1 /* 2 * Block driver for the QCOW format 3 * 4 * Copyright (c) 2004-2006 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu-common.h" 25 #include "block/block_int.h" 26 #include "qemu/module.h" 27 #include <zlib.h> 28 #include "qemu/aes.h" 29 #include "migration/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 uint16_t padding; 52 uint32_t crypt_method; 53 uint64_t l1_table_offset; 54 } QEMU_PACKED QCowHeader; 55 56 #define L2_CACHE_SIZE 16 57 58 typedef struct BDRVQcowState { 59 int cluster_bits; 60 int cluster_size; 61 int cluster_sectors; 62 int l2_bits; 63 int l2_size; 64 unsigned int l1_size; 65 uint64_t cluster_offset_mask; 66 uint64_t l1_table_offset; 67 uint64_t *l1_table; 68 uint64_t *l2_cache; 69 uint64_t l2_cache_offsets[L2_CACHE_SIZE]; 70 uint32_t l2_cache_counts[L2_CACHE_SIZE]; 71 uint8_t *cluster_cache; 72 uint8_t *cluster_data; 73 uint64_t cluster_cache_offset; 74 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ 75 uint32_t crypt_method_header; 76 AES_KEY aes_encrypt_key; 77 AES_KEY aes_decrypt_key; 78 CoMutex lock; 79 Error *migration_blocker; 80 } BDRVQcowState; 81 82 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 83 84 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) 85 { 86 const QCowHeader *cow_header = (const void *)buf; 87 88 if (buf_size >= sizeof(QCowHeader) && 89 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 90 be32_to_cpu(cow_header->version) == QCOW_VERSION) 91 return 100; 92 else 93 return 0; 94 } 95 96 static int qcow_open(BlockDriverState *bs, QDict *options, int flags, 97 Error **errp) 98 { 99 BDRVQcowState *s = bs->opaque; 100 unsigned int len, i, shift; 101 int ret; 102 QCowHeader header; 103 104 ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); 105 if (ret < 0) { 106 goto fail; 107 } 108 be32_to_cpus(&header.magic); 109 be32_to_cpus(&header.version); 110 be64_to_cpus(&header.backing_file_offset); 111 be32_to_cpus(&header.backing_file_size); 112 be32_to_cpus(&header.mtime); 113 be64_to_cpus(&header.size); 114 be32_to_cpus(&header.crypt_method); 115 be64_to_cpus(&header.l1_table_offset); 116 117 if (header.magic != QCOW_MAGIC) { 118 error_setg(errp, "Image not in qcow format"); 119 ret = -EINVAL; 120 goto fail; 121 } 122 if (header.version != QCOW_VERSION) { 123 char version[64]; 124 snprintf(version, sizeof(version), "QCOW version %" PRIu32, 125 header.version); 126 error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, 127 bs->device_name, "qcow", version); 128 ret = -ENOTSUP; 129 goto fail; 130 } 131 132 if (header.size <= 1) { 133 error_setg(errp, "Image size is too small (must be at least 2 bytes)"); 134 ret = -EINVAL; 135 goto fail; 136 } 137 if (header.cluster_bits < 9 || header.cluster_bits > 16) { 138 error_setg(errp, "Cluster size must be between 512 and 64k"); 139 ret = -EINVAL; 140 goto fail; 141 } 142 143 /* l2_bits specifies number of entries; storing a uint64_t in each entry, 144 * so bytes = num_entries << 3. */ 145 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) { 146 error_setg(errp, "L2 table size must be between 512 and 64k"); 147 ret = -EINVAL; 148 goto fail; 149 } 150 151 if (header.crypt_method > QCOW_CRYPT_AES) { 152 error_setg(errp, "invalid encryption method in qcow header"); 153 ret = -EINVAL; 154 goto fail; 155 } 156 s->crypt_method_header = header.crypt_method; 157 if (s->crypt_method_header) { 158 bs->encrypted = 1; 159 } 160 s->cluster_bits = header.cluster_bits; 161 s->cluster_size = 1 << s->cluster_bits; 162 s->cluster_sectors = 1 << (s->cluster_bits - 9); 163 s->l2_bits = header.l2_bits; 164 s->l2_size = 1 << s->l2_bits; 165 bs->total_sectors = header.size / 512; 166 