KVM: MMU: Modify kvm_shadow_walk.entry to accept u64 addr
[linux-2.6.git] / arch / x86 / kvm / mmu.c
1 /*
2  * Kernel-based Virtual Machine driver for Linux
3  *
4  * This module enables machines with Intel VT-x extensions to run virtual
5  * machines without emulation or binary translation.
6  *
7  * MMU support
8  *
9  * Copyright (C) 2006 Qumranet, Inc.
10  *
11  * Authors:
12  *   Yaniv Kamay  <yaniv@qumranet.com>
13  *   Avi Kivity   <avi@qumranet.com>
14  *
15  * This work is licensed under the terms of the GNU GPL, version 2.  See
16  * the COPYING file in the top-level directory.
17  *
18  */
19
20 #include "vmx.h"
21 #include "mmu.h"
22
23 #include <linux/kvm_host.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
26 #include <linux/mm.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
33 #include <asm/page.h>
34 #include <asm/cmpxchg.h>
35 #include <asm/io.h>
36
37 /*
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.
43  */
44 bool tdp_enabled = false;
45
46 #undef MMU_DEBUG
47
48 #undef AUDIT
49
50 #ifdef AUDIT
51 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
52 #else
53 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
54 #endif
55
56 #ifdef MMU_DEBUG
57
58 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
59 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
60
61 #else
62
63 #define pgprintk(x...) do { } while (0)
64 #define rmap_printk(x...) do { } while (0)
65
66 #endif
67
68 #if defined(MMU_DEBUG) || defined(AUDIT)
69 static int dbg = 0;
70 module_param(dbg, bool, 0644);
71 #endif
72
73 #ifndef MMU_DEBUG
74 #define ASSERT(x) do { } while (0)
75 #else
76 #define ASSERT(x)                                                       \
77         if (!(x)) {                                                     \
78                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
79                        __FILE__, __LINE__, #x);                         \
80         }
81 #endif
82
83 #define PT_FIRST_AVAIL_BITS_SHIFT 9
84 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
85
86 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
87
88 #define PT64_LEVEL_BITS 9
89
90 #define PT64_LEVEL_SHIFT(level) \
91                 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
92
93 #define PT64_LEVEL_MASK(level) \
94                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
95
96 #define PT64_INDEX(address, level)\
97         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
98
99
100 #define PT32_LEVEL_BITS 10
101
102 #define PT32_LEVEL_SHIFT(level) \
103                 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
104
105 #define PT32_LEVEL_MASK(level) \
106                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
107
108 #define PT32_INDEX(address, level)\
109         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
110
111
112 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
113 #define PT64_DIR_BASE_ADDR_MASK \
114         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
115
116 #define PT32_BASE_ADDR_MASK PAGE_MASK
117 #define PT32_DIR_BASE_ADDR_MASK \
118         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
119
120 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
121                         | PT64_NX_MASK)
122
123 #define PFERR_PRESENT_MASK (1U << 0)
124 #define PFERR_WRITE_MASK (1U << 1)
125 #define PFERR_USER_MASK (1U << 2)
126 #define PFERR_FETCH_MASK (1U << 4)
127
128 #define PT_DIRECTORY_LEVEL 2
129 #define PT_PAGE_TABLE_LEVEL 1
130
131 #define RMAP_EXT 4
132
133 #define ACC_EXEC_MASK    1
134 #define ACC_WRITE_MASK   PT_WRITABLE_MASK
135 #define ACC_USER_MASK    PT_USER_MASK
136 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
137
138 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
139
140 struct kvm_rmap_desc {
141         u64 *shadow_ptes[RMAP_EXT];
142         struct kvm_rmap_desc *more;
143 };
144
145 struct kvm_shadow_walk {
146         int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu,
147                      u64 addr, u64 *spte, int level);
148 };
149
150 static struct kmem_cache *pte_chain_cache;
151 static struct kmem_cache *rmap_desc_cache;
152 static struct kmem_cache *mmu_page_header_cache;
153
154 static u64 __read_mostly shadow_trap_nonpresent_pte;
155 static u64 __read_mostly shadow_notrap_nonpresent_pte;
156 static u64 __read_mostly shadow_base_present_pte;
157 static u64 __read_mostly shadow_nx_mask;
158 static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
159 static u64 __read_mostly shadow_user_mask;
160 static u64 __read_mostly shadow_accessed_mask;
161 static u64 __read_mostly shadow_dirty_mask;
162
163 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
164 {
165         shadow_trap_nonpresent_pte = trap_pte;
166         shadow_notrap_nonpresent_pte = notrap_pte;
167 }
168 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
169
170 void kvm_mmu_set_base_ptes(u64 base_pte)
171 {
172         shadow_base_present_pte = base_pte;
173 }
174 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
175
176 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
177                 u64 dirty_mask, u64 nx_mask, u64 x_mask)
178 {
179         shadow_user_mask = user_mask;
180         shadow_accessed_mask = accessed_mask;
181         shadow_dirty_mask = dirty_mask;
182         shadow_nx_mask = nx_mask;
183         shadow_x_mask = x_mask;
184 }
185 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
186
187 static int is_write_protection(struct kvm_vcpu *vcpu)
188 {
189         return vcpu->arch.cr0 & X86_CR0_WP;
190 }
191
192 static int is_cpuid_PSE36(void)
193 {
194         return 1;
195 }
196
197 static int is_nx(struct kvm_vcpu *vcpu)
198 {
199         return vcpu->arch.shadow_efer & EFER_NX;
200 }
201
202 static int is_present_pte(unsigned long pte)
203 {
204         return pte & PT_PRESENT_MASK;
205 }
206
207 static int is_shadow_present_pte(u64 pte)
208 {
209         return pte != shadow_trap_nonpresent_pte
210                 && pte != shadow_notrap_nonpresent_pte;
211 }
212
213 static int is_large_pte(u64 pte)
214 {
215         return pte & PT_PAGE_SIZE_MASK;
216 }
217
218 static int is_writeble_pte(unsigned long pte)
219 {
220         return pte & PT_WRITABLE_MASK;
221 }
222
223 static int is_dirty_pte(unsigned long pte)
224 {
225         return pte & shadow_dirty_mask;
226 }
227
228 static int is_rmap_pte(u64 pte)
229 {
230         return is_shadow_present_pte(pte);
231 }
232
233 static pfn_t spte_to_pfn(u64 pte)
234 {
235         return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
236 }
237
238 static gfn_t pse36_gfn_delta(u32 gpte)
239 {
240         int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
241
242         return (gpte & PT32_DIR_PSE36_MASK) << shift;
243 }
244
245 static void set_shadow_pte(u64 *sptep, u64 spte)
246 {
247 #ifdef CONFIG_X86_64
248         set_64bit((unsigned long *)sptep, spte);
249 #else
250         set_64bit((unsigned long long *)sptep, spte);
251 #endif
252 }
253
254 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
255                                   struct kmem_cache *base_cache, int min)
256 {
257         void *obj;
258
259         if (cache->nobjs >= min)
260                 return 0;
261         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
262                 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
263                 if (!obj)
264                         return -ENOMEM;
265                 cache->objects[cache->nobjs++] = obj;
266         }
267         return 0;
268 }
269
270 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
271 {
272         while (mc->nobjs)
273                 kfree(mc->objects[--mc->nobjs]);
274 }
275
276 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
277                                        int min)
278 {
279         struct page *page;
280
281         if (cache->nobjs >= min)
282                 return 0;
283         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
284                 page = alloc_page(GFP_KERNEL);
285                 if (!page)
286                         return -ENOMEM;
287                 set_page_private(page, 0);
288                 cache->objects[cache->nobjs++] = page_address(page);
289         }
290         return 0;
291 }
292
293 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
294 {
295         while (mc->nobjs)
296                 free_page((unsigned long)mc->objects[--mc->nobjs]);
297 }
298
299 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
300 {
301         int r;
302
303         r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
304                                    pte_chain_cache, 4);
305         if (r)
306                 goto out;
307         r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
308                                    rmap_desc_cache, 1);
309         if (r)
310                 goto out;
311         r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
312         if (r)
313                 goto out;
314         r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
315                                    mmu_page_header_cache, 4);
316 out:
317         return r;
318 }
319
320 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
321 {
322         mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
323         mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
324         mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
325         mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
326 }
327
328 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
329                                     size_t size)
330 {
331         void *p;
332
333         BUG_ON(!mc->nobjs);
334         p = mc->objects[--mc->nobjs];
335         memset(p, 0, size);
336         return p;
337 }
338
339 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
340 {
341         return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
342                                       sizeof(struct kvm_pte_chain));
343 }
344
345 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
346 {
347         kfree(pc);
348 }
349
350 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
351 {
352         return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
353                                       sizeof(struct kvm_rmap_desc));
354 }
355
356 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
357 {
358         kfree(rd);
359 }
360
361 /*
362  * Return the pointer to the largepage write count for a given
363  * gfn, handling slots that are not large page aligned.
