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  * Copyright 2010 Red Hat, Inc. and/or its affilates.
  11  *
  12  * Authors:
  13  *   Yaniv Kamay  <yaniv@qumranet.com>
  14  *   Avi Kivity   <avi@qumranet.com>
  15  *
  16  * This work is licensed under the terms of the GNU GPL, version 2.  See
  17  * the COPYING file in the top-level directory.
  18  *
  19  */
  20
  21 #include "mmu.h"
  22 #include "x86.h"
  23 #include "kvm_cache_regs.h"
  24
  25 #include <linux/kvm_host.h>
  26 #include <linux/types.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/highmem.h>
  30 #include <linux/module.h>
  31 #include <linux/swap.h>
  32 #include <linux/hugetlb.h>
  33 #include <linux/compiler.h>
  34 #include <linux/srcu.h>
  35 #include <linux/slab.h>
  36 #include <linux/uaccess.h>
  37
  38 #include <asm/page.h>
  39 #include <asm/cmpxchg.h>
  40 #include <asm/io.h>
  41 #include <asm/vmx.h>
  42
  43 /*
  44  * When setting this variable to true it enables Two-Dimensional-Paging
  45  * where the hardware walks 2 page tables:
  46  * 1. the guest-virtual to guest-physical
  47  * 2. while doing 1. it walks guest-physical to host-physical
  48  * If the hardware supports that we don't need to do shadow paging.
  49  */
  50 bool tdp_enabled = false;
  51
  52 #undef MMU_DEBUG
  53
  54 #undef AUDIT
  55
  56 #ifdef AUDIT
  57 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
  58 #else
  59 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
  60 #endif
  61
  62 #ifdef MMU_DEBUG
  63
  64 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
  65 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
  66
  67 #else
  68
  69 #define pgprintk(x...) do { } while (0)
  70 #define rmap_printk(x...) do { } while (0)
  71
  72 #endif
  73
  74 #if defined(MMU_DEBUG) || defined(AUDIT)
  75 static int dbg = 0;
  76 module_param(dbg, bool, 0644);
  77 #endif
  78
  79 static int oos_shadow = 1;
  80 module_param(oos_shadow, bool, 0644);
  81
  82 #ifndef MMU_DEBUG
  83 #define ASSERT(x) do { } while (0)
  84 #else
  85 #define ASSERT(x)                                                       \
  86         if (!(x)) {                                                     \
  87                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
  88                        __FILE__, __LINE__, #x);                         \
  89         }
  90 #endif
  91
  92 #define PT_FIRST_AVAIL_BITS_SHIFT 9
  93 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
  94
  95 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
  96
  97 #define PT64_LEVEL_BITS 9
  98
  99 #define PT64_LEVEL_SHIFT(level) \
 100                 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
 101
 102 #define PT64_LEVEL_MASK(level) \
 103                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
 104
 105 #define PT64_INDEX(address, level)\
 106         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
 107
 108
 109 #define PT32_LEVEL_BITS 10
 110
 111 #define PT32_LEVEL_SHIFT(level) \
 112                 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
 113
 114 #define PT32_LEVEL_MASK(level) \
 115                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
 116 #define PT32_LVL_OFFSET_MASK(level) \
 117         (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
 118                                                 * PT32_LEVEL_BITS))) - 1))
 119
 120 #define PT32_INDEX(address, level)\
 121         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
 122
 123
 124 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
 125 #define PT64_DIR_BASE_ADDR_MASK \
 126         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
 127 #define PT64_LVL_ADDR_MASK(level) \
 128         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
 129                                                 * PT64_LEVEL_BITS))) - 1))
 130 #define PT64_LVL_OFFSET_MASK(level) \
 131         (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \
 132                                                 * PT64_LEVEL_BITS))) - 1))
 133
 134 #define PT32_BASE_ADDR_MASK PAGE_MASK
 135 #define PT32_DIR_BASE_ADDR_MASK \
 136         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
 137 #define PT32_LVL_ADDR_MASK(level) \
 138         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \
 139                                             * PT32_LEVEL_BITS))) - 1))
 140
 141 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
 142                         | PT64_NX_MASK)
 143
 144 #define RMAP_EXT 4
 145
 146 #define ACC_EXEC_MASK    1
 147 #define ACC_WRITE_MASK   PT_WRITABLE_MASK
 148 #define ACC_USER_MASK    PT_USER_MASK
 149 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
 150
 151 #include <trace/events/kvm.h>
 152
 153 #define CREATE_TRACE_POINTS
 154 #include "mmutrace.h"
 155
 156 #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
 157
 158 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
 159
 160 struct kvm_rmap_desc {
 161         u64 *sptes[RMAP_EXT];
 162         struct kvm_rmap_desc *more;
 163 };
 164
 165 struct kvm_shadow_walk_iterator {
 166         u64 addr;
 167         hpa_t shadow_addr;
 168         int level;
 169         u64 *sptep;
 170         unsigned index;
 171 };
 172
 173 #define for_each_shadow_entry(_vcpu, _addr, _walker)    \
 174         for (shadow_walk_init(&(_walker), _vcpu, _addr);        \
 175              shadow_walk_okay(&(_walker));                      \
 176              shadow_walk_next(&(_walker)))
 177
 178 typedef int (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp);
 179
 180 static struct kmem_cache *pte_chain_cache;
 181 static struct kmem_cache *rmap_desc_cache;
 182 static struct kmem_cache *mmu_page_header_cache;
 183
 184 static u64 __read_mostly shadow_trap_nonpresent_pte;
 185 static u64 __read_mostly shadow_notrap_nonpresent_pte;
 186 static u64 __read_mostly shadow_base_present_pte;
 187 static u64 __read_mostly shadow_nx_mask;
 188 static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
 189 static u64 __read_mostly shadow_user_mask;
 190 static u64 __read_mostly shadow_accessed_mask;
 191 static u64 __read_mostly shadow_dirty_mask;
 192
 193 static inline u64 rsvd_bits(int s, int e)
 194 {
 195         return ((1ULL << (e - s + 1)) - 1) << s;
 196 }
 197
 198 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 199 {
 200         shadow_trap_nonpresent_pte = trap_pte;
 201         shadow_notrap_nonpresent_pte = notrap_pte;
 202 }
 203 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
 204
 205 void kvm_mmu_set_base_ptes(u64 base_pte)
 206 {
 207         shadow_base_present_pte = base_pte;
 208 }
 209 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
 210
 211 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
 212                 u64 dirty_mask, u64 nx_mask, u64 x_mask)
 213 {
 214         shadow_user_mask = user_mask;
 215         shadow_accessed_mask = accessed_mask;
 216         shadow_dirty_mask = dirty_mask;
 217         shadow_nx_mask = nx_mask;
 218         shadow_x_mask = x_mask;
 219 }
 220 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
 221
 222 static bool is_write_protection(struct kvm_vcpu *vcpu)
 223 {
 224         return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
 225 }
 226
 227 static int is_cpuid_PSE36(void)
 228 {
 229         return 1;
 230 }
 231
 232 static int is_nx(struct kvm_vcpu *vcpu)
 233 {
 234         return vcpu->arch.efer & EFER_NX;
 235 }
 236
 237 static int is_shadow_present_pte(u64 pte)
 238 {
 239         return pte != shadow_trap_nonpresent_pte
 240                 && pte != shadow_notrap_nonpresent_pte;
 241 }
 242
 243 static int is_large_pte(u64 pte)
 244 {
 245         return pte & PT_PAGE_SIZE_MASK;
 246 }
 247
 248 static int is_writable_pte(unsigned long pte)
 249 {
 250         return pte & PT_WRITABLE_MASK;
 251 }
 252
 253 static int is_dirty_gpte(unsigned long pte)
 254 {
 255         return pte & PT_DIRTY_MASK;
 256 }
 257
 258 static int is_rmap_spte(u64 pte)
 259 {
 260         return is_shadow_present_pte(pte);
 261 }
 262
 263 static int is_last_spte(u64 pte, int level)
 264 {
 265         if (level == PT_PAGE_TABLE_LEVEL)
 266                 return 1;
 267         if (is_large_pte(pte))
 268                 return 1;
 269         return 0;
 270 }
 271
 272 static pfn_t spte_to_pfn(u64 pte)
 273 {
 274         return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 275 }
 276
 277 static gfn_t pse36_gfn_delta(u32 gpte)
 278 {
 279         int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
 280
 281         return (gpte & PT32_DIR_PSE36_MASK) << shift;
 282 }
 283
 284 static void __set_spte(u64 *sptep, u64 spte)
 285 {
 286 #ifdef CONFIG_X86_64
 287         set_64bit((unsigned long *)sptep, spte);
 288 #else
 289         set_64bit((unsigned long long *)sptep, spte);
 290 #endif
 291 }
 292
 293 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 294                                   struct kmem_cache *base_cache, int min)
 295 {
 296         void *obj;
 297
 298         if (cache->nobjs >= min)
 299                 return 0;
 300         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 301                 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
 302                 if (!obj)
 303                         return -ENOMEM;
 304                 cache->objects[cache->nobjs++] = obj;
 305         }
 306         return 0;
 307 }
 308
 309 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc,
 310                                   struct kmem_cache *cache)
 311 {
 312         while (mc->nobjs)
 313                 kmem_cache_free(cache, mc->objects[--mc->nobjs]);
 314 }
 315
 316 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
 317                                        int min)
 318 {
 319         struct page *page;
 320
 321         if (cache->nobjs >= min)
 322                 return 0;
 323         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 324                 page = alloc_page(GFP_KERNEL);
 325                 if (!page)
 326                         return -ENOMEM;
 327                 cache->objects[cache->nobjs++] = page_address(page);
 328         }
 329         return 0;
 330 }
 331
 332 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
 333 {
 334         while (mc->nobjs)
 335                 free_page((unsigned long)mc->objects[--mc->nobjs]);
 336 }
 337
 338 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 339 {
 340         int r;
 341
 342         r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
 343                                    pte_chain_cache, 4);
 344         if (r)
 345                 goto out;
 346         r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
 347                                    rmap_desc_cache, 4);
 348         if (r)
 349                 goto out;
 350         r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
 351         if (r)
 352                 goto out;
 353         r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
 354                                    mmu_page_header_cache, 4);
 355 out:
 356         return r;
 357 }
 358
 359 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 360 {
 361         mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache, pte_chain_cache);
 362         mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache, rmap_desc_cache);
 363         mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
 364         mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache,
 365                                 mmu_page_header_cache);
 366 }
 367
 368 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
 369                                     size_t size)
 370 {
 371         void *p;
 372
 373         BUG_ON(!mc->nobjs);
 374         p = mc->objects[--mc->nobjs];
 375         return p;
 376 }
 377
 378 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
 379 {
 380         return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
 381                                       sizeof(struct kvm_pte_chain));
 382 }
 383
 384 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
 385 {
 386         kmem_cache_free(pte_chain_cache, pc);
 387 }
 388
 389 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
 390 {
 391         return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
 392                                       sizeof(struct kvm_rmap_desc));
 393 }
 394
 395 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 396 {
 397         kmem_cache_free(rmap_desc_cache, rd);
 398 }
 399
 400 static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index)
 401 {
 402         if (!sp->role.direct)
 403                 return sp->gfns[index];
 404
 405         return sp->gfn + (index << ((sp->role.level - 1) * PT64_LEVEL_BITS));
 406 }
 407
 408 static void kvm_mmu_page_set_gfn(struct kvm_mmu_page *sp, int index, gfn_t gfn)
 409 {
 410         if (sp->role.direct)
 411                 BUG_ON(gfn != kvm_mmu_page_get_gfn(sp, index));
 412         else
 413                 sp->gfns[index] = gfn;
 414 }
 415
 416 /*
 417  * Return the pointer to the largepage write count for a given
 418  * gfn, handling slots that are not large page aligned.
 419  */
 420 static int *slot_largepage_idx(gfn_t gfn,
 421                                struct kvm_memory_slot *slot,
 422                                int level)
 423 {
 424         unsigned long idx;
 425
 426         idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
 427               (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
 428         return &slot->lpage_info[level - 2][idx].write_count;
 429 }
 430
 431 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
 432 {
 433         struct kvm_memory_slot *slot;
 434         int *write_count;
 435         int i;
 436
 437         gfn = unalias_gfn(kvm, gfn);
 438
 439         slot = gfn_to_memslot_unaliased(kvm, gfn);
 440         for (i = PT_DIRECTORY_LEVEL;
 441              i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
 442                 write_count   = slot_largepage_idx(gfn, slot, i);
 443                 *write_count += 1;
 444         }
 445 }
 446
 447 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
 448 {
 449         struct kvm_memory_slot *slot;
 450         int *write_count;
 451         int i;
 452
 453         gfn = unalias_gfn(kvm, gfn);
 454         slot = gfn_to_memslot_unaliased(kvm, gfn);
 455         for (i = PT_DIRECTORY_LEVEL;
 456              i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
 457                 write_count   = slot_largepage_idx(gfn, slot, i);
 458                 *write_count -= 1;
 459                 WARN_ON(*write_count < 0);
 460         }
 461 }
 462
 463 static int has_wrprotected_page(struct kvm *kvm,
 464                                 gfn_t gfn,
 465                                 int level)
 466 {
 467         struct kvm_memory_slot *slot;
 468         int *largepage_idx;
 469
 470         gfn = unalias_gfn(kvm, gfn);
 471         slot = gfn_to_memslot_unaliased(kvm, gfn);
 472         if (slot) {
 473                 largepage_idx = slot_largepage_idx(gfn, slot, level);
 474                 return *largepage_idx;
 475         }
 476
 477         return 1;
 478 }
 479
 480 static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
 481 {
 482         unsigned long page_size;
 483         int i, ret = 0;
 484
 485         page_size = kvm_host_page_size(kvm, gfn);
 486
 487         for (i = PT_PAGE_TABLE_LEVEL;
 488              i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
 489                 if (page_size >= KVM_HPAGE_SIZE(i))
 490                         ret = i;
 491                 else
 492                         break;
 493         }
 494
 495         return ret;
 496 }
 497
 498 static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 499 {
 500         struct kvm_memory_slot *slot;
 501         int host_level, level, max_level;
 502
 503         slot = gfn_to_memslot(vcpu->kvm, large_gfn);
 504         if (slot && slot->dirty_bitmap)
 505                 return PT_PAGE_TABLE_LEVEL;
 506
 507         host_level = host_mapping_level(vcpu->kvm, large_gfn);
 508
 509         if (host_level == PT_PAGE_TABLE_LEVEL)
 510                 return host_level;
 511
 512         max_level = kvm_x86_ops->get_lpage_level() < host_level ?
