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
24 #include "qemu-common.h"
25 #include "block_int.h"
29 #include "block/qcow2.h"
30 #include "qemu-error.h"
35 Differences with QCOW:
37 - Support for multiple incremental snapshots.
38 - Memory management by reference counts.
39 - Clusters which have a reference count of one have the bit
40 QCOW_OFLAG_COPIED to optimize write performance.
41 - Size of compressed clusters is stored in sectors to reduce bit usage
42 in the cluster offsets.
43 - Support for storing additional data (such as the VM state) in the
45 - If a backing store is used, the cluster size is not constrained
46 (could be backported to QCOW).
47 - L2 tables have always a size of one cluster.
55 #define QCOW2_EXT_MAGIC_END 0
56 #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
57 #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
59 static int qcow2_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
61 const QCowHeader
*cow_header
= (const void *)buf
;
63 if (buf_size
>= sizeof(QCowHeader
) &&
64 be32_to_cpu(cow_header
->magic
) == QCOW_MAGIC
&&
65 be32_to_cpu(cow_header
->version
) >= 2)
73 * read qcow2 extension and fill bs
74 * start reading from start_offset
75 * finish reading upon magic of value 0 or when end_offset reached
76 * unknown magic is skipped (future extension this version knows nothing about)
77 * return 0 upon success, non-0 otherwise
79 static int qcow2_read_extensions(BlockDriverState
*bs
, uint64_t start_offset
,
80 uint64_t end_offset
, void **p_feature_table
)
82 BDRVQcowState
*s
= bs
->opaque
;
88 printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset
, end_offset
);
90 offset
= start_offset
;
91 while (offset
< end_offset
) {
95 if (offset
> s
->cluster_size
)
96 printf("qcow2_read_extension: suspicious offset %lu\n", offset
);
98 printf("attempting to read extended header in offset %lu\n", offset
);
101 if (bdrv_pread(bs
->file
, offset
, &ext
, sizeof(ext
)) != sizeof(ext
)) {
102 fprintf(stderr
, "qcow2_read_extension: ERROR: "
103 "pread fail from offset %" PRIu64
"\n",
107 be32_to_cpus(&ext
.magic
);
108 be32_to_cpus(&ext
.len
);
109 offset
+= sizeof(ext
);
111 printf("ext.magic = 0x%x\n", ext
.magic
);
113 if (ext
.len
> end_offset
- offset
) {
114 error_report("Header extension too large");
119 case QCOW2_EXT_MAGIC_END
:
122 case QCOW2_EXT_MAGIC_BACKING_FORMAT
:
123 if (ext
.len
>= sizeof(bs
->backing_format
)) {
124 fprintf(stderr
, "ERROR: ext_backing_format: len=%u too large"
126 ext
.len
, sizeof(bs
->backing_format
));
129 if (bdrv_pread(bs
->file
, offset
, bs
->backing_format
,
132 bs
->backing_format
[ext
.len
] = '\0';
134 printf("Qcow2: Got format extension %s\n", bs
->backing_format
);
138 case QCOW2_EXT_MAGIC_FEATURE_TABLE
:
139 if (p_feature_table
!= NULL
) {
140 void* feature_table
= g_malloc0(ext
.len
+ 2 * sizeof(Qcow2Feature
));
141 ret
= bdrv_pread(bs
->file
, offset
, feature_table
, ext
.len
);
146 *p_feature_table
= feature_table
;
151 /* unknown magic - save it in case we need to rewrite the header */
153 Qcow2UnknownHeaderExtension
*uext
;
155 uext
= g_malloc0(sizeof(*uext
) + ext
.len
);
156 uext
->magic
= ext
.magic
;
158 QLIST_INSERT_HEAD(&s
->unknown_header_ext
, uext
, next
);
160 ret
= bdrv_pread(bs
->file
, offset
, uext
->data
, uext
->len
);
168 offset
+= ((ext
.len
+ 7) & ~7);
174 static void cleanup_unknown_header_ext(BlockDriverState
*bs
)
176 BDRVQcowState
*s
= bs
->opaque
;
177 Qcow2UnknownHeaderExtension
*uext
, *next
;
179 QLIST_FOREACH_SAFE(uext
, &s
->unknown_header_ext
, next
, next
) {
180 QLIST_REMOVE(uext
, next
);
185 static void GCC_FMT_ATTR(2, 3) report_unsupported(BlockDriverState
*bs
,
186 const char *fmt
, ...)
