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 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
 657 {
 658         u64 *spte;
 659         int need_tlb_flush = 0;
 660
 661         while ((spte = rmap_next(kvm, rmapp, NULL))) {
 662                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 663                 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
 664                 rmap_remove(kvm, spte);
 665                 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
 666                 need_tlb_flush = 1;
 667         }
 668         return need_tlb_flush;
 669 }
 670
 671 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 672                           int (*handler)(struct kvm *kvm, unsigned long *rmapp))
 673 {
 674         int i;
 675         int retval = 0;
 676
 677         /*
 678          * If mmap_sem isn't taken, we can look the memslots with only
 679          * the mmu_lock by skipping over the slots with userspace_addr == 0.
 680          */
 681         for (i = 0; i < kvm->nmemslots; i++) {
 682                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 683                 unsigned long start = memslot->userspace_addr;
 684                 unsigned long end;
 685
 686                 /* mmu_lock protects userspace_addr */
 687                 if (!start)
 688                         continue;
 689
 690                 end = start + (memslot->npages << PAGE_SHIFT);
 691                 if (hva >= start && hva < end) {
 692                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
 693                         retval |= handler(kvm, &memslot->rmap[gfn_offset]);
 694                         retval |= handler(kvm,
 695                                           &memslot->lpage_info[
 696                                                   gfn_offset /
 697                                                   KVM_PAGES_PER_HPAGE].rmap_pde);
 698                 }
 699         }
 700
 701         return retval;
 702 }
 703
 704 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 705 {
 706         return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 707 }
 708
 709 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
 710 {
 711         u64 *spte;
 712         int young = 0;
 713
 714         spte = rmap_next(kvm, rmapp, NULL);
 715         while (spte) {
 716                 int _young;
 717                 u64 _spte = *spte;
 718                 BUG_ON(!(_spte & PT_PRESENT_MASK));
 719                 _young = _spte & PT_ACCESSED_MASK;
 720                 if (_young) {
 721                         young = 1;
 722                         clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
 723                 }
 724                 spte = rmap_next(kvm, rmapp, spte);
 725         }
 726         return young;
 727 }
 728
 729 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
 730 {
 731         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
 732 }
 733
 734 #ifdef MMU_DEBUG
 735 static int is_empty_shadow_page(u64 *spt)
 736 {
 737         u64 *pos;
 738         u64 *end;
 739
 740         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
 741                 if (is_shadow_present_pte(*pos)) {
 742                         printk(KERN_ERR "%s: %p %llx\n", __func__,
 743                                pos, *pos);
 744                         return 0;
 745                 }
 746         return 1;
 747 }
 748 #endif
 749
 750 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 751 {
 752         ASSERT(is_empty_shadow_page(sp->spt));
 753         list_del(&sp->link);
 754         __free_page(virt_to_page(sp->spt));
 755         __free_page(virt_to_page(sp->gfns));
 756         kfree(sp);
 757         ++kvm->arch.n_free_mmu_pages;
 758 }
 759
 760 static unsigned kvm_page_table_hashfn(gfn_t gfn)
 761 {
 762         return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
 763 }
 764
 765 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 766                                                u64 *parent_pte)
 767 {
 768         struct kvm_mmu_page *sp;
 769
 770         sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
 771         sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 772         sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 773         set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 774         list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
 775         ASSERT(is_empty_shadow_page(sp->spt));
 776         sp->slot_bitmap = 0;
 777         sp->multimapped = 0;
 778         sp->parent_pte = parent_pte;
 779         --vcpu->kvm->arch.n_free_mmu_pages;
 780         return sp;
 781 }
 782
 783 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
 784                                     struct kvm_mmu_page *sp, u64 *parent_pte)
 785 {
 786         struct kvm_pte_chain *pte_chain;
 787         struct hlist_node *node;
 788         int i;
 789
 790         if (!parent_pte)
 791                 return;
 792         if (!sp->multimapped) {
 793                 u64 *old = sp->parent_pte;
 794
 795                 if (!old) {
 796                         sp->parent_pte = parent_pte;
 797                         return;
 798                 }
 799                 sp->multimapped = 1;
 800                 pte_chain = mmu_alloc_pte_chain(vcpu);
 801                 INIT_HLIST_HEAD(&sp->parent_ptes);
 802                 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 803                 pte_chain->parent_ptes[0] = old;
 804         }
 805         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
 806                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
 807                         continue;
 808                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
 809                         if (!pte_chain->parent_ptes[i]) {
 810                                 pte_chain->parent_ptes[i] = parent_pte;
 811                                 return;
 812                         }
 813         }
 814         pte_chain = mmu_alloc_pte_chain(vcpu);
 815         BUG_ON(!pte_chain);
 816         hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 817         pte_chain->parent_ptes[0] = parent_pte;
 818 }
 819
 820 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
 821                                        u64 *parent_pte)
 822 {
 823         struct kvm_pte_chain *pte_chain;
 824         struct hlist_node *node;
 825         int i;
 826
 827         if (!sp->multimapped) {
 828                 BUG_ON(sp->parent_pte != parent_pte);
 829                 sp->parent_pte = NULL;
 830                 return;
 831         }
 832         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
 833                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 834                         if (!pte_chain->parent_ptes[i])
 835                                 break;
 836                         if (pte_chain->parent_ptes[i] != parent_pte)
 837                                 continue;
 838                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
 839                                 && pte_chain->parent_ptes[i + 1]) {
 840                                 pte_chain->parent_ptes[i]
 841                                         = pte_chain->parent_ptes[i + 1];
 842                                 ++i;
 843                         }
 844                         pte_chain->parent_ptes[i] = NULL;
 845                         if (i == 0) {
 846                                 hlist_del(&pte_chain->link);
 847                                 mmu_free_pte_chain(pte_chain);
 848                                 if (hlist_empty(&sp->parent_ptes)) {
 849                                         sp->multimapped = 0;
 850                                         sp->parent_pte = NULL;
 851                                 }
 852                         }
 853                         return;
 854                 }
 855         BUG();
 856 }
 857
 858 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
 859                                     struct kvm_mmu_page *sp)
 860 {
 861         int i;
 862
 863         for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
 864                 sp->spt[i] = shadow_trap_nonpresent_pte;
 865 }
 866
 867 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
 868 {
 869         unsigned index;
 870         struct hlist_head *bucket;
 871         struct kvm_mmu_page *sp;
 872         struct hlist_node *node;
 873
 874         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
 875         index = kvm_page_table_hashfn(gfn);
 876         bucket = &kvm->arch.mmu_page_hash[index];
 877         hlist_for_each_entry(sp, node, bucket, hash_link)
 878                 if (sp->gfn == gfn && !sp->role.metaphysical
 879                     && !sp->role.invalid) {
 880                         pgprintk("%s: found role %x\n",
 881                                  __func__, sp->role.word);
 882                         return sp;
 883                 }
 884         return NULL;
 885 }
 886
 887 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 888                                              gfn_t gfn,
 889                                              gva_t gaddr,
 890                                              unsigned level,
 891                                              int metaphysical,
 892                                              unsigned access,
 893                                              u64 *parent_pte)
 894 {
