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
  31 #include <asm/page.h>
  32 #include <asm/cmpxchg.h>
  33 #include <asm/io.h>
  34
  35 #undef MMU_DEBUG
  36
  37 #undef AUDIT
  38
  39 #ifdef AUDIT
  40 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg);
  41 #else
  42 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {}
  43 #endif
  44
  45 #ifdef MMU_DEBUG
  46
  47 #define pgprintk(x...) do { if (dbg) printk(x); } while (0)
  48 #define rmap_printk(x...) do { if (dbg) printk(x); } while (0)
  49
  50 #else
  51
  52 #define pgprintk(x...) do { } while (0)
  53 #define rmap_printk(x...) do { } while (0)
  54
  55 #endif
  56
  57 #if defined(MMU_DEBUG) || defined(AUDIT)
  58 static int dbg = 1;
  59 #endif
  60
  61 #ifndef MMU_DEBUG
  62 #define ASSERT(x) do { } while (0)
  63 #else
  64 #define ASSERT(x)                                                       \
  65         if (!(x)) {                                                     \
  66                 printk(KERN_WARNING "assertion failed %s:%d: %s\n",     \
  67                        __FILE__, __LINE__, #x);                         \
  68         }
  69 #endif
  70
  71 #define PT64_PT_BITS 9
  72 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
  73 #define PT32_PT_BITS 10
  74 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
  75
  76 #define PT_WRITABLE_SHIFT 1
  77
  78 #define PT_PRESENT_MASK (1ULL << 0)
  79 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
  80 #define PT_USER_MASK (1ULL << 2)
  81 #define PT_PWT_MASK (1ULL << 3)
  82 #define PT_PCD_MASK (1ULL << 4)
  83 #define PT_ACCESSED_MASK (1ULL << 5)
  84 #define PT_DIRTY_MASK (1ULL << 6)
  85 #define PT_PAGE_SIZE_MASK (1ULL << 7)
  86 #define PT_PAT_MASK (1ULL << 7)
  87 #define PT_GLOBAL_MASK (1ULL << 8)
  88 #define PT64_NX_SHIFT 63
  89 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
  90
  91 #define PT_PAT_SHIFT 7
  92 #define PT_DIR_PAT_SHIFT 12
  93 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
  94
  95 #define PT32_DIR_PSE36_SIZE 4
  96 #define PT32_DIR_PSE36_SHIFT 13
  97 #define PT32_DIR_PSE36_MASK \
  98         (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
  99
 100
 101 #define PT_FIRST_AVAIL_BITS_SHIFT 9
 102 #define PT64_SECOND_AVAIL_BITS_SHIFT 52
 103
 104 #define PT_SHADOW_IO_MARK (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)
 105
 106 #define VALID_PAGE(x) ((x) != INVALID_PAGE)
 107
 108 #define PT64_LEVEL_BITS 9
 109
 110 #define PT64_LEVEL_SHIFT(level) \
 111                 (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS)
 112
 113 #define PT64_LEVEL_MASK(level) \
 114                 (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level))
 115
 116 #define PT64_INDEX(address, level)\
 117         (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1))
 118
 119
 120 #define PT32_LEVEL_BITS 10
 121
 122 #define PT32_LEVEL_SHIFT(level) \
 123                 (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS)
 124
 125 #define PT32_LEVEL_MASK(level) \
 126                 (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level))
 127
 128 #define PT32_INDEX(address, level)\
 129         (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))
 130
 131
 132 #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
 133 #define PT64_DIR_BASE_ADDR_MASK \
 134         (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
 135
 136 #define PT32_BASE_ADDR_MASK PAGE_MASK
 137 #define PT32_DIR_BASE_ADDR_MASK \
 138         (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1))
 139
 140 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
 141                         | PT64_NX_MASK)
 142
 143 #define PFERR_PRESENT_MASK (1U << 0)
 144 #define PFERR_WRITE_MASK (1U << 1)
 145 #define PFERR_USER_MASK (1U << 2)
 146 #define PFERR_FETCH_MASK (1U << 4)
 147
 148 #define PT64_ROOT_LEVEL 4
 149 #define PT32_ROOT_LEVEL 2
 150 #define PT32E_ROOT_LEVEL 3
 151
 152 #define PT_DIRECTORY_LEVEL 2
 153 #define PT_PAGE_TABLE_LEVEL 1
 154
 155 #define RMAP_EXT 4
 156
 157 #define ACC_EXEC_MASK    1
 158 #define ACC_WRITE_MASK   PT_WRITABLE_MASK
 159 #define ACC_USER_MASK    PT_USER_MASK
 160 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
 161
 162 struct kvm_rmap_desc {
 163         u64 *shadow_ptes[RMAP_EXT];
 164         struct kvm_rmap_desc *more;
 165 };
 166
 167 static struct kmem_cache *pte_chain_cache;
 168 static struct kmem_cache *rmap_desc_cache;
 169 static struct kmem_cache *mmu_page_header_cache;
 170
 171 static u64 __read_mostly shadow_trap_nonpresent_pte;
 172 static u64 __read_mostly shadow_notrap_nonpresent_pte;
 173
 174 void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte)
 175 {
 176         shadow_trap_nonpresent_pte = trap_pte;
 177         shadow_notrap_nonpresent_pte = notrap_pte;
 178 }
 179 EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes);
 180
 181 static int is_write_protection(struct kvm_vcpu *vcpu)
 182 {
 183         return vcpu->arch.cr0 & X86_CR0_WP;
 184 }
 185
 186 static int is_cpuid_PSE36(void)
 187 {
 188         return 1;
 189 }
 190
 191 static int is_nx(struct kvm_vcpu *vcpu)
 192 {
 193         return vcpu->arch.shadow_efer & EFER_NX;
 194 }
 195
 196 static int is_present_pte(unsigned long pte)
 197 {
 198         return pte & PT_PRESENT_MASK;
 199 }
 200
 201 static int is_shadow_present_pte(u64 pte)
 202 {
 203         pte &= ~PT_SHADOW_IO_MARK;
 204         return pte != shadow_trap_nonpresent_pte
 205                 && pte != shadow_notrap_nonpresent_pte;
 206 }
 207
 208 static int is_writeble_pte(unsigned long pte)
 209 {
 210         return pte & PT_WRITABLE_MASK;
 211 }
 212
 213 static int is_dirty_pte(unsigned long pte)
 214 {
 215         return pte & PT_DIRTY_MASK;
 216 }
 217
 218 static int is_io_pte(unsigned long pte)
 219 {
 220         return pte & PT_SHADOW_IO_MARK;
 221 }
 222
 223 static int is_rmap_pte(u64 pte)
 224 {
 225         return pte != shadow_trap_nonpresent_pte
 226                 && pte != shadow_notrap_nonpresent_pte;
 227 }
 228
 229 static gfn_t pse36_gfn_delta(u32 gpte)
 230 {
 231         int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT;
 232
 233         return (gpte & PT32_DIR_PSE36_MASK) << shift;
 234 }
 235
 236 static void set_shadow_pte(u64 *sptep, u64 spte)
 237 {
 238 #ifdef CONFIG_X86_64
 239         set_64bit((unsigned long *)sptep, spte);
 240 #else
 241         set_64bit((unsigned long long *)sptep, spte);
 242 #endif
 243 }
 244
 245 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
 246                                   struct kmem_cache *base_cache, int min)
 247 {
 248         void *obj;
 249
 250         if (cache->nobjs >= min)
 251                 return 0;
 252         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 253                 obj = kmem_cache_zalloc(base_cache, GFP_KERNEL);
 254                 if (!obj)
 255                         return -ENOMEM;
 256                 cache->objects[cache->nobjs++] = obj;
 257         }
 258         return 0;
 259 }
 260
 261 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 262 {
 263         while (mc->nobjs)
 264                 kfree(mc->objects[--mc->nobjs]);
 265 }
 266
 267 static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
 268                                        int min)
 269 {
 270         struct page *page;
 271
 272         if (cache->nobjs >= min)
 273                 return 0;
 274         while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
 275                 page = alloc_page(GFP_KERNEL);
 276                 if (!page)
 277                         return -ENOMEM;
 278                 set_page_private(page, 0);
 279                 cache->objects[cache->nobjs++] = page_address(page);
 280         }
 281         return 0;
 282 }
 283
 284 static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
 285 {
 286         while (mc->nobjs)
 287                 free_page((unsigned long)mc->objects[--mc->nobjs]);
 288 }
 289
 290 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 291 {
 292         int r;
 293
 294         r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache,
 295                                    pte_chain_cache, 4);
 296         if (r)
 297                 goto out;
 298         r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache,
 299                                    rmap_desc_cache, 1);
 300         if (r)
 301                 goto out;
 302         r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
 303         if (r)
 304                 goto out;
 305         r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache,
 306                                    mmu_page_header_cache, 4);
 307 out:
 308         return r;
 309 }
 310
 311 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 312 {
 313         mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache);
 314         mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache);
 315         mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
 316         mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
 317 }
 318
 319 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
 320                                     size_t size)
 321 {
 322         void *p;
 323
 324         BUG_ON(!mc->nobjs);
 325         p = mc->objects[--mc->nobjs];
 326         memset(p, 0, size);
 327         return p;
 328 }
 329
 330 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
 331 {
 332         return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache,
 333                                       sizeof(struct kvm_pte_chain));
 334 }
 335
 336 static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
 337 {
 338         kfree(pc);
 339 }
 340
 341 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
 342 {
 343         return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache,
 344                                       sizeof(struct kvm_rmap_desc));
 345 }
 346
 347 static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 348 {
 349         kfree(rd);
 350 }
 351
 352 /*
 353  * Take gfn and return the reverse mapping to it.
