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"[PATCH] Fix leaks on /proc/{*/sched,sched_debug,timer_list,timer_stats}" and
[mmotm.git] / arch / x86 / kvm / mmu.c
blob20a2cd168fb9afb93f4ce3d361dbf909efcdfdcc
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, u64 data)
752 {
753 u64 *spte;
754 int need_tlb_flush = 0;
755
756 while ((spte = rmap_next(kvm, rmapp, NULL))) {
757 BUG_ON(!(*spte & PT_PRESENT_MASK));
758 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
759 rmap_remove(kvm, spte);
760 __set_spte(spte, shadow_trap_nonpresent_pte);
761 need_tlb_flush = 1;
762 }
763 return need_tlb_flush;
764 }
765
766 static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
767 {
768 int need_flush = 0;
769 u64 *spte, new_spte;
770 pte_t *ptep = (pte_t *)data;
771 pfn_t new_pfn;
772
773 WARN_ON(pte_huge(*ptep));
774 new_pfn = pte_pfn(*ptep);
775 spte = rmap_next(kvm, rmapp, NULL);
776 while (spte) {
777 BUG_ON(!is_shadow_present_pte(*spte));
778 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
779 need_flush = 1;
780 if (pte_write(*ptep)) {
781 rmap_remove(kvm, spte);
782 __set_spte(spte, shadow_trap_nonpresent_pte);
783 spte = rmap_next(kvm, rmapp, NULL);
784 } else {
785 new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
786 new_spte |= (u64)new_pfn << PAGE_SHIFT;
787
788 new_spte &= ~PT_WRITABLE_MASK;
789 new_spte &= ~SPTE_HOST_WRITEABLE;
790 if (is_writeble_pte(*spte))
791 kvm_set_pfn_dirty(spte_to_pfn(*spte));
792 __set_spte(spte, new_spte);
793 spte = rmap_next(kvm, rmapp, spte);
794 }
795 }
796 if (need_flush)
797 kvm_flush_remote_tlbs(kvm);
798
799 return 0;
800 }
801
802 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, u64 data,
803 int (*handler)(struct kvm *kvm, unsigned long *rmapp,
804 u64 data))
805 {
806 int i, j;
807 int retval = 0;
808
809 /*
810 * If mmap_sem isn't taken, we can look the memslots with only
811 * the mmu_lock by skipping over the slots with userspace_addr == 0.
812 */
813 for (i = 0; i < kvm->nmemslots; i++) {
814 struct kvm_memory_slot *memslot = &kvm->memslots[i];
815 unsigned long start = memslot->userspace_addr;
816 unsigned long end;
817
818 /* mmu_lock protects userspace_addr */
819 if (!start)
820 continue;
821
822 end = start + (memslot->npages << PAGE_SHIFT);
823 if (hva >= start && hva < end) {
824 gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
825
826 retval |= handler(kvm, &memslot->rmap[gfn_offset],
827 data);
828
829 for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
830 int idx = gfn_offset;
831 idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
832 retval |= handler(kvm,
833 &memslot->lpage_info[j][idx].rmap_pde,
834 data);
835 }
836 }
837 }
838
839 return retval;
840 }
841
842 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
843 {
844 return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
845 }
846
847 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
848 {
849 kvm_handle_hva(kvm, hva, (u64)&pte, kvm_set_pte_rmapp);
850 }
851
852 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, u64 data)
853 {
854 u64 *spte;
855 int young = 0;
856
857 /* always return old for EPT */
858 if (!shadow_accessed_mask)
859 return 0;
860
861 spte = rmap_next(kvm, rmapp, NULL);
862 while (spte) {
863 int _young;
864 u64 _spte = *spte;
865 BUG_ON(!(_spte & PT_PRESENT_MASK));
866 _young = _spte & PT_ACCESSED_MASK;
867 if (_young) {
868 young = 1;
869 clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
870 }
871 spte = rmap_next(kvm, rmapp, spte);
872 }
873 return young;
874 }
875
876 #define RMAP_RECYCLE_THRESHOLD 1000
877
878 static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
879 {
880 unsigned long *rmapp;
881 struct kvm_mmu_page *sp;
882
883 sp = page_header(__pa(spte));
884
885 gfn = unalias_gfn(vcpu->kvm, gfn);
886 rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
887
888 kvm_unmap_rmapp(vcpu->kvm, rmapp, 0);
889 kvm_flush_remote_tlbs(vcpu->kvm);
890 }
891
892 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
893 {
894 return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
895 }
896
897 #ifdef MMU_DEBUG
898 static int is_empty_shadow_page(u64 *spt)
899 {
900 u64 *pos;
901 u64 *end;
902
903 for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
904 if (is_shadow_present_pte(*pos)) {
905 printk(KERN_ERR "%s: %p %llx\n", __func__,
906 pos, *pos);
907 return 0;
908 }
909 return 1;
910 }
911 #endif
912
913 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
914 {
915 ASSERT(is_empty_shadow_page(sp->spt));
916 list_del(&sp->link);
917 __free_page(virt_to_page(sp->spt));
918 __free_page(virt_to_page(sp->gfns));
919 kfree(sp);
920 ++kvm->arch.n_free_mmu_pages;
921 }
922
923 static unsigned kvm_page_table_hashfn(gfn_t gfn)
924 {
925 return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
926 }
927
928 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
929 u64 *parent_pte)
930 {
931 struct kvm_mmu_page *sp;
932
933 sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
934 sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
935 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
936 set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
937 list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
938 INIT_LIST_HEAD(&sp->oos_link);
939 bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
940 sp->multimapped = 0;
941 sp->parent_pte = parent_pte;
942 --vcpu->kvm->arch.n_free_mmu_pages;
943 return sp;
944 }
945
946 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
947 struct kvm_mmu_page *sp, u64 *parent_pte)
948 {
949 struct kvm_pte_chain *pte_chain;
950 struct hlist_node *node;
951 int i;
952
953 if (!parent_pte)
954 return;
955 if (!sp->multimapped) {
956 u64 *old = sp->parent_pte;
957
958 if (!old) {
959 sp->parent_pte = parent_pte;
960 return;
961 }
962 sp->multimapped = 1;
963 pte_chain = mmu_alloc_pte_chain(vcpu);
964 INIT_HLIST_HEAD(&sp->parent_ptes);
965 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
966 pte_chain->parent_ptes[0] = old;
967 }
968 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
969 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
970 continue;
971 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
972 if (!pte_chain->parent_ptes[i]) {
973 pte_chain->parent_ptes[i] = parent_pte;
974 return;
975 }
976 }
977 pte_chain = mmu_alloc_pte_chain(vcpu);
978 BUG_ON(!pte_chain);
979 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
980 pte_chain->parent_ptes[0] = parent_pte;
981 }
982
983 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
984 u64 *parent_pte)
985 {
986 struct kvm_pte_chain *pte_chain;
987 struct hlist_node *node;
988 int i;
989
990 if (!sp->multimapped) {
991 BUG_ON(sp->parent_pte != parent_pte);
992 sp->parent_pte = NULL;
993 return;
994 }
995 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
996 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
997 if (!pte_chain->parent_ptes[i])
998 break;
999 if (pte_chain->parent_ptes[i] != parent_pte)
1000 continue;
1001 while (i + 1 < NR_PTE_CHAIN_ENTRIES
1002 && pte_chain->parent_ptes[i + 1]) {
1003 pte_chain->parent_ptes[i]
1004 = pte_chain->parent_ptes[i + 1];
1005 ++i;
1006 }
1007 pte_chain->parent_ptes[i] = NULL;
1008 if (i == 0) {
1009 hlist_del(&pte_chain->link);
1010 mmu_free_pte_chain(pte_chain);
1011 if (hlist_empty(&sp->parent_ptes)) {
1012 sp->multimapped = 0;
1013 sp->parent_pte = NULL;
1014 }
1015 }
1016 return;
1017 }
1018 BUG();
1019 }
1020
1021
1022 static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
1023 mmu_parent_walk_fn fn)
1024 {
1025 struct kvm_pte_chain *pte_chain;
1026 struct hlist_node *node;
1027 struct kvm_mmu_page *parent_sp;
1028 int i;
1029
1030 if (!sp->multimapped && sp->parent_pte) {
1031 parent_sp = page_header(__pa(sp->parent_pte));
1032 fn(vcpu, parent_sp);
1033 mmu_parent_walk(vcpu, parent_sp, fn);
1034 return;
1035 }
1036 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1037 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1038 if (!pte_chain->parent_ptes[i])
1039 break;
1040 parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
1041 fn(vcpu, parent_sp);
1042 mmu_parent_walk(vcpu, parent_sp, fn);
1043 }
1044 }
1045
1046 static void kvm_mmu_update_unsync_bitmap(u64 *spte)
1047 {
1048 unsigned int index;
1049 struct kvm_mmu_page *sp = page_header(__pa(spte));
1050
1051 index = spte - sp->spt;
1052 if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
1053 sp->unsync_children++;
1054 WARN_ON(!sp->unsync_children);
1055 }
1056
1057 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
1058 {
1059 struct kvm_pte_chain *pte_chain;
1060 struct hlist_node *node;
1061 int i;
1062
1063 if (!sp->parent_pte)
1064 return;
1065
1066 if (!sp->multimapped) {
1067 kvm_mmu_update_unsync_bitmap(sp->parent_pte);
1068 return;
1069 }
1070
1071 hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1072 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1073 if (!pte_chain->parent_ptes[i])
1074 break;
1075 kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
1076 }
1077 }
1078
1079 static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1080 {
1081 kvm_mmu_update_parents_unsync(sp);
1082 return 1;
1083 }
1084
1085 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu,
1086 struct kvm_mmu_page *sp)
1087 {
1088 mmu_parent_walk(vcpu, sp, unsync_walk_fn);
1089 kvm_mmu_update_parents_unsync(sp);
1090 }
1091
1092 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1093 struct kvm_mmu_page *sp)
1094 {
1095 int i;
1096
1097 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1098 sp->spt[i] = shadow_trap_nonpresent_pte;
1099 }
1100
1101 static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