 895         union kvm_mmu_page_role role;
 896         unsigned index;
 897         unsigned quadrant;
 898         struct hlist_head *bucket;
 899         struct kvm_mmu_page *sp;
 900         struct hlist_node *node;
 901
 902         role.word = 0;
 903         role.glevels = vcpu->arch.mmu.root_level;
 904         role.level = level;
 905         role.metaphysical = metaphysical;
 906         role.access = access;
 907         if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
 908                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
 909                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
 910                 role.quadrant = quadrant;
 911         }
 912         pgprintk("%s: looking gfn %lx role %x\n", __func__,
 913                  gfn, role.word);
 914         index = kvm_page_table_hashfn(gfn);
 915         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
 916         hlist_for_each_entry(sp, node, bucket, hash_link)
 917                 if (sp->gfn == gfn && sp->role.word == role.word) {
 918                         mmu_page_add_parent_pte(vcpu, sp, parent_pte);
 919                         pgprintk("%s: found\n", __func__);
 920                         return sp;
 921                 }
 922         ++vcpu->kvm->stat.mmu_cache_miss;
 923         sp = kvm_mmu_alloc_page(vcpu, parent_pte);
 924         if (!sp)
 925                 return sp;
 926         pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
 927         sp->gfn = gfn;
 928         sp->role = role;
 929         hlist_add_head(&sp->hash_link, bucket);
 930         if (!metaphysical)
 931                 rmap_write_protect(vcpu->kvm, gfn);
 932         if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
 933                 vcpu->arch.mmu.prefetch_page(vcpu, sp);
 934         else
 935                 nonpaging_prefetch_page(vcpu, sp);
 936         return sp;
 937 }
 938
 939 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
 940                                          struct kvm_mmu_page *sp)
 941 {
 942         unsigned i;
 943         u64 *pt;
 944         u64 ent;
 945
 946         pt = sp->spt;
 947
 948         if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
 949                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 950                         if (is_shadow_present_pte(pt[i]))
 951                                 rmap_remove(kvm, &pt[i]);
 952                         pt[i] = shadow_trap_nonpresent_pte;
 953                 }
 954                 kvm_flush_remote_tlbs(kvm);
 955                 return;
 956         }
 957
 958         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 959                 ent = pt[i];
 960
 961                 if (is_shadow_present_pte(ent)) {
 962                         if (!is_large_pte(ent)) {
 963                                 ent &= PT64_BASE_ADDR_MASK;
 964                                 mmu_page_remove_parent_pte(page_header(ent),
 965                                                            &pt[i]);
 966                         } else {
 967                                 --kvm->stat.lpages;
 968                                 rmap_remove(kvm, &pt[i]);
 969                         }
 970                 }
 971                 pt[i] = shadow_trap_nonpresent_pte;
 972         }
 973         kvm_flush_remote_tlbs(kvm);
 974 }
 975
 976 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
 977 {
 978         mmu_page_remove_parent_pte(sp, parent_pte);
 979 }
 980
 981 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
 982 {
 983         int i;
 984
 985         for (i = 0; i < KVM_MAX_VCPUS; ++i)
 986                 if (kvm->vcpus[i])
 987                         kvm->vcpus[i]->arch.last_pte_updated = NULL;
 988 }
 989
 990 static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 991 {
 992         u64 *parent_pte;
 993
 994         ++kvm->stat.mmu_shadow_zapped;
 995         while (sp->multimapped || sp->parent_pte) {
 996                 if (!sp->multimapped)
 997                         parent_pte = sp->parent_pte;
 998                 else {
 999                         struct kvm_pte_chain *chain;
1000
1001                         chain = container_of(sp->parent_ptes.first,
1002                                              struct kvm_pte_chain, link);
1003                         parent_pte = chain->parent_ptes[0];
1004                 }
1005                 BUG_ON(!parent_pte);
1006                 kvm_mmu_put_page(sp, parent_pte);
1007                 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
1008         }
1009         kvm_mmu_page_unlink_children(kvm, sp);
1010         if (!sp->root_count) {
1011                 if (!sp->role.metaphysical && !sp->role.invalid)
1012                         unaccount_shadowed(kvm, sp->gfn);
1013                 hlist_del(&sp->hash_link);
1014                 kvm_mmu_free_page(kvm, sp);
1015         } else {
1016                 int invalid = sp->role.invalid;
1017                 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1018                 sp->role.invalid = 1;
1019                 kvm_reload_remote_mmus(kvm);
1020                 if (!sp->role.metaphysical && !invalid)
1021                         unaccount_shadowed(kvm, sp->gfn);
1022         }
1023         kvm_mmu_reset_last_pte_updated(kvm);
1024 }
1025
1026 /*
1027  * Changing the number of mmu pages allocated to the vm
1028  * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1029  */
1030 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1031 {
1032         /*
1033          * If we set the number of mmu pages to be smaller be than the
1034          * number of actived pages , we must to free some mmu pages before we
1035          * change the value
1036          */
1037
1038         if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
1039             kvm_nr_mmu_pages) {
1040                 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
1041                                        - kvm->arch.n_free_mmu_pages;
1042
1043                 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
1044                         struct kvm_mmu_page *page;
1045
1046                         page = container_of(kvm->arch.active_mmu_pages.prev,
1047                                             struct kvm_mmu_page, link);
1048                         kvm_mmu_zap_page(kvm, page);
1049                         n_used_mmu_pages--;
1050                 }
1051                 kvm->arch.n_free_mmu_pages = 0;
1052         }
1053         else
1054                 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1055                                          - kvm->arch.n_alloc_mmu_pages;
1056
1057         kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1058 }
1059
1060 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1061 {
1062         unsigned index;
1063         struct hlist_head *bucket;
1064         struct kvm_mmu_page *sp;
1065         struct hlist_node *node, *n;
1066         int r;
1067
1068         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1069         r = 0;
1070         index = kvm_page_table_hashfn(gfn);
1071         bucket = &kvm->arch.mmu_page_hash[index];
1072         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1073                 if (sp->gfn == gfn && !sp->role.metaphysical) {
1074                         pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1075                                  sp->role.word);
1076                         kvm_mmu_zap_page(kvm, sp);
1077                         r = 1;
1078                 }
1079         return r;
1080 }
1081
1082 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1083 {
1084         struct kvm_mmu_page *sp;
1085
1086         while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
1087                 pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
1088                 kvm_mmu_zap_page(kvm, sp);
1089         }
1090 }
1091
1092 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1093 {
1094         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1095         struct kvm_mmu_page *sp = page_header(__pa(pte));
1096
1097         __set_bit(slot, &sp->slot_bitmap);
1098 }
1099
1100 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1101 {
1102         struct page *page;
1103
1104         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1105
1106         if (gpa == UNMAPPED_GVA)
1107                 return NULL;
1108
1109         down_read(&current->mm->mmap_sem);
1110         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1111         up_read(&current->mm->mmap_sem);
1112
1113         return page;
1114 }
1115
1116 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1117                          unsigned pt_access, unsigned pte_access,
1118                          int user_fault, int write_fault, int dirty,
1119                          int *ptwrite, int largepage, gfn_t gfn,
1120                          pfn_t pfn, bool speculative)
1121 {
1122         u64 spte;
1123         int was_rmapped = 0;
1124         int was_writeble = is_writeble_pte(*shadow_pte);
1125
1126         pgprintk("%s: spte %llx access %x write_fault %d"
1127                  " user_fault %d gfn %lx\n",
1128                  __func__, *shadow_pte, pt_access,
1129                  write_fault, user_fault, gfn);
1130
1131         if (is_rmap_pte(*shadow_pte)) {
1132                 /*
1133                  * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1134                  * the parent of the now unreachable PTE.
