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Merge branch 'acpi-pad' into release
[deliverable/linux.git] / arch / x86 / 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 "mmu.h"
21 #include "kvm_cache_regs.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 #include <asm/vmx.h>
37
38 /*
39 * When setting this variable to true it enables Two-Dimensional-Paging
40 * where the hardware walks 2 page tables:
41 * 1. the guest-virtual to guest-physical
42 * 2. while doing 1. it walks guest-physical to host-physical
43 * If the hardware supports that we don't need to do shadow paging.
44 */
45 bool tdp_enabled = false;
46
47 #undef MMU_DEBUG
48
49 #undef AUDIT
50
51 #ifdef AUDIT
52 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
53 #else
54 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
55 #endif
56
57 #ifdef MMU_DEBUG
58
59 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
60 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
61
62 #else
63
64 #define pgprintk(x...) do { } while (0)
65 #define rmap_printk(x...) do { } while (0)
66
67 #endif
68
69 #if defined(MMU_DEBUG) || defined(AUDIT)
70 static int dbg = 0;
71 module_param(dbg, bool, 0644);
72 #endif
73
74 static int oos_shadow = 1;
75 module_param(oos_shadow, bool, 0644);
76
77 #ifndef MMU_DEBUG
78 #define ASSERT(x) do { } while (0)
79 #else
80 #define ASSERT(x) \
81 if (!(x)) { \
82 printk(KERN_WARNING "assertion failed %s:%d: %s\n", \
83 __FILE__, __LINE__, #x); \
84 }
85 #endif
86
87 #define PT_FIRST_AVAIL_BITS_SHIFT 9
88 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
89
90 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
91
92 #define PT64_LEVEL_BITS 9
93
94 #define PT64_LEVEL_SHIFT(level) \
95 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
96
97 #define PT64_LEVEL_MASK(level) \
98 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
99
100 #define PT64_INDEX(address, level)\
101 (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
102
103
104 #define PT32_LEVEL_BITS 10
105
106 #define PT32_LEVEL_SHIFT(level) \
107 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
108
109 #define PT32_LEVEL_MASK(level) \
110 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
111 #define PT32_LVL_OFFSET_MASK(level) \
112 (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
113 * PT32_LEVEL_BITS))) - 1))
114
115 #define PT32_INDEX(address, level)\
116 (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
117
118
119 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
120 #define PT64_DIR_BASE_ADDR_MASK \
121 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
122 #define PT64_LVL_ADDR_MASK(level) \
123 (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
124 * PT64_LEVEL_BITS))) - 1))
125 #define PT64_LVL_OFFSET_MASK(level) \
126 (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
127 * PT64_LEVEL_BITS))) - 1))
128
129 #define PT32_BASE_ADDR_MASK PAGE_MASK
130 #define PT32_DIR_BASE_ADDR_MASK \
131 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
132 #define PT32_LVL_ADDR_MASK(level) \
133 (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
134 * PT32_LEVEL_BITS))) - 1))
135
136 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
137 | PT64_NX_MASK)
138
139 #define PFERR_PRESENT_MASK (1U << 0)
140 #define PFERR_WRITE_MASK (1U << 1)
141 #define PFERR_USER_MASK (1U << 2)
142 #define PFERR_RSVD_MASK (1U << 3)
143 #define PFERR_FETCH_MASK (1U << 4)
144
145 #define PT_PDPE_LEVEL 3
146 #define PT_DIRECTORY_LEVEL 2
147 #define PT_PAGE_TABLE_LEVEL 1
148
149 #define RMAP_EXT 4
150
151 #define ACC_EXEC_MASK 1
152 #define ACC_WRITE_MASK PT_WRITABLE_MASK
153 #define ACC_USER_MASK PT_USER_MASK
154 #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
155
156 #define CREATE_TRACE_POINTS
157 #include "mmutrace.h"
158
159 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
160
161 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
162
163 struct kvm_rmap_desc {
164 u64 *sptes[RMAP_EXT];
165 struct kvm_rmap_desc *more;
166 };
167
168 struct kvm_shadow_walk_iterator {
169 u64 addr;
170 hpa_t shadow_addr;
171 int level;
172 u64 *sptep;
173 unsigned index;
174 };
175
176 #define for_each_shadow_entry(_vcpu, _addr, _walker) \
177 for (shadow_walk_init(&(_walker), _vcpu, _addr); \
178 shadow_walk_okay(&(_walker)); \
179 shadow_walk_next(&(_walker)))
180
181
182 struct kvm_unsync_walk {
183 int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk);
184 };
185
186 typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
187
188 static struct kmem_cache *pte_chain_cache;
189 static struct kmem_cache *rmap_desc_cache;
190 static struct kmem_cache *mmu_page_header_cache;
191
192 static u64 __read_mostly shadow_trap_nonpresent_pte;
193 static u64 __read_mostly shadow_notrap_nonpresent_pte;
194 static u64 __read_mostly shadow_base_present_pte;
195 static u64 __read_mostly shadow_nx_mask;
196 static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
197 static u64 __read_mostly shadow_user_mask;
198 static u64 __read_mostly shadow_accessed_mask;
199 static u64 __read_mostly shadow_dirty_mask;
200
201 static inline u64 rsvd_bits(int s, int e)
202 {
203 return ((1ULL << (e - s + 1)) - 1) << s;
204 }
205
206 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
207 {
208 shadow_trap_nonpresent_pte = trap_pte;
209 shadow_notrap_nonpresent_pte = notrap_pte;
210 }
211 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
212
213 void kvm_mmu_set_base_ptes(u64 base_pte)
214 {
215 shadow_base_present_pte = base_pte;
216 }
217 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
218
219 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
220 u64 dirty_mask, u64 nx_mask, u64 x_mask)
221 {
222 shadow_user_mask = user_mask;
223 shadow_accessed_mask = accessed_mask;
224 shadow_dirty_mask = dirty_mask;
225 shadow_nx_mask = nx_mask;
226 shadow_x_mask = x_mask;
227 }
228 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
229
230 static int is_write_protection(struct kvm_vcpu *vcpu)
231 {
232 return vcpu->arch.cr0 & X86_CR0_WP;
233 }
234
235 static int is_cpuid_PSE36(void)
236 {
237 return 1;
238 }
239
240 static int is_nx(struct kvm_vcpu *vcpu)
241 {
242 return vcpu->arch.shadow_efer & EFER_NX;
243 }
244
245 static int is_shadow_present_pte(u64 pte)
246 {
247 return pte != shadow_trap_nonpresent_pte
248 && pte != shadow_notrap_nonpresent_pte;
249 }
250
251 static int is_large_pte(u64 pte)
252 {
253 return pte & PT_PAGE_SIZE_MASK;
254 }
255
256 static int is_writeble_pte(unsigned long pte)
257 {
258 return pte & PT_WRITABLE_MASK;
259 }
260
261 static int is_dirty_gpte(unsigned long pte)
262 {
263 return pte & PT_DIRTY_MASK;
264 }
265
266 static int is_rmap_spte(u64 pte)
267 {
268 return is_shadow_present_pte(pte);
269 }
270
271 static int is_last_spte(u64 pte, int level)
272 {
273 if (level == PT_PAGE_TABLE_LEVEL)
274 return 1;
275 if (is_large_pte(pte))
276 return 1;
277 return 0;
278 }
279
280 static pfn_t spte_to_pfn(u64 pte)
281 {
282 return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
283 }
284
285 static gfn_t pse36_gfn_delta(u32 gpte)
286 {
287 int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
288
289 return (gpte & PT32_DIR_PSE36_MASK) << shift;
290 }
291
292 static void __set_spte(u64 *sptep, u64 spte)
293 {
294 #ifdef CONFIG_X86_64
295 set_64bit((unsigned long *)sptep, spte);
296 #else
297 set_64bit((unsigned long long *)sptep, spte);
298 #endif
299 }
300
301 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
302 struct kmem_cache *base_cache, int min)
303 {
304 void *obj;
305
306 if (cache->nobjs >= min)
307 return 0;
308 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
309 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
310 if (!obj)
311 return -ENOMEM;
312 cache->objects[cache->nobjs++] = obj;
313 }
314 return 0;
315 }
316
317 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
318 {
319 while (mc->nobjs)
320 kfree(mc->objects[--mc->nobjs]);
321 }
322
323 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
324 int min)
325 {
326 struct page *page;
327
328 if (cache->nobjs >= min)
329 return 0;
330 while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
331 page = alloc_page(GFP_KERNEL);
332 if (!page)
333 return -ENOMEM;
334 set_page_private(page, 0);
335 cache->objects[cache->nobjs++] = page_address(page);
336 }
337 return 0;
338 }
339
340 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
341 {
342 while (mc->nobjs)
343 free_page((unsigned long)mc->objects[--mc->nobjs]);
344 }
345
346 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
347 {
348 int r;
349
350 r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
351 pte_chain_cache, 4);
352 if (r)
353 goto out;
354 r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
355 rmap_desc_cache, 4);
356 if (r)
357 goto out;
358 r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
359 if (r)
360 goto out;
361 r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
362 mmu_page_header_cache, 4);
363 out:
364 return r;
365 }
366
367 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
368 {
369 mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
370 mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
371 mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
372 mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
373 }
374
375 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
376 size_t size)
377 {
378 void *p;
379
380 BUG_ON(!mc->nobjs);
381 p = mc->objects[--mc->nobjs];
382 return p;
383 }
384
385 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
386 {
387 return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
388 sizeof(struct kvm_pte_chain));
389 }
390
391 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
392 {
393 kfree(pc);
394 }
395
396 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
397 {
398 return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
399 sizeof(struct kvm_rmap_desc));
400 }
401
402 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
403 {
404 kfree(rd);
405 }
406
407 /*
408 * Return the pointer to the largepage write count for a given
409 * gfn, handling slots that are not large page aligned.
410 */
411 static int *slot_largepage_idx(gfn_t gfn,
412 struct kvm_memory_slot *slot,
413 int level)
414 {
415 unsigned long idx;
416
417 idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
418 (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
419 return &slot->lpage_info[level - 2][idx].write_count;
420 }
421
422 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
423 {
424 struct kvm_memory_slot *slot;
425 int *write_count;
426 int i;
427
428 gfn = unalias_gfn(kvm, gfn);
429
430 slot = gfn_to_memslot_unaliased(kvm, gfn);
431 for (i = PT_DIRECTORY_LEVEL;
432 i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
433 write_count = slot_largepage_idx(gfn, slot, i);
434 *write_count += 1;
435 }
436 }
437
438 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
439 {
440 struct kvm_memory_slot *slot;
441 int *write_count;
442 int i;
443
444 gfn = unalias_gfn(kvm, gfn);
445 for (i = PT_DIRECTORY_LEVEL;
446 i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
447 slot = gfn_to_memslot_unaliased(kvm, gfn);
448 write_count = slot_largepage_idx(gfn, slot, i);
449 *write_count -= 1;
450 WARN_ON(*write_count < 0);
451 }
452 }
453
454 static int has_wrprotected_page(struct kvm *kvm,
455 gfn_t gfn,
456 int level)
457 {
458 struct kvm_memory_slot *slot;
459 int *largepage_idx;
460
461 gfn = unalias_gfn(kvm, gfn);
462 slot = gfn_to_memslot_unaliased(kvm, gfn);
463 if (slot) {
464 largepage_idx = slot_largepage_idx(gfn, slot, level);
465 return *largepage_idx;
466 }
467
468 return 1;
469 }
470
471 static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
472 {
473 unsigned long page_size = PAGE_SIZE;
474 struct vm_area_struct *vma;
475 unsigned long addr;
476 int i, ret = 0;
477
478 addr = gfn_to_hva(kvm, gfn);
479 if (kvm_is_error_hva(addr))
480 return page_size;
481
482 down_read(&current->mm->mmap_sem);
483 vma = find_vma(current->mm, addr);
484 if (!vma)
485 goto out;
486
487 page_size = vma_kernel_pagesize(vma);
488
489 out:
490 up_read(&current->mm->mmap_sem);
491
492 for (i = PT_PAGE_TABLE_LEVEL;
493 i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
494 if (page_size >= KVM_HPAGE_SIZE(i))
495 ret = i;
496 else
497 break;
498 }
499
500 return ret;
501 }
502
503 static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
504 {
505 struct kvm_memory_slot *slot;
506 int host_level;
507 int level = PT_PAGE_TABLE_LEVEL;
508
509 slot = gfn_to_memslot(vcpu->kvm, large_gfn);
510 if (slot && slot->dirty_bitmap)
511 return PT_PAGE_TABLE_LEVEL;
512
513 host_level = host_mapping_level(vcpu->kvm, large_gfn);
514
515 if (host_level == PT_PAGE_TABLE_LEVEL)
516 return host_level;
517
518 for (level = PT_DIRECTORY_LEVEL; level <= host_level; ++level) {
519
520 if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
521 break;
522 }
523
524 return level - 1;
525 }
526
527 /*
528 * Take gfn and return the reverse mapping to it.