192 vsnprintf(msg
, sizeof(msg
), fmt
, ap
);
195 qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE
,
196 bs
->device_name
, "qcow2", msg
);
199 static void report_unsupported_feature(BlockDriverState
*bs
,
200 Qcow2Feature
*table
, uint64_t mask
)
202 while (table
&& table
->name
[0] != '\0') {
203 if (table
->type
== QCOW2_FEAT_TYPE_INCOMPATIBLE
) {
204 if (mask
& (1 << table
->bit
)) {
205 report_unsupported(bs
, "%.46s",table
->name
);
206 mask
&= ~(1 << table
->bit
);
213 report_unsupported(bs
, "Unknown incompatible feature: %" PRIx64
, mask
);
217 static int qcow2_open(BlockDriverState
*bs
, int flags
)
219 BDRVQcowState
*s
= bs
->opaque
;
225 ret
= bdrv_pread(bs
->file
, 0, &header
, sizeof(header
));
229 be32_to_cpus(&header
.magic
);
230 be32_to_cpus(&header
.version
);
231 be64_to_cpus(&header
.backing_file_offset
);
232 be32_to_cpus(&header
.backing_file_size
);
233 be64_to_cpus(&header
.size
);
234 be32_to_cpus(&header
.cluster_bits
);
235 be32_to_cpus(&header
.crypt_method
);
236 be64_to_cpus(&header
.l1_table_offset
);
237 be32_to_cpus(&header
.l1_size
);
238 be64_to_cpus(&header
.refcount_table_offset
);
239 be32_to_cpus(&header
.refcount_table_clusters
);
240 be64_to_cpus(&header
.snapshots_offset
);
241 be32_to_cpus(&header
.nb_snapshots
);
243 if (header
.magic
!= QCOW_MAGIC
) {
247 if (header
.version
< 2 || header
.version
> 3) {
248 report_unsupported(bs
, "QCOW version %d", header
.version
);
253 s
->qcow_version
= header
.version
;
255 /* Initialise version 3 header fields */
256 if (header
.version
== 2) {
257 header
.incompatible_features
= 0;
258 header
.compatible_features
= 0;
259 header
.autoclear_features
= 0;
260 header
.refcount_order
= 4;
261 header
.header_length
= 72;
263 be64_to_cpus(&header
.incompatible_features
);
264 be64_to_cpus(&header
.compatible_features
);
265 be64_to_cpus(&header
.autoclear_features
);
266 be32_to_cpus(&header
.refcount_order
);
267 be32_to_cpus(&header
.header_length
);
270 if (header
.header_length
> sizeof(header
)) {
271 s
->unknown_header_fields_size
= header
.header_length
- sizeof(header
);
272 s
->unknown_header_fields
= g_malloc(s
->unknown_header_fields_size
);
273 ret
= bdrv_pread(bs
->file
, sizeof(header
), s
->unknown_header_fields
,
274 s
->unknown_header_fields_size
);
280 if (header
.backing_file_offset
) {
281 ext_end
= header
.backing_file_offset
;
283 ext_end
= 1 << header
.cluster_bits
;
286 /* Handle feature bits */
287 s
->incompatible_features
= header
.incompatible_features
;
288 s
->compatible_features
= header
.compatible_features
;
289 s
->autoclear_features
= header
.autoclear_features
;
291 if (s
->incompatible_features
!= 0) {
292 void *feature_table
= NULL
;
293 qcow2_read_extensions(bs
, header
.header_length
, ext_end
,
295 report_unsupported_feature(bs
, feature_table
,
296 s
->incompatible_features
);
301 if (!bs
->read_only
&& s
->autoclear_features
!= 0) {
302 s
->autoclear_features
= 0;
303 ret
= qcow2_update_header(bs
);
309 /* Check support for various header values */
310 if (header
.refcount_order
!= 4) {
311 report_unsupported(bs
, "%d bit reference counts",
312 1 << header
.refcount_order
);
317 if (header
.cluster_bits
< MIN_CLUSTER_BITS
||
318 header
.cluster_bits
> MAX_CLUSTER_BITS
) {
322 if (header
.crypt_method
> QCOW_CRYPT_AES
) {
326 s
->crypt_method_header
= header
.crypt_method
;
327 if (s
->crypt_method_header
) {
330 s
->cluster_bits
= header
.cluster_bits
;
331 s
->cluster_size
= 1 << s
->cluster_bits
;
332 s
->cluster_sectors
= 1 << (s
->cluster_bits
- 9);
333 s
->l2_bits
= s
->cluster_bits
- 3; /* L2 is always one cluster */
334 s
->l2_size
= 1 << s
->l2_bits
;
335 bs
->total_sectors
= header
.size
/ 512;
336 s
->csize_shift
= (62 - (s
->cluster_bits
- 8));
337 s
->csize_mask
= (1 << (s
->cluster_bits
- 8)) - 1;
338 s
->cluster_offset_mask
= (1LL << s
->csize_shift
) - 1;
339 s
->refcount_table_offset
= header
.refcount_table_offset
;
340 s
->refcount_table_size
=
341 header
.refcount_table_clusters
<< (s
->cluster_bits
- 3);
343 s
->snapshots_offset
= header
.snapshots_offset
;
344 s
->nb_snapshots
= header
.nb_snapshots
;
346 /* read the level 1 table */
347 s
->l1_size
= header
.l1_size
;
348 s
->l1_vm_state_index
= size_to_l1(s
, header
.size
);
349 /* the L1 table must contain at least enough entries to put
351 if (s
->l1_size
< s
->l1_vm_state_index
) {
355 s
->l1_table_offset
= header
.l1_table_offset
;
356 if (s
->l1_size
> 0) {
357 s
->l1_table
= g_malloc0(
358 align_offset(s
->l1_size
* sizeof(uint64_t), 512));
359 ret
= bdrv_pread(bs
->file
, s
->l1_table_offset
, s
->l1_table
,
360 s
->l1_size
* sizeof(uint64_t));
364 for(i
= 0;i
< s
->l1_size
; i
++) {
365 be64_to_cpus(&s
->l1_table
[i
]);
369 /* alloc L2 table/refcount block cache */
370 writethrough
= ((flags
& BDRV_O_CACHE_WB
) == 0);
371 s
->l2_table_cache
= qcow2_cache_create(bs
, L2_CACHE_SIZE
