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ivshmem: Fix unplug of device "ivshmem-plain"
[qemu/armbru.git] / block / qcow.c
blob385d935258f04bbb007e90b4f1eecef5a0f01cec
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 <zlib.h>
35 #include "qapi/qmp/qdict.h"
36 #include "qapi/qmp/qstring.h"
37 #include "qapi/qobject-input-visitor.h"
38 #include "qapi/qapi-visit-block-core.h"
39 #include "crypto/block.h"
40 #include "migration/blocker.h"
41 #include "crypto.h"
42
43 /**************************************************************/
44 /* QEMU COW block driver with compression and encryption support */
45
46 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
47 #define QCOW_VERSION 1
48
49 #define QCOW_CRYPT_NONE 0
50 #define QCOW_CRYPT_AES 1
51
52 #define QCOW_OFLAG_COMPRESSED (1LL << 63)
53
54 typedef struct QCowHeader {
55 uint32_t magic;
56 uint32_t version;
57 uint64_t backing_file_offset;
58 uint32_t backing_file_size;
59 uint32_t mtime;
60 uint64_t size; /* in bytes */
61 uint8_t cluster_bits;
62 uint8_t l2_bits;
63 uint16_t padding;
64 uint32_t crypt_method;
65 uint64_t l1_table_offset;
66 } QEMU_PACKED QCowHeader;
67
68 #define L2_CACHE_SIZE 16
69
70 typedef struct BDRVQcowState {
71 int cluster_bits;
72 int cluster_size;
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_put_str(encryptopts, "format", "qcow");
206 crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
207 if (!crypto_opts) {
208 ret = -EINVAL;
209 goto fail;
210 }
211
212 if (flags & BDRV_O_NO_IO) {
213 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
214 }
215 s->crypto = qcrypto_block_open(crypto_opts, "encrypt.",
216 NULL, NULL, cflags, errp);
217 if (!s->crypto) {
218 ret = -EINVAL;
219 goto fail;
220 }
221 } else {
222 error_setg(errp, "invalid encryption method in qcow header");
223 ret = -EINVAL;
224 goto fail;
225 }
226 bs->encrypted = true;
227 } else {
228 if (encryptfmt) {
229 error_setg(errp, "No encryption in image header, but options "
230 "specified format '%s'", encryptfmt);
231 ret = -EINVAL;
232 goto fail;
233 }
234 }
235 s->cluster_bits = header.cluster_bits;
236 s->cluster_size = 1 << s->cluster_bits;
237 s->l2_bits = header.l2_bits;
238 s->l2_size = 1 << s->l2_bits;
239 bs->total_sectors = header.size / 512;
240 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
241
242 /* read the level 1 table */
243 shift = s->cluster_bits + s->l2_bits;
244 if (header.size > UINT64_MAX - (1LL << shift)) {
245 error_setg(errp, "Image too large");
246 ret = -EINVAL;
247 goto fail;
248 } else {
249 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
250 if (l1_size > INT_MAX / sizeof(uint64_t)) {
251 error_setg(errp, "Image too large");
252 ret = -EINVAL;
253 goto fail;
254 }
255 s->l1_size = l1_size;
256 }
257
258 s->l1_table_offset = header.l1_table_offset;
259 s->l1_table = g_try_new(uint64_t, s->l1_size);
260 if (s->l1_table == NULL) {
261 error_setg(errp, "Could not allocate memory for L1 table");
262 ret = -ENOMEM;
263 goto fail;
264 }
265
266 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
267 s->l1_size * sizeof(uint64_t));
268 if (ret < 0) {
269 goto fail;
270 }
271
272 for(i = 0;i < s->l1_size; i++) {
273 be64_to_cpus(&s->l1_table[i]);
274 }
275
276 /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
277 s->l2_cache =
278 qemu_try_blockalign(bs->file->bs,
279 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
280 if (s->l2_cache == NULL) {
281 error_setg(errp, "Could not allocate L2 table cache");
282 ret = -ENOMEM;
283 goto fail;
284 }
285 s->cluster_cache = g_malloc(s->cluster_size);
286 s->cluster_data = g_malloc(s->cluster_size);
287 s->cluster_cache_offset = -1;
288
289 /* read the backing file name */
