Merge remote-tracking branch 'remotes/ehabkost/tags/python-next-pull-request' into...
[qemu.git] / block / qcow2.h
1 /*
2 * Block driver for the QCOW version 2 format
3 *
4 * Copyright (c) 2004-2006 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #ifndef BLOCK_QCOW2_H
26 #define BLOCK_QCOW2_H
27
28 #include "crypto/block.h"
29 #include "qemu/coroutine.h"
30 #include "qemu/units.h"
31 #include "block/block_int.h"
32
33 //#define DEBUG_ALLOC
34 //#define DEBUG_ALLOC2
35 //#define DEBUG_EXT
36
37 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
38
39 #define QCOW_CRYPT_NONE 0
40 #define QCOW_CRYPT_AES 1
41 #define QCOW_CRYPT_LUKS 2
42
43 #define QCOW_MAX_CRYPT_CLUSTERS 32
44 #define QCOW_MAX_SNAPSHOTS 65536
45
46 /* Field widths in qcow2 mean normal cluster offsets cannot reach
47 * 64PB; depending on cluster size, compressed clusters can have a
48 * smaller limit (64PB for up to 16k clusters, then ramps down to
49 * 512TB for 2M clusters). */
50 #define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1)
51
52 /* 8 MB refcount table is enough for 2 PB images at 64k cluster size
53 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
54 #define QCOW_MAX_REFTABLE_SIZE (8 * MiB)
55
56 /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
57 * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
58 #define QCOW_MAX_L1_SIZE (32 * MiB)
59
60 /* Allow for an average of 1k per snapshot table entry, should be plenty of
61 * space for snapshot names and IDs */
62 #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS)
63
64 /* Maximum amount of extra data per snapshot table entry to accept */
65 #define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024
66
67 /* Bitmap header extension constraints */
68 #define QCOW2_MAX_BITMAPS 65535
69 #define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS)
70
71 /* Maximum of parallel sub-request per guest request */
72 #define QCOW2_MAX_WORKERS 8
73
74 /* indicate that the refcount of the referenced cluster is exactly one. */
75 #define QCOW_OFLAG_COPIED (1ULL << 63)
76 /* indicate that the cluster is compressed (they never have the copied flag) */
77 #define QCOW_OFLAG_COMPRESSED (1ULL << 62)
78 /* The cluster reads as all zeros */
79 #define QCOW_OFLAG_ZERO (1ULL << 0)
80
81 #define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32
82
83 /* The subcluster X [0..31] is allocated */
84 #define QCOW_OFLAG_SUB_ALLOC(X) (1ULL << (X))
85 /* The subcluster X [0..31] reads as zeroes */
86 #define QCOW_OFLAG_SUB_ZERO(X) (QCOW_OFLAG_SUB_ALLOC(X) << 32)
87 /* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */
88 #define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \
89 (QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X))
90 /* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */
91 #define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \
92 (QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32)
93 /* L2 entry bitmap with all allocation bits set */
94 #define QCOW_L2_BITMAP_ALL_ALLOC (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32))
95 /* L2 entry bitmap with all "read as zeroes" bits set */
96 #define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32))
97
98 /* Size of normal and extended L2 entries */
99 #define L2E_SIZE_NORMAL (sizeof(uint64_t))
100 #define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2)
101
102 /* Size of L1 table entries */
103 #define L1E_SIZE (sizeof(uint64_t))
104
105 /* Size of reftable entries */
106 #define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))
107
108 #define MIN_CLUSTER_BITS 9
109 #define MAX_CLUSTER_BITS 21
110
111 /* Defined in the qcow2 spec (compressed cluster descriptor) */
112 #define QCOW2_COMPRESSED_SECTOR_SIZE 512U
113 #define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL))
114
115 /* Must be at least 2 to cover COW */
116 #define MIN_L2_CACHE_SIZE 2 /* cache entries */
117
118 /* Must be at least 4 to cover all cases of refcount table growth */
119 #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */
120
121 #ifdef CONFIG_LINUX
122 #define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB)
123 #define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */
124 #else
125 #define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB)
126 /* Cache clean interval is currently available only on Linux, so must be 0 */
127 #define DEFAULT_CACHE_CLEAN_INTERVAL 0
128 #endif
129
130 #define DEFAULT_CLUSTER_SIZE 65536
131
132 #define QCOW2_OPT_DATA_FILE "data-file"
