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Merge git://git.infradead.org/battery-2.6
[deliverable/linux.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
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 & X86_CR0_WP;
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 {
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_KERNEL);
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_cache_page(struct kvm_mmu_memory_cache *cache,
227 int min)
228 {
229 struct page *page;
230
231 if (cache->nobjs >= min)
232 return 0;
233 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
234 page = alloc_page(GFP_KERNEL);
235 if (!page)
236 return -ENOMEM;
237 set_page_private(page, 0);
238 cache->objects[cache->nobjs++] = page_address(page);
239 }
240 return 0;
241 }
242
243 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
244 {
245 while (mc->nobjs)
246 free_page((unsigned long)mc->objects[--mc->nobjs]);
247 }
248
249 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
250 {
251 int r;
252
253 kvm_mmu_free_some_pages(vcpu);
254 r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache,
255 pte_chain_cache, 4);
256 if (r)
257 goto out;
258 r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache,
259 rmap_desc_cache, 1);
260 if (r)
261 goto out;
262 r = mmu_topup_memory_cache_page(&vcpu->mmu_page_cache, 4);
263 if (r)
264 goto out;
265 r = mmu_topup_memory_cache(&vcpu->mmu_page_header_cache,
266 mmu_page_header_cache, 4);
267 out:
268 return r;
269 }
270
271 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
272 {
273 mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache);
274 mmu_free_memory_cache(&vcpu->mmu_rmap_desc_cache);
275 mmu_free_memory_cache_page(&vcpu->mmu_page_cache);
276 mmu_free_memory_cache(&vcpu->mmu_page_header_cache);
277 }
278
279 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
280 size_t size)
281 {
282 void *p;
283
284 BUG_ON(!mc->nobjs);
285 p = mc->objects[--mc->nobjs];
286 memset(p, 0, size);
287 return p;
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_pte_chain *pc)
297 {
298 kfree(pc);
299 }
300
301 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
302 {
303 return mmu_memory_cache_alloc(&vcpu->mmu_rmap_desc_cache,
304 sizeof(struct kvm_rmap_desc));
305 }
306
307 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
308 {
309 kfree(rd);
310 }
311
312 /*
313 * Reverse mapping data structures:
314 *
315 * If page->private bit zero is zero, then page->private points to the
316 * shadow page table entry that points to page_address(page).
317 *
318 * If page->private bit zero is one, (then page->private & ~1) points
319 * to a struct kvm_rmap_desc containing more mappings.
320 */
321 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
322 {
323 struct page *page;
324 struct kvm_rmap_desc *desc;
325 int i;
326
327 if (!is_rmap_pte(*spte))
328 return;
329 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
330 if (!page_private(page)) {
331 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
332 set_page_private(page,(unsigned long)spte);
333 } else if (!(page_private(page) & 1)) {
334 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
335 desc = mmu_alloc_rmap_desc(vcpu);
336 desc->shadow_ptes[0] = (u64 *)page_private(page);
337 desc->shadow_ptes[1] = spte;
338 set_page_private(page,(unsigned long)desc | 1);
339 } else {
340 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
341 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
342 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
343 desc = desc->more;
344 if (desc->shadow_ptes[RMAP_EXT-1]) {
345 desc->more = mmu_alloc_rmap_desc(vcpu);
346 desc = desc->more;
347 }
348 for (i = 0; desc->shadow_ptes[i]; ++i)
349 ;
350 desc->shadow_ptes[i] = spte;
351 }
352 }
353
354 static void rmap_desc_remove_entry(struct page *page,
355 struct kvm_rmap_desc *desc,
356 int i,
357 struct kvm_rmap_desc *prev_desc)
358 {
359 int j;
360
361 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
362 ;
363 desc->shadow_ptes[i] = desc->shadow_ptes[j];
364 desc->shadow_ptes[j] = NULL;
365 if (j != 0)
366 return;
367 if (!prev_desc && !desc->more)
368 set_page_private(page,(unsigned long)desc->shadow_ptes[0]);
369 else
370 if (prev_desc)
371 prev_desc->more = desc->more;
372 else