, writethrough
);
372 s
->refcount_block_cache
= qcow2_cache_create(bs
, REFCOUNT_CACHE_SIZE
,
375 s
->cluster_cache
= g_malloc(s
->cluster_size
);
376 /* one more sector for decompressed data alignment */
377 s
->cluster_data
= qemu_blockalign(bs
, QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
379 s
->cluster_cache_offset
= -1;
382 ret
= qcow2_refcount_init(bs
);
387 QLIST_INIT(&s
->cluster_allocs
);
389 /* read qcow2 extensions */
390 if (qcow2_read_extensions(bs
, header
.header_length
, ext_end
, NULL
)) {
395 /* read the backing file name */
396 if (header
.backing_file_offset
!= 0) {
397 len
= header
.backing_file_size
;
401 ret
= bdrv_pread(bs
->file
, header
.backing_file_offset
,
402 bs
->backing_file
, len
);
406 bs
->backing_file
[len
] = '\0';
409 ret
= qcow2_read_snapshots(bs
);
414 /* Initialise locks */
415 qemu_co_mutex_init(&s
->lock
);
419 BdrvCheckResult result
= {0};
420 qcow2_check_refcounts(bs
, &result
);
426 g_free(s
->unknown_header_fields
);
427 cleanup_unknown_header_ext(bs
);
428 qcow2_free_snapshots(bs
);
429 qcow2_refcount_close(bs
);
431 if (s
->l2_table_cache
) {
432 qcow2_cache_destroy(bs
, s
->l2_table_cache
);
434 g_free(s
->cluster_cache
);
435 qemu_vfree(s
->cluster_data
);
439 static int qcow2_set_key(BlockDriverState
*bs
, const char *key
)
441 BDRVQcowState
*s
= bs
->opaque
;
445 memset(keybuf
, 0, 16);
449 /* XXX: we could compress the chars to 7 bits to increase
451 for(i
= 0;i
< len
;i
++) {
454 s
->crypt_method
= s
->crypt_method_header
;
456 if (AES_set_encrypt_key(keybuf
, 128, &s
->aes_encrypt_key
) != 0)
458 if (AES_set_decrypt_key(keybuf
, 128, &s
->aes_decrypt_key
) != 0)
468 AES_encrypt(in
, tmp
, &s
->aes_encrypt_key
);
469 AES_decrypt(tmp
, out
, &s
->aes_decrypt_key
);
470 for(i
= 0; i
< 16; i
++)
471 printf(" %02x", tmp
[i
]);
473 for(i
= 0; i
< 16; i
++)
474 printf(" %02x", out
[i
]);
481 static int coroutine_fn
qcow2_co_is_allocated(BlockDriverState
*bs
,
482 int64_t sector_num
, int nb_sectors
, int *pnum
)
484 BDRVQcowState
*s
= bs
->opaque
;
485 uint64_t cluster_offset
;
489 /* FIXME We can get errors here, but the bdrv_co_is_allocated interface
490 * can't pass them on today */
491 qemu_co_mutex_lock(&s
->lock
);
492 ret
= qcow2_get_cluster_offset(bs
, sector_num
<< 9, pnum
, &cluster_offset
);
493 qemu_co_mutex_unlock(&s
->lock
);
498 return (cluster_offset
!= 0);
501 /* handle reading after the end of the backing file */
502 int qcow2_backing_read1(BlockDriverState
*bs
, QEMUIOVector
*qiov
,
503 int64_t sector_num
, int nb_sectors
)
506 if ((sector_num
+ nb_sectors
) <= bs
->total_sectors
)
508 if (sector_num
>= bs
->total_sectors
)
511 n1
= bs
->total_sectors
- sector_num
;
513 qemu_iovec_memset_skip(qiov
, 0, 512 * (nb_sectors
- n1
), 512 * n1
);
518 static coroutine_fn
int qcow2_co_readv(BlockDriverState
*bs
, int64_t sector_num
,
519 int remaining_sectors
, QEMUIOVector
*qiov
)
521 BDRVQcowState
*s
= bs
->opaque
;
522 int index_in_cluster
, n1
;
524 int cur_nr_sectors
; /* number of sectors in current iteration */
525 uint64_t cluster_offset
= 0;
526 uint64_t bytes_done
= 0;
527 QEMUIOVector hd_qiov
;
528 uint8_t *cluster_data
= NULL
;
530 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
532 qemu_co_mutex_lock(&s
->lock
);
534 while (remaining_sectors
!= 0) {
536 /* prepare next request */
537 cur_nr_sectors
= remaining_sectors
;
538 if (s
->crypt_method
) {
539 cur_nr_sectors
= MIN(cur_nr_sectors
,
540 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_sectors
);
543 ret
= qcow2_get_cluster_offset(bs
, sector_num
<< 9,
544 &cur_nr_sectors
, &cluster_offset
);
549 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
551 qemu_iovec_reset(&hd_qiov
);
552 qemu_iovec_copy(&hd_qiov
, qiov
, bytes_done
,
553 cur_nr_sectors
* 512);
556 case QCOW2_CLUSTER_UNALLOCATED
:
558 if (bs
->backing_hd
) {
559 /* read from the base image */
560 n1
= qcow2_backing_read1(bs
->backing_hd
, &hd_qiov
,
561 sector_num
, cur_nr_sectors
);
563 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_BACKING_AIO
);
564 qemu_co_mutex_unlock(&s
->lock
);
565 ret
= bdrv_co_readv(bs
->backing_hd
, sector_num
,
567 qemu_co_mutex_lock(&s
->lock
);
573 /* Note: in this case, no need to wait */
574 qemu_iovec_memset(&hd_qiov
, 0, 512 * cur_nr_sectors
);
578 case QCOW2_CLUSTER_ZERO
:
579 if (s
->qcow_version
< 3) {
583 qemu_iovec_memset(&hd_qiov
, 0, 512 * cur_nr_sectors
);
586 case QCOW2_CLUSTER_COMPRESSED
:
587 /* add AIO support for compressed blocks ? */
588 ret
= qcow2_decompress_cluster(bs
, cluster_offset
);
593 qemu_iovec_from_buffer(&hd_qiov
,
594 s
->cluster_cache
+ index_in_cluster
* 512,
595 512 * cur_nr_sectors
);
598 case QCOW2_CLUSTER_NORMAL
:
599 if ((cluster_offset
& 511) != 0) {
604 if (s
->crypt_method
) {
606 * For encrypted images, read everything into a temporary
607 * contiguous buffer on which the AES functions can work.
