1 /* 2 * Block driver for the QCOW version 2 format 3 * 4 * Copyright (c) 2004-2006 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #ifndef BLOCK_QCOW2_H 26 #define BLOCK_QCOW2_H 27 28 #include "crypto/block.h" 29 #include "qemu/coroutine.h" 30 #include "qemu/units.h" 31 #include "block/block_int.h" 32 33 //#define DEBUG_ALLOC 34 //#define DEBUG_ALLOC2 35 //#define DEBUG_EXT 36 37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) 38 39 #define QCOW_CRYPT_NONE 0 40 #define QCOW_CRYPT_AES 1 41 #define QCOW_CRYPT_LUKS 2 42 43 #define QCOW_MAX_CRYPT_CLUSTERS 32 44 #define QCOW_MAX_SNAPSHOTS 65536 45 46 /* Field widths in qcow2 mean normal cluster offsets cannot reach 47 * 64PB; depending on cluster size, compressed clusters can have a 48 * smaller limit (64PB for up to 16k clusters, then ramps down to 49 * 512TB for 2M clusters). */ 50 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) 51 52 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size 53 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 54 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB) 55 56 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size 57 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ 58 #define QCOW_MAX_L1_SIZE (32 * MiB) 59 60 /* Allow for an average of 1k per snapshot table entry, should be plenty of 61 * space for snapshot names and IDs */ 62 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) 63 64 /* Maximum amount of extra data per snapshot table entry to accept */ 65 #define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024 66 67 /* Bitmap header extension constraints */ 68 #define QCOW2_MAX_BITMAPS 65535 69 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) 70 71 /* Maximum of parallel sub-request per guest request */ 72 #define QCOW2_MAX_WORKERS 8 73 74 /* indicate that the refcount of the referenced cluster is exactly one. */ 75 #define QCOW_OFLAG_COPIED (1ULL << 63) 76 /* indicate that the cluster is compressed (they never have the copied flag) */ 77 #define QCOW_OFLAG_COMPRESSED (1ULL << 62) 78 /* The cluster reads as all zeros */ 79 #define QCOW_OFLAG_ZERO (1ULL << 0) 80 81 #define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32 82 83 /* The subcluster X [0..31] is allocated */ 84 #define QCOW_OFLAG_SUB_ALLOC(X) (1ULL << (X)) 85 /* The subcluster X [0..31] reads as zeroes */ 86 #define QCOW_OFLAG_SUB_ZERO(X) (QCOW_OFLAG_SUB_ALLOC(X) << 32) 87 /* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */ 88 #define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \ 89 (QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X)) 90 /* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */ 91 #define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \ 92 (QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32) 93 /* L2 entry bitmap with all allocation bits set */ 94 #define QCOW_L2_BITMAP_ALL_ALLOC (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32)) 95 /* L2 entry bitmap with all "read as zeroes" bits set */ 96 #define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32)) 97 98 /* Size of normal and extended L2 entries */ 99 #define L2E_SIZE_NORMAL (sizeof(uint64_t)) 100 #define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2) 101 102 /* Size of L1 table entries */ 103 #define L1E_SIZE (sizeof(uint64_t)) 104 105 /* Size of reftable entries */ 106 #define REFTABLE_ENTRY_SIZE (sizeof(uint64_t)) 107 108 #define MIN_CLUSTER_BITS 9 109 #define MAX_CLUSTER_BITS 21 110 111 /* Defined in the qcow2 spec (compressed cluster descriptor) */ 112 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U 113 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL)) 114 115 /* Must be at least 2 to cover COW */ 116 #define MIN_L2_CACHE_SIZE 2 /* cache entries */ 117 118 /* Must be at least 4 to cover all cases of refcount table growth */ 119 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ 120 121 #ifdef CONFIG_LINUX 122 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) 123 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ 124 #else 125 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB) 126 /* Cache clean interval is currently available only on Linux, so must be 0 */ 127 #define DEFAULT_CACHE_CLEAN_INTERVAL 0 128 #endif 129 130 #define DEFAULT_CLUSTER_SIZE 65536 131 132 #define QCOW2_OPT_DATA_FILE "data-file" 133 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" 134 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" 135 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" 136 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other" 137 #define QCOW2_OPT_OVERLAP "overlap-check" 138 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template" 139 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header" 140 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1" 141 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2" 142 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table" 143 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block" 144 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table" 145 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1" 146 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" 147 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory" 148 #define QCOW2_OPT_CACHE_SIZE "cache-size" 149 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" 150 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size" 151 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" 152 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval" 153 154 typedef struct QCowHeader { 155 uint32_t magic; 156 uint32_t version; 157 uint64_t backing_file_offset; 158 uint32_t backing_file_size; 159 uint32_t cluster_bits; 160 uint64_t size; /* in bytes */ 161 uint32_t crypt_method; 162 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 163 uint64_t l1_table_offset; 164 uint64_t refcount_table_offset; 165 uint32_t refcount_table_clusters; 166 uint32_t nb_snapshots; 167 uint64_t snapshots_offset; 168 169 /* The following fields are only valid for version >= 3 */ 170 uint64_t incompatible_features; 171 uint64_t compatible_features; 172 uint64_t autoclear_features; 173 174 uint32_t refcount_order; 175 uint32_t header_length; 176 177 /* Additional fields */ 178 uint8_t compression_type; 179 180 /* header must be a multiple of 8 */ 181 uint8_t padding[7]; 182 } QEMU_PACKED QCowHeader; 183 184 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8)); 185 186 typedef struct QEMU_PACKED QCowSnapshotHeader { 187 /* header is 8 byte aligned */ 188 uint64_t l1_table_offset; 189 190 uint32_t l1_size; 191 uint16_t id_str_size; 192 uint16_t name_size; 193 194 uint32_t date_sec; 195 uint32_t date_nsec; 196 197 uint64_t vm_clock_nsec; 198 199 uint32_t vm_state_size; 200 uint32_t extra_data_size; /* for extension */ 201 /* extra data follows */ 202 /* id_str follows */ 203 /* name follows */ 204 } QCowSnapshotHeader; 205 206 typedef struct QEMU_PACKED QCowSnapshotExtraData { 207 uint64_t vm_state_size_large; 208 uint64_t disk_size; 209 uint64_t icount; 210 } QCowSnapshotExtraData; 211 212 213 typedef struct QCowSnapshot { 214 uint64_t l1_table_offset; 215 uint32_t l1_size; 216 char *id_str; 217 char *name; 218 uint64_t disk_size; 219 uint64_t vm_state_size; 220 uint32_t date_sec; 221 uint32_t date_nsec; 222 uint64_t vm_clock_nsec; 223 /* icount value for the moment when snapshot was taken */ 224 uint64_t icount; 225 /* Size of all extra data, including QCowSnapshotExtraData if available */ 226 uint32_t extra_data_size; 227 /* Data beyond QCowSnapshotExtraData, if any */ 228 void *unknown_extra_data; 229 } QCowSnapshot; 230 231 struct Qcow2Cache; 232 typedef struct Qcow2Cache Qcow2Cache; 233 234 typedef struct Qcow2CryptoHeaderExtension { 235 uint64_t offset; 236 uint64_t length; 237 } QEMU_PACKED Qcow2CryptoHeaderExtension; 238 239 typedef struct Qcow2UnknownHeaderExtension { 240 uint32_t magic; 241 uint32_t len; 242 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 243 uint8_t data[]; 244 } Qcow2UnknownHeaderExtension; 245 246 enum { 247 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, 248 QCOW2_FEAT_TYPE_COMPATIBLE = 1, 249 QCOW2_FEAT_TYPE_AUTOCLEAR = 2, 250 }; 251 252 /* Incompatible feature bits */ 253 enum { 254 QCOW2_INCOMPAT_DIRTY_BITNR = 0, 255 QCOW2_INCOMPAT_CORRUPT_BITNR = 1, 256 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2, 257 