 513                 kvm_x86_ops->get_lpage_level() : host_level;
 514
 515         for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
 516                 if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
 517                         break;
 518
 519         return level - 1;
 520 }
 521
 522 /*
 523  * Take gfn and return the reverse mapping to it.
 524  * Note: gfn must be unaliased before this function get called
 525  */
 526
 527 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level)
 528 {
 529         struct kvm_memory_slot *slot;
 530         unsigned long idx;
 531
 532         slot = gfn_to_memslot(kvm, gfn);
 533         if (likely(level == PT_PAGE_TABLE_LEVEL))
 534                 return &slot->rmap[gfn - slot->base_gfn];
 535
 536         idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
 537                 (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
 538
 539         return &slot->lpage_info[level - 2][idx].rmap_pde;
 540 }
 541
 542 /*
 543  * Reverse mapping data structures:
 544  *
 545  * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
 546  * that points to page_address(page).
 547  *
 548  * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
 549  * containing more mappings.
 550  *
 551  * Returns the number of rmap entries before the spte was added or zero if
 552  * the spte was not added.
 553  *
 554  */
 555 static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
 556 {
 557         struct kvm_mmu_page *sp;
 558         struct kvm_rmap_desc *desc;
 559         unsigned long *rmapp;
 560         int i, count = 0;
 561
 562         if (!is_rmap_spte(*spte))
 563                 return count;
 564         gfn = unalias_gfn(vcpu->kvm, gfn);
 565         sp = page_header(__pa(spte));
 566         kvm_mmu_page_set_gfn(sp, spte - sp->spt, gfn);
 567         rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
 568         if (!*rmapp) {
 569                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
 570                 *rmapp = (unsigned long)spte;
 571         } else if (!(*rmapp & 1)) {
 572                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
 573                 desc = mmu_alloc_rmap_desc(vcpu);
 574                 desc->sptes[0] = (u64 *)*rmapp;
 575                 desc->sptes[1] = spte;
 576                 *rmapp = (unsigned long)desc | 1;
 577         } else {
 578                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
 579                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 580                 while (desc->sptes[RMAP_EXT-1] && desc->more) {
 581                         desc = desc->more;
 582                         count += RMAP_EXT;
 583                 }
 584                 if (desc->sptes[RMAP_EXT-1]) {
 585                         desc->more = mmu_alloc_rmap_desc(vcpu);
 586                         desc = desc->more;
 587                 }
 588                 for (i = 0; desc->sptes[i]; ++i)
 589                         ;
 590                 desc->sptes[i] = spte;
 591         }
 592         return count;
 593 }
 594
 595 static void rmap_desc_remove_entry(unsigned long *rmapp,
 596                                    struct kvm_rmap_desc *desc,
 597                                    int i,
 598                                    struct kvm_rmap_desc *prev_desc)
 599 {
 600         int j;
 601
 602         for (j = RMAP_EXT - 1; !desc->sptes[j] && j > i; --j)
 603                 ;
 604         desc->sptes[i] = desc->sptes[j];
 605         desc->sptes[j] = NULL;
 606         if (j != 0)
 607                 return;
 608         if (!prev_desc && !desc->more)
 609                 *rmapp = (unsigned long)desc->sptes[0];
 610         else
 611                 if (prev_desc)
 612                         prev_desc->more = desc->more;
 613                 else
 614                         *rmapp = (unsigned long)desc->more | 1;
 615         mmu_free_rmap_desc(desc);
 616 }
 617
 618 static void rmap_remove(struct kvm *kvm, u64 *spte)
 619 {
 620         struct kvm_rmap_desc *desc;
 621         struct kvm_rmap_desc *prev_desc;
 622         struct kvm_mmu_page *sp;
 623         pfn_t pfn;
 624         gfn_t gfn;
 625         unsigned long *rmapp;
 626         int i;
 627
 628         if (!is_rmap_spte(*spte))
 629                 return;
 630         sp = page_header(__pa(spte));
 631         pfn = spte_to_pfn(*spte);
 632         if (*spte & shadow_accessed_mask)
 633                 kvm_set_pfn_accessed(pfn);
 634         if (is_writable_pte(*spte))
 635                 kvm_set_pfn_dirty(pfn);
 636         gfn = kvm_mmu_page_get_gfn(sp, spte - sp->spt);
 637         rmapp = gfn_to_rmap(kvm, gfn, sp->role.level);
 638         if (!*rmapp) {
 639                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
 640                 BUG();
 641         } else if (!(*rmapp & 1)) {
 642                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
 643                 if ((u64 *)*rmapp != spte) {
 644                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
 645                                spte, *spte);
 646                         BUG();
 647                 }
 648                 *rmapp = 0;
 649         } else {
 650                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
 651                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 652                 prev_desc = NULL;
 653                 while (desc) {
 654                         for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i)
 655                                 if (desc->sptes[i] == spte) {
 656                                         rmap_desc_remove_entry(rmapp,
 657                                                                desc, i,
 658                                                                prev_desc);
 659                                         return;
 660                                 }
 661                         prev_desc = desc;
 662                         desc = desc->more;
 663                 }
 664                 pr_err("rmap_remove: %p %llx many->many\n", spte, *spte);
 665                 BUG();
 666         }
 667 }
 668
 669 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
 670 {
 671         struct kvm_rmap_desc *desc;
 672         u64 *prev_spte;
 673         int i;
 674
 675         if (!*rmapp)
 676                 return NULL;
 677         else if (!(*rmapp & 1)) {
 678                 if (!spte)
 679                         return (u64 *)*rmapp;
 680                 return NULL;
 681         }
 682         desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 683         prev_spte = NULL;
 684         while (desc) {
 685                 for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i) {
 686                         if (prev_spte == spte)
 687                                 return desc->sptes[i];
 688                         prev_spte = desc->sptes[i];
 689                 }
 690                 desc = desc->more;
 691         }
 692         return NULL;
 693 }
 694
 695 static int rmap_write_protect(struct kvm *kvm, u64 gfn)
 696 {
 697         unsigned long *rmapp;
 698         u64 *spte;
 699         int i, write_protected = 0;
 700
 701         gfn = unalias_gfn(kvm, gfn);
 702         rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL);
 703
 704         spte = rmap_next(kvm, rmapp, NULL);
 705         while (spte) {
 706                 BUG_ON(!spte);
 707                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 708                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 709                 if (is_writable_pte(*spte)) {
 710                         __set_spte(spte, *spte & ~PT_WRITABLE_MASK);
 711                         write_protected = 1;
 712                 }
 713                 spte = rmap_next(kvm, rmapp, spte);
 714         }
 715         if (write_protected) {
 716                 pfn_t pfn;
 717
 718                 spte = rmap_next(kvm, rmapp, NULL);
 719                 pfn = spte_to_pfn(*spte);
 720                 kvm_set_pfn_dirty(pfn);
 721         }
 722
 723         /* check for huge page mappings */
 724         for (i = PT_DIRECTORY_LEVEL;
 725              i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
 726                 rmapp = gfn_to_rmap(kvm, gfn, i);
 727                 spte = rmap_next(kvm, rmapp, NULL);
 728                 while (spte) {
 729                         BUG_ON(!spte);
 730                         BUG_ON(!(*spte & PT_PRESENT_MASK));
 731                         BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
 732                         pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
 733                         if (is_writable_pte(*spte)) {
 734                                 rmap_remove(kvm, spte);
 735                                 --kvm->stat.lpages;
 736                                 __set_spte(spte, shadow_trap_nonpresent_pte);
 737                                 spte = NULL;
 738                                 write_protected = 1;
 739                         }
 740                         spte = rmap_next(kvm, rmapp, spte);
 741                 }
 742         }
 743
 744         return write_protected;
 745 }
 746
 747 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
 748                            unsigned long data)
 749 {
 750         u64 *spte;
 751         int need_tlb_flush = 0;
 752
 753         while ((spte = rmap_next(kvm, rmapp, NULL))) {
 754                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 755                 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
 756                 rmap_remove(kvm, spte);
 757                 __set_spte(spte, shadow_trap_nonpresent_pte);
 758                 need_tlb_flush = 1;
 759         }
 760         return need_tlb_flush;
 761 }
 762
 763 static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 764                              unsigned long data)
 765 {
 766         int need_flush = 0;
 767         u64 *spte, new_spte;
 768         pte_t *ptep = (pte_t *)data;
 769         pfn_t new_pfn;
 770
 771         WARN_ON(pte_huge(*ptep));
 772         new_pfn = pte_pfn(*ptep);
 773         spte = rmap_next(kvm, rmapp, NULL);
 774         while (spte) {
 775                 BUG_ON(!is_shadow_present_pte(*spte));
 776                 rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte);
 777                 need_flush = 1;
 778                 if (pte_write(*ptep)) {
 779                         rmap_remove(kvm, spte);
 780                         __set_spte(spte, shadow_trap_nonpresent_pte);
 781                         spte = rmap_next(kvm, rmapp, NULL);
 782                 } else {
 783                         new_spte = *spte &~ (PT64_BASE_ADDR_MASK);
 784                         new_spte |= (u64)new_pfn << PAGE_SHIFT;
 785
 786                         new_spte &= ~PT_WRITABLE_MASK;
 787                         new_spte &= ~SPTE_HOST_WRITEABLE;
 788                         if (is_writable_pte(*spte))
 789                                 kvm_set_pfn_dirty(spte_to_pfn(*spte));
 790                         __set_spte(spte, new_spte);
 791                         spte = rmap_next(kvm, rmapp, spte);
 792                 }
 793         }
 794         if (need_flush)
 795                 kvm_flush_remote_tlbs(kvm);
 796
 797         return 0;
 798 }
 799
 800 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 801                           unsigned long data,
 802                           int (*handler)(struct kvm *kvm, unsigned long *rmapp,
 803                                          unsigned long data))
 804 {
 805         int i, j;
 806         int ret;
 807         int retval = 0;
 808         struct kvm_memslots *slots;
 809
 810         slots = kvm_memslots(kvm);
 811
 812         for (i = 0; i < slots->nmemslots; i++) {
 813                 struct kvm_memory_slot *memslot = &slots->memslots[i];
 814                 unsigned long start = memslot->userspace_addr;
 815                 unsigned long end;
 816
 817                 end = start + (memslot->npages << PAGE_SHIFT);
 818                 if (hva >= start && hva < end) {
 819                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
 820
 821                         ret = handler(kvm, &memslot->rmap[gfn_offset], data);
 822
 823                         for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
 824                                 int idx = gfn_offset;
 825                                 idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
 826                                 ret |= handler(kvm,
 827                                         &memslot->lpage_info[j][idx].rmap_pde,
 828                                         data);
 829                         }
 830                         trace_kvm_age_page(hva, memslot, ret);
 831                         retval |= ret;
 832                 }
 833         }
 834
 835         return retval;
 836 }
 837
 838 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 839 {
 840         return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp);
 841 }
 842
 843 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 844 {
 845         kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
 846 }
 847
 848 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
 849                          unsigned long data)
 850 {
 851         u64 *spte;
 852         int young = 0;
 853
 854         /*
 855          * Emulate the accessed bit for EPT, by checking if this page has
 856          * an EPT mapping, and clearing it if it does. On the next access,
 857          * a new EPT mapping will be established.
 858          * This has some overhead, but not as much as the cost of swapping
 859          * out actively used pages or breaking up actively used hugepages.