373 set_page_private(page,(unsigned long)desc->more | 1);
374 mmu_free_rmap_desc(desc);
375 }
376
377 static void rmap_remove(u64 *spte)
378 {
379 struct page *page;
380 struct kvm_rmap_desc *desc;
381 struct kvm_rmap_desc *prev_desc;
382 int i;
383
384 if (!is_rmap_pte(*spte))
385 return;
386 page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
387 if (!page_private(page)) {
388 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
389 BUG();
390 } else if (!(page_private(page) & 1)) {
391 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
392 if ((u64 *)page_private(page) != spte) {
393 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
394 spte, *spte);
395 BUG();
396 }
397 set_page_private(page,0);
398 } else {
399 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
400 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
401 prev_desc = NULL;
402 while (desc) {
403 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
404 if (desc->shadow_ptes[i] == spte) {
405 rmap_desc_remove_entry(page,
406 desc, i,
407 prev_desc);
408 return;
409 }
410 prev_desc = desc;
411 desc = desc->more;
412 }
413 BUG();
414 }
415 }
416
417 static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
418 {
419 struct kvm *kvm = vcpu->kvm;
420 struct page *page;
421 struct kvm_rmap_desc *desc;
422 u64 *spte;
423
424 page = gfn_to_page(kvm, gfn);
425 BUG_ON(!page);
426
427 while (page_private(page)) {
428 if (!(page_private(page) & 1))
429 spte = (u64 *)page_private(page);
430 else {
431 desc = (struct kvm_rmap_desc *)(page_private(page) & ~1ul);
432 spte = desc->shadow_ptes[0];
433 }
434 BUG_ON(!spte);
435 BUG_ON((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT
436 != page_to_pfn(page));
437 BUG_ON(!(*spte & PT_PRESENT_MASK));
438 BUG_ON(!(*spte & PT_WRITABLE_MASK));
439 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
440 rmap_remove(spte);
441 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
442 kvm_flush_remote_tlbs(vcpu->kvm);
443 }
444 }
445
446 #ifdef MMU_DEBUG
447 static int is_empty_shadow_page(u64 *spt)
448 {
449 u64 *pos;
450 u64 *end;
451
452 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
453 if (*pos != 0) {
454 printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
455 pos, *pos);
456 return 0;
457 }
458 return 1;
459 }
460 #endif
461
462 static void kvm_mmu_free_page(struct kvm *kvm,
463 struct kvm_mmu_page *page_head)
464 {
465 ASSERT(is_empty_shadow_page(page_head->spt));
466 list_del(&page_head->link);
467 __free_page(virt_to_page(page_head->spt));
468 kfree(page_head);
469 ++kvm->n_free_mmu_pages;
470 }
471
472 static unsigned kvm_page_table_hashfn(gfn_t gfn)
473 {
474 return gfn;
475 }
476
477 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
478 u64 *parent_pte)
479 {
480 struct kvm_mmu_page *page;
481
482 if (!vcpu->kvm->n_free_mmu_pages)
483 return NULL;
484
485 page = mmu_memory_cache_alloc(&vcpu->mmu_page_header_cache,
486 sizeof *page);
487 page->spt = mmu_memory_cache_alloc(&vcpu->mmu_page_cache, PAGE_SIZE);
488 set_page_private(virt_to_page(page->spt), (unsigned long)page);
489 list_add(&page->link, &vcpu->kvm->active_mmu_pages);
490 ASSERT(is_empty_shadow_page(page->spt));
491 page->slot_bitmap = 0;
492 page->multimapped = 0;
493 page->parent_pte = parent_pte;
494 --vcpu->kvm->n_free_mmu_pages;
495 return page;
496 }
497
498 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
499 struct kvm_mmu_page *page, u64 *parent_pte)
500 {
501 struct kvm_pte_chain *pte_chain;
502 struct hlist_node *node;
503 int i;
504
505 if (!parent_pte)
506 return;
507 if (!page->multimapped) {
508 u64 *old = page->parent_pte;
509
510 if (!old) {
511 page->parent_pte = parent_pte;
512 return;
513 }
514 page->multimapped = 1;
515 pte_chain = mmu_alloc_pte_chain(vcpu);
516 INIT_HLIST_HEAD(&page->parent_ptes);
517 hlist_add_head(&pte_chain->link, &page->parent_ptes);
518 pte_chain->parent_ptes[0] = old;
519 }
520 hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link) {
521 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
522 continue;
523 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
524 if (!pte_chain->parent_ptes[i]) {
525 pte_chain->parent_ptes[i] = parent_pte;
526 return;
527 }
528 }
529 pte_chain = mmu_alloc_pte_chain(vcpu);
530 BUG_ON(!pte_chain);
531 hlist_add_head(&pte_chain->link, &page->parent_ptes);
