KVM: MMU: Remove unused large page marker
[linux-2.6.git] / 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 #include <linux/types.h>
20 #include <linux/string.h>
21 #include <asm/page.h>
22 #include <linux/mm.h>
23 #include <linux/highmem.h>
24 #include <linux/module.h>
25 #include <asm/cmpxchg.h>
26
27 #include "vmx.h"
28 #include "kvm.h"
29
30 #undef MMU_DEBUG
31
32 #undef AUDIT
33
34 #ifdef AUDIT
35 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
36 #else
37 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
38 #endif
39
40 #ifdef MMU_DEBUG
41
42 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
43 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
44
45 #else
46
47 #define pgprintk(x...) do { } while (0)
48 #define rmap_printk(x...) do { } while (0)
49
50 #endif
51
52 #if defined(MMU_DEBUG) || defined(AUDIT)
53 static int dbg = 1;
54 #endif
55
56 #ifndef MMU_DEBUG
57 #define ASSERT(x) do { } while (0)
58 #else
59 #define ASSERT(x)                                                       \
60         if (!(x)) {                                                     \
61                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
62                        __FILE__, __LINE__, #x);                         \
63         }
64 #endif
65
66 #define PT64_PT_BITS 9
67 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
68 #define PT32_PT_BITS 10
69 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
70
71 #define PT_WRITABLE_SHIFT 1
72
73 #define PT_PRESENT_MASK (1ULL << 0)
74 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
75 #define PT_USER_MASK (1ULL << 2)
76 #define PT_PWT_MASK (1ULL << 3)
77 #define PT_PCD_MASK (1ULL << 4)
78 #define PT_ACCESSED_MASK (1ULL << 5)
79 #define PT_DIRTY_MASK (1ULL << 6)
80 #define PT_PAGE_SIZE_MASK (1ULL << 7)
81 #define PT_PAT_MASK (1ULL << 7)
82 #define PT_GLOBAL_MASK (1ULL << 8)
83 #define PT64_NX_MASK (1ULL << 63)
84
85 #define PT_PAT_SHIFT 7
86 #define PT_DIR_PAT_SHIFT 12
87 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
88
89 #define PT32_DIR_PSE36_SIZE 4
90 #define PT32_DIR_PSE36_SHIFT 13
91 #define PT32_DIR_PSE36_MASK (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
92
93
94 #define PT_FIRST_AVAIL_BITS_SHIFT 9
95 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
96
97 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
98
99 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
100
101 #define PT64_LEVEL_BITS 9
102
103 #define PT64_LEVEL_SHIFT(level) \
104                 ( PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS )
105
106 #define PT64_LEVEL_MASK(level) \
107                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
108
109 #define PT64_INDEX(address, level)\
110         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
111
112
113 #define PT32_LEVEL_BITS 10
114
115 #define PT32_LEVEL_SHIFT(level) \
116                 ( PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS )
117
118 #define PT32_LEVEL_MASK(level) \
119                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
120
121 #define PT32_INDEX(address, level)\
122         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
123
124
125 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
126 #define PT64_DIR_BASE_ADDR_MASK \
127         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
128
129 #define PT32_BASE_ADDR_MASK PAGE_MASK
130 #define PT32_DIR_BASE_ADDR_MASK \
131         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
132
133
134 #define PFERR_PRESENT_MASK (1U << 0)
135 #define PFERR_WRITE_MASK (1U << 1)
136 #define PFERR_USER_MASK (1U << 2)
137 #define PFERR_FETCH_MASK (1U << 4)
138
139 #define PT64_ROOT_LEVEL 4
140 #define PT32_ROOT_LEVEL 2
141 #define PT32E_ROOT_LEVEL 3
142
143 #define PT_DIRECTORY_LEVEL 2
144 #define PT_PAGE_TABLE_LEVEL 1
145
146 #define RMAP_EXT 4
147
148 struct kvm_rmap_desc {
149         u64 *shadow_ptes[RMAP_EXT];
150         struct kvm_rmap_desc *more;
151 };
152
153 static struct kmem_cache *pte_chain_cache;
154 static struct kmem_cache *rmap_desc_cache;
155 static struct kmem_cache *mmu_page_cache;
156 static struct kmem_cache *mmu_page_header_cache;
157
158 static int is_write_protection(struct kvm_vcpu *vcpu)
159 {
160         return vcpu->cr0 & CR0_WP_MASK;
161 }
162
163 static int is_cpuid_PSE36(void)
164 {
165         return 1;
166 }
167
168 static int is_nx(struct kvm_vcpu *vcpu)
169 {
170         return vcpu->shadow_efer & EFER_NX;
171 }
172
173 static int is_present_pte(unsigned long pte)
174 {
175         return pte & PT_PRESENT_MASK;
176 }
177
178 static int is_writeble_pte(unsigned long pte)
179 {
180         return pte & PT_WRITABLE_MASK;
181 }
182
183 static int is_io_pte(unsigned long pte)
184 {
185         return pte & PT_SHADOW_IO_MARK;
186 }
187
188 static int is_rmap_pte(u64 pte)
189 {
190         return (pte & (PT_WRITABLE_MASK | PT_PRESENT_MASK))
191                 == (PT_WRITABLE_MASK | PT_PRESENT_MASK);
192 }
193
194 static void set_shadow_pte(u64 *sptep, u64 spte)
195 {
196 #ifdef CONFIG_X86_64
197         set_64bit((unsigned long *)sptep, spte);
198 #else
199         set_64bit((unsigned long long *)sptep, spte);
200 #endif
201 }
202
203 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
204                                   struct kmem_cache *base_cache, int min,
205                                   gfp_t gfp_flags)
206 {
207         void *obj;
208
209         if (cache->nobjs >= min)
210                 return 0;
211         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
212                 obj = kmem_cache_zalloc(base_cache, gfp_flags);
213                 if (!obj)
214                         return -ENOMEM;
215                 cache->objects[cache->nobjs++] = obj;
216         }
217         return 0;
218 }
219
220 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
221 {
222         while (mc->nobjs)
223                 kfree(mc->objects[--mc->nobjs]);
224 }
225
226 static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags)
227 {
228         int r;
229
230         r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
231                                    pte_chain_cache, 4, gfp_flags);
232         if (r)
233                 goto out;
234         r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
235                                    rmap_desc_cache, 1, gfp_flags);
236         if (r)
237                 goto out;
238         r = mmu_topup_memory_cache(&vcpu->mmu_page_cache,
239                                    mmu_page_cache, 4, gfp_flags);
240         if (r)
241                 goto out;
242         r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
243                                    mmu_page_header_cache, 4, gfp_flags);
244 out:
245         return r;
246 }
247
248 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
249 {
250         int r;
251
