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ahci/qtest: don't use tcp sockets for migration tests
[qemu/kevin.git] / block / qcow.c
blob635085e27b497aa4ae83497a1d8e9c1f402b29ad
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 #include "qemu-common.h"
25 #include "block/block_int.h"
26 #include "qemu/module.h"
27 #include <zlib.h>
28 #include "qapi/qmp/qerror.h"
29 #include "crypto/cipher.h"
30 #include "migration/migration.h"
31
32 /**************************************************************/
33 /* QEMU COW block driver with compression and encryption support */
34
35 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
36 #define QCOW_VERSION 1
37
38 #define QCOW_CRYPT_NONE 0
39 #define QCOW_CRYPT_AES 1
40
41 #define QCOW_OFLAG_COMPRESSED (1LL << 63)
42
43 typedef struct QCowHeader {
44 uint32_t magic;
45 uint32_t version;
46 uint64_t backing_file_offset;
47 uint32_t backing_file_size;
48 uint32_t mtime;
49 uint64_t size; /* in bytes */
50 uint8_t cluster_bits;
51 uint8_t l2_bits;
52 uint16_t padding;
53 uint32_t crypt_method;
54 uint64_t l1_table_offset;
55 } QEMU_PACKED QCowHeader;
56
57 #define L2_CACHE_SIZE 16
58
59 typedef struct BDRVQcowState {
60 int cluster_bits;
61 int cluster_size;
62 int cluster_sectors;
63 int l2_bits;
64 int l2_size;
65 unsigned int l1_size;
66 uint64_t cluster_offset_mask;
67 uint64_t l1_table_offset;
68 uint64_t *l1_table;
69 uint64_t *l2_cache;
70 uint64_t l2_cache_offsets[L2_CACHE_SIZE];
71 uint32_t l2_cache_counts[L2_CACHE_SIZE];
72 uint8_t *cluster_cache;
73 uint8_t *cluster_data;
74 uint64_t cluster_cache_offset;
75 QCryptoCipher *cipher; /* NULL if no key yet */
76 uint32_t crypt_method_header;
77 CoMutex lock;
78 Error *migration_blocker;
79 } BDRVQcowState;
80
81 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
82
83 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
84 {
85 const QCowHeader *cow_header = (const void *)buf;
86
87 if (buf_size >= sizeof(QCowHeader) &&
88 be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
89 be32_to_cpu(cow_header->version) == QCOW_VERSION)
90 return 100;
91 else
92 return 0;
93 }
94
95 static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
96 Error **errp)
97 {
98 BDRVQcowState *s = bs->opaque;
99 unsigned int len, i, shift;
100 int ret;
101 QCowHeader header;
102
103 ret = bdrv_pread(bs->file->bs, 0, &header, sizeof(header));
104 if (ret < 0) {
105 goto fail;
106 }
107 be32_to_cpus(&header.magic);
108 be32_to_cpus(&header.version);
109 be64_to_cpus(&header.backing_file_offset);
110 be32_to_cpus(&header.backing_file_size);
111 be32_to_cpus(&header.mtime);
112 be64_to_cpus(&header.size);
113 be32_to_cpus(&header.crypt_method);
114 be64_to_cpus(&header.l1_table_offset);
115
116 if (header.magic != QCOW_MAGIC) {
117 error_setg(errp, "Image not in qcow format");
118 ret = -EINVAL;
119 goto fail;
120 }
121 if (header.version != QCOW_VERSION) {
122 char version[64];
123 snprintf(version, sizeof(version), "QCOW version %" PRIu32,
124 header.version);
125 error_setg(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
126 bdrv_get_device_or_node_name(bs), "qcow", version);
127 ret = -ENOTSUP;
128 goto fail;
129 }
130
131 if (header.size <= 1) {
132 error_setg(errp, "Image size is too small (must be at least 2 bytes)");
133 ret = -EINVAL;
134 goto fail;
135 }
136 if (header.cluster_bits < 9 || header.cluster_bits > 16) {
137 error_setg(errp, "Cluster size must be between 512 and 64k");
138 ret = -EINVAL;
139 goto fail;
140 }
141