529 * Note: gfn must be unaliased before this function get called
530 */
531
532 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
533 {
534 struct kvm_memory_slot *slot;
535 unsigned long idx;
536
537 slot = gfn_to_memslot(kvm, gfn);
538 if (likely(level == PT_PAGE_TABLE_LEVEL))
539 return &slot->rmap[gfn - slot->base_gfn];
540
541 idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
542 (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
543
544 return &slot->lpage_info[level - 2][idx].rmap_pde;
545 }
546
547 /*
548 * Reverse mapping data structures:
549 *
550 * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
551 * that points to page_address(page).
552 *
553 * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
554 * containing more mappings.
555 *
556 * Returns the number of rmap entries before the spte was added or zero if
557 * the spte was not added.
558 *
559 */
560 static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
561 {
562 struct kvm_mmu_page *sp;
563 struct kvm_rmap_desc *desc;
564 unsigned long *rmapp;
565 int i, count = 0;
566
567 if (!is_rmap_spte(*spte))
568 return count;
569 gfn = unalias_gfn(vcpu->kvm, gfn);
570 sp = page_header(__pa(spte));
571 sp->gfns[spte - sp->spt] = gfn;
572 rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
573 if (!*rmapp) {
574 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
575 *rmapp = (unsigned long)spte;
576 } else if (!(*rmapp & 1)) {
577 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
578 desc = mmu_alloc_rmap_desc(vcpu);
579 desc->sptes[0] = (u64 *)*rmapp;
580 desc->sptes[1] = spte;
581 *rmapp = (unsigned long)desc | 1;
582 } else {
583 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
584 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
585 while (desc->sptes[RMAP_EXT-1] && desc->more) {
586 desc = desc->more;
587 count += RMAP_EXT;
588 }
589 if (desc->sptes[RMAP_EXT-1]) {
590 desc->more = mmu_alloc_rmap_desc(vcpu);
591 desc = desc->more;
592 }
593 for (i = 0; desc->sptes[i]; ++i)
594 ;
595 desc->sptes[i] = spte;
596 }
597 return count;
598 }
599
600 static void rmap_desc_remove_entry(unsigned long *rmapp,
601 struct kvm_rmap_desc *desc,
602 int i,
603 struct kvm_rmap_desc *prev_desc)
604 {
605 int j;
606
607 for (j = RMAP_EXT - 1; !desc->sptes[j] && j > i; --j)
608 ;
609 desc->sptes[i] = desc->sptes[j];
610 desc->sptes[j] = NULL;
611 if (j != 0)
612 return;
613 if (!prev_desc && !desc->more)
614 *rmapp = (unsigned long)desc->sptes[0];
615 else
616 if (prev_desc)
617 prev_desc->more = desc->more;
618 else
619 *rmapp = (unsigned long)desc->more | 1;
620 mmu_free_rmap_desc(desc);
621 }
622
623 static void rmap_remove(struct kvm *kvm, u64 *spte)
624 {
625 struct kvm_rmap_desc *desc;
626 struct kvm_rmap_desc *prev_desc;
627 struct kvm_mmu_page *sp;
628 pfn_t pfn;
629 unsigned long *rmapp;
630 int i;
631
632 if (!is_rmap_spte(*spte))
633 return;
634 sp = page_header(__pa(spte));
635 pfn = spte_to_pfn(*spte);
636 if (*spte & shadow_accessed_mask)
637 kvm_set_pfn_accessed(pfn);
638 if (is_writeble_pte(*spte))
639 kvm_set_pfn_dirty(pfn);
640 rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level);
641 if (!*rmapp) {
642 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
643 BUG();
644 } else if (!(*rmapp & 1)) {
645 rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte);
646 if ((u64 *)*rmapp != spte) {
647 printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n",
648 spte, *spte);
649 BUG();
650 }
651 *rmapp = 0;
652 } else {
653 rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte);
654 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
655 prev_desc = NULL;
656 while (desc) {
657 for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i)
658 if (desc->sptes[i] == spte) {
659 rmap_desc_remove_entry(rmapp,
660 desc, i,
661 prev_desc);
662 return;
663 }
664 prev_desc = desc;
665 desc = desc->more;
666 }
667 BUG();
668 }
669 }
670
671 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
672 {
673 struct kvm_rmap_desc *desc;
674 struct kvm_rmap_desc *prev_desc;
675 u64 *prev_spte;
676 int i;
677
678 if (!*rmapp)
679 return NULL;
680 else if (!(*rmapp & 1)) {
681 if (!spte)
682 return (u64 *)*rmapp;
683 return NULL;
684 }
685 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
686 prev_desc = NULL;
687 prev_spte = NULL;
688 while (desc) {
689 for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i) {
690 if (prev_spte == spte)
691 return desc->sptes[i];
692 prev_spte = desc->sptes[i];
693 }
694 desc = desc->more;
695 }
696 return NULL;
697 }
698
699 static int rmap_write_protect(struct kvm *kvm, u64 gfn)
700 {
701 unsigned long *rmapp;
702 u64 *spte;
703 int i, write_protected = 0;
704
705 gfn = unalias_gfn(kvm, gfn);
706 rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL);
707
708 spte = rmap_next(kvm, rmapp, NULL);
709 while (spte) {
710 BUG_ON(!spte);
711 BUG_ON(!(*spte & PT_PRESENT_MASK));
712 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
713 if (is_writeble_pte(*spte)) {
714 __set_spte(spte, *spte & ~PT_WRITABLE_MASK);
715 write_protected = 1;
716 }
717 spte = rmap_next(kvm, rmapp, spte);
718 }
719 if (write_protected) {
720 pfn_t pfn;
721
722 spte = rmap_next(kvm, rmapp, NULL);
723 pfn = spte_to_pfn(*spte);
724 kvm_set_pfn_dirty(pfn);
725 }
726
727 /* check for huge page mappings */
728 for (i = PT_DIRECTORY_LEVEL;
729 i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
730 rmapp = gfn_to_rmap(kvm, gfn, i);
731 spte = rmap_next(kvm, rmapp, NULL);
732 while (spte) {
733 BUG_ON(!spte);
734 BUG_ON(!(*spte & PT_PRESENT_MASK));
735 BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
736 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
737 if (is_writeble_pte(*spte)) {
738 rmap_remove(kvm, spte);
739 --kvm->stat.lpages;
740 __set_spte(spte, shadow_trap_nonpresent_pte);
741 spte = NULL;
742 write_protected = 1;
743 }
744 spte = rmap_next(kvm, rmapp, spte);
745 }
746 }
747
748 return write_protected;
749 }
750
751 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
752 unsigned long data)
753 {
754 u64 *spte;
755 int need_tlb_flush = 0;
756
757 while ((spte = rmap_next(kvm, rmapp, NULL))) {
758 BUG_ON(!(*spte & PT_PRESENT_MASK));
759 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
760 rmap_remove(kvm, spte);
761 __set_spte(spte, shadow_trap_nonpresent_pte);
762 need_tlb_flush = 1;
763 }
764 return need_tlb_flush;
765 }
766
767 static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
768 unsigned long data)
769 {
770 int need_flush = 0;
771 u64 *spte, new_spte;
772 pte_t *ptep = (pte_t *)data;
773 pfn_t new_pfn;
774
775 WARN_ON(pte_huge(*ptep));
776 new_pfn = pte_pfn(*ptep);
777 spte = rmap_next(kvm, rmapp, NULL);
778 while (spte) {
779 BUG_ON(!is_shadow_present_pte(*spte));
780 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
781 need_flush = 1;
782 if (pte_write(*ptep)) {
783 rmap_remove(kvm, spte);
784 __set_spte(spte, shadow_trap_nonpresent_pte);
785 spte = rmap_next(kvm, rmapp, NULL);
786 } else {
787 new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
788 new_spte |= (u64)new_pfn << PAGE_SHIFT;
789
790 new_spte &= ~PT_WRITABLE_MASK;
791 new_spte &= ~SPTE_HOST_WRITEABLE;
792 if (is_writeble_pte(*spte))
793 kvm_set_pfn_dirty(spte_to_pfn(*spte));
794 __set_spte(spte, new_spte);
795 spte = rmap_next(kvm, rmapp, spte);
796 }
797 }
798 if (need_flush)
799 kvm_flush_remote_tlbs(kvm);
800
801 return 0;
802 }
803
804 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
805 unsigned long data,
806 int (*handler)(struct kvm *kvm, unsigned long *rmapp,
807 unsigned long data))
808 {
809 int i, j;
810 int retval = 0;
811
812 /*
813 * If mmap_sem isn't taken, we can look the memslots with only
814 * the mmu_lock by skipping over the slots with userspace_addr == 0.
