Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / drivers / 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 "kvm.h"
22
23 #include <linux/types.h>
24 #include <linux/string.h>
25 #include <linux/mm.h>
26 #include <linux/highmem.h>
27 #include <linux/module.h>
28
29 #include <asm/page.h>
30 #include <asm/cmpxchg.h>
31
32 #undef MMU_DEBUG
33
34 #undef AUDIT
35
36 #ifdef AUDIT
37 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
38 #else
39 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
40 #endif
41
42 #ifdef MMU_DEBUG
43
44 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
45 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
46
47 #else
48
49 #define pgprintk(x...) do { } while (0)
50 #define rmap_printk(x...) do { } while (0)
51
52 #endif
53
54 #if defined(MMU_DEBUG) || defined(AUDIT)
55 static int dbg = 1;
56 #endif
57
58 #ifndef MMU_DEBUG
59 #define ASSERT(x) do { } while (0)
60 #else
61 #define ASSERT(x)                                                       \
62         if (!(x)) {                                                     \
63                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
64                        __FILE__, __LINE__, #x);                         \
65         }
66 #endif
67
68 #define PT64_PT_BITS 9
69 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
70 #define PT32_PT_BITS 10
71 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
72
73 #define PT_WRITABLE_SHIFT 1
74
75 #define PT_PRESENT_MASK (1ULL << 0)
76 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
77 #define PT_USER_MASK (1ULL << 2)
78 #define PT_PWT_MASK (1ULL << 3)
79 #define PT_PCD_MASK (1ULL << 4)
80 #define PT_ACCESSED_MASK (1ULL << 5)
81 #define PT_DIRTY_MASK (1ULL << 6)
82 #define PT_PAGE_SIZE_MASK (1ULL << 7)
83 #define PT_PAT_MASK (1ULL << 7)
84 #define PT_GLOBAL_MASK (1ULL << 8)
85 #define PT64_NX_MASK (1ULL << 63)
86
87 #define PT_PAT_SHIFT 7
88 #define PT_DIR_PAT_SHIFT 12
89 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
90
91 #define PT32_DIR_PSE36_SIZE 4
92 #define PT32_DIR_PSE36_SHIFT 13
93 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
94
95
96 #define PT_FIRST_AVAIL_BITS_SHIFT 9
97 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
98
99 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
100
101 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
102
103 #define PT64_LEVEL_BITS 9
104
105 #define PT64_LEVEL_SHIFT(level) \
106                 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
107
108 #define PT64_LEVEL_MASK(level) \
109                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
110
111 #define PT64_INDEX(address, level)\
112         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
113
114
115 #define PT32_LEVEL_BITS 10
116
117 #define PT32_LEVEL_SHIFT(level) \
118                 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
119
120 #define PT32_LEVEL_MASK(level) \
121                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
122
123 #define PT32_INDEX(address, level)\
124         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
125
126
127 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
128 #define PT64_DIR_BASE_ADDR_MASK \
129         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
130
131 #define PT32_BASE_ADDR_MASK PAGE_MASK
132 #define PT32_DIR_BASE_ADDR_MASK \
133         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
134
135
136 #define PFERR_PRESENT_MASK (1U << 0)
137 #define PFERR_WRITE_MASK (1U << 1)
138 #define PFERR_USER_MASK (1U << 2)
139 #define PFERR_FETCH_MASK (1U << 4)
140
141 #define PT64_ROOT_LEVEL 4
142 #define PT32_ROOT_LEVEL 2
143 #define PT32E_ROOT_LEVEL 3
144
145 #define PT_DIRECTORY_LEVEL 2
146 #define PT_PAGE_TABLE_LEVEL 1
147
148 #define RMAP_EXT 4
149
150 struct kvm_rmap_desc {
151         u64 *shadow_ptes[RMAP_EXT];
152         struct kvm_rmap_desc *more;
153 };
154
155 static struct kmem_cache *pte_chain_cache;
156 static struct kmem_cache *rmap_desc_cache;
157 static struct kmem_cache *mmu_page_header_cache;
158
159 static int is_write_protection(struct kvm_vcpu *vcpu)
160 {
161         return vcpu->cr0 & CR0_WP_MASK;
162 }
163
164 static int is_cpuid_PSE36(void)
165 {
166         return 1;
167 }
168
169 static int is_nx(struct kvm_vcpu *vcpu)
170 {
171         return vcpu->shadow_efer & EFER_NX;
172 }
173
174 static int is_present_pte(unsigned long pte)
175 {
176         return pte & PT_PRESENT_MASK;
177 }
178
179 static int is_writeble_pte(unsigned long pte)
180 {
181         return pte & PT_WRITABLE_MASK;
182 }
183
184 static int is_io_pte(unsigned long pte)
185 {
186         return pte & PT_SHADOW_IO_MARK;
187 }
188
189 static int is_rmap_pte(u64 pte)
190 {
191         return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
192                 == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
193 }
194
195 static void set_shadow_pte(u64 *sptep, u64 spte)
196 {
197 #ifdef CONFIG_X86_64
198         set_64bit((unsigned long *)sptep, spte);
199 #else
200         set_64bit((unsigned long long *)sptep, spte);
201 #endif
202 }
203
204 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
205                                   struct kmem_cache *base_cache, int min,
206                                   gfp_t gfp_flags)
207 {
208         void *obj;
209
210         if (cache->nobjs >= min)
211                 return 0;
212         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
213                 obj = kmem_cache_zalloc(base_cache, gfp_flags);
214                 if (!obj)
215                         return -ENOMEM;
216                 cache->objects[cache->nobjs++] = obj;
217         }
218         return 0;
219 }
220
221 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
222 {
223         while (mc->nobjs)
224                 kfree(mc->objects[--mc->nobjs]);
225 }
226
227 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
228                                        int min, gfp_t gfp_flags)
229 {
230         struct page *page;
231
232         if (cache->nobjs >= min)
233                 return 0;
234         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
235                 page = alloc_page(gfp_flags);
236                 if (!page)
237                         return -ENOMEM;
238                 set_page_private(page, 0);
239                 cache->objects[cache->nobjs++] = page_address(page);
240         }
241         return 0;
242 }
243
244 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
245 {
246         while (mc->nobjs)
247                 free_page((unsigned long)mc->objects[--mc->nobjs]);
248 }
249
250 static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags)
251 {
252         int r;
253
254         r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
