aboutsummaryrefslogtreecommitdiff
path: root/block/qcow2.h
blob: f789ce3ae0ffb8047507f5f515c54beb8cafa840 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
/*
 * Block driver for the QCOW version 2 format
 *
 * Copyright (c) 2004-2006 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef BLOCK_QCOW2_H
#define BLOCK_QCOW2_H

#include "crypto/block.h"
#include "qemu/coroutine.h"
#include "qemu/units.h"
#include "block/block_int.h"

//#define DEBUG_ALLOC
//#define DEBUG_ALLOC2
//#define DEBUG_EXT

#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)

#define QCOW_CRYPT_NONE 0
#define QCOW_CRYPT_AES  1
#define QCOW_CRYPT_LUKS 2

#define QCOW_MAX_CRYPT_CLUSTERS 32
#define QCOW_MAX_SNAPSHOTS 65536

/* Field widths in qcow2 mean normal cluster offsets cannot reach
 * 64PB; depending on cluster size, compressed clusters can have a
 * smaller limit (64PB for up to 16k clusters, then ramps down to
 * 512TB for 2M clusters).  */
#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)

/* 8 MB refcount table is enough for 2 PB images at 64k cluster size
 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
#define QCOW_MAX_REFTABLE_SIZE (8 * MiB)

/* 32 MB L1 table is enough for 2 PB images at 64k cluster size
 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
#define QCOW_MAX_L1_SIZE (32 * MiB)

/* Allow for an average of 1k per snapshot table entry, should be plenty of
 * space for snapshot names and IDs */
#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)

/* Maximum amount of extra data per snapshot table entry to accept */
#define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024

/* Bitmap header extension constraints */
#define QCOW2_MAX_BITMAPS 65535
#define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)

/* Maximum of parallel sub-request per guest request */
#define QCOW2_MAX_WORKERS 8

/* indicate that the refcount of the referenced cluster is exactly one. */
#define QCOW_OFLAG_COPIED     (1ULL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
#define QCOW_OFLAG_COMPRESSED (1ULL << 62)
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0)

#define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32

/* The subcluster X [0..31] is allocated */
#define QCOW_OFLAG_SUB_ALLOC(X)   (1ULL << (X))
/* The subcluster X [0..31] reads as zeroes */
#define QCOW_OFLAG_SUB_ZERO(X)    (QCOW_OFLAG_SUB_ALLOC(X) << 32)
/* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */
#define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \
    (QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X))
/* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */
#define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \
    (QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32)
/* L2 entry bitmap with all allocation bits set */
#define QCOW_L2_BITMAP_ALL_ALLOC  (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32))
/* L2 entry bitmap with all "read as zeroes" bits set */
#define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32))

/* Size of normal and extended L2 entries */
#define L2E_SIZE_NORMAL   (sizeof(uint64_t))
#define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2)

/* Size of L1 table entries */
#define L1E_SIZE (sizeof(uint64_t))

/* Size of reftable entries */
#define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))

#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21

/* Defined in the qcow2 spec (compressed cluster descriptor) */
#define QCOW2_COMPRESSED_SECTOR_SIZE 512U

/* Must be at least 2 to cover COW */
#define MIN_L2_CACHE_SIZE 2 /* cache entries */

/* Must be at least 4 to cover all cases of refcount table growth */
#define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */

#ifdef CONFIG_LINUX
#define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
#define DEFAULT_CACHE_CLEAN_INTERVAL 600  /* seconds */
#else
#define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
/* Cache clean interval is currently available only on Linux, so must be 0 */
#define DEFAULT_CACHE_CLEAN_INTERVAL 0
#endif

#define DEFAULT_CLUSTER_SIZE 65536

#define QCOW2_OPT_DATA_FILE "data-file"
#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
#define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
#define QCOW2_OPT_DISCARD_NO_UNREF "discard-no-unref"
#define QCOW2_OPT_OVERLAP "overlap-check"
#define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
#define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
#define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
#define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
#define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
#define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
#define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
#define QCOW2_OPT_CACHE_SIZE "cache-size"
#define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
#define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
#define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
#define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"

typedef struct QCowHeader {
    uint32_t magic;
    uint32_t version;
    uint64_t backing_file_offset;
    uint32_t backing_file_size;
    uint32_t cluster_bits;
    uint64_t size; /* in bytes */
    uint32_t crypt_method;
    uint32_t l1_size; /* XXX: save number of clusters instead ? */
    uint64_t l1_table_offset;
    uint64_t refcount_table_offset;
    uint32_t refcount_table_clusters;
    uint32_t nb_snapshots;
    uint64_t snapshots_offset;