QCOW2_INCOMPAT_COMPRESSION_BITNR = 3, 258 QCOW2_INCOMPAT_EXTL2_BITNR = 4, 259 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR, 260 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR, 261 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR, 262 QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR, 263 QCOW2_INCOMPAT_EXTL2 = 1 << QCOW2_INCOMPAT_EXTL2_BITNR, 264 265 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY 266 | QCOW2_INCOMPAT_CORRUPT 267 | QCOW2_INCOMPAT_DATA_FILE 268 | QCOW2_INCOMPAT_COMPRESSION 269 | QCOW2_INCOMPAT_EXTL2, 270 }; 271 272 /* Compatible feature bits */ 273 enum { 274 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0, 275 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, 276 277 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, 278 }; 279 280 /* Autoclear feature bits */ 281 enum { 282 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0, 283 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, 284 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR, 285 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, 286 287 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS 288 | QCOW2_AUTOCLEAR_DATA_FILE_RAW, 289 }; 290 291 enum qcow2_discard_type { 292 QCOW2_DISCARD_NEVER = 0, 293 QCOW2_DISCARD_ALWAYS, 294 QCOW2_DISCARD_REQUEST, 295 QCOW2_DISCARD_SNAPSHOT, 296 QCOW2_DISCARD_OTHER, 297 QCOW2_DISCARD_MAX 298 }; 299 300 typedef struct Qcow2Feature { 301 uint8_t type; 302 uint8_t bit; 303 char name[46]; 304 } QEMU_PACKED Qcow2Feature; 305 306 typedef struct Qcow2DiscardRegion { 307 BlockDriverState *bs; 308 uint64_t offset; 309 uint64_t bytes; 310 QTAILQ_ENTRY(Qcow2DiscardRegion) next; 311 } Qcow2DiscardRegion; 312 313 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, 314 uint64_t index); 315 typedef void Qcow2SetRefcountFunc(void *refcount_array, 316 uint64_t index, uint64_t value); 317 318 typedef struct Qcow2BitmapHeaderExt { 319 uint32_t nb_bitmaps; 320 uint32_t reserved32; 321 uint64_t bitmap_directory_size; 322 uint64_t bitmap_directory_offset; 323 } QEMU_PACKED Qcow2BitmapHeaderExt; 324 325 #define QCOW2_MAX_THREADS 4 326 327 typedef struct BDRVQcow2State { 328 int cluster_bits; 329 int cluster_size; 330 int l2_slice_size; 331 int subcluster_bits; 332 int subcluster_size; 333 int subclusters_per_cluster; 334 int l2_bits; 335 int l2_size; 336 int l1_size; 337 int l1_vm_state_index; 338 int refcount_block_bits; 339 int refcount_block_size; 340 int csize_shift; 341 int csize_mask; 342 uint64_t cluster_offset_mask; 343 uint64_t l1_table_offset; 344 uint64_t *l1_table; 345 346 Qcow2Cache *l2_table_cache; 347 Qcow2Cache *refcount_block_cache; 348 QEMUTimer *cache_clean_timer; 349 unsigned cache_clean_interval; 350 351 QLIST_HEAD(, QCowL2Meta) cluster_allocs; 352 353 uint64_t *refcount_table; 354 uint64_t refcount_table_offset; 355 uint32_t refcount_table_size; 356 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */ 357 uint64_t free_cluster_index; 358 uint64_t free_byte_offset; 359 360 CoMutex lock; 361 362 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */ 363 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ 364 QCryptoBlock *crypto; /* Disk encryption format driver */ 365 bool crypt_physical_offset; /* Whether to use virtual or physical offset 366 for encryption initialization vector tweak */ 367 uint32_t crypt_method_header; 368 uint64_t snapshots_offset; 369 int snapshots_size; 370 unsigned int nb_snapshots; 371 QCowSnapshot *snapshots; 372 373 uint32_t nb_bitmaps; 374 uint64_t bitmap_directory_size; 375 uint64_t bitmap_directory_offset; 376 377 int flags; 378 int qcow_version; 379 bool use_lazy_refcounts; 380 int refcount_order; 381 int refcount_bits; 382 uint64_t refcount_max; 383 384 Qcow2GetRefcountFunc *get_refcount; 385 Qcow2SetRefcountFunc *set_refcount; 386 387 bool discard_passthrough[QCOW2_DISCARD_MAX]; 388 389 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */ 390 bool signaled_corruption; 391 392 uint64_t incompatible_features; 393 uint64_t compatible_features; 394 uint64_t autoclear_features; 395 396 size_t unknown_header_fields_size; 397 void *unknown_header_fields; 398 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 