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lasips2: rename LASIPS2Port irq field to birq
[qemu/kevin.git] / block / qcow.c
blob311aaa87052ed7ab5611525aede76b4600888953
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 "block/qdict.h"
30 #include "sysemu/block-backend.h"
31 #include "qemu/module.h"
32 #include "qemu/option.h"
33 #include "qemu/bswap.h"
34 #include "qemu/cutils.h"
35 #include "qemu/memalign.h"
36 #include <zlib.h>
37 #include "qapi/qmp/qdict.h"
38 #include "qapi/qmp/qstring.h"
39 #include "qapi/qobject-input-visitor.h"
40 #include "qapi/qapi-visit-block-core.h"
41 #include "crypto/block.h"
42 #include "migration/blocker.h"
43 #include "crypto.h"
44
45 /**************************************************************/
46 /* QEMU COW block driver with compression and encryption support */
47
48 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
49 #define QCOW_VERSION 1
50
51 #define QCOW_CRYPT_NONE 0
52 #define QCOW_CRYPT_AES 1
53
54 #define QCOW_OFLAG_COMPRESSED (1LL << 63)
55
56 typedef struct QCowHeader {
57 uint32_t magic;
58 uint32_t version;
59 uint64_t backing_file_offset;
60 uint32_t backing_file_size;
61 uint32_t mtime;
62 uint64_t size; /* in bytes */
63 uint8_t cluster_bits;
64 uint8_t l2_bits;
65 uint16_t padding;
66 uint32_t crypt_method;
67 uint64_t l1_table_offset;
68 } QEMU_PACKED QCowHeader;
69
70 #define L2_CACHE_SIZE 16
71
72 typedef struct BDRVQcowState {
73 int cluster_bits;
74 int cluster_size;
75 int l2_bits;
76 int l2_size;
77 unsigned int l1_size;
78 uint64_t cluster_offset_mask;
79 uint64_t l1_table_offset;
80 uint64_t *l1_table;
81 uint64_t *l2_cache;
82 uint64_t l2_cache_offsets[L2_CACHE_SIZE];
83 uint32_t l2_cache_counts[L2_CACHE_SIZE];
84 uint8_t *cluster_cache;
85 uint8_t *cluster_data;
86 uint64_t cluster_cache_offset;
87 QCryptoBlock *crypto; /* Disk encryption format driver */
88 uint32_t crypt_method_header;
89 CoMutex lock;
90 Error *migration_blocker;
91 } BDRVQcowState;
92
93 static QemuOptsList qcow_create_opts;
94
95 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
96
97 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
98 {
99 const QCowHeader *cow_header = (const void *)buf;
100
101 if (buf_size >= sizeof(QCowHeader) &&
102 be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
103 be32_to_cpu(cow_header->version) == QCOW_VERSION)
104 return 100;
105 else
106 return 0;
107 }
108
109 static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
110 Error **errp)
111 {
112 BDRVQcowState *s = bs->opaque;
113 unsigned int len, i, shift;
114 int ret;
115 QCowHeader header;
116 QCryptoBlockOpenOptions *crypto_opts = NULL;
117 unsigned int cflags = 0;
118 QDict *encryptopts = NULL;
119 const char *encryptfmt;
120
121 qdict_extract_subqdict(options, &encryptopts, "encrypt.");
122 encryptfmt = qdict_get_try_str(encryptopts, "format");
123
124 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
125 BDRV_CHILD_IMAGE, false, errp);
126 if (!bs->file) {
127 ret = -EINVAL;
128 goto fail;
129 }
130
131 ret = bdrv_pread(bs->file, 0, sizeof(header), &header, 0);
132 if (ret < 0) {
133 goto fail;
134 }
135 header.magic = be32_to_cpu(header.magic);
136 header.version = be32_to_cpu(header.version);
137 header.backing_file_offset = be64_to_cpu(header.backing_file_offset);
138 header.backing_file_size = be32_to_cpu(header.backing_file_size);
139 header.mtime = be32_to_cpu(header.mtime);
140 header.size = be64_to_cpu(header.size);
141 header.crypt_method = be32_to_cpu(header.crypt_method);
142 header.l1_table_offset = be64_to_cpu(header.l1_table_offset);
143
144 if (header.magic != QCOW_MAGIC) {
145 error_setg(errp, "Image not in qcow format");
146 ret = -EINVAL;
147 goto fail;
148 }
149 if (header.version != QCOW_VERSION) {
150 error_setg(errp, "qcow (v%d) does not support qcow version %" PRIu32,
151 QCOW_VERSION, header.version);
152 if (header.version == 2 || header.version == 3) {
153 error_append_hint(errp, "Try the 'qcow2' driver instead.\n");
154 }
155
156 ret = -ENOTSUP;
157 goto fail;
158 }
159
160 if (header.size <= 1) {
161 error_setg(errp, "Image size is too small (must be at least 2 bytes)");
162 ret = -EINVAL;
163 goto fail;
164 }
165 if (header.cluster_bits < 9 || header.cluster_bits > 16) {
166 error_setg(errp, "Cluster size must be between 512 and 64k");
167 ret = -EINVAL;
168 goto fail;
169 }
170
171 /* l2_bits specifies number of entries; storing a uint64_t in each entry,
172 * so bytes = num_entries << 3. */
173 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
174 error_setg(errp, "L2 table size must be between 512 and 64k");
175 ret = -EINVAL;
176 goto fail;
177 }
178
179 s->crypt_method_header = header.crypt_method;