255                                    pte_chain_cache, 4, gfp_flags);
256         if (r)
257                 goto out;
258         r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
259                                    rmap_desc_cache, 1, gfp_flags);
260         if (r)
261                 goto out;
262         r = mmu_topup_memory_cache_page(&vcpu->mmu_page_cache, 4, gfp_flags);
263         if (r)
264                 goto out;
265         r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
266                                    mmu_page_header_cache, 4, gfp_flags);
267 out:
268         return r;
269 }
270
271 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
272 {
273         int r;
274
275         r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
276         if (r < 0) {
277                 spin_unlock(&vcpu->kvm->lock);
278                 kvm_arch_ops->vcpu_put(vcpu);
279                 r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
280                 kvm_arch_ops->vcpu_load(vcpu);
281                 spin_lock(&vcpu->kvm->lock);
282         }
283         return r;
284 }
285
286 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
287 {
288         mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
289         mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
290         mmu_free_memory_cache_page(&vcpu->mmu_page_cache);
291         mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
292 }
293
294 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
295                                     size_t size)
296 {
297         void *p;
298
299         BUG_ON(!mc->nobjs);
300         p = mc->objects[--mc->nobjs];
301         memset(p, 0, size);
302         return p;
303 }
304
305 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
306 {
307         return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
308                                       sizeof(struct kvm_pte_chain));
309 }
310
311 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
312 {
313         kfree(pc);
314 }
315
316 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
317 {
318         return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
319                                       sizeof(struct kvm_rmap_desc));
320 }
321
322 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
323 {
324         kfree(rd);
325 }
326
327 /*
328  * Reverse mapping data structures:
329  *
330  * If page->private bit zero is zero, then page->private points to the
331  * shadow page table entry that points to page_address(page).
332  *
333  * If page->private bit zero is one, (then page->private & ~1) points
334  * to a struct kvm_rmap_desc containing more mappings.
335  */
336 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
337 {
338         struct page *page;
339         struct kvm_rmap_desc *desc;
340         int i;
341
342         if (!is_rmap_pte(*spte))
343                 return;
344         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
345         if (!page_private(page)) {
346                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
347                 set_page_private(page,(unsigned long)spte);
348         } else if (!(page_private(page) & 1)) {
349                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
350                 desc = mmu_alloc_rmap_desc(vcpu);
351                 desc->shadow_ptes[0] = (u64 *)page_private(page);
352                 desc->shadow_ptes[1] = spte;
353                 set_page_private(page,(unsigned long)desc | 1);
354         } else {
355                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
356                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
357                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
358                         desc = desc->more;
359                 if (desc->shadow_ptes[RMAP_EXT-1]) {
360                         desc->more = mmu_alloc_rmap_desc(vcpu);
361                         desc = desc->more;
362                 }
363                 for (i = 0; desc->shadow_ptes[i]; ++i)
364                         ;
365                 desc->shadow_ptes[i] = spte;
366         }
367 }
368
369 static void rmap_desc_remove_entry(struct page *page,
370                                    struct kvm_rmap_desc *desc,
371                                    int i,
372                                    struct kvm_rmap_desc *prev_desc)
373 {
374         int j;
375
376         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
377                 ;
378         desc->shadow_ptes[i] = desc->shadow_ptes[j];
379         desc->shadow_ptes[j] = NULL;
380         if (j != 0)
381                 return;
382         if (!prev_desc && !desc->more)
383                 set_page_private(page,(unsigned long)desc->shadow_ptes[0]);
384         else
385                 if (prev_desc)
386                         prev_desc->more = desc->more;
387                 else
388                         set_page_private(page,(unsigned long)desc->more | 1);
389         mmu_free_rmap_desc(desc);
390 }
391
392 static void rmap_remove(u64 *spte)
393 {
394         struct page *page;
395         struct kvm_rmap_desc *desc;
396         struct kvm_rmap_desc *prev_desc;
397         int i;
398
399         if (!is_rmap_pte(*spte))
400                 return;
401         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
402         if (!page_private(page)) {
403                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
404                 BUG();
405         } else if (!(page_private(page) & 1)) {
406                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
407                 if ((u64 *)page_private(page) != spte) {
408                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
409                                spte, *spte);
410                         BUG();
411                 }
412                 set_page_private(page,0);
413         } else {
414                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
415                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
416                 prev_desc = NULL;
417                 while (desc) {
418                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
419                                 if (desc->shadow_ptes[i] == spte) {
420                                         rmap_desc_remove_entry(page,
421                                                                desc, i,
422                                                                prev_desc);
423                                         return;
424                                 }
425                         prev_desc = desc;
426                         desc = desc->more;
427                 }
428                 BUG();
429         }
430 }
431