290 if (header.backing_file_offset != 0) {
291 len = header.backing_file_size;
292 if (len > 1023 || len >= sizeof(bs->backing_file)) {
293 error_setg(errp, "Backing file name too long");
294 ret = -EINVAL;
295 goto fail;
296 }
297 ret = bdrv_pread(bs->file, header.backing_file_offset,
298 bs->backing_file, len);
299 if (ret < 0) {
300 goto fail;
301 }
302 bs->backing_file[len] = '\0';
303 }
304
305 /* Disable migration when qcow images are used */
306 error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
307 "does not support live migration",
308 bdrv_get_device_or_node_name(bs));
309 ret = migrate_add_blocker(s->migration_blocker, &local_err);
310 if (local_err) {
311 error_propagate(errp, local_err);
312 error_free(s->migration_blocker);
313 goto fail;
314 }
315
316 qobject_unref(encryptopts);
317 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
318 qemu_co_mutex_init(&s->lock);
319 return 0;
320
321 fail:
322 g_free(s->l1_table);
323 qemu_vfree(s->l2_cache);
324 g_free(s->cluster_cache);
325 g_free(s->cluster_data);
326 qcrypto_block_free(s->crypto);
327 qobject_unref(encryptopts);
328 qapi_free_QCryptoBlockOpenOptions(crypto_opts);
329 return ret;
330 }
331
332
333 /* We have nothing to do for QCOW reopen, stubs just return
334 * success */
335 static int qcow_reopen_prepare(BDRVReopenState *state,
336 BlockReopenQueue *queue, Error **errp)
337 {
338 return 0;
339 }
340
341
342 /* 'allocate' is:
343 *
344 * 0 to not allocate.
345 *
346 * 1 to allocate a normal cluster (for sector-aligned byte offsets 'n_start'
347 * to 'n_end' within the cluster)
348 *
349 * 2 to allocate a compressed cluster of size
350 * 'compressed_size'. 'compressed_size' must be > 0 and <
351 * cluster_size
352 *
353 * return 0 if not allocated, 1 if *result is assigned, and negative
354 * errno on failure.
355 */
356 static int get_cluster_offset(BlockDriverState *bs,
357 uint64_t offset, int allocate,
358 int compressed_size,
359 int n_start, int n_end, uint64_t *result)
360 {
361 BDRVQcowState *s = bs->opaque;
362 int min_index, i, j, l1_index, l2_index, ret;
363 int64_t l2_offset;
364 uint64_t *l2_table, cluster_offset, tmp;
365 uint32_t min_count;
366 int new_l2_table;
367
368 *result = 0;
369 l1_index = offset >> (s->l2_bits + s->cluster_bits);
370 l2_offset = s->l1_table[l1_index];
371 new_l2_table = 0;
372 if (!l2_offset) {
373 if (!allocate)
374 return 0;
375 /* allocate a new l2 entry */
376 l2_offset = bdrv_getlength(bs->file->bs);
377 if (l2_offset < 0) {
378 return l2_offset;
379 }
380 /* round to cluster size */
381 l2_offset = QEMU_ALIGN_UP(l2_offset, s->cluster_size);
382 /* update the L1 entry */
383 s->l1_table[l1_index] = l2_offset;
384 tmp = cpu_to_be64(l2_offset);
385 BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
386 ret = bdrv_pwrite_sync(bs->file,
387 s->l1_table_offset + l1_index * sizeof(tmp),
388 &tmp, sizeof(tmp));
389 if (ret < 0) {
390 return ret;
391 }
392 new_l2_table = 1;
393 }
394 for(i = 0; i < L2_CACHE_SIZE; i++) {
395 if (l2_offset == s->l2_cache_offsets[i]) {
396 /* increment the hit count */
397 if (++s->l2_cache_counts[i] == 0xffffffff) {
398 for(j = 0; j < L2_CACHE_SIZE; j++) {
399 s->l2_cache_counts[j] >>= 1;
400 }
401 }
402 l2_table = s->l2_cache + (i << s->l2_bits);
403 goto found;
404 }
405 }
406 /* not found: load a new entry in the least used one */
407 min_index = 0;
408 min_count = 0xffffffff;
409 for(i = 0; i < L2_CACHE_SIZE; i++) {
410 if (s->l2_cache_counts[i] < min_count) {
411 min_count = s->l2_cache_counts[i];
412 min_index = i;
413 }
414 }
415 l2_table = s->l2_cache + (min_index << s->l2_bits);
416 BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
417 if (new_l2_table) {
