PPC: e500mc: add missing IVORs to bitmap
[qemu.git] / block / qcow.c
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_int.h"
26 #include "module.h"
27 #include <zlib.h>
28 #include "aes.h"
29 #include "migration.h"
30
31 /**************************************************************/
32 /* QEMU COW block driver with compression and encryption support */
33
34 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
35 #define QCOW_VERSION 1
36
37 #define QCOW_CRYPT_NONE 0
38 #define QCOW_CRYPT_AES 1
39
40 #define QCOW_OFLAG_COMPRESSED (1LL << 63)
41
42 typedef struct QCowHeader {
43 uint32_t magic;
44 uint32_t version;
45 uint64_t backing_file_offset;
46 uint32_t backing_file_size;
47 uint32_t mtime;
48 uint64_t size; /* in bytes */
49 uint8_t cluster_bits;
50 uint8_t l2_bits;
51 uint32_t crypt_method;
52 uint64_t l1_table_offset;
53 } QCowHeader;
54
55 #define L2_CACHE_SIZE 16
56
57 typedef struct BDRVQcowState {
58 int cluster_bits;
59 int cluster_size;
60 int cluster_sectors;
61 int l2_bits;
62 int l2_size;
63 int l1_size;
64 uint64_t cluster_offset_mask;
65 uint64_t l1_table_offset;
66 uint64_t *l1_table;
67 uint64_t *l2_cache;
68 uint64_t l2_cache_offsets[L2_CACHE_SIZE];
69 uint32_t l2_cache_counts[L2_CACHE_SIZE];
70 uint8_t *cluster_cache;
71 uint8_t *cluster_data;
72 uint64_t cluster_cache_offset;
73 uint32_t crypt_method; /* current crypt method, 0 if no key yet */
74 uint32_t crypt_method_header;
75 AES_KEY aes_encrypt_key;
76 AES_KEY aes_decrypt_key;
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, int flags)
96 {
97 BDRVQcowState *s = bs->opaque;
98 int len, i, shift, ret;
99 QCowHeader header;
100
101 ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
102 if (ret < 0) {
103 goto fail;
104 }
105 be32_to_cpus(&header.magic);
106 be32_to_cpus(&header.version);
107 be64_to_cpus(&header.backing_file_offset);
108 be32_to_cpus(&header.backing_file_size);
109 be32_to_cpus(&header.mtime);
110 be64_to_cpus(&header.size);
111 be32_to_cpus(&header.crypt_method);
112 be64_to_cpus(&header.l1_table_offset);
113
114 if (header.magic != QCOW_MAGIC) {
115 ret = -EINVAL;
116 goto fail;
117 }
118 if (header.version != QCOW_VERSION) {
119 char version[64];
120 snprintf(version, sizeof(version), "QCOW version %d", header.version);
121 qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE,
122 bs->device_name, "qcow", version);
123 ret = -ENOTSUP;
124 goto fail;
125 }
126
127 if (header.size <= 1 || header.cluster_bits < 9) {
128 ret = -EINVAL;
129 goto fail;
130 }
131 if (header.crypt_method > QCOW_CRYPT_AES) {
132 ret = -EINVAL;
133 goto fail;
134 }
135 s->crypt_method_header = header.crypt_method;
136 if (s->crypt_method_header) {
137 bs->encrypted = 1;
138 }
139 s->cluster_bits = header.cluster_bits;
140 s->cluster_size = 1 << s->cluster_bits;
141 s->cluster_sectors = 1 << (s->cluster_bits - 9);
142 s->l2_bits = header.l2_bits;
143 s->l2_size = 1 << s->l2_bits;
144 bs->total_sectors = header.size / 512;
145 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
