?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
tests/boot-sector: Add magic bytes to s390x boot code header
[qemu.git] / block / qcow.c
blob1f866af0d31efbaebd2d49b69aa984190475f044
1 /*
2 * Block driver for the QCOW 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 #include "qemu/osdep.h"
26 #include "qapi/error.h"
27 #include "qemu/error-report.h"
28 #include "block/block_int.h"
29 #include "sysemu/block-backend.h"
30 #include "qemu/module.h"
31 #include "qemu/option.h"
32 #include "qemu/bswap.h"
33 #include <zlib.h>
34 #include "qapi/qmp/qdict.h"
35 #include "qapi/qmp/qstring.h"
36 #include "qapi/qobject-input-visitor.h"
37 #include "qapi/qapi-visit-block-core.h"
38 #include "crypto/block.h"
39 #include "migration/blocker.h"
40 #include "crypto.h"
41
42 /**************************************************************/
43 /* QEMU COW block driver with compression and encryption support */
44
45 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
46 #define QCOW_VERSION 1
47
48 #define QCOW_CRYPT_NONE 0
49 #define QCOW_CRYPT_AES 1
50
51 #define QCOW_OFLAG_COMPRESSED (1LL << 63)
52
53 typedef struct QCowHeader {
54 uint32_t magic;
55 uint32_t version;
56 uint64_t backing_file_offset;
57 uint32_t backing_file_size;
58 uint32_t mtime;
59 uint64_t size; /* in bytes */
60 uint8_t cluster_bits;
61 uint8_t l2_bits;
62 uint16_t padding;
63 uint32_t crypt_method;
64 uint64_t l1_table_offset;
65 } QEMU_PACKED QCowHeader;
66
67 #define L2_CACHE_SIZE 16
68
69 typedef struct BDRVQcowState {
70 int cluster_bits;
71 int cluster_size;
72 int cluster_sectors;
73 int l2_bits;
74 int l2_size;
75 unsigned int l1_size;
76 uint64_t cluster_offset_mask;
77 uint64_t l1_table_offset;
78 uint64_t *l1_table;
79 uint64_t *l2_cache;
80 uint64_t l2_cache_offsets[L2_CACHE_SIZE];
81 uint32_t l2_cache_counts[L2_CACHE_SIZE];
82 uint8_t *cluster_cache;
83 uint8_t *cluster_data;
84 uint64_t cluster_cache_offset;
85 QCryptoBlock *crypto; /* Disk encryption format driver */
86 uint32_t crypt_method_header;
87 CoMutex lock;
88 Error *migration_blocker;
89 } BDRVQcowState;
90
91 static QemuOptsList qcow_create_opts;
92
93 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
94
95 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
96 {
97 const QCowHeader *cow_header = (const void *)buf;
98
99 if (buf_size >= sizeof(QCowHeader) &&
100 be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
101 be32_to_cpu(cow_header->version) == QCOW_VERSION)
102 return 100;
103 else
104 return 0;
105 }
106
107 static QemuOptsList qcow_runtime_opts = {
108 .name = "qcow",
109 .head = QTAILQ_HEAD_INITIALIZER(qcow_runtime_opts.head),
110 .desc = {
111 BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
112 { /* end of list */ }
113 },
114 };
115
116 static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
117 Error **errp)
118 {
119 BDRVQcowState *s = bs->opaque;
120 unsigned int len, i, shift;
121 int ret;
122 QCowHeader header;
123 Error *local_err = NULL;
124 QCryptoBlockOpenOptions *crypto_opts = NULL;
125 unsigned int cflags = 0;
126 QDict *encryptopts = NULL;
127 const char *encryptfmt;
128
129 qdict_extract_subqdict(options, &encryptopts, "encrypt.");
130 encryptfmt = qdict_get_try_str(encryptopts, "format");
131
132 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
133 false, errp);
134 if (!bs->file) {
135 ret = -EINVAL;
136 goto fail;
137 }
138
139 ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
140 if (ret < 0) {
141 goto fail;
142 }
143 be32_to_cpus(&header.magic);
144 be32_to_cpus(&header.version);
145 be64_to_cpus(&header.backing_file_offset);
146 be32_to_cpus(&header.backing_file_size);
147 be32_to_cpus(&header.mtime);
148 be64_to_cpus(&header.size);
149 be32_to_cpus(&header.crypt_method);
150 be64_to_cpus(&header.l1_table_offset);
151
152 if (header.magic != QCOW_MAGIC) {
153 error_setg(errp, "Image not in qcow format");
154 ret = -EINVAL;
155 goto fail;
156 }
157 if (header.version != QCOW_VERSION) {
158 error_setg(errp, "Unsupported qcow version %" PRIu32, header.version);
159 ret = -ENOTSUP;
160 goto fail;
161 }
162
163 if (header.size <= 1) {
164 error_setg(errp, "Image size is too small (must be at least 2 bytes)");
165 ret = -EINVAL;
166 goto fail;
167 }
168 if (header.cluster_bits < 9 || header.cluster_bits > 16) {
169 error_setg(errp, "Cluster size must be between 512 and 64k");
170 ret = -EINVAL;
171 goto fail;
172 }
173
174 /* l2_bits specifies number of entries; storing a uint64_t in each entry,
175 * so bytes = num_entries << 3. */
176 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
177 error_setg(errp, "L2 table size must be between 512 and 64k");
178 ret = -EINVAL;
179 goto fail;
180 }
181
182 s->crypt_method_header = header.crypt_method;
