block/qcow2.h

   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 #define MIN_CLUSTER_BITS 9
 103 #define MAX_CLUSTER_BITS 21
 104
 105 /* Defined in the qcow2 spec (compressed cluster descriptor) */
 106 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
 107 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL))
 108
 109 /* Must be at least 2 to cover COW */
 110 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
 111
 112 /* Must be at least 4 to cover all cases of refcount table growth */
 113 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
 114
 115 #ifdef CONFIG_LINUX
 116 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
 117 #define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
 118 #else
 119 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
 120 /* Cache clean interval is currently available only on Linux, so must be 0 */
 121 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
 122 #endif
 123
 124 #define DEFAULT_CLUSTER_SIZE 65536
 125
 126 #define QCOW2_OPT_DATA_FILE "data-file"
 127 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
 128 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
 129 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
 130 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
 131 #define QCOW2_OPT_OVERLAP "overlap-check"
 132 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
 133 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
 134 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
 135 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
 136 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
 137 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
 138 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
 139 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
 140 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
 141 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
 142 #define QCOW2_OPT_CACHE_SIZE "cache-size"
 143 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
 144 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
 145 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
 146 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
 147
 148 typedef struct QCowHeader {
 149     uint32_t magic;
 150     uint32_t version;
 151     uint64_t backing_file_offset;
 152     uint32_t backing_file_size;
 153     uint32_t cluster_bits;
 154     uint64_t size; /* in bytes */
 155     uint32_t crypt_method;
 156     uint32_t l1_size; /* XXX: save number of clusters instead ? */
 157     uint64_t l1_table_offset;
 158     uint64_t refcount_table_offset;
 159     uint32_t refcount_table_clusters;
 160     uint32_t nb_snapshots;
 161     uint64_t snapshots_offset;
 162
 163     /* The following fields are only valid for version >= 3 */
 164     uint64_t incompatible_features;
 165     uint64_t compatible_features;
 166     uint64_t autoclear_features;
 167
 168     uint32_t refcount_order;
 169     uint32_t header_length;
 170
 171     /* Additional fields */
 172     uint8_t compression_type;
 173
 174     /* header must be a multiple of 8 */
 175     uint8_t padding[7];
 176 } QEMU_PACKED QCowHeader;
 177
 178 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
 179
 180 typedef struct QEMU_PACKED QCowSnapshotHeader {
 181     /* header is 8 byte aligned */
 182     uint64_t l1_table_offset;
 183
 184     uint32_t l1_size;
 185     uint16_t id_str_size;
 186     uint16_t name_size;
 187
 188     uint32_t date_sec;
 189     uint32_t date_nsec;
 190
 191     uint64_t vm_clock_nsec;
 192
 193     uint32_t vm_state_size;
 194     uint32_t extra_data_size; /* for extension */
 195     /* extra data follows */
 196     /* id_str follows */
 197     /* name follows  */
 198 } QCowSnapshotHeader;
 199
 200 typedef struct QEMU_PACKED QCowSnapshotExtraData {
 201     uint64_t vm_state_size_large;
 202     uint64_t disk_size;
 203 } QCowSnapshotExtraData;
 204
 205
 206 typedef struct QCowSnapshot {
 207     uint64_t l1_table_offset;
 208     uint32_t l1_size;
 209     char *id_str;
 210     char *name;
 211     uint64_t disk_size;
 212     uint64_t vm_state_size;
 213     uint32_t date_sec;
 214     uint32_t date_nsec;
 215     uint64_t vm_clock_nsec;
 216     /* Size of all extra data, including QCowSnapshotExtraData if available */
 217     uint32_t extra_data_size;
 218     /* Data beyond QCowSnapshotExtraData, if any */
 219     void *unknown_extra_data;
 220 } QCowSnapshot;
 221
 222 struct Qcow2Cache;
 223 typedef struct Qcow2Cache Qcow2Cache;
 224
 225 typedef struct Qcow2CryptoHeaderExtension {
 226     uint64_t offset;
 227     uint64_t length;
 228 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 229
 230 typedef struct Qcow2UnknownHeaderExtension {
 231     uint32_t magic;
 232     uint32_t len;
 233     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 234     uint8_t data[];
 235 } Qcow2UnknownHeaderExtension;
 236
 237 enum {
 238     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 239     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 240     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 241 };
 242
 243 /* Incompatible feature bits */
 244 enum {
 245     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 246     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 247     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 248     QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
 249     QCOW2_INCOMPAT_EXTL2_BITNR      = 4,
