graph-lock: Unlock the AioContext while polling
[qemu/kevin.git] / block / qcow2.h
blobea9adb5706da1a3b8c54aaacc9cf5696132e1ce8
1 /*
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
22 * THE SOFTWARE.
25 #ifndef BLOCK_QCOW2_H
26 #define BLOCK_QCOW2_H
28 #include "crypto/block.h"
29 #include "qemu/coroutine.h"
30 #include "qemu/units.h"
31 #include "block/block_int.h"
33 //#define DEBUG_ALLOC
34 //#define DEBUG_ALLOC2
35 //#define DEBUG_EXT
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 /* Size of L1 table entries */
103 #define L1E_SIZE (sizeof(uint64_t))
105 /* Size of reftable entries */
106 #define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))
108 #define MIN_CLUSTER_BITS 9
109 #define MAX_CLUSTER_BITS 21
111 /* Defined in the qcow2 spec (compressed cluster descriptor) */
112 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
114 /* Must be at least 2 to cover COW */
115 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
117 /* Must be at least 4 to cover all cases of refcount table growth */
118 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
120 #ifdef CONFIG_LINUX
121 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
122 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
123 #else
124 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
125 /* Cache clean interval is currently available only on Linux, so must be 0 */
126 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
127 #endif
129 #define DEFAULT_CLUSTER_SIZE 65536
131 #define QCOW2_OPT_DATA_FILE "data-file"
132 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
133 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
134 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
135 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
136 #define QCOW2_OPT_DISCARD_NO_UNREF "discard-no-unref"
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"
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;
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;
174 uint32_t refcount_order;
175 uint32_t header_length;
177 /* Additional fields */
178 uint8_t compression_type;
180 /* header must be a multiple of 8 */
181 uint8_t padding[7];
182 } QEMU_PACKED QCowHeader;
184 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
186 typedef struct QEMU_PACKED QCowSnapshotHeader {
187 /* header is 8 byte aligned */
188 uint64_t l1_table_offset;
190 uint32_t l1_size;
191 uint16_t id_str_size;
192 uint16_t name_size;
194 uint32_t date_sec;
195 uint32_t date_nsec;
197 uint64_t vm_clock_nsec;
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;
206 typedef struct QEMU_PACKED QCowSnapshotExtraData {
207 uint64_t vm_state_size_large;
208 uint64_t disk_size;
209 uint64_t icount;
210 } QCowSnapshotExtraData;
213 typedef struct QCowSnapshot {
214 uint64_t l1_table_offset;
215 uint32_t l1_size;
216 char *id_str;
217 char *name;
218 uint64_t disk_size;
219 uint64_t vm_state_size;
220 uint32_t date_sec;
221 uint32_t date_nsec;
222 uint64_t vm_clock_nsec;
223 /* icount value for the moment when snapshot was taken */
224 uint64_t icount;
225 /* Size of all extra data, including QCowSnapshotExtraData if available */
226 uint32_t extra_data_size;
227 /* Data beyond QCowSnapshotExtraData, if any */
228 void *unknown_extra_data;
229 } QCowSnapshot;
231 struct Qcow2Cache;
232 typedef struct Qcow2Cache Qcow2Cache;
234 typedef struct Qcow2CryptoHeaderExtension {
235 uint64_t offset;
236 uint64_t length;
237 } QEMU_PACKED Qcow2CryptoHeaderExtension;
239 typedef struct Qcow2UnknownHeaderExtension {
240 uint32_t magic;
241 uint32_t len;
242 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
243 uint8_t data[];
244 } Qcow2UnknownHeaderExtension;
246 enum {
247 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
248 QCOW2_FEAT_TYPE_COMPATIBLE = 1,
249 QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
252 /* Incompatible feature bits */
253 enum {
254 QCOW2_INCOMPAT_DIRTY_BITNR = 0,
255 QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
256 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
257 QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
258 QCOW2_INCOMPAT_EXTL2_BITNR = 4,
259 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
260 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
261 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
262 QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