418 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
419 ret = bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
420 s->l2_size * sizeof(uint64_t));
421 if (ret < 0) {
422 return ret;
423 }
424 } else {
425 ret = bdrv_pread(bs->file, l2_offset, l2_table,
426 s->l2_size * sizeof(uint64_t));
427 if (ret < 0) {
428 return ret;
429 }
430 }
431 s->l2_cache_offsets[min_index] = l2_offset;
432 s->l2_cache_counts[min_index] = 1;
433 found:
434 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
435 cluster_offset = be64_to_cpu(l2_table[l2_index]);
436 if (!cluster_offset ||
437 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
438 if (!allocate)
439 return 0;
440 BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC);
441 assert(QEMU_IS_ALIGNED(n_start | n_end, BDRV_SECTOR_SIZE));
442 /* allocate a new cluster */
443 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
444 (n_end - n_start) < s->cluster_size) {
445 /* if the cluster is already compressed, we must
446 decompress it in the case it is not completely
447 overwritten */
448 if (decompress_cluster(bs, cluster_offset) < 0) {
449 return -EIO;
450 }
451 cluster_offset = bdrv_getlength(bs->file->bs);
452 if ((int64_t) cluster_offset < 0) {
453 return cluster_offset;
454 }
455 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
456 /* write the cluster content */
457 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
458 ret = bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache,
459 s->cluster_size);
460 if (ret < 0) {
461 return ret;
462 }
463 } else {
464 cluster_offset = bdrv_getlength(bs->file->bs);
465 if ((int64_t) cluster_offset < 0) {
466 return cluster_offset;
467 }
468 if (allocate == 1) {
469 /* round to cluster size */
470 cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
471 if (cluster_offset + s->cluster_size > INT64_MAX) {
472 return -E2BIG;
473 }
474 ret = bdrv_truncate(bs->file, cluster_offset + s->cluster_size,
475 PREALLOC_MODE_OFF, NULL);
476 if (ret < 0) {
477 return ret;
478 }
479 /* if encrypted, we must initialize the cluster
480 content which won't be written */
481 if (bs->encrypted &&
482 (n_end - n_start) < s->cluster_size) {
483 uint64_t start_offset;
484 assert(s->crypto);
485 start_offset = offset & ~(s->cluster_size - 1);
486 for (i = 0; i < s->cluster_size; i += BDRV_SECTOR_SIZE) {
487 if (i < n_start || i >= n_end) {
488 memset(s->cluster_data, 0x00, BDRV_SECTOR_SIZE);
489 if (qcrypto_block_encrypt(s->crypto,
490 start_offset + i,
491 s->cluster_data,
492 BDRV_SECTOR_SIZE,
493 NULL) < 0) {
494 return -EIO;
495 }
496 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
497 ret = bdrv_pwrite(bs->file,
498 cluster_offset + i,
499 s->cluster_data,
500 BDRV_SECTOR_SIZE);
501 if (ret < 0) {
502 return ret;
503 }
504 }
505 }
506 }
507 } else if (allocate == 2) {
508 cluster_offset |= QCOW_OFLAG_COMPRESSED |
509 (uint64_t)compressed_size << (63 - s->cluster_bits);
510 }
511 }
512 /* update L2 table */
513 tmp = cpu_to_be64(cluster_offset);
514 l2_table[l2_index] = tmp;
515 if (allocate == 2) {
516 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
517 } else {
518 BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
519 }
520 ret = bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
521 &tmp, sizeof(tmp));
522 if (ret < 0) {
523 return ret;
524 }
525 }
526 *result = cluster_offset;
527 return 1;
528 }
529
530 static int coroutine_fn qcow_co_block_status(BlockDriverState *bs,
531 bool want_zero,
532 int64_t offset, int64_t bytes,
533 int64_t *pnum, int64_t *map,
534 BlockDriverState **file)
535 {
536 BDRVQcowState *s = bs->opaque;
537 int index_in_cluster, ret;
538 int64_t n;
539 uint64_t cluster_offset;
