2 * Block driver for the QCOW version 2 format
4 * Copyright (c) 2004-2006 Fabrice Bellard
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:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
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
28 #include "crypto/block.h"
29 #include "qemu/coroutine.h"
30 #include "qemu/units.h"
31 #include "block/block_int.h"
34 //#define DEBUG_ALLOC2
37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
39 #define QCOW_CRYPT_NONE 0
40 #define QCOW_CRYPT_AES 1
41 #define QCOW_CRYPT_LUKS 2
43 #define QCOW_MAX_CRYPT_CLUSTERS 32
44 #define QCOW_MAX_SNAPSHOTS 65536
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)
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)
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)
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)
64 /* Maximum amount of extra data per snapshot table entry to accept */
65 #define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024
67 /* Bitmap header extension constraints */
68 #define QCOW2_MAX_BITMAPS 65535
69 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
71 /* Maximum of parallel sub-request per guest request */
72 #define QCOW2_MAX_WORKERS 8
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)
81 #define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32
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))
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)
102 #define MIN_CLUSTER_BITS 9
103 #define MAX_CLUSTER_BITS 21
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))
109 /* Must be at least 2 to cover COW */
110 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
112 /* Must be at least 4 to cover all cases of refcount table growth */
113 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
116 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
117 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
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
124 #define DEFAULT_CLUSTER_SIZE 65536
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"
148 typedef struct QCowHeader
{
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
;
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
;
168 uint32_t refcount_order
;
169 uint32_t header_length
;
171 /* Additional fields */
172 uint8_t compression_type
;
174 /* header must be a multiple of 8 */
176 } QEMU_PACKED QCowHeader
;
178 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader
), 8));
180 typedef struct QEMU_PACKED QCowSnapshotHeader
{
181 /* header is 8 byte aligned */
182 uint64_t l1_table_offset
;
185 uint16_t id_str_size
;
191 uint64_t vm_clock_nsec
;
193 uint32_t vm_state_size
;
194 uint32_t extra_data_size
; /* for extension */
195 /* extra data follows */
198 } QCowSnapshotHeader
;
200 typedef struct QEMU_PACKED QCowSnapshotExtraData
{
201 uint64_t vm_state_size_large
;
203 } QCowSnapshotExtraData
;
206 typedef struct QCowSnapshot
{
207 uint64_t l1_table_offset
;
212 uint64_t vm_state_size
;
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
;
223 typedef struct Qcow2Cache Qcow2Cache
;
225 typedef struct Qcow2CryptoHeaderExtension
{
228 } QEMU_PACKED Qcow2CryptoHeaderExtension
;
230 typedef struct Qcow2UnknownHeaderExtension
{
233 QLIST_ENTRY(Qcow2UnknownHeaderExtension
) next
;
235 } Qcow2UnknownHeaderExtension
;
238 QCOW2_FEAT_TYPE_INCOMPATIBLE
= 0,
239 QCOW2_FEAT_TYPE_COMPATIBLE
= 1,
240 QCOW2_FEAT_TYPE_AUTOCLEAR
= 2,
243 /* Incompatible feature bits */
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
,
256 QCOW2_INCOMPAT_MASK
= QCOW2_INCOMPAT_DIRTY
257 | QCOW2_INCOMPAT_CORRUPT
258 | QCOW2_INCOMPAT_DATA_FILE
259 | QCOW2_INCOMPAT_COMPRESSION
260 | QCOW2_INCOMPAT_EXTL2
,
263 /* Compatible feature bits */
265 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
= 0,
266 QCOW2_COMPAT_LAZY_REFCOUNTS
= 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR
,
268 QCOW2_COMPAT_FEAT_MASK
= QCOW2_COMPAT_LAZY_REFCOUNTS
,
271 /* Autoclear feature bits */
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
,
278 QCOW2_AUTOCLEAR_MASK
= QCOW2_AUTOCLEAR_BITMAPS
279 | QCOW2_AUTOCLEAR_DATA_FILE_RAW
,
282 enum qcow2_discard_type
{
283 QCOW2_DISCARD_NEVER
= 0,
284 QCOW2_DISCARD_ALWAYS
,
285 QCOW2_DISCARD_REQUEST
,
286 QCOW2_DISCARD_SNAPSHOT
,
291 typedef struct Qcow2Feature