133 #define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
134 #define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
135 #define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
136 #define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
137 #define QCOW2_OPT_OVERLAP "overlap-check"
138 #define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template"
139 #define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
140 #define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
141 #define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
142 #define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
143 #define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
144 #define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
145 #define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
146 #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
147 #define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory"
148 #define QCOW2_OPT_CACHE_SIZE "cache-size"
149 #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size"
150 #define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size"
151 #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size"
152 #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval"
153
154 typedef struct QCowHeader {
155 uint32_t magic;
156 uint32_t version;
157 uint64_t backing_file_offset;
158 uint32_t backing_file_size;
159 uint32_t cluster_bits;
160 uint64_t size; /* in bytes */
161 uint32_t crypt_method;
162 uint32_t l1_size; /* XXX: save number of clusters instead ? */
163 uint64_t l1_table_offset;
164 uint64_t refcount_table_offset;
165 uint32_t refcount_table_clusters;
166 uint32_t nb_snapshots;
167 uint64_t snapshots_offset;
168
169 /* The following fields are only valid for version >= 3 */
170 uint64_t incompatible_features;
171 uint64_t compatible_features;
172 uint64_t autoclear_features;
173
174 uint32_t refcount_order;
175 uint32_t header_length;
176
177 /* Additional fields */
178 uint8_t compression_type;
179
180 /* header must be a multiple of 8 */
181 uint8_t padding[7];
182 } QEMU_PACKED QCowHeader;
183
184 QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
185
186 typedef struct QEMU_PACKED QCowSnapshotHeader {
187 /* header is 8 byte aligned */
188 uint64_t l1_table_offset;
189
190 uint32_t l1_size;
191 uint16_t id_str_size;
192 uint16_t name_size;
193
194 uint32_t date_sec;
195 uint32_t date_nsec;
196
197 uint64_t vm_clock_nsec;
198
199 uint32_t vm_state_size;
200 uint32_t extra_data_size; /* for extension */
201 /* extra data follows */
202 /* id_str follows */
203 /* name follows */
204 } QCowSnapshotHeader;
205
206 typedef struct QEMU_PACKED QCowSnapshotExtraData {
207 uint64_t vm_state_size_large;
208 uint64_t disk_size;
209 } QCowSnapshotExtraData;
210
211
212 typedef struct QCowSnapshot {
213 uint64_t l1_table_offset;
214 uint32_t l1_size;
215 char *id_str;
216 char *name;
217 uint64_t disk_size;
218 uint64_t vm_state_size;
219 uint32_t date_sec;
220 uint32_t date_nsec;
221 uint64_t vm_clock_nsec;
222 /* Size of all extra data, including QCowSnapshotExtraData if available */
223 uint32_t extra_data_size;
224 /* Data beyond QCowSnapshotExtraData, if any */
225 void *unknown_extra_data;
226 } QCowSnapshot;
227
228 struct Qcow2Cache;
229 typedef struct Qcow2Cache Qcow2Cache;
230
231 typedef struct Qcow2CryptoHeaderExtension {
232 uint64_t offset;
233 uint64_t length;
234 } QEMU_PACKED Qcow2CryptoHeaderExtension;
235
236 typedef struct Qcow2UnknownHeaderExtension {
237 uint32_t magic;
238 uint32_t len;
239 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
240 uint8_t data[];
241 } Qcow2UnknownHeaderExtension;
242
243 enum {
244 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
245 QCOW2_FEAT_TYPE_COMPATIBLE = 1,
246 QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
247 };
248
249 /* Incompatible feature bits */
250 enum {
251 QCOW2_INCOMPAT_DIRTY_BITNR = 0,
252 QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
253 QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
254 QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
255 QCOW2_INCOMPAT_EXTL2_BITNR = 4,
256 QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
257 QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
258 QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
259 QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
260 QCOW2_INCOMPAT_EXTL2 = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
261