1135                  */
1136                 if (largepage && !is_large_pte(*shadow_pte)) {
1137                         struct kvm_mmu_page *child;
1138                         u64 pte = *shadow_pte;
1139
1140                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1141                         mmu_page_remove_parent_pte(child, shadow_pte);
1142                 } else if (pfn != spte_to_pfn(*shadow_pte)) {
1143                         pgprintk("hfn old %lx new %lx\n",
1144                                  spte_to_pfn(*shadow_pte), pfn);
1145                         rmap_remove(vcpu->kvm, shadow_pte);
1146                 } else {
1147                         if (largepage)
1148                                 was_rmapped = is_large_pte(*shadow_pte);
1149                         else
1150                                 was_rmapped = 1;
1151                 }
1152         }
1153
1154         /*
1155          * We don't set the accessed bit, since we sometimes want to see
1156          * whether the guest actually used the pte (in order to detect
1157          * demand paging).
1158          */
1159         spte = shadow_base_present_pte | shadow_dirty_mask;
1160         if (!speculative)
1161                 pte_access |= PT_ACCESSED_MASK;
1162         if (!dirty)
1163                 pte_access &= ~ACC_WRITE_MASK;
1164         if (pte_access & ACC_EXEC_MASK)
1165                 spte |= shadow_x_mask;
1166         else
1167                 spte |= shadow_nx_mask;
1168         if (pte_access & ACC_USER_MASK)
1169                 spte |= shadow_user_mask;
1170         if (largepage)
1171                 spte |= PT_PAGE_SIZE_MASK;
1172
1173         spte |= (u64)pfn << PAGE_SHIFT;
1174
1175         if ((pte_access & ACC_WRITE_MASK)
1176             || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1177                 struct kvm_mmu_page *shadow;
1178
1179                 spte |= PT_WRITABLE_MASK;
1180
1181                 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1182                 if (shadow ||
1183                    (largepage && has_wrprotected_page(vcpu->kvm, gfn))) {
1184                         pgprintk("%s: found shadow page for %lx, marking ro\n",
1185                                  __func__, gfn);
1186                         pte_access &= ~ACC_WRITE_MASK;
1187                         if (is_writeble_pte(spte)) {
1188                                 spte &= ~PT_WRITABLE_MASK;
1189                                 kvm_x86_ops->tlb_flush(vcpu);
1190                         }
1191                         if (write_fault)
1192                                 *ptwrite = 1;
1193                 }
1194         }
1195
1196         if (pte_access & ACC_WRITE_MASK)
1197                 mark_page_dirty(vcpu->kvm, gfn);
1198
1199         pgprintk("%s: setting spte %llx\n", __func__, spte);
1200         pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1201                  (spte&PT_PAGE_SIZE_MASK)? "2MB" : "4kB",
1202                  (spte&PT_WRITABLE_MASK)?"RW":"R", gfn, spte, shadow_pte);
1203         set_shadow_pte(shadow_pte, spte);
1204         if (!was_rmapped && (spte & PT_PAGE_SIZE_MASK)
1205             && (spte & PT_PRESENT_MASK))
1206                 ++vcpu->kvm->stat.lpages;
1207
1208         page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
1209         if (!was_rmapped) {
1210                 rmap_add(vcpu, shadow_pte, gfn, largepage);
1211                 if (!is_rmap_pte(*shadow_pte))
1212                         kvm_release_pfn_clean(pfn);
1213         } else {
1214                 if (was_writeble)
1215                         kvm_release_pfn_dirty(pfn);
1216                 else
1217                         kvm_release_pfn_clean(pfn);
1218         }
1219         if (speculative) {
1220                 vcpu->arch.last_pte_updated = shadow_pte;
1221                 vcpu->arch.last_pte_gfn = gfn;
1222         }
1223 }
1224
1225 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1226 {
1227 }
1228
1229 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1230                            int largepage, gfn_t gfn, pfn_t pfn,
1231                            int level)
1232 {
1233         hpa_t table_addr = vcpu->arch.mmu.root_hpa;
1234         int pt_write = 0;
1235
1236         for (; ; level--) {
1237                 u32 index = PT64_INDEX(v, level);
1238                 u64 *table;
1239
1240                 ASSERT(VALID_PAGE(table_addr));
1241                 table = __va(table_addr);
1242
1243                 if (level == 1) {
1244                         mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
1245                                      0, write, 1, &pt_write, 0, gfn, pfn, false);
1246                         return pt_write;
1247                 }
1248
1249                 if (largepage && level == 2) {
1250                         mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
1251                                      0, write, 1, &pt_write, 1, gfn, pfn, false);
1252                         return pt_write;
1253                 }
1254
1255                 if (table[index] == shadow_trap_nonpresent_pte) {
1256                         struct kvm_mmu_page *new_table;
1257                         gfn_t pseudo_gfn;
1258
1259                         pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
1260                                 >> PAGE_SHIFT;
1261                         new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
1262                                                      v, level - 1,
1263                                                      1, ACC_ALL, &table[index]);
1264                         if (!new_table) {
1265                                 pgprintk("nonpaging_map: ENOMEM\n");
1266                                 kvm_release_pfn_clean(pfn);
1267                                 return -ENOMEM;
1268                         }
1269
1270                         set_shadow_pte(&table[index],
1271                                        __pa(new_table->spt)
1272                                        | PT_PRESENT_MASK | PT_WRITABLE_MASK
1273                                        | shadow_user_mask | shadow_x_mask);
1274                 }
1275                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
1276         }
1277 }
1278
1279 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1280 {
1281         int r;
1282         int largepage = 0;
1283         pfn_t pfn;
1284         unsigned long mmu_seq;
1285
1286         down_read(&current->mm->mmap_sem);
1287         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1288                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1289                 largepage = 1;
1290         }
1291
1292         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1293         /* implicit mb(), we'll read before PT lock is unlocked */
1294         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1295         up_read(&current->mm->mmap_sem);
1296
1297         /* mmio */
1298         if (is_error_pfn(pfn)) {
1299                 kvm_release_pfn_clean(pfn);
1300                 return 1;
1301         }
1302
1303         spin_lock(&vcpu->kvm->mmu_lock);
1304         if (mmu_notifier_retry(vcpu, mmu_seq))
1305                 goto out_unlock;
1306         kvm_mmu_free_some_pages(vcpu);
1307         r = __direct_map(vcpu, v, write, largepage, gfn, pfn,
1308                          PT32E_ROOT_LEVEL);
1309         spin_unlock(&vcpu->kvm->mmu_lock);
1310
1311
1312         return r;
1313
1314 out_unlock:
1315         spin_unlock(&vcpu->kvm->mmu_lock);
1316         kvm_release_pfn_clean(pfn);
1317         return 0;