{
295 } QEMU_PACKED Qcow2Feature
;
297 typedef struct Qcow2DiscardRegion
{
298 BlockDriverState
*bs
;
301 QTAILQ_ENTRY(Qcow2DiscardRegion
) next
;
302 } Qcow2DiscardRegion
;
304 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array
,
306 typedef void Qcow2SetRefcountFunc(void *refcount_array
,
307 uint64_t index
, uint64_t value
);
309 typedef struct Qcow2BitmapHeaderExt
{
312 uint64_t bitmap_directory_size
;
313 uint64_t bitmap_directory_offset
;
314 } QEMU_PACKED Qcow2BitmapHeaderExt
;
316 #define QCOW2_MAX_THREADS 4
318 typedef struct BDRVQcow2State
{
324 int subclusters_per_cluster
;
328 int l1_vm_state_index
;
329 int refcount_block_bits
;
330 int refcount_block_size
;
333 uint64_t cluster_offset_mask
;
334 uint64_t l1_table_offset
;
337 Qcow2Cache
* l2_table_cache
;
338 Qcow2Cache
* refcount_block_cache
;
339 QEMUTimer
*cache_clean_timer
;
340 unsigned cache_clean_interval
;
342 QLIST_HEAD(, QCowL2Meta
) cluster_allocs
;
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
;
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
;
361 unsigned int nb_snapshots
;
362 QCowSnapshot
*snapshots
;
365 uint64_t bitmap_directory_size
;
366 uint64_t bitmap_directory_offset
;
370 bool use_lazy_refcounts
;
373 uint64_t refcount_max
;
375 Qcow2GetRefcountFunc
*get_refcount
;
376 Qcow2SetRefcountFunc
*set_refcount
;
378 bool discard_passthrough
[QCOW2_DISCARD_MAX
];
380 int overlap_check
; /* bitmask of Qcow2MetadataOverlap values */
381 bool signaled_corruption
;
383 uint64_t incompatible_features
;
384 uint64_t compatible_features
;
385 uint64_t autoclear_features
;
387 size_t unknown_header_fields_size
;
388 void* unknown_header_fields
;
389 QLIST_HEAD(, Qcow2UnknownHeaderExtension
) unknown_header_ext
;
390 QTAILQ_HEAD (, Qcow2DiscardRegion
) discards
;
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
396 char *image_backing_file
;
397 char *image_backing_format
;
398 char *image_data_file
;
400 CoQueue thread_task_queue
;
403 BdrvChild
*data_file
;
405 bool metadata_preallocation_checked
;
406 bool metadata_preallocation
;
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.
413 Qcow2CompressionType compression_type
;
416 typedef struct Qcow2COWRegion
{
418 * Offset of the COW region in bytes from the start of the first cluster
419 * touched by the request.
423 /** Number of bytes to copy */
428 * Describes an in-flight (part of a) write request that writes to clusters
429 * that are not referenced in their L2 table yet.
431 typedef struct QCowL2Meta
433 /** Guest offset of the first newly allocated cluster */
436 /** Host offset of the first newly allocated cluster */
437 uint64_t alloc_offset
;
439 /** Number of newly allocated clusters */
442 /** Do not free the old clusters */
443 bool keep_old_clusters
;
446 * Requests that overlap with this allocation and wait to be restarted
447 * when the allocating request has completed.
449 CoQueue dependent_requests
;
452 * The COW Region between the start of the first allocated cluster and the
453 * area the guest actually writes to.
455 Qcow2COWRegion cow_start
;
458 * The COW Region between the area the guest actually writes to and the
459 * end of the last allocated cluster.
461 Qcow2COWRegion cow_end
;
464 * Indicates that COW regions are already handled and do not require
465 * any more processing.
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).
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.
482 QEMUIOVector
*data_qiov
;
483 size_t data_qiov_offset
;
485 /** Pointer to next L2Meta of the same write request */
486 struct QCowL2Meta
*next
;
488 QLIST_ENTRY(QCowL2Meta
) next_in_flight
;
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).
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:
501 * |--------------+---------------------------|
502 * | Cluster type | Possible subcluster types |
503 * |--------------+---------------------------|
504 * | UNALLOCATED | UNALLOCATED_PLAIN |
506 * |--------------+---------------------------|
507 * | NORMAL | UNALLOCATED_ALLOC |
510 * |--------------+---------------------------|
511 * | COMPRESSED | COMPRESSED |
512 * |--------------+---------------------------|
514 * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
515 * the image should be marked corrupt.