180 if (s->crypt_method_header) {
181 if (bdrv_uses_whitelist() &&
182 s->crypt_method_header == QCOW_CRYPT_AES) {
183 error_setg(errp,
184 "Use of AES-CBC encrypted qcow images is no longer "
185 "supported in system emulators");
186 error_append_hint(errp,
187 "You can use 'qemu-img convert' to convert your "
188 "image to an alternative supported format, such "
189 "as unencrypted qcow, or raw with the LUKS "
190 "format instead.\n");
191 ret = -ENOSYS;
192 goto fail;
193 }
194 if (s->crypt_method_header == QCOW_CRYPT_AES) {
195 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) {
196 error_setg(errp,
197 "Header reported 'aes' encryption format but "
198 "options specify '%s'", encryptfmt);
199 ret = -EINVAL;
200 goto fail;
201 }
202 qdict_put_str(encryptopts, "format", "qcow");
203 crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
204 if (!crypto_opts) {
205 ret = -EINVAL;
206 goto fail;
207 }
208
209 if (flags & BDRV_O_NO_IO) {
210 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
211 }
212 s->crypto = qcrypto_block_open(crypto_opts, "encrypt.",
213 NULL, NULL, cflags, 1, errp);
214 if (!s->crypto) {
215 ret = -EINVAL;
216 goto fail;
217 }
218 } else {
219 error_setg(errp, "invalid encryption method in qcow header");
220 ret = -EINVAL;
221 goto fail;
222 }
223 bs->encrypted = true;
224 } else {
225 if (encryptfmt) {
226 error_setg(errp, "No encryption in image header, but options "
227 "specified format '%s'", encryptfmt);
228 ret = -EINVAL;
229 goto fail;
230 }
231 }
232 s->cluster_bits = header.cluster_bits;
233 s->cluster_size = 1 << s->cluster_bits;
234 s->l2_bits = header.l2_bits;
235 s->l2_size = 1 << s->l2_bits;
236 bs->total_sectors = header.size / 512;
237 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
238
239 /* read the level 1 table */
240 shift = s->cluster_bits + s->l2_bits;
241 if (header.size > UINT64_MAX - (1LL << shift)) {
242 error_setg(errp, "Image too large");
243 ret = -EINVAL;
244 goto fail;
245 } else {
246 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
247 if (l1_size > INT_MAX / sizeof(uint64_t)) {
248 error_setg(errp, "Image too large");
249 ret = -EINVAL;
250 goto fail;
251 }
252 s->l1_size = l1_size;
253 }
254
255 s->l1_table_offset = header.l1_table_offset;
256 s->l1_table = g_try_new(uint64_t, s->l1_size);
257 if (s->l1_table == NULL) {
258 error_setg(errp, "Could not allocate memory for L1 table");
259 ret = -ENOMEM;
260 goto fail;
261 }
262
263 ret = bdrv_pread(bs->file, s->l1_table_offset,
264 s->l1_size * sizeof(uint64_t), s->l1_table, 0);
265 if (ret < 0) {
266 goto fail;
267 }
268
269 for(i = 0;i < s->l1_size; i++) {
270 s->l1_table[i] = be64_to_cpu(s->l1_table[i]);
271 }
272
273 /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
274 s->l2_cache =
275 qemu_try_blockalign(bs->file->bs,
276 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
277 if (s->l2_cache == NULL) {
278 error_setg(errp, "Could not allocate L2 table cache");
279 ret = -ENOMEM;
280 goto fail;
281 }
282 s->cluster_cache = g_malloc(s->cluster_size);
283 s->cluster_data = g_malloc(s->cluster_size);
284 s->cluster_cache_offset = -1;
285
286 /* read the backing file name */
287 if (header.backing_file_offset != 0) {
288 len = header.backing_file_size;
289 if (len > 1023 || len >= sizeof(bs->backing_file)) {
290 error_setg(errp, "Backing file name too long");
291 ret = -EINVAL;
292 goto fail;
293 }
294 ret = bdrv_pread(bs->file, header.backing_file_offset, len,
295 bs->auto_backing_file, 0);
296 if (ret < 0) {
297 goto fail;
298 }
299 bs->auto_backing_file[len] = '\0';
300 pstrcpy(bs->backing_file, sizeof(bs->backing_file),
301 bs->auto_backing_file);
302 }
303
304 /* Disable migration when qcow images are used */
305 error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
306 "does not support live migration",
307 bdrv_get_device_or_node_name(bs));
308 ret = migrate_add_blocker(s->migration_blocker, errp);
309 if (ret < 0) {
310 error_free(s->migration_blocker);
311 goto fail;
312 }
313
314 qobject_unref(encryptopts);
315 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
316 qemu_co_mutex_init(&s->lock);
317 return 0;
318
319 fail:
320 g_free(s->l1_table);
321 qemu_vfree(s->l2_cache);
322 g_free(s->cluster_cache);
323 g_free(s->cluster_data);
324 qcrypto_block_free(s->crypto);
325 qobject_unref(encryptopts);
326 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
327 return ret;
328 }
329
330
331 /* We have nothing to do for QCOW reopen, stubs just return
332 * success */
333 static int qcow_reopen_prepare(BDRVReopenState *state,
334 BlockReopenQueue *queue, Error **errp)
335 {
336 return 0;
337 }
338
339
340 /* 'allocate' is:
341 *
342 * 0 to not allocate.