252         r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
253         if (r < 0) {
254                 spin_unlock(&vcpu->kvm->lock);
255                 kvm_arch_ops->vcpu_put(vcpu);
256                 r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
257                 kvm_arch_ops->vcpu_load(vcpu);
258                 spin_lock(&vcpu->kvm->lock);
259         }
260         return r;
261 }
262
263 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
264 {
265         mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
266         mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
267         mmu_free_memory_cache(&vcpu->mmu_page_cache);
268         mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
269 }
270
271 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
272                                     size_t size)
273 {
274         void *p;
275
276         BUG_ON(!mc->nobjs);
277         p = mc->objects[--mc->nobjs];
278         memset(p, 0, size);
279         return p;
280 }
281
282 static void mmu_memory_cache_free(struct kvm_mmu_memory_cache *mc, void *obj)
283 {
284         if (mc->nobjs < KVM_NR_MEM_OBJS)
285                 mc->objects[mc->nobjs++] = obj;
286         else
287                 kfree(obj);
288 }
289
290 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
291 {
292         return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
293                                       sizeof(struct kvm_pte_chain));
294 }
295
296 static void mmu_free_pte_chain(struct kvm_vcpu *vcpu,
297                                struct kvm_pte_chain *pc)
298 {
299         mmu_memory_cache_free(&vcpu->mmu_pte_chain_cache, pc);
300 }
301
302 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
303 {
304         return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
305                                       sizeof(struct kvm_rmap_desc));
306 }
307
308 static void mmu_free_rmap_desc(struct kvm_vcpu *vcpu,
309                                struct kvm_rmap_desc *rd)
310 {
311         mmu_memory_cache_free(&vcpu->mmu_rmap_desc_cache, rd);
312 }
313
314 /*
315  * Reverse mapping data structures:
316  *
317  * If page->private bit zero is zero, then page->private points to the
318  * shadow page table entry that points to page_address(page).
319  *
320  * If page->private bit zero is one, (then page->private & ~1) points
321  * to a struct kvm_rmap_desc containing more mappings.
322  */
323 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
324 {
325         struct page *page;
326         struct kvm_rmap_desc *desc;
327         int i;
328
329         if (!is_rmap_pte(*spte))
330                 return;
331         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
332         if (!page_private(page)) {
333                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
334                 set_page_private(page,(unsigned long)spte);
335         } else if (!(page_private(page) & 1)) {
336                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
337                 desc = mmu_alloc_rmap_desc(vcpu);
338                 desc->shadow_ptes[0] = (u64 *)page_private(page);
339                 desc->shadow_ptes[1] = spte;
340                 set_page_private(page,(unsigned long)desc | 1);
341         } else {
342                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
343                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
344                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
345                         desc = desc->more;
346                 if (desc->shadow_ptes[RMAP_EXT-1]) {
347                         desc->more = mmu_alloc_rmap_desc(vcpu);
348                         desc = desc->more;
349                 }
350                 for (i = 0; desc->shadow_ptes[i]; ++i)
351                         ;
352                 desc->shadow_ptes[i] = spte;
353         }
354 }
355
356 static void rmap_desc_remove_entry(struct kvm_vcpu *vcpu,
357                                    struct page *page,
358                                    struct kvm_rmap_desc *desc,
359                                    int i,
360                                    struct kvm_rmap_desc *prev_desc)
361 {
362         int j;
363
364         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
365                 ;
366         desc->shadow_ptes[i] = desc->shadow_ptes[j];
367         desc->shadow_ptes[j] = NULL;
368         if (j != 0)
369                 return;
370         if (!prev_desc && !desc->more)
371                 set_page_private(page,(unsigned long)desc->shadow_ptes[0]);
372         else
373                 if (prev_desc)
374                         prev_desc->more = desc->more;
375                 else
376                         set_page_private(page,(unsigned long)desc->more | 1);
377         mmu_free_rmap_desc(vcpu, desc);
378 }
379
380 static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte)
381 {
382         struct page *page;
383         struct kvm_rmap_desc *desc;
384         struct kvm_rmap_desc *prev_desc;
385         int i;
386
387         if (!is_rmap_pte(*spte))
388                 return;
389         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
390         if (!page_private(page)) {
391                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
392                 BUG();
393         } else if (!(page_private(page) & 1)) {
394                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
395                 if ((u64 *)page_private(page) != spte) {
396                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
397                                spte, *spte);
398                         BUG();
399                 }
400                 set_page_private(page,0);
401         } else {
402                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
403                 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
404                 prev_desc = NULL;
405                 while (desc) {
406                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
407                                 if (desc->shadow_ptes[i] == spte) {
408                                         rmap_desc_remove_entry(vcpu, page,
409                                                                desc, i,
410                                                                prev_desc);
411                                         return;
412                                 }
413                         prev_desc = desc;
414                         desc = desc->more;
415                 }
416                 BUG();
417         }
418 }
419
420 static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
421 {
422         struct kvm *kvm = vcpu->kvm;
423         struct page *page;
424         struct kvm_rmap_desc *desc;
425         u64 *spte;
426
427         page = gfn_to_page(kvm, gfn);