 860          */
 861         if (!shadow_accessed_mask)
 862                 return kvm_unmap_rmapp(kvm, rmapp, data);
 863
 864         spte = rmap_next(kvm, rmapp, NULL);
 865         while (spte) {
 866                 int _young;
 867                 u64 _spte = *spte;
 868                 BUG_ON(!(_spte & PT_PRESENT_MASK));
 869                 _young = _spte & PT_ACCESSED_MASK;
 870                 if (_young) {
 871                         young = 1;
 872                         clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
 873                 }
 874                 spte = rmap_next(kvm, rmapp, spte);
 875         }
 876         return young;
 877 }
 878
 879 #define RMAP_RECYCLE_THRESHOLD 1000
 880
 881 static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
 882 {
 883         unsigned long *rmapp;
 884         struct kvm_mmu_page *sp;
 885
 886         sp = page_header(__pa(spte));
 887
 888         gfn = unalias_gfn(vcpu->kvm, gfn);
 889         rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level);
 890
 891         kvm_unmap_rmapp(vcpu->kvm, rmapp, 0);
 892         kvm_flush_remote_tlbs(vcpu->kvm);
 893 }
 894
 895 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
 896 {
 897         return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp);
 898 }
 899
 900 #ifdef MMU_DEBUG
 901 static int is_empty_shadow_page(u64 *spt)
 902 {
 903         u64 *pos;
 904         u64 *end;
 905
 906         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
 907                 if (is_shadow_present_pte(*pos)) {
 908                         printk(KERN_ERR "%s: %p %llx\n", __func__,
 909                                pos, *pos);
 910                         return 0;
 911                 }
 912         return 1;
 913 }
 914 #endif
 915
 916 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 917 {
 918         ASSERT(is_empty_shadow_page(sp->spt));
 919         hlist_del(&sp->hash_link);
 920         list_del(&sp->link);
 921         __free_page(virt_to_page(sp->spt));
 922         if (!sp->role.direct)
 923                 __free_page(virt_to_page(sp->gfns));
 924         kmem_cache_free(mmu_page_header_cache, sp);
 925         ++kvm->arch.n_free_mmu_pages;
 926 }
 927
 928 static unsigned kvm_page_table_hashfn(gfn_t gfn)
 929 {
 930         return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
 931 }
 932
 933 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 934                                                u64 *parent_pte, int direct)
 935 {
 936         struct kvm_mmu_page *sp;
 937
 938         sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
 939         sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 940         if (!direct)
 941                 sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache,
 942                                                   PAGE_SIZE);
 943         set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 944         list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
 945         bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
 946         sp->multimapped = 0;
 947         sp->parent_pte = parent_pte;
 948         --vcpu->kvm->arch.n_free_mmu_pages;
 949         return sp;
 950 }
 951
 952 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
 953                                     struct kvm_mmu_page *sp, u64 *parent_pte)
 954 {
 955         struct kvm_pte_chain *pte_chain;
 956         struct hlist_node *node;
 957         int i;
 958
 959         if (!parent_pte)
 960                 return;
 961         if (!sp->multimapped) {
 962                 u64 *old = sp->parent_pte;
 963
 964                 if (!old) {
 965                         sp->parent_pte = parent_pte;
 966                         return;
 967                 }
 968                 sp->multimapped = 1;
 969                 pte_chain = mmu_alloc_pte_chain(vcpu);
 970                 INIT_HLIST_HEAD(&sp->parent_ptes);
 971                 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 972                 pte_chain->parent_ptes[0] = old;
 973         }
 974         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
 975                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
 976                         continue;
 977                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
 978                         if (!pte_chain->parent_ptes[i]) {
 979                                 pte_chain->parent_ptes[i] = parent_pte;
 980                                 return;
 981                         }
 982         }
 983         pte_chain = mmu_alloc_pte_chain(vcpu);
 984         BUG_ON(!pte_chain);
 985         hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 986         pte_chain->parent_ptes[0] = parent_pte;
 987 }
 988
 989 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
 990                                        u64 *parent_pte)
 991 {
 992         struct kvm_pte_chain *pte_chain;
 993         struct hlist_node *node;
 994         int i;
 995
 996         if (!sp->multimapped) {
 997                 BUG_ON(sp->parent_pte != parent_pte);
 998                 sp->parent_pte = NULL;
 999                 return;
1000         }
1001         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1002                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1003                         if (!pte_chain->parent_ptes[i])
1004                                 break;
1005                         if (pte_chain->parent_ptes[i] != parent_pte)
1006                                 continue;
1007                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
1008                                 && pte_chain->parent_ptes[i + 1]) {
1009                                 pte_chain->parent_ptes[i]
1010                                         = pte_chain->parent_ptes[i + 1];
1011                                 ++i;
1012                         }
1013                         pte_chain->parent_ptes[i] = NULL;
1014                         if (i == 0) {
1015                                 hlist_del(&pte_chain->link);
1016                                 mmu_free_pte_chain(pte_chain);
1017                                 if (hlist_empty(&sp->parent_ptes)) {
1018                                         sp->multimapped = 0;
1019                                         sp->parent_pte = NULL;
1020                                 }
1021                         }
1022                         return;
1023                 }
1024         BUG();
1025 }
1026
1027
1028 static void mmu_parent_walk(struct kvm_mmu_page *sp, mmu_parent_walk_fn fn)
1029 {
1030         struct kvm_pte_chain *pte_chain;
1031         struct hlist_node *node;
1032         struct kvm_mmu_page *parent_sp;
1033         int i;
1034
1035         if (!sp->multimapped && sp->parent_pte) {
1036                 parent_sp = page_header(__pa(sp->parent_pte));
1037                 fn(parent_sp);
1038                 mmu_parent_walk(parent_sp, fn);
1039                 return;
1040         }
1041         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1042                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1043                         if (!pte_chain->parent_ptes[i])
1044                                 break;
1045                         parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
1046                         fn(parent_sp);
1047                         mmu_parent_walk(parent_sp, fn);
1048                 }
1049 }
1050
1051 static void kvm_mmu_update_unsync_bitmap(u64 *spte)
1052 {
1053         unsigned int index;
1054         struct kvm_mmu_page *sp = page_header(__pa(spte));
1055
1056         index = spte - sp->spt;
1057         if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
1058                 sp->unsync_children++;
1059         WARN_ON(!sp->unsync_children);
1060 }
1061
1062 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
1063 {
1064         struct kvm_pte_chain *pte_chain;
1065         struct hlist_node *node;
1066         int i;
1067
1068         if (!sp->parent_pte)
1069                 return;
1070
1071         if (!sp->multimapped) {
1072                 kvm_mmu_update_unsync_bitmap(sp->parent_pte);
1073                 return;
1074         }
1075
1076         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
1077                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
1078                         if (!pte_chain->parent_ptes[i])
1079                                 break;
1080                         kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
1081                 }
1082 }
1083
1084 static int unsync_walk_fn(struct kvm_mmu_page *sp)
1085 {
1086         kvm_mmu_update_parents_unsync(sp);
1087         return 1;
1088 }
1089
1090 static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp)
1091 {
1092         mmu_parent_walk(sp, unsync_walk_fn);
1093         kvm_mmu_update_parents_unsync(sp);
1094 }
1095
1096 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1097                                     struct kvm_mmu_page *sp)
1098 {
1099         int i;
1100
1101         for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1102                 sp->spt[i] = shadow_trap_nonpresent_pte;
1103 }
1104
1105 static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
1106                                struct kvm_mmu_page *sp)
1107 {
1108         return 1;
1109 }
1110
1111 static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
1112 {
1113 }
1114
1115 #define KVM_PAGE_ARRAY_NR 16
1116
1117 struct kvm_mmu_pages {
1118         struct mmu_page_and_offset {
1119                 struct kvm_mmu_page *sp;
1120                 unsigned int idx;
1121         } page[KVM_PAGE_ARRAY_NR];
1122         unsigned int nr;
1123 };
1124
1125 #define for_each_unsync_children(bitmap, idx)           \
1126         for (idx = find_first_bit(bitmap, 512);         \
1127              idx < 512;                                 \
1128              idx = find_next_bit(bitmap, 512, idx+1))
1129
1130 static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
1131                          int idx)
1132 {
1133         int i;
1134
1135         if (sp->unsync)
1136                 for (i=0; i < pvec->nr; i++)
1137                         if (pvec->page[i].sp == sp)
1138                                 return 0;
1139
1140         pvec->page[pvec->nr].sp = sp;
1141         pvec->page[pvec->nr].idx = idx;
1142         pvec->nr++;
1143         return (pvec->nr == KVM_PAGE_ARRAY_NR);
1144 }
1145
1146 static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
1147                            struct kvm_mmu_pages *pvec)
1148 {
1149         int i, ret, nr_unsync_leaf = 0;
1150
1151         for_each_unsync_children(sp->unsync_child_bitmap, i) {
1152                 u64 ent = sp->spt[i];
1153
1154                 if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
1155                         struct kvm_mmu_page *child;
1156                         child = page_header(ent & PT64_BASE_ADDR_MASK);
1157
1158                         if (child->unsync_children) {
1159                                 if (mmu_pages_add(pvec, child, i))
1160                                         return -ENOSPC;
1161
1162                                 ret = __mmu_unsync_walk(child, pvec);
1163                                 if (!ret)
1164                                         __clear_bit(i, sp->unsync_child_bitmap);
1165                                 else if (ret > 0)
1166                                         nr_unsync_leaf += ret;
1167                                 else
1168                                         return ret;
1169                         }
1170
1171                         if (child->unsync) {
1172                                 nr_unsync_leaf++;
1173                                 if (mmu_pages_add(pvec, child, i))
1174                                         return -ENOSPC;
1175                         }
1176                 }
1177         }
1178
1179         if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
1180                 sp->unsync_children = 0;
1181
1182         return nr_unsync_leaf;
1183 }
1184
1185 static int mmu_unsync_walk(struct kvm_mmu_page *sp,
1186                            struct kvm_mmu_pages *pvec)
1187 {
1188         if (!sp->unsync_children)
1189                 return 0;
1190
1191         mmu_pages_add(pvec, sp, 0);
1192         return __mmu_unsync_walk(sp, pvec);
1193 }
1194
1195 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1196 {
1197         WARN_ON(!sp->unsync);
1198         trace_kvm_mmu_sync_page(sp);
1199         sp->unsync = 0;
1200         --kvm->stat.mmu_unsync;
1201 }
1202
1203 static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
1204                                     struct list_head *invalid_list);
1205 static void kvm_mmu_commit_zap_page(struct kvm *kvm,
1206                                     struct list_head *invalid_list);
1207
1208 #define for_each_gfn_sp(kvm, sp, gfn, pos)                              \
1209   hlist_for_each_entry(sp, pos,                                         \
1210    &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link)   \
1211         if ((sp)->gfn != (gfn)) {} else
1212
1213 #define for_each_gfn_indirect_valid_sp(kvm, sp, gfn, pos)               \
1214   hlist_for_each_entry(sp, pos,                                         \
1215    &(kvm)->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)], hash_link)   \
1216                 if ((sp)->gfn != (gfn) || (sp)->role.direct ||          \
1217                         (sp)->role.invalid) {} else
1218
1219 static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
1220                            struct list_head *invalid_list, bool clear_unsync)
1221 {
1222         if (sp->role.cr4_pae != !!is_pae(vcpu)) {
1223                 kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
1224                 return 1;
1225         }
1226
1227         if (clear_unsync) {
1228                 if (rmap_write_protect(vcpu->kvm, sp->gfn))
1229                         kvm_flush_remote_tlbs(vcpu->kvm);
1230                 kvm_unlink_unsync_page(vcpu->kvm, sp);
1231         }
1232
1233         if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
1234                 kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list);
1235                 return 1;
1236         }
1237
1238         kvm_mmu_flush_tlb(vcpu);
1239         return 0;
1240 }
1241
1242 static void mmu_convert_notrap(struct kvm_mmu_page *sp);
1243 static int kvm_sync_page_transient(struct kvm_vcpu *vcpu,
1244                                    struct kvm_mmu_page *sp)
1245 {
1246         LIST_HEAD(invalid_list);
1247         int ret;
1248
1249         ret = __kvm_sync_page(vcpu, sp, &invalid_list, false);
1250         if (!ret)
1251                 mmu_convert_notrap(sp);
1252         else
1253                 kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
1254
1255         return ret;
1256 }
1257
1258 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
1259                          struct list_head *invalid_list)
1260 {
1261         return __kvm_sync_page(vcpu, sp, invalid_list, true);
1262 }
1263
1264 /* @gfn should be write-protected at the call site */
1265 static void kvm_sync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
1266 {
1267         struct kvm_mmu_page *s;
1268         struct hlist_node *node;
1269         LIST_HEAD(invalid_list);
1270         bool flush = false;
1271
1272         for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
1273                 if (!s->unsync)
1274                         continue;
1275
1276                 WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
1277                 if ((s->role.cr4_pae != !!is_pae(vcpu)) ||
1278                         (vcpu->arch.mmu.sync_page(vcpu, s))) {
1279                         kvm_mmu_prepare_zap_page(vcpu->kvm, s, &invalid_list);
1280                         continue;
1281                 }
1282                 kvm_unlink_unsync_page(vcpu->kvm, s);
1283                 flush = true;
1284         }
1285
1286         kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
1287         if (flush)
1288                 kvm_mmu_flush_tlb(vcpu);
1289 }
1290
1291 struct mmu_page_path {
1292         struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
1293         unsigned int idx[PT64_ROOT_LEVEL-1];
1294 };
1295
1296 #define for_each_sp(pvec, sp, parents, i)                       \
1297                 for (i = mmu_pages_next(&pvec, &parents, -1),   \
1298                         sp = pvec.page[i].sp;                   \
1299                         i < pvec.nr && ({ sp = pvec.page[i].sp; 1;});   \
1300                         i = mmu_pages_next(&pvec, &parents, i))
1301
1302 static int mmu_pages_next(struct kvm_mmu_pages *pvec,
1303                           struct mmu_page_path *parents,
1304                           int i)
1305 {
1306         int n;
1307
1308         for (n = i+1; n < pvec->nr; n++) {
1309                 struct kvm_mmu_page *sp = pvec->page[n].sp;
1310
1311                 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1312                         parents->idx[0] = pvec->page[n].idx;
1313                         return n;
1314                 }
1315
1316                 parents->parent[sp->role.level-2] = sp;
1317                 parents->idx[sp->role.level-1] = pvec->page[n].idx;
1318         }
1319
1320         return n;
1321 }
1322
1323 static void mmu_pages_clear_parents(struct mmu_page_path *parents)
1324 {
1325         struct kvm_mmu_page *sp;
1326         unsigned int level = 0;
1327
1328         do {
1329                 unsigned int idx = parents->idx[level];
1330
1331                 sp = parents->parent[level];
1332                 if (!sp)
1333                         return;
1334
1335                 --sp->unsync_children;
1336                 WARN_ON((int)sp->unsync_children < 0);
1337                 __clear_bit(idx, sp->unsync_child_bitmap);
1338                 level++;
1339         } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
1340 }
1341
1342 static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
1343                                struct mmu_page_path *parents,
1344                                struct kvm_mmu_pages *pvec)
1345 {
1346         parents->parent[parent->role.level-1] = NULL;
1347         pvec->nr = 0;
1348 }
1349
1350 static void mmu_sync_children(struct kvm_vcpu *vcpu,
1351                               struct kvm_mmu_page *parent)
1352 {
1353         int i;
1354         struct kvm_mmu_page *sp;
1355         struct mmu_page_path parents;
1356         struct kvm_mmu_pages pages;
1357         LIST_HEAD(invalid_list);
1358
1359         kvm_mmu_pages_init(parent, &parents, &pages);
1360         while (mmu_unsync_walk(parent, &pages)) {
1361                 int protected = 0;
1362
1363                 for_each_sp(pages, sp, parents, i)
1364                         protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
1365
1366                 if (protected)
1367                         kvm_flush_remote_tlbs(vcpu->kvm);
1368
1369                 for_each_sp(pages, sp, parents, i) {
1370                         kvm_sync_page(vcpu, sp, &invalid_list);
