| 1 | /* |
| 2 | * Kernel-based Virtual Machine driver for Linux |
| 3 | * |
| 4 | * This module enables machines with Intel VT-x extensions to run virtual |
| 5 | * machines without emulation or binary translation. |
| 6 | * |
| 7 | * MMU support |
| 8 | * |
| 9 | * Copyright (C) 2006 Qumranet, Inc. |
| 10 | * |
| 11 | * Authors: |
| 12 | * Yaniv Kamay <yaniv@qumranet.com> |
| 13 | * Avi Kivity <avi@qumranet.com> |
| 14 | * |
| 15 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 16 | * the COPYING file in the top-level directory. |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | #include "mmu.h" |
| 21 | #include "x86.h" |
| 22 | #include "kvm_cache_regs.h" |
| 23 | |
| 24 | #include <linux/kvm_host.h> |
| 25 | #include <linux/types.h> |
| 26 | #include <linux/string.h> |
| 27 | #include <linux/mm.h> |
| 28 | #include <linux/highmem.h> |
| 29 | #include <linux/module.h> |
| 30 | #include <linux/swap.h> |
| 31 | #include <linux/hugetlb.h> |
| 32 | #include <linux/compiler.h> |
| 33 | #include <linux/srcu.h> |
| 34 | |
| 35 | #include <asm/page.h> |
| 36 | #include <asm/cmpxchg.h> |
| 37 | #include <asm/io.h> |
| 38 | #include <asm/vmx.h> |
| 39 | |
| 40 | /* |
| 41 | * When setting this variable to true it enables Two-Dimensional-Paging |
| 42 | * where the hardware walks 2 page tables: |
| 43 | * 1. the guest-virtual to guest-physical |
| 44 | * 2. while doing 1. it walks guest-physical to host-physical |
| 45 | * If the hardware supports that we don't need to do shadow paging. |
| 46 | */ |
| 47 | bool tdp_enabled = false; |
| 48 | |
| 49 | #undef MMU_DEBUG |
| 50 | |
| 51 | #undef AUDIT |
| 52 | |
| 53 | #ifdef AUDIT |
| 54 | static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg); |
| 55 | #else |
| 56 | static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {} |
| 57 | #endif |
| 58 | |
| 59 | #ifdef MMU_DEBUG |
| 60 | |
| 61 | #define pgprintk(x...) do { if (dbg) printk(x); } while (0) |
| 62 | #define rmap_printk(x...) do { if (dbg) printk(x); } while (0) |
| 63 | |
| 64 | #else |
| 65 | |
| 66 | #define pgprintk(x...) do { } while (0) |
| 67 | #define rmap_printk(x...) do { } while (0) |
| 68 | |
| 69 | #endif |
| 70 | |
| 71 | #if defined(MMU_DEBUG) || defined(AUDIT) |
| 72 | static int dbg = 0; |
| 73 | module_param(dbg, bool, 0644); |
| 74 | #endif |
| 75 | |
| 76 | static int oos_shadow = 1; |
| 77 | module_param(oos_shadow, bool, 0644); |
| 78 | |
| 79 | #ifndef MMU_DEBUG |
| 80 | #define ASSERT(x) do { } while (0) |
| 81 | #else |
| 82 | #define ASSERT(x) \ |
| 83 | if (!(x)) { \ |
| 84 | printk(KERN_WARNING "assertion failed %s:%d: %s\n", \ |
| 85 | __FILE__, __LINE__, #x); \ |
| 86 | } |
| 87 | #endif |
| 88 | |
| 89 | #define PT_FIRST_AVAIL_BITS_SHIFT 9 |
| 90 | #define PT64_SECOND_AVAIL_BITS_SHIFT 52 |
| 91 | |
| 92 | #define VALID_PAGE(x) ((x) != INVALID_PAGE) |
| 93 | |
| 94 | #define PT64_LEVEL_BITS 9 |
| 95 | |
| 96 | #define PT64_LEVEL_SHIFT(level) \ |
| 97 | (PAGE_SHIFT + (level - 1) * PT64_LEVEL_BITS) |
| 98 | |
| 99 | #define PT64_LEVEL_MASK(level) \ |
| 100 | (((1ULL << PT64_LEVEL_BITS) - 1) << PT64_LEVEL_SHIFT(level)) |
| 101 | |
| 102 | #define PT64_INDEX(address, level)\ |
| 103 | (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1)) |
| 104 | |
| 105 | |
| 106 | #define PT32_LEVEL_BITS 10 |
| 107 | |
| 108 | #define PT32_LEVEL_SHIFT(level) \ |
| 109 | (PAGE_SHIFT + (level - 1) * PT32_LEVEL_BITS) |
| 110 | |
| 111 | #define PT32_LEVEL_MASK(level) \ |
| 112 | (((1ULL << PT32_LEVEL_BITS) - 1) << PT32_LEVEL_SHIFT(level)) |
| 113 | #define PT32_LVL_OFFSET_MASK(level) \ |
| 114 | (PT32_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \ |
| 115 | * PT32_LEVEL_BITS))) - 1)) |
| 116 | |
| 117 | #define PT32_INDEX(address, level)\ |
| 118 | (((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1)) |
| 119 | |
| 120 | |
| 121 | #define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)) |
| 122 | #define PT64_DIR_BASE_ADDR_MASK \ |
| 123 | (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1)) |
| 124 | #define PT64_LVL_ADDR_MASK(level) \ |
| 125 | (PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \ |
| 126 | * PT64_LEVEL_BITS))) - 1)) |
| 127 | #define PT64_LVL_OFFSET_MASK(level) \ |
| 128 | (PT64_BASE_ADDR_MASK & ((1ULL << (PAGE_SHIFT + (((level) - 1) \ |
| 129 | * PT64_LEVEL_BITS))) - 1)) |
| 130 | |
| 131 | #define PT32_BASE_ADDR_MASK PAGE_MASK |
| 132 | #define PT32_DIR_BASE_ADDR_MASK \ |
| 133 | (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + PT32_LEVEL_BITS)) - 1)) |
| 134 | #define PT32_LVL_ADDR_MASK(level) \ |
| 135 | (PAGE_MASK & ~((1ULL << (PAGE_SHIFT + (((level) - 1) \ |
| 136 | * PT32_LEVEL_BITS))) - 1)) |
| 137 | |
| 138 | #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \ |
| 139 | | PT64_NX_MASK) |
| 140 | |
| 141 | #define RMAP_EXT 4 |
| 142 | |
| 143 | #define ACC_EXEC_MASK 1 |
| 144 | #define ACC_WRITE_MASK PT_WRITABLE_MASK |
| 145 | #define ACC_USER_MASK PT_USER_MASK |
| 146 | #define ACC_ALL (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK) |
| 147 | |
| 148 | #include <trace/events/kvm.h> |
| 149 | |
| 150 | #undef TRACE_INCLUDE_FILE |
| 151 | #define CREATE_TRACE_POINTS |
| 152 | #include "mmutrace.h" |
| 153 | |
| 154 | #define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT) |
| 155 | |
| 156 | #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) |
| 157 | |
| 158 | struct kvm_rmap_desc { |
| 159 | u64 *sptes[RMAP_EXT]; |
| 160 | struct kvm_rmap_desc *more; |
| 161 | }; |
| 162 | |
| 163 | struct kvm_shadow_walk_iterator { |
| 164 | u64 addr; |
| 165 | hpa_t shadow_addr; |
| 166 | int level; |
| 167 | u64 *sptep; |
| 168 | unsigned index; |
| 169 | }; |
| 170 | |
| 171 | #define for_each_shadow_entry(_vcpu, _addr, _walker) \ |
| 172 | for (shadow_walk_init(&(_walker), _vcpu, _addr); \ |
| 173 | shadow_walk_okay(&(_walker)); \ |
| 174 | shadow_walk_next(&(_walker))) |
| 175 | |
| 176 | |
| 177 | struct kvm_unsync_walk { |
| 178 | int (*entry) (struct kvm_mmu_page *sp, struct kvm_unsync_walk *walk); |
| 179 | }; |
| 180 | |
| 181 | typedef int (*mmu_parent_walk_fn) (struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp); |
| 182 | |
| 183 | static struct kmem_cache *pte_chain_cache; |
| 184 | static struct kmem_cache *rmap_desc_cache; |
| 185 | static struct kmem_cache *mmu_page_header_cache; |
| 186 | |
| 187 | static u64 __read_mostly shadow_trap_nonpresent_pte; |
| 188 | static u64 __read_mostly shadow_notrap_nonpresent_pte; |
| 189 | static u64 __read_mostly shadow_base_present_pte; |
| 190 | static u64 __read_mostly shadow_nx_mask; |
| 191 | static u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */ |
| 192 | static u64 __read_mostly shadow_user_mask; |
| 193 | static u64 __read_mostly shadow_accessed_mask; |
| 194 | static u64 __read_mostly shadow_dirty_mask; |
| 195 | |
| 196 | static inline u64 rsvd_bits(int s, int e) |
| 197 | { |
| 198 | return ((1ULL << (e - s + 1)) - 1) << s; |
| 199 | } |
| 200 | |
| 201 | void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte) |
| 202 | { |
| 203 | shadow_trap_nonpresent_pte = trap_pte; |
| 204 | shadow_notrap_nonpresent_pte = notrap_pte; |
| 205 | } |
| 206 | EXPORT_SYMBOL_GPL(kvm_mmu_set_nonpresent_ptes); |
| 207 | |
| 208 | void kvm_mmu_set_base_ptes(u64 base_pte) |
| 209 | { |
| 210 | shadow_base_present_pte = base_pte; |
| 211 | } |
| 212 | EXPORT_SYMBOL_GPL(kvm_mmu_set_base_ptes); |
| 213 | |
| 214 | void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask, |
| 215 | u64 dirty_mask, u64 nx_mask, u64 x_mask) |
| 216 | { |
| 217 | shadow_user_mask = user_mask; |
| 218 | shadow_accessed_mask = accessed_mask; |
| 219 | shadow_dirty_mask = dirty_mask; |
| 220 | shadow_nx_mask = nx_mask; |
| 221 | shadow_x_mask = x_mask; |
| 222 | } |
| 223 | EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes); |
| 224 | |
| 225 | static int is_write_protection(struct kvm_vcpu *vcpu) |
| 226 | { |
| 227 | return kvm_read_cr0_bits(vcpu, X86_CR0_WP); |
| 228 | } |
| 229 | |
| 230 | static int is_cpuid_PSE36(void) |
| 231 | { |
| 232 | return 1; |
| 233 | } |
| 234 | |
| 235 | static int is_nx(struct kvm_vcpu *vcpu) |
| 236 | { |
| 237 | return vcpu->arch.efer & EFER_NX; |
| 238 | } |
| 239 | |
| 240 | static int is_shadow_present_pte(u64 pte) |
| 241 | { |
| 242 | return pte != shadow_trap_nonpresent_pte |
| 243 | && pte != shadow_notrap_nonpresent_pte; |
| 244 | } |
| 245 | |
| 246 | static int is_large_pte(u64 pte) |
| 247 | { |
| 248 | return pte & PT_PAGE_SIZE_MASK; |
| 249 | } |
| 250 | |
| 251 | static int is_writable_pte(unsigned long pte) |
| 252 | { |
| 253 | return pte & PT_WRITABLE_MASK; |
| 254 | } |
| 255 | |
| 256 | static int is_dirty_gpte(unsigned long pte) |
| 257 | { |
| 258 | return pte & PT_DIRTY_MASK; |
| 259 | } |
| 260 | |
| 261 | static int is_rmap_spte(u64 pte) |
| 262 | { |
| 263 | return is_shadow_present_pte(pte); |
| 264 | } |
| 265 | |
| 266 | static int is_last_spte(u64 pte, int level) |
| 267 | { |
| 268 | if (level == PT_PAGE_TABLE_LEVEL) |
| 269 | return 1; |
| 270 | if (is_large_pte(pte)) |
| 271 | return 1; |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | static pfn_t spte_to_pfn(u64 pte) |
| 276 | { |
| 277 | return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 278 | } |
| 279 | |
| 280 | static gfn_t pse36_gfn_delta(u32 gpte) |
| 281 | { |
| 282 | int shift = 32 - PT32_DIR_PSE36_SHIFT - PAGE_SHIFT; |
| 283 | |
| 284 | return (gpte & PT32_DIR_PSE36_MASK) << shift; |
| 285 | } |
| 286 | |
| 287 | static void __set_spte(u64 *sptep, u64 spte) |
| 288 | { |
| 289 | #ifdef CONFIG_X86_64 |
| 290 | set_64bit((unsigned long *)sptep, spte); |
| 291 | #else |
| 292 | set_64bit((unsigned long long *)sptep, spte); |
| 293 | #endif |
| 294 | } |
| 295 | |
| 296 | static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, |
| 297 | struct kmem_cache *base_cache, int min) |
| 298 | { |
| 299 | void *obj; |
| 300 | |
| 301 | if (cache->nobjs >= min) |
| 302 | return 0; |
| 303 | while (cache->nobjs < ARRAY_SIZE(cache->objects)) { |
| 304 | obj = kmem_cache_zalloc(base_cache, GFP_KERNEL); |
| 305 | if (!obj) |
| 306 | return -ENOMEM; |
| 307 | cache->objects[cache->nobjs++] = obj; |
| 308 | } |
| 309 | return 0; |
| 310 | } |
| 311 | |
| 312 | static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) |
| 313 | { |
| 314 | while (mc->nobjs) |
| 315 | kfree(mc->objects[--mc->nobjs]); |
| 316 | } |
| 317 | |
| 318 | static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, |
| 319 | int min) |
| 320 | { |
| 321 | struct page *page; |
| 322 | |
| 323 | if (cache->nobjs >= min) |
| 324 | return 0; |
| 325 | while (cache->nobjs < ARRAY_SIZE(cache->objects)) { |
| 326 | page = alloc_page(GFP_KERNEL); |
| 327 | if (!page) |
| 328 | return -ENOMEM; |
| 329 | set_page_private(page, 0); |
| 330 | cache->objects[cache->nobjs++] = page_address(page); |
| 331 | } |
| 332 | return 0; |
| 333 | } |
| 334 | |
| 335 | static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc) |
| 336 | { |
| 337 | while (mc->nobjs) |
| 338 | free_page((unsigned long)mc->objects[--mc->nobjs]); |
| 339 | } |
| 340 | |
| 341 | static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) |
| 342 | { |
| 343 | int r; |
| 344 | |
| 345 | r = mmu_topup_memory_cache(&vcpu->arch.mmu_pte_chain_cache, |
| 346 | pte_chain_cache, 4); |
| 347 | if (r) |
| 348 | goto out; |
| 349 | r = mmu_topup_memory_cache(&vcpu->arch.mmu_rmap_desc_cache, |
| 350 | rmap_desc_cache, 4); |
| 351 | if (r) |
| 352 | goto out; |
| 353 | r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8); |
| 354 | if (r) |
| 355 | goto out; |
| 356 | r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, |
| 357 | mmu_page_header_cache, 4); |
| 358 | out: |
| 359 | return r; |
| 360 | } |
| 361 | |
| 362 | static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) |
| 363 | { |
| 364 | mmu_free_memory_cache(&vcpu->arch.mmu_pte_chain_cache); |
| 365 | mmu_free_memory_cache(&vcpu->arch.mmu_rmap_desc_cache); |
| 366 | mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache); |
| 367 | mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache); |
| 368 | } |
| 369 | |
| 370 | static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc, |
| 371 | size_t size) |
| 372 | { |
| 373 | void *p; |
| 374 | |
| 375 | BUG_ON(!mc->nobjs); |
| 376 | p = mc->objects[--mc->nobjs]; |
| 377 | return p; |
| 378 | } |
| 379 | |
| 380 | static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu) |
| 381 | { |
| 382 | return mmu_memory_cache_alloc(&vcpu->arch.mmu_pte_chain_cache, |
| 383 | sizeof(struct kvm_pte_chain)); |
| 384 | } |
| 385 | |
| 386 | static void mmu_free_pte_chain(struct kvm_pte_chain *pc) |
| 387 | { |
| 388 | kfree(pc); |
| 389 | } |
| 390 | |
| 391 | static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu) |
| 392 | { |
| 393 | return mmu_memory_cache_alloc(&vcpu->arch.mmu_rmap_desc_cache, |
| 394 | sizeof(struct kvm_rmap_desc)); |
| 395 | } |
| 396 | |
| 397 | static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd) |
| 398 | { |
| 399 | kfree(rd); |
| 400 | } |
| 401 | |
| 402 | /* |
| 403 | * Return the pointer to the largepage write count for a given |
| 404 | * gfn, handling slots that are not large page aligned. |
| 405 | */ |
| 406 | static int *slot_largepage_idx(gfn_t gfn, |
| 407 | struct kvm_memory_slot *slot, |
| 408 | int level) |
| 409 | { |
| 410 | unsigned long idx; |
| 411 | |
| 412 | idx = (gfn / KVM_PAGES_PER_HPAGE(level)) - |
| 413 | (slot->base_gfn / KVM_PAGES_PER_HPAGE(level)); |
| 414 | return &slot->lpage_info[level - 2][idx].write_count; |
| 415 | } |
| 416 | |
| 417 | static void account_shadowed(struct kvm *kvm, gfn_t gfn) |
| 418 | { |
| 419 | struct kvm_memory_slot *slot; |
| 420 | int *write_count; |
| 421 | int i; |
| 422 | |
| 423 | gfn = unalias_gfn(kvm, gfn); |
| 424 | |
| 425 | slot = gfn_to_memslot_unaliased(kvm, gfn); |
| 426 | for (i = PT_DIRECTORY_LEVEL; |
| 427 | i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { |
| 428 | write_count = slot_largepage_idx(gfn, slot, i); |
| 429 | *write_count += 1; |
| 430 | } |
| 431 | } |
| 432 | |
| 433 | static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn) |
| 434 | { |
| 435 | struct kvm_memory_slot *slot; |
| 436 | int *write_count; |
| 437 | int i; |
| 438 | |