142 /* l2_bits specifies number of entries; storing a uint64_t in each entry,
143 * so bytes = num_entries << 3. */
144 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
145 error_setg(errp, "L2 table size must be between 512 and 64k");
146 ret = -EINVAL;
147 goto fail;
148 }
149
150 if (header.crypt_method > QCOW_CRYPT_AES) {
151 error_setg(errp, "invalid encryption method in qcow header");
152 ret = -EINVAL;
153 goto fail;
154 }
155 if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) {
156 error_setg(errp, "AES cipher not available");
157 ret = -EINVAL;
158 goto fail;
159 }
160 s->crypt_method_header = header.crypt_method;
161 if (s->crypt_method_header) {
162 bs->encrypted = 1;
163 }
164 s->cluster_bits = header.cluster_bits;
165 s->cluster_size = 1 << s->cluster_bits;
166 s->cluster_sectors = 1 << (s->cluster_bits - 9);
167 s->l2_bits = header.l2_bits;
168 s->l2_size = 1 << s->l2_bits;
169 bs->total_sectors = header.size / 512;
170 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
171
172 /* read the level 1 table */
173 shift = s->cluster_bits + s->l2_bits;
174 if (header.size > UINT64_MAX - (1LL << shift)) {
175 error_setg(errp, "Image too large");
176 ret = -EINVAL;
177 goto fail;
178 } else {
179 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
180 if (l1_size > INT_MAX / sizeof(uint64_t)) {
181 error_setg(errp, "Image too large");
182 ret = -EINVAL;
183 goto fail;
184 }
185 s->l1_size = l1_size;
186 }
187
188 s->l1_table_offset = header.l1_table_offset;
189 s->l1_table = g_try_new(uint64_t, s->l1_size);
190 if (s->l1_table == NULL) {
191 error_setg(errp, "Could not allocate memory for L1 table");
192 ret = -ENOMEM;
193 goto fail;
194 }
195
196 ret = bdrv_pread(bs->file->bs, s->l1_table_offset, s->l1_table,
197 s->l1_size * sizeof(uint64_t));
198 if (ret < 0) {
199 goto fail;
200 }
201
202 for(i = 0;i < s->l1_size; i++) {
203 be64_to_cpus(&s->l1_table[i]);
204 }
205
206 /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
207 s->l2_cache =
208 qemu_try_blockalign(bs->file->bs,
209 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
210 if (s->l2_cache == NULL) {
211 error_setg(errp, "Could not allocate L2 table cache");
212 ret = -ENOMEM;
213 goto fail;
214 }
215 s->cluster_cache = g_malloc(s->cluster_size);
216 s->cluster_data = g_malloc(s->cluster_size);
217 s->cluster_cache_offset = -1;
218
219 /* read the backing file name */
220 if (header.backing_file_offset != 0) {
221 len = header.backing_file_size;
222 if (len > 1023 || len >= sizeof(bs->backing_file)) {
223 error_setg(errp, "Backing file name too long");
224 ret = -EINVAL;
225 goto fail;
226 }
227 ret = bdrv_pread(bs->file->bs, header.backing_file_offset,
228 bs->backing_file, len);
229 if (ret < 0) {
230 goto fail;
231 }
232 bs->backing_file[len] = '\0';
233 }
234
235 /* Disable migration when qcow images are used */
236 error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
237 "does not support live migration",
238 bdrv_get_device_or_node_name(bs));
239 migrate_add_blocker(s->migration_blocker);
240
241 qemu_co_mutex_init(&s->lock);
242 return 0;
243
244 fail:
245 g_free(s->l1_table);
246 qemu_vfree(s->l2_cache);
247 g_free(s->cluster_cache);
248 g_free(s->cluster_data);
249 return ret;
250 }
251
252
253 /* We have nothing to do for QCOW reopen, stubs just return
254 * success */
255 static int qcow_reopen_prepare(BDRVReopenState *state,
256 BlockReopenQueue *queue, Error **errp)
257 {
258 return 0;
259 }
260
261 static int qcow_set_key(BlockDriverState *bs, const char *key)