263 QCOW2_INCOMPAT_EXTL2 = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
265 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
266 | QCOW2_INCOMPAT_CORRUPT
267 | QCOW2_INCOMPAT_DATA_FILE
268 | QCOW2_INCOMPAT_COMPRESSION
269 | QCOW2_INCOMPAT_EXTL2,
272 /* Compatible feature bits */
273 enum {
274 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
275 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
277 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
280 /* Autoclear feature bits */
281 enum {
282 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
283 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
284 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
285 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
287 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS
288 | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
291 enum qcow2_discard_type {
292 QCOW2_DISCARD_NEVER = 0,
293 QCOW2_DISCARD_ALWAYS,
294 QCOW2_DISCARD_REQUEST,
295 QCOW2_DISCARD_SNAPSHOT,
296 QCOW2_DISCARD_OTHER,
297 QCOW2_DISCARD_MAX
300 typedef struct Qcow2Feature {
301 uint8_t type;
302 uint8_t bit;
303 char name[46];
304 } QEMU_PACKED Qcow2Feature;
306 typedef struct Qcow2DiscardRegion {
307 BlockDriverState *bs;
308 uint64_t offset;
309 uint64_t bytes;
310 QTAILQ_ENTRY(Qcow2DiscardRegion) next;
311 } Qcow2DiscardRegion;
313 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
314 uint64_t index);
315 typedef void Qcow2SetRefcountFunc(void *refcount_array,
316 uint64_t index, uint64_t value);
318 typedef struct Qcow2BitmapHeaderExt {
319 uint32_t nb_bitmaps;
320 uint32_t reserved32;
321 uint64_t bitmap_directory_size;
322 uint64_t bitmap_directory_offset;
323 } QEMU_PACKED Qcow2BitmapHeaderExt;
325 #define QCOW2_MAX_THREADS 4
327 typedef struct BDRVQcow2State {
328 int cluster_bits;
329 int cluster_size;
330 int l2_slice_size;
331 int subcluster_bits;
332 int subcluster_size;
333 int subclusters_per_cluster;
334 int l2_bits;
335 int l2_size;
336 int l1_size;
337 int l1_vm_state_index;
338 int refcount_block_bits;
339 int refcount_block_size;
340 int csize_shift;
341 int csize_mask;
342 uint64_t cluster_offset_mask;
343 uint64_t l1_table_offset;
344 uint64_t *l1_table;
346 Qcow2Cache *l2_table_cache;
347 Qcow2Cache *refcount_block_cache;
348 QEMUTimer *cache_clean_timer;
349 unsigned cache_clean_interval;
351 QLIST_HEAD(, QCowL2Meta) cluster_allocs;
353 uint64_t *refcount_table;
354 uint64_t refcount_table_offset;
355 uint32_t refcount_table_size;
356 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
357 uint64_t free_cluster_index;
358 uint64_t free_byte_offset;
360 CoMutex lock;
362 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
363 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
364 QCryptoBlock *crypto; /* Disk encryption format driver */
365 bool crypt_physical_offset; /* Whether to use virtual or physical offset
366 for encryption initialization vector tweak */
367 uint32_t crypt_method_header;
368 uint64_t snapshots_offset;
369 int snapshots_size;
370 unsigned int nb_snapshots;
371 QCowSnapshot *snapshots;
373 uint32_t nb_bitmaps;
374 uint64_t bitmap_directory_size;
375 uint64_t bitmap_directory_offset;
377 int flags;
378 int qcow_version;
379 bool use_lazy_refcounts;
380 int refcount_order;
381 int refcount_bits;
382 uint64_t refcount_max;
384 Qcow2GetRefcountFunc *get_refcount;
385 Qcow2SetRefcountFunc *set_refcount;
387 bool discard_passthrough[QCOW2_DISCARD_MAX];
389 bool discard_no_unref;
391 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
392 bool signaled_corruption;
394 uint64_t incompatible_features;
395 uint64_t compatible_features;
396 uint64_t autoclear_features;
398 size_t unknown_header_fields_size;
399 void *unknown_header_fields;
400 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
401 QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
402 bool cache_discards;
404 /* Backing file path and format as stored in the image (this is not the
405 * effective path/format, which may be the result of a runtime option
406 * override) */
407 char *image_backing_file;
408 char *image_backing_format;
409 char *image_data_file;
411 CoQueue thread_task_queue;
412 int nb_threads;
414 BdrvChild *data_file;
416 bool metadata_preallocation_checked;
417 bool metadata_preallocation;
419 * Compression type used for the image. Default: 0 - ZLIB
420 * The image compression type is set on image creation.
