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