399 QTAILQ_HEAD (, Qcow2DiscardRegion) discards; 400 bool cache_discards; 401 402 /* Backing file path and format as stored in the image (this is not the 403 * effective path/format, which may be the result of a runtime option 404 * override) */ 405 char *image_backing_file; 406 char *image_backing_format; 407 char *image_data_file; 408 409 CoQueue thread_task_queue; 410 int nb_threads; 411 412 BdrvChild *data_file; 413 414 bool metadata_preallocation_checked; 415 bool metadata_preallocation; 416 /* 417 * Compression type used for the image. Default: 0 - ZLIB 418 * The image compression type is set on image creation. 419 * For now, the only way to change the compression type 420 * is to convert the image with the desired compression type set. 421 */ 422 Qcow2CompressionType compression_type; 423 } BDRVQcow2State; 424 425 typedef struct Qcow2COWRegion { 426 /** 427 * Offset of the COW region in bytes from the start of the first cluster 428 * touched by the request. 429 */ 430 unsigned offset; 431 432 /** Number of bytes to copy */ 433 unsigned nb_bytes; 434 } Qcow2COWRegion; 435 436 /** 437 * Describes an in-flight (part of a) write request that writes to clusters 438 * that need to have their L2 table entries updated (because they are 439 * newly allocated or need changes in their L2 bitmaps) 440 */ 441 typedef struct QCowL2Meta 442 { 443 /** Guest offset of the first updated cluster */ 444 uint64_t offset; 445 446 /** Host offset of the first updated cluster */ 447 uint64_t alloc_offset; 448 449 /** Number of updated clusters */ 450 int nb_clusters; 451 452 /** Do not free the old clusters */ 453 bool keep_old_clusters; 454 455 /** 456 * Requests that overlap with this allocation and wait to be restarted 457 * when the allocating request has completed. 458 */ 459 CoQueue dependent_requests; 460 461 /** 462 * The COW Region immediately before the area the guest actually 463 * writes to. This (part of the) write request starts at 464 * cow_start.offset + cow_start.nb_bytes. 465 */ 466 Qcow2COWRegion cow_start; 467 468 /** 469 * The COW Region immediately after the area the guest actually 470 * writes to. This (part of the) write request ends at cow_end.offset 471 * (which must always be set even when cow_end.nb_bytes is 0). 472 */ 473 Qcow2COWRegion cow_end; 474 475 /* 476 * Indicates that COW regions are already handled and do not require 477 * any more processing. 478 */ 479 bool skip_cow; 480 481 /** 482 * Indicates that this is not a normal write request but a preallocation. 483 * If the image has extended L2 entries this means that no new individual 484 * subclusters will be marked as allocated in the L2 bitmap (but any 485 * existing contents of that bitmap will be kept). 486 */ 487 bool prealloc; 488 489 /** 490 * The I/O vector with the data from the actual guest write request. 491 * If non-NULL, this is meant to be merged together with the data 492 * from @cow_start and @cow_end into one single write operation. 493 */ 494 QEMUIOVector *data_qiov; 495 size_t data_qiov_offset; 496 497 /** Pointer to next L2Meta of the same write request */ 498 struct QCowL2Meta *next; 499 500 QLIST_ENTRY(QCowL2Meta) next_in_flight; 501 } QCowL2Meta; 502 503 /* 504 * In images with standard L2 entries all clusters are treated as if 505 * they had one subcluster so QCow2ClusterType and QCow2SubclusterType 506 * can be mapped to each other and have the exact same meaning 507 * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images). 508 * 509 * In images with extended L2 entries QCow2ClusterType refers to the 510 * complete cluster and QCow2SubclusterType to each of the individual 511 * subclusters, so there are several possible combinations: 512 * 513 * |--------------+---------------------------| 514 * | Cluster type | Possible subcluster types | 515 * |--------------+---------------------------| 516 * | UNALLOCATED | UNALLOCATED_PLAIN | 517 * | | ZERO_PLAIN | 518 * |--------------+---------------------------| 519 * | NORMAL | UNALLOCATED_ALLOC | 520 * | | ZERO_ALLOC | 521 * | | NORMAL | 522 * |--------------+---------------------------| 523 * | COMPRESSED | COMPRESSED | 524 * |--------------+---------------------------| 525 * 526 * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and 527 * the image should be marked corrupt. 