532 pte_chain->parent_ptes[0] = parent_pte;
533 }
534
535 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
536 u64 *parent_pte)
537 {
538 struct kvm_pte_chain *pte_chain;
539 struct hlist_node *node;
540 int i;
541
542 if (!page->multimapped) {
543 BUG_ON(page->parent_pte != parent_pte);
544 page->parent_pte = NULL;
545 return;
546 }
547 hlist_for_each_entry(pte_chain, node, &page->parent_ptes, link)
548 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
549 if (!pte_chain->parent_ptes[i])
550 break;
551 if (pte_chain->parent_ptes[i] != parent_pte)
552 continue;
553 while (i + 1 < NR_PTE_CHAIN_ENTRIES
554 && pte_chain->parent_ptes[i + 1]) {
555 pte_chain->parent_ptes[i]
556 = pte_chain->parent_ptes[i + 1];
557 ++i;
558 }
559 pte_chain->parent_ptes[i] = NULL;
560 if (i == 0) {
561 hlist_del(&pte_chain->link);
562 mmu_free_pte_chain(pte_chain);
563 if (hlist_empty(&page->parent_ptes)) {
564 page->multimapped = 0;
565 page->parent_pte = NULL;
566 }
567 }
568 return;
569 }
570 BUG();
571 }
572
573 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm_vcpu *vcpu,
574 gfn_t gfn)
575 {
576 unsigned index;
577 struct hlist_head *bucket;
578 struct kvm_mmu_page *page;
579 struct hlist_node *node;
580
581 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
582 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
583 bucket = &vcpu->kvm->mmu_page_hash[index];
584 hlist_for_each_entry(page, node, bucket, hash_link)
585 if (page->gfn == gfn && !page->role.metaphysical) {
586 pgprintk("%s: found role %x\n",
587 __FUNCTION__, page->role.word);
588 return page;
589 }
590 return NULL;
591 }
592
593 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
594 gfn_t gfn,
595 gva_t gaddr,
596 unsigned level,
597 int metaphysical,
598 unsigned hugepage_access,
599 u64 *parent_pte)
600 {
601 union kvm_mmu_page_role role;
602 unsigned index;
603 unsigned quadrant;
604 struct hlist_head *bucket;
605 struct kvm_mmu_page *page;
606 struct hlist_node *node;
607
608 role.word = 0;
609 role.glevels = vcpu->mmu.root_level;
610 role.level = level;
611 role.metaphysical = metaphysical;
612 role.hugepage_access = hugepage_access;
613 if (vcpu->mmu.root_level <= PT32_ROOT_LEVEL) {
614 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
615 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
616 role.quadrant = quadrant;
617 }
618 pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
619 gfn, role.word);
620 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
621 bucket = &vcpu->kvm->mmu_page_hash[index];
622 hlist_for_each_entry(page, node, bucket, hash_link)
623 if (page->gfn == gfn && page->role.word == role.word) {
624 mmu_page_add_parent_pte(vcpu, page, parent_pte);
625 pgprintk("%s: found\n", __FUNCTION__);
626 return page;
627 }
628 page = kvm_mmu_alloc_page(vcpu, parent_pte);
629 if (!page)
630 return page;
631 pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
632 page->gfn = gfn;
633 page->role = role;
634 hlist_add_head(&page->hash_link, bucket);
635 if (!metaphysical)
636 rmap_write_protect(vcpu, gfn);
637 return page;
638 }
639
640 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
641 struct kvm_mmu_page *page)
642 {
643 unsigned i;
644 u64 *pt;
645 u64 ent;
646
647 pt = page->spt;
648
649 if (page->role.level == PT_PAGE_TABLE_LEVEL) {
650 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
651 if (pt[i] & PT_PRESENT_MASK)
652 rmap_remove(&pt[i]);
653 pt[i] = 0;
654 }
655 kvm_flush_remote_tlbs(kvm);
656 return;
657 }
658
659 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
660 ent = pt[i];
661
662 pt[i] = 0;
663 if (!(ent & PT_PRESENT_MASK))
664 continue;
665 ent &= PT64_BASE_ADDR_MASK;
666 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
667 }
668 kvm_flush_remote_tlbs(kvm);
669 }
670
671 static void kvm_mmu_put_page(struct kvm_mmu_page *page,
672 u64 *parent_pte)
673 {
674 mmu_page_remove_parent_pte(page, parent_pte);
675 }
676
677 static void kvm_mmu_zap_page(struct kvm *kvm,
678 struct kvm_mmu_page *page)
679 {
680 u64 *parent_pte;
681
682 while (page->multimapped || page->parent_pte) {
683 if (!page->multimapped)
684 parent_pte = page->parent_pte;
685 else {
686 struct kvm_pte_chain *chain;
687
688 chain = container_of(page->parent_ptes.first,
689 struct kvm_pte_chain, link);
