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KVM: MMU: mmu_convert_notrap helper
[linux-2.6.git] / arch / x86 / kvm / mmu.c
blob57c7580e7f98abdb144451530e184993315f072c
1 /*
2 * Kernel-based Virtual Machine driver for Linux
3 *
4 * This module enables machines with Intel VT-x extensions to run virtual
5 * machines without emulation or binary translation.
6 *
7 * MMU support
8 *
9 * Copyright (C) 2006 Qumranet, Inc.
10 *
11 * Authors:
12 * Yaniv Kamay <yaniv@qumranet.com>
13 * Avi Kivity <avi@qumranet.com>
14 *
15 * This work is licensed under the terms of the GNU GPL, version 2. See
16 * the COPYING file in the top-level directory.
17 *
18 */
19
20 #include "vmx.h"
21 #include "mmu.h"
22
23 #include <linux/kvm_host.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
26 #include <linux/mm.h>
27 #include <linux/highmem.h>
28 #include <linux/module.h>
29 #include <linux/swap.h>
30 #include <linux/hugetlb.h>
31 #include <linux/compiler.h>
32
33 #include <asm/page.h>
34 #include <asm/cmpxchg.h>
35 #include <asm/io.h>
36
37 /*
38 * When setting this variable to true it enables Two-Dimensional-Paging
39 * where the hardware walks 2 page tables:
40 * 1. the guest-virtual to guest-physical
41 * 2. while doing 1. it walks guest-physical to host-physical
42 * If the hardware supports that we don't need to do shadow paging.
43 */
44 bool tdp_enabled = false;
45
46 #undef MMU_DEBUG
47
48 #undef AUDIT
49
50 #ifdef AUDIT
51 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
52 #else
53 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
54 #endif
55
56 #ifdef MMU_DEBUG
57
58 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
59 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
60
61 #else
62
63 #define pgprintk(x...) do { } while (0)
64 #define rmap_printk(x...) do { } while (0)
65
66 #endif
67
68 #if defined(MMU_DEBUG) || defined(AUDIT)
69 static int dbg = 0;
70 module_param(dbg, bool, 0644);
71 #endif
72
73 #ifndef MMU_DEBUG
74 #define ASSERT(x) do { } while (0)
75 #else
76 #define ASSERT(x) \
77 if (!(x)) { \
78 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
79 __FILE__, __LINE__, #x); \
80 }
81 #endif
82
83 #define PT_FIRST_AVAIL_BITS_SHIFT 9
84 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
85
86 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
87
88 #define PT64_LEVEL_BITS 9
89
90 #define PT64_LEVEL_SHIFT(level) \
91 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
92
93 #define PT64_LEVEL_MASK(level) \
94 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
95
96 #define PT64_INDEX(address, level)\
97 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
98
99
100 #define PT32_LEVEL_BITS 10
101
102 #define PT32_LEVEL_SHIFT(level) \
103 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
104
105 #define PT32_LEVEL_MASK(level) \
106 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
107
108 #define PT32_INDEX(address, level)\
109 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
110
111
112 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
113 #define PT64_DIR_BASE_ADDR_MASK \
114 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
115
116 #define PT32_BASE_ADDR_MASK PAGE_MASK
117 #define PT32_DIR_BASE_ADDR_MASK \
118 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
119
120 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
121 | PT64_NX_MASK)
122
123 #define PFERR_PRESENT_MASK (1U << 0)
124 #define PFERR_WRITE_MASK (1U << 1)
125 #define PFERR_USER_MASK (1U << 2)
126 #define PFERR_FETCH_MASK (1U << 4)
127
128 #define PT_DIRECTORY_LEVEL 2
129 #define PT_PAGE_TABLE_LEVEL 1
130
131 #define RMAP_EXT 4
132
133 #define ACC_EXEC_MASK 1
134 #define ACC_WRITE_MASK PT_WRITABLE_MASK
135 #define ACC_USER_MASK PT_USER_MASK
136 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
137
138 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
139
140 struct kvm_rmap_desc {
141 u64 *shadow_ptes[RMAP_EXT];
142 struct kvm_rmap_desc *more;
143 };
144
145 struct kvm_shadow_walk {
146 int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu,
147 u64 addr, u64 *spte, int level);
148 };
149
150 typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
151
152 static struct kmem_cache *pte_chain_cache;
153 static struct kmem_cache *rmap_desc_cache;
154 static struct kmem_cache *mmu_page_header_cache;
155
156 static u64 __read_mostly shadow_trap_nonpresent_pte;
157 static u64 __read_mostly shadow_notrap_nonpresent_pte;
158 static u64 __read_mostly shadow_base_present_pte;
159 static u64 __read_mostly shadow_nx_mask;
160 static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
161 static u64 __read_mostly shadow_user_mask;
162 static u64 __read_mostly shadow_accessed_mask;
163 static u64 __read_mostly shadow_dirty_mask;
164
165 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
166 {
167 shadow_trap_nonpresent_pte = trap_pte;
168 shadow_notrap_nonpresent_pte = notrap_pte;
169 }
170 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
171
172 void kvm_mmu_set_base_ptes(u64 base_pte)
173 {
174 shadow_base_present_pte = base_pte;
175 }
176 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
177
178 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
179 u64 dirty_mask, u64 nx_mask, u64 x_mask)
180 {
181 shadow_user_mask = user_mask;
182 shadow_accessed_mask = accessed_mask;
183 shadow_dirty_mask = dirty_mask;
184 shadow_nx_mask = nx_mask;
185 shadow_x_mask = x_mask;
186 }
187 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
188
189 static int is_write_protection(struct kvm_vcpu *vcpu)
190 {
191 return vcpu->arch.cr0 & X86_CR0_WP;
192 }
193
194 static int is_cpuid_PSE36(void)
195 {
196 return 1;
197 }
198
199 static int is_nx(struct kvm_vcpu *vcpu)
200 {
201 return vcpu->arch.shadow_efer & EFER_NX;
202 }
203
204 static int is_present_pte(unsigned long pte)
205 {
206 return pte & PT_PRESENT_MASK;
207 }
208
209 static int is_shadow_present_pte(u64 pte)
210 {
211 return pte != shadow_trap_nonpresent_pte
212 && pte != shadow_notrap_nonpresent_pte;
213 }
214
215 static int is_large_pte(u64 pte)
216 {
217 return pte & PT_PAGE_SIZE_MASK;
218 }
219
220 static int is_writeble_pte(unsigned long pte)
221 {
222 return pte & PT_WRITABLE_MASK;
223 }
224
225 static int is_dirty_pte(unsigned long pte)
226 {
227 return pte & shadow_dirty_mask;
228 }
229
230 static int is_rmap_pte(u64 pte)
231 {
232 return is_shadow_present_pte(pte);
233 }
234
235 static pfn_t spte_to_pfn(u64 pte)
236 {
237 return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
238 }
239
240 static gfn_t pse36_gfn_delta(u32 gpte)
241 {
242 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
243
244 return (gpte & PT32_DIR_PSE36_MASK) << shift;
245 }
246
247 static void set_shadow_pte(u64 *sptep, u64 spte)
248 {
249 #ifdef CONFIG_X86_64
250 set_64bit((unsigned long *)sptep, spte);
251 #else
252 set_64bit((unsigned long long *)sptep, spte);
253 #endif
254 }
255
256 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
257 struct kmem_cache *base_cache, int min)
258 {
259 void *obj;
260
261 if (cache->nobjs >= min)
262 return 0;
263 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
264 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
265 if (!obj)
266 return -ENOMEM;
267 cache->objects[cache->nobjs++] = obj;
268 }
269 return 0;
270 }
271
272 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
273 {
274 while (mc->nobjs)
275 kfree(mc->objects[--mc->nobjs]);
276 }
277
278 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
279 int min)
280 {
281 struct page *page;
282
283 if (cache->nobjs >= min)
284 return 0;
285 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
286 page = alloc_page(GFP_KERNEL);
287 if (!page)
288 return -ENOMEM;
289 set_page_private(page, 0);
290 cache->objects[cache->nobjs++] = page_address(page);
291 }
292 return 0;
293 }
294
295 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
296 {
297 while (mc->nobjs)
298 free_page((unsigned long)mc->objects[--mc->nobjs]);
299 }
300
301 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
302 {
303 int r;
304
305 r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
306 pte_chain_cache, 4);
307 if (r)
308 goto out;
309 r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
310 rmap_desc_cache, 1);
311 if (r)
312 goto out;
313 r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
314 if (r)
315 goto out;
316 r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
317 mmu_page_header_cache, 4);
318 out:
319 return r;
320 }
321
322 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
323 {
324 mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
325 mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
326 mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
327 mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
328 }
329
330 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
331 size_t size)
332 {
333 void *p;
334
335 BUG_ON(!mc->nobjs);
336 p = mc->objects[--mc->nobjs];
337 memset(p, 0, size);
338 return p;
339 }
340
341 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
342 {
343 return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
344 sizeof(struct kvm_pte_chain));
345 }
346
347 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
348 {
349 kfree(pc);
350 }
351
352 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
353 {
354 return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
355 sizeof(struct kvm_rmap_desc));
356 }
357
358 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
359 {
360 kfree(rd);
361 }
362
363 /*
364 * Return the pointer to the largepage write count for a given
365 * gfn, handling slots that are not large page aligned.