1102 struct kvm_mmu_page *sp)
1103 {
1104 return 1;
1105 }
1106
1107 static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
1108 {
1109 }
1110
1111 #define KVM_PAGE_ARRAY_NR 16
1112
1113 struct kvm_mmu_pages {
1114 struct mmu_page_and_offset {
1115 struct kvm_mmu_page *sp;
1116 unsigned int idx;
1117 } page[KVM_PAGE_ARRAY_NR];
1118 unsigned int nr;
1119 };
1120
1121 #define for_each_unsync_children(bitmap, idx) \
1122 for (idx = find_first_bit(bitmap, 512); \
1123 idx < 512; \
1124 idx = find_next_bit(bitmap, 512, idx+1))
1125
1126 static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
1127 int idx)
1128 {
1129 int i;
1130
1131 if (sp->unsync)
1132 for (i=0; i < pvec->nr; i++)
1133 if (pvec->page[i].sp == sp)
1134 return 0;
1135
1136 pvec->page[pvec->nr].sp = sp;
1137 pvec->page[pvec->nr].idx = idx;
1138 pvec->nr++;
1139 return (pvec->nr == KVM_PAGE_ARRAY_NR);
1140 }
1141
1142 static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
1143 struct kvm_mmu_pages *pvec)
1144 {
1145 int i, ret, nr_unsync_leaf = 0;
1146
1147 for_each_unsync_children(sp->unsync_child_bitmap, i) {
1148 u64 ent = sp->spt[i];
1149
1150 if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
1151 struct kvm_mmu_page *child;
1152 child = page_header(ent & PT64_BASE_ADDR_MASK);
1153
1154 if (child->unsync_children) {
1155 if (mmu_pages_add(pvec, child, i))
1156 return -ENOSPC;
1157
1158 ret = __mmu_unsync_walk(child, pvec);
1159 if (!ret)
1160 __clear_bit(i, sp->unsync_child_bitmap);
1161 else if (ret > 0)
1162 nr_unsync_leaf += ret;
1163 else
1164 return ret;
1165 }
1166
1167 if (child->unsync) {
1168 nr_unsync_leaf++;
1169 if (mmu_pages_add(pvec, child, i))
1170 return -ENOSPC;
1171 }
1172 }
1173 }
1174
1175 if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
1176 sp->unsync_children = 0;
1177
1178 return nr_unsync_leaf;
1179 }
1180
1181 static int mmu_unsync_walk(struct kvm_mmu_page *sp,
1182 struct kvm_mmu_pages *pvec)
1183 {
1184 if (!sp->unsync_children)
1185 return 0;
1186
1187 mmu_pages_add(pvec, sp, 0);
1188 return __mmu_unsync_walk(sp, pvec);
1189 }
1190
1191 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
1192 {
1193 unsigned index;
1194 struct hlist_head *bucket;
1195 struct kvm_mmu_page *sp;
1196 struct hlist_node *node;
1197
1198 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1199 index = kvm_page_table_hashfn(gfn);
1200 bucket = &kvm->arch.mmu_page_hash[index];
1201 hlist_for_each_entry(sp, node, bucket, hash_link)
1202 if (sp->gfn == gfn && !sp->role.direct
1203 && !sp->role.invalid) {
1204 pgprintk("%s: found role %x\n",
1205 __func__, sp->role.word);
1206 return sp;
1207 }
1208 return NULL;
1209 }
1210
1211 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1212 {
1213 WARN_ON(!sp->unsync);
1214 sp->unsync = 0;
1215 --kvm->stat.mmu_unsync;
1216 }
1217
1218 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
1219
1220 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1221 {
1222 if (sp->role.glevels != vcpu->arch.mmu.root_level) {
1223 kvm_mmu_zap_page(vcpu->kvm, sp);
1224 return 1;
1225 }
1226
1227 trace_kvm_mmu_sync_page(sp);
1228 if (rmap_write_protect(vcpu->kvm, sp->gfn))
1229 kvm_flush_remote_tlbs(vcpu->kvm);
1230 kvm_unlink_unsync_page(vcpu->kvm, sp);
1231 if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
1232 kvm_mmu_zap_page(vcpu->kvm, sp);
1233 return 1;
1234 }
1235
1236 kvm_mmu_flush_tlb(vcpu);
1237 return 0;
1238 }
1239
1240 struct mmu_page_path {
1241 struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
1242 unsigned int idx[PT64_ROOT_LEVEL-1];
1243 };
1244
1245 #define for_each_sp(pvec, sp, parents, i) \
1246 for (i = mmu_pages_next(&pvec, &parents, -1), \
1247 sp = pvec.page[i].sp; \
1248 i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \
1249 i = mmu_pages_next(&pvec, &parents, i))
1250
1251 static int mmu_pages_next(struct kvm_mmu_pages *pvec,
1252 struct mmu_page_path *parents,
1253 int i)
1254 {
1255 int n;
1256
1257 for (n = i+1; n < pvec->nr; n++) {
1258 struct kvm_mmu_page *sp = pvec->page[n].sp;
1259
1260 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1261 parents->idx[0] = pvec->page[n].idx;
1262 return n;
1263 }
1264
1265 parents->parent[sp->role.level-2] = sp;
1266 parents->idx[sp->role.level-1] = pvec->page[n].idx;
1267 }
1268
1269 return n;
1270 }
1271
1272 static void mmu_pages_clear_parents(struct mmu_page_path *parents)
1273 {
1274 struct kvm_mmu_page *sp;
1275 unsigned int level = 0;
1276
1277 do {
1278 unsigned int idx = parents->idx[level];
1279
1280 sp = parents->parent[level];
1281 if (!sp)
1282 return;
1283
1284 --sp->unsync_children;
1285 WARN_ON((int)sp->unsync_children < 0);
1286 __clear_bit(idx, sp->unsync_child_bitmap);
1287 level++;
1288 } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
1289 }
1290
1291 static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
1292 struct mmu_page_path *parents,
1293 struct kvm_mmu_pages *pvec)
1294 {
1295 parents->parent[parent->role.level-1] = NULL;
1296 pvec->nr = 0;
1297 }
1298
1299 static void mmu_sync_children(struct kvm_vcpu *vcpu,
1300 struct kvm_mmu_page *parent)
1301 {
1302 int i;
1303 struct kvm_mmu_page *sp;
1304 struct mmu_page_path parents;
1305 struct kvm_mmu_pages pages;
1306
1307 kvm_mmu_pages_init(parent, &parents, &pages);
1308 while (mmu_unsync_walk(parent, &pages)) {
1309 int protected = 0;
1310
1311 for_each_sp(pages, sp, parents, i)
1312 protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
1313
1314 if (protected)
1315 kvm_flush_remote_tlbs(vcpu->kvm);
1316
1317 for_each_sp(pages, sp, parents, i) {
1318 kvm_sync_page(vcpu, sp);
1319 mmu_pages_clear_parents(&parents);
1320 }
1321 cond_resched_lock(&vcpu->kvm->mmu_lock);
1322 kvm_mmu_pages_init(parent, &parents, &pages);
1323 }
1324 }
1325
1326 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
1327 gfn_t gfn,
1328 gva_t gaddr,
1329 unsigned level,
1330 int direct,
1331 unsigned access,
1332 u64 *parent_pte)
1333 {
1334 union kvm_mmu_page_role role;
1335 unsigned index;
1336 unsigned quadrant;
1337 struct hlist_head *bucket;
1338 struct kvm_mmu_page *sp;
1339 struct hlist_node *node, *tmp;
1340
1341 role = vcpu->arch.mmu.base_role;
1342 role.level = level;
1343 role.direct = direct;
1344 role.access = access;
1345 if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
1346 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
1347 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
1348 role.quadrant = quadrant;
1349 }
1350 index = kvm_page_table_hashfn(gfn);
1351 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1352 hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
1353 if (sp->gfn == gfn) {
1354 if (sp->unsync)
1355 if (kvm_sync_page(vcpu, sp))
1356 continue;
1357
1358 if (sp->role.word != role.word)
1359 continue;
1360
1361 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
1362 if (sp->unsync_children) {
1363 set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
1364 kvm_mmu_mark_parents_unsync(vcpu, sp);
1365 }
1366 trace_kvm_mmu_get_page(sp, false);
1367 return sp;
1368 }
1369 ++vcpu->kvm->stat.mmu_cache_miss;
1370 sp = kvm_mmu_alloc_page(vcpu, parent_pte);
1371 if (!sp)
1372 return sp;
1373 sp->gfn = gfn;
1374 sp->role = role;
1375 hlist_add_head(&sp->hash_link, bucket);
1376 if (!direct) {
1377 if (rmap_write_protect(vcpu->kvm, gfn))
1378 kvm_flush_remote_tlbs(vcpu->kvm);
1379 account_shadowed(vcpu->kvm, gfn);
1380 }
1381 if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
1382 vcpu->arch.mmu.prefetch_page(vcpu, sp);
1383 else
1384 nonpaging_prefetch_page(vcpu, sp);
1385 trace_kvm_mmu_get_page(sp, true);
1386 return sp;
1387 }
1388
1389 static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
1390 struct kvm_vcpu *vcpu, u64 addr)
1391 {
1392 iterator->addr = addr;
1393 iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
1394 iterator->level = vcpu->arch.mmu.shadow_root_level;
1395 if (iterator->level == PT32E_ROOT_LEVEL) {
1396 iterator->shadow_addr
1397 = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
1398 iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
1399 --iterator->level;
1400 if (!iterator->shadow_addr)
1401 iterator->level = 0;
1402 }
1403 }
1404
1405 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
1406 {
1407 if (iterator->level < PT_PAGE_TABLE_LEVEL)
1408 return false;
1409
1410 if (iterator->level == PT_PAGE_TABLE_LEVEL)
1411 if (is_large_pte(*iterator->sptep))
1412 return false;
1413
1414 iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
1415 iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
1416 return true;
1417 }
1418
1419 static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
1420 {
1421 iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
1422 --iterator->level;
1423 }
1424
1425 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1426 struct kvm_mmu_page *sp)
1427 {
1428 unsigned i;
1429 u64 *pt;
1430 u64 ent;
1431
1432 pt = sp->spt;
1433
1434 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1435 ent = pt[i];
1436
1437 if (is_shadow_present_pte(ent)) {
1438 if (!is_last_spte(ent, sp->role.level)) {
1439 ent &= PT64_BASE_ADDR_MASK;
1440 mmu_page_remove_parent_pte(page_header(ent),
1441 &pt[i]);
1442 } else {
1443 if (is_large_pte(ent))
1444 --kvm->stat.lpages;
1445 rmap_remove(kvm, &pt[i]);
1446 }
1447 }
1448 pt[i] = shadow_trap_nonpresent_pte;
1449 }
1450 }
1451
1452 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1453 {
1454 mmu_page_remove_parent_pte(sp, parent_pte);
1455 }
1456
1457 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1458 {
1459 int i;
1460 struct kvm_vcpu *vcpu;
1461
1462 kvm_for_each_vcpu(i, vcpu, kvm)
1463 vcpu->arch.last_pte_updated = NULL;
1464 }