262 QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
263 | QCOW2_INCOMPAT_CORRUPT
264 | QCOW2_INCOMPAT_DATA_FILE
265 | QCOW2_INCOMPAT_COMPRESSION
266 | QCOW2_INCOMPAT_EXTL2,
267 };
268
269 /* Compatible feature bits */
270 enum {
271 QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
272 QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
273
274 QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
275 };
276
277 /* Autoclear feature bits */
278 enum {
279 QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0,
280 QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1,
281 QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR,
282 QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
283
284 QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS
285 | QCOW2_AUTOCLEAR_DATA_FILE_RAW,
286 };
287
288 enum qcow2_discard_type {
289 QCOW2_DISCARD_NEVER = 0,
290 QCOW2_DISCARD_ALWAYS,
291 QCOW2_DISCARD_REQUEST,
292 QCOW2_DISCARD_SNAPSHOT,
293 QCOW2_DISCARD_OTHER,
294 QCOW2_DISCARD_MAX
295 };
296
297 typedef struct Qcow2Feature {
298 uint8_t type;
299 uint8_t bit;
300 char name[46];
301 } QEMU_PACKED Qcow2Feature;
302
303 typedef struct Qcow2DiscardRegion {
304 BlockDriverState *bs;
305 uint64_t offset;
306 uint64_t bytes;
307 QTAILQ_ENTRY(Qcow2DiscardRegion) next;
308 } Qcow2DiscardRegion;
309
310 typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array,
311 uint64_t index);
312 typedef void Qcow2SetRefcountFunc(void *refcount_array,
313 uint64_t index, uint64_t value);
314
315 typedef struct Qcow2BitmapHeaderExt {
316 uint32_t nb_bitmaps;
317 uint32_t reserved32;
318 uint64_t bitmap_directory_size;
319 uint64_t bitmap_directory_offset;
320 } QEMU_PACKED Qcow2BitmapHeaderExt;
321
322 #define QCOW2_MAX_THREADS 4
323
324 typedef struct BDRVQcow2State {
325 int cluster_bits;
326 int cluster_size;
327 int l2_slice_size;
328 int subcluster_bits;
329 int subcluster_size;
330 int subclusters_per_cluster;
331 int l2_bits;
332 int l2_size;
333 int l1_size;
334 int l1_vm_state_index;
335 int refcount_block_bits;
336 int refcount_block_size;
337 int csize_shift;
338 int csize_mask;
339 uint64_t cluster_offset_mask;
340 uint64_t l1_table_offset;
341 uint64_t *l1_table;
342
343 Qcow2Cache* l2_table_cache;
344 Qcow2Cache* refcount_block_cache;
345 QEMUTimer *cache_clean_timer;
346 unsigned cache_clean_interval;
347
348 QLIST_HEAD(, QCowL2Meta) cluster_allocs;
349
350 uint64_t *refcount_table;
351 uint64_t refcount_table_offset;
352 uint32_t refcount_table_size;
353 uint32_t max_refcount_table_index; /* Last used entry in refcount_table */
354 uint64_t free_cluster_index;
355 uint64_t free_byte_offset;
356
357 CoMutex lock;
358
359 Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */
360 QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
361 QCryptoBlock *crypto; /* Disk encryption format driver */
362 bool crypt_physical_offset; /* Whether to use virtual or physical offset
363 for encryption initialization vector tweak */
364 uint32_t crypt_method_header;
365 uint64_t snapshots_offset;
366 int snapshots_size;
367 unsigned int nb_snapshots;
368 QCowSnapshot *snapshots;
369
370 uint32_t nb_bitmaps;
371 uint64_t bitmap_directory_size;
372 uint64_t bitmap_directory_offset;
373
374 int flags;
375 int qcow_version;
376 bool use_lazy_refcounts;
377 int refcount_order;
378 int refcount_bits;
379 uint64_t refcount_max;
380
381 Qcow2GetRefcountFunc *get_refcount;
382 Qcow2SetRefcountFunc *set_refcount;
383
384 bool discard_passthrough[QCOW2_DISCARD_MAX];
385
386 int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
387 bool signaled_corruption;
388
389 uint64_t incompatible_features;
390 uint64_t compatible_features;
391 uint64_t autoclear_features;
392
393 size_t unknown_header_fields_size;
394 void* unknown_header_fields;
395 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
396 QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
397 bool cache_discards;
398
399 /* Backing file path and format as stored in the image (this is not the
400 * effective path/format, which may be the result of a runtime option
401 * override) */
402 char *image_backing_file;
403 char *image_backing_format;
404 char *image_data_file;
405
406 CoQueue thread_task_queue;
407 int nb_threads;
408
409 BdrvChild *data_file;
410
411 bool metadata_preallocation_checked;
412 bool metadata_preallocation;
413 /*
414 * Compression type used for the image. Default: 0 - ZLIB
415 * The image compression type is set on image creation.