 250     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 251     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 252     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 253     QCOW2_INCOMPAT_COMPRESSION      = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
 254     QCOW2_INCOMPAT_EXTL2            = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
 255
 256     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 257                                     | QCOW2_INCOMPAT_CORRUPT
 258                                     | QCOW2_INCOMPAT_DATA_FILE
 259                                     | QCOW2_INCOMPAT_COMPRESSION
 260                                     | QCOW2_INCOMPAT_EXTL2,
 261 };
 262
 263 /* Compatible feature bits */
 264 enum {
 265     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 266     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 267
 268     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 269 };
 270
 271 /* Autoclear feature bits */
 272 enum {
 273     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 274     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 275     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 276     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 277
 278     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 279                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 280 };
 281
 282 enum qcow2_discard_type {
 283     QCOW2_DISCARD_NEVER = 0,
 284     QCOW2_DISCARD_ALWAYS,
 285     QCOW2_DISCARD_REQUEST,
 286     QCOW2_DISCARD_SNAPSHOT,
 287     QCOW2_DISCARD_OTHER,
 288     QCOW2_DISCARD_MAX
 289 };
 290
 291 typedef struct Qcow2Feature {
 292     uint8_t type;
 293     uint8_t bit;
 294     char    name[46];
 295 } QEMU_PACKED Qcow2Feature;
 296
 297 typedef struct Qcow2DiscardRegion {
 298     BlockDriverState *bs;
 299     uint64_t offset;
 300     uint64_t bytes;
 301     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 302 } Qcow2DiscardRegion;
 303
 304 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 305                                       uint64_t index);
 306 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 307                                   uint64_t index, uint64_t value);
 308
 309 typedef struct Qcow2BitmapHeaderExt {
 310     uint32_t nb_bitmaps;
 311     uint32_t reserved32;
 312     uint64_t bitmap_directory_size;
 313     uint64_t bitmap_directory_offset;
 314 } QEMU_PACKED Qcow2BitmapHeaderExt;
 315
 316 #define QCOW2_MAX_THREADS 4
 317
 318 typedef struct BDRVQcow2State {
 319     int cluster_bits;
 320     int cluster_size;
 321     int l2_slice_size;
 322     int subcluster_bits;
 323     int subcluster_size;
 324     int subclusters_per_cluster;
 325     int l2_bits;
 326     int l2_size;
 327     int l1_size;
 328     int l1_vm_state_index;
 329     int refcount_block_bits;
 330     int refcount_block_size;
 331     int csize_shift;
 332     int csize_mask;
 333     uint64_t cluster_offset_mask;
 334     uint64_t l1_table_offset;
 335     uint64_t *l1_table;
 336
 337     Qcow2Cache* l2_table_cache;
 338     Qcow2Cache* refcount_block_cache;
 339     QEMUTimer *cache_clean_timer;
 340     unsigned cache_clean_interval;
 341
 342     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 343
 344     uint64_t *refcount_table;
 345     uint64_t refcount_table_offset;
 346     uint32_t refcount_table_size;
 347     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 348     uint64_t free_cluster_index;
 349     uint64_t free_byte_offset;
 350
 351     CoMutex lock;
 352
 353     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 354     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 355     QCryptoBlock *crypto; /* Disk encryption format driver */
 356     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 357                                    for encryption initialization vector tweak */
 358     uint32_t crypt_method_header;
 359     uint64_t snapshots_offset;
 360     int snapshots_size;
 361     unsigned int nb_snapshots;
 362     QCowSnapshot *snapshots;
 363
 364     uint32_t nb_bitmaps;
 365     uint64_t bitmap_directory_size;
 366     uint64_t bitmap_directory_offset;
 367
 368     int flags;
 369     int qcow_version;
 370     bool use_lazy_refcounts;
 371     int refcount_order;
 372     int refcount_bits;
 373     uint64_t refcount_max;
 374
 375     Qcow2GetRefcountFunc *get_refcount;
 376     Qcow2SetRefcountFunc *set_refcount;
 377
 378     bool discard_passthrough[QCOW2_DISCARD_MAX];
 379
 380     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 381     bool signaled_corruption;
 382
 383     uint64_t incompatible_features;
 384     uint64_t compatible_features;
 385     uint64_t autoclear_features;
 386
 387     size_t unknown_header_fields_size;
 388     void* unknown_header_fields;
 389     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 390     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 391     bool cache_discards;
 392
 393     /* Backing file path and format as stored in the image (this is not the
 394      * effective path/format, which may be the result of a runtime option
 395      * override) */
 396     char *image_backing_file;
 397     char *image_backing_format;
 398     char *image_data_file;
 399
 400     CoQueue thread_task_queue;
 401     int nb_threads;
 402
 403     BdrvChild *data_file;
 404
 405     bool metadata_preallocation_checked;
 406     bool metadata_preallocation;
 407     /*
 408      * Compression type used for the image. Default: 0 - ZLIB
 409      * The image compression type is set on image creation.