 354  * Note: gfn must be unaliased before this function get called
 355  */
 356
 357 static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn)
 358 {
 359         struct kvm_memory_slot *slot;
 360
 361         slot = gfn_to_memslot(kvm, gfn);
 362         return &slot->rmap[gfn - slot->base_gfn];
 363 }
 364
 365 /*
 366  * Reverse mapping data structures:
 367  *
 368  * If rmapp bit zero is zero, then rmapp point to the shadw page table entry
 369  * that points to page_address(page).
 370  *
 371  * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc
 372  * containing more mappings.
 373  */
 374 static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn)
 375 {
 376         struct kvm_mmu_page *sp;
 377         struct kvm_rmap_desc *desc;
 378         unsigned long *rmapp;
 379         int i;
 380
 381         if (!is_rmap_pte(*spte))
 382                 return;
 383         gfn = unalias_gfn(vcpu->kvm, gfn);
 384         sp = page_header(__pa(spte));
 385         sp->gfns[spte - sp->spt] = gfn;
 386         rmapp = gfn_to_rmap(vcpu->kvm, gfn);
 387         if (!*rmapp) {
 388                 rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte);
 389                 *rmapp = (unsigned long)spte;
 390         } else if (!(*rmapp & 1)) {
 391                 rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte);
 392                 desc = mmu_alloc_rmap_desc(vcpu);
 393                 desc->shadow_ptes[0] = (u64 *)*rmapp;
 394                 desc->shadow_ptes[1] = spte;
 395                 *rmapp = (unsigned long)desc | 1;
 396         } else {
 397                 rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte);
 398                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 399                 while (desc->shadow_ptes[RMAP_EXT-1] && desc->more)
 400                         desc = desc->more;
 401                 if (desc->shadow_ptes[RMAP_EXT-1]) {
 402                         desc->more = mmu_alloc_rmap_desc(vcpu);
 403                         desc = desc->more;
 404                 }
 405                 for (i = 0; desc->shadow_ptes[i]; ++i)
 406                         ;
 407                 desc->shadow_ptes[i] = spte;
 408         }
 409 }
 410
 411 static void rmap_desc_remove_entry(unsigned long *rmapp,
 412                                    struct kvm_rmap_desc *desc,
 413                                    int i,
 414                                    struct kvm_rmap_desc *prev_desc)
 415 {
 416         int j;
 417
 418         for (j = RMAP_EXT - 1; !desc->shadow_ptes[j] && j > i; --j)
 419                 ;
 420         desc->shadow_ptes[i] = desc->shadow_ptes[j];
 421         desc->shadow_ptes[j] = NULL;
 422         if (j != 0)
 423                 return;
 424         if (!prev_desc && !desc->more)
 425                 *rmapp = (unsigned long)desc->shadow_ptes[0];
 426         else
 427                 if (prev_desc)
 428                         prev_desc->more = desc->more;
 429                 else
 430                         *rmapp = (unsigned long)desc->more | 1;
 431         mmu_free_rmap_desc(desc);
 432 }
 433
 434 static void rmap_remove(struct kvm *kvm, u64 *spte)
 435 {
 436         struct kvm_rmap_desc *desc;
 437         struct kvm_rmap_desc *prev_desc;
 438         struct kvm_mmu_page *sp;
 439         struct page *page;
 440         unsigned long *rmapp;
 441         int i;
 442
 443         if (!is_rmap_pte(*spte))
 444                 return;
 445         sp = page_header(__pa(spte));
 446         page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
 447         mark_page_accessed(page);
 448         if (is_writeble_pte(*spte))
 449                 kvm_release_page_dirty(page);
 450         else
 451                 kvm_release_page_clean(page);
 452         rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt]);
 453         if (!*rmapp) {
 454                 printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte);
 455                 BUG();
 456         } else if (!(*rmapp & 1)) {
 457                 rmap_printk("rmap_remove:  %p %llx 1->0\n", spte, *spte);
 458                 if ((u64 *)*rmapp != spte) {
 459                         printk(KERN_ERR "rmap_remove:  %p %llx 1->BUG\n",
 460                                spte, *spte);
 461                         BUG();
 462                 }
 463                 *rmapp = 0;
 464         } else {
 465                 rmap_printk("rmap_remove:  %p %llx many->many\n", spte, *spte);
 466                 desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 467                 prev_desc = NULL;
 468                 while (desc) {
 469                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
 470                                 if (desc->shadow_ptes[i] == spte) {
 471                                         rmap_desc_remove_entry(rmapp,
 472                                                                desc, i,
 473                                                                prev_desc);
 474                                         return;
 475                                 }
 476                         prev_desc = desc;
 477                         desc = desc->more;
 478                 }
 479                 BUG();
 480         }
 481 }
 482
 483 static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte)
 484 {
 485         struct kvm_rmap_desc *desc;
 486         struct kvm_rmap_desc *prev_desc;
 487         u64 *prev_spte;
 488         int i;
 489
 490         if (!*rmapp)
 491                 return NULL;
 492         else if (!(*rmapp & 1)) {
 493                 if (!spte)
 494                         return (u64 *)*rmapp;
 495                 return NULL;
 496         }
 497         desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
 498         prev_desc = NULL;
 499         prev_spte = NULL;
 500         while (desc) {
 501                 for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i) {
 502                         if (prev_spte == spte)
 503                                 return desc->shadow_ptes[i];
 504                         prev_spte = desc->shadow_ptes[i];
 505                 }
 506                 desc = desc->more;
 507         }
 508         return NULL;
 509 }
 510
 511 static void rmap_write_protect(struct kvm *kvm, u64 gfn)
 512 {
 513         unsigned long *rmapp;
 514         u64 *spte;
 515         int write_protected = 0;
 516
 517         gfn = unalias_gfn(kvm, gfn);
 518         rmapp = gfn_to_rmap(kvm, gfn);
 519
 520         spte = rmap_next(kvm, rmapp, NULL);
 521         while (spte) {
 522                 BUG_ON(!spte);
 523                 BUG_ON(!(*spte & PT_PRESENT_MASK));
 524                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 525                 if (is_writeble_pte(*spte)) {
 526                         set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
 527                         write_protected = 1;
 528                 }
 529                 spte = rmap_next(kvm, rmapp, spte);
 530         }
 531         if (write_protected)
 532                 kvm_flush_remote_tlbs(kvm);
 533 }
 534
 535 #ifdef MMU_DEBUG
 536 static int is_empty_shadow_page(u64 *spt)
 537 {
 538         u64 *pos;
 539         u64 *end;
 540
 541         for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++)
 542                 if ((*pos & ~PT_SHADOW_IO_MARK) != shadow_trap_nonpresent_pte) {
 543                         printk(KERN_ERR "%s: %p %llx\n", __FUNCTION__,
 544                                pos, *pos);
 545                         return 0;
 546                 }
 547         return 1;
 548 }
 549 #endif
 550
 551 static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 552 {
 553         ASSERT(is_empty_shadow_page(sp->spt));
 554         list_del(&sp->link);
 555         __free_page(virt_to_page(sp->spt));
 556         __free_page(virt_to_page(sp->gfns));
 557         kfree(sp);
 558         ++kvm->arch.n_free_mmu_pages;
 559 }
 560
 561 static unsigned kvm_page_table_hashfn(gfn_t gfn)
 562 {
 563         return gfn;
 564 }
 565
 566 static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
 567                                                u64 *parent_pte)
 568 {
 569         struct kvm_mmu_page *sp;
 570
 571         sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp);
 572         sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 573         sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE);
 574         set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