343 *
344 * 1 to allocate a normal cluster (for sector-aligned byte offsets 'n_start'
345 * to 'n_end' within the cluster)
346 *
347 * 2 to allocate a compressed cluster of size
348 * 'compressed_size'. 'compressed_size' must be > 0 and <
349 * cluster_size
350 *
351 * return 0 if not allocated, 1 if *result is assigned, and negative
352 * errno on failure.
353 */
354 static int get_cluster_offset(BlockDriverState *bs,
355 uint64_t offset, int allocate,
356 int compressed_size,
357 int n_start, int n_end, uint64_t *result)
358 {
359 BDRVQcowState *s = bs->opaque;
360 int min_index, i, j, l1_index, l2_index, ret;
361 int64_t l2_offset;
362 uint64_t *l2_table, cluster_offset, tmp;
363 uint32_t min_count;
364 int new_l2_table;
365
366 *result = 0;
367 l1_index = offset >> (s->l2_bits + s->cluster_bits);
368 l2_offset = s->l1_table[l1_index];
369 new_l2_table = 0;
370 if (!l2_offset) {
371 if (!allocate)
372 return 0;
373 /* allocate a new l2 entry */
374 l2_offset = bdrv_getlength(bs->file->bs);
375 if (l2_offset < 0) {
376 return l2_offset;
377 }
378 /* round to cluster size */
379 l2_offset = QEMU_ALIGN_UP(l2_offset, s->cluster_size);
380 /* update the L1 entry */
381 s->l1_table[l1_index] = l2_offset;
382 tmp = cpu_to_be64(l2_offset);
383 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
384 ret = bdrv_pwrite_sync(bs->file,
385 s->l1_table_offset + l1_index * sizeof(tmp),
386 sizeof(tmp), &tmp, 0);
387 if (ret < 0) {
388 return ret;
389 }
390 new_l2_table = 1;
391 }
392 for(i = 0; i < L2_CACHE_SIZE; i++) {
393 if (l2_offset == s->l2_cache_offsets[i]) {
394 /* increment the hit count */
395 if (++s->l2_cache_counts[i] == 0xffffffff) {
396 for(j = 0; j < L2_CACHE_SIZE; j++) {
397 s->l2_cache_counts[j] >>= 1;
398 }
399 }
400 l2_table = s->l2_cache + (i << s->l2_bits);
401 goto found;
402 }
403 }
404 /* not found: load a new entry in the least used one */
405 min_index = 0;
406 min_count = 0xffffffff;
407 for(i = 0; i < L2_CACHE_SIZE; i++) {
408 if (s->l2_cache_counts[i] < min_count) {
409 min_count = s->l2_cache_counts[i];
410 min_index = i;
411 }
412 }
413 l2_table = s->l2_cache + (min_index << s->l2_bits);
414 BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
415 if (new_l2_table) {
416 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
417 ret = bdrv_pwrite_sync(bs->file, l2_offset,
418 s->l2_size * sizeof(uint64_t), l2_table, 0);
419 if (ret < 0) {
420 return ret;
421 }
422 } else {
423 ret = bdrv_pread(bs->file, l2_offset, s->l2_size * sizeof(uint64_t),
424 l2_table, 0);
425 if (ret < 0) {
426 return ret;
427 }
428 }
429 s->l2_cache_offsets[min_index] = l2_offset;
430 s->l2_cache_counts[min_index] = 1;
431 found:
432 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
433 cluster_offset = be64_to_cpu(l2_table[l2_index]);
434 if (!cluster_offset ||
435 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
436 if (!allocate)
437 return 0;
438 BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC);
439 assert(QEMU_IS_ALIGNED(n_start | n_end, BDRV_SECTOR_SIZE));
440 /* allocate a new cluster */
441 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
442 (n_end - n_start) < s->cluster_size) {
443 /* if the cluster is already compressed, we must
444 decompress it in the case it is not completely
445 overwritten */
446 if (decompress_cluster(bs, cluster_offset) < 0) {
447 return -EIO;
448 }
449 cluster_offset = bdrv_getlength(bs->file->bs);
450 if ((int64_t) cluster_offset < 0) {
451 return cluster_offset;
452 }
453 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
454 /* write the cluster content */
455 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
456 ret = bdrv_pwrite(bs->file, cluster_offset, s->cluster_size,
457 s->cluster_cache, 0);
458 if (ret < 0) {
459 return ret;
460 }
461 } else {
462 cluster_offset = bdrv_getlength(bs->file->bs);
463 if ((int64_t) cluster_offset < 0) {
464 return cluster_offset;
465 }
466 if (allocate == 1) {
467 /* round to cluster size */
468 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
469 if (cluster_offset + s->cluster_size > INT64_MAX) {
470 return -E2BIG;
471 }
472 ret = bdrv_truncate(bs->file, cluster_offset + s->cluster_size,
473 false, PREALLOC_MODE_OFF, 0, NULL);