1318 }
1319
1320
1321 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1322 {
1323         int i;
1324         struct kvm_mmu_page *sp;
1325
1326         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1327                 return;
1328         spin_lock(&vcpu->kvm->mmu_lock);
1329         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1330                 hpa_t root = vcpu->arch.mmu.root_hpa;
1331
1332                 sp = page_header(root);
1333                 --sp->root_count;
1334                 if (!sp->root_count && sp->role.invalid)
1335                         kvm_mmu_zap_page(vcpu->kvm, sp);
1336                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1337                 spin_unlock(&vcpu->kvm->mmu_lock);
1338                 return;
1339         }
1340         for (i = 0; i < 4; ++i) {
1341                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1342
1343                 if (root) {
1344                         root &= PT64_BASE_ADDR_MASK;
1345                         sp = page_header(root);
1346                         --sp->root_count;
1347                         if (!sp->root_count && sp->role.invalid)
1348                                 kvm_mmu_zap_page(vcpu->kvm, sp);
1349                 }
1350                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1351         }
1352         spin_unlock(&vcpu->kvm->mmu_lock);
1353         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1354 }
1355
1356 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1357 {
1358         int i;
1359         gfn_t root_gfn;
1360         struct kvm_mmu_page *sp;
1361         int metaphysical = 0;
1362
1363         root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1364
1365         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1366                 hpa_t root = vcpu->arch.mmu.root_hpa;
1367
1368                 ASSERT(!VALID_PAGE(root));
1369                 if (tdp_enabled)
1370                         metaphysical = 1;
1371                 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1372                                       PT64_ROOT_LEVEL, metaphysical,
1373                                       ACC_ALL, NULL);
1374                 root = __pa(sp->spt);
1375                 ++sp->root_count;
1376                 vcpu->arch.mmu.root_hpa = root;
1377                 return;
1378         }
1379         metaphysical = !is_paging(vcpu);
1380         if (tdp_enabled)
1381                 metaphysical = 1;
1382         for (i = 0; i < 4; ++i) {
1383                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1384
1385                 ASSERT(!VALID_PAGE(root));
1386                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1387                         if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1388                                 vcpu->arch.mmu.pae_root[i] = 0;
1389                                 continue;
1390                         }
1391                         root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1392                 } else if (vcpu->arch.mmu.root_level == 0)
1393                         root_gfn = 0;
1394                 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1395                                       PT32_ROOT_LEVEL, metaphysical,
1396                                       ACC_ALL, NULL);
1397                 root = __pa(sp->spt);
1398                 ++sp->root_count;
1399                 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1400         }
1401         vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1402 }
1403
1404 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1405 {
1406         return vaddr;
1407 }
1408
1409 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1410                                 u32 error_code)
1411 {
1412         gfn_t gfn;
1413         int r;
1414
1415         pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
1416         r = mmu_topup_memory_caches(vcpu);
1417         if (r)
1418                 return r;
1419
1420         ASSERT(vcpu);
1421         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1422
1423         gfn = gva >> PAGE_SHIFT;
1424
1425         return nonpaging_map(vcpu, gva & PAGE_MASK,
1426                              error_code & PFERR_WRITE_MASK, gfn);
1427 }
1428
1429 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
1430                                 u32 error_code)
1431 {
1432         pfn_t pfn;
1433         int r;
1434         int largepage = 0;
1435         gfn_t gfn = gpa >> PAGE_SHIFT;
1436         unsigned long mmu_seq;
1437
1438         ASSERT(vcpu);
1439         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1440
1441         r = mmu_topup_memory_caches(vcpu);
1442         if (r)
1443                 return r;
1444
1445         down_read(&current->mm->mmap_sem);
1446         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1447                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1448                 largepage = 1;
1449         }
1450         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1451         /* implicit mb(), we'll read before PT lock is unlocked */
1452         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1453         up_read(&current->mm->mmap_sem);
1454         if (is_error_pfn(pfn)) {
1455                 kvm_release_pfn_clean(pfn);
1456                 return 1;
1457         }
1458         spin_lock(&vcpu->kvm->mmu_lock);
1459         if (mmu_notifier_retry(vcpu, mmu_seq))
1460                 goto out_unlock;
1461         kvm_mmu_free_some_pages(vcpu);
1462         r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
1463                          largepage, gfn, pfn, kvm_x86_ops->get_tdp_level());
1464         spin_unlock(&vcpu->kvm->mmu_lock);
1465
1466         return r;
1467
1468 out_unlock:
1469         spin_unlock(&vcpu->kvm->mmu_lock);
1470         kvm_release_pfn_clean(pfn);
1471         return 0;
1472 }
1473
1474 static void nonpaging_free(struct kvm_vcpu *vcpu)
1475 {
1476         mmu_free_roots(vcpu);
1477 }
1478
1479 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1480 {
1481         struct kvm_mmu *context = &vcpu->arch.mmu;
1482
1483         context->new_cr3 = nonpaging_new_cr3;
1484         context->page_fault = nonpaging_page_fault;
1485         context->gva_to_gpa = nonpaging_gva_to_gpa;
1486         context->free = nonpaging_free;
1487         context->prefetch_page = nonpaging_prefetch_page;
1488         context->root_level = 0;
1489         context->shadow_root_level = PT32E_ROOT_LEVEL;
1490         context->root_hpa = INVALID_PAGE;
1491         return 0;
1492 }
1493
1494 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1495 {
1496         ++vcpu->stat.tlb_flush;
1497         kvm_x86_ops->tlb_flush(vcpu);
1498 }
1499
1500 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1501 {
1502         pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
1503         mmu_free_roots(vcpu);
1504 }
1505
1506 static void inject_page_fault(struct kvm_vcpu *vcpu,
1507                               u64 addr,
1508                               u32 err_code)
1509 {
1510         kvm_inject_page_fault(vcpu, addr, err_code);
1511 }
1512
1513 static void paging_free(struct kvm_vcpu *vcpu)
1514 {
1515         nonpaging_free(vcpu);
1516 }
1517
1518 #define PTTYPE 64
1519 #include "paging_tmpl.h"
1520 #undef PTTYPE
1521
1522 #define PTTYPE 32
1523 #include "paging_tmpl.h"
1524 #undef PTTYPE
1525
1526 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1527 {
1528         struct kvm_mmu *context = &vcpu->arch.mmu;
1529
1530         ASSERT(is_pae(vcpu));