540
541 qemu_co_mutex_lock(&s->lock);
542 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
543 qemu_co_mutex_unlock(&s->lock);
544 if (ret < 0) {
545 return ret;
546 }
547 index_in_cluster = offset & (s->cluster_size - 1);
548 n = s->cluster_size - index_in_cluster;
549 if (n > bytes) {
550 n = bytes;
551 }
552 *pnum = n;
553 if (!cluster_offset) {
554 return 0;
555 }
556 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
557 return BDRV_BLOCK_DATA;
558 }
559 *map = cluster_offset | index_in_cluster;
560 *file = bs->file->bs;
561 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
562 }
563
564 static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
565 const uint8_t *buf, int buf_size)
566 {
567 z_stream strm1, *strm = &strm1;
568 int ret, out_len;
569
570 memset(strm, 0, sizeof(*strm));
571
572 strm->next_in = (uint8_t *)buf;
573 strm->avail_in = buf_size;
574 strm->next_out = out_buf;
575 strm->avail_out = out_buf_size;
576
577 ret = inflateInit2(strm, -12);
578 if (ret != Z_OK)
579 return -1;
580 ret = inflate(strm, Z_FINISH);
581 out_len = strm->next_out - out_buf;
582 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
583 out_len != out_buf_size) {
584 inflateEnd(strm);
585 return -1;
586 }
587 inflateEnd(strm);
588 return 0;
589 }
590
591 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
592 {
593 BDRVQcowState *s = bs->opaque;
594 int ret, csize;
595 uint64_t coffset;
596
597 coffset = cluster_offset & s->cluster_offset_mask;
598 if (s->cluster_cache_offset != coffset) {
599 csize = cluster_offset >> (63 - s->cluster_bits);
600 csize &= (s->cluster_size - 1);
601 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
602 ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
603 if (ret != csize)
604 return -1;
605 if (decompress_buffer(s->cluster_cache, s->cluster_size,
606 s->cluster_data, csize) < 0) {
607 return -1;
608 }
609 s->cluster_cache_offset = coffset;
610 }
611 return 0;
612 }
613
614 static void qcow_refresh_limits(BlockDriverState *bs, Error **errp)
615 {
616 /* At least encrypted images require 512-byte alignment. Apply the
617 * limit universally, rather than just on encrypted images, as
618 * it's easier to let the block layer handle rounding than to
619 * audit this code further. */
620 bs->bl.request_alignment = BDRV_SECTOR_SIZE;
621 }
622
623 static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
624 uint64_t bytes, QEMUIOVector *qiov,
625 int flags)
626 {
627 BDRVQcowState *s = bs->opaque;
628 int offset_in_cluster;
629 int ret = 0, n;
630 uint64_t cluster_offset;
631 struct iovec hd_iov;
632 QEMUIOVector hd_qiov;
633 uint8_t *buf;
634 void *orig_buf;
635
636 assert(!flags);
637 if (qiov->niov > 1) {
638 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
639 if (buf == NULL) {
640 return -ENOMEM;
641 }
642 } else {
643 orig_buf = NULL;
644 buf = (uint8_t *)qiov->iov->iov_base;
645 }
646
647 qemu_co_mutex_lock(&s->lock);
648
649 while (bytes != 0) {
650 /* prepare next request */
651 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
652 if (ret < 0) {
653 break;
654 }
655 offset_in_cluster = offset & (s->cluster_size - 1);
656 n = s->cluster_size - offset_in_cluster;
657 if (n > bytes) {
658 n = bytes;
659 }
660
661 if (!cluster_offset) {
662 if (bs->backing) {
663 /* read from the base image */
664 hd_iov.iov_base = (void *)buf;
665 hd_iov.iov_len = n;
666 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
667 qemu_co_mutex_unlock(&s->lock);
668 /* qcow2 emits this on bs->file instead of bs->backing */
669 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
670 ret = bdrv_co_preadv(bs->backing, offset, n, &hd_qiov, 0);
671 qemu_co_mutex_lock(&s->lock);
672 if (ret < 0) {
