arch/x86/kvm/mmu.c

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