    /* The following fields are only valid for version >= 3 */
    uint64_t incompatible_features;
    uint64_t compatible_features;
    uint64_t autoclear_features;

    uint32_t refcount_order;
    uint32_t header_length;

    /* Additional fields */
    uint8_t compression_type;

    /* header must be a multiple of 8 */
    uint8_t padding[7];
} QEMU_PACKED QCowHeader;

QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));

typedef struct QEMU_PACKED QCowSnapshotHeader {
    /* header is 8 byte aligned */
    uint64_t l1_table_offset;

    uint32_t l1_size;
    uint16_t id_str_size;
    uint16_t name_size;

    uint32_t date_sec;
    uint32_t date_nsec;

    uint64_t vm_clock_nsec;

    uint32_t vm_state_size;
    uint32_t extra_data_size; /* for extension */
    /* extra data follows */
    /* id_str follows */
    /* name follows  */
} QCowSnapshotHeader;

typedef struct QEMU_PACKED QCowSnapshotExtraData {
    uint64_t vm_state_size_large;
    uint64_t disk_size;
    uint64_t icount;
} QCowSnapshotExtraData;


typedef struct QCowSnapshot {
    uint64_t l1_table_offset;
    uint32_t l1_size;
    char *id_str;
    char *name;
    uint64_t disk_size;
    uint64_t vm_state_size;
    uint32_t date_sec;
    uint32_t date_nsec;
    uint64_t vm_clock_nsec;
    /* icount value for the moment when snapshot was taken */
    uint64_t icount;
    /* Size of all extra data, including QCowSnapshotExtraData if available */
    uint32_t extra_data_size;
    /* Data beyond QCowSnapshotExtraData, if any */
    void *unknown_extra_data;
} QCowSnapshot;

struct Qcow2Cache;
typedef struct Qcow2Cache Qcow2Cache;

typedef struct Qcow2CryptoHeaderExtension {
    uint64_t offset;
    uint64_t length;
} QEMU_PACKED Qcow2CryptoHeaderExtension;

typedef struct Qcow2UnknownHeaderExtension {
    uint32_t magic;
    uint32_t len;
    QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
    uint8_t data[];
} Qcow2UnknownHeaderExtension;

enum {
    QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
    QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
    QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
};

/* Incompatible feature bits */
enum {
    QCOW2_INCOMPAT_DIRTY_BITNR      = 0,
    QCOW2_INCOMPAT_CORRUPT_BITNR    = 1,
    QCOW2_INCOMPAT_DATA_FILE_BITNR  = 2,
    QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
    QCOW2_INCOMPAT_EXTL2_BITNR      = 4,
    QCOW2_INCOMPAT_DIRTY            = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
    QCOW2_INCOMPAT_CORRUPT          = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
    QCOW2_INCOMPAT_DATA_FILE        = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
    QCOW2_INCOMPAT_COMPRESSION      = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
    QCOW2_INCOMPAT_EXTL2            = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,

    QCOW2_INCOMPAT_MASK             = QCOW2_INCOMPAT_DIRTY
                                    | QCOW2_INCOMPAT_CORRUPT
                                    | QCOW2_INCOMPAT_DATA_FILE
                                    | QCOW2_INCOMPAT_COMPRESSION
                                    | QCOW2_INCOMPAT_EXTL2,
};

/* Compatible feature bits */
enum {
    QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
    QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,

    QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
};

/* Autoclear feature bits */
enum {
    QCOW2_AUTOCLEAR_BITMAPS_BITNR       = 0,
    QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
    QCOW2_AUTOCLEAR_BITMAPS             = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
    QCOW2_AUTOCLEAR_DATA_FILE_RAW       = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,