428         BUG_ON(!page);
429
430         while (page_private(page)) {
431                 if (!(page_private(page) & 1))
432                         spte = (u64 *)page_private(page);
433                 else {
434                         desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
435                         spte = desc->shadow_ptes[0];
436                 }
437                 BUG_ON(!spte);
438                 BUG_ON((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT
439                        != page_to_pfn(page));
440                 BUG_ON(!(*spte & PT_PRESENT_MASK));
441                 BUG_ON(!(*spte & PT_WRITABLE_MASK));
442                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
443                 rmap_remove(vcpu, spte);
444                 kvm_arch_ops->tlb_flush(vcpu);
445                 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
446         }
447 }
448
449 #ifdef MMU_DEBUG
450 static int is_empty_shadow_page(u64 *spt)
451 {
452         u64 *pos;
453         u64 *end;
454
455         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
456                 if (*pos != 0) {
457                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
458                                pos, *pos);
459                         return 0;
460                 }
461         return 1;
462 }
463 #endif
464
465 static void kvm_mmu_free_page(struct kvm_vcpu *vcpu,
466                               struct kvm_mmu_page *page_head)
467 {
468         ASSERT(is_empty_shadow_page(page_head->spt));
469         list_del(&page_head->link);
470         mmu_memory_cache_free(&vcpu->mmu_page_cache, page_head->spt);
471         mmu_memory_cache_free(&vcpu->mmu_page_header_cache, page_head);
472         ++vcpu->kvm->n_free_mmu_pages;
473 }
474
475 static unsigned kvm_page_table_hashfn(gfn_t gfn)
476 {
477         return gfn;
478 }
479
480 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
481                                                u64 *parent_pte)
482 {
483         struct kvm_mmu_page *page;
484
485         if (!vcpu->kvm->n_free_mmu_pages)
486                 return NULL;
487
488         page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache,
489                                       sizeof *page);
490         page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
491         set_page_private(virt_to_page(page->spt), (unsigned long)page);
492         list_add(&page->link, &vcpu->kvm->active_mmu_pages);
493         ASSERT(is_empty_shadow_page(page->spt));
494         page->slot_bitmap = 0;
495         page->multimapped = 0;
496         page->parent_pte = parent_pte;
497         --vcpu->kvm->n_free_mmu_pages;
498         return page;
499 }
500
501 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
502                                     struct kvm_mmu_page *page, u64 *parent_pte)
503 {
504         struct kvm_pte_chain *pte_chain;
505         struct hlist_node *node;
506         int i;
507
508         if (!parent_pte)
509                 return;
510         if (!page->multimapped) {
511                 u64 *old = page->parent_pte;
512
513                 if (!old) {
514                         page->parent_pte = parent_pte;
515                         return;
516                 }
517                 page->multimapped = 1;
518                 pte_chain = mmu_alloc_pte_chain(vcpu);
519                 INIT_HLIST_HEAD(&page->parent_ptes);
520                 hlist_add_head(&pte_chain->link, &page->parent_ptes);
521                 pte_chain->parent_ptes[0] = old;
522         }
523         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
524                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
525                         continue;
526                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
527                         if (!pte_chain->parent_ptes[i]) {
528                                 pte_chain->parent_ptes[i] = parent_pte;
529                                 return;
530                         }
531         }
532         pte_chain = mmu_alloc_pte_chain(vcpu);
533         BUG_ON(!pte_chain);
534         hlist_add_head(&pte_chain->link, &page->parent_ptes);
535         pte_chain->parent_ptes[0] = parent_pte;
536 }
537
538 static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu,
539                                        struct kvm_mmu_page *page,
540                                        u64 *parent_pte)
541 {
542         struct kvm_pte_chain *pte_chain;
543         struct hlist_node *node;
544         int i;
545
546         if (!page->multimapped) {
547                 BUG_ON(page->parent_pte != parent_pte);
548                 page->parent_pte = NULL;
549                 return;
550         }
551         hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
552                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
553                         if (!pte_chain->parent_ptes[i])
554                                 break;
555                         if (pte_chain->parent_ptes[i] != parent_pte)
556                                 continue;
557                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
558                                 && pte_chain->parent_ptes[i + 1]) {
559                                 pte_chain->parent_ptes[i]
560                                         = pte_chain->parent_ptes[i + 1];
561                                 ++i;
562                         }
563                         pte_chain->parent_ptes[i] = NULL;
564                         if (i == 0) {
565                                 hlist_del(&pte_chain->link);
566                                 mmu_free_pte_chain(vcpu, pte_chain);
567                                 if (hlist_empty(&page->parent_ptes)) {
568                                         page->multimapped = 0;
569                                         page->parent_pte = NULL;
570                                 }
571                         }
572                         return;
573                 }
574         BUG();
575 }
576
577 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
578                                                 gfn_t gfn)
579 {
580         unsigned index;
581         struct hlist_head *bucket;
582         struct kvm_mmu_page *page;
583         struct hlist_node *node;
584
585         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
586         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
587         bucket = &vcpu->kvm->mmu_page_hash[index];
588         hlist_for_each_entry(page, node, bucket, hash_link)
589                 if (page->gfn == gfn && !page->role.metaphysical) {
590                         pgprintk("%s: found role %x\n",
591                                  __FUNCTION__, page->role.word);
592                         return page;
593                 }