364  */
365 static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
366 {
367         unsigned long idx;
368
369         idx = (gfn / KVM_PAGES_PER_HPAGE) -
370               (slot->base_gfn / KVM_PAGES_PER_HPAGE);
371         return &slot->lpage_info[idx].write_count;
372 }
373
374 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
375 {
376         int *write_count;
377
378         write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
379         *write_count += 1;
380 }
381
382 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
383 {
384         int *write_count;
385
386         write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
387         *write_count -= 1;
388         WARN_ON(*write_count < 0);
389 }
390
391 static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
392 {
393         struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
394         int *largepage_idx;
395
396         if (slot) {
397                 largepage_idx = slot_largepage_idx(gfn, slot);
398                 return *largepage_idx;
399         }
400
401         return 1;
402 }
403
404 static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
405 {
406         struct vm_area_struct *vma;
407         unsigned long addr;
408
409         addr = gfn_to_hva(kvm, gfn);
410         if (kvm_is_error_hva(addr))
411                 return 0;
412
413         vma = find_vma(current->mm, addr);
414         if (vma && is_vm_hugetlb_page(vma))
415                 return 1;
416
417         return 0;
418 }
419
420 static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
421 {
422         struct kvm_memory_slot *slot;
423
424         if (has_wrprotected_page(vcpu->kvm, large_gfn))
425                 return 0;
426
427         if (!host_largepage_backed(vcpu->kvm, large_gfn))
428                 return 0;
429
430         slot = gfn_to_memslot(vcpu->kvm, large_gfn);
431         if (slot && slot->dirty_bitmap)
432                 return 0;
433
434         return 1;
435 }
436
437 /*
438  * Take gfn and return the reverse mapping to it.
439  * Note: gfn must be unaliased before this function get called
440  */
441
442 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
443 {
444         struct kvm_memory_slot *slot;
445         unsigned long idx;
446
447         slot = gfn_to_memslot(kvm, gfn);
448         if (!lpage)
449                 return &slot->rmap[gfn - slot->base_gfn];
450
451         idx = (gfn / KVM_PAGES_PER_HPAGE) -
452               (slot->base_gfn / KVM_PAGES_PER_HPAGE);
453
454         return &slot->lpage_info[idx].rmap_pde;
455 }
456
457 /*
458  * Reverse mapping data structures:
459  *
460  * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
461  * that points to page_address(page).
462  *
463  * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
464  * containing more mappings.
465  */
466 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
467 {
468         struct kvm_mmu_page *sp;
469         struct kvm_rmap_desc *desc;
470         unsigned long *rmapp;
471         int i;
472
473         if (!is_rmap_pte(*spte))
474                 return;
475         gfn = unalias_gfn(vcpu->kvm, gfn);
476         sp = page_header(__pa(spte));
477         sp->gfns[spte - sp->spt] = gfn;
478         rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
479         if (!*rmapp) {
480                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
481                 *rmapp = (unsigned long)spte;
482         } else if (!(*rmapp & 1)) {
483                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
484                 desc = mmu_alloc_rmap_desc(vcpu);
485                 desc->shadow_ptes[0] = (u64 *)*rmapp;
486                 desc->shadow_ptes[1] = spte;
487                 *rmapp = (unsigned long)desc | 1;
488         } else {
489                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
490                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
491                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
492                         desc = desc->more;
493                 if (desc->shadow_ptes[RMAP_EXT-1]) {
494                         desc->more = mmu_alloc_rmap_desc(vcpu);
495                         desc = desc->more;
496                 }
497                 for (i = 0; desc->shadow_ptes[i]; ++i)
498                         ;
499                 desc->shadow_ptes[i] = spte;
500         }
501 }
502
503 static void rmap_desc_remove_entry(unsigned long *rmapp,
504                                    struct kvm_rmap_desc *desc,
505                                    int i,
506                                    struct kvm_rmap_desc *prev_desc)
507 {
508         int j;
509
510         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
511                 ;
512         desc->shadow_ptes[i] = desc->shadow_ptes[j];
513         desc->shadow_ptes[j] = NULL;
514         if (j != 0)
515                 return;
516         if (!prev_desc && !desc->more)
517                 *rmapp = (unsigned long)desc->shadow_ptes[0];
518         else
519                 if (prev_desc)
520                         prev_desc->more = desc->more;
521                 else
522                         *rmapp = (unsigned long)desc->more | 1;
523         mmu_free_rmap_desc(desc);
524 }
525
526 static void rmap_remove(struct kvm *kvm, u64 *spte)
527 {
528         struct kvm_rmap_desc *desc;
529         struct kvm_rmap_desc *prev_desc;
530         struct kvm_mmu_page *sp;
531         pfn_t pfn;
532         unsigned long *rmapp;
533         int i;
534
535         if (!is_rmap_pte(*spte))
536                 return;
537         sp = page_header(__pa(spte));
538         pfn = spte_to_pfn(*spte);
539         if (*spte & shadow_accessed_mask)
540                 kvm_set_pfn_accessed(pfn);
541         if (is_writeble_pte(*spte))
542                 kvm_release_pfn_dirty(pfn);
543         else
544                 kvm_release_pfn_clean(pfn);
545         rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
546         if (!*rmapp) {
547                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
548                 BUG();
549         } else if (!(*rmapp & 1)) {
550                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
551                 if ((u64 *)*rmapp != spte) {
552                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
553                                spte, *spte);
554                         BUG();
555                 }
556                 *rmapp = 0;
557         } else {
558                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
559                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
560                 prev_desc = NULL;
561                 while (desc) {
562                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
563                                 if (desc->shadow_ptes[i] == spte) {
564                                         rmap_desc_remove_entry(rmapp,
565                                                                desc, i,
566                                                                prev_desc);
567                                         return;
568                                 }
569                         prev_desc = desc;
570                         desc = desc->more;
571                 }
572                 BUG();
573         }
574 }
575
576 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
577 {
578         struct kvm_rmap_desc *desc;
579         struct kvm_rmap_desc *prev_desc;
580         u64 *prev_spte;
581         int i;
582
583         if (!*rmapp)
584                 return NULL;
585         else if (!(*rmapp & 1)) {
586                 if (!spte)
587                         return (u64 *)*rmapp;
588                 return NULL;
589         }
590         desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
591         prev_desc = NULL;
592         prev_spte = NULL;
593         while (desc) {
594                 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
595                         if (prev_spte == spte)
596                                 return desc->shadow_ptes[i];
597                         prev_spte = desc->shadow_ptes[i];
598                 }
599                 desc = desc->more;
600         }
601         return NULL;
602 }
603
604 static void rmap_write_protect(struct kvm *kvm, u64 gfn)
605 {
606         unsigned long *rmapp;
607         u64 *spte;
608         int write_protected = 0;
609
610         gfn = unalias_gfn(kvm, gfn);
611         rmapp = gfn_to_rmap(kvm, gfn, 0);
612
613         spte = rmap_next(kvm, rmapp, NULL);
614         while (spte) {
615                 BUG_ON(!spte);
616                 BUG_ON(!(*spte & PT_PRESENT_MASK));
617                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
618                 if (is_writeble_pte(*spte)) {
619                         set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
620                         write_protected = 1;
621                 }
622                 spte = rmap_next(kvm, rmapp, spte);
623         }
624         if (write_protected) {
625                 pfn_t pfn;
626
627                 spte = rmap_next(kvm, rmapp, NULL);
628                 pfn = spte_to_pfn(*spte);
629                 kvm_set_pfn_dirty(pfn);
630         }
631
632         /* check for huge page mappings */
633         rmapp = gfn_to_rmap(kvm, gfn, 1);
634         spte = rmap_next(kvm, rmapp, NULL);
635         while (spte) {
636                 BUG_ON(!spte);
637                 BUG_ON(!(*spte & PT_PRESENT_MASK));
638                 BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
639                 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
640                 if (is_writeble_pte(*spte)) {
641                         rmap_remove(kvm, spte);
642                         --kvm->stat.lpages;
643                         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
644                         spte = NULL;
645                         write_protected = 1;
646                 }
647                 spte = rmap_next(kvm, rmapp, spte);
648         }
649
650         if (write_protected)
651                 kvm_flush_remote_tlbs(kvm);
652
653         account_shadowed(kvm, gfn);
654 }
655
656 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
657 {
658         u64 *spte;
659         int need_tlb_flush = 0;
660
661         while ((spte = rmap_next(kvm, rmapp, NULL))) {
662                 BUG_ON(!(*spte & PT_PRESENT_MASK));
663                 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
664                 rmap_remove(kvm, spte);
665                 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
666                 need_tlb_flush = 1;
667         }
668         return need_tlb_flush;
669 }
670
671 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
672                           int (*handler)(struct kvm *kvm, unsigned long *rmapp))
673 {
674         int i;
675         int retval = 0;
676
677         /*
678          * If mmap_sem isn't taken, we can look the memslots with only
679          * the mmu_lock by skipping over the slots with userspace_addr == 0.
