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