1371                         mmu_pages_clear_parents(&parents);
1372                 }
1373                 kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
1374                 cond_resched_lock(&vcpu->kvm->mmu_lock);
1375                 kvm_mmu_pages_init(parent, &parents, &pages);
1376         }
1377 }
1378
1379 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
1380                                              gfn_t gfn,
1381                                              gva_t gaddr,
1382                                              unsigned level,
1383                                              int direct,
1384                                              unsigned access,
1385                                              u64 *parent_pte)
1386 {
1387         union kvm_mmu_page_role role;
1388         unsigned quadrant;
1389         struct kvm_mmu_page *sp;
1390         struct hlist_node *node;
1391         bool need_sync = false;
1392
1393         role = vcpu->arch.mmu.base_role;
1394         role.level = level;
1395         role.direct = direct;
1396         if (role.direct)
1397                 role.cr4_pae = 0;
1398         role.access = access;
1399         if (!tdp_enabled && vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
1400                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
1401                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
1402                 role.quadrant = quadrant;
1403         }
1404         for_each_gfn_sp(vcpu->kvm, sp, gfn, node) {
1405                 if (!need_sync && sp->unsync)
1406                         need_sync = true;
1407
1408                 if (sp->role.word != role.word)
1409                         continue;
1410
1411                 if (sp->unsync && kvm_sync_page_transient(vcpu, sp))
1412                         break;
1413
1414                 mmu_page_add_parent_pte(vcpu, sp, parent_pte);
1415                 if (sp->unsync_children) {
1416                         set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
1417                         kvm_mmu_mark_parents_unsync(sp);
1418                 } else if (sp->unsync)
1419                         kvm_mmu_mark_parents_unsync(sp);
1420
1421                 trace_kvm_mmu_get_page(sp, false);
1422                 return sp;
1423         }
1424         ++vcpu->kvm->stat.mmu_cache_miss;
1425         sp = kvm_mmu_alloc_page(vcpu, parent_pte, direct);
1426         if (!sp)
1427                 return sp;
1428         sp->gfn = gfn;
1429         sp->role = role;
1430         hlist_add_head(&sp->hash_link,
1431                 &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]);
1432         if (!direct) {
1433                 if (rmap_write_protect(vcpu->kvm, gfn))
1434                         kvm_flush_remote_tlbs(vcpu->kvm);
1435                 if (level > PT_PAGE_TABLE_LEVEL && need_sync)
1436                         kvm_sync_pages(vcpu, gfn);
1437
1438                 account_shadowed(vcpu->kvm, gfn);
1439         }
1440         if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
1441                 vcpu->arch.mmu.prefetch_page(vcpu, sp);
1442         else
1443                 nonpaging_prefetch_page(vcpu, sp);
1444         trace_kvm_mmu_get_page(sp, true);
1445         return sp;
1446 }
1447
1448 static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
1449                              struct kvm_vcpu *vcpu, u64 addr)
1450 {
1451         iterator->addr = addr;
1452         iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
1453         iterator->level = vcpu->arch.mmu.shadow_root_level;
1454         if (iterator->level == PT32E_ROOT_LEVEL) {
1455                 iterator->shadow_addr
1456                         = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
1457                 iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
1458                 --iterator->level;
1459                 if (!iterator->shadow_addr)
1460                         iterator->level = 0;
1461         }
1462 }
1463
1464 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
1465 {
1466         if (iterator->level < PT_PAGE_TABLE_LEVEL)
1467                 return false;
1468
1469         if (iterator->level == PT_PAGE_TABLE_LEVEL)
1470                 if (is_large_pte(*iterator->sptep))
1471                         return false;
1472
1473         iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
1474         iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
1475         return true;
1476 }
1477
1478 static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
1479 {
1480         iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
1481         --iterator->level;
1482 }
1483
1484 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1485                                          struct kvm_mmu_page *sp)
1486 {
1487         unsigned i;
1488         u64 *pt;
1489         u64 ent;
1490
1491         pt = sp->spt;
1492
1493         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1494                 ent = pt[i];
1495
1496                 if (is_shadow_present_pte(ent)) {
1497                         if (!is_last_spte(ent, sp->role.level)) {
1498                                 ent &= PT64_BASE_ADDR_MASK;
1499                                 mmu_page_remove_parent_pte(page_header(ent),
1500                                                            &pt[i]);
1501                         } else {
1502                                 if (is_large_pte(ent))
1503                                         --kvm->stat.lpages;
1504                                 rmap_remove(kvm, &pt[i]);
1505                         }
1506                 }
1507                 pt[i] = shadow_trap_nonpresent_pte;
1508         }
1509 }
1510
1511 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1512 {
1513         mmu_page_remove_parent_pte(sp, parent_pte);
1514 }
1515
1516 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1517 {
1518         int i;
1519         struct kvm_vcpu *vcpu;
1520
1521         kvm_for_each_vcpu(i, vcpu, kvm)
1522                 vcpu->arch.last_pte_updated = NULL;
1523 }
1524
1525 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1526 {
1527         u64 *parent_pte;
1528
1529         while (sp->multimapped || sp->parent_pte) {
1530                 if (!sp->multimapped)
1531                         parent_pte = sp->parent_pte;
1532                 else {
1533                         struct kvm_pte_chain *chain;
1534
1535                         chain = container_of(sp->parent_ptes.first,
1536                                              struct kvm_pte_chain, link);
1537                         parent_pte = chain->parent_ptes[0];
1538                 }
1539                 BUG_ON(!parent_pte);
1540                 kvm_mmu_put_page(sp, parent_pte);
1541                 __set_spte(parent_pte, shadow_trap_nonpresent_pte);
1542         }
1543 }
1544
1545 static int mmu_zap_unsync_children(struct kvm *kvm,
1546                                    struct kvm_mmu_page *parent,
1547                                    struct list_head *invalid_list)
1548 {
1549         int i, zapped = 0;
1550         struct mmu_page_path parents;
1551         struct kvm_mmu_pages pages;
1552
1553         if (parent->role.level == PT_PAGE_TABLE_LEVEL)
1554                 return 0;
1555
1556         kvm_mmu_pages_init(parent, &parents, &pages);
1557         while (mmu_unsync_walk(parent, &pages)) {
1558                 struct kvm_mmu_page *sp;
1559
1560                 for_each_sp(pages, sp, parents, i) {
1561                         kvm_mmu_prepare_zap_page(kvm, sp, invalid_list);
1562                         mmu_pages_clear_parents(&parents);
1563                         zapped++;
1564                 }
1565                 kvm_mmu_pages_init(parent, &parents, &pages);
1566         }
1567
1568         return zapped;
1569 }
1570
1571 static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp,
1572                                     struct list_head *invalid_list)
1573 {
1574         int ret;
1575
1576         trace_kvm_mmu_prepare_zap_page(sp);
1577         ++kvm->stat.mmu_shadow_zapped;
1578         ret = mmu_zap_unsync_children(kvm, sp, invalid_list);
1579         kvm_mmu_page_unlink_children(kvm, sp);
1580         kvm_mmu_unlink_parents(kvm, sp);
1581         if (!sp->role.invalid && !sp->role.direct)
1582                 unaccount_shadowed(kvm, sp->gfn);
1583         if (sp->unsync)
1584                 kvm_unlink_unsync_page(kvm, sp);
1585         if (!sp->root_count) {
1586                 /* Count self */
1587                 ret++;
1588                 list_move(&sp->link, invalid_list);
1589         } else {
1590                 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1591                 kvm_reload_remote_mmus(kvm);
1592         }
1593
1594         sp->role.invalid = 1;
1595         kvm_mmu_reset_last_pte_updated(kvm);
1596         return ret;
1597 }
1598
1599 static void kvm_mmu_commit_zap_page(struct kvm *kvm,
1600                                     struct list_head *invalid_list)
1601 {
1602         struct kvm_mmu_page *sp;
1603
1604         if (list_empty(invalid_list))
1605                 return;
1606
1607         kvm_flush_remote_tlbs(kvm);
1608
1609         do {
1610                 sp = list_first_entry(invalid_list, struct kvm_mmu_page, link);
1611                 WARN_ON(!sp->role.invalid || sp->root_count);
1612                 kvm_mmu_free_page(kvm, sp);
1613         } while (!list_empty(invalid_list));
1614
1615 }
1616
1617 /*
1618  * Changing the number of mmu pages allocated to the vm
1619  * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1620  */
1621 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1622 {
1623         int used_pages;
1624         LIST_HEAD(invalid_list);
1625
1626         used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages;
1627         used_pages = max(0, used_pages);
1628
1629         /*
1630          * If we set the number of mmu pages to be smaller be than the
1631          * number of actived pages , we must to free some mmu pages before we
1632          * change the value
1633          */
1634
1635         if (used_pages > kvm_nr_mmu_pages) {
1636                 while (used_pages > kvm_nr_mmu_pages &&
1637                         !list_empty(&kvm->arch.active_mmu_pages)) {
1638                         struct kvm_mmu_page *page;
1639
1640                         page = container_of(kvm->arch.active_mmu_pages.prev,
1641                                             struct kvm_mmu_page, link);
1642                         used_pages -= kvm_mmu_prepare_zap_page(kvm, page,
1643                                                                &invalid_list);
1644                 }
1645                 kvm_mmu_commit_zap_page(kvm, &invalid_list);
1646                 kvm_nr_mmu_pages = used_pages;
1647                 kvm->arch.n_free_mmu_pages = 0;
1648         }
1649         else
1650                 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1651                                          - kvm->arch.n_alloc_mmu_pages;
1652
1653         kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1654 }
1655
1656 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1657 {
1658         struct kvm_mmu_page *sp;
1659         struct hlist_node *node;
1660         LIST_HEAD(invalid_list);
1661         int r;
1662
1663         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1664         r = 0;
1665
1666         for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
1667                 pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1668                          sp->role.word);
1669                 r = 1;
1670                 kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
1671         }
1672         kvm_mmu_commit_zap_page(kvm, &invalid_list);
1673         return r;
1674 }
1675
1676 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1677 {
1678         struct kvm_mmu_page *sp;
1679         struct hlist_node *node;
1680         LIST_HEAD(invalid_list);
1681
1682         for_each_gfn_indirect_valid_sp(kvm, sp, gfn, node) {
1683                 pgprintk("%s: zap %lx %x\n",
1684                          __func__, gfn, sp->role.word);
1685                 kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list);
1686         }
1687         kvm_mmu_commit_zap_page(kvm, &invalid_list);
1688 }
1689
1690 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1691 {
1692         int slot = memslot_id(kvm, gfn);
1693         struct kvm_mmu_page *sp = page_header(__pa(pte));
1694
1695         __set_bit(slot, sp->slot_bitmap);
1696 }
1697
1698 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
1699 {
1700         int i;
1701         u64 *pt = sp->spt;
1702
1703         if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
1704                 return;
1705
1706         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1707                 if (pt[i] == shadow_notrap_nonpresent_pte)
1708                         __set_spte(&pt[i], shadow_trap_nonpresent_pte);
1709         }
1710 }
1711
1712 /*
1713  * The function is based on mtrr_type_lookup() in
1714  * arch/x86/kernel/cpu/mtrr/generic.c
1715  */
1716 static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
1717                          u64 start, u64 end)
1718 {
1719         int i;
1720         u64 base, mask;
1721         u8 prev_match, curr_match;
1722         int num_var_ranges = KVM_NR_VAR_MTRR;
1723
1724         if (!mtrr_state->enabled)
1725                 return 0xFF;
1726
1727         /* Make end inclusive end, instead of exclusive */
1728         end--;
1729
1730         /* Look in fixed ranges. Just return the type as per start */
1731         if (mtrr_state->have_fixed && (start < 0x100000)) {
1732                 int idx;
1733
1734                 if (start < 0x80000) {
1735                         idx = 0;
1736                         idx += (start >> 16);
1737                         return mtrr_state->fixed_ranges[idx];
1738                 } else if (start < 0xC0000) {
1739                         idx = 1 * 8;
1740                         idx += ((start - 0x80000) >> 14);
1741                         return mtrr_state->fixed_ranges[idx];
1742                 } else if (start < 0x1000000) {
1743                         idx = 3 * 8;
1744                         idx += ((start - 0xC0000) >> 12);
1745                         return mtrr_state->fixed_ranges[idx];
1746                 }
1747         }
1748
1749         /*
1750          * Look in variable ranges
1751          * Look of multiple ranges matching this address and pick type
1752          * as per MTRR precedence
1753          */
1754         if (!(mtrr_state->enabled & 2))
1755                 return mtrr_state->def_type;
1756
1757         prev_match = 0xFF;
1758         for (i = 0; i < num_var_ranges; ++i) {
1759                 unsigned short start_state, end_state;
1760
1761                 if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
1762                         continue;
1763
1764                 base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
1765                        (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
1766                 mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
1767                        (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
1768
1769                 start_state = ((start & mask) == (base & mask));
1770                 end_state = ((end & mask) == (base & mask));
1771                 if (start_state != end_state)
1772                         return 0xFE;
1773
1774                 if ((start & mask) != (base & mask))
1775                         continue;
1776
1777                 curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
1778                 if (prev_match == 0xFF) {
1779                         prev_match = curr_match;
1780                         continue;
1781                 }
1782
1783                 if (prev_match == MTRR_TYPE_UNCACHABLE ||
1784                     curr_match == MTRR_TYPE_UNCACHABLE)
1785                         return MTRR_TYPE_UNCACHABLE;
1786
1787                 if ((prev_match == MTRR_TYPE_WRBACK &&
1788                      curr_match == MTRR_TYPE_WRTHROUGH) ||
1789                     (prev_match == MTRR_TYPE_WRTHROUGH &&
1790                      curr_match == MTRR_TYPE_WRBACK)) {
1791                         prev_match = MTRR_TYPE_WRTHROUGH;
1792                         curr_match = MTRR_TYPE_WRTHROUGH;
1793                 }
1794
1795                 if (prev_match != curr_match)
1796                         return MTRR_TYPE_UNCACHABLE;
1797         }
1798
1799         if (prev_match != 0xFF)
1800                 return prev_match;
1801
1802         return mtrr_state->def_type;
1803 }
1804
1805 u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
1806 {
1807         u8 mtrr;
1808
1809         mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
1810                              (gfn << PAGE_SHIFT) + PAGE_SIZE);
1811         if (mtrr == 0xfe || mtrr == 0xff)
1812                 mtrr = MTRR_TYPE_WRBACK;
1813         return mtrr;
1814 }
1815 EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type);
1816
1817 static void __kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1818 {
1819         trace_kvm_mmu_unsync_page(sp);
1820         ++vcpu->kvm->stat.mmu_unsync;
1821         sp->unsync = 1;
1822
1823         kvm_mmu_mark_parents_unsync(sp);
1824         mmu_convert_notrap(sp);
1825 }
1826
1827 static void kvm_unsync_pages(struct kvm_vcpu *vcpu,  gfn_t gfn)
1828 {
1829         struct kvm_mmu_page *s;
1830         struct hlist_node *node;
1831
1832         for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
1833                 if (s->unsync)
1834                         continue;
1835                 WARN_ON(s->role.level != PT_PAGE_TABLE_LEVEL);
1836                 __kvm_unsync_page(vcpu, s);
1837         }
1838 }
1839
1840 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
1841                                   bool can_unsync)
1842 {
1843         struct kvm_mmu_page *s;
1844         struct hlist_node *node;
1845         bool need_unsync = false;
1846
1847         for_each_gfn_indirect_valid_sp(vcpu->kvm, s, gfn, node) {
1848                 if (s->role.level != PT_PAGE_TABLE_LEVEL)
1849                         return 1;
1850
1851                 if (!need_unsync && !s->unsync) {
1852                         if (!can_unsync || !oos_shadow)
1853                                 return 1;
1854                         need_unsync = true;
1855                 }
1856         }
1857         if (need_unsync)
1858                 kvm_unsync_pages(vcpu, gfn);
1859         return 0;
1860 }
1861
1862 static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1863                     unsigned pte_access, int user_fault,
1864                     int write_fault, int dirty, int level,
1865                     gfn_t gfn, pfn_t pfn, bool speculative,
1866                     bool can_unsync, bool reset_host_protection)
1867 {
1868         u64 spte;
1869         int ret = 0;
1870
1871         /*
1872          * We don't set the accessed bit, since we sometimes want to see
1873          * whether the guest actually used the pte (in order to detect
1874          * demand paging).