| 439 | gfn = unalias_gfn(kvm, gfn); |
| 440 | for (i = PT_DIRECTORY_LEVEL; |
| 441 | i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { |
| 442 | slot = gfn_to_memslot_unaliased(kvm, gfn); |
| 443 | write_count = slot_largepage_idx(gfn, slot, i); |
| 444 | *write_count -= 1; |
| 445 | WARN_ON(*write_count < 0); |
| 446 | } |
| 447 | } |
| 448 | |
| 449 | static int has_wrprotected_page(struct kvm *kvm, |
| 450 | gfn_t gfn, |
| 451 | int level) |
| 452 | { |
| 453 | struct kvm_memory_slot *slot; |
| 454 | int *largepage_idx; |
| 455 | |
| 456 | gfn = unalias_gfn(kvm, gfn); |
| 457 | slot = gfn_to_memslot_unaliased(kvm, gfn); |
| 458 | if (slot) { |
| 459 | largepage_idx = slot_largepage_idx(gfn, slot, level); |
| 460 | return *largepage_idx; |
| 461 | } |
| 462 | |
| 463 | return 1; |
| 464 | } |
| 465 | |
| 466 | static int host_mapping_level(struct kvm *kvm, gfn_t gfn) |
| 467 | { |
| 468 | unsigned long page_size; |
| 469 | int i, ret = 0; |
| 470 | |
| 471 | page_size = kvm_host_page_size(kvm, gfn); |
| 472 | |
| 473 | for (i = PT_PAGE_TABLE_LEVEL; |
| 474 | i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) { |
| 475 | if (page_size >= KVM_HPAGE_SIZE(i)) |
| 476 | ret = i; |
| 477 | else |
| 478 | break; |
| 479 | } |
| 480 | |
| 481 | return ret; |
| 482 | } |
| 483 | |
| 484 | static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) |
| 485 | { |
| 486 | struct kvm_memory_slot *slot; |
| 487 | int host_level, level, max_level; |
| 488 | |
| 489 | slot = gfn_to_memslot(vcpu->kvm, large_gfn); |
| 490 | if (slot && slot->dirty_bitmap) |
| 491 | return PT_PAGE_TABLE_LEVEL; |
| 492 | |
| 493 | host_level = host_mapping_level(vcpu->kvm, large_gfn); |
| 494 | |
| 495 | if (host_level == PT_PAGE_TABLE_LEVEL) |
| 496 | return host_level; |
| 497 | |
| 498 | max_level = kvm_x86_ops->get_lpage_level() < host_level ? |
| 499 | kvm_x86_ops->get_lpage_level() : host_level; |
| 500 | |
| 501 | for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level) |
| 502 | if (has_wrprotected_page(vcpu->kvm, large_gfn, level)) |
| 503 | break; |
| 504 | |
| 505 | return level - 1; |
| 506 | } |
| 507 | |
| 508 | /* |
| 509 | * Take gfn and return the reverse mapping to it. |
| 510 | * Note: gfn must be unaliased before this function get called |
| 511 | */ |
| 512 | |
| 513 | static unsigned long *gfn_to_rmap(struct kvm *kvm, gfn_t gfn, int level) |
| 514 | { |
| 515 | struct kvm_memory_slot *slot; |
| 516 | unsigned long idx; |
| 517 | |
| 518 | slot = gfn_to_memslot(kvm, gfn); |
| 519 | if (likely(level == PT_PAGE_TABLE_LEVEL)) |
| 520 | return &slot->rmap[gfn - slot->base_gfn]; |
| 521 | |
| 522 | idx = (gfn / KVM_PAGES_PER_HPAGE(level)) - |
| 523 | (slot->base_gfn / KVM_PAGES_PER_HPAGE(level)); |
| 524 | |
| 525 | return &slot->lpage_info[level - 2][idx].rmap_pde; |
| 526 | } |
| 527 | |
| 528 | /* |
| 529 | * Reverse mapping data structures: |
| 530 | * |
| 531 | * If rmapp bit zero is zero, then rmapp point to the shadw page table entry |
| 532 | * that points to page_address(page). |
| 533 | * |
| 534 | * If rmapp bit zero is one, (then rmap & ~1) points to a struct kvm_rmap_desc |
| 535 | * containing more mappings. |
| 536 | * |
| 537 | * Returns the number of rmap entries before the spte was added or zero if |
| 538 | * the spte was not added. |
| 539 | * |
| 540 | */ |
| 541 | static int rmap_add(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) |
| 542 | { |
| 543 | struct kvm_mmu_page *sp; |
| 544 | struct kvm_rmap_desc *desc; |
| 545 | unsigned long *rmapp; |
| 546 | int i, count = 0; |
| 547 | |
| 548 | if (!is_rmap_spte(*spte)) |
| 549 | return count; |
| 550 | gfn = unalias_gfn(vcpu->kvm, gfn); |
| 551 | sp = page_header(__pa(spte)); |
| 552 | sp->gfns[spte - sp->spt] = gfn; |
| 553 | rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level); |
| 554 | if (!*rmapp) { |
| 555 | rmap_printk("rmap_add: %p %llx 0->1\n", spte, *spte); |
| 556 | *rmapp = (unsigned long)spte; |
| 557 | } else if (!(*rmapp & 1)) { |
| 558 | rmap_printk("rmap_add: %p %llx 1->many\n", spte, *spte); |
| 559 | desc = mmu_alloc_rmap_desc(vcpu); |
| 560 | desc->sptes[0] = (u64 *)*rmapp; |
| 561 | desc->sptes[1] = spte; |
| 562 | *rmapp = (unsigned long)desc | 1; |
| 563 | } else { |
| 564 | rmap_printk("rmap_add: %p %llx many->many\n", spte, *spte); |
| 565 | desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); |
| 566 | while (desc->sptes[RMAP_EXT-1] && desc->more) { |
| 567 | desc = desc->more; |
| 568 | count += RMAP_EXT; |
| 569 | } |
| 570 | if (desc->sptes[RMAP_EXT-1]) { |
| 571 | desc->more = mmu_alloc_rmap_desc(vcpu); |
| 572 | desc = desc->more; |
| 573 | } |
| 574 | for (i = 0; desc->sptes[i]; ++i) |
| 575 | ; |
| 576 | desc->sptes[i] = spte; |
| 577 | } |
| 578 | return count; |
| 579 | } |
| 580 | |
| 581 | static void rmap_desc_remove_entry(unsigned long *rmapp, |
| 582 | struct kvm_rmap_desc *desc, |
| 583 | int i, |
| 584 | struct kvm_rmap_desc *prev_desc) |
| 585 | { |
| 586 | int j; |
| 587 | |
| 588 | for (j = RMAP_EXT - 1; !desc->sptes[j] && j > i; --j) |
| 589 | ; |
| 590 | desc->sptes[i] = desc->sptes[j]; |
| 591 | desc->sptes[j] = NULL; |
| 592 | if (j != 0) |
| 593 | return; |
| 594 | if (!prev_desc && !desc->more) |
| 595 | *rmapp = (unsigned long)desc->sptes[0]; |
| 596 | else |
| 597 | if (prev_desc) |
| 598 | prev_desc->more = desc->more; |
| 599 | else |
| 600 | *rmapp = (unsigned long)desc->more | 1; |
| 601 | mmu_free_rmap_desc(desc); |
| 602 | } |
| 603 | |
| 604 | static void rmap_remove(struct kvm *kvm, u64 *spte) |
| 605 | { |
| 606 | struct kvm_rmap_desc *desc; |
| 607 | struct kvm_rmap_desc *prev_desc; |
| 608 | struct kvm_mmu_page *sp; |
| 609 | pfn_t pfn; |
| 610 | unsigned long *rmapp; |
| 611 | int i; |
| 612 | |
| 613 | if (!is_rmap_spte(*spte)) |
| 614 | return; |
| 615 | sp = page_header(__pa(spte)); |
| 616 | pfn = spte_to_pfn(*spte); |
| 617 | if (*spte & shadow_accessed_mask) |
| 618 | kvm_set_pfn_accessed(pfn); |
| 619 | if (is_writable_pte(*spte)) |
| 620 | kvm_set_pfn_dirty(pfn); |
| 621 | rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level); |
| 622 | if (!*rmapp) { |
| 623 | printk(KERN_ERR "rmap_remove: %p %llx 0->BUG\n", spte, *spte); |
| 624 | BUG(); |
| 625 | } else if (!(*rmapp & 1)) { |
| 626 | rmap_printk("rmap_remove: %p %llx 1->0\n", spte, *spte); |
| 627 | if ((u64 *)*rmapp != spte) { |
| 628 | printk(KERN_ERR "rmap_remove: %p %llx 1->BUG\n", |
| 629 | spte, *spte); |
| 630 | BUG(); |
| 631 | } |
| 632 | *rmapp = 0; |
| 633 | } else { |
| 634 | rmap_printk("rmap_remove: %p %llx many->many\n", spte, *spte); |
| 635 | desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); |
| 636 | prev_desc = NULL; |
| 637 | while (desc) { |
| 638 | for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i) |
| 639 | if (desc->sptes[i] == spte) { |
| 640 | rmap_desc_remove_entry(rmapp, |
| 641 | desc, i, |
| 642 | prev_desc); |
| 643 | return; |
| 644 | } |
| 645 | prev_desc = desc; |
| 646 | desc = desc->more; |
| 647 | } |
| 648 | pr_err("rmap_remove: %p %llx many->many\n", spte, *spte); |
| 649 | BUG(); |
| 650 | } |
| 651 | } |
| 652 | |
| 653 | static u64 *rmap_next(struct kvm *kvm, unsigned long *rmapp, u64 *spte) |
| 654 | { |
| 655 | struct kvm_rmap_desc *desc; |
| 656 | struct kvm_rmap_desc *prev_desc; |
| 657 | u64 *prev_spte; |
| 658 | int i; |
| 659 | |
| 660 | if (!*rmapp) |
| 661 | return NULL; |
| 662 | else if (!(*rmapp & 1)) { |
| 663 | if (!spte) |
| 664 | return (u64 *)*rmapp; |
| 665 | return NULL; |
| 666 | } |
| 667 | desc = (struct kvm_rmap_desc *)(*rmapp & ~1ul); |
| 668 | prev_desc = NULL; |
| 669 | prev_spte = NULL; |
| 670 | while (desc) { |
| 671 | for (i = 0; i < RMAP_EXT && desc->sptes[i]; ++i) { |
| 672 | if (prev_spte == spte) |
| 673 | return desc->sptes[i]; |
| 674 | prev_spte = desc->sptes[i]; |
| 675 | } |
| 676 | desc = desc->more; |
| 677 | } |
| 678 | return NULL; |
| 679 | } |
| 680 | |
| 681 | static int rmap_write_protect(struct kvm *kvm, u64 gfn) |
| 682 | { |
| 683 | unsigned long *rmapp; |
| 684 | u64 *spte; |
| 685 | int i, write_protected = 0; |
| 686 | |
| 687 | gfn = unalias_gfn(kvm, gfn); |
| 688 | rmapp = gfn_to_rmap(kvm, gfn, PT_PAGE_TABLE_LEVEL); |
| 689 | |
| 690 | spte = rmap_next(kvm, rmapp, NULL); |
| 691 | while (spte) { |
| 692 | BUG_ON(!spte); |
| 693 | BUG_ON(!(*spte & PT_PRESENT_MASK)); |
| 694 | rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte); |
| 695 | if (is_writable_pte(*spte)) { |
| 696 | __set_spte(spte, *spte & ~PT_WRITABLE_MASK); |
| 697 | write_protected = 1; |
| 698 | } |
| 699 | spte = rmap_next(kvm, rmapp, spte); |
| 700 | } |
| 701 | if (write_protected) { |
| 702 | pfn_t pfn; |
| 703 | |
| 704 | spte = rmap_next(kvm, rmapp, NULL); |
| 705 | pfn = spte_to_pfn(*spte); |
| 706 | kvm_set_pfn_dirty(pfn); |
| 707 | } |
| 708 | |
| 709 | /* check for huge page mappings */ |
| 710 | for (i = PT_DIRECTORY_LEVEL; |
| 711 | i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) { |
| 712 | rmapp = gfn_to_rmap(kvm, gfn, i); |
| 713 | spte = rmap_next(kvm, rmapp, NULL); |
| 714 | while (spte) { |
| 715 | BUG_ON(!spte); |
| 716 | BUG_ON(!(*spte & PT_PRESENT_MASK)); |
| 717 | BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)); |
| 718 | pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn); |
| 719 | if (is_writable_pte(*spte)) { |
| 720 | rmap_remove(kvm, spte); |
| 721 | --kvm->stat.lpages; |
| 722 | __set_spte(spte, shadow_trap_nonpresent_pte); |
| 723 | spte = NULL; |
| 724 | write_protected = 1; |
| 725 | } |
| 726 | spte = rmap_next(kvm, rmapp, spte); |
| 727 | } |
| 728 | } |
| 729 | |
| 730 | return write_protected; |
| 731 | } |
| 732 | |
| 733 | static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp, |
| 734 | unsigned long data) |
| 735 | { |
| 736 | u64 *spte; |
| 737 | int need_tlb_flush = 0; |
| 738 | |
| 739 | while ((spte = rmap_next(kvm, rmapp, NULL))) { |
| 740 | BUG_ON(!(*spte & PT_PRESENT_MASK)); |
| 741 | rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte); |
| 742 | rmap_remove(kvm, spte); |
| 743 | __set_spte(spte, shadow_trap_nonpresent_pte); |
| 744 | need_tlb_flush = 1; |
| 745 | } |
| 746 | return need_tlb_flush; |
| 747 | } |
| 748 | |
| 749 | static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp, |
| 750 | unsigned long data) |
| 751 | { |
| 752 | int need_flush = 0; |
| 753 | u64 *spte, new_spte; |
| 754 | pte_t *ptep = (pte_t *)data; |
| 755 | pfn_t new_pfn; |
| 756 | |
| 757 | WARN_ON(pte_huge(*ptep)); |
| 758 | new_pfn = pte_pfn(*ptep); |
| 759 | spte = rmap_next(kvm, rmapp, NULL); |
| 760 | while (spte) { |
| 761 | BUG_ON(!is_shadow_present_pte(*spte)); |
| 762 | rmap_printk("kvm_set_pte_rmapp: spte %p %llx\n", spte, *spte); |
| 763 | need_flush = 1; |
| 764 | if (pte_write(*ptep)) { |
| 765 | rmap_remove(kvm, spte); |
| 766 | __set_spte(spte, shadow_trap_nonpresent_pte); |
| 767 | spte = rmap_next(kvm, rmapp, NULL); |
| 768 | } else { |
| 769 | new_spte = *spte &~ (PT64_BASE_ADDR_MASK); |
| 770 | new_spte |= (u64)new_pfn << PAGE_SHIFT; |
| 771 | |
| 772 | new_spte &= ~PT_WRITABLE_MASK; |
| 773 | new_spte &= ~SPTE_HOST_WRITEABLE; |
| 774 | if (is_writable_pte(*spte)) |
| 775 | kvm_set_pfn_dirty(spte_to_pfn(*spte)); |
| 776 | __set_spte(spte, new_spte); |
| 777 | spte = rmap_next(kvm, rmapp, spte); |
| 778 | } |
| 779 | } |
| 780 | if (need_flush) |
| 781 | kvm_flush_remote_tlbs(kvm); |
| 782 | |
| 783 | return 0; |
| 784 | } |
| 785 | |
| 786 | static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, |
| 787 | unsigned long data, |
| 788 | int (*handler)(struct kvm *kvm, unsigned long *rmapp, |
| 789 | unsigned long data)) |
| 790 | { |
| 791 | int i, j; |
| 792 | int ret; |
| 793 | int retval = 0; |
| 794 | struct kvm_memslots *slots; |
| 795 | |
| 796 | slots = rcu_dereference(kvm->memslots); |
| 797 | |
| 798 | for (i = 0; i < slots->nmemslots; i++) { |
| 799 | struct kvm_memory_slot *memslot = &slots->memslots[i]; |
| 800 | unsigned long start = memslot->userspace_addr; |
| 801 | unsigned long end; |
| 802 | |
| 803 | end = start + (memslot->npages << PAGE_SHIFT); |
| 804 | if (hva >= start && hva < end) { |
| 805 | gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT; |
| 806 | |
| 807 | ret = handler(kvm, &memslot->rmap[gfn_offset], data); |
| 808 | |
| 809 | for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) { |
| 810 | int idx = gfn_offset; |
| 811 | idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j); |
| 812 | ret |= handler(kvm, |
| 813 | &memslot->lpage_info[j][idx].rmap_pde, |
| 814 | data); |
| 815 | } |
| 816 | trace_kvm_age_page(hva, memslot, ret); |
| 817 | retval |= ret; |
| 818 | } |
| 819 | } |
| 820 | |
| 821 | return retval; |
| 822 | } |
| 823 | |
| 824 | int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) |
| 825 | { |
| 826 | return kvm_handle_hva(kvm, hva, 0, kvm_unmap_rmapp); |
| 827 | } |
| 828 | |
| 829 | void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte) |
| 830 | { |
| 831 | kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp); |
| 832 | } |
| 833 | |
| 834 | static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp, |
| 835 | unsigned long data) |
| 836 | { |
| 837 | u64 *spte; |
| 838 | int young = 0; |
| 839 | |
| 840 | /* |
| 841 | * Emulate the accessed bit for EPT, by checking if this page has |
| 842 | * an EPT mapping, and clearing it if it does. On the next access, |
| 843 | * a new EPT mapping will be established. |
| 844 | * This has some overhead, but not as much as the cost of swapping |
| 845 | * out actively used pages or breaking up actively used hugepages. |
| 846 | */ |
| 847 | if (!shadow_accessed_mask) |
| 848 | return kvm_unmap_rmapp(kvm, rmapp, data); |
| 849 | |
| 850 | spte = rmap_next(kvm, rmapp, NULL); |
| 851 | while (spte) { |
| 852 | int _young; |
| 853 | u64 _spte = *spte; |
| 854 | BUG_ON(!(_spte & PT_PRESENT_MASK)); |
| 855 | _young = _spte & PT_ACCESSED_MASK; |
| 856 | if (_young) { |
| 857 | young = 1; |
| 858 | clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); |
| 859 | } |
| 860 | spte = rmap_next(kvm, rmapp, spte); |
| 861 | } |
| 862 | return young; |
| 863 | } |
| 864 | |
| 865 | #define RMAP_RECYCLE_THRESHOLD 1000 |
| 866 | |
| 867 | static void rmap_recycle(struct kvm_vcpu *vcpu, u64 *spte, gfn_t gfn) |