421 * For now, the only way to change the compression type
422 * is to convert the image with the desired compression type set.
424 Qcow2CompressionType compression_type;
425 } BDRVQcow2State;
427 typedef struct Qcow2COWRegion {
429 * Offset of the COW region in bytes from the start of the first cluster
430 * touched by the request.
432 unsigned offset;
434 /** Number of bytes to copy */
435 unsigned nb_bytes;
436 } Qcow2COWRegion;
439 * Describes an in-flight (part of a) write request that writes to clusters
440 * that need to have their L2 table entries updated (because they are
441 * newly allocated or need changes in their L2 bitmaps)
443 typedef struct QCowL2Meta
445 /** Guest offset of the first updated cluster */
446 uint64_t offset;
448 /** Host offset of the first updated cluster */
449 uint64_t alloc_offset;
451 /** Number of updated clusters */
452 int nb_clusters;
454 /** Do not free the old clusters */
455 bool keep_old_clusters;
458 * Requests that overlap with this allocation and wait to be restarted
459 * when the allocating request has completed.
461 CoQueue dependent_requests;
464 * The COW Region immediately before the area the guest actually
465 * writes to. This (part of the) write request starts at
466 * cow_start.offset + cow_start.nb_bytes.
468 Qcow2COWRegion cow_start;
471 * The COW Region immediately after the area the guest actually
472 * writes to. This (part of the) write request ends at cow_end.offset
473 * (which must always be set even when cow_end.nb_bytes is 0).
475 Qcow2COWRegion cow_end;
478 * Indicates that COW regions are already handled and do not require
479 * any more processing.
481 bool skip_cow;
484 * Indicates that this is not a normal write request but a preallocation.
485 * If the image has extended L2 entries this means that no new individual
486 * subclusters will be marked as allocated in the L2 bitmap (but any
487 * existing contents of that bitmap will be kept).
489 bool prealloc;
492 * The I/O vector with the data from the actual guest write request.
493 * If non-NULL, this is meant to be merged together with the data
494 * from @cow_start and @cow_end into one single write operation.
496 QEMUIOVector *data_qiov;
497 size_t data_qiov_offset;
499 /** Pointer to next L2Meta of the same write request */
500 struct QCowL2Meta *next;
502 QLIST_ENTRY(QCowL2Meta) next_in_flight;
503 } QCowL2Meta;
506 * In images with standard L2 entries all clusters are treated as if
507 * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
508 * can be mapped to each other and have the exact same meaning
509 * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
511 * In images with extended L2 entries QCow2ClusterType refers to the
512 * complete cluster and QCow2SubclusterType to each of the individual
513 * subclusters, so there are several possible combinations:
515 * |--------------+---------------------------|
516 * | Cluster type | Possible subcluster types |
517 * |--------------+---------------------------|
518 * | UNALLOCATED | UNALLOCATED_PLAIN |
519 * | | ZERO_PLAIN |
520 * |--------------+---------------------------|
521 * | NORMAL | UNALLOCATED_ALLOC |
522 * | | ZERO_ALLOC |
523 * | | NORMAL |
524 * |--------------+---------------------------|
525 * | COMPRESSED | COMPRESSED |
526 * |--------------+---------------------------|
528 * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
529 * the image should be marked corrupt.
