arch/x86/kvm/mmu.c

   1 /*
   2  * Kernel-based Virtual Machine driver for Linux
   3  *
   4  * This module enables machines with Intel VT-x extensions to run virtual
   5  * machines without emulation or binary translation.
   6  *
   7  * MMU support
   8  *
   9  * Copyright (C) 2006 Qumranet, Inc.
  10  *
  11  * Authors:
  12  *   Yaniv Kamay  <yaniv@qumranet.com>
  13  *   Avi Kivity   <avi@qumranet.com>
  14  *
  15  * This work is licensed under the terms of the GNU GPL, version 2.  See
  16  * the COPYING file in the top-level directory.
  17  *
  18  */
  19
  20 #include "mmu.h"
  21
  22 #include <linux/kvm_host.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/mm.h>
  26 #include <linux/highmem.h>
  27 #include <linux/module.h>
  28 #include <linux/swap.h>
  29 #include <linux/hugetlb.h>
  30 #include <linux/compiler.h>
  31
  32 #include <asm/page.h>
  33 #include <asm/cmpxchg.h>
  34 #include <asm/io.h>
  35 #include <asm/vmx.h>
  36
  37 /*
  38  * When setting this variable to true it enables Two-Dimensional-Paging
  39  * where the hardware walks 2 page tables:
  40  * 1. the guest-virtual to guest-physical
  41  * 2. while doing 1. it walks guest-physical to host-physical
  42  * If the hardware supports that we don't need to do shadow paging.
  43  */
  44 bool tdp_enabled = false;
  45
  46 #undef MMU_DEBUG
  47
  48 #undef AUDIT
  49
  50 #ifdef AUDIT
  51 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
  52 #else
  53 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
  54 #endif
  55
  56 #ifdef MMU_DEBUG
  57
  58 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
  59 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
  60
  61 #else
  62
  63 #define pgprintk(x...) do { } while (0)
  64 #define rmap_printk(x...) do { } while (0)
  65
  66 #endif
  67
  68 #if defined(MMU_DEBUG) || defined(AUDIT)
  69 static int dbg = 0;
  70 module_param(dbg, bool, 0644);
  71 #endif
  72
  73 static int oos_shadow = 1;
  74 module_param(oos_shadow, bool, 0644);
  75
  76 #ifndef MMU_DEBUG
  77 #define ASSERT(x) do { } while (0)
  78 #else
  79 #define ASSERT(x)                                                       \
  80         if (!(x)) {                                                     \
  81                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
  82                        __FILE__, __LINE__, #x);                         \
  83         }
  84 #endif
  85
  86 #define PT_FIRST_AVAIL_BITS_SHIFT 9
  87 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
  88
  89 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
  90
  91 #define PT64_LEVEL_BITS 9
  92
  93 #define PT64_LEVEL_SHIFT(level) \
  94                 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
  95
  96 #define PT64_LEVEL_MASK(level) \
  97                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
  98
  99 #define PT64_INDEX(address, level)\
 100         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
 101
 102
 103 #define PT32_LEVEL_BITS 10
 104
 105 #define PT32_LEVEL_SHIFT(level) \
 106                 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
 107
 108 #define PT32_LEVEL_MASK(level) \
 109                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
 110
 111 #define PT32_INDEX(address, level)\
 112         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
 113
 114
 115 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
 116 #define PT64_DIR_BASE_ADDR_MASK \
 117         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
 118
 119 #define PT32_BASE_ADDR_MASK PAGE_MASK
 120 #define PT32_DIR_BASE_ADDR_MASK \
 121         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
 122
 123 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
 124                         | PT64_NX_MASK)
 125
 126 #define PFERR_PRESENT_MASK (1U << 0)
 127 #define PFERR_WRITE_MASK (1U << 1)
 128 #define PFERR_USER_MASK (1U << 2)
 129 #define PFERR_FETCH_MASK (1U << 4)
 130
 131 #define PT_DIRECTORY_LEVEL 2
 132 #define PT_PAGE_TABLE_LEVEL 1
 133
 134 #define RMAP_EXT 4
 135
 136 #define ACC_EXEC_MASK    1
 137 #define ACC_WRITE_MASK   PT_WRITABLE_MASK
 138 #define ACC_USER_MASK    PT_USER_MASK
 139 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
 140
 141 #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)
 142
 143 struct kvm_rmap_desc {
 144         u64 *shadow_ptes[RMAP_EXT];
 145         struct kvm_rmap_desc *more;
 146 };
 147
 148 struct kvm_shadow_walk {
 149         int (*entry)(struct kvm_shadow_walk *walk, struct kvm_vcpu *vcpu,
 150                      u64 addr, u64 *spte, int level);
 151 };
 152
 153 struct kvm_shadow_walk_iterator {
 154         u64 addr;
 155         hpa_t shadow_addr;
 156         int level;
 157         u64 *sptep;
 158         unsigned index;
 159 };
 160
 161 #define for_each_shadow_entry(_vcpu, _addr, _walker)    \
 162         for (shadow_walk_init(&(_walker), _vcpu, _addr);        \
 163              shadow_walk_okay(&(_walker));                      \
 164              shadow_walk_next(&(_walker)))
 165
 166
 167 struct kvm_unsync_walk {
 168         int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk);
 169 };
 170
 171 typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp);
 172
 173 static struct kmem_cache *pte_chain_cache;
 174 static struct kmem_cache *rmap_desc_cache;
 175 static struct kmem_cache *mmu_page_header_cache;
 176
 177 static u64 __read_mostly shadow_trap_nonpresent_pte;
 178 static u64 __read_mostly shadow_notrap_nonpresent_pte;
 179 static u64 __read_mostly shadow_base_present_pte;
 180 static u64 __read_mostly shadow_nx_mask;
 181 static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
 182 static u64 __read_mostly shadow_user_mask;
 183 static u64 __read_mostly shadow_accessed_mask;
 184 static u64 __read_mostly shadow_dirty_mask;
 185 static u64 __read_mostly shadow_mt_mask;
 186
 187 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 188 {
 189         shadow_trap_nonpresent_pte = trap_pte;
 190         shadow_notrap_nonpresent_pte = notrap_pte;
 191 }
 192 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
 193
 194 void kvm_mmu_set_base_ptes(u64 base_pte)
 195 {
 196         shadow_base_present_pte = base_pte;
 197 }
 198 EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes);
 199
 200 void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
 201                 u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 mt_mask)
 202 {
 203         shadow_user_mask = user_mask;
 204         shadow_accessed_mask = accessed_mask;
 205         shadow_dirty_mask = dirty_mask;
 206         shadow_nx_mask = nx_mask;
 207         shadow_x_mask = x_mask;
 208         shadow_mt_mask = mt_mask;
 209 }
 210 EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
 211
 212 static int is_write_protection(struct kvm_vcpu *vcpu)
 213 {
 214         return vcpu->arch.cr0 & X86_CR0_WP;
 215 }
 216
 217 static int is_cpuid_PSE36(void)
 218 {
 219         return 1;
 220 }
 221
 222 static int is_nx(struct kvm_vcpu *vcpu)
 223 {
 224         return vcpu->arch.shadow_efer & EFER_NX;
 225 }
 226
 227 static int is_present_pte(unsigned long pte)
 228 {
 229         return pte & PT_PRESENT_MASK;
 230 }
 231
 232 static int is_shadow_present_pte(u64 pte)
 233 {
 234         return pte != shadow_trap_nonpresent_pte
 235                 && pte != shadow_notrap_nonpresent_pte;
 236 }
 237
 238 static int is_large_pte(u64 pte)
 239 {
 240         return pte & PT_PAGE_SIZE_MASK;
 241 }
 242
 243 static int is_writeble_pte(unsigned long pte)
 244 {
 245         return pte & PT_WRITABLE_MASK;
 246 }
 247
 248 static int is_dirty_pte(unsigned long pte)
 249 {
 250         return pte & shadow_dirty_mask;
 251 }
 252
 253 static int is_rmap_pte(u64 pte)
 254 {
 255         return is_shadow_present_pte(pte);
 256 }
 257
 258 static pfn_t spte_to_pfn(u64 pte)
 259 {
 260         return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 261 }
 262
 263 static gfn_t pse36_gfn_delta(u32 gpte)
 264 {
 265         int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
 266
 267         return (gpte & PT32_DIR_PSE36_MASK) << shift;
 268 }
 269
 270 static void set_shadow_pte(u64 *sptep, u64 spte)
 271 {
 272 #ifdef CONFIG_X86_64
 273         set_64bit((unsigned long *)sptep, spte);
 274 #else
 275         set_64bit((unsigned long long *)sptep, spte);
 276 #endif
 277 }
 278
 279 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 280                                   struct kmem_cache *base_cache, int min)
 281 {
 282         void *obj;
 283
 284         if (cache->nobjs >= min)
 285                 return 0;
 286         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 287                 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
 288                 if (!obj)
 289                         return -ENOMEM;
 290                 cache->objects[cache->nobjs++] = obj;
 291         }
 292         return 0;
 293 }
 294
 295 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 296 {
 297         while (mc->nobjs)
 298                 kfree(mc->objects[--mc->nobjs]);
 299 }
 300
 301 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
 302                                        int min)
 303 {
 304         struct page *page;
 305
 306         if (cache->nobjs >= min)
 307                 return 0;
 308         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 309                 page = alloc_page(GFP_KERNEL);
 310                 if (!page)
 311                         return -ENOMEM;
 312                 set_page_private(page, 0);
 313                 cache->objects[cache->nobjs++] = page_address(page);
 314         }
 315         return 0;
 316 }
 317
 318 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
 319 {
 320         while (mc->nobjs)
 321                 free_page((unsigned long)mc->objects[--mc->nobjs]);
 322 }
 323
 324 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 325 {
 326         int r;
 327
 328         r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
 329                                    pte_chain_cache, 4);
 330         if (r)
 331                 goto out;
 332         r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
 333                                    rmap_desc_cache, 4);
 334         if (r)
 335                 goto out;
 336         r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
 337         if (r)
 338                 goto out;
 339         r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
 340                                    mmu_page_header_cache, 4);
 341 out:
 342         return r;
 343 }
 344
 345 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 346 {
 347         mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
 348         mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
 349         mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
 350         mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
 351 }
 352
 353 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
 354                                     size_t size)
 355 {
 356         void *p;
 357
 358         BUG_ON(!mc->nobjs);
 359         p = mc->objects[--mc->nobjs];
 360         memset(p, 0, size);
 361         return p;
 362 }
 363
 364 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
 365 {
 366         return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
 367                                       sizeof(struct kvm_pte_chain));
 368 }
 369
 370 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
 371 {
 372         kfree(pc);
 373 }
 374
 375 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
 376 {
 377         return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
 378                                       sizeof(struct kvm_rmap_desc));
 379 }
 380
 381 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 382 {
 383         kfree(rd);
 384 }
 385
 386 /*
 387  * Return the pointer to the largepage write count for a given
 388  * gfn, handling slots that are not large page aligned.
 389  */
 390 static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
 391 {
 392         unsigned long idx;
 393
 394         idx = (gfn / KVM_PAGES_PER_HPAGE) -
 395               (slot->base_gfn / KVM_PAGES_PER_HPAGE);
 396         return &slot->lpage_info[idx].write_count;
 397 }
 398
 399 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
 400 {
 401         int *write_count;
 402
 403         gfn = unalias_gfn(kvm, gfn);
 404         write_count = slot_largepage_idx(gfn,
 405                                          gfn_to_memslot_unaliased(kvm, gfn));
 406         *write_count += 1;
 407 }
 408
 409 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
 410 {
 411         int *write_count;
 412
 413         gfn = unalias_gfn(kvm, gfn);
 414         write_count = slot_largepage_idx(gfn,
 415                                          gfn_to_memslot_unaliased(kvm, gfn));
 416         *write_count -= 1;
 417         WARN_ON(*write_count < 0);
 418 }
 419
 420 static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
 421 {
 422         struct kvm_memory_slot *slot;
 423         int *largepage_idx;
 424
 425         gfn = unalias_gfn(kvm, gfn);
 426         slot = gfn_to_memslot_unaliased(kvm, gfn);
 427         if (slot) {
 428                 largepage_idx = slot_largepage_idx(gfn, slot);
 429                 return *largepage_idx;
 430         }
 431
 432         return 1;
 433 }
 434
 435 static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
 436 {
 437         struct vm_area_struct *vma;
 438         unsigned long addr;
 439         int ret = 0;
 440
 441         addr = gfn_to_hva(kvm, gfn);
 442         if (kvm_is_error_hva(addr))
 443                 return ret;
 444
 445         down_read(&current->mm->mmap_sem);
 446         vma = find_vma(current->mm, addr);
 447         if (vma && is_vm_hugetlb_page(vma))
 448                 ret = 1;
 449         up_read(&current->mm->mmap_sem);
 450
 451         return ret;
 452 }
 453
 454 static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 455 {
 456         struct kvm_memory_slot *slot;
 457
 458         if (has_wrprotected_page(vcpu->kvm, large_gfn))
 459                 return 0;
 460
 461         if (!host_largepage_backed(vcpu->kvm, large_gfn))
 462                 return 0;
 463
 464         slot = gfn_to_memslot(vcpu->kvm, large_gfn);
 465         if (slot && slot->dirty_bitmap)
 466                 return 0;
 467
 468         return 1;
 469 }
 470
 471 /*
 472  * Take gfn and return the reverse mapping to it.