1465
1466 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1467 {
1468 u64 *parent_pte;
1469
1470 while (sp->multimapped || sp->parent_pte) {
1471 if (!sp->multimapped)
1472 parent_pte = sp->parent_pte;
1473 else {
1474 struct kvm_pte_chain *chain;
1475
1476 chain = container_of(sp->parent_ptes.first,
1477 struct kvm_pte_chain, link);
1478 parent_pte = chain->parent_ptes[0];
1479 }
1480 BUG_ON(!parent_pte);
1481 kvm_mmu_put_page(sp, parent_pte);
1482 __set_spte(parent_pte, shadow_trap_nonpresent_pte);
1483 }
1484 }
1485
1486 static int mmu_zap_unsync_children(struct kvm *kvm,
1487 struct kvm_mmu_page *parent)
1488 {
1489 int i, zapped = 0;
1490 struct mmu_page_path parents;
1491 struct kvm_mmu_pages pages;
1492
1493 if (parent->role.level == PT_PAGE_TABLE_LEVEL)
1494 return 0;
1495
1496 kvm_mmu_pages_init(parent, &parents, &pages);
1497 while (mmu_unsync_walk(parent, &pages)) {
1498 struct kvm_mmu_page *sp;
1499
1500 for_each_sp(pages, sp, parents, i) {
1501 kvm_mmu_zap_page(kvm, sp);
1502 mmu_pages_clear_parents(&parents);
1503 }
1504 zapped += pages.nr;
1505 kvm_mmu_pages_init(parent, &parents, &pages);
1506 }
1507
1508 return zapped;
1509 }
1510
1511 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1512 {
1513 int ret;
1514
1515 trace_kvm_mmu_zap_page(sp);
1516 ++kvm->stat.mmu_shadow_zapped;
1517 ret = mmu_zap_unsync_children(kvm, sp);
1518 kvm_mmu_page_unlink_children(kvm, sp);
1519 kvm_mmu_unlink_parents(kvm, sp);
1520 kvm_flush_remote_tlbs(kvm);
1521 if (!sp->role.invalid && !sp->role.direct)
1522 unaccount_shadowed(kvm, sp->gfn);
1523 if (sp->unsync)
1524 kvm_unlink_unsync_page(kvm, sp);
1525 if (!sp->root_count) {
1526 hlist_del(&sp->hash_link);
1527 kvm_mmu_free_page(kvm, sp);
1528 } else {
1529 sp->role.invalid = 1;
1530 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1531 kvm_reload_remote_mmus(kvm);
1532 }
1533 kvm_mmu_reset_last_pte_updated(kvm);
1534 return ret;
1535 }
1536
1537 /*
1538 * Changing the number of mmu pages allocated to the vm
1539 * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1540 */
1541 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1542 {
1543 int used_pages;
1544
1545 used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
1546 used_pages = max(0, used_pages);
1547
1548 /*
1549 * If we set the number of mmu pages to be smaller be than the
1550 * number of actived pages , we must to free some mmu pages before we
1551 * change the value
1552 */
1553
1554 if (used_pages > kvm_nr_mmu_pages) {
1555 while (used_pages > kvm_nr_mmu_pages) {
1556 struct kvm_mmu_page *page;
1557
1558 page = container_of(kvm->arch.active_mmu_pages.prev,
1559 struct kvm_mmu_page, link);
1560 kvm_mmu_zap_page(kvm, page);
1561 used_pages--;
1562 }
1563 kvm->arch.n_free_mmu_pages = 0;
1564 }
1565 else
1566 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1567 - kvm->arch.n_alloc_mmu_pages;
1568
1569 kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1570 }
1571
1572 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1573 {
1574 unsigned index;
1575 struct hlist_head *bucket;
1576 struct kvm_mmu_page *sp;
1577 struct hlist_node *node, *n;
1578 int r;
1579
1580 pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1581 r = 0;
1582 index = kvm_page_table_hashfn(gfn);
1583 bucket = &kvm->arch.mmu_page_hash[index];
1584 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1585 if (sp->gfn == gfn && !sp->role.direct) {
1586 pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1587 sp->role.word);
1588 r = 1;
1589 if (kvm_mmu_zap_page(kvm, sp))
1590 n = bucket->first;
1591 }
1592 return r;
1593 }
1594
1595 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1596 {
1597 unsigned index;
1598 struct hlist_head *bucket;
1599 struct kvm_mmu_page *sp;
1600 struct hlist_node *node, *nn;
1601
1602 index = kvm_page_table_hashfn(gfn);
1603 bucket = &kvm->arch.mmu_page_hash[index];
1604 hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) {
1605 if (sp->gfn == gfn && !sp->role.direct
1606 && !sp->role.invalid) {
1607 pgprintk("%s: zap %lx %x\n",
1608 __func__, gfn, sp->role.word);
1609 kvm_mmu_zap_page(kvm, sp);
1610 }
1611 }
1612 }
1613
1614 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1615 {
1616 int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1617 struct kvm_mmu_page *sp = page_header(__pa(pte));
1618
1619 __set_bit(slot, sp->slot_bitmap);
1620 }
1621
1622 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
1623 {
1624 int i;
1625 u64 *pt = sp->spt;
1626
1627 if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
1628 return;
1629
1630 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1631 if (pt[i] == shadow_notrap_nonpresent_pte)
1632 __set_spte(&pt[i], shadow_trap_nonpresent_pte);
1633 }
1634 }
1635
1636 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1637 {
1638 struct page *page;
1639
1640 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1641
1642 if (gpa == UNMAPPED_GVA)
1643 return NULL;
1644
1645 page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1646
1647 return page;
1648 }
1649
1650 /*
1651 * The function is based on mtrr_type_lookup() in
1652 * arch/x86/kernel/cpu/mtrr/generic.c
1653 */
1654 static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
1655 u64 start, u64 end)
1656 {
1657 int i;
1658 u64 base, mask;
1659 u8 prev_match, curr_match;
1660 int num_var_ranges = KVM_NR_VAR_MTRR;
1661
1662 if (!mtrr_state->enabled)
1663 return 0xFF;
1664
1665 /* Make end inclusive end, instead of exclusive */
1666 end--;
1667
1668 /* Look in fixed ranges. Just return the type as per start */
1669 if (mtrr_state->have_fixed && (start < 0x100000)) {
1670 int idx;
1671
1672 if (start < 0x80000) {
1673 idx = 0;
1674 idx += (start >> 16);
1675 return mtrr_state->fixed_ranges[idx];
1676 } else if (start < 0xC0000) {
1677 idx = 1 * 8;
1678 idx += ((start - 0x80000) >> 14);
1679 return mtrr_state->fixed_ranges[idx];
1680 } else if (start < 0x1000000) {
1681 idx = 3 * 8;
1682 idx += ((start - 0xC0000) >> 12);
1683 return mtrr_state->fixed_ranges[idx];
1684 }
1685 }
1686
1687 /*
1688 * Look in variable ranges
1689 * Look of multiple ranges matching this address and pick type
1690 * as per MTRR precedence
1691 */
1692 if (!(mtrr_state->enabled & 2))
1693 return mtrr_state->def_type;
1694
1695 prev_match = 0xFF;
1696 for (i = 0; i < num_var_ranges; ++i) {
1697 unsigned short start_state, end_state;
1698
1699 if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
1700 continue;
1701
1702 base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
1703 (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
1704 mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
1705 (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
1706
1707 start_state = ((start & mask) == (base & mask));
1708 end_state = ((end & mask) == (base & mask));
1709 if (start_state != end_state)
1710 return 0xFE;
1711
1712 if ((start & mask) != (base & mask))
1713 continue;
1714
1715 curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
1716 if (prev_match == 0xFF) {
1717 prev_match = curr_match;
1718 continue;
1719 }
1720
1721 if (prev_match == MTRR_TYPE_UNCACHABLE ||
1722 curr_match == MTRR_TYPE_UNCACHABLE)
1723 return MTRR_TYPE_UNCACHABLE;
1724
1725 if ((prev_match == MTRR_TYPE_WRBACK &&
1726 curr_match == MTRR_TYPE_WRTHROUGH) ||
1727 (prev_match == MTRR_TYPE_WRTHROUGH &&
1728 curr_match == MTRR_TYPE_WRBACK)) {
1729 prev_match = MTRR_TYPE_WRTHROUGH;
1730 curr_match = MTRR_TYPE_WRTHROUGH;
1731 }
1732
1733 if (prev_match != curr_match)
1734 return MTRR_TYPE_UNCACHABLE;
1735 }
1736
1737 if (prev_match != 0xFF)
1738 return prev_match;
1739
1740 return mtrr_state->def_type;
1741 }
1742
1743 u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
1744 {
1745 u8 mtrr;
1746
1747 mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
1748 (gfn << PAGE_SHIFT) + PAGE_SIZE);
1749 if (mtrr == 0xfe || mtrr == 0xff)
1750 mtrr = MTRR_TYPE_WRBACK;
1751 return mtrr;
1752 }
1753 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
1754
1755 static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1756 {
1757 unsigned index;
1758 struct hlist_head *bucket;
1759 struct kvm_mmu_page *s;
1760 struct hlist_node *node, *n;
1761
1762 trace_kvm_mmu_unsync_page(sp);
1763 index = kvm_page_table_hashfn(sp->gfn);
1764 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1765 /* don't unsync if pagetable is shadowed with multiple roles */
1766 hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
1767 if (s->gfn != sp->gfn || s->role.direct)
1768 continue;
1769 if (s->role.word != sp->role.word)
1770 return 1;
1771 }
1772 ++vcpu->kvm->stat.mmu_unsync;
1773 sp->unsync = 1;
1774
1775 kvm_mmu_mark_parents_unsync(vcpu, sp);
1776
1777 mmu_convert_notrap(sp);
1778 return 0;
1779 }
1780
1781 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
1782 bool can_unsync)
1783 {
1784 struct kvm_mmu_page *shadow;
1785
1786 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1787 if (shadow) {
1788 if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
1789 return 1;
1790 if (shadow->unsync)
1791 return 0;
1792 if (can_unsync && oos_shadow)
1793 return kvm_unsync_page(vcpu, shadow);
1794 return 1;
1795 }
1796 return 0;
1797 }
1798
1799 static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1800 unsigned pte_access, int user_fault,
1801 int write_fault, int dirty, int level,
1802 gfn_t gfn, pfn_t pfn, bool speculative,
1803 bool can_unsync, bool reset_host_protection)
1804 {
1805 u64 spte;
1806 int ret = 0;
1807
1808 /*
1809 * We don't set the accessed bit, since we sometimes want to see
1810 * whether the guest actually used the pte (in order to detect
1811 * demand paging).