183 if (s->crypt_method_header) {
184 if (bdrv_uses_whitelist() &&
185 s->crypt_method_header == QCOW_CRYPT_AES) {
186 error_setg(errp,
187 "Use of AES-CBC encrypted qcow images is no longer "
188 "supported in system emulators");
189 error_append_hint(errp,
190 "You can use 'qemu-img convert' to convert your "
191 "image to an alternative supported format, such "
192 "as unencrypted qcow, or raw with the LUKS "
193 "format instead.\n");
194 ret = -ENOSYS;
195 goto fail;
196 }
197 if (s->crypt_method_header == QCOW_CRYPT_AES) {
198 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) {
199 error_setg(errp,
200 "Header reported 'aes' encryption format but "
201 "options specify '%s'", encryptfmt);
202 ret = -EINVAL;
203 goto fail;
204 }
205 qdict_del(encryptopts, "format");
206 crypto_opts = block_crypto_open_opts_init(
207 Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp);
208 if (!crypto_opts) {
209 ret = -EINVAL;
210 goto fail;
211 }
212
213 if (flags & BDRV_O_NO_IO) {
214 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
215 }
216 s->crypto = qcrypto_block_open(crypto_opts, "encrypt.",
217 NULL, NULL, cflags, errp);
218 if (!s->crypto) {
219 ret = -EINVAL;
220 goto fail;
221 }
222 } else {
223 error_setg(errp, "invalid encryption method in qcow header");
224 ret = -EINVAL;
225 goto fail;
226 }
227 bs->encrypted = true;
228 } else {
229 if (encryptfmt) {
230 error_setg(errp, "No encryption in image header, but options "
231 "specified format '%s'", encryptfmt);
232 ret = -EINVAL;
233 goto fail;
234 }
235 }
236 s->cluster_bits = header.cluster_bits;
237 s->cluster_size = 1 << s->cluster_bits;
238 s->cluster_sectors = 1 << (s->cluster_bits - 9);
239 s->l2_bits = header.l2_bits;
240 s->l2_size = 1 << s->l2_bits;
241 bs->total_sectors = header.size / 512;
242 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
243
244 /* read the level 1 table */
245 shift = s->cluster_bits + s->l2_bits;
246 if (header.size > UINT64_MAX - (1LL << shift)) {
247 error_setg(errp, "Image too large");
248 ret = -EINVAL;
249 goto fail;
250 } else {
251 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
252 if (l1_size > INT_MAX / sizeof(uint64_t)) {
253 error_setg(errp, "Image too large");
254 ret = -EINVAL;
255 goto fail;
256 }
257 s->l1_size = l1_size;
258 }
259
260 s->l1_table_offset = header.l1_table_offset;
261 s->l1_table = g_try_new(uint64_t, s->l1_size);
262 if (s->l1_table == NULL) {
263 error_setg(errp, "Could not allocate memory for L1 table");
264 ret = -ENOMEM;
265 goto fail;
266 }
267
268 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
269 s->l1_size * sizeof(uint64_t));
270 if (ret < 0) {
271 goto fail;
272 }
273
274 for(i = 0;i < s->l1_size; i++) {
275 be64_to_cpus(&s->l1_table[i]);
276 }
277
278 /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
279 s->l2_cache =
280 qemu_try_blockalign(bs->file->bs,
281 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
282 if (s->l2_cache == NULL) {
283 error_setg(errp, "Could not allocate L2 table cache");
284 ret = -ENOMEM;
285 goto fail;
286 }
287 s->cluster_cache = g_malloc(s->cluster_size);
288 s->cluster_data = g_malloc(s->cluster_size);
289 s->cluster_cache_offset = -1;
290
291 /* read the backing file name */
292 if (header.backing_file_offset != 0) {
293 len = header.backing_file_size;
294 if (len > 1023 || len >= sizeof(bs->backing_file)) {
295 error_setg(errp, "Backing file name too long");
296 ret = -EINVAL;
297 goto fail;
298 }
299 ret = bdrv_pread(bs->file, header.backing_file_offset,
300 bs->backing_file, len);
301 if (ret < 0) {
302 goto fail;
303 }
304 bs->backing_file[len] = '\0';
305 }
306
307 /* Disable migration when qcow images are used */
308 error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
309 "does not support live migration",
310 bdrv_get_device_or_node_name(bs));
311 ret = migrate_add_blocker(s->migration_blocker, &local_err);
312 if (local_err) {
313 error_propagate(errp, local_err);
314 error_free(s->migration_blocker);
315 goto fail;
316 }
317
318 qobject_unref(encryptopts);
319 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
320 qemu_co_mutex_init(&s->lock);
321 return 0;
322
323 fail:
324 g_free(s->l1_table);
325 qemu_vfree(s->l2_cache);
326 g_free(s->cluster_cache);
327 g_free(s->cluster_data);
328 qcrypto_block_free(s->crypto);
329 qobject_unref(encryptopts);
330 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
331 return ret;
332 }
333
334
335 /* We have nothing to do for QCOW reopen, stubs just return
336 * success */
337 static int qcow_reopen_prepare(BDRVReopenState *state,
338 BlockReopenQueue *queue, Error **errp)
339 {
340 return 0;
341 }
342
343
344 /* 'allocate' is:
345 *
346 * 0 to not allocate.