 473  * Note: gfn must be unaliased before this function get called
 474  */
 475
 476 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int lpage)
 477 {
 478         struct kvm_memory_slot *slot;
 479         unsigned long idx;
 480
 481         slot = gfn_to_memslot(kvm, gfn);
 482         if (!lpage)
 483                 return &slot->rmap[gfn - slot->base_gfn];
 484
 485         idx = (gfn / KVM_PAGES_PER_HPAGE) -
 486               (slot->base_gfn / KVM_PAGES_PER_HPAGE);
 487
 488         return &slot->lpage_info[idx].rmap_pde;
 489 }
 490
 491 /*
 492  * Reverse mapping data structures:
 493  *
 494  * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
 495  * that points to page_address(page).
 496  *
 497  * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
 498  * containing more mappings.
 499  */
 500 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn, int lpage)
 501 {
 502         struct kvm_mmu_page *sp;
 503         struct kvm_rmap_desc *desc;
 504         unsigned long *rmapp;
 505         int i;
 506
 507         if (!is_rmap_pte(*spte))
 508                 return;
 509         gfn = unalias_gfn(vcpu->kvm, gfn);
 510         sp = page_header(__pa(spte));
 511         sp->gfns[spte - sp->spt] = gfn;
 512         rmapp = gfn_to_rmap(vcpu->kvm, gfn, lpage);
 513         if (!*rmapp) {
 514                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
 515                 *rmapp = (unsigned long)spte;
 516         } else if (!(*rmapp & 1)) {
 517                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
 518                 desc = mmu_alloc_rmap_desc(vcpu);
 519                 desc->shadow_ptes[0] = (u64 *)*rmapp;
 520                 desc->shadow_ptes[1] = spte;
 521                 *rmapp = (unsigned long)desc | 1;
 522         } else {
 523                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
 524                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 525                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
 526                         desc = desc->more;
 527                 if (desc->shadow_ptes[RMAP_EXT-1]) {
 528                         desc->more = mmu_alloc_rmap_desc(vcpu);
 529                         desc = desc->more;
 530                 }
 531                 for (i = 0; desc->shadow_ptes[i]; ++i)
 532                         ;
 533                 desc->shadow_ptes[i] = spte;
 534         }
 535 }
 536
 537 static void rmap_desc_remove_entry(unsigned long *rmapp,
 538                                    struct kvm_rmap_desc *desc,
 539                                    int i,
 540                                    struct kvm_rmap_desc *prev_desc)
 541 {
 542         int j;
 543
 544         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
 545                 ;
 546         desc->shadow_ptes[i] = desc->shadow_ptes[j];
 547         desc->shadow_ptes[j] = NULL;
 548         if (j != 0)
 549                 return;
 550         if (!prev_desc && !desc->more)
 551                 *rmapp = (unsigned long)desc->shadow_ptes[0];
 552         else
 553                 if (prev_desc)
 554                         prev_desc->more = desc->more;
 555                 else
 556                         *rmapp = (unsigned long)desc->more | 1;
 557         mmu_free_rmap_desc(desc);
 558 }
 559
 560 static void rmap_remove(struct kvm *kvm, u64 *spte)
 561 {
 562         struct kvm_rmap_desc *desc;
 563         struct kvm_rmap_desc *prev_desc;
 564         struct kvm_mmu_page *sp;
 565         pfn_t pfn;
 566         unsigned long *rmapp;
 567         int i;
 568
 569         if (!is_rmap_pte(*spte))
 570                 return;
 571         sp = page_header(__pa(spte));
 572         pfn = spte_to_pfn(*spte);
 573         if (*spte & shadow_accessed_mask)
 574                 kvm_set_pfn_accessed(pfn);
 575         if (is_writeble_pte(*spte))
 576                 kvm_release_pfn_dirty(pfn);
 577         else
 578                 kvm_release_pfn_clean(pfn);
 579         rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], is_large_pte(*spte));
 580         if (!*rmapp) {
 581                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
 582                 BUG();
 583         } else if (!(*rmapp & 1)) {
 584                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
 585                 if ((u64 *)*rmapp != spte) {
 586                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
 587                                spte, *spte);
 588                         BUG();
 589                 }
 590                 *rmapp = 0;
 591         } else {
 592                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
 593                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 594                 prev_desc = NULL;
 595                 while (desc) {
 596                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
 597                                 if (desc->shadow_ptes[i] == spte) {
 598                                         rmap_desc_remove_entry(rmapp,
 599                                                                desc, i,
 600                                                                prev_desc);
 601                                         return;
 602                                 }
 603                         prev_desc = desc;
 604                         desc = desc->more;
 605                 }
 606                 BUG();
 607         }
 608 }
 609
 610 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
 611 {
 612         struct kvm_rmap_desc *desc;
 613         struct kvm_rmap_desc *prev_desc;
 614         u64 *prev_spte;
 615         int i;
 616
 617         if (!*rmapp)
 618                 return NULL;
 619         else if (!(*rmapp & 1)) {
 620                 if (!spte)
 621                         return (u64 *)*rmapp;
 622                 return NULL;
 623         }
 624         desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 625         prev_desc = NULL;
 626         prev_spte = NULL;
 627         while (desc) {
 628                 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
 629                         if (prev_spte == spte)
 630                                 return desc->shadow_ptes[i];
 631                         prev_spte = desc->shadow_ptes[i];
 632                 }
 633                 desc = desc->more;
 634         }
 635         return NULL;
 636 }
 637
 638 static int rmap_write_protect(struct kvm *kvm, u64 gfn)
 639 {
 640         unsigned long *rmapp;
 641         u64 *spte;
 642         int write_protected = 0;
 643
 644         gfn = unalias_gfn(kvm, gfn);
 645         rmapp = gfn_to_rmap(kvm, gfn, 0);
 646
 647         spte = rmap_next(kvm, rmapp, NULL);
 648         while (spte) {
 649                 BUG_ON(!spte);
 650                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 651                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 652                 if (is_writeble_pte(*spte)) {
 653                         set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
 654                         write_protected = 1;
 655                 }
 656                 spte = rmap_next(kvm, rmapp, spte);
 657         }
 658         if (write_protected) {
 659                 pfn_t pfn;
 660
 661                 spte = rmap_next(kvm, rmapp, NULL);
 662                 pfn = spte_to_pfn(*spte);
 663                 kvm_set_pfn_dirty(pfn);
 664         }
 665
 666         /* check for huge page mappings */
 667         rmapp = gfn_to_rmap(kvm, gfn, 1);
 668         spte = rmap_next(kvm, rmapp, NULL);
 669         while (spte) {
 670                 BUG_ON(!spte);
 671                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 672                 BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
 673                 pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
 674                 if (is_writeble_pte(*spte)) {
 675                         rmap_remove(kvm, spte);
 676                         --kvm->stat.lpages;
 677                         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
 678                         spte = NULL;
 679                         write_protected = 1;
 680                 }
 681                 spte = rmap_next(kvm, rmapp, spte);
 682         }
 683
 684         return write_protected;
 685 }
 686
 687 static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
 688 {
 689         u64 *spte;
 690         int need_tlb_flush = 0;
 691
 692         while ((spte = rmap_next(kvm, rmapp, NULL))) {
 693                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 694                 rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
 695                 rmap_remove(kvm, spte);
 696                 set_shadow_pte(spte, shadow_trap_nonpresent_pte);
 697                 need_tlb_flush = 1;
 698         }
 699         return need_tlb_flush;
 700 }
 701
 702 static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
 703                           int (*handler)(struct kvm *kvm, unsigned long *rmapp))
 704 {
 705         int i;
 706         int retval = 0;
 707
 708         /*
 709          * If mmap_sem isn't taken, we can look the memslots with only
 710          * the mmu_lock by skipping over the slots with userspace_addr == 0.
 711          */
 712         for (i = 0; i < kvm->nmemslots; i++) {
 713                 struct kvm_memory_slot *memslot = &kvm->memslots[i];
 714                 unsigned long start = memslot->userspace_addr;
 715                 unsigned long end;
 716
 717                 /* mmu_lock protects userspace_addr */
 718                 if (!start)
 719                         continue;
 720
 721                 end = start + (memslot->npages << PAGE_SHIFT);
 722                 if (hva >= start && hva < end) {
 723                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
 724                         retval |= handler(kvm, &memslot->rmap[gfn_offset]);
 725                         retval |= handler(kvm,
 726                                           &memslot->lpage_info[
 727                                                   gfn_offset /
 728                                                   KVM_PAGES_PER_HPAGE].rmap_pde);
 729                 }
 730         }
 731
 732         return retval;
 733 }
 734
 735 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
 736 {
 737         return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
 738 }
 739
 740 static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
 741 {
 742         u64 *spte;
 743         int young = 0;
 744
 745         /* always return old for EPT */
 746         if (!shadow_accessed_mask)
 747                 return 0;
 748
 749         spte = rmap_next(kvm, rmapp, NULL);
 750         while (spte) {
 751                 int _young;
 752                 u64 _spte = *spte;
 753                 BUG_ON(!(_spte & PT_PRESENT_MASK));
 754                 _young = _spte & PT_ACCESSED_MASK;
 755                 if (_young) {
 756                         young = 1;
 757                         clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
 758                 }
 759                 spte = rmap_next(kvm, rmapp, spte);
 760         }
 761         return young;
 762 }
 763
 764 int kvm_age_hva(struct kvm *kvm, unsigned long hva)
 765 {
 766         return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
 767 }
 768
 769 #ifdef MMU_DEBUG
 770 static int is_empty_shadow_page(u64 *spt)
 771 {
 772         u64 *pos;
 773         u64 *end;
 774
 775         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
 776                 if (is_shadow_present_pte(*pos)) {
 777                         printk(KERN_ERR "%s: %p %llx\n", __func__,
 778                                pos, *pos);
 779                         return 0;
 780                 }
 781         return 1;
 782 }
 783 #endif
 784
 785 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 786 {
 787         ASSERT(is_empty_shadow_page(sp->spt));
 788         list_del(&sp->link);
 789         __free_page(virt_to_page(sp->spt));
 790         __free_page(virt_to_page(sp->gfns));
 791         kfree(sp);
 792         ++kvm->arch.n_free_mmu_pages;
 793 }
 794
 795 static unsigned kvm_page_table_hashfn(gfn_t gfn)
 796 {
 797         return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1);
 798 }
 799
 800 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 801                                                u64 *parent_pte)
 802 {
 803         struct kvm_mmu_page *sp;
 804
 805         sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
 806         sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 807         sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 808         set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 809         list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
 810         INIT_LIST_HEAD(&sp->oos_link);
 811         ASSERT(is_empty_shadow_page(sp->spt));
 812         bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
 813         sp->multimapped = 0;
 814         sp->parent_pte = parent_pte;
 815         --vcpu->kvm->arch.n_free_mmu_pages;
 816         return sp;
 817 }
 818
 819 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
 820                                     struct kvm_mmu_page *sp, u64 *parent_pte)
 821 {
 822         struct kvm_pte_chain *pte_chain;
 823         struct hlist_node *node;
 824         int i;
 825
 826         if (!parent_pte)
 827                 return;
 828         if (!sp->multimapped) {
 829                 u64 *old = sp->parent_pte;
 830
 831                 if (!old) {
 832                         sp->parent_pte = parent_pte;
 833                         return;
 834                 }
 835                 sp->multimapped = 1;
 836                 pte_chain = mmu_alloc_pte_chain(vcpu);
 837                 INIT_HLIST_HEAD(&sp->parent_ptes);
 838                 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 839                 pte_chain->parent_ptes[0] = old;
 840         }
 841         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
 842                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
 843                         continue;
 844                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
 845                         if (!pte_chain->parent_ptes[i]) {
 846                                 pte_chain->parent_ptes[i] = parent_pte;
 847                                 return;
 848                         }
 849         }
 850         pte_chain = mmu_alloc_pte_chain(vcpu);
 851         BUG_ON(!pte_chain);
 852         hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 853         pte_chain->parent_ptes[0] = parent_pte;
 854 }
 855
 856 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
 857                                        u64 *parent_pte)
 858 {
 859         struct kvm_pte_chain *pte_chain;
 860         struct hlist_node *node;
 861         int i;
 862
 863         if (!sp->multimapped) {
 864                 BUG_ON(sp->parent_pte != parent_pte);
 865                 sp->parent_pte = NULL;
 866                 return;
 867         }
 868         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
 869                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 870                         if (!pte_chain->parent_ptes[i])
 871                                 break;
 872                         if (pte_chain->parent_ptes[i] != parent_pte)
 873                                 continue;
 874                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
 875                                 && pte_chain->parent_ptes[i + 1]) {
 876                                 pte_chain->parent_ptes[i]
 877                                         = pte_chain->parent_ptes[i + 1];