262 {
263 BDRVQcowState *s = bs->opaque;
264 uint8_t keybuf[16];
265 int len, i;
266 Error *err;
267
268 memset(keybuf, 0, 16);
269 len = strlen(key);
270 if (len > 16)
271 len = 16;
272 /* XXX: we could compress the chars to 7 bits to increase
273 entropy */
274 for(i = 0;i < len;i++) {
275 keybuf[i] = key[i];
276 }
277 assert(bs->encrypted);
278
279 qcrypto_cipher_free(s->cipher);
280 s->cipher = qcrypto_cipher_new(
281 QCRYPTO_CIPHER_ALG_AES_128,
282 QCRYPTO_CIPHER_MODE_CBC,
283 keybuf, G_N_ELEMENTS(keybuf),
284 &err);
285
286 if (!s->cipher) {
287 /* XXX would be nice if errors in this method could
288 * be properly propagate to the caller. Would need
289 * the bdrv_set_key() API signature to be fixed. */
290 error_free(err);
291 return -1;
292 }
293 return 0;
294 }
295
296 /* The crypt function is compatible with the linux cryptoloop
297 algorithm for < 4 GB images. NOTE: out_buf == in_buf is
298 supported */
299 static int encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
300 uint8_t *out_buf, const uint8_t *in_buf,
301 int nb_sectors, bool enc, Error **errp)
302 {
303 union {
304 uint64_t ll[2];
305 uint8_t b[16];
306 } ivec;
307 int i;
308 int ret;
309
310 for(i = 0; i < nb_sectors; i++) {
311 ivec.ll[0] = cpu_to_le64(sector_num);
312 ivec.ll[1] = 0;
313 if (qcrypto_cipher_setiv(s->cipher,
314 ivec.b, G_N_ELEMENTS(ivec.b),
315 errp) < 0) {
316 return -1;
317 }
318 if (enc) {
319 ret = qcrypto_cipher_encrypt(s->cipher,
320 in_buf,
321 out_buf,
322 512,
323 errp);
324 } else {
325 ret = qcrypto_cipher_decrypt(s->cipher,
326 in_buf,
327 out_buf,
328 512,
329 errp);
330 }
331 if (ret < 0) {
332 return -1;
333 }
334 sector_num++;
335 in_buf += 512;
336 out_buf += 512;
337 }
338 return 0;
339 }
340
341 /* 'allocate' is:
342 *
343 * 0 to not allocate.
344 *
345 * 1 to allocate a normal cluster (for sector indexes 'n_start' to
346 * 'n_end')
347 *
348 * 2 to allocate a compressed cluster of size
349 * 'compressed_size'. 'compressed_size' must be > 0 and <
350 * cluster_size
351 *
352 * return 0 if not allocated.
353 */
354 static uint64_t get_cluster_offset(BlockDriverState *bs,
355 uint64_t offset, int allocate,
356 int compressed_size,
357 int n_start, int n_end)
358 {
359 BDRVQcowState *s = bs->opaque;
360 int min_index, i, j, l1_index, l2_index;
361 uint64_t l2_offset, *l2_table, cluster_offset, tmp;
362 uint32_t min_count;
363 int new_l2_table;
364
365 l1_index = offset >> (s->l2_bits + s->cluster_bits);
366 l2_offset = s->l1_table[l1_index];
367 new_l2_table = 0;
368 if (!l2_offset) {
369 if (!allocate)
370 return 0;
371 /* allocate a new l2 entry */
372 l2_offset = bdrv_getlength(bs->file->bs);
373 /* round to cluster size */
374 l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1);
375 /* update the L1 entry */
376 s->l1_table[l1_index] = l2_offset;
377 tmp = cpu_to_be64(l2_offset);
378 if (bdrv_pwrite_sync(bs->file->bs,
379 s->l1_table_offset + l1_index * sizeof(tmp),
380 &tmp, sizeof(tmp)) < 0)
381 return 0;
382 new_l2_table = 1;
383 }
384 for(i = 0; i < L2_CACHE_SIZE; i++) {
385 if (l2_offset == s->l2_cache_offsets[i]) {
386 /* increment the hit count */
387 if (++s->l2_cache_counts[i] == 0xffffffff) {
388 for(j = 0; j < L2_CACHE_SIZE; j++) {
389 s->l2_cache_counts[j] >>= 1;
390 }
391 }
392 l2_table = s->l2_cache + (i << s->l2_bits);
393 goto found;
394 }
395 }
396 /* not found: load a new entry in the least used one */
397 min_index = 0;
398 min_count = 0xffffffff;
399 for(i = 0; i < L2_CACHE_SIZE; i++) {