347 *
348 * 1 to allocate a normal cluster (for sector indexes 'n_start' to
349 * 'n_end')
350 *
351 * 2 to allocate a compressed cluster of size
352 * 'compressed_size'. 'compressed_size' must be > 0 and <
353 * cluster_size
354 *
355 * return 0 if not allocated, 1 if *result is assigned, and negative
356 * errno on failure.
357 */
358 static int get_cluster_offset(BlockDriverState *bs,
359 uint64_t offset, int allocate,
360 int compressed_size,
361 int n_start, int n_end, uint64_t *result)
362 {
363 BDRVQcowState *s = bs->opaque;
364 int min_index, i, j, l1_index, l2_index, ret;
365 int64_t l2_offset;
366 uint64_t *l2_table, cluster_offset, tmp;
367 uint32_t min_count;
368 int new_l2_table;
369
370 *result = 0;
371 l1_index = offset >> (s->l2_bits + s->cluster_bits);
372 l2_offset = s->l1_table[l1_index];
373 new_l2_table = 0;
374 if (!l2_offset) {
375 if (!allocate)
376 return 0;
377 /* allocate a new l2 entry */
378 l2_offset = bdrv_getlength(bs->file->bs);
379 if (l2_offset < 0) {
380 return l2_offset;
381 }
382 /* round to cluster size */
383 l2_offset = QEMU_ALIGN_UP(l2_offset, s->cluster_size);
384 /* update the L1 entry */
385 s->l1_table[l1_index] = l2_offset;
386 tmp = cpu_to_be64(l2_offset);
387 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
388 ret = bdrv_pwrite_sync(bs->file,
389 s->l1_table_offset + l1_index * sizeof(tmp),
390 &tmp, sizeof(tmp));
391 if (ret < 0) {
392 return ret;
393 }
394 new_l2_table = 1;
395 }
396 for(i = 0; i < L2_CACHE_SIZE; i++) {
397 if (l2_offset == s->l2_cache_offsets[i]) {
398 /* increment the hit count */
399 if (++s->l2_cache_counts[i] == 0xffffffff) {
400 for(j = 0; j < L2_CACHE_SIZE; j++) {
401 s->l2_cache_counts[j] >>= 1;
402 }
403 }
404 l2_table = s->l2_cache + (i << s->l2_bits);
405 goto found;
406 }
407 }
408 /* not found: load a new entry in the least used one */
409 min_index = 0;
410 min_count = 0xffffffff;
411 for(i = 0; i < L2_CACHE_SIZE; i++) {
412 if (s->l2_cache_counts[i] < min_count) {
413 min_count = s->l2_cache_counts[i];
414 min_index = i;
415 }
416 }
417 l2_table = s->l2_cache + (min_index << s->l2_bits);
418 BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
419 if (new_l2_table) {
420 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
421 ret = bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
422 s->l2_size * sizeof(uint64_t));
423 if (ret < 0) {
424 return ret;
425 }
426 } else {
427 ret = bdrv_pread(bs->file, l2_offset, l2_table,
428 s->l2_size * sizeof(uint64_t));
429 if (ret < 0) {
430 return ret;
431 }
432 }
433 s->l2_cache_offsets[min_index] = l2_offset;
434 s->l2_cache_counts[min_index] = 1;
435 found:
436 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
437 cluster_offset = be64_to_cpu(l2_table[l2_index]);
438 if (!cluster_offset ||
439 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
440 if (!allocate)
441 return 0;
442 BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC);
443 /* allocate a new cluster */
444 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
445 (n_end - n_start) < s->cluster_sectors) {
446 /* if the cluster is already compressed, we must
447 decompress it in the case it is not completely
448 overwritten */
449 if (decompress_cluster(bs, cluster_offset) < 0) {
450 return -EIO;
451 }
452 cluster_offset = bdrv_getlength(bs->file->bs);
453 if ((int64_t) cluster_offset < 0) {
454 return cluster_offset;
455 }
456 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
457 /* write the cluster content */
458 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
459 ret = bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache,
460 s->cluster_size);
461 if (ret < 0) {
462 return ret;
463 }
464 } else {
465 cluster_offset = bdrv_getlength(bs->file->bs);
466 if ((int64_t) cluster_offset < 0) {
467 return cluster_offset;
468 }
469 if (allocate == 1) {
470 /* round to cluster size */
471 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
472 if (cluster_offset + s->cluster_size > INT64_MAX) {
473 return -E2BIG;
474 }