474 if (ret < 0) {
475 return ret;
476 }
477 /* if encrypted, we must initialize the cluster
478 content which won't be written */
479 if (bs->encrypted &&
480 (n_end - n_start) < s->cluster_size) {
481 uint64_t start_offset;
482 assert(s->crypto);
483 start_offset = offset & ~(s->cluster_size - 1);
484 for (i = 0; i < s->cluster_size; i += BDRV_SECTOR_SIZE) {
485 if (i < n_start || i >= n_end) {
486 memset(s->cluster_data, 0x00, BDRV_SECTOR_SIZE);
487 if (qcrypto_block_encrypt(s->crypto,
488 start_offset + i,
489 s->cluster_data,
490 BDRV_SECTOR_SIZE,
491 NULL) < 0) {
492 return -EIO;
493 }
494 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
495 ret = bdrv_pwrite(bs->file, cluster_offset + i,
496 BDRV_SECTOR_SIZE,
497 s->cluster_data, 0);
498 if (ret < 0) {
499 return ret;
500 }
501 }
502 }
503 }
504 } else if (allocate == 2) {
505 cluster_offset |= QCOW_OFLAG_COMPRESSED |
506 (uint64_t)compressed_size << (63 - s->cluster_bits);
507 }
508 }
509 /* update L2 table */
510 tmp = cpu_to_be64(cluster_offset);
511 l2_table[l2_index] = tmp;
512 if (allocate == 2) {
513 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
514 } else {
515 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
516 }
517 ret = bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
518 sizeof(tmp), &tmp, 0);
519 if (ret < 0) {
520 return ret;
521 }
522 }
523 *result = cluster_offset;
524 return 1;
525 }
526
527 static int coroutine_fn qcow_co_block_status(BlockDriverState *bs,
528 bool want_zero,
529 int64_t offset, int64_t bytes,
530 int64_t *pnum, int64_t *map,
531 BlockDriverState **file)
532 {
533 BDRVQcowState *s = bs->opaque;
534 int index_in_cluster, ret;
535 int64_t n;
536 uint64_t cluster_offset;
537
538 qemu_co_mutex_lock(&s->lock);
539 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
540 qemu_co_mutex_unlock(&s->lock);
541 if (ret < 0) {
542 return ret;
543 }
544 index_in_cluster = offset & (s->cluster_size - 1);
545 n = s->cluster_size - index_in_cluster;
546 if (n > bytes) {
547 n = bytes;
548 }
549 *pnum = n;
550 if (!cluster_offset) {
551 return 0;
552 }
553 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
554 return BDRV_BLOCK_DATA;
555 }
556 *map = cluster_offset | index_in_cluster;
557 *file = bs->file->bs;
558 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
559 }
560
561 static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
562 const uint8_t *buf, int buf_size)
563 {
564 z_stream strm1, *strm = &strm1;
565 int ret, out_len;
566
567 memset(strm, 0, sizeof(*strm));
568
569 strm->next_in = (uint8_t *)buf;
570 strm->avail_in = buf_size;
571 strm->next_out = out_buf;
572 strm->avail_out = out_buf_size;
573
574 ret = inflateInit2(strm, -12);
575 if (ret != Z_OK)
576 return -1;
577 ret = inflate(strm, Z_FINISH);
578 out_len = strm->next_out - out_buf;
579 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
580 out_len != out_buf_size) {
581 inflateEnd(strm);
582 return -1;
583 }
584 inflateEnd(strm);
585 return 0;
586 }
587
588 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
589 {
590 BDRVQcowState *s = bs->opaque;
591 int ret, csize;
592 uint64_t coffset;
593
594 coffset = cluster_offset & s->cluster_offset_mask;
595 if (s->cluster_cache_offset != coffset) {
596 csize = cluster_offset >> (63 - s->cluster_bits);
597 csize &= (s->cluster_size - 1);
598 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
599 ret = bdrv_pread(bs->file, coffset, csize, s->cluster_data, 0);
600 if (ret < 0)
601 return -1;
602 if (decompress_buffer(s->cluster_cache, s->cluster_size,
603 s->cluster_data, csize) < 0) {
604 return -1;
605 }
606 s->cluster_cache_offset = coffset;
607 }
608 return 0;
609 }
610
611 static void qcow_refresh_limits(BlockDriverState *bs, Error **errp)
612 {
613 /* At least encrypted images require 512-byte alignment. Apply the
614 * limit universally, rather than just on encrypted images, as
615 * it's easier to let the block layer handle rounding than to
616 * audit this code further. */
617 bs->bl.request_alignment = BDRV_SECTOR_SIZE;
618 }
619
620 static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, int64_t offset,
621 int64_t bytes, QEMUIOVector *qiov,
622 BdrvRequestFlags flags)
623 {