400 if (s->l2_cache_counts[i] < min_count) {
401 min_count = s->l2_cache_counts[i];
402 min_index = i;
403 }
404 }
405 l2_table = s->l2_cache + (min_index << s->l2_bits);
406 if (new_l2_table) {
407 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
408 if (bdrv_pwrite_sync(bs->file->bs, l2_offset, l2_table,
409 s->l2_size * sizeof(uint64_t)) < 0)
410 return 0;
411 } else {
412 if (bdrv_pread(bs->file->bs, l2_offset, l2_table,
413 s->l2_size * sizeof(uint64_t)) !=
414 s->l2_size * sizeof(uint64_t))
415 return 0;
416 }
417 s->l2_cache_offsets[min_index] = l2_offset;
418 s->l2_cache_counts[min_index] = 1;
419 found:
420 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
421 cluster_offset = be64_to_cpu(l2_table[l2_index]);
422 if (!cluster_offset ||
423 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
424 if (!allocate)
425 return 0;
426 /* allocate a new cluster */
427 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
428 (n_end - n_start) < s->cluster_sectors) {
429 /* if the cluster is already compressed, we must
430 decompress it in the case it is not completely
431 overwritten */
432 if (decompress_cluster(bs, cluster_offset) < 0)
433 return 0;
434 cluster_offset = bdrv_getlength(bs->file->bs);
435 cluster_offset = (cluster_offset + s->cluster_size - 1) &
436 ~(s->cluster_size - 1);
437 /* write the cluster content */
438 if (bdrv_pwrite(bs->file->bs, cluster_offset, s->cluster_cache,
439 s->cluster_size) !=
440 s->cluster_size)
441 return -1;
442 } else {
443 cluster_offset = bdrv_getlength(bs->file->bs);
444 if (allocate == 1) {
445 /* round to cluster size */
446 cluster_offset = (cluster_offset + s->cluster_size - 1) &
447 ~(s->cluster_size - 1);
448 bdrv_truncate(bs->file->bs, cluster_offset + s->cluster_size);
449 /* if encrypted, we must initialize the cluster
450 content which won't be written */
451 if (bs->encrypted &&
452 (n_end - n_start) < s->cluster_sectors) {
453 uint64_t start_sect;
454 assert(s->cipher);
455 start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
456 memset(s->cluster_data + 512, 0x00, 512);
457 for(i = 0; i < s->cluster_sectors; i++) {
458 if (i < n_start || i >= n_end) {
459 Error *err = NULL;
460 if (encrypt_sectors(s, start_sect + i,
461 s->cluster_data,
462 s->cluster_data + 512, 1,
463 true, &err) < 0) {
464 error_free(err);
465 errno = EIO;
466 return -1;
467 }
468 if (bdrv_pwrite(bs->file->bs,
469 cluster_offset + i * 512,
470 s->cluster_data, 512) != 512)
471 return -1;
472 }
473 }
474 }
475 } else if (allocate == 2) {
476 cluster_offset |= QCOW_OFLAG_COMPRESSED |
477 (uint64_t)compressed_size << (63 - s->cluster_bits);
478 }
479 }
480 /* update L2 table */
481 tmp = cpu_to_be64(cluster_offset);
482 l2_table[l2_index] = tmp;
483 if (bdrv_pwrite_sync(bs->file->bs, l2_offset + l2_index * sizeof(tmp),
484 &tmp, sizeof(tmp)) < 0)
485 return 0;
486 }
487 return cluster_offset;
488 }
489
490 static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs,
491 int64_t sector_num, int nb_sectors, int *pnum)
492 {
493 BDRVQcowState *s = bs->opaque;
494 int index_in_cluster, n;
495 uint64_t cluster_offset;
496
497 qemu_co_mutex_lock(&s->lock);
498 cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
499 qemu_co_mutex_unlock(&s->lock);
500 index_in_cluster = sector_num & (s->cluster_sectors - 1);
501 n = s->cluster_sectors - index_in_cluster;
502 if (n > nb_sectors)
503 n = nb_sectors;
504 *pnum = n;
505 if (!cluster_offset) {
506 return 0;
507 }
508 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->cipher) {