1875          */
1876         spte = shadow_base_present_pte | shadow_dirty_mask;
1877         if (!speculative)
1878                 spte |= shadow_accessed_mask;
1879         if (!dirty)
1880                 pte_access &= ~ACC_WRITE_MASK;
1881         if (pte_access & ACC_EXEC_MASK)
1882                 spte |= shadow_x_mask;
1883         else
1884                 spte |= shadow_nx_mask;
1885         if (pte_access & ACC_USER_MASK)
1886                 spte |= shadow_user_mask;
1887         if (level > PT_PAGE_TABLE_LEVEL)
1888                 spte |= PT_PAGE_SIZE_MASK;
1889         if (tdp_enabled)
1890                 spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn,
1891                         kvm_is_mmio_pfn(pfn));
1892
1893         if (reset_host_protection)
1894                 spte |= SPTE_HOST_WRITEABLE;
1895
1896         spte |= (u64)pfn << PAGE_SHIFT;
1897
1898         if ((pte_access & ACC_WRITE_MASK)
1899             || (!tdp_enabled && write_fault && !is_write_protection(vcpu)
1900                 && !user_fault)) {
1901
1902                 if (level > PT_PAGE_TABLE_LEVEL &&
1903                     has_wrprotected_page(vcpu->kvm, gfn, level)) {
1904                         ret = 1;
1905                         rmap_remove(vcpu->kvm, sptep);
1906                         spte = shadow_trap_nonpresent_pte;
1907                         goto set_pte;
1908                 }
1909
1910                 spte |= PT_WRITABLE_MASK;
1911
1912                 if (!tdp_enabled && !(pte_access & ACC_WRITE_MASK))
1913                         spte &= ~PT_USER_MASK;
1914
1915                 /*
1916                  * Optimization: for pte sync, if spte was writable the hash
1917                  * lookup is unnecessary (and expensive). Write protection
1918                  * is responsibility of mmu_get_page / kvm_sync_page.
1919                  * Same reasoning can be applied to dirty page accounting.
1920                  */
1921                 if (!can_unsync && is_writable_pte(*sptep))
1922                         goto set_pte;
1923
1924                 if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
1925                         pgprintk("%s: found shadow page for %lx, marking ro\n",
1926                                  __func__, gfn);
1927                         ret = 1;
1928                         pte_access &= ~ACC_WRITE_MASK;
1929                         if (is_writable_pte(spte))
1930                                 spte &= ~PT_WRITABLE_MASK;
1931                 }
1932         }
1933
1934         if (pte_access & ACC_WRITE_MASK)
1935                 mark_page_dirty(vcpu->kvm, gfn);
1936
1937 set_pte:
1938         __set_spte(sptep, spte);
1939         return ret;
1940 }
1941
1942 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
1943                          unsigned pt_access, unsigned pte_access,
1944                          int user_fault, int write_fault, int dirty,
1945                          int *ptwrite, int level, gfn_t gfn,
1946                          pfn_t pfn, bool speculative,
1947                          bool reset_host_protection)
1948 {
1949         int was_rmapped = 0;
1950         int was_writable = is_writable_pte(*sptep);
1951         int rmap_count;
1952
1953         pgprintk("%s: spte %llx access %x write_fault %d"
1954                  " user_fault %d gfn %lx\n",
1955                  __func__, *sptep, pt_access,
1956                  write_fault, user_fault, gfn);
1957
1958         if (is_rmap_spte(*sptep)) {
1959                 /*
1960                  * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1961                  * the parent of the now unreachable PTE.
1962                  */
1963                 if (level > PT_PAGE_TABLE_LEVEL &&
1964                     !is_large_pte(*sptep)) {
1965                         struct kvm_mmu_page *child;
1966                         u64 pte = *sptep;
1967
1968                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1969                         mmu_page_remove_parent_pte(child, sptep);
1970                         __set_spte(sptep, shadow_trap_nonpresent_pte);
1971                         kvm_flush_remote_tlbs(vcpu->kvm);
1972                 } else if (pfn != spte_to_pfn(*sptep)) {
1973                         pgprintk("hfn old %lx new %lx\n",
1974                                  spte_to_pfn(*sptep), pfn);
1975                         rmap_remove(vcpu->kvm, sptep);
1976                         __set_spte(sptep, shadow_trap_nonpresent_pte);
1977                         kvm_flush_remote_tlbs(vcpu->kvm);
1978                 } else
1979                         was_rmapped = 1;
1980         }
1981
1982         if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
1983                       dirty, level, gfn, pfn, speculative, true,
1984                       reset_host_protection)) {
1985                 if (write_fault)
1986                         *ptwrite = 1;
1987                 kvm_mmu_flush_tlb(vcpu);
1988         }
1989
1990         pgprintk("%s: setting spte %llx\n", __func__, *sptep);
1991         pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1992                  is_large_pte(*sptep)? "2MB" : "4kB",
1993                  *sptep & PT_PRESENT_MASK ?"RW":"R", gfn,
1994                  *sptep, sptep);
1995         if (!was_rmapped && is_large_pte(*sptep))
1996                 ++vcpu->kvm->stat.lpages;
1997
1998         page_header_update_slot(vcpu->kvm, sptep, gfn);
1999         if (!was_rmapped) {
2000                 rmap_count = rmap_add(vcpu, sptep, gfn);
2001                 kvm_release_pfn_clean(pfn);
2002                 if (rmap_count > RMAP_RECYCLE_THRESHOLD)
2003                         rmap_recycle(vcpu, sptep, gfn);
2004         } else {
2005                 if (was_writable)
2006                         kvm_release_pfn_dirty(pfn);
2007                 else
2008                         kvm_release_pfn_clean(pfn);
2009         }
2010         if (speculative) {
2011                 vcpu->arch.last_pte_updated = sptep;
2012                 vcpu->arch.last_pte_gfn = gfn;
2013         }
2014 }
2015
2016 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
2017 {
2018 }
2019
2020 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
2021                         int level, gfn_t gfn, pfn_t pfn)
2022 {
2023         struct kvm_shadow_walk_iterator iterator;
2024         struct kvm_mmu_page *sp;
2025         int pt_write = 0;
2026         gfn_t pseudo_gfn;
2027
2028         for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
2029                 if (iterator.level == level) {
2030                         mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
2031                                      0, write, 1, &pt_write,
2032                                      level, gfn, pfn, false, true);
2033                         ++vcpu->stat.pf_fixed;
2034                         break;
2035                 }
2036
2037                 if (*iterator.sptep == shadow_trap_nonpresent_pte) {
2038                         u64 base_addr = iterator.addr;
2039
2040                         base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
2041                         pseudo_gfn = base_addr >> PAGE_SHIFT;
2042                         sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
2043                                               iterator.level - 1,
2044                                               1, ACC_ALL, iterator.sptep);
2045                         if (!sp) {
2046                                 pgprintk("nonpaging_map: ENOMEM\n");
2047                                 kvm_release_pfn_clean(pfn);
2048                                 return -ENOMEM;
2049                         }
2050
2051                         __set_spte(iterator.sptep,
2052                                    __pa(sp->spt)
2053                                    | PT_PRESENT_MASK | PT_WRITABLE_MASK
2054                                    | shadow_user_mask | shadow_x_mask);
2055                 }
2056         }
2057         return pt_write;
2058 }
2059
2060 static void kvm_send_hwpoison_signal(struct kvm *kvm, gfn_t gfn)
2061 {
2062         char buf[1];
2063         void __user *hva;
2064         int r;
2065
2066         /* Touch the page, so send SIGBUS */
2067         hva = (void __user *)gfn_to_hva(kvm, gfn);
2068         r = copy_from_user(buf, hva, 1);
2069 }
2070
2071 static int kvm_handle_bad_page(struct kvm *kvm, gfn_t gfn, pfn_t pfn)
2072 {
2073         kvm_release_pfn_clean(pfn);
2074         if (is_hwpoison_pfn(pfn)) {
2075                 kvm_send_hwpoison_signal(kvm, gfn);
2076                 return 0;
2077         }
2078         return 1;
2079 }
2080
2081 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
2082 {
2083         int r;
2084         int level;
2085         pfn_t pfn;
2086         unsigned long mmu_seq;
2087
2088         level = mapping_level(vcpu, gfn);
2089
2090         /*
2091          * This path builds a PAE pagetable - so we can map 2mb pages at
2092          * maximum. Therefore check if the level is larger than that.