594         return NULL;
595 }
596
597 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
598                                              gfn_t gfn,
599                                              gva_t gaddr,
600                                              unsigned level,
601                                              int metaphysical,
602                                              unsigned hugepage_access,
603                                              u64 *parent_pte)
604 {
605         union kvm_mmu_page_role role;
606         unsigned index;
607         unsigned quadrant;
608         struct hlist_head *bucket;
609         struct kvm_mmu_page *page;
610         struct hlist_node *node;
611
612         role.word = 0;
613         role.glevels = vcpu->mmu.root_level;
614         role.level = level;
615         role.metaphysical = metaphysical;
616         role.hugepage_access = hugepage_access;
617         if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
618                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
619                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
620                 role.quadrant = quadrant;
621         }
622         pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
623                  gfn, role.word);
624         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
625         bucket = &vcpu->kvm->mmu_page_hash[index];
626         hlist_for_each_entry(page, node, bucket, hash_link)
627                 if (page->gfn == gfn && page->role.word == role.word) {
628                         mmu_page_add_parent_pte(vcpu, page, parent_pte);
629                         pgprintk("%s: found\n", __FUNCTION__);
630                         return page;
631                 }
632         page = kvm_mmu_alloc_page(vcpu, parent_pte);
633         if (!page)
634                 return page;
635         pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
636         page->gfn = gfn;
637         page->role = role;
638         hlist_add_head(&page->hash_link, bucket);
639         if (!metaphysical)
640                 rmap_write_protect(vcpu, gfn);
641         return page;
642 }
643
644 static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
645                                          struct kvm_mmu_page *page)
646 {
647         unsigned i;
648         u64 *pt;
649         u64 ent;
650
651         pt = page->spt;
652
653         if (page->role.level == PT_PAGE_TABLE_LEVEL) {
654                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
655                         if (pt[i] & PT_PRESENT_MASK)
656                                 rmap_remove(vcpu, &pt[i]);
657                         pt[i] = 0;
658                 }
659                 kvm_arch_ops->tlb_flush(vcpu);
660                 return;
661         }
662
663         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
664                 ent = pt[i];
665
666                 pt[i] = 0;
667                 if (!(ent & PT_PRESENT_MASK))
668                         continue;
669                 ent &= PT64_BASE_ADDR_MASK;
670                 mmu_page_remove_parent_pte(vcpu, page_header(ent), &pt[i]);
671         }
672 }
673
674 static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
675                              struct kvm_mmu_page *page,
676                              u64 *parent_pte)
677 {
678         mmu_page_remove_parent_pte(vcpu, page, parent_pte);
679 }
680
681 static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
682                              struct kvm_mmu_page *page)
683 {
684         u64 *parent_pte;
685
686         while (page->multimapped || page->parent_pte) {
687                 if (!page->multimapped)
688                         parent_pte = page->parent_pte;
689                 else {
690                         struct kvm_pte_chain *chain;
691
692                         chain = container_of(page->parent_ptes.first,
693                                              struct kvm_pte_chain, link);
694                         parent_pte = chain->parent_ptes[0];
695                 }
696                 BUG_ON(!parent_pte);
697                 kvm_mmu_put_page(vcpu, page, parent_pte);
698                 set_shadow_pte(parent_pte, 0);
699         }
700         kvm_mmu_page_unlink_children(vcpu, page);
701         if (!page->root_count) {
702                 hlist_del(&page->hash_link);
703                 kvm_mmu_free_page(vcpu, page);
704         } else
705                 list_move(&page->link, &vcpu->kvm->active_mmu_pages);
706 }
707
708 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
709 {
710         unsigned index;
711         struct hlist_head *bucket;
712         struct kvm_mmu_page *page;
713         struct hlist_node *node, *n;
714         int r;
715
716         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
717         r = 0;
718         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
719         bucket = &vcpu->kvm->mmu_page_hash[index];
720         hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
721                 if (page->gfn == gfn && !page->role.metaphysical) {
722                         pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
723                                  page->role.word);
724                         kvm_mmu_zap_page(vcpu, page);
725                         r = 1;
726                 }
727         return r;
728 }
729
730 static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
731 {
732         struct kvm_mmu_page *page;
733
734         while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
735                 pgprintk("%s: zap %lx %x\n",
736                          __FUNCTION__, gfn, page->role.word);
737                 kvm_mmu_zap_page(vcpu, page);
738         }
739 }
740
741 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
742 {
743         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
744         struct kvm_mmu_page *page_head = page_header(__pa(pte));
745
746         __set_bit(slot, &page_head->slot_bitmap);
747 }
748
749 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
750 {
751         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
752
753         return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
754 }
755
756 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
757 {
758         struct page *page;
759
760         ASSERT((gpa & HPA_ERR_MASK) == 0);
761         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
762         if (!page)
763                 return gpa | HPA_ERR_MASK;
764         return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
765                 | (gpa & (PAGE_SIZE-1));
766 }
767
768 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
769 {
770         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
771
772         if (gpa == UNMAPPED_GVA)