509 return BDRV_BLOCK_DATA;
510 }
511 cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
512 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset;
513 }
514
515 static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
516 const uint8_t *buf, int buf_size)
517 {
518 z_stream strm1, *strm = &strm1;
519 int ret, out_len;
520
521 memset(strm, 0, sizeof(*strm));
522
523 strm->next_in = (uint8_t *)buf;
524 strm->avail_in = buf_size;
525 strm->next_out = out_buf;
526 strm->avail_out = out_buf_size;
527
528 ret = inflateInit2(strm, -12);
529 if (ret != Z_OK)
530 return -1;
531 ret = inflate(strm, Z_FINISH);
532 out_len = strm->next_out - out_buf;
533 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
534 out_len != out_buf_size) {
535 inflateEnd(strm);
536 return -1;
537 }
538 inflateEnd(strm);
539 return 0;
540 }
541
542 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
543 {
544 BDRVQcowState *s = bs->opaque;
545 int ret, csize;
546 uint64_t coffset;
547
548 coffset = cluster_offset & s->cluster_offset_mask;
549 if (s->cluster_cache_offset != coffset) {
550 csize = cluster_offset >> (63 - s->cluster_bits);
551 csize &= (s->cluster_size - 1);
552 ret = bdrv_pread(bs->file->bs, coffset, s->cluster_data, csize);
553 if (ret != csize)
554 return -1;
555 if (decompress_buffer(s->cluster_cache, s->cluster_size,
556 s->cluster_data, csize) < 0) {
557 return -1;
558 }
559 s->cluster_cache_offset = coffset;
560 }
561 return 0;
562 }
563
564 static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
565 int nb_sectors, QEMUIOVector *qiov)
566 {
567 BDRVQcowState *s = bs->opaque;
568 int index_in_cluster;
569 int ret = 0, n;
570 uint64_t cluster_offset;
571 struct iovec hd_iov;
572 QEMUIOVector hd_qiov;
573 uint8_t *buf;
574 void *orig_buf;
575 Error *err = NULL;
576
577 if (qiov->niov > 1) {
578 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
579 if (buf == NULL) {
580 return -ENOMEM;
581 }
582 } else {
583 orig_buf = NULL;
584 buf = (uint8_t *)qiov->iov->iov_base;
585 }
586
587 qemu_co_mutex_lock(&s->lock);
588
589 while (nb_sectors != 0) {
590 /* prepare next request */
591 cluster_offset = get_cluster_offset(bs, sector_num << 9,
592 0, 0, 0, 0);
593 index_in_cluster = sector_num & (s->cluster_sectors - 1);
594 n = s->cluster_sectors - index_in_cluster;
595 if (n > nb_sectors) {
596 n = nb_sectors;
597 }
598
599 if (!cluster_offset) {
600 if (bs->backing) {
601 /* read from the base image */
602 hd_iov.iov_base = (void *)buf;
603 hd_iov.iov_len = n * 512;
604 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
605 qemu_co_mutex_unlock(&s->lock);
606 ret = bdrv_co_readv(bs->backing->bs, sector_num,
607 n, &hd_qiov);
608 qemu_co_mutex_lock(&s->lock);
609 if (ret < 0) {
610 goto fail;
611 }
612 } else {
613 /* Note: in this case, no need to wait */
614 memset(buf, 0, 512 * n);
615 }
616 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
617 /* add AIO support for compressed blocks ? */
618 if (decompress_cluster(bs, cluster_offset) < 0) {
619 goto fail;
620 }
621 memcpy(buf,
622 s->cluster_cache + index_in_cluster * 512, 512 * n);
623 } else {
624 if ((cluster_offset & 511) != 0) {
625 goto fail;
626 }
627 hd_iov.iov_base = (void *)buf;
628 hd_iov.iov_len = n * 512;
629 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
630 qemu_co_mutex_unlock(&s->lock);
631 ret = bdrv_co_readv(bs->file->bs,
632 (cluster_offset >> 9) + index_in_cluster,
633 n, &hd_qiov);
634 qemu_co_mutex_lock(&s->lock);
635 if (ret < 0) {