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; 167 168 /* read the level 1 table */ 169 shift = s->cluster_bits + s->l2_bits; 170 if (header.size > UINT64_MAX - (1LL << shift)) { 171 error_setg(errp, "Image too large"); 172 ret = -EINVAL; 173 goto fail; 174 } else { 175 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift; 176 if (l1_size > INT_MAX / sizeof(uint64_t)) { 177 error_setg(errp, "Image too large"); 178 ret = -EINVAL; 179 goto fail; 180 } 181 s->l1_size = l1_size; 182 } 183 184 s->l1_table_offset = header.l1_table_offset; 185 s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t)); 186 187 ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table, 188 s->l1_size * sizeof(uint64_t)); 189 if (ret < 0) { 190 goto fail; 191 } 192 193 for(i = 0;i < s->l1_size; i++) { 194 be64_to_cpus(&s->l1_table[i]); 195 } 196 /* alloc L2 cache */ 197 s->l2_cache = g_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); 198 s->cluster_cache = g_malloc(s->cluster_size); 199 s->cluster_data = g_malloc(s->cluster_size); 200 s->cluster_cache_offset = -1; 201 202 /* read the backing file name */ 203 if (header.backing_file_offset != 0) { 204 len = header.backing_file_size; 205 if (len > 1023) { 206 error_setg(errp, "Backing file name too long"); 207 ret = -EINVAL; 208 goto fail; 209 } 210 ret = bdrv_pread(bs->file, header.backing_file_offset, 211 bs->backing_file, len); 212 if (ret < 0) { 213 goto fail; 214 } 215 bs->backing_file[len] = '\0'; 216 } 217 218 /* Disable migration when qcow images are used */ 219 error_set(&s->migration_blocker, 220 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 221 "qcow", bs->device_name, "live migration"); 222 migrate_add_blocker(s->migration_blocker); 223 224 qemu_co_mutex_init(&s->lock); 225 return 0; 226 227 fail: 228 g_free(s->l1_table); 229 g_free(s->l2_cache); 230 g_free(s->cluster_cache); 231 g_free(s->cluster_data); 232 return ret; 233 } 234 235 236 /* We have nothing to do for QCOW reopen, stubs just return 237 * success */ 238 static int qcow_reopen_prepare(BDRVReopenState *state, 239 BlockReopenQueue *queue, Error **errp) 240 { 241 return 0; 242 } 243 244 static int qcow_set_key(BlockDriverState *bs, const char *key) 245 { 246 BDRVQcowState *s = bs->opaque; 247 uint8_t keybuf[16]; 248 int len, i; 249 250 memset(keybuf, 0, 16); 251 len = strlen(key); 252 if (len > 16) 253 len = 16; 254 /* XXX: we could compress the chars to 7 bits to increase 255 entropy */ 256 for(i = 0;i < len;i++) { 257 keybuf[i] = key[i]; 258 } 259 s->crypt_method = s->crypt_method_header; 260 261 if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) 262 return -1; 263 if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) 264 return -1; 265 return 0; 266 } 267 268 /* The crypt function is compatible with the linux cryptoloop 269 algorithm for < 4 GB images. NOTE: out_buf == in_buf is 270 supported */ 271 static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 272 uint8_t *out_buf, const uint8_t *in_buf, 273 int nb_sectors, int enc, 274 const AES_KEY *key) 275 { 276 union { 277 uint64_t ll[2]; 278 uint8_t b[16]; 279 } ivec; 280 int i; 281 282 for(i = 0; i < nb_sectors; i++) { 283 ivec.ll[0] = cpu_to_le64(sector_num); 284 ivec.ll[1] = 0; 285 AES_cbc_encrypt(in_buf, out_buf, 512, key, 286 ivec.b, enc); 287 sector_num++; 288 in_buf += 512; 289 out_buf += 512; 290 } 291 } 292 293 /* 'allocate' is: 294 * 295 * 0 to not allocate. 296 * 297 * 1 to allocate a normal cluster (for sector indexes 'n_start' to 298 * 'n_end') 299 * 300 * 2 to allocate a compressed cluster of size 301 * 'compressed_size'. 'compressed_size' must be > 0 and < 302 * cluster_size 303 * 304 * return 0 if not allocated. 