532 typedef enum QCow2ClusterType {
533 QCOW2_CLUSTER_UNALLOCATED,
534 QCOW2_CLUSTER_ZERO_PLAIN,
535 QCOW2_CLUSTER_ZERO_ALLOC,
536 QCOW2_CLUSTER_NORMAL,
537 QCOW2_CLUSTER_COMPRESSED,
538 } QCow2ClusterType;
540 typedef enum QCow2SubclusterType {
541 QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
542 QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
543 QCOW2_SUBCLUSTER_ZERO_PLAIN,
544 QCOW2_SUBCLUSTER_ZERO_ALLOC,
545 QCOW2_SUBCLUSTER_NORMAL,
546 QCOW2_SUBCLUSTER_COMPRESSED,
547 QCOW2_SUBCLUSTER_INVALID,
548 } QCow2SubclusterType;
550 typedef enum QCow2MetadataOverlap {
551 QCOW2_OL_MAIN_HEADER_BITNR = 0,
552 QCOW2_OL_ACTIVE_L1_BITNR = 1,
553 QCOW2_OL_ACTIVE_L2_BITNR = 2,
554 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
555 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
556 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
557 QCOW2_OL_INACTIVE_L1_BITNR = 6,
558 QCOW2_OL_INACTIVE_L2_BITNR = 7,
559 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
561 QCOW2_OL_MAX_BITNR = 9,
563 QCOW2_OL_NONE = 0,
564 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
565 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
566 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
567 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
568 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
569 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
570 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
571 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
572 * reads. */
573 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
574 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
575 } QCow2MetadataOverlap;
577 /* Perform all overlap checks which can be done in constant time */
578 #define QCOW2_OL_CONSTANT \
579 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
580 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
582 /* Perform all overlap checks which don't require disk access */
583 #define QCOW2_OL_CACHED \
584 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
585 QCOW2_OL_INACTIVE_L1)
587 /* Perform all overlap checks */
588 #define QCOW2_OL_ALL \
589 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
591 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
592 #define L1E_RESERVED_MASK 0x7f000000000001ffULL
593 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
594 #define L2E_STD_RESERVED_MASK 0x3f000000000001feULL
596 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
597 #define REFT_RESERVED_MASK 0x1ffULL
599 #define INV_OFFSET (-1ULL)
601 static inline bool has_subclusters(BDRVQcow2State *s)
603 return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
606 static inline size_t l2_entry_size(BDRVQcow2State *s)
608 return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
611 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
612 int idx)
614 idx *= l2_entry_size(s) / sizeof(uint64_t);
615 return be64_to_cpu(l2_slice[idx]);
618 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
619 int idx)
621 if (has_subclusters(s)) {
622 idx *= l2_entry_size(s) / sizeof(uint64_t);
623 return be64_to_cpu(l2_slice[idx + 1]);
624 } else {
625 return 0; /* For convenience only; this value has no meaning. */
629 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
630 int idx, uint64_t entry)
632 idx *= l2_entry_size(s) / sizeof(uint64_t);
633 l2_slice[idx] = cpu_to_be64(entry);
636 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
637 int idx, uint64_t bitmap)
639 assert(has_subclusters(s));
640 idx *= l2_entry_size(s) / sizeof(uint64_t);
641 l2_slice[idx + 1] = cpu_to_be64(bitmap);
644 static inline bool has_data_file(BlockDriverState *bs)
646 BDRVQcow2State *s = bs->opaque;
647 return (s->data_file != bs->file);
650 static inline bool data_file_is_raw(BlockDriverState *bs)
652 BDRVQcow2State *s = bs->opaque;
653 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
656 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
658 return offset & ~(s->cluster_size - 1);
661 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
663 return offset & (s->cluster_size - 1);
666 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
668 return offset & (s->subcluster_size - 1);
671 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
673 return (size + (s->cluster_size - 1)) >> s->cluster_bits;
676 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
678 return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
681 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
683 int shift = s->cluster_bits + s->l2_bits;
684 return (size + (1ULL << shift) - 1) >> shift;
687 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
689 return offset >> (s->l2_bits + s->cluster_bits);
692 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
694 return (offset >> s->cluster_bits) & (s->l2_size - 1);
697 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
699 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
702 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
704 return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
707 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
709 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
712 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
713 uint64_t l2_entry)
715 BDRVQcow2State *s = bs->opaque;
717 if (l2_entry & QCOW_OFLAG_COMPRESSED) {
718 return QCOW2_CLUSTER_COMPRESSED;
719 } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
720 if (l2_entry & L2E_OFFSET_MASK) {
721 return QCOW2_CLUSTER_ZERO_ALLOC;
723 return QCOW2_CLUSTER_ZERO_PLAIN;
724 } else if (!(l2_entry & L2E_OFFSET_MASK)) {
725 /* Offset 0 generally means unallocated, but it is ambiguous with
726 * external data files because 0 is a valid offset there. However, all
727 * clusters in external data files always have refcount 1, so we can
728 * rely on QCOW_OFLAG_COPIED to disambiguate. */
729 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
730 return QCOW2_CLUSTER_NORMAL;
731 } else {
732 return QCOW2_CLUSTER_UNALLOCATED;
734 } else {
735 return QCOW2_CLUSTER_NORMAL;
740 * In an image without subsclusters @l2_bitmap is ignored and
741 * @sc_index must be 0.