636 break;
637 }
638 if (bs->encrypted) {
639 assert(s->cipher);
640 if (encrypt_sectors(s, sector_num, buf, buf,
641 n, false, &err) < 0) {
642 goto fail;
643 }
644 }
645 }
646 ret = 0;
647
648 nb_sectors -= n;
649 sector_num += n;
650 buf += n * 512;
651 }
652
653 done:
654 qemu_co_mutex_unlock(&s->lock);
655
656 if (qiov->niov > 1) {
657 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
658 qemu_vfree(orig_buf);
659 }
660
661 return ret;
662
663 fail:
664 error_free(err);
665 ret = -EIO;
666 goto done;
667 }
668
669 static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
670 int nb_sectors, QEMUIOVector *qiov)
671 {
672 BDRVQcowState *s = bs->opaque;
673 int index_in_cluster;
674 uint64_t cluster_offset;
675 const uint8_t *src_buf;
676 int ret = 0, n;
677 uint8_t *cluster_data = NULL;
678 struct iovec hd_iov;
679 QEMUIOVector hd_qiov;
680 uint8_t *buf;
681 void *orig_buf;
682
683 s->cluster_cache_offset = -1; /* disable compressed cache */
684
685 if (qiov->niov > 1) {
686 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
687 if (buf == NULL) {
688 return -ENOMEM;
689 }
690 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
691 } else {
692 orig_buf = NULL;
693 buf = (uint8_t *)qiov->iov->iov_base;
694 }
695
696 qemu_co_mutex_lock(&s->lock);
697
698 while (nb_sectors != 0) {
699
700 index_in_cluster = sector_num & (s->cluster_sectors - 1);
701 n = s->cluster_sectors - index_in_cluster;
702 if (n > nb_sectors) {
703 n = nb_sectors;
704 }
705 cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0,
706 index_in_cluster,
707 index_in_cluster + n);
708 if (!cluster_offset || (cluster_offset & 511) != 0) {
709 ret = -EIO;
710 break;
711 }
712 if (bs->encrypted) {
713 Error *err = NULL;
714 assert(s->cipher);
715 if (!cluster_data) {
716 cluster_data = g_malloc0(s->cluster_size);
717 }
718 if (encrypt_sectors(s, sector_num, cluster_data, buf,
719 n, true, &err) < 0) {
720 error_free(err);
721 ret = -EIO;
722 break;
723 }
724 src_buf = cluster_data;
725 } else {
726 src_buf = buf;
727 }
728
729 hd_iov.iov_base = (void *)src_buf;
730 hd_iov.iov_len = n * 512;
731 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
732 qemu_co_mutex_unlock(&s->lock);
733 ret = bdrv_co_writev(bs->file->bs,
734 (cluster_offset >> 9) + index_in_cluster,
735 n, &hd_qiov);
736 qemu_co_mutex_lock(&s->lock);
737 if (ret < 0) {
738 break;
739 }
740 ret = 0;
741
742 nb_sectors -= n;
743 sector_num += n;
744 buf += n * 512;
745 }
746 qemu_co_mutex_unlock(&s->lock);
747
748 if (qiov->niov > 1) {
749 qemu_vfree(orig_buf);
750 }
751 g_free(cluster_data);
752
753 return ret;
754 }
755
756 static void qcow_close(BlockDriverState *bs)
757 {
758 BDRVQcowState *s = bs->opaque;
759
760 qcrypto_cipher_free(s->cipher);
761 s->cipher = NULL;
762 g_free(s->l1_table);
763 qemu_vfree(s->l2_cache);
764 g_free(s->cluster_cache);
765 g_free(s->cluster_data);
766
767 migrate_del_blocker(s->migration_blocker);
768 error_free(s->migration_blocker);
769 }
770
771 static int qcow_create(const char *filename, QemuOpts *opts, Error **errp)
772 {
773 int header_size, backing_filename_len, l1_size, shift, i;
774 QCowHeader header;
775 uint8_t *tmp;
776 int64_t total_size = 0;
777 char *backing_file = NULL;
778 int flags = 0;
779 Error *local_err = NULL;
780 int ret;
781 BlockDriverState *qcow_bs;
782
783 /* Read out options */
784 total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
785 BDRV_SECTOR_SIZE);
786 backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