475 ret = bdrv_truncate(bs->file, cluster_offset + s->cluster_size,
476 PREALLOC_MODE_OFF, NULL);
477 if (ret < 0) {
478 return ret;
479 }
480 /* if encrypted, we must initialize the cluster
481 content which won't be written */
482 if (bs->encrypted &&
483 (n_end - n_start) < s->cluster_sectors) {
484 uint64_t start_sect;
485 assert(s->crypto);
486 start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
487 for(i = 0; i < s->cluster_sectors; i++) {
488 if (i < n_start || i >= n_end) {
489 memset(s->cluster_data, 0x00, 512);
490 if (qcrypto_block_encrypt(s->crypto,
491 (start_sect + i) *
492 BDRV_SECTOR_SIZE,
493 s->cluster_data,
494 BDRV_SECTOR_SIZE,
495 NULL) < 0) {
496 return -EIO;
497 }
498 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
499 ret = bdrv_pwrite(bs->file,
500 cluster_offset + i * 512,
501 s->cluster_data, 512);
502 if (ret < 0) {
503 return ret;
504 }
505 }
506 }
507 }
508 } else if (allocate == 2) {
509 cluster_offset |= QCOW_OFLAG_COMPRESSED |
510 (uint64_t)compressed_size << (63 - s->cluster_bits);
511 }
512 }
513 /* update L2 table */
514 tmp = cpu_to_be64(cluster_offset);
515 l2_table[l2_index] = tmp;
516 if (allocate == 2) {
517 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
518 } else {
519 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
520 }
521 ret = bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
522 &tmp, sizeof(tmp));
523 if (ret < 0) {
524 return ret;
525 }
526 }
527 *result = cluster_offset;
528 return 1;
529 }
530
531 static int coroutine_fn qcow_co_block_status(BlockDriverState *bs,
532 bool want_zero,
533 int64_t offset, int64_t bytes,
534 int64_t *pnum, int64_t *map,
535 BlockDriverState **file)
536 {
537 BDRVQcowState *s = bs->opaque;
538 int index_in_cluster, ret;
539 int64_t n;
540 uint64_t cluster_offset;
541
542 qemu_co_mutex_lock(&s->lock);
543 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
544 qemu_co_mutex_unlock(&s->lock);
545 if (ret < 0) {
546 return ret;
547 }
548 index_in_cluster = offset & (s->cluster_size - 1);
549 n = s->cluster_size - index_in_cluster;
550 if (n > bytes) {
551 n = bytes;
552 }
553 *pnum = n;
554 if (!cluster_offset) {
555 return 0;
556 }
557 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
558 return BDRV_BLOCK_DATA;
559 }
560 *map = cluster_offset | index_in_cluster;
561 *file = bs->file->bs;
562 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
563 }
564
565 static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
566 const uint8_t *buf, int buf_size)
567 {
568 z_stream strm1, *strm = &strm1;
569 int ret, out_len;
570
571 memset(strm, 0, sizeof(*strm));
572
573 strm->next_in = (uint8_t *)buf;
574 strm->avail_in = buf_size;
575 strm->next_out = out_buf;
576 strm->avail_out = out_buf_size;
577
578 ret = inflateInit2(strm, -12);
579 if (ret != Z_OK)
580 return -1;
581 ret = inflate(strm, Z_FINISH);
582 out_len = strm->next_out - out_buf;
583 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
584 out_len != out_buf_size) {
585 inflateEnd(strm);
586 return -1;
587 }
588 inflateEnd(strm);
589 return 0;
590 }
591
592 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
593 {
594 BDRVQcowState *s = bs->opaque;
595 int ret, csize;
596 uint64_t coffset;
597
598 coffset = cluster_offset & s->cluster_offset_mask;
599 if (s->cluster_cache_offset != coffset) {
600 csize = cluster_offset >> (63 - s->cluster_bits);
601 csize &= (s->cluster_size - 1);
602 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
603 ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
604 if (ret != csize)
605 return -1;
606 if (decompress_buffer(s->cluster_cache, s->cluster_size,
607 s->cluster_data, csize) < 0) {
608 return -1;
609 }
610 s->cluster_cache_offset = coffset;
611 }
612 return 0;
613 }
614
615 static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
616 int nb_sectors, QEMUIOVector *qiov)
617 {
618 BDRVQcowState *s = bs->opaque;
619 int index_in_cluster;
620 int ret = 0, n;
621 uint64_t cluster_offset;
622 struct iovec hd_iov;
623 QEMUIOVector hd_qiov;
624 uint8_t *buf;
625 void *orig_buf;