 410      * For now, the only way to change the compression type
 411      * is to convert the image with the desired compression type set.
 412      */
 413     Qcow2CompressionType compression_type;
 414 } BDRVQcow2State;
 415
 416 typedef struct Qcow2COWRegion {
 417     /**
 418      * Offset of the COW region in bytes from the start of the first cluster
 419      * touched by the request.
 420      */
 421     unsigned    offset;
 422
 423     /** Number of bytes to copy */
 424     unsigned    nb_bytes;
 425 } Qcow2COWRegion;
 426
 427 /**
 428  * Describes an in-flight (part of a) write request that writes to clusters
 429  * that are not referenced in their L2 table yet.
 430  */
 431 typedef struct QCowL2Meta
 432 {
 433     /** Guest offset of the first newly allocated cluster */
 434     uint64_t offset;
 435
 436     /** Host offset of the first newly allocated cluster */
 437     uint64_t alloc_offset;
 438
 439     /** Number of newly allocated clusters */
 440     int nb_clusters;
 441
 442     /** Do not free the old clusters */
 443     bool keep_old_clusters;
 444
 445     /**
 446      * Requests that overlap with this allocation and wait to be restarted
 447      * when the allocating request has completed.
 448      */
 449     CoQueue dependent_requests;
 450
 451     /**
 452      * The COW Region between the start of the first allocated cluster and the
 453      * area the guest actually writes to.
 454      */
 455     Qcow2COWRegion cow_start;
 456
 457     /**
 458      * The COW Region between the area the guest actually writes to and the
 459      * end of the last allocated cluster.
 460      */
 461     Qcow2COWRegion cow_end;
 462
 463     /*
 464      * Indicates that COW regions are already handled and do not require
 465      * any more processing.
 466      */
 467     bool skip_cow;
 468
 469     /**
 470      * Indicates that this is not a normal write request but a preallocation.
 471      * If the image has extended L2 entries this means that no new individual
 472      * subclusters will be marked as allocated in the L2 bitmap (but any
 473      * existing contents of that bitmap will be kept).
 474      */
 475     bool prealloc;
 476
 477     /**
 478      * The I/O vector with the data from the actual guest write request.
 479      * If non-NULL, this is meant to be merged together with the data
 480      * from @cow_start and @cow_end into one single write operation.
 481      */
 482     QEMUIOVector *data_qiov;
 483     size_t data_qiov_offset;
 484
 485     /** Pointer to next L2Meta of the same write request */
 486     struct QCowL2Meta *next;
 487
 488     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 489 } QCowL2Meta;
 490
 491 /*
 492  * In images with standard L2 entries all clusters are treated as if
 493  * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
 494  * can be mapped to each other and have the exact same meaning
 495  * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
 496  *
 497  * In images with extended L2 entries QCow2ClusterType refers to the
 498  * complete cluster and QCow2SubclusterType to each of the individual
 499  * subclusters, so there are several possible combinations:
 500  *
 501  *     |--------------+---------------------------|
 502  *     | Cluster type | Possible subcluster types |
 503  *     |--------------+---------------------------|
 504  *     | UNALLOCATED  |         UNALLOCATED_PLAIN |
 505  *     |              |                ZERO_PLAIN |
 506  *     |--------------+---------------------------|
 507  *     | NORMAL       |         UNALLOCATED_ALLOC |
 508  *     |              |                ZERO_ALLOC |
 509  *     |              |                    NORMAL |
 510  *     |--------------+---------------------------|
 511  *     | COMPRESSED   |                COMPRESSED |
 512  *     |--------------+---------------------------|
 513  *
 514  * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
 515  * the image should be marked corrupt.