815 */
816 for (i = 0; i < kvm->nmemslots; i++) {
817 struct kvm_memory_slot *memslot = &kvm->memslots[i];
818 unsigned long start = memslot->userspace_addr;
819 unsigned long end;
820
821 /* mmu_lock protects userspace_addr */
822 if (!start)
823 continue;
824
825 end = start + (memslot->npages << PAGE_SHIFT);
826 if (hva >= start && hva < end) {
827 gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
828
829 retval |= handler(kvm, &memslot->rmap[gfn_offset],
830 data);
831
832 for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
833 int idx = gfn_offset;
834 idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
835 retval |= handler(kvm,
836 &memslot->lpage_info[j][idx].rmap_pde,
837 data);
838 }
839 }
840 }
841
842 return retval;
843 }
844
845 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
846 {
847 return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
848 }
849
850 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
851 {
852 kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
853 }
854
855 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
856 unsigned long data)
857 {
858 u64 *spte;
859 int young = 0;
860
861 /* always return old for EPT */
862 if (!shadow_accessed_mask)
863 return 0;
864
865 spte = rmap_next(kvm, rmapp, NULL);
866 while (spte) {
867 int _young;
868 u64 _spte = *spte;
869 BUG_ON(!(_spte & PT_PRESENT_MASK));
870 _young = _spte & PT_ACCESSED_MASK;
871 if (_young) {
872 young = 1;
873 clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
874 }
875 spte = rmap_next(kvm, rmapp, spte);
876 }
877 return young;
878 }
879
880 #define RMAP_RECYCLE_THRESHOLD 1000
881
882 static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
883 {
884 unsigned long *rmapp;
885 struct kvm_mmu_page *sp;
886
887 sp = page_header(__pa(spte));
888
889 gfn = unalias_gfn(vcpu->kvm, gfn);
890 rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
891
892 kvm_unmap_rmapp(vcpu->kvm, rmapp, 0);
893 kvm_flush_remote_tlbs(vcpu->kvm);
894 }
895
896 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
897 {
898 return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
899 }
900
901 #ifdef MMU_DEBUG
902 static int is_empty_shadow_page(u64 *spt)
903 {
904 u64 *pos;
905 u64 *end;
906
907 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
908 if (is_shadow_present_pte(*pos)) {
909 printk(KERN_ERR "%s: %p %llx\n", __func__,
910 pos, *pos);
911 return 0;
912 }
913 return 1;
914 }
915 #endif
916
917 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
918 {
919 ASSERT(is_empty_shadow_page(sp->spt));
920 list_del(&sp->link);
921 __free_page(virt_to_page(sp->spt));
922 __free_page(virt_to_page(sp->gfns));
923 kfree(sp);
924 ++kvm->arch.n_free_mmu_pages;
925 }
926
927 static unsigned kvm_page_table_hashfn(gfn_t gfn)
928 {
929 return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
930 }
931
932 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
933 u64 *parent_pte)
934 {
935 struct kvm_mmu_page *sp;
936
937 sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
938 sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
939 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
940 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
941 list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
942 INIT_LIST_HEAD(&sp->oos_link);
943 bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
944 sp->multimapped = 0;
945 sp->parent_pte = parent_pte;
946 --vcpu->kvm->arch.n_free_mmu_pages;
947 return sp;
948 }
949
950 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
951 struct kvm_mmu_page *sp, u64 *parent_pte)
952 {
953 struct kvm_pte_chain *pte_chain;
954 struct hlist_node *node;
955 int i;
956
957 if (!parent_pte)
958 return;
959 if (!sp->multimapped) {
960 u64 *old = sp->parent_pte;
961
962 if (!old) {
963 sp->parent_pte = parent_pte;
964 return;
965 }
966 sp->multimapped = 1;
967 pte_chain = mmu_alloc_pte_chain(vcpu);
968 INIT_HLIST_HEAD(&sp->parent_ptes);
969 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
970 pte_chain->parent_ptes[0] = old;
971 }
972 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
973 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
974 continue;
975 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
976 if (!pte_chain->parent_ptes[i]) {
977 pte_chain->parent_ptes[i] = parent_pte;
978 return;
979 }
980 }
981 pte_chain = mmu_alloc_pte_chain(vcpu);
982 BUG_ON(!pte_chain);
983 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
984 pte_chain->parent_ptes[0] = parent_pte;
985 }
986
987 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
988 u64 *parent_pte)
989 {
990 struct kvm_pte_chain *pte_chain;
991 struct hlist_node *node;
992 int i;
993
994 if (!sp->multimapped) {
995 BUG_ON(sp->parent_pte != parent_pte);
996 sp->parent_pte = NULL;
997 return;
998 }
999 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1000 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1001 if (!pte_chain->parent_ptes[i])
1002 break;
1003 if (pte_chain->parent_ptes[i] != parent_pte)
1004 continue;
1005 while (i + 1 < NR_PTE_CHAIN_ENTRIES
1006 && pte_chain->parent_ptes[i + 1]) {
1007 pte_chain->parent_ptes[i]
1008 = pte_chain->parent_ptes[i + 1];
1009 ++i;
1010 }
1011 pte_chain->parent_ptes[i] = NULL;
1012 if (i == 0) {
1013 hlist_del(&pte_chain->link);
1014 mmu_free_pte_chain(pte_chain);
1015 if (hlist_empty(&sp->parent_ptes)) {
1016 sp->multimapped = 0;
1017 sp->parent_pte = NULL;
1018 }
1019 }
1020 return;
1021 }
1022 BUG();
1023 }
1024
1025
1026 static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
1027 mmu_parent_walk_fn fn)
1028 {
1029 struct kvm_pte_chain *pte_chain;
1030 struct hlist_node *node;
1031 struct kvm_mmu_page *parent_sp;
1032 int i;
1033
1034 if (!sp->multimapped && sp->parent_pte) {
1035 parent_sp = page_header(__pa(sp->parent_pte));
1036 fn(vcpu, parent_sp);
1037 mmu_parent_walk(vcpu, parent_sp, fn);
1038 return;
1039 }
1040 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1041 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1042 if (!pte_chain->parent_ptes[i])
1043 break;
1044 parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
1045 fn(vcpu, parent_sp);
1046 mmu_parent_walk(vcpu, parent_sp, fn);
1047 }
1048 }
1049
1050 static void kvm_mmu_update_unsync_bitmap(u64 *spte)
1051 {
1052 unsigned int index;
1053 struct kvm_mmu_page *sp = page_header(__pa(spte));
1054
1055 index = spte - sp->spt;
1056 if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
1057 sp->unsync_children++;
1058 WARN_ON(!sp->unsync_children);
1059 }
1060
1061 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
1062 {
1063 struct kvm_pte_chain *pte_chain;
1064 struct hlist_node *node;
1065 int i;
1066
1067 if (!sp->parent_pte)
1068 return;
1069
1070 if (!sp->multimapped) {
1071 kvm_mmu_update_unsync_bitmap(sp->parent_pte);
1072 return;
1073 }
1074
1075 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1076 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1077 if (!pte_chain->parent_ptes[i])
1078 break;
1079 kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
1080 }
1081 }
1082
1083 static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1084 {
1085 kvm_mmu_update_parents_unsync(sp);
1086 return 1;
1087 }
1088
1089 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu,
1090 struct kvm_mmu_page *sp)
1091 {
1092 mmu_parent_walk(vcpu, sp, unsync_walk_fn);
1093 kvm_mmu_update_parents_unsync(sp);
1094 }
1095
1096 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1097 struct kvm_mmu_page *sp)
1098 {
1099 int i;
1100
1101 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1102 sp->spt[i] = shadow_trap_nonpresent_pte;
1103 }
1104
1105 static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
1106 struct kvm_mmu_page *sp)
1107 {
1108 return 1;
1109 }
1110
1111 static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
1112 {
1113 }
1114
1115 #define KVM_PAGE_ARRAY_NR 16
1116
1117 struct kvm_mmu_pages {
1118 struct mmu_page_and_offset {
1119 struct kvm_mmu_page *sp;
1120 unsigned int idx;
1121 } page[KVM_PAGE_ARRAY_NR];
1122 unsigned int nr;
1123 };
1124
1125 #define for_each_unsync_children(bitmap, idx) \
1126 for (idx = find_first_bit(bitmap, 512); \
1127 idx < 512; \
1128 idx = find_next_bit(bitmap, 512, idx+1))
1129
1130 static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
1131 int idx)
1132 {
1133 int i;
1134
1135 if (sp->unsync)
1136 for (i=0; i < pvec->nr; i++)
1137 if (pvec->page[i].sp == sp)
1138 return 0;
1139
1140 pvec->page[pvec->nr].sp = sp;
1141 pvec->page[pvec->nr].idx = idx;
1142 pvec->nr++;
1143 return (pvec->nr == KVM_PAGE_ARRAY_NR);
1144 }
1145
1146 static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
1147 struct kvm_mmu_pages *pvec)
1148 {
1149 int i, ret, nr_unsync_leaf = 0;
1150
1151 for_each_unsync_children(sp->unsync_child_bitmap, i) {
1152 u64 ent = sp->spt[i];
1153
1154 if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
1155 struct kvm_mmu_page *child;
1156 child = page_header(ent & PT64_BASE_ADDR_MASK);
1157
1158 if (child->unsync_children) {
1159 if (mmu_pages_add(pvec, child, i))
1160 return -ENOSPC;
1161
1162 ret = __mmu_unsync_walk(child, pvec);
1163 if (!ret)
1164 __clear_bit(i, sp->unsync_child_bitmap);
1165 else if (ret > 0)
1166 nr_unsync_leaf += ret;
1167 else
1168 return ret;
1169 }
1170
1171 if (child->unsync) {
1172 nr_unsync_leaf++;
1173 if (mmu_pages_add(pvec, child, i))
1174 return -ENOSPC;
1175 }
1176 }
1177 }
1178
1179 if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
1180 sp->unsync_children = 0;
1181
1182 return nr_unsync_leaf;
1183 }
1184
1185 static int mmu_unsync_walk(struct kvm_mmu_page *sp,
1186 struct kvm_mmu_pages *pvec)
1187 {
1188 if (!sp->unsync_children)
1189 return 0;
1190
1191 mmu_pages_add(pvec, sp, 0);
1192 return __mmu_unsync_walk(sp, pvec);
1193 }
1194
1195 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
1196 {
1197 unsigned index;
1198 struct hlist_head *bucket;
1199 struct kvm_mmu_page *sp;
1200 struct hlist_node *node;
1201
1202 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1203 index = kvm_page_table_hashfn(gfn);
1204 bucket = &kvm->arch.mmu_page_hash[index];
1205 hlist_for_each_entry(sp, node, bucket, hash_link)
1206 if (sp->gfn == gfn && !sp->role.direct
1207 && !sp->role.invalid) {
1208 pgprintk("%s: found role %x\n",
1209 __func__, sp->role.word);
1210 return sp;
1211 }
1212 return NULL;
1213 }
1214
1215 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1216 {
1217 WARN_ON(!sp->unsync);
1218 sp->unsync = 0;
1219 --kvm->stat.mmu_unsync;
1220 }
1221
1222 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
1223
1224 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1225 {
1226 if (sp->role.glevels != vcpu->arch.mmu.root_level) {
1227 kvm_mmu_zap_page(vcpu->kvm, sp);
1228 return 1;
1229 }
1230
1231 trace_kvm_mmu_sync_page(sp);
1232 if (rmap_write_protect(vcpu->kvm, sp->gfn))
1233 kvm_flush_remote_tlbs(vcpu->kvm);
1234 kvm_unlink_unsync_page(vcpu->kvm, sp);
1235 if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
1236 kvm_mmu_zap_page(vcpu->kvm, sp);
1237 return 1;
1238 }
1239
1240 kvm_mmu_flush_tlb(vcpu);
1241 return 0;
1242 }
1243
1244 struct mmu_page_path {
1245 struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
1246 unsigned int idx[PT64_ROOT_LEVEL-1];
1247 };
1248
1249 #define for_each_sp(pvec, sp, parents, i) \
1250 for (i = mmu_pages_next(&pvec, &parents, -1), \
1251 sp = pvec.page[i].sp; \
1252 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1253 i = mmu_pages_next(&pvec, &parents, i))
1254
1255 static int mmu_pages_next(struct kvm_mmu_pages *pvec,
1256 struct mmu_page_path *parents,
1257 int i)
1258 {
1259 int n;
1260
1261 for (n = i+1; n < pvec->nr; n++) {
1262 struct kvm_mmu_page *sp = pvec->page[n].sp;
1263
1264 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1265 parents->idx[0] = pvec->page[n].idx;
1266 return n;
1267 }
1268
1269 parents->parent[sp->role.level-2] = sp;
1270 parents->idx[sp->role.level-1] = pvec->page[n].idx;
1271 }
1272
1273 return n;
1274 }
1275
1276 static void mmu_pages_clear_parents(struct mmu_page_path *parents)
1277 {
1278 struct kvm_mmu_page *sp;
1279 unsigned int level = 0;
1280
1281 do {
1282 unsigned int idx = parents->idx[level];
1283
1284 sp = parents->parent[level];
1285 if (!sp)
1286 return;
1287
1288 --sp->unsync_children;
1289 WARN_ON((int)sp->unsync_children < 0);
1290 __clear_bit(idx, sp->unsync_child_bitmap);
1291 level++;
1292 } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
1293 }
1294
1295 static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
1296 struct mmu_page_path *parents,
1297 struct kvm_mmu_pages *pvec)
1298 {
1299 parents->parent[parent->role.level-1] = NULL;
1300 pvec->nr = 0;
1301 }
1302
1303 static void mmu_sync_children(struct kvm_vcpu *vcpu,
1304 struct kvm_mmu_page *parent)
1305 {
1306 int i;
1307 struct kvm_mmu_page *sp;
1308 struct mmu_page_path parents;
1309 struct kvm_mmu_pages pages;
1310
1311 kvm_mmu_pages_init(parent, &parents, &pages);
1312 while (mmu_unsync_walk(parent, &pages)) {
1313 int protected = 0;
1314
1315 for_each_sp(pages, sp, parents, i)
1316 protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
1317
1318 if (protected)
1319 kvm_flush_remote_tlbs(vcpu->kvm);
1320
1321 for_each_sp(pages, sp, parents, i) {
1322 kvm_sync_page(vcpu, sp);
1323 mmu_pages_clear_parents(&parents);
1324 }
1325 cond_resched_lock(&vcpu->kvm->mmu_lock);
1326 kvm_mmu_pages_init(parent, &parents, &pages);
1327 }
1328 }
1329
1330 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