680          */
681         for (i = 0; i < kvm->nmemslots; i++) {
682                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
683                 unsigned long start = memslot->userspace_addr;
684                 unsigned long end;
685
686                 /* mmu_lock protects userspace_addr */
687                 if (!start)
688                         continue;
689
690                 end = start + (memslot->npages << PAGE_SHIFT);
691                 if (hva >= start && hva < end) {
692                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
693                         retval |= handler(kvm, &memslot->rmap[gfn_offset]);
694                         retval |= handler(kvm,
695                                           &memslot->lpage_info[
696                                                   gfn_offset /
697                                                   KVM_PAGES_PER_HPAGE].rmap_pde);
698                 }
699         }
700
701         return retval;
702 }
703
704 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
705 {
706         return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
707 }
708
709 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
710 {
711         u64 *spte;
712         int young = 0;
713
714         /* always return old for EPT */
715         if (!shadow_accessed_mask)
716                 return 0;
717
718         spte = rmap_next(kvm, rmapp, NULL);
719         while (spte) {
720                 int _young;
721                 u64 _spte = *spte;
722                 BUG_ON(!(_spte & PT_PRESENT_MASK));
723                 _young = _spte & PT_ACCESSED_MASK;
724                 if (_young) {
725                         young = 1;
726                         clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
727                 }
728                 spte = rmap_next(kvm, rmapp, spte);
729         }
730         return young;
731 }
732
733 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
734 {
735         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
736 }
737
738 #ifdef MMU_DEBUG
739 static int is_empty_shadow_page(u64 *spt)
740 {
741         u64 *pos;
742         u64 *end;
743
744         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
745                 if (is_shadow_present_pte(*pos)) {
746                         printk(KERN_ERR "%s: %p %llx\n", __func__,
747                                pos, *pos);
748                         return 0;
749                 }
750         return 1;
751 }
752 #endif
753
754 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
755 {
756         ASSERT(is_empty_shadow_page(sp->spt));
757         list_del(&sp->link);
758         __free_page(virt_to_page(sp->spt));
759         __free_page(virt_to_page(sp->gfns));
760         kfree(sp);
761         ++kvm->arch.n_free_mmu_pages;
762 }
763
764 static unsigned kvm_page_table_hashfn(gfn_t gfn)
765 {
766         return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
767 }
768
769 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
770                                                u64 *parent_pte)
771 {
772         struct kvm_mmu_page *sp;
773
774         sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
775         sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
776         sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
777         set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
778         list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
779         ASSERT(is_empty_shadow_page(sp->spt));
780         sp->slot_bitmap = 0;
781         sp->multimapped = 0;
782         sp->parent_pte = parent_pte;
783         --vcpu->kvm->arch.n_free_mmu_pages;
784         return sp;
785 }
786
787 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
788                                     struct kvm_mmu_page *sp, u64 *parent_pte)
789 {
790         struct kvm_pte_chain *pte_chain;
791         struct hlist_node *node;
792         int i;
793
794         if (!parent_pte)
795                 return;
796         if (!sp->multimapped) {
797                 u64 *old = sp->parent_pte;
798
799                 if (!old) {
800                         sp->parent_pte = parent_pte;
801                         return;
802                 }
803                 sp->multimapped = 1;
804                 pte_chain = mmu_alloc_pte_chain(vcpu);
805                 INIT_HLIST_HEAD(&sp->parent_ptes);
806                 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
807                 pte_chain->parent_ptes[0] = old;
808         }
809         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
810                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
811                         continue;
812                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
813                         if (!pte_chain->parent_ptes[i]) {
814                                 pte_chain->parent_ptes[i] = parent_pte;
815                                 return;
816                         }
817         }
818         pte_chain = mmu_alloc_pte_chain(vcpu);
819         BUG_ON(!pte_chain);
820         hlist_add_head(&pte_chain->link, &sp->parent_ptes);
821         pte_chain->parent_ptes[0] = parent_pte;
822 }
823
824 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
825                                        u64 *parent_pte)
826 {
827         struct kvm_pte_chain *pte_chain;
828         struct hlist_node *node;
829         int i;
830
831         if (!sp->multimapped) {
832                 BUG_ON(sp->parent_pte != parent_pte);
833                 sp->parent_pte = NULL;
834                 return;
835         }
836         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
837                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
838                         if (!pte_chain->parent_ptes[i])
839                                 break;
840                         if (pte_chain->parent_ptes[i] != parent_pte)
841                                 continue;
842                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
843                                 && pte_chain->parent_ptes[i + 1]) {
844                                 pte_chain->parent_ptes[i]
845                                         = pte_chain->parent_ptes[i + 1];
846                                 ++i;
847                         }
848                         pte_chain->parent_ptes[i] = NULL;
849                         if (i == 0) {
850                                 hlist_del(&pte_chain->link);
851                                 mmu_free_pte_chain(pte_chain);
852                                 if (hlist_empty(&sp->parent_ptes)) {
853                                         sp->multimapped = 0;
854                                         sp->parent_pte = NULL;
855                                 }
856                         }
857                         return;
858                 }
859         BUG();
860 }
861
862 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
863                                     struct kvm_mmu_page *sp)
864 {
865         int i;
866
867         for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
868                 sp->spt[i] = shadow_trap_nonpresent_pte;
869 }
870
871 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
872 {
873         unsigned index;
874         struct hlist_head *bucket;
875         struct kvm_mmu_page *sp;
876         struct hlist_node *node;
877
878         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
879         index = kvm_page_table_hashfn(gfn);
880         bucket = &kvm->arch.mmu_page_hash[index];
881         hlist_for_each_entry(sp, node, bucket, hash_link)
882                 if (sp->gfn == gfn && !sp->role.metaphysical
883                     && !sp->role.invalid) {
884                         pgprintk("%s: found role %x\n",
885                                  __func__, sp->role.word);
886                         return sp;
887                 }
888         return NULL;
889 }
890
891 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
892                                              gfn_t gfn,
893                                              gva_t gaddr,
894                                              unsigned level,
895                                              int metaphysical,
896                                              unsigned access,
897                                              u64 *parent_pte)
898 {
899         union kvm_mmu_page_role role;
900         unsigned index;
901         unsigned quadrant;
902         struct hlist_head *bucket;
903         struct kvm_mmu_page *sp;
904         struct hlist_node *node;
905
906         role.word = 0;
907         role.glevels = vcpu->arch.mmu.root_level;
908         role.level = level;
909         role.metaphysical = metaphysical;
910         role.access = access;
911         if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
912                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
913                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
914                 role.quadrant = quadrant;
915         }
916         pgprintk("%s: looking gfn %lx role %x\n", __func__,
917                  gfn, role.word);
918         index = kvm_page_table_hashfn(gfn);
919         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
920         hlist_for_each_entry(sp, node, bucket, hash_link)
921                 if (sp->gfn == gfn && sp->role.word == role.word) {
922                         mmu_page_add_parent_pte(vcpu, sp, parent_pte);
923                         pgprintk("%s: found\n", __func__);
924                         return sp;
925                 }
926         ++vcpu->kvm->stat.mmu_cache_miss;
927         sp = kvm_mmu_alloc_page(vcpu, parent_pte);
928         if (!sp)
929                 return sp;
930         pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
931         sp->gfn = gfn;
932         sp->role = role;
933         hlist_add_head(&sp->hash_link, bucket);
934         if (!metaphysical)
935                 rmap_write_protect(vcpu->kvm, gfn);
936         if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
937                 vcpu->arch.mmu.prefetch_page(vcpu, sp);
938         else
939                 nonpaging_prefetch_page(vcpu, sp);
940         return sp;
941 }
942
943 static int walk_shadow(struct kvm_shadow_walk *walker,
944                        struct kvm_vcpu *vcpu, u64 addr)
945 {
946         hpa_t shadow_addr;
947         int level;
948         int r;
949         u64 *sptep;
950         unsigned index;
951
952         shadow_addr = vcpu->arch.mmu.root_hpa;
953         level = vcpu->arch.mmu.shadow_root_level;
954         if (level == PT32E_ROOT_LEVEL) {
955                 shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
956                 shadow_addr &= PT64_BASE_ADDR_MASK;
957                 --level;
958         }
959
960         while (level >= PT_PAGE_TABLE_LEVEL) {
961                 index = SHADOW_PT_INDEX(addr, level);
962                 sptep = ((u64 *)__va(shadow_addr)) + index;
963                 r = walker->entry(walker, vcpu, addr, sptep, level);
964                 if (r)
965                         return r;
966                 shadow_addr = *sptep & PT64_BASE_ADDR_MASK;
967                 --level;
968         }
969         return 0;
970 }
971
972 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
973                                          struct kvm_mmu_page *sp)
974 {
975         unsigned i;
976         u64 *pt;
977         u64 ent;
978