 878                                 ++i;
 879                         }
 880                         pte_chain->parent_ptes[i] = NULL;
 881                         if (i == 0) {
 882                                 hlist_del(&pte_chain->link);
 883                                 mmu_free_pte_chain(pte_chain);
 884                                 if (hlist_empty(&sp->parent_ptes)) {
 885                                         sp->multimapped = 0;
 886                                         sp->parent_pte = NULL;
 887                                 }
 888                         }
 889                         return;
 890                 }
 891         BUG();
 892 }
 893
 894
 895 static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 896                             mmu_parent_walk_fn fn)
 897 {
 898         struct kvm_pte_chain *pte_chain;
 899         struct hlist_node *node;
 900         struct kvm_mmu_page *parent_sp;
 901         int i;
 902
 903         if (!sp->multimapped && sp->parent_pte) {
 904                 parent_sp = page_header(__pa(sp->parent_pte));
 905                 fn(vcpu, parent_sp);
 906                 mmu_parent_walk(vcpu, parent_sp, fn);
 907                 return;
 908         }
 909         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
 910                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 911                         if (!pte_chain->parent_ptes[i])
 912                                 break;
 913                         parent_sp = page_header(__pa(pte_chain->parent_ptes[i]));
 914                         fn(vcpu, parent_sp);
 915                         mmu_parent_walk(vcpu, parent_sp, fn);
 916                 }
 917 }
 918
 919 static void kvm_mmu_update_unsync_bitmap(u64 *spte)
 920 {
 921         unsigned int index;
 922         struct kvm_mmu_page *sp = page_header(__pa(spte));
 923
 924         index = spte - sp->spt;
 925         if (!__test_and_set_bit(index, sp->unsync_child_bitmap))
 926                 sp->unsync_children++;
 927         WARN_ON(!sp->unsync_children);
 928 }
 929
 930 static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp)
 931 {
 932         struct kvm_pte_chain *pte_chain;
 933         struct hlist_node *node;
 934         int i;
 935
 936         if (!sp->parent_pte)
 937                 return;
 938
 939         if (!sp->multimapped) {
 940                 kvm_mmu_update_unsync_bitmap(sp->parent_pte);
 941                 return;
 942         }
 943
 944         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
 945                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 946                         if (!pte_chain->parent_ptes[i])
 947                                 break;
 948                         kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]);
 949                 }
 950 }
 951
 952 static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
 953 {
 954         kvm_mmu_update_parents_unsync(sp);
 955         return 1;
 956 }
 957
 958 static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu,
 959                                         struct kvm_mmu_page *sp)
 960 {
 961         mmu_parent_walk(vcpu, sp, unsync_walk_fn);
 962         kvm_mmu_update_parents_unsync(sp);
 963 }
 964
 965 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
 966                                     struct kvm_mmu_page *sp)
 967 {
 968         int i;
 969
 970         for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
 971                 sp->spt[i] = shadow_trap_nonpresent_pte;
 972 }
 973
 974 static int nonpaging_sync_page(struct kvm_vcpu *vcpu,
 975                                struct kvm_mmu_page *sp)
 976 {
 977         return 1;
 978 }
 979
 980 static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
 981 {
 982 }
 983
 984 #define KVM_PAGE_ARRAY_NR 16
 985
 986 struct kvm_mmu_pages {
 987         struct mmu_page_and_offset {
 988                 struct kvm_mmu_page *sp;
 989                 unsigned int idx;
 990         } page[KVM_PAGE_ARRAY_NR];
 991         unsigned int nr;
 992 };
 993
 994 #define for_each_unsync_children(bitmap, idx)           \
 995         for (idx = find_first_bit(bitmap, 512);         \
 996              idx < 512;                                 \
 997              idx = find_next_bit(bitmap, 512, idx+1))
 998
 999 int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp,
1000                    int idx)
1001 {
1002         int i;
1003
1004         if (sp->unsync)
1005                 for (i=0; i < pvec->nr; i++)
1006                         if (pvec->page[i].sp == sp)
1007                                 return 0;
1008
1009         pvec->page[pvec->nr].sp = sp;
1010         pvec->page[pvec->nr].idx = idx;
1011         pvec->nr++;
1012         return (pvec->nr == KVM_PAGE_ARRAY_NR);
1013 }
1014
1015 static int __mmu_unsync_walk(struct kvm_mmu_page *sp,
1016                            struct kvm_mmu_pages *pvec)
1017 {
1018         int i, ret, nr_unsync_leaf = 0;
1019
1020         for_each_unsync_children(sp->unsync_child_bitmap, i) {
1021                 u64 ent = sp->spt[i];
1022
1023                 if (is_shadow_present_pte(ent) && !is_large_pte(ent)) {
1024                         struct kvm_mmu_page *child;
1025                         child = page_header(ent & PT64_BASE_ADDR_MASK);
1026
1027                         if (child->unsync_children) {
1028                                 if (mmu_pages_add(pvec, child, i))
1029                                         return -ENOSPC;
1030
1031                                 ret = __mmu_unsync_walk(child, pvec);
1032                                 if (!ret)
1033                                         __clear_bit(i, sp->unsync_child_bitmap);
1034                                 else if (ret > 0)
1035                                         nr_unsync_leaf += ret;
1036                                 else
1037                                         return ret;
1038                         }
1039
1040                         if (child->unsync) {
1041                                 nr_unsync_leaf++;
1042                                 if (mmu_pages_add(pvec, child, i))
1043                                         return -ENOSPC;
1044                         }
1045                 }
1046         }
1047
1048         if (find_first_bit(sp->unsync_child_bitmap, 512) == 512)
1049                 sp->unsync_children = 0;
1050
1051         return nr_unsync_leaf;
1052 }
1053
1054 static int mmu_unsync_walk(struct kvm_mmu_page *sp,
1055                            struct kvm_mmu_pages *pvec)
1056 {
1057         if (!sp->unsync_children)
1058                 return 0;
1059
1060         mmu_pages_add(pvec, sp, 0);
1061         return __mmu_unsync_walk(sp, pvec);
1062 }
1063
1064 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
1065 {
1066         unsigned index;
1067         struct hlist_head *bucket;
1068         struct kvm_mmu_page *sp;
1069         struct hlist_node *node;
1070
1071         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1072         index = kvm_page_table_hashfn(gfn);
1073         bucket = &kvm->arch.mmu_page_hash[index];
1074         hlist_for_each_entry(sp, node, bucket, hash_link)
1075                 if (sp->gfn == gfn && !sp->role.metaphysical
1076                     && !sp->role.invalid) {
1077                         pgprintk("%s: found role %x\n",
1078                                  __func__, sp->role.word);
1079                         return sp;
1080                 }
1081         return NULL;
1082 }
1083
1084 static void kvm_unlink_unsync_global(struct kvm *kvm, struct kvm_mmu_page *sp)
1085 {
1086         list_del(&sp->oos_link);
1087         --kvm->stat.mmu_unsync_global;
1088 }
1089
1090 static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1091 {
1092         WARN_ON(!sp->unsync);
1093         sp->unsync = 0;
1094         if (sp->global)
1095                 kvm_unlink_unsync_global(kvm, sp);
1096         --kvm->stat.mmu_unsync;
1097 }
1098
1099 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp);
1100
1101 static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1102 {
1103         if (sp->role.glevels != vcpu->arch.mmu.root_level) {
1104                 kvm_mmu_zap_page(vcpu->kvm, sp);
1105                 return 1;
1106         }
1107
1108         if (rmap_write_protect(vcpu->kvm, sp->gfn))
1109                 kvm_flush_remote_tlbs(vcpu->kvm);
1110         kvm_unlink_unsync_page(vcpu->kvm, sp);
1111         if (vcpu->arch.mmu.sync_page(vcpu, sp)) {
1112                 kvm_mmu_zap_page(vcpu->kvm, sp);
1113                 return 1;
1114         }
1115
1116         kvm_mmu_flush_tlb(vcpu);
1117         return 0;
1118 }
1119
1120 struct mmu_page_path {
1121         struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1];
1122         unsigned int idx[PT64_ROOT_LEVEL-1];
1123 };
1124
1125 #define for_each_sp(pvec, sp, parents, i)                       \
1126                 for (i = mmu_pages_next(&pvec, &parents, -1),   \
1127                         sp = pvec.page[i].sp;                   \
1128                         i < pvec.nr && ({ sp = pvec.page[i].sp; 1;});   \
1129                         i = mmu_pages_next(&pvec, &parents, i))
1130
1131 int mmu_pages_next(struct kvm_mmu_pages *pvec, struct mmu_page_path *parents,
1132                    int i)
1133 {
1134         int n;
1135
1136         for (n = i+1; n < pvec->nr; n++) {
1137                 struct kvm_mmu_page *sp = pvec->page[n].sp;
1138
1139                 if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1140                         parents->idx[0] = pvec->page[n].idx;
1141                         return n;
1142                 }
1143
1144                 parents->parent[sp->role.level-2] = sp;
1145                 parents->idx[sp->role.level-1] = pvec->page[n].idx;
1146         }
1147
1148         return n;
1149 }
1150
1151 void mmu_pages_clear_parents(struct mmu_page_path *parents)
1152 {
1153         struct kvm_mmu_page *sp;
1154         unsigned int level = 0;
1155
1156         do {
1157                 unsigned int idx = parents->idx[level];
1158
1159                 sp = parents->parent[level];
1160                 if (!sp)
1161                         return;
1162
1163                 --sp->unsync_children;
1164                 WARN_ON((int)sp->unsync_children < 0);
1165                 __clear_bit(idx, sp->unsync_child_bitmap);
1166                 level++;
1167         } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children);
1168 }
1169
1170 static void kvm_mmu_pages_init(struct kvm_mmu_page *parent,
1171                                struct mmu_page_path *parents,
1172                                struct kvm_mmu_pages *pvec)
1173 {
1174         parents->parent[parent->role.level-1] = NULL;
1175         pvec->nr = 0;
1176 }
1177
1178 static void mmu_sync_children(struct kvm_vcpu *vcpu,
1179                               struct kvm_mmu_page *parent)
1180 {
1181         int i;
1182         struct kvm_mmu_page *sp;
1183         struct mmu_page_path parents;
1184         struct kvm_mmu_pages pages;
1185
1186         kvm_mmu_pages_init(parent, &parents, &pages);
1187         while (mmu_unsync_walk(parent, &pages)) {
1188                 int protected = 0;
1189
1190                 for_each_sp(pages, sp, parents, i)
1191                         protected |= rmap_write_protect(vcpu->kvm, sp->gfn);
1192
1193                 if (protected)
1194                         kvm_flush_remote_tlbs(vcpu->kvm);
1195
1196                 for_each_sp(pages, sp, parents, i) {
1197                         kvm_sync_page(vcpu, sp);
1198                         mmu_pages_clear_parents(&parents);
1199                 }
1200                 cond_resched_lock(&vcpu->kvm->mmu_lock);
1201                 kvm_mmu_pages_init(parent, &parents, &pages);
1202         }
1203 }
1204
1205 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
1206                                              gfn_t gfn,
1207                                              gva_t gaddr,
1208                                              unsigned level,
1209                                              int metaphysical,
1210                                              unsigned access,
1211                                              u64 *parent_pte)
1212 {
1213         union kvm_mmu_page_role role;
1214         unsigned index;
1215         unsigned quadrant;
1216         struct hlist_head *bucket;
1217         struct kvm_mmu_page *sp;
1218         struct hlist_node *node, *tmp;
1219
1220         role = vcpu->arch.mmu.base_role;
1221         role.level = level;
1222         role.metaphysical = metaphysical;
1223         role.access = access;
1224         if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
1225                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
1226                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
1227                 role.quadrant = quadrant;
1228         }
1229         pgprintk("%s: looking gfn %lx role %x\n", __func__,
1230                  gfn, role.word);
1231         index = kvm_page_table_hashfn(gfn);
1232         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1233         hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link)
1234                 if (sp->gfn == gfn) {
1235                         if (sp->unsync)
1236                                 if (kvm_sync_page(vcpu, sp))
1237                                         continue;
1238
1239                         if (sp->role.word != role.word)
1240                                 continue;
1241
1242                         mmu_page_add_parent_pte(vcpu, sp, parent_pte);
1243                         if (sp->unsync_children) {
1244                                 set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
1245                                 kvm_mmu_mark_parents_unsync(vcpu, sp);
1246                         }
1247                         pgprintk("%s: found\n", __func__);
1248                         return sp;
1249                 }
1250         ++vcpu->kvm->stat.mmu_cache_miss;
1251         sp = kvm_mmu_alloc_page(vcpu, parent_pte);
1252         if (!sp)
1253                 return sp;
1254         pgprintk("%s: adding gfn %lx role %x\n", __func__, gfn, role.word);
1255         sp->gfn = gfn;
1256         sp->role = role;
1257         sp->global = role.cr4_pge;
1258         hlist_add_head(&sp->hash_link, bucket);
1259         if (!metaphysical) {
1260                 if (rmap_write_protect(vcpu->kvm, gfn))
1261                         kvm_flush_remote_tlbs(vcpu->kvm);
1262                 account_shadowed(vcpu->kvm, gfn);
1263         }
1264         if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte)
1265                 vcpu->arch.mmu.prefetch_page(vcpu, sp);
1266         else
1267                 nonpaging_prefetch_page(vcpu, sp);
1268         return sp;
1269 }
1270
1271 static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator,
1272                              struct kvm_vcpu *vcpu, u64 addr)
1273 {
1274         iterator->addr = addr;
1275         iterator->shadow_addr = vcpu->arch.mmu.root_hpa;
1276         iterator->level = vcpu->arch.mmu.shadow_root_level;
1277         if (iterator->level == PT32E_ROOT_LEVEL) {
1278                 iterator->shadow_addr
1279                         = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
1280                 iterator->shadow_addr &= PT64_BASE_ADDR_MASK;
1281                 --iterator->level;
1282                 if (!iterator->shadow_addr)
1283                         iterator->level = 0;
1284         }
1285 }
1286
1287 static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator)
1288 {
1289         if (iterator->level < PT_PAGE_TABLE_LEVEL)
1290                 return false;
