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 /* 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 } QCowSnapshotExtraData;
 210
 211
 212 typedef struct QCowSnapshot {
 213     uint64_t l1_table_offset;
 214     uint32_t l1_size;
 215     char *id_str;
 216     char *name;
 217     uint64_t disk_size;
 218     uint64_t vm_state_size;
 219     uint32_t date_sec;
 220     uint32_t date_nsec;
 221     uint64_t vm_clock_nsec;
 222     /* Size of all extra data, including QCowSnapshotExtraData if available */
 223     uint32_t extra_data_size;
 224     /* Data beyond QCowSnapshotExtraData, if any */
 225     void *unknown_extra_data;
 226 } QCowSnapshot;
 227
 228 struct Qcow2Cache;
 229 typedef struct Qcow2Cache Qcow2Cache;
 230
 231 typedef struct Qcow2CryptoHeaderExtension {
 232     uint64_t offset;
 233     uint64_t length;
 234 } QEMU_PACKED Qcow2CryptoHeaderExtension;
 235
 236 typedef struct Qcow2UnknownHeaderExtension {
 237     uint32_t magic;
 238     uint32_t len;
 239     QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
 240     uint8_t data[];
 241 } Qcow2UnknownHeaderExtension;
 242
 243 enum {
 244     QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
 245     QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
 246     QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
 247 };
 248
 249 /* Incompatible feature bits */
 250 enum {
 251     QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
 252     QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
 253     QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
 254     QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
 255     QCOW2_INCOMPAT_EXTL2_BITNR      = 4,
 256     QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
 257     QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
 258     QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
 259     QCOW2_INCOMPAT_COMPRESSION      = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
 260     QCOW2_INCOMPAT_EXTL2            = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
 261
 262     QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
 263                                     | QCOW2_INCOMPAT_CORRUPT
 264                                     | QCOW2_INCOMPAT_DATA_FILE
 265                                     | QCOW2_INCOMPAT_COMPRESSION
 266                                     | QCOW2_INCOMPAT_EXTL2,
 267 };
 268
 269 /* Compatible feature bits */
 270 enum {
 271     QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
 272     QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
 273
 274     QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
 275 };
 276
 277 /* Autoclear feature bits */
 278 enum {
 279     QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
 280     QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
 281     QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
 282     QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
 283
 284     QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
 285                                         | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
 286 };
 287
 288 enum qcow2_discard_type {
 289     QCOW2_DISCARD_NEVER = 0,
 290     QCOW2_DISCARD_ALWAYS,
 291     QCOW2_DISCARD_REQUEST,
 292     QCOW2_DISCARD_SNAPSHOT,
 293     QCOW2_DISCARD_OTHER,
 294     QCOW2_DISCARD_MAX
 295 };
 296
 297 typedef struct Qcow2Feature {
 298     uint8_t type;
 299     uint8_t bit;
 300     char    name[46];
 301 } QEMU_PACKED Qcow2Feature;
 302
 303 typedef struct Qcow2DiscardRegion {
 304     BlockDriverState *bs;
 305     uint64_t offset;
 306     uint64_t bytes;
 307     QTAILQ_ENTRY(Qcow2DiscardRegion) next;
 308 } Qcow2DiscardRegion;
 309
 310 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
 311                                       uint64_t index);
 312 typedef void Qcow2SetRefcountFunc(void *refcount_array,
 313                                   uint64_t index, uint64_t value);
 314
 315 typedef struct Qcow2BitmapHeaderExt {
 316     uint32_t nb_bitmaps;
 317     uint32_t reserved32;
 318     uint64_t bitmap_directory_size;
 319     uint64_t bitmap_directory_offset;
 320 } QEMU_PACKED Qcow2BitmapHeaderExt;
 321
 322 #define QCOW2_MAX_THREADS 4
 323
 324 typedef struct BDRVQcow2State {
 325     int cluster_bits;
 326     int cluster_size;
 327     int l2_slice_size;
 328     int subcluster_bits;
 329     int subcluster_size;
 330     int subclusters_per_cluster;
 331     int l2_bits;