673 break;
674 }
675 } else {
676 /* Note: in this case, no need to wait */
677 memset(buf, 0, n);
678 }
679 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
680 /* add AIO support for compressed blocks ? */
681 if (decompress_cluster(bs, cluster_offset) < 0) {
682 ret = -EIO;
683 break;
684 }
685 memcpy(buf, s->cluster_cache + offset_in_cluster, n);
686 } else {
687 if ((cluster_offset & 511) != 0) {
688 ret = -EIO;
689 break;
690 }
691 hd_iov.iov_base = (void *)buf;
692 hd_iov.iov_len = n;
693 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
694 qemu_co_mutex_unlock(&s->lock);
695 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
696 ret = bdrv_co_preadv(bs->file, cluster_offset + offset_in_cluster,
697 n, &hd_qiov, 0);
698 qemu_co_mutex_lock(&s->lock);
699 if (ret < 0) {
700 break;
701 }
702 if (bs->encrypted) {
703 assert(s->crypto);
704 if (qcrypto_block_decrypt(s->crypto,
705 offset, buf, n, NULL) < 0) {
706 ret = -EIO;
707 break;
708 }
709 }
710 }
711 ret = 0;
712
713 bytes -= n;
714 offset += n;
715 buf += n;
716 }
717
718 qemu_co_mutex_unlock(&s->lock);
719
720 if (qiov->niov > 1) {
721 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
722 qemu_vfree(orig_buf);
723 }
724
725 return ret;
726 }
727
728 static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
729 uint64_t bytes, QEMUIOVector *qiov,
730 int flags)
731 {
732 BDRVQcowState *s = bs->opaque;
733 int offset_in_cluster;
734 uint64_t cluster_offset;
735 int ret = 0, n;
736 struct iovec hd_iov;
737 QEMUIOVector hd_qiov;
738 uint8_t *buf;
739 void *orig_buf;
740
741 assert(!flags);
742 s->cluster_cache_offset = -1; /* disable compressed cache */
743
744 /* We must always copy the iov when encrypting, so we
745 * don't modify the original data buffer during encryption */
746 if (bs->encrypted || qiov->niov > 1) {
747 buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
748 if (buf == NULL) {
749 return -ENOMEM;
750 }
751 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
752 } else {
753 orig_buf = NULL;
754 buf = (uint8_t *)qiov->iov->iov_base;
755 }
756
757 qemu_co_mutex_lock(&s->lock);
758
759 while (bytes != 0) {
760 offset_in_cluster = offset & (s->cluster_size - 1);
761 n = s->cluster_size - offset_in_cluster;
762 if (n > bytes) {
763 n = bytes;
764 }
765 ret = get_cluster_offset(bs, offset, 1, 0, offset_in_cluster,
766 offset_in_cluster + n, &cluster_offset);
767 if (ret < 0) {
768 break;
769 }
770 if (!cluster_offset || (cluster_offset & 511) != 0) {
771 ret = -EIO;
772 break;
773 }
774 if (bs->encrypted) {
775 assert(s->crypto);
776 if (qcrypto_block_encrypt(s->crypto, offset, buf, n, NULL) < 0) {
777 ret = -EIO;
778 break;
779 }
780 }
781
782 hd_iov.iov_base = (void *)buf;
783 hd_iov.iov_len = n;
784 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
785 qemu_co_mutex_unlock(&s->lock);
786 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
787 ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
788 n, &hd_qiov, 0);
789 qemu_co_mutex_lock(&s->lock);
790 if (ret < 0) {
791 break;
792 }
793 ret = 0;
794
795 bytes -= n;
796 offset += n;
797 buf += n;
798 }
799 qemu_co_mutex_unlock(&s->lock);
800
801 qemu_vfree(orig_buf);
802
803 return ret;
804 }
805
806 static void qcow_close(BlockDriverState *bs)
807 {
808 BDRVQcowState *s = bs->opaque;
809
810 qcrypto_block_free(s->crypto);
811 s->crypto = NULL;
812 g_free(s->l1_table);
813 qemu_vfree(s->l2_cache);
814 g_free(s->cluster_cache);
815 g_free(s->cluster_data);
816
817 migrate_del_blocker(s->migration_blocker);
818 error_free(s->migration_blocker);
819 }
820
821 static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
822 Error **errp)
823 {
824 BlockdevCreateOptionsQcow *qcow_opts;