1291         iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level);
1292         iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index;
1293         return true;
1294 }
1295
1296 static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator)
1297 {
1298         iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK;
1299         --iterator->level;
1300 }
1301
1302 static int walk_shadow(struct kvm_shadow_walk *walker,
1303                        struct kvm_vcpu *vcpu, u64 addr)
1304 {
1305         struct kvm_shadow_walk_iterator iterator;
1306         int r;
1307
1308         for_each_shadow_entry(vcpu, addr, iterator) {
1309                 r = walker->entry(walker, vcpu, addr,
1310                                   iterator.sptep, iterator.level);
1311                 if (r)
1312                         return r;
1313         }
1314         return 0;
1315 }
1316
1317 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
1318                                          struct kvm_mmu_page *sp)
1319 {
1320         unsigned i;
1321         u64 *pt;
1322         u64 ent;
1323
1324         pt = sp->spt;
1325
1326         if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
1327                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1328                         if (is_shadow_present_pte(pt[i]))
1329                                 rmap_remove(kvm, &pt[i]);
1330                         pt[i] = shadow_trap_nonpresent_pte;
1331                 }
1332                 return;
1333         }
1334
1335         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1336                 ent = pt[i];
1337
1338                 if (is_shadow_present_pte(ent)) {
1339                         if (!is_large_pte(ent)) {
1340                                 ent &= PT64_BASE_ADDR_MASK;
1341                                 mmu_page_remove_parent_pte(page_header(ent),
1342                                                            &pt[i]);
1343                         } else {
1344                                 --kvm->stat.lpages;
1345                                 rmap_remove(kvm, &pt[i]);
1346                         }
1347                 }
1348                 pt[i] = shadow_trap_nonpresent_pte;
1349         }
1350 }
1351
1352 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
1353 {
1354         mmu_page_remove_parent_pte(sp, parent_pte);
1355 }
1356
1357 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
1358 {
1359         int i;
1360
1361         for (i = 0; i < KVM_MAX_VCPUS; ++i)
1362                 if (kvm->vcpus[i])
1363                         kvm->vcpus[i]->arch.last_pte_updated = NULL;
1364 }
1365
1366 static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp)
1367 {
1368         u64 *parent_pte;
1369
1370         while (sp->multimapped || sp->parent_pte) {
1371                 if (!sp->multimapped)
1372                         parent_pte = sp->parent_pte;
1373                 else {
1374                         struct kvm_pte_chain *chain;
1375
1376                         chain = container_of(sp->parent_ptes.first,
1377                                              struct kvm_pte_chain, link);
1378                         parent_pte = chain->parent_ptes[0];
1379                 }
1380                 BUG_ON(!parent_pte);
1381                 kvm_mmu_put_page(sp, parent_pte);
1382                 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
1383         }
1384 }
1385
1386 static int mmu_zap_unsync_children(struct kvm *kvm,
1387                                    struct kvm_mmu_page *parent)
1388 {
1389         int i, zapped = 0;
1390         struct mmu_page_path parents;
1391         struct kvm_mmu_pages pages;
1392
1393         if (parent->role.level == PT_PAGE_TABLE_LEVEL)
1394                 return 0;
1395
1396         kvm_mmu_pages_init(parent, &parents, &pages);
1397         while (mmu_unsync_walk(parent, &pages)) {
1398                 struct kvm_mmu_page *sp;
1399
1400                 for_each_sp(pages, sp, parents, i) {
1401                         kvm_mmu_zap_page(kvm, sp);
1402                         mmu_pages_clear_parents(&parents);
1403                 }
1404                 zapped += pages.nr;
1405                 kvm_mmu_pages_init(parent, &parents, &pages);
1406         }
1407
1408         return zapped;
1409 }
1410
1411 static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
1412 {
1413         int ret;
1414         ++kvm->stat.mmu_shadow_zapped;
1415         ret = mmu_zap_unsync_children(kvm, sp);
1416         kvm_mmu_page_unlink_children(kvm, sp);
1417         kvm_mmu_unlink_parents(kvm, sp);
1418         kvm_flush_remote_tlbs(kvm);
1419         if (!sp->role.invalid && !sp->role.metaphysical)
1420                 unaccount_shadowed(kvm, sp->gfn);
1421         if (sp->unsync)
1422                 kvm_unlink_unsync_page(kvm, sp);
1423         if (!sp->root_count) {
1424                 hlist_del(&sp->hash_link);
1425                 kvm_mmu_free_page(kvm, sp);
1426         } else {
1427                 sp->role.invalid = 1;
1428                 list_move(&sp->link, &kvm->arch.active_mmu_pages);
1429                 kvm_reload_remote_mmus(kvm);
1430         }
1431         kvm_mmu_reset_last_pte_updated(kvm);
1432         return ret;
1433 }
1434
1435 /*
1436  * Changing the number of mmu pages allocated to the vm
1437  * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
1438  */
1439 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
1440 {
1441         /*
1442          * If we set the number of mmu pages to be smaller be than the
1443          * number of actived pages , we must to free some mmu pages before we
1444          * change the value
1445          */
1446
1447         if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
1448             kvm_nr_mmu_pages) {
1449                 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
1450                                        - kvm->arch.n_free_mmu_pages;
1451
1452                 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
1453                         struct kvm_mmu_page *page;
1454
1455                         page = container_of(kvm->arch.active_mmu_pages.prev,
1456                                             struct kvm_mmu_page, link);
1457                         kvm_mmu_zap_page(kvm, page);
1458                         n_used_mmu_pages--;
1459                 }
1460                 kvm->arch.n_free_mmu_pages = 0;
1461         }
1462         else
1463                 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
1464                                          - kvm->arch.n_alloc_mmu_pages;
1465
1466         kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
1467 }
1468
1469 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
1470 {
1471         unsigned index;
1472         struct hlist_head *bucket;
1473         struct kvm_mmu_page *sp;
1474         struct hlist_node *node, *n;
1475         int r;
1476
1477         pgprintk("%s: looking for gfn %lx\n", __func__, gfn);
1478         r = 0;
1479         index = kvm_page_table_hashfn(gfn);
1480         bucket = &kvm->arch.mmu_page_hash[index];
1481         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
1482                 if (sp->gfn == gfn && !sp->role.metaphysical) {
1483                         pgprintk("%s: gfn %lx role %x\n", __func__, gfn,
1484                                  sp->role.word);
1485                         r = 1;
1486                         if (kvm_mmu_zap_page(kvm, sp))
1487                                 n = bucket->first;
1488                 }
1489         return r;
1490 }
1491
1492 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
1493 {
1494         struct kvm_mmu_page *sp;
1495
1496         while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
1497                 pgprintk("%s: zap %lx %x\n", __func__, gfn, sp->role.word);
1498                 kvm_mmu_zap_page(kvm, sp);
1499         }
1500 }
1501
1502 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
1503 {
1504         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
1505         struct kvm_mmu_page *sp = page_header(__pa(pte));
1506
1507         __set_bit(slot, sp->slot_bitmap);
1508 }
1509
1510 static void mmu_convert_notrap(struct kvm_mmu_page *sp)
1511 {
1512         int i;
1513         u64 *pt = sp->spt;
1514
1515         if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte)
1516                 return;
1517
1518         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1519                 if (pt[i] == shadow_notrap_nonpresent_pte)
1520                         set_shadow_pte(&pt[i], shadow_trap_nonpresent_pte);
1521         }
1522 }
1523
1524 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
1525 {
1526         struct page *page;
1527
1528         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1529
1530         if (gpa == UNMAPPED_GVA)
1531                 return NULL;
1532
1533         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1534
1535         return page;
1536 }
1537
1538 /*
1539  * The function is based on mtrr_type_lookup() in
1540  * arch/x86/kernel/cpu/mtrr/generic.c
1541  */
1542 static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
1543                          u64 start, u64 end)
1544 {
1545         int i;
1546         u64 base, mask;
1547         u8 prev_match, curr_match;
1548         int num_var_ranges = KVM_NR_VAR_MTRR;
1549
1550         if (!mtrr_state->enabled)
1551                 return 0xFF;
1552
1553         /* Make end inclusive end, instead of exclusive */
1554         end--;
1555
1556         /* Look in fixed ranges. Just return the type as per start */
1557         if (mtrr_state->have_fixed && (start < 0x100000)) {
1558                 int idx;
1559
1560                 if (start < 0x80000) {
1561                         idx = 0;
1562                         idx += (start >> 16);
1563                         return mtrr_state->fixed_ranges[idx];
1564                 } else if (start < 0xC0000) {
1565                         idx = 1 * 8;
1566                         idx += ((start - 0x80000) >> 14);
1567                         return mtrr_state->fixed_ranges[idx];
1568                 } else if (start < 0x1000000) {
1569                         idx = 3 * 8;
1570                         idx += ((start - 0xC0000) >> 12);
1571                         return mtrr_state->fixed_ranges[idx];
1572                 }
1573         }
1574
1575         /*
1576          * Look in variable ranges
1577          * Look of multiple ranges matching this address and pick type
1578          * as per MTRR precedence
1579          */
1580         if (!(mtrr_state->enabled & 2))
1581                 return mtrr_state->def_type;
1582
1583         prev_match = 0xFF;
1584         for (i = 0; i < num_var_ranges; ++i) {
1585                 unsigned short start_state, end_state;
1586
1587                 if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11)))
1588                         continue;
1589
1590                 base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) +
1591                        (mtrr_state->var_ranges[i].base_lo & PAGE_MASK);
1592                 mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) +
1593                        (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK);
1594
1595                 start_state = ((start & mask) == (base & mask));
1596                 end_state = ((end & mask) == (base & mask));
1597                 if (start_state != end_state)
1598                         return 0xFE;
1599
1600                 if ((start & mask) != (base & mask))
1601                         continue;
1602
1603                 curr_match = mtrr_state->var_ranges[i].base_lo & 0xff;
1604                 if (prev_match == 0xFF) {
1605                         prev_match = curr_match;
1606                         continue;
1607                 }
1608
1609                 if (prev_match == MTRR_TYPE_UNCACHABLE ||
1610                     curr_match == MTRR_TYPE_UNCACHABLE)
1611                         return MTRR_TYPE_UNCACHABLE;
1612
1613                 if ((prev_match == MTRR_TYPE_WRBACK &&
1614                      curr_match == MTRR_TYPE_WRTHROUGH) ||
1615                     (prev_match == MTRR_TYPE_WRTHROUGH &&
1616                      curr_match == MTRR_TYPE_WRBACK)) {
1617                         prev_match = MTRR_TYPE_WRTHROUGH;
1618                         curr_match = MTRR_TYPE_WRTHROUGH;
1619                 }
1620
1621                 if (prev_match != curr_match)
1622                         return MTRR_TYPE_UNCACHABLE;
1623         }
1624
1625         if (prev_match != 0xFF)
1626                 return prev_match;
1627
1628         return mtrr_state->def_type;
1629 }
1630
1631 static u8 get_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
1632 {
1633         u8 mtrr;
1634
1635         mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT,
1636                              (gfn << PAGE_SHIFT) + PAGE_SIZE);
1637         if (mtrr == 0xfe || mtrr == 0xff)
1638                 mtrr = MTRR_TYPE_WRBACK;
1639         return mtrr;
1640 }
1641
1642 static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
1643 {
1644         unsigned index;
1645         struct hlist_head *bucket;
1646         struct kvm_mmu_page *s;
1647         struct hlist_node *node, *n;
1648
1649         index = kvm_page_table_hashfn(sp->gfn);
1650         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1651         /* don't unsync if pagetable is shadowed with multiple roles */
1652         hlist_for_each_entry_safe(s, node, n, bucket, hash_link) {
1653                 if (s->gfn != sp->gfn || s->role.metaphysical)
1654                         continue;
1655                 if (s->role.word != sp->role.word)
1656                         return 1;
1657         }
1658         ++vcpu->kvm->stat.mmu_unsync;
1659         sp->unsync = 1;
1660
1661         if (sp->global) {
1662                 list_add(&sp->oos_link, &vcpu->kvm->arch.oos_global_pages);
1663                 ++vcpu->kvm->stat.mmu_unsync_global;
1664         } else
1665                 kvm_mmu_mark_parents_unsync(vcpu, sp);
1666
1667         mmu_convert_notrap(sp);
1668         return 0;
1669 }
1670
1671 static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn,
1672                                   bool can_unsync)
1673 {
1674         struct kvm_mmu_page *shadow;
1675
1676         shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
1677         if (shadow) {
1678                 if (shadow->role.level != PT_PAGE_TABLE_LEVEL)
1679                         return 1;
1680                 if (shadow->unsync)
1681                         return 0;
1682                 if (can_unsync && oos_shadow)
1683                         return kvm_unsync_page(vcpu, shadow);
1684                 return 1;
1685         }
1686         return 0;
1687 }
1688
1689 static int set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1690                     unsigned pte_access, int user_fault,
1691                     int write_fault, int dirty, int largepage,
1692                     int global, gfn_t gfn, pfn_t pfn, bool speculative,
1693                     bool can_unsync)
1694 {
1695         u64 spte;
1696         int ret = 0;
1697         u64 mt_mask = shadow_mt_mask;
1698         struct kvm_mmu_page *sp = page_header(__pa(shadow_pte));
1699
1700         if (!global && sp->global) {
1701                 sp->global = 0;
1702                 if (sp->unsync) {
1703                         kvm_unlink_unsync_global(vcpu->kvm, sp);
1704                         kvm_mmu_mark_parents_unsync(vcpu, sp);
1705                 }
1706         }
1707
1708         /*
1709          * We don't set the accessed bit, since we sometimes want to see
1710          * whether the guest actually used the pte (in order to detect
1711          * demand paging).