366 */
367 static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
368 {
369 unsigned long idx;
370
371 idx = (gfn / KVM_PAGES_PER_HPAGE) -
372 (slot->base_gfn / KVM_PAGES_PER_HPAGE);
373 return &slot->lpage_info[idx].write_count;
374 }
375
376 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
377 {
378 int *write_count;
379
380 write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
381 *write_count += 1;
382 }
383
384 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
385 {
386 int *write_count;
387
388 write_count = slot_largepage_idx(gfn, gfn_to_memslot(kvm, gfn));
389 *write_count -= 1;
390 WARN_ON(*write_count < 0);
391 }
392
393 static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
394 {
395 struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
396 int *largepage_idx;
397
398 if (slot) {
399 largepage_idx = slot_largepage_idx(gfn, slot);
400 return *largepage_idx;
401 }
402
403 return 1;
404 }
405
406 static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
407 {
408 struct vm_area_struct *vma;
409 unsigned long addr;
410 int ret = 0;
411
412 addr = gfn_to_hva(kvm, gfn);
413 if (kvm_is_error_hva(addr))
414 return ret;
415
416 down_read(&current->mm->mmap_sem);
417 vma = find_vma(current->mm, addr);
418 if (vma && is_vm_hugetlb_page(vma))
419 ret = 1;
420 up_read(&current->mm->mmap_sem);
421
422 return ret;
423 }
424
425 static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
426 {
427 struct kvm_memory_slot *slot;
428
429 if (has_wrprotected_page(vcpu->kvm, large_gfn))
430 return 0;
431
432 if (!host_largepage_backed(vcpu->kvm, large_gfn))
433 return 0;
434
435 slot = gfn_to_memslot(vcpu->kvm, large_gfn);
436 if (slot && slot->dirty_bitmap)
437 return 0;
438
439 return 1;
440 }
441
442 /*
443 * Take gfn and return the reverse mapping to it.
444 * Note: gfn must be unaliased before this function get called
445 */
446
447 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
448 {
449 struct kvm_memory_slot *slot;
450 unsigned long idx;
451
452 slot = gfn_to_memslot(kvm, gfn);
453 if (!lpage)
454 return &slot->rmap[gfn - slot->base_gfn];
455
456 idx = (gfn / KVM_PAGES_PER_HPAGE) -
457 (slot->base_gfn / KVM_PAGES_PER_HPAGE);
458
459 return &slot->lpage_info[idx].rmap_pde;
460 }
461
462 /*
463 * Reverse mapping data structures:
464 *
465 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
466 * that points to page_address(page).
467 *
468 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
469 * containing more mappings.
470 */
471 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
472 {
473 struct kvm_mmu_page *sp;
474 struct kvm_rmap_desc *desc;
475 unsigned long *rmapp;
476 int i;
477
478 if (!is_rmap_pte(*spte))
479 return;
480 gfn = unalias_gfn(vcpu->kvm, gfn);
481 sp = page_header(__pa(spte));
482 sp->gfns[spte - sp->spt] = gfn;
483 rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
484 if (!*rmapp) {
485 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
486 *rmapp = (unsigned long)spte;
487 } else if (!(*rmapp & 1)) {
488 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
489 desc = mmu_alloc_rmap_desc(vcpu);
490 desc->shadow_ptes[0] = (u64 *)*rmapp;
491 desc->shadow_ptes[1] = spte;
492 *rmapp = (unsigned long)desc | 1;
493 } else {
494 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
495 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
496 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
497 desc = desc->more;
498 if (desc->shadow_ptes[RMAP_EXT-1]) {
499 desc->more = mmu_alloc_rmap_desc(vcpu);
500 desc = desc->more;
501 }
502 for (i = 0; desc->shadow_ptes[i]; ++i)
503 ;
504 desc->shadow_ptes[i] = spte;
505 }
506 }
507
508 static void rmap_desc_remove_entry(unsigned long *rmapp,
509 struct kvm_rmap_desc *desc,
510 int i,
511 struct kvm_rmap_desc *prev_desc)
512 {
513 int j;
514
515 for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
516 ;
517 desc->shadow_ptes[i] = desc->shadow_ptes[j];
518 desc->shadow_ptes[j] = NULL;
519 if (j != 0)
520 return;
521 if (!prev_desc && !desc->more)
522 *rmapp = (unsigned long)desc->shadow_ptes[0];
523 else
524 if (prev_desc)
525 prev_desc->more = desc->more;
526 else
527 *rmapp = (unsigned long)desc->more | 1;
528 mmu_free_rmap_desc(desc);
529 }
530
531 static void rmap_remove(struct kvm *kvm, u64 *spte)
532 {
533 struct kvm_rmap_desc *desc;
534 struct kvm_rmap_desc *prev_desc;
535 struct kvm_mmu_page *sp;
536 pfn_t pfn;
537 unsigned long *rmapp;
538 int i;
539
540 if (!is_rmap_pte(*spte))
541 return;
542 sp = page_header(__pa(spte));
543 pfn = spte_to_pfn(*spte);
544 if (*spte & shadow_accessed_mask)
545 kvm_set_pfn_accessed(pfn);
546 if (is_writeble_pte(*spte))
547 kvm_release_pfn_dirty(pfn);
548 else
549 kvm_release_pfn_clean(pfn);
550 rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
551 if (!*rmapp) {
552 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
553 BUG();
554 } else if (!(*rmapp & 1)) {
555 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
556 if ((u64 *)*rmapp != spte) {
557 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
558 spte, *spte);
559 BUG();
560 }
561 *rmapp = 0;
562 } else {
563 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
564 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
565 prev_desc = NULL;
566 while (desc) {
567 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
568 if (desc->shadow_ptes[i] == spte) {
569 rmap_desc_remove_entry(rmapp,
570 desc, i,
571 prev_desc);
572 return;
573 }
574 prev_desc = desc;
575 desc = desc->more;
576 }
577 BUG();
578 }
579 }
580
581 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
582 {
583 struct kvm_rmap_desc *desc;
584 struct kvm_rmap_desc *prev_desc;
585 u64 *prev_spte;
586 int i;
587
588 if (!*rmapp)
589 return NULL;
590 else if (!(*rmapp & 1)) {
591 if (!spte)
592 return (u64 *)*rmapp;
593 return NULL;
594 }
595 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
596 prev_desc = NULL;
597 prev_spte = NULL;
598 while (desc) {
599 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
600 if (prev_spte == spte)
601 return desc->shadow_ptes[i];
602 prev_spte = desc->shadow_ptes[i];
603 }
604 desc = desc->more;
605 }
606 return NULL;
607 }
608
609 static void rmap_write_protect(struct kvm *kvm, u64 gfn)
610 {
611 unsigned long *rmapp;
612 u64 *spte;
613 int write_protected = 0;
614
615 gfn = unalias_gfn(kvm, gfn);
616 rmapp = gfn_to_rmap(kvm, gfn, 0);
617
618 spte = rmap_next(kvm, rmapp, NULL);
619 while (spte) {
620 BUG_ON(!spte);
621 BUG_ON(!(*spte & PT_PRESENT_MASK));
622 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
623 if (is_writeble_pte(*spte)) {
624 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
625 write_protected = 1;
626 }
627 spte = rmap_next(kvm, rmapp, spte);
628 }
629 if (write_protected) {
630 pfn_t pfn;
631
632 spte = rmap_next(kvm, rmapp, NULL);
633 pfn = spte_to_pfn(*spte);
634 kvm_set_pfn_dirty(pfn);
635 }
636
637 /* check for huge page mappings */
638 rmapp = gfn_to_rmap(kvm, gfn, 1);
639 spte = rmap_next(kvm, rmapp, NULL);
640 while (spte) {
641 BUG_ON(!spte);
642 BUG_ON(!(*spte & PT_PRESENT_MASK));
643 BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
644 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
645 if (is_writeble_pte(*spte)) {
646 rmap_remove(kvm, spte);
647 --kvm->stat.lpages;
648 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
649 spte = NULL;
650 write_protected = 1;
651 }
652 spte = rmap_next(kvm, rmapp, spte);
653 }
654
655 if (write_protected)
656 kvm_flush_remote_tlbs(kvm);
657
658 account_shadowed(kvm, gfn);
659 }
660
661 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
662 {
663 u64 *spte;
664 int need_tlb_flush = 0;
665
666 while ((spte = rmap_next(kvm, rmapp, NULL))) {
667 BUG_ON(!(*spte & PT_PRESENT_MASK));
668 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
669 rmap_remove(kvm, spte);
670 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
671 need_tlb_flush = 1;
672 }
673 return need_tlb_flush;
674 }
675
676 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
677 int (*handler)(struct kvm *kvm, unsigned long *rmapp))
678 {
679 int i;
680 int retval = 0;
681
682 /*
683 * If mmap_sem isn't taken, we can look the memslots with only
684 * the mmu_lock by skipping over the slots with userspace_addr == 0.