 516  */
 517
 518 typedef enum QCow2ClusterType {
 519     QCOW2_CLUSTER_UNALLOCATED,
 520     QCOW2_CLUSTER_ZERO_PLAIN,
 521     QCOW2_CLUSTER_ZERO_ALLOC,
 522     QCOW2_CLUSTER_NORMAL,
 523     QCOW2_CLUSTER_COMPRESSED,
 524 } QCow2ClusterType;
 525
 526 typedef enum QCow2SubclusterType {
 527     QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
 528     QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
 529     QCOW2_SUBCLUSTER_ZERO_PLAIN,
 530     QCOW2_SUBCLUSTER_ZERO_ALLOC,
 531     QCOW2_SUBCLUSTER_NORMAL,
 532     QCOW2_SUBCLUSTER_COMPRESSED,
 533     QCOW2_SUBCLUSTER_INVALID,
 534 } QCow2SubclusterType;
 535
 536 typedef enum QCow2MetadataOverlap {
 537     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 538     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 539     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 540     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 541     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 542     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 543     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 544     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 545     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 546
 547     QCOW2_OL_MAX_BITNR              = 9,
 548
 549     QCOW2_OL_NONE             = 0,
 550     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 551     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 552     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 553     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 554     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 555     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 556     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 557     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 558      * reads. */
 559     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 560     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 561 } QCow2MetadataOverlap;
 562
 563 /* Perform all overlap checks which can be done in constant time */
 564 #define QCOW2_OL_CONSTANT \
 565     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 566      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 567
 568 /* Perform all overlap checks which don't require disk access */
 569 #define QCOW2_OL_CACHED \
 570     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 571      QCOW2_OL_INACTIVE_L1)
 572
 573 /* Perform all overlap checks */
 574 #define QCOW2_OL_ALL \
 575     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 576
 577 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 578 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 579 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 580
 581 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 582
 583 #define INV_OFFSET (-1ULL)
 584
 585 static inline bool has_subclusters(BDRVQcow2State *s)
 586 {
 587     return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
 588 }
 589
 590 static inline size_t l2_entry_size(BDRVQcow2State *s)
 591 {
 592     return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
 593 }
 594
 595 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 596                                     int idx)
 597 {
 598     idx *= l2_entry_size(s) / sizeof(uint64_t);
 599     return be64_to_cpu(l2_slice[idx]);
 600 }
 601
 602 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 603                                      int idx)
 604 {
 605     if (has_subclusters(s)) {
 606         idx *= l2_entry_size(s) / sizeof(uint64_t);
 607         return be64_to_cpu(l2_slice[idx + 1]);
 608     } else {
 609         return 0; /* For convenience only; this value has no meaning. */
 610     }
 611 }
 612
 613 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 614                                 int idx, uint64_t entry)
 615 {
 616     idx *= l2_entry_size(s) / sizeof(uint64_t);
 617     l2_slice[idx] = cpu_to_be64(entry);
 618 }
 619
 620 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 621                                  int idx, uint64_t bitmap)
 622 {
 623     assert(has_subclusters(s));
 624     idx *= l2_entry_size(s) / sizeof(uint64_t);
 625     l2_slice[idx + 1] = cpu_to_be64(bitmap);
 626 }
 627
 628 static inline bool has_data_file(BlockDriverState *bs)
 629 {
 630     BDRVQcow2State *s = bs->opaque;
 631     return (s->data_file != bs->file);
 632 }
 633
 634 static inline bool data_file_is_raw(BlockDriverState *bs)
 635 {
 636     BDRVQcow2State *s = bs->opaque;
 637     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 638 }
 639
 640 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 641 {
 642     return offset & ~(s->cluster_size - 1);
 643 }
 644
 645 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 646 {
 647     return offset & (s->cluster_size - 1);
 648 }
 649
 650 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
 651 {
 652     return offset & (s->subcluster_size - 1);
 653 }
 654
 655 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 656 {
 657     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 658 }
 659
 660 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
 661 {
 662     return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
 663 }
 664
 665 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 666 {
 667     int shift = s->cluster_bits + s->l2_bits;
 668     return (size + (1ULL << shift) - 1) >> shift;
 669 }
 670
 671 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 672 {
 673     return offset >> (s->l2_bits + s->cluster_bits);
 674 }
 675
 676 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 677 {
 678     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 679 }
 680
 681 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 682 {
 683     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 684 }
 685
 686 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
 687 {
 688     return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
 689 }
 690
 691 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 692 {
 693     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 694 }
 695
 696 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 697                                                       uint64_t l2_entry)
 698 {
 699     BDRVQcow2State *s = bs->opaque;
 700
 701     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 702         return QCOW2_CLUSTER_COMPRESSED;
 703     } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
 704         if (l2_entry & L2E_OFFSET_MASK) {
 705             return QCOW2_CLUSTER_ZERO_ALLOC;
 706         }
 707         return QCOW2_CLUSTER_ZERO_PLAIN;
 708     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 709         /* Offset 0 generally means unallocated, but it is ambiguous with
 710          * external data files because 0 is a valid offset there. However, all
 711          * clusters in external data files always have refcount 1, so we can
 712          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 713         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 714             return QCOW2_CLUSTER_NORMAL;
 715         } else {
 716             return QCOW2_CLUSTER_UNALLOCATED;
 717         }
 718     } else {
 719         return QCOW2_CLUSTER_NORMAL;
 720     }
 721 }
 722
 723 /*
 724  * In an image without subsclusters @l2_bitmap is ignored and
 725  * @sc_index must be 0.