1712          */
1713         spte = shadow_base_present_pte | shadow_dirty_mask;
1714         if (!speculative)
1715                 spte |= shadow_accessed_mask;
1716         if (!dirty)
1717                 pte_access &= ~ACC_WRITE_MASK;
1718         if (pte_access & ACC_EXEC_MASK)
1719                 spte |= shadow_x_mask;
1720         else
1721                 spte |= shadow_nx_mask;
1722         if (pte_access & ACC_USER_MASK)
1723                 spte |= shadow_user_mask;
1724         if (largepage)
1725                 spte |= PT_PAGE_SIZE_MASK;
1726         if (mt_mask) {
1727                 if (!kvm_is_mmio_pfn(pfn)) {
1728                         mt_mask = get_memory_type(vcpu, gfn) <<
1729                                 kvm_x86_ops->get_mt_mask_shift();
1730                         mt_mask |= VMX_EPT_IGMT_BIT;
1731                 } else
1732                         mt_mask = MTRR_TYPE_UNCACHABLE <<
1733                                 kvm_x86_ops->get_mt_mask_shift();
1734                 spte |= mt_mask;
1735         }
1736
1737         spte |= (u64)pfn << PAGE_SHIFT;
1738
1739         if ((pte_access & ACC_WRITE_MASK)
1740             || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
1741
1742                 if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) {
1743                         ret = 1;
1744                         spte = shadow_trap_nonpresent_pte;
1745                         goto set_pte;
1746                 }
1747
1748                 spte |= PT_WRITABLE_MASK;
1749
1750                 /*
1751                  * Optimization: for pte sync, if spte was writable the hash
1752                  * lookup is unnecessary (and expensive). Write protection
1753                  * is responsibility of mmu_get_page / kvm_sync_page.
1754                  * Same reasoning can be applied to dirty page accounting.
1755                  */
1756                 if (!can_unsync && is_writeble_pte(*shadow_pte))
1757                         goto set_pte;
1758
1759                 if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
1760                         pgprintk("%s: found shadow page for %lx, marking ro\n",
1761                                  __func__, gfn);
1762                         ret = 1;
1763                         pte_access &= ~ACC_WRITE_MASK;
1764                         if (is_writeble_pte(spte))
1765                                 spte &= ~PT_WRITABLE_MASK;
1766                 }
1767         }
1768
1769         if (pte_access & ACC_WRITE_MASK)
1770                 mark_page_dirty(vcpu->kvm, gfn);
1771
1772 set_pte:
1773         set_shadow_pte(shadow_pte, spte);
1774         return ret;
1775 }
1776
1777 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
1778                          unsigned pt_access, unsigned pte_access,
1779                          int user_fault, int write_fault, int dirty,
1780                          int *ptwrite, int largepage, int global,
1781                          gfn_t gfn, pfn_t pfn, bool speculative)
1782 {
1783         int was_rmapped = 0;
1784         int was_writeble = is_writeble_pte(*shadow_pte);
1785
1786         pgprintk("%s: spte %llx access %x write_fault %d"
1787                  " user_fault %d gfn %lx\n",
1788                  __func__, *shadow_pte, pt_access,
1789                  write_fault, user_fault, gfn);
1790
1791         if (is_rmap_pte(*shadow_pte)) {
1792                 /*
1793                  * If we overwrite a PTE page pointer with a 2MB PMD, unlink
1794                  * the parent of the now unreachable PTE.
1795                  */
1796                 if (largepage && !is_large_pte(*shadow_pte)) {
1797                         struct kvm_mmu_page *child;
1798                         u64 pte = *shadow_pte;
1799
1800                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1801                         mmu_page_remove_parent_pte(child, shadow_pte);
1802                 } else if (pfn != spte_to_pfn(*shadow_pte)) {
1803                         pgprintk("hfn old %lx new %lx\n",
1804                                  spte_to_pfn(*shadow_pte), pfn);
1805                         rmap_remove(vcpu->kvm, shadow_pte);
1806                 } else {
1807                         if (largepage)
1808                                 was_rmapped = is_large_pte(*shadow_pte);
1809                         else
1810                                 was_rmapped = 1;
1811                 }
1812         }
1813         if (set_spte(vcpu, shadow_pte, pte_access, user_fault, write_fault,
1814                       dirty, largepage, global, gfn, pfn, speculative, true)) {
1815                 if (write_fault)
1816                         *ptwrite = 1;
1817                 kvm_x86_ops->tlb_flush(vcpu);
1818         }
1819
1820         pgprintk("%s: setting spte %llx\n", __func__, *shadow_pte);
1821         pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n",
1822                  is_large_pte(*shadow_pte)? "2MB" : "4kB",
1823                  is_present_pte(*shadow_pte)?"RW":"R", gfn,
1824                  *shadow_pte, shadow_pte);
1825         if (!was_rmapped && is_large_pte(*shadow_pte))
1826                 ++vcpu->kvm->stat.lpages;
1827
1828         page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
1829         if (!was_rmapped) {
1830                 rmap_add(vcpu, shadow_pte, gfn, largepage);
1831                 if (!is_rmap_pte(*shadow_pte))
1832                         kvm_release_pfn_clean(pfn);
1833         } else {
1834                 if (was_writeble)
1835                         kvm_release_pfn_dirty(pfn);
1836                 else
1837                         kvm_release_pfn_clean(pfn);
1838         }
1839         if (speculative) {
1840                 vcpu->arch.last_pte_updated = shadow_pte;
1841                 vcpu->arch.last_pte_gfn = gfn;
1842         }
1843 }
1844
1845 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
1846 {
1847 }
1848
1849 struct direct_shadow_walk {
1850         struct kvm_shadow_walk walker;
1851         pfn_t pfn;
1852         int write;
1853         int largepage;
1854         int pt_write;
1855 };
1856
1857 static int direct_map_entry(struct kvm_shadow_walk *_walk,
1858                             struct kvm_vcpu *vcpu,
1859                             u64 addr, u64 *sptep, int level)
1860 {
1861         struct direct_shadow_walk *walk =
1862                 container_of(_walk, struct direct_shadow_walk, walker);
1863         struct kvm_mmu_page *sp;
1864         gfn_t pseudo_gfn;
1865         gfn_t gfn = addr >> PAGE_SHIFT;
1866
1867         if (level == PT_PAGE_TABLE_LEVEL
1868             || (walk->largepage && level == PT_DIRECTORY_LEVEL)) {
1869                 mmu_set_spte(vcpu, sptep, ACC_ALL, ACC_ALL,
1870                              0, walk->write, 1, &walk->pt_write,
1871                              walk->largepage, 0, gfn, walk->pfn, false);
1872                 ++vcpu->stat.pf_fixed;
1873                 return 1;
1874         }
1875
1876         if (*sptep == shadow_trap_nonpresent_pte) {
1877                 pseudo_gfn = (addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
1878                 sp = kvm_mmu_get_page(vcpu, pseudo_gfn, (gva_t)addr, level - 1,
1879                                       1, ACC_ALL, sptep);
1880                 if (!sp) {
1881                         pgprintk("nonpaging_map: ENOMEM\n");
1882                         kvm_release_pfn_clean(walk->pfn);
1883                         return -ENOMEM;
1884                 }
1885
1886                 set_shadow_pte(sptep,
1887                                __pa(sp->spt)
1888                                | PT_PRESENT_MASK | PT_WRITABLE_MASK
1889                                | shadow_user_mask | shadow_x_mask);
1890         }
1891         return 0;
1892 }
1893
1894 static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
1895                         int largepage, gfn_t gfn, pfn_t pfn)
1896 {
1897         int r;
1898         struct direct_shadow_walk walker = {
1899                 .walker = { .entry = direct_map_entry, },
1900                 .pfn = pfn,
1901                 .largepage = largepage,
1902                 .write = write,
1903                 .pt_write = 0,
1904         };
1905
1906         r = walk_shadow(&walker.walker, vcpu, gfn << PAGE_SHIFT);
1907         if (r < 0)
1908                 return r;
1909         return walker.pt_write;
1910 }
1911
1912 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1913 {
1914         int r;
1915         int largepage = 0;
1916         pfn_t pfn;
1917         unsigned long mmu_seq;
1918
1919         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
1920                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
1921                 largepage = 1;
1922         }
1923
1924         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1925         smp_rmb();
1926         pfn = gfn_to_pfn(vcpu->kvm, gfn);
1927
1928         /* mmio */
1929         if (is_error_pfn(pfn)) {
1930                 kvm_release_pfn_clean(pfn);
1931                 return 1;
1932         }
1933
1934         spin_lock(&vcpu->kvm->mmu_lock);
1935         if (mmu_notifier_retry(vcpu, mmu_seq))
1936                 goto out_unlock;
1937         kvm_mmu_free_some_pages(vcpu);
1938         r = __direct_map(vcpu, v, write, largepage, gfn, pfn);
1939         spin_unlock(&vcpu->kvm->mmu_lock);
1940
1941
1942         return r;
1943
1944 out_unlock:
1945         spin_unlock(&vcpu->kvm->mmu_lock);
1946         kvm_release_pfn_clean(pfn);
1947         return 0;
1948 }
1949
1950
1951 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1952 {
1953         int i;
1954         struct kvm_mmu_page *sp;
1955
1956         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1957                 return;
1958         spin_lock(&vcpu->kvm->mmu_lock);
1959         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1960                 hpa_t root = vcpu->arch.mmu.root_hpa;
1961
1962                 sp = page_header(root);
1963                 --sp->root_count;
1964                 if (!sp->root_count && sp->role.invalid)
1965                         kvm_mmu_zap_page(vcpu->kvm, sp);
1966                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1967                 spin_unlock(&vcpu->kvm->mmu_lock);
1968                 return;
1969         }
1970         for (i = 0; i < 4; ++i) {
1971                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1972
1973                 if (root) {
1974                         root &= PT64_BASE_ADDR_MASK;
1975                         sp = page_header(root);
1976                         --sp->root_count;
1977                         if (!sp->root_count && sp->role.invalid)
1978                                 kvm_mmu_zap_page(vcpu->kvm, sp);
1979                 }
1980                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1981         }
1982         spin_unlock(&vcpu->kvm->mmu_lock);
1983         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1984 }
1985
1986 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1987 {
1988         int i;
1989         gfn_t root_gfn;
1990         struct kvm_mmu_page *sp;
1991         int metaphysical = 0;
1992
1993         root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1994
1995         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1996                 hpa_t root = vcpu->arch.mmu.root_hpa;
1997
1998                 ASSERT(!VALID_PAGE(root));
1999                 if (tdp_enabled)
2000                         metaphysical = 1;
2001                 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
2002                                       PT64_ROOT_LEVEL, metaphysical,
2003                                       ACC_ALL, NULL);
2004                 root = __pa(sp->spt);
2005                 ++sp->root_count;
2006                 vcpu->arch.mmu.root_hpa = root;
2007                 return;
2008         }
2009         metaphysical = !is_paging(vcpu);
2010         if (tdp_enabled)
2011                 metaphysical = 1;
2012         for (i = 0; i < 4; ++i) {
2013                 hpa_t root = vcpu->arch.mmu.pae_root[i];
2014
2015                 ASSERT(!VALID_PAGE(root));
2016                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
2017                         if (!is_present_pte(vcpu->arch.pdptrs[i])) {
2018                                 vcpu->arch.mmu.pae_root[i] = 0;
2019                                 continue;
2020                         }
2021                         root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
2022                 } else if (vcpu->arch.mmu.root_level == 0)
2023                         root_gfn = 0;
2024                 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
2025                                       PT32_ROOT_LEVEL, metaphysical,
2026                                       ACC_ALL, NULL);
2027                 root = __pa(sp->spt);
2028                 ++sp->root_count;
2029                 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
2030         }
2031         vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
2032 }
2033
2034 static void mmu_sync_roots(struct kvm_vcpu *vcpu)
2035 {
2036         int i;
2037         struct kvm_mmu_page *sp;
2038
2039         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
2040                 return;