 575         list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
 576         ASSERT(is_empty_shadow_page(sp->spt));
 577         sp->slot_bitmap = 0;
 578         sp->multimapped = 0;
 579         sp->parent_pte = parent_pte;
 580         --vcpu->kvm->arch.n_free_mmu_pages;
 581         return sp;
 582 }
 583
 584 static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
 585                                     struct kvm_mmu_page *sp, u64 *parent_pte)
 586 {
 587         struct kvm_pte_chain *pte_chain;
 588         struct hlist_node *node;
 589         int i;
 590
 591         if (!parent_pte)
 592                 return;
 593         if (!sp->multimapped) {
 594                 u64 *old = sp->parent_pte;
 595
 596                 if (!old) {
 597                         sp->parent_pte = parent_pte;
 598                         return;
 599                 }
 600                 sp->multimapped = 1;
 601                 pte_chain = mmu_alloc_pte_chain(vcpu);
 602                 INIT_HLIST_HEAD(&sp->parent_ptes);
 603                 hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 604                 pte_chain->parent_ptes[0] = old;
 605         }
 606         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) {
 607                 if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1])
 608                         continue;
 609                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i)
 610                         if (!pte_chain->parent_ptes[i]) {
 611                                 pte_chain->parent_ptes[i] = parent_pte;
 612                                 return;
 613                         }
 614         }
 615         pte_chain = mmu_alloc_pte_chain(vcpu);
 616         BUG_ON(!pte_chain);
 617         hlist_add_head(&pte_chain->link, &sp->parent_ptes);
 618         pte_chain->parent_ptes[0] = parent_pte;
 619 }
 620
 621 static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp,
 622                                        u64 *parent_pte)
 623 {
 624         struct kvm_pte_chain *pte_chain;
 625         struct hlist_node *node;
 626         int i;
 627
 628         if (!sp->multimapped) {
 629                 BUG_ON(sp->parent_pte != parent_pte);
 630                 sp->parent_pte = NULL;
 631                 return;
 632         }
 633         hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link)
 634                 for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) {
 635                         if (!pte_chain->parent_ptes[i])
 636                                 break;
 637                         if (pte_chain->parent_ptes[i] != parent_pte)
 638                                 continue;
 639                         while (i + 1 < NR_PTE_CHAIN_ENTRIES
 640                                 && pte_chain->parent_ptes[i + 1]) {
 641                                 pte_chain->parent_ptes[i]
 642                                         = pte_chain->parent_ptes[i + 1];
 643                                 ++i;
 644                         }
 645                         pte_chain->parent_ptes[i] = NULL;
 646                         if (i == 0) {
 647                                 hlist_del(&pte_chain->link);
 648                                 mmu_free_pte_chain(pte_chain);
 649                                 if (hlist_empty(&sp->parent_ptes)) {
 650                                         sp->multimapped = 0;
 651                                         sp->parent_pte = NULL;
 652                                 }
 653                         }
 654                         return;
 655                 }
 656         BUG();
 657 }
 658
 659 static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn)
 660 {
 661         unsigned index;
 662         struct hlist_head *bucket;
 663         struct kvm_mmu_page *sp;
 664         struct hlist_node *node;
 665
 666         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
 667         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 668         bucket = &kvm->arch.mmu_page_hash[index];
 669         hlist_for_each_entry(sp, node, bucket, hash_link)
 670                 if (sp->gfn == gfn && !sp->role.metaphysical) {
 671                         pgprintk("%s: found role %x\n",
 672                                  __FUNCTION__, sp->role.word);
 673                         return sp;
 674                 }
 675         return NULL;
 676 }
 677
 678 static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
 679                                              gfn_t gfn,
 680                                              gva_t gaddr,
 681                                              unsigned level,
 682                                              int metaphysical,
 683                                              unsigned access,
 684                                              u64 *parent_pte,
 685                                              bool *new_page)
 686 {
 687         union kvm_mmu_page_role role;
 688         unsigned index;
 689         unsigned quadrant;
 690         struct hlist_head *bucket;
 691         struct kvm_mmu_page *sp;
 692         struct hlist_node *node;
 693
 694         role.word = 0;
 695         role.glevels = vcpu->arch.mmu.root_level;
 696         role.level = level;
 697         role.metaphysical = metaphysical;
 698         role.access = access;
 699         if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) {
 700                 quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
 701                 quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
 702                 role.quadrant = quadrant;
 703         }
 704         pgprintk("%s: looking gfn %lx role %x\n", __FUNCTION__,
 705                  gfn, role.word);
 706         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 707         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
 708         hlist_for_each_entry(sp, node, bucket, hash_link)
 709                 if (sp->gfn == gfn && sp->role.word == role.word) {
 710                         mmu_page_add_parent_pte(vcpu, sp, parent_pte);
 711                         pgprintk("%s: found\n", __FUNCTION__);
 712                         return sp;
 713                 }
 714         ++vcpu->kvm->stat.mmu_cache_miss;
 715         sp = kvm_mmu_alloc_page(vcpu, parent_pte);
 716         if (!sp)
 717                 return sp;
 718         pgprintk("%s: adding gfn %lx role %x\n", __FUNCTION__, gfn, role.word);
 719         sp->gfn = gfn;
 720         sp->role = role;
 721         hlist_add_head(&sp->hash_link, bucket);
 722         vcpu->arch.mmu.prefetch_page(vcpu, sp);
 723         if (!metaphysical)
 724                 rmap_write_protect(vcpu->kvm, gfn);
 725         if (new_page)
 726                 *new_page = 1;
 727         return sp;
 728 }
 729
 730 static void kvm_mmu_page_unlink_children(struct kvm *kvm,
 731                                          struct kvm_mmu_page *sp)
 732 {
 733         unsigned i;
 734         u64 *pt;
 735         u64 ent;
 736
 737         pt = sp->spt;
 738
 739         if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
 740                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 741                         if (is_shadow_present_pte(pt[i]))
 742                                 rmap_remove(kvm, &pt[i]);
 743                         pt[i] = shadow_trap_nonpresent_pte;
 744                 }
 745                 kvm_flush_remote_tlbs(kvm);
 746                 return;
 747         }
 748
 749         for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 750                 ent = pt[i];
 751
 752                 pt[i] = shadow_trap_nonpresent_pte;
 753                 if (!is_shadow_present_pte(ent))
 754                         continue;
 755                 ent &= PT64_BASE_ADDR_MASK;
 756                 mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
 757         }
 758         kvm_flush_remote_tlbs(kvm);
 759 }
 760
 761 static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte)
 762 {
 763         mmu_page_remove_parent_pte(sp, parent_pte);
 764 }
 765
 766 static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm)
 767 {
 768         int i;
 769
 770         for (i = 0; i < KVM_MAX_VCPUS; ++i)
 771                 if (kvm->vcpus[i])
 772                         kvm->vcpus[i]->arch.last_pte_updated = NULL;
 773 }
 774
 775 static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 776 {
 777         u64 *parent_pte;
 778
 779         ++kvm->stat.mmu_shadow_zapped;
 780         while (sp->multimapped || sp->parent_pte) {
 781                 if (!sp->multimapped)