1812 */
1813 spte = shadow_base_present_pte | shadow_dirty_mask;
1814 if (!speculative)
1815 spte |= shadow_accessed_mask;
1816 if (!dirty)
1817 pte_access &= ~ACC_WRITE_MASK;
1818 if (pte_access & ACC_EXEC_MASK)
1819 spte |= shadow_x_mask;
1820 else
1821 spte |= shadow_nx_mask;
1822 if (pte_access & ACC_USER_MASK)
1823 spte |= shadow_user_mask;
1824 if (level > PT_PAGE_TABLE_LEVEL)
1825 spte |= PT_PAGE_SIZE_MASK;
1826 if (tdp_enabled)
1827 spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
1828 kvm_is_mmio_pfn(pfn));
1829
1830 if (reset_host_protection)
1831 spte |= SPTE_HOST_WRITEABLE;
1832
1833 spte |= (u64)pfn << PAGE_SHIFT;
1834
1835 if ((pte_access & ACC_WRITE_MASK)
1836 || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1837
1838 if (level > PT_PAGE_TABLE_LEVEL &&
1839 has_wrprotected_page(vcpu->kvm, gfn, level)) {
1840 ret = 1;
1841 spte = shadow_trap_nonpresent_pte;
1842 goto set_pte;
1843 }
1844
1845 spte |= PT_WRITABLE_MASK;
1846
1847 /*
1848 * Optimization: for pte sync, if spte was writable the hash
1849 * lookup is unnecessary (and expensive). Write protection
1850 * is responsibility of mmu_get_page / kvm_sync_page.
1851 * Same reasoning can be applied to dirty page accounting.
1852 */
1853 if (!can_unsync && is_writeble_pte(*sptep))
1854 goto set_pte;
1855
1856 if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
1857 pgprintk("%s: found shadow page for %lx, marking ro\n",
1858 __func__, gfn);
1859 ret = 1;
1860 pte_access &= ~ACC_WRITE_MASK;
1861 if (is_writeble_pte(spte))
1862 spte &= ~PT_WRITABLE_MASK;
1863 }
1864 }
1865
1866 if (pte_access & ACC_WRITE_MASK)
1867 mark_page_dirty(vcpu->kvm, gfn);
1868
1869 set_pte:
1870 __set_spte(sptep, spte);
1871 return ret;
1872 }
1873
1874 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1875 unsigned pt_access, unsigned pte_access,
1876 int user_fault, int write_fault, int dirty,
1877 int *ptwrite, int level, gfn_t gfn,
1878 pfn_t pfn, bool speculative,
1879 bool reset_host_protection)
1880 {
1881 int was_rmapped = 0;
1882 int was_writeble = is_writeble_pte(*sptep);
1883 int rmap_count;
1884
1885 pgprintk("%s: spte %llx access %x write_fault %d"
1886 " user_fault %d gfn %lx\n",
1887 __func__, *sptep, pt_access,
1888 write_fault, user_fault, gfn);
1889
1890 if (is_rmap_spte(*sptep)) {
1891 /*
1892 * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1893 * the parent of the now unreachable PTE.
1894 */
1895 if (level > PT_PAGE_TABLE_LEVEL &&
1896 !is_large_pte(*sptep)) {
1897 struct kvm_mmu_page *child;
1898 u64 pte = *sptep;
1899
1900 child = page_header(pte & PT64_BASE_ADDR_MASK);
1901 mmu_page_remove_parent_pte(child, sptep);
1902 } else if (pfn != spte_to_pfn(*sptep)) {
1903 pgprintk("hfn old %lx new %lx\n",
1904 spte_to_pfn(*sptep), pfn);
1905 rmap_remove(vcpu->kvm, sptep);
1906 } else
1907 was_rmapped = 1;
1908 }
1909
1910 if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
1911 dirty, level, gfn, pfn, speculative, true,
1912 reset_host_protection)) {
1913 if (write_fault)
1914 *ptwrite = 1;
1915 kvm_x86_ops->tlb_flush(vcpu);
1916 }
1917
1918 pgprintk("%s: setting spte %llx\n", __func__, *sptep);
1919 pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1920 is_large_pte(*sptep)? "2MB" : "4kB",
1921 *sptep & PT_PRESENT_MASK ?"RW":"R", gfn,
1922 *sptep, sptep);
1923 if (!was_rmapped && is_large_pte(*sptep))
1924 ++vcpu->kvm->stat.lpages;
1925
1926 page_header_update_slot(vcpu->kvm, sptep, gfn);
1927 if (!was_rmapped) {
1928 rmap_count = rmap_add(vcpu, sptep, gfn);
1929 kvm_release_pfn_clean(pfn);
1930 if (rmap_count > RMAP_RECYCLE_THRESHOLD)
1931 rmap_recycle(vcpu, sptep, gfn);
1932 } else {
1933 if (was_writeble)
1934 kvm_release_pfn_dirty(pfn);
1935 else
1936 kvm_release_pfn_clean(pfn);
1937 }
1938 if (speculative) {
1939 vcpu->arch.last_pte_updated = sptep;
1940 vcpu->arch.last_pte_gfn = gfn;
1941 }
1942 }
1943
1944 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1945 {
1946 }
1947
1948 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1949 int level, gfn_t gfn, pfn_t pfn)
1950 {
1951 struct kvm_shadow_walk_iterator iterator;
1952 struct kvm_mmu_page *sp;
1953 int pt_write = 0;
1954 gfn_t pseudo_gfn;
1955
1956 for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
1957 if (iterator.level == level) {
1958 mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
1959 0, write, 1, &pt_write,
1960 level, gfn, pfn, false, true);
1961 ++vcpu->stat.pf_fixed;
1962 break;
1963 }
1964
1965 if (*iterator.sptep == shadow_trap_nonpresent_pte) {
1966 pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1967 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
1968 iterator.level - 1,
1969 1, ACC_ALL, iterator.sptep);
1970 if (!sp) {
1971 pgprintk("nonpaging_map: ENOMEM\n");
1972 kvm_release_pfn_clean(pfn);
1973 return -ENOMEM;
1974 }
1975
1976 __set_spte(iterator.sptep,
1977 __pa(sp->spt)
1978 | PT_PRESENT_MASK | PT_WRITABLE_MASK
1979 | shadow_user_mask | shadow_x_mask);
1980 }
1981 }
1982 return pt_write;
1983 }
1984
1985 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1986 {
1987 int r;
1988 int level;
1989 pfn_t pfn;
1990 unsigned long mmu_seq;
1991
1992 level = mapping_level(vcpu, gfn);
1993
1994 /*
1995 * This path builds a PAE pagetable - so we can map 2mb pages at
1996 * maximum. Therefore check if the level is larger than that.