2041         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
2042                 hpa_t root = vcpu->arch.mmu.root_hpa;
2043                 sp = page_header(root);
2044                 mmu_sync_children(vcpu, sp);
2045                 return;
2046         }
2047         for (i = 0; i < 4; ++i) {
2048                 hpa_t root = vcpu->arch.mmu.pae_root[i];
2049
2050                 if (root) {
2051                         root &= PT64_BASE_ADDR_MASK;
2052                         sp = page_header(root);
2053                         mmu_sync_children(vcpu, sp);
2054                 }
2055         }
2056 }
2057
2058 static void mmu_sync_global(struct kvm_vcpu *vcpu)
2059 {
2060         struct kvm *kvm = vcpu->kvm;
2061         struct kvm_mmu_page *sp, *n;
2062
2063         list_for_each_entry_safe(sp, n, &kvm->arch.oos_global_pages, oos_link)
2064                 kvm_sync_page(vcpu, sp);
2065 }
2066
2067 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
2068 {
2069         spin_lock(&vcpu->kvm->mmu_lock);
2070         mmu_sync_roots(vcpu);
2071         spin_unlock(&vcpu->kvm->mmu_lock);
2072 }
2073
2074 void kvm_mmu_sync_global(struct kvm_vcpu *vcpu)
2075 {
2076         spin_lock(&vcpu->kvm->mmu_lock);
2077         mmu_sync_global(vcpu);
2078         spin_unlock(&vcpu->kvm->mmu_lock);
2079 }
2080
2081 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
2082 {
2083         return vaddr;
2084 }
2085
2086 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
2087                                 u32 error_code)
2088 {
2089         gfn_t gfn;
2090         int r;
2091
2092         pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);
2093         r = mmu_topup_memory_caches(vcpu);
2094         if (r)
2095                 return r;
2096
2097         ASSERT(vcpu);
2098         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2099
2100         gfn = gva >> PAGE_SHIFT;
2101
2102         return nonpaging_map(vcpu, gva & PAGE_MASK,
2103                              error_code & PFERR_WRITE_MASK, gfn);
2104 }
2105
2106 static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
2107                                 u32 error_code)
2108 {
2109         pfn_t pfn;
2110         int r;
2111         int largepage = 0;
2112         gfn_t gfn = gpa >> PAGE_SHIFT;
2113         unsigned long mmu_seq;
2114
2115         ASSERT(vcpu);
2116         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
2117
2118         r = mmu_topup_memory_caches(vcpu);
2119         if (r)
2120                 return r;
2121
2122         if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
2123                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
2124                 largepage = 1;
2125         }
2126         mmu_seq = vcpu->kvm->mmu_notifier_seq;
2127         smp_rmb();
2128         pfn = gfn_to_pfn(vcpu->kvm, gfn);
2129         if (is_error_pfn(pfn)) {
2130                 kvm_release_pfn_clean(pfn);
2131                 return 1;
2132         }
2133         spin_lock(&vcpu->kvm->mmu_lock);
2134         if (mmu_notifier_retry(vcpu, mmu_seq))
2135                 goto out_unlock;
2136         kvm_mmu_free_some_pages(vcpu);
2137         r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
2138                          largepage, gfn, pfn);
2139         spin_unlock(&vcpu->kvm->mmu_lock);
2140
2141         return r;
2142
2143 out_unlock:
2144         spin_unlock(&vcpu->kvm->mmu_lock);
2145         kvm_release_pfn_clean(pfn);
2146         return 0;
2147 }
2148
2149 static void nonpaging_free(struct kvm_vcpu *vcpu)
2150 {
2151         mmu_free_roots(vcpu);
2152 }
2153
2154 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
2155 {
2156         struct kvm_mmu *context = &vcpu->arch.mmu;
2157
2158         context->new_cr3 = nonpaging_new_cr3;
2159         context->page_fault = nonpaging_page_fault;
2160         context->gva_to_gpa = nonpaging_gva_to_gpa;
2161         context->free = nonpaging_free;
2162         context->prefetch_page = nonpaging_prefetch_page;
2163         context->sync_page = nonpaging_sync_page;
2164         context->invlpg = nonpaging_invlpg;
2165         context->root_level = 0;
2166         context->shadow_root_level = PT32E_ROOT_LEVEL;
2167         context->root_hpa = INVALID_PAGE;
2168         return 0;
2169 }
2170
2171 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2172 {
2173         ++vcpu->stat.tlb_flush;
2174         kvm_x86_ops->tlb_flush(vcpu);
2175 }
2176
2177 static void paging_new_cr3(struct kvm_vcpu *vcpu)
2178 {
2179         pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
2180         mmu_free_roots(vcpu);
2181 }
2182
2183 static void inject_page_fault(struct kvm_vcpu *vcpu,
2184                               u64 addr,
2185                               u32 err_code)
2186 {
2187         kvm_inject_page_fault(vcpu, addr, err_code);
2188 }
2189
2190 static void paging_free(struct kvm_vcpu *vcpu)
2191 {
2192         nonpaging_free(vcpu);
2193 }
2194
2195 #define PTTYPE 64
2196 #include "paging_tmpl.h"
2197 #undef PTTYPE
2198
2199 #define PTTYPE 32
2200 #include "paging_tmpl.h"
2201 #undef PTTYPE
2202
2203 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
2204 {
2205         struct kvm_mmu *context = &vcpu->arch.mmu;
2206
2207         ASSERT(is_pae(vcpu));
2208         context->new_cr3 = paging_new_cr3;
2209         context->page_fault = paging64_page_fault;
2210         context->gva_to_gpa = paging64_gva_to_gpa;
2211         context->prefetch_page = paging64_prefetch_page;
2212         context->sync_page = paging64_sync_page;
2213         context->invlpg = paging64_invlpg;
2214         context->free = paging_free;
2215         context->root_level = level;
2216         context->shadow_root_level = level;
2217         context->root_hpa = INVALID_PAGE;
2218         return 0;
2219 }
2220
2221 static int paging64_init_context(struct kvm_vcpu *vcpu)
2222 {
2223         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
2224 }
2225
2226 static int paging32_init_context(struct kvm_vcpu *vcpu)
2227 {
2228         struct kvm_mmu *context = &vcpu->arch.mmu;
2229
2230         context->new_cr3 = paging_new_cr3;
2231         context->page_fault = paging32_page_fault;
2232         context->gva_to_gpa = paging32_gva_to_gpa;
2233         context->free = paging_free;
2234         context->prefetch_page = paging32_prefetch_page;
2235         context->sync_page = paging32_sync_page;
2236         context->invlpg = paging32_invlpg;
2237         context->root_level = PT32_ROOT_LEVEL;
2238         context->shadow_root_level = PT32E_ROOT_LEVEL;
2239         context->root_hpa = INVALID_PAGE;
2240         return 0;
2241 }
2242
2243 static int paging32E_init_context(struct kvm_vcpu *vcpu)
2244 {
2245         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
2246 }
2247
2248 static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
2249 {
2250         struct kvm_mmu *context = &vcpu->arch.mmu;
2251
2252         context->new_cr3 = nonpaging_new_cr3;
2253         context->page_fault = tdp_page_fault;
2254         context->free = nonpaging_free;
2255         context->prefetch_page = nonpaging_prefetch_page;
2256         context->sync_page = nonpaging_sync_page;
2257         context->invlpg = nonpaging_invlpg;
2258         context->shadow_root_level = kvm_x86_ops->get_tdp_level();
2259         context->root_hpa = INVALID_PAGE;
2260
2261         if (!is_paging(vcpu)) {
2262                 context->gva_to_gpa = nonpaging_gva_to_gpa;
2263                 context->root_level = 0;
2264         } else if (is_long_mode(vcpu)) {
2265                 context->gva_to_gpa = paging64_gva_to_gpa;
2266                 context->root_level = PT64_ROOT_LEVEL;
2267         } else if (is_pae(vcpu)) {
2268                 context->gva_to_gpa = paging64_gva_to_gpa;
2269                 context->root_level = PT32E_ROOT_LEVEL;
2270         } else {
2271                 context->gva_to_gpa = paging32_gva_to_gpa;
2272                 context->root_level = PT32_ROOT_LEVEL;
2273         }
2274
2275         return 0;
2276 }
2277
2278 static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
2279 {
2280         int r;
2281
2282         ASSERT(vcpu);
2283         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2284
2285         if (!is_paging(vcpu))
2286                 r = nonpaging_init_context(vcpu);
2287         else if (is_long_mode(vcpu))
2288                 r = paging64_init_context(vcpu);
2289         else if (is_pae(vcpu))
2290                 r = paging32E_init_context(vcpu);
2291         else
2292                 r = paging32_init_context(vcpu);
2293
2294         vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level;
2295
2296         return r;
2297 }
2298
2299 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
2300 {
2301         vcpu->arch.update_pte.pfn = bad_pfn;
2302
2303         if (tdp_enabled)
2304                 return init_kvm_tdp_mmu(vcpu);
2305         else
2306                 return init_kvm_softmmu(vcpu);
2307 }
2308
2309 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
2310 {
2311         ASSERT(vcpu);
2312         if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
2313                 vcpu->arch.mmu.free(vcpu);
2314                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
2315         }
2316 }
2317
2318 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
2319 {
2320         destroy_kvm_mmu(vcpu);
2321         return init_kvm_mmu(vcpu);
2322 }
2323 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
2324
2325 int kvm_mmu_load(struct kvm_vcpu *vcpu)
2326 {
2327         int r;
2328
2329         r = mmu_topup_memory_caches(vcpu);
2330         if (r)
2331                 goto out;
2332         spin_lock(&vcpu->kvm->mmu_lock);
2333         kvm_mmu_free_some_pages(vcpu);
2334         mmu_alloc_roots(vcpu);
2335         mmu_sync_roots(vcpu);
2336         spin_unlock(&vcpu->kvm->mmu_lock);
2337         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
2338         kvm_mmu_flush_tlb(vcpu);
2339 out:
2340         return r;
2341 }
2342 EXPORT_SYMBOL_GPL(kvm_mmu_load);
2343
2344 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
2345 {
2346         mmu_free_roots(vcpu);
2347 }
2348
2349 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
2350                                   struct kvm_mmu_page *sp,
2351                                   u64 *spte)
2352 {
2353         u64 pte;
2354         struct kvm_mmu_page *child;
2355
2356         pte = *spte;
2357         if (is_shadow_present_pte(pte)) {
2358                 if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
2359                     is_large_pte(pte))
2360                         rmap_remove(vcpu->kvm, spte);
2361                 else {
2362                         child = page_header(pte & PT64_BASE_ADDR_MASK);
2363                         mmu_page_remove_parent_pte(child, spte);
2364                 }
2365         }
2366         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
2367         if (is_large_pte(pte))
2368                 --vcpu->kvm->stat.lpages;
2369 }
2370
2371 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
2372                                   struct kvm_mmu_page *sp,
2373                                   u64 *spte,
2374                                   const void *new)
2375 {
2376         if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
2377                 if (!vcpu->arch.update_pte.largepage ||
2378                     sp->role.glevels == PT32_ROOT_LEVEL) {
2379                         ++vcpu->kvm->stat.mmu_pde_zapped;
2380                         return;
2381                 }
2382         }
2383
2384         ++vcpu->kvm->stat.mmu_pte_updated;
2385         if (sp->role.glevels == PT32_ROOT_LEVEL)
2386                 paging32_update_pte(vcpu, sp, spte, new);
2387         else
2388                 paging64_update_pte(vcpu, sp, spte, new);
2389 }
2390
2391 static bool need_remote_flush(u64 old, u64 new)
2392 {
2393         if (!is_shadow_present_pte(old))
2394                 return false;
2395         if (!is_shadow_present_pte(new))
2396                 return true;
2397         if ((old ^ new) & PT64_BASE_ADDR_MASK)
2398                 return true;
2399         old ^= PT64_NX_MASK;
2400         new ^= PT64_NX_MASK;
2401         return (old & ~new & PT64_PERM_MASK) != 0;
2402 }
2403
2404 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
2405 {
2406         if (need_remote_flush(old, new))
2407                 kvm_flush_remote_tlbs(vcpu->kvm);
2408         else
2409                 kvm_mmu_flush_tlb(vcpu);
2410 }
2411
2412 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
2413 {
2414         u64 *spte = vcpu->arch.last_pte_updated;
2415
2416         return !!(spte && (*spte & shadow_accessed_mask));
2417 }
2418
2419 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2420                                           const u8 *new, int bytes)
2421 {
2422         gfn_t gfn;
2423         int r;
2424         u64 gpte = 0;
2425         pfn_t pfn;
2426
2427         vcpu->arch.update_pte.largepage = 0;
2428
2429         if (bytes != 4 && bytes != 8)
2430                 return;
2431
2432         /*
2433          * Assume that the pte write on a page table of the same type
2434          * as the current vcpu paging mode.  This is nearly always true
2435          * (might be false while changing modes).  Note it is verified later
2436          * by update_pte().