146
147 /* read the level 1 table */
148 shift = s->cluster_bits + s->l2_bits;
149 s->l1_size = (header.size + (1LL << shift) - 1) >> shift;
150
151 s->l1_table_offset = header.l1_table_offset;
152 s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
153
154 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
155 s->l1_size * sizeof(uint64_t));
156 if (ret < 0) {
157 goto fail;
158 }
159
160 for(i = 0;i < s->l1_size; i++) {
161 be64_to_cpus(&s->l1_table[i]);
162 }
163 /* alloc L2 cache */
164 s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
165 s->cluster_cache = g_malloc(s->cluster_size);
166 s->cluster_data = g_malloc(s->cluster_size);
167 s->cluster_cache_offset = -1;
168
169 /* read the backing file name */
170 if (header.backing_file_offset != 0) {
171 len = header.backing_file_size;
172 if (len > 1023) {
173 len = 1023;
174 }
175 ret = bdrv_pread(bs->file, header.backing_file_offset,
176 bs->backing_file, len);
177 if (ret < 0) {
178 goto fail;
179 }
180 bs->backing_file[len] = '\0';
181 }
182
183 /* Disable migration when qcow images are used */
184 error_set(&s->migration_blocker,
185 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
186 "qcow", bs->device_name, "live migration");
187 migrate_add_blocker(s->migration_blocker);
188
189 qemu_co_mutex_init(&s->lock);
190 return 0;
191
192 fail:
193 g_free(s->l1_table);
194 g_free(s->l2_cache);
195 g_free(s->cluster_cache);
196 g_free(s->cluster_data);
197 return ret;
198 }
199
200 static int qcow_set_key(BlockDriverState *bs, const char *key)
201 {
202 BDRVQcowState *s = bs->opaque;
203 uint8_t keybuf[16];
204 int len, i;
205
206 memset(keybuf, 0, 16);
207 len = strlen(key);
208 if (len > 16)
209 len = 16;
210 /* XXX: we could compress the chars to 7 bits to increase
211 entropy */
212 for(i = 0;i < len;i++) {
213 keybuf[i] = key[i];
214 }
215 s->crypt_method = s->crypt_method_header;
216
217 if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
218 return -1;
219 if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
220 return -1;
221 return 0;
222 }
223
224 /* The crypt function is compatible with the linux cryptoloop
225 algorithm for < 4 GB images. NOTE: out_buf == in_buf is
226 supported */
227 static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
228 uint8_t *out_buf, const uint8_t *in_buf,
229 int nb_sectors, int enc,
230 const AES_KEY *key)
231 {
232 union {
233 uint64_t ll[2];
234 uint8_t b[16];
235 } ivec;
236 int i;
237
238 for(i = 0; i < nb_sectors; i++) {
239 ivec.ll[0] = cpu_to_le64(sector_num);
240 ivec.ll[1] = 0;
241 AES_cbc_encrypt(in_buf, out_buf, 512, key,
242 ivec.b, enc);
243 sector_num++;
244 in_buf += 512;
245 out_buf += 512;
246 }
247 }
248
249 /* 'allocate' is:
250 *
251 * 0 to not allocate.
252 *
253 * 1 to allocate a normal cluster (for sector indexes 'n_start' to
254 * 'n_end')
255 *
256 * 2 to allocate a compressed cluster of size
257 * 'compressed_size'. 'compressed_size' must be > 0 and <
258 * cluster_size
259 *
260 * return 0 if not allocated.