685 */
686 for (i = 0; i < kvm->nmemslots; i++) {
687 struct kvm_memory_slot *memslot = &kvm->memslots[i];
688 unsigned long start = memslot->userspace_addr;
689 unsigned long end;
690
691 /* mmu_lock protects userspace_addr */
692 if (!start)
693 continue;
694
695 end = start + (memslot->npages << PAGE_SHIFT);
696 if (hva >= start && hva < end) {
697 gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
698 retval |= handler(kvm, &memslot->rmap[gfn_offset]);
699 retval |= handler(kvm,
700 &memslot->lpage_info[
701 gfn_offset /
702 KVM_PAGES_PER_HPAGE].rmap_pde);
703 }
704 }
705
706 return retval;
707 }
708
709 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
710 {
711 return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
712 }
713
714 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
715 {
716 u64 *spte;
717 int young = 0;
718
719 /* always return old for EPT */
720 if (!shadow_accessed_mask)
721 return 0;
722
723 spte = rmap_next(kvm, rmapp, NULL);
724 while (spte) {
725 int _young;
726 u64 _spte = *spte;
727 BUG_ON(!(_spte & PT_PRESENT_MASK));
728 _young = _spte & PT_ACCESSED_MASK;
729 if (_young) {
730 young = 1;
731 clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
732 }
733 spte = rmap_next(kvm, rmapp, spte);
734 }
735 return young;
736 }
737
738 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
739 {
740 return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
741 }
742
743 #ifdef MMU_DEBUG
744 static int is_empty_shadow_page(u64 *spt)
745 {
746 u64 *pos;
747 u64 *end;
748
749 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
750 if (is_shadow_present_pte(*pos)) {
751 printk(KERN_ERR "%s: %p %llx\n", __func__,
752 pos, *pos);
753 return 0;
754 }
755 return 1;
756 }
757 #endif
758
759 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
760 {
761 ASSERT(is_empty_shadow_page(sp->spt));
762 list_del(&sp->link);
763 __free_page(virt_to_page(sp->spt));
764 __free_page(virt_to_page(sp->gfns));
765 kfree(sp);
766 ++kvm->arch.n_free_mmu_pages;
767 }
768
769 static unsigned kvm_page_table_hashfn(gfn_t gfn)
770 {
771 return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
772 }
773
774 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
775 u64 *parent_pte)
776 {
777 struct kvm_mmu_page *sp;
778
779 sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
780 sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
781 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
782 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
783 list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
784 ASSERT(is_empty_shadow_page(sp->spt));
785 sp->slot_bitmap = 0;
786 sp->multimapped = 0;
787 sp->parent_pte = parent_pte;
788 --vcpu->kvm->arch.n_free_mmu_pages;
789 return sp;
790 }
791
792 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
793 struct kvm_mmu_page *sp, u64 *parent_pte)
794 {
795 struct kvm_pte_chain *pte_chain;
796 struct hlist_node *node;
797 int i;
798
799 if (!parent_pte)
800 return;
801 if (!sp->multimapped) {
802 u64 *old = sp->parent_pte;
803
804 if (!old) {
805 sp->parent_pte = parent_pte;
806 return;
807 }
808 sp->multimapped = 1;
809 pte_chain = mmu_alloc_pte_chain(vcpu);
810 INIT_HLIST_HEAD(&sp->parent_ptes);
811 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
812 pte_chain->parent_ptes[0] = old;
813 }
814 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
815 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
816 continue;
817 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
818 if (!pte_chain->parent_ptes[i]) {
819 pte_chain->parent_ptes[i] = parent_pte;
820 return;
821 }
822 }
823 pte_chain = mmu_alloc_pte_chain(vcpu);
824 BUG_ON(!pte_chain);
825 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
826 pte_chain->parent_ptes[0] = parent_pte;
827 }
828
829 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
830 u64 *parent_pte)
831 {
832 struct kvm_pte_chain *pte_chain;
833 struct hlist_node *node;
834 int i;
835
836 if (!sp->multimapped) {
837 BUG_ON(sp->parent_pte != parent_pte);
838 sp->parent_pte = NULL;
839 return;
840 }
841 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
842 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
843 if (!pte_chain->parent_ptes[i])
844 break;
845 if (pte_chain->parent_ptes[i] != parent_pte)
846 continue;
847 while (i + 1 < NR_PTE_CHAIN_ENTRIES
848 && pte_chain->parent_ptes[i + 1]) {
849 pte_chain->parent_ptes[i]
850 = pte_chain->parent_ptes[i + 1];
851 ++i;
852 }
853 pte_chain->parent_ptes[i] = NULL;
854 if (i == 0) {
855 hlist_del(&pte_chain->link);
856 mmu_free_pte_chain(pte_chain);
857 if (hlist_empty(&sp->parent_ptes)) {
858 sp->multimapped = 0;
859 sp->parent_pte = NULL;
860 }
861 }
862 return;
863 }
864 BUG();
865 }
866
867
868 static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
869 mmu_parent_walk_fn fn)
870 {
871 struct kvm_pte_chain *pte_chain;
872 struct hlist_node *node;
873 struct kvm_mmu_page *parent_sp;
874 int i;
875
876 if (!sp->multimapped && sp->parent_pte) {
877 parent_sp = page_header(__pa(sp->parent_pte));
878 fn(vcpu, parent_sp);
879 mmu_parent_walk(vcpu, parent_sp, fn);
880 return;
881 }
882 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
883 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
884 if (!pte_chain->parent_ptes[i])
885 break;
886 parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
887 fn(vcpu, parent_sp);
888 mmu_parent_walk(vcpu, parent_sp, fn);
889 }
890 }
891
892 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
893 struct kvm_mmu_page *sp)
894 {
895 int i;
896
897 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
898 sp->spt[i] = shadow_trap_nonpresent_pte;
899 }
900
901 static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
902 struct kvm_mmu_page *sp)
903 {
904 return 1;
905 }
906
907 static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
908 {
909 }
910
911 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
912 {
913 unsigned index;
914 struct hlist_head *bucket;
915 struct kvm_mmu_page *sp;
916 struct hlist_node *node;
917
918 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
919 index = kvm_page_table_hashfn(gfn);
920 bucket = &kvm->arch.mmu_page_hash[index];
921 hlist_for_each_entry(sp, node, bucket, hash_link)
922 if (sp->gfn == gfn && !sp->role.metaphysical
923 && !sp->role.invalid) {
924 pgprintk("%s: found role %x\n",
925 __func__, sp->role.word);
926 return sp;
927 }
928 return NULL;
929 }
930
931 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
932 gfn_t gfn,
933 gva_t gaddr,
934 unsigned level,
935 int metaphysical,
936 unsigned access,
937 u64 *parent_pte)
938 {
939 union kvm_mmu_page_role role;
940 unsigned index;
941 unsigned quadrant;
942 struct hlist_head *bucket;
943 struct kvm_mmu_page *sp;
944 struct hlist_node *node;
945
946 role.word = 0;
947 role.glevels = vcpu->arch.mmu.root_level;
948 role.level = level;
949 role.metaphysical = metaphysical;
950 role.access = access;
951 if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
952 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
953 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
954 role.quadrant = quadrant;
955 }
956 pgprintk("%s: looking gfn %lx role %x\n", __func__,
957 gfn, role.word);
958 index = kvm_page_table_hashfn(gfn);
959 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
960 hlist_for_each_entry(sp, node, bucket, hash_link)
961 if (sp->gfn == gfn && sp->role.word == role.word) {
962 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
963 pgprintk("%s: found\n", __func__);
964 return sp;
965 }
966 ++vcpu->kvm->stat.mmu_cache_miss;
967 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
968 if (!sp)
969 return sp;
970 pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
971 sp->gfn = gfn;
972 sp->role = role;
973 hlist_add_head(&sp->hash_link, bucket);
974 if (!metaphysical)
975 rmap_write_protect(vcpu->kvm, gfn);
976 if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
977 vcpu->arch.mmu.prefetch_page(vcpu, sp);
978 else
979 nonpaging_prefetch_page(vcpu, sp);
980 return sp;
981 }
982
983 static int walk_shadow(struct kvm_shadow_walk *walker,
984 struct kvm_vcpu *vcpu, u64 addr)
985 {
986 hpa_t shadow_addr;
987 int level;
988 int r;
989 u64 *sptep;
990 unsigned index;
991
992 shadow_addr = vcpu->arch.mmu.root_hpa;
993 level = vcpu->arch.mmu.shadow_root_level;
994 if (level == PT32E_ROOT_LEVEL) {
995 shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
996 shadow_addr &= PT64_BASE_ADDR_MASK;
997 --level;
998 }
999
1000 while (level >= PT_PAGE_TABLE_LEVEL) {
1001 index = SHADOW_PT_INDEX(addr, level);
1002 sptep = ((u64 *)__va(shadow_addr)) + index;
1003 r = walker->entry(walker, vcpu, addr, sptep, level);
1004 if (r)
1005 return r;
1006 shadow_addr = *sptep & PT64_BASE_ADDR_MASK;
1007 --level;
1008 }
1009 return 0;
1010 }
1011
1012 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1013 struct kvm_mmu_page *sp)
1014 {
1015 unsigned i;
1016 u64 *pt;
1017 u64 ent;
1018
1019 pt = sp->spt;
1020
1021 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1022 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1023 if (is_shadow_present_pte(pt[i]))