2093          */
2094         if (level > PT_DIRECTORY_LEVEL)
2095                 level = PT_DIRECTORY_LEVEL;
2096
2097         gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2098
2099         mmu_seq = vcpu->kvm->mmu_notifier_seq;
2100         smp_rmb();
2101         pfn = gfn_to_pfn(vcpu->kvm, gfn);
2102
2103         /* mmio */
2104         if (is_error_pfn(pfn))
2105                 return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
2106
2107         spin_lock(&vcpu->kvm->mmu_lock);
2108         if (mmu_notifier_retry(vcpu, mmu_seq))
2109                 goto out_unlock;
2110         kvm_mmu_free_some_pages(vcpu);
2111         r = __direct_map(vcpu, v, write, level, gfn, pfn);
2112         spin_unlock(&vcpu->kvm->mmu_lock);
2113
2114
2115         return r;
2116
2117 out_unlock:
2118         spin_unlock(&vcpu->kvm->mmu_lock);
2119         kvm_release_pfn_clean(pfn);
2120         return 0;
2121 }
2122
2123
2124 static void mmu_free_roots(struct kvm_vcpu *vcpu)
2125 {
2126         int i;
2127         struct kvm_mmu_page *sp;
2128         LIST_HEAD(invalid_list);
2129
2130         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2131                 return;
2132         spin_lock(&vcpu->kvm->mmu_lock);
2133         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2134                 hpa_t root = vcpu->arch.mmu.root_hpa;
2135
2136                 sp = page_header(root);
2137                 --sp->root_count;
2138                 if (!sp->root_count && sp->role.invalid) {
2139                         kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list);
2140                         kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
2141                 }
2142                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2143                 spin_unlock(&vcpu->kvm->mmu_lock);
2144                 return;
2145         }
2146         for (i = 0; i < 4; ++i) {
2147                 hpa_t root = vcpu->arch.mmu.pae_root[i];
2148
2149                 if (root) {
2150                         root &= PT64_BASE_ADDR_MASK;
2151                         sp = page_header(root);
2152                         --sp->root_count;
2153                         if (!sp->root_count && sp->role.invalid)
2154                                 kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
2155                                                          &invalid_list);
2156                 }
2157                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2158         }
2159         kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
2160         spin_unlock(&vcpu->kvm->mmu_lock);
2161         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2162 }
2163
2164 static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn)
2165 {
2166         int ret = 0;
2167
2168         if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) {
2169                 set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests);
2170                 ret = 1;
2171         }
2172
2173         return ret;
2174 }
2175
2176 static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
2177 {
2178         int i;
2179         gfn_t root_gfn;
2180         struct kvm_mmu_page *sp;
2181         int direct = 0;
2182         u64 pdptr;
2183
2184         root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
2185
2186         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2187                 hpa_t root = vcpu->arch.mmu.root_hpa;
2188
2189                 ASSERT(!VALID_PAGE(root));
2190                 if (mmu_check_root(vcpu, root_gfn))
2191                         return 1;
2192                 if (tdp_enabled) {
2193                         direct = 1;
2194                         root_gfn = 0;
2195                 }
2196                 spin_lock(&vcpu->kvm->mmu_lock);
2197                 kvm_mmu_free_some_pages(vcpu);
2198                 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
2199                                       PT64_ROOT_LEVEL, direct,
2200                                       ACC_ALL, NULL);
2201                 root = __pa(sp->spt);
2202                 ++sp->root_count;
2203                 spin_unlock(&vcpu->kvm->mmu_lock);
2204                 vcpu->arch.mmu.root_hpa = root;
2205                 return 0;
2206         }
2207         direct = !is_paging(vcpu);
2208         for (i = 0; i < 4; ++i) {
2209                 hpa_t root = vcpu->arch.mmu.pae_root[i];
2210
2211                 ASSERT(!VALID_PAGE(root));
2212                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
2213                         pdptr = kvm_pdptr_read(vcpu, i);
2214                         if (!is_present_gpte(pdptr)) {
2215                                 vcpu->arch.mmu.pae_root[i] = 0;
2216                                 continue;
2217                         }
2218                         root_gfn = pdptr >> PAGE_SHIFT;
2219                 } else if (vcpu->arch.mmu.root_level == 0)
2220                         root_gfn = 0;
2221                 if (mmu_check_root(vcpu, root_gfn))
2222                         return 1;
2223                 if (tdp_enabled) {
2224                         direct = 1;
2225                         root_gfn = i << 30;
2226                 }
2227                 spin_lock(&vcpu->kvm->mmu_lock);
2228                 kvm_mmu_free_some_pages(vcpu);
2229                 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
2230                                       PT32_ROOT_LEVEL, direct,
2231                                       ACC_ALL, NULL);
2232                 root = __pa(sp->spt);
2233                 ++sp->root_count;
2234                 spin_unlock(&vcpu->kvm->mmu_lock);
2235
2236                 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
2237         }
2238         vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
2239         return 0;
2240 }
2241
2242 static void mmu_sync_roots(struct kvm_vcpu *vcpu)
2243 {
2244         int i;
2245         struct kvm_mmu_page *sp;
2246
2247         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2248                 return;
2249         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2250                 hpa_t root = vcpu->arch.mmu.root_hpa;
2251                 sp = page_header(root);
2252                 mmu_sync_children(vcpu, sp);
2253                 return;
2254         }
2255         for (i = 0; i < 4; ++i) {
2256                 hpa_t root = vcpu->arch.mmu.pae_root[i];
2257
2258                 if (root && VALID_PAGE(root)) {
2259                         root &= PT64_BASE_ADDR_MASK;
2260                         sp = page_header(root);
2261                         mmu_sync_children(vcpu, sp);
2262                 }
2263         }
2264 }
2265
2266 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
2267 {
2268         spin_lock(&vcpu->kvm->mmu_lock);
2269         mmu_sync_roots(vcpu);
2270         spin_unlock(&vcpu->kvm->mmu_lock);
2271 }
2272
2273 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
2274                                   u32 access, u32 *error)
2275 {
2276         if (error)
2277                 *error = 0;
2278         return vaddr;
2279 }
2280
2281 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
2282                                 u32 error_code)
2283 {
2284         gfn_t gfn;
2285         int r;
2286
2287         pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
2288         r = mmu_topup_memory_caches(vcpu);
2289         if (r)
2290                 return r;
2291
2292         ASSERT(vcpu);
2293         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2294
2295         gfn = gva >> PAGE_SHIFT;
2296
2297         return nonpaging_map(vcpu, gva & PAGE_MASK,
2298                              error_code & PFERR_WRITE_MASK, gfn);
2299 }
2300
2301 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
2302                                 u32 error_code)
2303 {
2304         pfn_t pfn;
2305         int r;
2306         int level;
2307         gfn_t gfn = gpa >> PAGE_SHIFT;
2308         unsigned long mmu_seq;
2309
2310         ASSERT(vcpu);
2311         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2312
2313         r = mmu_topup_memory_caches(vcpu);
2314         if (r)
2315                 return r;
2316
2317         level = mapping_level(vcpu, gfn);
2318
2319         gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1);
2320
2321         mmu_seq = vcpu->kvm->mmu_notifier_seq;
2322         smp_rmb();
2323         pfn = gfn_to_pfn(vcpu->kvm, gfn);
2324         if (is_error_pfn(pfn))
2325                 return kvm_handle_bad_page(vcpu->kvm, gfn, pfn);
2326         spin_lock(&vcpu->kvm->mmu_lock);
2327         if (mmu_notifier_retry(vcpu, mmu_seq))
2328                 goto out_unlock;
2329         kvm_mmu_free_some_pages(vcpu);
2330         r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
2331                          level, gfn, pfn);
2332         spin_unlock(&vcpu->kvm->mmu_lock);
2333
2334         return r;
2335
2336 out_unlock:
2337         spin_unlock(&vcpu->kvm->mmu_lock);
2338         kvm_release_pfn_clean(pfn);
2339         return 0;
2340 }
2341
2342 static void nonpaging_free(struct kvm_vcpu *vcpu)
2343 {
2344         mmu_free_roots(vcpu);
2345 }
2346
2347 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
2348 {
2349         struct kvm_mmu *context = &vcpu->arch.mmu;
2350
2351         context->new_cr3 = nonpaging_new_cr3;
2352         context->page_fault = nonpaging_page_fault;
2353         context->gva_to_gpa = nonpaging_gva_to_gpa;
2354         context->free = nonpaging_free;
2355         context->prefetch_page = nonpaging_prefetch_page;
2356         context->sync_page = nonpaging_sync_page;
2357         context->invlpg = nonpaging_invlpg;
2358         context->root_level = 0;
2359         context->shadow_root_level = PT32E_ROOT_LEVEL;
2360         context->root_hpa = INVALID_PAGE;
2361         return 0;
2362 }
2363
2364 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2365 {
2366         ++vcpu->stat.tlb_flush;
2367         set_bit(KVM_REQ_TLB_FLUSH, &vcpu->requests);
2368 }
2369
2370 static void paging_new_cr3(struct kvm_vcpu *vcpu)
2371 {
2372         pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
2373         mmu_free_roots(vcpu);
2374 }
2375
2376 static void inject_page_fault(struct kvm_vcpu *vcpu,
2377                               u64 addr,
2378                               u32 err_code)
2379 {
2380         kvm_inject_page_fault(vcpu, addr, err_code);
2381 }
2382
2383 static void paging_free(struct kvm_vcpu *vcpu)
2384 {
2385         nonpaging_free(vcpu);
2386 }
2387
2388 static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level)
2389 {
2390         int bit7;
2391
2392         bit7 = (gpte >> 7) & 1;
2393         return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0;
2394 }
2395
2396 #define PTTYPE 64
2397 #include "paging_tmpl.h"
2398 #undef PTTYPE
2399
2400 #define PTTYPE 32
2401 #include "paging_tmpl.h"
2402 #undef PTTYPE
2403
2404 static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level)
2405 {
2406         struct kvm_mmu *context = &vcpu->arch.mmu;
2407         int maxphyaddr = cpuid_maxphyaddr(vcpu);
2408         u64 exb_bit_rsvd = 0;
2409
2410         if (!is_nx(vcpu))
2411                 exb_bit_rsvd = rsvd_bits(63, 63);
2412         switch (level) {
2413         case PT32_ROOT_LEVEL:
2414                 /* no rsvd bits for 2 level 4K page table entries */
2415                 context->rsvd_bits_mask[0][1] = 0;
2416                 context->rsvd_bits_mask[0][0] = 0;
2417                 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0];
2418
2419                 if (!is_pse(vcpu)) {
2420                         context->rsvd_bits_mask[1][1] = 0;
2421                         break;
2422                 }
2423
2424                 if (is_cpuid_PSE36())
2425                         /* 36bits PSE 4MB page */
2426                         context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21);
2427                 else
2428                         /* 32 bits PSE 4MB page */
2429                         context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21);
2430                 break;
2431         case PT32E_ROOT_LEVEL:
2432                 context->rsvd_bits_mask[0][2] =
2433                         rsvd_bits(maxphyaddr, 63) |
2434                         rsvd_bits(7, 8) | rsvd_bits(1, 2);      /* PDPTE */
2435                 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2436                         rsvd_bits(maxphyaddr, 62);      /* PDE */
2437                 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2438                         rsvd_bits(maxphyaddr, 62);      /* PTE */
2439                 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2440                         rsvd_bits(maxphyaddr, 62) |
2441                         rsvd_bits(13, 20);              /* large page */
2442                 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0];
2443                 break;
2444         case PT64_ROOT_LEVEL:
2445                 context->rsvd_bits_mask[0][3] = exb_bit_rsvd |
2446                         rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2447                 context->rsvd_bits_mask[0][2] = exb_bit_rsvd |
2448                         rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8);
2449                 context->rsvd_bits_mask[0][1] = exb_bit_rsvd |
2450                         rsvd_bits(maxphyaddr, 51);
2451                 context->rsvd_bits_mask[0][0] = exb_bit_rsvd |
2452                         rsvd_bits(maxphyaddr, 51);
2453                 context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3];
2454                 context->rsvd_bits_mask[1][2] = exb_bit_rsvd |
2455                         rsvd_bits(maxphyaddr, 51) |
2456                         rsvd_bits(13, 29);
2457                 context->rsvd_bits_mask[1][1] = exb_bit_rsvd |
2458                         rsvd_bits(maxphyaddr, 51) |
2459                         rsvd_bits(13, 20);              /* large page */
2460                 context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[0][0];
2461                 break;
2462         }
2463 }
2464
2465 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
2466 {
2467         struct kvm_mmu *context = &vcpu->arch.mmu;
2468
2469         ASSERT(is_pae(vcpu));
2470         context->new_cr3 = paging_new_cr3;
2471         context->page_fault = paging64_page_fault;
2472         context->gva_to_gpa = paging64_gva_to_gpa;
2473         context->prefetch_page = paging64_prefetch_page;
2474         context->sync_page = paging64_sync_page;
2475         context->invlpg = paging64_invlpg;
2476         context->free = paging_free;
2477         context->root_level = level;
2478         context->shadow_root_level = level;
2479         context->root_hpa = INVALID_PAGE;
2480         return 0;
2481 }
2482
2483 static int paging64_init_context(struct kvm_vcpu *vcpu)
2484 {
2485         reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2486         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
2487 }
2488
2489 static int paging32_init_context(struct kvm_vcpu *vcpu)
2490 {
2491         struct kvm_mmu *context = &vcpu->arch.mmu;
2492
2493         reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2494         context->new_cr3 = paging_new_cr3;
2495         context->page_fault = paging32_page_fault;
2496         context->gva_to_gpa = paging32_gva_to_gpa;
2497         context->free = paging_free;
2498         context->prefetch_page = paging32_prefetch_page;
2499         context->sync_page = paging32_sync_page;
2500         context->invlpg = paging32_invlpg;
2501         context->root_level = PT32_ROOT_LEVEL;
2502         context->shadow_root_level = PT32E_ROOT_LEVEL;
2503         context->root_hpa = INVALID_PAGE;
2504         return 0;
2505 }
2506
2507 static int paging32E_init_context(struct kvm_vcpu *vcpu)
2508 {
2509         reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2510         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
2511 }
2512
2513 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
2514 {
2515         struct kvm_mmu *context = &vcpu->arch.mmu;
2516
2517         context->new_cr3 = nonpaging_new_cr3;
2518         context->page_fault = tdp_page_fault;
2519         context->free = nonpaging_free;
2520         context->prefetch_page = nonpaging_prefetch_page;
2521         context->sync_page = nonpaging_sync_page;
2522         context->invlpg = nonpaging_invlpg;
2523         context->shadow_root_level = kvm_x86_ops->get_tdp_level();
2524         context->root_hpa = INVALID_PAGE;
2525
2526         if (!is_paging(vcpu)) {
2527                 context->gva_to_gpa = nonpaging_gva_to_gpa;
2528                 context->root_level = 0;
2529         } else if (is_long_mode(vcpu)) {
2530                 reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL);
2531                 context->gva_to_gpa = paging64_gva_to_gpa;
2532                 context->root_level = PT64_ROOT_LEVEL;
2533         } else if (is_pae(vcpu)) {
2534                 reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL);
2535                 context->gva_to_gpa = paging64_gva_to_gpa;
2536                 context->root_level = PT32E_ROOT_LEVEL;
2537         } else {
2538                 reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL);
2539                 context->gva_to_gpa = paging32_gva_to_gpa;
2540                 context->root_level = PT32_ROOT_LEVEL;
2541         }
2542
2543         return 0;
2544 }
2545
2546 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
2547 {
2548         int r;
2549
2550         ASSERT(vcpu);
2551         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2552
2553         if (!is_paging(vcpu))
2554                 r = nonpaging_init_context(vcpu);
2555         else if (is_long_mode(vcpu))
2556                 r = paging64_init_context(vcpu);
2557         else if (is_pae(vcpu))
2558                 r = paging32E_init_context(vcpu);
2559         else
2560                 r = paging32_init_context(vcpu);
2561
2562         vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu);
2563         vcpu->arch.mmu.base_role.cr0_wp = is_write_protection(vcpu);
2564
2565         return r;
2566 }
2567
2568 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
2569 {
2570         vcpu->arch.update_pte.pfn = bad_pfn;
2571
2572         if (tdp_enabled)
2573                 return init_kvm_tdp_mmu(vcpu);
2574         else
2575                 return init_kvm_softmmu(vcpu);
2576 }
2577
2578 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
2579 {
2580         ASSERT(vcpu);
2581         if (VALID_PAGE(vcpu->arch.mmu.root_hpa))
2582                 /* mmu.free() should set root_hpa = INVALID_PAGE */
2583                 vcpu->arch.mmu.free(vcpu);
2584 }
2585
2586 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
2587 {
2588         destroy_kvm_mmu(vcpu);
2589         return init_kvm_mmu(vcpu);
2590 }
2591 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
2592
2593 int kvm_mmu_load(struct kvm_vcpu *vcpu)
2594 {
2595         int r;
2596
2597         r = mmu_topup_memory_caches(vcpu);
2598         if (r)
2599                 goto out;
2600         r = mmu_alloc_roots(vcpu);
2601         spin_lock(&vcpu->kvm->mmu_lock);
2602         mmu_sync_roots(vcpu);
2603         spin_unlock(&vcpu->kvm->mmu_lock);
2604         if (r)
2605                 goto out;
2606         /* set_cr3() should ensure TLB has been flushed */
2607         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
2608 out:
2609         return r;
2610 }
2611 EXPORT_SYMBOL_GPL(kvm_mmu_load);
2612
2613 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
2614 {
2615         mmu_free_roots(vcpu);
2616 }
2617
2618 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
2619                                   struct kvm_mmu_page *sp,
2620                                   u64 *spte)
2621 {
2622         u64 pte;
2623         struct kvm_mmu_page *child;
2624
2625         pte = *spte;
2626         if (is_shadow_present_pte(pte)) {
2627                 if (is_last_spte(pte, sp->role.level))
2628                         rmap_remove(vcpu->kvm, spte);
2629                 else {
2630                         child = page_header(pte & PT64_BASE_ADDR_MASK);
2631                         mmu_page_remove_parent_pte(child, spte);
2632                 }
2633         }
2634         __set_spte(spte, shadow_trap_nonpresent_pte);
2635         if (is_large_pte(pte))
2636                 --vcpu->kvm->stat.lpages;
2637 }
2638
2639 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
2640                                   struct kvm_mmu_page *sp,
2641                                   u64 *spte,
2642                                   const void *new)
2643 {
2644         if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
2645                 ++vcpu->kvm->stat.mmu_pde_zapped;
2646                 return;
2647         }
2648
2649         ++vcpu->kvm->stat.mmu_pte_updated;
2650         if (!sp->role.cr4_pae)
2651                 paging32_update_pte(vcpu, sp, spte, new);
2652         else
2653                 paging64_update_pte(vcpu, sp, spte, new);
2654 }
2655
2656 static bool need_remote_flush(u64 old, u64 new)
2657 {
2658         if (!is_shadow_present_pte(old))
2659                 return false;
2660         if (!is_shadow_present_pte(new))
2661                 return true;
2662         if ((old ^ new) & PT64_BASE_ADDR_MASK)
2663                 return true;
2664         old ^= PT64_NX_MASK;
2665         new ^= PT64_NX_MASK;
2666         return (old & ~new & PT64_PERM_MASK) != 0;
2667 }
2668
2669 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, bool zap_page,
2670                                     bool remote_flush, bool local_flush)
2671 {
2672         if (zap_page)
2673                 return;
2674
2675         if (remote_flush)
2676                 kvm_flush_remote_tlbs(vcpu->kvm);
2677         else if (local_flush)
2678                 kvm_mmu_flush_tlb(vcpu);
2679 }
2680
2681 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
2682 {
2683         u64 *spte = vcpu->arch.last_pte_updated;
2684
2685         return !!(spte && (*spte & shadow_accessed_mask));
2686 }
2687
2688 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2689                                           u64 gpte)
2690 {
2691         gfn_t gfn;
2692         pfn_t pfn;
2693
2694         if (!is_present_gpte(gpte))
2695                 return;
2696         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
2697
2698         vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
2699         smp_rmb();
2700         pfn = gfn_to_pfn(vcpu->kvm, gfn);
2701
2702         if (is_error_pfn(pfn)) {
2703                 kvm_release_pfn_clean(pfn);
2704                 return;
2705         }
2706         vcpu->arch.update_pte.gfn = gfn;
2707         vcpu->arch.update_pte.pfn = pfn;
2708 }
2709
2710 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
2711 {
2712         u64 *spte = vcpu->arch.last_pte_updated;
2713
2714         if (spte
2715             && vcpu->arch.last_pte_gfn == gfn
2716             && shadow_accessed_mask
2717             && !(*spte & shadow_accessed_mask)
2718             && is_shadow_present_pte(*spte))
2719                 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
2720 }
2721
2722 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2723                        const u8 *new, int bytes,
2724                        bool guest_initiated)
2725 {
2726         gfn_t gfn = gpa >> PAGE_SHIFT;
2727         struct kvm_mmu_page *sp;
2728         struct hlist_node *node;
2729         LIST_HEAD(invalid_list);
2730         u64 entry, gentry;
2731         u64 *spte;
2732         unsigned offset = offset_in_page(gpa);
2733         unsigned pte_size;
2734         unsigned page_offset;
2735         unsigned misaligned;
2736         unsigned quadrant;
2737         int level;
2738         int flooded = 0;
2739         int npte;
2740         int r;
2741         int invlpg_counter;
2742         bool remote_flush, local_flush, zap_page;
2743
2744         zap_page = remote_flush = local_flush = false;
2745
2746         pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
2747
2748         invlpg_counter = atomic_read(&vcpu->kvm->arch.invlpg_counter);
2749
2750         /*
2751          * Assume that the pte write on a page table of the same type
2752          * as the current vcpu paging mode.  This is nearly always true
2753          * (might be false while changing modes).  Note it is verified later
2754          * by update_pte().