611 qemu_blockalign(bs
, QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
614 assert(cur_nr_sectors
<=
615 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_sectors
);
616 qemu_iovec_reset(&hd_qiov
);
617 qemu_iovec_add(&hd_qiov
, cluster_data
,
618 512 * cur_nr_sectors
);
621 BLKDBG_EVENT(bs
->file
, BLKDBG_READ_AIO
);
622 qemu_co_mutex_unlock(&s
->lock
);
623 ret
= bdrv_co_readv(bs
->file
,
624 (cluster_offset
>> 9) + index_in_cluster
,
625 cur_nr_sectors
, &hd_qiov
);
626 qemu_co_mutex_lock(&s
->lock
);
630 if (s
->crypt_method
) {
631 qcow2_encrypt_sectors(s
, sector_num
, cluster_data
,
632 cluster_data
, cur_nr_sectors
, 0, &s
->aes_decrypt_key
);
633 qemu_iovec_reset(&hd_qiov
);
634 qemu_iovec_copy(&hd_qiov
, qiov
, bytes_done
,
635 cur_nr_sectors
* 512);
636 qemu_iovec_from_buffer(&hd_qiov
, cluster_data
,
637 512 * cur_nr_sectors
);
642 g_assert_not_reached();
647 remaining_sectors
-= cur_nr_sectors
;
648 sector_num
+= cur_nr_sectors
;
649 bytes_done
+= cur_nr_sectors
* 512;
654 qemu_co_mutex_unlock(&s
->lock
);
656 qemu_iovec_destroy(&hd_qiov
);
657 qemu_vfree(cluster_data
);
662 static void run_dependent_requests(BDRVQcowState
*s
, QCowL2Meta
*m
)
664 /* Take the request off the list of running requests */
665 if (m
->nb_clusters
!= 0) {
666 QLIST_REMOVE(m
, next_in_flight
);
669 /* Restart all dependent requests */
670 if (!qemu_co_queue_empty(&m
->dependent_requests
)) {
671 qemu_co_mutex_unlock(&s
->lock
);
672 qemu_co_queue_restart_all(&m
->dependent_requests
);
673 qemu_co_mutex_lock(&s
->lock
);
677 static coroutine_fn
int qcow2_co_writev(BlockDriverState
*bs
,
679 int remaining_sectors
,
682 BDRVQcowState
*s
= bs
->opaque
;
683 int index_in_cluster
;
686 int cur_nr_sectors
; /* number of sectors in current iteration */
687 uint64_t cluster_offset
;
688 QEMUIOVector hd_qiov
;
689 uint64_t bytes_done
= 0;
690 uint8_t *cluster_data
= NULL
;
691 QCowL2Meta l2meta
= {
695 trace_qcow2_writev_start_req(qemu_coroutine_self(), sector_num
,
698 qemu_co_queue_init(&l2meta
.dependent_requests
);
700 qemu_iovec_init(&hd_qiov
, qiov
->niov
);
702 s
->cluster_cache_offset
= -1; /* disable compressed cache */
704 qemu_co_mutex_lock(&s
->lock
);
706 while (remaining_sectors
!= 0) {
708 trace_qcow2_writev_start_part(qemu_coroutine_self());
709 index_in_cluster
= sector_num
& (s
->cluster_sectors
- 1);
710 n_end
= index_in_cluster
+ remaining_sectors
;
711 if (s
->crypt_method
&&
712 n_end
> QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_sectors
) {
713 n_end
= QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_sectors
;
716 ret
= qcow2_alloc_cluster_offset(bs
, sector_num
<< 9,
717 index_in_cluster
, n_end
, &cur_nr_sectors
, &l2meta
);
722 cluster_offset
= l2meta
.cluster_offset
;
723 assert((cluster_offset
& 511) == 0);
725 qemu_iovec_reset(&hd_qiov
);
726 qemu_iovec_copy(&hd_qiov
, qiov
, bytes_done
,
727 cur_nr_sectors
* 512);
729 if (s
->crypt_method
) {
731 cluster_data
= qemu_blockalign(bs
, QCOW_MAX_CRYPT_CLUSTERS
*
735 assert(hd_qiov
.size
<=
736 QCOW_MAX_CRYPT_CLUSTERS
* s
->cluster_size
);
737 qemu_iovec_to_buffer(&hd_qiov
, cluster_data
);
739 qcow2_encrypt_sectors(s
, sector_num
, cluster_data
,
740 cluster_data
, cur_nr_sectors
, 1, &s
->aes_encrypt_key
);
742 qemu_iovec_reset(&hd_qiov
);
743 qemu_iovec_add(&hd_qiov
, cluster_data
,
744 cur_nr_sectors
* 512);
747 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_AIO
);
748 qemu_co_mutex_unlock(&s
->lock
);
749 trace_qcow2_writev_data(qemu_coroutine_self(),
750 (cluster_offset
>> 9) + index_in_cluster
);
751 ret
= bdrv_co_writev(bs
->file
,
752 (cluster_offset
>> 9) + index_in_cluster
,
753 cur_nr_sectors
, &hd_qiov
);
754 qemu_co_mutex_lock(&s
->lock
);
759 ret
= qcow2_alloc_cluster_link_l2(bs
, &l2meta
);
764 run_dependent_requests(s
, &l2meta
);
766 remaining_sectors
-= cur_nr_sectors
;
767 sector_num
+= cur_nr_sectors
;
768 bytes_done
+= cur_nr_sectors
* 512;
769 trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors
);
774 run_dependent_requests(s
, &l2meta
);
776 qemu_co_mutex_unlock(&s
->lock
);
778 qemu_iovec_destroy(&hd_qiov
);
779 qemu_vfree(cluster_data
);
780 trace_qcow2_writev_done_req(qemu_coroutine_self(), ret
);
785 static void qcow2_close(BlockDriverState
*bs
)
787 BDRVQcowState
*s
= bs
->opaque
;
790 qcow2_cache_flush(bs
, s
->l2_table_cache
);
791 qcow2_cache_flush(bs
, s
->refcount_block_cache
);
793 qcow2_cache_destroy(bs
, s
->l2_table_cache
);
794 qcow2_cache_destroy(bs
, s
->refcount_block_cache
);
796 g_free(s
->unknown_header_fields
);
797 cleanup_unknown_header_ext(bs
);
799 g_free(s
->cluster_cache
);
800 qemu_vfree(s
->cluster_data
);
801 qcow2_refcount_close(bs
);
802 qcow2_free_snapshots(bs
);
805 static void qcow2_invalidate_cache(BlockDriverState
*bs
)
807 BDRVQcowState
*s
= bs
->opaque
;
808 int flags
= s
->flags
;
809 AES_KEY aes_encrypt_key
;
810 AES_KEY aes_decrypt_key
;
811 uint32_t crypt_method
= 0;
814 * Backing files are read-only which makes all of their metadata immutable,
815 * that means we don't have to worry about reopening them here.