    QCOW2_AUTOCLEAR_MASK                = QCOW2_AUTOCLEAR_BITMAPS
                                        | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
};

enum qcow2_discard_type {
    QCOW2_DISCARD_NEVER = 0,
    QCOW2_DISCARD_ALWAYS,
    QCOW2_DISCARD_REQUEST,
    QCOW2_DISCARD_SNAPSHOT,
    QCOW2_DISCARD_OTHER,
    QCOW2_DISCARD_MAX
};

typedef struct Qcow2Feature {
    uint8_t type;
    uint8_t bit;
    char    name[46];
} QEMU_PACKED Qcow2Feature;

typedef struct Qcow2DiscardRegion {
    BlockDriverState *bs;
    uint64_t offset;
    uint64_t bytes;
    QTAILQ_ENTRY(Qcow2DiscardRegion) next;
} Qcow2DiscardRegion;

typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
                                      uint64_t index);
typedef void Qcow2SetRefcountFunc(void *refcount_array,
                                  uint64_t index, uint64_t value);

typedef struct Qcow2BitmapHeaderExt {
    uint32_t nb_bitmaps;
    uint32_t reserved32;
    uint64_t bitmap_directory_size;
    uint64_t bitmap_directory_offset;
} QEMU_PACKED Qcow2BitmapHeaderExt;

#define QCOW2_MAX_THREADS 4

typedef struct BDRVQcow2State {
    int cluster_bits;
    int cluster_size;
    int l2_slice_size;
    int subcluster_bits;
    int subcluster_size;
    int subclusters_per_cluster;
    int l2_bits;
    int l2_size;
    int l1_size;
    int l1_vm_state_index;
    int refcount_block_bits;
    int refcount_block_size;
    int csize_shift;
    int csize_mask;
    uint64_t cluster_offset_mask;
    uint64_t l1_table_offset;
    uint64_t *l1_table;

    Qcow2Cache *l2_table_cache;
    Qcow2Cache *refcount_block_cache;
    QEMUTimer *cache_clean_timer;
    unsigned cache_clean_interval;

    QLIST_HEAD(, QCowL2Meta) cluster_allocs;

    uint64_t *refcount_table;
    uint64_t refcount_table_offset;
    uint32_t refcount_table_size;
    uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
    uint64_t free_cluster_index;
    uint64_t free_byte_offset;

    CoMutex lock;

    Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
    QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
    QCryptoBlock *crypto; /* Disk encryption format driver */
    bool crypt_physical_offset; /* Whether to use virtual or physical offset
                                   for encryption initialization vector tweak */
    uint32_t crypt_method_header;
    uint64_t snapshots_offset;
    int snapshots_size;
    unsigned int nb_snapshots;
    QCowSnapshot *snapshots;

    uint32_t nb_bitmaps;
    uint64_t bitmap_directory_size;
    uint64_t bitmap_directory_offset;

    int flags;
    int qcow_version;
    bool use_lazy_refcounts;
    int refcount_order;
    int refcount_bits;
    uint64_t refcount_max;

    Qcow2GetRefcountFunc *get_refcount;
    Qcow2SetRefcountFunc *set_refcount;

    bool discard_passthrough[QCOW2_DISCARD_MAX];

    bool discard_no_unref;

    int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
    bool signaled_corruption;

    uint64_t incompatible_features;
    uint64_t compatible_features;
    uint64_t autoclear_features;

    size_t unknown_header_fields_size;
    void *unknown_header_fields;
    QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
    QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
    bool cache_discards;

    /* Backing file path and format as stored in the image (this is not the
     * effective path/format, which may be the result of a runtime option
     * override) */
    char *image_backing_file;
    char *image_backing_format;
    char *image_data_file;

    CoQueue thread_task_queue;
    int nb_threads;

    BdrvChild *data_file;

    bool metadata_preallocation_checked;
    bool metadata_preallocation;
    /*
     * Compression type used for the image. Default: 0 - ZLIB
     * The image compression type is set on image creation.
     * For now, the only way to change the compression type
     * is to convert the image with the desired compression type set.
     */
    Qcow2CompressionType compression_type;
} BDRVQcow2State;

typedef struct Qcow2COWRegion {
    /**
     * Offset of the COW region in bytes from the start of the first cluster
     * touched by the request.
     */
    unsigned    offset;

    /** Number of bytes to copy */
    unsigned    nb_bytes;
} Qcow2COWRegion;