 332     int l2_size;
 333     int l1_size;
 334     int l1_vm_state_index;
 335     int refcount_block_bits;
 336     int refcount_block_size;
 337     int csize_shift;
 338     int csize_mask;
 339     uint64_t cluster_offset_mask;
 340     uint64_t l1_table_offset;
 341     uint64_t *l1_table;
 342
 343     Qcow2Cache* l2_table_cache;
 344     Qcow2Cache* refcount_block_cache;
 345     QEMUTimer *cache_clean_timer;
 346     unsigned cache_clean_interval;
 347
 348     QLIST_HEAD(, QCowL2Meta) cluster_allocs;
 349
 350     uint64_t *refcount_table;
 351     uint64_t refcount_table_offset;
 352     uint32_t refcount_table_size;
 353     uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
 354     uint64_t free_cluster_index;
 355     uint64_t free_byte_offset;
 356
 357     CoMutex lock;
 358
 359     Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
 360     QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
 361     QCryptoBlock *crypto; /* Disk encryption format driver */
 362     bool crypt_physical_offset; /* Whether to use virtual or physical offset
 363                                    for encryption initialization vector tweak */
 364     uint32_t crypt_method_header;
 365     uint64_t snapshots_offset;
 366     int snapshots_size;
 367     unsigned int nb_snapshots;
 368     QCowSnapshot *snapshots;
 369
 370     uint32_t nb_bitmaps;
 371     uint64_t bitmap_directory_size;
 372     uint64_t bitmap_directory_offset;
 373
 374     int flags;
 375     int qcow_version;
 376     bool use_lazy_refcounts;
 377     int refcount_order;
 378     int refcount_bits;
 379     uint64_t refcount_max;
 380
 381     Qcow2GetRefcountFunc *get_refcount;
 382     Qcow2SetRefcountFunc *set_refcount;
 383
 384     bool discard_passthrough[QCOW2_DISCARD_MAX];
 385
 386     int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
 387     bool signaled_corruption;
 388
 389     uint64_t incompatible_features;
 390     uint64_t compatible_features;
 391     uint64_t autoclear_features;
 392
 393     size_t unknown_header_fields_size;
 394     void* unknown_header_fields;
 395     QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
 396     QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
 397     bool cache_discards;
 398
 399     /* Backing file path and format as stored in the image (this is not the
 400      * effective path/format, which may be the result of a runtime option
 401      * override) */
 402     char *image_backing_file;
 403     char *image_backing_format;
 404     char *image_data_file;
 405
 406     CoQueue thread_task_queue;
 407     int nb_threads;
 408
 409     BdrvChild *data_file;
 410
 411     bool metadata_preallocation_checked;
 412     bool metadata_preallocation;
 413     /*
 414      * Compression type used for the image. Default: 0 - ZLIB
 415      * The image compression type is set on image creation.
 416      * For now, the only way to change the compression type
 417      * is to convert the image with the desired compression type set.
 418      */
 419     Qcow2CompressionType compression_type;
 420 } BDRVQcow2State;
 421
 422 typedef struct Qcow2COWRegion {
 423     /**
 424      * Offset of the COW region in bytes from the start of the first cluster
 425      * touched by the request.
 426      */
 427     unsigned    offset;
 428
 429     /** Number of bytes to copy */
 430     unsigned    nb_bytes;
 431 } Qcow2COWRegion;
 432
 433 /**
 434  * Describes an in-flight (part of a) write request that writes to clusters
 435  * that are not referenced in their L2 table yet.
 436  */
 437 typedef struct QCowL2Meta
 438 {
 439     /** Guest offset of the first newly allocated cluster */
 440     uint64_t offset;
 441
 442     /** Host offset of the first newly allocated cluster */
 443     uint64_t alloc_offset;
 444
 445     /** Number of newly allocated clusters */
 446     int nb_clusters;
 447
 448     /** Do not free the old clusters */
 449     bool keep_old_clusters;
 450
 451     /**
 452      * Requests that overlap with this allocation and wait to be restarted
 453      * when the allocating request has completed.
 454      */
 455     CoQueue dependent_requests;
 456
 457     /**
 458      * The COW Region between the start of the first allocated cluster and the
 459      * area the guest actually writes to.
 460      */
 461     Qcow2COWRegion cow_start;
 462
 463     /**
 464      * The COW Region between the area the guest actually writes to and the
 465      * end of the last allocated cluster.