| 868 | { |
| 869 | unsigned long *rmapp; |
| 870 | struct kvm_mmu_page *sp; |
| 871 | |
| 872 | sp = page_header(__pa(spte)); |
| 873 | |
| 874 | gfn = unalias_gfn(vcpu->kvm, gfn); |
| 875 | rmapp = gfn_to_rmap(vcpu->kvm, gfn, sp->role.level); |
| 876 | |
| 877 | kvm_unmap_rmapp(vcpu->kvm, rmapp, 0); |
| 878 | kvm_flush_remote_tlbs(vcpu->kvm); |
| 879 | } |
| 880 | |
| 881 | int kvm_age_hva(struct kvm *kvm, unsigned long hva) |
| 882 | { |
| 883 | return kvm_handle_hva(kvm, hva, 0, kvm_age_rmapp); |
| 884 | } |
| 885 | |
| 886 | #ifdef MMU_DEBUG |
| 887 | static int is_empty_shadow_page(u64 *spt) |
| 888 | { |
| 889 | u64 *pos; |
| 890 | u64 *end; |
| 891 | |
| 892 | for (pos = spt, end = pos + PAGE_SIZE / sizeof(u64); pos != end; pos++) |
| 893 | if (is_shadow_present_pte(*pos)) { |
| 894 | printk(KERN_ERR "%s: %p %llx\n", __func__, |
| 895 | pos, *pos); |
| 896 | return 0; |
| 897 | } |
| 898 | return 1; |
| 899 | } |
| 900 | #endif |
| 901 | |
| 902 | static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) |
| 903 | { |
| 904 | ASSERT(is_empty_shadow_page(sp->spt)); |
| 905 | list_del(&sp->link); |
| 906 | __free_page(virt_to_page(sp->spt)); |
| 907 | __free_page(virt_to_page(sp->gfns)); |
| 908 | kfree(sp); |
| 909 | ++kvm->arch.n_free_mmu_pages; |
| 910 | } |
| 911 | |
| 912 | static unsigned kvm_page_table_hashfn(gfn_t gfn) |
| 913 | { |
| 914 | return gfn & ((1 << KVM_MMU_HASH_SHIFT) - 1); |
| 915 | } |
| 916 | |
| 917 | static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, |
| 918 | u64 *parent_pte) |
| 919 | { |
| 920 | struct kvm_mmu_page *sp; |
| 921 | |
| 922 | sp = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache, sizeof *sp); |
| 923 | sp->spt = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); |
| 924 | sp->gfns = mmu_memory_cache_alloc(&vcpu->arch.mmu_page_cache, PAGE_SIZE); |
| 925 | set_page_private(virt_to_page(sp->spt), (unsigned long)sp); |
| 926 | list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); |
| 927 | INIT_LIST_HEAD(&sp->oos_link); |
| 928 | bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); |
| 929 | sp->multimapped = 0; |
| 930 | sp->parent_pte = parent_pte; |
| 931 | --vcpu->kvm->arch.n_free_mmu_pages; |
| 932 | return sp; |
| 933 | } |
| 934 | |
| 935 | static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu, |
| 936 | struct kvm_mmu_page *sp, u64 *parent_pte) |
| 937 | { |
| 938 | struct kvm_pte_chain *pte_chain; |
| 939 | struct hlist_node *node; |
| 940 | int i; |
| 941 | |
| 942 | if (!parent_pte) |
| 943 | return; |
| 944 | if (!sp->multimapped) { |
| 945 | u64 *old = sp->parent_pte; |
| 946 | |
| 947 | if (!old) { |
| 948 | sp->parent_pte = parent_pte; |
| 949 | return; |
| 950 | } |
| 951 | sp->multimapped = 1; |
| 952 | pte_chain = mmu_alloc_pte_chain(vcpu); |
| 953 | INIT_HLIST_HEAD(&sp->parent_ptes); |
| 954 | hlist_add_head(&pte_chain->link, &sp->parent_ptes); |
| 955 | pte_chain->parent_ptes[0] = old; |
| 956 | } |
| 957 | hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) { |
| 958 | if (pte_chain->parent_ptes[NR_PTE_CHAIN_ENTRIES-1]) |
| 959 | continue; |
| 960 | for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) |
| 961 | if (!pte_chain->parent_ptes[i]) { |
| 962 | pte_chain->parent_ptes[i] = parent_pte; |
| 963 | return; |
| 964 | } |
| 965 | } |
| 966 | pte_chain = mmu_alloc_pte_chain(vcpu); |
| 967 | BUG_ON(!pte_chain); |
| 968 | hlist_add_head(&pte_chain->link, &sp->parent_ptes); |
| 969 | pte_chain->parent_ptes[0] = parent_pte; |
| 970 | } |
| 971 | |
| 972 | static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, |
| 973 | u64 *parent_pte) |
| 974 | { |
| 975 | struct kvm_pte_chain *pte_chain; |
| 976 | struct hlist_node *node; |
| 977 | int i; |
| 978 | |
| 979 | if (!sp->multimapped) { |
| 980 | BUG_ON(sp->parent_pte != parent_pte); |
| 981 | sp->parent_pte = NULL; |
| 982 | return; |
| 983 | } |
| 984 | hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) |
| 985 | for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { |
| 986 | if (!pte_chain->parent_ptes[i]) |
| 987 | break; |
| 988 | if (pte_chain->parent_ptes[i] != parent_pte) |
| 989 | continue; |
| 990 | while (i + 1 < NR_PTE_CHAIN_ENTRIES |
| 991 | && pte_chain->parent_ptes[i + 1]) { |
| 992 | pte_chain->parent_ptes[i] |
| 993 | = pte_chain->parent_ptes[i + 1]; |
| 994 | ++i; |
| 995 | } |
| 996 | pte_chain->parent_ptes[i] = NULL; |
| 997 | if (i == 0) { |
| 998 | hlist_del(&pte_chain->link); |
| 999 | mmu_free_pte_chain(pte_chain); |
| 1000 | if (hlist_empty(&sp->parent_ptes)) { |
| 1001 | sp->multimapped = 0; |
| 1002 | sp->parent_pte = NULL; |
| 1003 | } |
| 1004 | } |
| 1005 | return; |
| 1006 | } |
| 1007 | BUG(); |
| 1008 | } |
| 1009 | |
| 1010 | |
| 1011 | static void mmu_parent_walk(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, |
| 1012 | mmu_parent_walk_fn fn) |
| 1013 | { |
| 1014 | struct kvm_pte_chain *pte_chain; |
| 1015 | struct hlist_node *node; |
| 1016 | struct kvm_mmu_page *parent_sp; |
| 1017 | int i; |
| 1018 | |
| 1019 | if (!sp->multimapped && sp->parent_pte) { |
| 1020 | parent_sp = page_header(__pa(sp->parent_pte)); |
| 1021 | fn(vcpu, parent_sp); |
| 1022 | mmu_parent_walk(vcpu, parent_sp, fn); |
| 1023 | return; |
| 1024 | } |
| 1025 | hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) |
| 1026 | for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { |
| 1027 | if (!pte_chain->parent_ptes[i]) |
| 1028 | break; |
| 1029 | parent_sp = page_header(__pa(pte_chain->parent_ptes[i])); |
| 1030 | fn(vcpu, parent_sp); |
| 1031 | mmu_parent_walk(vcpu, parent_sp, fn); |
| 1032 | } |
| 1033 | } |
| 1034 | |
| 1035 | static void kvm_mmu_update_unsync_bitmap(u64 *spte) |
| 1036 | { |
| 1037 | unsigned int index; |
| 1038 | struct kvm_mmu_page *sp = page_header(__pa(spte)); |
| 1039 | |
| 1040 | index = spte - sp->spt; |
| 1041 | if (!__test_and_set_bit(index, sp->unsync_child_bitmap)) |
| 1042 | sp->unsync_children++; |
| 1043 | WARN_ON(!sp->unsync_children); |
| 1044 | } |
| 1045 | |
| 1046 | static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp) |
| 1047 | { |
| 1048 | struct kvm_pte_chain *pte_chain; |
| 1049 | struct hlist_node *node; |
| 1050 | int i; |
| 1051 | |
| 1052 | if (!sp->parent_pte) |
| 1053 | return; |
| 1054 | |
| 1055 | if (!sp->multimapped) { |
| 1056 | kvm_mmu_update_unsync_bitmap(sp->parent_pte); |
| 1057 | return; |
| 1058 | } |
| 1059 | |
| 1060 | hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) |
| 1061 | for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { |
| 1062 | if (!pte_chain->parent_ptes[i]) |
| 1063 | break; |
| 1064 | kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]); |
| 1065 | } |
| 1066 | } |
| 1067 | |
| 1068 | static int unsync_walk_fn(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| 1069 | { |
| 1070 | kvm_mmu_update_parents_unsync(sp); |
| 1071 | return 1; |
| 1072 | } |
| 1073 | |
| 1074 | static void kvm_mmu_mark_parents_unsync(struct kvm_vcpu *vcpu, |
| 1075 | struct kvm_mmu_page *sp) |
| 1076 | { |
| 1077 | mmu_parent_walk(vcpu, sp, unsync_walk_fn); |
| 1078 | kvm_mmu_update_parents_unsync(sp); |
| 1079 | } |
| 1080 | |
| 1081 | static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, |
| 1082 | struct kvm_mmu_page *sp) |
| 1083 | { |
| 1084 | int i; |
| 1085 | |
| 1086 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) |
| 1087 | sp->spt[i] = shadow_trap_nonpresent_pte; |
| 1088 | } |
| 1089 | |
| 1090 | static int nonpaging_sync_page(struct kvm_vcpu *vcpu, |
| 1091 | struct kvm_mmu_page *sp) |
| 1092 | { |
| 1093 | return 1; |
| 1094 | } |
| 1095 | |
| 1096 | static void nonpaging_invlpg(struct kvm_vcpu *vcpu, gva_t gva) |
| 1097 | { |
| 1098 | } |
| 1099 | |
| 1100 | #define KVM_PAGE_ARRAY_NR 16 |
| 1101 | |
| 1102 | struct kvm_mmu_pages { |
| 1103 | struct mmu_page_and_offset { |
| 1104 | struct kvm_mmu_page *sp; |
| 1105 | unsigned int idx; |
| 1106 | } page[KVM_PAGE_ARRAY_NR]; |
| 1107 | unsigned int nr; |
| 1108 | }; |
| 1109 | |
| 1110 | #define for_each_unsync_children(bitmap, idx) \ |
| 1111 | for (idx = find_first_bit(bitmap, 512); \ |
| 1112 | idx < 512; \ |
| 1113 | idx = find_next_bit(bitmap, 512, idx+1)) |
| 1114 | |
| 1115 | static int mmu_pages_add(struct kvm_mmu_pages *pvec, struct kvm_mmu_page *sp, |
| 1116 | int idx) |
| 1117 | { |
| 1118 | int i; |
| 1119 | |
| 1120 | if (sp->unsync) |
| 1121 | for (i=0; i < pvec->nr; i++) |
| 1122 | if (pvec->page[i].sp == sp) |
| 1123 | return 0; |
| 1124 | |
| 1125 | pvec->page[pvec->nr].sp = sp; |
| 1126 | pvec->page[pvec->nr].idx = idx; |
| 1127 | pvec->nr++; |
| 1128 | return (pvec->nr == KVM_PAGE_ARRAY_NR); |
| 1129 | } |
| 1130 | |
| 1131 | static int __mmu_unsync_walk(struct kvm_mmu_page *sp, |
| 1132 | struct kvm_mmu_pages *pvec) |
| 1133 | { |
| 1134 | int i, ret, nr_unsync_leaf = 0; |
| 1135 | |
| 1136 | for_each_unsync_children(sp->unsync_child_bitmap, i) { |
| 1137 | u64 ent = sp->spt[i]; |
| 1138 | |
| 1139 | if (is_shadow_present_pte(ent) && !is_large_pte(ent)) { |
| 1140 | struct kvm_mmu_page *child; |
| 1141 | child = page_header(ent & PT64_BASE_ADDR_MASK); |
| 1142 | |
| 1143 | if (child->unsync_children) { |
| 1144 | if (mmu_pages_add(pvec, child, i)) |
| 1145 | return -ENOSPC; |
| 1146 | |
| 1147 | ret = __mmu_unsync_walk(child, pvec); |
| 1148 | if (!ret) |
| 1149 | __clear_bit(i, sp->unsync_child_bitmap); |
| 1150 | else if (ret > 0) |
| 1151 | nr_unsync_leaf += ret; |
| 1152 | else |
| 1153 | return ret; |
| 1154 | } |
| 1155 | |
| 1156 | if (child->unsync) { |
| 1157 | nr_unsync_leaf++; |
| 1158 | if (mmu_pages_add(pvec, child, i)) |
| 1159 | return -ENOSPC; |
| 1160 | } |
| 1161 | } |
| 1162 | } |
| 1163 | |
| 1164 | if (find_first_bit(sp->unsync_child_bitmap, 512) == 512) |
| 1165 | sp->unsync_children = 0; |
| 1166 | |
| 1167 | return nr_unsync_leaf; |
| 1168 | } |
| 1169 | |
| 1170 | static int mmu_unsync_walk(struct kvm_mmu_page *sp, |
| 1171 | struct kvm_mmu_pages *pvec) |
| 1172 | { |
| 1173 | if (!sp->unsync_children) |
| 1174 | return 0; |
| 1175 | |
| 1176 | mmu_pages_add(pvec, sp, 0); |
| 1177 | return __mmu_unsync_walk(sp, pvec); |
| 1178 | } |
| 1179 | |
| 1180 | static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) |
| 1181 | { |
| 1182 | unsigned index; |
| 1183 | struct hlist_head *bucket; |
| 1184 | struct kvm_mmu_page *sp; |
| 1185 | struct hlist_node *node; |
| 1186 | |
| 1187 | pgprintk("%s: looking for gfn %lx\n", __func__, gfn); |
| 1188 | index = kvm_page_table_hashfn(gfn); |
| 1189 | bucket = &kvm->arch.mmu_page_hash[index]; |
| 1190 | hlist_for_each_entry(sp, node, bucket, hash_link) |
| 1191 | if (sp->gfn == gfn && !sp->role.direct |
| 1192 | && !sp->role.invalid) { |
| 1193 | pgprintk("%s: found role %x\n", |
| 1194 | __func__, sp->role.word); |
| 1195 | return sp; |
| 1196 | } |
| 1197 | return NULL; |
| 1198 | } |
| 1199 | |
| 1200 | static void kvm_unlink_unsync_page(struct kvm *kvm, struct kvm_mmu_page *sp) |
| 1201 | { |
| 1202 | WARN_ON(!sp->unsync); |
| 1203 | sp->unsync = 0; |
| 1204 | --kvm->stat.mmu_unsync; |
| 1205 | } |
| 1206 | |
| 1207 | static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp); |
| 1208 | |
| 1209 | static int kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| 1210 | { |
| 1211 | if (sp->role.glevels != vcpu->arch.mmu.root_level) { |
| 1212 | kvm_mmu_zap_page(vcpu->kvm, sp); |
| 1213 | return 1; |
| 1214 | } |
| 1215 | |
| 1216 | trace_kvm_mmu_sync_page(sp); |
| 1217 | if (rmap_write_protect(vcpu->kvm, sp->gfn)) |
| 1218 | kvm_flush_remote_tlbs(vcpu->kvm); |
| 1219 | kvm_unlink_unsync_page(vcpu->kvm, sp); |
| 1220 | if (vcpu->arch.mmu.sync_page(vcpu, sp)) { |
| 1221 | kvm_mmu_zap_page(vcpu->kvm, sp); |
| 1222 | return 1; |
| 1223 | } |
| 1224 | |
| 1225 | kvm_mmu_flush_tlb(vcpu); |
| 1226 | return 0; |
| 1227 | } |
| 1228 | |
| 1229 | struct mmu_page_path { |
| 1230 | struct kvm_mmu_page *parent[PT64_ROOT_LEVEL-1]; |
| 1231 | unsigned int idx[PT64_ROOT_LEVEL-1]; |
| 1232 | }; |
| 1233 | |
| 1234 | #define for_each_sp(pvec, sp, parents, i) \ |
| 1235 | for (i = mmu_pages_next(&pvec, &parents, -1), \ |
| 1236 | sp = pvec.page[i].sp; \ |
| 1237 | i < pvec.nr && ({ sp = pvec.page[i].sp; 1;}); \ |
| 1238 | i = mmu_pages_next(&pvec, &parents, i)) |
| 1239 | |
| 1240 | static int mmu_pages_next(struct kvm_mmu_pages *pvec, |
| 1241 | struct mmu_page_path *parents, |
| 1242 | int i) |
| 1243 | { |
| 1244 | int n; |
| 1245 | |
| 1246 | for (n = i+1; n < pvec->nr; n++) { |
| 1247 | struct kvm_mmu_page *sp = pvec->page[n].sp; |
| 1248 | |
| 1249 | if (sp->role.level == PT_PAGE_TABLE_LEVEL) { |
| 1250 | parents->idx[0] = pvec->page[n].idx; |
| 1251 | return n; |
| 1252 | } |
| 1253 | |
| 1254 | parents->parent[sp->role.level-2] = sp; |
| 1255 | parents->idx[sp->role.level-1] = pvec->page[n].idx; |
| 1256 | } |
| 1257 | |
| 1258 | return n; |
| 1259 | } |
| 1260 | |
| 1261 | static void mmu_pages_clear_parents(struct mmu_page_path *parents) |
| 1262 | { |
| 1263 | struct kvm_mmu_page *sp; |
| 1264 | unsigned int level = 0; |
| 1265 | |
| 1266 | do { |
| 1267 | unsigned int idx = parents->idx[level]; |
| 1268 | |
| 1269 | sp = parents->parent[level]; |
| 1270 | if (!sp) |
| 1271 | return; |
| 1272 | |
| 1273 | --sp->unsync_children; |
| 1274 | WARN_ON((int)sp->unsync_children < 0); |
| 1275 | __clear_bit(idx, sp->unsync_child_bitmap); |
| 1276 | level++; |
| 1277 | } while (level < PT64_ROOT_LEVEL-1 && !sp->unsync_children); |
| 1278 | } |
| 1279 | |
| 1280 | static void kvm_mmu_pages_init(struct kvm_mmu_page *parent, |
| 1281 | struct mmu_page_path *parents, |
| 1282 | struct kvm_mmu_pages *pvec) |
| 1283 | { |
| 1284 | parents->parent[parent->role.level-1] = NULL; |
| 1285 | pvec->nr = 0; |
| 1286 | } |
| 1287 | |
| 1288 | static void mmu_sync_children(struct kvm_vcpu *vcpu, |
| 1289 | struct kvm_mmu_page *parent) |
| 1290 | { |
| 1291 | int i; |
| 1292 | struct kvm_mmu_page *sp; |
| 1293 | struct mmu_page_path parents; |
| 1294 | struct kvm_mmu_pages pages; |
| 1295 | |
| 1296 | kvm_mmu_pages_init(parent, &parents, &pages); |
| 1297 | while (mmu_unsync_walk(parent, &pages)) { |
| 1298 | int protected = 0; |
| 1299 | |
| 1300 | for_each_sp(pages, sp, parents, i) |
| 1301 | protected |= rmap_write_protect(vcpu->kvm, sp->gfn); |
| 1302 | |
| 1303 | if (protected) |