825 int header_size, backing_filename_len, l1_size, shift, i;
826 QCowHeader header;
827 uint8_t *tmp;
828 int64_t total_size = 0;
829 int ret;
830 BlockDriverState *bs;
831 BlockBackend *qcow_blk;
832 QCryptoBlock *crypto = NULL;
833
834 assert(opts->driver == BLOCKDEV_DRIVER_QCOW);
835 qcow_opts = &opts->u.qcow;
836
837 /* Sanity checks */
838 total_size = qcow_opts->size;
839 if (total_size == 0) {
840 error_setg(errp, "Image size is too small, cannot be zero length");
841 return -EINVAL;
842 }
843
844 if (qcow_opts->has_encrypt &&
845 qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW)
846 {
847 error_setg(errp, "Unsupported encryption format");
848 return -EINVAL;
849 }
850
851 /* Create BlockBackend to write to the image */
852 bs = bdrv_open_blockdev_ref(qcow_opts->file, errp);
853 if (bs == NULL) {
854 return -EIO;
855 }
856
857 qcow_blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
858 ret = blk_insert_bs(qcow_blk, bs, errp);
859 if (ret < 0) {
860 goto exit;
861 }
862 blk_set_allow_write_beyond_eof(qcow_blk, true);
863
864 /* Create image format */
865 ret = blk_truncate(qcow_blk, 0, PREALLOC_MODE_OFF, errp);
866 if (ret < 0) {
867 goto exit;
868 }
869
870 memset(&header, 0, sizeof(header));
871 header.magic = cpu_to_be32(QCOW_MAGIC);
872 header.version = cpu_to_be32(QCOW_VERSION);
873 header.size = cpu_to_be64(total_size);
874 header_size = sizeof(header);
875 backing_filename_len = 0;
876 if (qcow_opts->has_backing_file) {
877 if (strcmp(qcow_opts->backing_file, "fat:")) {
878 header.backing_file_offset = cpu_to_be64(header_size);
879 backing_filename_len = strlen(qcow_opts->backing_file);
880 header.backing_file_size = cpu_to_be32(backing_filename_len);
881 header_size += backing_filename_len;
882 } else {
883 /* special backing file for vvfat */
884 qcow_opts->has_backing_file = false;
885 }
886 header.cluster_bits = 9; /* 512 byte cluster to avoid copying
887 unmodified sectors */
888 header.l2_bits = 12; /* 32 KB L2 tables */
889 } else {
890 header.cluster_bits = 12; /* 4 KB clusters */
891 header.l2_bits = 9; /* 4 KB L2 tables */
892 }
893 header_size = (header_size + 7) & ~7;
894 shift = header.cluster_bits + header.l2_bits;
895 l1_size = (total_size + (1LL << shift) - 1) >> shift;
896
897 header.l1_table_offset = cpu_to_be64(header_size);
898
899 if (qcow_opts->has_encrypt) {
900 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
901
902 crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.",
903 NULL, NULL, NULL, errp);
904 if (!crypto) {
905 ret = -EINVAL;
906 goto exit;
907 }
908 } else {
909 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
910 }
911
912 /* write all the data */
913 ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0);
914 if (ret != sizeof(header)) {
915 goto exit;
916 }
917
918 if (qcow_opts->has_backing_file) {
919 ret = blk_pwrite(qcow_blk, sizeof(header),
920 qcow_opts->backing_file, backing_filename_len, 0);
921 if (ret != backing_filename_len) {
922 goto exit;
923 }
924 }
925
926 tmp = g_malloc0(BDRV_SECTOR_SIZE);
927 for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE);
928 i++) {
929 ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i,
930 tmp, BDRV_SECTOR_SIZE, 0);
931 if (ret != BDRV_SECTOR_SIZE) {
932 g_free(tmp);
933 goto exit;
934 }
935 }
936
937 g_free(tmp);
938 ret = 0;
939 exit:
940 blk_unref(qcow_blk);
941 bdrv_unref(bs);
942 qcrypto_block_free(crypto);
943 return ret;
944 }
945
946 static int coroutine_fn qcow_co_create_opts(const char *filename,
947 QemuOpts *opts, Error **errp)
948 {
949 BlockdevCreateOptions *create_options = NULL;
950 BlockDriverState *bs = NULL;
951 QDict *qdict;
952 Visitor *v;
953 const char *val;