1024 rmap_remove(kvm, &pt[i]);
1025 pt[i] = shadow_trap_nonpresent_pte;
1026 }
1027 return;
1028 }
1029
1030 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1031 ent = pt[i];
1032
1033 if (is_shadow_present_pte(ent)) {
1034 if (!is_large_pte(ent)) {
1035 ent &= PT64_BASE_ADDR_MASK;
1036 mmu_page_remove_parent_pte(page_header(ent),
1037 &pt[i]);
1038 } else {
1039 --kvm->stat.lpages;
1040 rmap_remove(kvm, &pt[i]);
1041 }
1042 }
1043 pt[i] = shadow_trap_nonpresent_pte;
1044 }
1045 }
1046
1047 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1048 {
1049 mmu_page_remove_parent_pte(sp, parent_pte);
1050 }
1051
1052 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1053 {
1054 int i;
1055
1056 for (i = 0; i < KVM_MAX_VCPUS; ++i)
1057 if (kvm->vcpus[i])
1058 kvm->vcpus[i]->arch.last_pte_updated = NULL;
1059 }
1060
1061 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1062 {
1063 u64 *parent_pte;
1064
1065 while (sp->multimapped || sp->parent_pte) {
1066 if (!sp->multimapped)
1067 parent_pte = sp->parent_pte;
1068 else {
1069 struct kvm_pte_chain *chain;
1070
1071 chain = container_of(sp->parent_ptes.first,
1072 struct kvm_pte_chain, link);
1073 parent_pte = chain->parent_ptes[0];
1074 }
1075 BUG_ON(!parent_pte);
1076 kvm_mmu_put_page(sp, parent_pte);
1077 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
1078 }
1079 }
1080
1081 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1082 {
1083 ++kvm->stat.mmu_shadow_zapped;
1084 kvm_mmu_page_unlink_children(kvm, sp);
1085 kvm_mmu_unlink_parents(kvm, sp);
1086 kvm_flush_remote_tlbs(kvm);
1087 if (!sp->role.invalid && !sp->role.metaphysical)
1088 unaccount_shadowed(kvm, sp->gfn);
1089 if (!sp->root_count) {
1090 hlist_del(&sp->hash_link);
1091 kvm_mmu_free_page(kvm, sp);
1092 } else {
1093 sp->role.invalid = 1;
1094 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1095 kvm_reload_remote_mmus(kvm);
1096 }
1097 kvm_mmu_reset_last_pte_updated(kvm);
1098 return 0;
1099 }
1100
1101 /*
1102 * Changing the number of mmu pages allocated to the vm
1103 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1104 */
1105 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1106 {
1107 /*
1108 * If we set the number of mmu pages to be smaller be than the
1109 * number of actived pages , we must to free some mmu pages before we
1110 * change the value
1111 */
1112
1113 if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
1114 kvm_nr_mmu_pages) {
1115 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
1116 - kvm->arch.n_free_mmu_pages;
1117
1118 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
1119 struct kvm_mmu_page *page;
1120
1121 page = container_of(kvm->arch.active_mmu_pages.prev,
1122 struct kvm_mmu_page, link);
1123 kvm_mmu_zap_page(kvm, page);
1124 n_used_mmu_pages--;
1125 }
1126 kvm->arch.n_free_mmu_pages = 0;
1127 }
1128 else
1129 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1130 - kvm->arch.n_alloc_mmu_pages;
1131
1132 kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1133 }
1134
1135 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1136 {
1137 unsigned index;
1138 struct hlist_head *bucket;
1139 struct kvm_mmu_page *sp;
1140 struct hlist_node *node, *n;
1141 int r;
1142
1143 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1144 r = 0;
1145 index = kvm_page_table_hashfn(gfn);
1146 bucket = &kvm->arch.mmu_page_hash[index];
1147 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1148 if (sp->gfn == gfn && !sp->role.metaphysical) {
1149 pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1150 sp->role.word);
1151 r = 1;
1152 if (kvm_mmu_zap_page(kvm, sp))
1153 n = bucket->first;
1154 }
1155 return r;
1156 }
1157
1158 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1159 {
1160 struct kvm_mmu_page *sp;
1161
1162 while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
1163 pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
1164 kvm_mmu_zap_page(kvm, sp);
1165 }
1166 }
1167
1168 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1169 {
1170 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1171 struct kvm_mmu_page *sp = page_header(__pa(pte));
1172
1173 __set_bit(slot, &sp->slot_bitmap);
1174 }
1175
1176 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
1177 {
1178 int i;
1179 u64 *pt = sp->spt;
1180
1181 if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
1182 return;
1183
1184 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1185 if (pt[i] == shadow_notrap_nonpresent_pte)
1186 set_shadow_pte(&pt[i], shadow_trap_nonpresent_pte);
1187 }
1188 }
1189
1190 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1191 {
1192 struct page *page;
1193
1194 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1195
1196 if (gpa == UNMAPPED_GVA)
1197 return NULL;
1198
1199 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1200
1201 return page;
1202 }
1203
1204 static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1205 unsigned pte_access, int user_fault,
1206 int write_fault, int dirty, int largepage,
1207 gfn_t gfn, pfn_t pfn, bool speculative)
1208 {
1209 u64 spte;
1210 int ret = 0;
1211 /*
1212 * We don't set the accessed bit, since we sometimes want to see
1213 * whether the guest actually used the pte (in order to detect
1214 * demand paging).
1215 */
1216 spte = shadow_base_present_pte | shadow_dirty_mask;
1217 if (!speculative)
1218 spte |= shadow_accessed_mask;
1219 if (!dirty)
1220 pte_access &= ~ACC_WRITE_MASK;
1221 if (pte_access & ACC_EXEC_MASK)
1222 spte |= shadow_x_mask;
1223 else
1224 spte |= shadow_nx_mask;
1225 if (pte_access & ACC_USER_MASK)
1226 spte |= shadow_user_mask;
1227 if (largepage)
1228 spte |= PT_PAGE_SIZE_MASK;
1229
1230 spte |= (u64)pfn << PAGE_SHIFT;
1231
1232 if ((pte_access & ACC_WRITE_MASK)
1233 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1234 struct kvm_mmu_page *shadow;
1235
1236 if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) {
1237 ret = 1;
1238 spte = shadow_trap_nonpresent_pte;
1239 goto set_pte;
1240 }
1241
1242 spte |= PT_WRITABLE_MASK;
1243
1244 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1245 if (shadow) {
1246 pgprintk("%s: found shadow page for %lx, marking ro\n",
1247 __func__, gfn);
1248 ret = 1;
1249 pte_access &= ~ACC_WRITE_MASK;
1250 if (is_writeble_pte(spte))
1251 spte &= ~PT_WRITABLE_MASK;
1252 }
1253 }
1254
1255 if (pte_access & ACC_WRITE_MASK)
1256 mark_page_dirty(vcpu->kvm, gfn);
1257
1258 set_pte:
1259 set_shadow_pte(shadow_pte, spte);
1260 return ret;
1261 }
1262
1263
1264 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1265 unsigned pt_access, unsigned pte_access,
1266 int user_fault, int write_fault, int dirty,
1267 int *ptwrite, int largepage, gfn_t gfn,
1268 pfn_t pfn, bool speculative)
1269 {
1270 int was_rmapped = 0;
1271 int was_writeble = is_writeble_pte(*shadow_pte);
1272
1273 pgprintk("%s: spte %llx access %x write_fault %d"
1274 " user_fault %d gfn %lx\n",
1275 __func__, *shadow_pte, pt_access,
1276 write_fault, user_fault, gfn);
1277
1278 if (is_rmap_pte(*shadow_pte)) {
1279 /*
1280 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1281 * the parent of the now unreachable PTE.
1282 */
1283 if (largepage && !is_large_pte(*shadow_pte)) {
1284 struct kvm_mmu_page *child;
1285 u64 pte = *shadow_pte;
1286
1287 child = page_header(pte & PT64_BASE_ADDR_MASK);
1288 mmu_page_remove_parent_pte(child, shadow_pte);
1289 } else if (pfn != spte_to_pfn(*shadow_pte)) {
1290 pgprintk("hfn old %lx new %lx\n",
1291 spte_to_pfn(*shadow_pte), pfn);
1292 rmap_remove(vcpu->kvm, shadow_pte);
1293 } else {
1294 if (largepage)
1295 was_rmapped = is_large_pte(*shadow_pte);
1296 else
1297 was_rmapped = 1;
1298 }
1299 }
1300 if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
1301 dirty, largepage, gfn, pfn, speculative)) {
1302 if (write_fault)
1303 *ptwrite = 1;
1304 kvm_x86_ops->tlb_flush(vcpu);
1305 }
1306
1307 pgprintk("%s: setting spte %llx\n", __func__, *shadow_pte);
1308 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1309 is_large_pte(*shadow_pte)? "2MB" : "4kB",
1310 is_present_pte(*shadow_pte)?"RW":"R", gfn,
1311 *shadow_pte, shadow_pte);
1312 if (!was_rmapped && is_large_pte(*shadow_pte))
1313 ++vcpu->kvm->stat.lpages;
1314
1315 page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
1316 if (!was_rmapped) {
1317 rmap_add(vcpu, shadow_pte, gfn, largepage);
1318 if (!is_rmap_pte(*shadow_pte))
1319 kvm_release_pfn_clean(pfn);
1320 } else {
1321 if (was_writeble)
1322 kvm_release_pfn_dirty(pfn);
1323 else
1324 kvm_release_pfn_clean(pfn);
1325 }
1326 if (speculative) {
1327 vcpu->arch.last_pte_updated = shadow_pte;
1328 vcpu->arch.last_pte_gfn = gfn;
1329 }
1330 }
1331
1332 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1333 {
1334 }
1335
1336 struct direct_shadow_walk {
1337 struct kvm_shadow_walk walker;
1338 pfn_t pfn;
1339 int write;
1340 int largepage;
1341 int pt_write;
1342 };
1343
1344 static int direct_map_entry(struct kvm_shadow_walk *_walk,
1345 struct kvm_vcpu *vcpu,
1346 u64 addr, u64 *sptep, int level)
1347 {
1348 struct direct_shadow_walk *walk =
1349 container_of(_walk, struct direct_shadow_walk, walker);
1350 struct kvm_mmu_page *sp;
1351 gfn_t pseudo_gfn;