 782                         parent_pte = sp->parent_pte;
 783                 else {
 784                         struct kvm_pte_chain *chain;
 785
 786                         chain = container_of(sp->parent_ptes.first,
 787                                              struct kvm_pte_chain, link);
 788                         parent_pte = chain->parent_ptes[0];
 789                 }
 790                 BUG_ON(!parent_pte);
 791                 kvm_mmu_put_page(sp, parent_pte);
 792                 set_shadow_pte(parent_pte, shadow_trap_nonpresent_pte);
 793         }
 794         kvm_mmu_page_unlink_children(kvm, sp);
 795         if (!sp->root_count) {
 796                 hlist_del(&sp->hash_link);
 797                 kvm_mmu_free_page(kvm, sp);
 798         } else
 799                 list_move(&sp->link, &kvm->arch.active_mmu_pages);
 800         kvm_mmu_reset_last_pte_updated(kvm);
 801 }
 802
 803 /*
 804  * Changing the number of mmu pages allocated to the vm
 805  * Note: if kvm_nr_mmu_pages is too small, you will get dead lock
 806  */
 807 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages)
 808 {
 809         /*
 810          * If we set the number of mmu pages to be smaller be than the
 811          * number of actived pages , we must to free some mmu pages before we
 812          * change the value
 813          */
 814
 815         if ((kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages) >
 816             kvm_nr_mmu_pages) {
 817                 int n_used_mmu_pages = kvm->arch.n_alloc_mmu_pages
 818                                        - kvm->arch.n_free_mmu_pages;
 819
 820                 while (n_used_mmu_pages > kvm_nr_mmu_pages) {
 821                         struct kvm_mmu_page *page;
 822
 823                         page = container_of(kvm->arch.active_mmu_pages.prev,
 824                                             struct kvm_mmu_page, link);
 825                         kvm_mmu_zap_page(kvm, page);
 826                         n_used_mmu_pages--;
 827                 }
 828                 kvm->arch.n_free_mmu_pages = 0;
 829         }
 830         else
 831                 kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages
 832                                          - kvm->arch.n_alloc_mmu_pages;
 833
 834         kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages;
 835 }
 836
 837 static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn)
 838 {
 839         unsigned index;
 840         struct hlist_head *bucket;
 841         struct kvm_mmu_page *sp;
 842         struct hlist_node *node, *n;
 843         int r;
 844
 845         pgprintk("%s: looking for gfn %lx\n", __FUNCTION__, gfn);
 846         r = 0;
 847         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
 848         bucket = &kvm->arch.mmu_page_hash[index];
 849         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link)
 850                 if (sp->gfn == gfn && !sp->role.metaphysical) {
 851                         pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
 852                                  sp->role.word);
 853                         kvm_mmu_zap_page(kvm, sp);
 854                         r = 1;
 855                 }
 856         return r;
 857 }
 858
 859 static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
 860 {
 861         struct kvm_mmu_page *sp;
 862
 863         while ((sp = kvm_mmu_lookup_page(kvm, gfn)) != NULL) {
 864                 pgprintk("%s: zap %lx %x\n", __FUNCTION__, gfn, sp->role.word);
 865                 kvm_mmu_zap_page(kvm, sp);
 866         }
 867 }
 868
 869 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
 870 {
 871         int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
 872         struct kvm_mmu_page *sp = page_header(__pa(pte));
 873
 874         __set_bit(slot, &sp->slot_bitmap);
 875 }
 876
 877 struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
 878 {
 879         struct page *page;
 880
 881         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
 882
 883         if (gpa == UNMAPPED_GVA)
 884                 return NULL;
 885
 886         down_read(&current->mm->mmap_sem);
 887         page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
 888         up_read(&current->mm->mmap_sem);
 889
 890         return page;
 891 }
 892
 893 static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
 894                          unsigned pt_access, unsigned pte_access,
 895                          int user_fault, int write_fault, int dirty,
 896                          int *ptwrite, gfn_t gfn, struct page *page)
 897 {
 898         u64 spte;
 899         int was_rmapped = is_rmap_pte(*shadow_pte);
 900         int was_writeble = is_writeble_pte(*shadow_pte);
 901
 902         pgprintk("%s: spte %llx access %x write_fault %d"
 903                  " user_fault %d gfn %lx\n",
 904                  __FUNCTION__, *shadow_pte, pt_access,
 905                  write_fault, user_fault, gfn);
 906
 907         /*
 908          * We don't set the accessed bit, since we sometimes want to see
 909          * whether the guest actually used the pte (in order to detect
 910          * demand paging).
 911          */
 912         spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
 913         if (!dirty)
 914                 pte_access &= ~ACC_WRITE_MASK;
 915         if (!(pte_access & ACC_EXEC_MASK))
 916                 spte |= PT64_NX_MASK;
 917
 918         spte |= PT_PRESENT_MASK;
 919         if (pte_access & ACC_USER_MASK)
 920                 spte |= PT_USER_MASK;
 921
 922         if (is_error_page(page)) {
 923                 set_shadow_pte(shadow_pte,
 924                                shadow_trap_nonpresent_pte | PT_SHADOW_IO_MARK);
 925                 kvm_release_page_clean(page);
 926                 return;
 927         }
 928
 929         spte |= page_to_phys(page);
 930
 931         if ((pte_access & ACC_WRITE_MASK)
 932             || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
 933                 struct kvm_mmu_page *shadow;
 934
 935                 spte |= PT_WRITABLE_MASK;
 936                 if (user_fault) {
 937                         mmu_unshadow(vcpu->kvm, gfn);
 938                         goto unshadowed;
 939                 }
 940
 941                 shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn);
 942                 if (shadow) {
 943                         pgprintk("%s: found shadow page for %lx, marking ro\n",
 944                                  __FUNCTION__, gfn);
 945                         pte_access &= ~ACC_WRITE_MASK;
 946                         if (is_writeble_pte(spte)) {
 947                                 spte &= ~PT_WRITABLE_MASK;
 948                                 kvm_x86_ops->tlb_flush(vcpu);
 949                         }
 950                         if (write_fault)
 951                                 *ptwrite = 1;
 952                 }
 953         }
 954
 955 unshadowed:
 956
 957         if (pte_access & ACC_WRITE_MASK)
 958                 mark_page_dirty(vcpu->kvm, gfn);
 959
 960         pgprintk("%s: setting spte %llx\n", __FUNCTION__, spte);
 961         set_shadow_pte(shadow_pte, spte);
 962         page_header_update_slot(vcpu->kvm, shadow_pte, gfn);
 963         if (!was_rmapped) {
 964                 rmap_add(vcpu, shadow_pte, gfn);
 965                 if (!is_rmap_pte(*shadow_pte))
 966                         kvm_release_page_clean(page);
 967         } else {
 968                 if (was_writeble)
 969                         kvm_release_page_dirty(page);
 970                 else
 971                         kvm_release_page_clean(page);
 972         }
 973         if (!ptwrite || !*ptwrite)
 974                 vcpu->arch.last_pte_updated = shadow_pte;
 975 }
 976
 977 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
 978 {
 979 }
 980
 981 static int __nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write,
 982                            gfn_t gfn, struct page *page)
 983 {
 984         int level = PT32E_ROOT_LEVEL;
 985         hpa_t table_addr = vcpu->arch.mmu.root_hpa;
 986         int pt_write = 0;
 987
 988         for (; ; level--) {
 989                 u32 index = PT64_INDEX(v, level);
 990                 u64 *table;
 991
 992                 ASSERT(VALID_PAGE(table_addr));
 993                 table = __va(table_addr);
 994
 995                 if (level == 1) {
 996                         mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
 997                                      0, write, 1, &pt_write, gfn, page);