 726  * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
 727  * (this checks the whole entry and bitmap, not only the bits related
 728  * to subcluster @sc_index).
 729  */
 730 static inline
 731 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
 732                                               uint64_t l2_entry,
 733                                               uint64_t l2_bitmap,
 734                                               unsigned sc_index)
 735 {
 736     BDRVQcow2State *s = bs->opaque;
 737     QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
 738     assert(sc_index < s->subclusters_per_cluster);
 739
 740     if (has_subclusters(s)) {
 741         switch (type) {
 742         case QCOW2_CLUSTER_COMPRESSED:
 743             return QCOW2_SUBCLUSTER_COMPRESSED;
 744         case QCOW2_CLUSTER_NORMAL:
 745             if ((l2_bitmap >> 32) & l2_bitmap) {
 746                 return QCOW2_SUBCLUSTER_INVALID;
 747             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 748                 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 749             } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
 750                 return QCOW2_SUBCLUSTER_NORMAL;
 751             } else {
 752                 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
 753             }
 754         case QCOW2_CLUSTER_UNALLOCATED:
 755             if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
 756                 return QCOW2_SUBCLUSTER_INVALID;
 757             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 758                 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 759             } else {
 760                 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 761             }
 762         default:
 763             g_assert_not_reached();
 764         }
 765     } else {
 766         switch (type) {
 767         case QCOW2_CLUSTER_COMPRESSED:
 768             return QCOW2_SUBCLUSTER_COMPRESSED;
 769         case QCOW2_CLUSTER_ZERO_PLAIN:
 770             return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 771         case QCOW2_CLUSTER_ZERO_ALLOC:
 772             return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 773         case QCOW2_CLUSTER_NORMAL:
 774             return QCOW2_SUBCLUSTER_NORMAL;
 775         case QCOW2_CLUSTER_UNALLOCATED:
 776             return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 777         default:
 778             g_assert_not_reached();
 779         }
 780     }
 781 }
 782
 783 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
 784 {
 785     return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
 786             type == QCOW2_CLUSTER_ZERO_ALLOC);
 787 }
 788
 789 /* Check whether refcounts are eager or lazy */
 790 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 791 {
 792     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 793 }
 794
 795 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 796 {
 797     return m->offset + m->cow_start.offset;
 798 }
 799
 800 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 801 {
 802     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 803 }
 804
 805 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 806 {
 807     return r1 > r2 ? r1 - r2 : r2 - r1;
 808 }
 809
 810 static inline
 811 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 812 {
 813     return offset >> (s->refcount_block_bits + s->cluster_bits);
 814 }
 815
 816 /* qcow2.c functions */
 817 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 818                                      int refcount_order, bool generous_increase,
 819                                      uint64_t *refblock_count);
 820
 821 int qcow2_mark_dirty(BlockDriverState *bs);
 822 int qcow2_mark_corrupt(BlockDriverState *bs);
 823 int qcow2_mark_consistent(BlockDriverState *bs);
 824 int qcow2_update_header(BlockDriverState *bs);
 825
 826 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 827                              int64_t size, const char *message_format, ...)