818 if (s
->crypt_method
) {
819 crypt_method
= s
->crypt_method
;
820 memcpy(&aes_encrypt_key
, &s
->aes_encrypt_key
, sizeof(aes_encrypt_key
));
821 memcpy(&aes_decrypt_key
, &s
->aes_decrypt_key
, sizeof(aes_decrypt_key
));
826 memset(s
, 0, sizeof(BDRVQcowState
));
827 qcow2_open(bs
, flags
);
830 s
->crypt_method
= crypt_method
;
831 memcpy(&s
->aes_encrypt_key
, &aes_encrypt_key
, sizeof(aes_encrypt_key
));
832 memcpy(&s
->aes_decrypt_key
, &aes_decrypt_key
, sizeof(aes_decrypt_key
));
836 static size_t header_ext_add(char *buf
, uint32_t magic
, const void *s
,
837 size_t len
, size_t buflen
)
839 QCowExtension
*ext_backing_fmt
= (QCowExtension
*) buf
;
840 size_t ext_len
= sizeof(QCowExtension
) + ((len
+ 7) & ~7);
842 if (buflen
< ext_len
) {
846 *ext_backing_fmt
= (QCowExtension
) {
847 .magic
= cpu_to_be32(magic
),
848 .len
= cpu_to_be32(len
),
850 memcpy(buf
+ sizeof(QCowExtension
), s
, len
);
856 * Updates the qcow2 header, including the variable length parts of it, i.e.
857 * the backing file name and all extensions. qcow2 was not designed to allow
858 * such changes, so if we run out of space (we can only use the first cluster)
859 * this function may fail.
861 * Returns 0 on success, -errno in error cases.
863 int qcow2_update_header(BlockDriverState
*bs
)
865 BDRVQcowState
*s
= bs
->opaque
;
868 size_t buflen
= s
->cluster_size
;
871 uint32_t refcount_table_clusters
;
872 size_t header_length
;
873 Qcow2UnknownHeaderExtension
*uext
;
875 buf
= qemu_blockalign(bs
, buflen
);
877 /* Header structure */
878 header
= (QCowHeader
*) buf
;
880 if (buflen
< sizeof(*header
)) {
885 header_length
= sizeof(*header
) + s
->unknown_header_fields_size
;
886 total_size
= bs
->total_sectors
* BDRV_SECTOR_SIZE
;
887 refcount_table_clusters
= s
->refcount_table_size
>> (s
->cluster_bits
- 3);
889 *header
= (QCowHeader
) {
890 /* Version 2 fields */
891 .magic
= cpu_to_be32(QCOW_MAGIC
),
892 .version
= cpu_to_be32(s
->qcow_version
),
893 .backing_file_offset
= 0,
894 .backing_file_size
= 0,
895 .cluster_bits
= cpu_to_be32(s
->cluster_bits
),
896 .size
= cpu_to_be64(total_size
),
897 .crypt_method
= cpu_to_be32(s
->crypt_method_header
),
898 .l1_size
= cpu_to_be32(s
->l1_size
),
899 .l1_table_offset
= cpu_to_be64(s
->l1_table_offset
),
900 .refcount_table_offset
= cpu_to_be64(s
->refcount_table_offset
),
901 .refcount_table_clusters
= cpu_to_be32(refcount_table_clusters
),
902 .nb_snapshots
= cpu_to_be32(s
->nb_snapshots
),
903 .snapshots_offset
= cpu_to_be64(s
->snapshots_offset
),
905 /* Version 3 fields */
906 .incompatible_features
= cpu_to_be64(s
->incompatible_features
),
907 .compatible_features
= cpu_to_be64(s
->compatible_features
),
908 .autoclear_features
= cpu_to_be64(s
->autoclear_features
),
909 .refcount_order
= cpu_to_be32(3 + REFCOUNT_SHIFT
),
910 .header_length
= cpu_to_be32(header_length
),
913 /* For older versions, write a shorter header */
914 switch (s
->qcow_version
) {
916 ret
= offsetof(QCowHeader
, incompatible_features
);
919 ret
= sizeof(*header
);
927 memset(buf
, 0, buflen
);
929 /* Preserve any unknown field in the header */
930 if (s
->unknown_header_fields_size
) {
931 if (buflen
< s
->unknown_header_fields_size
) {
936 memcpy(buf
, s
->unknown_header_fields
, s
->unknown_header_fields_size
);
937 buf
+= s
->unknown_header_fields_size
;
938 buflen
-= s
->unknown_header_fields_size
;
941 /* Backing file format header extension */
942 if (*bs
->backing_format
) {
943 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_BACKING_FORMAT
,
944 bs
->backing_format
, strlen(bs
->backing_format
),
955 Qcow2Feature features
[] = {
956 /* no feature defined yet */
959 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_FEATURE_TABLE
,
960 features
, sizeof(features
), buflen
);
967 /* Keep unknown header extensions */
968 QLIST_FOREACH(uext
, &s
->unknown_header_ext
, next
) {
969 ret
= header_ext_add(buf
, uext
->magic
, uext
->data
, uext
->len
, buflen
);
978 /* End of header extensions */
979 ret
= header_ext_add(buf
, QCOW2_EXT_MAGIC_END
, NULL
, 0, buflen
);
987 /* Backing file name */
988 if (*bs
->backing_file
) {
989 size_t backing_file_len
= strlen(bs
->backing_file
);
991 if (buflen
< backing_file_len
) {
996 strncpy(buf
, bs
->backing_file
, buflen
);
998 header
->backing_file_offset
= cpu_to_be64(buf
- ((char*) header
));
999 header
->backing_file_size
= cpu_to_be32(backing_file_len
);
1002 /* Write the new header */
1003 ret
= bdrv_pwrite(bs
->file
, 0, header
, s
->cluster_size
);
1014 static int qcow2_change_backing_file(BlockDriverState
*bs
,
1015 const char *backing_file
, const char *backing_fmt
)
1017 pstrcpy(bs
->backing_file
, sizeof(bs
->backing_file
), backing_file
?: "");
1018 pstrcpy(bs
->backing_format
, sizeof(bs
->backing_format
), backing_fmt
?: "");
1020 return qcow2_update_header(bs
);
1023 static int preallocate(BlockDriverState
*bs
)
1025 uint64_t nb_sectors
;
1031 nb_sectors
= bdrv_getlength(bs
) >> 9;
1033 qemu_co_queue_init(&meta
.dependent_requests
);
1034 meta
.cluster_offset
= 0;
1036 while (nb_sectors
) {
1037 num
= MIN(nb_sectors
, INT_MAX
>> 9);
1038 ret
= qcow2_alloc_cluster_offset(bs
, offset
, 0, num
, &num
, &meta
);
1043 ret
= qcow2_alloc_cluster_link_l2(bs
, &meta
);
1045 qcow2_free_any_clusters(bs
, meta
.cluster_offset
, meta
.nb_clusters
);
1049 /* There are no dependent requests, but we need to remove our request
1050 * from the list of in-flight requests */
1051 run_dependent_requests(bs
->opaque
, &meta
);
1053 /* TODO Preallocate data if requested */
1060 * It is expected that the image file is large enough to actually contain
1061 * all of the allocated clusters (otherwise we get failing reads after
1062 * EOF). Extend the image to the last allocated sector.