261 */
262 static uint64_t get_cluster_offset(BlockDriverState *bs,
263 uint64_t offset, int allocate,
264 int compressed_size,
265 int n_start, int n_end)
266 {
267 BDRVQcowState *s = bs->opaque;
268 int min_index, i, j, l1_index, l2_index;
269 uint64_t l2_offset, *l2_table, cluster_offset, tmp;
270 uint32_t min_count;
271 int new_l2_table;
272
273 l1_index = offset >> (s->l2_bits + s->cluster_bits);
274 l2_offset = s->l1_table[l1_index];
275 new_l2_table = 0;
276 if (!l2_offset) {
277 if (!allocate)
278 return 0;
279 /* allocate a new l2 entry */
280 l2_offset = bdrv_getlength(bs->file);
281 /* round to cluster size */
282 l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1);
283 /* update the L1 entry */
284 s->l1_table[l1_index] = l2_offset;
285 tmp = cpu_to_be64(l2_offset);
286 if (bdrv_pwrite_sync(bs->file,
287 s->l1_table_offset + l1_index * sizeof(tmp),
288 &tmp, sizeof(tmp)) < 0)
289 return 0;
290 new_l2_table = 1;
291 }
292 for(i = 0; i < L2_CACHE_SIZE; i++) {
293 if (l2_offset == s->l2_cache_offsets[i]) {
294 /* increment the hit count */
295 if (++s->l2_cache_counts[i] == 0xffffffff) {
296 for(j = 0; j < L2_CACHE_SIZE; j++) {
297 s->l2_cache_counts[j] >>= 1;
298 }
299 }
300 l2_table = s->l2_cache + (i << s->l2_bits);
301 goto found;
302 }
303 }
304 /* not found: load a new entry in the least used one */
305 min_index = 0;
306 min_count = 0xffffffff;
307 for(i = 0; i < L2_CACHE_SIZE; i++) {
308 if (s->l2_cache_counts[i] < min_count) {
309 min_count = s->l2_cache_counts[i];
310 min_index = i;
311 }
312 }
313 l2_table = s->l2_cache + (min_index << s->l2_bits);
314 if (new_l2_table) {
315 memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
316 if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
317 s->l2_size * sizeof(uint64_t)) < 0)
318 return 0;
319 } else {
320 if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
321 s->l2_size * sizeof(uint64_t))
322 return 0;
323 }
324 s->l2_cache_offsets[min_index] = l2_offset;
325 s->l2_cache_counts[min_index] = 1;
326 found:
327 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
328 cluster_offset = be64_to_cpu(l2_table[l2_index]);
329 if (!cluster_offset ||
330 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
331 if (!allocate)
332 return 0;
333 /* allocate a new cluster */
334 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
335 (n_end - n_start) < s->cluster_sectors) {
336 /* if the cluster is already compressed, we must
337 decompress it in the case it is not completely
338 overwritten */
339 if (decompress_cluster(bs, cluster_offset) < 0)
340 return 0;
341 cluster_offset = bdrv_getlength(bs->file);
342 cluster_offset = (cluster_offset + s->cluster_size - 1) &
343 ~(s->cluster_size - 1);
344 /* write the cluster content */
345 if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) !=
346 s->cluster_size)
347 return -1;
348 } else {
349 cluster_offset = bdrv_getlength(bs->file);
350 if (allocate == 1) {
351 /* round to cluster size */
352 cluster_offset = (cluster_offset + s->cluster_size - 1) &
353 ~(s->cluster_size - 1);
354 bdrv_truncate(bs->file, cluster_offset + s->cluster_size);
355 /* if encrypted, we must initialize the cluster
356 content which won't be written */
357 if (s->crypt_method &&
358 (n_end - n_start) < s->cluster_sectors) {
359 uint64_t start_sect;
360 start_sect = (offset & ~(s->cluster_size - 1)) >> 9;
361 memset(s->cluster_data + 512, 0x00, 512);
362 for(i = 0; i < s->cluster_sectors; i++) {