| 1304 | kvm_flush_remote_tlbs(vcpu->kvm); |
| 1305 | |
| 1306 | for_each_sp(pages, sp, parents, i) { |
| 1307 | kvm_sync_page(vcpu, sp); |
| 1308 | mmu_pages_clear_parents(&parents); |
| 1309 | } |
| 1310 | cond_resched_lock(&vcpu->kvm->mmu_lock); |
| 1311 | kvm_mmu_pages_init(parent, &parents, &pages); |
| 1312 | } |
| 1313 | } |
| 1314 | |
| 1315 | static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, |
| 1316 | gfn_t gfn, |
| 1317 | gva_t gaddr, |
| 1318 | unsigned level, |
| 1319 | int direct, |
| 1320 | unsigned access, |
| 1321 | u64 *parent_pte) |
| 1322 | { |
| 1323 | union kvm_mmu_page_role role; |
| 1324 | unsigned index; |
| 1325 | unsigned quadrant; |
| 1326 | struct hlist_head *bucket; |
| 1327 | struct kvm_mmu_page *sp; |
| 1328 | struct hlist_node *node, *tmp; |
| 1329 | |
| 1330 | role = vcpu->arch.mmu.base_role; |
| 1331 | role.level = level; |
| 1332 | role.direct = direct; |
| 1333 | role.access = access; |
| 1334 | if (vcpu->arch.mmu.root_level <= PT32_ROOT_LEVEL) { |
| 1335 | quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level)); |
| 1336 | quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1; |
| 1337 | role.quadrant = quadrant; |
| 1338 | } |
| 1339 | index = kvm_page_table_hashfn(gfn); |
| 1340 | bucket = &vcpu->kvm->arch.mmu_page_hash[index]; |
| 1341 | hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link) |
| 1342 | if (sp->gfn == gfn) { |
| 1343 | if (sp->unsync) |
| 1344 | if (kvm_sync_page(vcpu, sp)) |
| 1345 | continue; |
| 1346 | |
| 1347 | if (sp->role.word != role.word) |
| 1348 | continue; |
| 1349 | |
| 1350 | mmu_page_add_parent_pte(vcpu, sp, parent_pte); |
| 1351 | if (sp->unsync_children) { |
| 1352 | set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests); |
| 1353 | kvm_mmu_mark_parents_unsync(vcpu, sp); |
| 1354 | } |
| 1355 | trace_kvm_mmu_get_page(sp, false); |
| 1356 | return sp; |
| 1357 | } |
| 1358 | ++vcpu->kvm->stat.mmu_cache_miss; |
| 1359 | sp = kvm_mmu_alloc_page(vcpu, parent_pte); |
| 1360 | if (!sp) |
| 1361 | return sp; |
| 1362 | sp->gfn = gfn; |
| 1363 | sp->role = role; |
| 1364 | hlist_add_head(&sp->hash_link, bucket); |
| 1365 | if (!direct) { |
| 1366 | if (rmap_write_protect(vcpu->kvm, gfn)) |
| 1367 | kvm_flush_remote_tlbs(vcpu->kvm); |
| 1368 | account_shadowed(vcpu->kvm, gfn); |
| 1369 | } |
| 1370 | if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) |
| 1371 | vcpu->arch.mmu.prefetch_page(vcpu, sp); |
| 1372 | else |
| 1373 | nonpaging_prefetch_page(vcpu, sp); |
| 1374 | trace_kvm_mmu_get_page(sp, true); |
| 1375 | return sp; |
| 1376 | } |
| 1377 | |
| 1378 | static void shadow_walk_init(struct kvm_shadow_walk_iterator *iterator, |
| 1379 | struct kvm_vcpu *vcpu, u64 addr) |
| 1380 | { |
| 1381 | iterator->addr = addr; |
| 1382 | iterator->shadow_addr = vcpu->arch.mmu.root_hpa; |
| 1383 | iterator->level = vcpu->arch.mmu.shadow_root_level; |
| 1384 | if (iterator->level == PT32E_ROOT_LEVEL) { |
| 1385 | iterator->shadow_addr |
| 1386 | = vcpu->arch.mmu.pae_root[(addr >> 30) & 3]; |
| 1387 | iterator->shadow_addr &= PT64_BASE_ADDR_MASK; |
| 1388 | --iterator->level; |
| 1389 | if (!iterator->shadow_addr) |
| 1390 | iterator->level = 0; |
| 1391 | } |
| 1392 | } |
| 1393 | |
| 1394 | static bool shadow_walk_okay(struct kvm_shadow_walk_iterator *iterator) |
| 1395 | { |
| 1396 | if (iterator->level < PT_PAGE_TABLE_LEVEL) |
| 1397 | return false; |
| 1398 | |
| 1399 | if (iterator->level == PT_PAGE_TABLE_LEVEL) |
| 1400 | if (is_large_pte(*iterator->sptep)) |
| 1401 | return false; |
| 1402 | |
| 1403 | iterator->index = SHADOW_PT_INDEX(iterator->addr, iterator->level); |
| 1404 | iterator->sptep = ((u64 *)__va(iterator->shadow_addr)) + iterator->index; |
| 1405 | return true; |
| 1406 | } |
| 1407 | |
| 1408 | static void shadow_walk_next(struct kvm_shadow_walk_iterator *iterator) |
| 1409 | { |
| 1410 | iterator->shadow_addr = *iterator->sptep & PT64_BASE_ADDR_MASK; |
| 1411 | --iterator->level; |
| 1412 | } |
| 1413 | |
| 1414 | static void kvm_mmu_page_unlink_children(struct kvm *kvm, |
| 1415 | struct kvm_mmu_page *sp) |
| 1416 | { |
| 1417 | unsigned i; |
| 1418 | u64 *pt; |
| 1419 | u64 ent; |
| 1420 | |
| 1421 | pt = sp->spt; |
| 1422 | |
| 1423 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| 1424 | ent = pt[i]; |
| 1425 | |
| 1426 | if (is_shadow_present_pte(ent)) { |
| 1427 | if (!is_last_spte(ent, sp->role.level)) { |
| 1428 | ent &= PT64_BASE_ADDR_MASK; |
| 1429 | mmu_page_remove_parent_pte(page_header(ent), |
| 1430 | &pt[i]); |
| 1431 | } else { |
| 1432 | if (is_large_pte(ent)) |
| 1433 | --kvm->stat.lpages; |
| 1434 | rmap_remove(kvm, &pt[i]); |
| 1435 | } |
| 1436 | } |
| 1437 | pt[i] = shadow_trap_nonpresent_pte; |
| 1438 | } |
| 1439 | } |
| 1440 | |
| 1441 | static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte) |
| 1442 | { |
| 1443 | mmu_page_remove_parent_pte(sp, parent_pte); |
| 1444 | } |
| 1445 | |
| 1446 | static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm) |
| 1447 | { |
| 1448 | int i; |
| 1449 | struct kvm_vcpu *vcpu; |
| 1450 | |
| 1451 | kvm_for_each_vcpu(i, vcpu, kvm) |
| 1452 | vcpu->arch.last_pte_updated = NULL; |
| 1453 | } |
| 1454 | |
| 1455 | static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) |
| 1456 | { |
| 1457 | u64 *parent_pte; |
| 1458 | |
| 1459 | while (sp->multimapped || sp->parent_pte) { |
| 1460 | if (!sp->multimapped) |
| 1461 | parent_pte = sp->parent_pte; |
| 1462 | else { |
| 1463 | struct kvm_pte_chain *chain; |
| 1464 | |
| 1465 | chain = container_of(sp->parent_ptes.first, |
| 1466 | struct kvm_pte_chain, link); |
| 1467 | parent_pte = chain->parent_ptes[0]; |
| 1468 | } |
| 1469 | BUG_ON(!parent_pte); |
| 1470 | kvm_mmu_put_page(sp, parent_pte); |
| 1471 | __set_spte(parent_pte, shadow_trap_nonpresent_pte); |
| 1472 | } |
| 1473 | } |
| 1474 | |
| 1475 | static int mmu_zap_unsync_children(struct kvm *kvm, |
| 1476 | struct kvm_mmu_page *parent) |
| 1477 | { |
| 1478 | int i, zapped = 0; |
| 1479 | struct mmu_page_path parents; |
| 1480 | struct kvm_mmu_pages pages; |
| 1481 | |
| 1482 | if (parent->role.level == PT_PAGE_TABLE_LEVEL) |
| 1483 | return 0; |
| 1484 | |
| 1485 | kvm_mmu_pages_init(parent, &parents, &pages); |
| 1486 | while (mmu_unsync_walk(parent, &pages)) { |
| 1487 | struct kvm_mmu_page *sp; |
| 1488 | |
| 1489 | for_each_sp(pages, sp, parents, i) { |
| 1490 | kvm_mmu_zap_page(kvm, sp); |
| 1491 | mmu_pages_clear_parents(&parents); |
| 1492 | } |
| 1493 | zapped += pages.nr; |
| 1494 | kvm_mmu_pages_init(parent, &parents, &pages); |
| 1495 | } |
| 1496 | |
| 1497 | return zapped; |
| 1498 | } |
| 1499 | |
| 1500 | static int kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp) |
| 1501 | { |
| 1502 | int ret; |
| 1503 | |
| 1504 | trace_kvm_mmu_zap_page(sp); |
| 1505 | ++kvm->stat.mmu_shadow_zapped; |
| 1506 | ret = mmu_zap_unsync_children(kvm, sp); |
| 1507 | kvm_mmu_page_unlink_children(kvm, sp); |
| 1508 | kvm_mmu_unlink_parents(kvm, sp); |
| 1509 | kvm_flush_remote_tlbs(kvm); |
| 1510 | if (!sp->role.invalid && !sp->role.direct) |
| 1511 | unaccount_shadowed(kvm, sp->gfn); |
| 1512 | if (sp->unsync) |
| 1513 | kvm_unlink_unsync_page(kvm, sp); |
| 1514 | if (!sp->root_count) { |
| 1515 | hlist_del(&sp->hash_link); |
| 1516 | kvm_mmu_free_page(kvm, sp); |
| 1517 | } else { |
| 1518 | sp->role.invalid = 1; |
| 1519 | list_move(&sp->link, &kvm->arch.active_mmu_pages); |
| 1520 | kvm_reload_remote_mmus(kvm); |
| 1521 | } |
| 1522 | kvm_mmu_reset_last_pte_updated(kvm); |
| 1523 | return ret; |
| 1524 | } |
| 1525 | |
| 1526 | /* |
| 1527 | * Changing the number of mmu pages allocated to the vm |
| 1528 | * Note: if kvm_nr_mmu_pages is too small, you will get dead lock |
| 1529 | */ |
| 1530 | void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages) |
| 1531 | { |
| 1532 | int used_pages; |
| 1533 | |
| 1534 | used_pages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages; |
| 1535 | used_pages = max(0, used_pages); |
| 1536 | |
| 1537 | /* |
| 1538 | * If we set the number of mmu pages to be smaller be than the |
| 1539 | * number of actived pages , we must to free some mmu pages before we |
| 1540 | * change the value |
| 1541 | */ |
| 1542 | |
| 1543 | if (used_pages > kvm_nr_mmu_pages) { |
| 1544 | while (used_pages > kvm_nr_mmu_pages) { |
| 1545 | struct kvm_mmu_page *page; |
| 1546 | |
| 1547 | page = container_of(kvm->arch.active_mmu_pages.prev, |
| 1548 | struct kvm_mmu_page, link); |
| 1549 | kvm_mmu_zap_page(kvm, page); |
| 1550 | used_pages--; |
| 1551 | } |
| 1552 | kvm->arch.n_free_mmu_pages = 0; |
| 1553 | } |
| 1554 | else |
| 1555 | kvm->arch.n_free_mmu_pages += kvm_nr_mmu_pages |
| 1556 | - kvm->arch.n_alloc_mmu_pages; |
| 1557 | |
| 1558 | kvm->arch.n_alloc_mmu_pages = kvm_nr_mmu_pages; |
| 1559 | } |
| 1560 | |
| 1561 | static int kvm_mmu_unprotect_page(struct kvm *kvm, gfn_t gfn) |
| 1562 | { |
| 1563 | unsigned index; |
| 1564 | struct hlist_head *bucket; |
| 1565 | struct kvm_mmu_page *sp; |
| 1566 | struct hlist_node *node, *n; |
| 1567 | int r; |
| 1568 | |
| 1569 | pgprintk("%s: looking for gfn %lx\n", __func__, gfn); |
| 1570 | r = 0; |
| 1571 | index = kvm_page_table_hashfn(gfn); |
| 1572 | bucket = &kvm->arch.mmu_page_hash[index]; |
| 1573 | hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) |
| 1574 | if (sp->gfn == gfn && !sp->role.direct) { |
| 1575 | pgprintk("%s: gfn %lx role %x\n", __func__, gfn, |
| 1576 | sp->role.word); |
| 1577 | r = 1; |
| 1578 | if (kvm_mmu_zap_page(kvm, sp)) |
| 1579 | n = bucket->first; |
| 1580 | } |
| 1581 | return r; |
| 1582 | } |
| 1583 | |
| 1584 | static void mmu_unshadow(struct kvm *kvm, gfn_t gfn) |
| 1585 | { |
| 1586 | unsigned index; |
| 1587 | struct hlist_head *bucket; |
| 1588 | struct kvm_mmu_page *sp; |
| 1589 | struct hlist_node *node, *nn; |
| 1590 | |
| 1591 | index = kvm_page_table_hashfn(gfn); |
| 1592 | bucket = &kvm->arch.mmu_page_hash[index]; |
| 1593 | hlist_for_each_entry_safe(sp, node, nn, bucket, hash_link) { |
| 1594 | if (sp->gfn == gfn && !sp->role.direct |
| 1595 | && !sp->role.invalid) { |
| 1596 | pgprintk("%s: zap %lx %x\n", |
| 1597 | __func__, gfn, sp->role.word); |
| 1598 | kvm_mmu_zap_page(kvm, sp); |
| 1599 | } |
| 1600 | } |
| 1601 | } |
| 1602 | |
| 1603 | static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn) |
| 1604 | { |
| 1605 | int slot = memslot_id(kvm, gfn); |
| 1606 | struct kvm_mmu_page *sp = page_header(__pa(pte)); |
| 1607 | |
| 1608 | __set_bit(slot, sp->slot_bitmap); |
| 1609 | } |
| 1610 | |
| 1611 | static void mmu_convert_notrap(struct kvm_mmu_page *sp) |
| 1612 | { |
| 1613 | int i; |
| 1614 | u64 *pt = sp->spt; |
| 1615 | |
| 1616 | if (shadow_trap_nonpresent_pte == shadow_notrap_nonpresent_pte) |
| 1617 | return; |
| 1618 | |
| 1619 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| 1620 | if (pt[i] == shadow_notrap_nonpresent_pte) |
| 1621 | __set_spte(&pt[i], shadow_trap_nonpresent_pte); |
| 1622 | } |
| 1623 | } |
| 1624 | |
| 1625 | struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva) |
| 1626 | { |
| 1627 | struct page *page; |
| 1628 | |
| 1629 | gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); |
| 1630 | |
| 1631 | if (gpa == UNMAPPED_GVA) |
| 1632 | return NULL; |
| 1633 | |
| 1634 | page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT); |
| 1635 | |
| 1636 | return page; |
| 1637 | } |
| 1638 | |
| 1639 | /* |
| 1640 | * The function is based on mtrr_type_lookup() in |
| 1641 | * arch/x86/kernel/cpu/mtrr/generic.c |
| 1642 | */ |
| 1643 | static int get_mtrr_type(struct mtrr_state_type *mtrr_state, |
| 1644 | u64 start, u64 end) |
| 1645 | { |
| 1646 | int i; |
| 1647 | u64 base, mask; |
| 1648 | u8 prev_match, curr_match; |
| 1649 | int num_var_ranges = KVM_NR_VAR_MTRR; |
| 1650 | |
| 1651 | if (!mtrr_state->enabled) |
| 1652 | return 0xFF; |
| 1653 | |
| 1654 | /* Make end inclusive end, instead of exclusive */ |
| 1655 | end--; |
| 1656 | |
| 1657 | /* Look in fixed ranges. Just return the type as per start */ |
| 1658 | if (mtrr_state->have_fixed && (start < 0x100000)) { |
| 1659 | int idx; |
| 1660 | |
| 1661 | if (start < 0x80000) { |
| 1662 | idx = 0; |
| 1663 | idx += (start >> 16); |
| 1664 | return mtrr_state->fixed_ranges[idx]; |
| 1665 | } else if (start < 0xC0000) { |
| 1666 | idx = 1 * 8; |
| 1667 | idx += ((start - 0x80000) >> 14); |
| 1668 | return mtrr_state->fixed_ranges[idx]; |
| 1669 | } else if (start < 0x1000000) { |
| 1670 | idx = 3 * 8; |
| 1671 | idx += ((start - 0xC0000) >> 12); |
| 1672 | return mtrr_state->fixed_ranges[idx]; |
| 1673 | } |
| 1674 | } |
| 1675 | |
| 1676 | /* |
| 1677 | * Look in variable ranges |
| 1678 | * Look of multiple ranges matching this address and pick type |
| 1679 | * as per MTRR precedence |
| 1680 | */ |
| 1681 | if (!(mtrr_state->enabled & 2)) |
| 1682 | return mtrr_state->def_type; |
| 1683 | |
| 1684 | prev_match = 0xFF; |
| 1685 | for (i = 0; i < num_var_ranges; ++i) { |
| 1686 | unsigned short start_state, end_state; |
| 1687 | |
| 1688 | if (!(mtrr_state->var_ranges[i].mask_lo & (1 << 11))) |
| 1689 | continue; |
| 1690 | |
| 1691 | base = (((u64)mtrr_state->var_ranges[i].base_hi) << 32) + |
| 1692 | (mtrr_state->var_ranges[i].base_lo & PAGE_MASK); |
| 1693 | mask = (((u64)mtrr_state->var_ranges[i].mask_hi) << 32) + |
| 1694 | (mtrr_state->var_ranges[i].mask_lo & PAGE_MASK); |
| 1695 | |
| 1696 | start_state = ((start & mask) == (base & mask)); |
| 1697 | end_state = ((end & mask) == (base & mask)); |
| 1698 | if (start_state != end_state) |
| 1699 | return 0xFE; |
| 1700 | |
| 1701 | if ((start & mask) != (base & mask)) |
| 1702 | continue; |
| 1703 | |
| 1704 | curr_match = mtrr_state->var_ranges[i].base_lo & 0xff; |
| 1705 | if (prev_match == 0xFF) { |
| 1706 | prev_match = curr_match; |
| 1707 | continue; |
| 1708 | } |
| 1709 | |
| 1710 | if (prev_match == MTRR_TYPE_UNCACHABLE || |
| 1711 | curr_match == MTRR_TYPE_UNCACHABLE) |
| 1712 | return MTRR_TYPE_UNCACHABLE; |
| 1713 | |
| 1714 | if ((prev_match == MTRR_TYPE_WRBACK && |
| 1715 | curr_match == MTRR_TYPE_WRTHROUGH) || |
| 1716 | (prev_match == MTRR_TYPE_WRTHROUGH && |
| 1717 | curr_match == MTRR_TYPE_WRBACK)) { |
| 1718 | prev_match = MTRR_TYPE_WRTHROUGH; |
| 1719 | curr_match = MTRR_TYPE_WRTHROUGH; |
| 1720 | } |