1352 gfn_t gfn = addr >> PAGE_SHIFT;
1353
1354 if (level == PT_PAGE_TABLE_LEVEL
1355 || (walk->largepage && level == PT_DIRECTORY_LEVEL)) {
1356 mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL,
1357 0, walk->write, 1, &walk->pt_write,
1358 walk->largepage, gfn, walk->pfn, false);
1359 ++vcpu->stat.pf_fixed;
1360 return 1;
1361 }
1362
1363 if (*sptep == shadow_trap_nonpresent_pte) {
1364 pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1365 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1,
1366 1, ACC_ALL, sptep);
1367 if (!sp) {
1368 pgprintk("nonpaging_map: ENOMEM\n");
1369 kvm_release_pfn_clean(walk->pfn);
1370 return -ENOMEM;
1371 }
1372
1373 set_shadow_pte(sptep,
1374 __pa(sp->spt)
1375 | PT_PRESENT_MASK | PT_WRITABLE_MASK
1376 | shadow_user_mask | shadow_x_mask);
1377 }
1378 return 0;
1379 }
1380
1381 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1382 int largepage, gfn_t gfn, pfn_t pfn)
1383 {
1384 int r;
1385 struct direct_shadow_walk walker = {
1386 .walker = { .entry = direct_map_entry, },
1387 .pfn = pfn,
1388 .largepage = largepage,
1389 .write = write,
1390 .pt_write = 0,
1391 };
1392
1393 r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT);
1394 if (r < 0)
1395 return r;
1396 return walker.pt_write;
1397 }
1398
1399 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1400 {
1401 int r;
1402 int largepage = 0;
1403 pfn_t pfn;
1404 unsigned long mmu_seq;
1405
1406 if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1407 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1408 largepage = 1;
1409 }
1410
1411 mmu_seq = vcpu->kvm->mmu_notifier_seq;
1412 smp_rmb();
1413 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1414
1415 /* mmio */
1416 if (is_error_pfn(pfn)) {
1417 kvm_release_pfn_clean(pfn);
1418 return 1;
1419 }
1420
1421 spin_lock(&vcpu->kvm->mmu_lock);
1422 if (mmu_notifier_retry(vcpu, mmu_seq))
1423 goto out_unlock;
1424 kvm_mmu_free_some_pages(vcpu);
1425 r = __direct_map(vcpu, v, write, largepage, gfn, pfn);
1426 spin_unlock(&vcpu->kvm->mmu_lock);
1427
1428
1429 return r;
1430
1431 out_unlock:
1432 spin_unlock(&vcpu->kvm->mmu_lock);
1433 kvm_release_pfn_clean(pfn);
1434 return 0;
1435 }
1436
1437
1438 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1439 {
1440 int i;
1441 struct kvm_mmu_page *sp;
1442
1443 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1444 return;
1445 spin_lock(&vcpu->kvm->mmu_lock);
1446 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1447 hpa_t root = vcpu->arch.mmu.root_hpa;
1448
1449 sp = page_header(root);
1450 --sp->root_count;
1451 if (!sp->root_count && sp->role.invalid)
1452 kvm_mmu_zap_page(vcpu->kvm, sp);
1453 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1454 spin_unlock(&vcpu->kvm->mmu_lock);
1455 return;
1456 }
1457 for (i = 0; i < 4; ++i) {
1458 hpa_t root = vcpu->arch.mmu.pae_root[i];
1459
1460 if (root) {
1461 root &= PT64_BASE_ADDR_MASK;
1462 sp = page_header(root);
1463 --sp->root_count;
1464 if (!sp->root_count && sp->role.invalid)
1465 kvm_mmu_zap_page(vcpu->kvm, sp);
1466 }
1467 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1468 }
1469 spin_unlock(&vcpu->kvm->mmu_lock);
1470 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1471 }
1472
1473 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1474 {
1475 int i;
1476 gfn_t root_gfn;
1477 struct kvm_mmu_page *sp;
1478 int metaphysical = 0;
1479
1480 root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1481
1482 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1483 hpa_t root = vcpu->arch.mmu.root_hpa;
1484
1485 ASSERT(!VALID_PAGE(root));
1486 if (tdp_enabled)
1487 metaphysical = 1;
1488 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1489 PT64_ROOT_LEVEL, metaphysical,
1490 ACC_ALL, NULL);
1491 root = __pa(sp->spt);
1492 ++sp->root_count;
1493 vcpu->arch.mmu.root_hpa = root;
1494 return;
1495 }
1496 metaphysical = !is_paging(vcpu);
1497 if (tdp_enabled)
1498 metaphysical = 1;
1499 for (i = 0; i < 4; ++i) {
1500 hpa_t root = vcpu->arch.mmu.pae_root[i];
1501
1502 ASSERT(!VALID_PAGE(root));
1503 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1504 if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1505 vcpu->arch.mmu.pae_root[i] = 0;
1506 continue;
1507 }
1508 root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1509 } else if (vcpu->arch.mmu.root_level == 0)
1510 root_gfn = 0;
1511 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1512 PT32_ROOT_LEVEL, metaphysical,
1513 ACC_ALL, NULL);
1514 root = __pa(sp->spt);
1515 ++sp->root_count;
1516 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1517 }
1518 vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1519 }
1520
1521 static void mmu_sync_children(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1522 {
1523 }
1524
1525 static void mmu_sync_roots(struct kvm_vcpu *vcpu)
1526 {
1527 int i;
1528 struct kvm_mmu_page *sp;
1529
1530 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1531 return;
1532 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1533 hpa_t root = vcpu->arch.mmu.root_hpa;
1534 sp = page_header(root);
1535 mmu_sync_children(vcpu, sp);
1536 return;
1537 }
1538 for (i = 0; i < 4; ++i) {
1539 hpa_t root = vcpu->arch.mmu.pae_root[i];
1540
1541 if (root) {
1542 root &= PT64_BASE_ADDR_MASK;
1543 sp = page_header(root);
1544 mmu_sync_children(vcpu, sp);
1545 }
1546 }
1547 }
1548
1549 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
1550 {
1551 spin_lock(&vcpu->kvm->mmu_lock);
1552 mmu_sync_roots(vcpu);
1553 spin_unlock(&vcpu->kvm->mmu_lock);
1554 }
1555
1556 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1557 {
1558 return vaddr;
1559 }
1560
1561 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1562 u32 error_code)
1563 {
1564 gfn_t gfn;
1565 int r;
1566
1567 pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
1568 r = mmu_topup_memory_caches(vcpu);
1569 if (r)
1570 return r;
1571
1572 ASSERT(vcpu);
1573 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1574
1575 gfn = gva >> PAGE_SHIFT;
1576
1577 return nonpaging_map(vcpu, gva & PAGE_MASK,
1578 error_code & PFERR_WRITE_MASK, gfn);
1579 }
1580
1581 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
1582 u32 error_code)
1583 {
1584 pfn_t pfn;
1585 int r;
1586 int largepage = 0;
1587 gfn_t gfn = gpa >> PAGE_SHIFT;
1588 unsigned long mmu_seq;
1589
1590 ASSERT(vcpu);
1591 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1592
1593 r = mmu_topup_memory_caches(vcpu);
1594 if (r)
1595 return r;
1596
1597 if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1598 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1599 largepage = 1;
1600 }
1601 mmu_seq = vcpu->kvm->mmu_notifier_seq;
1602 smp_rmb();
1603 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1604 if (is_error_pfn(pfn)) {
1605 kvm_release_pfn_clean(pfn);
1606 return 1;
1607 }
1608 spin_lock(&vcpu->kvm->mmu_lock);
1609 if (mmu_notifier_retry(vcpu, mmu_seq))
1610 goto out_unlock;
1611 kvm_mmu_free_some_pages(vcpu);
1612 r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
1613 largepage, gfn, pfn);
1614 spin_unlock(&vcpu->kvm->mmu_lock);
1615
1616 return r;
1617
1618 out_unlock:
1619 spin_unlock(&vcpu->kvm->mmu_lock);
1620 kvm_release_pfn_clean(pfn);
1621 return 0;
1622 }
1623
1624 static void nonpaging_free(struct kvm_vcpu *vcpu)
1625 {
1626 mmu_free_roots(vcpu);
1627 }
1628
1629 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1630 {
1631 struct kvm_mmu *context = &vcpu->arch.mmu;
1632
1633 context->new_cr3 = nonpaging_new_cr3;
1634 context->page_fault = nonpaging_page_fault;
1635 context->gva_to_gpa = nonpaging_gva_to_gpa;
1636 context->free = nonpaging_free;
1637 context->prefetch_page = nonpaging_prefetch_page;
1638 context->sync_page = nonpaging_sync_page;
1639 context->invlpg = nonpaging_invlpg;
1640 context->root_level = 0;
1641 context->shadow_root_level = PT32E_ROOT_LEVEL;
1642 context->root_hpa = INVALID_PAGE;
1643 return 0;
1644 }
1645
1646 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1647 {
1648 ++vcpu->stat.tlb_flush;
1649 kvm_x86_ops->tlb_flush(vcpu);
1650 }
1651
1652 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1653 {
1654 pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
1655 mmu_free_roots(vcpu);
1656 }
1657
1658 static void inject_page_fault(struct kvm_vcpu *vcpu,
1659 u64 addr,
1660 u32 err_code)
1661 {
1662 kvm_inject_page_fault(vcpu, addr, err_code);
1663 }
1664
1665 static void paging_free(struct kvm_vcpu *vcpu)
1666 {
1667 nonpaging_free(vcpu);
1668 }
1669
1670 #define PTTYPE 64
1671 #include "paging_tmpl.h"
1672 #undef PTTYPE
1673
1674 #define PTTYPE 32
1675 #include "paging_tmpl.h"
1676 #undef PTTYPE
1677
1678 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1679 {
1680 struct kvm_mmu *context = &vcpu->arch.mmu;
1681
1682 ASSERT(is_pae(vcpu));
1683 context->new_cr3 = paging_new_cr3;
1684 context->page_fault = paging64_page_fault;
1685 context->gva_to_gpa = paging64_gva_to_gpa;
1686 context->prefetch_page = paging64_prefetch_page;
1687 context->sync_page = paging64_sync_page;
1688 context->invlpg = paging64_invlpg;
1689 context->free = paging_free;
1690 context->root_level = level;