 466      */
 467     Qcow2COWRegion cow_end;
 468
 469     /*
 470      * Indicates that COW regions are already handled and do not require
 471      * any more processing.
 472      */
 473     bool skip_cow;
 474
 475     /**
 476      * Indicates that this is not a normal write request but a preallocation.
 477      * If the image has extended L2 entries this means that no new individual
 478      * subclusters will be marked as allocated in the L2 bitmap (but any
 479      * existing contents of that bitmap will be kept).
 480      */
 481     bool prealloc;
 482
 483     /**
 484      * The I/O vector with the data from the actual guest write request.
 485      * If non-NULL, this is meant to be merged together with the data
 486      * from @cow_start and @cow_end into one single write operation.
 487      */
 488     QEMUIOVector *data_qiov;
 489     size_t data_qiov_offset;
 490
 491     /** Pointer to next L2Meta of the same write request */
 492     struct QCowL2Meta *next;
 493
 494     QLIST_ENTRY(QCowL2Meta) next_in_flight;
 495 } QCowL2Meta;
 496
 497 /*
 498  * In images with standard L2 entries all clusters are treated as if
 499  * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
 500  * can be mapped to each other and have the exact same meaning
 501  * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
 502  *
 503  * In images with extended L2 entries QCow2ClusterType refers to the
 504  * complete cluster and QCow2SubclusterType to each of the individual
 505  * subclusters, so there are several possible combinations:
 506  *
 507  *     |--------------+---------------------------|
 508  *     | Cluster type | Possible subcluster types |
 509  *     |--------------+---------------------------|
 510  *     | UNALLOCATED  |         UNALLOCATED_PLAIN |
 511  *     |              |                ZERO_PLAIN |
 512  *     |--------------+---------------------------|
 513  *     | NORMAL       |         UNALLOCATED_ALLOC |
 514  *     |              |                ZERO_ALLOC |
 515  *     |              |                    NORMAL |
 516  *     |--------------+---------------------------|
 517  *     | COMPRESSED   |                COMPRESSED |
 518  *     |--------------+---------------------------|
 519  *
 520  * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
 521  * the image should be marked corrupt.
 522  */
 523
 524 typedef enum QCow2ClusterType {
 525     QCOW2_CLUSTER_UNALLOCATED,
 526     QCOW2_CLUSTER_ZERO_PLAIN,
 527     QCOW2_CLUSTER_ZERO_ALLOC,
 528     QCOW2_CLUSTER_NORMAL,
 529     QCOW2_CLUSTER_COMPRESSED,
 530 } QCow2ClusterType;
 531
 532 typedef enum QCow2SubclusterType {
 533     QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
 534     QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
 535     QCOW2_SUBCLUSTER_ZERO_PLAIN,
 536     QCOW2_SUBCLUSTER_ZERO_ALLOC,
 537     QCOW2_SUBCLUSTER_NORMAL,
 538     QCOW2_SUBCLUSTER_COMPRESSED,
 539     QCOW2_SUBCLUSTER_INVALID,
 540 } QCow2SubclusterType;
 541
 542 typedef enum QCow2MetadataOverlap {
 543     QCOW2_OL_MAIN_HEADER_BITNR      = 0,
 544     QCOW2_OL_ACTIVE_L1_BITNR        = 1,
 545     QCOW2_OL_ACTIVE_L2_BITNR        = 2,
 546     QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
 547     QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
 548     QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
 549     QCOW2_OL_INACTIVE_L1_BITNR      = 6,
 550     QCOW2_OL_INACTIVE_L2_BITNR      = 7,
 551     QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
 552
 553     QCOW2_OL_MAX_BITNR              = 9,
 554
 555     QCOW2_OL_NONE             = 0,
 556     QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
 557     QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
 558     QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
 559     QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
 560     QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
 561     QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
 562     QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
 563     /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
 564      * reads. */
 565     QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
 566     QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
 567 } QCow2MetadataOverlap;
 568
 569 /* Perform all overlap checks which can be done in constant time */
 570 #define QCOW2_OL_CONSTANT \
 571     (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
 572      QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
 573
 574 /* Perform all overlap checks which don't require disk access */
 575 #define QCOW2_OL_CACHED \
 576     (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
 577      QCOW2_OL_INACTIVE_L1)
 578
 579 /* Perform all overlap checks */
 580 #define QCOW2_OL_ALL \
 581     (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