416 * For now, the only way to change the compression type
417 * is to convert the image with the desired compression type set.
418 */
419 Qcow2CompressionType compression_type;
420 } BDRVQcow2State;
421
422 typedef struct Qcow2COWRegion {
423 /**
424 * Offset of the COW region in bytes from the start of the first cluster
425 * touched by the request.
426 */
427 unsigned offset;
428
429 /** Number of bytes to copy */
430 unsigned nb_bytes;
431 } Qcow2COWRegion;
432
433 /**
434 * Describes an in-flight (part of a) write request that writes to clusters
435 * that are not referenced in their L2 table yet.
436 */
437 typedef struct QCowL2Meta
438 {
439 /** Guest offset of the first newly allocated cluster */
440 uint64_t offset;
441
442 /** Host offset of the first newly allocated cluster */
443 uint64_t alloc_offset;
444
445 /** Number of newly allocated clusters */
446 int nb_clusters;
447
448 /** Do not free the old clusters */
449 bool keep_old_clusters;
450
451 /**
452 * Requests that overlap with this allocation and wait to be restarted
453 * when the allocating request has completed.
454 */
455 CoQueue dependent_requests;
456
457 /**
458 * The COW Region between the start of the first allocated cluster and the
459 * area the guest actually writes to.
460 */
461 Qcow2COWRegion cow_start;
462
463 /**
464 * The COW Region between the area the guest actually writes to and the
465 * end of the last allocated cluster.
466 */
467 Qcow2COWRegion cow_end;
468
469 /*
470 * Indicates that COW regions are already handled and do not require
471 * any more processing.
472 */
473 bool skip_cow;
474
475 /**
476 * Indicates that this is not a normal write request but a preallocation.
477 * If the image has extended L2 entries this means that no new individual
478 * subclusters will be marked as allocated in the L2 bitmap (but any
479 * existing contents of that bitmap will be kept).
480 */
481 bool prealloc;
482
483 /**
484 * The I/O vector with the data from the actual guest write request.
485 * If non-NULL, this is meant to be merged together with the data
486 * from @cow_start and @cow_end into one single write operation.
487 */
488 QEMUIOVector *data_qiov;
489 size_t data_qiov_offset;
490
491 /** Pointer to next L2Meta of the same write request */
492 struct QCowL2Meta *next;
493
494 QLIST_ENTRY(QCowL2Meta) next_in_flight;
495 } QCowL2Meta;
496
497 /*
498 * In images with standard L2 entries all clusters are treated as if
499 * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
500 * can be mapped to each other and have the exact same meaning
501 * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
502 *
503 * In images with extended L2 entries QCow2ClusterType refers to the
504 * complete cluster and QCow2SubclusterType to each of the individual
505 * subclusters, so there are several possible combinations:
506 *
507 * |--------------+---------------------------|
508 * | Cluster type | Possible subcluster types |
509 * |--------------+---------------------------|
510 * | UNALLOCATED | UNALLOCATED_PLAIN |
511 * | | ZERO_PLAIN |
512 * |--------------+---------------------------|
513 * | NORMAL | UNALLOCATED_ALLOC |
514 * | | ZERO_ALLOC |
515 * | | NORMAL |
516 * |--------------+---------------------------|
517 * | COMPRESSED | COMPRESSED |
518 * |--------------+---------------------------|
519 *
520 * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
521 * the image should be marked corrupt.