787 if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) {
788 flags |= BLOCK_FLAG_ENCRYPT;
789 }
790
791 ret = bdrv_create_file(filename, opts, &local_err);
792 if (ret < 0) {
793 error_propagate(errp, local_err);
794 goto cleanup;
795 }
796
797 qcow_bs = NULL;
798 ret = bdrv_open(&qcow_bs, filename, NULL, NULL,
799 BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err);
800 if (ret < 0) {
801 error_propagate(errp, local_err);
802 goto cleanup;
803 }
804
805 ret = bdrv_truncate(qcow_bs, 0);
806 if (ret < 0) {
807 goto exit;
808 }
809
810 memset(&header, 0, sizeof(header));
811 header.magic = cpu_to_be32(QCOW_MAGIC);
812 header.version = cpu_to_be32(QCOW_VERSION);
813 header.size = cpu_to_be64(total_size);
814 header_size = sizeof(header);
815 backing_filename_len = 0;
816 if (backing_file) {
817 if (strcmp(backing_file, "fat:")) {
818 header.backing_file_offset = cpu_to_be64(header_size);
819 backing_filename_len = strlen(backing_file);
820 header.backing_file_size = cpu_to_be32(backing_filename_len);
821 header_size += backing_filename_len;
822 } else {
823 /* special backing file for vvfat */
824 backing_file = NULL;
825 }
826 header.cluster_bits = 9; /* 512 byte cluster to avoid copying
827 unmodified sectors */
828 header.l2_bits = 12; /* 32 KB L2 tables */
829 } else {
830 header.cluster_bits = 12; /* 4 KB clusters */
831 header.l2_bits = 9; /* 4 KB L2 tables */
832 }
833 header_size = (header_size + 7) & ~7;
834 shift = header.cluster_bits + header.l2_bits;
835 l1_size = (total_size + (1LL << shift) - 1) >> shift;
836
837 header.l1_table_offset = cpu_to_be64(header_size);
838 if (flags & BLOCK_FLAG_ENCRYPT) {
839 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
840 } else {
841 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
842 }
843
844 /* write all the data */
845 ret = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header));
846 if (ret != sizeof(header)) {
847 goto exit;
848 }
849
850 if (backing_file) {
851 ret = bdrv_pwrite(qcow_bs, sizeof(header),
852 backing_file, backing_filename_len);
853 if (ret != backing_filename_len) {
854 goto exit;
855 }
856 }
857
858 tmp = g_malloc0(BDRV_SECTOR_SIZE);
859 for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/
860 BDRV_SECTOR_SIZE); i++) {
861 ret = bdrv_pwrite(qcow_bs, header_size +
862 BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE);
863 if (ret != BDRV_SECTOR_SIZE) {
864 g_free(tmp);
865 goto exit;
866 }
867 }
868
869 g_free(tmp);
870 ret = 0;
871 exit:
872 bdrv_unref(qcow_bs);
873 cleanup:
874 g_free(backing_file);
875 return ret;
876 }
877
878 static int qcow_make_empty(BlockDriverState *bs)
879 {
880 BDRVQcowState *s = bs->opaque;
881 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
882 int ret;
883
884 memset(s->l1_table, 0, l1_length);
885 if (bdrv_pwrite_sync(bs->file->bs, s->l1_table_offset, s->l1_table,
886 l1_length) < 0)
887 return -1;
888 ret = bdrv_truncate(bs->file->bs, s->l1_table_offset + l1_length);
889 if (ret < 0)
890 return ret;
891
892 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
893 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
894 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
895
896 return 0;
897 }
898
899 /* XXX: put compressed sectors first, then all the cluster aligned
900 tables to avoid losing bytes in alignment */
901 static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
902 const uint8_t *buf, int nb_sectors)
903 {
904 BDRVQcowState *s = bs->opaque;
905 z_stream strm;
906 int ret, out_len;