624 BDRVQcowState *s = bs->opaque;
625 int offset_in_cluster;
626 int ret = 0, n;
627 uint64_t cluster_offset;
628 uint8_t *buf;
629 void *orig_buf;
630
631 assert(!flags);
632 if (qiov->niov > 1) {
633 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
634 if (buf == NULL) {
635 return -ENOMEM;
636 }
637 } else {
638 orig_buf = NULL;
639 buf = (uint8_t *)qiov->iov->iov_base;
640 }
641
642 qemu_co_mutex_lock(&s->lock);
643
644 while (bytes != 0) {
645 /* prepare next request */
646 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
647 if (ret < 0) {
648 break;
649 }
650 offset_in_cluster = offset & (s->cluster_size - 1);
651 n = s->cluster_size - offset_in_cluster;
652 if (n > bytes) {
653 n = bytes;
654 }
655
656 if (!cluster_offset) {
657 if (bs->backing) {
658 /* read from the base image */
659 qemu_co_mutex_unlock(&s->lock);
660 /* qcow2 emits this on bs->file instead of bs->backing */
661 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
662 ret = bdrv_co_pread(bs->backing, offset, n, buf, 0);
663 qemu_co_mutex_lock(&s->lock);
664 if (ret < 0) {
665 break;
666 }
667 } else {
668 /* Note: in this case, no need to wait */
669 memset(buf, 0, n);
670 }
671 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
672 /* add AIO support for compressed blocks ? */
673 if (decompress_cluster(bs, cluster_offset) < 0) {
674 ret = -EIO;
675 break;
676 }
677 memcpy(buf, s->cluster_cache + offset_in_cluster, n);
678 } else {
679 if ((cluster_offset & 511) != 0) {
680 ret = -EIO;
681 break;
682 }
683 qemu_co_mutex_unlock(&s->lock);
684 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
685 ret = bdrv_co_pread(bs->file, cluster_offset + offset_in_cluster,
686 n, buf, 0);
687 qemu_co_mutex_lock(&s->lock);
688 if (ret < 0) {
689 break;
690 }
691 if (bs->encrypted) {
692 assert(s->crypto);
693 if (qcrypto_block_decrypt(s->crypto,
694 offset, buf, n, NULL) < 0) {
695 ret = -EIO;
696 break;
697 }
698 }
699 }
700 ret = 0;
701
702 bytes -= n;
703 offset += n;
704 buf += n;
705 }
706
707 qemu_co_mutex_unlock(&s->lock);
708
709 if (qiov->niov > 1) {
710 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
711 qemu_vfree(orig_buf);
712 }
713
714 return ret;
715 }
716
717 static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, int64_t offset,
718 int64_t bytes, QEMUIOVector *qiov,
719 BdrvRequestFlags flags)
720 {
721 BDRVQcowState *s = bs->opaque;
722 int offset_in_cluster;
723 uint64_t cluster_offset;
724 int ret = 0, n;
725 uint8_t *buf;
726 void *orig_buf;
727
728 assert(!flags);
729 s->cluster_cache_offset = -1; /* disable compressed cache */
730
731 /* We must always copy the iov when encrypting, so we
732 * don't modify the original data buffer during encryption */
733 if (bs->encrypted || qiov->niov > 1) {
734 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
735 if (buf == NULL) {
736 return -ENOMEM;
737 }
738 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
739 } else {
740 orig_buf = NULL;
741 buf = (uint8_t *)qiov->iov->iov_base;
742 }
743
744 qemu_co_mutex_lock(&s->lock);
745
746 while (bytes != 0) {
747 offset_in_cluster = offset & (s->cluster_size - 1);
748 n = s->cluster_size - offset_in_cluster;
749 if (n > bytes) {
750 n = bytes;
751 }
752 ret = get_cluster_offset(bs, offset, 1, 0, offset_in_cluster,
753 offset_in_cluster + n, &cluster_offset);
754 if (ret < 0) {
755 break;
756 }
757 if (!cluster_offset || (cluster_offset & 511) != 0) {
758 ret = -EIO;
759 break;
760 }
761 if (bs->encrypted) {
762 assert(s->crypto);
763 if (qcrypto_block_encrypt(s->crypto, offset, buf, n, NULL) < 0) {
764 ret = -EIO;
765 break;
766 }
767 }
768
769 qemu_co_mutex_unlock(&s->lock);
770 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
771 ret = bdrv_co_pwrite(bs->file, cluster_offset + offset_in_cluster,
772 n, buf, 0);
773 qemu_co_mutex_lock(&s->lock);
774 if (ret < 0) {
775 break;
776 }
777 ret = 0;
778
779 bytes -= n;
780 offset += n;
781 buf += n;
782 }
783 qemu_co_mutex_unlock(&s->lock);
784
785 qemu_vfree(orig_buf);
786
787 return ret;
788 }
789
790 static void qcow_close(BlockDriverState *bs)
791 {
792 BDRVQcowState *s = bs->opaque;
793
794 qcrypto_block_free(s->crypto);
795 s->crypto = NULL;
796 g_free(s->l1_table);