979         pt = sp->spt;
980
981         if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
982                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
983                         if (is_shadow_present_pte(pt[i]))
984                                 rmap_remove(kvm, &pt[i]);
985                         pt[i] = shadow_trap_nonpresent_pte;
986                 }
987                 return;
988         }
989
990         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
991                 ent = pt[i];
992
993                 if (is_shadow_present_pte(ent)) {
994                         if (!is_large_pte(ent)) {
995                                 ent &= PT64_BASE_ADDR_MASK;
996                                 mmu_page_remove_parent_pte(page_header(ent),
997                                                            &pt[i]);
998                         } else {
999                                 --kvm->stat.lpages;
1000                                 rmap_remove(kvm, &pt[i]);
1001                         }
1002                 }
1003                 pt[i] = shadow_trap_nonpresent_pte;
1004         }
1005 }
1006
1007 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1008 {
1009         mmu_page_remove_parent_pte(sp, parent_pte);
1010 }
1011
1012 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1013 {
1014         int i;
1015
1016         for (i = 0; i < KVM_MAX_VCPUS; ++i)
1017                 if (kvm->vcpus[i])
1018                         kvm->vcpus[i]->arch.last_pte_updated = NULL;
1019 }
1020
1021 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1022 {
1023         u64 *parent_pte;
1024
1025         while (sp->multimapped || sp->parent_pte) {
1026                 if (!sp->multimapped)
1027                         parent_pte = sp->parent_pte;
1028                 else {
1029                         struct kvm_pte_chain *chain;
1030
1031                         chain = container_of(sp->parent_ptes.first,
1032                                              struct kvm_pte_chain, link);
1033                         parent_pte = chain->parent_ptes[0];
1034                 }
1035                 BUG_ON(!parent_pte);
1036                 kvm_mmu_put_page(sp, parent_pte);
1037                 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
1038         }
1039 }
1040
1041 static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1042 {
1043         ++kvm->stat.mmu_shadow_zapped;
1044         kvm_mmu_page_unlink_children(kvm, sp);
1045         kvm_mmu_unlink_parents(kvm, sp);
1046         kvm_flush_remote_tlbs(kvm);
1047         if (!sp->role.invalid && !sp->role.metaphysical)
1048                 unaccount_shadowed(kvm, sp->gfn);
1049         if (!sp->root_count) {
1050                 hlist_del(&sp->hash_link);
1051                 kvm_mmu_free_page(kvm, sp);
1052         } else {
1053                 sp->role.invalid = 1;
1054                 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1055                 kvm_reload_remote_mmus(kvm);
1056         }
1057         kvm_mmu_reset_last_pte_updated(kvm);
1058 }
1059
1060 /*
1061  * Changing the number of mmu pages allocated to the vm
1062  * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1063  */
1064 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1065 {
1066         /*
1067          * If we set the number of mmu pages to be smaller be than the
1068          * number of actived pages , we must to free some mmu pages before we
1069          * change the value
1070          */
1071
1072         if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
1073             kvm_nr_mmu_pages) {
1074                 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
1075                                        - kvm->arch.n_free_mmu_pages;
1076
1077                 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
1078                         struct kvm_mmu_page *page;
1079
1080                         page = container_of(kvm->arch.active_mmu_pages.prev,
1081                                             struct kvm_mmu_page, link);
1082                         kvm_mmu_zap_page(kvm, page);
1083                         n_used_mmu_pages--;
1084                 }
1085                 kvm->arch.n_free_mmu_pages = 0;
1086         }
1087         else
1088                 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1089                                          - kvm->arch.n_alloc_mmu_pages;
1090
1091         kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1092 }
1093
1094 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1095 {
1096         unsigned index;
1097         struct hlist_head *bucket;
1098         struct kvm_mmu_page *sp;
1099         struct hlist_node *node, *n;
1100         int r;
1101
1102         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1103         r = 0;
1104         index = kvm_page_table_hashfn(gfn);
1105         bucket = &kvm->arch.mmu_page_hash[index];
1106         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1107                 if (sp->gfn == gfn && !sp->role.metaphysical) {
1108                         pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1109                                  sp->role.word);
1110                         kvm_mmu_zap_page(kvm, sp);
1111                         r = 1;
1112                 }
1113         return r;
1114 }
1115
1116 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1117 {
1118         struct kvm_mmu_page *sp;
1119
1120         while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
1121                 pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
1122                 kvm_mmu_zap_page(kvm, sp);
1123         }
1124 }
1125
1126 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1127 {
1128         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1129         struct kvm_mmu_page *sp = page_header(__pa(pte));
1130
1131         __set_bit(slot, &sp->slot_bitmap);
1132 }
1133
1134 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1135 {
1136         struct page *page;
1137
1138         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1139
1140         if (gpa == UNMAPPED_GVA)
1141                 return NULL;
1142
1143         down_read(&current->mm->mmap_sem);
1144         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1145         up_read(&current->mm->mmap_sem);
1146
1147         return page;
1148 }
1149
1150 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1151                          unsigned pt_access, unsigned pte_access,
1152                          int user_fault, int write_fault, int dirty,
1153                          int *ptwrite, int largepage, gfn_t gfn,
1154                          pfn_t pfn, bool speculative)
1155 {
1156         u64 spte;
1157         int was_rmapped = 0;
1158         int was_writeble = is_writeble_pte(*shadow_pte);
1159
1160         pgprintk("%s: spte %llx access %x write_fault %d"
1161                  " user_fault %d gfn %lx\n",
1162                  __func__, *shadow_pte, pt_access,
1163                  write_fault, user_fault, gfn);
1164
1165         if (is_rmap_pte(*shadow_pte)) {
1166                 /*
1167                  * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1168                  * the parent of the now unreachable PTE.
1169                  */
1170                 if (largepage && !is_large_pte(*shadow_pte)) {
1171                         struct kvm_mmu_page *child;
1172                         u64 pte = *shadow_pte;
1173
1174                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1175                         mmu_page_remove_parent_pte(child, shadow_pte);
1176                 } else if (pfn != spte_to_pfn(*shadow_pte)) {
1177                         pgprintk("hfn old %lx new %lx\n",
1178                                  spte_to_pfn(*shadow_pte), pfn);
1179                         rmap_remove(vcpu->kvm, shadow_pte);
1180                 } else {
1181                         if (largepage)
1182                                 was_rmapped = is_large_pte(*shadow_pte);
1183                         else
1184                                 was_rmapped = 1;
1185                 }
1186         }
1187
1188         /*
1189          * We don't set the accessed bit, since we sometimes want to see
1190          * whether the guest actually used the pte (in order to detect
1191          * demand paging).
1192          */
1193         spte = shadow_base_present_pte | shadow_dirty_mask;
1194         if (!speculative)
1195                 spte |= shadow_accessed_mask;
1196         if (!dirty)
1197                 pte_access &= ~ACC_WRITE_MASK;
1198         if (pte_access & ACC_EXEC_MASK)
1199                 spte |= shadow_x_mask;
1200         else
1201                 spte |= shadow_nx_mask;
1202         if (pte_access & ACC_USER_MASK)
1203                 spte |= shadow_user_mask;
1204         if (largepage)
1205                 spte |= PT_PAGE_SIZE_MASK;
1206
1207         spte |= (u64)pfn << PAGE_SHIFT;
1208
1209         if ((pte_access & ACC_WRITE_MASK)
1210             || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1211                 struct kvm_mmu_page *shadow;
1212
1213                 spte |= PT_WRITABLE_MASK;
1214
1215                 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1216                 if (shadow ||
1217                    (largepage && has_wrprotected_page(vcpu->kvm, gfn))) {
1218                         pgprintk("%s: found shadow page for %lx, marking ro\n",
1219                                  __func__, gfn);
1220                         pte_access &= ~ACC_WRITE_MASK;
1221                         if (is_writeble_pte(spte)) {
1222                                 spte &= ~PT_WRITABLE_MASK;
1223                                 kvm_x86_ops->tlb_flush(vcpu);
1224                         }
1225                         if (write_fault)
1226                                 *ptwrite = 1;
1227                 }
1228         }
1229
1230         if (pte_access & ACC_WRITE_MASK)
1231                 mark_page_dirty(vcpu->kvm, gfn);
1232
1233         pgprintk("%s: setting spte %llx\n", __func__, spte);
1234         pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1235                  (spte&PT_PAGE_SIZE_MASK)? "2MB" : "4kB",
1236                  (spte&PT_WRITABLE_MASK)?"RW":"R", gfn, spte, shadow_pte);
1237         set_shadow_pte(shadow_pte, spte);
1238         if (!was_rmapped && (spte & PT_PAGE_SIZE_MASK)
1239             && (spte & PT_PRESENT_MASK))
1240                 ++vcpu->kvm->stat.lpages;
1241
1242         page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
1243         if (!was_rmapped) {
1244                 rmap_add(vcpu, shadow_pte, gfn, largepage);
1245                 if (!is_rmap_pte(*shadow_pte))
1246                         kvm_release_pfn_clean(pfn);
1247         } else {
1248                 if (was_writeble)
1249                         kvm_release_pfn_dirty(pfn);
1250                 else
1251                         kvm_release_pfn_clean(pfn);
1252         }
1253         if (speculative) {
1254                 vcpu->arch.last_pte_updated = shadow_pte;
1255                 vcpu->arch.last_pte_gfn = gfn;
1256         }
1257 }
1258
1259 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1260 {
1261 }
1262
1263 struct direct_shadow_walk {
1264         struct kvm_shadow_walk walker;
1265         pfn_t pfn;
1266         int write;
1267         int largepage;
1268         int pt_write;
1269 };
1270
1271 static int direct_map_entry(struct kvm_shadow_walk *_walk,