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
,
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
;
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,
547 QCOW2_OL_MAX_BITNR
= 9,
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
559 QCOW2_OL_INACTIVE_L2
= (1 << QCOW2_OL_INACTIVE_L2_BITNR
),
560 QCOW2_OL_BITMAP_DIRECTORY
= (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR
),
561 } QCow2MetadataOverlap
;
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)
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)
573 /* Perform all overlap checks */
574 #define QCOW2_OL_ALL \
575 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
577 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
578 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
579 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
581 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
583 #define INV_OFFSET (-1ULL)
585 static inline bool has_subclusters(BDRVQcow2State
*s
)
587 return s
->incompatible_features
& QCOW2_INCOMPAT_EXTL2
;
590 static inline size_t l2_entry_size(BDRVQcow2State
*s
)
592 return has_subclusters(s
) ? L2E_SIZE_EXTENDED
: L2E_SIZE_NORMAL
;
595 static inline uint64_t get_l2_entry(BDRVQcow2State
*s
, uint64_t *l2_slice
,
598 idx
*= l2_entry_size(s
) / sizeof(uint64_t);
599 return be64_to_cpu(l2_slice
[idx
]);
602 static inline uint64_t get_l2_bitmap(BDRVQcow2State
*s
, uint64_t *l2_slice
,
605 if (has_subclusters(s
)) {
606 idx
*= l2_entry_size(s
) / sizeof(uint64_t);
607 return be64_to_cpu(l2_slice
[idx
+ 1]);
609 return 0; /* For convenience only; this value has no meaning. */
613 static inline void set_l2_entry(BDRVQcow2State
*s
, uint64_t *l2_slice
,
614 int idx
, uint64_t entry
)
616 idx
*= l2_entry_size(s
) / sizeof(uint64_t);
617 l2_slice
[idx
] = cpu_to_be64(entry
);
620 static inline void set_l2_bitmap(BDRVQcow2State
*s
, uint64_t *l2_slice
,
621 int idx
, uint64_t bitmap
)
623 assert(has_subclusters(s
));
624 idx
*= l2_entry_size(s
) / sizeof(uint64_t);
625 l2_slice
[idx
+ 1] = cpu_to_be64(bitmap
);
628 static inline bool has_data_file(BlockDriverState
*bs
)
630 BDRVQcow2State
*s
= bs
->opaque
;
631 return (s
->data_file
!= bs
->file
);
634 static inline bool data_file_is_raw(BlockDriverState
*bs
)
636 BDRVQcow2State
*s
= bs
->opaque
;
637 return !!(s
->autoclear_features
& QCOW2_AUTOCLEAR_DATA_FILE_RAW
);
640 static inline int64_t start_of_cluster(BDRVQcow2State
*s
, int64_t offset
)
642 return offset
& ~(s
->cluster_size
- 1);
645 static inline int64_t offset_into_cluster(BDRVQcow2State
*s
, int64_t offset
)
647 return offset
& (s
->cluster_size
- 1);
650 static inline int64_t offset_into_subcluster(BDRVQcow2State
*s
, int64_t offset
)
652 return offset
& (s
->subcluster_size
- 1);
655 static inline uint64_t size_to_clusters(BDRVQcow2State
*s
, uint64_t size
)
657 return (size
+ (s
->cluster_size
- 1)) >> s
->cluster_bits
;
660 static inline uint64_t size_to_subclusters(BDRVQcow2State
*s
, uint64_t size
)
662 return (size
+ (s
->subcluster_size
- 1)) >> s
->subcluster_bits
;
665 static inline int64_t size_to_l1(BDRVQcow2State
*s
, int64_t size
)
667 int shift
= s
->cluster_bits
+ s
->l2_bits
;
668 return (size
+ (1ULL << shift
) - 1) >> shift
;
671 static inline int offset_to_l1_index(BDRVQcow2State
*s
, uint64_t offset
)
673 return offset
>> (s
->l2_bits
+ s
->cluster_bits
);
676 static inline int offset_to_l2_index(BDRVQcow2State
*s
, int64_t offset
)
678 return (offset
>> s
->cluster_bits
) & (s
->l2_size
- 1);
681 static inline int offset_to_l2_slice_index(BDRVQcow2State
*s
, int64_t offset
)
683 return (offset
>> s
->cluster_bits
) & (s
->l2_slice_size
- 1);
686 static inline int offset_to_sc_index(BDRVQcow2State
*s
, int64_t offset
)
688 return (offset
>> s
->subcluster_bits
) & (s
->subclusters_per_cluster
- 1);
691 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State
*s
)
693 return (int64_t)s
->l1_vm_state_index
<< (s
->cluster_bits
+ s
->l2_bits
);
696 static inline QCow2ClusterType
qcow2_get_cluster_type(BlockDriverState
*bs
,
699 BDRVQcow2State
*s
= bs
->opaque
;
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
;
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
;
716 return QCOW2_CLUSTER_UNALLOCATED
;
719 return QCOW2_CLUSTER_NORMAL
;
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).