690 parent_pte = chain->parent_ptes[0];
691 }
692 BUG_ON(!parent_pte);
693 kvm_mmu_put_page(page, parent_pte);
694 set_shadow_pte(parent_pte, 0);
695 }
696 kvm_mmu_page_unlink_children(kvm, page);
697 if (!page->root_count) {
698 hlist_del(&page->hash_link);
699 kvm_mmu_free_page(kvm, page);
700 } else
701 list_move(&page->link, &kvm->active_mmu_pages);
702 }
703
704 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
705 {
706 unsigned index;
707 struct hlist_head *bucket;
708 struct kvm_mmu_page *page;
709 struct hlist_node *node, *n;
710 int r;
711
712 pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
713 r = 0;
714 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
715 bucket = &vcpu->kvm->mmu_page_hash[index];
716 hlist_for_each_entry_safe(page, node, n, bucket, hash_link)
717 if (page->gfn == gfn && !page->role.metaphysical) {
718 pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
719 page->role.word);
720 kvm_mmu_zap_page(vcpu->kvm, page);
721 r = 1;
722 }
723 return r;
724 }
725
726 static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
727 {
728 struct kvm_mmu_page *page;
729
730 while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
731 pgprintk("%s: zap %lx %x\n",
732 __FUNCTION__, gfn, page->role.word);
733 kvm_mmu_zap_page(vcpu->kvm, page);
734 }
735 }
736
737 static void page_header_update_slot(struct kvm *kvm, void *pte, gpa_t gpa)
738 {
739 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gpa >> PAGE_SHIFT));
740 struct kvm_mmu_page *page_head = page_header(__pa(pte));
741
742 __set_bit(slot, &page_head->slot_bitmap);
743 }
744
745 hpa_t safe_gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
746 {
747 hpa_t hpa = gpa_to_hpa(vcpu, gpa);
748
749 return is_error_hpa(hpa) ? bad_page_address | (gpa & ~PAGE_MASK): hpa;
750 }
751
752 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa)
753 {
754 struct page *page;
755
756 ASSERT((gpa & HPA_ERR_MASK) == 0);
757 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
758 if (!page)
759 return gpa | HPA_ERR_MASK;
760 return ((hpa_t)page_to_pfn(page) << PAGE_SHIFT)
761 | (gpa & (PAGE_SIZE-1));
762 }
763
764 hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva)
765 {
766 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
767
768 if (gpa == UNMAPPED_GVA)
769 return UNMAPPED_GVA;
770 return gpa_to_hpa(vcpu, gpa);
771 }
772
773 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
774 {
775 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
776
777 if (gpa == UNMAPPED_GVA)
778 return NULL;
779 return pfn_to_page(gpa_to_hpa(vcpu, gpa) >> PAGE_SHIFT);
780 }
781
782 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
783 {
784 }
785
786 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
787 {
788 int level = PT32E_ROOT_LEVEL;
789 hpa_t table_addr = vcpu->mmu.root_hpa;
790
791 for (; ; level--) {
792 u32 index = PT64_INDEX(v, level);
793 u64 *table;
794 u64 pte;
795
796 ASSERT(VALID_PAGE(table_addr));
797 table = __va(table_addr);
798
799 if (level == 1) {
800 pte = table[index];
801 if (is_present_pte(pte) && is_writeble_pte(pte))
802 return 0;
803 mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
804 page_header_update_slot(vcpu->kvm, table, v);
805 table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |
806 PT_USER_MASK;
807 rmap_add(vcpu, &table[index]);
808 return 0;
809 }
810
811 if (table[index] == 0) {
812 struct kvm_mmu_page *new_table;
813 gfn_t pseudo_gfn;
814
815 pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
816 >> PAGE_SHIFT;
817 new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
818 v, level - 1,
819 1, 0, &table[index]);
820 if (!new_table) {
821 pgprintk("nonpaging_map: ENOMEM\n");
822 return -ENOMEM;
823 }
824
825 table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
826 | PT_WRITABLE_MASK | PT_USER_MASK;
827 }
828 table_addr = table[index] & PT64_BASE_ADDR_MASK;
829 }
830 }
831
832 static void mmu_free_roots(struct kvm_vcpu *vcpu)
833 {
834 int i;
835 struct kvm_mmu_page *page;
836
837 if (!VALID_PAGE(vcpu->mmu.root_hpa))
838 return;
839 #ifdef CONFIG_X86_64
840 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
841 hpa_t root = vcpu->mmu.root_hpa;
842
843 page = page_header(root);
844 --page->root_count;
845 vcpu->mmu.root_hpa = INVALID_PAGE;
846 return;
847 }
848 #endif