1272                             struct kvm_vcpu *vcpu,
1273                             u64 addr, u64 *sptep, int level)
1274 {
1275         struct direct_shadow_walk *walk =
1276                 container_of(_walk, struct direct_shadow_walk, walker);
1277         struct kvm_mmu_page *sp;
1278         gfn_t pseudo_gfn;
1279         gfn_t gfn = addr >> PAGE_SHIFT;
1280
1281         if (level == PT_PAGE_TABLE_LEVEL
1282             || (walk->largepage && level == PT_DIRECTORY_LEVEL)) {
1283                 mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL,
1284                              0, walk->write, 1, &walk->pt_write,
1285                              walk->largepage, gfn, walk->pfn, false);
1286                 ++vcpu->stat.pf_fixed;
1287                 return 1;
1288         }
1289
1290         if (*sptep == shadow_trap_nonpresent_pte) {
1291                 pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1292                 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1,
1293                                       1, ACC_ALL, sptep);
1294                 if (!sp) {
1295                         pgprintk("nonpaging_map: ENOMEM\n");
1296                         kvm_release_pfn_clean(walk->pfn);
1297                         return -ENOMEM;
1298                 }
1299
1300                 set_shadow_pte(sptep,
1301                                __pa(sp->spt)
1302                                | PT_PRESENT_MASK | PT_WRITABLE_MASK
1303                                | shadow_user_mask | shadow_x_mask);
1304         }
1305         return 0;
1306 }
1307
1308 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1309                         int largepage, gfn_t gfn, pfn_t pfn)
1310 {
1311         int r;
1312         struct direct_shadow_walk walker = {
1313                 .walker = { .entry = direct_map_entry, },
1314                 .pfn = pfn,
1315                 .largepage = largepage,
1316                 .write = write,
1317                 .pt_write = 0,
1318         };
1319
1320         r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT);
1321         if (r < 0)
1322                 return r;
1323         return walker.pt_write;
1324 }
1325
1326 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1327 {
1328         int r;
1329         int largepage = 0;
1330         pfn_t pfn;
1331         unsigned long mmu_seq;
1332
1333         down_read(&current->mm->mmap_sem);
1334         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1335                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1336                 largepage = 1;
1337         }
1338
1339         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1340         /* implicit mb(), we'll read before PT lock is unlocked */
1341         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1342         up_read(&current->mm->mmap_sem);
1343
1344         /* mmio */
1345         if (is_error_pfn(pfn)) {
1346                 kvm_release_pfn_clean(pfn);
1347                 return 1;
1348         }
1349
1350         spin_lock(&vcpu->kvm->mmu_lock);
1351         if (mmu_notifier_retry(vcpu, mmu_seq))
1352                 goto out_unlock;
1353         kvm_mmu_free_some_pages(vcpu);
1354         r = __direct_map(vcpu, v, write, largepage, gfn, pfn);
1355         spin_unlock(&vcpu->kvm->mmu_lock);
1356
1357
1358         return r;
1359
1360 out_unlock:
1361         spin_unlock(&vcpu->kvm->mmu_lock);
1362         kvm_release_pfn_clean(pfn);
1363         return 0;
1364 }
1365
1366
1367 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1368 {
1369         int i;
1370         struct kvm_mmu_page *sp;
1371
1372         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1373                 return;
1374         spin_lock(&vcpu->kvm->mmu_lock);
1375         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1376                 hpa_t root = vcpu->arch.mmu.root_hpa;
1377
1378                 sp = page_header(root);
1379                 --sp->root_count;
1380                 if (!sp->root_count && sp->role.invalid)
1381                         kvm_mmu_zap_page(vcpu->kvm, sp);
1382                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1383                 spin_unlock(&vcpu->kvm->mmu_lock);
1384                 return;
1385         }
1386         for (i = 0; i < 4; ++i) {
1387                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1388
1389                 if (root) {
1390                         root &= PT64_BASE_ADDR_MASK;
1391                         sp = page_header(root);
1392                         --sp->root_count;
1393                         if (!sp->root_count && sp->role.invalid)
1394                                 kvm_mmu_zap_page(vcpu->kvm, sp);
1395                 }
1396                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1397         }
1398         spin_unlock(&vcpu->kvm->mmu_lock);
1399         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1400 }
1401
1402 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1403 {
1404         int i;
1405         gfn_t root_gfn;
1406         struct kvm_mmu_page *sp;
1407         int metaphysical = 0;
1408
1409         root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1410
1411         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1412                 hpa_t root = vcpu->arch.mmu.root_hpa;
1413
1414                 ASSERT(!VALID_PAGE(root));
1415                 if (tdp_enabled)
1416                         metaphysical = 1;
1417                 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1418                                       PT64_ROOT_LEVEL, metaphysical,
1419                                       ACC_ALL, NULL);
1420                 root = __pa(sp->spt);
1421                 ++sp->root_count;
1422                 vcpu->arch.mmu.root_hpa = root;
1423                 return;
1424         }
1425         metaphysical = !is_paging(vcpu);
1426         if (tdp_enabled)
1427                 metaphysical = 1;
1428         for (i = 0; i < 4; ++i) {
1429                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1430
1431                 ASSERT(!VALID_PAGE(root));
1432                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1433                         if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1434                                 vcpu->arch.mmu.pae_root[i] = 0;
1435                                 continue;
1436                         }
1437                         root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1438                 } else if (vcpu->arch.mmu.root_level == 0)
1439                         root_gfn = 0;
1440                 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1441                                       PT32_ROOT_LEVEL, metaphysical,
1442                                       ACC_ALL, NULL);
1443                 root = __pa(sp->spt);
1444                 ++sp->root_count;
1445                 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1446         }
1447         vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1448 }
1449
1450 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1451 {
1452         return vaddr;
1453 }
1454
1455 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1456                                 u32 error_code)
1457 {
1458         gfn_t gfn;
1459         int r;
1460
1461         pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
1462         r = mmu_topup_memory_caches(vcpu);
1463         if (r)
1464                 return r;
1465
1466         ASSERT(vcpu);
1467         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1468
1469         gfn = gva >> PAGE_SHIFT;
1470
1471         return nonpaging_map(vcpu, gva & PAGE_MASK,
1472                              error_code & PFERR_WRITE_MASK, gfn);
1473 }
1474
1475 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
1476                                 u32 error_code)
1477 {
1478         pfn_t pfn;
1479         int r;
1480         int largepage = 0;
1481         gfn_t gfn = gpa >> PAGE_SHIFT;
1482         unsigned long mmu_seq;
1483
1484         ASSERT(vcpu);
1485         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1486
1487         r = mmu_topup_memory_caches(vcpu);
1488         if (r)
1489                 return r;
1490
1491         down_read(&current->mm->mmap_sem);
1492         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1493                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1494                 largepage = 1;
1495         }
1496         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1497         /* implicit mb(), we'll read before PT lock is unlocked */
1498         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1499         up_read(&current->mm->mmap_sem);
1500         if (is_error_pfn(pfn)) {
1501                 kvm_release_pfn_clean(pfn);
1502                 return 1;
1503         }
1504         spin_lock(&vcpu->kvm->mmu_lock);
1505         if (mmu_notifier_retry(vcpu, mmu_seq))
1506                 goto out_unlock;
1507         kvm_mmu_free_some_pages(vcpu);
1508         r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
1509                          largepage, gfn, pfn);
1510         spin_unlock(&vcpu->kvm->mmu_lock);
1511
1512         return r;
1513
1514 out_unlock:
1515         spin_unlock(&vcpu->kvm->mmu_lock);
1516         kvm_release_pfn_clean(pfn);
1517         return 0;
1518 }
1519
1520 static void nonpaging_free(struct kvm_vcpu *vcpu)
1521 {
1522         mmu_free_roots(vcpu);
1523 }
1524
1525 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1526 {
1527         struct kvm_mmu *context = &vcpu->arch.mmu;
1528
1529         context->new_cr3 = nonpaging_new_cr3;
1530         context->page_fault = nonpaging_page_fault;
1531         context->gva_to_gpa = nonpaging_gva_to_gpa;
1532         context->free = nonpaging_free;
1533         context->prefetch_page = nonpaging_prefetch_page;
1534         context->root_level = 0;
1535         context->shadow_root_level = PT32E_ROOT_LEVEL;
1536         context->root_hpa = INVALID_PAGE;
1537         return 0;
1538 }
1539
1540 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1541 {
1542         ++vcpu->stat.tlb_flush;
1543         kvm_x86_ops->tlb_flush(vcpu);
1544 }
1545
1546 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1547 {
1548         pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
1549         mmu_free_roots(vcpu);
1550 }
1551
1552 static void inject_page_fault(struct kvm_vcpu *vcpu,
1553                               u64 addr,
1554                               u32 err_code)
1555 {
1556         kvm_inject_page_fault(vcpu, addr, err_code);
1557 }
1558
1559 static void paging_free(struct kvm_vcpu *vcpu)
1560 {
1561         nonpaging_free(vcpu);
1562 }
1563
1564 #define PTTYPE 64
1565 #include "paging_tmpl.h"
1566 #undef PTTYPE
1567
1568 #define PTTYPE 32
1569 #include "paging_tmpl.h"
1570 #undef PTTYPE
1571
1572 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1573 {
1574         struct kvm_mmu *context = &vcpu->arch.mmu;
1575
1576         ASSERT(is_pae(vcpu));
1577         context->new_cr3 = paging_new_cr3;
1578         context->page_fault = paging64_page_fault;
1579         context->gva_to_gpa = paging64_gva_to_gpa;
1580         context->prefetch_page = paging64_prefetch_page;
1581         context->free = paging_free;
1582         context->root_level = level;
1583         context->shadow_root_level = level;
1584         context->root_hpa = INVALID_PAGE;
1585         return 0;
1586 }
1587