363 if (i < n_start || i >= n_end) {
364 encrypt_sectors(s, start_sect + i,
365 s->cluster_data,
366 s->cluster_data + 512, 1, 1,
367 &s->aes_encrypt_key);
368 if (bdrv_pwrite(bs->file, cluster_offset + i * 512,
369 s->cluster_data, 512) != 512)
370 return -1;
371 }
372 }
373 }
374 } else if (allocate == 2) {
375 cluster_offset |= QCOW_OFLAG_COMPRESSED |
376 (uint64_t)compressed_size << (63 - s->cluster_bits);
377 }
378 }
379 /* update L2 table */
380 tmp = cpu_to_be64(cluster_offset);
381 l2_table[l2_index] = tmp;
382 if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
383 &tmp, sizeof(tmp)) < 0)
384 return 0;
385 }
386 return cluster_offset;
387 }
388
389 static int coroutine_fn qcow_co_is_allocated(BlockDriverState *bs,
390 int64_t sector_num, int nb_sectors, int *pnum)
391 {
392 BDRVQcowState *s = bs->opaque;
393 int index_in_cluster, n;
394 uint64_t cluster_offset;
395
396 qemu_co_mutex_lock(&s->lock);
397 cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0);
398 qemu_co_mutex_unlock(&s->lock);
399 index_in_cluster = sector_num & (s->cluster_sectors - 1);
400 n = s->cluster_sectors - index_in_cluster;
401 if (n > nb_sectors)
402 n = nb_sectors;
403 *pnum = n;
404 return (cluster_offset != 0);
405 }
406
407 static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
408 const uint8_t *buf, int buf_size)
409 {
410 z_stream strm1, *strm = &strm1;
411 int ret, out_len;
412
413 memset(strm, 0, sizeof(*strm));
414
415 strm->next_in = (uint8_t *)buf;
416 strm->avail_in = buf_size;
417 strm->next_out = out_buf;
418 strm->avail_out = out_buf_size;
419
420 ret = inflateInit2(strm, -12);
421 if (ret != Z_OK)
422 return -1;
423 ret = inflate(strm, Z_FINISH);
424 out_len = strm->next_out - out_buf;
425 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
426 out_len != out_buf_size) {
427 inflateEnd(strm);
428 return -1;
429 }
430 inflateEnd(strm);
431 return 0;
432 }
433
434 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
435 {
436 BDRVQcowState *s = bs->opaque;
437 int ret, csize;
438 uint64_t coffset;
439
440 coffset = cluster_offset & s->cluster_offset_mask;
441 if (s->cluster_cache_offset != coffset) {
442 csize = cluster_offset >> (63 - s->cluster_bits);
443 csize &= (s->cluster_size - 1);
444 ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
445 if (ret != csize)
446 return -1;
447 if (decompress_buffer(s->cluster_cache, s->cluster_size,
448 s->cluster_data, csize) < 0) {
449 return -1;
450 }
451 s->cluster_cache_offset = coffset;
452 }
453 return 0;
454 }
455
456 static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num,
457 int nb_sectors, QEMUIOVector *qiov)
458 {
459 BDRVQcowState *s = bs->opaque;
460 int index_in_cluster;
461 int ret = 0, n;
462 uint64_t cluster_offset;
463 struct iovec hd_iov;
464 QEMUIOVector hd_qiov;
465 uint8_t *buf;
466 void *orig_buf;
467
468 if (qiov->niov > 1) {
469 buf = orig_buf = qemu_blockalign(bs, qiov->size);
470 } else {
471 orig_buf = NULL;
472 buf = (uint8_t *)qiov->iov->iov_base;
473 }
474
475 qemu_co_mutex_lock(&s->lock);
476
477 while (nb_sectors != 0) {
478 /* prepare next request */
479 cluster_offset = get_cluster_offset(bs, sector_num << 9,
480 0, 0, 0, 0);
481 index_in_cluster = sector_num & (s->cluster_sectors - 1);
482 n = s->cluster_sectors - index_in_cluster;
483 if (n > nb_sectors) {
484 n = nb_sectors;
485 }
486
487 if (!cluster_offset) {
488 if (bs->backing_hd) {
489 /* read from the base image */
490 hd_iov.iov_base = (void *)buf;
491 hd_iov.iov_len = n * 512;