305 */ 306 static uint64_t get_cluster_offset(BlockDriverState *bs, 307 uint64_t offset, int allocate, 308 int compressed_size, 309 int n_start, int n_end) 310 { 311 BDRVQcowState *s = bs->opaque; 312 int min_index, i, j, l1_index, l2_index; 313 uint64_t l2_offset, *l2_table, cluster_offset, tmp; 314 uint32_t min_count; 315 int new_l2_table; 316 317 l1_index = offset >> (s->l2_bits + s->cluster_bits); 318 l2_offset = s->l1_table[l1_index]; 319 new_l2_table = 0; 320 if (!l2_offset) { 321 if (!allocate) 322 return 0; 323 /* allocate a new l2 entry */ 324 l2_offset = bdrv_getlength(bs->file); 325 /* round to cluster size */ 326 l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); 327 /* update the L1 entry */ 328 s->l1_table[l1_index] = l2_offset; 329 tmp = cpu_to_be64(l2_offset); 330 if (bdrv_pwrite_sync(bs->file, 331 s->l1_table_offset + l1_index * sizeof(tmp), 332 &tmp, sizeof(tmp)) < 0) 333 return 0; 334 new_l2_table = 1; 335 } 336 for(i = 0; i < L2_CACHE_SIZE; i++) { 337 if (l2_offset == s->l2_cache_offsets[i]) { 338 /* increment the hit count */ 339 if (++s->l2_cache_counts[i] == 0xffffffff) { 340 for(j = 0; j < L2_CACHE_SIZE; j++) { 341 s->l2_cache_counts[j] >>= 1; 342 } 343 } 344 l2_table = s->l2_cache + (i << s->l2_bits); 345 goto found; 346 } 347 } 348 /* not found: load a new entry in the least used one */ 349 min_index = 0; 350 min_count = 0xffffffff; 351 for(i = 0; i < L2_CACHE_SIZE; i++) { 352 if (s->l2_cache_counts[i] < min_count) { 353 min_count = s->l2_cache_counts[i]; 354 min_index = i; 355 } 356 } 357 l2_table = s->l2_cache + (min_index << s->l2_bits); 358 if (new_l2_table) { 359 memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); 360 if (bdrv_pwrite_sync(bs->file, l2_offset, l2_table, 361 s->l2_size * sizeof(uint64_t)) < 0) 362 return 0; 363 } else { 364 if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) != 365 s->l2_size * sizeof(uint64_t)) 366 return 0; 367 } 368 s->l2_cache_offsets[min_index] = l2_offset; 369 s->l2_cache_counts[min_index] = 1; 370 found: 371 l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1); 372 cluster_offset = be64_to_cpu(l2_table[l2_index]); 373 if (!cluster_offset || 374 ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) { 375 if (!allocate) 376 return 0; 377 /* allocate a new cluster */ 378 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) && 379 (n_end - n_start) < s->cluster_sectors) { 380 /* if the cluster is already compressed, we must 381 decompress it in the case it is not completely 382 overwritten */ 383 if (decompress_cluster(bs, cluster_offset) < 0) 384 return 0; 385 cluster_offset = bdrv_getlength(bs->file); 386 cluster_offset = (cluster_offset + s->cluster_size - 1) & 387 ~(s->cluster_size - 1); 388 /* write the cluster content */ 389 if (bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache, s->cluster_size) != 390 s->cluster_size) 391 return -1; 392 } else { 393 cluster_offset = bdrv_getlength(bs->file); 394 if (allocate == 1) { 395 /* round to cluster size */ 396 cluster_offset = (cluster_offset + s->cluster_size - 1) & 397 ~(s->cluster_size - 1); 398 bdrv_truncate(bs->file, cluster_offset + s->cluster_size); 399 /* if encrypted, we must initialize the cluster 400 content which won't be written */ 401 if (s->crypt_method && 402 (n_end - n_start) < s->cluster_sectors) { 403 uint64_t start_sect; 404 start_sect = (offset & ~(s->cluster_size - 1)) >> 9; 405 memset(s->cluster_data + 512, 0x00, 512); 406 for(i = 0; i < s->cluster_sectors; i++) { 407 if (i < n_start || i >= n_end) { 408 encrypt_sectors(s, start_sect + i, 409 s->cluster_data, 410 s->cluster_data + 512, 1, 1, 411 &s->aes_encrypt_key); 412 if (bdrv_pwrite(bs->file, cluster_offset + i * 