| 1721 | |
| 1722 | if (prev_match != curr_match) |
| 1723 | return MTRR_TYPE_UNCACHABLE; |
| 1724 | } |
| 1725 | |
| 1726 | if (prev_match != 0xFF) |
| 1727 | return prev_match; |
| 1728 | |
| 1729 | return mtrr_state->def_type; |
| 1730 | } |
| 1731 | |
| 1732 | u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn) |
| 1733 | { |
| 1734 | u8 mtrr; |
| 1735 | |
| 1736 | mtrr = get_mtrr_type(&vcpu->arch.mtrr_state, gfn << PAGE_SHIFT, |
| 1737 | (gfn << PAGE_SHIFT) + PAGE_SIZE); |
| 1738 | if (mtrr == 0xfe || mtrr == 0xff) |
| 1739 | mtrr = MTRR_TYPE_WRBACK; |
| 1740 | return mtrr; |
| 1741 | } |
| 1742 | EXPORT_SYMBOL_GPL(kvm_get_guest_memory_type); |
| 1743 | |
| 1744 | static int kvm_unsync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) |
| 1745 | { |
| 1746 | unsigned index; |
| 1747 | struct hlist_head *bucket; |
| 1748 | struct kvm_mmu_page *s; |
| 1749 | struct hlist_node *node, *n; |
| 1750 | |
| 1751 | trace_kvm_mmu_unsync_page(sp); |
| 1752 | index = kvm_page_table_hashfn(sp->gfn); |
| 1753 | bucket = &vcpu->kvm->arch.mmu_page_hash[index]; |
| 1754 | /* don't unsync if pagetable is shadowed with multiple roles */ |
| 1755 | hlist_for_each_entry_safe(s, node, n, bucket, hash_link) { |
| 1756 | if (s->gfn != sp->gfn || s->role.direct) |
| 1757 | continue; |
| 1758 | if (s->role.word != sp->role.word) |
| 1759 | return 1; |
| 1760 | } |
| 1761 | ++vcpu->kvm->stat.mmu_unsync; |
| 1762 | sp->unsync = 1; |
| 1763 | |
| 1764 | kvm_mmu_mark_parents_unsync(vcpu, sp); |
| 1765 | |
| 1766 | mmu_convert_notrap(sp); |
| 1767 | return 0; |
| 1768 | } |
| 1769 | |
| 1770 | static int mmu_need_write_protect(struct kvm_vcpu *vcpu, gfn_t gfn, |
| 1771 | bool can_unsync) |
| 1772 | { |
| 1773 | struct kvm_mmu_page *shadow; |
| 1774 | |
| 1775 | shadow = kvm_mmu_lookup_page(vcpu->kvm, gfn); |
| 1776 | if (shadow) { |
| 1777 | if (shadow->role.level != PT_PAGE_TABLE_LEVEL) |
| 1778 | return 1; |
| 1779 | if (shadow->unsync) |
| 1780 | return 0; |
| 1781 | if (can_unsync && oos_shadow) |
| 1782 | return kvm_unsync_page(vcpu, shadow); |
| 1783 | return 1; |
| 1784 | } |
| 1785 | return 0; |
| 1786 | } |
| 1787 | |
| 1788 | static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, |
| 1789 | unsigned pte_access, int user_fault, |
| 1790 | int write_fault, int dirty, int level, |
| 1791 | gfn_t gfn, pfn_t pfn, bool speculative, |
| 1792 | bool can_unsync, bool reset_host_protection) |
| 1793 | { |
| 1794 | u64 spte; |
| 1795 | int ret = 0; |
| 1796 | |
| 1797 | /* |
| 1798 | * We don't set the accessed bit, since we sometimes want to see |
| 1799 | * whether the guest actually used the pte (in order to detect |
| 1800 | * demand paging). |
| 1801 | */ |
| 1802 | spte = shadow_base_present_pte | shadow_dirty_mask; |
| 1803 | if (!speculative) |
| 1804 | spte |= shadow_accessed_mask; |
| 1805 | if (!dirty) |
| 1806 | pte_access &= ~ACC_WRITE_MASK; |
| 1807 | if (pte_access & ACC_EXEC_MASK) |
| 1808 | spte |= shadow_x_mask; |
| 1809 | else |
| 1810 | spte |= shadow_nx_mask; |
| 1811 | if (pte_access & ACC_USER_MASK) |
| 1812 | spte |= shadow_user_mask; |
| 1813 | if (level > PT_PAGE_TABLE_LEVEL) |
| 1814 | spte |= PT_PAGE_SIZE_MASK; |
| 1815 | if (tdp_enabled) |
| 1816 | spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn, |
| 1817 | kvm_is_mmio_pfn(pfn)); |
| 1818 | |
| 1819 | if (reset_host_protection) |
| 1820 | spte |= SPTE_HOST_WRITEABLE; |
| 1821 | |
| 1822 | spte |= (u64)pfn << PAGE_SHIFT; |
| 1823 | |
| 1824 | if ((pte_access & ACC_WRITE_MASK) |
| 1825 | || (write_fault && !is_write_protection(vcpu) && !user_fault)) { |
| 1826 | |
| 1827 | if (level > PT_PAGE_TABLE_LEVEL && |
| 1828 | has_wrprotected_page(vcpu->kvm, gfn, level)) { |
| 1829 | ret = 1; |
| 1830 | spte = shadow_trap_nonpresent_pte; |
| 1831 | goto set_pte; |
| 1832 | } |
| 1833 | |
| 1834 | spte |= PT_WRITABLE_MASK; |
| 1835 | |
| 1836 | /* |
| 1837 | * Optimization: for pte sync, if spte was writable the hash |
| 1838 | * lookup is unnecessary (and expensive). Write protection |
| 1839 | * is responsibility of mmu_get_page / kvm_sync_page. |
| 1840 | * Same reasoning can be applied to dirty page accounting. |
| 1841 | */ |
| 1842 | if (!can_unsync && is_writable_pte(*sptep)) |
| 1843 | goto set_pte; |
| 1844 | |
| 1845 | if (mmu_need_write_protect(vcpu, gfn, can_unsync)) { |
| 1846 | pgprintk("%s: found shadow page for %lx, marking ro\n", |
| 1847 | __func__, gfn); |
| 1848 | ret = 1; |
| 1849 | pte_access &= ~ACC_WRITE_MASK; |
| 1850 | if (is_writable_pte(spte)) |
| 1851 | spte &= ~PT_WRITABLE_MASK; |
| 1852 | } |
| 1853 | } |
| 1854 | |
| 1855 | if (pte_access & ACC_WRITE_MASK) |
| 1856 | mark_page_dirty(vcpu->kvm, gfn); |
| 1857 | |
| 1858 | set_pte: |
| 1859 | __set_spte(sptep, spte); |
| 1860 | return ret; |
| 1861 | } |
| 1862 | |
| 1863 | static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, |
| 1864 | unsigned pt_access, unsigned pte_access, |
| 1865 | int user_fault, int write_fault, int dirty, |
| 1866 | int *ptwrite, int level, gfn_t gfn, |
| 1867 | pfn_t pfn, bool speculative, |
| 1868 | bool reset_host_protection) |
| 1869 | { |
| 1870 | int was_rmapped = 0; |
| 1871 | int was_writable = is_writable_pte(*sptep); |
| 1872 | int rmap_count; |
| 1873 | |
| 1874 | pgprintk("%s: spte %llx access %x write_fault %d" |
| 1875 | " user_fault %d gfn %lx\n", |
| 1876 | __func__, *sptep, pt_access, |
| 1877 | write_fault, user_fault, gfn); |
| 1878 | |
| 1879 | if (is_rmap_spte(*sptep)) { |
| 1880 | /* |
| 1881 | * If we overwrite a PTE page pointer with a 2MB PMD, unlink |
| 1882 | * the parent of the now unreachable PTE. |
| 1883 | */ |
| 1884 | if (level > PT_PAGE_TABLE_LEVEL && |
| 1885 | !is_large_pte(*sptep)) { |
| 1886 | struct kvm_mmu_page *child; |
| 1887 | u64 pte = *sptep; |
| 1888 | |
| 1889 | child = page_header(pte & PT64_BASE_ADDR_MASK); |
| 1890 | mmu_page_remove_parent_pte(child, sptep); |
| 1891 | } else if (pfn != spte_to_pfn(*sptep)) { |
| 1892 | pgprintk("hfn old %lx new %lx\n", |
| 1893 | spte_to_pfn(*sptep), pfn); |
| 1894 | rmap_remove(vcpu->kvm, sptep); |
| 1895 | } else |
| 1896 | was_rmapped = 1; |
| 1897 | } |
| 1898 | |
| 1899 | if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault, |
| 1900 | dirty, level, gfn, pfn, speculative, true, |
| 1901 | reset_host_protection)) { |
| 1902 | if (write_fault) |
| 1903 | *ptwrite = 1; |
| 1904 | kvm_x86_ops->tlb_flush(vcpu); |
| 1905 | } |
| 1906 | |
| 1907 | pgprintk("%s: setting spte %llx\n", __func__, *sptep); |
| 1908 | pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n", |
| 1909 | is_large_pte(*sptep)? "2MB" : "4kB", |
| 1910 | *sptep & PT_PRESENT_MASK ?"RW":"R", gfn, |
| 1911 | *sptep, sptep); |
| 1912 | if (!was_rmapped && is_large_pte(*sptep)) |
| 1913 | ++vcpu->kvm->stat.lpages; |
| 1914 | |
| 1915 | page_header_update_slot(vcpu->kvm, sptep, gfn); |
| 1916 | if (!was_rmapped) { |
| 1917 | rmap_count = rmap_add(vcpu, sptep, gfn); |
| 1918 | kvm_release_pfn_clean(pfn); |
| 1919 | if (rmap_count > RMAP_RECYCLE_THRESHOLD) |
| 1920 | rmap_recycle(vcpu, sptep, gfn); |
| 1921 | } else { |
| 1922 | if (was_writable) |
| 1923 | kvm_release_pfn_dirty(pfn); |
| 1924 | else |
| 1925 | kvm_release_pfn_clean(pfn); |
| 1926 | } |
| 1927 | if (speculative) { |
| 1928 | vcpu->arch.last_pte_updated = sptep; |
| 1929 | vcpu->arch.last_pte_gfn = gfn; |
| 1930 | } |
| 1931 | } |
| 1932 | |
| 1933 | static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) |
| 1934 | { |
| 1935 | } |
| 1936 | |
| 1937 | static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, |
| 1938 | int level, gfn_t gfn, pfn_t pfn) |
| 1939 | { |
| 1940 | struct kvm_shadow_walk_iterator iterator; |
| 1941 | struct kvm_mmu_page *sp; |
| 1942 | int pt_write = 0; |
| 1943 | gfn_t pseudo_gfn; |
| 1944 | |
| 1945 | for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) { |
| 1946 | if (iterator.level == level) { |
| 1947 | mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL, |
| 1948 | 0, write, 1, &pt_write, |
| 1949 | level, gfn, pfn, false, true); |
| 1950 | ++vcpu->stat.pf_fixed; |
| 1951 | break; |
| 1952 | } |
| 1953 | |
| 1954 | if (*iterator.sptep == shadow_trap_nonpresent_pte) { |
| 1955 | pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 1956 | sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr, |
| 1957 | iterator.level - 1, |
| 1958 | 1, ACC_ALL, iterator.sptep); |
| 1959 | if (!sp) { |
| 1960 | pgprintk("nonpaging_map: ENOMEM\n"); |
| 1961 | kvm_release_pfn_clean(pfn); |
| 1962 | return -ENOMEM; |
| 1963 | } |
| 1964 | |
| 1965 | __set_spte(iterator.sptep, |
| 1966 | __pa(sp->spt) |
| 1967 | | PT_PRESENT_MASK | PT_WRITABLE_MASK |
| 1968 | | shadow_user_mask | shadow_x_mask); |
| 1969 | } |
| 1970 | } |
| 1971 | return pt_write; |
| 1972 | } |
| 1973 | |
| 1974 | static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) |
| 1975 | { |
| 1976 | int r; |
| 1977 | int level; |
| 1978 | pfn_t pfn; |
| 1979 | unsigned long mmu_seq; |
| 1980 | |
| 1981 | level = mapping_level(vcpu, gfn); |
| 1982 | |
| 1983 | /* |
| 1984 | * This path builds a PAE pagetable - so we can map 2mb pages at |
| 1985 | * maximum. Therefore check if the level is larger than that. |
| 1986 | */ |
| 1987 | if (level > PT_DIRECTORY_LEVEL) |
| 1988 | level = PT_DIRECTORY_LEVEL; |
| 1989 | |
| 1990 | gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); |
| 1991 | |
| 1992 | mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| 1993 | smp_rmb(); |
| 1994 | pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| 1995 | |
| 1996 | /* mmio */ |
| 1997 | if (is_error_pfn(pfn)) { |
| 1998 | kvm_release_pfn_clean(pfn); |
| 1999 | return 1; |
| 2000 | } |
| 2001 | |
| 2002 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2003 | if (mmu_notifier_retry(vcpu, mmu_seq)) |
| 2004 | goto out_unlock; |
| 2005 | kvm_mmu_free_some_pages(vcpu); |
| 2006 | r = __direct_map(vcpu, v, write, level, gfn, pfn); |
| 2007 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2008 | |
| 2009 | |
| 2010 | return r; |
| 2011 | |
| 2012 | out_unlock: |
| 2013 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2014 | kvm_release_pfn_clean(pfn); |
| 2015 | return 0; |
| 2016 | } |
| 2017 | |
| 2018 | |
| 2019 | static void mmu_free_roots(struct kvm_vcpu *vcpu) |
| 2020 | { |
| 2021 | int i; |
| 2022 | struct kvm_mmu_page *sp; |
| 2023 | |
| 2024 | if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) |
| 2025 | return; |
| 2026 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2027 | if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { |
| 2028 | hpa_t root = vcpu->arch.mmu.root_hpa; |
| 2029 | |
| 2030 | sp = page_header(root); |
| 2031 | --sp->root_count; |
| 2032 | if (!sp->root_count && sp->role.invalid) |
| 2033 | kvm_mmu_zap_page(vcpu->kvm, sp); |
| 2034 | vcpu->arch.mmu.root_hpa = INVALID_PAGE; |
| 2035 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2036 | return; |
| 2037 | } |
| 2038 | for (i = 0; i < 4; ++i) { |
| 2039 | hpa_t root = vcpu->arch.mmu.pae_root[i]; |
| 2040 | |
| 2041 | if (root) { |
| 2042 | root &= PT64_BASE_ADDR_MASK; |
| 2043 | sp = page_header(root); |
| 2044 | --sp->root_count; |
| 2045 | if (!sp->root_count && sp->role.invalid) |
| 2046 | kvm_mmu_zap_page(vcpu->kvm, sp); |
| 2047 | } |
| 2048 | vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; |
| 2049 | } |
| 2050 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2051 | vcpu->arch.mmu.root_hpa = INVALID_PAGE; |
| 2052 | } |
| 2053 | |
| 2054 | static int mmu_check_root(struct kvm_vcpu *vcpu, gfn_t root_gfn) |
| 2055 | { |
| 2056 | int ret = 0; |
| 2057 | |
| 2058 | if (!kvm_is_visible_gfn(vcpu->kvm, root_gfn)) { |
| 2059 | set_bit(KVM_REQ_TRIPLE_FAULT, &vcpu->requests); |
| 2060 | ret = 1; |
| 2061 | } |
| 2062 | |
| 2063 | return ret; |
| 2064 | } |
| 2065 | |
| 2066 | static int mmu_alloc_roots(struct kvm_vcpu *vcpu) |
| 2067 | { |
| 2068 | int i; |
| 2069 | gfn_t root_gfn; |
| 2070 | struct kvm_mmu_page *sp; |
| 2071 | int direct = 0; |
| 2072 | u64 pdptr; |
| 2073 | |
| 2074 | root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT; |
| 2075 | |
| 2076 | if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { |
| 2077 | hpa_t root = vcpu->arch.mmu.root_hpa; |
| 2078 | |
| 2079 | ASSERT(!VALID_PAGE(root)); |
| 2080 | if (tdp_enabled) |
| 2081 | direct = 1; |
| 2082 | if (mmu_check_root(vcpu, root_gfn)) |
| 2083 | return 1; |
| 2084 | sp = kvm_mmu_get_page(vcpu, root_gfn, 0, |
| 2085 | PT64_ROOT_LEVEL, direct, |
| 2086 | ACC_ALL, NULL); |
| 2087 | root = __pa(sp->spt); |
| 2088 | ++sp->root_count; |
| 2089 | vcpu->arch.mmu.root_hpa = root; |
| 2090 | return 0; |
| 2091 | } |
| 2092 | direct = !is_paging(vcpu); |
| 2093 | if (tdp_enabled) |
| 2094 | direct = 1; |
| 2095 | for (i = 0; i < 4; ++i) { |
| 2096 | hpa_t root = vcpu->arch.mmu.pae_root[i]; |
| 2097 | |
| 2098 | ASSERT(!VALID_PAGE(root)); |
| 2099 | if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) { |
| 2100 | pdptr = kvm_pdptr_read(vcpu, i); |
| 2101 | if (!is_present_gpte(pdptr)) { |
| 2102 | vcpu->arch.mmu.pae_root[i] = 0; |
| 2103 | continue; |
| 2104 | } |
| 2105 | root_gfn = pdptr >> PAGE_SHIFT; |
| 2106 | } else if (vcpu->arch.mmu.root_level == 0) |
| 2107 | root_gfn = 0; |
| 2108 | if (mmu_check_root(vcpu, root_gfn)) |
| 2109 | return 1; |
| 2110 | sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30, |
| 2111 | PT32_ROOT_LEVEL, direct, |
| 2112 | ACC_ALL, NULL); |
| 2113 | root = __pa(sp->spt); |
| 2114 | ++sp->root_count; |
| 2115 | vcpu->arch.mmu.pae_root[i] = root | PT_PRESENT_MASK; |
| 2116 | } |
| 2117 | vcpu->arch.mmu.root_hpa = __pa(vcpu->arch.mmu.pae_root); |
| 2118 | return 0; |
| 2119 | } |
| 2120 | |
| 2121 | static void mmu_sync_roots(struct kvm_vcpu *vcpu) |
| 2122 | { |
| 2123 | int i; |
| 2124 | struct kvm_mmu_page *sp; |
| 2125 | |
| 2126 | if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) |
| 2127 | return; |
| 2128 | if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { |
| 2129 | hpa_t root = vcpu->arch.mmu.root_hpa; |
| 2130 | sp = page_header(root); |
| 2131 | mmu_sync_children(vcpu, sp); |
| 2132 | return; |
| 2133 | } |
| 2134 | for (i = 0; i < 4; ++i) { |
| 2135 | hpa_t root = vcpu->arch.mmu.pae_root[i]; |
| 2136 | |
| 2137 | if (root && VALID_PAGE(root)) { |
| 2138 | root &= PT64_BASE_ADDR_MASK; |