1531         context->new_cr3 = paging_new_cr3;
1532         context->page_fault = paging64_page_fault;
1533         context->gva_to_gpa = paging64_gva_to_gpa;
1534         context->prefetch_page = paging64_prefetch_page;
1535         context->free = paging_free;
1536         context->root_level = level;
1537         context->shadow_root_level = level;
1538         context->root_hpa = INVALID_PAGE;
1539         return 0;
1540 }
1541
1542 static int paging64_init_context(struct kvm_vcpu *vcpu)
1543 {
1544         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1545 }
1546
1547 static int paging32_init_context(struct kvm_vcpu *vcpu)
1548 {
1549         struct kvm_mmu *context = &vcpu->arch.mmu;
1550
1551         context->new_cr3 = paging_new_cr3;
1552         context->page_fault = paging32_page_fault;
1553         context->gva_to_gpa = paging32_gva_to_gpa;
1554         context->free = paging_free;
1555         context->prefetch_page = paging32_prefetch_page;
1556         context->root_level = PT32_ROOT_LEVEL;
1557         context->shadow_root_level = PT32E_ROOT_LEVEL;
1558         context->root_hpa = INVALID_PAGE;
1559         return 0;
1560 }
1561
1562 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1563 {
1564         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1565 }
1566
1567 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
1568 {
1569         struct kvm_mmu *context = &vcpu->arch.mmu;
1570
1571         context->new_cr3 = nonpaging_new_cr3;
1572         context->page_fault = tdp_page_fault;
1573         context->free = nonpaging_free;
1574         context->prefetch_page = nonpaging_prefetch_page;
1575         context->shadow_root_level = kvm_x86_ops->get_tdp_level();
1576         context->root_hpa = INVALID_PAGE;
1577
1578         if (!is_paging(vcpu)) {
1579                 context->gva_to_gpa = nonpaging_gva_to_gpa;
1580                 context->root_level = 0;
1581         } else if (is_long_mode(vcpu)) {
1582                 context->gva_to_gpa = paging64_gva_to_gpa;
1583                 context->root_level = PT64_ROOT_LEVEL;
1584         } else if (is_pae(vcpu)) {
1585                 context->gva_to_gpa = paging64_gva_to_gpa;
1586                 context->root_level = PT32E_ROOT_LEVEL;
1587         } else {
1588                 context->gva_to_gpa = paging32_gva_to_gpa;
1589                 context->root_level = PT32_ROOT_LEVEL;
1590         }
1591
1592         return 0;
1593 }
1594
1595 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
1596 {
1597         ASSERT(vcpu);
1598         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1599
1600         if (!is_paging(vcpu))
1601                 return nonpaging_init_context(vcpu);
1602         else if (is_long_mode(vcpu))
1603                 return paging64_init_context(vcpu);
1604         else if (is_pae(vcpu))
1605                 return paging32E_init_context(vcpu);
1606         else
1607                 return paging32_init_context(vcpu);
1608 }
1609
1610 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1611 {
1612         vcpu->arch.update_pte.pfn = bad_pfn;
1613
1614         if (tdp_enabled)
1615                 return init_kvm_tdp_mmu(vcpu);
1616         else
1617                 return init_kvm_softmmu(vcpu);
1618 }
1619
1620 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1621 {
1622         ASSERT(vcpu);
1623         if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1624                 vcpu->arch.mmu.free(vcpu);
1625                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1626         }
1627 }
1628
1629 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1630 {
1631         destroy_kvm_mmu(vcpu);
1632         return init_kvm_mmu(vcpu);
1633 }
1634 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1635
1636 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1637 {
1638         int r;
1639
1640         r = mmu_topup_memory_caches(vcpu);
1641         if (r)
1642                 goto out;
1643         spin_lock(&vcpu->kvm->mmu_lock);
1644         kvm_mmu_free_some_pages(vcpu);
1645         mmu_alloc_roots(vcpu);
1646         spin_unlock(&vcpu->kvm->mmu_lock);
1647         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1648         kvm_mmu_flush_tlb(vcpu);
1649 out:
1650         return r;
1651 }
1652 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1653
1654 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1655 {
1656         mmu_free_roots(vcpu);
1657 }
1658
1659 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1660                                   struct kvm_mmu_page *sp,
1661                                   u64 *spte)
1662 {
1663         u64 pte;
1664         struct kvm_mmu_page *child;
1665
1666         pte = *spte;
1667         if (is_shadow_present_pte(pte)) {
1668                 if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
1669                     is_large_pte(pte))
1670                         rmap_remove(vcpu->kvm, spte);
1671                 else {
1672                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1673                         mmu_page_remove_parent_pte(child, spte);
1674                 }
1675         }
1676         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1677         if (is_large_pte(pte))
1678                 --vcpu->kvm->stat.lpages;
1679 }
1680
1681 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1682                                   struct kvm_mmu_page *sp,
1683                                   u64 *spte,
1684                                   const void *new)
1685 {
1686         if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1687                 if (!vcpu->arch.update_pte.largepage ||
1688                     sp->role.glevels == PT32_ROOT_LEVEL) {
1689                         ++vcpu->kvm->stat.mmu_pde_zapped;
1690                         return;
1691                 }
1692         }
1693
1694         ++vcpu->kvm->stat.mmu_pte_updated;
1695         if (sp->role.glevels == PT32_ROOT_LEVEL)
1696                 paging32_update_pte(vcpu, sp, spte, new);
1697         else
1698                 paging64_update_pte(vcpu, sp, spte, new);
1699 }
1700
1701 static bool need_remote_flush(u64 old, u64 new)
1702 {
1703         if (!is_shadow_present_pte(old))
1704                 return false;
1705         if (!is_shadow_present_pte(new))
1706                 return true;
1707         if ((old ^ new) & PT64_BASE_ADDR_MASK)
1708                 return true;
1709         old ^= PT64_NX_MASK;
1710         new ^= PT64_NX_MASK;
1711         return (old & ~new & PT64_PERM_MASK) != 0;
1712 }
1713
1714 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1715 {
1716         if (need_remote_flush(old, new))
1717                 kvm_flush_remote_tlbs(vcpu->kvm);
1718         else
1719                 kvm_mmu_flush_tlb(vcpu);
1720 }
1721
1722 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1723 {
1724         u64 *spte = vcpu->arch.last_pte_updated;
1725
1726         return !!(spte && (*spte & shadow_accessed_mask));
1727 }
1728
1729 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1730                                           const u8 *new, int bytes)
1731 {
1732         gfn_t gfn;
1733         int r;
1734         u64 gpte = 0;
1735         pfn_t pfn;
1736
1737         vcpu->arch.update_pte.largepage = 0;
1738
1739         if (bytes != 4 && bytes != 8)
1740                 return;
1741
1742         /*
1743          * Assume that the pte write on a page table of the same type
1744          * as the current vcpu paging mode.  This is nearly always true
1745          * (might be false while changing modes).  Note it is verified later
1746          * by update_pte().