742 * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
743 * (this checks the whole entry and bitmap, not only the bits related
744 * to subcluster @sc_index).
746 static inline
747 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
748 uint64_t l2_entry,
749 uint64_t l2_bitmap,
750 unsigned sc_index)
752 BDRVQcow2State *s = bs->opaque;
753 QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
754 assert(sc_index < s->subclusters_per_cluster);
756 if (has_subclusters(s)) {
757 switch (type) {
758 case QCOW2_CLUSTER_COMPRESSED:
759 return QCOW2_SUBCLUSTER_COMPRESSED;
760 case QCOW2_CLUSTER_NORMAL:
761 if ((l2_bitmap >> 32) & l2_bitmap) {
762 return QCOW2_SUBCLUSTER_INVALID;
763 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
764 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
765 } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
766 return QCOW2_SUBCLUSTER_NORMAL;
767 } else {
768 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
770 case QCOW2_CLUSTER_UNALLOCATED:
771 if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
772 return QCOW2_SUBCLUSTER_INVALID;
773 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
774 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
775 } else {
776 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
778 default:
779 g_assert_not_reached();
781 } else {
782 switch (type) {
783 case QCOW2_CLUSTER_COMPRESSED:
784 return QCOW2_SUBCLUSTER_COMPRESSED;
785 case QCOW2_CLUSTER_ZERO_PLAIN:
786 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
787 case QCOW2_CLUSTER_ZERO_ALLOC:
788 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
789 case QCOW2_CLUSTER_NORMAL:
790 return QCOW2_SUBCLUSTER_NORMAL;
791 case QCOW2_CLUSTER_UNALLOCATED:
792 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
793 default:
794 g_assert_not_reached();
799 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
801 return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
802 type == QCOW2_CLUSTER_ZERO_ALLOC);
805 /* Check whether refcounts are eager or lazy */
806 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
808 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
811 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
813 return m->offset + m->cow_start.offset;
816 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
818 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
821 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
823 return r1 > r2 ? r1 - r2 : r2 - r1;
826 static inline
827 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
829 return offset >> (s->refcount_block_bits + s->cluster_bits);
832 /* qcow2.c functions */
833 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
834 int refcount_order, bool generous_increase,
835 uint64_t *refblock_count);
837 int qcow2_mark_dirty(BlockDriverState *bs);
838 int qcow2_mark_corrupt(BlockDriverState *bs);
839 int qcow2_mark_consistent(BlockDriverState *bs);
840 int qcow2_update_header(BlockDriverState *bs);
842 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
843 int64_t size, const char *message_format, ...)
844 G_GNUC_PRINTF(5, 6);
846 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
847 uint64_t entries, size_t entry_len,
848 int64_t max_size_bytes, const char *table_name,
849 Error **errp);
851 /* qcow2-refcount.c functions */
852 int coroutine_fn GRAPH_RDLOCK qcow2_refcount_init(BlockDriverState *bs);
853 void qcow2_refcount_close(BlockDriverState *bs);
855 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
856 uint64_t *refcount);
858 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
859 uint64_t addend, bool decrease,
860 enum qcow2_discard_type type);
862 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
863 uint64_t additional_clusters, bool exact_size,
864 int new_refblock_index,
865 uint64_t new_refblock_offset);
867 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
868 int64_t coroutine_fn qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
869 int64_t nb_clusters);
870 int64_t coroutine_fn qcow2_alloc_bytes(BlockDriverState *bs, int size);
871 void qcow2_free_clusters(BlockDriverState *bs,
872 int64_t offset, int64_t size,
873 enum qcow2_discard_type type);
874 void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
875 enum qcow2_discard_type type);
877 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
878 int64_t l1_table_offset, int l1_size, int addend);
880 int qcow2_flush_caches(BlockDriverState *bs);
881 int qcow2_write_caches(BlockDriverState *bs);
882 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
883 BdrvCheckMode fix);
885 void qcow2_process_discards(BlockDriverState *bs, int ret);
887 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
888 int64_t size);
889 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
890 int64_t size, bool data_file);
891 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
892 void **refcount_table,
893 int64_t *refcount_table_size,
894 int64_t offset, int64_t size);
896 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
897 BlockDriverAmendStatusCB *status_cb,
898 void *cb_opaque, Error **errp);