626
627 if (qiov->niov > 1) {
628 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
629 if (buf == NULL) {
630 return -ENOMEM;
631 }
632 } else {
633 orig_buf = NULL;
634 buf = (uint8_t *)qiov->iov->iov_base;
635 }
636
637 qemu_co_mutex_lock(&s->lock);
638
639 while (nb_sectors != 0) {
640 /* prepare next request */
641 ret = get_cluster_offset(bs, sector_num << 9,
642 0, 0, 0, 0, &cluster_offset);
643 if (ret < 0) {
644 break;
645 }
646 index_in_cluster = sector_num & (s->cluster_sectors - 1);
647 n = s->cluster_sectors - index_in_cluster;
648 if (n > nb_sectors) {
649 n = nb_sectors;
650 }
651
652 if (!cluster_offset) {
653 if (bs->backing) {
654 /* read from the base image */
655 hd_iov.iov_base = (void *)buf;
656 hd_iov.iov_len = n * 512;
657 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
658 qemu_co_mutex_unlock(&s->lock);
659 /* qcow2 emits this on bs->file instead of bs->backing */
660 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
661 ret = bdrv_co_readv(bs->backing, sector_num, n, &hd_qiov);
662 qemu_co_mutex_lock(&s->lock);
663 if (ret < 0) {
664 break;
665 }
666 } else {
667 /* Note: in this case, no need to wait */
668 memset(buf, 0, 512 * n);
669 }
670 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
671 /* add AIO support for compressed blocks ? */
672 if (decompress_cluster(bs, cluster_offset) < 0) {
673 ret = -EIO;
674 break;
675 }
676 memcpy(buf,
677 s->cluster_cache + index_in_cluster * 512, 512 * n);
678 } else {
679 if ((cluster_offset & 511) != 0) {
680 ret = -EIO;
681 break;
682 }
683 hd_iov.iov_base = (void *)buf;
684 hd_iov.iov_len = n * 512;
685 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
686 qemu_co_mutex_unlock(&s->lock);
687 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
688 ret = bdrv_co_readv(bs->file,
689 (cluster_offset >> 9) + index_in_cluster,
690 n, &hd_qiov);
691 qemu_co_mutex_lock(&s->lock);
692 if (ret < 0) {
693 break;
694 }
695 if (bs->encrypted) {
696 assert(s->crypto);
697 if (qcrypto_block_decrypt(s->crypto,
698 sector_num * BDRV_SECTOR_SIZE, buf,
699 n * BDRV_SECTOR_SIZE, NULL) < 0) {
700 ret = -EIO;
701 break;
702 }
703 }
704 }
705 ret = 0;
706
707 nb_sectors -= n;
708 sector_num += n;
709 buf += n * 512;
710 }
711
712 qemu_co_mutex_unlock(&s->lock);
713
714 if (qiov->niov > 1) {
715 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
716 qemu_vfree(orig_buf);
717 }
718
719 return ret;
720 }
721
722 static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
723 int nb_sectors, QEMUIOVector *qiov,
724 int flags)
725 {
726 BDRVQcowState *s = bs->opaque;
727 int index_in_cluster;
728 uint64_t cluster_offset;
729 int ret = 0, n;
730 struct iovec hd_iov;
731 QEMUIOVector hd_qiov;
732 uint8_t *buf;
733 void *orig_buf;
734
735 assert(!flags);
736 s->cluster_cache_offset = -1; /* disable compressed cache */
737
738 /* We must always copy the iov when encrypting, so we
739 * don't modify the original data buffer during encryption */
740 if (bs->encrypted || qiov->niov > 1) {
741 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
742 if (buf == NULL) {
743 return -ENOMEM;
744 }
745 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
746 } else {
747 orig_buf = NULL;
748 buf = (uint8_t *)qiov->iov->iov_base;
749 }
750
751 qemu_co_mutex_lock(&s->lock);
752
753 while (nb_sectors != 0) {
754
755 index_in_cluster = sector_num & (s->cluster_sectors - 1);
756 n = s->cluster_sectors - index_in_cluster;
757 if (n > nb_sectors) {
758 n = nb_sectors;
759 }
760 ret = get_cluster_offset(bs, sector_num << 9, 1, 0,
761 index_in_cluster,
762 index_in_cluster + n, &cluster_offset);
763 if (ret < 0) {
764 break;
765 }
766 if (!cluster_offset || (cluster_offset & 511) != 0) {
767 ret = -EIO;
768 break;
769 }
770 if (bs->encrypted) {
771 assert(s->crypto);
772 if (qcrypto_block_encrypt(s->crypto, sector_num * BDRV_SECTOR_SIZE,
773 buf, n * BDRV_SECTOR_SIZE, NULL) < 0) {
774 ret = -EIO;
775 break;
776 }
777 }
778
779 hd_iov.iov_base = (void *)buf;
780 hd_iov.iov_len = n * 512;
781 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