797 qemu_vfree(s->l2_cache);
798 g_free(s->cluster_cache);
799 g_free(s->cluster_data);
800
801 migrate_del_blocker(s->migration_blocker);
802 error_free(s->migration_blocker);
803 }
804
805 static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
806 Error **errp)
807 {
808 BlockdevCreateOptionsQcow *qcow_opts;
809 int header_size, backing_filename_len, l1_size, shift, i;
810 QCowHeader header;
811 uint8_t *tmp;
812 int64_t total_size = 0;
813 int ret;
814 BlockDriverState *bs;
815 BlockBackend *qcow_blk;
816 QCryptoBlock *crypto = NULL;
817
818 assert(opts->driver == BLOCKDEV_DRIVER_QCOW);
819 qcow_opts = &opts->u.qcow;
820
821 /* Sanity checks */
822 total_size = qcow_opts->size;
823 if (total_size == 0) {
824 error_setg(errp, "Image size is too small, cannot be zero length");
825 return -EINVAL;
826 }
827
828 if (qcow_opts->has_encrypt &&
829 qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW)
830 {
831 error_setg(errp, "Unsupported encryption format");
832 return -EINVAL;
833 }
834
835 /* Create BlockBackend to write to the image */
836 bs = bdrv_open_blockdev_ref(qcow_opts->file, errp);
837 if (bs == NULL) {
838 return -EIO;
839 }
840
841 qcow_blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE,
842 BLK_PERM_ALL, errp);
843 if (!qcow_blk) {
844 ret = -EPERM;
845 goto exit;
846 }
847 blk_set_allow_write_beyond_eof(qcow_blk, true);
848
849 /* Create image format */
850 memset(&header, 0, sizeof(header));
851 header.magic = cpu_to_be32(QCOW_MAGIC);
852 header.version = cpu_to_be32(QCOW_VERSION);
853 header.size = cpu_to_be64(total_size);
854 header_size = sizeof(header);
855 backing_filename_len = 0;
856 if (qcow_opts->has_backing_file) {
857 if (strcmp(qcow_opts->backing_file, "fat:")) {
858 header.backing_file_offset = cpu_to_be64(header_size);
859 backing_filename_len = strlen(qcow_opts->backing_file);
860 header.backing_file_size = cpu_to_be32(backing_filename_len);
861 header_size += backing_filename_len;
862 } else {
863 /* special backing file for vvfat */
864 qcow_opts->has_backing_file = false;
865 }
866 header.cluster_bits = 9; /* 512 byte cluster to avoid copying
867 unmodified sectors */
868 header.l2_bits = 12; /* 32 KB L2 tables */
869 } else {
870 header.cluster_bits = 12; /* 4 KB clusters */
871 header.l2_bits = 9; /* 4 KB L2 tables */
872 }
873 header_size = (header_size + 7) & ~7;
874 shift = header.cluster_bits + header.l2_bits;
875 l1_size = (total_size + (1LL << shift) - 1) >> shift;
876
877 header.l1_table_offset = cpu_to_be64(header_size);
878
879 if (qcow_opts->has_encrypt) {
880 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
881
882 crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.",
883 NULL, NULL, NULL, errp);
884 if (!crypto) {
885 ret = -EINVAL;
886 goto exit;
887 }
888 } else {
889 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
890 }
891
892 /* write all the data */
893 ret = blk_pwrite(qcow_blk, 0, sizeof(header), &header, 0);
894 if (ret < 0) {
895 goto exit;
896 }
897
898 if (qcow_opts->has_backing_file) {
899 ret = blk_pwrite(qcow_blk, sizeof(header), backing_filename_len,
900 qcow_opts->backing_file, 0);
901 if (ret < 0) {
902 goto exit;
903 }
904 }
905
906 tmp = g_malloc0(BDRV_SECTOR_SIZE);
907 for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE);
908 i++) {
909 ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i,
910 BDRV_SECTOR_SIZE, tmp, 0);
911 if (ret < 0) {
912 g_free(tmp);
913 goto exit;
914 }
915 }
916
917 g_free(tmp);
918 ret = 0;
919 exit:
920 blk_unref(qcow_blk);
921 bdrv_unref(bs);
922 qcrypto_block_free(crypto);
923 return ret;
924 }
925
926 static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
927 const char *filename,
928 QemuOpts *opts, Error **errp)
929 {
930 BlockdevCreateOptions *create_options = NULL;
931 BlockDriverState *bs = NULL;
932 QDict *qdict = NULL;
933 Visitor *v;
934 const char *val;
935 int ret;
936 char *backing_fmt;
937
938 static const QDictRenames opt_renames[] = {
939 { BLOCK_OPT_BACKING_FILE, "backing-file" },
940 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
941 { NULL, NULL },
942 };
943
944 /*
945 * We can't actually store a backing format, but can check that
946 * the user's request made sense.