1331 gfn_t gfn,
1332 gva_t gaddr,
1333 unsigned level,
1334 int direct,
1335 unsigned access,
1336 u64 *parent_pte)
1337 {
1338 union kvm_mmu_page_role role;
1339 unsigned index;
1340 unsigned quadrant;
1341 struct hlist_head *bucket;
1342 struct kvm_mmu_page *sp;
1343 struct hlist_node *node, *tmp;
1344
1345 role = vcpu->arch.mmu.base_role;
1346 role.level = level;
1347 role.direct = direct;
1348 role.access = access;
1349 if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
1350 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
1351 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
1352 role.quadrant = quadrant;
1353 }
1354 index = kvm_page_table_hashfn(gfn);
1355 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1356 hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
1357 if (sp->gfn == gfn) {
1358 if (sp->unsync)
1359 if (kvm_sync_page(vcpu, sp))
1360 continue;
1361
1362 if (sp->role.word != role.word)
1363 continue;
1364
1365 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
1366 if (sp->unsync_children) {
1367 set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
1368 kvm_mmu_mark_parents_unsync(vcpu, sp);
1369 }
1370 trace_kvm_mmu_get_page(sp, false);
1371 return sp;
1372 }
1373 ++vcpu->kvm->stat.mmu_cache_miss;
1374 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
1375 if (!sp)
1376 return sp;
1377 sp->gfn = gfn;
1378 sp->role = role;
1379 hlist_add_head(&sp->hash_link, bucket);
1380 if (!direct) {
1381 if (rmap_write_protect(vcpu->kvm, gfn))
1382 kvm_flush_remote_tlbs(vcpu->kvm);
1383 account_shadowed(vcpu->kvm, gfn);
1384 }
1385 if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
1386 vcpu->arch.mmu.prefetch_page(vcpu, sp);
1387 else
1388 nonpaging_prefetch_page(vcpu, sp);
1389 trace_kvm_mmu_get_page(sp, true);
1390 return sp;
1391 }
1392
1393 static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
1394 struct kvm_vcpu *vcpu, u64 addr)
1395 {
1396 iterator->addr = addr;
1397 iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
1398 iterator->level = vcpu->arch.mmu.shadow_root_level;
1399 if (iterator->level == PT32E_ROOT_LEVEL) {
1400 iterator->shadow_addr
1401 = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
1402 iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
1403 --iterator->level;
1404 if (!iterator->shadow_addr)
1405 iterator->level = 0;
1406 }
1407 }
1408
1409 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
1410 {
1411 if (iterator->level < PT_PAGE_TABLE_LEVEL)
1412 return false;
1413
1414 if (iterator->level == PT_PAGE_TABLE_LEVEL)
1415 if (is_large_pte(*iterator->sptep))
1416 return false;
1417
1418 iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
1419 iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
1420 return true;
1421 }
1422
1423 static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
1424 {
1425 iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
1426 --iterator->level;
1427 }
1428
1429 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1430 struct kvm_mmu_page *sp)
1431 {
1432 unsigned i;
1433 u64 *pt;
1434 u64 ent;
1435
1436 pt = sp->spt;
1437
1438 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1439 ent = pt[i];
1440
1441 if (is_shadow_present_pte(ent)) {
1442 if (!is_last_spte(ent, sp->role.level)) {
1443 ent &= PT64_BASE_ADDR_MASK;
1444 mmu_page_remove_parent_pte(page_header(ent),
1445 &pt[i]);
1446 } else {
1447 if (is_large_pte(ent))
1448 --kvm->stat.lpages;
1449 rmap_remove(kvm, &pt[i]);
1450 }
1451 }
1452 pt[i] = shadow_trap_nonpresent_pte;
1453 }
1454 }
1455
1456 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1457 {
1458 mmu_page_remove_parent_pte(sp, parent_pte);
1459 }
1460
1461 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1462 {
1463 int i;
1464 struct kvm_vcpu *vcpu;
1465
1466 kvm_for_each_vcpu(i, vcpu, kvm)
1467 vcpu->arch.last_pte_updated = NULL;
1468 }
1469
1470 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1471 {
1472 u64 *parent_pte;
1473
1474 while (sp->multimapped || sp->parent_pte) {
1475 if (!sp->multimapped)
1476 parent_pte = sp->parent_pte;
1477 else {
1478 struct kvm_pte_chain *chain;
1479
1480 chain = container_of(sp->parent_ptes.first,
1481 struct kvm_pte_chain, link);
1482 parent_pte = chain->parent_ptes[0];
1483 }
1484 BUG_ON(!parent_pte);
1485 kvm_mmu_put_page(sp, parent_pte);
1486 __set_spte(parent_pte, shadow_trap_nonpresent_pte);
1487 }
1488 }
1489
1490 static int mmu_zap_unsync_children(struct kvm *kvm,
1491 struct kvm_mmu_page *parent)
1492 {
1493 int i, zapped = 0;
1494 struct mmu_page_path parents;
1495 struct kvm_mmu_pages pages;
1496
1497 if (parent->role.level == PT_PAGE_TABLE_LEVEL)
1498 return 0;
1499
1500 kvm_mmu_pages_init(parent, &parents, &pages);
1501 while (mmu_unsync_walk(parent, &pages)) {
1502 struct kvm_mmu_page *sp;
1503
1504 for_each_sp(pages, sp, parents, i) {
1505 kvm_mmu_zap_page(kvm, sp);
1506 mmu_pages_clear_parents(&parents);
1507 }
1508 zapped += pages.nr;
1509 kvm_mmu_pages_init(parent, &parents, &pages);
1510 }
1511
1512 return zapped;
1513 }
1514
1515 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1516 {
1517 int ret;
1518
1519 trace_kvm_mmu_zap_page(sp);
1520 ++kvm->stat.mmu_shadow_zapped;
1521 ret = mmu_zap_unsync_children(kvm, sp);
1522 kvm_mmu_page_unlink_children(kvm, sp);
1523 kvm_mmu_unlink_parents(kvm, sp);
1524 kvm_flush_remote_tlbs(kvm);
1525 if (!sp->role.invalid && !sp->role.direct)
1526 unaccount_shadowed(kvm, sp->gfn);
1527 if (sp->unsync)
1528 kvm_unlink_unsync_page(kvm, sp);
1529 if (!sp->root_count) {
1530 hlist_del(&sp->hash_link);
1531 kvm_mmu_free_page(kvm, sp);
1532 } else {
1533 sp->role.invalid = 1;
1534 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1535 kvm_reload_remote_mmus(kvm);
1536 }
1537 kvm_mmu_reset_last_pte_updated(kvm);
1538 return ret;
1539 }
1540
1541 /*
1542 * Changing the number of mmu pages allocated to the vm
1543 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1544 */
1545 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1546 {
1547 int used_pages;
1548
1549 used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
1550 used_pages = max(0, used_pages);
1551
1552 /*
1553 * If we set the number of mmu pages to be smaller be than the
1554 * number of actived pages , we must to free some mmu pages before we
1555 * change the value
1556 */
1557
1558 if (used_pages > kvm_nr_mmu_pages) {
1559 while (used_pages > kvm_nr_mmu_pages) {
1560 struct kvm_mmu_page *page;
1561
1562 page = container_of(kvm->arch.active_mmu_pages.prev,
1563 struct kvm_mmu_page, link);
1564 kvm_mmu_zap_page(kvm, page);
1565 used_pages--;
1566 }
1567 kvm->arch.n_free_mmu_pages = 0;
1568 }
1569 else
1570 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1571 - kvm->arch.n_alloc_mmu_pages;
1572
1573 kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1574 }
1575
1576 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1577 {
1578 unsigned index;
1579 struct hlist_head *bucket;
1580 struct kvm_mmu_page *sp;
1581 struct hlist_node *node, *n;
1582 int r;
1583
1584 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1585 r = 0;
1586 index = kvm_page_table_hashfn(gfn);
1587 bucket = &kvm->arch.mmu_page_hash[index];
1588 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1589 if (sp->gfn == gfn && !sp->role.direct) {
1590 pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1591 sp->role.word);
1592 r = 1;
1593 if (kvm_mmu_zap_page(kvm, sp))
1594 n = bucket->first;
1595 }
1596 return r;
1597 }
1598
1599 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1600 {
1601 unsigned index;
1602 struct hlist_head *bucket;
1603 struct kvm_mmu_page *sp;
1604 struct hlist_node *node, *nn;
1605
1606 index = kvm_page_table_hashfn(gfn);
1607 bucket = &kvm->arch.mmu_page_hash[index];
1608 hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {
1609 if (sp->gfn == gfn && !sp->role.direct
1610 && !sp->role.invalid) {
1611 pgprintk("%s: zap %lx %x\n",
1612 __func__, gfn, sp->role.word);
1613 kvm_mmu_zap_page(kvm, sp);
1614 }
1615 }
1616 }
1617
1618 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1619 {
1620 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1621 struct kvm_mmu_page *sp = page_header(__pa(pte));
1622
1623 __set_bit(slot, sp->slot_bitmap);
1624 }
1625
1626 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
1627 {
1628 int i;
1629 u64 *pt = sp->spt;
1630
1631 if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
1632 return;
1633
1634 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1635 if (pt[i] == shadow_notrap_nonpresent_pte)
1636 __set_spte(&pt[i], shadow_trap_nonpresent_pte);
1637 }
1638 }
1639
1640 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1641 {
1642 struct page *page;
1643
1644 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1645
1646 if (gpa == UNMAPPED_GVA)
1647 return NULL;
1648
1649 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1650
1651 return page;
1652 }
1653
1654 /*
1655 * The function is based on mtrr_type_lookup() in
1656 * arch/x86/kernel/cpu/mtrr/generic.c
1657 */
1658 static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
1659 u64 start, u64 end)
1660 {
1661 int i;
1662 u64 base, mask;
1663 u8 prev_match, curr_match;
1664 int num_var_ranges = KVM_NR_VAR_MTRR;
1665
1666 if (!mtrr_state->enabled)
1667 return 0xFF;
1668
1669 /* Make end inclusive end, instead of exclusive */
1670 end--;
1671
1672 /* Look in fixed ranges. Just return the type as per start */
1673 if (mtrr_state->have_fixed && (start < 0x100000)) {
1674 int idx;
1675
1676 if (start < 0x80000) {
1677 idx = 0;
1678 idx += (start >> 16);
1679 return mtrr_state->fixed_ranges[idx];
1680 } else if (start < 0xC0000) {
1681 idx = 1 * 8;
1682 idx += ((start - 0x80000) >> 14);
1683 return mtrr_state->fixed_ranges[idx];
1684 } else if (start < 0x1000000) {
1685 idx = 3 * 8;
1686 idx += ((start - 0xC0000) >> 12);
1687 return mtrr_state->fixed_ranges[idx];
1688 }
1689 }
1690
1691 /*
1692 * Look in variable ranges
1693 * Look of multiple ranges matching this address and pick type
1694 * as per MTRR precedence
1695 */
1696 if (!(mtrr_state->enabled & 2))
1697 return mtrr_state->def_type;
1698
1699 prev_match = 0xFF;
1700 for (i = 0; i < num_var_ranges; ++i) {
1701 unsigned short start_state, end_state;
1702
1703 if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
1704 continue;
1705
1706 base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
1707 (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
1708 mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
1709 (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
1710
1711 start_state = ((start & mask) == (base & mask));
1712 end_state = ((end & mask) == (base & mask));
1713 if (start_state != end_state)
1714 return 0xFE;
1715
1716 if ((start & mask) != (base & mask))
1717 continue;
1718
1719 curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
1720 if (prev_match == 0xFF) {
1721 prev_match = curr_match;
1722 continue;
1723 }
1724
1725 if (prev_match == MTRR_TYPE_UNCACHABLE ||
1726 curr_match == MTRR_TYPE_UNCACHABLE)
1727 return MTRR_TYPE_UNCACHABLE;
1728
1729 if ((prev_match == MTRR_TYPE_WRBACK &&
1730 curr_match == MTRR_TYPE_WRTHROUGH) ||
1731 (prev_match == MTRR_TYPE_WRTHROUGH &&
1732 curr_match == MTRR_TYPE_WRBACK)) {
1733 prev_match = MTRR_TYPE_WRTHROUGH;
1734 curr_match = MTRR_TYPE_WRTHROUGH;
1735 }
1736
1737 if (prev_match != curr_match)
1738 return MTRR_TYPE_UNCACHABLE;
1739 }
1740
1741 if (prev_match != 0xFF)
1742 return prev_match;
1743
1744 return mtrr_state->def_type;
1745 }
1746
1747 u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
1748 {
1749 u8 mtrr;
1750
1751 mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
1752 (gfn << PAGE_SHIFT) + PAGE_SIZE);
1753 if (mtrr == 0xfe || mtrr == 0xff)
1754 mtrr = MTRR_TYPE_WRBACK;
1755 return mtrr;
1756 }
1757 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
1758
1759 static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1760 {
1761 unsigned index;
1762 struct hlist_head *bucket;
1763 struct kvm_mmu_page *s;
1764 struct hlist_node *node, *n;
1765
1766 trace_kvm_mmu_unsync_page(sp);
1767 index = kvm_page_table_hashfn(sp->gfn);
1768 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1769 /* don't unsync if pagetable is shadowed with multiple roles */
1770 hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
1771 if (s->gfn != sp->gfn || s->role.direct)
1772 continue;
1773 if (s->role.word != sp->role.word)
1774 return 1;
1775 }
1776 ++vcpu->kvm->stat.mmu_unsync;
1777 sp->unsync = 1;
1778
1779 kvm_mmu_mark_parents_unsync(vcpu, sp);
1780
1781 mmu_convert_notrap(sp);
1782 return 0;
1783 }
1784
1785 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
1786 bool can_unsync)
1787 {
1788 struct kvm_mmu_page *shadow;
1789
1790 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1791 if (shadow) {
1792 if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
1793 return 1;
1794 if (shadow->unsync)
1795 return 0;
1796 if (can_unsync && oos_shadow)
1797 return kvm_unsync_page(vcpu, shadow);
1798 return 1;
1799 }
1800 return 0;
1801 }
1802
1803 static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1804 unsigned pte_access, int user_fault,
1805 int write_fault, int dirty, int level,
1806 gfn_t gfn, pfn_t pfn, bool speculative,
1807 bool can_unsync, bool reset_host_protection)
1808 {
1809 u64 spte;
1810 int ret = 0;
1811
1812 /*
1813 * We don't set the accessed bit, since we sometimes want to see
1814 * whether the guest actually used the pte (in order to detect
1815 * demand paging).