1588 static int paging64_init_context(struct kvm_vcpu *vcpu)
1589 {
1590         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1591 }
1592
1593 static int paging32_init_context(struct kvm_vcpu *vcpu)
1594 {
1595         struct kvm_mmu *context = &vcpu->arch.mmu;
1596
1597         context->new_cr3 = paging_new_cr3;
1598         context->page_fault = paging32_page_fault;
1599         context->gva_to_gpa = paging32_gva_to_gpa;
1600         context->free = paging_free;
1601         context->prefetch_page = paging32_prefetch_page;
1602         context->root_level = PT32_ROOT_LEVEL;
1603         context->shadow_root_level = PT32E_ROOT_LEVEL;
1604         context->root_hpa = INVALID_PAGE;
1605         return 0;
1606 }
1607
1608 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1609 {
1610         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1611 }
1612
1613 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
1614 {
1615         struct kvm_mmu *context = &vcpu->arch.mmu;
1616
1617         context->new_cr3 = nonpaging_new_cr3;
1618         context->page_fault = tdp_page_fault;
1619         context->free = nonpaging_free;
1620         context->prefetch_page = nonpaging_prefetch_page;
1621         context->shadow_root_level = kvm_x86_ops->get_tdp_level();
1622         context->root_hpa = INVALID_PAGE;
1623
1624         if (!is_paging(vcpu)) {
1625                 context->gva_to_gpa = nonpaging_gva_to_gpa;
1626                 context->root_level = 0;
1627         } else if (is_long_mode(vcpu)) {
1628                 context->gva_to_gpa = paging64_gva_to_gpa;
1629                 context->root_level = PT64_ROOT_LEVEL;
1630         } else if (is_pae(vcpu)) {
1631                 context->gva_to_gpa = paging64_gva_to_gpa;
1632                 context->root_level = PT32E_ROOT_LEVEL;
1633         } else {
1634                 context->gva_to_gpa = paging32_gva_to_gpa;
1635                 context->root_level = PT32_ROOT_LEVEL;
1636         }
1637
1638         return 0;
1639 }
1640
1641 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
1642 {
1643         ASSERT(vcpu);
1644         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1645
1646         if (!is_paging(vcpu))
1647                 return nonpaging_init_context(vcpu);
1648         else if (is_long_mode(vcpu))
1649                 return paging64_init_context(vcpu);
1650         else if (is_pae(vcpu))
1651                 return paging32E_init_context(vcpu);
1652         else
1653                 return paging32_init_context(vcpu);
1654 }
1655
1656 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1657 {
1658         vcpu->arch.update_pte.pfn = bad_pfn;
1659
1660         if (tdp_enabled)
1661                 return init_kvm_tdp_mmu(vcpu);
1662         else
1663                 return init_kvm_softmmu(vcpu);
1664 }
1665
1666 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1667 {
1668         ASSERT(vcpu);
1669         if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1670                 vcpu->arch.mmu.free(vcpu);
1671                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1672         }
1673 }
1674
1675 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1676 {
1677         destroy_kvm_mmu(vcpu);
1678         return init_kvm_mmu(vcpu);
1679 }
1680 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1681
1682 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1683 {
1684         int r;
1685
1686         r = mmu_topup_memory_caches(vcpu);
1687         if (r)
1688                 goto out;
1689         spin_lock(&vcpu->kvm->mmu_lock);
1690         kvm_mmu_free_some_pages(vcpu);
1691         mmu_alloc_roots(vcpu);
1692         spin_unlock(&vcpu->kvm->mmu_lock);
1693         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1694         kvm_mmu_flush_tlb(vcpu);
1695 out:
1696         return r;
1697 }
1698 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1699
1700 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1701 {
1702         mmu_free_roots(vcpu);
1703 }
1704
1705 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1706                                   struct kvm_mmu_page *sp,
1707                                   u64 *spte)
1708 {
1709         u64 pte;
1710         struct kvm_mmu_page *child;
1711
1712         pte = *spte;
1713         if (is_shadow_present_pte(pte)) {
1714                 if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
1715                     is_large_pte(pte))
1716                         rmap_remove(vcpu->kvm, spte);
1717                 else {
1718                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1719                         mmu_page_remove_parent_pte(child, spte);
1720                 }
1721         }
1722         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1723         if (is_large_pte(pte))
1724                 --vcpu->kvm->stat.lpages;
1725 }
1726
1727 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1728                                   struct kvm_mmu_page *sp,
1729                                   u64 *spte,
1730                                   const void *new)
1731 {
1732         if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1733                 if (!vcpu->arch.update_pte.largepage ||
1734                     sp->role.glevels == PT32_ROOT_LEVEL) {
1735                         ++vcpu->kvm->stat.mmu_pde_zapped;
1736                         return;
1737                 }
1738         }
1739
1740         ++vcpu->kvm->stat.mmu_pte_updated;
1741         if (sp->role.glevels == PT32_ROOT_LEVEL)
1742                 paging32_update_pte(vcpu, sp, spte, new);
1743         else
1744                 paging64_update_pte(vcpu, sp, spte, new);
1745 }
1746
1747 static bool need_remote_flush(u64 old, u64 new)
1748 {
1749         if (!is_shadow_present_pte(old))
1750                 return false;
1751         if (!is_shadow_present_pte(new))
1752                 return true;
1753         if ((old ^ new) & PT64_BASE_ADDR_MASK)
1754                 return true;
1755         old ^= PT64_NX_MASK;
1756         new ^= PT64_NX_MASK;
1757         return (old & ~new & PT64_PERM_MASK) != 0;
1758 }
1759
1760 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1761 {
1762         if (need_remote_flush(old, new))
1763                 kvm_flush_remote_tlbs(vcpu->kvm);
1764         else
1765                 kvm_mmu_flush_tlb(vcpu);
1766 }
1767
1768 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1769 {
1770         u64 *spte = vcpu->arch.last_pte_updated;
1771
1772         return !!(spte && (*spte & shadow_accessed_mask));
1773 }
1774
1775 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1776                                           const u8 *new, int bytes)
1777 {
1778         gfn_t gfn;
1779         int r;
1780         u64 gpte = 0;
1781         pfn_t pfn;
1782
1783         vcpu->arch.update_pte.largepage = 0;
1784
1785         if (bytes != 4 && bytes != 8)
1786                 return;
1787
1788         /*
1789          * Assume that the pte write on a page table of the same type
1790          * as the current vcpu paging mode.  This is nearly always true
1791          * (might be false while changing modes).  Note it is verified later
1792          * by update_pte().
1793          */
1794         if (is_pae(vcpu)) {
1795                 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1796                 if ((bytes == 4) && (gpa % 4 == 0)) {
1797                         r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1798                         if (r)
1799                                 return;
1800                         memcpy((void *)&gpte + (gpa % 8), new, 4);
1801                 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1802                         memcpy((void *)&gpte, new, 8);
1803                 }
1804         } else {
1805                 if ((bytes == 4) && (gpa % 4 == 0))
1806                         memcpy((void *)&gpte, new, 4);
1807         }
1808         if (!is_present_pte(gpte))
1809                 return;
1810         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1811
1812         down_read(&current->mm->mmap_sem);
1813         if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
1814                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1815                 vcpu->arch.update_pte.largepage = 1;
1816         }
1817         vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
1818         /* implicit mb(), we'll read before PT lock is unlocked */
1819         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1820         up_read(&current->mm->mmap_sem);
1821
1822         if (is_error_pfn(pfn)) {
1823                 kvm_release_pfn_clean(pfn);
1824                 return;
1825         }
1826         vcpu->arch.update_pte.gfn = gfn;
1827         vcpu->arch.update_pte.pfn = pfn;
1828 }
1829
1830 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1831 {
1832         u64 *spte = vcpu->arch.last_pte_updated;
1833
1834         if (spte
1835             && vcpu->arch.last_pte_gfn == gfn
1836             && shadow_accessed_mask
1837             && !(*spte & shadow_accessed_mask)
1838             && is_shadow_present_pte(*spte))
1839                 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
1840 }
1841
1842 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1843                        const u8 *new, int bytes)
1844 {
1845         gfn_t gfn = gpa >> PAGE_SHIFT;
1846         struct kvm_mmu_page *sp;
1847         struct hlist_node *node, *n;
1848         struct hlist_head *bucket;
1849         unsigned index;
1850         u64 entry, gentry;
1851         u64 *spte;
1852         unsigned offset = offset_in_page(gpa);
1853         unsigned pte_size;
1854         unsigned page_offset;
1855         unsigned misaligned;
1856         unsigned quadrant;
1857         int level;
1858         int flooded = 0;
1859         int npte;
1860         int r;
1861
1862         pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
1863         mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1864         spin_lock(&vcpu->kvm->mmu_lock);
1865         kvm_mmu_access_page(vcpu, gfn);
1866         kvm_mmu_free_some_pages(vcpu);
1867         ++vcpu->kvm->stat.mmu_pte_write;
1868         kvm_mmu_audit(vcpu, "pre pte write");
1869         if (gfn == vcpu->arch.last_pt_write_gfn
1870             && !last_updated_pte_accessed(vcpu)) {
1871                 ++vcpu->arch.last_pt_write_count;
1872                 if (vcpu->arch.last_pt_write_count >= 3)
1873                         flooded = 1;
1874         } else {
1875                 vcpu->arch.last_pt_write_gfn = gfn;
1876                 vcpu->arch.last_pt_write_count = 1;
1877                 vcpu->arch.last_pte_updated = NULL;
1878         }
1879         index = kvm_page_table_hashfn(gfn);
1880         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1881         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1882                 if (sp->gfn != gfn || sp->role.metaphysical || sp->role.invalid)
1883                         continue;
1884                 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1885                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1886                 misaligned |= bytes < 4;
1887                 if (misaligned || flooded) {
1888                         /*
1889                          * Misaligned accesses are too much trouble to fix
1890                          * up; also, they usually indicate a page is not used
1891                          * as a page table.