432 static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
433 {
434         struct kvm *kvm = vcpu->kvm;
435         struct page *page;
436         struct kvm_rmap_desc *desc;
437         u64 *spte;
438
439         page = gfn_to_page(kvm, gfn);
440         BUG_ON(!page);
441
442         while (page_private(page)) {
443                 if (!(page_private(page) & 1))
444                         spte = (u64 *)page_private(page);
445                 else {
446                         desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
447                         spte = desc->shadow_ptes[0];
448                 }
449                 BUG_ON(!spte);
450                 BUG_ON((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT
451                        != page_to_pfn(page));
452                 BUG_ON(!(*spte & PT_PRESENT_MASK));
453                 BUG_ON(!(*spte & PT_WRITABLE_MASK));
454                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
455                 rmap_remove(spte);
456                 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
457                 kvm_flush_remote_tlbs(vcpu->kvm);
458         }
459 }
460
461 #ifdef MMU_DEBUG
462 static int is_empty_shadow_page(u64 *spt)
463 {
464         u64 *pos;
465         u64 *end;
466
467         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
468                 if (*pos != 0) {
469                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
470                                pos, *pos);
471                         return 0;
472                 }
473         return 1;
474 }
475 #endif
476
477 static void kvm_mmu_free_page(struct kvm *kvm,
478                               struct kvm_mmu_page *page_head)
479 {
480         ASSERT(is_empty_shadow_page(page_head->spt));
481         list_del(&page_head->link);
482         __free_page(virt_to_page(page_head->spt));
483         kfree(page_head);
484         ++kvm->n_free_mmu_pages;
485 }
486
487 static unsigned kvm_page_table_hashfn(gfn_t gfn)
488 {
489         return gfn;
490 }
491
492 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
493                                                u64 *parent_pte)
494 {
495         struct kvm_mmu_page *page;
496
497         if (!vcpu->kvm->n_free_mmu_pages)
498                 return NULL;
499
500         page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache,
501                                       sizeof *page);
502         page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
503         set_page_private(virt_to_page(page->spt), (unsigned long)page);
504         list_add(&page->link, &vcpu->kvm->active_mmu_pages);
505         ASSERT(is_empty_shadow_page(page->spt));
506         page->slot_bitmap = 0;
507         page->multimapped = 0;
508         page->parent_pte = parent_pte;
509         --vcpu->kvm->n_free_mmu_pages;
510         return page;
511 }
512
513 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
514                                     struct kvm_mmu_page *page, u64 *parent_pte)
515 {
516         struct kvm_pte_chain *pte_chain;
517         struct hlist_node *node;
518         int i;
519
520         if (!parent_pte)
521                 return;
522         if (!page->multimapped) {
523                 u64 *old = page->parent_pte;
524
525                 if (!old) {
526                         page->parent_pte = parent_pte;
527                         return;
528                 }
529                 page->multimapped = 1;
530                 pte_chain = mmu_alloc_pte_chain(vcpu);
531                 INIT_HLIST_HEAD(&page->parent_ptes);
532                 hlist_add_head(&pte_chain->link, &page->parent_ptes);
533                 pte_chain->parent_ptes[0] = old;
534         }
535         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
536                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
537                         continue;
538                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
539                         if (!pte_chain->parent_ptes[i]) {
540                                 pte_chain->parent_ptes[i] = parent_pte;
541                                 return;
542                         }
543         }
544         pte_chain = mmu_alloc_pte_chain(vcpu);
545         BUG_ON(!pte_chain);
546         hlist_add_head(&pte_chain->link, &page->parent_ptes);
547         pte_chain->parent_ptes[0] = parent_pte;
548 }
549
550 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
551                                        u64 *parent_pte)
552 {
553         struct kvm_pte_chain *pte_chain;
554         struct hlist_node *node;
555         int i;
556
557         if (!page->multimapped) {
558                 BUG_ON(page->parent_pte != parent_pte);
559                 page->parent_pte = NULL;
560                 return;
561         }
562         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
563                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
564                         if (!pte_chain->parent_ptes[i])
565                                 break;
566                         if (pte_chain->parent_ptes[i] != parent_pte)
567                                 continue;
568                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
569                                 && pte_chain->parent_ptes[i + 1]) {
570                                 pte_chain->parent_ptes[i]
571                                         = pte_chain->parent_ptes[i + 1];
572                                 ++i;
573                         }
574                         pte_chain->parent_ptes[i] = NULL;
575                         if (i == 0) {
576                                 hlist_del(&pte_chain->link);
577                                 mmu_free_pte_chain(pte_chain);
578                                 if (hlist_empty(&page->parent_ptes)) {
579                                         page->multimapped = 0;
580                                         page->parent_pte = NULL;
581                                 }
582                         }
583                         return;
584                 }
585         BUG();
586 }
587
588 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
589                                                 gfn_t gfn)
590 {
591         unsigned index;
592         struct hlist_head *bucket;
593         struct kvm_mmu_page *page;
594         struct hlist_node *node;
595
596         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
597         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
598         bucket = &vcpu->kvm->mmu_page_hash[index];
599         hlist_for_each_entry(page, node, bucket, hash_link)
600                 if (page->gfn == gfn && !page->role.metaphysical) {
601                         pgprintk("%s: found role %x\n",