 582
 583 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
 584 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 585 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
 586
 587 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
 588
 589 #define INV_OFFSET (-1ULL)
 590
 591 static inline bool has_subclusters(BDRVQcow2State *s)
 592 {
 593     return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
 594 }
 595
 596 static inline size_t l2_entry_size(BDRVQcow2State *s)
 597 {
 598     return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
 599 }
 600
 601 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 602                                     int idx)
 603 {
 604     idx *= l2_entry_size(s) / sizeof(uint64_t);
 605     return be64_to_cpu(l2_slice[idx]);
 606 }
 607
 608 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 609                                      int idx)
 610 {
 611     if (has_subclusters(s)) {
 612         idx *= l2_entry_size(s) / sizeof(uint64_t);
 613         return be64_to_cpu(l2_slice[idx + 1]);
 614     } else {
 615         return 0; /* For convenience only; this value has no meaning. */
 616     }
 617 }
 618
 619 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
 620                                 int idx, uint64_t entry)
 621 {
 622     idx *= l2_entry_size(s) / sizeof(uint64_t);
 623     l2_slice[idx] = cpu_to_be64(entry);
 624 }
 625
 626 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
 627                                  int idx, uint64_t bitmap)
 628 {
 629     assert(has_subclusters(s));
 630     idx *= l2_entry_size(s) / sizeof(uint64_t);
 631     l2_slice[idx + 1] = cpu_to_be64(bitmap);
 632 }
 633
 634 static inline bool has_data_file(BlockDriverState *bs)
 635 {
 636     BDRVQcow2State *s = bs->opaque;
 637     return (s->data_file != bs->file);
 638 }
 639
 640 static inline bool data_file_is_raw(BlockDriverState *bs)
 641 {
 642     BDRVQcow2State *s = bs->opaque;
 643     return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
 644 }
 645
 646 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 647 {
 648     return offset & ~(s->cluster_size - 1);
 649 }
 650
 651 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
 652 {
 653     return offset & (s->cluster_size - 1);
 654 }
 655
 656 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
 657 {
 658     return offset & (s->subcluster_size - 1);
 659 }
 660
 661 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
 662 {
 663     return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 664 }
 665
 666 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
 667 {
 668     return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
 669 }
 670
 671 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
 672 {
 673     int shift = s->cluster_bits + s->l2_bits;
 674     return (size + (1ULL << shift) - 1) >> shift;
 675 }
 676
 677 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
 678 {
 679     return offset >> (s->l2_bits + s->cluster_bits);
 680 }
 681
 682 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
 683 {
 684     return (offset >> s->cluster_bits) & (s->l2_size - 1);
 685 }
 686
 687 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
 688 {
 689     return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
 690 }
 691
 692 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
 693 {
 694     return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
 695 }
 696
 697 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
 698 {
 699     return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
 700 }
 701
 702 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 703                                                       uint64_t l2_entry)
 704 {
 705     BDRVQcow2State *s = bs->opaque;
 706
 707     if (l2_entry & QCOW_OFLAG_COMPRESSED) {
 708         return QCOW2_CLUSTER_COMPRESSED;
 709     } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
 710         if (l2_entry & L2E_OFFSET_MASK) {
 711             return QCOW2_CLUSTER_ZERO_ALLOC;
 712         }
 713         return QCOW2_CLUSTER_ZERO_PLAIN;
 714     } else if (!(l2_entry & L2E_OFFSET_MASK)) {
 715         /* Offset 0 generally means unallocated, but it is ambiguous with
 716          * external data files because 0 is a valid offset there. However, all
 717          * clusters in external data files always have refcount 1, so we can
 718          * rely on QCOW_OFLAG_COPIED to disambiguate. */
 719         if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
 720             return QCOW2_CLUSTER_NORMAL;
 721         } else {
 722             return QCOW2_CLUSTER_UNALLOCATED;
 723         }
 724     } else {
 725         return QCOW2_CLUSTER_NORMAL;
 726     }
 727 }
 728
 729 /*
 730  * In an image without subsclusters @l2_bitmap is ignored and
 731  * @sc_index must be 0.