954 Error *local_err = NULL;
955 int ret;
956
957 static const QDictRenames opt_renames[] = {
958 { BLOCK_OPT_BACKING_FILE, "backing-file" },
959 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
960 { NULL, NULL },
961 };
962
963 /* Parse options and convert legacy syntax */
964 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
965
966 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
967 if (val && !strcmp(val, "on")) {
968 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
969 } else if (val && !strcmp(val, "off")) {
970 qdict_del(qdict, BLOCK_OPT_ENCRYPT);
971 }
972
973 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
974 if (val && !strcmp(val, "aes")) {
975 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
976 }
977
978 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
979 ret = -EINVAL;
980 goto fail;
981 }
982
983 /* Create and open the file (protocol layer) */
984 ret = bdrv_create_file(filename, opts, &local_err);
985 if (ret < 0) {
986 error_propagate(errp, local_err);
987 goto fail;
988 }
989
990 bs = bdrv_open(filename, NULL, NULL,
991 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
992 if (bs == NULL) {
993 ret = -EIO;
994 goto fail;
995 }
996
997 /* Now get the QAPI type BlockdevCreateOptions */
998 qdict_put_str(qdict, "driver", "qcow");
999 qdict_put_str(qdict, "file", bs->node_name);
1000
1001 v = qobject_input_visitor_new_flat_confused(qdict, errp);
1002 if (!v) {
1003 ret = -EINVAL;
1004 goto fail;
1005 }
1006
1007 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
1008 visit_free(v);
1009
1010 if (local_err) {
1011 error_propagate(errp, local_err);
1012 ret = -EINVAL;
1013 goto fail;
1014 }
1015
1016 /* Silently round up size */
1017 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW);
1018 create_options->u.qcow.size =
1019 ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE);
1020
1021 /* Create the qcow image (format layer) */
1022 ret = qcow_co_create(create_options, errp);
1023 if (ret < 0) {
1024 goto fail;
1025 }
1026
1027 ret = 0;
1028 fail:
1029 qobject_unref(qdict);
1030 bdrv_unref(bs);
1031 qapi_free_BlockdevCreateOptions(create_options);
1032 return ret;
1033 }
1034
1035 static int qcow_make_empty(BlockDriverState *bs)
1036 {
1037 BDRVQcowState *s = bs->opaque;
1038 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
1039 int ret;
1040
1041 memset(s->l1_table, 0, l1_length);
1042 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
1043 l1_length) < 0)
1044 return -1;
1045 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length,
1046 PREALLOC_MODE_OFF, NULL);
1047 if (ret < 0)
1048 return ret;
1049
1050 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
1051 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
1052 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
1053
1054 return 0;
1055 }
1056
1057 /* XXX: put compressed sectors first, then all the cluster aligned
1058 tables to avoid losing bytes in alignment */
1059 static coroutine_fn int
1060 qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
1061 uint64_t bytes, QEMUIOVector *qiov)
1062 {
1063 BDRVQcowState *s = bs->opaque;
1064 QEMUIOVector hd_qiov;
1065 struct iovec iov;
1066 z_stream strm;
1067 int ret, out_len;
1068 uint8_t *buf, *out_buf;
1069 uint64_t cluster_offset;
1070
1071 buf = qemu_blockalign(bs, s->cluster_size);
1072 if (bytes != s->cluster_size) {
1073 if (bytes > s->cluster_size ||
1074 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS)
1075 {
1076 qemu_vfree(buf);
1077 return -EINVAL;
1078 }
1079 /* Zero-pad last write if image size is not cluster aligned */
1080 memset(buf + bytes, 0, s->cluster_size - bytes);
1081 }
1082 qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