782 qemu_co_mutex_unlock(&s->lock);
783 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
784 ret = bdrv_co_writev(bs->file,
785 (cluster_offset >> 9) + index_in_cluster,
786 n, &hd_qiov);
787 qemu_co_mutex_lock(&s->lock);
788 if (ret < 0) {
789 break;
790 }
791 ret = 0;
792
793 nb_sectors -= n;
794 sector_num += n;
795 buf += n * 512;
796 }
797 qemu_co_mutex_unlock(&s->lock);
798
799 qemu_vfree(orig_buf);
800
801 return ret;
802 }
803
804 static void qcow_close(BlockDriverState *bs)
805 {
806 BDRVQcowState *s = bs->opaque;
807
808 qcrypto_block_free(s->crypto);
809 s->crypto = NULL;
810 g_free(s->l1_table);
811 qemu_vfree(s->l2_cache);
812 g_free(s->cluster_cache);
813 g_free(s->cluster_data);
814
815 migrate_del_blocker(s->migration_blocker);
816 error_free(s->migration_blocker);
817 }
818
819 static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
820 Error **errp)
821 {
822 BlockdevCreateOptionsQcow *qcow_opts;
823 int header_size, backing_filename_len, l1_size, shift, i;
824 QCowHeader header;
825 uint8_t *tmp;
826 int64_t total_size = 0;
827 int ret;
828 BlockDriverState *bs;
829 BlockBackend *qcow_blk;
830 QCryptoBlock *crypto = NULL;
831
832 assert(opts->driver == BLOCKDEV_DRIVER_QCOW);
833 qcow_opts = &opts->u.qcow;
834
835 /* Sanity checks */
836 total_size = qcow_opts->size;
837 if (total_size == 0) {
838 error_setg(errp, "Image size is too small, cannot be zero length");
839 return -EINVAL;
840 }
841
842 if (qcow_opts->has_encrypt &&
843 qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW)
844 {
845 error_setg(errp, "Unsupported encryption format");
846 return -EINVAL;
847 }
848
849 /* Create BlockBackend to write to the image */
850 bs = bdrv_open_blockdev_ref(qcow_opts->file, errp);
851 if (bs == NULL) {
852 return -EIO;
853 }
854
855 qcow_blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
856 ret = blk_insert_bs(qcow_blk, bs, errp);
857 if (ret < 0) {
858 goto exit;
859 }
860 blk_set_allow_write_beyond_eof(qcow_blk, true);
861
862 /* Create image format */
863 ret = blk_truncate(qcow_blk, 0, PREALLOC_MODE_OFF, errp);
864 if (ret < 0) {
865 goto exit;
866 }
867
868 memset(&header, 0, sizeof(header));
869 header.magic = cpu_to_be32(QCOW_MAGIC);
870 header.version = cpu_to_be32(QCOW_VERSION);
871 header.size = cpu_to_be64(total_size);
872 header_size = sizeof(header);
873 backing_filename_len = 0;
874 if (qcow_opts->has_backing_file) {
875 if (strcmp(qcow_opts->backing_file, "fat:")) {
876 header.backing_file_offset = cpu_to_be64(header_size);
877 backing_filename_len = strlen(qcow_opts->backing_file);
878 header.backing_file_size = cpu_to_be32(backing_filename_len);
879 header_size += backing_filename_len;
880 } else {
881 /* special backing file for vvfat */
882 qcow_opts->has_backing_file = false;
883 }
884 header.cluster_bits = 9; /* 512 byte cluster to avoid copying
885 unmodified sectors */
886 header.l2_bits = 12; /* 32 KB L2 tables */
887 } else {
888 header.cluster_bits = 12; /* 4 KB clusters */
889 header.l2_bits = 9; /* 4 KB L2 tables */
890 }
891 header_size = (header_size + 7) & ~7;
892 shift = header.cluster_bits + header.l2_bits;
893 l1_size = (total_size + (1LL << shift) - 1) >> shift;
894
895 header.l1_table_offset = cpu_to_be64(header_size);
896
897 if (qcow_opts->has_encrypt) {
898 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
899
900 crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.",
901 NULL, NULL, NULL, errp);
902 if (!crypto) {
903 ret = -EINVAL;
904 goto exit;
905 }
906 } else {
907 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
908 }
909
910 /* write all the data */
911 ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0);
912 if (ret != sizeof(header)) {
913 goto exit;
914 }
915
916 if (qcow_opts->has_backing_file) {
917 ret = blk_pwrite(qcow_blk, sizeof(header),
918 qcow_opts->backing_file, backing_filename_len, 0);
919 if (ret != backing_filename_len) {
920 goto exit;
921 }
922 }
923
924 tmp = g_malloc0(BDRV_SECTOR_SIZE);
925 for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE);