2755          */
2756         if ((is_pae(vcpu) && bytes == 4) || !new) {
2757                 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2758                 if (is_pae(vcpu)) {
2759                         gpa &= ~(gpa_t)7;
2760                         bytes = 8;
2761                 }
2762                 r = kvm_read_guest(vcpu->kvm, gpa, &gentry, min(bytes, 8));
2763                 if (r)
2764                         gentry = 0;
2765                 new = (const u8 *)&gentry;
2766         }
2767
2768         switch (bytes) {
2769         case 4:
2770                 gentry = *(const u32 *)new;
2771                 break;
2772         case 8:
2773                 gentry = *(const u64 *)new;
2774                 break;
2775         default:
2776                 gentry = 0;
2777                 break;
2778         }
2779
2780         mmu_guess_page_from_pte_write(vcpu, gpa, gentry);
2781         spin_lock(&vcpu->kvm->mmu_lock);
2782         if (atomic_read(&vcpu->kvm->arch.invlpg_counter) != invlpg_counter)
2783                 gentry = 0;
2784         kvm_mmu_access_page(vcpu, gfn);
2785         kvm_mmu_free_some_pages(vcpu);
2786         ++vcpu->kvm->stat.mmu_pte_write;
2787         kvm_mmu_audit(vcpu, "pre pte write");
2788         if (guest_initiated) {
2789                 if (gfn == vcpu->arch.last_pt_write_gfn
2790                     && !last_updated_pte_accessed(vcpu)) {
2791                         ++vcpu->arch.last_pt_write_count;
2792                         if (vcpu->arch.last_pt_write_count >= 3)
2793                                 flooded = 1;
2794                 } else {
2795                         vcpu->arch.last_pt_write_gfn = gfn;
2796                         vcpu->arch.last_pt_write_count = 1;
2797                         vcpu->arch.last_pte_updated = NULL;
2798                 }
2799         }
2800
2801         for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node) {
2802                 pte_size = sp->role.cr4_pae ? 8 : 4;
2803                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
2804                 misaligned |= bytes < 4;
2805                 if (misaligned || flooded) {
2806                         /*
2807                          * Misaligned accesses are too much trouble to fix
2808                          * up; also, they usually indicate a page is not used
2809                          * as a page table.
2810                          *
2811                          * If we're seeing too many writes to a page,
2812                          * it may no longer be a page table, or we may be
2813                          * forking, in which case it is better to unmap the
2814                          * page.
2815                          */
2816                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2817                                  gpa, bytes, sp->role.word);
2818                         zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
2819                                                      &invalid_list);
2820                         ++vcpu->kvm->stat.mmu_flooded;
2821                         continue;
2822                 }
2823                 page_offset = offset;
2824                 level = sp->role.level;
2825                 npte = 1;
2826                 if (!sp->role.cr4_pae) {
2827                         page_offset <<= 1;      /* 32->64 */
2828                         /*
2829                          * A 32-bit pde maps 4MB while the shadow pdes map
2830                          * only 2MB.  So we need to double the offset again
2831                          * and zap two pdes instead of one.
2832                          */
2833                         if (level == PT32_ROOT_LEVEL) {
2834                                 page_offset &= ~7; /* kill rounding error */
2835                                 page_offset <<= 1;
2836                                 npte = 2;
2837                         }
2838                         quadrant = page_offset >> PAGE_SHIFT;
2839                         page_offset &= ~PAGE_MASK;
2840                         if (quadrant != sp->role.quadrant)
2841                                 continue;
2842                 }
2843                 local_flush = true;
2844                 spte = &sp->spt[page_offset / sizeof(*spte)];
2845                 while (npte--) {
2846                         entry = *spte;
2847                         mmu_pte_write_zap_pte(vcpu, sp, spte);
2848                         if (gentry)
2849                                 mmu_pte_write_new_pte(vcpu, sp, spte, &gentry);
2850                         if (!remote_flush && need_remote_flush(entry, *spte))
2851                                 remote_flush = true;
2852                         ++spte;
2853                 }
2854         }
2855         mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush);
2856         kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
2857         kvm_mmu_audit(vcpu, "post pte write");
2858         spin_unlock(&vcpu->kvm->mmu_lock);
2859         if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2860                 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2861                 vcpu->arch.update_pte.pfn = bad_pfn;
2862         }
2863 }
2864
2865 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2866 {
2867         gpa_t gpa;
2868         int r;
2869
2870         if (tdp_enabled)
2871                 return 0;
2872
2873         gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
2874
2875         spin_lock(&vcpu->kvm->mmu_lock);
2876         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2877         spin_unlock(&vcpu->kvm->mmu_lock);
2878         return r;
2879 }
2880 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2881
2882 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2883 {
2884         int free_pages;
2885         LIST_HEAD(invalid_list);
2886
2887         free_pages = vcpu->kvm->arch.n_free_mmu_pages;
2888         while (free_pages < KVM_REFILL_PAGES &&
2889                !list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2890                 struct kvm_mmu_page *sp;
2891
2892                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2893                                   struct kvm_mmu_page, link);
2894                 free_pages += kvm_mmu_prepare_zap_page(vcpu->kvm, sp,
2895                                                        &invalid_list);
2896                 ++vcpu->kvm->stat.mmu_recycled;
2897         }
2898         kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list);
2899 }
2900
2901 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2902 {
2903         int r;
2904         enum emulation_result er;
2905
2906         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2907         if (r < 0)
2908                 goto out;
2909
2910         if (!r) {
2911                 r = 1;
2912                 goto out;
2913         }
2914
2915         r = mmu_topup_memory_caches(vcpu);
2916         if (r)
2917                 goto out;
2918
2919         er = emulate_instruction(vcpu, cr2, error_code, 0);
2920
2921         switch (er) {
2922         case EMULATE_DONE:
2923                 return 1;
2924         case EMULATE_DO_MMIO:
2925                 ++vcpu->stat.mmio_exits;
2926                 /* fall through */
2927         case EMULATE_FAIL:
2928                 return 0;
2929         default:
2930                 BUG();
2931         }
2932 out:
2933         return r;
2934 }
2935 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2936
2937 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2938 {
2939         vcpu->arch.mmu.invlpg(vcpu, gva);
2940         kvm_mmu_flush_tlb(vcpu);
2941         ++vcpu->stat.invlpg;
2942 }
2943 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2944
2945 void kvm_enable_tdp(void)
2946 {
2947         tdp_enabled = true;
2948 }
2949 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2950
2951 void kvm_disable_tdp(void)
2952 {
2953         tdp_enabled = false;
2954 }
2955 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2956
2957 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2958 {
2959         free_page((unsigned long)vcpu->arch.mmu.pae_root);
2960 }
2961
2962 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2963 {
2964         struct page *page;
2965         int i;
2966
2967         ASSERT(vcpu);
2968
2969         /*
2970          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2971          * Therefore we need to allocate shadow page tables in the first
2972          * 4GB of memory, which happens to fit the DMA32 zone.
2973          */
2974         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2975         if (!page)
2976                 return -ENOMEM;
2977
2978         vcpu->arch.mmu.pae_root = page_address(page);
2979         for (i = 0; i < 4; ++i)
2980                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2981
2982         return 0;
2983 }
2984
2985 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2986 {
2987         ASSERT(vcpu);
2988         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2989
2990         return alloc_mmu_pages(vcpu);
2991 }
2992
2993 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2994 {
2995         ASSERT(vcpu);
2996         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2997
2998         return init_kvm_mmu(vcpu);
2999 }
3000
3001 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
3002 {
3003         ASSERT(vcpu);
3004
3005         destroy_kvm_mmu(vcpu);
3006         free_mmu_pages(vcpu);
3007         mmu_free_memory_caches(vcpu);
3008 }
3009
3010 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
3011 {
3012         struct kvm_mmu_page *sp;
3013
3014         list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
3015                 int i;
3016                 u64 *pt;
3017
3018                 if (!test_bit(slot, sp->slot_bitmap))
3019                         continue;
3020
3021                 pt = sp->spt;
3022                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
3023                         /* avoid RMW */
3024                         if (is_writable_pte(pt[i]))
3025                                 pt[i] &= ~PT_WRITABLE_MASK;
3026         }
3027         kvm_flush_remote_tlbs(kvm);
3028 }
3029
3030 void kvm_mmu_zap_all(struct kvm *kvm)
3031 {
3032         struct kvm_mmu_page *sp, *node;
3033         LIST_HEAD(invalid_list);
3034
3035         spin_lock(&kvm->mmu_lock);
3036 restart:
3037         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
3038                 if (kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list))
3039                         goto restart;
3040
3041         kvm_mmu_commit_zap_page(kvm, &invalid_list);
3042         spin_unlock(&kvm->mmu_lock);
3043 }
3044
3045 static int kvm_mmu_remove_some_alloc_mmu_pages(struct kvm *kvm,
3046                                                struct list_head *invalid_list)
3047 {
3048         struct kvm_mmu_page *page;
3049
3050         page = container_of(kvm->arch.active_mmu_pages.prev,
3051                             struct kvm_mmu_page, link);
3052         return kvm_mmu_prepare_zap_page(kvm, page, invalid_list);
3053 }
3054
3055 static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
3056 {
3057         struct kvm *kvm;
3058         struct kvm *kvm_freed = NULL;
3059         int cache_count = 0;
3060
3061         spin_lock(&kvm_lock);
3062
3063         list_for_each_entry(kvm, &vm_list, vm_list) {
3064                 int npages, idx, freed_pages;
3065                 LIST_HEAD(invalid_list);
3066
3067                 idx = srcu_read_lock(&kvm->srcu);
3068                 spin_lock(&kvm->mmu_lock);
3069                 npages = kvm->arch.n_alloc_mmu_pages -
3070                          kvm->arch.n_free_mmu_pages;
3071                 cache_count += npages;
3072                 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
3073                         freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm,
3074                                                           &invalid_list);
3075                         cache_count -= freed_pages;
3076                         kvm_freed = kvm;
3077                 }
3078                 nr_to_scan--;
3079
3080                 kvm_mmu_commit_zap_page(kvm, &invalid_list);
3081                 spin_unlock(&kvm->mmu_lock);
3082                 srcu_read_unlock(&kvm->srcu, idx);
3083         }
3084         if (kvm_freed)
3085                 list_move_tail(&kvm_freed->vm_list, &vm_list);
3086
3087         spin_unlock(&kvm_lock);
3088
3089         return cache_count;
3090 }
3091
3092 static struct shrinker mmu_shrinker = {
3093         .shrink = mmu_shrink,
3094         .seeks = DEFAULT_SEEKS * 10,
3095 };
3096
3097 static void mmu_destroy_caches(void)
3098 {
3099         if (pte_chain_cache)
3100                 kmem_cache_destroy(pte_chain_cache);
3101         if (rmap_desc_cache)
3102                 kmem_cache_destroy(rmap_desc_cache);
3103         if (mmu_page_header_cache)
3104                 kmem_cache_destroy(mmu_page_header_cache);
3105 }
3106
3107 void kvm_mmu_module_exit(void)
3108 {
3109         mmu_destroy_caches();
3110         unregister_shrinker(&mmu_shrinker);
3111 }
3112
3113 int kvm_mmu_module_init(void)
3114 {
3115         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
3116                                             sizeof(struct kvm_pte_chain),
3117                                             0, 0, NULL);
3118         if (!pte_chain_cache)
3119                 goto nomem;
3120         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
3121                                             sizeof(struct kvm_rmap_desc),
3122                                             0, 0, NULL);
3123         if (!rmap_desc_cache)
3124                 goto nomem;
3125
3126         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
3127                                                   sizeof(struct kvm_mmu_page),
3128                                                   0, 0, NULL);
3129         if (!mmu_page_header_cache)
3130                 goto nomem;
3131
3132         register_shrinker(&mmu_shrinker);
3133
3134         return 0;
3135
3136 nomem:
3137         mmu_destroy_caches();
3138         return -ENOMEM;
3139 }
3140
3141 /*
3142  * Caculate mmu pages needed for kvm.