1997 */
1998 if (level > PT_DIRECTORY_LEVEL)
1999 level = PT_DIRECTORY_LEVEL;
2000
2001 gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2002
2003 mmu_seq = vcpu->kvm->mmu_notifier_seq;
2004 smp_rmb();
2005 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2006
2007 /* mmio */
2008 if (is_error_pfn(pfn)) {
2009 kvm_release_pfn_clean(pfn);
2010 return 1;
2011 }
2012
2013 spin_lock(&vcpu->kvm->mmu_lock);
2014 if (mmu_notifier_retry(vcpu, mmu_seq))
2015 goto out_unlock;
2016 kvm_mmu_free_some_pages(vcpu);
2017 r = __direct_map(vcpu, v, write, level, gfn, pfn);
2018 spin_unlock(&vcpu->kvm->mmu_lock);
2019
2020
2021 return r;
2022
2023 out_unlock:
2024 spin_unlock(&vcpu->kvm->mmu_lock);
2025 kvm_release_pfn_clean(pfn);
2026 return 0;
2027 }
2028
2029
2030 static void mmu_free_roots(struct kvm_vcpu *vcpu)
2031 {
2032 int i;
2033 struct kvm_mmu_page *sp;
2034
2035 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2036 return;
2037 spin_lock(&vcpu->kvm->mmu_lock);
2038 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2039 hpa_t root = vcpu->arch.mmu.root_hpa;
2040
2041 sp = page_header(root);
2042 --sp->root_count;
2043 if (!sp->root_count && sp->role.invalid)
2044 kvm_mmu_zap_page(vcpu->kvm, sp);
2045 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2046 spin_unlock(&vcpu->kvm->mmu_lock);
2047 return;
2048 }
2049 for (i = 0; i < 4; ++i) {
2050 hpa_t root = vcpu->arch.mmu.pae_root[i];
2051
2052 if (root) {
2053 root &= PT64_BASE_ADDR_MASK;
2054 sp = page_header(root);
2055 --sp->root_count;
2056 if (!sp->root_count && sp->role.invalid)
2057 kvm_mmu_zap_page(vcpu->kvm, sp);
2058 }
2059 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2060 }
2061 spin_unlock(&vcpu->kvm->mmu_lock);
2062 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2063 }
2064
2065 static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
2066 {
2067 int ret = 0;
2068
2069 if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
2070 set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
2071 ret = 1;
2072 }
2073
2074 return ret;
2075 }
2076
2077 static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
2078 {
2079 int i;
2080 gfn_t root_gfn;
2081 struct kvm_mmu_page *sp;
2082 int direct = 0;
2083 u64 pdptr;
2084
2085 root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
2086
2087 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2088 hpa_t root = vcpu->arch.mmu.root_hpa;
2089
2090 ASSERT(!VALID_PAGE(root));
2091 if (tdp_enabled)
2092 direct = 1;
2093 if (mmu_check_root(vcpu, root_gfn))
2094 return 1;
2095 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
2096 PT64_ROOT_LEVEL, direct,
2097 ACC_ALL, NULL);
2098 root = __pa(sp->spt);
2099 ++sp->root_count;
2100 vcpu->arch.mmu.root_hpa = root;
2101 return 0;
2102 }
2103 direct = !is_paging(vcpu);
2104 if (tdp_enabled)
2105 direct = 1;
2106 for (i = 0; i < 4; ++i) {
2107 hpa_t root = vcpu->arch.mmu.pae_root[i];
2108
2109 ASSERT(!VALID_PAGE(root));
2110 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
2111 pdptr = kvm_pdptr_read(vcpu, i);
2112 if (!is_present_gpte(pdptr)) {
2113 vcpu->arch.mmu.pae_root[i] = 0;
2114 continue;
2115 }
2116 root_gfn = pdptr >> PAGE_SHIFT;
2117 } else if (vcpu->arch.mmu.root_level == 0)
2118 root_gfn = 0;
2119 if (mmu_check_root(vcpu, root_gfn))
2120 return 1;
2121 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
2122 PT32_ROOT_LEVEL, direct,
2123 ACC_ALL, NULL);
2124 root = __pa(sp->spt);
2125 ++sp->root_count;
2126 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
2127 }
2128 vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
2129 return 0;
2130 }
2131
2132 static void mmu_sync_roots(struct kvm_vcpu *vcpu)
2133 {
2134 int i;
2135 struct kvm_mmu_page *sp;
2136
2137 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2138 return;
2139 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2140 hpa_t root = vcpu->arch.mmu.root_hpa;
2141 sp = page_header(root);
2142 mmu_sync_children(vcpu, sp);
2143 return;
2144 }
2145 for (i = 0; i < 4; ++i) {
2146 hpa_t root = vcpu->arch.mmu.pae_root[i];
2147
2148 if (root && VALID_PAGE(root)) {
2149 root &= PT64_BASE_ADDR_MASK;
2150 sp = page_header(root);
2151 mmu_sync_children(vcpu, sp);
2152 }
2153 }
2154 }
2155
2156 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
2157 {
2158 spin_lock(&vcpu->kvm->mmu_lock);
2159 mmu_sync_roots(vcpu);
2160 spin_unlock(&vcpu->kvm->mmu_lock);
2161 }
2162
2163 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
2164 {
2165 return vaddr;
2166 }
2167
2168 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
2169 u32 error_code)
2170 {
2171 gfn_t gfn;
2172 int r;
2173
2174 pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
2175 r = mmu_topup_memory_caches(vcpu);
2176 if (r)
2177 return r;
2178
2179 ASSERT(vcpu);
2180 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2181
2182 gfn = gva >> PAGE_SHIFT;
2183
2184 return nonpaging_map(vcpu, gva & PAGE_MASK,
2185 error_code & PFERR_WRITE_MASK, gfn);
2186 }
2187
2188 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
2189 u32 error_code)
2190 {
2191 pfn_t pfn;
2192 int r;
2193 int level;
2194 gfn_t gfn = gpa >> PAGE_SHIFT;
2195 unsigned long mmu_seq;
2196
2197 ASSERT(vcpu);
2198 ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2199
2200 r = mmu_topup_memory_caches(vcpu);
2201 if (r)
2202 return r;
2203
2204 level = mapping_level(vcpu, gfn);
2205
2206 gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2207
2208 mmu_seq = vcpu->kvm->mmu_notifier_seq;
2209 smp_rmb();
2210 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2211 if (is_error_pfn(pfn)) {
2212 kvm_release_pfn_clean(pfn);
2213 return 1;
2214 }
2215 spin_lock(&vcpu->kvm->mmu_lock);
2216 if (mmu_notifier_retry(vcpu, mmu_seq))
2217 goto out_unlock;
2218 kvm_mmu_free_some_pages(vcpu);
2219 r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
2220 level, gfn, pfn);
2221 spin_unlock(&vcpu->kvm->mmu_lock);
2222
2223 return r;
2224
2225 out_unlock:
2226 spin_unlock(&vcpu->kvm->mmu_lock);
2227 kvm_release_pfn_clean(pfn);
2228 return 0;
2229 }
2230
2231 static void nonpaging_free(struct kvm_vcpu *vcpu)
2232 {
2233 mmu_free_roots(vcpu);
2234 }
2235
2236 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
2237 {
2238 struct kvm_mmu *context = &vcpu->arch.mmu;
2239
2240 context->new_cr3 = nonpaging_new_cr3;
2241 context->page_fault = nonpaging_page_fault;
2242 context->gva_to_gpa = nonpaging_gva_to_gpa;
2243 context->free = nonpaging_free;
2244 context->prefetch_page = nonpaging_prefetch_page;
2245 context->sync_page = nonpaging_sync_page;
2246 context->invlpg = nonpaging_invlpg;
2247 context->root_level = 0;
2248 context->shadow_root_level = PT32E_ROOT_LEVEL;
2249 context->root_hpa = INVALID_PAGE;
2250 return 0;
2251 }
2252
2253 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2254 {
2255 ++vcpu->stat.tlb_flush;
2256 kvm_x86_ops->tlb_flush(vcpu);
2257 }
2258
2259 static void paging_new_cr3(struct kvm_vcpu *vcpu)
2260 {
2261 pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
2262 mmu_free_roots(vcpu);
2263 }
2264
2265 static void inject_page_fault(struct kvm_vcpu *vcpu,
2266 u64 addr,
2267 u32 err_code)
2268 {
2269 kvm_inject_page_fault(vcpu, addr, err_code);
2270 }
2271
2272 static void paging_free(struct kvm_vcpu *vcpu)
2273 {
2274 nonpaging_free(vcpu);
2275 }
2276
2277 static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level)
2278 {
2279 int bit7;
2280
2281 bit7 = (gpte >> 7) & 1;
2282 return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0;
2283 }
2284
2285 #define PTTYPE 64
2286 #include "paging_tmpl.h"
2287 #undef PTTYPE
2288
2289 #define PTTYPE 32
2290 #include "paging_tmpl.h"
2291 #undef PTTYPE
2292
2293 static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level)
2294 {
2295 struct kvm_mmu *context = &vcpu->arch.mmu;
2296 int maxphyaddr = cpuid_maxphyaddr(vcpu);
2297 u64 exb_bit_rsvd = 0;
2298
2299 if (!is_nx(vcpu))
2300 exb_bit_rsvd = rsvd_bits(63, 63);
2301 switch (level) {
2302 case PT32_ROOT_LEVEL:
2303 /* no rsvd bits for 2 level 4K page table entries */
2304 context->rsvd_bits_mask[0][1] = 0;
2305 context->rsvd_bits_mask[0][0] = 0;
2306 if (is_cpuid_PSE36())
2307 /* 36bits PSE 4MB page */
2308 context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21);
2309 else
2310 /* 32 bits PSE 4MB page */
2311 context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21);
2312 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2313 break;
2314 case PT32E_ROOT_LEVEL:
2315 context->rsvd_bits_mask[0][2] =
2316 rsvd_bits(maxphyaddr, 63) |
2317 rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */
2318 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2319 rsvd_bits(maxphyaddr, 62); /* PDE */
2320 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2321 rsvd_bits(maxphyaddr, 62); /* PTE */
2322 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2323 rsvd_bits(maxphyaddr, 62) |
2324 rsvd_bits(13, 20); /* large page */
2325 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2326 break;
2327 case PT64_ROOT_LEVEL:
2328 context->rsvd_bits_mask[0][3] = exb_bit_rsvd |
2329 rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2330 context->rsvd_bits_mask[0][2] = exb_bit_rsvd |
2331 rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2332 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2333 rsvd_bits(maxphyaddr, 51);
2334 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2335 rsvd_bits(maxphyaddr, 51);
2336 context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];
2337 context->rsvd_bits_mask[1][2] = exb_bit_rsvd |
2338 rsvd_bits(maxphyaddr, 51) |
2339 rsvd_bits(13, 29);
2340 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2341 rsvd_bits(maxphyaddr, 51) |
2342 rsvd_bits(13, 20); /* large page */
2343 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0];
2344 break;
2345 }
2346 }
2347
2348 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
2349 {
2350 struct kvm_mmu *context = &vcpu->arch.mmu;
2351
2352 ASSERT(is_pae(vcpu));
2353 context->new_cr3 = paging_new_cr3;
2354 context->page_fault = paging64_page_fault;
2355 context->gva_to_gpa = paging64_gva_to_gpa;
2356 context->prefetch_page = paging64_prefetch_page;
2357 context->sync_page = paging64_sync_page;