1816 */
1817 spte = shadow_base_present_pte | shadow_dirty_mask;
1818 if (!speculative)
1819 spte |= shadow_accessed_mask;
1820 if (!dirty)
1821 pte_access &= ~ACC_WRITE_MASK;
1822 if (pte_access & ACC_EXEC_MASK)
1823 spte |= shadow_x_mask;
1824 else
1825 spte |= shadow_nx_mask;
1826 if (pte_access & ACC_USER_MASK)
1827 spte |= shadow_user_mask;
1828 if (level > PT_PAGE_TABLE_LEVEL)
1829 spte |= PT_PAGE_SIZE_MASK;
1830 if (tdp_enabled)
1831 spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
1832 kvm_is_mmio_pfn(pfn));
1833
1834 if (reset_host_protection)
1835 spte |= SPTE_HOST_WRITEABLE;
1836
1837 spte |= (u64)pfn << PAGE_SHIFT;
1838
1839 if ((pte_access & ACC_WRITE_MASK)
1840 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1841
1842 if (level > PT_PAGE_TABLE_LEVEL &&
1843 has_wrprotected_page(vcpu->kvm, gfn, level)) {
1844 ret = 1;
1845 spte = shadow_trap_nonpresent_pte;
1846 goto set_pte;
1847 }
1848
1849 spte |= PT_WRITABLE_MASK;
1850
1851 /*
1852 * Optimization: for pte sync, if spte was writable the hash
1853 * lookup is unnecessary (and expensive). Write protection
1854 * is responsibility of mmu_get_page / kvm_sync_page.
1855 * Same reasoning can be applied to dirty page accounting.
1856 */
1857 if (!can_unsync && is_writeble_pte(*sptep))
1858 goto set_pte;
1859
1860 if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
1861 pgprintk("%s: found shadow page for %lx, marking ro\n",
1862 __func__, gfn);
1863 ret = 1;
1864 pte_access &= ~ACC_WRITE_MASK;
1865 if (is_writeble_pte(spte))
1866 spte &= ~PT_WRITABLE_MASK;
1867 }
1868 }
1869
1870 if (pte_access & ACC_WRITE_MASK)
1871 mark_page_dirty(vcpu->kvm, gfn);
1872
1873 set_pte:
1874 __set_spte(sptep, spte);
1875 return ret;
1876 }
1877
1878 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1879 unsigned pt_access, unsigned pte_access,
1880 int user_fault, int write_fault, int dirty,
1881 int *ptwrite, int level, gfn_t gfn,
1882 pfn_t pfn, bool speculative,
1883 bool reset_host_protection)
1884 {
1885 int was_rmapped = 0;
1886 int was_writeble = is_writeble_pte(*sptep);
1887 int rmap_count;
1888
1889 pgprintk("%s: spte %llx access %x write_fault %d"
1890 " user_fault %d gfn %lx\n",
1891 __func__, *sptep, pt_access,
1892 write_fault, user_fault, gfn);
1893
1894 if (is_rmap_spte(*sptep)) {
1895 /*
1896 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1897 * the parent of the now unreachable PTE.
1898 */
1899 if (level > PT_PAGE_TABLE_LEVEL &&
1900 !is_large_pte(*sptep)) {
1901 struct kvm_mmu_page *child;
1902 u64 pte = *sptep;
1903
1904 child = page_header(pte & PT64_BASE_ADDR_MASK);
1905 mmu_page_remove_parent_pte(child, sptep);
1906 } else if (pfn != spte_to_pfn(*sptep)) {
1907 pgprintk("hfn old %lx new %lx\n",
1908 spte_to_pfn(*sptep), pfn);
1909 rmap_remove(vcpu->kvm, sptep);
1910 } else
1911 was_rmapped = 1;
1912 }
1913
1914 if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
1915 dirty, level, gfn, pfn, speculative, true,
1916 reset_host_protection)) {
1917 if (write_fault)
1918 *ptwrite = 1;
1919 kvm_x86_ops->tlb_flush(vcpu);
1920 }
1921
1922 pgprintk("%s: setting spte %llx\n", __func__, *sptep);
1923 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1924 is_large_pte(*sptep)? "2MB" : "4kB",
1925 *sptep & PT_PRESENT_MASK ?"RW":"R", gfn,
1926 *sptep, sptep);
1927 if (!was_rmapped && is_large_pte(*sptep))
1928 ++vcpu->kvm->stat.lpages;
1929
1930 page_header_update_slot(vcpu->kvm, sptep, gfn);
1931 if (!was_rmapped) {
1932 rmap_count = rmap_add(vcpu, sptep, gfn);
1933 kvm_release_pfn_clean(pfn);
1934 if (rmap_count > RMAP_RECYCLE_THRESHOLD)
1935 rmap_recycle(vcpu, sptep, gfn);
1936 } else {
1937 if (was_writeble)
1938 kvm_release_pfn_dirty(pfn);
1939 else
1940 kvm_release_pfn_clean(pfn);
1941 }
1942 if (speculative) {
1943 vcpu->arch.last_pte_updated = sptep;
1944 vcpu->arch.last_pte_gfn = gfn;
1945 }
1946 }
1947
1948 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1949 {
1950 }
1951
1952 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1953 int level, gfn_t gfn, pfn_t pfn)
1954 {
1955 struct kvm_shadow_walk_iterator iterator;
1956 struct kvm_mmu_page *sp;
1957 int pt_write = 0;
1958 gfn_t pseudo_gfn;
1959
1960 for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
1961 if (iterator.level == level) {
1962 mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
1963 0, write, 1, &pt_write,
1964 level, gfn, pfn, false, true);
1965 ++vcpu->stat.pf_fixed;
1966 break;
1967 }
1968
1969 if (*iterator.sptep == shadow_trap_nonpresent_pte) {
1970 pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1971 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
1972 iterator.level - 1,
1973 1, ACC_ALL, iterator.sptep);
1974 if (!sp) {
1975 pgprintk("nonpaging_map: ENOMEM\n");
1976 kvm_release_pfn_clean(pfn);
1977 return -ENOMEM;
1978 }
1979
1980 __set_spte(iterator.sptep,
1981 __pa(sp->spt)
1982 | PT_PRESENT_MASK | PT_WRITABLE_MASK
1983 | shadow_user_mask | shadow_x_mask);
1984 }
1985 }
1986 return pt_write;
1987 }
1988
1989 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1990 {
1991 int r;
1992 int level;
1993 pfn_t pfn;
1994 unsigned long mmu_seq;
1995
1996 level = mapping_level(vcpu, gfn);
1997
1998 /*
1999 * This path builds a PAE pagetable - so we can map 2mb pages at
2000 * maximum. Therefore check if the level is larger than that.
2001 */
2002 if (level > PT_DIRECTORY_LEVEL)
2003 level = PT_DIRECTORY_LEVEL;
2004
2005 gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2006
2007 mmu_seq = vcpu->kvm->mmu_notifier_seq;
2008 smp_rmb();
2009 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2010
2011 /* mmio */
2012 if (is_error_pfn(pfn)) {
2013 kvm_release_pfn_clean(pfn);
2014 return 1;
2015 }
2016
2017 spin_lock(&vcpu->kvm->mmu_lock);
2018 if (mmu_notifier_retry(vcpu, mmu_seq))
2019 goto out_unlock;
2020 kvm_mmu_free_some_pages(vcpu);
2021 r = __direct_map(vcpu, v, write, level, gfn, pfn);
2022 spin_unlock(&vcpu->kvm->mmu_lock);
2023
2024
2025 return r;
2026
2027 out_unlock:
2028 spin_unlock(&vcpu->kvm->mmu_lock);
2029 kvm_release_pfn_clean(pfn);
2030 return 0;
2031 }
2032
2033
2034 static void mmu_free_roots(struct kvm_vcpu *vcpu)
2035 {
2036 int i;
2037 struct kvm_mmu_page *sp;
2038
2039 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2040 return;
2041 spin_lock(&vcpu->kvm->mmu_lock);
2042 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2043 hpa_t root = vcpu->arch.mmu.root_hpa;
2044
2045 sp = page_header(root);
2046 --sp->root_count;
2047 if (!sp->root_count && sp->role.invalid)
2048 kvm_mmu_zap_page(vcpu->kvm, sp);
2049 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2050 spin_unlock(&vcpu->kvm->mmu_lock);
2051 return;
2052 }
2053 for (i = 0; i < 4; ++i) {
2054 hpa_t root = vcpu->arch.mmu.pae_root[i];
2055
2056 if (root) {
2057 root &= PT64_BASE_ADDR_MASK;
2058 sp = page_header(root);
2059 --sp->root_count;
2060 if (!sp->root_count && sp->role.invalid)
2061 kvm_mmu_zap_page(vcpu->kvm, sp);
2062 }
2063 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2064 }
2065 spin_unlock(&vcpu->kvm->mmu_lock);
2066 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2067 }
2068
2069 static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
2070 {
2071 int ret = 0;
2072
2073 if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
2074 set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
2075 ret = 1;
2076 }
2077
2078 return ret;
2079 }
2080
2081 static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
2082 {
2083 int i;
2084 gfn_t root_gfn;
2085 struct kvm_mmu_page *sp;
2086 int direct = 0;
2087 u64 pdptr;
2088
2089 root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
2090
2091 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2092 hpa_t root = vcpu->arch.mmu.root_hpa;
2093
2094 ASSERT(!VALID_PAGE(root));
2095 if (tdp_enabled)
2096 direct = 1;
2097 if (mmu_check_root(vcpu, root_gfn))
2098 return 1;
2099 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
2100 PT64_ROOT_LEVEL, direct,
2101 ACC_ALL, NULL);
2102 root = __pa(sp->spt);
2103 ++sp->root_count;
2104 vcpu->arch.mmu.root_hpa = root;
2105 return 0;
2106 }
2107 direct = !is_paging(vcpu);
2108 if (tdp_enabled)
2109 direct = 1;
2110 for (i = 0; i < 4; ++i) {
2111 hpa_t root = vcpu->arch.mmu.pae_root[i];
2112
2113 ASSERT(!VALID_PAGE(root));
2114 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
2115 pdptr = kvm_pdptr_read(vcpu, i);
2116 if (!is_present_gpte(pdptr)) {
2117 vcpu->arch.mmu.pae_root[i] = 0;
2118 continue;
2119 }
2120 root_gfn = pdptr >> PAGE_SHIFT;
2121 } else if (vcpu->arch.mmu.root_level == 0)
2122 root_gfn = 0;
2123 if (mmu_check_root(vcpu, root_gfn))
2124 return 1;
2125 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
2126 PT32_ROOT_LEVEL, direct,
2127 ACC_ALL, NULL);
2128 root = __pa(sp->spt);
2129 ++sp->root_count;
2130 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
2131 }
2132 vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
2133 return 0;
2134 }
2135
2136 static void mmu_sync_roots(struct kvm_vcpu *vcpu)
2137 {
2138 int i;
2139 struct kvm_mmu_page *sp;
2140
2141 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2142 return;
2143 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2144 hpa_t root = vcpu->arch.mmu.root_hpa;
2145 sp = page_header(root);
2146 mmu_sync_children(vcpu, sp);
2147 return;
2148 }
2149 for (i = 0; i < 4; ++i) {
2150 hpa_t root = vcpu->arch.mmu.pae_root[i];
2151
2152 if (root && VALID_PAGE(root)) {
2153 root &= PT64_BASE_ADDR_MASK;
2154 sp = page_header(root);
2155 mmu_sync_children(vcpu, sp);
2156 }
2157 }
2158 }
2159
2160 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
2161 {
2162 spin_lock(&vcpu->kvm->mmu_lock);
2163 mmu_sync_roots(vcpu);
2164 spin_unlock(&vcpu->kvm->mmu_lock);
2165 }
2166
2167 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
2168 {
2169 return vaddr;
2170 }
2171
2172 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
2173 u32 error_code)
2174 {
2175 gfn_t gfn;
2176 int r;
2177
2178 pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
2179 r = mmu_topup_memory_caches(vcpu);
2180 if (r)
2181 return r;
2182
2183 ASSERT(vcpu);
2184 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2185
2186 gfn = gva >> PAGE_SHIFT;
2187
2188 return nonpaging_map(vcpu, gva & PAGE_MASK,
2189 error_code & PFERR_WRITE_MASK, gfn);
2190 }
2191
2192 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
2193 u32 error_code)
2194 {
2195 pfn_t pfn;
2196 int r;
2197 int level;
2198 gfn_t gfn = gpa >> PAGE_SHIFT;
2199 unsigned long mmu_seq;
2200
2201 ASSERT(vcpu);
2202 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2203
2204 r = mmu_topup_memory_caches(vcpu);
2205 if (r)
2206 return r;
2207
2208 level = mapping_level(vcpu, gfn);
2209
2210 gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2211
2212 mmu_seq = vcpu->kvm->mmu_notifier_seq;
2213 smp_rmb();
2214 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2215 if (is_error_pfn(pfn)) {
2216 kvm_release_pfn_clean(pfn);
2217 return 1;
2218 }
2219 spin_lock(&vcpu->kvm->mmu_lock);