773                 return UNMAPPED_GVA;
774         return gpa_to_hpa(vcpu, gpa);
775 }
776
777 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
778 {
779         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
780
781         if (gpa == UNMAPPED_GVA)
782                 return NULL;
783         return pfn_to_page(gpa_to_hpa(vcpu, gpa) >> PAGE_SHIFT);
784 }
785
786 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
787 {
788 }
789
790 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
791 {
792         int level = PT32E_ROOT_LEVEL;
793         hpa_t table_addr = vcpu->mmu.root_hpa;
794
795         for (; ; level--) {
796                 u32 index = PT64_INDEX(v, level);
797                 u64 *table;
798                 u64 pte;
799
800                 ASSERT(VALID_PAGE(table_addr));
801                 table = __va(table_addr);
802
803                 if (level == 1) {
804                         pte = table[index];
805                         if (is_present_pte(pte) && is_writeble_pte(pte))
806                                 return 0;
807                         mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
808                         page_header_update_slot(vcpu->kvm, table, v);
809                         table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
810                                                                 PT_USER_MASK;
811                         rmap_add(vcpu, &table[index]);
812                         return 0;
813                 }
814
815                 if (table[index] == 0) {
816                         struct kvm_mmu_page *new_table;
817                         gfn_t pseudo_gfn;
818
819                         pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
820                                 >> PAGE_SHIFT;
821                         new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
822                                                      v, level - 1,
823                                                      1, 0, &table[index]);
824                         if (!new_table) {
825                                 pgprintk("nonpaging_map: ENOMEM\n");
826                                 return -ENOMEM;
827                         }
828
829                         table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
830                                 | PT_WRITABLE_MASK | PT_USER_MASK;
831                 }
832                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
833         }
834 }
835
836 static void mmu_free_roots(struct kvm_vcpu *vcpu)
837 {
838         int i;
839         struct kvm_mmu_page *page;
840
841 #ifdef CONFIG_X86_64
842         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
843                 hpa_t root = vcpu->mmu.root_hpa;
844
845                 ASSERT(VALID_PAGE(root));
846                 page = page_header(root);
847                 --page->root_count;
848                 vcpu->mmu.root_hpa = INVALID_PAGE;
849                 return;
850         }
851 #endif
852         for (i = 0; i < 4; ++i) {
853                 hpa_t root = vcpu->mmu.pae_root[i];
854
855                 if (root) {
856                         ASSERT(VALID_PAGE(root));
857                         root &= PT64_BASE_ADDR_MASK;
858                         page = page_header(root);
859                         --page->root_count;
860                 }
861                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
862         }
863         vcpu->mmu.root_hpa = INVALID_PAGE;
864 }
865
866 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
867 {
868         int i;
869         gfn_t root_gfn;
870         struct kvm_mmu_page *page;
871
872         root_gfn = vcpu->cr3 >> PAGE_SHIFT;
873
874 #ifdef CONFIG_X86_64
875         if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
876                 hpa_t root = vcpu->mmu.root_hpa;
877
878                 ASSERT(!VALID_PAGE(root));
879                 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
880                                         PT64_ROOT_LEVEL, 0, 0, NULL);
881                 root = __pa(page->spt);
882                 ++page->root_count;
883                 vcpu->mmu.root_hpa = root;
884                 return;
885         }
886 #endif
887         for (i = 0; i < 4; ++i) {
888                 hpa_t root = vcpu->mmu.pae_root[i];
889
890                 ASSERT(!VALID_PAGE(root));
891                 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
892                         if (!is_present_pte(vcpu->pdptrs[i])) {
893                                 vcpu->mmu.pae_root[i] = 0;
894                                 continue;
895                         }
896                         root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
897                 } else if (vcpu->mmu.root_level == 0)
898                         root_gfn = 0;
899                 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
900                                         PT32_ROOT_LEVEL, !is_paging(vcpu),
901                                         0, NULL);
902                 root = __pa(page->spt);
903                 ++page->root_count;
904                 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
905         }
906         vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
907 }
908
909 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
910 {
911         return vaddr;
912 }
913
914 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
915                                u32 error_code)
916 {
917         gpa_t addr = gva;
918         hpa_t paddr;
919         int r;
920
921         r = mmu_topup_memory_caches(vcpu);
922         if (r)
923                 return r;
924
925         ASSERT(vcpu);
926         ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
927
928
929         paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
930
931         if (is_error_hpa(paddr))
932                 return 1;
933
934         return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
935 }
936
937 static void nonpaging_free(struct kvm_vcpu *vcpu)
938 {
939         mmu_free_roots(vcpu);
940 }
941
942 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
943 {
944         struct kvm_mmu *context = &vcpu->mmu;
945
946         context->new_cr3 = nonpaging_new_cr3;
947         context->page_fault = nonpaging_page_fault;
948         context->gva_to_gpa = nonpaging_gva_to_gpa;
949         context->free = nonpaging_free;
950         context->root_level = 0;
951         context->shadow_root_level = PT32E_ROOT_LEVEL;
952         mmu_alloc_roots(vcpu);
953         ASSERT(VALID_PAGE(context->root_hpa));
954         kvm_arch_ops->set_cr3(vcpu, context->root_hpa);
955         return 0;
956 }
957
958 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
959 {
960         ++vcpu->stat.tlb_flush;
961         kvm_arch_ops->tlb_flush(vcpu);