849 for (i = 0; i < 4; ++i) {
850 hpa_t root = vcpu->mmu.pae_root[i];
851
852 if (root) {
853 root &= PT64_BASE_ADDR_MASK;
854 page = page_header(root);
855 --page->root_count;
856 }
857 vcpu->mmu.pae_root[i] = INVALID_PAGE;
858 }
859 vcpu->mmu.root_hpa = INVALID_PAGE;
860 }
861
862 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
863 {
864 int i;
865 gfn_t root_gfn;
866 struct kvm_mmu_page *page;
867
868 root_gfn = vcpu->cr3 >> PAGE_SHIFT;
869
870 #ifdef CONFIG_X86_64
871 if (vcpu->mmu.shadow_root_level == PT64_ROOT_LEVEL) {
872 hpa_t root = vcpu->mmu.root_hpa;
873
874 ASSERT(!VALID_PAGE(root));
875 page = kvm_mmu_get_page(vcpu, root_gfn, 0,
876 PT64_ROOT_LEVEL, 0, 0, NULL);
877 root = __pa(page->spt);
878 ++page->root_count;
879 vcpu->mmu.root_hpa = root;
880 return;
881 }
882 #endif
883 for (i = 0; i < 4; ++i) {
884 hpa_t root = vcpu->mmu.pae_root[i];
885
886 ASSERT(!VALID_PAGE(root));
887 if (vcpu->mmu.root_level == PT32E_ROOT_LEVEL) {
888 if (!is_present_pte(vcpu->pdptrs[i])) {
889 vcpu->mmu.pae_root[i] = 0;
890 continue;
891 }
892 root_gfn = vcpu->pdptrs[i] >> PAGE_SHIFT;
893 } else if (vcpu->mmu.root_level == 0)
894 root_gfn = 0;
895 page = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
896 PT32_ROOT_LEVEL, !is_paging(vcpu),
897 0, NULL);
898 root = __pa(page->spt);
899 ++page->root_count;
900 vcpu->mmu.pae_root[i] = root | PT_PRESENT_MASK;
901 }
902 vcpu->mmu.root_hpa = __pa(vcpu->mmu.pae_root);
903 }
904
905 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
906 {
907 return vaddr;
908 }
909
910 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
911 u32 error_code)
912 {
913 gpa_t addr = gva;
914 hpa_t paddr;
915 int r;
916
917 r = mmu_topup_memory_caches(vcpu);
918 if (r)
919 return r;
920
921 ASSERT(vcpu);
922 ASSERT(VALID_PAGE(vcpu->mmu.root_hpa));
923
924
925 paddr = gpa_to_hpa(vcpu , addr & PT64_BASE_ADDR_MASK);
926
927 if (is_error_hpa(paddr))
928 return 1;
929
930 return nonpaging_map(vcpu, addr & PAGE_MASK, paddr);
931 }
932
933 static void nonpaging_free(struct kvm_vcpu *vcpu)
934 {
935 mmu_free_roots(vcpu);
936 }
937
938 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
939 {
940 struct kvm_mmu *context = &vcpu->mmu;
941
942 context->new_cr3 = nonpaging_new_cr3;
943 context->page_fault = nonpaging_page_fault;
944 context->gva_to_gpa = nonpaging_gva_to_gpa;
945 context->free = nonpaging_free;
946 context->root_level = 0;
947 context->shadow_root_level = PT32E_ROOT_LEVEL;
948 context->root_hpa = INVALID_PAGE;
949 return 0;
950 }
951
952 static void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
953 {
954 ++vcpu->stat.tlb_flush;
955 kvm_x86_ops->tlb_flush(vcpu);
956 }
957
958 static void paging_new_cr3(struct kvm_vcpu *vcpu)
959 {
960 pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->cr3);
961 mmu_free_roots(vcpu);
962 }
963
964 static void inject_page_fault(struct kvm_vcpu *vcpu,
965 u64 addr,
966 u32 err_code)
967 {
968 kvm_x86_ops->inject_page_fault(vcpu, addr, err_code);
969 }
970
971 static void paging_free(struct kvm_vcpu *vcpu)
972 {
973 nonpaging_free(vcpu);
974 }
975
976 #define PTTYPE 64
977 #include "paging_tmpl.h"
978 #undef PTTYPE
979
980 #define PTTYPE 32
981 #include "paging_tmpl.h"
982 #undef PTTYPE
983
984 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
985 {
986 struct kvm_mmu *context = &vcpu->mmu;
987
988 ASSERT(is_pae(vcpu));
989 context->new_cr3 = paging_new_cr3;
990 context->page_fault = paging64_page_fault;
991 context->gva_to_gpa = paging64_gva_to_gpa;
992 context->free = paging_free;
993 context->root_level = level;
994 context->shadow_root_level = level;
995 context->root_hpa = INVALID_PAGE;
996 return 0;
997 }
998
999 static int paging64_init_context(struct kvm_vcpu *vcpu)
1000 {
1001 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1002 }
1003
1004 static int paging32_init_context(struct kvm_vcpu *vcpu)
1005 {
1006 struct kvm_mmu *context = &vcpu->mmu;
1007
1008 context->new_cr3 = paging_new_cr3;
1009 context->page_fault = paging32_page_fault;
1010 context->gva_to_gpa = paging32_gva_to_gpa;
1011 context->free = paging_free;
1012 context->root_level = PT32_ROOT_LEVEL;
1013 context->shadow_root_level = PT32E_ROOT_LEVEL;
1014 context->root_hpa = INVALID_PAGE;
1015 return 0;
1016 }
1017
1018 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1019 {