602                                  __FUNCTION__, page->role.word);
603                         return page;
604                 }
605         return NULL;
606 }
607
608 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
609                                              gfn_t gfn,
610                                              gva_t gaddr,
611                                              unsigned level,
612                                              int metaphysical,
613                                              unsigned hugepage_access,
614                                              u64 *parent_pte)
615 {
616         union kvm_mmu_page_role role;
617         unsigned index;
618         unsigned quadrant;
619         struct hlist_head *bucket;
620         struct kvm_mmu_page *page;
621         struct hlist_node *node;
622
623         role.word = 0;
624         role.glevels = vcpu->mmu.root_level;
625         role.level = level;
626         role.metaphysical = metaphysical;
627         role.hugepage_access = hugepage_access;
628         if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
629                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
630                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
631                 role.quadrant = quadrant;
632         }
633         pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
634                  gfn, role.word);
635         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
636         bucket = &vcpu->kvm->mmu_page_hash[index];
637         hlist_for_each_entry(page, node, bucket, hash_link)
638                 if (page->gfn == gfn && page->role.word == role.word) {
639                         mmu_page_add_parent_pte(vcpu, page, parent_pte);
640                         pgprintk("%s: found\n", __FUNCTION__);
641                         return page;
642                 }
643         page = kvm_mmu_alloc_page(vcpu, parent_pte);
644         if (!page)
645                 return page;
646         pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
647         page->gfn = gfn;
648         page->role = role;
649         hlist_add_head(&page->hash_link, bucket);
650         if (!metaphysical)
651                 rmap_write_protect(vcpu, gfn);
652         return page;
653 }
654
655 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
656                                          struct kvm_mmu_page *page)
657 {
658         unsigned i;
659         u64 *pt;
660         u64 ent;
661
662         pt = page->spt;
663
664         if (page->role.level == PT_PAGE_TABLE_LEVEL) {
665                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
666                         if (pt[i] & PT_PRESENT_MASK)
667                                 rmap_remove(&pt[i]);
668                         pt[i] = 0;
669                 }
670                 kvm_flush_remote_tlbs(kvm);
671                 return;
672         }
673
674         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
675                 ent = pt[i];
676
677                 pt[i] = 0;
678                 if (!(ent & PT_PRESENT_MASK))
679                         continue;
680                 ent &= PT64_BASE_ADDR_MASK;
681                 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
682         }
683         kvm_flush_remote_tlbs(kvm);
684 }
685
686 static void kvm_mmu_put_page(struct kvm_mmu_page *page,
687                              u64 *parent_pte)
688 {
689         mmu_page_remove_parent_pte(page, parent_pte);
690 }
691
692 static void kvm_mmu_zap_page(struct kvm *kvm,
693                              struct kvm_mmu_page *page)
694 {
695         u64 *parent_pte;
696
697         while (page->multimapped || page->parent_pte) {
698                 if (!page->multimapped)
699                         parent_pte = page->parent_pte;
700                 else {
701                         struct kvm_pte_chain *chain;
702
703                         chain = container_of(page->parent_ptes.first,
704                                              struct kvm_pte_chain, link);
705                         parent_pte = chain->parent_ptes[0];
706                 }
707                 BUG_ON(!parent_pte);
708                 kvm_mmu_put_page(page, parent_pte);
709                 set_shadow_pte(parent_pte, 0);
710         }
711         kvm_mmu_page_unlink_children(kvm, page);
712         if (!page->root_count) {
713                 hlist_del(&page->hash_link);
714                 kvm_mmu_free_page(kvm, page);
715         } else
716                 list_move(&page->link, &kvm->active_mmu_pages);
717 }
718
719 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
720 {
721         unsigned index;
722         struct hlist_head *bucket;
723         struct kvm_mmu_page *page;
724         struct hlist_node *node, *n;
725         int r;
726
727         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
728         r = 0;
729         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
730         bucket = &vcpu->kvm->mmu_page_hash[index];
731         hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
732                 if (page->gfn == gfn && !page->role.metaphysical) {
733                         pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
734                                  page->role.word);
735                         kvm_mmu_zap_page(vcpu->kvm, page);
736                         r = 1;
737                 }
738         return r;
739 }
740
741 static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
742 {
743         struct kvm_mmu_page *page;
744
745         while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
746                 pgprintk("%s: zap %lx %x\n",
747                          __FUNCTION__, gfn, page->role.word);
748                 kvm_mmu_zap_page(vcpu->kvm, page);
749         }
750 }
751
752 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
753 {
754         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
755         struct kvm_mmu_page *page_head = page_header(__pa(pte));
756
757         __set_bit(slot, &page_head->slot_bitmap);
758 }
759
760 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
761 {
762         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
763
764         return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
765 }
766
767 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
768 {
769         struct page *page;
770
771         ASSERT((gpa & HPA_ERR_MASK) == 0);
772         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
773         if (!page)
774                 return gpa | HPA_ERR_MASK;
775         return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
776                 | (gpa & (PAGE_SIZE-1));
777 }
778
779 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