899 int coroutine_fn GRAPH_RDLOCK qcow2_shrink_reftable(BlockDriverState *bs);
900 int64_t coroutine_fn qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
902 int coroutine_fn GRAPH_RDLOCK
903 qcow2_detect_metadata_preallocation(BlockDriverState *bs);
905 /* qcow2-cluster.c functions */
906 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
907 bool exact_size);
909 int coroutine_fn GRAPH_RDLOCK
910 qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
912 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
913 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
914 uint8_t *buf, int nb_sectors, bool enc, Error **errp);
916 int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
917 unsigned int *bytes, uint64_t *host_offset,
918 QCow2SubclusterType *subcluster_type);
919 int coroutine_fn qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
920 unsigned int *bytes,
921 uint64_t *host_offset, QCowL2Meta **m);
922 int coroutine_fn qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
923 uint64_t offset,
924 int compressed_size,
925 uint64_t *host_offset);
926 void qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry,
927 uint64_t *coffset, int *csize);
929 int coroutine_fn GRAPH_RDLOCK
930 qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
932 void coroutine_fn qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
933 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
934 uint64_t bytes, enum qcow2_discard_type type,
935 bool full_discard);
937 int coroutine_fn GRAPH_RDLOCK
938 qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
939 int flags);
941 int qcow2_expand_zero_clusters(BlockDriverState *bs,
942 BlockDriverAmendStatusCB *status_cb,
943 void *cb_opaque);
945 /* qcow2-snapshot.c functions */
946 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
947 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
948 int qcow2_snapshot_delete(BlockDriverState *bs,
949 const char *snapshot_id,
950 const char *name,
951 Error **errp);
952 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
953 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
954 const char *snapshot_id,
955 const char *name,
956 Error **errp);
958 void qcow2_free_snapshots(BlockDriverState *bs);
959 int coroutine_fn GRAPH_RDLOCK
960 qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
961 int qcow2_write_snapshots(BlockDriverState *bs);
963 int coroutine_fn GRAPH_RDLOCK
964 qcow2_check_read_snapshot_table(BlockDriverState *bs, BdrvCheckResult *result,
965 BdrvCheckMode fix);
967 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
968 BdrvCheckResult *result,
969 BdrvCheckMode fix);
971 /* qcow2-cache.c functions */
972 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
973 unsigned table_size);
974 int qcow2_cache_destroy(Qcow2Cache *c);
976 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
977 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
978 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
979 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
980 Qcow2Cache *dependency);
981 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
983 void qcow2_cache_clean_unused(Qcow2Cache *c);
984 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
986 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
987 void **table);
988 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
989 void **table);
990 void qcow2_cache_put(Qcow2Cache *c, void **table);
991 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
992 void qcow2_cache_discard(Qcow2Cache *c, void *table);
994 /* qcow2-bitmap.c functions */
995 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
996 void **refcount_table,
997 int64_t *refcount_table_size);
998 bool coroutine_fn qcow2_load_dirty_bitmaps(BlockDriverState *bs,
999 bool *header_updated, Error **errp);
1000 bool qcow2_get_bitmap_info_list(BlockDriverState *bs,
1001 Qcow2BitmapInfoList **info_list, Error **errp);
1002 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
1003 int coroutine_fn qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
1004 bool qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
1005 bool release_stored, Error **errp);
1006 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
1007 bool coroutine_fn qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
1008 const char *name,
1009 uint32_t granularity,
1010 Error **errp);
1011 int coroutine_fn qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
1012 const char *name,
1013 Error **errp);
1014 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
1015 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
1016 uint32_t cluster_size);
1018 ssize_t coroutine_fn
1019 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
1020 const void *src, size_t src_size);
1021 ssize_t coroutine_fn
1022 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
1023 const void *src, size_t src_size);
1024 int coroutine_fn
1025 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
1026 uint64_t guest_offset, void *buf, size_t len);
1027 int coroutine_fn
1028 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
1029 uint64_t guest_offset, void *buf, size_t len);
1031 #endif