907 uint8_t *out_buf;
908 uint64_t cluster_offset;
909
910 if (nb_sectors != s->cluster_sectors) {
911 ret = -EINVAL;
912
913 /* Zero-pad last write if image size is not cluster aligned */
914 if (sector_num + nb_sectors == bs->total_sectors &&
915 nb_sectors < s->cluster_sectors) {
916 uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
917 memset(pad_buf, 0, s->cluster_size);
918 memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE);
919 ret = qcow_write_compressed(bs, sector_num,
920 pad_buf, s->cluster_sectors);
921 qemu_vfree(pad_buf);
922 }
923 return ret;
924 }
925
926 out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
927
928 /* best compression, small window, no zlib header */
929 memset(&strm, 0, sizeof(strm));
930 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
931 Z_DEFLATED, -12,
932 9, Z_DEFAULT_STRATEGY);
933 if (ret != 0) {
934 ret = -EINVAL;
935 goto fail;
936 }
937
938 strm.avail_in = s->cluster_size;
939 strm.next_in = (uint8_t *)buf;
940 strm.avail_out = s->cluster_size;
941 strm.next_out = out_buf;
942
943 ret = deflate(&strm, Z_FINISH);
944 if (ret != Z_STREAM_END && ret != Z_OK) {
945 deflateEnd(&strm);
946 ret = -EINVAL;
947 goto fail;
948 }
949 out_len = strm.next_out - out_buf;
950
951 deflateEnd(&strm);
952
953 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
954 /* could not compress: write normal cluster */
955 ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
956 if (ret < 0) {
957 goto fail;
958 }
959 } else {
960 cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
961 out_len, 0, 0);
962 if (cluster_offset == 0) {
963 ret = -EIO;
964 goto fail;
965 }
966
967 cluster_offset &= s->cluster_offset_mask;
968 ret = bdrv_pwrite(bs->file->bs, cluster_offset, out_buf, out_len);
969 if (ret < 0) {
970 goto fail;
971 }
972 }
973
974 ret = 0;
975 fail:
976 g_free(out_buf);
977 return ret;
978 }
979
980 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
981 {
982 BDRVQcowState *s = bs->opaque;
983 bdi->cluster_size = s->cluster_size;
984 return 0;
985 }
986
987 static QemuOptsList qcow_create_opts = {
988 .name = "qcow-create-opts",
989 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
990 .desc = {
991 {
992 .name = BLOCK_OPT_SIZE,
993 .type = QEMU_OPT_SIZE,
994 .help = "Virtual disk size"
995 },
996 {
997 .name = BLOCK_OPT_BACKING_FILE,
998 .type = QEMU_OPT_STRING,
999 .help = "File name of a base image"
1000 },
1001 {
1002 .name = BLOCK_OPT_ENCRYPT,
1003 .type = QEMU_OPT_BOOL,
1004 .help = "Encrypt the image",
1005 .def_value_str = "off"
1006 },
1007 { /* end of list */ }
1008 }
1009 };
1010
1011 static BlockDriver bdrv_qcow = {
1012 .format_name = "qcow",
1013 .instance_size = sizeof(BDRVQcowState),
1014 .bdrv_probe = qcow_probe,
1015 .bdrv_open = qcow_open,
1016 .bdrv_close = qcow_close,
1017 .bdrv_reopen_prepare = qcow_reopen_prepare,
1018 .bdrv_create = qcow_create,
1019 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1020 .supports_backing = true,
1021
1022 .bdrv_co_readv = qcow_co_readv,
1023 .bdrv_co_writev = qcow_co_writev,
1024 .bdrv_co_get_block_status = qcow_co_get_block_status,
1025
1026 .bdrv_set_key = qcow_set_key,
1027 .bdrv_make_empty = qcow_make_empty,
1028 .bdrv_write_compressed = qcow_write_compressed,
1029 .bdrv_get_info = qcow_get_info,
1030
1031 .create_opts = &qcow_create_opts,
1032 };
1033
1034 static void bdrv_qcow_init(void)
1035 {
1036 bdrv_register(&bdrv_qcow);
1037 }
1038
1039 block_init(bdrv_qcow_init);
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