/**
 * Describes an in-flight (part of a) write request that writes to clusters
 * that need to have their L2 table entries updated (because they are
 * newly allocated or need changes in their L2 bitmaps)
 */
typedef struct QCowL2Meta
{
    /** Guest offset of the first updated cluster */
    uint64_t offset;

    /** Host offset of the first updated cluster */
    uint64_t alloc_offset;

    /** Number of updated clusters */
    int nb_clusters;

    /** Do not free the old clusters */
    bool keep_old_clusters;

    /**
     * Requests that overlap with this allocation and wait to be restarted
     * when the allocating request has completed.
     */
    CoQueue dependent_requests;

    /**
     * The COW Region immediately before the area the guest actually
     * writes to. This (part of the) write request starts at
     * cow_start.offset + cow_start.nb_bytes.
     */
    Qcow2COWRegion cow_start;

    /**
     * The COW Region immediately after the area the guest actually
     * writes to. This (part of the) write request ends at cow_end.offset
     * (which must always be set even when cow_end.nb_bytes is 0).
     */
    Qcow2COWRegion cow_end;

    /*
     * Indicates that COW regions are already handled and do not require
     * any more processing.
     */
    bool skip_cow;

    /**
     * Indicates that this is not a normal write request but a preallocation.
     * If the image has extended L2 entries this means that no new individual
     * subclusters will be marked as allocated in the L2 bitmap (but any
     * existing contents of that bitmap will be kept).
     */
    bool prealloc;

    /**
     * The I/O vector with the data from the actual guest write request.
     * If non-NULL, this is meant to be merged together with the data
     * from @cow_start and @cow_end into one single write operation.
     */
    QEMUIOVector *data_qiov;
    size_t data_qiov_offset;

    /** Pointer to next L2Meta of the same write request */
    struct QCowL2Meta *next;

    QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;

/*
 * In images with standard L2 entries all clusters are treated as if
 * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
 * can be mapped to each other and have the exact same meaning
 * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
 *
 * In images with extended L2 entries QCow2ClusterType refers to the
 * complete cluster and QCow2SubclusterType to each of the individual
 * subclusters, so there are several possible combinations:
 *
 *     |--------------+---------------------------|
 *     | Cluster type | Possible subcluster types |
 *     |--------------+---------------------------|
 *     | UNALLOCATED  |         UNALLOCATED_PLAIN |
 *     |              |                ZERO_PLAIN |
 *     |--------------+---------------------------|
 *     | NORMAL       |         UNALLOCATED_ALLOC |
 *     |              |                ZERO_ALLOC |
 *     |              |                    NORMAL |
 *     |--------------+---------------------------|
 *     | COMPRESSED   |                COMPRESSED |
 *     |--------------+---------------------------|
 *
 * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
 * the image should be marked corrupt.
 */

typedef enum QCow2ClusterType {
    QCOW2_CLUSTER_UNALLOCATED,
    QCOW2_CLUSTER_ZERO_PLAIN,
    QCOW2_CLUSTER_ZERO_ALLOC,
    QCOW2_CLUSTER_NORMAL,
    QCOW2_CLUSTER_COMPRESSED,
} QCow2ClusterType;

typedef enum QCow2SubclusterType {
    QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
    QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
    QCOW2_SUBCLUSTER_ZERO_PLAIN,
    QCOW2_SUBCLUSTER_ZERO_ALLOC,
    QCOW2_SUBCLUSTER_NORMAL,
    QCOW2_SUBCLUSTER_COMPRESSED,
    QCOW2_SUBCLUSTER_INVALID,
} QCow2SubclusterType;

typedef enum QCow2MetadataOverlap {
    QCOW2_OL_MAIN_HEADER_BITNR      = 0,
    QCOW2_OL_ACTIVE_L1_BITNR        = 1,
    QCOW2_OL_ACTIVE_L2_BITNR        = 2,
    QCOW2_OL_REFCOUNT_TABLE_BITNR   = 3,
    QCOW2_OL_REFCOUNT_BLOCK_BITNR   = 4,
    QCOW2_OL_SNAPSHOT_TABLE_BITNR   = 5,
    QCOW2_OL_INACTIVE_L1_BITNR      = 6,
    QCOW2_OL_INACTIVE_L2_BITNR      = 7,
    QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,