1747          */
1748         if (is_pae(vcpu)) {
1749                 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1750                 if ((bytes == 4) && (gpa % 4 == 0)) {
1751                         r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1752                         if (r)
1753                                 return;
1754                         memcpy((void *)&gpte + (gpa % 8), new, 4);
1755                 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1756                         memcpy((void *)&gpte, new, 8);
1757                 }
1758         } else {
1759                 if ((bytes == 4) && (gpa % 4 == 0))
1760                         memcpy((void *)&gpte, new, 4);
1761         }
1762         if (!is_present_pte(gpte))
1763                 return;
1764         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1765
1766         down_read(&current->mm->mmap_sem);
1767         if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
1768                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1769                 vcpu->arch.update_pte.largepage = 1;
1770         }
1771         vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
1772         /* implicit mb(), we'll read before PT lock is unlocked */
1773         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1774         up_read(&current->mm->mmap_sem);
1775
1776         if (is_error_pfn(pfn)) {
1777                 kvm_release_pfn_clean(pfn);
1778                 return;
1779         }
1780         vcpu->arch.update_pte.gfn = gfn;
1781         vcpu->arch.update_pte.pfn = pfn;
1782 }
1783
1784 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
1785 {
1786         u64 *spte = vcpu->arch.last_pte_updated;
1787
1788         if (spte
1789             && vcpu->arch.last_pte_gfn == gfn
1790             && shadow_accessed_mask
1791             && !(*spte & shadow_accessed_mask)
1792             && is_shadow_present_pte(*spte))
1793                 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
1794 }
1795
1796 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1797                        const u8 *new, int bytes)
1798 {
1799         gfn_t gfn = gpa >> PAGE_SHIFT;
1800         struct kvm_mmu_page *sp;
1801         struct hlist_node *node, *n;
1802         struct hlist_head *bucket;
1803         unsigned index;
1804         u64 entry, gentry;
1805         u64 *spte;
1806         unsigned offset = offset_in_page(gpa);
1807         unsigned pte_size;
1808         unsigned page_offset;
1809         unsigned misaligned;
1810         unsigned quadrant;
1811         int level;
1812         int flooded = 0;
1813         int npte;
1814         int r;
1815
1816         pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
1817         mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1818         spin_lock(&vcpu->kvm->mmu_lock);
1819         kvm_mmu_access_page(vcpu, gfn);
1820         kvm_mmu_free_some_pages(vcpu);
1821         ++vcpu->kvm->stat.mmu_pte_write;
1822         kvm_mmu_audit(vcpu, "pre pte write");
1823         if (gfn == vcpu->arch.last_pt_write_gfn
1824             && !last_updated_pte_accessed(vcpu)) {
1825                 ++vcpu->arch.last_pt_write_count;
1826                 if (vcpu->arch.last_pt_write_count >= 3)
1827                         flooded = 1;
1828         } else {
1829                 vcpu->arch.last_pt_write_gfn = gfn;
1830                 vcpu->arch.last_pt_write_count = 1;
1831                 vcpu->arch.last_pte_updated = NULL;
1832         }
1833         index = kvm_page_table_hashfn(gfn);
1834         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1835         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1836                 if (sp->gfn != gfn || sp->role.metaphysical)
1837                         continue;
1838                 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1839                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1840                 misaligned |= bytes < 4;
1841                 if (misaligned || flooded) {
1842                         /*
1843                          * Misaligned accesses are too much trouble to fix
1844                          * up; also, they usually indicate a page is not used
1845                          * as a page table.
1846                          *
1847                          * If we're seeing too many writes to a page,
1848                          * it may no longer be a page table, or we may be
1849                          * forking, in which case it is better to unmap the
1850                          * page.
1851                          */
1852                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1853                                  gpa, bytes, sp->role.word);
1854                         kvm_mmu_zap_page(vcpu->kvm, sp);
1855                         ++vcpu->kvm->stat.mmu_flooded;
1856                         continue;
1857                 }
1858                 page_offset = offset;
1859                 level = sp->role.level;
1860                 npte = 1;
1861                 if (sp->role.glevels == PT32_ROOT_LEVEL) {
1862                         page_offset <<= 1;      /* 32->64 */
1863                         /*
1864                          * A 32-bit pde maps 4MB while the shadow pdes map
1865                          * only 2MB.  So we need to double the offset again
1866                          * and zap two pdes instead of one.
1867                          */
1868                         if (level == PT32_ROOT_LEVEL) {
1869                                 page_offset &= ~7; /* kill rounding error */
1870                                 page_offset <<= 1;
1871                                 npte = 2;
1872                         }
1873                         quadrant = page_offset >> PAGE_SHIFT;
1874                         page_offset &= ~PAGE_MASK;
1875                         if (quadrant != sp->role.quadrant)
1876                                 continue;
1877                 }
1878                 spte = &sp->spt[page_offset / sizeof(*spte)];
1879                 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
1880                         gentry = 0;
1881                         r = kvm_read_guest_atomic(vcpu->kvm,
1882                                                   gpa & ~(u64)(pte_size - 1),
1883                                                   &gentry, pte_size);
1884                         new = (const void *)&gentry;
1885                         if (r < 0)
1886                                 new = NULL;
1887                 }
1888                 while (npte--) {
1889                         entry = *spte;
1890                         mmu_pte_write_zap_pte(vcpu, sp, spte);
1891                         if (new)
1892                                 mmu_pte_write_new_pte(vcpu, sp, spte, new);
1893                         mmu_pte_write_flush_tlb(vcpu, entry, *spte);
1894                         ++spte;
1895                 }
1896         }
1897         kvm_mmu_audit(vcpu, "post pte write");
1898         spin_unlock(&vcpu->kvm->mmu_lock);
1899         if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
1900                 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
1901                 vcpu->arch.update_pte.pfn = bad_pfn;
1902         }
1903 }
1904
1905 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1906 {
1907         gpa_t gpa;
1908         int r;
1909
1910         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1911
1912         spin_lock(&vcpu->kvm->mmu_lock);
1913         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1914         spin_unlock(&vcpu->kvm->mmu_lock);
1915         return r;
1916 }
1917 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
1918
1919 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1920 {
1921         while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
1922                 struct kvm_mmu_page *sp;
1923
1924                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
1925                                   struct kvm_mmu_page, link);
1926                 kvm_mmu_zap_page(vcpu->kvm, sp);
1927                 ++vcpu->kvm->stat.mmu_recycled;
1928         }
1929 }
1930
1931 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
1932 {
1933         int r;
1934         enum emulation_result er;
1935
1936         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
1937         if (r < 0)
1938                 goto out;
1939
1940         if (!r) {
1941                 r = 1;
1942                 goto out;
1943         }
1944
1945         r = mmu_topup_memory_caches(vcpu);
1946         if (r)
1947                 goto out;
1948
1949         er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
1950
1951         switch (er) {
1952         case EMULATE_DONE:
1953                 return 1;
1954         case EMULATE_DO_MMIO:
1955                 ++vcpu->stat.mmio_exits;
1956                 return 0;
1957         case EMULATE_FAIL:
1958                 kvm_report_emulation_failure(vcpu, "pagetable");
1959                 return 1;
1960         default:
1961                 BUG();
1962         }
1963 out:
1964         return r;
1965 }
1966 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
1967
1968 void kvm_enable_tdp(void)
1969 {
1970         tdp_enabled = true;
1971 }
1972 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
1973
1974 void kvm_disable_tdp(void)
1975 {
1976         tdp_enabled = false;
1977 }
1978 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
1979
1980 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1981 {
1982         struct kvm_mmu_page *sp;
1983
1984         while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
1985                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
1986                                   struct kvm_mmu_page, link);
1987                 kvm_mmu_zap_page(vcpu->kvm, sp);
1988                 cond_resched();
1989         }
1990         free_page((unsigned long)vcpu->arch.mmu.pae_root);
1991 }
1992
1993 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1994 {
1995         struct page *page;
1996         int i;
1997
1998         ASSERT(vcpu);
1999
2000         if (vcpu->kvm->arch.n_requested_mmu_pages)
2001                 vcpu->kvm->arch.n_free_mmu_pages =
2002                                         vcpu->kvm->arch.n_requested_mmu_pages;
2003         else
2004                 vcpu->kvm->arch.n_free_mmu_pages =
2005                                         vcpu->kvm->arch.n_alloc_mmu_pages;
2006         /*
2007          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2008          * Therefore we need to allocate shadow page tables in the first
2009          * 4GB of memory, which happens to fit the DMA32 zone.