528 */ 529 530 typedef enum QCow2ClusterType { 531 QCOW2_CLUSTER_UNALLOCATED, 532 QCOW2_CLUSTER_ZERO_PLAIN, 533 QCOW2_CLUSTER_ZERO_ALLOC, 534 QCOW2_CLUSTER_NORMAL, 535 QCOW2_CLUSTER_COMPRESSED, 536 } QCow2ClusterType; 537 538 typedef enum QCow2SubclusterType { 539 QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN, 540 QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC, 541 QCOW2_SUBCLUSTER_ZERO_PLAIN, 542 QCOW2_SUBCLUSTER_ZERO_ALLOC, 543 QCOW2_SUBCLUSTER_NORMAL, 544 QCOW2_SUBCLUSTER_COMPRESSED, 545 QCOW2_SUBCLUSTER_INVALID, 546 } QCow2SubclusterType; 547 548 typedef enum QCow2MetadataOverlap { 549 QCOW2_OL_MAIN_HEADER_BITNR = 0, 550 QCOW2_OL_ACTIVE_L1_BITNR = 1, 551 QCOW2_OL_ACTIVE_L2_BITNR = 2, 552 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3, 553 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4, 554 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5, 555 QCOW2_OL_INACTIVE_L1_BITNR = 6, 556 QCOW2_OL_INACTIVE_L2_BITNR = 7, 557 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8, 558 559 QCOW2_OL_MAX_BITNR = 9, 560 561 QCOW2_OL_NONE = 0, 562 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR), 563 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR), 564 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR), 565 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR), 566 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR), 567 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR), 568 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR), 569 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv 570 * reads. */ 571 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR), 572 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR), 573 } QCow2MetadataOverlap; 574 575 /* Perform all overlap checks which can be done in constant time */ 576 #define QCOW2_OL_CONSTANT \ 577 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \ 578 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY) 579 580 /* Perform all overlap checks which don't require disk access */ 581 #define QCOW2_OL_CACHED \ 582 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \ 583 QCOW2_OL_INACTIVE_L1) 584 585 /* Perform all overlap checks */ 586 #define QCOW2_OL_ALL \ 587 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2) 588 589 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL 590 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL 591 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL 592 593 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL 594 595 #define INV_OFFSET (-1ULL) 596 597 static inline bool has_subclusters(BDRVQcow2State *s) 598 { 599 return s->incompatible_features & QCOW2_INCOMPAT_EXTL2; 600 } 601 602 static inline size_t l2_entry_size(BDRVQcow2State *s) 603 { 604 return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; 605 } 606 607 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice, 608 int idx) 609 { 610 idx *= l2_entry_size(s) / sizeof(uint64_t); 611 return be64_to_cpu(l2_slice[idx]); 612 } 613 614 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice, 615 int idx) 616 { 617 if (has_subclusters(s)) { 618 idx *= l2_entry_size(s) / sizeof(uint64_t); 619 return be64_to_cpu(l2_slice[idx + 1]); 620 } else { 621 return 0; /* For convenience only; this value has no meaning. */ 622 } 623 } 624 625 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice, 626 int idx, uint64_t entry) 627 { 628 idx *= l2_entry_size(s) / sizeof(uint64_t); 629 l2_slice[idx] = cpu_to_be64(entry); 630 } 631 632 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice, 633 int idx, uint64_t bitmap) 634 { 635 assert(has_subclusters(s)); 636 idx *= l2_entry_size(s) / sizeof(uint64_t); 637 l2_slice[idx + 1] = cpu_to_be64(bitmap); 638 } 639 640 static inline bool has_data_file(BlockDriverState *bs) 641 { 642 BDRVQcow2State *s = bs->opaque; 643 return (s->data_file != bs->file); 644 } 645 646 static inline bool data_file_is_raw(BlockDriverState *bs) 647 { 648 BDRVQcow2State *s = bs->opaque; 649 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW); 650 } 651 652 