926 i++) {
927 ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i,
928 tmp, BDRV_SECTOR_SIZE, 0);
929 if (ret != BDRV_SECTOR_SIZE) {
930 g_free(tmp);
931 goto exit;
932 }
933 }
934
935 g_free(tmp);
936 ret = 0;
937 exit:
938 blk_unref(qcow_blk);
939 qcrypto_block_free(crypto);
940 return ret;
941 }
942
943 static int coroutine_fn qcow_co_create_opts(const char *filename,
944 QemuOpts *opts, Error **errp)
945 {
946 BlockdevCreateOptions *create_options = NULL;
947 BlockDriverState *bs = NULL;
948 QDict *qdict = NULL;
949 QObject *qobj;
950 Visitor *v;
951 const char *val;
952 Error *local_err = NULL;
953 int ret;
954
955 static const QDictRenames opt_renames[] = {
956 { BLOCK_OPT_BACKING_FILE, "backing-file" },
957 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
958 { NULL, NULL },
959 };
960
961 /* Parse options and convert legacy syntax */
962 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
963
964 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
965 if (val && !strcmp(val, "on")) {
966 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
967 } else if (val && !strcmp(val, "off")) {
968 qdict_del(qdict, BLOCK_OPT_ENCRYPT);
969 }
970
971 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
972 if (val && !strcmp(val, "aes")) {
973 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
974 }
975
976 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
977 ret = -EINVAL;
978 goto fail;
979 }
980
981 /* Create and open the file (protocol layer) */
982 ret = bdrv_create_file(filename, opts, &local_err);
983 if (ret < 0) {
984 error_propagate(errp, local_err);
985 goto fail;
986 }
987
988 bs = bdrv_open(filename, NULL, NULL,
989 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
990 if (bs == NULL) {
991 ret = -EIO;
992 goto fail;
993 }
994
995 /* Now get the QAPI type BlockdevCreateOptions */
996 qdict_put_str(qdict, "driver", "qcow");
997 qdict_put_str(qdict, "file", bs->node_name);
998
999 qobj = qdict_crumple(qdict, errp);
1000 qobject_unref(qdict);
1001 qdict = qobject_to(QDict, qobj);
1002 if (qdict == NULL) {
1003 ret = -EINVAL;
1004 goto fail;
1005 }
1006
1007 v = qobject_input_visitor_new_keyval(QOBJECT(qdict));
1008 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
1009 visit_free(v);
1010
1011 if (local_err) {
1012 error_propagate(errp, local_err);
1013 ret = -EINVAL;
1014 goto fail;
1015 }
1016
1017 /* Silently round up size */
1018 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW);
1019 create_options->u.qcow.size =
1020 ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE);
1021
1022 /* Create the qcow image (format layer) */
1023 ret = qcow_co_create(create_options, errp);
1024 if (ret < 0) {
1025 goto fail;
1026 }
1027
1028 ret = 0;
1029 fail:
1030 qobject_unref(qdict);
1031 bdrv_unref(bs);
1032 qapi_free_BlockdevCreateOptions(create_options);
1033 return ret;
1034 }
1035
1036 static int qcow_make_empty(BlockDriverState *bs)
1037 {
1038 BDRVQcowState *s = bs->opaque;
1039 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
1040 int ret;
1041
1042 memset(s->l1_table, 0, l1_length);
1043 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
1044 l1_length) < 0)
1045 return -1;
1046 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length,
1047 PREALLOC_MODE_OFF, NULL);
1048 if (ret < 0)
1049 return ret;
1050
1051 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
1052 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
1053 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
1054
1055 return 0;
1056 }
1057
1058 /* XXX: put compressed sectors first, then all the cluster aligned
1059 tables to avoid losing bytes in alignment */
1060 static coroutine_fn int
1061 qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
1062 uint64_t bytes, QEMUIOVector *qiov)
1063 {
1064 BDRVQcowState *s = bs->opaque;
1065 QEMUIOVector hd_qiov;
1066 struct iovec iov;
1067 z_stream strm;
1068 int ret, out_len;
1069 uint8_t *buf, *out_buf;
1070 uint64_t cluster_offset;
1071
1072 buf = qemu_blockalign(bs, s->cluster_size);