780 {
781         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
782
783         if (gpa == UNMAPPED_GVA)
784                 return UNMAPPED_GVA;
785         return gpa_to_hpa(vcpu, gpa);
786 }
787
788 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
789 {
790         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
791
792         if (gpa == UNMAPPED_GVA)
793                 return NULL;
794         return pfn_to_page(gpa_to_hpa(vcpu, gpa) >> PAGE_SHIFT);
795 }
796
797 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
798 {
799 }
800
801 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
802 {
803         int level = PT32E_ROOT_LEVEL;
804         hpa_t table_addr = vcpu->mmu.root_hpa;
805
806         for (; ; level--) {
807                 u32 index = PT64_INDEX(v, level);
808                 u64 *table;
809                 u64 pte;
810
811                 ASSERT(VALID_PAGE(table_addr));
812                 table = __va(table_addr);
813
814                 if (level == 1) {
815                         pte = table[index];
816                         if (is_present_pte(pte) && is_writeble_pte(pte))
817                                 return 0;
818                         mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
819                         page_header_update_slot(vcpu->kvm, table, v);
820                         table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
821                                                                 PT_USER_MASK;
822                         rmap_add(vcpu, &table[index]);
823                         return 0;
824                 }
825
826                 if (table[index] == 0) {
827                         struct kvm_mmu_page *new_table;
828                         gfn_t pseudo_gfn;
829
830                         pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
831                                 >> PAGE_SHIFT;
832                         new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
833                                                      v, level - 1,
834                                                      1, 0, &table[index]);
835                         if (!new_table) {
836                                 pgprintk("nonpaging_map: ENOMEM\n");
837                                 return -ENOMEM;
838                         }
839
840                         table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
841                                 | PT_WRITABLE_MASK | PT_USER_MASK;
842                 }
843                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
844         }
845 }
846
847 static void mmu_free_roots(struct kvm_vcpu *vcpu)
848 {
849         int i;
850         struct kvm_mmu_page *page;
851
852         if (!VALID_PAGE(vcpu->mmu.root_hpa))
853                 return;
854 #ifdef CONFIG_X86_64
855         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
856                 hpa_t root = vcpu->mmu.root_hpa;
857
858                 page = page_header(root);
859                 --page->root_count;
860                 vcpu->mmu.root_hpa = INVALID_PAGE;
861                 return;
862         }
863 #endif
864         for (i = 0; i < 4; ++i) {
865                 hpa_t root = vcpu->mmu.pae_root[i];
866
867                 if (root) {
868                         root &= PT64_BASE_ADDR_MASK;
869                         page = page_header(root);
870                         --page->root_count;
871                 }
872                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
873         }
874         vcpu->mmu.root_hpa = INVALID_PAGE;
875 }
876
877 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
878 {
879         int i;
880         gfn_t root_gfn;
881         struct kvm_mmu_page *page;
882
883         root_gfn = vcpu->cr3 >> PAGE_SHIFT;
884
885 #ifdef CONFIG_X86_64
886         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
887                 hpa_t root = vcpu->mmu.root_hpa;
888
889                 ASSERT(!VALID_PAGE(root));
890                 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
891                                         PT64_ROOT_LEVEL, 0, 0, NULL);
892                 root = __pa(page->spt);
893                 ++page->root_count;
894                 vcpu->mmu.root_hpa = root;
895                 return;
896         }
897 #endif
898         for (i = 0; i < 4; ++i) {
899                 hpa_t root = vcpu->mmu.pae_root[i];
900
901                 ASSERT(!VALID_PAGE(root));
902                 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
903                         if (!is_present_pte(vcpu->pdptrs[i])) {
904                                 vcpu->mmu.pae_root[i] = 0;
905                                 continue;
906                         }
907                         root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
908                 } else if (vcpu->mmu.root_level == 0)
909                         root_gfn = 0;
910                 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
911                                         PT32_ROOT_LEVEL, !is_paging(vcpu),
912                                         0, NULL);
913                 root = __pa(page->spt);
914                 ++page->root_count;
915                 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
916         }
917         vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
918 }
919
920 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
921 {
922         return vaddr;
923 }
924
925 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
926                                u32 error_code)
927 {
928         gpa_t addr = gva;
929         hpa_t paddr;
930         int r;
931
932         r = mmu_topup_memory_caches(vcpu);
933         if (r)
934                 return r;
935
936         ASSERT(vcpu);
937         ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
938
939
940         paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
941
942         if (is_error_hpa(paddr))
943                 return 1;
944
945         return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
946 }
947
948 static void nonpaging_free(struct kvm_vcpu *vcpu)
949 {
950         mmu_free_roots(vcpu);
951 }
952
953 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
954 {
955         struct kvm_mmu *context = &vcpu->mmu;
956
957         context->new_cr3 = nonpaging_new_cr3;
958         context->page_fault = nonpaging_page_fault;
959         context->gva_to_gpa = nonpaging_gva_to_gpa;
960         context->free = nonpaging_free;
961         context->root_level = 0;
962         context->shadow_root_level = PT32E_ROOT_LEVEL;
963         context->root_hpa = INVALID_PAGE;
964         return 0;
965 }
966
967 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