1691 context->shadow_root_level = level;
1692 context->root_hpa = INVALID_PAGE;
1693 return 0;
1694 }
1695
1696 static int paging64_init_context(struct kvm_vcpu *vcpu)
1697 {
1698 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1699 }
1700
1701 static int paging32_init_context(struct kvm_vcpu *vcpu)
1702 {
1703 struct kvm_mmu *context = &vcpu->arch.mmu;
1704
1705 context->new_cr3 = paging_new_cr3;
1706 context->page_fault = paging32_page_fault;
1707 context->gva_to_gpa = paging32_gva_to_gpa;
1708 context->free = paging_free;
1709 context->prefetch_page = paging32_prefetch_page;
1710 context->sync_page = paging32_sync_page;
1711 context->invlpg = paging32_invlpg;
1712 context->root_level = PT32_ROOT_LEVEL;
1713 context->shadow_root_level = PT32E_ROOT_LEVEL;
1714 context->root_hpa = INVALID_PAGE;
1715 return 0;
1716 }
1717
1718 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1719 {
1720 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1721 }
1722
1723 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
1724 {
1725 struct kvm_mmu *context = &vcpu->arch.mmu;
1726
1727 context->new_cr3 = nonpaging_new_cr3;
1728 context->page_fault = tdp_page_fault;
1729 context->free = nonpaging_free;
1730 context->prefetch_page = nonpaging_prefetch_page;
1731 context->sync_page = nonpaging_sync_page;
1732 context->invlpg = nonpaging_invlpg;
1733 context->shadow_root_level = kvm_x86_ops->get_tdp_level();
1734 context->root_hpa = INVALID_PAGE;
1735
1736 if (!is_paging(vcpu)) {
1737 context->gva_to_gpa = nonpaging_gva_to_gpa;
1738 context->root_level = 0;
1739 } else if (is_long_mode(vcpu)) {
1740 context->gva_to_gpa = paging64_gva_to_gpa;
1741 context->root_level = PT64_ROOT_LEVEL;
1742 } else if (is_pae(vcpu)) {
1743 context->gva_to_gpa = paging64_gva_to_gpa;
1744 context->root_level = PT32E_ROOT_LEVEL;
1745 } else {
1746 context->gva_to_gpa = paging32_gva_to_gpa;
1747 context->root_level = PT32_ROOT_LEVEL;
1748 }
1749
1750 return 0;
1751 }
1752
1753 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
1754 {
1755 ASSERT(vcpu);
1756 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1757
1758 if (!is_paging(vcpu))
1759 return nonpaging_init_context(vcpu);
1760 else if (is_long_mode(vcpu))
1761 return paging64_init_context(vcpu);
1762 else if (is_pae(vcpu))
1763 return paging32E_init_context(vcpu);
1764 else
1765 return paging32_init_context(vcpu);
1766 }
1767
1768 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1769 {
1770 vcpu->arch.update_pte.pfn = bad_pfn;
1771
1772 if (tdp_enabled)
1773 return init_kvm_tdp_mmu(vcpu);
1774 else
1775 return init_kvm_softmmu(vcpu);
1776 }
1777
1778 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1779 {
1780 ASSERT(vcpu);
1781 if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1782 vcpu->arch.mmu.free(vcpu);
1783 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1784 }
1785 }
1786
1787 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1788 {
1789 destroy_kvm_mmu(vcpu);
1790 return init_kvm_mmu(vcpu);
1791 }
1792 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1793
1794 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1795 {
1796 int r;
1797
1798 r = mmu_topup_memory_caches(vcpu);
1799 if (r)
1800 goto out;
1801 spin_lock(&vcpu->kvm->mmu_lock);
1802 kvm_mmu_free_some_pages(vcpu);
1803 mmu_alloc_roots(vcpu);
1804 mmu_sync_roots(vcpu);
1805 spin_unlock(&vcpu->kvm->mmu_lock);
1806 kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1807 kvm_mmu_flush_tlb(vcpu);
1808 out:
1809 return r;
1810 }
1811 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1812
1813 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1814 {
1815 mmu_free_roots(vcpu);
1816 }
1817
1818 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1819 struct kvm_mmu_page *sp,
1820 u64 *spte)
1821 {
1822 u64 pte;
1823 struct kvm_mmu_page *child;
1824
1825 pte = *spte;
1826 if (is_shadow_present_pte(pte)) {
1827 if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
1828 is_large_pte(pte))
1829 rmap_remove(vcpu->kvm, spte);
1830 else {
1831 child = page_header(pte & PT64_BASE_ADDR_MASK);
1832 mmu_page_remove_parent_pte(child, spte);
1833 }
1834 }
1835 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1836 if (is_large_pte(pte))
1837 --vcpu->kvm->stat.lpages;
1838 }
1839
1840 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1841 struct kvm_mmu_page *sp,
1842 u64 *spte,
1843 const void *new)
1844 {
1845 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1846 if (!vcpu->arch.update_pte.largepage ||
1847 sp->role.glevels == PT32_ROOT_LEVEL) {
1848 ++vcpu->kvm->stat.mmu_pde_zapped;
1849 return;
1850 }
1851 }
1852
1853 ++vcpu->kvm->stat.mmu_pte_updated;
1854 if (sp->role.glevels == PT32_ROOT_LEVEL)
1855 paging32_update_pte(vcpu, sp, spte, new);
1856 else
1857 paging64_update_pte(vcpu, sp, spte, new);
1858 }
1859
1860 static bool need_remote_flush(u64 old, u64 new)
1861 {
1862 if (!is_shadow_present_pte(old))
1863 return false;
1864 if (!is_shadow_present_pte(new))
1865 return true;
1866 if ((old ^ new) & PT64_BASE_ADDR_MASK)
1867 return true;
1868 old ^= PT64_NX_MASK;
1869 new ^= PT64_NX_MASK;
1870 return (old & ~new & PT64_PERM_MASK) != 0;
1871 }
1872
1873 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1874 {
1875 if (need_remote_flush(old, new))
1876 kvm_flush_remote_tlbs(vcpu->kvm);
1877 else
1878 kvm_mmu_flush_tlb(vcpu);
1879 }
1880
1881 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1882 {
1883 u64 *spte = vcpu->arch.last_pte_updated;
1884
1885 return !!(spte && (*spte & shadow_accessed_mask));
1886 }
1887
1888 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1889 const u8 *new, int bytes)
1890 {
1891 gfn_t gfn;
1892 int r;
1893 u64 gpte = 0;
1894 pfn_t pfn;
1895
1896 vcpu->arch.update_pte.largepage = 0;
1897
1898 if (bytes != 4 && bytes != 8)
1899 return;
1900
1901 /*
1902 * Assume that the pte write on a page table of the same type
1903 * as the current vcpu paging mode. This is nearly always true
1904 * (might be false while changing modes). Note it is verified later
1905 * by update_pte().
1906 */
1907 if (is_pae(vcpu)) {
1908 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1909 if ((bytes == 4) && (gpa % 4 == 0)) {
1910 r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1911 if (r)
1912 return;
1913 memcpy((void *)&gpte + (gpa % 8), new, 4);
1914 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1915 memcpy((void *)&gpte, new, 8);
1916 }
1917 } else {
1918 if ((bytes == 4) && (gpa % 4 == 0))
1919 memcpy((void *)&gpte, new, 4);
1920 }
1921 if (!is_present_pte(gpte))
1922 return;
1923 gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1924
1925 if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
1926 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1927 vcpu->arch.update_pte.largepage = 1;
1928 }
1929 vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
1930 smp_rmb();
1931 pfn = gfn_to_pfn(vcpu->kvm, gfn);
1932
1933 if (is_error_pfn(pfn)) {
1934 kvm_release_pfn_clean(pfn);
1935 return;
1936 }
1937 vcpu->arch.update_pte.gfn = gfn;
1938 vcpu->arch.update_pte.pfn = pfn;
1939 }
1940
1941 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1942 {
1943 u64 *spte = vcpu->arch.last_pte_updated;
1944
1945 if (spte
1946 && vcpu->arch.last_pte_gfn == gfn
1947 && shadow_accessed_mask
1948 && !(*spte & shadow_accessed_mask)
1949 && is_shadow_present_pte(*spte))
1950 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
1951 }
1952
1953 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1954 const u8 *new, int bytes)
1955 {
1956 gfn_t gfn = gpa >> PAGE_SHIFT;
1957 struct kvm_mmu_page *sp;
1958 struct hlist_node *node, *n;
1959 struct hlist_head *bucket;
1960 unsigned index;
1961 u64 entry, gentry;
1962 u64 *spte;
1963 unsigned offset = offset_in_page(gpa);
1964 unsigned pte_size;
1965 unsigned page_offset;
1966 unsigned misaligned;
1967 unsigned quadrant;
1968 int level;
1969 int flooded = 0;
1970 int npte;
1971 int r;
1972
1973 pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
1974 mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1975 spin_lock(&vcpu->kvm->mmu_lock);
1976 kvm_mmu_access_page(vcpu, gfn);
1977 kvm_mmu_free_some_pages(vcpu);
1978 ++vcpu->kvm->stat.mmu_pte_write;
1979 kvm_mmu_audit(vcpu, "pre pte write");
1980 if (gfn == vcpu->arch.last_pt_write_gfn
1981 && !last_updated_pte_accessed(vcpu)) {
1982 ++vcpu->arch.last_pt_write_count;
1983 if (vcpu->arch.last_pt_write_count >= 3)
1984 flooded = 1;
1985 } else {
1986 vcpu->arch.last_pt_write_gfn = gfn;
1987 vcpu->arch.last_pt_write_count = 1;
1988 vcpu->arch.last_pte_updated = NULL;
1989 }
1990 index = kvm_page_table_hashfn(gfn);
1991 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1992 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1993 if (sp->gfn != gfn || sp->role.metaphysical || sp->role.invalid)
1994 continue;
1995 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1996 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1997 misaligned |= bytes < 4;
1998 if (misaligned || flooded) {
1999 /*
2000 * Misaligned accesses are too much trouble to fix
2001 * up; also, they usually indicate a page is not used
2002 * as a page table.