1064 if (meta
.cluster_offset
!= 0) {
1066 memset(buf
, 0, 512);
1067 ret
= bdrv_write(bs
->file
, (meta
.cluster_offset
>> 9) + num
- 1, buf
, 1);
1076 static int qcow2_create2(const char *filename
, int64_t total_size
,
1077 const char *backing_file
, const char *backing_format
,
1078 int flags
, size_t cluster_size
, int prealloc
,
1079 QEMUOptionParameter
*options
, int version
)
1081 /* Calculate cluster_bits */
1083 cluster_bits
= ffs(cluster_size
) - 1;
1084 if (cluster_bits
< MIN_CLUSTER_BITS
|| cluster_bits
> MAX_CLUSTER_BITS
||
1085 (1 << cluster_bits
) != cluster_size
)
1088 "Cluster size must be a power of two between %d and %dk",
1089 1 << MIN_CLUSTER_BITS
, 1 << (MAX_CLUSTER_BITS
- 10));
1094 * Open the image file and write a minimal qcow2 header.
1096 * We keep things simple and start with a zero-sized image. We also
1097 * do without refcount blocks or a L1 table for now. We'll fix the
1098 * inconsistency later.
1100 * We do need a refcount table because growing the refcount table means
1101 * allocating two new refcount blocks - the seconds of which would be at
1102 * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
1103 * size for any qcow2 image.
1105 BlockDriverState
* bs
;
1107 uint8_t* refcount_table
;
1110 ret
= bdrv_create_file(filename
, options
);
1115 ret
= bdrv_file_open(&bs
, filename
, BDRV_O_RDWR
);
1120 /* Write the header */
1121 memset(&header
, 0, sizeof(header
));
1122 header
.magic
= cpu_to_be32(QCOW_MAGIC
);
1123 header
.version
= cpu_to_be32(version
);
1124 header
.cluster_bits
= cpu_to_be32(cluster_bits
);
1125 header
.size
= cpu_to_be64(0);
1126 header
.l1_table_offset
= cpu_to_be64(0);
1127 header
.l1_size
= cpu_to_be32(0);
1128 header
.refcount_table_offset
= cpu_to_be64(cluster_size
);
1129 header
.refcount_table_clusters
= cpu_to_be32(1);
1130 header
.refcount_order
= cpu_to_be32(3 + REFCOUNT_SHIFT
);
1131 header
.header_length
= cpu_to_be32(sizeof(header
));
1133 if (flags
& BLOCK_FLAG_ENCRYPT
) {
1134 header
.crypt_method
= cpu_to_be32(QCOW_CRYPT_AES
);
1136 header
.crypt_method
= cpu_to_be32(QCOW_CRYPT_NONE
);
1139 ret
= bdrv_pwrite(bs
, 0, &header
, sizeof(header
));
1144 /* Write an empty refcount table */
1145 refcount_table
= g_malloc0(cluster_size
);
1146 ret
= bdrv_pwrite(bs
, cluster_size
, refcount_table
, cluster_size
);
1147 g_free(refcount_table
);
1156 * And now open the image and make it consistent first (i.e. increase the
1157 * refcount of the cluster that is occupied by the header and the refcount
1160 BlockDriver
* drv
= bdrv_find_format("qcow2");
1161 assert(drv
!= NULL
);
1162 ret
= bdrv_open(bs
, filename
,
1163 BDRV_O_RDWR
| BDRV_O_CACHE_WB
| BDRV_O_NO_FLUSH
, drv
);
1168 ret
= qcow2_alloc_clusters(bs
, 2 * cluster_size
);
1172 } else if (ret
!= 0) {
1173 error_report("Huh, first cluster in empty image is already in use?");
1177 /* Okay, now that we have a valid image, let's give it the right size */
1178 ret
= bdrv_truncate(bs
, total_size
* BDRV_SECTOR_SIZE
);
1183 /* Want a backing file? There you go.*/
1185 ret
= bdrv_change_backing_file(bs
, backing_file
, backing_format
);
1191 /* And if we're supposed to preallocate metadata, do that now */
1193 BDRVQcowState
*s
= bs
->opaque
;
1194 qemu_co_mutex_lock(&s
->lock
);
1195 ret
= preallocate(bs
);
1196 qemu_co_mutex_unlock(&s
->lock
);
1208 static int qcow2_create(const char *filename
, QEMUOptionParameter
*options
)
1210 const char *backing_file
= NULL
;
1211 const char *backing_fmt
= NULL
;
1212 uint64_t sectors
= 0;
1214 size_t cluster_size
= DEFAULT_CLUSTER_SIZE
;
1218 /* Read out options */
1219 while (options
&& options
->name
) {
1220 if (!strcmp(options
->name
, BLOCK_OPT_SIZE
)) {
1221 sectors
= options
->value
.n
/ 512;
1222 } else if (!strcmp(options
->name
, BLOCK_OPT_BACKING_FILE
)) {
1223 backing_file
= options
->value
.s
;
1224 } else if (!strcmp(options
->name
, BLOCK_OPT_BACKING_FMT
)) {
1225 backing_fmt
= options
->value
.s
;
1226 } else if (!strcmp(options
->name
, BLOCK_OPT_ENCRYPT
)) {
1227 flags
|= options
->value
.n
? BLOCK_FLAG_ENCRYPT
: 0;
1228 } else if (!strcmp(options
->name
, BLOCK_OPT_CLUSTER_SIZE
)) {
1229 if (options
->value
.n
) {
1230 cluster_size
= options
->value
.n
;
1232 } else if (!strcmp(options