522 */
523
524 typedef enum QCow2ClusterType {
525 QCOW2_CLUSTER_UNALLOCATED,
526 QCOW2_CLUSTER_ZERO_PLAIN,
527 QCOW2_CLUSTER_ZERO_ALLOC,
528 QCOW2_CLUSTER_NORMAL,
529 QCOW2_CLUSTER_COMPRESSED,
530 } QCow2ClusterType;
531
532 typedef enum QCow2SubclusterType {
533 QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
534 QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
535 QCOW2_SUBCLUSTER_ZERO_PLAIN,
536 QCOW2_SUBCLUSTER_ZERO_ALLOC,
537 QCOW2_SUBCLUSTER_NORMAL,
538 QCOW2_SUBCLUSTER_COMPRESSED,
539 QCOW2_SUBCLUSTER_INVALID,
540 } QCow2SubclusterType;
541
542 typedef enum QCow2MetadataOverlap {
543 QCOW2_OL_MAIN_HEADER_BITNR = 0,
544 QCOW2_OL_ACTIVE_L1_BITNR = 1,
545 QCOW2_OL_ACTIVE_L2_BITNR = 2,
546 QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
547 QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
548 QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
549 QCOW2_OL_INACTIVE_L1_BITNR = 6,
550 QCOW2_OL_INACTIVE_L2_BITNR = 7,
551 QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8,
552
553 QCOW2_OL_MAX_BITNR = 9,
554
555 QCOW2_OL_NONE = 0,
556 QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
557 QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
558 QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
559 QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
560 QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
561 QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
562 QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
563 /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
564 * reads. */
565 QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
566 QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR),
567 } QCow2MetadataOverlap;
568
569 /* Perform all overlap checks which can be done in constant time */
570 #define QCOW2_OL_CONSTANT \
571 (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
572 QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY)
573
574 /* Perform all overlap checks which don't require disk access */
575 #define QCOW2_OL_CACHED \
576 (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
577 QCOW2_OL_INACTIVE_L1)
578
579 /* Perform all overlap checks */
580 #define QCOW2_OL_ALL \
581 (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
582
583 #define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
584 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
585 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
586
587 #define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
588
589 #define INV_OFFSET (-1ULL)
590
591 static inline bool has_subclusters(BDRVQcow2State *s)
592 {
593 return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
594 }
595
596 static inline size_t l2_entry_size(BDRVQcow2State *s)
597 {
598 return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
599 }
600
601 static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
602 int idx)
603 {
604 idx *= l2_entry_size(s) / sizeof(uint64_t);
605 return be64_to_cpu(l2_slice[idx]);
606 }
607
608 static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
609 int idx)
610 {
611 if (has_subclusters(s)) {
612 idx *= l2_entry_size(s) / sizeof(uint64_t);
613 return be64_to_cpu(l2_slice[idx + 1]);
614 } else {
615 return 0; /* For convenience only; this value has no meaning. */
616 }
617 }
618
619 static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
620 int idx, uint64_t entry)
621 {
622 idx *= l2_entry_size(s) / sizeof(uint64_t);
623 l2_slice[idx] = cpu_to_be64(entry);
624 }
625
626 static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
627 int idx, uint64_t bitmap)
628 {
629 assert(has_subclusters(s));
630 idx *= l2_entry_size(s) / sizeof(uint64_t);
631 l2_slice[idx + 1] = cpu_to_be64(bitmap);
632 }
633
634 static inline bool has_data_file(BlockDriverState *bs)
635 {
636 BDRVQcow2State *s = bs->opaque;
637 return (s->data_file != bs->file);
638 }
639
640 static inline bool data_file_is_raw(BlockDriverState *bs)
641 {
642 BDRVQcow2State *s = bs->opaque;
643 return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW);
644 }
645
646 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
647 {
648 return offset & ~(s->cluster_size - 1);
649 }
650
651 static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset)
652 {
653 return offset & (s->cluster_size - 1);
654 }
655
656 static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
657 {
658 return offset & (s->subcluster_size - 1);
659 }
660
661 static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
662 {
663 return (size + (s->cluster_size - 1)) >> s->cluster_bits;
664 }
665
666 static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
667 {
668 return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
669 }
670
671 static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
672 {
673 int shift = s->cluster_bits + s->l2_bits;
674 return (size + (1ULL << shift) - 1) >> shift;
675 }
676
677 static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset)
678 {
679 return offset >> (s->l2_bits + s->cluster_bits);
680 }
681
682 static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset)
683 {
684 return (offset >> s->cluster_bits) & (s->l2_size - 1);
685 }
686
687 static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset)
688 {
689 return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
690 }
691
692 static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
693 {
694 return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
695 }
696
697 static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
698 {
699 return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
700 }
701
702 static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
703 uint64_t l2_entry)
704 {
705 BDRVQcow2State *s = bs->opaque;
706
707 if (l2_entry & QCOW_OFLAG_COMPRESSED) {
708 return QCOW2_CLUSTER_COMPRESSED;
709 } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
710 if (l2_entry & L2E_OFFSET_MASK) {
711 return QCOW2_CLUSTER_ZERO_ALLOC;
712 }
713 return QCOW2_CLUSTER_ZERO_PLAIN;
714 } else if (!(l2_entry & L2E_OFFSET_MASK)) {
715 /* Offset 0 generally means unallocated, but it is ambiguous with
716 * external data files because 0 is a valid offset there. However, all
717 * clusters in external data files always have refcount 1, so we can
718 * rely on QCOW_OFLAG_COPIED to disambiguate. */
719 if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) {
720 return QCOW2_CLUSTER_NORMAL;
721 } else {
722 return QCOW2_CLUSTER_UNALLOCATED;
723 }
724 } else {
725 return QCOW2_CLUSTER_NORMAL;
726 }
727 }
728
729 /*
730 * In an image without subsclusters @l2_bitmap is ignored and
731 * @sc_index must be 0.