492 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
493 qemu_co_mutex_unlock(&s->lock);
494 ret = bdrv_co_readv(bs->backing_hd, sector_num,
495 n, &hd_qiov);
496 qemu_co_mutex_lock(&s->lock);
497 if (ret < 0) {
498 goto fail;
499 }
500 } else {
501 /* Note: in this case, no need to wait */
502 memset(buf, 0, 512 * n);
503 }
504 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
505 /* add AIO support for compressed blocks ? */
506 if (decompress_cluster(bs, cluster_offset) < 0) {
507 goto fail;
508 }
509 memcpy(buf,
510 s->cluster_cache + index_in_cluster * 512, 512 * n);
511 } else {
512 if ((cluster_offset & 511) != 0) {
513 goto fail;
514 }
515 hd_iov.iov_base = (void *)buf;
516 hd_iov.iov_len = n * 512;
517 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
518 qemu_co_mutex_unlock(&s->lock);
519 ret = bdrv_co_readv(bs->file,
520 (cluster_offset >> 9) + index_in_cluster,
521 n, &hd_qiov);
522 qemu_co_mutex_lock(&s->lock);
523 if (ret < 0) {
524 break;
525 }
526 if (s->crypt_method) {
527 encrypt_sectors(s, sector_num, buf, buf,
528 n, 0,
529 &s->aes_decrypt_key);
530 }
531 }
532 ret = 0;
533
534 nb_sectors -= n;
535 sector_num += n;
536 buf += n * 512;
537 }
538
539 done:
540 qemu_co_mutex_unlock(&s->lock);
541
542 if (qiov->niov > 1) {
543 qemu_iovec_from_buffer(qiov, orig_buf, qiov->size);
544 qemu_vfree(orig_buf);
545 }
546
547 return ret;
548
549 fail:
550 ret = -EIO;
551 goto done;
552 }
553
554 static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num,
555 int nb_sectors, QEMUIOVector *qiov)
556 {
557 BDRVQcowState *s = bs->opaque;
558 int index_in_cluster;
559 uint64_t cluster_offset;
560 const uint8_t *src_buf;
561 int ret = 0, n;
562 uint8_t *cluster_data = NULL;
563 struct iovec hd_iov;
564 QEMUIOVector hd_qiov;
565 uint8_t *buf;
566 void *orig_buf;
567
568 s->cluster_cache_offset = -1; /* disable compressed cache */
569
570 if (qiov->niov > 1) {
571 buf = orig_buf = qemu_blockalign(bs, qiov->size);
572 qemu_iovec_to_buffer(qiov, buf);
573 } else {
574 orig_buf = NULL;
575 buf = (uint8_t *)qiov->iov->iov_base;
576 }
577
578 qemu_co_mutex_lock(&s->lock);
579
580 while (nb_sectors != 0) {
581
582 index_in_cluster = sector_num & (s->cluster_sectors - 1);
583 n = s->cluster_sectors - index_in_cluster;
584 if (n > nb_sectors) {
585 n = nb_sectors;
586 }
587 cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0,
588 index_in_cluster,
589 index_in_cluster + n);
590 if (!cluster_offset || (cluster_offset & 511) != 0) {
591 ret = -EIO;
592 break;
593 }
594 if (s->crypt_method) {
595 if (!cluster_data) {
596 cluster_data = g_malloc0(s->cluster_size);
597 }
598 encrypt_sectors(s, sector_num, cluster_data, buf,
599 n, 1, &s->aes_encrypt_key);
600 src_buf = cluster_data;
601 } else {
602 src_buf = buf;
603 }
604
605 hd_iov.iov_base = (void *)src_buf;
606 hd_iov.iov_len = n * 512;
607 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1);
608 qemu_co_mutex_unlock(&s->lock);
609 ret = bdrv_co_writev(bs->file,
610 (cluster_offset >> 9) + index_in_cluster,
611 n, &hd_qiov);
612 qemu_co_mutex_lock(&s->lock);
613 if (ret < 0) {
614 break;
615 }
616 ret = 0;
617
618 nb_sectors -= n;
619 sector_num += n;
620 buf += n * 512;
621 }
622 qemu_co_mutex_unlock(&s->lock);
623
624 if (qiov->niov > 1) {
625 qemu_vfree(orig_buf);
626 }
627 g_free(cluster_data);
628
629 return ret;
630 }
631
632 static void qcow_close(BlockDriverState *bs)
633 {
634 BDRVQcowState *s = bs->opaque;
635
636 g_free(s->l1_table);