    QCOW2_OL_MAX_BITNR              = 9,

    QCOW2_OL_NONE             = 0,
    QCOW2_OL_MAIN_HEADER      = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
    QCOW2_OL_ACTIVE_L1        = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
    QCOW2_OL_ACTIVE_L2        = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
    QCOW2_OL_REFCOUNT_TABLE   = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
    QCOW2_OL_REFCOUNT_BLOCK   = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
    QCOW2_OL_SNAPSHOT_TABLE   = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
    QCOW2_OL_INACTIVE_L1      = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
    /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
     * reads. */
    QCOW2_OL_INACTIVE_L2      = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
    QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
} QCow2MetadataOverlap;

/* Perform all overlap checks which can be done in constant time */
#define QCOW2_OL_CONSTANT \
    (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
     QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)

/* Perform all overlap checks which don't require disk access */
#define QCOW2_OL_CACHED \
    (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
     QCOW2_OL_INACTIVE_L1)

/* Perform all overlap checks */
#define QCOW2_OL_ALL \
    (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)

#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
#define L1E_RESERVED_MASK 0x7f000000000001ffULL
#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
#define L2E_STD_RESERVED_MASK 0x3f000000000001feULL

#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
#define REFT_RESERVED_MASK 0x1ffULL

#define INV_OFFSET (-1ULL)

static inline bool has_subclusters(BDRVQcow2State *s)
{
    return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
}

static inline size_t l2_entry_size(BDRVQcow2State *s)
{
    return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
}

static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
                                    int idx)
{
    idx *= l2_entry_size(s) / sizeof(uint64_t);
    return be64_to_cpu(l2_slice[idx]);
}

static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
                                     int idx)
{
    if (has_subclusters(s)) {
        idx *= l2_entry_size(s) / sizeof(uint64_t);
        return be64_to_cpu(l2_slice[idx + 1]);
    } else {
        return 0; /* For convenience only; this value has no meaning. */
    }
}

static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
                                int idx, uint64_t entry)
{
    idx *= l2_entry_size(s) / sizeof(uint64_t);
    l2_slice[idx] = cpu_to_be64(entry);
}

static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
                                 int idx, uint64_t bitmap)
{
    assert(has_subclusters(s));
    idx *= l2_entry_size(s) / sizeof(uint64_t);
    l2_slice[idx + 1] = cpu_to_be64(bitmap);
}

static inline bool has_data_file(BlockDriverState *bs)
{
    BDRVQcow2State *s = bs->opaque;
    return (s->data_file != bs->file);
}

static inline bool data_file_is_raw(BlockDriverState *bs)
{
    BDRVQcow2State *s = bs->opaque;
    return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
}

static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
{
    return offset & ~(s->cluster_size - 1);
}

static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
{
    return offset & (s->cluster_size - 1);
}

static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
{
    return offset & (s->subcluster_size - 1);
}

static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
{
    return (size + (s->cluster_size - 1)) >> s->cluster_bits;
}

static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
{
    return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
}

static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
{
    int shift = s->cluster_bits + s->l2_bits;
    return (size + (1ULL << shift) - 1) >> shift;
}

static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
{
    return offset >> (s->l2_bits + s->cluster_bits);
}

static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
{
    return (offset >> s->cluster_bits) & (s->l2_size - 1);
}

static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
{
    return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
}

static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
{
    return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
}

static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
{
    return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
}

static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
                                                      uint64_t l2_entry)
{
    BDRVQcow2State *s = bs->opaque;

    if (l2_entry & QCOW_OFLAG_COMPRESSED) {
        return QCOW2_CLUSTER_COMPRESSED;
    } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
        if (l2_entry & L2E_OFFSET_MASK) {
            return QCOW2_CLUSTER_ZERO_ALLOC;
        }
        return QCOW2_CLUSTER_ZERO_PLAIN;
    } else if (!(l2_entry & L2E_OFFSET_MASK)) {
        /* Offset 0 generally means unallocated, but it is ambiguous with
         * external data files because 0 is a valid offset there. However, all
         * clusters in external data files always have refcount 1, so we can
         * rely on QCOW_OFLAG_COPIED to disambiguate. */
        if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
            return QCOW2_CLUSTER_NORMAL;
        } else {
            return QCOW2_CLUSTER_UNALLOCATED;
        }
    } else {
        return QCOW2_CLUSTER_NORMAL;
    }
}