512, 413 s->cluster_data, 512) != 512) 414 return -1; 415 } 416 } 417 } 418 } else if (allocate == 2) { 419 cluster_offset |= QCOW_OFLAG_COMPRESSED | 420 (uint64_t)compressed_size << (63 - s->cluster_bits); 421 } 422 } 423 /* update L2 table */ 424 tmp = cpu_to_be64(cluster_offset); 425 l2_table[l2_index] = tmp; 426 if (bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), 427 &tmp, sizeof(tmp)) < 0) 428 return 0; 429 } 430 return cluster_offset; 431 } 432 433 static int64_t coroutine_fn qcow_co_get_block_status(BlockDriverState *bs, 434 int64_t sector_num, int nb_sectors, int *pnum) 435 { 436 BDRVQcowState *s = bs->opaque; 437 int index_in_cluster, n; 438 uint64_t cluster_offset; 439 440 qemu_co_mutex_lock(&s->lock); 441 cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); 442 qemu_co_mutex_unlock(&s->lock); 443 index_in_cluster = sector_num & (s->cluster_sectors - 1); 444 n = s->cluster_sectors - index_in_cluster; 445 if (n > nb_sectors) 446 n = nb_sectors; 447 *pnum = n; 448 if (!cluster_offset) { 449 return 0; 450 } 451 if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypt_method) { 452 return BDRV_BLOCK_DATA; 453 } 454 cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); 455 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | cluster_offset; 456 } 457 458 static int decompress_buffer(uint8_t *out_buf, int out_buf_size, 459 const uint8_t *buf, int buf_size) 460 { 461 z_stream strm1, *strm = &strm1; 462 int ret, out_len; 463 464 memset(strm, 0, sizeof(*strm)); 465 466 strm->next_in = (uint8_t *)buf; 467 strm->avail_in = buf_size; 468 strm->next_out = out_buf; 469 strm->avail_out = out_buf_size; 470 471 ret = inflateInit2(strm, -12); 472 if (ret != Z_OK) 473 return -1; 474 ret = inflate(strm, Z_FINISH); 475 out_len = strm->next_out - out_buf; 476 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || 477 out_len != out_buf_size) { 478 inflateEnd(strm); 479 return -1; 480 } 481 inflateEnd(strm); 482 return 0; 483 } 484 485 static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) 486 { 487 BDRVQcowState *s = bs->opaque; 488 int ret, csize; 489 uint64_t coffset; 490 491 coffset = cluster_offset & s->cluster_offset_mask; 492 if (s->cluster_cache_offset != coffset) { 493 csize = cluster_offset >> (63 - s->cluster_bits); 494 csize &= (s->cluster_size - 1); 495 ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize); 496 if (ret != csize) 497 return -1; 498 if (decompress_buffer(s->cluster_cache, s->cluster_size, 499 s->cluster_data, csize) < 0) { 500 return -1; 501 } 502 s->cluster_cache_offset = coffset; 503 } 504 return 0; 505 } 506 507 static coroutine_fn int qcow_co_readv(BlockDriverState *bs, int64_t sector_num, 508 int nb_sectors, QEMUIOVector *qiov) 509 { 510 BDRVQcowState *s = bs->opaque; 511 int index_in_cluster; 512 int ret = 0, n; 513 uint64_t cluster_offset; 514 struct iovec hd_iov; 515 QEMUIOVector hd_qiov; 516 uint8_t *buf; 517 void *orig_buf; 518 519 if (qiov->niov > 1) { 520 buf = orig_buf = qemu_blockalign(bs, qiov->size); 521 } else { 522 orig_buf = NULL; 523 buf = (uint8_t *)qiov->iov->iov_base; 524 } 525 526 qemu_co_mutex_lock(&s->lock); 527 528 while (nb_sectors != 0) { 529 /* prepare next request */ 530 cluster_offset = get_cluster_offset(bs, sector_num << 9, 531 0, 0, 0, 0); 532 index_in_cluster = sector_num & (s->cluster_sectors - 1); 533 n = s->cluster_sectors - index_in_cluster; 534 if (n > nb_sectors) { 535 n = nb_sectors; 536 } 537 538 if (!cluster_offset) { 539 if (bs->backing_hd) { 540 /* read from the base image */ 541 hd_iov.iov_base = (void *)buf; 542 hd_iov.iov_len = n * 512; 543 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); 544 qemu_co_mutex_unlock(&s->lock); 