2003 *
2004 * If we're seeing too many writes to a page,
2005 * it may no longer be a page table, or we may be
2006 * forking, in which case it is better to unmap the
2007 * page.
2008 */
2009 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2010 gpa, bytes, sp->role.word);
2011 if (kvm_mmu_zap_page(vcpu->kvm, sp))
2012 n = bucket->first;
2013 ++vcpu->kvm->stat.mmu_flooded;
2014 continue;
2015 }
2016 page_offset = offset;
2017 level = sp->role.level;
2018 npte = 1;
2019 if (sp->role.glevels == PT32_ROOT_LEVEL) {
2020 page_offset <<= 1; /* 32->64 */
2021 /*
2022 * A 32-bit pde maps 4MB while the shadow pdes map
2023 * only 2MB. So we need to double the offset again
2024 * and zap two pdes instead of one.
2025 */
2026 if (level == PT32_ROOT_LEVEL) {
2027 page_offset &= ~7; /* kill rounding error */
2028 page_offset <<= 1;
2029 npte = 2;
2030 }
2031 quadrant = page_offset >> PAGE_SHIFT;
2032 page_offset &= ~PAGE_MASK;
2033 if (quadrant != sp->role.quadrant)
2034 continue;
2035 }
2036 spte = &sp->spt[page_offset / sizeof(*spte)];
2037 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
2038 gentry = 0;
2039 r = kvm_read_guest_atomic(vcpu->kvm,
2040 gpa & ~(u64)(pte_size - 1),
2041 &gentry, pte_size);
2042 new = (const void *)&gentry;
2043 if (r < 0)
2044 new = NULL;
2045 }
2046 while (npte--) {
2047 entry = *spte;
2048 mmu_pte_write_zap_pte(vcpu, sp, spte);
2049 if (new)
2050 mmu_pte_write_new_pte(vcpu, sp, spte, new);
2051 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
2052 ++spte;
2053 }
2054 }
2055 kvm_mmu_audit(vcpu, "post pte write");
2056 spin_unlock(&vcpu->kvm->mmu_lock);
2057 if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2058 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2059 vcpu->arch.update_pte.pfn = bad_pfn;
2060 }
2061 }
2062
2063 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2064 {
2065 gpa_t gpa;
2066 int r;
2067
2068 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
2069
2070 spin_lock(&vcpu->kvm->mmu_lock);
2071 r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2072 spin_unlock(&vcpu->kvm->mmu_lock);
2073 return r;
2074 }
2075 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2076
2077 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2078 {
2079 while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
2080 struct kvm_mmu_page *sp;
2081
2082 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2083 struct kvm_mmu_page, link);
2084 kvm_mmu_zap_page(vcpu->kvm, sp);
2085 ++vcpu->kvm->stat.mmu_recycled;
2086 }
2087 }
2088
2089 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2090 {
2091 int r;
2092 enum emulation_result er;
2093
2094 r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2095 if (r < 0)
2096 goto out;
2097
2098 if (!r) {
2099 r = 1;
2100 goto out;
2101 }
2102
2103 r = mmu_topup_memory_caches(vcpu);
2104 if (r)
2105 goto out;
2106
2107 er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
2108
2109 switch (er) {
2110 case EMULATE_DONE:
2111 return 1;
2112 case EMULATE_DO_MMIO:
2113 ++vcpu->stat.mmio_exits;
2114 return 0;
2115 case EMULATE_FAIL:
2116 kvm_report_emulation_failure(vcpu, "pagetable");
2117 return 1;
2118 default:
2119 BUG();
2120 }
2121 out:
2122 return r;
2123 }
2124 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2125
2126 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2127 {
2128 spin_lock(&vcpu->kvm->mmu_lock);
2129 vcpu->arch.mmu.invlpg(vcpu, gva);
2130 spin_unlock(&vcpu->kvm->mmu_lock);
2131 kvm_mmu_flush_tlb(vcpu);
2132 ++vcpu->stat.invlpg;
2133 }
2134 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2135
2136 void kvm_enable_tdp(void)
2137 {
2138 tdp_enabled = true;
2139 }
2140 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2141
2142 void kvm_disable_tdp(void)
2143 {
2144 tdp_enabled = false;
2145 }
2146 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2147
2148 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2149 {
2150 struct kvm_mmu_page *sp;
2151
2152 while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2153 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
2154 struct kvm_mmu_page, link);
2155 kvm_mmu_zap_page(vcpu->kvm, sp);
2156 cond_resched();
2157 }
2158 free_page((unsigned long)vcpu->arch.mmu.pae_root);
2159 }
2160
2161 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2162 {
2163 struct page *page;
2164 int i;
2165
2166 ASSERT(vcpu);
2167
2168 if (vcpu->kvm->arch.n_requested_mmu_pages)
2169 vcpu->kvm->arch.n_free_mmu_pages =
2170 vcpu->kvm->arch.n_requested_mmu_pages;
2171 else
2172 vcpu->kvm->arch.n_free_mmu_pages =
2173 vcpu->kvm->arch.n_alloc_mmu_pages;
2174 /*
2175 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2176 * Therefore we need to allocate shadow page tables in the first
2177 * 4GB of memory, which happens to fit the DMA32 zone.
2178 */
2179 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2180 if (!page)
2181 goto error_1;
2182 vcpu->arch.mmu.pae_root = page_address(page);
2183 for (i = 0; i < 4; ++i)
2184 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2185
2186 return 0;
2187
2188 error_1:
2189 free_mmu_pages(vcpu);
2190 return -ENOMEM;
2191 }
2192
2193 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2194 {
2195 ASSERT(vcpu);
2196 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2197
2198 return alloc_mmu_pages(vcpu);
2199 }
2200
2201 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2202 {
2203 ASSERT(vcpu);
2204 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2205
2206 return init_kvm_mmu(vcpu);
2207 }
2208
2209 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2210 {
2211 ASSERT(vcpu);
2212
2213 destroy_kvm_mmu(vcpu);
2214 free_mmu_pages(vcpu);
2215 mmu_free_memory_caches(vcpu);
2216 }
2217
2218 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2219 {
2220 struct kvm_mmu_page *sp;
2221
2222 spin_lock(&kvm->mmu_lock);
2223 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2224 int i;
2225 u64 *pt;
2226
2227 if (!test_bit(slot, &sp->slot_bitmap))
2228 continue;
2229
2230 pt = sp->spt;
2231 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2232 /* avoid RMW */
2233 if (pt[i] & PT_WRITABLE_MASK)
2234 pt[i] &= ~PT_WRITABLE_MASK;
2235 }
2236 kvm_flush_remote_tlbs(kvm);
2237 spin_unlock(&kvm->mmu_lock);
2238 }
2239
2240 void kvm_mmu_zap_all(struct kvm *kvm)
2241 {
2242 struct kvm_mmu_page *sp, *node;
2243
2244 spin_lock(&kvm->mmu_lock);
2245 list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2246 if (kvm_mmu_zap_page(kvm, sp))
2247 node = container_of(kvm->arch.active_mmu_pages.next,
2248 struct kvm_mmu_page, link);
2249 spin_unlock(&kvm->mmu_lock);
2250
2251 kvm_flush_remote_tlbs(kvm);
2252 }
2253
2254 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2255 {
2256 struct kvm_mmu_page *page;
2257
2258 page = container_of(kvm->arch.active_mmu_pages.prev,
2259 struct kvm_mmu_page, link);
2260 kvm_mmu_zap_page(kvm, page);
2261 }
2262
2263 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2264 {
2265 struct kvm *kvm;
2266 struct kvm *kvm_freed = NULL;
2267 int cache_count = 0;
2268
2269 spin_lock(&kvm_lock);
2270
2271 list_for_each_entry(kvm, &vm_list, vm_list) {
2272 int npages;
2273
2274 if (!down_read_trylock(&kvm->slots_lock))
2275 continue;
2276 spin_lock(&kvm->mmu_lock);
2277 npages = kvm->arch.n_alloc_mmu_pages -
2278 kvm->arch.n_free_mmu_pages;
2279 cache_count += npages;
2280 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2281 kvm_mmu_remove_one_alloc_mmu_page(kvm);
2282 cache_count--;
2283 kvm_freed = kvm;
2284 }
2285 nr_to_scan--;
2286
2287 spin_unlock(&kvm->mmu_lock);
2288 up_read(&kvm->slots_lock);
2289 }
2290 if (kvm_freed)
2291 list_move_tail(&kvm_freed->vm_list, &vm_list);
2292
2293 spin_unlock(&kvm_lock);
2294
2295 return cache_count;
2296 }
2297
2298 static struct shrinker mmu_shrinker = {
2299 .shrink = mmu_shrink,
2300 .seeks = DEFAULT_SEEKS * 10,
2301 };
2302
2303 static void mmu_destroy_caches(void)
2304 {
2305 if (pte_chain_cache)
2306 kmem_cache_destroy(pte_chain_cache);
2307 if (rmap_desc_cache)
2308 kmem_cache_destroy(rmap_desc_cache);
2309 if (mmu_page_header_cache)
2310 kmem_cache_destroy(mmu_page_header_cache);
2311 }
2312
2313 void kvm_mmu_module_exit(void)
2314 {
2315 mmu_destroy_caches();
2316 unregister_shrinker(&mmu_shrinker);
2317 }
2318
2319 int kvm_mmu_module_init(void)
2320 {
2321 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2322 sizeof(struct kvm_pte_chain),
2323 0, 0, NULL);
2324 if (!pte_chain_cache)
2325 goto nomem;
2326 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2327 sizeof(struct kvm_rmap_desc),
2328 0, 0, NULL);
2329 if (!rmap_desc_cache)
2330 goto nomem;
2331
2332 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2333 sizeof(struct kvm_mmu_page),
2334 0, 0, NULL);
2335 if (!mmu_page_header_cache)
2336 goto nomem;
2337
2338 register_shrinker(&mmu_shrinker);
2339
2340 return 0;
2341
2342 nomem:
2343 mmu_destroy_caches();
2344 return -ENOMEM;
2345 }
2346
2347 /*
2348 * Caculate mmu pages needed for kvm.