2220 if (mmu_notifier_retry(vcpu, mmu_seq))
2221 goto out_unlock;
2222 kvm_mmu_free_some_pages(vcpu);
2223 r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
2224 level, gfn, pfn);
2225 spin_unlock(&vcpu->kvm->mmu_lock);
2226
2227 return r;
2228
2229 out_unlock:
2230 spin_unlock(&vcpu->kvm->mmu_lock);
2231 kvm_release_pfn_clean(pfn);
2232 return 0;
2233 }
2234
2235 static void nonpaging_free(struct kvm_vcpu *vcpu)
2236 {
2237 mmu_free_roots(vcpu);
2238 }
2239
2240 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
2241 {
2242 struct kvm_mmu *context = &vcpu->arch.mmu;
2243
2244 context->new_cr3 = nonpaging_new_cr3;
2245 context->page_fault = nonpaging_page_fault;
2246 context->gva_to_gpa = nonpaging_gva_to_gpa;
2247 context->free = nonpaging_free;
2248 context->prefetch_page = nonpaging_prefetch_page;
2249 context->sync_page = nonpaging_sync_page;
2250 context->invlpg = nonpaging_invlpg;
2251 context->root_level = 0;
2252 context->shadow_root_level = PT32E_ROOT_LEVEL;
2253 context->root_hpa = INVALID_PAGE;
2254 return 0;
2255 }
2256
2257 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2258 {
2259 ++vcpu->stat.tlb_flush;
2260 kvm_x86_ops->tlb_flush(vcpu);
2261 }
2262
2263 static void paging_new_cr3(struct kvm_vcpu *vcpu)
2264 {
2265 pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
2266 mmu_free_roots(vcpu);
2267 }
2268
2269 static void inject_page_fault(struct kvm_vcpu *vcpu,
2270 u64 addr,
2271 u32 err_code)
2272 {
2273 kvm_inject_page_fault(vcpu, addr, err_code);
2274 }
2275
2276 static void paging_free(struct kvm_vcpu *vcpu)
2277 {
2278 nonpaging_free(vcpu);
2279 }
2280
2281 static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level)
2282 {
2283 int bit7;
2284
2285 bit7 = (gpte >> 7) & 1;
2286 return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0;
2287 }
2288
2289 #define PTTYPE 64
2290 #include "paging_tmpl.h"
2291 #undef PTTYPE
2292
2293 #define PTTYPE 32
2294 #include "paging_tmpl.h"
2295 #undef PTTYPE
2296
2297 static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level)
2298 {
2299 struct kvm_mmu *context = &vcpu->arch.mmu;
2300 int maxphyaddr = cpuid_maxphyaddr(vcpu);
2301 u64 exb_bit_rsvd = 0;
2302
2303 if (!is_nx(vcpu))
2304 exb_bit_rsvd = rsvd_bits(63, 63);
2305 switch (level) {
2306 case PT32_ROOT_LEVEL:
2307 /* no rsvd bits for 2 level 4K page table entries */
2308 context->rsvd_bits_mask[0][1] = 0;
2309 context->rsvd_bits_mask[0][0] = 0;
2310 if (is_cpuid_PSE36())
2311 /* 36bits PSE 4MB page */
2312 context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21);
2313 else
2314 /* 32 bits PSE 4MB page */
2315 context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21);
2316 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2317 break;
2318 case PT32E_ROOT_LEVEL:
2319 context->rsvd_bits_mask[0][2] =
2320 rsvd_bits(maxphyaddr, 63) |
2321 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
2322 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2323 rsvd_bits(maxphyaddr, 62); /* PDE */
2324 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2325 rsvd_bits(maxphyaddr, 62); /* PTE */
2326 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2327 rsvd_bits(maxphyaddr, 62) |
2328 rsvd_bits(13, 20); /* large page */
2329 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2330 break;
2331 case PT64_ROOT_LEVEL:
2332 context->rsvd_bits_mask[0][3] = exb_bit_rsvd |
2333 rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2334 context->rsvd_bits_mask[0][2] = exb_bit_rsvd |
2335 rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2336 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2337 rsvd_bits(maxphyaddr, 51);
2338 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2339 rsvd_bits(maxphyaddr, 51);
2340 context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];
2341 context->rsvd_bits_mask[1][2] = exb_bit_rsvd |
2342 rsvd_bits(maxphyaddr, 51) |
2343 rsvd_bits(13, 29);
2344 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2345 rsvd_bits(maxphyaddr, 51) |
2346 rsvd_bits(13, 20); /* large page */
2347 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2348 break;
2349 }
2350 }
2351
2352 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
2353 {
2354 struct kvm_mmu *context = &vcpu->arch.mmu;
2355
2356 ASSERT(is_pae(vcpu));
2357 context->new_cr3 = paging_new_cr3;
2358 context->page_fault = paging64_page_fault;
2359 context->gva_to_gpa = paging64_gva_to_gpa;
2360 context->prefetch_page = paging64_prefetch_page;
2361 context->sync_page = paging64_sync_page;
2362 context->invlpg = paging64_invlpg;
2363 context->free = paging_free;
2364 context->root_level = level;
2365 context->shadow_root_level = level;
2366 context->root_hpa = INVALID_PAGE;
2367 return 0;
2368 }
2369
2370 static int paging64_init_context(struct kvm_vcpu *vcpu)
2371 {
2372 reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2373 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
2374 }
2375
2376 static int paging32_init_context(struct kvm_vcpu *vcpu)
2377 {
2378 struct kvm_mmu *context = &vcpu->arch.mmu;
2379
2380 reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2381 context->new_cr3 = paging_new_cr3;
2382 context->page_fault = paging32_page_fault;
2383 context->gva_to_gpa = paging32_gva_to_gpa;
2384 context->free = paging_free;
2385 context->prefetch_page = paging32_prefetch_page;
2386 context->sync_page = paging32_sync_page;
2387 context->invlpg = paging32_invlpg;
2388 context->root_level = PT32_ROOT_LEVEL;
2389 context->shadow_root_level = PT32E_ROOT_LEVEL;
2390 context->root_hpa = INVALID_PAGE;
2391 return 0;
2392 }
2393
2394 static int paging32E_init_context(struct kvm_vcpu *vcpu)
2395 {
2396 reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2397 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
2398 }
2399
2400 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
2401 {
2402 struct kvm_mmu *context = &vcpu->arch.mmu;
2403
2404 context->new_cr3 = nonpaging_new_cr3;
2405 context->page_fault = tdp_page_fault;
2406 context->free = nonpaging_free;
2407 context->prefetch_page = nonpaging_prefetch_page;
2408 context->sync_page = nonpaging_sync_page;
2409 context->invlpg = nonpaging_invlpg;
2410 context->shadow_root_level = kvm_x86_ops->get_tdp_level();
2411 context->root_hpa = INVALID_PAGE;
2412
2413 if (!is_paging(vcpu)) {
2414 context->gva_to_gpa = nonpaging_gva_to_gpa;
2415 context->root_level = 0;
2416 } else if (is_long_mode(vcpu)) {
2417 reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2418 context->gva_to_gpa = paging64_gva_to_gpa;
2419 context->root_level = PT64_ROOT_LEVEL;
2420 } else if (is_pae(vcpu)) {
2421 reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2422 context->gva_to_gpa = paging64_gva_to_gpa;
2423 context->root_level = PT32E_ROOT_LEVEL;
2424 } else {
2425 reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2426 context->gva_to_gpa = paging32_gva_to_gpa;
2427 context->root_level = PT32_ROOT_LEVEL;
2428 }
2429
2430 return 0;
2431 }
2432
2433 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
2434 {
2435 int r;
2436
2437 ASSERT(vcpu);
2438 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2439
2440 if (!is_paging(vcpu))
2441 r = nonpaging_init_context(vcpu);
2442 else if (is_long_mode(vcpu))
2443 r = paging64_init_context(vcpu);
2444 else if (is_pae(vcpu))
2445 r = paging32E_init_context(vcpu);
2446 else
2447 r = paging32_init_context(vcpu);
2448
2449 vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level;
2450
2451 return r;
2452 }
2453
2454 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
2455 {
2456 vcpu->arch.update_pte.pfn = bad_pfn;
2457
2458 if (tdp_enabled)
2459 return init_kvm_tdp_mmu(vcpu);
2460 else
2461 return init_kvm_softmmu(vcpu);
2462 }
2463
2464 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
2465 {
2466 ASSERT(vcpu);
2467 if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
2468 vcpu->arch.mmu.free(vcpu);
2469 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2470 }
2471 }
2472
2473 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
2474 {
2475 destroy_kvm_mmu(vcpu);
2476 return init_kvm_mmu(vcpu);
2477 }
2478 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
2479
2480 int kvm_mmu_load(struct kvm_vcpu *vcpu)
2481 {
2482 int r;
2483
2484 r = mmu_topup_memory_caches(vcpu);
2485 if (r)
2486 goto out;
2487 spin_lock(&vcpu->kvm->mmu_lock);
2488 kvm_mmu_free_some_pages(vcpu);
2489 r = mmu_alloc_roots(vcpu);
2490 mmu_sync_roots(vcpu);
2491 spin_unlock(&vcpu->kvm->mmu_lock);
2492 if (r)
2493 goto out;
2494 /* set_cr3() should ensure TLB has been flushed */
2495 kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
2496 out:
2497 return r;
2498 }
2499 EXPORT_SYMBOL_GPL(kvm_mmu_load);
2500
2501 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
2502 {
2503 mmu_free_roots(vcpu);
2504 }
2505
2506 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
2507 struct kvm_mmu_page *sp,
2508 u64 *spte)
2509 {
2510 u64 pte;
2511 struct kvm_mmu_page *child;
2512
2513 pte = *spte;
2514 if (is_shadow_present_pte(pte)) {
2515 if (is_last_spte(pte, sp->role.level))
2516 rmap_remove(vcpu->kvm, spte);
2517 else {
2518 child = page_header(pte & PT64_BASE_ADDR_MASK);
2519 mmu_page_remove_parent_pte(child, spte);
2520 }
2521 }
2522 __set_spte(spte, shadow_trap_nonpresent_pte);
2523 if (is_large_pte(pte))
2524 --vcpu->kvm->stat.lpages;
2525 }
2526
2527 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
2528 struct kvm_mmu_page *sp,
2529 u64 *spte,
2530 const void *new)
2531 {
2532 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
2533 ++vcpu->kvm->stat.mmu_pde_zapped;
2534 return;
2535 }
2536
2537 ++vcpu->kvm->stat.mmu_pte_updated;
2538 if (sp->role.glevels == PT32_ROOT_LEVEL)
2539 paging32_update_pte(vcpu, sp, spte, new);
2540 else
2541 paging64_update_pte(vcpu, sp, spte, new);
2542 }
2543
2544 static bool need_remote_flush(u64 old, u64 new)
2545 {
2546 if (!is_shadow_present_pte(old))
2547 return false;
2548 if (!is_shadow_present_pte(new))
2549 return true;
2550 if ((old ^ new) & PT64_BASE_ADDR_MASK)
2551 return true;
2552 old ^= PT64_NX_MASK;
2553 new ^= PT64_NX_MASK;
2554 return (old & ~new & PT64_PERM_MASK) != 0;
2555 }
2556
2557 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
2558 {
2559 if (need_remote_flush(old, new))
2560 kvm_flush_remote_tlbs(vcpu->kvm);
2561 else
2562 kvm_mmu_flush_tlb(vcpu);
2563 }
2564
2565 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
2566 {
2567 u64 *spte = vcpu->arch.last_pte_updated;
2568
2569 return !!(spte && (*spte & shadow_accessed_mask));
2570 }
2571
2572 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2573 const u8 *new, int bytes)
2574 {
2575 gfn_t gfn;
2576 int r;
2577 u64 gpte = 0;
2578 pfn_t pfn;
2579
2580 if (bytes != 4 && bytes != 8)
2581 return;
2582
2583 /*
2584 * Assume that the pte write on a page table of the same type
2585 * as the current vcpu paging mode. This is nearly always true
2586 * (might be false while changing modes). Note it is verified later
2587 * by update_pte().
