
== shadow_notrap_nonpresent_pte
3039 && !is_error_hpa(hpa
))
3040 printk(KERN_ERR
"audit: (%s) notrap shadow,"
3041 " valid guest gva %lx\n", audit_msg
, va
);
3042 kvm_release_pfn_clean(pfn
);
3048 static void audit_mappings(struct kvm_vcpu
*vcpu
)
3052 if (vcpu
->arch
.mmu
.root_level
== 4)
3053 audit_mappings_page(vcpu
, vcpu
->arch
.mmu
.root_hpa
, 0, 4);
3055 for (i
= 0; i
< 4; ++i
)
3056 if (vcpu
->arch
.mmu
.pae_root
[i
] & PT_PRESENT_MASK
)
3057 audit_mappings_page(vcpu
,
3058 vcpu
->arch
.mmu
.pae_root
[i
],
3063 static int count_rmaps(struct kvm_vcpu
*vcpu
)
3068 for (i
= 0; i
< KVM_MEMORY_SLOTS
; ++i
) {
3069 struct kvm_memory_slot
*m
= &vcpu
->kvm
->memslots
[i
];
3070 struct kvm_rmap_desc
*d
;
3072 for (j
= 0; j
< m
->npages
; ++j
) {
3073 unsigned long *rmapp
= &m
->rmap
[j
];
3077 if (!(*rmapp
& 1)) {
3081 d
= (struct kvm_rmap_desc
*)(*rmapp
& ~1ul);
3083 for (k
= 0; k
< RMAP_EXT
; ++k
)
3084 if (d
->shadow_ptes
[k
])
3095 static int count_writable_mappings(struct kvm_vcpu
*vcpu
)
3098 struct kvm_mmu_page
*sp
;
3101 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3104 if (sp
->role
.level
!= PT_PAGE_TABLE_LEVEL
)
3107 for (i
= 0; i
< PT64_ENT_PER_PAGE
; ++i
) {
3110 if (!(ent
& PT_PRESENT_MASK
))
3112 if (!(ent
& PT_WRITABLE_MASK
))
3120 static void audit_rmap(struct kvm_vcpu
*vcpu
)
3122 int n_rmap
= count_rmaps(vcpu
);
3123 int n_actual
= count_writable_mappings(vcpu
);
3125 if (n_rmap
!= n_actual
)
3126 printk(KERN_ERR
"%s: (%s) rmap %d actual %d\n",
3127 __func__
, audit_msg
, n_rmap
, n_actual
);
3130 static void audit_write_protection(struct kvm_vcpu
*vcpu
)
3132 struct kvm_mmu_page
*sp
;
3133 struct kvm_memory_slot
*slot
;
3134 unsigned long *rmapp
;
3137 list_for_each_entry(sp
, &vcpu
->kvm
->arch
.active_mmu_pages
, link
) {
3138 if (sp
->role
.direct
)
3141 gfn
= unalias_gfn(vcpu
->kvm
, sp
->gfn
);
3142 slot
= gfn_to_memslot_unaliased(vcpu
->kvm
, sp
->gfn
);
3143 rmapp
= &slot
->rmap
[gfn
- slot
->base_gfn
];
3145 printk(KERN_ERR
"%s: (%s) shadow page has writable"
3146 " mappings: gfn %lx role %x\n",
3147 __func__
, audit_msg
, sp
->gfn
,
3152 static void kvm_mmu_audit(struct kvm_vcpu
*vcpu
, const char *msg
)
3159 audit_write_protection(vcpu
);
3160 audit_mappings(vcpu
);