1020 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1021 }
1022
1023 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1024 {
1025 ASSERT(vcpu);
1026 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1027
1028 if (!is_paging(vcpu))
1029 return nonpaging_init_context(vcpu);
1030 else if (is_long_mode(vcpu))
1031 return paging64_init_context(vcpu);
1032 else if (is_pae(vcpu))
1033 return paging32E_init_context(vcpu);
1034 else
1035 return paging32_init_context(vcpu);
1036 }
1037
1038 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1039 {
1040 ASSERT(vcpu);
1041 if (VALID_PAGE(vcpu->mmu.root_hpa)) {
1042 vcpu->mmu.free(vcpu);
1043 vcpu->mmu.root_hpa = INVALID_PAGE;
1044 }
1045 }
1046
1047 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1048 {
1049 destroy_kvm_mmu(vcpu);
1050 return init_kvm_mmu(vcpu);
1051 }
1052
1053 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1054 {
1055 int r;
1056
1057 mutex_lock(&vcpu->kvm->lock);
1058 r = mmu_topup_memory_caches(vcpu);
1059 if (r)
1060 goto out;
1061 mmu_alloc_roots(vcpu);
1062 kvm_x86_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
1063 kvm_mmu_flush_tlb(vcpu);
1064 out:
1065 mutex_unlock(&vcpu->kvm->lock);
1066 return r;
1067 }
1068 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1069
1070 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1071 {
1072 mmu_free_roots(vcpu);
1073 }
1074
1075 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1076 struct kvm_mmu_page *page,
1077 u64 *spte)
1078 {
1079 u64 pte;
1080 struct kvm_mmu_page *child;
1081
1082 pte = *spte;
1083 if (is_present_pte(pte)) {
1084 if (page->role.level == PT_PAGE_TABLE_LEVEL)
1085 rmap_remove(spte);
1086 else {
1087 child = page_header(pte & PT64_BASE_ADDR_MASK);
1088 mmu_page_remove_parent_pte(child, spte);
1089 }
1090 }
1091 *spte = 0;
1092 kvm_flush_remote_tlbs(vcpu->kvm);
1093 }
1094
1095 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1096 struct kvm_mmu_page *page,
1097 u64 *spte,
1098 const void *new, int bytes)
1099 {
1100 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1101 return;
1102
1103 if (page->role.glevels == PT32_ROOT_LEVEL)
1104 paging32_update_pte(vcpu, page, spte, new, bytes);
1105 else
1106 paging64_update_pte(vcpu, page, spte, new, bytes);
1107 }
1108
1109 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1110 const u8 *new, int bytes)
1111 {
1112 gfn_t gfn = gpa >> PAGE_SHIFT;
1113 struct kvm_mmu_page *page;
1114 struct hlist_node *node, *n;
1115 struct hlist_head *bucket;
1116 unsigned index;
1117 u64 *spte;
1118 unsigned offset = offset_in_page(gpa);
1119 unsigned pte_size;
1120 unsigned page_offset;
1121 unsigned misaligned;
1122 unsigned quadrant;
1123 int level;
1124 int flooded = 0;
1125 int npte;
1126
1127 pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1128 if (gfn == vcpu->last_pt_write_gfn) {
1129 ++vcpu->last_pt_write_count;
1130 if (vcpu->last_pt_write_count >= 3)
1131 flooded = 1;
1132 } else {
1133 vcpu->last_pt_write_gfn = gfn;
1134 vcpu->last_pt_write_count = 1;
1135 }
1136 index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1137 bucket = &vcpu->kvm->mmu_page_hash[index];
1138 hlist_for_each_entry_safe(page, node, n, bucket, hash_link) {
1139 if (page->gfn != gfn || page->role.metaphysical)
1140 continue;
1141 pte_size = page->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1142 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1143 misaligned |= bytes < 4;
1144 if (misaligned || flooded) {
1145 /*
1146 * Misaligned accesses are too much trouble to fix
1147 * up; also, they usually indicate a page is not used
1148 * as a page table.
1149 *
1150 * If we're seeing too many writes to a page,
1151 * it may no longer be a page table, or we may be
1152 * forking, in which case it is better to unmap the
1153 * page.
1154 */
1155 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1156 gpa, bytes, page->role.word);
1157 kvm_mmu_zap_page(vcpu->kvm, page);
1158 continue;
1159 }
1160 page_offset = offset;
1161 level = page->role.level;
1162 npte = 1;
1163 if (page->role.glevels == PT32_ROOT_LEVEL) {
1164 page_offset <<= 1; /* 32->64 */
1165 /*
1166 * A 32-bit pde maps 4MB while the shadow pdes map
1167 * only 2MB. So we need to double the offset again
1168 * and zap two pdes instead of one.