732 * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
733 * (this checks the whole entry and bitmap, not only the bits related
734 * to subcluster @sc_index).
735 */
736 static inline
737 QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
738 uint64_t l2_entry,
739 uint64_t l2_bitmap,
740 unsigned sc_index)
741 {
742 BDRVQcow2State *s = bs->opaque;
743 QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
744 assert(sc_index < s->subclusters_per_cluster);
745
746 if (has_subclusters(s)) {
747 switch (type) {
748 case QCOW2_CLUSTER_COMPRESSED:
749 return QCOW2_SUBCLUSTER_COMPRESSED;
750 case QCOW2_CLUSTER_NORMAL:
751 if ((l2_bitmap >> 32) & l2_bitmap) {
752 return QCOW2_SUBCLUSTER_INVALID;
753 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
754 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
755 } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
756 return QCOW2_SUBCLUSTER_NORMAL;
757 } else {
758 return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
759 }
760 case QCOW2_CLUSTER_UNALLOCATED:
761 if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
762 return QCOW2_SUBCLUSTER_INVALID;
763 } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
764 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
765 } else {
766 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
767 }
768 default:
769 g_assert_not_reached();
770 }
771 } else {
772 switch (type) {
773 case QCOW2_CLUSTER_COMPRESSED:
774 return QCOW2_SUBCLUSTER_COMPRESSED;
775 case QCOW2_CLUSTER_ZERO_PLAIN:
776 return QCOW2_SUBCLUSTER_ZERO_PLAIN;
777 case QCOW2_CLUSTER_ZERO_ALLOC:
778 return QCOW2_SUBCLUSTER_ZERO_ALLOC;
779 case QCOW2_CLUSTER_NORMAL:
780 return QCOW2_SUBCLUSTER_NORMAL;
781 case QCOW2_CLUSTER_UNALLOCATED:
782 return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
783 default:
784 g_assert_not_reached();
785 }
786 }
787 }
788
789 static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
790 {
791 return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
792 type == QCOW2_CLUSTER_ZERO_ALLOC);
793 }
794
795 /* Check whether refcounts are eager or lazy */
796 static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
797 {
798 return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
799 }
800
801 static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
802 {
803 return m->offset + m->cow_start.offset;
804 }
805
806 static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
807 {
808 return m->offset + m->cow_end.offset + m->cow_end.nb_bytes;
809 }
810
811 static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2)
812 {
813 return r1 > r2 ? r1 - r2 : r2 - r1;
814 }
815
816 static inline
817 uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset)
818 {
819 return offset >> (s->refcount_block_bits + s->cluster_bits);
820 }
821
822 /* qcow2.c functions */
823 int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
824 int refcount_order, bool generous_increase,
825 uint64_t *refblock_count);
826
827 int qcow2_mark_dirty(BlockDriverState *bs);
828 int qcow2_mark_corrupt(BlockDriverState *bs);
829 int qcow2_mark_consistent(BlockDriverState *bs);
830 int qcow2_update_header(BlockDriverState *bs);
831
832 void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
833 int64_t size, const char *message_format, ...)