2010          */
2011         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2012         if (!page)
2013                 goto error_1;
2014         vcpu->arch.mmu.pae_root = page_address(page);
2015         for (i = 0; i < 4; ++i)
2016                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2017
2018         return 0;
2019
2020 error_1:
2021         free_mmu_pages(vcpu);
2022         return -ENOMEM;
2023 }
2024
2025 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2026 {
2027         ASSERT(vcpu);
2028         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2029
2030         return alloc_mmu_pages(vcpu);
2031 }
2032
2033 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2034 {
2035         ASSERT(vcpu);
2036         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2037
2038         return init_kvm_mmu(vcpu);
2039 }
2040
2041 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2042 {
2043         ASSERT(vcpu);
2044
2045         destroy_kvm_mmu(vcpu);
2046         free_mmu_pages(vcpu);
2047         mmu_free_memory_caches(vcpu);
2048 }
2049
2050 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2051 {
2052         struct kvm_mmu_page *sp;
2053
2054         list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2055                 int i;
2056                 u64 *pt;
2057
2058                 if (!test_bit(slot, &sp->slot_bitmap))
2059                         continue;
2060
2061                 pt = sp->spt;
2062                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2063                         /* avoid RMW */
2064                         if (pt[i] & PT_WRITABLE_MASK)
2065                                 pt[i] &= ~PT_WRITABLE_MASK;
2066         }
2067 }
2068
2069 void kvm_mmu_zap_all(struct kvm *kvm)
2070 {
2071         struct kvm_mmu_page *sp, *node;
2072
2073         spin_lock(&kvm->mmu_lock);
2074         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2075                 kvm_mmu_zap_page(kvm, sp);
2076         spin_unlock(&kvm->mmu_lock);
2077
2078         kvm_flush_remote_tlbs(kvm);
2079 }
2080
2081 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2082 {
2083         struct kvm_mmu_page *page;
2084
2085         page = container_of(kvm->arch.active_mmu_pages.prev,
2086                             struct kvm_mmu_page, link);
2087         kvm_mmu_zap_page(kvm, page);
2088 }
2089
2090 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2091 {
2092         struct kvm *kvm;
2093         struct kvm *kvm_freed = NULL;
2094         int cache_count = 0;
2095
2096         spin_lock(&kvm_lock);
2097
2098         list_for_each_entry(kvm, &vm_list, vm_list) {
2099                 int npages;
2100
2101                 if (!down_read_trylock(&kvm->slots_lock))
2102                         continue;
2103                 spin_lock(&kvm->mmu_lock);
2104                 npages = kvm->arch.n_alloc_mmu_pages -
2105                          kvm->arch.n_free_mmu_pages;
2106                 cache_count += npages;
2107                 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2108                         kvm_mmu_remove_one_alloc_mmu_page(kvm);
2109                         cache_count--;
2110                         kvm_freed = kvm;
2111                 }
2112                 nr_to_scan--;
2113
2114                 spin_unlock(&kvm->mmu_lock);
2115                 up_read(&kvm->slots_lock);
2116         }
2117         if (kvm_freed)
2118                 list_move_tail(&kvm_freed->vm_list, &vm_list);
2119
2120         spin_unlock(&kvm_lock);
2121
2122         return cache_count;
2123 }
2124
2125 static struct shrinker mmu_shrinker = {
2126         .shrink = mmu_shrink,
2127         .seeks = DEFAULT_SEEKS * 10,
2128 };
2129
2130 static void mmu_destroy_caches(void)
2131 {
2132         if (pte_chain_cache)
2133                 kmem_cache_destroy(pte_chain_cache);
2134         if (rmap_desc_cache)
2135                 kmem_cache_destroy(rmap_desc_cache);
2136         if (mmu_page_header_cache)
2137                 kmem_cache_destroy(mmu_page_header_cache);
2138 }
2139
2140 void kvm_mmu_module_exit(void)
2141 {
2142         mmu_destroy_caches();
2143         unregister_shrinker(&mmu_shrinker);
2144 }
2145
2146 int kvm_mmu_module_init(void)
2147 {
2148         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2149                                             sizeof(struct kvm_pte_chain),
2150                                             0, 0, NULL);
2151         if (!pte_chain_cache)
2152                 goto nomem;
2153         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2154                                             sizeof(struct kvm_rmap_desc),
2155                                             0, 0, NULL);
2156         if (!rmap_desc_cache)
2157                 goto nomem;
2158
2159         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2160                                                   sizeof(struct kvm_mmu_page),
2161                                                   0, 0, NULL);
2162         if (!mmu_page_header_cache)
2163                 goto nomem;
2164
2165         register_shrinker(&mmu_shrinker);
2166
2167         return 0;
2168
2169 nomem:
2170         mmu_destroy_caches();
2171         return -ENOMEM;
2172 }
2173
2174 /*
2175  * Caculate mmu pages needed for kvm.