1169 */
1170 if (level == PT32_ROOT_LEVEL) {
1171 page_offset &= ~7; /* kill rounding error */
1172 page_offset <<= 1;
1173 npte = 2;
1174 }
1175 quadrant = page_offset >> PAGE_SHIFT;
1176 page_offset &= ~PAGE_MASK;
1177 if (quadrant != page->role.quadrant)
1178 continue;
1179 }
1180 spte = &page->spt[page_offset / sizeof(*spte)];
1181 while (npte--) {
1182 mmu_pte_write_zap_pte(vcpu, page, spte);
1183 mmu_pte_write_new_pte(vcpu, page, spte, new, bytes);
1184 ++spte;
1185 }
1186 }
1187 }
1188
1189 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1190 {
1191 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, gva);
1192
1193 return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT);
1194 }
1195
1196 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1197 {
1198 while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) {
1199 struct kvm_mmu_page *page;
1200
1201 page = container_of(vcpu->kvm->active_mmu_pages.prev,
1202 struct kvm_mmu_page, link);
1203 kvm_mmu_zap_page(vcpu->kvm, page);
1204 }
1205 }
1206
1207 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1208 {
1209 struct kvm_mmu_page *page;
1210
1211 while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
1212 page = container_of(vcpu->kvm->active_mmu_pages.next,
1213 struct kvm_mmu_page, link);
1214 kvm_mmu_zap_page(vcpu->kvm, page);
1215 }
1216 free_page((unsigned long)vcpu->mmu.pae_root);
1217 }
1218
1219 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1220 {
1221 struct page *page;
1222 int i;
1223
1224 ASSERT(vcpu);
1225
1226 vcpu->kvm->n_free_mmu_pages = KVM_NUM_MMU_PAGES;
1227
1228 /*
1229 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1230 * Therefore we need to allocate shadow page tables in the first
1231 * 4GB of memory, which happens to fit the DMA32 zone.
1232 */
1233 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1234 if (!page)
1235 goto error_1;
1236 vcpu->mmu.pae_root = page_address(page);
1237 for (i = 0; i < 4; ++i)
1238 vcpu->mmu.pae_root[i] = INVALID_PAGE;
1239
1240 return 0;
1241
1242 error_1:
1243 free_mmu_pages(vcpu);
1244 return -ENOMEM;
1245 }
1246
1247 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1248 {
1249 ASSERT(vcpu);
1250 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1251
1252 return alloc_mmu_pages(vcpu);
1253 }
1254
1255 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1256 {
1257 ASSERT(vcpu);
1258 ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
1259
1260 return init_kvm_mmu(vcpu);
1261 }
1262
1263 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1264 {
1265 ASSERT(vcpu);
1266
1267 destroy_kvm_mmu(vcpu);
1268 free_mmu_pages(vcpu);
1269 mmu_free_memory_caches(vcpu);
1270 }
1271
1272 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1273 {
1274 struct kvm_mmu_page *page;
1275
1276 list_for_each_entry(page, &kvm->active_mmu_pages, link) {
1277 int i;
1278 u64 *pt;
1279
1280 if (!test_bit(slot, &page->slot_bitmap))
1281 continue;
1282
1283 pt = page->spt;
1284 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1285 /* avoid RMW */
1286 if (pt[i] & PT_WRITABLE_MASK) {
1287 rmap_remove(&pt[i]);
1288 pt[i] &= ~PT_WRITABLE_MASK;
1289 }
1290 }
1291 }
1292
1293 void kvm_mmu_zap_all(struct kvm *kvm)
1294 {
1295 struct kvm_mmu_page *page, *node;
1296
1297 list_for_each_entry_safe(page, node, &kvm->active_mmu_pages, link)
1298 kvm_mmu_zap_page(kvm, page);
1299
1300 kvm_flush_remote_tlbs(kvm);
1301 }
1302
1303 void kvm_mmu_module_exit(void)
1304 {
1305 if (pte_chain_cache)
1306 kmem_cache_destroy(pte_chain_cache);
1307 if (rmap_desc_cache)
1308 kmem_cache_destroy(rmap_desc_cache);
1309 if (mmu_page_header_cache)
1310 kmem_cache_destroy(mmu_page_header_cache);
1311 }
1312
1313 int kvm_mmu_module_init(void)
1314 {
1315 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1316 sizeof(struct kvm_pte_chain),
1317 0, 0, NULL);
1318 if (!pte_chain_cache)
1319 goto nomem;
1320 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1321 sizeof(struct kvm_rmap_desc),
1322 0, 0, NULL);
1323 if (!rmap_desc_cache)
1324 goto nomem;
1325
1326 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1327 sizeof(struct kvm_mmu_page),