637 g_free(s->l2_cache);
638 g_free(s->cluster_cache);
639 g_free(s->cluster_data);
640
641 migrate_del_blocker(s->migration_blocker);
642 error_free(s->migration_blocker);
643 }
644
645 static int qcow_create(const char *filename, QEMUOptionParameter *options)
646 {
647 int header_size, backing_filename_len, l1_size, shift, i;
648 QCowHeader header;
649 uint8_t *tmp;
650 int64_t total_size = 0;
651 const char *backing_file = NULL;
652 int flags = 0;
653 int ret;
654 BlockDriverState *qcow_bs;
655
656 /* Read out options */
657 while (options && options->name) {
658 if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
659 total_size = options->value.n / 512;
660 } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
661 backing_file = options->value.s;
662 } else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
663 flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
664 }
665 options++;
666 }
667
668 ret = bdrv_create_file(filename, options);
669 if (ret < 0) {
670 return ret;
671 }
672
673 ret = bdrv_file_open(&qcow_bs, filename, BDRV_O_RDWR);
674 if (ret < 0) {
675 return ret;
676 }
677
678 ret = bdrv_truncate(qcow_bs, 0);
679 if (ret < 0) {
680 goto exit;
681 }
682
683 memset(&header, 0, sizeof(header));
684 header.magic = cpu_to_be32(QCOW_MAGIC);
685 header.version = cpu_to_be32(QCOW_VERSION);
686 header.size = cpu_to_be64(total_size * 512);
687 header_size = sizeof(header);
688 backing_filename_len = 0;
689 if (backing_file) {
690 if (strcmp(backing_file, "fat:")) {
691 header.backing_file_offset = cpu_to_be64(header_size);
692 backing_filename_len = strlen(backing_file);
693 header.backing_file_size = cpu_to_be32(backing_filename_len);
694 header_size += backing_filename_len;
695 } else {
696 /* special backing file for vvfat */
697 backing_file = NULL;
698 }
699 header.cluster_bits = 9; /* 512 byte cluster to avoid copying
700 unmodifyed sectors */
701 header.l2_bits = 12; /* 32 KB L2 tables */
702 } else {
703 header.cluster_bits = 12; /* 4 KB clusters */
704 header.l2_bits = 9; /* 4 KB L2 tables */
705 }
706 header_size = (header_size + 7) & ~7;
707 shift = header.cluster_bits + header.l2_bits;
708 l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift;
709
710 header.l1_table_offset = cpu_to_be64(header_size);
711 if (flags & BLOCK_FLAG_ENCRYPT) {
712 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
713 } else {
714 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
715 }
716
717 /* write all the data */
718 ret = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header));
719 if (ret != sizeof(header)) {
720 goto exit;
721 }
722
723 if (backing_file) {
724 ret = bdrv_pwrite(qcow_bs, sizeof(header),
725 backing_file, backing_filename_len);
726 if (ret != backing_filename_len) {
727 goto exit;
728 }
729 }
730
731 tmp = g_malloc0(BDRV_SECTOR_SIZE);
732 for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/
733 BDRV_SECTOR_SIZE); i++) {
734 ret = bdrv_pwrite(qcow_bs, header_size +
735 BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE);
736 if (ret != BDRV_SECTOR_SIZE) {
737 g_free(tmp);
738 goto exit;
739 }
740 }
741
742 g_free(tmp);
743 ret = 0;
744 exit:
745 bdrv_delete(qcow_bs);
746 return ret;
747 }
748
749 static int qcow_make_empty(BlockDriverState *bs)
750 {
751 BDRVQcowState *s = bs->opaque;
752 uint32_t l1_length = s->l1_size * sizeof(uint64_t);
753 int ret;
754
755 memset(s->l1_table, 0, l1_length);
756 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