->name
, BLOCK_OPT_PREALLOC
)) {
1233 if (!options
->value
.s
|| !strcmp(options
->value
.s
, "off")) {
1235 } else if (!strcmp(options
->value
.s
, "metadata")) {
1238 fprintf(stderr
, "Invalid preallocation mode: '%s'\n",
1242 } else if (!strcmp(options
->name
, BLOCK_OPT_COMPAT_LEVEL
)) {
1243 if (!options
->value
.s
|| !strcmp(options
->value
.s
, "0.10")) {
1245 } else if (!strcmp(options
->value
.s
, "1.1")) {
1248 fprintf(stderr
, "Invalid compatibility level: '%s'\n",
1256 if (backing_file
&& prealloc
) {
1257 fprintf(stderr
, "Backing file and preallocation cannot be used at "
1262 return qcow2_create2(filename
, sectors
, backing_file
, backing_fmt
, flags
,
1263 cluster_size
, prealloc
, options
, version
);
1266 static int qcow2_make_empty(BlockDriverState
*bs
)
1269 /* XXX: not correct */
1270 BDRVQcowState
*s
= bs
->opaque
;
1271 uint32_t l1_length
= s
->l1_size
* sizeof(uint64_t);
1274 memset(s
->l1_table
, 0, l1_length
);
1275 if (bdrv_pwrite(bs
->file
, s
->l1_table_offset
, s
->l1_table
, l1_length
) < 0)
1277 ret
= bdrv_truncate(bs
->file
, s
->l1_table_offset
+ l1_length
);
1286 static coroutine_fn
int qcow2_co_write_zeroes(BlockDriverState
*bs
,
1287 int64_t sector_num
, int nb_sectors
)
1290 BDRVQcowState
*s
= bs
->opaque
;
1292 /* Emulate misaligned zero writes */
1293 if (sector_num
% s
->cluster_sectors
|| nb_sectors
% s
->cluster_sectors
) {
1297 /* Whatever is left can use real zero clusters */
1298 qemu_co_mutex_lock(&s
->lock
);
1299 ret
= qcow2_zero_clusters(bs
, sector_num
<< BDRV_SECTOR_BITS
,
1301 qemu_co_mutex_unlock(&s
->lock
);
1306 static coroutine_fn
int qcow2_co_discard(BlockDriverState
*bs
,
1307 int64_t sector_num
, int nb_sectors
)
1310 BDRVQcowState
*s
= bs
->opaque
;
1312 qemu_co_mutex_lock(&s
->lock
);
1313 ret
= qcow2_discard_clusters(bs
, sector_num
<< BDRV_SECTOR_BITS
,
1315 qemu_co_mutex_unlock(&s
->lock
);
1319 static int qcow2_truncate(BlockDriverState
*bs
, int64_t offset
)
1321 BDRVQcowState
*s
= bs
->opaque
;
1322 int ret
, new_l1_size
;
1325 error_report("The new size must be a multiple of 512");
1329 /* cannot proceed if image has snapshots */
1330 if (s
->nb_snapshots
) {
1331 error_report("Can't resize an image which has snapshots");
1335 /* shrinking is currently not supported */
1336 if (offset
< bs
->total_sectors
* 512) {
1337 error_report("qcow2 doesn't support shrinking images yet");
1341 new_l1_size
= size_to_l1(s
, offset
);
1342 ret
= qcow2_grow_l1_table(bs
, new_l1_size
, true);
1347 /* write updated header.size */
1348 offset
= cpu_to_be64(offset
);
1349 ret
= bdrv_pwrite_sync(bs
->file
, offsetof(QCowHeader
, size
),
1350 &offset
, sizeof(uint64_t));
1355 s
->l1_vm_state_index
= new_l1_size
;
1359 /* XXX: put compressed sectors first, then all the cluster aligned
1360 tables to avoid losing bytes in alignment */
1361 static int qcow2_write_compressed(BlockDriverState
*bs
, int64_t sector_num
,
1362 const uint8_t *buf
, int nb_sectors
)
1364 BDRVQcowState
*s
= bs
->opaque
;
1368 uint64_t cluster_offset
;
1370 if (nb_sectors
== 0) {
1371 /* align end of file to a sector boundary to ease reading with
1372 sector based I/Os */
1373 cluster_offset
= bdrv_getlength(bs
->file
);
1374 cluster_offset
= (cluster_offset
+ 511) & ~511;
1375 bdrv_truncate(bs
->file
, cluster_offset
);
1379 if (nb_sectors
!= s
->cluster_sectors
)
1382 out_buf
= g_malloc(s
->cluster_size
+ (s
->cluster_size
/ 1000) + 128);
1384 /* best compression, small window, no zlib header */
1385 memset(&strm
, 0, sizeof(strm
));
1386 ret
= deflateInit2(&strm
, Z_DEFAULT_COMPRESSION
,
1388 9, Z_DEFAULT_STRATEGY
);
1394 strm
.avail_in
= s
->cluster_size
;
1395 strm
.next_in
= (uint8_t *)buf
;
1396 strm
.avail_out
= s
->cluster_size
;
1397 strm
.next_out
= out_buf
;
1399 ret
= deflate(&strm
, Z_FINISH
);
1400 if (ret
!= Z_STREAM_END
&& ret
!= Z_OK
) {
1405 out_len
= strm
.next_out
- out_buf
;
1409 if (ret
!= Z_STREAM_END
|| out_len
>= s
->cluster_size
) {
1410 /* could not compress: write normal cluster */
1411 ret
= bdrv_write(bs
, sector_num
, buf
, s
->cluster_sectors
);
1416 cluster_offset
= qcow2_alloc_compressed_cluster_offset(bs
,
1417 sector_num
<< 9, out_len
);
1418 if (!cluster_offset
) {