1328 0, 0, NULL);
1329 if (!mmu_page_header_cache)
1330 goto nomem;
1331
1332 return 0;
1333
1334 nomem:
1335 kvm_mmu_module_exit();
1336 return -ENOMEM;
1337 }
1338
1339 #ifdef AUDIT
1340
1341 static const char *audit_msg;
1342
1343 static gva_t canonicalize(gva_t gva)
1344 {
1345 #ifdef CONFIG_X86_64
1346 gva = (long long)(gva << 16) >> 16;
1347 #endif
1348 return gva;
1349 }
1350
1351 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1352 gva_t va, int level)
1353 {
1354 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1355 int i;
1356 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1357
1358 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1359 u64 ent = pt[i];
1360
1361 if (!(ent & PT_PRESENT_MASK))
1362 continue;
1363
1364 va = canonicalize(va);
1365 if (level > 1)
1366 audit_mappings_page(vcpu, ent, va, level - 1);
1367 else {
1368 gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, va);
1369 hpa_t hpa = gpa_to_hpa(vcpu, gpa);
1370
1371 if ((ent & PT_PRESENT_MASK)
1372 && (ent & PT64_BASE_ADDR_MASK) != hpa)
1373 printk(KERN_ERR "audit error: (%s) levels %d"
1374 " gva %lx gpa %llx hpa %llx ent %llx\n",
1375 audit_msg, vcpu->mmu.root_level,
1376 va, gpa, hpa, ent);
1377 }
1378 }
1379 }
1380
1381 static void audit_mappings(struct kvm_vcpu *vcpu)
1382 {
1383 unsigned i;
1384
1385 if (vcpu->mmu.root_level == 4)
1386 audit_mappings_page(vcpu, vcpu->mmu.root_hpa, 0, 4);
1387 else
1388 for (i = 0; i < 4; ++i)
1389 if (vcpu->mmu.pae_root[i] & PT_PRESENT_MASK)
1390 audit_mappings_page(vcpu,
1391 vcpu->mmu.pae_root[i],
1392 i << 30,
1393 2);
1394 }
1395
1396 static int count_rmaps(struct kvm_vcpu *vcpu)
1397 {
1398 int nmaps = 0;
1399 int i, j, k;
1400
1401 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1402 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1403 struct kvm_rmap_desc *d;
1404
1405 for (j = 0; j < m->npages; ++j) {
1406 struct page *page = m->phys_mem[j];
1407
1408 if (!page->private)
1409 continue;
1410 if (!(page->private & 1)) {
1411 ++nmaps;
1412 continue;
1413 }
1414 d = (struct kvm_rmap_desc *)(page->private & ~1ul);
1415 while (d) {
1416 for (k = 0; k < RMAP_EXT; ++k)
1417 if (d->shadow_ptes[k])
1418 ++nmaps;
1419 else
1420 break;
1421 d = d->more;
1422 }
1423 }
1424 }
1425 return nmaps;
1426 }
1427
1428 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1429 {
1430 int nmaps = 0;
1431 struct kvm_mmu_page *page;
1432 int i;
1433
1434 list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1435 u64 *pt = page->spt;
1436
1437 if (page->role.level != PT_PAGE_TABLE_LEVEL)
1438 continue;
1439
1440 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1441 u64 ent = pt[i];
1442
1443 if (!(ent & PT_PRESENT_MASK))
1444 continue;
1445 if (!(ent & PT_WRITABLE_MASK))
1446 continue;
1447 ++nmaps;
1448 }
1449 }
1450 return nmaps;
1451 }
1452
1453 static void audit_rmap(struct kvm_vcpu *vcpu)
1454 {
1455 int n_rmap = count_rmaps(vcpu);
1456 int n_actual = count_writable_mappings(vcpu);
1457
1458 if (n_rmap != n_actual)
1459 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1460 __FUNCTION__, audit_msg, n_rmap, n_actual);
1461 }
1462
1463 static void audit_write_protection(struct kvm_vcpu *vcpu)
1464 {
1465 struct kvm_mmu_page *page;
1466
1467 list_for_each_entry(page, &vcpu->kvm->active_mmu_pages, link) {
1468 hfn_t hfn;
1469 struct page *pg;
1470
1471 if (page->role.metaphysical)
1472 continue;
1473
1474 hfn = gpa_to_hpa(vcpu, (gpa_t)page->gfn << PAGE_SHIFT)
1475 >> PAGE_SHIFT;
1476 pg = pfn_to_page(hfn);
1477 if (pg->private)
1478 printk(KERN_ERR "%s: (%s) shadow page has writable"
1479 " mappings: gfn %lx role %x\n",
1480 __FUNCTION__, audit_msg, page->gfn,
1481 page->role.word);
1482 }
1483 }
1484
1485 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1486 {
1487 int olddbg = dbg;
1488
1489 dbg = 0;
1490 audit_msg = msg;
1491 audit_rmap(vcpu);
1492 audit_write_protection(vcpu);
1493 audit_mappings(vcpu);
1494 dbg = olddbg;
1495 }
1496
1497 #endif
Linux kernel - Deliverables
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