757 l1_length) < 0)
758 return -1;
759 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length);
760 if (ret < 0)
761 return ret;
762
763 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
764 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
765 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
766
767 return 0;
768 }
769
770 /* XXX: put compressed sectors first, then all the cluster aligned
771 tables to avoid losing bytes in alignment */
772 static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
773 const uint8_t *buf, int nb_sectors)
774 {
775 BDRVQcowState *s = bs->opaque;
776 z_stream strm;
777 int ret, out_len;
778 uint8_t *out_buf;
779 uint64_t cluster_offset;
780
781 if (nb_sectors != s->cluster_sectors)
782 return -EINVAL;
783
784 out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
785
786 /* best compression, small window, no zlib header */
787 memset(&strm, 0, sizeof(strm));
788 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
789 Z_DEFLATED, -12,
790 9, Z_DEFAULT_STRATEGY);
791 if (ret != 0) {
792 ret = -EINVAL;
793 goto fail;
794 }
795
796 strm.avail_in = s->cluster_size;
797 strm.next_in = (uint8_t *)buf;
798 strm.avail_out = s->cluster_size;
799 strm.next_out = out_buf;
800
801 ret = deflate(&strm, Z_FINISH);
802 if (ret != Z_STREAM_END && ret != Z_OK) {
803 deflateEnd(&strm);
804 ret = -EINVAL;
805 goto fail;
806 }
807 out_len = strm.next_out - out_buf;
808
809 deflateEnd(&strm);
810
811 if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
812 /* could not compress: write normal cluster */
813 ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors);
814 if (ret < 0) {
815 goto fail;
816 }
817 } else {
818 cluster_offset = get_cluster_offset(bs, sector_num << 9, 2,
819 out_len, 0, 0);
820 if (cluster_offset == 0) {
821 ret = -EIO;
822 goto fail;
823 }
824
825 cluster_offset &= s->cluster_offset_mask;
826 ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len);
827 if (ret < 0) {
828 goto fail;
829 }
830 }
831
832 ret = 0;
833 fail:
834 g_free(out_buf);
835 return ret;
836 }
837
838 static coroutine_fn int qcow_co_flush(BlockDriverState *bs)
839 {
840 return bdrv_co_flush(bs->file);
841 }
842
843 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
844 {
845 BDRVQcowState *s = bs->opaque;
846 bdi->cluster_size = s->cluster_size;
847 return 0;
848 }
849
850
851 static QEMUOptionParameter qcow_create_options[] = {
852 {
853 .name = BLOCK_OPT_SIZE,
854 .type = OPT_SIZE,
855 .help = "Virtual disk size"
856 },
857 {
858 .name = BLOCK_OPT_BACKING_FILE,
859 .type = OPT_STRING,
860 .help = "File name of a base image"
861 },
862 {
863 .name = BLOCK_OPT_ENCRYPT,
864 .type = OPT_FLAG,
865 .help = "Encrypt the image"
866 },
867 { NULL }
868 };
869
870 static BlockDriver bdrv_qcow = {
871 .format_name = "qcow",
872 .instance_size = sizeof(BDRVQcowState),
873 .bdrv_probe = qcow_probe,
874 .bdrv_open = qcow_open,
875 .bdrv_close = qcow_close,
876 .bdrv_create = qcow_create,
877
878 .bdrv_co_readv = qcow_co_readv,
879 .bdrv_co_writev = qcow_co_writev,
880 .bdrv_co_flush_to_disk = qcow_co_flush,
881 .bdrv_co_is_allocated = qcow_co_is_allocated,
882
883 .bdrv_set_key = qcow_set_key,
884 .bdrv_make_empty = qcow_make_empty,
885 .bdrv_write_compressed = qcow_write_compressed,
886 .bdrv_get_info = qcow_get_info,
887
888 .create_options = qcow_create_options,
889 };
890
891 static void bdrv_qcow_init(void)
892 {
893 bdrv_register(&bdrv_qcow);
894 }
895
896 block_init(bdrv_qcow_init);