1422 cluster_offset
&= s
->cluster_offset_mask
;
1423 BLKDBG_EVENT(bs
->file
, BLKDBG_WRITE_COMPRESSED
);
1424 ret
= bdrv_pwrite(bs
->file
, cluster_offset
, out_buf
, out_len
);
1436 static coroutine_fn
int qcow2_co_flush_to_os(BlockDriverState
*bs
)
1438 BDRVQcowState
*s
= bs
->opaque
;
1441 qemu_co_mutex_lock(&s
->lock
);
1442 ret
= qcow2_cache_flush(bs
, s
->l2_table_cache
);
1444 qemu_co_mutex_unlock(&s
->lock
);
1448 ret
= qcow2_cache_flush(bs
, s
->refcount_block_cache
);
1450 qemu_co_mutex_unlock(&s
->lock
);
1453 qemu_co_mutex_unlock(&s
->lock
);
1458 static int64_t qcow2_vm_state_offset(BDRVQcowState
*s
)
1460 return (int64_t)s
->l1_vm_state_index
<< (s
->cluster_bits
+ s
->l2_bits
);
1463 static int qcow2_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
1465 BDRVQcowState
*s
= bs
->opaque
;
1466 bdi
->cluster_size
= s
->cluster_size
;
1467 bdi
->vm_state_offset
= qcow2_vm_state_offset(s
);
1472 static int qcow2_check(BlockDriverState
*bs
, BdrvCheckResult
*result
)
1474 return qcow2_check_refcounts(bs
, result
);
1478 static void dump_refcounts(BlockDriverState
*bs
)
1480 BDRVQcowState
*s
= bs
->opaque
;
1481 int64_t nb_clusters
, k
, k1
, size
;
1484 size
= bdrv_getlength(bs
->file
);
1485 nb_clusters
= size_to_clusters(s
, size
);
1486 for(k
= 0; k
< nb_clusters
;) {
1488 refcount
= get_refcount(bs
, k
);
1490 while (k
< nb_clusters
&& get_refcount(bs
, k
) == refcount
)
1492 printf("%" PRId64
": refcount=%d nb=%" PRId64
"\n", k
, refcount
,
1498 static int qcow2_save_vmstate(BlockDriverState
*bs
, const uint8_t *buf
,
1499 int64_t pos
, int size
)
1501 BDRVQcowState
*s
= bs
->opaque
;
1502 int growable
= bs
->growable
;
1505 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_SAVE
);
1507 ret
= bdrv_pwrite(bs
, qcow2_vm_state_offset(s
) + pos
, buf
, size
);
1508 bs
->growable
= growable
;
1513 static int qcow2_load_vmstate(BlockDriverState
*bs
, uint8_t *buf
,
1514 int64_t pos
, int size
)
1516 BDRVQcowState
*s
= bs
->opaque
;
1517 int growable
= bs
->growable
;
1520 BLKDBG_EVENT(bs
->file
, BLKDBG_VMSTATE_LOAD
);
1522 ret
= bdrv_pread(bs
, qcow2_vm_state_offset(s
) + pos
, buf
, size
);
1523 bs
->growable
= growable
;
1528 static QEMUOptionParameter qcow2_create_options
[] = {
1530 .name
= BLOCK_OPT_SIZE
,
1532 .help
= "Virtual disk size"
1535 .name
= BLOCK_OPT_COMPAT_LEVEL
,
1537 .help
= "Compatibility level (0.10 or 1.1)"
1540 .name
= BLOCK_OPT_BACKING_FILE
,
1542 .help
= "File name of a base image"
1545 .name
= BLOCK_OPT_BACKING_FMT
,
1547 .help
= "Image format of the base image"
1550 .name
= BLOCK_OPT_ENCRYPT
,
1552 .help
= "Encrypt the image"
1555 .name
= BLOCK_OPT_CLUSTER_SIZE
,
1557 .help
= "qcow2 cluster size",
1558 .value
= { .n
= DEFAULT_CLUSTER_SIZE
},
1561 .name
= BLOCK_OPT_PREALLOC
,
1563 .help
= "Preallocation mode (allowed values: off, metadata)"
1568 static BlockDriver bdrv_qcow2
= {
1569 .format_name
= "qcow2",
1570 .instance_size
= sizeof(BDRVQcowState
),
1571 .bdrv_probe
= qcow2_probe
,
1572 .bdrv_open
= qcow2_open
,
1573 .bdrv_close
= qcow2_close
,
1574 .bdrv_create
= qcow2_create
,
1575 .bdrv_co_is_allocated
= qcow2_co_is_allocated
,
1576 .bdrv_set_key
= qcow2_set_key
,
1577 .bdrv_make_empty
= qcow2_make_empty
,
1579 .bdrv_co_readv
= qcow2_co_readv
,
1580 .bdrv_co_writev
= qcow2_co_writev
,
1581 .bdrv_co_flush_to_os
= qcow2_co_flush_to_os
,
1583 .bdrv_co_write_zeroes
= qcow2_co_write_zeroes
,
1584 .bdrv_co_discard
= qcow2_co_discard
,
1585 .bdrv_truncate
= qcow2_truncate
,
1586 .bdrv_write_compressed
= qcow2_write_compressed
,
1588 .bdrv_snapshot_create
= qcow2_snapshot_create
,
1589 .bdrv_snapshot_goto
= qcow2_snapshot_goto
,
1590 .bdrv_snapshot_delete
= qcow2_snapshot_delete
,
1591 .bdrv_snapshot_list
= qcow2_snapshot_list
,
1592 .bdrv_snapshot_load_tmp
= qcow2_snapshot_load_tmp
,
1593 .bdrv_get_info
= qcow2_get_info
,
1595 .bdrv_save_vmstate
= qcow2_save_vmstate
,
1596 .bdrv_load_vmstate
= qcow2_load_vmstate
,
1598 .bdrv_change_backing_file
= qcow2_change_backing_file
,
1600 .bdrv_invalidate_cache
= qcow2_invalidate_cache
,
1602 .create_options
= qcow2_create_options
,
1603 .bdrv_check
= qcow2_check
,
1606 static void bdrv_qcow2_init(void)
1608 bdrv_register(&bdrv_qcow2
);
1611 block_init(bdrv_qcow2_init
);