 732  * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
 733  * (this checks the whole entry and bitmap, not only the bits related
 734  * to subcluster @sc_index).
 735  */
 736 static inline
 737 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
 738                                               uint64_t l2_entry,
 739                                               uint64_t l2_bitmap,
 740                                               unsigned sc_index)
 741 {
 742     BDRVQcow2State *s = bs->opaque;
 743     QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
 744     assert(sc_index < s->subclusters_per_cluster);
 745
 746     if (has_subclusters(s)) {
 747         switch (type) {
 748         case QCOW2_CLUSTER_COMPRESSED:
 749             return QCOW2_SUBCLUSTER_COMPRESSED;
 750         case QCOW2_CLUSTER_NORMAL:
 751             if ((l2_bitmap >> 32) & l2_bitmap) {
 752                 return QCOW2_SUBCLUSTER_INVALID;
 753             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 754                 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 755             } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
 756                 return QCOW2_SUBCLUSTER_NORMAL;
 757             } else {
 758                 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
 759             }
 760         case QCOW2_CLUSTER_UNALLOCATED:
 761             if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
 762                 return QCOW2_SUBCLUSTER_INVALID;
 763             } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
 764                 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 765             } else {
 766                 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 767             }
 768         default:
 769             g_assert_not_reached();
 770         }
 771     } else {
 772         switch (type) {
 773         case QCOW2_CLUSTER_COMPRESSED:
 774             return QCOW2_SUBCLUSTER_COMPRESSED;
 775         case QCOW2_CLUSTER_ZERO_PLAIN:
 776             return QCOW2_SUBCLUSTER_ZERO_PLAIN;
 777         case QCOW2_CLUSTER_ZERO_ALLOC:
 778             return QCOW2_SUBCLUSTER_ZERO_ALLOC;
 779         case QCOW2_CLUSTER_NORMAL:
 780             return QCOW2_SUBCLUSTER_NORMAL;
 781         case QCOW2_CLUSTER_UNALLOCATED:
 782             return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
 783         default:
 784             g_assert_not_reached();
 785         }
 786     }
 787 }
 788
 789 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
 790 {
 791     return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
 792             type == QCOW2_CLUSTER_ZERO_ALLOC);
 793 }
 794
 795 /* Check whether refcounts are eager or lazy */
 796 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
 797 {
 798     return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
 799 }
 800
 801 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
 802 {
 803     return m->offset + m->cow_start.offset;
 804 }
 805
 806 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 807 {
 808     return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
 809 }
 810
 811 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
 812 {
 813     return r1 > r2 ? r1 - r2 : r2 - r1;
 814 }
 815
 816 static inline
 817 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
 818 {
 819     return offset >> (s->refcount_block_bits + s->cluster_bits);
 820 }
 821
 822 /* qcow2.c functions */
 823 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
 824                                      int refcount_order, bool generous_increase,
 825                                      uint64_t *refblock_count);
 826
 827 int qcow2_mark_dirty(BlockDriverState *bs);
 828 int qcow2_mark_corrupt(BlockDriverState *bs);
 829 int qcow2_mark_consistent(BlockDriverState *bs);
 830 int qcow2_update_header(BlockDriverState *bs);
 831
 832 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
 833                              int64_t size, const char *message_format, ...)