1073 if (bytes != s->cluster_size) {
1074 if (bytes > s->cluster_size ||
1075 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS)
1076 {
1077 qemu_vfree(buf);
1078 return -EINVAL;
1079 }
1080 /* Zero-pad last write if image size is not cluster aligned */
1081 memset(buf + bytes, 0, s->cluster_size - bytes);
1082 }
1083 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
1084
1085 out_buf = g_malloc(s->cluster_size);
1086
1087 /* best compression, small window, no zlib header */
1088 memset(&strm, 0, sizeof(strm));
1089 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
1090 Z_DEFLATED, -12,
1091 9, Z_DEFAULT_STRATEGY);
1092 if (ret != 0) {
1093 ret = -EINVAL;
1094 goto fail;
1095 }
1096
1097 strm.avail_in = s->cluster_size;
1098 strm.next_in = (uint8_t *)buf;
1099 strm.avail_out = s->cluster_size;
1100 strm.next_out = out_buf;
1101
1102 ret = deflate(&strm, Z_FINISH);
1103 if (ret != Z_STREAM_END && ret != Z_OK) {
1104 deflateEnd(&strm);
1105 ret = -EINVAL;
1106 goto fail;
1107 }
1108 out_len = strm.next_out - out_buf;
1109
1110 deflateEnd(&strm);
1111
1112 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
1113 /* could not compress: write normal cluster */
1114 ret = qcow_co_writev(bs, offset >> BDRV_SECTOR_BITS,
1115 bytes >> BDRV_SECTOR_BITS, qiov, 0);
1116 if (ret < 0) {
1117 goto fail;
1118 }
1119 goto success;
1120 }
1121 qemu_co_mutex_lock(&s->lock);
1122 ret = get_cluster_offset(bs, offset, 2, out_len, 0, 0, &cluster_offset);
1123 qemu_co_mutex_unlock(&s->lock);
1124 if (ret < 0) {
1125 goto fail;
1126 }
1127 if (cluster_offset == 0) {
1128 ret = -EIO;
1129 goto fail;
1130 }
1131 cluster_offset &= s->cluster_offset_mask;
1132
1133 iov = (struct iovec) {
1134 .iov_base = out_buf,
1135 .iov_len = out_len,
1136 };
1137 qemu_iovec_init_external(&hd_qiov, &iov, 1);
1138 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
1139 ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
1140 if (ret < 0) {
1141 goto fail;
1142 }
1143 success:
1144 ret = 0;
1145 fail:
1146 qemu_vfree(buf);
1147 g_free(out_buf);
1148 return ret;
1149 }
1150
1151 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1152 {
1153 BDRVQcowState *s = bs->opaque;
1154 bdi->cluster_size = s->cluster_size;
1155 return 0;
1156 }
1157
1158 static QemuOptsList qcow_create_opts = {
1159 .name = "qcow-create-opts",
1160 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
1161 .desc = {
1162 {
1163 .name = BLOCK_OPT_SIZE,
1164 .type = QEMU_OPT_SIZE,
1165 .help = "Virtual disk size"
1166 },
1167 {
1168 .name = BLOCK_OPT_BACKING_FILE,
1169 .type = QEMU_OPT_STRING,
1170 .help = "File name of a base image"
1171 },
1172 {
1173 .name = BLOCK_OPT_ENCRYPT,
1174 .type = QEMU_OPT_BOOL,
1175 .help = "Encrypt the image with format 'aes'. (Deprecated "
1176 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)",
1177 },
1178 {
1179 .name = BLOCK_OPT_ENCRYPT_FORMAT,
1180 .type = QEMU_OPT_STRING,
1181 .help = "Encrypt the image, format choices: 'aes'",
1182 },
1183 BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
1184 { /* end of list */ }
1185 }
1186 };
1187
1188 static BlockDriver bdrv_qcow = {
1189 .format_name = "qcow",
1190 .instance_size = sizeof(BDRVQcowState),
1191 .bdrv_probe = qcow_probe,
1192 .bdrv_open = qcow_open,
1193 .bdrv_close = qcow_close,
1194 .bdrv_child_perm = bdrv_format_default_perms,
1195 .bdrv_reopen_prepare = qcow_reopen_prepare,
1196 .bdrv_co_create = qcow_co_create,
1197 .bdrv_co_create_opts = qcow_co_create_opts,
1198 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1199 .supports_backing = true,
1200
1201 .bdrv_co_readv = qcow_co_readv,
1202 .bdrv_co_writev = qcow_co_writev,
1203 .bdrv_co_block_status = qcow_co_block_status,
1204
1205 .bdrv_make_empty = qcow_make_empty,
1206 .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
1207 .bdrv_get_info = qcow_get_info,
1208
1209 .create_opts = &qcow_create_opts,
1210 };
1211
1212 static void bdrv_qcow_init(void)
1213 {
1214 bdrv_register(&bdrv_qcow);
1215 }
1216
1217 block_init(bdrv_qcow_init);
QEmu