| 2139 | sp = page_header(root); |
| 2140 | mmu_sync_children(vcpu, sp); |
| 2141 | } |
| 2142 | } |
| 2143 | } |
| 2144 | |
| 2145 | void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) |
| 2146 | { |
| 2147 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2148 | mmu_sync_roots(vcpu); |
| 2149 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2150 | } |
| 2151 | |
| 2152 | static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr, |
| 2153 | u32 access, u32 *error) |
| 2154 | { |
| 2155 | if (error) |
| 2156 | *error = 0; |
| 2157 | return vaddr; |
| 2158 | } |
| 2159 | |
| 2160 | static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, |
| 2161 | u32 error_code) |
| 2162 | { |
| 2163 | gfn_t gfn; |
| 2164 | int r; |
| 2165 | |
| 2166 | pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code); |
| 2167 | r = mmu_topup_memory_caches(vcpu); |
| 2168 | if (r) |
| 2169 | return r; |
| 2170 | |
| 2171 | ASSERT(vcpu); |
| 2172 | ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| 2173 | |
| 2174 | gfn = gva >> PAGE_SHIFT; |
| 2175 | |
| 2176 | return nonpaging_map(vcpu, gva & PAGE_MASK, |
| 2177 | error_code & PFERR_WRITE_MASK, gfn); |
| 2178 | } |
| 2179 | |
| 2180 | static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, |
| 2181 | u32 error_code) |
| 2182 | { |
| 2183 | pfn_t pfn; |
| 2184 | int r; |
| 2185 | int level; |
| 2186 | gfn_t gfn = gpa >> PAGE_SHIFT; |
| 2187 | unsigned long mmu_seq; |
| 2188 | |
| 2189 | ASSERT(vcpu); |
| 2190 | ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| 2191 | |
| 2192 | r = mmu_topup_memory_caches(vcpu); |
| 2193 | if (r) |
| 2194 | return r; |
| 2195 | |
| 2196 | level = mapping_level(vcpu, gfn); |
| 2197 | |
| 2198 | gfn &= ~(KVM_PAGES_PER_HPAGE(level) - 1); |
| 2199 | |
| 2200 | mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| 2201 | smp_rmb(); |
| 2202 | pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| 2203 | if (is_error_pfn(pfn)) { |
| 2204 | kvm_release_pfn_clean(pfn); |
| 2205 | return 1; |
| 2206 | } |
| 2207 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2208 | if (mmu_notifier_retry(vcpu, mmu_seq)) |
| 2209 | goto out_unlock; |
| 2210 | kvm_mmu_free_some_pages(vcpu); |
| 2211 | r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK, |
| 2212 | level, gfn, pfn); |
| 2213 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2214 | |
| 2215 | return r; |
| 2216 | |
| 2217 | out_unlock: |
| 2218 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2219 | kvm_release_pfn_clean(pfn); |
| 2220 | return 0; |
| 2221 | } |
| 2222 | |
| 2223 | static void nonpaging_free(struct kvm_vcpu *vcpu) |
| 2224 | { |
| 2225 | mmu_free_roots(vcpu); |
| 2226 | } |
| 2227 | |
| 2228 | static int nonpaging_init_context(struct kvm_vcpu *vcpu) |
| 2229 | { |
| 2230 | struct kvm_mmu *context = &vcpu->arch.mmu; |
| 2231 | |
| 2232 | context->new_cr3 = nonpaging_new_cr3; |
| 2233 | context->page_fault = nonpaging_page_fault; |
| 2234 | context->gva_to_gpa = nonpaging_gva_to_gpa; |
| 2235 | context->free = nonpaging_free; |
| 2236 | context->prefetch_page = nonpaging_prefetch_page; |
| 2237 | context->sync_page = nonpaging_sync_page; |
| 2238 | context->invlpg = nonpaging_invlpg; |
| 2239 | context->root_level = 0; |
| 2240 | context->shadow_root_level = PT32E_ROOT_LEVEL; |
| 2241 | context->root_hpa = INVALID_PAGE; |
| 2242 | return 0; |
| 2243 | } |
| 2244 | |
| 2245 | void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu) |
| 2246 | { |
| 2247 | ++vcpu->stat.tlb_flush; |
| 2248 | kvm_x86_ops->tlb_flush(vcpu); |
| 2249 | } |
| 2250 | |
| 2251 | static void paging_new_cr3(struct kvm_vcpu *vcpu) |
| 2252 | { |
| 2253 | pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3); |
| 2254 | mmu_free_roots(vcpu); |
| 2255 | } |
| 2256 | |
| 2257 | static void inject_page_fault(struct kvm_vcpu *vcpu, |
| 2258 | u64 addr, |
| 2259 | u32 err_code) |
| 2260 | { |
| 2261 | kvm_inject_page_fault(vcpu, addr, err_code); |
| 2262 | } |
| 2263 | |
| 2264 | static void paging_free(struct kvm_vcpu *vcpu) |
| 2265 | { |
| 2266 | nonpaging_free(vcpu); |
| 2267 | } |
| 2268 | |
| 2269 | static bool is_rsvd_bits_set(struct kvm_vcpu *vcpu, u64 gpte, int level) |
| 2270 | { |
| 2271 | int bit7; |
| 2272 | |
| 2273 | bit7 = (gpte >> 7) & 1; |
| 2274 | return (gpte & vcpu->arch.mmu.rsvd_bits_mask[bit7][level-1]) != 0; |
| 2275 | } |
| 2276 | |
| 2277 | #define PTTYPE 64 |
| 2278 | #include "paging_tmpl.h" |
| 2279 | #undef PTTYPE |
| 2280 | |
| 2281 | #define PTTYPE 32 |
| 2282 | #include "paging_tmpl.h" |
| 2283 | #undef PTTYPE |
| 2284 | |
| 2285 | static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, int level) |
| 2286 | { |
| 2287 | struct kvm_mmu *context = &vcpu->arch.mmu; |
| 2288 | int maxphyaddr = cpuid_maxphyaddr(vcpu); |
| 2289 | u64 exb_bit_rsvd = 0; |
| 2290 | |
| 2291 | if (!is_nx(vcpu)) |
| 2292 | exb_bit_rsvd = rsvd_bits(63, 63); |
| 2293 | switch (level) { |
| 2294 | case PT32_ROOT_LEVEL: |
| 2295 | /* no rsvd bits for 2 level 4K page table entries */ |
| 2296 | context->rsvd_bits_mask[0][1] = 0; |
| 2297 | context->rsvd_bits_mask[0][0] = 0; |
| 2298 | if (is_cpuid_PSE36()) |
| 2299 | /* 36bits PSE 4MB page */ |
| 2300 | context->rsvd_bits_mask[1][1] = rsvd_bits(17, 21); |
| 2301 | else |
| 2302 | /* 32 bits PSE 4MB page */ |
| 2303 | context->rsvd_bits_mask[1][1] = rsvd_bits(13, 21); |
| 2304 | context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0]; |
| 2305 | break; |
| 2306 | case PT32E_ROOT_LEVEL: |
| 2307 | context->rsvd_bits_mask[0][2] = |
| 2308 | rsvd_bits(maxphyaddr, 63) | |
| 2309 | rsvd_bits(7, 8) | rsvd_bits(1, 2); /* PDPTE */ |
| 2310 | context->rsvd_bits_mask[0][1] = exb_bit_rsvd | |
| 2311 | rsvd_bits(maxphyaddr, 62); /* PDE */ |
| 2312 | context->rsvd_bits_mask[0][0] = exb_bit_rsvd | |
| 2313 | rsvd_bits(maxphyaddr, 62); /* PTE */ |
| 2314 | context->rsvd_bits_mask[1][1] = exb_bit_rsvd | |
| 2315 | rsvd_bits(maxphyaddr, 62) | |
| 2316 | rsvd_bits(13, 20); /* large page */ |
| 2317 | context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0]; |
| 2318 | break; |
| 2319 | case PT64_ROOT_LEVEL: |
| 2320 | context->rsvd_bits_mask[0][3] = exb_bit_rsvd | |
| 2321 | rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); |
| 2322 | context->rsvd_bits_mask[0][2] = exb_bit_rsvd | |
| 2323 | rsvd_bits(maxphyaddr, 51) | rsvd_bits(7, 8); |
| 2324 | context->rsvd_bits_mask[0][1] = exb_bit_rsvd | |
| 2325 | rsvd_bits(maxphyaddr, 51); |
| 2326 | context->rsvd_bits_mask[0][0] = exb_bit_rsvd | |
| 2327 | rsvd_bits(maxphyaddr, 51); |
| 2328 | context->rsvd_bits_mask[1][3] = context->rsvd_bits_mask[0][3]; |
| 2329 | context->rsvd_bits_mask[1][2] = exb_bit_rsvd | |
| 2330 | rsvd_bits(maxphyaddr, 51) | |
| 2331 | rsvd_bits(13, 29); |
| 2332 | context->rsvd_bits_mask[1][1] = exb_bit_rsvd | |
| 2333 | rsvd_bits(maxphyaddr, 51) | |
| 2334 | rsvd_bits(13, 20); /* large page */ |
| 2335 | context->rsvd_bits_mask[1][0] = context->rsvd_bits_mask[1][0]; |
| 2336 | break; |
| 2337 | } |
| 2338 | } |
| 2339 | |
| 2340 | static int paging64_init_context_common(struct kvm_vcpu *vcpu, int level) |
| 2341 | { |
| 2342 | struct kvm_mmu *context = &vcpu->arch.mmu; |
| 2343 | |
| 2344 | ASSERT(is_pae(vcpu)); |
| 2345 | context->new_cr3 = paging_new_cr3; |
| 2346 | context->page_fault = paging64_page_fault; |
| 2347 | context->gva_to_gpa = paging64_gva_to_gpa; |
| 2348 | context->prefetch_page = paging64_prefetch_page; |
| 2349 | context->sync_page = paging64_sync_page; |
| 2350 | context->invlpg = paging64_invlpg; |
| 2351 | context->free = paging_free; |
| 2352 | context->root_level = level; |
| 2353 | context->shadow_root_level = level; |
| 2354 | context->root_hpa = INVALID_PAGE; |
| 2355 | return 0; |
| 2356 | } |
| 2357 | |
| 2358 | static int paging64_init_context(struct kvm_vcpu *vcpu) |
| 2359 | { |
| 2360 | reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); |
| 2361 | return paging64_init_context_common(vcpu, PT64_ROOT_LEVEL); |
| 2362 | } |
| 2363 | |
| 2364 | static int paging32_init_context(struct kvm_vcpu *vcpu) |
| 2365 | { |
| 2366 | struct kvm_mmu *context = &vcpu->arch.mmu; |
| 2367 | |
| 2368 | reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); |
| 2369 | context->new_cr3 = paging_new_cr3; |
| 2370 | context->page_fault = paging32_page_fault; |
| 2371 | context->gva_to_gpa = paging32_gva_to_gpa; |
| 2372 | context->free = paging_free; |
| 2373 | context->prefetch_page = paging32_prefetch_page; |
| 2374 | context->sync_page = paging32_sync_page; |
| 2375 | context->invlpg = paging32_invlpg; |
| 2376 | context->root_level = PT32_ROOT_LEVEL; |
| 2377 | context->shadow_root_level = PT32E_ROOT_LEVEL; |
| 2378 | context->root_hpa = INVALID_PAGE; |
| 2379 | return 0; |
| 2380 | } |
| 2381 | |
| 2382 | static int paging32E_init_context(struct kvm_vcpu *vcpu) |
| 2383 | { |
| 2384 | reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); |
| 2385 | return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL); |
| 2386 | } |
| 2387 | |
| 2388 | static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu) |
| 2389 | { |
| 2390 | struct kvm_mmu *context = &vcpu->arch.mmu; |
| 2391 | |
| 2392 | context->new_cr3 = nonpaging_new_cr3; |
| 2393 | context->page_fault = tdp_page_fault; |
| 2394 | context->free = nonpaging_free; |
| 2395 | context->prefetch_page = nonpaging_prefetch_page; |
| 2396 | context->sync_page = nonpaging_sync_page; |
| 2397 | context->invlpg = nonpaging_invlpg; |
| 2398 | context->shadow_root_level = kvm_x86_ops->get_tdp_level(); |
| 2399 | context->root_hpa = INVALID_PAGE; |
| 2400 | |
| 2401 | if (!is_paging(vcpu)) { |
| 2402 | context->gva_to_gpa = nonpaging_gva_to_gpa; |
| 2403 | context->root_level = 0; |
| 2404 | } else if (is_long_mode(vcpu)) { |
| 2405 | reset_rsvds_bits_mask(vcpu, PT64_ROOT_LEVEL); |
| 2406 | context->gva_to_gpa = paging64_gva_to_gpa; |
| 2407 | context->root_level = PT64_ROOT_LEVEL; |
| 2408 | } else if (is_pae(vcpu)) { |
| 2409 | reset_rsvds_bits_mask(vcpu, PT32E_ROOT_LEVEL); |
| 2410 | context->gva_to_gpa = paging64_gva_to_gpa; |
| 2411 | context->root_level = PT32E_ROOT_LEVEL; |
| 2412 | } else { |
| 2413 | reset_rsvds_bits_mask(vcpu, PT32_ROOT_LEVEL); |
| 2414 | context->gva_to_gpa = paging32_gva_to_gpa; |
| 2415 | context->root_level = PT32_ROOT_LEVEL; |
| 2416 | } |
| 2417 | |
| 2418 | return 0; |
| 2419 | } |
| 2420 | |
| 2421 | static int init_kvm_softmmu(struct kvm_vcpu *vcpu) |
| 2422 | { |
| 2423 | int r; |
| 2424 | |
| 2425 | ASSERT(vcpu); |
| 2426 | ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| 2427 | |
| 2428 | if (!is_paging(vcpu)) |
| 2429 | r = nonpaging_init_context(vcpu); |
| 2430 | else if (is_long_mode(vcpu)) |
| 2431 | r = paging64_init_context(vcpu); |
| 2432 | else if (is_pae(vcpu)) |
| 2433 | r = paging32E_init_context(vcpu); |
| 2434 | else |
| 2435 | r = paging32_init_context(vcpu); |
| 2436 | |
| 2437 | vcpu->arch.mmu.base_role.glevels = vcpu->arch.mmu.root_level; |
| 2438 | |
| 2439 | return r; |
| 2440 | } |
| 2441 | |
| 2442 | static int init_kvm_mmu(struct kvm_vcpu *vcpu) |
| 2443 | { |
| 2444 | vcpu->arch.update_pte.pfn = bad_pfn; |
| 2445 | |
| 2446 | if (tdp_enabled) |
| 2447 | return init_kvm_tdp_mmu(vcpu); |
| 2448 | else |
| 2449 | return init_kvm_softmmu(vcpu); |
| 2450 | } |
| 2451 | |
| 2452 | static void destroy_kvm_mmu(struct kvm_vcpu *vcpu) |
| 2453 | { |
| 2454 | ASSERT(vcpu); |
| 2455 | if (VALID_PAGE(vcpu->arch.mmu.root_hpa)) { |
| 2456 | vcpu->arch.mmu.free(vcpu); |
| 2457 | vcpu->arch.mmu.root_hpa = INVALID_PAGE; |
| 2458 | } |
| 2459 | } |
| 2460 | |
| 2461 | int kvm_mmu_reset_context(struct kvm_vcpu *vcpu) |
| 2462 | { |
| 2463 | destroy_kvm_mmu(vcpu); |
| 2464 | return init_kvm_mmu(vcpu); |
| 2465 | } |
| 2466 | EXPORT_SYMBOL_GPL(kvm_mmu_reset_context); |
| 2467 | |
| 2468 | int kvm_mmu_load(struct kvm_vcpu *vcpu) |
| 2469 | { |
| 2470 | int r; |
| 2471 | |
| 2472 | r = mmu_topup_memory_caches(vcpu); |
| 2473 | if (r) |
| 2474 | goto out; |
| 2475 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2476 | kvm_mmu_free_some_pages(vcpu); |
| 2477 | r = mmu_alloc_roots(vcpu); |
| 2478 | mmu_sync_roots(vcpu); |
| 2479 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2480 | if (r) |
| 2481 | goto out; |
| 2482 | /* set_cr3() should ensure TLB has been flushed */ |
| 2483 | kvm_x86_ops->set_cr3(vcpu, vcpu->arch.mmu.root_hpa); |
| 2484 | out: |
| 2485 | return r; |
| 2486 | } |
| 2487 | EXPORT_SYMBOL_GPL(kvm_mmu_load); |
| 2488 | |
| 2489 | void kvm_mmu_unload(struct kvm_vcpu *vcpu) |
| 2490 | { |
| 2491 | mmu_free_roots(vcpu); |
| 2492 | } |
| 2493 | |
| 2494 | static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu, |
| 2495 | struct kvm_mmu_page *sp, |
| 2496 | u64 *spte) |
| 2497 | { |
| 2498 | u64 pte; |
| 2499 | struct kvm_mmu_page *child; |
| 2500 | |
| 2501 | pte = *spte; |
| 2502 | if (is_shadow_present_pte(pte)) { |
| 2503 | if (is_last_spte(pte, sp->role.level)) |
| 2504 | rmap_remove(vcpu->kvm, spte); |
| 2505 | else { |
| 2506 | child = page_header(pte & PT64_BASE_ADDR_MASK); |
| 2507 | mmu_page_remove_parent_pte(child, spte); |
| 2508 | } |
| 2509 | } |
| 2510 | __set_spte(spte, shadow_trap_nonpresent_pte); |
| 2511 | if (is_large_pte(pte)) |
| 2512 | --vcpu->kvm->stat.lpages; |
| 2513 | } |
| 2514 | |
| 2515 | static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, |
| 2516 | struct kvm_mmu_page *sp, |
| 2517 | u64 *spte, |
| 2518 | const void *new) |
| 2519 | { |
| 2520 | if (sp->role.level != PT_PAGE_TABLE_LEVEL) { |
| 2521 | ++vcpu->kvm->stat.mmu_pde_zapped; |
| 2522 | return; |
| 2523 | } |
| 2524 | |
| 2525 | ++vcpu->kvm->stat.mmu_pte_updated; |
| 2526 | if (sp->role.glevels == PT32_ROOT_LEVEL) |
| 2527 | paging32_update_pte(vcpu, sp, spte, new); |
| 2528 | else |
| 2529 | paging64_update_pte(vcpu, sp, spte, new); |
| 2530 | } |
| 2531 | |
| 2532 | static bool need_remote_flush(u64 old, u64 new) |
| 2533 | { |
| 2534 | if (!is_shadow_present_pte(old)) |
| 2535 | return false; |
| 2536 | if (!is_shadow_present_pte(new)) |
| 2537 | return true; |
| 2538 | if ((old ^ new) & PT64_BASE_ADDR_MASK) |
| 2539 | return true; |
| 2540 | old ^= PT64_NX_MASK; |
| 2541 | new ^= PT64_NX_MASK; |
| 2542 | return (old & ~new & PT64_PERM_MASK) != 0; |
| 2543 | } |
| 2544 | |