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset) 653 { 654 return offset & ~(s->cluster_size - 1); 655 } 656 657 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset) 658 { 659 return offset & (s->cluster_size - 1); 660 } 661 662 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset) 663 { 664 return offset & (s->subcluster_size - 1); 665 } 666 667 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size) 668 { 669 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 670 } 671 672 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size) 673 { 674 return (size + (s->subcluster_size - 1)) >> s->subcluster_bits; 675 } 676 677 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size) 678 { 679 int shift = s->cluster_bits + s->l2_bits; 680 return (size + (1ULL << shift) - 1) >> shift; 681 } 682 683 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset) 684 { 685 return offset >> (s->l2_bits + s->cluster_bits); 686 } 687 688 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset) 689 { 690 return (offset >> s->cluster_bits) & (s->l2_size - 1); 691 } 692 693 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset) 694 { 695 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1); 696 } 697 698 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset) 699 { 700 return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1); 701 } 702 703 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s) 704 { 705 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits); 706 } 707 708 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs, 709 uint64_t l2_entry) 710 { 711 BDRVQcow2State *s = bs->opaque; 712 713 if (l2_entry & QCOW_OFLAG_COMPRESSED) { 714 return QCOW2_CLUSTER_COMPRESSED; 715 } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) { 716 if (l2_entry & L2E_OFFSET_MASK) { 717 return QCOW2_CLUSTER_ZERO_ALLOC; 718 } 719 return QCOW2_CLUSTER_ZERO_PLAIN; 720 } else if (!(l2_entry & L2E_OFFSET_MASK)) { 721 /* Offset 0 generally means unallocated, but it is ambiguous with 722 * external data files because 0 is a valid offset there. However, all 723 * clusters in external data files always have refcount 1, so we can 724 * rely on QCOW_OFLAG_COPIED to disambiguate. */ 725 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) { 726 return QCOW2_CLUSTER_NORMAL; 727 } else { 728 return QCOW2_CLUSTER_UNALLOCATED; 729 } 730 } else { 731 return QCOW2_CLUSTER_NORMAL; 732 } 733 } 734 735 /* 736 * In an image without subsclusters @l2_bitmap is ignored and 737 * @sc_index must be 0. 738 * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected 739 * (this checks the whole entry and bitmap, not only the bits related 740 * to subcluster @sc_index). 741 */ 742 static inline 743 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs, 744 uint64_t l2_entry, 745 uint64_t l2_bitmap, 746 unsigned sc_index) 747 { 748 BDRVQcow2State *s = bs->opaque; 749 QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry); 750 assert(sc_index < s->subclusters_per_cluster); 751 752 if (has_subclusters(s)) { 753 switch (type) { 754 case QCOW2_CLUSTER_COMPRESSED: 755 return QCOW2_SUBCLUSTER_COMPRESSED; 756 case QCOW2_CLUSTER_NORMAL: 757 if ((l2_bitmap >> 32) & l2_bitmap) { 758 return QCOW2_SUBCLUSTER_INVALID; 759 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) { 760 return QCOW2_SUBCLUSTER_ZERO_ALLOC; 761 } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) { 762 return QCOW2_SUBCLUSTER_NORMAL; 763 } else { 764 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC; 765 } 766 case QCOW2_CLUSTER_UNALLOCATED: 767 if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) { 768 return QCOW2_SUBCLUSTER_INVALID; 769 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) { 770 return QCOW2_SUBCLUSTER_ZERO_PLAIN; 771 } else { 772 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN; 773 } 774 default: 775 g_assert_not_reached(); 776 } 777 } else { 778 switch (type) { 779 case QCOW2_CLUSTER_COMPRESSED: 780 return QCOW2_SUBCLUSTER_COMPRESSED; 781 case QCOW2_CLUSTER_ZERO_PLAIN: 782 return QCOW2_SUBCLUSTER_ZERO_PLAIN; 783 case QCOW2_CLUSTER_ZERO_ALLOC: 784 return QCOW2_SUBCLUSTER_ZERO_ALLOC; 785 case QCOW2_CLUSTER_NORMAL: 786 return