/*
 * In an image without subsclusters @l2_bitmap is ignored and
 * @sc_index must be 0.
 * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
 * (this checks the whole entry and bitmap, not only the bits related
 * to subcluster @sc_index).
 */
static inline
QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
                                              uint64_t l2_entry,
                                              uint64_t l2_bitmap,
                                              unsigned sc_index)
{
    BDRVQcow2State *s = bs->opaque;
    QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
    assert(sc_index < s->subclusters_per_cluster);

    if (has_subclusters(s)) {
        switch (type) {
        case QCOW2_CLUSTER_COMPRESSED:
            return QCOW2_SUBCLUSTER_COMPRESSED;
        case QCOW2_CLUSTER_NORMAL:
            if ((l2_bitmap >> 32) & l2_bitmap) {
                return QCOW2_SUBCLUSTER_INVALID;
            } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
                return QCOW2_SUBCLUSTER_ZERO_ALLOC;
            } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
                return QCOW2_SUBCLUSTER_NORMAL;
            } else {
                return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
            }
        case QCOW2_CLUSTER_UNALLOCATED:
            if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
                return QCOW2_SUBCLUSTER_INVALID;
            } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
                return QCOW2_SUBCLUSTER_ZERO_PLAIN;
            } else {
                return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
            }
        default:
            g_assert_not_reached();
        }
    } else {
        switch (type) {
        case QCOW2_CLUSTER_COMPRESSED:
            return QCOW2_SUBCLUSTER_COMPRESSED;
        case QCOW2_CLUSTER_ZERO_PLAIN:
            return QCOW2_SUBCLUSTER_ZERO_PLAIN;
        case QCOW2_CLUSTER_ZERO_ALLOC:
            return QCOW2_SUBCLUSTER_ZERO_ALLOC;
        case QCOW2_CLUSTER_NORMAL:
            return QCOW2_SUBCLUSTER_NORMAL;
        case QCOW2_CLUSTER_UNALLOCATED:
            return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
        default:
            g_assert_not_reached();
        }
    }
}

static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
{
    return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
            type == QCOW2_CLUSTER_ZERO_ALLOC);
}

/* Check whether refcounts are eager or lazy */
static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
{
    return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
}

static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
{
    return m->offset + m->cow_start.offset;
}

static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
{
    return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
}

static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
{
    return r1 > r2 ? r1 - r2 : r2 - r1;
}

static inline
uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
{
    return offset >> (s->refcount_block_bits + s->cluster_bits);
}

/* qcow2.c functions */
int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
                                     int refcount_order, bool generous_increase,
                                     uint64_t *refblock_count);

int qcow2_mark_dirty(BlockDriverState *bs);
int qcow2_mark_corrupt(BlockDriverState *bs);
int qcow2_update_header(BlockDriverState *bs);

void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
                             int64_t size, const char *message_format, ...)
                             G_GNUC_PRINTF(5, 6);

int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
                         uint64_t entries, size_t entry_len,
                         int64_t max_size_bytes, const char *table_name,
                         Error **errp);

/* qcow2-refcount.c functions */
int coroutine_fn GRAPH_RDLOCK qcow2_refcount_init(BlockDriverState *bs);
void qcow2_refcount_close(BlockDriverState *bs);

int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
                       uint64_t *refcount);

int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
                                  uint64_t addend, bool decrease,
                                  enum qcow2_discard_type type);

int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
                            uint64_t additional_clusters, bool exact_size,
                            int new_refblock_index,
                            uint64_t new_refblock_offset);

int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
int64_t coroutine_fn qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
                                             int64_t nb_clusters);
int64_t coroutine_fn GRAPH_RDLOCK qcow2_alloc_bytes(BlockDriverState *bs, int size);
void qcow2_free_clusters(BlockDriverState *bs,
                          int64_t offset, int64_t size,
                          enum qcow2_discard_type type);
void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
                            enum qcow2_discard_type type);

int qcow2_update_snapshot_refcount(BlockDriverState *bs,
    int64_t l1_table_offset, int l1_size, int addend);