731 QCow2SubclusterType
qcow2_get_subcluster_type(BlockDriverState
*bs
,
736 BDRVQcow2State
*s
= bs
->opaque
;
737 QCow2ClusterType type
= qcow2_get_cluster_type(bs
, l2_entry
);
738 assert(sc_index
< s
->subclusters_per_cluster
);
740 if (has_subclusters(s
)) {
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
;
752 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC
;
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
;
760 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN
;
763 g_assert_not_reached();
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
;
778 g_assert_not_reached();
783 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type
)
785 return (type
== QCOW2_CLUSTER_COMPRESSED
|| type
== QCOW2_CLUSTER_NORMAL
||
786 type
== QCOW2_CLUSTER_ZERO_ALLOC
);
789 /* Check whether refcounts are eager or lazy */
790 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State
*s
)
792 return !(s
->incompatible_features
& QCOW2_INCOMPAT_DIRTY
);
795 static inline uint64_t l2meta_cow_start(QCowL2Meta
*m
)
797 return m
->offset
+ m
->cow_start
.offset
;
800 static inline uint64_t l2meta_cow_end(QCowL2Meta
*m
)
802 return m
->offset
+ m
->cow_end
.offset
+ m
->cow_end
.nb_bytes
;
805 static inline uint64_t refcount_diff(uint64_t r1
, uint64_t r2
)
807 return r1
> r2
? r1
- r2
: r2
- r1
;
811 uint32_t offset_to_reftable_index(BDRVQcow2State
*s
, uint64_t offset
)
813 return offset
>> (s
->refcount_block_bits
+ s
->cluster_bits
);
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
);
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
);
826 void qcow2_signal_corruption(BlockDriverState
*bs
, bool fatal
, int64_t offset
,
827 int64_t size
, const char *message_format
, ...)
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
,
835 /* qcow2-refcount.c functions */
836 int qcow2_refcount_init(BlockDriverState
*bs
);
837 void qcow2_refcount_close(BlockDriverState
*bs
);
839 int qcow2_get_refcount(BlockDriverState
*bs
, int64_t cluster_index
,
842 int qcow2_update_cluster_refcount(BlockDriverState
*bs
, int64_t cluster_index
,
843 uint64_t addend
, bool decrease
,
844 enum qcow2_discard_type type
);
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
);
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
);
861 int qcow2_update_snapshot_refcount(BlockDriverState
*bs
,
862 int64_t l1_table_offset
, int l1_size
, int addend
);
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
,
869 void qcow2_process_discards(BlockDriverState
*bs
, int ret
);
871 int qcow2_check_metadata_overlap(BlockDriverState
*bs
, int ign
, int64_t offset
,
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
);
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
);
887 /* qcow2-cluster.c functions */
888 int qcow2_grow_l1_table(BlockDriverState
*bs
, uint64_t min_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
);
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
,
901 int qcow2_alloc_compressed_cluster_offset(BlockDriverState
*bs
,
904 uint64_t *host_offset
);
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
,
911 int qcow2_subcluster_zeroize(BlockDriverState
*bs
, uint64_t offset
,
912 uint64_t bytes
, int flags
);
914 int qcow2_expand_zero_clusters(BlockDriverState
*bs
,
915 BlockDriverAmendStatusCB
*status_cb
,
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
,
925 int qcow2_snapshot_list(BlockDriverState
*bs
, QEMUSnapshotInfo
**psn_tab
);
926 int qcow2_snapshot_load_tmp(BlockDriverState
*bs
,
927 const char *snapshot_id
,
931 void qcow2_free_snapshots(BlockDriverState
*bs
);
932 int qcow2_read_snapshots(BlockDriverState
*bs
, Error
**errp
);
933 int qcow2_write_snapshots(BlockDriverState
*bs
);
935 int coroutine_fn
qcow2_check_read_snapshot_table(BlockDriverState
*bs
,
936 BdrvCheckResult
*result
,
938 int coroutine_fn
qcow2_check_fix_snapshot_table(BlockDriverState
*bs
,
939 BdrvCheckResult
*result
,
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
);
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
);
954 void qcow2_cache_clean_unused(Qcow2Cache
*c
);
955 int qcow2_cache_empty(BlockDriverState
*bs
, Qcow2Cache
*c
);
957 int qcow2_cache_get(BlockDriverState
*bs
, Qcow2Cache
*c
, uint64_t offset
,
959 int qcow2_cache_get_empty(BlockDriverState
*bs
, Qcow2Cache
*c
, uint64_t offset
,
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
);
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
,
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
,
979 uint32_t granularity
,
981 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState
*bs
,
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
);
989 qcow2_co_compress(BlockDriverState
*bs
, void *dest
, size_t dest_size
,
990 const void *src
, size_t src_size
);
992 qcow2_co_decompress(BlockDriverState
*bs
, void *dest
, size_t dest_size
,
993 const void *src
, size_t src_size
);
995 qcow2_co_encrypt(BlockDriverState
*bs
, uint64_t host_offset
,
996 uint64_t guest_offset
, void *buf
, size_t len
);
998 qcow2_co_decrypt(BlockDriverState
*bs
, uint64_t host_offset
,
999 uint64_t guest_offset
, void *buf
, size_t len
);