2437          */
2438         if (is_pae(vcpu)) {
2439                 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
2440                 if ((bytes == 4) && (gpa % 4 == 0)) {
2441                         r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
2442                         if (r)
2443                                 return;
2444                         memcpy((void *)&gpte + (gpa % 8), new, 4);
2445                 } else if ((bytes == 8) && (gpa % 8 == 0)) {
2446                         memcpy((void *)&gpte, new, 8);
2447                 }
2448         } else {
2449                 if ((bytes == 4) && (gpa % 4 == 0))
2450                         memcpy((void *)&gpte, new, 4);
2451         }
2452         if (!is_present_pte(gpte))
2453                 return;
2454         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
2455
2456         if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
2457                 gfn &= ~(KVM_PAGES_PER_HPAGE-1);
2458                 vcpu->arch.update_pte.largepage = 1;
2459         }
2460         vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
2461         smp_rmb();
2462         pfn = gfn_to_pfn(vcpu->kvm, gfn);
2463
2464         if (is_error_pfn(pfn)) {
2465                 kvm_release_pfn_clean(pfn);
2466                 return;
2467         }
2468         vcpu->arch.update_pte.gfn = gfn;
2469         vcpu->arch.update_pte.pfn = pfn;
2470 }
2471
2472 static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
2473 {
2474         u64 *spte = vcpu->arch.last_pte_updated;
2475
2476         if (spte
2477             && vcpu->arch.last_pte_gfn == gfn
2478             && shadow_accessed_mask
2479             && !(*spte & shadow_accessed_mask)
2480             && is_shadow_present_pte(*spte))
2481                 set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
2482 }
2483
2484 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
2485                        const u8 *new, int bytes,
2486                        bool guest_initiated)
2487 {
2488         gfn_t gfn = gpa >> PAGE_SHIFT;
2489         struct kvm_mmu_page *sp;
2490         struct hlist_node *node, *n;
2491         struct hlist_head *bucket;
2492         unsigned index;
2493         u64 entry, gentry;
2494         u64 *spte;
2495         unsigned offset = offset_in_page(gpa);
2496         unsigned pte_size;
2497         unsigned page_offset;
2498         unsigned misaligned;
2499         unsigned quadrant;
2500         int level;
2501         int flooded = 0;
2502         int npte;
2503         int r;
2504
2505         pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
2506         mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
2507         spin_lock(&vcpu->kvm->mmu_lock);
2508         kvm_mmu_access_page(vcpu, gfn);
2509         kvm_mmu_free_some_pages(vcpu);
2510         ++vcpu->kvm->stat.mmu_pte_write;
2511         kvm_mmu_audit(vcpu, "pre pte write");
2512         if (guest_initiated) {
2513                 if (gfn == vcpu->arch.last_pt_write_gfn
2514                     && !last_updated_pte_accessed(vcpu)) {
2515                         ++vcpu->arch.last_pt_write_count;
2516                         if (vcpu->arch.last_pt_write_count >= 3)
2517                                 flooded = 1;
2518                 } else {
2519                         vcpu->arch.last_pt_write_gfn = gfn;
2520                         vcpu->arch.last_pt_write_count = 1;
2521                         vcpu->arch.last_pte_updated = NULL;
2522                 }
2523         }
2524         index = kvm_page_table_hashfn(gfn);
2525         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
2526         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
2527                 if (sp->gfn != gfn || sp->role.metaphysical || sp->role.invalid)
2528                         continue;
2529                 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
2530                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
2531                 misaligned |= bytes < 4;
2532                 if (misaligned || flooded) {
2533                         /*
2534                          * Misaligned accesses are too much trouble to fix
2535                          * up; also, they usually indicate a page is not used
2536                          * as a page table.
2537                          *
2538                          * If we're seeing too many writes to a page,
2539                          * it may no longer be a page table, or we may be
2540                          * forking, in which case it is better to unmap the
2541                          * page.
2542                          */
2543                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
2544                                  gpa, bytes, sp->role.word);
2545                         if (kvm_mmu_zap_page(vcpu->kvm, sp))
2546                                 n = bucket->first;
2547                         ++vcpu->kvm->stat.mmu_flooded;
2548                         continue;
2549                 }
2550                 page_offset = offset;
2551                 level = sp->role.level;
2552                 npte = 1;
2553                 if (sp->role.glevels == PT32_ROOT_LEVEL) {
2554                         page_offset <<= 1;      /* 32->64 */
2555                         /*
2556                          * A 32-bit pde maps 4MB while the shadow pdes map
2557                          * only 2MB.  So we need to double the offset again
2558                          * and zap two pdes instead of one.
2559                          */
2560                         if (level == PT32_ROOT_LEVEL) {
2561                                 page_offset &= ~7; /* kill rounding error */
2562                                 page_offset <<= 1;
2563                                 npte = 2;
2564                         }
2565                         quadrant = page_offset >> PAGE_SHIFT;
2566                         page_offset &= ~PAGE_MASK;
2567                         if (quadrant != sp->role.quadrant)
2568                                 continue;
2569                 }
2570                 spte = &sp->spt[page_offset / sizeof(*spte)];
2571                 if ((gpa & (pte_size - 1)) || (bytes < pte_size)) {
2572                         gentry = 0;
2573                         r = kvm_read_guest_atomic(vcpu->kvm,
2574                                                   gpa & ~(u64)(pte_size - 1),
2575                                                   &gentry, pte_size);
2576                         new = (const void *)&gentry;
2577                         if (r < 0)
2578                                 new = NULL;
2579                 }
2580                 while (npte--) {
2581                         entry = *spte;
2582                         mmu_pte_write_zap_pte(vcpu, sp, spte);
2583                         if (new)
2584                                 mmu_pte_write_new_pte(vcpu, sp, spte, new);
2585                         mmu_pte_write_flush_tlb(vcpu, entry, *spte);
2586                         ++spte;
2587                 }
2588         }
2589         kvm_mmu_audit(vcpu, "post pte write");
2590         spin_unlock(&vcpu->kvm->mmu_lock);
2591         if (!is_error_pfn(vcpu->arch.update_pte.pfn)) {
2592                 kvm_release_pfn_clean(vcpu->arch.update_pte.pfn);
2593                 vcpu->arch.update_pte.pfn = bad_pfn;
2594         }
2595 }
2596
2597 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
2598 {
2599         gpa_t gpa;
2600         int r;
2601
2602         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
2603
2604         spin_lock(&vcpu->kvm->mmu_lock);
2605         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
2606         spin_unlock(&vcpu->kvm->mmu_lock);
2607         return r;
2608 }
2609 EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt);
2610
2611 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
2612 {
2613         while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
2614                 struct kvm_mmu_page *sp;
2615
2616                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
2617                                   struct kvm_mmu_page, link);
2618                 kvm_mmu_zap_page(vcpu->kvm, sp);
2619                 ++vcpu->kvm->stat.mmu_recycled;
2620         }
2621 }
2622
2623 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
2624 {
2625         int r;
2626         enum emulation_result er;
2627
2628         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
2629         if (r < 0)
2630                 goto out;
2631
2632         if (!r) {
2633                 r = 1;
2634                 goto out;
2635         }
2636
2637         r = mmu_topup_memory_caches(vcpu);
2638         if (r)
2639                 goto out;
2640
2641         er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
2642
2643         switch (er) {
2644         case EMULATE_DONE:
2645                 return 1;
2646         case EMULATE_DO_MMIO:
2647                 ++vcpu->stat.mmio_exits;
2648                 return 0;
2649         case EMULATE_FAIL:
2650                 kvm_report_emulation_failure(vcpu, "pagetable");
2651                 return 1;
2652         default:
2653                 BUG();
2654         }
2655 out:
2656         return r;
2657 }
2658 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
2659
2660 void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
2661 {
2662         vcpu->arch.mmu.invlpg(vcpu, gva);
2663         kvm_mmu_flush_tlb(vcpu);
2664         ++vcpu->stat.invlpg;
2665 }
2666 EXPORT_SYMBOL_GPL(kvm_mmu_invlpg);
2667
2668 void kvm_enable_tdp(void)
2669 {
2670         tdp_enabled = true;
2671 }
2672 EXPORT_SYMBOL_GPL(kvm_enable_tdp);
2673
2674 void kvm_disable_tdp(void)
2675 {
2676         tdp_enabled = false;
2677 }
2678 EXPORT_SYMBOL_GPL(kvm_disable_tdp);
2679
2680 static void free_mmu_pages(struct kvm_vcpu *vcpu)
2681 {
2682         struct kvm_mmu_page *sp;
2683
2684         while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
2685                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
2686                                   struct kvm_mmu_page, link);
2687                 kvm_mmu_zap_page(vcpu->kvm, sp);
2688                 cond_resched();
2689         }
2690         free_page((unsigned long)vcpu->arch.mmu.pae_root);
2691 }
2692
2693 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
2694 {
2695         struct page *page;
2696         int i;
2697
2698         ASSERT(vcpu);
2699
2700         if (vcpu->kvm->arch.n_requested_mmu_pages)
2701                 vcpu->kvm->arch.n_free_mmu_pages =
2702                                         vcpu->kvm->arch.n_requested_mmu_pages;
2703         else
2704                 vcpu->kvm->arch.n_free_mmu_pages =
2705                                         vcpu->kvm->arch.n_alloc_mmu_pages;
2706         /*
2707          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
2708          * Therefore we need to allocate shadow page tables in the first
2709          * 4GB of memory, which happens to fit the DMA32 zone.