2358 context->invlpg = paging64_invlpg;
2359 context->free = paging_free;
2360 context->root_level = level;
2361 context->shadow_root_level = level;
2362 context->root_hpa = INVALID_PAGE;
2363 return 0;
2364 }
2365
2366 static int paging64_init_context(struct kvm_vcpu *vcpu)
2367 {
2368 reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2369 return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
2370 }
2371
2372 static int paging32_init_context(struct kvm_vcpu *vcpu)
2373 {
2374 struct kvm_mmu *context = &vcpu->arch.mmu;
2375
2376 reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2377 context->new_cr3 = paging_new_cr3;
2378 context->page_fault = paging32_page_fault;
2379 context->gva_to_gpa = paging32_gva_to_gpa;
2380 context->free = paging_free;
2381 context->prefetch_page = paging32_prefetch_page;
2382 context->sync_page = paging32_sync_page;
2383 context->invlpg = paging32_invlpg;
2384 context->root_level = PT32_ROOT_LEVEL;
2385 context->shadow_root_level = PT32E_ROOT_LEVEL;
2386 context->root_hpa = INVALID_PAGE;
2387 return 0;
2388 }
2389
2390 static int paging32E_init_context(struct kvm_vcpu *vcpu)
2391 {
2392 reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2393 return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
2394 }
2395
2396 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
2397 {
2398 struct kvm_mmu *context = &vcpu->arch.mmu;
2399
2400 context->new_cr3 = nonpaging_new_cr3;
2401 context->page_fault = tdp_page_fault;
2402 context->free = nonpaging_free;
2403 context->prefetch_page = nonpaging_prefetch_page;
2404 context->sync_page = nonpaging_sync_page;
2405 context->invlpg = nonpaging_invlpg;
2406 context->shadow_root_level = kvm_x86_ops->get_tdp_level();
2407 context->root_hpa = INVALID_PAGE;
2408
2409 if (!is_paging(vcpu)) {
2410 context->gva_to_gpa = nonpaging_gva_to_gpa;
2411 context->root_level = 0;
2412 } else if (is_long_mode(vcpu)) {
2413 reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2414 context->gva_to_gpa = paging64_gva_to_gpa;
2415 context->root_level = PT64_ROOT_LEVEL;
2416 } else if (is_pae(vcpu)) {
2417 reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2418 context->gva_to_gpa = paging64_gva_to_gpa;
2419 context->root_level = PT32E_ROOT_LEVEL;
2420 } else {
2421 reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2422 context->gva_to_gpa = paging32_gva_to_gpa;
2423 context->root_level = PT32_ROOT_LEVEL;
2424 }
2425
2426 return 0;
2427 }
2428
2429 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
2430 {
2431 int r;
2432
2433 ASSERT(vcpu);
2434 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2435
2436 if (!is_paging(vcpu))
2437 r = nonpaging_init_context(vcpu);
2438 else if (is_long_mode(vcpu))
2439 r = paging64_init_context(vcpu);
2440 else if (is_pae(vcpu))
2441 r = paging32E_init_context(vcpu);
2442 else
2443 r = paging32_init_context(vcpu);
2444
2445 vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level;
2446
2447 return r;
2448 }
2449
2450 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
2451 {
2452 vcpu->arch.update_pte.pfn = bad_pfn;
2453
2454 if (tdp_enabled)
2455 return init_kvm_tdp_mmu(vcpu);
2456 else
2457 return init_kvm_softmmu(vcpu);
2458 }
2459
2460 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
2461 {
2462 ASSERT(vcpu);
2463 if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
2464 vcpu->arch.mmu.free(vcpu);
2465 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2466 }
2467 }
2468
2469 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
2470 {
2471 destroy_kvm_mmu(vcpu);
2472 return init_kvm_mmu(vcpu);
2473 }
2474 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
2475
2476 int kvm_mmu_load(struct kvm_vcpu *vcpu)
2477 {
2478 int r;
2479
2480 r = mmu_topup_memory_caches(vcpu);
2481 if (r)
2482 goto out;
2483 spin_lock(&vcpu->kvm->mmu_lock);
2484 kvm_mmu_free_some_pages(vcpu);
2485 r = mmu_alloc_roots(vcpu);
2486 mmu_sync_roots(vcpu);
2487 spin_unlock(&vcpu->kvm->mmu_lock);
2488 if (r)
2489 goto out;
2490 /* set_cr3() should ensure TLB has been flushed */
2491 kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
2492 out:
2493 return r;
2494 }
2495 EXPORT_SYMBOL_GPL(kvm_mmu_load);
2496
2497 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
2498 {
2499 mmu_free_roots(vcpu);
2500 }
2501
2502 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
2503 struct kvm_mmu_page *sp,
2504 u64 *spte)
2505 {
2506 u64 pte;
2507 struct kvm_mmu_page *child;
2508
2509 pte = *spte;
2510 if (is_shadow_present_pte(pte)) {
2511 if (is_last_spte(pte, sp->role.level))
2512 rmap_remove(vcpu->kvm, spte);
2513 else {
2514 child = page_header(pte & PT64_BASE_ADDR_MASK);
2515 mmu_page_remove_parent_pte(child, spte);
2516 }
2517 }
2518 __set_spte(spte, shadow_trap_nonpresent_pte);
2519 if (is_large_pte(pte))
2520 --vcpu->kvm->stat.lpages;
2521 }
2522
2523 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
2524 struct kvm_mmu_page *sp,
2525 u64 *spte,
2526 const void *new)
2527 {
2528 if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
2529 ++vcpu->kvm->stat.mmu_pde_zapped;
2530 return;
2531 }
2532
2533 ++vcpu->kvm->stat.mmu_pte_updated;
2534 if (sp->role.glevels == PT32_ROOT_LEVEL)
2535 paging32_update_pte(vcpu, sp, spte, new);
2536 else
2537 paging64_update_pte(vcpu, sp, spte, new);
2538 }
2539
2540 static bool need_remote_flush(u64 old, u64 new)
2541 {
2542 if (!is_shadow_present_pte(old))
2543 return false;
2544 if (!is_shadow_present_pte(new))
2545 return true;
2546 if ((old ^ new) & PT64_BASE_ADDR_MASK)
2547 return true;
2548 old ^= PT64_NX_MASK;
2549 new ^= PT64_NX_MASK;
2550 return (old & ~new & PT64_PERM_MASK) != 0;
2551 }
2552
2553 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
2554 {
2555 if (need_remote_flush(old, new))
2556 kvm_flush_remote_tlbs(vcpu->kvm);
2557 else
2558 kvm_mmu_flush_tlb(vcpu);
2559 }
2560
2561 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
2562 {
2563 u64 *spte = vcpu->arch.last_pte_updated;
2564
2565 return !!(spte && (*spte & shadow_accessed_mask));
2566 }
2567
2568 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2569 const u8 *new, int bytes)
2570 {
2571 gfn_t gfn;
2572 int r;
2573 u64 gpte = 0;
2574 pfn_t pfn;
2575
2576 if (bytes != 4 && bytes != 8)
2577 return;
2578
2579 /*
2580 * Assume that the pte write on a page table of the same type
2581 * as the current vcpu paging mode. This is nearly always true
2582 * (might be false while changing modes). Note it is verified later
2583 * by update_pte().
2584 */
2585 if (is_pae(vcpu)) {
2586 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2587 if ((bytes == 4) && (gpa % 4 == 0)) {
2588 r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
2589 if (r)
2590 return;
2591 memcpy((void *)&gpte + (gpa % 8), new, 4);
2592 } else if ((bytes == 8) && (gpa % 8 == 0)) {
2593 memcpy((void *)&gpte, new, 8);
2594 }
2595 } else {
2596 if ((bytes == 4) && (gpa % 4 == 0))
2597 memcpy((void *)&gpte, new, 4);
2598 }
2599 if (!is_present_gpte(gpte))
2600 return;
2601 gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
2602
2603 vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
2604 smp_rmb();
2605 pfn = gfn_to_pfn(vcpu->kvm, gfn);
2606
2607 if (is_error_pfn(pfn)) {
2608 kvm_release_pfn_clean(pfn);
2609 return;
2610 }
2611 vcpu->arch.update_pte.gfn = gfn;
2612 vcpu->arch.update_pte.pfn = pfn;
2613 }
2614
2615 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
2616 {
2617 u64 *spte = vcpu->arch.last_pte_updated;
2618
2619 if (spte
2620 && vcpu->arch.last_pte_gfn == gfn
2621 && shadow_accessed_mask
2622 && !(*spte & shadow_accessed_mask)
2623 && is_shadow_present_pte(*spte))
2624 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
2625 }
2626
2627 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2628 const u8 *new, int bytes,
2629 bool guest_initiated)
2630 {
2631 gfn_t gfn = gpa >> PAGE_SHIFT;
2632 struct kvm_mmu_page *sp;
2633 struct hlist_node *node, *n;
2634 struct hlist_head *bucket;
2635 unsigned index;
2636 u64 entry, gentry;
2637 u64 *spte;
2638 unsigned offset = offset_in_page(gpa);
2639 unsigned pte_size;
2640 unsigned page_offset;
2641 unsigned misaligned;
2642 unsigned quadrant;
2643 int level;
2644 int flooded = 0;
2645 int npte;
2646 int r;
2647
2648 pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
2649 mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
2650 spin_lock(&vcpu->kvm->mmu_lock);
2651 kvm_mmu_access_page(vcpu, gfn);
2652 kvm_mmu_free_some_pages(vcpu);
2653 ++vcpu->kvm->stat.mmu_pte_write;
2654 kvm_mmu_audit(vcpu, "pre pte write");
2655 if (guest_initiated) {
2656 if (gfn == vcpu->arch.last_pt_write_gfn
2657 && !last_updated_pte_accessed(vcpu)) {
2658 ++vcpu->arch.last_pt_write_count;
2659 if (vcpu->arch.last_pt_write_count >= 3)
2660 flooded = 1;
2661 } else {
2662 vcpu->arch.last_pt_write_gfn = gfn;
2663 vcpu->arch.last_pt_write_count = 1;
2664 vcpu->arch.last_pte_updated = NULL;
2665 }
2666 }
2667 index = kvm_page_table_hashfn(gfn);
2668 bucket = &vcpu->kvm->arch.mmu_page_hash[index];
2669 hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
2670 if (sp->gfn != gfn || sp->role.direct || sp->role.invalid)
2671 continue;
2672 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
2673 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
2674 misaligned |= bytes < 4;
2675 if (misaligned || flooded) {
2676 /*
2677 * Misaligned accesses are too much trouble to fix
2678 * up; also, they usually indicate a page is not used
2679 * as a page table.
2680 *
2681 * If we're seeing too many writes to a page,
2682 * it may no longer be a page table, or we may be
2683 * forking, in which case it is better to unmap the
2684 * page.
2685 */
2686 pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2687 gpa, bytes, sp->role.word);
2688 if (kvm_mmu_zap_page(vcpu->kvm, sp))
2689 n = bucket->first;
2690 ++vcpu->kvm->stat.mmu_flooded;
2691 continue;
2692 }
2693 page_offset = offset;
2694 level = sp->role.level;
2695 npte = 1;
2696 if (sp->role.glevels == PT32_ROOT_LEVEL) {
2697 page_offset <<= 1; /* 32->64 */
2698 /*
2699 * A 32-bit pde maps 4MB while the shadow pdes map
2700 * only 2MB. So we need to double the offset again
2701 * and zap two pdes instead of one.