QCOW2_SUBCLUSTER_NORMAL; 787 case QCOW2_CLUSTER_UNALLOCATED: 788 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN; 789 default: 790 g_assert_not_reached(); 791 } 792 } 793 } 794 795 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type) 796 { 797 return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL || 798 type == QCOW2_CLUSTER_ZERO_ALLOC); 799 } 800 801 /* Check whether refcounts are eager or lazy */ 802 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s) 803 { 804 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY); 805 } 806 807 static inline uint64_t l2meta_cow_start(QCowL2Meta *m) 808 { 809 return m->offset + m->cow_start.offset; 810 } 811 812 static inline uint64_t l2meta_cow_end(QCowL2Meta *m) 813 { 814 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes; 815 } 816 817 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2) 818 { 819 return r1 > r2 ? r1 - r2 : r2 - r1; 820 } 821 822 static inline 823 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset) 824 { 825 return offset >> (s->refcount_block_bits + s->cluster_bits); 826 } 827 828 /* qcow2.c functions */ 829 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, 830 int refcount_order, bool generous_increase, 831 uint64_t *refblock_count); 832 833 int qcow2_mark_dirty(BlockDriverState *bs); 834 int qcow2_mark_corrupt(BlockDriverState *bs); 835 int qcow2_mark_consistent(BlockDriverState *bs); 836 int qcow2_update_header(BlockDriverState *bs); 837 838 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, 839 int64_t size, const char *message_format, ...) 840 GCC_FMT_ATTR(5, 6); 841 842 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, 843 uint64_t entries, size_t entry_len, 844 int64_t max_size_bytes, const char *table_name, 845 Error **errp); 846 847 /* qcow2-refcount.c functions */ 848 int qcow2_refcount_init(BlockDriverState *bs); 849 void qcow2_refcount_close(BlockDriverState *bs); 850 851 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, 852 uint64_t *refcount); 853 854 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, 855 uint64_t addend, bool decrease, 856 enum qcow2_discard_type type); 857 858 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset, 859 uint64_t additional_clusters, bool exact_size, 860 int new_refblock_index, 861 uint64_t new_refblock_offset); 862 863 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); 864 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, 865 int64_t nb_clusters); 866 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 867 void qcow2_free_clusters(BlockDriverState *bs, 868 int64_t offset, int64_t size, 869 enum qcow2_discard_type type); 870 void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry, 871 enum qcow2_discard_type type); 872 873 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 874 int64_t l1_table_offset, int l1_size, int addend); 875 876 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs); 877 int coroutine_fn qcow2_write_caches(BlockDriverState *bs); 878 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 879 BdrvCheckMode fix); 880 881 void qcow2_process_discards(BlockDriverState *bs, int ret); 882 883 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, 884 int64_t size); 885 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, 886 int64_t size, bool data_file); 887 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res, 888 void **refcount_table, 889 int64_t *refcount_table_size, 890 int64_t offset, int64_t size); 891 892 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, 893 BlockDriverAmendStatusCB *status_cb, 894 void *cb_opaque, Error **errp); 895 int qcow2_shrink_reftable(BlockDriverState *bs); 896 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size); 897 int qcow2_detect_metadata_preallocation(BlockDriverState *bs); 898 899 /* qcow2-cluster.c functions */ 900 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, 901 bool exact_size); 902 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size); 903 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); 904 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num, 905 uint8_t *buf, int nb_sectors, bool enc, Error **errp); 906 907 