 834                              GCC_FMT_ATTR(5, 6);
 835
 836 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
 837                          uint64_t entries, size_t entry_len,
 838                          int64_t max_size_bytes, const char *table_name,
 839                          Error **errp);
 840
 841 /* qcow2-refcount.c functions */
 842 int qcow2_refcount_init(BlockDriverState *bs);
 843 void qcow2_refcount_close(BlockDriverState *bs);
 844
 845 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
 846                        uint64_t *refcount);
 847
 848 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
 849                                   uint64_t addend, bool decrease,
 850                                   enum qcow2_discard_type type);
 851
 852 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
 853                             uint64_t additional_clusters, bool exact_size,
 854                             int new_refblock_index,
 855                             uint64_t new_refblock_offset);
 856
 857 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 858 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
 859                                 int64_t nb_clusters);
 860 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 861 void qcow2_free_clusters(BlockDriverState *bs,
 862                           int64_t offset, int64_t size,
 863                           enum qcow2_discard_type type);
 864 void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
 865                             enum qcow2_discard_type type);
 866
 867 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 868     int64_t l1_table_offset, int l1_size, int addend);
 869
 870 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
 871 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
 872 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 873                           BdrvCheckMode fix);
 874
 875 void qcow2_process_discards(BlockDriverState *bs, int ret);
 876
 877 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
 878                                  int64_t size);
 879 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
 880                                   int64_t size, bool data_file);
 881 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
 882                              void **refcount_table,
 883                              int64_t *refcount_table_size,
 884                              int64_t offset, int64_t size);
 885
 886 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
 887                                 BlockDriverAmendStatusCB *status_cb,
 888                                 void *cb_opaque, Error **errp);
 889 int qcow2_shrink_reftable(BlockDriverState *bs);
 890 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
 891 int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
 892
 893 /* qcow2-cluster.c functions */
 894 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
 895                         bool exact_size);
 896 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
 897 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
 898 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
 899                           uint8_t *buf, int nb_sectors, bool enc, Error **errp);
 900
 901 int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
 902                           unsigned int *bytes, uint64_t *host_offset,
 903                           QCow2SubclusterType *subcluster_type);
 904 int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
 905                             unsigned int *bytes, uint64_t *host_offset,
 906                             QCowL2Meta **m);
 907 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 908                                           uint64_t offset,
 909                                           int compressed_size,
 910                                           uint64_t *host_offset);
 911
 912 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 913 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
 914 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
 915                           uint64_t bytes, enum qcow2_discard_type type,
 916                           bool full_discard);
 917 int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset,
 918                              uint64_t bytes, int flags);
 919
 920 int qcow2_expand_zero_clusters(BlockDriverState *bs,
 921                                BlockDriverAmendStatusCB *status_cb,
 922                                void *cb_opaque);
 923
 924 /* qcow2-snapshot.c functions */
 925 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 926 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 927 int qcow2_snapshot_delete(BlockDriverState *bs,
 928                           const char *snapshot_id,
 929                           const char *name,
 930                           Error **errp);
 931 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 932 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
 933                             const char *snapshot_id,
 934                             const char *name,
 935                             Error **errp);
 936
 937 void qcow2_free_snapshots(BlockDriverState *bs);
 938 int qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
 939 int qcow2_write_snapshots(BlockDriverState *bs);
 940
 941 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
 942                                                  BdrvCheckResult *result,
 943                                                  BdrvCheckMode fix);
 944 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
 945                                                 BdrvCheckResult *result,
 946                                                 BdrvCheckMode fix);
 947
 948 /* qcow2-cache.c functions */
 949 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
 950                                unsigned table_size);
 951 int qcow2_cache_destroy(Qcow2Cache *c);
 952
 953 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
 954 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
 955 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
 956 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
 957     Qcow2Cache *dependency);
 958 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 959
 960 void qcow2_cache_clean_unused(Qcow2Cache *c);
 961 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 962
 963 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 964     void **table);
 965 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
 966     void **table);
 967 void qcow2_cache_put(Qcow2Cache *c, void **table);
 968 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
 969 void qcow2_cache_discard(Qcow2Cache *c, void *table);
 970
 971 /* qcow2-bitmap.c functions */
 972 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
 973                                   void **refcount_table,
 974                                   int64_t *refcount_table_size);
 975 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
 976 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
 977                                                 Error **errp);
 978 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
 979 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
 980 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
 981                                           bool release_stored, Error **errp);
 982 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
 983 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
 984                                          const char *name,
 985                                          uint32_t granularity,
 986                                          Error **errp);
 987 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 988                                             const char *name,
 989                                             Error **errp);
 990 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
 991 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
 992                                                 uint32_t cluster_size);
 993
 994 ssize_t coroutine_fn
 995 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
 996                   const void *src, size_t src_size);
 997 ssize_t coroutine_fn
 998 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
 999                     const void *src, size_t src_size);
1000 int coroutine_fn
1001 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
1002                  uint64_t guest_offset, void *buf, size_t len);
1003 int coroutine_fn
1004 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
1005                  uint64_t guest_offset, void *buf, size_t len);
1006
1007 #endif