947 */
948 backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
949 if (backing_fmt && !bdrv_find_format(backing_fmt)) {
950 error_setg(errp, "unrecognized backing format '%s'", backing_fmt);
951 ret = -EINVAL;
952 goto fail;
953 }
954
955 /* Parse options and convert legacy syntax */
956 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
957
958 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
959 if (val && !strcmp(val, "on")) {
960 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
961 } else if (val && !strcmp(val, "off")) {
962 qdict_del(qdict, BLOCK_OPT_ENCRYPT);
963 }
964
965 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
966 if (val && !strcmp(val, "aes")) {
967 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
968 }
969
970 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
971 ret = -EINVAL;
972 goto fail;
973 }
974
975 /* Create and open the file (protocol layer) */
976 ret = bdrv_create_file(filename, opts, errp);
977 if (ret < 0) {
978 goto fail;
979 }
980
981 bs = bdrv_open(filename, NULL, NULL,
982 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
983 if (bs == NULL) {
984 ret = -EIO;
985 goto fail;
986 }
987
988 /* Now get the QAPI type BlockdevCreateOptions */
989 qdict_put_str(qdict, "driver", "qcow");
990 qdict_put_str(qdict, "file", bs->node_name);
991
992 v = qobject_input_visitor_new_flat_confused(qdict, errp);
993 if (!v) {
994 ret = -EINVAL;
995 goto fail;
996 }
997
998 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
999 visit_free(v);
1000 if (!create_options) {
1001 ret = -EINVAL;
1002 goto fail;
1003 }
1004
1005 /* Silently round up size */
1006 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW);
1007 create_options->u.qcow.size =
1008 ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE);
1009
1010 /* Create the qcow image (format layer) */
1011 ret = qcow_co_create(create_options, errp);
1012 if (ret < 0) {
1013 goto fail;
1014 }
1015
1016 ret = 0;
1017 fail:
1018 g_free(backing_fmt);
1019 qobject_unref(qdict);
1020 bdrv_unref(bs);
1021 qapi_free_BlockdevCreateOptions(create_options);
1022 return ret;
1023 }
1024
1025 static int qcow_make_empty(BlockDriverState *bs)
1026 {
1027 BDRVQcowState *s = bs->opaque;
1028 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
1029 int ret;
1030
1031 memset(s->l1_table, 0, l1_length);
1032 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, l1_length, s->l1_table,
1033 0) < 0)
1034 return -1;
1035 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length, false,
1036 PREALLOC_MODE_OFF, 0, NULL);
1037 if (ret < 0)
1038 return ret;
1039
1040 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
1041 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
1042 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
1043
1044 return 0;
1045 }
1046
1047 /* XXX: put compressed sectors first, then all the cluster aligned
1048 tables to avoid losing bytes in alignment */
1049 static coroutine_fn int
1050 qcow_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes,
1051 QEMUIOVector *qiov)
1052 {
1053 BDRVQcowState *s = bs->opaque;
1054 z_stream strm;
1055 int ret, out_len;
1056 uint8_t *buf, *out_buf;
1057 uint64_t cluster_offset;
1058
1059 buf = qemu_blockalign(bs, s->cluster_size);
1060 if (bytes != s->cluster_size) {
1061 if (bytes > s->cluster_size ||
1062 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS)
1063 {
1064 qemu_vfree(buf);
1065 return -EINVAL;
1066 }
1067 /* Zero-pad last write if image size is not cluster aligned */
1068 memset(buf + bytes, 0, s->cluster_size - bytes);
1069 }
1070 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
1071
1072 out_buf = g_malloc(s->cluster_size);
1073
1074 /* best compression, small window, no zlib header */
1075 memset(&strm, 0, sizeof(strm));