2702 */
2703 if (level == PT32_ROOT_LEVEL) {
2704 page_offset &= ~7; /* kill rounding error */
2705 page_offset <<= 1;
2706 npte = 2;
2707 }
2708 quadrant = page_offset >> PAGE_SHIFT;
2709 page_offset &= ~PAGE_MASK;
2710 if (quadrant != sp->role.quadrant)
2711 continue;
2712 }
2713 spte = &sp->spt[page_offset / sizeof(*spte)];
2714 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
2715 gentry = 0;
2716 r = kvm_read_guest_atomic(vcpu->kvm,
2717 gpa & ~(u64)(pte_size - 1),
2718 &gentry, pte_size);
2719 new = (const void *)&gentry;
2720 if (r < 0)
2721 new = NULL;
2722 }
2723 while (npte--) {
2724 entry = *spte;
2725 mmu_pte_write_zap_pte(vcpu, sp, spte);
2726 if (new)
2727 mmu_pte_write_new_pte(vcpu, sp, spte, new);
2728 mmu_pte_write_flush_tlb(vcpu, entry, *spte);
2729 ++spte;
2730 }
2731 }
2732 kvm_mmu_audit(vcpu, "post pte write");
2733 spin_unlock(&vcpu->kvm->mmu_lock);
2734 if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2735 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2736 vcpu->arch.update_pte.pfn = bad_pfn;
2737 }
2738 }
2739
2740 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2741 {
2742 gpa_t gpa;
2743 int r;
2744
2745 if (tdp_enabled)
2746 return 0;
2747
2748 gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
2749
2750 spin_lock(&vcpu->kvm->mmu_lock);
2751 r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2752 spin_unlock(&vcpu->kvm->mmu_lock);
2753 return r;
2754 }
2755 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2756
2757 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2758 {
2759 while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES &&
2760 !list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2761 struct kvm_mmu_page *sp;
2762
2763 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2764 struct kvm_mmu_page, link);
2765 kvm_mmu_zap_page(vcpu->kvm, sp);
2766 ++vcpu->kvm->stat.mmu_recycled;
2767 }
2768 }
2769
2770 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2771 {
2772 int r;
2773 enum emulation_result er;
2774
2775 r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2776 if (r < 0)
2777 goto out;
2778
2779 if (!r) {
2780 r = 1;
2781 goto out;
2782 }
2783
2784 r = mmu_topup_memory_caches(vcpu);
2785 if (r)
2786 goto out;
2787
2788 er = emulate_instruction(vcpu, cr2, error_code, 0);
2789
2790 switch (er) {
2791 case EMULATE_DONE:
2792 return 1;
2793 case EMULATE_DO_MMIO:
2794 ++vcpu->stat.mmio_exits;
2795 return 0;
2796 case EMULATE_FAIL:
2797 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
2798 vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
2799 return 0;
2800 default:
2801 BUG();
2802 }
2803 out:
2804 return r;
2805 }
2806 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2807
2808 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2809 {
2810 vcpu->arch.mmu.invlpg(vcpu, gva);
2811 kvm_mmu_flush_tlb(vcpu);
2812 ++vcpu->stat.invlpg;
2813 }
2814 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2815
2816 void kvm_enable_tdp(void)
2817 {
2818 tdp_enabled = true;
2819 }
2820 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2821
2822 void kvm_disable_tdp(void)
2823 {
2824 tdp_enabled = false;
2825 }
2826 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2827
2828 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2829 {
2830 free_page((unsigned long)vcpu->arch.mmu.pae_root);
2831 }
2832
2833 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2834 {
2835 struct page *page;
2836 int i;
2837
2838 ASSERT(vcpu);
2839
2840 /*
2841 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2842 * Therefore we need to allocate shadow page tables in the first
2843 * 4GB of memory, which happens to fit the DMA32 zone.
2844 */
2845 page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2846 if (!page)
2847 goto error_1;
2848 vcpu->arch.mmu.pae_root = page_address(page);
2849 for (i = 0; i < 4; ++i)
2850 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2851
2852 return 0;
2853
2854 error_1:
2855 free_mmu_pages(vcpu);
2856 return -ENOMEM;
2857 }
2858
2859 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2860 {
2861 ASSERT(vcpu);
2862 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2863
2864 return alloc_mmu_pages(vcpu);
2865 }
2866
2867 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2868 {
2869 ASSERT(vcpu);
2870 ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2871
2872 return init_kvm_mmu(vcpu);
2873 }
2874
2875 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2876 {
2877 ASSERT(vcpu);
2878
2879 destroy_kvm_mmu(vcpu);
2880 free_mmu_pages(vcpu);
2881 mmu_free_memory_caches(vcpu);
2882 }
2883
2884 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2885 {
2886 struct kvm_mmu_page *sp;
2887
2888 list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2889 int i;
2890 u64 *pt;
2891
2892 if (!test_bit(slot, sp->slot_bitmap))
2893 continue;
2894
2895 pt = sp->spt;
2896 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2897 /* avoid RMW */
2898 if (pt[i] & PT_WRITABLE_MASK)
2899 pt[i] &= ~PT_WRITABLE_MASK;
2900 }
2901 kvm_flush_remote_tlbs(kvm);
2902 }
2903
2904 void kvm_mmu_zap_all(struct kvm *kvm)
2905 {
2906 struct kvm_mmu_page *sp, *node;
2907
2908 spin_lock(&kvm->mmu_lock);
2909 list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2910 if (kvm_mmu_zap_page(kvm, sp))
2911 node = container_of(kvm->arch.active_mmu_pages.next,
2912 struct kvm_mmu_page, link);
2913 spin_unlock(&kvm->mmu_lock);
2914
2915 kvm_flush_remote_tlbs(kvm);
2916 }
2917
2918 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2919 {
2920 struct kvm_mmu_page *page;
2921
2922 page = container_of(kvm->arch.active_mmu_pages.prev,
2923 struct kvm_mmu_page, link);
2924 kvm_mmu_zap_page(kvm, page);
2925 }
2926
2927 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2928 {
2929 struct kvm *kvm;
2930 struct kvm *kvm_freed = NULL;
2931 int cache_count = 0;
2932
2933 spin_lock(&kvm_lock);
2934
2935 list_for_each_entry(kvm, &vm_list, vm_list) {
2936 int npages;
2937
2938 if (!down_read_trylock(&kvm->slots_lock))
2939 continue;
2940 spin_lock(&kvm->mmu_lock);
2941 npages = kvm->arch.n_alloc_mmu_pages -
2942 kvm->arch.n_free_mmu_pages;
2943 cache_count += npages;
2944 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2945 kvm_mmu_remove_one_alloc_mmu_page(kvm);
2946 cache_count--;
2947 kvm_freed = kvm;
2948 }
2949 nr_to_scan--;
2950
2951 spin_unlock(&kvm->mmu_lock);
2952 up_read(&kvm->slots_lock);
2953 }
2954 if (kvm_freed)
2955 list_move_tail(&kvm_freed->vm_list, &vm_list);
2956
2957 spin_unlock(&kvm_lock);
2958
2959 return cache_count;
2960 }
2961
2962 static struct shrinker mmu_shrinker = {
2963 .shrink = mmu_shrink,
2964 .seeks = DEFAULT_SEEKS * 10,
2965 };
2966
2967 static void mmu_destroy_caches(void)
2968 {
2969 if (pte_chain_cache)
2970 kmem_cache_destroy(pte_chain_cache);
2971 if (rmap_desc_cache)
2972 kmem_cache_destroy(rmap_desc_cache);
2973 if (mmu_page_header_cache)
2974 kmem_cache_destroy(mmu_page_header_cache);
2975 }
2976
2977 void kvm_mmu_module_exit(void)
2978 {
2979 mmu_destroy_caches();
2980 unregister_shrinker(&mmu_shrinker);
2981 }
2982
2983 int kvm_mmu_module_init(void)
2984 {
2985 pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2986 sizeof(struct kvm_pte_chain),
2987 0, 0, NULL);
2988 if (!pte_chain_cache)
2989 goto nomem;
2990 rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2991 sizeof(struct kvm_rmap_desc),
2992 0, 0, NULL);
2993 if (!rmap_desc_cache)
2994 goto nomem;
2995
2996 mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2997 sizeof(struct kvm_mmu_page),
2998 0, 0, NULL);
2999 if (!mmu_page_header_cache)
3000 goto nomem;
3001
3002 register_shrinker(&mmu_shrinker);
3003
3004 return 0;
3005
3006 nomem:
3007 mmu_destroy_caches();
3008 return -ENOMEM;
3009 }
3010
3011 /*
3012 * Caculate mmu pages needed for kvm.