3143  */
3144 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
3145 {
3146         int i;
3147         unsigned int nr_mmu_pages;
3148         unsigned int  nr_pages = 0;
3149         struct kvm_memslots *slots;
3150
3151         slots = kvm_memslots(kvm);
3152
3153         for (i = 0; i < slots->nmemslots; i++)
3154                 nr_pages += slots->memslots[i].npages;
3155
3156         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
3157         nr_mmu_pages = max(nr_mmu_pages,
3158                         (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
3159
3160         return nr_mmu_pages;
3161 }
3162
3163 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3164                                 unsigned len)
3165 {
3166         if (len > buffer->len)
3167                 return NULL;
3168         return buffer->ptr;
3169 }
3170
3171 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
3172                                 unsigned len)
3173 {
3174         void *ret;
3175
3176         ret = pv_mmu_peek_buffer(buffer, len);
3177         if (!ret)
3178                 return ret;
3179         buffer->ptr += len;
3180         buffer->len -= len;
3181         buffer->processed += len;
3182         return ret;
3183 }
3184
3185 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
3186                              gpa_t addr, gpa_t value)
3187 {
3188         int bytes = 8;
3189         int r;
3190
3191         if (!is_long_mode(vcpu) && !is_pae(vcpu))
3192                 bytes = 4;
3193
3194         r = mmu_topup_memory_caches(vcpu);
3195         if (r)
3196                 return r;
3197
3198         if (!emulator_write_phys(vcpu, addr, &value, bytes))
3199                 return -EFAULT;
3200
3201         return 1;
3202 }
3203
3204 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
3205 {
3206         (void)kvm_set_cr3(vcpu, vcpu->arch.cr3);
3207         return 1;
3208 }
3209
3210 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
3211 {
3212         spin_lock(&vcpu->kvm->mmu_lock);
3213         mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
3214         spin_unlock(&vcpu->kvm->mmu_lock);
3215         return 1;
3216 }
3217
3218 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
3219                              struct kvm_pv_mmu_op_buffer *buffer)
3220 {
3221         struct kvm_mmu_op_header *header;
3222
3223         header = pv_mmu_peek_buffer(buffer, sizeof *header);
3224         if (!header)
3225                 return 0;
3226         switch (header->op) {
3227         case KVM_MMU_OP_WRITE_PTE: {
3228                 struct kvm_mmu_op_write_pte *wpte;
3229
3230                 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
3231                 if (!wpte)
3232                         return 0;
3233                 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
3234                                         wpte->pte_val);
3235         }
3236         case KVM_MMU_OP_FLUSH_TLB: {
3237                 struct kvm_mmu_op_flush_tlb *ftlb;
3238
3239                 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
3240                 if (!ftlb)
3241                         return 0;
3242                 return kvm_pv_mmu_flush_tlb(vcpu);
3243         }
3244         case KVM_MMU_OP_RELEASE_PT: {
3245                 struct kvm_mmu_op_release_pt *rpt;
3246
3247                 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
3248                 if (!rpt)
3249                         return 0;
3250                 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
3251         }
3252         default: return 0;
3253         }
3254 }
3255
3256 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
3257                   gpa_t addr, unsigned long *ret)
3258 {
3259         int r;
3260         struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
3261
3262         buffer->ptr = buffer->buf;
3263         buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
3264         buffer->processed = 0;
3265
3266         r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
3267         if (r)
3268                 goto out;
3269
3270         while (buffer->len) {
3271                 r = kvm_pv_mmu_op_one(vcpu, buffer);
3272                 if (r < 0)
3273                         goto out;
3274                 if (r == 0)
3275                         break;
3276         }
3277
3278         r = 1;
3279 out:
3280         *ret = buffer->processed;
3281         return r;
3282 }
3283
3284 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4])
3285 {
3286         struct kvm_shadow_walk_iterator iterator;
3287         int nr_sptes = 0;
3288
3289         spin_lock(&vcpu->kvm->mmu_lock);
3290         for_each_shadow_entry(vcpu, addr, iterator) {
3291                 sptes[iterator.level-1] = *iterator.sptep;
3292                 nr_sptes++;
3293                 if (!is_shadow_present_pte(*iterator.sptep))
3294                         break;
3295         }
3296         spin_unlock(&vcpu->kvm->mmu_lock);
3297
3298         return nr_sptes;
3299 }
3300 EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy);
3301
3302 #ifdef AUDIT
3303
3304 static const char *audit_msg;
3305
3306 static gva_t canonicalize(gva_t gva)
3307 {
3308 #ifdef CONFIG_X86_64
3309         gva = (long long)(gva << 16) >> 16;
3310 #endif
3311         return gva;
3312 }
3313
3314
3315 typedef void (*inspect_spte_fn) (struct kvm *kvm, u64 *sptep);
3316
3317 static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
3318                             inspect_spte_fn fn)
3319 {
3320         int i;
3321
3322         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3323                 u64 ent = sp->spt[i];
3324
3325                 if (is_shadow_present_pte(ent)) {
3326                         if (!is_last_spte(ent, sp->role.level)) {
3327                                 struct kvm_mmu_page *child;
3328                                 child = page_header(ent & PT64_BASE_ADDR_MASK);
3329                                 __mmu_spte_walk(kvm, child, fn);
3330                         } else
3331                                 fn(kvm, &sp->spt[i]);
3332                 }
3333         }
3334 }
3335
3336 static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
3337 {
3338         int i;
3339         struct kvm_mmu_page *sp;
3340
3341         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
3342                 return;
3343         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
3344                 hpa_t root = vcpu->arch.mmu.root_hpa;
3345                 sp = page_header(root);
3346                 __mmu_spte_walk(vcpu->kvm, sp, fn);
3347                 return;
3348         }
3349         for (i = 0; i < 4; ++i) {
3350                 hpa_t root = vcpu->arch.mmu.pae_root[i];
3351
3352                 if (root && VALID_PAGE(root)) {
3353                         root &= PT64_BASE_ADDR_MASK;
3354                         sp = page_header(root);
3355                         __mmu_spte_walk(vcpu->kvm, sp, fn);
3356                 }
3357         }
3358         return;
3359 }
3360
3361 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
3362                                 gva_t va, int level)
3363 {
3364         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
3365         int i;
3366         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
3367
3368         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
3369                 u64 ent = pt[i];
3370
3371                 if (ent == shadow_trap_nonpresent_pte)
3372                         continue;
3373
3374                 va = canonicalize(va);
3375                 if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
3376                         audit_mappings_page(vcpu, ent, va, level - 1);
3377                 else {
3378                         gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL);
3379                         gfn_t gfn = gpa >> PAGE_SHIFT;
3380                         pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
3381                         hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
3382
3383                         if (is_error_pfn(pfn)) {
3384                                 kvm_release_pfn_clean(pfn);
3385                                 continue;
3386                         }
3387
3388                         if (is_shadow_present_pte(ent)
3389                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
3390                                 printk(KERN_ERR "xx audit error: (%s) levels %d"
3391                                        " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3392                                        audit_msg, vcpu->arch.mmu.root_level,
3393                                        va, gpa, hpa, ent,
3394                                        is_shadow_present_pte(ent));
3395                         else if (ent == shadow_notrap_nonpresent_pte
3396                                  && !is_error_hpa(hpa))
3397                                 printk(KERN_ERR "audit: (%s) notrap shadow,"
3398                                        " valid guest gva %lx\n", audit_msg, va);
3399                         kvm_release_pfn_clean(pfn);
3400
3401                 }
3402         }
3403 }
3404
3405 static void audit_mappings(struct kvm_vcpu *vcpu)
3406 {
3407         unsigned i;
3408
3409         if (vcpu->arch.mmu.root_level == 4)
3410                 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
3411         else
3412                 for (i = 0; i < 4; ++i)
3413                         if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
3414                                 audit_mappings_page(vcpu,
3415                                                     vcpu->arch.mmu.pae_root[i],
3416                                                     i << 30,
3417                                                     2);
3418 }
3419
3420 static int count_rmaps(struct kvm_vcpu *vcpu)
3421 {
3422         struct kvm *kvm = vcpu->kvm;
3423         struct kvm_memslots *slots;
3424         int nmaps = 0;
3425         int i, j, k, idx;
3426
3427         idx = srcu_read_lock(&kvm->srcu);
3428         slots = kvm_memslots(kvm);
3429         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
3430                 struct kvm_memory_slot *m = &slots->memslots[i];
3431                 struct kvm_rmap_desc *d;
3432
3433                 for (j = 0; j < m->npages; ++j) {
3434                         unsigned long *rmapp = &m->rmap[j];
3435
3436                         if (!*rmapp)
3437                                 continue;
3438                         if (!(*rmapp & 1)) {
3439                                 ++nmaps;
3440                                 continue;
3441                         }
3442                         d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
3443                         while (d) {
3444                                 for (k = 0; k < RMAP_EXT; ++k)
3445                                         if (d->sptes[k])
3446                                                 ++nmaps;
3447                                         else
3448                                                 break;
3449                                 d = d->more;
3450                         }
3451                 }
3452         }
3453         srcu_read_unlock(&kvm->srcu, idx);
3454         return nmaps;
3455 }
3456
3457 void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
3458 {
3459         unsigned long *rmapp;
3460         struct kvm_mmu_page *rev_sp;
3461         gfn_t gfn;
3462
3463         if (is_writable_pte(*sptep)) {
3464                 rev_sp = page_header(__pa(sptep));
3465                 gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);
3466
3467                 if (!gfn_to_memslot(kvm, gfn)) {
3468                         if (!printk_ratelimit())
3469                                 return;
3470                         printk(KERN_ERR "%s: no memslot for gfn %ld\n",
3471                                          audit_msg, gfn);
3472                         printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n",
3473                                audit_msg, (long int)(sptep - rev_sp->spt),
3474                                         rev_sp->gfn);
3475                         dump_stack();
3476                         return;
3477                 }
3478
3479                 rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);
3480                 if (!*rmapp) {
3481                         if (!printk_ratelimit())
3482                                 return;
3483                         printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
3484                                          audit_msg, *sptep);
3485                         dump_stack();
3486                 }
3487         }
3488
3489 }
3490
3491 void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
3492 {
3493         mmu_spte_walk(vcpu, inspect_spte_has_rmap);
3494 }
3495
3496 static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
3497 {
3498         struct kvm_mmu_page *sp;
3499         int i;
3500
3501         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3502                 u64 *pt = sp->spt;
3503
3504                 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
3505                         continue;
3506
3507                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3508                         u64 ent = pt[i];
3509
3510                         if (!(ent & PT_PRESENT_MASK))
3511                                 continue;
3512                         if (!is_writable_pte(ent))
3513                                 continue;
3514                         inspect_spte_has_rmap(vcpu->kvm, &pt[i]);
3515                 }
3516         }
3517         return;
3518 }
3519
3520 static void audit_rmap(struct kvm_vcpu *vcpu)
3521 {
3522         check_writable_mappings_rmap(vcpu);
3523         count_rmaps(vcpu);
3524 }
3525
3526 static void audit_write_protection(struct kvm_vcpu *vcpu)
3527 {
3528         struct kvm_mmu_page *sp;
3529         struct kvm_memory_slot *slot;
3530         unsigned long *rmapp;
3531         u64 *spte;
3532         gfn_t gfn;
3533
3534         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3535                 if (sp->role.direct)
3536                         continue;
3537                 if (sp->unsync)
3538                         continue;
3539
3540                 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
3541                 slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
3542                 rmapp = &slot->rmap[gfn - slot->base_gfn];
3543
3544                 spte = rmap_next(vcpu->kvm, rmapp, NULL);
3545                 while (spte) {
3546                         if (is_writable_pte(*spte))
3547                                 printk(KERN_ERR "%s: (%s) shadow page has "
3548                                 "writable mappings: gfn %lx role %x\n",
3549                                __func__, audit_msg, sp->gfn,
3550                                sp->role.word);
3551                         spte = rmap_next(vcpu->kvm, rmapp, spte);
3552                 }
3553         }
3554 }
3555
3556 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
3557 {
3558         int olddbg = dbg;
3559
3560         dbg = 0;
3561         audit_msg = msg;
3562         audit_rmap(vcpu);
3563         audit_write_protection(vcpu);
3564         if (strcmp("pre pte write", audit_msg) != 0)
3565                 audit_mappings(vcpu);
3566         audit_writable_sptes_have_rmaps(vcpu);
3567         dbg = olddbg;
3568 }
3569
3570 #endif