 998                         return pt_write || is_io_pte(table[index]);
 999                 }
1000
1001                 if (table[index] == shadow_trap_nonpresent_pte) {
1002                         struct kvm_mmu_page *new_table;
1003                         gfn_t pseudo_gfn;
1004
1005                         pseudo_gfn = (v & PT64_DIR_BASE_ADDR_MASK)
1006                                 >> PAGE_SHIFT;
1007                         new_table = kvm_mmu_get_page(vcpu, pseudo_gfn,
1008                                                      v, level - 1,
1009                                                      1, ACC_ALL, &table[index],
1010                                                      NULL);
1011                         if (!new_table) {
1012                                 pgprintk("nonpaging_map: ENOMEM\n");
1013                                 kvm_release_page_clean(page);
1014                                 return -ENOMEM;
1015                         }
1016
1017                         table[index] = __pa(new_table->spt) | PT_PRESENT_MASK
1018                                 | PT_WRITABLE_MASK | PT_USER_MASK;
1019                 }
1020                 table_addr = table[index] & PT64_BASE_ADDR_MASK;
1021         }
1022 }
1023
1024 static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
1025 {
1026         int r;
1027
1028         struct page *page;
1029
1030         down_read(&vcpu->kvm->slots_lock);
1031
1032         down_read(&current->mm->mmap_sem);
1033         page = gfn_to_page(vcpu->kvm, gfn);
1034         up_read(&current->mm->mmap_sem);
1035
1036         spin_lock(&vcpu->kvm->mmu_lock);
1037         kvm_mmu_free_some_pages(vcpu);
1038         r = __nonpaging_map(vcpu, v, write, gfn, page);
1039         spin_unlock(&vcpu->kvm->mmu_lock);
1040
1041         up_read(&vcpu->kvm->slots_lock);
1042
1043         return r;
1044 }
1045
1046
1047 static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu,
1048                                     struct kvm_mmu_page *sp)
1049 {
1050         int i;
1051
1052         for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1053                 sp->spt[i] = shadow_trap_nonpresent_pte;
1054 }
1055
1056 static void mmu_free_roots(struct kvm_vcpu *vcpu)
1057 {
1058         int i;
1059         struct kvm_mmu_page *sp;
1060
1061         if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
1062                 return;
1063         spin_lock(&vcpu->kvm->mmu_lock);
1064 #ifdef CONFIG_X86_64
1065         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1066                 hpa_t root = vcpu->arch.mmu.root_hpa;
1067
1068                 sp = page_header(root);
1069                 --sp->root_count;
1070                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1071                 spin_unlock(&vcpu->kvm->mmu_lock);
1072                 return;
1073         }
1074 #endif
1075         for (i = 0; i < 4; ++i) {
1076                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1077
1078                 if (root) {
1079                         root &= PT64_BASE_ADDR_MASK;
1080                         sp = page_header(root);
1081                         --sp->root_count;
1082                 }
1083                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1084         }
1085         spin_unlock(&vcpu->kvm->mmu_lock);
1086         vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1087 }
1088
1089 static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
1090 {
1091         int i;
1092         gfn_t root_gfn;
1093         struct kvm_mmu_page *sp;
1094
1095         root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
1096
1097 #ifdef CONFIG_X86_64
1098         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
1099                 hpa_t root = vcpu->arch.mmu.root_hpa;
1100
1101                 ASSERT(!VALID_PAGE(root));
1102                 sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
1103                                       PT64_ROOT_LEVEL, 0, ACC_ALL, NULL, NULL);
1104                 root = __pa(sp->spt);
1105                 ++sp->root_count;
1106                 vcpu->arch.mmu.root_hpa = root;
1107                 return;
1108         }
1109 #endif
1110         for (i = 0; i < 4; ++i) {
1111                 hpa_t root = vcpu->arch.mmu.pae_root[i];
1112
1113                 ASSERT(!VALID_PAGE(root));
1114                 if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
1115                         if (!is_present_pte(vcpu->arch.pdptrs[i])) {
1116                                 vcpu->arch.mmu.pae_root[i] = 0;
1117                                 continue;
1118                         }
1119                         root_gfn = vcpu->arch.pdptrs[i] >> PAGE_SHIFT;
1120                 } else if (vcpu->arch.mmu.root_level == 0)
1121                         root_gfn = 0;
1122                 sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
1123                                       PT32_ROOT_LEVEL, !is_paging(vcpu),
1124                                       ACC_ALL, NULL, NULL);
1125                 root = __pa(sp->spt);
1126                 ++sp->root_count;
1127                 vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK;
1128         }
1129         vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root);
1130 }
1131
1132 static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
1133 {
1134         return vaddr;
1135 }
1136
1137 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
1138                                 u32 error_code)
1139 {
1140         gfn_t gfn;
1141         int r;
1142
1143         pgprintk("%s: gva %lx error %x\n", __FUNCTION__, gva, error_code);
1144         r = mmu_topup_memory_caches(vcpu);
1145         if (r)
1146                 return r;
1147
1148         ASSERT(vcpu);
1149         ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
1150
1151         gfn = gva >> PAGE_SHIFT;
1152
1153         return nonpaging_map(vcpu, gva & PAGE_MASK,
1154                              error_code & PFERR_WRITE_MASK, gfn);
1155 }
1156
1157 static void nonpaging_free(struct kvm_vcpu *vcpu)
1158 {
1159         mmu_free_roots(vcpu);
1160 }
1161
1162 static int nonpaging_init_context(struct kvm_vcpu *vcpu)
1163 {
1164         struct kvm_mmu *context = &vcpu->arch.mmu;
1165
1166         context->new_cr3 = nonpaging_new_cr3;
1167         context->page_fault = nonpaging_page_fault;
1168         context->gva_to_gpa = nonpaging_gva_to_gpa;
1169         context->free = nonpaging_free;
1170         context->prefetch_page = nonpaging_prefetch_page;
1171         context->root_level = 0;
1172         context->shadow_root_level = PT32E_ROOT_LEVEL;
1173         context->root_hpa = INVALID_PAGE;
1174         return 0;
1175 }
1176
1177 void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
1178 {
1179         ++vcpu->stat.tlb_flush;
1180         kvm_x86_ops->tlb_flush(vcpu);
1181 }
1182
1183 static void paging_new_cr3(struct kvm_vcpu *vcpu)
1184 {
1185         pgprintk("%s: cr3 %lx\n", __FUNCTION__, vcpu->arch.cr3);
1186         mmu_free_roots(vcpu);
1187 }
1188
1189 static void inject_page_fault(struct kvm_vcpu *vcpu,
1190                               u64 addr,
1191                               u32 err_code)
1192 {
1193         kvm_inject_page_fault(vcpu, addr, err_code);
1194 }
1195
1196 static void paging_free(struct kvm_vcpu *vcpu)
1197 {
1198         nonpaging_free(vcpu);
1199 }
1200
1201 #define PTTYPE 64
1202 #include "paging_tmpl.h"
1203 #undef PTTYPE
1204
1205 #define PTTYPE 32
1206 #include "paging_tmpl.h"
1207 #undef PTTYPE
1208
1209 static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level)
1210 {
1211         struct kvm_mmu *context = &vcpu->arch.mmu;
1212
1213         ASSERT(is_pae(vcpu));
1214         context->new_cr3 = paging_new_cr3;
1215         context->page_fault = paging64_page_fault;
1216         context->gva_to_gpa = paging64_gva_to_gpa;
1217         context->prefetch_page = paging64_prefetch_page;
1218         context->free = paging_free;
1219         context->root_level = level;
1220         context->shadow_root_level = level;
1221         context->root_hpa = INVALID_PAGE;
1222         return 0;
1223 }
1224
1225 static int paging64_init_context(struct kvm_vcpu *vcpu)
1226 {
1227         return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL);
1228 }
1229
1230 static int paging32_init_context(struct kvm_vcpu *vcpu)
1231 {
1232         struct kvm_mmu *context = &vcpu->arch.mmu;
1233
1234         context->new_cr3 = paging_new_cr3;
1235         context->page_fault = paging32_page_fault;