968 {
969         ++vcpu->stat.tlb_flush;
970         kvm_arch_ops->tlb_flush(vcpu);
971 }
972
973 static void paging_new_cr3(struct kvm_vcpu *vcpu)
974 {
975         pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
976         mmu_free_roots(vcpu);
977 }
978
979 static void inject_page_fault(struct kvm_vcpu *vcpu,
980                               u64 addr,
981                               u32 err_code)
982 {
983         kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
984 }
985
986 static void paging_free(struct kvm_vcpu *vcpu)
987 {
988         nonpaging_free(vcpu);
989 }
990
991 #define PTTYPE 64
992 #include "paging_tmpl.h"
993 #undef PTTYPE
994
995 #define PTTYPE 32
996 #include "paging_tmpl.h"
997 #undef PTTYPE
998
999 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1000 {
1001         struct kvm_mmu *context = &vcpu->mmu;
1002
1003         ASSERT(is_pae(vcpu));
1004         context->new_cr3 = paging_new_cr3;
1005         context->page_fault = paging64_page_fault;
1006         context->gva_to_gpa = paging64_gva_to_gpa;
1007         context->free = paging_free;
1008         context->root_level = level;
1009         context->shadow_root_level = level;
1010         context->root_hpa = INVALID_PAGE;
1011         return 0;
1012 }
1013
1014 static int paging64_init_context(struct kvm_vcpu *vcpu)
1015 {
1016         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1017 }
1018
1019 static int paging32_init_context(struct kvm_vcpu *vcpu)
1020 {
1021         struct kvm_mmu *context = &vcpu->mmu;
1022
1023         context->new_cr3 = paging_new_cr3;
1024         context->page_fault = paging32_page_fault;
1025         context->gva_to_gpa = paging32_gva_to_gpa;
1026         context->free = paging_free;
1027         context->root_level = PT32_ROOT_LEVEL;
1028         context->shadow_root_level = PT32E_ROOT_LEVEL;
1029         context->root_hpa = INVALID_PAGE;
1030         return 0;
1031 }
1032
1033 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1034 {
1035         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1036 }
1037
1038 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1039 {
1040         ASSERT(vcpu);
1041         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1042
1043         if (!is_paging(vcpu))
1044                 return nonpaging_init_context(vcpu);
1045         else if (is_long_mode(vcpu))
1046                 return paging64_init_context(vcpu);
1047         else if (is_pae(vcpu))
1048                 return paging32E_init_context(vcpu);
1049         else
1050                 return paging32_init_context(vcpu);
1051 }
1052
1053 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1054 {
1055         ASSERT(vcpu);
1056         if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1057                 vcpu->mmu.free(vcpu);
1058                 vcpu->mmu.root_hpa = INVALID_PAGE;
1059         }
1060 }
1061
1062 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1063 {
1064         destroy_kvm_mmu(vcpu);
1065         return init_kvm_mmu(vcpu);
1066 }
1067
1068 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1069 {
1070         int r;
1071
1072         spin_lock(&vcpu->kvm->lock);
1073         r = mmu_topup_memory_caches(vcpu);
1074         if (r)
1075                 goto out;
1076         mmu_alloc_roots(vcpu);
1077         kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
1078         kvm_mmu_flush_tlb(vcpu);
1079 out:
1080         spin_unlock(&vcpu->kvm->lock);
1081         return r;
1082 }
1083 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1084
1085 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1086 {
1087         mmu_free_roots(vcpu);
1088 }
1089
1090 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1091                                   struct kvm_mmu_page *page,
1092                                   u64 *spte)
1093 {
1094         u64 pte;
1095         struct kvm_mmu_page *child;
1096
1097         pte = *spte;
1098         if (is_present_pte(pte)) {
1099                 if (page->role.level == PT_PAGE_TABLE_LEVEL)
1100                         rmap_remove(spte);
1101                 else {
1102                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1103                         mmu_page_remove_parent_pte(child, spte);
1104                 }
1105         }
1106         *spte = 0;
1107         kvm_flush_remote_tlbs(vcpu->kvm);
1108 }
1109
1110 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1111                                   struct kvm_mmu_page *page,
1112                                   u64 *spte,
1113                                   const void *new, int bytes)
1114 {
1115         if (page->role.level != PT_PAGE_TABLE_LEVEL)
1116                 return;
1117
1118         if (page->role.glevels == PT32_ROOT_LEVEL)
1119                 paging32_update_pte(vcpu, page, spte, new, bytes);
1120         else
1121                 paging64_update_pte(vcpu, page, spte, new, bytes);
1122 }
1123
1124 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1125                        const u8 *old, const u8 *new, int bytes)
1126 {
1127         gfn_t gfn = gpa >> PAGE_SHIFT;
1128         struct kvm_mmu_page *page;
1129         struct hlist_node *node, *n;
1130         struct hlist_head *bucket;
1131         unsigned index;
1132         u64 *spte;
1133         unsigned offset = offset_in_page(gpa);
1134         unsigned pte_size;
1135         unsigned page_offset;
1136         unsigned misaligned;
1137         unsigned quadrant;
1138         int level;
1139         int flooded = 0;
1140         int npte;
1141
1142         pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1143         if (gfn == vcpu->last_pt_write_gfn) {
1144                 ++vcpu->last_pt_write_count;
1145                 if (vcpu->last_pt_write_count >= 3)
1146                         flooded = 1;
1147         } else {
1148                 vcpu->last_pt_write_gfn = gfn;
1149                 vcpu->last_pt_write_count = 1;
1150         }
1151         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1152         bucket = &vcpu->kvm->mmu_page_hash[index];
1153         hlist_for_each_entry_safe(page, node, n, bucket, hash_link) {
1154                 if (page->gfn != gfn || page->role.metaphysical)
1155                         continue;
1156                 pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1157                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1158                 misaligned |= bytes < 4;
1159                 if (misaligned || flooded) {
1160                         /*
1161                          * Misaligned accesses are too much trouble to fix
1162                          * up; also, they usually indicate a page is not used
1163                          * as a page table.