| 2545 | static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new) |
| 2546 | { |
| 2547 | if (need_remote_flush(old, new)) |
| 2548 | kvm_flush_remote_tlbs(vcpu->kvm); |
| 2549 | else |
| 2550 | kvm_mmu_flush_tlb(vcpu); |
| 2551 | } |
| 2552 | |
| 2553 | static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu) |
| 2554 | { |
| 2555 | u64 *spte = vcpu->arch.last_pte_updated; |
| 2556 | |
| 2557 | return !!(spte && (*spte & shadow_accessed_mask)); |
| 2558 | } |
| 2559 | |
| 2560 | static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, |
| 2561 | const u8 *new, int bytes) |
| 2562 | { |
| 2563 | gfn_t gfn; |
| 2564 | int r; |
| 2565 | u64 gpte = 0; |
| 2566 | pfn_t pfn; |
| 2567 | |
| 2568 | if (bytes != 4 && bytes != 8) |
| 2569 | return; |
| 2570 | |
| 2571 | /* |
| 2572 | * Assume that the pte write on a page table of the same type |
| 2573 | * as the current vcpu paging mode. This is nearly always true |
| 2574 | * (might be false while changing modes). Note it is verified later |
| 2575 | * by update_pte(). |
| 2576 | */ |
| 2577 | if (is_pae(vcpu)) { |
| 2578 | /* Handle a 32-bit guest writing two halves of a 64-bit gpte */ |
| 2579 | if ((bytes == 4) && (gpa % 4 == 0)) { |
| 2580 | r = kvm_read_guest(vcpu->kvm, gpa & ~(u64)7, &gpte, 8); |
| 2581 | if (r) |
| 2582 | return; |
| 2583 | memcpy((void *)&gpte + (gpa % 8), new, 4); |
| 2584 | } else if ((bytes == 8) && (gpa % 8 == 0)) { |
| 2585 | memcpy((void *)&gpte, new, 8); |
| 2586 | } |
| 2587 | } else { |
| 2588 | if ((bytes == 4) && (gpa % 4 == 0)) |
| 2589 | memcpy((void *)&gpte, new, 4); |
| 2590 | } |
| 2591 | if (!is_present_gpte(gpte)) |
| 2592 | return; |
| 2593 | gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; |
| 2594 | |
| 2595 | vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq; |
| 2596 | smp_rmb(); |
| 2597 | pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| 2598 | |
| 2599 | if (is_error_pfn(pfn)) { |
| 2600 | kvm_release_pfn_clean(pfn); |
| 2601 | return; |
| 2602 | } |
| 2603 | vcpu->arch.update_pte.gfn = gfn; |
| 2604 | vcpu->arch.update_pte.pfn = pfn; |
| 2605 | } |
| 2606 | |
| 2607 | static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn) |
| 2608 | { |
| 2609 | u64 *spte = vcpu->arch.last_pte_updated; |
| 2610 | |
| 2611 | if (spte |
| 2612 | && vcpu->arch.last_pte_gfn == gfn |
| 2613 | && shadow_accessed_mask |
| 2614 | && !(*spte & shadow_accessed_mask) |
| 2615 | && is_shadow_present_pte(*spte)) |
| 2616 | set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); |
| 2617 | } |
| 2618 | |
| 2619 | void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, |
| 2620 | const u8 *new, int bytes, |
| 2621 | bool guest_initiated) |
| 2622 | { |
| 2623 | gfn_t gfn = gpa >> PAGE_SHIFT; |
| 2624 | struct kvm_mmu_page *sp; |
| 2625 | struct hlist_node *node, *n; |
| 2626 | struct hlist_head *bucket; |
| 2627 | unsigned index; |
| 2628 | u64 entry, gentry; |
| 2629 | u64 *spte; |
| 2630 | unsigned offset = offset_in_page(gpa); |
| 2631 | unsigned pte_size; |
| 2632 | unsigned page_offset; |
| 2633 | unsigned misaligned; |
| 2634 | unsigned quadrant; |
| 2635 | int level; |
| 2636 | int flooded = 0; |
| 2637 | int npte; |
| 2638 | int r; |
| 2639 | |
| 2640 | pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); |
| 2641 | mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes); |
| 2642 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2643 | kvm_mmu_access_page(vcpu, gfn); |
| 2644 | kvm_mmu_free_some_pages(vcpu); |
| 2645 | ++vcpu->kvm->stat.mmu_pte_write; |
| 2646 | kvm_mmu_audit(vcpu, "pre pte write"); |
| 2647 | if (guest_initiated) { |
| 2648 | if (gfn == vcpu->arch.last_pt_write_gfn |
| 2649 | && !last_updated_pte_accessed(vcpu)) { |
| 2650 | ++vcpu->arch.last_pt_write_count; |
| 2651 | if (vcpu->arch.last_pt_write_count >= 3) |
| 2652 | flooded = 1; |
| 2653 | } else { |
| 2654 | vcpu->arch.last_pt_write_gfn = gfn; |
| 2655 | vcpu->arch.last_pt_write_count = 1; |
| 2656 | vcpu->arch.last_pte_updated = NULL; |
| 2657 | } |
| 2658 | } |
| 2659 | index = kvm_page_table_hashfn(gfn); |
| 2660 | bucket = &vcpu->kvm->arch.mmu_page_hash[index]; |
| 2661 | hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) { |
| 2662 | if (sp->gfn != gfn || sp->role.direct || sp->role.invalid) |
| 2663 | continue; |
| 2664 | pte_size = sp->role.glevels == PT32_ROOT_LEVEL ? 4 : 8; |
| 2665 | misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1); |
| 2666 | misaligned |= bytes < 4; |
| 2667 | if (misaligned || flooded) { |
| 2668 | /* |
| 2669 | * Misaligned accesses are too much trouble to fix |
| 2670 | * up; also, they usually indicate a page is not used |
| 2671 | * as a page table. |
| 2672 | * |
| 2673 | * If we're seeing too many writes to a page, |
| 2674 | * it may no longer be a page table, or we may be |
| 2675 | * forking, in which case it is better to unmap the |
| 2676 | * page. |
| 2677 | */ |
| 2678 | pgprintk("misaligned: gpa %llx bytes %d role %x\n", |
| 2679 | gpa, bytes, sp->role.word); |
| 2680 | if (kvm_mmu_zap_page(vcpu->kvm, sp)) |
| 2681 | n = bucket->first; |
| 2682 | ++vcpu->kvm->stat.mmu_flooded; |
| 2683 | continue; |
| 2684 | } |
| 2685 | page_offset = offset; |
| 2686 | level = sp->role.level; |
| 2687 | npte = 1; |
| 2688 | if (sp->role.glevels == PT32_ROOT_LEVEL) { |
| 2689 | page_offset <<= 1; /* 32->64 */ |
| 2690 | /* |
| 2691 | * A 32-bit pde maps 4MB while the shadow pdes map |
| 2692 | * only 2MB. So we need to double the offset again |
| 2693 | * and zap two pdes instead of one. |
| 2694 | */ |
| 2695 | if (level == PT32_ROOT_LEVEL) { |
| 2696 | page_offset &= ~7; /* kill rounding error */ |
| 2697 | page_offset <<= 1; |
| 2698 | npte = 2; |
| 2699 | } |
| 2700 | quadrant = page_offset >> PAGE_SHIFT; |
| 2701 | page_offset &= ~PAGE_MASK; |
| 2702 | if (quadrant != sp->role.quadrant) |
| 2703 | continue; |
| 2704 | } |
| 2705 | spte = &sp->spt[page_offset / sizeof(*spte)]; |
| 2706 | if ((gpa & (pte_size - 1)) || (bytes < pte_size)) { |
| 2707 | gentry = 0; |
| 2708 | r = kvm_read_guest_atomic(vcpu->kvm, |
| 2709 | gpa & ~(u64)(pte_size - 1), |
| 2710 | &gentry, pte_size); |
| 2711 | new = (const void *)&gentry; |
| 2712 | if (r < 0) |
| 2713 | new = NULL; |
| 2714 | } |
| 2715 | while (npte--) { |
| 2716 | entry = *spte; |
| 2717 | mmu_pte_write_zap_pte(vcpu, sp, spte); |
| 2718 | if (new) |
| 2719 | mmu_pte_write_new_pte(vcpu, sp, spte, new); |
| 2720 | mmu_pte_write_flush_tlb(vcpu, entry, *spte); |
| 2721 | ++spte; |
| 2722 | } |
| 2723 | } |
| 2724 | kvm_mmu_audit(vcpu, "post pte write"); |
| 2725 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2726 | if (!is_error_pfn(vcpu->arch.update_pte.pfn)) { |
| 2727 | kvm_release_pfn_clean(vcpu->arch.update_pte.pfn); |
| 2728 | vcpu->arch.update_pte.pfn = bad_pfn; |
| 2729 | } |
| 2730 | } |
| 2731 | |
| 2732 | int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) |
| 2733 | { |
| 2734 | gpa_t gpa; |
| 2735 | int r; |
| 2736 | |
| 2737 | if (tdp_enabled) |
| 2738 | return 0; |
| 2739 | |
| 2740 | gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL); |
| 2741 | |
| 2742 | spin_lock(&vcpu->kvm->mmu_lock); |
| 2743 | r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT); |
| 2744 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 2745 | return r; |
| 2746 | } |
| 2747 | EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt); |
| 2748 | |
| 2749 | void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) |
| 2750 | { |
| 2751 | while (vcpu->kvm->arch.n_free_mmu_pages < KVM_REFILL_PAGES && |
| 2752 | !list_empty(&vcpu->kvm->arch.active_mmu_pages)) { |
| 2753 | struct kvm_mmu_page *sp; |
| 2754 | |
| 2755 | sp = container_of(vcpu->kvm->arch.active_mmu_pages.prev, |
| 2756 | struct kvm_mmu_page, link); |
| 2757 | kvm_mmu_zap_page(vcpu->kvm, sp); |
| 2758 | ++vcpu->kvm->stat.mmu_recycled; |
| 2759 | } |
| 2760 | } |
| 2761 | |
| 2762 | int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code) |
| 2763 | { |
| 2764 | int r; |
| 2765 | enum emulation_result er; |
| 2766 | |
| 2767 | r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code); |
| 2768 | if (r < 0) |
| 2769 | goto out; |
| 2770 | |
| 2771 | if (!r) { |
| 2772 | r = 1; |
| 2773 | goto out; |
| 2774 | } |
| 2775 | |
| 2776 | r = mmu_topup_memory_caches(vcpu); |
| 2777 | if (r) |
| 2778 | goto out; |
| 2779 | |
| 2780 | er = emulate_instruction(vcpu, cr2, error_code, 0); |
| 2781 | |
| 2782 | switch (er) { |
| 2783 | case EMULATE_DONE: |
| 2784 | return 1; |
| 2785 | case EMULATE_DO_MMIO: |
| 2786 | ++vcpu->stat.mmio_exits; |
| 2787 | return 0; |
| 2788 | case EMULATE_FAIL: |
| 2789 | vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; |
| 2790 | vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; |
| 2791 | vcpu->run->internal.ndata = 0; |
| 2792 | return 0; |
| 2793 | default: |
| 2794 | BUG(); |
| 2795 | } |
| 2796 | out: |
| 2797 | return r; |
| 2798 | } |
| 2799 | EXPORT_SYMBOL_GPL(kvm_mmu_page_fault); |
| 2800 | |
| 2801 | void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva) |
| 2802 | { |
| 2803 | vcpu->arch.mmu.invlpg(vcpu, gva); |
| 2804 | kvm_mmu_flush_tlb(vcpu); |
| 2805 | ++vcpu->stat.invlpg; |
| 2806 | } |
| 2807 | EXPORT_SYMBOL_GPL(kvm_mmu_invlpg); |
| 2808 | |
| 2809 | void kvm_enable_tdp(void) |
| 2810 | { |
| 2811 | tdp_enabled = true; |
| 2812 | } |
| 2813 | EXPORT_SYMBOL_GPL(kvm_enable_tdp); |
| 2814 | |
| 2815 | void kvm_disable_tdp(void) |
| 2816 | { |
| 2817 | tdp_enabled = false; |
| 2818 | } |
| 2819 | EXPORT_SYMBOL_GPL(kvm_disable_tdp); |
| 2820 | |
| 2821 | static void free_mmu_pages(struct kvm_vcpu *vcpu) |
| 2822 | { |
| 2823 | free_page((unsigned long)vcpu->arch.mmu.pae_root); |
| 2824 | } |
| 2825 | |
| 2826 | static int alloc_mmu_pages(struct kvm_vcpu *vcpu) |
| 2827 | { |
| 2828 | struct page *page; |
| 2829 | int i; |
| 2830 | |
| 2831 | ASSERT(vcpu); |
| 2832 | |
| 2833 | /* |
| 2834 | * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64. |
| 2835 | * Therefore we need to allocate shadow page tables in the first |
| 2836 | * 4GB of memory, which happens to fit the DMA32 zone. |
| 2837 | */ |
| 2838 | page = alloc_page(GFP_KERNEL | __GFP_DMA32); |
| 2839 | if (!page) |
| 2840 | return -ENOMEM; |
| 2841 | |
| 2842 | vcpu->arch.mmu.pae_root = page_address(page); |
| 2843 | for (i = 0; i < 4; ++i) |
| 2844 | vcpu->arch.mmu.pae_root[i] = INVALID_PAGE; |
| 2845 | |
| 2846 | return 0; |
| 2847 | } |
| 2848 | |
| 2849 | int kvm_mmu_create(struct kvm_vcpu *vcpu) |
| 2850 | { |
| 2851 | ASSERT(vcpu); |
| 2852 | ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| 2853 | |
| 2854 | return alloc_mmu_pages(vcpu); |
| 2855 | } |
| 2856 | |
| 2857 | int kvm_mmu_setup(struct kvm_vcpu *vcpu) |
| 2858 | { |
| 2859 | ASSERT(vcpu); |
| 2860 | ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa)); |
| 2861 | |
| 2862 | return init_kvm_mmu(vcpu); |
| 2863 | } |
| 2864 | |
| 2865 | void kvm_mmu_destroy(struct kvm_vcpu *vcpu) |
| 2866 | { |
| 2867 | ASSERT(vcpu); |
| 2868 | |
| 2869 | destroy_kvm_mmu(vcpu); |
| 2870 | free_mmu_pages(vcpu); |
| 2871 | mmu_free_memory_caches(vcpu); |
| 2872 | } |
| 2873 | |
| 2874 | void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot) |
| 2875 | { |
| 2876 | struct kvm_mmu_page *sp; |
| 2877 | |
| 2878 | list_for_each_entry(sp, &kvm->arch.active_mmu_pages, link) { |
| 2879 | int i; |
| 2880 | u64 *pt; |
| 2881 | |
| 2882 | if (!test_bit(slot, sp->slot_bitmap)) |
| 2883 | continue; |
| 2884 | |
| 2885 | pt = sp->spt; |
| 2886 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) |
| 2887 | /* avoid RMW */ |
| 2888 | if (pt[i] & PT_WRITABLE_MASK) |
| 2889 | pt[i] &= ~PT_WRITABLE_MASK; |
| 2890 | } |
| 2891 | kvm_flush_remote_tlbs(kvm); |
| 2892 | } |
| 2893 | |
| 2894 | void kvm_mmu_zap_all(struct kvm *kvm) |
| 2895 | { |
| 2896 | struct kvm_mmu_page *sp, *node; |
| 2897 | |
| 2898 | spin_lock(&kvm->mmu_lock); |
| 2899 | list_for_each_entry_safe(sp, node, &kvm->arch.active_mmu_pages, link) |
| 2900 | if (kvm_mmu_zap_page(kvm, sp)) |
| 2901 | node = container_of(kvm->arch.active_mmu_pages.next, |
| 2902 | struct kvm_mmu_page, link); |
| 2903 | spin_unlock(&kvm->mmu_lock); |
| 2904 | |
| 2905 | kvm_flush_remote_tlbs(kvm); |
| 2906 | } |
| 2907 | |
| 2908 | static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm) |
| 2909 | { |
| 2910 | struct kvm_mmu_page *page; |
| 2911 | |
| 2912 | page = container_of(kvm->arch.active_mmu_pages.prev, |
| 2913 | struct kvm_mmu_page, link); |
| 2914 | kvm_mmu_zap_page(kvm, page); |
| 2915 | } |
| 2916 | |
| 2917 | static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) |
| 2918 | { |
| 2919 | struct kvm *kvm; |
| 2920 | struct kvm *kvm_freed = NULL; |
| 2921 | int cache_count = 0; |
| 2922 | |
| 2923 | spin_lock(&kvm_lock); |
| 2924 | |
| 2925 | list_for_each_entry(kvm, &vm_list, vm_list) { |
| 2926 | int npages, idx; |
| 2927 | |
| 2928 | idx = srcu_read_lock(&kvm->srcu); |
| 2929 | spin_lock(&kvm->mmu_lock); |
| 2930 | npages = kvm->arch.n_alloc_mmu_pages - |
| 2931 | kvm->arch.n_free_mmu_pages; |
| 2932 | cache_count += npages; |
| 2933 | if (!kvm_freed && nr_to_scan > 0 && npages > 0) { |
| 2934 | kvm_mmu_remove_one_alloc_mmu_page(kvm); |
| 2935 | cache_count--; |
| 2936 | kvm_freed = kvm; |
| 2937 | } |
| 2938 | nr_to_scan--; |
| 2939 | |
| 2940 | spin_unlock(&kvm->mmu_lock); |
| 2941 | srcu_read_unlock(&kvm->srcu, idx); |
| 2942 | } |
| 2943 | if (kvm_freed) |
| 2944 | list_move_tail(&kvm_freed->vm_list, &vm_list); |
| 2945 | |
| 2946 | spin_unlock(&kvm_lock); |
| 2947 | |
| 2948 | return cache_count; |
| 2949 | } |
| 2950 | |
| 2951 | static struct shrinker mmu_shrinker = { |
| 2952 | .shrink = mmu_shrink, |
| 2953 | .seeks = DEFAULT_SEEKS * 10, |
| 2954 | }; |
| 2955 | |
| 2956 | static void mmu_destroy_caches(void) |
| 2957 | { |
| 2958 | if (pte_chain_cache) |
| 2959 | kmem_cache_destroy(pte_chain_cache); |
| 2960 | if (rmap_desc_cache) |
| 2961 | kmem_cache_destroy(rmap_desc_cache); |
| 2962 | if (mmu_page_header_cache) |
| 2963 | kmem_cache_destroy(mmu_page_header_cache); |
| 2964 | } |
| 2965 | |
| 2966 | void kvm_mmu_module_exit(void) |
| 2967 | { |
| 2968 | mmu_destroy_caches(); |
| 2969 | unregister_shrinker(&mmu_shrinker); |
| 2970 | } |
| 2971 | |
| 2972 | int kvm_mmu_module_init(void) |
| 2973 | { |