1083
1084 out_buf = g_malloc(s->cluster_size);
1085
1086 /* best compression, small window, no zlib header */
1087 memset(&strm, 0, sizeof(strm));
1088 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
1089 Z_DEFLATED, -12,
1090 9, Z_DEFAULT_STRATEGY);
1091 if (ret != 0) {
1092 ret = -EINVAL;
1093 goto fail;
1094 }
1095
1096 strm.avail_in = s->cluster_size;
1097 strm.next_in = (uint8_t *)buf;
1098 strm.avail_out = s->cluster_size;
1099 strm.next_out = out_buf;
1100
1101 ret = deflate(&strm, Z_FINISH);
1102 if (ret != Z_STREAM_END && ret != Z_OK) {
1103 deflateEnd(&strm);
1104 ret = -EINVAL;
1105 goto fail;
1106 }
1107 out_len = strm.next_out - out_buf;
1108
1109 deflateEnd(&strm);
1110
1111 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
1112 /* could not compress: write normal cluster */
1113 ret = qcow_co_pwritev(bs, offset, bytes, qiov, 0);
1114 if (ret < 0) {
1115 goto fail;
1116 }
1117 goto success;
1118 }
1119 qemu_co_mutex_lock(&s->lock);
1120 ret = get_cluster_offset(bs, offset, 2, out_len, 0, 0, &cluster_offset);
1121 qemu_co_mutex_unlock(&s->lock);
1122 if (ret < 0) {
1123 goto fail;
1124 }
1125 if (cluster_offset == 0) {
1126 ret = -EIO;
1127 goto fail;
1128 }
1129 cluster_offset &= s->cluster_offset_mask;
1130
1131 iov = (struct iovec) {
1132 .iov_base = out_buf,
1133 .iov_len = out_len,
1134 };
1135 qemu_iovec_init_external(&hd_qiov, &iov, 1);
1136 BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
1137 ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
1138 if (ret < 0) {
1139 goto fail;
1140 }
1141 success:
1142 ret = 0;
1143 fail:
1144 qemu_vfree(buf);
1145 g_free(out_buf);
1146 return ret;
1147 }
1148
1149 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1150 {
1151 BDRVQcowState *s = bs->opaque;
1152 bdi->cluster_size = s->cluster_size;
1153 return 0;
1154 }
1155
1156 static QemuOptsList qcow_create_opts = {
1157 .name = "qcow-create-opts",
1158 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
1159 .desc = {
1160 {
1161 .name = BLOCK_OPT_SIZE,
1162 .type = QEMU_OPT_SIZE,
1163 .help = "Virtual disk size"
1164 },
1165 {
1166 .name = BLOCK_OPT_BACKING_FILE,
1167 .type = QEMU_OPT_STRING,
1168 .help = "File name of a base image"
1169 },
1170 {
1171 .name = BLOCK_OPT_ENCRYPT,
1172 .type = QEMU_OPT_BOOL,
1173 .help = "Encrypt the image with format 'aes'. (Deprecated "
1174 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)",
1175 },
1176 {
1177 .name = BLOCK_OPT_ENCRYPT_FORMAT,
1178 .type = QEMU_OPT_STRING,
1179 .help = "Encrypt the image, format choices: 'aes'",
1180 },
1181 BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
1182 { /* end of list */ }
1183 }
1184 };
1185
1186 static BlockDriver bdrv_qcow = {
1187 .format_name = "qcow",
1188 .instance_size = sizeof(BDRVQcowState),
1189 .bdrv_probe = qcow_probe,
1190 .bdrv_open = qcow_open,
1191 .bdrv_close = qcow_close,
1192 .bdrv_child_perm = bdrv_format_default_perms,
1193 .bdrv_reopen_prepare = qcow_reopen_prepare,
1194 .bdrv_co_create = qcow_co_create,
1195 .bdrv_co_create_opts = qcow_co_create_opts,
1196 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1197 .supports_backing = true,
1198 .bdrv_refresh_limits = qcow_refresh_limits,
1199
1200 .bdrv_co_preadv = qcow_co_preadv,
1201 .bdrv_co_pwritev = qcow_co_pwritev,
1202 .bdrv_co_block_status = qcow_co_block_status,
1203
1204 .bdrv_make_empty = qcow_make_empty,
1205 .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
1206 .bdrv_get_info = qcow_get_info,
1207
1208 .create_opts = &qcow_create_opts,
1209 };
1210
1211 static void bdrv_qcow_init(void)
1212 {
1213 bdrv_register(&bdrv_qcow);
1214 }
1215
1216 block_init(bdrv_qcow_init);
armbru's QEMU hackery