1892                          *
1893                          * If we're seeing too many writes to a page,
1894                          * it may no longer be a page table, or we may be
1895                          * forking, in which case it is better to unmap the
1896                          * page.
1897                          */
1898                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1899                                  gpa, bytes, sp->role.word);
1900                         kvm_mmu_zap_page(vcpu->kvm, sp);
1901                         ++vcpu->kvm->stat.mmu_flooded;
1902                         continue;
1903                 }
1904                 page_offset = offset;
1905                 level = sp->role.level;
1906                 npte = 1;
1907                 if (sp->role.glevels == PT32_ROOT_LEVEL) {
1908                         page_offset <<= 1;      /* 32->64 */
1909                         /*
1910                          * A 32-bit pde maps 4MB while the shadow pdes map
1911                          * only 2MB.  So we need to double the offset again
1912                          * and zap two pdes instead of one.
1913                          */
1914                         if (level == PT32_ROOT_LEVEL) {
1915                                 page_offset &= ~7; /* kill rounding error */
1916                                 page_offset <<= 1;
1917                                 npte = 2;
1918                         }
1919                         quadrant = page_offset >> PAGE_SHIFT;
1920                         page_offset &= ~PAGE_MASK;
1921                         if (quadrant != sp->role.quadrant)
1922                                 continue;
1923                 }
1924                 spte = &sp->spt[page_offset / sizeof(*spte)];
1925                 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
1926                         gentry = 0;
1927                         r = kvm_read_guest_atomic(vcpu->kvm,
1928                                                   gpa & ~(u64)(pte_size - 1),
1929                                                   &gentry, pte_size);
1930                         new = (const void *)&gentry;
1931                         if (r < 0)
1932                                 new = NULL;
1933                 }
1934                 while (npte--) {
1935                         entry = *spte;
1936                         mmu_pte_write_zap_pte(vcpu, sp, spte);
1937                         if (new)
1938                                 mmu_pte_write_new_pte(vcpu, sp, spte, new);
1939                         mmu_pte_write_flush_tlb(vcpu, entry, *spte);
1940                         ++spte;
1941                 }
1942         }
1943         kvm_mmu_audit(vcpu, "post pte write");
1944         spin_unlock(&vcpu->kvm->mmu_lock);
1945         if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
1946                 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
1947                 vcpu->arch.update_pte.pfn = bad_pfn;
1948         }
1949 }
1950
1951 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1952 {
1953         gpa_t gpa;
1954         int r;
1955
1956         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1957
1958         spin_lock(&vcpu->kvm->mmu_lock);
1959         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1960         spin_unlock(&vcpu->kvm->mmu_lock);
1961         return r;
1962 }
1963 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
1964
1965 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1966 {
1967         while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
1968                 struct kvm_mmu_page *sp;
1969
1970                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
1971                                   struct kvm_mmu_page, link);
1972                 kvm_mmu_zap_page(vcpu->kvm, sp);
1973                 ++vcpu->kvm->stat.mmu_recycled;
1974         }
1975 }
1976
1977 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
1978 {
1979         int r;
1980         enum emulation_result er;
1981
1982         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
1983         if (r < 0)
1984                 goto out;
1985
1986         if (!r) {
1987                 r = 1;
1988                 goto out;
1989         }
1990
1991         r = mmu_topup_memory_caches(vcpu);
1992         if (r)
1993                 goto out;
1994
1995         er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
1996
1997         switch (er) {
1998         case EMULATE_DONE:
1999                 return 1;
2000         case EMULATE_DO_MMIO:
2001                 ++vcpu->stat.mmio_exits;
2002                 return 0;
2003         case EMULATE_FAIL:
2004                 kvm_report_emulation_failure(vcpu, "pagetable");
2005                 return 1;
2006         default:
2007                 BUG();
2008         }
2009 out:
2010         return r;
2011 }
2012 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2013
2014 void kvm_enable_tdp(void)
2015 {
2016         tdp_enabled = true;
2017 }
2018 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2019
2020 void kvm_disable_tdp(void)
2021 {
2022         tdp_enabled = false;
2023 }
2024 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2025
2026 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2027 {
2028         struct kvm_mmu_page *sp;
2029
2030         while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2031                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
2032                                   struct kvm_mmu_page, link);
2033                 kvm_mmu_zap_page(vcpu->kvm, sp);
2034                 cond_resched();
2035         }
2036         free_page((unsigned long)vcpu->arch.mmu.pae_root);
2037 }
2038
2039 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2040 {
2041         struct page *page;
2042         int i;
2043
2044         ASSERT(vcpu);
2045
2046         if (vcpu->kvm->arch.n_requested_mmu_pages)
2047                 vcpu->kvm->arch.n_free_mmu_pages =
2048                                         vcpu->kvm->arch.n_requested_mmu_pages;
2049         else
2050                 vcpu->kvm->arch.n_free_mmu_pages =
2051                                         vcpu->kvm->arch.n_alloc_mmu_pages;
2052         /*
2053          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2054          * Therefore we need to allocate shadow page tables in the first
2055          * 4GB of memory, which happens to fit the DMA32 zone.
2056          */
2057         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2058         if (!page)
2059                 goto error_1;
2060         vcpu->arch.mmu.pae_root = page_address(page);
2061         for (i = 0; i < 4; ++i)
2062                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2063
2064         return 0;
2065
2066 error_1:
2067         free_mmu_pages(vcpu);
2068         return -ENOMEM;
2069 }
2070
2071 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2072 {
2073         ASSERT(vcpu);
2074         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2075
2076         return alloc_mmu_pages(vcpu);
2077 }
2078
2079 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2080 {
2081         ASSERT(vcpu);
2082         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2083
2084         return init_kvm_mmu(vcpu);
2085 }
2086
2087 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2088 {
2089         ASSERT(vcpu);
2090
2091         destroy_kvm_mmu(vcpu);
2092         free_mmu_pages(vcpu);
2093         mmu_free_memory_caches(vcpu);
2094 }
2095
2096 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2097 {
2098         struct kvm_mmu_page *sp;
2099
2100         spin_lock(&kvm->mmu_lock);
2101         list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2102                 int i;
2103                 u64 *pt;
2104
2105                 if (!test_bit(slot, &sp->slot_bitmap))
2106                         continue;
2107
2108                 pt = sp->spt;
2109                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2110                         /* avoid RMW */
2111                         if (pt[i] & PT_WRITABLE_MASK)
2112                                 pt[i] &= ~PT_WRITABLE_MASK;
2113         }
2114         kvm_flush_remote_tlbs(kvm);
2115         spin_unlock(&kvm->mmu_lock);
2116 }
2117
2118 void kvm_mmu_zap_all(struct kvm *kvm)
2119 {
2120         struct kvm_mmu_page *sp, *node;
2121
2122         spin_lock(&kvm->mmu_lock);
2123         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2124                 kvm_mmu_zap_page(kvm, sp);
2125         spin_unlock(&kvm->mmu_lock);
2126
2127         kvm_flush_remote_tlbs(kvm);
2128 }
2129
2130 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2131 {
2132         struct kvm_mmu_page *page;
2133
2134         page = container_of(kvm->arch.active_mmu_pages.prev,
2135                             struct kvm_mmu_page, link);
2136         kvm_mmu_zap_page(kvm, page);
2137 }
2138
2139 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2140 {
2141         struct kvm *kvm;
2142         struct kvm *kvm_freed = NULL;
2143         int cache_count = 0;
2144
2145         spin_lock(&kvm_lock);
2146
2147         list_for_each_entry(kvm, &vm_list, vm_list) {
2148                 int npages;
2149
2150                 if (!down_read_trylock(&kvm->slots_lock))
2151                         continue;
2152                 spin_lock(&kvm->mmu_lock);
2153                 npages = kvm->arch.n_alloc_mmu_pages -
2154                          kvm->arch.n_free_mmu_pages;
2155                 cache_count += npages;
2156                 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2157                         kvm_mmu_remove_one_alloc_mmu_page(kvm);
2158                         cache_count--;
2159                         kvm_freed = kvm;
2160                 }
2161                 nr_to_scan--;
2162
2163                 spin_unlock(&kvm->mmu_lock);
2164                 up_read(&kvm->slots_lock);
2165         }
2166         if (kvm_freed)
2167                 list_move_tail(&kvm_freed->vm_list, &vm_list);
2168
2169         spin_unlock(&kvm_lock);
2170
2171         return cache_count;
2172 }
2173
2174 static struct shrinker mmu_shrinker = {
2175         .shrink = mmu_shrink,
2176         .seeks = DEFAULT_SEEKS * 10,
2177 };
2178
2179 static void mmu_destroy_caches(void)
2180 {
2181         if (pte_chain_cache)
2182                 kmem_cache_destroy(pte_chain_cache);
2183         if (rmap_desc_cache)
2184                 kmem_cache_destroy(rmap_desc_cache);
2185         if (mmu_page_header_cache)
2186                 kmem_cache_destroy(mmu_page_header_cache);
2187 }
2188
2189 void kvm_mmu_module_exit(void)
2190 {
2191         mmu_destroy_caches();
2192         unregister_shrinker(&mmu_shrinker);
2193 }
2194
2195 int kvm_mmu_module_init(void)
2196 {
2197         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2198                                             sizeof(struct kvm_pte_chain),
2199                                             0, 0, NULL);
2200         if (!pte_chain_cache)
2201                 goto nomem;
2202         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2203                                             sizeof(struct kvm_rmap_desc),
2204                                             0, 0, NULL);
2205         if (!rmap_desc_cache)
2206                 goto nomem;
2207
2208         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2209                                                   sizeof(struct kvm_mmu_page),
2210                                                   0, 0, NULL);
2211         if (!mmu_page_header_cache)
2212                 goto nomem;
2213
2214         register_shrinker(&mmu_shrinker);
2215
2216         return 0;
2217
2218 nomem:
2219         mmu_destroy_caches();
2220         return -ENOMEM;
2221 }
2222
2223 /*
2224  * Caculate mmu pages needed for kvm.