1164                          *
1165                          * If we're seeing too many writes to a page,
1166                          * it may no longer be a page table, or we may be
1167                          * forking, in which case it is better to unmap the
1168                          * page.
1169                          */
1170                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1171                                  gpa, bytes, page->role.word);
1172                         kvm_mmu_zap_page(vcpu->kvm, page);
1173                         continue;
1174                 }
1175                 page_offset = offset;
1176                 level = page->role.level;
1177                 npte = 1;
1178                 if (page->role.glevels == PT32_ROOT_LEVEL) {
1179                         page_offset <<= 1;      /* 32->64 */
1180                         /*
1181                          * A 32-bit pde maps 4MB while the shadow pdes map
1182                          * only 2MB.  So we need to double the offset again
1183                          * and zap two pdes instead of one.
1184                          */
1185                         if (level == PT32_ROOT_LEVEL) {
1186                                 page_offset &= ~7; /* kill rounding error */
1187                                 page_offset <<= 1;
1188                                 npte = 2;
1189                         }
1190                         quadrant = page_offset >> PAGE_SHIFT;
1191                         page_offset &= ~PAGE_MASK;
1192                         if (quadrant != page->role.quadrant)
1193                                 continue;
1194                 }
1195                 spte = &page->spt[page_offset / sizeof(*spte)];
1196                 while (npte--) {
1197                         mmu_pte_write_zap_pte(vcpu, page, spte);
1198                         mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
1199                         ++spte;
1200                 }
1201         }
1202 }
1203
1204 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1205 {
1206         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1207
1208         return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
1209 }
1210
1211 void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1212 {
1213         while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1214                 struct kvm_mmu_page *page;
1215
1216                 page = container_of(vcpu->kvm->active_mmu_pages.prev,
1217                                     struct kvm_mmu_page, link);
1218                 kvm_mmu_zap_page(vcpu->kvm, page);
1219         }
1220 }
1221 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
1222
1223 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1224 {
1225         struct kvm_mmu_page *page;
1226
1227         while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1228                 page = container_of(vcpu->kvm->active_mmu_pages.next,
1229                                     struct kvm_mmu_page, link);
1230                 kvm_mmu_zap_page(vcpu->kvm, page);
1231         }
1232         free_page((unsigned long)vcpu->mmu.pae_root);
1233 }
1234
1235 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1236 {
1237         struct page *page;
1238         int i;
1239
1240         ASSERT(vcpu);
1241
1242         vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES;
1243
1244         /*
1245          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1246          * Therefore we need to allocate shadow page tables in the first
1247          * 4GB of memory, which happens to fit the DMA32 zone.
1248          */
1249         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1250         if (!page)
1251                 goto error_1;
1252         vcpu->mmu.pae_root = page_address(page);
1253         for (i = 0; i < 4; ++i)
1254                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1255
1256         return 0;
1257
1258 error_1:
1259         free_mmu_pages(vcpu);
1260         return -ENOMEM;
1261 }
1262
1263 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1264 {
1265         ASSERT(vcpu);
1266         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1267
1268         return alloc_mmu_pages(vcpu);
1269 }
1270
1271 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1272 {
1273         ASSERT(vcpu);
1274         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1275
1276         return init_kvm_mmu(vcpu);
1277 }
1278
1279 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1280 {
1281         ASSERT(vcpu);
1282
1283         destroy_kvm_mmu(vcpu);
1284         free_mmu_pages(vcpu);
1285         mmu_free_memory_caches(vcpu);
1286 }
1287
1288 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1289 {
1290         struct kvm_mmu_page *page;
1291
1292         list_for_each_entry(page, &kvm->active_mmu_pages, link) {
1293                 int i;
1294                 u64 *pt;
1295
1296                 if (!test_bit(slot, &page->slot_bitmap))
1297                         continue;
1298
1299                 pt = page->spt;
1300                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1301                         /* avoid RMW */
1302                         if (pt[i] & PT_WRITABLE_MASK) {
1303                                 rmap_remove(&pt[i]);
1304                                 pt[i] &= ~PT_WRITABLE_MASK;
1305                         }
1306         }
1307 }
1308
1309 void kvm_mmu_zap_all(struct kvm *kvm)
1310 {
1311         struct kvm_mmu_page *page, *node;
1312
1313         list_for_each_entry_safe(page, node, &kvm->active_mmu_pages, link)
1314                 kvm_mmu_zap_page(kvm, page);
1315
1316         kvm_flush_remote_tlbs(kvm);
1317 }
1318
1319 void kvm_mmu_module_exit(void)
1320 {
1321         if (pte_chain_cache)
1322                 kmem_cache_destroy(pte_chain_cache);
1323         if (rmap_desc_cache)
1324                 kmem_cache_destroy(rmap_desc_cache);
1325         if (mmu_page_header_cache)
1326                 kmem_cache_destroy(mmu_page_header_cache);
1327 }
1328
1329 int kvm_mmu_module_init(void)
1330 {
1331         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1332                                             sizeof(struct kvm_pte_chain),
1333                                             0, 0, NULL);
1334         if (!pte_chain_cache)
1335                 goto nomem;