2349 */
2350 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
2351 {
2352 int i;
2353 unsigned int nr_mmu_pages;
2354 unsigned int nr_pages = 0;
2355
2356 for (i = 0; i < kvm->nmemslots; i++)
2357 nr_pages += kvm->memslots[i].npages;
2358
2359 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
2360 nr_mmu_pages = max(nr_mmu_pages,
2361 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
2362
2363 return nr_mmu_pages;
2364 }
2365
2366 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2367 unsigned len)
2368 {
2369 if (len > buffer->len)
2370 return NULL;
2371 return buffer->ptr;
2372 }
2373
2374 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2375 unsigned len)
2376 {
2377 void *ret;
2378
2379 ret = pv_mmu_peek_buffer(buffer, len);
2380 if (!ret)
2381 return ret;
2382 buffer->ptr += len;
2383 buffer->len -= len;
2384 buffer->processed += len;
2385 return ret;
2386 }
2387
2388 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
2389 gpa_t addr, gpa_t value)
2390 {
2391 int bytes = 8;
2392 int r;
2393
2394 if (!is_long_mode(vcpu) && !is_pae(vcpu))
2395 bytes = 4;
2396
2397 r = mmu_topup_memory_caches(vcpu);
2398 if (r)
2399 return r;
2400
2401 if (!emulator_write_phys(vcpu, addr, &value, bytes))
2402 return -EFAULT;
2403
2404 return 1;
2405 }
2406
2407 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2408 {
2409 kvm_x86_ops->tlb_flush(vcpu);
2410 return 1;
2411 }
2412
2413 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
2414 {
2415 spin_lock(&vcpu->kvm->mmu_lock);
2416 mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
2417 spin_unlock(&vcpu->kvm->mmu_lock);
2418 return 1;
2419 }
2420
2421 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
2422 struct kvm_pv_mmu_op_buffer *buffer)
2423 {
2424 struct kvm_mmu_op_header *header;
2425
2426 header = pv_mmu_peek_buffer(buffer, sizeof *header);
2427 if (!header)
2428 return 0;
2429 switch (header->op) {
2430 case KVM_MMU_OP_WRITE_PTE: {
2431 struct kvm_mmu_op_write_pte *wpte;
2432
2433 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
2434 if (!wpte)
2435 return 0;
2436 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
2437 wpte->pte_val);
2438 }
2439 case KVM_MMU_OP_FLUSH_TLB: {
2440 struct kvm_mmu_op_flush_tlb *ftlb;
2441
2442 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
2443 if (!ftlb)
2444 return 0;
2445 return kvm_pv_mmu_flush_tlb(vcpu);
2446 }
2447 case KVM_MMU_OP_RELEASE_PT: {
2448 struct kvm_mmu_op_release_pt *rpt;
2449
2450 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
2451 if (!rpt)
2452 return 0;
2453 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
2454 }
2455 default: return 0;
2456 }
2457 }
2458
2459 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
2460 gpa_t addr, unsigned long *ret)
2461 {
2462 int r;
2463 struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
2464
2465 buffer->ptr = buffer->buf;
2466 buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
2467 buffer->processed = 0;
2468
2469 r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
2470 if (r)
2471 goto out;
2472
2473 while (buffer->len) {
2474 r = kvm_pv_mmu_op_one(vcpu, buffer);
2475 if (r < 0)
2476 goto out;
2477 if (r == 0)
2478 break;
2479 }
2480
2481 r = 1;
2482 out:
2483 *ret = buffer->processed;
2484 return r;
2485 }
2486
2487 #ifdef AUDIT
2488
2489 static const char *audit_msg;
2490
2491 static gva_t canonicalize(gva_t gva)
2492 {
2493 #ifdef CONFIG_X86_64
2494 gva = (long long)(gva << 16) >> 16;
2495 #endif
2496 return gva;
2497 }
2498
2499 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
2500 gva_t va, int level)
2501 {
2502 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
2503 int i;
2504 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
2505
2506 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
2507 u64 ent = pt[i];
2508
2509 if (ent == shadow_trap_nonpresent_pte)
2510 continue;
2511
2512 va = canonicalize(va);
2513 if (level > 1) {
2514 if (ent == shadow_notrap_nonpresent_pte)
2515 printk(KERN_ERR "audit: (%s) nontrapping pte"
2516 " in nonleaf level: levels %d gva %lx"
2517 " level %d pte %llx\n", audit_msg,
2518 vcpu->arch.mmu.root_level, va, level, ent);
2519
2520 audit_mappings_page(vcpu, ent, va, level - 1);
2521 } else {
2522 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
2523 hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
2524
2525 if (is_shadow_present_pte(ent)
2526 && (ent & PT64_BASE_ADDR_MASK) != hpa)
2527 printk(KERN_ERR "xx audit error: (%s) levels %d"
2528 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2529 audit_msg, vcpu->arch.mmu.root_level,
2530 va, gpa, hpa, ent,
2531 is_shadow_present_pte(ent));
2532 else if (ent == shadow_notrap_nonpresent_pte
2533 && !is_error_hpa(hpa))
2534 printk(KERN_ERR "audit: (%s) notrap shadow,"
2535 " valid guest gva %lx\n", audit_msg, va);
2536 kvm_release_pfn_clean(pfn);
2537
2538 }
2539 }
2540 }
2541
2542 static void audit_mappings(struct kvm_vcpu *vcpu)
2543 {
2544 unsigned i;
2545
2546 if (vcpu->arch.mmu.root_level == 4)
2547 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
2548 else
2549 for (i = 0; i < 4; ++i)
2550 if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
2551 audit_mappings_page(vcpu,
2552 vcpu->arch.mmu.pae_root[i],
2553 i << 30,
2554 2);
2555 }
2556
2557 static int count_rmaps(struct kvm_vcpu *vcpu)
2558 {
2559 int nmaps = 0;
2560 int i, j, k;
2561
2562 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
2563 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
2564 struct kvm_rmap_desc *d;
2565
2566 for (j = 0; j < m->npages; ++j) {
2567 unsigned long *rmapp = &m->rmap[j];
2568
2569 if (!*rmapp)
2570 continue;
2571 if (!(*rmapp & 1)) {
2572 ++nmaps;
2573 continue;
2574 }
2575 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
2576 while (d) {
2577 for (k = 0; k < RMAP_EXT; ++k)
2578 if (d->shadow_ptes[k])
2579 ++nmaps;
2580 else
2581 break;
2582 d = d->more;
2583 }
2584 }
2585 }
2586 return nmaps;
2587 }
2588
2589 static int count_writable_mappings(struct kvm_vcpu *vcpu)
2590 {
2591 int nmaps = 0;
2592 struct kvm_mmu_page *sp;
2593 int i;
2594
2595 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2596 u64 *pt = sp->spt;
2597
2598 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
2599 continue;
2600
2601 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
2602 u64 ent = pt[i];
2603
2604 if (!(ent & PT_PRESENT_MASK))
2605 continue;
2606 if (!(ent & PT_WRITABLE_MASK))
2607 continue;
2608 ++nmaps;
2609 }
2610 }
2611 return nmaps;
2612 }
2613
2614 static void audit_rmap(struct kvm_vcpu *vcpu)
2615 {
2616 int n_rmap = count_rmaps(vcpu);
2617 int n_actual = count_writable_mappings(vcpu);
2618
2619 if (n_rmap != n_actual)
2620 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
2621 __func__, audit_msg, n_rmap, n_actual);
2622 }
2623
2624 static void audit_write_protection(struct kvm_vcpu *vcpu)
2625 {
2626 struct kvm_mmu_page *sp;
2627 struct kvm_memory_slot *slot;
2628 unsigned long *rmapp;
2629 gfn_t gfn;
2630
2631 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2632 if (sp->role.metaphysical)
2633 continue;
2634
2635 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
2636 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
2637 rmapp = &slot->rmap[gfn - slot->base_gfn];
2638 if (*rmapp)
2639 printk(KERN_ERR "%s: (%s) shadow page has writable"
2640 " mappings: gfn %lx role %x\n",
2641 __func__, audit_msg, sp->gfn,
2642 sp->role.word);
2643 }
2644 }
2645
2646 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
2647 {
2648 int olddbg = dbg;
2649
2650 dbg = 0;
2651 audit_msg = msg;
2652 audit_rmap(vcpu);
2653 audit_write_protection(vcpu);
2654 audit_mappings(vcpu);
2655 dbg = olddbg;
2656 }
2657
2658 #endif
Linus' kernel tree