int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset, 908 unsigned int *bytes, uint64_t *host_offset, 909 QCow2SubclusterType *subcluster_type); 910 int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset, 911 unsigned int *bytes, uint64_t *host_offset, 912 QCowL2Meta **m); 913 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 914 uint64_t offset, 915 int compressed_size, 916 uint64_t *host_offset); 917 918 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 919 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m); 920 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset, 921 uint64_t bytes, enum qcow2_discard_type type, 922 bool full_discard); 923 int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, 924 uint64_t bytes, int flags); 925 926 int qcow2_expand_zero_clusters(BlockDriverState *bs, 927 BlockDriverAmendStatusCB *status_cb, 928 void *cb_opaque); 929 930 /* qcow2-snapshot.c functions */ 931 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 932 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 933 int qcow2_snapshot_delete(BlockDriverState *bs, 934 const char *snapshot_id, 935 const char *name, 936 Error **errp); 937 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 938 int qcow2_snapshot_load_tmp(BlockDriverState *bs, 939 const char *snapshot_id, 940 const char *name, 941 Error **errp); 942 943 void qcow2_free_snapshots(BlockDriverState *bs); 944 int qcow2_read_snapshots(BlockDriverState *bs, Error **errp); 945 int qcow2_write_snapshots(BlockDriverState *bs); 946 947 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs, 948 BdrvCheckResult *result, 949 BdrvCheckMode fix); 950 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs, 951 BdrvCheckResult *result, 952 BdrvCheckMode fix); 953 954 /* qcow2-cache.c functions */ 955 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 956 unsigned table_size); 957 int qcow2_cache_destroy(Qcow2Cache *c); 958 959 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 960 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 961 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c); 962 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 963 Qcow2Cache *dependency); 964 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 965 966 void qcow2_cache_clean_unused(Qcow2Cache *c); 967 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c); 968 969 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 970 void **table); 971 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 972 void **table); 973 void qcow2_cache_put(Qcow2Cache *c, void **table); 974 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset); 975 void qcow2_cache_discard(Qcow2Cache *c, void *table); 976 977 /* qcow2-bitmap.c functions */ 978 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 979 void **refcount_table, 980 int64_t *refcount_table_size); 981 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp); 982 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs, 983 Error **errp); 984 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp); 985 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp); 986 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, 987 bool release_stored, Error **errp); 988 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp); 989 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, 990 const char *name, 991 uint32_t granularity, 992 Error **errp); 993 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, 994 const char *name, 995 Error **errp); 996 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs); 997 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs, 998 uint32_t cluster_size); 999 1000 ssize_t coroutine_fn 1001 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size, 1002 const void *src, size_t src_size); 1003 ssize_t coroutine_fn 1004 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size, 1005 const void *src, size_t src_size); 1006 int coroutine_fn 1007 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset, 1008 uint64_t guest_offset, void *buf, size_t len); 1009 int coroutine_fn 1010 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset, 1011 uint64_t guest_offset, void *buf, size_t len); 1012 1013 #endif 1014