3013 */
3014 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
3015 {
3016 int i;
3017 unsigned int nr_mmu_pages;
3018 unsigned int nr_pages = 0;
3019
3020 for (i = 0; i < kvm->nmemslots; i++)
3021 nr_pages += kvm->memslots[i].npages;
3022
3023 nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
3024 nr_mmu_pages = max(nr_mmu_pages,
3025 (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
3026
3027 return nr_mmu_pages;
3028 }
3029
3030 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3031 unsigned len)
3032 {
3033 if (len > buffer->len)
3034 return NULL;
3035 return buffer->ptr;
3036 }
3037
3038 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3039 unsigned len)
3040 {
3041 void *ret;
3042
3043 ret = pv_mmu_peek_buffer(buffer, len);
3044 if (!ret)
3045 return ret;
3046 buffer->ptr += len;
3047 buffer->len -= len;
3048 buffer->processed += len;
3049 return ret;
3050 }
3051
3052 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
3053 gpa_t addr, gpa_t value)
3054 {
3055 int bytes = 8;
3056 int r;
3057
3058 if (!is_long_mode(vcpu) && !is_pae(vcpu))
3059 bytes = 4;
3060
3061 r = mmu_topup_memory_caches(vcpu);
3062 if (r)
3063 return r;
3064
3065 if (!emulator_write_phys(vcpu, addr, &value, bytes))
3066 return -EFAULT;
3067
3068 return 1;
3069 }
3070
3071 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
3072 {
3073 kvm_set_cr3(vcpu, vcpu->arch.cr3);
3074 return 1;
3075 }
3076
3077 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
3078 {
3079 spin_lock(&vcpu->kvm->mmu_lock);
3080 mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
3081 spin_unlock(&vcpu->kvm->mmu_lock);
3082 return 1;
3083 }
3084
3085 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
3086 struct kvm_pv_mmu_op_buffer *buffer)
3087 {
3088 struct kvm_mmu_op_header *header;
3089
3090 header = pv_mmu_peek_buffer(buffer, sizeof *header);
3091 if (!header)
3092 return 0;
3093 switch (header->op) {
3094 case KVM_MMU_OP_WRITE_PTE: {
3095 struct kvm_mmu_op_write_pte *wpte;
3096
3097 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
3098 if (!wpte)
3099 return 0;
3100 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
3101 wpte->pte_val);
3102 }
3103 case KVM_MMU_OP_FLUSH_TLB: {
3104 struct kvm_mmu_op_flush_tlb *ftlb;
3105
3106 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
3107 if (!ftlb)
3108 return 0;
3109 return kvm_pv_mmu_flush_tlb(vcpu);
3110 }
3111 case KVM_MMU_OP_RELEASE_PT: {
3112 struct kvm_mmu_op_release_pt *rpt;
3113
3114 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
3115 if (!rpt)
3116 return 0;
3117 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
3118 }
3119 default: return 0;
3120 }
3121 }
3122
3123 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
3124 gpa_t addr, unsigned long *ret)
3125 {
3126 int r;
3127 struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
3128
3129 buffer->ptr = buffer->buf;
3130 buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
3131 buffer->processed = 0;
3132
3133 r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
3134 if (r)
3135 goto out;
3136
3137 while (buffer->len) {
3138 r = kvm_pv_mmu_op_one(vcpu, buffer);
3139 if (r < 0)
3140 goto out;
3141 if (r == 0)
3142 break;
3143 }
3144
3145 r = 1;
3146 out:
3147 *ret = buffer->processed;
3148 return r;
3149 }
3150
3151 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
3152 {
3153 struct kvm_shadow_walk_iterator iterator;
3154 int nr_sptes = 0;
3155
3156 spin_lock(&vcpu->kvm->mmu_lock);
3157 for_each_shadow_entry(vcpu, addr, iterator) {
3158 sptes[iterator.level-1] = *iterator.sptep;
3159 nr_sptes++;
3160 if (!is_shadow_present_pte(*iterator.sptep))
3161 break;
3162 }
3163 spin_unlock(&vcpu->kvm->mmu_lock);
3164
3165 return nr_sptes;
3166 }
3167 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
3168
3169 #ifdef AUDIT
3170
3171 static const char *audit_msg;
3172
3173 static gva_t canonicalize(gva_t gva)
3174 {
3175 #ifdef CONFIG_X86_64
3176 gva = (long long)(gva << 16) >> 16;
3177 #endif
3178 return gva;
3179 }
3180
3181
3182 typedef void (*inspect_spte_fn) (struct kvm *kvm, struct kvm_mmu_page *sp,
3183 u64 *sptep);
3184
3185 static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
3186 inspect_spte_fn fn)
3187 {
3188 int i;
3189
3190 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3191 u64 ent = sp->spt[i];
3192
3193 if (is_shadow_present_pte(ent)) {
3194 if (!is_last_spte(ent, sp->role.level)) {
3195 struct kvm_mmu_page *child;
3196 child = page_header(ent & PT64_BASE_ADDR_MASK);
3197 __mmu_spte_walk(kvm, child, fn);
3198 } else
3199 fn(kvm, sp, &sp->spt[i]);
3200 }
3201 }
3202 }
3203
3204 static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
3205 {
3206 int i;
3207 struct kvm_mmu_page *sp;
3208
3209 if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
3210 return;
3211 if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
3212 hpa_t root = vcpu->arch.mmu.root_hpa;
3213 sp = page_header(root);
3214 __mmu_spte_walk(vcpu->kvm, sp, fn);
3215 return;
3216 }
3217 for (i = 0; i < 4; ++i) {
3218 hpa_t root = vcpu->arch.mmu.pae_root[i];
3219
3220 if (root && VALID_PAGE(root)) {
3221 root &= PT64_BASE_ADDR_MASK;
3222 sp = page_header(root);
3223 __mmu_spte_walk(vcpu->kvm, sp, fn);
3224 }
3225 }
3226 return;
3227 }
3228
3229 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
3230 gva_t va, int level)
3231 {
3232 u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
3233 int i;
3234 gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
3235
3236 for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
3237 u64 ent = pt[i];
3238
3239 if (ent == shadow_trap_nonpresent_pte)
3240 continue;
3241
3242 va = canonicalize(va);
3243 if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
3244 audit_mappings_page(vcpu, ent, va, level - 1);
3245 else {
3246 gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
3247 gfn_t gfn = gpa >> PAGE_SHIFT;
3248 pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
3249 hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
3250
3251 if (is_error_pfn(pfn)) {
3252 kvm_release_pfn_clean(pfn);
3253 continue;
3254 }
3255
3256 if (is_shadow_present_pte(ent)
3257 && (ent & PT64_BASE_ADDR_MASK) != hpa)
3258 printk(KERN_ERR "xx audit error: (%s) levels %d"
3259 " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3260 audit_msg, vcpu->arch.mmu.root_level,
3261 va, gpa, hpa, ent,
3262 is_shadow_present_pte(ent));
3263 else if (ent == shadow_notrap_nonpresent_pte
3264 && !is_error_hpa(hpa))
3265 printk(KERN_ERR "audit: (%s) notrap shadow,"
3266 " valid guest gva %lx\n", audit_msg, va);
3267 kvm_release_pfn_clean(pfn);
3268
3269 }
3270 }
3271 }
3272
3273 static void audit_mappings(struct kvm_vcpu *vcpu)
3274 {
3275 unsigned i;
3276
3277 if (vcpu->arch.mmu.root_level == 4)
3278 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
3279 else
3280 for (i = 0; i < 4; ++i)
3281 if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
3282 audit_mappings_page(vcpu,
3283 vcpu->arch.mmu.pae_root[i],
3284 i << 30,
3285 2);
3286 }
3287
3288 static int count_rmaps(struct kvm_vcpu *vcpu)
3289 {
3290 int nmaps = 0;
3291 int i, j, k;
3292
3293 for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
3294 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
3295 struct kvm_rmap_desc *d;
3296
3297 for (j = 0; j < m->npages; ++j) {
3298 unsigned long *rmapp = &m->rmap[j];
3299
3300 if (!*rmapp)
3301 continue;
3302 if (!(*rmapp & 1)) {
3303 ++nmaps;
3304 continue;
3305 }
3306 d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
3307 while (d) {
3308 for (k = 0; k < RMAP_EXT; ++k)
3309 if (d->sptes[k])
3310 ++nmaps;
3311 else
3312 break;
3313 d = d->more;
3314 }
3315 }
3316 }
3317 return nmaps;
3318 }
3319
3320 void inspect_spte_has_rmap(struct kvm *kvm, struct kvm_mmu_page *sp, u64 *sptep)
3321 {
3322 unsigned long *rmapp;
3323 struct kvm_mmu_page *rev_sp;
3324 gfn_t gfn;
3325
3326 if (*sptep & PT_WRITABLE_MASK) {
3327 rev_sp = page_header(__pa(sptep));
3328 gfn = rev_sp->gfns[sptep - rev_sp->spt];
3329
3330 if (!gfn_to_memslot(kvm, gfn)) {
3331 if (!printk_ratelimit())
3332 return;
3333 printk(KERN_ERR "%s: no memslot for gfn %ld\n",
3334 audit_msg, gfn);
3335 printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n",
3336 audit_msg, sptep - rev_sp->spt,
3337 rev_sp->gfn);
3338 dump_stack();
3339 return;
3340 }
3341
3342 rmapp = gfn_to_rmap(kvm, rev_sp->gfns[sptep - rev_sp->spt],
3343 is_large_pte(*sptep));
3344 if (!*rmapp) {
3345 if (!printk_ratelimit())
3346 return;
3347 printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
3348 audit_msg, *sptep);
3349 dump_stack();
3350 }
3351 }
3352
3353 }
3354
3355 void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
3356 {
3357 mmu_spte_walk(vcpu, inspect_spte_has_rmap);
3358 }
3359
3360 static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
3361 {
3362 struct kvm_mmu_page *sp;
3363 int i;
3364
3365 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3366 u64 *pt = sp->spt;
3367
3368 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
3369 continue;
3370
3371 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3372 u64 ent = pt[i];
3373
3374 if (!(ent & PT_PRESENT_MASK))
3375 continue;
3376 if (!(ent & PT_WRITABLE_MASK))
3377 continue;
3378 inspect_spte_has_rmap(vcpu->kvm, sp, &pt[i]);
3379 }
3380 }
3381 return;
3382 }
3383
3384 static void audit_rmap(struct kvm_vcpu *vcpu)
3385 {
3386 check_writable_mappings_rmap(vcpu);
3387 count_rmaps(vcpu);
3388 }
3389
3390 static void audit_write_protection(struct kvm_vcpu *vcpu)
3391 {
3392 struct kvm_mmu_page *sp;
3393 struct kvm_memory_slot *slot;
3394 unsigned long *rmapp;
3395 u64 *spte;
3396 gfn_t gfn;
3397
3398 list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3399 if (sp->role.direct)
3400 continue;
3401 if (sp->unsync)
3402 continue;
3403
3404 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
3405 slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
3406 rmapp = &slot->rmap[gfn - slot->base_gfn];
3407
3408 spte = rmap_next(vcpu->kvm, rmapp, NULL);
3409 while (spte) {
3410 if (*spte & PT_WRITABLE_MASK)
3411 printk(KERN_ERR "%s: (%s) shadow page has "
3412 "writable mappings: gfn %lx role %x\n",
3413 __func__, audit_msg, sp->gfn,
3414 sp->role.word);
3415 spte = rmap_next(vcpu->kvm, rmapp, spte);
3416 }
3417 }
3418 }
3419
3420 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
3421 {
3422 int olddbg = dbg;
3423
3424 dbg = 0;
3425 audit_msg = msg;
3426 audit_rmap(vcpu);
3427 audit_write_protection(vcpu);
3428 if (strcmp("pre pte write", audit_msg) != 0)
3429 audit_mappings(vcpu);
3430 audit_writable_sptes_have_rmaps(vcpu);
3431 dbg = olddbg;
3432 }
3433
3434 #endif
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