2588 */
2589 if (is_pae(vcpu)) {
2590 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2591 if ((bytes == 4) && (gpa % 4 == 0)) {
2592 r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
2593 if (r)
2594 return;
2595 memcpy((void *)&gpte + (gpa % 8), new, 4);
2596 } else if ((bytes == 8) && (gpa % 8 == 0)) {
2597 memcpy((void *)&gpte, new, 8);
2598 }
2599 } else {
2600 if ((bytes == 4) && (gpa % 4 == 0))
2601 memcpy((void *)&gpte, new, 4);
2602 }
2603 if (!is_present_gpte(gpte))
2604 return;
2605 gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
2606
2607 vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
2608 smp_rmb();
2609 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2610
2611 if (is_error_pfn(pfn)) {
2612 kvm_release_pfn_clean(pfn);
2613 return;
2614 }
2615 vcpu->arch.update_pte.gfn = gfn;
2616 vcpu->arch.update_pte.pfn = pfn;
2617 }
2618
2619 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
2620 {
2621 u64 *spte = vcpu->arch.last_pte_updated;
2622
2623 if (spte
2624 && vcpu->arch.last_pte_gfn == gfn
2625 && shadow_accessed_mask
2626 && !(*spte & shadow_accessed_mask)
2627 && is_shadow_present_pte(*spte))
2628 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
2629 }
2630
2631 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2632 const u8 *new, int bytes,
2633 bool guest_initiated)
2634 {
2635 gfn_t gfn = gpa >> PAGE_SHIFT;
2636 struct kvm_mmu_page *sp;
2637 struct hlist_node *node, *n;
2638 struct hlist_head *bucket;
2639 unsigned index;
2640 u64 entry, gentry;
2641 u64 *spte;
2642 unsigned offset = offset_in_page(gpa);
2643 unsigned pte_size;
2644 unsigned page_offset;
2645 unsigned misaligned;
2646 unsigned quadrant;
2647 int level;
2648 int flooded = 0;
2649 int npte;
2650 int r;
2651
2652 pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
2653 mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
2654 spin_lock(&vcpu->kvm->mmu_lock);
2655 kvm_mmu_access_page(vcpu, gfn);
2656 kvm_mmu_free_some_pages(vcpu);
2657 ++vcpu->kvm->stat.mmu_pte_write;
2658 kvm_mmu_audit(vcpu, "pre pte write");
2659 if (guest_initiated) {
2660 if (gfn == vcpu->arch.last_pt_write_gfn
2661 && !last_updated_pte_accessed(vcpu)) {
2662 ++vcpu->arch.last_pt_write_count;
2663 if (vcpu->arch.last_pt_write_count >= 3)
2664 flooded = 1;
2665 } else {
2666 vcpu->arch.last_pt_write_gfn = gfn;
2667 vcpu->arch.last_pt_write_count = 1;
2668 vcpu->arch.last_pte_updated = NULL;
2669 }
2670 }
2671 index = kvm_page_table_hashfn(gfn);
2672 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
2673 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
2674 if (sp->gfn != gfn || sp->role.direct || sp->role.invalid)
2675 continue;
2676 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
2677 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
2678 misaligned |= bytes < 4;
2679 if (misaligned || flooded) {
2680 /*
2681 * Misaligned accesses are too much trouble to fix
2682 * up; also, they usually indicate a page is not used
2683 * as a page table.
2684 *
2685 * If we're seeing too many writes to a page,
2686 * it may no longer be a page table, or we may be
2687 * forking, in which case it is better to unmap the
2688 * page.
2689 */
2690 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2691 gpa, bytes, sp->role.word);
2692 if (kvm_mmu_zap_page(vcpu->kvm, sp))
2693 n = bucket->first;
2694 ++vcpu->kvm->stat.mmu_flooded;
2695 continue;
2696 }
2697 page_offset = offset;
2698 level = sp->role.level;
2699 npte = 1;
2700 if (sp->role.glevels == PT32_ROOT_LEVEL) {
2701 page_offset <<= 1; /* 32->64 */
2702 /*
2703 * A 32-bit pde maps 4MB while the shadow pdes map
2704 * only 2MB. So we need to double the offset again
2705 * and zap two pdes instead of one.
2706 */
2707 if (level == PT32_ROOT_LEVEL) {
2708 page_offset &= ~7; /* kill rounding error */
2709 page_offset <<= 1;
2710 npte = 2;
2711 }
2712 quadrant = page_offset >> PAGE_SHIFT;
2713 page_offset &= ~PAGE_MASK;
2714 if (quadrant != sp->role.quadrant)
2715 continue;
2716 }
2717 spte = &sp->spt[page_offset / sizeof(*spte)];
2718 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
2719 gentry = 0;
2720 r = kvm_read_guest_atomic(vcpu->kvm,
2721 gpa & ~(u64)(pte_size - 1),
2722 &gentry, pte_size);
2723 new = (const void *)&gentry;
2724 if (r < 0)
2725 new = NULL;
2726 }
2727 while (npte--) {
2728 entry = *spte;
2729 mmu_pte_write_zap_pte(vcpu, sp, spte);
2730 if (new)
2731 mmu_pte_write_new_pte(vcpu, sp, spte, new);
2732 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
2733 ++spte;
2734 }
2735 }
2736 kvm_mmu_audit(vcpu, "post pte write");
2737 spin_unlock(&vcpu->kvm->mmu_lock);
2738 if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2739 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2740 vcpu->arch.update_pte.pfn = bad_pfn;
2741 }
2742 }
2743
2744 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2745 {
2746 gpa_t gpa;
2747 int r;
2748
2749 if (tdp_enabled)
2750 return 0;
2751
2752 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
2753
2754 spin_lock(&vcpu->kvm->mmu_lock);
2755 r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2756 spin_unlock(&vcpu->kvm->mmu_lock);
2757 return r;
2758 }
2759 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2760
2761 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2762 {
2763 while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES &&
2764 !list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2765 struct kvm_mmu_page *sp;
2766
2767 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2768 struct kvm_mmu_page, link);
2769 kvm_mmu_zap_page(vcpu->kvm, sp);
2770 ++vcpu->kvm->stat.mmu_recycled;
2771 }
2772 }
2773
2774 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2775 {
2776 int r;
2777 enum emulation_result er;
2778
2779 r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2780 if (r < 0)
2781 goto out;
2782
2783 if (!r) {
2784 r = 1;
2785 goto out;
2786 }
2787
2788 r = mmu_topup_memory_caches(vcpu);
2789 if (r)
2790 goto out;
2791
2792 er = emulate_instruction(vcpu, cr2, error_code, 0);
2793
2794 switch (er) {
2795 case EMULATE_DONE:
2796 return 1;
2797 case EMULATE_DO_MMIO:
2798 ++vcpu->stat.mmio_exits;
2799 return 0;
2800 case EMULATE_FAIL:
2801 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
2802 vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
2803 vcpu->run->internal.ndata = 0;
2804 return 0;
2805 default:
2806 BUG();
2807 }
2808 out:
2809 return r;
2810 }
2811 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2812
2813 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2814 {
2815 vcpu->arch.mmu.invlpg(vcpu, gva);
2816 kvm_mmu_flush_tlb(vcpu);
2817 ++vcpu->stat.invlpg;
2818 }
2819 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2820
2821 void kvm_enable_tdp(void)
2822 {
2823 tdp_enabled = true;
2824 }
2825 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2826
2827 void kvm_disable_tdp(void)
2828 {
2829 tdp_enabled = false;
2830 }
2831 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2832
2833 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2834 {
2835 free_page((unsigned long)vcpu->arch.mmu.pae_root);
2836 }
2837
2838 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2839 {
2840 struct page *page;
2841 int i;
2842
2843 ASSERT(vcpu);
2844
2845 /*
2846 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2847 * Therefore we need to allocate shadow page tables in the first
2848 * 4GB of memory, which happens to fit the DMA32 zone.
2849 */
2850 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2851 if (!page)
2852 goto error_1;
2853 vcpu->arch.mmu.pae_root = page_address(page);
2854 for (i = 0; i < 4; ++i)
2855 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2856
2857 return 0;
2858
2859 error_1:
2860 free_mmu_pages(vcpu);
2861 return -ENOMEM;
2862 }
2863
2864 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2865 {
2866 ASSERT(vcpu);
2867 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2868
2869 return alloc_mmu_pages(vcpu);
2870 }
2871
2872 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2873 {
2874 ASSERT(vcpu);
2875 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2876
2877 return init_kvm_mmu(vcpu);
2878 }
2879
2880 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2881 {
2882 ASSERT(vcpu);
2883
2884 destroy_kvm_mmu(vcpu);
2885 free_mmu_pages(vcpu);
2886 mmu_free_memory_caches(vcpu);
2887 }
2888
2889 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2890 {
2891 struct kvm_mmu_page *sp;
2892
2893 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2894 int i;
2895 u64 *pt;
2896
2897 if (!test_bit(slot, sp->slot_bitmap))
2898 continue;
2899
2900 pt = sp->spt;
2901 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2902 /* avoid RMW */
2903 if (pt[i] & PT_WRITABLE_MASK)
2904 pt[i] &= ~PT_WRITABLE_MASK;
2905 }
2906 kvm_flush_remote_tlbs(kvm);
2907 }
2908
2909 void kvm_mmu_zap_all(struct kvm *kvm)
2910 {
2911 struct kvm_mmu_page *sp, *node;
2912
2913 spin_lock(&kvm->mmu_lock);
2914 list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2915 if (kvm_mmu_zap_page(kvm, sp))
2916 node = container_of(kvm->arch.active_mmu_pages.next,
2917 struct kvm_mmu_page, link);
2918 spin_unlock(&kvm->mmu_lock);
2919
2920 kvm_flush_remote_tlbs(kvm);
2921 }
2922
2923 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2924 {
2925 struct kvm_mmu_page *page;
2926
2927 page = container_of(kvm->arch.active_mmu_pages.prev,
2928 struct kvm_mmu_page, link);
2929 kvm_mmu_zap_page(kvm, page);
2930 }
2931
2932 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2933 {
2934 struct kvm *kvm;
2935 struct kvm *kvm_freed = NULL;
2936 int cache_count = 0;
2937
2938 spin_lock(&kvm_lock);
2939
2940 list_for_each_entry(kvm, &vm_list, vm_list) {
2941 int npages;
2942
2943 if (!down_read_trylock(&kvm->slots_lock))
2944 continue;
2945 spin_lock(&kvm->mmu_lock);
2946 npages = kvm->arch.n_alloc_mmu_pages -
2947 kvm->arch.n_free_mmu_pages;
2948 cache_count += npages;
2949 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2950 kvm_mmu_remove_one_alloc_mmu_page(kvm);
2951 cache_count--;
2952 kvm_freed = kvm;
2953 }
2954 nr_to_scan--;
2955
2956 spin_unlock(&kvm->mmu_lock);
2957 up_read(&kvm->slots_lock);
2958 }
2959 if (kvm_freed)
2960 list_move_tail(&kvm_freed->vm_list, &vm_list);
2961
2962 spin_unlock(&kvm_lock);
2963
2964 return cache_count;
2965 }
2966
2967 static struct shrinker mmu_shrinker = {
2968 .shrink = mmu_shrink,
2969 .seeks = DEFAULT_SEEKS * 10,
2970 };
2971
2972 static void mmu_destroy_caches(void)
2973 {
2974 if (pte_chain_cache)
2975 kmem_cache_destroy(pte_chain_cache);
2976 if (rmap_desc_cache)
2977 kmem_cache_destroy(rmap_desc_cache);
2978 if (mmu_page_header_cache)
2979 kmem_cache_destroy(mmu_page_header_cache);
2980 }
2981
2982 void kvm_mmu_module_exit(void)
2983 {
2984 mmu_destroy_caches();
2985 unregister_shrinker(&mmu_shrinker);
2986 }
2987
2988 int kvm_mmu_module_init(void)
2989 {
2990 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2991 sizeof(struct kvm_pte_chain),
2992 0, 0, NULL);
2993 if (!pte_chain_cache)
2994 goto nomem;
2995 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2996 sizeof(struct kvm_rmap_desc),
2997 0, 0, NULL);
2998 if (!rmap_desc_cache)
2999 goto nomem;
3000
3001 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
3002 sizeof(struct kvm_mmu_page),
3003 0, 0, NULL);
3004 if (!mmu_page_header_cache)
3005 goto nomem;
3006
3007 register_shrinker(&mmu_shrinker);
3008
3009 return 0;
3010
3011 nomem:
3012 mmu_destroy_caches();
3013 return -ENOMEM;
3014 }
3015
3016 /*
3017 * Caculate mmu pages needed for kvm.