545 ret = bdrv_co_readv(bs->backing_hd, sector_num, 546 n, &hd_qiov); 547 qemu_co_mutex_lock(&s->lock); 548 if (ret < 0) { 549 goto fail; 550 } 551 } else { 552 /* Note: in this case, no need to wait */ 553 memset(buf, 0, 512 * n); 554 } 555 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { 556 /* add AIO support for compressed blocks ? */ 557 if (decompress_cluster(bs, cluster_offset) < 0) { 558 goto fail; 559 } 560 memcpy(buf, 561 s->cluster_cache + index_in_cluster * 512, 512 * n); 562 } else { 563 if ((cluster_offset & 511) != 0) { 564 goto fail; 565 } 566 hd_iov.iov_base = (void *)buf; 567 hd_iov.iov_len = n * 512; 568 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); 569 qemu_co_mutex_unlock(&s->lock); 570 ret = bdrv_co_readv(bs->file, 571 (cluster_offset >> 9) + index_in_cluster, 572 n, &hd_qiov); 573 qemu_co_mutex_lock(&s->lock); 574 if (ret < 0) { 575 break; 576 } 577 if (s->crypt_method) { 578 encrypt_sectors(s, sector_num, buf, buf, 579 n, 0, 580 &s->aes_decrypt_key); 581 } 582 } 583 ret = 0; 584 585 nb_sectors -= n; 586 sector_num += n; 587 buf += n * 512; 588 } 589 590 done: 591 qemu_co_mutex_unlock(&s->lock); 592 593 if (qiov->niov > 1) { 594 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size); 595 qemu_vfree(orig_buf); 596 } 597 598 return ret; 599 600 fail: 601 ret = -EIO; 602 goto done; 603 } 604 605 static coroutine_fn int qcow_co_writev(BlockDriverState *bs, int64_t sector_num, 606 int nb_sectors, QEMUIOVector *qiov) 607 { 608 BDRVQcowState *s = bs->opaque; 609 int index_in_cluster; 610 uint64_t cluster_offset; 611 const uint8_t *src_buf; 612 int ret = 0, n; 613 uint8_t *cluster_data = NULL; 614 struct iovec hd_iov; 615 QEMUIOVector hd_qiov; 616 uint8_t *buf; 617 void *orig_buf; 618 619 s->cluster_cache_offset = -1; /* disable compressed cache */ 620 621 if (qiov->niov > 1) { 622 buf = orig_buf = qemu_blockalign(bs, qiov->size); 623 qemu_iovec_to_buf(qiov, 0, buf, qiov->size); 624 } else { 625 orig_buf = NULL; 626 buf = (uint8_t *)qiov->iov->iov_base; 627 } 628 629 qemu_co_mutex_lock(&s->lock); 630 631 while (nb_sectors != 0) { 632 633 index_in_cluster = sector_num & (s->cluster_sectors - 1); 634 n = s->cluster_sectors - index_in_cluster; 635 if (n > nb_sectors) { 636 n = nb_sectors; 637 } 638 cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, 639 index_in_cluster, 640 index_in_cluster + n); 641 if (!cluster_offset || (cluster_offset & 511) != 0) { 642 ret = -EIO; 643 break; 644 } 645 if (s->crypt_method) { 646 if (!cluster_data) { 647 cluster_data = g_malloc0(s->cluster_size); 648 } 649 encrypt_sectors(s, sector_num, cluster_data, buf, 650 n, 1, &s->aes_encrypt_key); 651 src_buf = cluster_data; 652 } else { 653 src_buf = buf; 654 } 655 656 hd_iov.iov_base = (void *)src_buf; 657 hd_iov.iov_len = n * 512; 658 qemu_iovec_init_external(&hd_qiov, &hd_iov, 1); 659 qemu_co_mutex_unlock(&s->lock); 660 ret = bdrv_co_writev(bs->file, 661 (cluster_offset >> 9) + index_in_cluster, 662 n, &hd_qiov); 663 qemu_co_mutex_lock(&s->lock); 664 if (ret < 0) { 665 break; 666 } 667 ret = 0; 668 669 nb_sectors -= n; 670 sector_num += n; 671 buf += n * 512; 672 } 673 qemu_co_mutex_unlock(&s->lock); 674 675 if (qiov->niov > 1) { 676 qemu_vfree(orig_buf); 677 } 678 g_free(cluster_data); 679 680 return ret; 681 } 682 683 static void qcow_close(BlockDriverState *bs) 684 { 685 BDRVQcowState *s = bs->opaque; 686 687 g_free(s->l1_table); 688 g_free(s->l2_cache); 689 g_free(s->cluster_cache); 690 g_free(s->cluster_data); 691 692 migrate_del_blocker(s->migration_blocker); 693 error_free(s->migration_blocker); 694 } 695 696 static int qcow_create(const char *filename, QemuOpts *opts, Error **errp) 697 { 698 int header_size, backing_filename_len, l1_size, shift, i; 699 QCowHeader header; 700 uint8_t *tmp; 701 int64_t total_size = 0; 702 char *backing_file = NULL; 703 int flags = 0; 704 Error *local_err = NULL; 705 int ret; 706 BlockDriverState *qcow_bs; 707 708 /* Read out options */ 709 total_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0) / 512; 710 backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 711 if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { 712 flags |= BLOCK_FLAG_ENCRYPT; 713 } 714 715 ret = bdrv_create_file(filename, opts, &local_err); 716 if (ret < 0) { 717 error_propagate(errp, local_err); 718 goto cleanup; 719 } 720 721 qcow_bs = NULL; 722 ret = bdrv_open(&qcow_bs, filename, NULL, NULL, 723 BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err); 724 if (ret < 0) { 725 error_propagate(errp, local_err); 726 goto cleanup; 727 } 728 729 ret = bdrv_truncate(qcow_bs, 0); 730 if (ret < 0) { 731 goto exit; 732 } 733 734 memset(&header, 0, sizeof(header)); 735 header.magic = cpu_to_be32(QCOW_MAGIC); 736 header.version = cpu_to_be32(QCOW_VERSION); 737 header.size = cpu_to_be64(total_size * 512); 738 header_size = sizeof(header); 739 backing_filename_len = 0; 740 if (backing_file) { 741 if (strcmp(backing_file, "fat:")) { 742 header.backing_file_offset = cpu_to_be64(header_size); 743 backing_filename_len = strlen(backing_file); 744 header.backing_file_size = cpu_to_be32(backing_filename_len); 745 header_size += backing_filename_len; 746 } else { 747 /* special backing file for vvfat */ 748 backing_file = NULL; 749 } 750 header.cluster_bits = 9; /* 512 byte cluster to avoid copying 751 unmodified sectors */ 752 header.l2_bits = 12; /* 32 KB L2 tables */ 753 } else { 754 header.cluster_bits = 12; /* 4 KB clusters */ 755 header.l2_bits = 9; /* 4 KB L2 tables */ 756 } 757 header_size = (header_size + 7) & ~7; 758 shift = header.cluster_bits + header.l2_bits; 759 l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; 760 761 header.l1_table_offset = cpu_to_be64(header_size); 762 if (flags & BLOCK_FLAG_ENCRYPT) { 763 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); 764 } else { 765 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 766 } 767 768 /* write all the data */ 769 ret = bdrv_pwrite(qcow_bs, 0, &header, sizeof(header)); 770 if (ret != sizeof(header)) { 771 goto exit; 772 } 773 774 if (backing_file) { 775 ret = bdrv_pwrite(qcow_bs, sizeof(header), 776 backing_file, backing_filename_len); 777 if (ret != backing_filename_len) { 778 goto exit; 779 } 780 } 781 782 tmp = g_malloc0(BDRV_SECTOR_SIZE); 783 for (i = 0; i < ((sizeof(uint64_t)*l1_size + BDRV_SECTOR_SIZE - 1)/ 784 BDRV_SECTOR_SIZE); i++) { 785 ret = bdrv_pwrite(qcow_bs, header_size + 786 BDRV_SECTOR_SIZE*i, tmp, BDRV_SECTOR_SIZE); 787 if (ret != BDRV_SECTOR_SIZE) { 788 g_free(tmp); 789 goto exit; 790 } 791 } 792 793 g_free(tmp); 794 ret = 0; 795 exit: 796 bdrv_unref(qcow_bs); 797 cleanup: 798 g_free(backing_file); 799 return ret; 800 } 801 802 static int qcow_make_empty(BlockDriverState *bs) 803 { 804 BDRVQcowState *s = bs->opaque; 805 uint32_t l1_length = s->l1_size * sizeof(uint64_t); 806 int ret; 807 808 memset(s->l1_table, 0, l1_length); 809 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table, 810 l1_length) < 0) 811 return -1; 812 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length); 813 if (ret < 0) 814 return ret; 815 816 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); 817 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); 818 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); 819 820 return 0; 821 } 822 823 /* XXX: put compressed sectors first, then all the