962 }
963
964 static void paging_new_cr3(struct kvm_vcpu *vcpu)
965 {
966         pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
967         mmu_free_roots(vcpu);
968         if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES))
969                 kvm_mmu_free_some_pages(vcpu);
970         mmu_alloc_roots(vcpu);
971         kvm_mmu_flush_tlb(vcpu);
972         kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
973 }
974
975 static void inject_page_fault(struct kvm_vcpu *vcpu,
976                               u64 addr,
977                               u32 err_code)
978 {
979         kvm_arch_ops->inject_page_fault(vcpu, addr, err_code);
980 }
981
982 static void paging_free(struct kvm_vcpu *vcpu)
983 {
984         nonpaging_free(vcpu);
985 }
986
987 #define PTTYPE 64
988 #include "paging_tmpl.h"
989 #undef PTTYPE
990
991 #define PTTYPE 32
992 #include "paging_tmpl.h"
993 #undef PTTYPE
994
995 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
996 {
997         struct kvm_mmu *context = &vcpu->mmu;
998
999         ASSERT(is_pae(vcpu));
1000         context->new_cr3 = paging_new_cr3;
1001         context->page_fault = paging64_page_fault;
1002         context->gva_to_gpa = paging64_gva_to_gpa;
1003         context->free = paging_free;
1004         context->root_level = level;
1005         context->shadow_root_level = level;
1006         mmu_alloc_roots(vcpu);
1007         ASSERT(VALID_PAGE(context->root_hpa));
1008         kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
1009                     (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
1010         return 0;
1011 }
1012
1013 static int paging64_init_context(struct kvm_vcpu *vcpu)
1014 {
1015         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1016 }
1017
1018 static int paging32_init_context(struct kvm_vcpu *vcpu)
1019 {
1020         struct kvm_mmu *context = &vcpu->mmu;
1021
1022         context->new_cr3 = paging_new_cr3;
1023         context->page_fault = paging32_page_fault;
1024         context->gva_to_gpa = paging32_gva_to_gpa;
1025         context->free = paging_free;
1026         context->root_level = PT32_ROOT_LEVEL;
1027         context->shadow_root_level = PT32E_ROOT_LEVEL;
1028         mmu_alloc_roots(vcpu);
1029         ASSERT(VALID_PAGE(context->root_hpa));
1030         kvm_arch_ops->set_cr3(vcpu, context->root_hpa |
1031                     (vcpu->cr3 & (CR3_PCD_MASK | CR3_WPT_MASK)));
1032         return 0;
1033 }
1034
1035 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1036 {
1037         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1038 }
1039
1040 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1041 {
1042         ASSERT(vcpu);
1043         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1044
1045         mmu_topup_memory_caches(vcpu);
1046         if (!is_paging(vcpu))
1047                 return nonpaging_init_context(vcpu);
1048         else if (is_long_mode(vcpu))
1049                 return paging64_init_context(vcpu);
1050         else if (is_pae(vcpu))
1051                 return paging32E_init_context(vcpu);
1052         else
1053                 return paging32_init_context(vcpu);
1054 }
1055
1056 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1057 {
1058         ASSERT(vcpu);
1059         if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1060                 vcpu->mmu.free(vcpu);
1061                 vcpu->mmu.root_hpa = INVALID_PAGE;
1062         }
1063 }
1064
1065 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1066 {
1067         int r;
1068
1069         destroy_kvm_mmu(vcpu);
1070         r = init_kvm_mmu(vcpu);
1071         if (r < 0)
1072                 goto out;
1073         r = mmu_topup_memory_caches(vcpu);
1074 out:
1075         return r;
1076 }
1077
1078 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1079                                   struct kvm_mmu_page *page,
1080                                   u64 *spte)
1081 {
1082         u64 pte;
1083         struct kvm_mmu_page *child;
1084
1085         pte = *spte;
1086         if (is_present_pte(pte)) {
1087                 if (page->role.level == PT_PAGE_TABLE_LEVEL)
1088                         rmap_remove(vcpu, spte);
1089                 else {
1090                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1091                         mmu_page_remove_parent_pte(vcpu, child, spte);
1092                 }
1093         }
1094         *spte = 0;
1095 }
1096
1097 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1098                                   struct kvm_mmu_page *page,
1099                                   u64 *spte,
1100                                   const void *new, int bytes)
1101 {
1102         if (page->role.level != PT_PAGE_TABLE_LEVEL)
1103                 return;
1104
1105         if (page->role.glevels == PT32_ROOT_LEVEL)
1106                 paging32_update_pte(vcpu, page, spte, new, bytes);
1107         else
1108                 paging64_update_pte(vcpu, page, spte, new, bytes);
1109 }
1110
1111 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1112                        const u8 *old, const u8 *new, int bytes)
1113 {
1114         gfn_t gfn = gpa >> PAGE_SHIFT;
1115         struct kvm_mmu_page *page;
1116         struct hlist_node *node, *n;
1117         struct hlist_head *bucket;
1118         unsigned index;
1119         u64 *spte;
1120         unsigned offset = offset_in_page(gpa);
1121         unsigned pte_size;
1122         unsigned page_offset;
1123         unsigned misaligned;
1124         unsigned quadrant;
1125         int level;
1126         int flooded = 0;
1127         int npte;
1128
1129         pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1130         if (gfn == vcpu->last_pt_write_gfn) {
1131                 ++vcpu->last_pt_write_count;
1132                 if (vcpu->last_pt_write_count >= 3)
1133                         flooded = 1;
1134         } else {
1135                 vcpu->last_pt_write_gfn = gfn;
1136                 vcpu->last_pt_write_count = 1;
1137         }
1138         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1139         bucket = &vcpu->kvm->mmu_page_hash[index];
1140         hlist_for_each_entry_safe(page, node, n, bucket, hash_link) {
1141                 if (page->gfn != gfn || page->role.metaphysical)
1142                         continue;
1143                 pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1144                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1145                 misaligned |= bytes < 4;
1146                 if (misaligned || flooded) {
1147                         /*
1148                          * Misaligned accesses are too much trouble to fix
1149                          * up; also, they usually indicate a page is not used
1150                          * as a page table.