 828                              GCC_FMT_ATTR(5, 6);
 829
 830 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 831                          uint64_t entries, size_t entry_len,
 832                          int64_t max_size_bytes, const char *table_name,
 833                          Error **errp);
 834
 835 /* qcow2-refcount.c functions */
 836 int qcow2_refcount_init(BlockDriverState *bs);
 837 void qcow2_refcount_close(BlockDriverState *bs);
 838
 839 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 840                        uint64_t *refcount);
 841
 842 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 843                                   uint64_t addend, bool decrease,
 844                                   enum qcow2_discard_type type);
 845
 846 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 847                             uint64_t additional_clusters, bool exact_size,
 848                             int new_refblock_index,
 849                             uint64_t new_refblock_offset);
 850
 851 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 852 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 853                                 int64_t nb_clusters);
 854 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 855 void qcow2_free_clusters(BlockDriverState *bs,
 856                           int64_t offset, int64_t size,
 857                           enum qcow2_discard_type type);
 858 void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
 859                              int nb_clusters, enum qcow2_discard_type type);
 860
 861 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 862     int64_t l1_table_offset, int l1_size, int addend);
 863
 864 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 865 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 866 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 867                           BdrvCheckMode fix);
 868
 869 void qcow2_process_discards(BlockDriverState *bs, int ret);
 870
 871 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 872                                  int64_t size);
 873 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 874                                   int64_t size, bool data_file);
 875 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 876                              void **refcount_table,
 877                              int64_t *refcount_table_size,
 878                              int64_t offset, int64_t size);
 879
 880 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 881                                 BlockDriverAmendStatusCB *status_cb,
 882                                 void *cb_opaque, Error **errp);
 883 int qcow2_shrink_reftable(BlockDriverState *bs);
 884 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 885 int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
 886
 887 /* qcow2-cluster.c functions */
 888 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 889                         bool exact_size);
 890 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 891 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 892 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 893                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 894
 895 int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
 896                           unsigned int *bytes, uint64_t *host_offset,
 897                           QCow2SubclusterType *subcluster_type);
 898 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 899                                unsigned int *bytes, uint64_t *host_offset,
 900                                QCowL2Meta **m);
 901 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 902                                           uint64_t offset,
 903                                           int compressed_size,
 904                                           uint64_t *host_offset);
 905
 906 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 907 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 908 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 909                           uint64_t bytes, enum qcow2_discard_type type,
 910                           bool full_discard);
 911 int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset,
 912                              uint64_t bytes, int flags);
 913
 914 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 915                                BlockDriverAmendStatusCB *status_cb,
 916                                void *cb_opaque);
 917
 918 /* qcow2-snapshot.c functions */
 919 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 920 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 921 int qcow2_snapshot_delete(BlockDriverState *bs,
 922                           const char *snapshot_id,
 923                           const char *name,
 924                           Error **errp);
 925 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 926 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 927                             const char *snapshot_id,
 928                             const char *name,
 929                             Error **errp);
 930
 931 void qcow2_free_snapshots(BlockDriverState *bs);
 932 int qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
 933 int qcow2_write_snapshots(BlockDriverState *bs);
 934
 935 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
 936                                                  BdrvCheckResult *result,
 937                                                  BdrvCheckMode fix);
 938 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
 939                                                 BdrvCheckResult *result,
 940                                                 BdrvCheckMode fix);
 941
 942 /* qcow2-cache.c functions */
 943 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 944                                unsigned table_size);
 945 int qcow2_cache_destroy(Qcow2Cache *c);
 946
 947 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 948 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 949 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 950 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 951     Qcow2Cache *dependency);
 952 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 953
 954 void qcow2_cache_clean_unused(Qcow2Cache *c);
 955 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 956
 957 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 958     void **table);
 959 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 960     void **table);
 961 void qcow2_cache_put(Qcow2Cache *c, void **table);
 962 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 963 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 964
 965 /* qcow2-bitmap.c functions */
 966 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 967                                   void **refcount_table,
 968                                   int64_t *refcount_table_size);
 969 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 970 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
 971                                                 Error **errp);
 972 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 973 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
 974 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
 975                                           bool release_stored, Error **errp);
 976 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 977 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
 978                                          const char *name,
 979                                          uint32_t granularity,
 980                                          Error **errp);
 981 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 982                                             const char *name,
 983                                             Error **errp);
 984 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
 985 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
 986                                                 uint32_t cluster_size);
 987
 988 ssize_t coroutine_fn
 989 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
 990                   const void *src, size_t src_size);
 991 ssize_t coroutine_fn
 992 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
 993                     const void *src, size_t src_size);
 994 int coroutine_fn
 995 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
 996                  uint64_t guest_offset, void *buf, size_t len);
 997 int coroutine_fn
 998 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
 999                  uint64_t guest_offset, void *buf, size_t len);
1000
1001 #endif