| 2974 | pte_chain_cache = kmem_cache_create("kvm_pte_chain", |
| 2975 | sizeof(struct kvm_pte_chain), |
| 2976 | 0, 0, NULL); |
| 2977 | if (!pte_chain_cache) |
| 2978 | goto nomem; |
| 2979 | rmap_desc_cache = kmem_cache_create("kvm_rmap_desc", |
| 2980 | sizeof(struct kvm_rmap_desc), |
| 2981 | 0, 0, NULL); |
| 2982 | if (!rmap_desc_cache) |
| 2983 | goto nomem; |
| 2984 | |
| 2985 | mmu_page_header_cache = kmem_cache_create("kvm_mmu_page_header", |
| 2986 | sizeof(struct kvm_mmu_page), |
| 2987 | 0, 0, NULL); |
| 2988 | if (!mmu_page_header_cache) |
| 2989 | goto nomem; |
| 2990 | |
| 2991 | register_shrinker(&mmu_shrinker); |
| 2992 | |
| 2993 | return 0; |
| 2994 | |
| 2995 | nomem: |
| 2996 | mmu_destroy_caches(); |
| 2997 | return -ENOMEM; |
| 2998 | } |
| 2999 | |
| 3000 | /* |
| 3001 | * Caculate mmu pages needed for kvm. |
| 3002 | */ |
| 3003 | unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm) |
| 3004 | { |
| 3005 | int i; |
| 3006 | unsigned int nr_mmu_pages; |
| 3007 | unsigned int nr_pages = 0; |
| 3008 | struct kvm_memslots *slots; |
| 3009 | |
| 3010 | slots = rcu_dereference(kvm->memslots); |
| 3011 | for (i = 0; i < slots->nmemslots; i++) |
| 3012 | nr_pages += slots->memslots[i].npages; |
| 3013 | |
| 3014 | nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000; |
| 3015 | nr_mmu_pages = max(nr_mmu_pages, |
| 3016 | (unsigned int) KVM_MIN_ALLOC_MMU_PAGES); |
| 3017 | |
| 3018 | return nr_mmu_pages; |
| 3019 | } |
| 3020 | |
| 3021 | static void *pv_mmu_peek_buffer(struct kvm_pv_mmu_op_buffer *buffer, |
| 3022 | unsigned len) |
| 3023 | { |
| 3024 | if (len > buffer->len) |
| 3025 | return NULL; |
| 3026 | return buffer->ptr; |
| 3027 | } |
| 3028 | |
| 3029 | static void *pv_mmu_read_buffer(struct kvm_pv_mmu_op_buffer *buffer, |
| 3030 | unsigned len) |
| 3031 | { |
| 3032 | void *ret; |
| 3033 | |
| 3034 | ret = pv_mmu_peek_buffer(buffer, len); |
| 3035 | if (!ret) |
| 3036 | return ret; |
| 3037 | buffer->ptr += len; |
| 3038 | buffer->len -= len; |
| 3039 | buffer->processed += len; |
| 3040 | return ret; |
| 3041 | } |
| 3042 | |
| 3043 | static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu, |
| 3044 | gpa_t addr, gpa_t value) |
| 3045 | { |
| 3046 | int bytes = 8; |
| 3047 | int r; |
| 3048 | |
| 3049 | if (!is_long_mode(vcpu) && !is_pae(vcpu)) |
| 3050 | bytes = 4; |
| 3051 | |
| 3052 | r = mmu_topup_memory_caches(vcpu); |
| 3053 | if (r) |
| 3054 | return r; |
| 3055 | |
| 3056 | if (!emulator_write_phys(vcpu, addr, &value, bytes)) |
| 3057 | return -EFAULT; |
| 3058 | |
| 3059 | return 1; |
| 3060 | } |
| 3061 | |
| 3062 | static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu) |
| 3063 | { |
| 3064 | kvm_set_cr3(vcpu, vcpu->arch.cr3); |
| 3065 | return 1; |
| 3066 | } |
| 3067 | |
| 3068 | static int kvm_pv_mmu_release_pt(struct kvm_vcpu *vcpu, gpa_t addr) |
| 3069 | { |
| 3070 | spin_lock(&vcpu->kvm->mmu_lock); |
| 3071 | mmu_unshadow(vcpu->kvm, addr >> PAGE_SHIFT); |
| 3072 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 3073 | return 1; |
| 3074 | } |
| 3075 | |
| 3076 | static int kvm_pv_mmu_op_one(struct kvm_vcpu *vcpu, |
| 3077 | struct kvm_pv_mmu_op_buffer *buffer) |
| 3078 | { |
| 3079 | struct kvm_mmu_op_header *header; |
| 3080 | |
| 3081 | header = pv_mmu_peek_buffer(buffer, sizeof *header); |
| 3082 | if (!header) |
| 3083 | return 0; |
| 3084 | switch (header->op) { |
| 3085 | case KVM_MMU_OP_WRITE_PTE: { |
| 3086 | struct kvm_mmu_op_write_pte *wpte; |
| 3087 | |
| 3088 | wpte = pv_mmu_read_buffer(buffer, sizeof *wpte); |
| 3089 | if (!wpte) |
| 3090 | return 0; |
| 3091 | return kvm_pv_mmu_write(vcpu, wpte->pte_phys, |
| 3092 | wpte->pte_val); |
| 3093 | } |
| 3094 | case KVM_MMU_OP_FLUSH_TLB: { |
| 3095 | struct kvm_mmu_op_flush_tlb *ftlb; |
| 3096 | |
| 3097 | ftlb = pv_mmu_read_buffer(buffer, sizeof *ftlb); |
| 3098 | if (!ftlb) |
| 3099 | return 0; |
| 3100 | return kvm_pv_mmu_flush_tlb(vcpu); |
| 3101 | } |
| 3102 | case KVM_MMU_OP_RELEASE_PT: { |
| 3103 | struct kvm_mmu_op_release_pt *rpt; |
| 3104 | |
| 3105 | rpt = pv_mmu_read_buffer(buffer, sizeof *rpt); |
| 3106 | if (!rpt) |
| 3107 | return 0; |
| 3108 | return kvm_pv_mmu_release_pt(vcpu, rpt->pt_phys); |
| 3109 | } |
| 3110 | default: return 0; |
| 3111 | } |
| 3112 | } |
| 3113 | |
| 3114 | int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, |
| 3115 | gpa_t addr, unsigned long *ret) |
| 3116 | { |
| 3117 | int r; |
| 3118 | struct kvm_pv_mmu_op_buffer *buffer = &vcpu->arch.mmu_op_buffer; |
| 3119 | |
| 3120 | buffer->ptr = buffer->buf; |
| 3121 | buffer->len = min_t(unsigned long, bytes, sizeof buffer->buf); |
| 3122 | buffer->processed = 0; |
| 3123 | |
| 3124 | r = kvm_read_guest(vcpu->kvm, addr, buffer->buf, buffer->len); |
| 3125 | if (r) |
| 3126 | goto out; |
| 3127 | |
| 3128 | while (buffer->len) { |
| 3129 | r = kvm_pv_mmu_op_one(vcpu, buffer); |
| 3130 | if (r < 0) |
| 3131 | goto out; |
| 3132 | if (r == 0) |
| 3133 | break; |
| 3134 | } |
| 3135 | |
| 3136 | r = 1; |
| 3137 | out: |
| 3138 | *ret = buffer->processed; |
| 3139 | return r; |
| 3140 | } |
| 3141 | |
| 3142 | int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]) |
| 3143 | { |
| 3144 | struct kvm_shadow_walk_iterator iterator; |
| 3145 | int nr_sptes = 0; |
| 3146 | |
| 3147 | spin_lock(&vcpu->kvm->mmu_lock); |
| 3148 | for_each_shadow_entry(vcpu, addr, iterator) { |
| 3149 | sptes[iterator.level-1] = *iterator.sptep; |
| 3150 | nr_sptes++; |
| 3151 | if (!is_shadow_present_pte(*iterator.sptep)) |
| 3152 | break; |
| 3153 | } |
| 3154 | spin_unlock(&vcpu->kvm->mmu_lock); |
| 3155 | |
| 3156 | return nr_sptes; |
| 3157 | } |
| 3158 | EXPORT_SYMBOL_GPL(kvm_mmu_get_spte_hierarchy); |
| 3159 | |
| 3160 | #ifdef AUDIT |
| 3161 | |
| 3162 | static const char *audit_msg; |
| 3163 | |
| 3164 | static gva_t canonicalize(gva_t gva) |
| 3165 | { |
| 3166 | #ifdef CONFIG_X86_64 |
| 3167 | gva = (long long)(gva << 16) >> 16; |
| 3168 | #endif |
| 3169 | return gva; |
| 3170 | } |
| 3171 | |
| 3172 | |
| 3173 | typedef void (*inspect_spte_fn) (struct kvm *kvm, struct kvm_mmu_page *sp, |
| 3174 | u64 *sptep); |
| 3175 | |
| 3176 | static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp, |
| 3177 | inspect_spte_fn fn) |
| 3178 | { |
| 3179 | int i; |
| 3180 | |
| 3181 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| 3182 | u64 ent = sp->spt[i]; |
| 3183 | |
| 3184 | if (is_shadow_present_pte(ent)) { |
| 3185 | if (!is_last_spte(ent, sp->role.level)) { |
| 3186 | struct kvm_mmu_page *child; |
| 3187 | child = page_header(ent & PT64_BASE_ADDR_MASK); |
| 3188 | __mmu_spte_walk(kvm, child, fn); |
| 3189 | } else |
| 3190 | fn(kvm, sp, &sp->spt[i]); |
| 3191 | } |
| 3192 | } |
| 3193 | } |
| 3194 | |
| 3195 | static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn) |
| 3196 | { |
| 3197 | int i; |
| 3198 | struct kvm_mmu_page *sp; |
| 3199 | |
| 3200 | if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) |
| 3201 | return; |
| 3202 | if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) { |
| 3203 | hpa_t root = vcpu->arch.mmu.root_hpa; |
| 3204 | sp = page_header(root); |
| 3205 | __mmu_spte_walk(vcpu->kvm, sp, fn); |
| 3206 | return; |
| 3207 | } |
| 3208 | for (i = 0; i < 4; ++i) { |
| 3209 | hpa_t root = vcpu->arch.mmu.pae_root[i]; |
| 3210 | |
| 3211 | if (root && VALID_PAGE(root)) { |
| 3212 | root &= PT64_BASE_ADDR_MASK; |
| 3213 | sp = page_header(root); |
| 3214 | __mmu_spte_walk(vcpu->kvm, sp, fn); |
| 3215 | } |
| 3216 | } |
| 3217 | return; |
| 3218 | } |
| 3219 | |
| 3220 | static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte, |
| 3221 | gva_t va, int level) |
| 3222 | { |
| 3223 | u64 *pt = __va(page_pte & PT64_BASE_ADDR_MASK); |
| 3224 | int i; |
| 3225 | gva_t va_delta = 1ul << (PAGE_SHIFT + 9 * (level - 1)); |
| 3226 | |
| 3227 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i, va += va_delta) { |
| 3228 | u64 ent = pt[i]; |
| 3229 | |
| 3230 | if (ent == shadow_trap_nonpresent_pte) |
| 3231 | continue; |
| 3232 | |
| 3233 | va = canonicalize(va); |
| 3234 | if (is_shadow_present_pte(ent) && !is_last_spte(ent, level)) |
| 3235 | audit_mappings_page(vcpu, ent, va, level - 1); |
| 3236 | else { |
| 3237 | gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL); |
| 3238 | gfn_t gfn = gpa >> PAGE_SHIFT; |
| 3239 | pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn); |
| 3240 | hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT; |
| 3241 | |
| 3242 | if (is_error_pfn(pfn)) { |
| 3243 | kvm_release_pfn_clean(pfn); |
| 3244 | continue; |
| 3245 | } |
| 3246 | |
| 3247 | if (is_shadow_present_pte(ent) |
| 3248 | && (ent & PT64_BASE_ADDR_MASK) != hpa) |
| 3249 | printk(KERN_ERR "xx audit error: (%s) levels %d" |
| 3250 | " gva %lx gpa %llx hpa %llx ent %llx %d\n", |
| 3251 | audit_msg, vcpu->arch.mmu.root_level, |
| 3252 | va, gpa, hpa, ent, |
| 3253 | is_shadow_present_pte(ent)); |
| 3254 | else if (ent == shadow_notrap_nonpresent_pte |
| 3255 | && !is_error_hpa(hpa)) |
| 3256 | printk(KERN_ERR "audit: (%s) notrap shadow," |
| 3257 | " valid guest gva %lx\n", audit_msg, va); |
| 3258 | kvm_release_pfn_clean(pfn); |
| 3259 | |
| 3260 | } |
| 3261 | } |
| 3262 | } |
| 3263 | |
| 3264 | static void audit_mappings(struct kvm_vcpu *vcpu) |
| 3265 | { |
| 3266 | unsigned i; |
| 3267 | |
| 3268 | if (vcpu->arch.mmu.root_level == 4) |
| 3269 | audit_mappings_page(vcpu, vcpu->arch.mmu.root_hpa, 0, 4); |
| 3270 | else |
| 3271 | for (i = 0; i < 4; ++i) |
| 3272 | if (vcpu->arch.mmu.pae_root[i] & PT_PRESENT_MASK) |
| 3273 | audit_mappings_page(vcpu, |
| 3274 | vcpu->arch.mmu.pae_root[i], |
| 3275 | i << 30, |
| 3276 | 2); |
| 3277 | } |
| 3278 | |
| 3279 | static int count_rmaps(struct kvm_vcpu *vcpu) |
| 3280 | { |
| 3281 | int nmaps = 0; |
| 3282 | int i, j, k, idx; |
| 3283 | |
| 3284 | idx = srcu_read_lock(&kvm->srcu); |
| 3285 | slots = rcu_dereference(kvm->memslots); |
| 3286 | for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { |
| 3287 | struct kvm_memory_slot *m = &slots->memslots[i]; |
| 3288 | struct kvm_rmap_desc *d; |
| 3289 | |
| 3290 | for (j = 0; j < m->npages; ++j) { |
| 3291 | unsigned long *rmapp = &m->rmap[j]; |
| 3292 | |
| 3293 | if (!*rmapp) |
| 3294 | continue; |
| 3295 | if (!(*rmapp & 1)) { |
| 3296 | ++nmaps; |
| 3297 | continue; |
| 3298 | } |
| 3299 | d = (struct kvm_rmap_desc *)(*rmapp & ~1ul); |
| 3300 | while (d) { |
| 3301 | for (k = 0; k < RMAP_EXT; ++k) |
| 3302 | if (d->sptes[k]) |
| 3303 | ++nmaps; |
| 3304 | else |
| 3305 | break; |
| 3306 | d = d->more; |
| 3307 | } |
| 3308 | } |
| 3309 | } |
| 3310 | srcu_read_unlock(&kvm->srcu, idx); |
| 3311 | return nmaps; |
| 3312 | } |
| 3313 | |
| 3314 | void inspect_spte_has_rmap(struct kvm *kvm, struct kvm_mmu_page *sp, u64 *sptep) |
| 3315 | { |
| 3316 | unsigned long *rmapp; |
| 3317 | struct kvm_mmu_page *rev_sp; |
| 3318 | gfn_t gfn; |
| 3319 | |
| 3320 | if (*sptep & PT_WRITABLE_MASK) { |
| 3321 | rev_sp = page_header(__pa(sptep)); |
| 3322 | gfn = rev_sp->gfns[sptep - rev_sp->spt]; |
| 3323 | |
| 3324 | if (!gfn_to_memslot(kvm, gfn)) { |
| 3325 | if (!printk_ratelimit()) |
| 3326 | return; |
| 3327 | printk(KERN_ERR "%s: no memslot for gfn %ld\n", |
| 3328 | audit_msg, gfn); |
| 3329 | printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n", |
| 3330 | audit_msg, sptep - rev_sp->spt, |
| 3331 | rev_sp->gfn); |
| 3332 | dump_stack(); |
| 3333 | return; |
| 3334 | } |
| 3335 | |
| 3336 | rmapp = gfn_to_rmap(kvm, rev_sp->gfns[sptep - rev_sp->spt], |
| 3337 | is_large_pte(*sptep)); |
| 3338 | if (!*rmapp) { |
| 3339 | if (!printk_ratelimit()) |
| 3340 | return; |
| 3341 | printk(KERN_ERR "%s: no rmap for writable spte %llx\n", |
| 3342 | audit_msg, *sptep); |
| 3343 | dump_stack(); |
| 3344 | } |
| 3345 | } |
| 3346 | |
| 3347 | } |
| 3348 | |
| 3349 | void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu) |
| 3350 | { |
| 3351 | mmu_spte_walk(vcpu, inspect_spte_has_rmap); |
| 3352 | } |
| 3353 | |
| 3354 | static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu) |
| 3355 | { |
| 3356 | struct kvm_mmu_page *sp; |
| 3357 | int i; |
| 3358 | |
| 3359 | list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) { |
| 3360 | u64 *pt = sp->spt; |
| 3361 | |
| 3362 | if (sp->role.level != PT_PAGE_TABLE_LEVEL) |
| 3363 | continue; |
| 3364 | |
| 3365 | for (i = 0; i < PT64_ENT_PER_PAGE; ++i) { |
| 3366 | u64 ent = pt[i]; |
| 3367 | |
| 3368 | if (!(ent & PT_PRESENT_MASK)) |
| 3369 | continue; |
| 3370 | if (!(ent & PT_WRITABLE_MASK)) |
| 3371 | continue; |
| 3372 | inspect_spte_has_rmap(vcpu->kvm, sp, &pt[i]); |
| 3373 | } |
| 3374 | } |
| 3375 | return; |
| 3376 | } |
| 3377 | |
| 3378 | static void audit_rmap(struct kvm_vcpu *vcpu) |
| 3379 | { |
| 3380 | check_writable_mappings_rmap(vcpu); |
| 3381 | count_rmaps(vcpu); |
| 3382 | } |
| 3383 | |
| 3384 | static void audit_write_protection(struct kvm_vcpu *vcpu) |
| 3385 | { |
| 3386 | struct kvm_mmu_page *sp; |
| 3387 | struct kvm_memory_slot *slot; |
| 3388 | unsigned long *rmapp; |
| 3389 | u64 *spte; |
| 3390 | gfn_t gfn; |
| 3391 | |
| 3392 | list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) { |
| 3393 | if (sp->role.direct) |
| 3394 | continue; |
| 3395 | if (sp->unsync) |
| 3396 | continue; |
| 3397 | |
| 3398 | gfn = unalias_gfn(vcpu->kvm, sp->gfn); |
| 3399 | slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn); |
| 3400 | rmapp = &slot->rmap[gfn - slot->base_gfn]; |
| 3401 | |
| 3402 | spte = rmap_next(vcpu->kvm, rmapp, NULL); |
| 3403 | while (spte) { |
| 3404 | if (*spte & PT_WRITABLE_MASK) |
| 3405 | printk(KERN_ERR "%s: (%s) shadow page has " |
| 3406 | "writable mappings: gfn %lx role %x\n", |
| 3407 | __func__, audit_msg, sp->gfn, |
| 3408 | sp->role.word); |
| 3409 | spte = rmap_next(vcpu->kvm, rmapp, spte); |
| 3410 | } |
| 3411 | } |
| 3412 | } |
| 3413 | |
| 3414 | static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) |
| 3415 | { |
| 3416 | int olddbg = dbg; |
| 3417 | |
| 3418 | dbg = 0; |
| 3419 | audit_msg = msg; |
| 3420 | audit_rmap(vcpu); |
| 3421 | audit_write_protection(vcpu); |
| 3422 | if (strcmp("pre pte write", audit_msg) != 0) |
| 3423 | audit_mappings(vcpu); |
| 3424 | audit_writable_sptes_have_rmaps(vcpu); |
| 3425 | dbg = olddbg; |
| 3426 | } |
| 3427 | |
| 3428 | #endif |