1236         context->gva_to_gpa = paging32_gva_to_gpa;
1237         context->free = paging_free;
1238         context->prefetch_page = paging32_prefetch_page;
1239         context->root_level = PT32_ROOT_LEVEL;
1240         context->shadow_root_level = PT32E_ROOT_LEVEL;
1241         context->root_hpa = INVALID_PAGE;
1242         return 0;
1243 }
1244
1245 static int paging32E_init_context(struct kvm_vcpu *vcpu)
1246 {
1247         return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
1248 }
1249
1250 static int init_kvm_mmu(struct kvm_vcpu *vcpu)
1251 {
1252         ASSERT(vcpu);
1253         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1254
1255         if (!is_paging(vcpu))
1256                 return nonpaging_init_context(vcpu);
1257         else if (is_long_mode(vcpu))
1258                 return paging64_init_context(vcpu);
1259         else if (is_pae(vcpu))
1260                 return paging32E_init_context(vcpu);
1261         else
1262                 return paging32_init_context(vcpu);
1263 }
1264
1265 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
1266 {
1267         ASSERT(vcpu);
1268         if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) {
1269                 vcpu->arch.mmu.free(vcpu);
1270                 vcpu->arch.mmu.root_hpa = INVALID_PAGE;
1271         }
1272 }
1273
1274 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
1275 {
1276         destroy_kvm_mmu(vcpu);
1277         return init_kvm_mmu(vcpu);
1278 }
1279 EXPORT_SYMBOL_GPL(kvm_mmu_reset_context);
1280
1281 int kvm_mmu_load(struct kvm_vcpu *vcpu)
1282 {
1283         int r;
1284
1285         r = mmu_topup_memory_caches(vcpu);
1286         if (r)
1287                 goto out;
1288         spin_lock(&vcpu->kvm->mmu_lock);
1289         kvm_mmu_free_some_pages(vcpu);
1290         mmu_alloc_roots(vcpu);
1291         spin_unlock(&vcpu->kvm->mmu_lock);
1292         kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa);
1293         kvm_mmu_flush_tlb(vcpu);
1294 out:
1295         return r;
1296 }
1297 EXPORT_SYMBOL_GPL(kvm_mmu_load);
1298
1299 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
1300 {
1301         mmu_free_roots(vcpu);
1302 }
1303
1304 static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
1305                                   struct kvm_mmu_page *sp,
1306                                   u64 *spte)
1307 {
1308         u64 pte;
1309         struct kvm_mmu_page *child;
1310
1311         pte = *spte;
1312         if (is_shadow_present_pte(pte)) {
1313                 if (sp->role.level == PT_PAGE_TABLE_LEVEL)
1314                         rmap_remove(vcpu->kvm, spte);
1315                 else {
1316                         child = page_header(pte & PT64_BASE_ADDR_MASK);
1317                         mmu_page_remove_parent_pte(child, spte);
1318                 }
1319         }
1320         set_shadow_pte(spte, shadow_trap_nonpresent_pte);
1321 }
1322
1323 static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
1324                                   struct kvm_mmu_page *sp,
1325                                   u64 *spte,
1326                                   const void *new, int bytes,
1327                                   int offset_in_pte)
1328 {
1329         if (sp->role.level != PT_PAGE_TABLE_LEVEL) {
1330                 ++vcpu->kvm->stat.mmu_pde_zapped;
1331                 return;
1332         }
1333
1334         ++vcpu->kvm->stat.mmu_pte_updated;
1335         if (sp->role.glevels == PT32_ROOT_LEVEL)
1336                 paging32_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1337         else
1338                 paging64_update_pte(vcpu, sp, spte, new, bytes, offset_in_pte);
1339 }
1340
1341 static bool need_remote_flush(u64 old, u64 new)
1342 {
1343         if (!is_shadow_present_pte(old))
1344                 return false;
1345         if (!is_shadow_present_pte(new))
1346                 return true;
1347         if ((old ^ new) & PT64_BASE_ADDR_MASK)
1348                 return true;
1349         old ^= PT64_NX_MASK;
1350         new ^= PT64_NX_MASK;
1351         return (old & ~new & PT64_PERM_MASK) != 0;
1352 }
1353
1354 static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new)
1355 {
1356         if (need_remote_flush(old, new))
1357                 kvm_flush_remote_tlbs(vcpu->kvm);
1358         else
1359                 kvm_mmu_flush_tlb(vcpu);
1360 }
1361
1362 static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu)
1363 {
1364         u64 *spte = vcpu->arch.last_pte_updated;
1365
1366         return !!(spte && (*spte & PT_ACCESSED_MASK));
1367 }
1368
1369 static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1370                                           const u8 *new, int bytes)
1371 {
1372         gfn_t gfn;
1373         int r;
1374         u64 gpte = 0;
1375         struct page *page;
1376
1377         if (bytes != 4 && bytes != 8)
1378                 return;
1379
1380         /*
1381          * Assume that the pte write on a page table of the same type
1382          * as the current vcpu paging mode.  This is nearly always true
1383          * (might be false while changing modes).  Note it is verified later
1384          * by update_pte().
1385          */
1386         if (is_pae(vcpu)) {
1387                 /* Handle a 32-bit guest writing two halves of a 64-bit gpte */
1388                 if ((bytes == 4) && (gpa % 4 == 0)) {
1389                         r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8);
1390                         if (r)
1391                                 return;
1392                         memcpy((void *)&gpte + (gpa % 8), new, 4);
1393                 } else if ((bytes == 8) && (gpa % 8 == 0)) {
1394                         memcpy((void *)&gpte, new, 8);
1395                 }
1396         } else {
1397                 if ((bytes == 4) && (gpa % 4 == 0))
1398                         memcpy((void *)&gpte, new, 4);
1399         }
1400         if (!is_present_pte(gpte))
1401                 return;
1402         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
1403
1404         down_read(&current->mm->mmap_sem);
1405         page = gfn_to_page(vcpu->kvm, gfn);
1406         up_read(&current->mm->mmap_sem);
1407
1408         vcpu->arch.update_pte.gfn = gfn;
1409         vcpu->arch.update_pte.page = gfn_to_page(vcpu->kvm, gfn);
1410 }
1411
1412 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
1413                        const u8 *new, int bytes)
1414 {
1415         gfn_t gfn = gpa >> PAGE_SHIFT;
1416         struct kvm_mmu_page *sp;
1417         struct hlist_node *node, *n;
1418         struct hlist_head *bucket;
1419         unsigned index;
1420         u64 entry;
1421         u64 *spte;
1422         unsigned offset = offset_in_page(gpa);
1423         unsigned pte_size;
1424         unsigned page_offset;
1425         unsigned misaligned;
1426         unsigned quadrant;
1427         int level;
1428         int flooded = 0;
1429         int npte;
1430
1431         pgprintk("%s: gpa %llx bytes %d\n", __FUNCTION__, gpa, bytes);
1432         mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
1433         spin_lock(&vcpu->kvm->mmu_lock);
1434         kvm_mmu_free_some_pages(vcpu);
1435         ++vcpu->kvm->stat.mmu_pte_write;
1436         kvm_mmu_audit(vcpu, "pre pte write");
1437         if (gfn == vcpu->arch.last_pt_write_gfn
1438             && !last_updated_pte_accessed(vcpu)) {
1439                 ++vcpu->arch.last_pt_write_count;
1440                 if (vcpu->arch.last_pt_write_count >= 3)
1441                         flooded = 1;
1442         } else {
1443                 vcpu->arch.last_pt_write_gfn = gfn;
1444                 vcpu->arch.last_pt_write_count = 1;
1445                 vcpu->arch.last_pte_updated = NULL;
1446         }
1447         index = kvm_page_table_hashfn(gfn) % KVM_NUM_MMU_PAGES;
1448         bucket = &vcpu->kvm->arch.mmu_page_hash[index];
1449         hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
1450                 if (sp->gfn != gfn || sp->role.metaphysical)
1451                         continue;
1452                 pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8;
1453                 misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
1454                 misaligned |= bytes < 4;
1455                 if (misaligned || flooded) {
1456                         /*
1457                          * Misaligned accesses are too much trouble to fix
1458                          * up; also, they usually indicate a page is not used
1459                          * as a page table.