1076 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
1077 Z_DEFLATED, -12,
1078 9, Z_DEFAULT_STRATEGY);
1079 if (ret != 0) {
1080 ret = -EINVAL;
1081 goto fail;
1082 }
1083
1084 strm.avail_in = s->cluster_size;
1085 strm.next_in = (uint8_t *)buf;
1086 strm.avail_out = s->cluster_size;
1087 strm.next_out = out_buf;
1088
1089 ret = deflate(&strm, Z_FINISH);
1090 if (ret != Z_STREAM_END && ret != Z_OK) {
1091 deflateEnd(&strm);
1092 ret = -EINVAL;
1093 goto fail;
1094 }
1095 out_len = strm.next_out - out_buf;
1096
1097 deflateEnd(&strm);
1098
1099 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
1100 /* could not compress: write normal cluster */
1101 ret = qcow_co_pwritev(bs, offset, bytes, qiov, 0);
1102 if (ret < 0) {
1103 goto fail;
1104 }
1105 goto success;
1106 }
1107 qemu_co_mutex_lock(&s->lock);
1108 ret = get_cluster_offset(bs, offset, 2, out_len, 0, 0, &cluster_offset);
1109 qemu_co_mutex_unlock(&s->lock);
1110 if (ret < 0) {
1111 goto fail;
1112 }
1113 if (cluster_offset == 0) {
1114 ret = -EIO;
1115 goto fail;
1116 }
1117 cluster_offset &= s->cluster_offset_mask;
1118
1119 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
1120 ret = bdrv_co_pwrite(bs->file, cluster_offset, out_len, out_buf, 0);
1121 if (ret < 0) {
1122 goto fail;
1123 }
1124 success:
1125 ret = 0;
1126 fail:
1127 qemu_vfree(buf);
1128 g_free(out_buf);
1129 return ret;
1130 }
1131
1132 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1133 {
1134 BDRVQcowState *s = bs->opaque;
1135 bdi->cluster_size = s->cluster_size;
1136 return 0;
1137 }
1138
1139 static QemuOptsList qcow_create_opts = {
1140 .name = "qcow-create-opts",
1141 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
1142 .desc = {
1143 {
1144 .name = BLOCK_OPT_SIZE,
1145 .type = QEMU_OPT_SIZE,
1146 .help = "Virtual disk size"
1147 },
1148 {
1149 .name = BLOCK_OPT_BACKING_FILE,
1150 .type = QEMU_OPT_STRING,
1151 .help = "File name of a base image"
1152 },
1153 {
1154 .name = BLOCK_OPT_BACKING_FMT,
1155 .type = QEMU_OPT_STRING,
1156 .help = "Format of the backing image",
1157 },
1158 {
1159 .name = BLOCK_OPT_ENCRYPT,
1160 .type = QEMU_OPT_BOOL,
1161 .help = "Encrypt the image with format 'aes'. (Deprecated "
1162 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)",
1163 },
1164 {
1165 .name = BLOCK_OPT_ENCRYPT_FORMAT,
1166 .type = QEMU_OPT_STRING,
1167 .help = "Encrypt the image, format choices: 'aes'",
1168 },
1169 BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
1170 { /* end of list */ }
1171 }
1172 };
1173
1174 static const char *const qcow_strong_runtime_opts[] = {
1175 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
1176
1177 NULL
1178 };
1179
1180 static BlockDriver bdrv_qcow = {
1181 .format_name = "qcow",
1182 .instance_size = sizeof(BDRVQcowState),
1183 .bdrv_probe = qcow_probe,
1184 .bdrv_open = qcow_open,
1185 .bdrv_close = qcow_close,
1186 .bdrv_child_perm = bdrv_default_perms,
1187 .bdrv_reopen_prepare = qcow_reopen_prepare,
1188 .bdrv_co_create = qcow_co_create,
1189 .bdrv_co_create_opts = qcow_co_create_opts,
1190 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1191 .is_format = true,
1192 .supports_backing = true,
1193 .bdrv_refresh_limits = qcow_refresh_limits,
1194
1195 .bdrv_co_preadv = qcow_co_preadv,
1196 .bdrv_co_pwritev = qcow_co_pwritev,
1197 .bdrv_co_block_status = qcow_co_block_status,
1198
1199 .bdrv_make_empty = qcow_make_empty,
1200 .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
1201 .bdrv_get_info = qcow_get_info,
1202
1203 .create_opts = &qcow_create_opts,
1204 .strong_runtime_opts = qcow_strong_runtime_opts,
1205 };
1206
1207 static void bdrv_qcow_init(void)
1208 {
1209 bdrv_register(&bdrv_qcow);
1210 }
1211
1212 block_init(bdrv_qcow_init);
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