1151                          *
1152                          * If we're seeing too many writes to a page,
1153                          * it may no longer be a page table, or we may be
1154                          * forking, in which case it is better to unmap the
1155                          * page.
1156                          */
1157                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1158                                  gpa, bytes, page->role.word);
1159                         kvm_mmu_zap_page(vcpu, page);
1160                         continue;
1161                 }
1162                 page_offset = offset;
1163                 level = page->role.level;
1164                 npte = 1;
1165                 if (page->role.glevels == PT32_ROOT_LEVEL) {
1166                         page_offset <<= 1;      /* 32->64 */
1167                         /*
1168                          * A 32-bit pde maps 4MB while the shadow pdes map
1169                          * only 2MB.  So we need to double the offset again
1170                          * and zap two pdes instead of one.
1171                          */
1172                         if (level == PT32_ROOT_LEVEL) {
1173                                 page_offset &= ~7; /* kill rounding error */
1174                                 page_offset <<= 1;
1175                                 npte = 2;
1176                         }
1177                         quadrant = page_offset >> PAGE_SHIFT;
1178                         page_offset &= ~PAGE_MASK;
1179                         if (quadrant != page->role.quadrant)
1180                                 continue;
1181                 }
1182                 spte = &page->spt[page_offset / sizeof(*spte)];
1183                 while (npte--) {
1184                         mmu_pte_write_zap_pte(vcpu, page, spte);
1185                         mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
1186                         ++spte;
1187                 }
1188         }
1189 }
1190
1191 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1192 {
1193         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1194
1195         return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
1196 }
1197
1198 void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1199 {
1200         while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1201                 struct kvm_mmu_page *page;
1202
1203                 page = container_of(vcpu->kvm->active_mmu_pages.prev,
1204                                     struct kvm_mmu_page, link);
1205                 kvm_mmu_zap_page(vcpu, page);
1206         }
1207 }
1208 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
1209
1210 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1211 {
1212         struct kvm_mmu_page *page;
1213
1214         while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1215                 page = container_of(vcpu->kvm->active_mmu_pages.next,
1216                                     struct kvm_mmu_page, link);
1217                 kvm_mmu_zap_page(vcpu, page);
1218         }
1219         free_page((unsigned long)vcpu->mmu.pae_root);
1220 }
1221
1222 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1223 {
1224         struct page *page;
1225         int i;
1226
1227         ASSERT(vcpu);
1228
1229         vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES;
1230
1231         /*
1232          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1233          * Therefore we need to allocate shadow page tables in the first
1234          * 4GB of memory, which happens to fit the DMA32 zone.
1235          */
1236         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1237         if (!page)
1238                 goto error_1;
1239         vcpu->mmu.pae_root = page_address(page);
1240         for (i = 0; i < 4; ++i)
1241                 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1242
1243         return 0;
1244
1245 error_1:
1246         free_mmu_pages(vcpu);
1247         return -ENOMEM;
1248 }
1249
1250 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1251 {
1252         ASSERT(vcpu);
1253         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1254
1255         return alloc_mmu_pages(vcpu);
1256 }
1257
1258 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1259 {
1260         ASSERT(vcpu);
1261         ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1262
1263         return init_kvm_mmu(vcpu);
1264 }
1265
1266 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1267 {
1268         ASSERT(vcpu);
1269
1270         destroy_kvm_mmu(vcpu);
1271         free_mmu_pages(vcpu);
1272         mmu_free_memory_caches(vcpu);
1273 }
1274
1275 void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
1276 {
1277         struct kvm *kvm = vcpu->kvm;
1278         struct kvm_mmu_page *page;
1279
1280         list_for_each_entry(page, &kvm->active_mmu_pages, link) {
1281                 int i;
1282                 u64 *pt;
1283
1284                 if (!test_bit(slot, &page->slot_bitmap))
1285                         continue;
1286
1287                 pt = page->spt;
1288                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1289                         /* avoid RMW */
1290                         if (pt[i] & PT_WRITABLE_MASK) {
1291                                 rmap_remove(vcpu, &pt[i]);
1292                                 pt[i] &= ~PT_WRITABLE_MASK;
1293                         }
1294         }
1295 }
1296
1297 void kvm_mmu_zap_all(struct kvm_vcpu *vcpu)
1298 {
1299         destroy_kvm_mmu(vcpu);
1300
1301         while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1302                 struct kvm_mmu_page *page;
1303
1304                 page = container_of(vcpu->kvm->active_mmu_pages.next,
1305                                     struct kvm_mmu_page, link);
1306                 kvm_mmu_zap_page(vcpu, page);
1307         }
1308
1309         mmu_free_memory_caches(vcpu);
1310         kvm_arch_ops->tlb_flush(vcpu);
1311         init_kvm_mmu(vcpu);
1312 }
1313
1314 void kvm_mmu_module_exit(void)
1315 {
1316         if (pte_chain_cache)
1317                 kmem_cache_destroy(pte_chain_cache);
1318         if (rmap_desc_cache)
1319                 kmem_cache_destroy(rmap_desc_cache);
1320         if (mmu_page_cache)
1321                 kmem_cache_destroy(mmu_page_cache);
1322         if (mmu_page_header_cache)
1323                 kmem_cache_destroy(mmu_page_header_cache);
1324 }
1325
1326 int kvm_mmu_module_init(void)
1327 {
1328         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1329                                             sizeof(struct kvm_pte_chain),
1330                                             0, 0, NULL, NULL);
1331         if (!pte_chain_cache)
1332                 goto nomem;