1460                          *
1461                          * If we're seeing too many writes to a page,
1462                          * it may no longer be a page table, or we may be
1463                          * forking, in which case it is better to unmap the
1464                          * page.
1465                          */
1466                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
1467                                  gpa, bytes, sp->role.word);
1468                         kvm_mmu_zap_page(vcpu->kvm, sp);
1469                         ++vcpu->kvm->stat.mmu_flooded;
1470                         continue;
1471                 }
1472                 page_offset = offset;
1473                 level = sp->role.level;
1474                 npte = 1;
1475                 if (sp->role.glevels == PT32_ROOT_LEVEL) {
1476                         page_offset <<= 1;      /* 32->64 */
1477                         /*
1478                          * A 32-bit pde maps 4MB while the shadow pdes map
1479                          * only 2MB.  So we need to double the offset again
1480                          * and zap two pdes instead of one.
1481                          */
1482                         if (level == PT32_ROOT_LEVEL) {
1483                                 page_offset &= ~7; /* kill rounding error */
1484                                 page_offset <<= 1;
1485                                 npte = 2;
1486                         }
1487                         quadrant = page_offset >> PAGE_SHIFT;
1488                         page_offset &= ~PAGE_MASK;
1489                         if (quadrant != sp->role.quadrant)
1490                                 continue;
1491                 }
1492                 spte = &sp->spt[page_offset / sizeof(*spte)];
1493                 while (npte--) {
1494                         entry = *spte;
1495                         mmu_pte_write_zap_pte(vcpu, sp, spte);
1496                         mmu_pte_write_new_pte(vcpu, sp, spte, new, bytes,
1497                                               page_offset & (pte_size - 1));
1498                         mmu_pte_write_flush_tlb(vcpu, entry, *spte);
1499                         ++spte;
1500                 }
1501         }
1502         kvm_mmu_audit(vcpu, "post pte write");
1503         spin_unlock(&vcpu->kvm->mmu_lock);
1504         if (vcpu->arch.update_pte.page) {
1505                 kvm_release_page_clean(vcpu->arch.update_pte.page);
1506                 vcpu->arch.update_pte.page = NULL;
1507         }
1508 }
1509
1510 int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
1511 {
1512         gpa_t gpa;
1513         int r;
1514
1515         down_read(&vcpu->kvm->slots_lock);
1516         gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
1517         up_read(&vcpu->kvm->slots_lock);
1518
1519         spin_lock(&vcpu->kvm->mmu_lock);
1520         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
1521         spin_unlock(&vcpu->kvm->mmu_lock);
1522         return r;
1523 }
1524
1525 void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
1526 {
1527         while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES) {
1528                 struct kvm_mmu_page *sp;
1529
1530                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev,
1531                                   struct kvm_mmu_page, link);
1532                 kvm_mmu_zap_page(vcpu->kvm, sp);
1533                 ++vcpu->kvm->stat.mmu_recycled;
1534         }
1535 }
1536
1537 int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
1538 {
1539         int r;
1540         enum emulation_result er;
1541
1542         r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code);
1543         if (r < 0)
1544                 goto out;
1545
1546         if (!r) {
1547                 r = 1;
1548                 goto out;
1549         }
1550
1551         r = mmu_topup_memory_caches(vcpu);
1552         if (r)
1553                 goto out;
1554
1555         er = emulate_instruction(vcpu, vcpu->run, cr2, error_code, 0);
1556
1557         switch (er) {
1558         case EMULATE_DONE:
1559                 return 1;
1560         case EMULATE_DO_MMIO:
1561                 ++vcpu->stat.mmio_exits;
1562                 return 0;
1563         case EMULATE_FAIL:
1564                 kvm_report_emulation_failure(vcpu, "pagetable");
1565                 return 1;
1566         default:
1567                 BUG();
1568         }
1569 out:
1570         return r;
1571 }
1572 EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
1573
1574 static void free_mmu_pages(struct kvm_vcpu *vcpu)
1575 {
1576         struct kvm_mmu_page *sp;
1577
1578         while (!list_empty(&vcpu->kvm->arch.active_mmu_pages)) {
1579                 sp = container_of(vcpu->kvm->arch.active_mmu_pages.next,
1580                                   struct kvm_mmu_page, link);
1581                 kvm_mmu_zap_page(vcpu->kvm, sp);
1582         }
1583         free_page((unsigned long)vcpu->arch.mmu.pae_root);
1584 }
1585
1586 static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
1587 {
1588         struct page *page;
1589         int i;
1590
1591         ASSERT(vcpu);
1592
1593         if (vcpu->kvm->arch.n_requested_mmu_pages)
1594                 vcpu->kvm->arch.n_free_mmu_pages =
1595                                         vcpu->kvm->arch.n_requested_mmu_pages;
1596         else
1597                 vcpu->kvm->arch.n_free_mmu_pages =
1598                                         vcpu->kvm->arch.n_alloc_mmu_pages;
1599         /*
1600          * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
1601          * Therefore we need to allocate shadow page tables in the first
1602          * 4GB of memory, which happens to fit the DMA32 zone.
1603          */
1604         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
1605         if (!page)
1606                 goto error_1;
1607         vcpu->arch.mmu.pae_root = page_address(page);
1608         for (i = 0; i < 4; ++i)
1609                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
1610
1611         return 0;
1612
1613 error_1:
1614         free_mmu_pages(vcpu);
1615         return -ENOMEM;
1616 }
1617
1618 int kvm_mmu_create(struct kvm_vcpu *vcpu)
1619 {
1620         ASSERT(vcpu);
1621         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1622
1623         return alloc_mmu_pages(vcpu);
1624 }
1625
1626 int kvm_mmu_setup(struct kvm_vcpu *vcpu)
1627 {
1628         ASSERT(vcpu);
1629         ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
1630
1631         return init_kvm_mmu(vcpu);
1632 }
1633
1634 void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
1635 {
1636         ASSERT(vcpu);
1637
1638         destroy_kvm_mmu(vcpu);
1639         free_mmu_pages(vcpu);
1640         mmu_free_memory_caches(vcpu);
1641 }
1642
1643 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
1644 {
1645         struct kvm_mmu_page *sp;
1646
1647         list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) {
1648                 int i;
1649                 u64 *pt;
1650
1651                 if (!test_bit(slot, &sp->slot_bitmap))
1652                         continue;
1653
1654                 pt = sp->spt;
1655                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
1656                         /* avoid RMW */
1657                         if (pt[i] & PT_WRITABLE_MASK)
1658                                 pt[i] &= ~PT_WRITABLE_MASK;
1659         }
1660 }
1661
1662 void kvm_mmu_zap_all(struct kvm *kvm)
1663 {
1664         struct kvm_mmu_page *sp, *node;
1665
1666         spin_lock(&kvm->mmu_lock);
1667         list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link)
1668                 kvm_mmu_zap_page(kvm, sp);
1669         spin_unlock(&kvm->mmu_lock);
1670
1671         kvm_flush_remote_tlbs(kvm);
1672 }
1673
1674 void kvm_mmu_module_exit(void)
1675 {
1676         if (pte_chain_cache)
1677                 kmem_cache_destroy(pte_chain_cache);
1678         if (rmap_desc_cache)
1679                 kmem_cache_destroy(rmap_desc_cache);
1680         if (mmu_page_header_cache)
1681                 kmem_cache_destroy(mmu_page_header_cache);
1682 }
1683
1684 int kvm_mmu_module_init(void)
1685 {
1686         pte_chain_cache = kmem_cache_create("kvm_pte_chain",
1687                                             sizeof(struct kvm_pte_chain),
1688                                             0, 0, NULL);
1689         if (!pte_chain_cache)
1690                 goto nomem;
1691         rmap_desc_cache = kmem_cache_create("kvm_rmap_desc",
1692                                             sizeof(struct kvm_rmap_desc),
1693                                             0, 0, NULL);
1694         if (!rmap_desc_cache)
1695                 goto nomem;
1696
1697         mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header",
1698                                                   sizeof(struct kvm_mmu_page),
1699                                                   0, 0, NULL);
1700         if (!mmu_page_header_cache)
1701                 goto nomem;
1702
1703         return 0;
1704
1705 nomem:
1706         kvm_mmu_module_exit();
1707         return -ENOMEM;
1708 }
1709
1710 /*
1711  * Caculate mmu pages needed for kvm.