2710          */
2711         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
2712         if (!page)
2713                 goto error_1;
2714         vcpu->arch.mmu.pae_root = page_address(page);
2715         for (i = 0; i < 4; ++i)
2716                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
2717
2718         return 0;
2719
2720 error_1:
2721         free_mmu_pages(vcpu);
2722         return -ENOMEM;
2723 }
2724
2725 int kvm_mmu_create(struct kvm_vcpu *vcpu)
2726 {
2727         ASSERT(vcpu);
2728         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2729
2730         return alloc_mmu_pages(vcpu);
2731 }
2732
2733 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
2734 {
2735         ASSERT(vcpu);
2736         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
2737
2738         return init_kvm_mmu(vcpu);
2739 }
2740
2741 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
2742 {
2743         ASSERT(vcpu);
2744
2745         destroy_kvm_mmu(vcpu);
2746         free_mmu_pages(vcpu);
2747         mmu_free_memory_caches(vcpu);
2748 }
2749
2750 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
2751 {
2752         struct kvm_mmu_page *sp;
2753
2754         spin_lock(&kvm->mmu_lock);
2755         list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
2756                 int i;
2757                 u64 *pt;
2758
2759                 if (!test_bit(slot, sp->slot_bitmap))
2760                         continue;
2761
2762                 pt = sp->spt;
2763                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
2764                         /* avoid RMW */
2765                         if (pt[i] & PT_WRITABLE_MASK)
2766                                 pt[i] &= ~PT_WRITABLE_MASK;
2767         }
2768         kvm_flush_remote_tlbs(kvm);
2769         spin_unlock(&kvm->mmu_lock);
2770 }
2771
2772 void kvm_mmu_zap_all(struct kvm *kvm)
2773 {
2774         struct kvm_mmu_page *sp, *node;
2775
2776         spin_lock(&kvm->mmu_lock);
2777         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
2778                 if (kvm_mmu_zap_page(kvm, sp))
2779                         node = container_of(kvm->arch.active_mmu_pages.next,
2780                                             struct kvm_mmu_page, link);
2781         spin_unlock(&kvm->mmu_lock);
2782
2783         kvm_flush_remote_tlbs(kvm);
2784 }
2785
2786 static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm)
2787 {
2788         struct kvm_mmu_page *page;
2789
2790         page = container_of(kvm->arch.active_mmu_pages.prev,
2791                             struct kvm_mmu_page, link);
2792         kvm_mmu_zap_page(kvm, page);
2793 }
2794
2795 static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
2796 {
2797         struct kvm *kvm;
2798         struct kvm *kvm_freed = NULL;
2799         int cache_count = 0;
2800
2801         spin_lock(&kvm_lock);
2802
2803         list_for_each_entry(kvm, &vm_list, vm_list) {
2804                 int npages;
2805
2806                 if (!down_read_trylock(&kvm->slots_lock))
2807                         continue;
2808                 spin_lock(&kvm->mmu_lock);
2809                 npages = kvm->arch.n_alloc_mmu_pages -
2810                          kvm->arch.n_free_mmu_pages;
2811                 cache_count += npages;
2812                 if (!kvm_freed && nr_to_scan > 0 && npages > 0) {
2813                         kvm_mmu_remove_one_alloc_mmu_page(kvm);
2814                         cache_count--;
2815                         kvm_freed = kvm;
2816                 }
2817                 nr_to_scan--;
2818
2819                 spin_unlock(&kvm->mmu_lock);
2820                 up_read(&kvm->slots_lock);
2821         }
2822         if (kvm_freed)
2823                 list_move_tail(&kvm_freed->vm_list, &vm_list);
2824
2825         spin_unlock(&kvm_lock);
2826
2827         return cache_count;
2828 }
2829
2830 static struct shrinker mmu_shrinker = {
2831         .shrink = mmu_shrink,
2832         .seeks = DEFAULT_SEEKS * 10,
2833 };
2834
2835 static void mmu_destroy_caches(void)
2836 {
2837         if (pte_chain_cache)
2838                 kmem_cache_destroy(pte_chain_cache);
2839         if (rmap_desc_cache)
2840                 kmem_cache_destroy(rmap_desc_cache);
2841         if (mmu_page_header_cache)
2842                 kmem_cache_destroy(mmu_page_header_cache);
2843 }
2844
2845 void kvm_mmu_module_exit(void)
2846 {
2847         mmu_destroy_caches();
2848         unregister_shrinker(&mmu_shrinker);
2849 }
2850
2851 int kvm_mmu_module_init(void)
2852 {
2853         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
2854                                             sizeof(struct kvm_pte_chain),
2855                                             0, 0, NULL);
2856         if (!pte_chain_cache)
2857                 goto nomem;
2858         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
2859                                             sizeof(struct kvm_rmap_desc),
2860                                             0, 0, NULL);
2861         if (!rmap_desc_cache)
2862                 goto nomem;
2863
2864         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
2865                                                   sizeof(struct kvm_mmu_page),
2866                                                   0, 0, NULL);
2867         if (!mmu_page_header_cache)
2868                 goto nomem;
2869
2870         register_shrinker(&mmu_shrinker);
2871
2872         return 0;
2873
2874 nomem:
2875         mmu_destroy_caches();
2876         return -ENOMEM;
2877 }
2878
2879 /*
2880  * Caculate mmu pages needed for kvm.
2881  */
2882 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
2883 {
2884         int i;
2885         unsigned int nr_mmu_pages;
2886         unsigned int  nr_pages = 0;
2887
2888         for (i = 0; i < kvm->nmemslots; i++)
2889                 nr_pages += kvm->memslots[i].npages;
2890
2891         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
2892         nr_mmu_pages = max(nr_mmu_pages,
2893                         (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
2894
2895         return nr_mmu_pages;
2896 }
2897
2898 static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2899                                 unsigned len)
2900 {
2901         if (len > buffer->len)
2902                 return NULL;
2903         return buffer->ptr;
2904 }
2905
2906 static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer,
2907                                 unsigned len)
2908 {
2909         void *ret;
2910
2911         ret = pv_mmu_peek_buffer(buffer, len);
2912         if (!ret)
2913                 return ret;
2914         buffer->ptr += len;
2915         buffer->len -= len;
2916         buffer->processed += len;
2917         return ret;
2918 }
2919
2920 static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
2921                              gpa_t addr, gpa_t value)
2922 {
2923         int bytes = 8;
2924         int r;
2925
2926         if (!is_long_mode(vcpu) && !is_pae(vcpu))
2927                 bytes = 4;
2928
2929         r = mmu_topup_memory_caches(vcpu);
2930         if (r)
2931                 return r;
2932
2933         if (!emulator_write_phys(vcpu, addr, &value, bytes))
2934                 return -EFAULT;
2935
2936         return 1;
2937 }
2938
2939 static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
2940 {
2941         kvm_x86_ops->tlb_flush(vcpu);
2942         set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests);
2943         return 1;
2944 }
2945
2946 static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr)
2947 {
2948         spin_lock(&vcpu->kvm->mmu_lock);
2949         mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT);
2950         spin_unlock(&vcpu->kvm->mmu_lock);
2951         return 1;
2952 }
2953
2954 static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu,
2955                              struct kvm_pv_mmu_op_buffer *buffer)
2956 {
2957         struct kvm_mmu_op_header *header;
2958
2959         header = pv_mmu_peek_buffer(buffer, sizeof *header);
2960         if (!header)
2961                 return 0;
2962         switch (header->op) {
2963         case KVM_MMU_OP_WRITE_PTE: {
2964                 struct kvm_mmu_op_write_pte *wpte;
2965
2966                 wpte = pv_mmu_read_buffer(buffer, sizeof *wpte);
2967                 if (!wpte)
2968                         return 0;
2969                 return kvm_pv_mmu_write(vcpu, wpte->pte_phys,
2970                                         wpte->pte_val);
2971         }
2972         case KVM_MMU_OP_FLUSH_TLB: {
2973                 struct kvm_mmu_op_flush_tlb *ftlb;
2974
2975                 ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb);
2976                 if (!ftlb)
2977                         return 0;
2978                 return kvm_pv_mmu_flush_tlb(vcpu);
2979         }
2980         case KVM_MMU_OP_RELEASE_PT: {
2981                 struct kvm_mmu_op_release_pt *rpt;
2982
2983                 rpt = pv_mmu_read_buffer(buffer, sizeof *rpt);
2984                 if (!rpt)
2985                         return 0;
2986                 return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys);
2987         }
2988         default: return 0;
2989         }
2990 }
2991
2992 int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
2993                   gpa_t addr, unsigned long *ret)
2994 {
2995         int r;
2996         struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer;
2997
2998         buffer->ptr = buffer->buf;
2999         buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf);
3000         buffer->processed = 0;
3001
3002         r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len);
3003         if (r)
3004                 goto out;
3005
3006         while (buffer->len) {
3007                 r = kvm_pv_mmu_op_one(vcpu, buffer);
3008                 if (r < 0)
3009                         goto out;
3010                 if (r == 0)
3011                         break;
3012         }
3013
3014         r = 1;
3015 out:
3016         *ret = buffer->processed;
3017         return r;
3018 }
3019
3020 #ifdef AUDIT
3021
3022 static const char *audit_msg;
3023
3024 static gva_t canonicalize(gva_t gva)
3025 {
3026 #ifdef CONFIG_X86_64
3027         gva = (long long)(gva << 16) >> 16;
3028 #endif
3029         return gva;
3030 }
3031
3032 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
3033                                 gva_t va, int level)
3034 {
3035         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
3036         int i;
3037         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
3038
3039         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
3040                 u64 ent = pt[i];
3041
3042                 if (ent == shadow_trap_nonpresent_pte)
3043                         continue;
3044
3045                 va = canonicalize(va);
3046                 if (level > 1) {
3047                         if (ent == shadow_notrap_nonpresent_pte)
3048                                 printk(KERN_ERR "audit: (%s) nontrapping pte"
3049                                        " in nonleaf level: levels %d gva %lx"
3050                                        " level %d pte %llx\n", audit_msg,
3051                                        vcpu->arch.mmu.root_level, va, level, ent);
3052
3053                         audit_mappings_page(vcpu, ent, va, level - 1);
3054                 } else {
3055                         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
3056                         hpa_t hpa = (hpa_t)gpa_to_pfn(vcpu, gpa) << PAGE_SHIFT;
3057
3058                         if (is_shadow_present_pte(ent)
3059                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
3060                                 printk(KERN_ERR "xx audit error: (%s) levels %d"
3061                                        " gva %lx gpa %llx hpa %llx ent %llx %d\n",
3062                                        audit_msg, vcpu->arch.mmu.root_level,
3063                                        va, gpa, hpa, ent,
3064                                        is_shadow_present_pte(ent));
3065                         else if (ent == shadow_notrap_nonpresent_pte
3066                                  && !is_error_hpa(hpa))
3067                                 printk(KERN_ERR "audit: (%s) notrap shadow,"
3068                                        " valid guest gva %lx\n", audit_msg, va);
3069                         kvm_release_pfn_clean(pfn);
3070
3071                 }
3072         }
3073 }
3074
3075 static void audit_mappings(struct kvm_vcpu *vcpu)
3076 {
3077         unsigned i;
3078
3079         if (vcpu->arch.mmu.root_level == 4)
3080                 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
3081         else
3082                 for (i = 0; i < 4; ++i)
3083                         if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
3084                                 audit_mappings_page(vcpu,
3085                                                     vcpu->arch.mmu.pae_root[i],
3086                                                     i << 30,
3087                                                     2);
3088 }
3089
3090 static int count_rmaps(struct kvm_vcpu *vcpu)
3091 {
3092         int nmaps = 0;
3093         int i, j, k;
3094
3095         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
3096                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
3097                 struct kvm_rmap_desc *d;
3098
3099                 for (j = 0; j < m->npages; ++j) {
3100                         unsigned long *rmapp = &m->rmap[j];
3101
3102                         if (!*rmapp)
3103                                 continue;
3104                         if (!(*rmapp & 1)) {
3105                                 ++nmaps;
3106                                 continue;
3107                         }
3108                         d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
3109                         while (d) {
3110                                 for (k = 0; k < RMAP_EXT; ++k)
3111                                         if (d->shadow_ptes[k])
3112                                                 ++nmaps;
3113                                         else
3114                                                 break;
3115                                 d = d->more;
3116                         }
3117                 }
3118         }
3119         return nmaps;
3120 }
3121
3122 static int count_writable_mappings(struct kvm_vcpu *vcpu)
3123 {
3124         int nmaps = 0;
3125         struct kvm_mmu_page *sp;
3126         int i;
3127
3128         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3129                 u64 *pt = sp->spt;
3130
3131                 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
3132                         continue;
3133
3134                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
3135                         u64 ent = pt[i];
3136
3137                         if (!(ent & PT_PRESENT_MASK))
3138                                 continue;
3139                         if (!(ent & PT_WRITABLE_MASK))
3140                                 continue;
3141                         ++nmaps;
3142                 }
3143         }
3144         return nmaps;
3145 }
3146
3147 static void audit_rmap(struct kvm_vcpu *vcpu)
3148 {
3149         int n_rmap = count_rmaps(vcpu);
3150         int n_actual = count_writable_mappings(vcpu);
3151
3152         if (n_rmap != n_actual)
3153                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
3154                        __func__, audit_msg, n_rmap, n_actual);
3155 }
3156
3157 static void audit_write_protection(struct kvm_vcpu *vcpu)
3158 {
3159         struct kvm_mmu_page *sp;
3160         struct kvm_memory_slot *slot;
3161         unsigned long *rmapp;
3162         gfn_t gfn;
3163
3164         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
3165                 if (sp->role.metaphysical)
3166                         continue;
3167
3168                 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
3169                 slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
3170                 rmapp = &slot->rmap[gfn - slot->base_gfn];
3171                 if (*rmapp)
3172                         printk(KERN_ERR "%s: (%s) shadow page has writable"
3173                                " mappings: gfn %lx role %x\n",
3174                                __func__, audit_msg, sp->gfn,
3175                                sp->role.word);
3176         }
3177 }
3178
3179 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
3180 {
3181         int olddbg = dbg;
3182
3183         dbg = 0;
3184         audit_msg = msg;
3185         audit_rmap(vcpu);
3186         audit_write_protection(vcpu);
3187         audit_mappings(vcpu);
3188         dbg = olddbg;
3189 }
3190
3191 #endif