834 GCC_FMT_ATTR(5, 6);
835
836 int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
837 uint64_t entries, size_t entry_len,
838 int64_t max_size_bytes, const char *table_name,
839 Error **errp);
840
841 /* qcow2-refcount.c functions */
842 int qcow2_refcount_init(BlockDriverState *bs);
843 void qcow2_refcount_close(BlockDriverState *bs);
844
845 int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index,
846 uint64_t *refcount);
847
848 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
849 uint64_t addend, bool decrease,
850 enum qcow2_discard_type type);
851
852 int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset,
853 uint64_t additional_clusters, bool exact_size,
854 int new_refblock_index,
855 uint64_t new_refblock_offset);
856
857 int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
858 int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
859 int64_t nb_clusters);
860 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
861 void qcow2_free_clusters(BlockDriverState *bs,
862 int64_t offset, int64_t size,
863 enum qcow2_discard_type type);
864 void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
865 enum qcow2_discard_type type);
866
867 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
868 int64_t l1_table_offset, int l1_size, int addend);
869
870 int coroutine_fn qcow2_flush_caches(BlockDriverState *bs);
871 int coroutine_fn qcow2_write_caches(BlockDriverState *bs);
872 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
873 BdrvCheckMode fix);
874
875 void qcow2_process_discards(BlockDriverState *bs, int ret);
876
877 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
878 int64_t size);
879 int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
880 int64_t size, bool data_file);
881 int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res,
882 void **refcount_table,
883 int64_t *refcount_table_size,
884 int64_t offset, int64_t size);
885
886 int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order,
887 BlockDriverAmendStatusCB *status_cb,
888 void *cb_opaque, Error **errp);
889 int qcow2_shrink_reftable(BlockDriverState *bs);
890 int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size);
891 int qcow2_detect_metadata_preallocation(BlockDriverState *bs);
892
893 /* qcow2-cluster.c functions */
894 int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
895 bool exact_size);
896 int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size);
897 int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
898 int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
899 uint8_t *buf, int nb_sectors, bool enc, Error **errp);
900
901 int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
902 unsigned int *bytes, uint64_t *host_offset,
903 QCow2SubclusterType *subcluster_type);
904 int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
905 unsigned int *bytes, uint64_t *host_offset,
906 QCowL2Meta **m);
907 int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
908 uint64_t offset,
909 int compressed_size,
910 uint64_t *host_offset);
911
912 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
913 void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
914 int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
915 uint64_t bytes, enum qcow2_discard_type type,
916 bool full_discard);
917 int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset,
918 uint64_t bytes, int flags);
919
920 int qcow2_expand_zero_clusters(BlockDriverState *bs,
921 BlockDriverAmendStatusCB *status_cb,
922 void *cb_opaque);
923
924 /* qcow2-snapshot.c functions */
925 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
926 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
927 int qcow2_snapshot_delete(BlockDriverState *bs,
928 const char *snapshot_id,
929 const char *name,
930 Error **errp);
931 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
932 int qcow2_snapshot_load_tmp(BlockDriverState *bs,
933 const char *snapshot_id,
934 const char *name,
935 Error **errp);
936
937 void qcow2_free_snapshots(BlockDriverState *bs);
938 int qcow2_read_snapshots(BlockDriverState *bs, Error **errp);
939 int qcow2_write_snapshots(BlockDriverState *bs);
940
941 int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs,
942 BdrvCheckResult *result,
943 BdrvCheckMode fix);
944 int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs,
945 BdrvCheckResult *result,
946 BdrvCheckMode fix);
947
948 /* qcow2-cache.c functions */
949 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables,
950 unsigned table_size);
951 int qcow2_cache_destroy(Qcow2Cache *c);
952
953 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
954 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
955 int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c);
956 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
957 Qcow2Cache *dependency);
958 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
959
960 void qcow2_cache_clean_unused(Qcow2Cache *c);
961 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
962
963 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
964 void **table);
965 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
966 void **table);
967 void qcow2_cache_put(Qcow2Cache *c, void **table);
968 void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset);
969 void qcow2_cache_discard(Qcow2Cache *c, void *table);
970
971 /* qcow2-bitmap.c functions */
972 int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
973 void **refcount_table,
974 int64_t *refcount_table_size);
975 bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
976 Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
977 Error **errp);
978 int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
979 int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
980 void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
981 bool release_stored, Error **errp);
982 int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
983 bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
984 const char *name,
985 uint32_t granularity,
986 Error **errp);
987 int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
988 const char *name,
989 Error **errp);
990 bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
991 uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
992 uint32_t cluster_size);
993
994 ssize_t coroutine_fn
995 qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
996 const void *src, size_t src_size);
997 ssize_t coroutine_fn
998 qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size,
999 const void *src, size_t src_size);
1000 int coroutine_fn
1001 qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset,
1002 uint64_t guest_offset, void *buf, size_t len);
1003 int coroutine_fn
1004 qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset,
1005 uint64_t guest_offset, void *buf, size_t len);
1006
1007 #endif