3018 */
3019 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
3020 {
3021 int i;
3022 unsigned int nr_mmu_pages;
3023 unsigned int nr_pages = 0;
3024
3025 for (i = 0; i < kvm->nmemslots; i++)
3026 nr_pages += kvm->memslots[i].npages;
3027
3028 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
3029 nr_mmu_pages = max(nr_mmu_pages,
3030 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
3031
3032 return nr_mmu_pages;
3033 }
3034
3035 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3036 unsigned len)
3037 {
3038 if (len > buffer->len)
3039 return NULL;
3040 return buffer->ptr;
3041 }
3042
3043 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3044 unsigned len)
3045 {
3046 void *ret;
3047
3048 ret = pv_mmu_peek_buffer(buffer, len);
3049 if (!ret)
3050 return ret;
3051 buffer->ptr += len;
3052 buffer->len -= len;
3053 buffer->processed += len;
3054 return ret;
3055 }
3056
3057 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
3058 gpa_t addr, gpa_t value)
3059 {
3060 int bytes = 8;
3061 int r;
3062
3063 if (!is_long_mode(vcpu) && !is_pae(vcpu))
3064 bytes = 4;
3065
3066 r = mmu_topup_memory_caches(vcpu);
3067 if (r)
3068 return r;
3069
3070 if (!emulator_write_phys(vcpu, addr, &value, bytes))
3071 return -EFAULT;
3072
3073 return 1;
3074 }
3075
3076 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
3077 {
3078 kvm_set_cr3(vcpu, vcpu->arch.cr3);
3079 return 1;
3080 }
3081
3082 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
3083 {
3084 spin_lock(&vcpu->kvm->mmu_lock);
3085 mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
3086 spin_unlock(&vcpu->kvm->mmu_lock);
3087 return 1;
3088 }
3089
3090 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
3091 struct kvm_pv_mmu_op_buffer *buffer)
3092 {
3093 struct kvm_mmu_op_header *header;
3094
3095 header = pv_mmu_peek_buffer(buffer, sizeof *header);
3096 if (!header)
3097 return 0;
3098 switch (header->op) {
3099 case KVM_MMU_OP_WRITE_PTE: {
3100 struct kvm_mmu_op_write_pte *wpte;
3101
3102 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
3103 if (!wpte)
3104 return 0;
3105 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
3106 wpte->pte_val);
3107 }
3108 case KVM_MMU_OP_FLUSH_TLB: {
3109 struct kvm_mmu_op_flush_tlb *ftlb;
3110
3111 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
3112 if (!ftlb)
3113 return 0;
3114 return kvm_pv_mmu_flush_tlb(vcpu);
3115 }
3116 case KVM_MMU_OP_RELEASE_PT: {
3117 struct kvm_mmu_op_release_pt *rpt;
3118
3119 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
3120 if (!rpt)
3121 return 0;
3122 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
3123 }
3124 default: return 0;
3125 }
3126 }
3127
3128 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
3129 gpa_t addr, unsigned long *ret)
3130 {
3131 int r;
3132 struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
3133
3134 buffer->ptr = buffer->buf;
3135 buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
3136 buffer->processed = 0;
3137
3138 r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
3139 if (r)
3140 goto out;
3141
3142 while (buffer->len) {
3143 r = kvm_pv_mmu_op_one(vcpu, buffer);
3144 if (r < 0)
3145 goto out;
3146 if (r == 0)
3147 break;
3148 }
3149
3150 r = 1;
3151 out:
3152 *ret = buffer->processed;
3153 return r;
3154 }
3155
3156 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
3157 {
3158 struct kvm_shadow_walk_iterator iterator;
3159 int nr_sptes = 0;
3160
3161 spin_lock(&vcpu->kvm->mmu_lock);
3162 for_each_shadow_entry(vcpu, addr, iterator) {
3163 sptes[iterator.level-1] = *iterator.sptep;
3164 nr_sptes++;
3165 if (!is_shadow_present_pte(*iterator.sptep))
3166 break;
3167 }
3168 spin_unlock(&vcpu->kvm->mmu_lock);
3169
3170 return nr_sptes;
3171 }
3172 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
3173
3174 #ifdef AUDIT
3175
3176 static const char *audit_msg;
3177
3178 static gva_t canonicalize(gva_t gva)
3179 {
3180 #ifdef CONFIG_X86_64
3181 gva = (long long)(gva << 16) >> 16;
3182 #endif
3183 return gva;
3184 }
3185
3186
3187 typedef void (*inspect_spte_fn) (struct kvm *kvm, struct kvm_mmu_page *sp,
3188 u64 *sptep);
3189
3190 static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
3191 inspect_spte_fn fn)
3192 {
3193 int i;
3194
3195 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3196 u64 ent = sp->spt[i];
3197
3198 if (is_shadow_present_pte(ent)) {
3199 if (!is_last_spte(ent, sp->role.level)) {
3200 struct kvm_mmu_page *child;
3201 child = page_header(ent & PT64_BASE_ADDR_MASK);
3202 __mmu_spte_walk(kvm, child, fn);
3203 } else
3204 fn(kvm, sp, &sp->spt[i]);
3205 }
3206 }
3207 }
3208
3209 static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
3210 {
3211 int i;
3212 struct kvm_mmu_page *sp;
3213
3214 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
3215 return;
3216 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
3217 hpa_t root = vcpu->arch.mmu.root_hpa;
3218 sp = page_header(root);
3219 __mmu_spte_walk(vcpu->kvm, sp, fn);
3220 return;
3221 }
3222 for (i = 0; i < 4; ++i) {
3223 hpa_t root = vcpu->arch.mmu.pae_root[i];
3224
3225 if (root && VALID_PAGE(root)) {
3226 root &= PT64_BASE_ADDR_MASK;
3227 sp = page_header(root);
3228 __mmu_spte_walk(vcpu->kvm, sp, fn);
3229 }
3230 }
3231 return;
3232 }
3233
3234 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
3235 gva_t va, int level)
3236 {
3237 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
3238 int i;
3239 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
3240
3241 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
3242 u64 ent = pt[i];
3243
3244 if (ent == shadow_trap_nonpresent_pte)
3245 continue;
3246
3247 va = canonicalize(va);
3248 if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
3249 audit_mappings_page(vcpu, ent, va, level - 1);
3250 else {
3251 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
3252 gfn_t gfn = gpa >> PAGE_SHIFT;
3253 pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
3254 hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
3255
3256 if (is_error_pfn(pfn)) {
3257 kvm_release_pfn_clean(pfn);
3258 continue;
3259 }
3260
3261 if (is_shadow_present_pte(ent)
3262 && (ent & PT64_BASE_ADDR_MASK) != hpa)
3263 printk(KERN_ERR "xx audit error: (%s) levels %d"
3264 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3265 audit_msg, vcpu->arch.mmu.root_level,
3266 va, gpa, hpa, ent,
3267 is_shadow_present_pte(ent));
3268 else if (ent == shadow_notrap_nonpresent_pte
3269 && !is_error_hpa(hpa))
3270 printk(KERN_ERR "audit: (%s) notrap shadow,"
3271 " valid guest gva %lx\n", audit_msg, va);
3272 kvm_release_pfn_clean(pfn);
3273
3274 }
3275 }
3276 }
3277
3278 static void audit_mappings(struct kvm_vcpu *vcpu)
3279 {
3280 unsigned i;
3281
3282 if (vcpu->arch.mmu.root_level == 4)
3283 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
3284 else
3285 for (i = 0; i < 4; ++i)
3286 if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
3287 audit_mappings_page(vcpu,
3288 vcpu->arch.mmu.pae_root[i],
3289 i << 30,
3290 2);
3291 }
3292
3293 static int count_rmaps(struct kvm_vcpu *vcpu)
3294 {
3295 int nmaps = 0;
3296 int i, j, k;
3297
3298 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
3299 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
3300 struct kvm_rmap_desc *d;
3301
3302 for (j = 0; j < m->npages; ++j) {
3303 unsigned long *rmapp = &m->rmap[j];
3304
3305 if (!*rmapp)
3306 continue;
3307 if (!(*rmapp & 1)) {
3308 ++nmaps;
3309 continue;
3310 }
3311 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
3312 while (d) {
3313 for (k = 0; k < RMAP_EXT; ++k)
3314 if (d->sptes[k])
3315 ++nmaps;
3316 else
3317 break;
3318 d = d->more;
3319 }
3320 }
3321 }
3322 return nmaps;
3323 }
3324
3325 void inspect_spte_has_rmap(struct kvm *kvm, struct kvm_mmu_page *sp, u64 *sptep)
3326 {
3327 unsigned long *rmapp;
3328 struct kvm_mmu_page *rev_sp;
3329 gfn_t gfn;
3330
3331 if (*sptep & PT_WRITABLE_MASK) {
3332 rev_sp = page_header(__pa(sptep));
3333 gfn = rev_sp->gfns[sptep - rev_sp->spt];
3334
3335 if (!gfn_to_memslot(kvm, gfn)) {
3336 if (!printk_ratelimit())
3337 return;
3338 printk(KERN_ERR "%s: no memslot for gfn %ld\n",
3339 audit_msg, gfn);
3340 printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n",
3341 audit_msg, sptep - rev_sp->spt,
3342 rev_sp->gfn);
3343 dump_stack();
3344 return;
3345 }
3346
3347 rmapp = gfn_to_rmap(kvm, rev_sp->gfns[sptep - rev_sp->spt],
3348 is_large_pte(*sptep));
3349 if (!*rmapp) {
3350 if (!printk_ratelimit())
3351 return;
3352 printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
3353 audit_msg, *sptep);
3354 dump_stack();
3355 }
3356 }
3357
3358 }
3359
3360 void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
3361 {
3362 mmu_spte_walk(vcpu, inspect_spte_has_rmap);
3363 }
3364
3365 static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
3366 {
3367 struct kvm_mmu_page *sp;
3368 int i;
3369
3370 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3371 u64 *pt = sp->spt;
3372
3373 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
3374 continue;
3375
3376 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3377 u64 ent = pt[i];
3378
3379 if (!(ent & PT_PRESENT_MASK))
3380 continue;
3381 if (!(ent & PT_WRITABLE_MASK))
3382 continue;
3383 inspect_spte_has_rmap(vcpu->kvm, sp, &pt[i]);
3384 }
3385 }
3386 return;
3387 }
3388
3389 static void audit_rmap(struct kvm_vcpu *vcpu)
3390 {
3391 check_writable_mappings_rmap(vcpu);
3392 count_rmaps(vcpu);
3393 }
3394
3395 static void audit_write_protection(struct kvm_vcpu *vcpu)
3396 {
3397 struct kvm_mmu_page *sp;
3398 struct kvm_memory_slot *slot;
3399 unsigned long *rmapp;
3400 u64 *spte;
3401 gfn_t gfn;
3402
3403 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3404 if (sp->role.direct)
3405 continue;
3406 if (sp->unsync)
3407 continue;
3408
3409 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
3410 slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
3411 rmapp = &slot->rmap[gfn - slot->base_gfn];
3412
3413 spte = rmap_next(vcpu->kvm, rmapp, NULL);
3414 while (spte) {
3415 if (*spte & PT_WRITABLE_MASK)
3416 printk(KERN_ERR "%s: (%s) shadow page has "
3417 "writable mappings: gfn %lx role %x\n",
3418 __func__, audit_msg, sp->gfn,
3419 sp->role.word);
3420 spte = rmap_next(vcpu->kvm, rmapp, spte);
3421 }
3422 }
3423 }
3424
3425 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
3426 {
3427 int olddbg = dbg;
3428
3429 dbg = 0;
3430 audit_msg = msg;
3431 audit_rmap(vcpu);
3432 audit_write_protection(vcpu);
3433 if (strcmp("pre pte write", audit_msg) != 0)
3434 audit_mappings(vcpu);
3435 audit_writable_sptes_have_rmaps(vcpu);
3436 dbg = olddbg;
3437 }
3438
3439 #endif
Linux kernel - Deliverables
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