1336         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1337                                             sizeof(struct kvm_rmap_desc),
1338                                             0, 0, NULL);
1339         if (!rmap_desc_cache)
1340                 goto nomem;
1341
1342         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1343                                                   sizeof(struct kvm_mmu_page),
1344                                                   0, 0, NULL);
1345         if (!mmu_page_header_cache)
1346                 goto nomem;
1347
1348         return 0;
1349
1350 nomem:
1351         kvm_mmu_module_exit();
1352         return -ENOMEM;
1353 }
1354
1355 #ifdef AUDIT
1356
1357 static const char *audit_msg;
1358
1359 static gva_t canonicalize(gva_t gva)
1360 {
1361 #ifdef CONFIG_X86_64
1362         gva = (long long)(gva << 16) >> 16;
1363 #endif
1364         return gva;
1365 }
1366
1367 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1368                                 gva_t va, int level)
1369 {
1370         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1371         int i;
1372         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1373
1374         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1375                 u64 ent = pt[i];
1376
1377                 if (!(ent & PT_PRESENT_MASK))
1378                         continue;
1379
1380                 va = canonicalize(va);
1381                 if (level > 1)
1382                         audit_mappings_page(vcpu, ent, va, level - 1);
1383                 else {
1384                         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1385                         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
1386
1387                         if ((ent & PT_PRESENT_MASK)
1388                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
1389                                 printk(KERN_ERR "audit error: (%s) levels %d"
1390                                        " gva %lx gpa %llx hpa %llx ent %llx\n",
1391                                        audit_msg, vcpu->mmu.root_level,
1392                                        va, gpa, hpa, ent);
1393                 }
1394         }
1395 }
1396
1397 static void audit_mappings(struct kvm_vcpu *vcpu)
1398 {
1399         unsigned i;
1400
1401         if (vcpu->mmu.root_level == 4)
1402                 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1403         else
1404                 for (i = 0; i < 4; ++i)
1405                         if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1406                                 audit_mappings_page(vcpu,
1407                                                     vcpu->mmu.pae_root[i],
1408                                                     i << 30,
1409                                                     2);
1410 }
1411
1412 static int count_rmaps(struct kvm_vcpu *vcpu)
1413 {
1414         int nmaps = 0;
1415         int i, j, k;
1416
1417         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1418                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1419                 struct kvm_rmap_desc *d;
1420
1421                 for (j = 0; j < m->npages; ++j) {
1422                         struct page *page = m->phys_mem[j];
1423
1424                         if (!page->private)
1425                                 continue;
1426                         if (!(page->private & 1)) {
1427                                 ++nmaps;
1428                                 continue;
1429                         }
1430                         d = (struct kvm_rmap_desc *)(page->private & ~1ul);
1431                         while (d) {
1432                                 for (k = 0; k < RMAP_EXT; ++k)
1433                                         if (d->shadow_ptes[k])
1434                                                 ++nmaps;
1435                                         else
1436                                                 break;
1437                                 d = d->more;
1438                         }
1439                 }
1440         }
1441         return nmaps;
1442 }
1443
1444 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1445 {
1446         int nmaps = 0;
1447         struct kvm_mmu_page *page;
1448         int i;
1449
1450         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1451                 u64 *pt = page->spt;
1452
1453                 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1454                         continue;
1455
1456                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1457                         u64 ent = pt[i];
1458
1459                         if (!(ent & PT_PRESENT_MASK))
1460                                 continue;
1461                         if (!(ent & PT_WRITABLE_MASK))
1462                                 continue;
1463                         ++nmaps;
1464                 }
1465         }
1466         return nmaps;
1467 }
1468
1469 static void audit_rmap(struct kvm_vcpu *vcpu)
1470 {
1471         int n_rmap = count_rmaps(vcpu);
1472         int n_actual = count_writable_mappings(vcpu);
1473
1474         if (n_rmap != n_actual)
1475                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1476                        __FUNCTION__, audit_msg, n_rmap, n_actual);
1477 }
1478
1479 static void audit_write_protection(struct kvm_vcpu *vcpu)
1480 {
1481         struct kvm_mmu_page *page;
1482
1483         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1484                 hfn_t hfn;
1485                 struct page *pg;
1486
1487                 if (page->role.metaphysical)
1488                         continue;
1489
1490                 hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT)
1491                         >> PAGE_SHIFT;
1492                 pg = pfn_to_page(hfn);
1493                 if (pg->private)
1494                         printk(KERN_ERR "%s: (%s) shadow page has writable"
1495                                " mappings: gfn %lx role %x\n",
1496                                __FUNCTION__, audit_msg, page->gfn,
1497                                page->role.word);
1498         }
1499 }
1500
1501 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1502 {
1503         int olddbg = dbg;
1504
1505         dbg = 0;
1506         audit_msg = msg;
1507         audit_rmap(vcpu);
1508         audit_write_protection(vcpu);
1509         audit_mappings(vcpu);
1510         dbg = olddbg;
1511 }
1512
1513 #endif