int qcow2_flush_caches(BlockDriverState *bs);
int qcow2_write_caches(BlockDriverState *bs);
int coroutine_fn qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                                       BdrvCheckMode fix);

void qcow2_process_discards(BlockDriverState *bs, int ret);

int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
                                 int64_t size);
int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
                                  int64_t size, bool data_file);
int coroutine_fn qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
                                          void **refcount_table,
                                          int64_t *refcount_table_size,
                                          int64_t offset, int64_t size);

int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
                                BlockDriverAmendStatusCB *status_cb,
                                void *cb_opaque, Error **errp);
int coroutine_fn GRAPH_RDLOCK qcow2_shrink_reftable(BlockDriverState *bs);
int64_t coroutine_fn qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);

int coroutine_fn GRAPH_RDLOCK
qcow2_detect_metadata_preallocation(BlockDriverState *bs);

/* qcow2-cluster.c functions */
int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
                        bool exact_size);

int coroutine_fn GRAPH_RDLOCK
qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);

int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
                          uint8_t *buf, int nb_sectors, bool enc, Error **errp);

int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
                          unsigned int *bytes, uint64_t *host_offset,
                          QCow2SubclusterType *subcluster_type);
int coroutine_fn qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
                                         unsigned int *bytes,
                                         uint64_t *host_offset, QCowL2Meta **m);
int coroutine_fn GRAPH_RDLOCK
qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, uint64_t offset,
                                      int compressed_size, uint64_t *host_offset);
void qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry,
                                     uint64_t *coffset, int *csize);

int coroutine_fn GRAPH_RDLOCK
qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);

void coroutine_fn qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
                          uint64_t bytes, enum qcow2_discard_type type,
                          bool full_discard);

int coroutine_fn GRAPH_RDLOCK
qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
                         int flags);

int qcow2_expand_zero_clusters(BlockDriverState *bs,
                               BlockDriverAmendStatusCB *status_cb,
                               void *cb_opaque);

/* qcow2-snapshot.c functions */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
int qcow2_snapshot_delete(BlockDriverState *bs,
                          const char *snapshot_id,
                          const char *name,
                          Error **errp);
int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
int qcow2_snapshot_load_tmp(BlockDriverState *bs,
                            const char *snapshot_id,
                            const char *name,
                            Error **errp);

void qcow2_free_snapshots(BlockDriverState *bs);
int coroutine_fn GRAPH_RDLOCK
qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
int qcow2_write_snapshots(BlockDriverState *bs);

int coroutine_fn GRAPH_RDLOCK
qcow2_check_read_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
                                BdrvCheckMode fix);

int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
                                                BdrvCheckResult *result,
                                                BdrvCheckMode fix);

/* qcow2-cache.c functions */
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
                               unsigned table_size);
int qcow2_cache_destroy(Qcow2Cache *c);

void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
    Qcow2Cache *dependency);
void qcow2_cache_depends_on_flush(Qcow2Cache *c);

void qcow2_cache_clean_unused(Qcow2Cache *c);
int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);

int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
    void **table);
int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
    void **table);
void qcow2_cache_put(Qcow2Cache *c, void **table);
void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
void qcow2_cache_discard(Qcow2Cache *c, void *table);

/* qcow2-bitmap.c functions */
int coroutine_fn
qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                              void **refcount_table,
                              int64_t *refcount_table_size);
bool coroutine_fn GRAPH_RDLOCK
qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated, Error **errp);
bool qcow2_get_bitmap_info_list(BlockDriverState *bs,
                                Qcow2BitmapInfoList **info_list, Error **errp);
int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
int coroutine_fn qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
bool qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
                                          bool release_stored, Error **errp);
int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
bool coroutine_fn qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
                                                      const char *name,
                                                      uint32_t granularity,
                                                      Error **errp);
int coroutine_fn qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
                                                         const char *name,
                                                         Error **errp);
bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
                                                uint32_t cluster_size);

ssize_t coroutine_fn
qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
                  const void *src, size_t src_size);
ssize_t coroutine_fn
qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
                    const void *src, size_t src_size);
int coroutine_fn
qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
                 uint64_t guest_offset, void *buf, size_t len);
int coroutine_fn
qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
                 uint64_t guest_offset, void *buf, size_t len);

#endif