2225  */
2226 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
2227 {
2228         int i;
2229         unsigned int nr_mmu_pages;
2230         unsigned int  nr_pages = 0;
2231
2232         for (i = 0; i < kvm->nmemslots; i++)
2233                 nr_pages += kvm->memslots[i].npages;
2234
2235         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
2236         nr_mmu_pages = max(nr_mmu_pages,
2237                         (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
2238
2239         return nr_mmu_pages;
2240 }
2241
2242 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2243                                 unsigned len)
2244 {
2245         if (len > buffer->len)
2246                 return NULL;
2247         return buffer->ptr;
2248 }
2249
2250 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2251                                 unsigned len)
2252 {
2253         void *ret;
2254
2255         ret = pv_mmu_peek_buffer(buffer, len);
2256         if (!ret)
2257                 return ret;
2258         buffer->ptr += len;
2259         buffer->len -= len;
2260         buffer->processed += len;
2261         return ret;
2262 }
2263
2264 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
2265                              gpa_t addr, gpa_t value)
2266 {
2267         int bytes = 8;
2268         int r;
2269
2270         if (!is_long_mode(vcpu) && !is_pae(vcpu))
2271                 bytes = 4;
2272
2273         r = mmu_topup_memory_caches(vcpu);
2274         if (r)
2275                 return r;
2276
2277         if (!emulator_write_phys(vcpu, addr, &value, bytes))
2278                 return -EFAULT;
2279
2280         return 1;
2281 }
2282
2283 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2284 {
2285         kvm_x86_ops->tlb_flush(vcpu);
2286         return 1;
2287 }
2288
2289 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
2290 {
2291         spin_lock(&vcpu->kvm->mmu_lock);
2292         mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
2293         spin_unlock(&vcpu->kvm->mmu_lock);
2294         return 1;
2295 }
2296
2297 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
2298                              struct kvm_pv_mmu_op_buffer *buffer)
2299 {
2300         struct kvm_mmu_op_header *header;
2301
2302         header = pv_mmu_peek_buffer(buffer, sizeof *header);
2303         if (!header)
2304                 return 0;
2305         switch (header->op) {
2306         case KVM_MMU_OP_WRITE_PTE: {
2307                 struct kvm_mmu_op_write_pte *wpte;
2308
2309                 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
2310                 if (!wpte)
2311                         return 0;
2312                 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
2313                                         wpte->pte_val);
2314         }
2315         case KVM_MMU_OP_FLUSH_TLB: {
2316                 struct kvm_mmu_op_flush_tlb *ftlb;
2317
2318                 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
2319                 if (!ftlb)
2320                         return 0;
2321                 return kvm_pv_mmu_flush_tlb(vcpu);
2322         }
2323         case KVM_MMU_OP_RELEASE_PT: {
2324                 struct kvm_mmu_op_release_pt *rpt;
2325
2326                 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
2327                 if (!rpt)
2328                         return 0;
2329                 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
2330         }
2331         default: return 0;
2332         }
2333 }
2334
2335 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
2336                   gpa_t addr, unsigned long *ret)
2337 {
2338         int r;
2339         struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
2340
2341         buffer->ptr = buffer->buf;
2342         buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
2343         buffer->processed = 0;
2344
2345         r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
2346         if (r)
2347                 goto out;
2348
2349         while (buffer->len) {
2350                 r = kvm_pv_mmu_op_one(vcpu, buffer);
2351                 if (r < 0)
2352                         goto out;
2353                 if (r == 0)
2354                         break;
2355         }
2356
2357         r = 1;
2358 out:
2359         *ret = buffer->processed;
2360         return r;
2361 }
2362
2363 #ifdef AUDIT
2364
2365 static const char *audit_msg;
2366
2367 static gva_t canonicalize(gva_t gva)
2368 {
2369 #ifdef CONFIG_X86_64
2370         gva = (long long)(gva << 16) >> 16;
2371 #endif
2372         return gva;
2373 }
2374
2375 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
2376                                 gva_t va, int level)
2377 {
2378         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
2379         int i;
2380         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
2381
2382         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
2383                 u64 ent = pt[i];
2384
2385                 if (ent == shadow_trap_nonpresent_pte)
2386                         continue;
2387
2388                 va = canonicalize(va);
2389                 if (level > 1) {
2390                         if (ent == shadow_notrap_nonpresent_pte)
2391                                 printk(KERN_ERR "audit: (%s) nontrapping pte"
2392                                        " in nonleaf level: levels %d gva %lx"
2393                                        " level %d pte %llx\n", audit_msg,
2394                                        vcpu->arch.mmu.root_level, va, level, ent);
2395
2396                         audit_mappings_page(vcpu, ent, va, level - 1);
2397                 } else {
2398                         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
2399                         hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
2400
2401                         if (is_shadow_present_pte(ent)
2402                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
2403                                 printk(KERN_ERR "xx audit error: (%s) levels %d"
2404                                        " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2405                                        audit_msg, vcpu->arch.mmu.root_level,
2406                                        va, gpa, hpa, ent,
2407                                        is_shadow_present_pte(ent));
2408                         else if (ent == shadow_notrap_nonpresent_pte
2409                                  && !is_error_hpa(hpa))
2410                                 printk(KERN_ERR "audit: (%s) notrap shadow,"
2411                                        " valid guest gva %lx\n", audit_msg, va);
2412                         kvm_release_pfn_clean(pfn);
2413
2414                 }
2415         }
2416 }
2417
2418 static void audit_mappings(struct kvm_vcpu *vcpu)
2419 {
2420         unsigned i;
2421
2422         if (vcpu->arch.mmu.root_level == 4)
2423                 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
2424         else
2425                 for (i = 0; i < 4; ++i)
2426                         if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
2427                                 audit_mappings_page(vcpu,
2428                                                     vcpu->arch.mmu.pae_root[i],
2429                                                     i << 30,
2430                                                     2);
2431 }
2432
2433 static int count_rmaps(struct kvm_vcpu *vcpu)
2434 {
2435         int nmaps = 0;
2436         int i, j, k;
2437
2438         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
2439                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
2440                 struct kvm_rmap_desc *d;
2441
2442                 for (j = 0; j < m->npages; ++j) {
2443                         unsigned long *rmapp = &m->rmap[j];
2444
2445                         if (!*rmapp)
2446                                 continue;
2447                         if (!(*rmapp & 1)) {
2448                                 ++nmaps;
2449                                 continue;
2450                         }
2451                         d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
2452                         while (d) {
2453                                 for (k = 0; k < RMAP_EXT; ++k)
2454                                         if (d->shadow_ptes[k])
2455                                                 ++nmaps;
2456                                         else
2457                                                 break;
2458                                 d = d->more;
2459                         }
2460                 }
2461         }
2462         return nmaps;
2463 }
2464
2465 static int count_writable_mappings(struct kvm_vcpu *vcpu)
2466 {
2467         int nmaps = 0;
2468         struct kvm_mmu_page *sp;
2469         int i;
2470
2471         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2472                 u64 *pt = sp->spt;
2473
2474                 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
2475                         continue;
2476
2477                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
2478                         u64 ent = pt[i];
2479
2480                         if (!(ent & PT_PRESENT_MASK))
2481                                 continue;
2482                         if (!(ent & PT_WRITABLE_MASK))
2483                                 continue;
2484                         ++nmaps;
2485                 }
2486         }
2487         return nmaps;
2488 }
2489
2490 static void audit_rmap(struct kvm_vcpu *vcpu)
2491 {
2492         int n_rmap = count_rmaps(vcpu);
2493         int n_actual = count_writable_mappings(vcpu);
2494
2495         if (n_rmap != n_actual)
2496                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
2497                        __func__, audit_msg, n_rmap, n_actual);
2498 }
2499
2500 static void audit_write_protection(struct kvm_vcpu *vcpu)
2501 {
2502         struct kvm_mmu_page *sp;
2503         struct kvm_memory_slot *slot;
2504         unsigned long *rmapp;
2505         gfn_t gfn;
2506
2507         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2508                 if (sp->role.metaphysical)
2509                         continue;
2510
2511                 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
2512                 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
2513                 rmapp = &slot->rmap[gfn - slot->base_gfn];
2514                 if (*rmapp)
2515                         printk(KERN_ERR "%s: (%s) shadow page has writable"
2516                                " mappings: gfn %lx role %x\n",
2517                                __func__, audit_msg, sp->gfn,
2518                                sp->role.word);
2519         }
2520 }
2521
2522 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
2523 {
2524         int olddbg = dbg;
2525
2526         dbg = 0;
2527         audit_msg = msg;
2528         audit_rmap(vcpu);
2529         audit_write_protection(vcpu);
2530         audit_mappings(vcpu);
2531         dbg = olddbg;
2532 }
2533
2534 #endif