1712  */
1713 unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
1714 {
1715         int i;
1716         unsigned int nr_mmu_pages;
1717         unsigned int  nr_pages = 0;
1718
1719         for (i = 0; i < kvm->nmemslots; i++)
1720                 nr_pages += kvm->memslots[i].npages;
1721
1722         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
1723         nr_mmu_pages = max(nr_mmu_pages,
1724                         (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
1725
1726         return nr_mmu_pages;
1727 }
1728
1729 #ifdef AUDIT
1730
1731 static const char *audit_msg;
1732
1733 static gva_t canonicalize(gva_t gva)
1734 {
1735 #ifdef CONFIG_X86_64
1736         gva = (long long)(gva << 16) >> 16;
1737 #endif
1738         return gva;
1739 }
1740
1741 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
1742                                 gva_t va, int level)
1743 {
1744         u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK);
1745         int i;
1746         gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1));
1747
1748         for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) {
1749                 u64 ent = pt[i];
1750
1751                 if (ent == shadow_trap_nonpresent_pte)
1752                         continue;
1753
1754                 va = canonicalize(va);
1755                 if (level > 1) {
1756                         if (ent == shadow_notrap_nonpresent_pte)
1757                                 printk(KERN_ERR "audit: (%s) nontrapping pte"
1758                                        " in nonleaf level: levels %d gva %lx"
1759                                        " level %d pte %llx\n", audit_msg,
1760                                        vcpu->arch.mmu.root_level, va, level, ent);
1761
1762                         audit_mappings_page(vcpu, ent, va, level - 1);
1763                 } else {
1764                         gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
1765                         struct page *page = gpa_to_page(vcpu, gpa);
1766                         hpa_t hpa = page_to_phys(page);
1767
1768                         if (is_shadow_present_pte(ent)
1769                             && (ent & PT64_BASE_ADDR_MASK) != hpa)
1770                                 printk(KERN_ERR "xx audit error: (%s) levels %d"
1771                                        " gva %lx gpa %llx hpa %llx ent %llx %d\n",
1772                                        audit_msg, vcpu->arch.mmu.root_level,
1773                                        va, gpa, hpa, ent,
1774                                        is_shadow_present_pte(ent));
1775                         else if (ent == shadow_notrap_nonpresent_pte
1776                                  && !is_error_hpa(hpa))
1777                                 printk(KERN_ERR "audit: (%s) notrap shadow,"
1778                                        " valid guest gva %lx\n", audit_msg, va);
1779                         kvm_release_page_clean(page);
1780
1781                 }
1782         }
1783 }
1784
1785 static void audit_mappings(struct kvm_vcpu *vcpu)
1786 {
1787         unsigned i;
1788
1789         if (vcpu->arch.mmu.root_level == 4)
1790                 audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4);
1791         else
1792                 for (i = 0; i < 4; ++i)
1793                         if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK)
1794                                 audit_mappings_page(vcpu,
1795                                                     vcpu->arch.mmu.pae_root[i],
1796                                                     i << 30,
1797                                                     2);
1798 }
1799
1800 static int count_rmaps(struct kvm_vcpu *vcpu)
1801 {
1802         int nmaps = 0;
1803         int i, j, k;
1804
1805         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
1806                 struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
1807                 struct kvm_rmap_desc *d;
1808
1809                 for (j = 0; j < m->npages; ++j) {
1810                         unsigned long *rmapp = &m->rmap[j];
1811
1812                         if (!*rmapp)
1813                                 continue;
1814                         if (!(*rmapp & 1)) {
1815                                 ++nmaps;
1816                                 continue;
1817                         }
1818                         d = (struct kvm_rmap_desc *)(*rmapp & ~1ul);
1819                         while (d) {
1820                                 for (k = 0; k < RMAP_EXT; ++k)
1821                                         if (d->shadow_ptes[k])
1822                                                 ++nmaps;
1823                                         else
1824                                                 break;
1825                                 d = d->more;
1826                         }
1827                 }
1828         }
1829         return nmaps;
1830 }
1831
1832 static int count_writable_mappings(struct kvm_vcpu *vcpu)
1833 {
1834         int nmaps = 0;
1835         struct kvm_mmu_page *sp;
1836         int i;
1837
1838         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
1839                 u64 *pt = sp->spt;
1840
1841                 if (sp->role.level != PT_PAGE_TABLE_LEVEL)
1842                         continue;
1843
1844                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
1845                         u64 ent = pt[i];
1846
1847                         if (!(ent & PT_PRESENT_MASK))
1848                                 continue;
1849                         if (!(ent & PT_WRITABLE_MASK))
1850                                 continue;
1851                         ++nmaps;
1852                 }
1853         }
1854         return nmaps;
1855 }
1856
1857 static void audit_rmap(struct kvm_vcpu *vcpu)
1858 {
1859         int n_rmap = count_rmaps(vcpu);
1860         int n_actual = count_writable_mappings(vcpu);
1861
1862         if (n_rmap != n_actual)
1863                 printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
1864                        __FUNCTION__, audit_msg, n_rmap, n_actual);
1865 }
1866
1867 static void audit_write_protection(struct kvm_vcpu *vcpu)
1868 {
1869         struct kvm_mmu_page *sp;
1870         struct kvm_memory_slot *slot;
1871         unsigned long *rmapp;
1872         gfn_t gfn;
1873
1874         list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
1875                 if (sp->role.metaphysical)
1876                         continue;
1877
1878                 slot = gfn_to_memslot(vcpu->kvm, sp->gfn);
1879                 gfn = unalias_gfn(vcpu->kvm, sp->gfn);
1880                 rmapp = &slot->rmap[gfn - slot->base_gfn];
1881                 if (*rmapp)
1882                         printk(KERN_ERR "%s: (%s) shadow page has writable"
1883                                " mappings: gfn %lx role %x\n",
1884                                __FUNCTION__, audit_msg, sp->gfn,
1885                                sp->role.word);
1886         }
1887 }
1888
1889 static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
1890 {
1891         int olddbg = dbg;
1892
1893         dbg = 0;
1894         audit_msg = msg;
1895         audit_rmap(vcpu);
1896         audit_write_protection(vcpu);
1897         audit_mappings(vcpu);
1898         dbg = olddbg;
1899 }
1900
1901 #endif