1333         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1334                                             sizeof(struct kvm_rmap_desc),
1335                                             0, 0, NULL, NULL);
1336         if (!rmap_desc_cache)
1337                 goto nomem;
1338
1339         mmu_page_cache = kmem_cache_create("kvm_mmu_page",
1340                                            PAGE_SIZE,
1341                                            PAGE_SIZE, 0, NULL, NULL);
1342         if (!mmu_page_cache)
1343                 goto nomem;
1344
1345         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1346                                                   sizeof(struct kvm_mmu_page),
1347                                                   0, 0, NULL, NULL);
1348         if (!mmu_page_header_cache)
1349                 goto nomem;
1350
1351         return 0;
1352
1353 nomem:
1354         kvm_mmu_module_exit();
1355         return -ENOMEM;
1356 }
1357
1358 #ifdef AUDIT
1359
1360 static const char *audit_msg;
1361
1362 static gva_t canonicalize(gva_t gva)
1363 {
1364 #ifdef CONFIG_X86_64
1365         gva = (long long)(gva << 16) >> 16;
1366 #endif
1367         return gva;
1368 }
1369
1370 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1371                                 gva_t va, int level)
1372 {
1373         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1374         int i;
1375         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1376
1377         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1378                 u64 ent = pt[i];
1379
1380                 if (!(ent & PT_PRESENT_MASK))
1381                         continue;
1382
1383                 va = canonicalize(va);
1384                 if (level > 1)
1385                         audit_mappings_page(vcpu, ent, va, level - 1);
1386                 else {
1387                         gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1388                         hpa_t hpa = gpa_to_hpa(vcpu, gpa);
1389
1390                         if ((ent & PT_PRESENT_MASK)
1391                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
1392                                 printk(KERN_ERR "audit error: (%s) levels %d"
1393                                        " gva %lx gpa %llx hpa %llx ent %llx\n",
1394                                        audit_msg, vcpu->mmu.root_level,
1395                                        va, gpa, hpa, ent);
1396                 }
1397         }
1398 }
1399
1400 static void audit_mappings(struct kvm_vcpu *vcpu)
1401 {
1402         unsigned i;
1403
1404         if (vcpu->mmu.root_level == 4)
1405                 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1406         else
1407                 for (i = 0; i < 4; ++i)
1408                         if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1409                                 audit_mappings_page(vcpu,
1410                                                     vcpu->mmu.pae_root[i],
1411                                                     i << 30,
1412                                                     2);
1413 }
1414
1415 static int count_rmaps(struct kvm_vcpu *vcpu)
1416 {
1417         int nmaps = 0;
1418         int i, j, k;
1419
1420         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1421                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1422                 struct kvm_rmap_desc *d;
1423
1424                 for (j = 0; j < m->npages; ++j) {
1425                         struct page *page = m->phys_mem[j];
1426
1427                         if (!page->private)
1428                                 continue;
1429                         if (!(page->private & 1)) {
1430                                 ++nmaps;
1431                                 continue;
1432                         }
1433                         d = (struct kvm_rmap_desc *)(page->private & ~1ul);
1434                         while (d) {
1435                                 for (k = 0; k < RMAP_EXT; ++k)
1436                                         if (d->shadow_ptes[k])
1437                                                 ++nmaps;
1438                                         else
1439                                                 break;
1440                                 d = d->more;
1441                         }
1442                 }
1443         }
1444         return nmaps;
1445 }
1446
1447 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1448 {
1449         int nmaps = 0;
1450         struct kvm_mmu_page *page;
1451         int i;
1452
1453         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1454                 u64 *pt = page->spt;
1455
1456                 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1457                         continue;
1458
1459                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1460                         u64 ent = pt[i];
1461
1462                         if (!(ent & PT_PRESENT_MASK))
1463                                 continue;
1464                         if (!(ent & PT_WRITABLE_MASK))
1465                                 continue;
1466                         ++nmaps;
1467                 }
1468         }
1469         return nmaps;
1470 }
1471
1472 static void audit_rmap(struct kvm_vcpu *vcpu)
1473 {
1474         int n_rmap = count_rmaps(vcpu);
1475         int n_actual = count_writable_mappings(vcpu);
1476
1477         if (n_rmap != n_actual)
1478                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1479                        __FUNCTION__, audit_msg, n_rmap, n_actual);
1480 }
1481
1482 static void audit_write_protection(struct kvm_vcpu *vcpu)
1483 {
1484         struct kvm_mmu_page *page;
1485
1486         list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1487                 hfn_t hfn;
1488                 struct page *pg;
1489
1490                 if (page->role.metaphysical)
1491                         continue;
1492
1493                 hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT)
1494                         >> PAGE_SHIFT;
1495                 pg = pfn_to_page(hfn);
1496                 if (pg->private)
1497                         printk(KERN_ERR "%s: (%s) shadow page has writable"
1498                                " mappings: gfn %lx role %x\n",
1499                                __FUNCTION__, audit_msg, page->gfn,
1500                                page->role.word);
1501         }
1502 }
1503
1504 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1505 {
1506         int olddbg = dbg;
1507
1508         dbg = 0;
1509         audit_msg = msg;
1510         audit_rmap(vcpu);
1511         audit_write_protection(vcpu);
1512         audit_mappings(vcpu);
1513         dbg = olddbg;
1514 }
1515
1516 #endif