cluster aligned 824 tables to avoid losing bytes in alignment */ 825 static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, 826 const uint8_t *buf, int nb_sectors) 827 { 828 BDRVQcowState *s = bs->opaque; 829 z_stream strm; 830 int ret, out_len; 831 uint8_t *out_buf; 832 uint64_t cluster_offset; 833 834 if (nb_sectors != s->cluster_sectors) { 835 ret = -EINVAL; 836 837 /* Zero-pad last write if image size is not cluster aligned */ 838 if (sector_num + nb_sectors == bs->total_sectors && 839 nb_sectors < s->cluster_sectors) { 840 uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); 841 memset(pad_buf, 0, s->cluster_size); 842 memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); 843 ret = qcow_write_compressed(bs, sector_num, 844 pad_buf, s->cluster_sectors); 845 qemu_vfree(pad_buf); 846 } 847 return ret; 848 } 849 850 out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); 851 852 /* best compression, small window, no zlib header */ 853 memset(&strm, 0, sizeof(strm)); 854 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, 855 Z_DEFLATED, -12, 856 9, Z_DEFAULT_STRATEGY); 857 if (ret != 0) { 858 ret = -EINVAL; 859 goto fail; 860 } 861 862 strm.avail_in = s->cluster_size; 863 strm.next_in = (uint8_t *)buf; 864 strm.avail_out = s->cluster_size; 865 strm.next_out = out_buf; 866 867 ret = deflate(&strm, Z_FINISH); 868 if (ret != Z_STREAM_END && ret != Z_OK) { 869 deflateEnd(&strm); 870 ret = -EINVAL; 871 goto fail; 872 } 873 out_len = strm.next_out - out_buf; 874 875 deflateEnd(&strm); 876 877 if (ret != Z_STREAM_END || out_len >= s->cluster_size) { 878 /* could not compress: write normal cluster */ 879 ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); 880 if (ret < 0) { 881 goto fail; 882 } 883 } else { 884 cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, 885 out_len, 0, 0); 886 if (cluster_offset == 0) { 887 ret = -EIO; 888 goto fail; 889 } 890 891 cluster_offset &= s->cluster_offset_mask; 892 ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); 893 if (ret < 0) { 894 goto fail; 895 } 896 } 897 898 ret = 0; 899 fail: 900 g_free(out_buf); 901 return ret; 902 } 903 904 static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 905 { 906 BDRVQcowState *s = bs->opaque; 907 bdi->cluster_size = s->cluster_size; 908 return 0; 909 } 910 911 static QemuOptsList qcow_create_opts = { 912 .name = "qcow-create-opts", 913 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head), 914 .desc = { 915 { 916 .name = BLOCK_OPT_SIZE, 917 .type = QEMU_OPT_SIZE, 918 .help = "Virtual disk size" 919 }, 920 { 921 .name = BLOCK_OPT_BACKING_FILE, 922 .type = QEMU_OPT_STRING, 923 .help = "File name of a base image" 924 }, 925 { 926 .name = BLOCK_OPT_ENCRYPT, 927 .type = QEMU_OPT_BOOL, 928 .help = "Encrypt the image", 929 .def_value_str = "off" 930 }, 931 { /* end of list */ } 932 } 933 }; 934 935 static BlockDriver bdrv_qcow = { 936 .format_name = "qcow", 937 .instance_size = sizeof(BDRVQcowState), 938 .bdrv_probe = qcow_probe, 939 .bdrv_open = qcow_open, 940 .bdrv_close = qcow_close, 941 .bdrv_reopen_prepare = qcow_reopen_prepare, 942 .bdrv_create = qcow_create, 943 .bdrv_has_zero_init = bdrv_has_zero_init_1, 944 .supports_backing = true, 945 946 .bdrv_co_readv = qcow_co_readv, 947 .bdrv_co_writev = qcow_co_writev, 948 .bdrv_co_get_block_status = qcow_co_get_block_status, 949 950 .bdrv_set_key = qcow_set_key, 951 .bdrv_make_empty = qcow_make_empty, 952 .bdrv_write_compressed = qcow_write_compressed, 953 .bdrv_get_info = qcow_get_info, 954 955 .create_opts = &qcow_create_opts, 956 }; 957 958 static void bdrv_qcow_init(void) 959 { 960 bdrv_register(&bdrv_qcow); 961 } 962 963 block_init(bdrv_qcow_init); 964