2176  */
2177 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
2178 {
2179         int i;
2180         unsigned int nr_mmu_pages;
2181         unsigned int  nr_pages = 0;
2182
2183         for (i = 0; i < kvm->nmemslots; i++)
2184                 nr_pages += kvm->memslots[i].npages;
2185
2186         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
2187         nr_mmu_pages = max(nr_mmu_pages,
2188                         (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
2189
2190         return nr_mmu_pages;
2191 }
2192
2193 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2194                                 unsigned len)
2195 {
2196         if (len > buffer->len)
2197                 return NULL;
2198         return buffer->ptr;
2199 }
2200
2201 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2202                                 unsigned len)
2203 {
2204         void *ret;
2205
2206         ret = pv_mmu_peek_buffer(buffer, len);
2207         if (!ret)
2208                 return ret;
2209         buffer->ptr += len;
2210         buffer->len -= len;
2211         buffer->processed += len;
2212         return ret;
2213 }
2214
2215 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
2216                              gpa_t addr, gpa_t value)
2217 {
2218         int bytes = 8;
2219         int r;
2220
2221         if (!is_long_mode(vcpu) && !is_pae(vcpu))
2222                 bytes = 4;
2223
2224         r = mmu_topup_memory_caches(vcpu);
2225         if (r)
2226                 return r;
2227
2228         if (!emulator_write_phys(vcpu, addr, &value, bytes))
2229                 return -EFAULT;
2230
2231         return 1;
2232 }
2233
2234 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2235 {
2236         kvm_x86_ops->tlb_flush(vcpu);
2237         return 1;
2238 }
2239
2240 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
2241 {
2242         spin_lock(&vcpu->kvm->mmu_lock);
2243         mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
2244         spin_unlock(&vcpu->kvm->mmu_lock);
2245         return 1;
2246 }
2247
2248 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
2249                              struct kvm_pv_mmu_op_buffer *buffer)
2250 {
2251         struct kvm_mmu_op_header *header;
2252
2253         header = pv_mmu_peek_buffer(buffer, sizeof *header);
2254         if (!header)
2255                 return 0;
2256         switch (header->op) {
2257         case KVM_MMU_OP_WRITE_PTE: {
2258                 struct kvm_mmu_op_write_pte *wpte;
2259
2260                 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
2261                 if (!wpte)
2262                         return 0;
2263                 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
2264                                         wpte->pte_val);
2265         }
2266         case KVM_MMU_OP_FLUSH_TLB: {
2267                 struct kvm_mmu_op_flush_tlb *ftlb;
2268
2269                 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
2270                 if (!ftlb)
2271                         return 0;
2272                 return kvm_pv_mmu_flush_tlb(vcpu);
2273         }
2274         case KVM_MMU_OP_RELEASE_PT: {
2275                 struct kvm_mmu_op_release_pt *rpt;
2276
2277                 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
2278                 if (!rpt)
2279                         return 0;
2280                 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
2281         }
2282         default: return 0;
2283         }
2284 }
2285
2286 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
2287                   gpa_t addr, unsigned long *ret)
2288 {
2289         int r;
2290         struct kvm_pv_mmu_op_buffer buffer;
2291
2292         buffer.ptr = buffer.buf;
2293         buffer.len = min_t(unsigned long, bytes, sizeof buffer.buf);
2294         buffer.processed = 0;
2295
2296         r = kvm_read_guest(vcpu->kvm, addr, buffer.buf, buffer.len);
2297         if (r)
2298                 goto out;
2299
2300         while (buffer.len) {
2301                 r = kvm_pv_mmu_op_one(vcpu, &buffer);
2302                 if (r < 0)
2303                         goto out;
2304                 if (r == 0)
2305                         break;
2306         }
2307
2308         r = 1;
2309 out:
2310         *ret = buffer.processed;
2311         return r;
2312 }
2313
2314 #ifdef AUDIT
2315
2316 static const char *audit_msg;
2317
2318 static gva_t canonicalize(gva_t gva)
2319 {
2320 #ifdef CONFIG_X86_64
2321         gva = (long long)(gva << 16) >> 16;
2322 #endif
2323         return gva;
2324 }
2325
2326 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
2327                                 gva_t va, int level)
2328 {
2329         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
2330         int i;
2331         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
2332
2333         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
2334                 u64 ent = pt[i];
2335
2336                 if (ent == shadow_trap_nonpresent_pte)
2337                         continue;
2338
2339                 va = canonicalize(va);
2340                 if (level > 1) {
2341                         if (ent == shadow_notrap_nonpresent_pte)
2342                                 printk(KERN_ERR "audit: (%s) nontrapping pte"
2343                                        " in nonleaf level: levels %d gva %lx"
2344                                        " level %d pte %llx\n", audit_msg,
2345                                        vcpu->arch.mmu.root_level, va, level, ent);
2346
2347                         audit_mappings_page(vcpu, ent, va, level - 1);
2348                 } else {
2349                         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
2350                         hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
2351
2352                         if (is_shadow_present_pte(ent)
2353                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
2354                                 printk(KERN_ERR "xx audit error: (%s) levels %d"
2355                                        " gva %lx gpa %llx hpa %llx ent %llx %d\n",
2356                                        audit_msg, vcpu->arch.mmu.root_level,
2357                                        va, gpa, hpa, ent,
2358                                        is_shadow_present_pte(ent));
2359                         else if (ent == shadow_notrap_nonpresent_pte
2360                                  && !is_error_hpa(hpa))
2361                                 printk(KERN_ERR "audit: (%s) notrap shadow,"
2362                                        " valid guest gva %lx\n", audit_msg, va);
2363                         kvm_release_pfn_clean(pfn);
2364
2365                 }
2366         }
2367 }
2368
2369 static void audit_mappings(struct kvm_vcpu *vcpu)
2370 {
2371         unsigned i;
2372
2373         if (vcpu->arch.mmu.root_level == 4)
2374                 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
2375         else
2376                 for (i = 0; i < 4; ++i)
2377                         if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
2378                                 audit_mappings_page(vcpu,
2379                                                     vcpu->arch.mmu.pae_root[i],
2380                                                     i << 30,
2381                                                     2);
2382 }
2383
2384 static int count_rmaps(struct kvm_vcpu *vcpu)
2385 {
2386         int nmaps = 0;
2387         int i, j, k;
2388
2389         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
2390                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
2391                 struct kvm_rmap_desc *d;
2392
2393                 for (j = 0; j < m->npages; ++j) {
2394                         unsigned long *rmapp = &m->rmap[j];
2395
2396                         if (!*rmapp)
2397                                 continue;
2398                         if (!(*rmapp & 1)) {
2399                                 ++nmaps;
2400                                 continue;
2401                         }
2402                         d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
2403                         while (d) {
2404                                 for (k = 0; k < RMAP_EXT; ++k)
2405                                         if (d->shadow_ptes[k])
2406                                                 ++nmaps;
2407                                         else
2408                                                 break;
2409                                 d = d->more;
2410                         }
2411                 }
2412         }
2413         return nmaps;
2414 }
2415
2416 static int count_writable_mappings(struct kvm_vcpu *vcpu)
2417 {
2418         int nmaps = 0;
2419         struct kvm_mmu_page *sp;
2420         int i;
2421
2422         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2423                 u64 *pt = sp->spt;
2424
2425                 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
2426                         continue;
2427
2428                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
2429                         u64 ent = pt[i];
2430
2431                         if (!(ent & PT_PRESENT_MASK))
2432                                 continue;
2433                         if (!(ent & PT_WRITABLE_MASK))
2434                                 continue;
2435                         ++nmaps;
2436                 }
2437         }
2438         return nmaps;
2439 }
2440
2441 static void audit_rmap(struct kvm_vcpu *vcpu)
2442 {
2443         int n_rmap = count_rmaps(vcpu);
2444         int n_actual = count_writable_mappings(vcpu);
2445
2446         if (n_rmap != n_actual)
2447                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
2448                        __func__, audit_msg, n_rmap, n_actual);
2449 }
2450
2451 static void audit_write_protection(struct kvm_vcpu *vcpu)
2452 {
2453         struct kvm_mmu_page *sp;
2454         struct kvm_memory_slot *slot;
2455         unsigned long *rmapp;
2456         gfn_t gfn;
2457
2458         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
2459                 if (sp->role.metaphysical)
2460                         continue;
2461
2462                 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
2463                 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
2464                 rmapp = &slot->rmap[gfn - slot->base_gfn];
2465                 if (*rmapp)
2466                         printk(KERN_ERR "%s: (%s) shadow page has writable"
2467                                " mappings: gfn %lx role %x\n",
2468                                __func__, audit_msg, sp->gfn,
2469                                sp->role.word);
2470         }
2471 }
2472
2473 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
2474 {
2475         int olddbg = dbg;
2476
2477         dbg = 0;
2478         audit_msg = msg;
2479         audit_rmap(vcpu);
2480         audit_write_protection(vcpu);
2481         audit_mappings(vcpu);
2482         dbg = olddbg;
2483 }
2484
2485 #endif