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 coroutine_fn GRAPH_RDLOCK 96 decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 97 98 static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) 99 { 100 const QCowHeader *cow_header = (const void *)buf; 101 102 if (buf_size >= sizeof(QCowHeader) && 103 be32_to_cpu(cow_header->magic) == QCOW_MAGIC && 104 be32_to_cpu(cow_header->version) == QCOW_VERSION) 105 return 100; 106 else 107 return 0; 108 } 109 110 static int qcow_open(BlockDriverState *bs, QDict *options, int flags, 111 Error **errp) 112 { 113 BDRVQcowState *s = bs->opaque; 114 unsigned int len, i, shift; 115 int ret; 116 QCowHeader header; 117 QCryptoBlockOpenOptions *crypto_opts = NULL; 118 unsigned int cflags = 0; 119 QDict *encryptopts = NULL; 120 const char *encryptfmt; 121 122 qdict_extract_subqdict(options, &encryptopts, "encrypt."); 123 encryptfmt = qdict_get_try_str(encryptopts, "format"); 124 125 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 126 if (ret < 0) { 127 goto fail; 128 } 129 130 ret = bdrv_pread(bs->file, 0, sizeof(header), &header, 0); 131 if (ret < 0) { 132 goto fail; 133 } 134 header.magic = be32_to_cpu(header.magic); 135 header.version = be32_to_cpu(header.version); 136 header.backing_file_offset = be64_to_cpu(header.backing_file_offset); 137 header.backing_file_size = be32_to_cpu(header.backing_file_size); 138 header.mtime = be32_to_cpu(header.mtime); 139 header.size = be64_to_cpu(header.size); 140 header.crypt_method = be32_to_cpu(header.crypt_method); 141 header.l1_table_offset = be64_to_cpu(header.l1_table_offset); 142 143 if (header.magic != QCOW_MAGIC) { 144 error_setg(errp, "Image not in qcow format"); 145 ret = -EINVAL; 146 goto fail; 147 } 148 if (header.version != QCOW_VERSION) { 149 error_setg(errp, "qcow (v%d) does not support qcow version %" PRIu32, 150 QCOW_VERSION, header.version); 151 if (header.version == 2 || header.version == 3) { 152 error_append_hint(errp, "Try the 'qcow2' driver instead.\n"); 153 } 154 155 ret = -ENOTSUP; 156 goto fail; 157 } 158 159 if (header.size <= 1) { 160 error_setg(errp, "Image size is too small (must be at least 2 bytes)"); 161 ret = -EINVAL; 162 goto fail; 163 } 164 if (header.cluster_bits < 9 || header.cluster_bits > 16) { 165 error_setg(errp, "Cluster size must be between 512 and 64k"); 166 ret = -EINVAL; 167 goto fail; 168 } 169 170 /* l2_bits specifies number of entries; storing a uint64_t in each entry, 171 * so bytes = num_entries << 3. */ 172 if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) { 173 error_setg(errp, "L2 table size must be between 512 and 64k"); 174 ret = -EINVAL; 175 goto fail; 176 } 177 178 s->crypt_method_header = header.crypt_method; 179 if (s->crypt_method_header) { 180 if (bdrv_uses_whitelist() && 181 s->crypt_method_header == QCOW_CRYPT_AES) { 182 error_setg(errp, 183 "Use of AES-CBC encrypted qcow images is no longer " 184 "supported in system emulators"); 185 error_append_hint(errp, 186 "You can use 'qemu-img convert' to convert your " 187 "image to an alternative supported format, such " 188 "as unencrypted qcow, or raw with the LUKS " 189 "format instead.\n"); 190 ret = -ENOSYS; 191 goto fail; 192 } 193 if (s->crypt_method_header == QCOW_CRYPT_AES) { 194 if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { 195 error_setg(errp, 196 "Header reported 'aes' encryption format but " 197 "options specify '%s'", encryptfmt); 198 ret = -EINVAL; 199 goto fail; 200 } 201 qdict_put_str(encryptopts, "format", "qcow"); 202 crypto_opts = block_crypto_open_opts_init(encryptopts, errp); 203 if (!crypto_opts) { 204 ret = -EINVAL; 205 goto fail; 206 } 207 208 if (flags & BDRV_O_NO_IO) { 209 cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; 210 } 211 s->crypto = qcrypto_block_open(crypto_opts, "encrypt.", 212 NULL, NULL, cflags, 1, errp); 213 if (!s->crypto) { 214 ret = -EINVAL; 215 goto fail; 216 } 217 } else { 218 error_setg(errp, "invalid encryption method in qcow header"); 219 ret = -EINVAL; 220 goto fail; 221 } 222 bs->encrypted = true; 223 } else { 224 if (encryptfmt) { 225 error_setg(errp, "No encryption in image header, but options " 226 "specified format '%s'", encryptfmt); 227 ret = -EINVAL; 228 goto fail; 229 } 230 } 231 s->cluster_bits = header.cluster_bits; 232 s->cluster_size = 1 << s->cluster_bits; 233 s->l2_bits = header.l2_bits; 234 s->l2_size = 1 << s->l2_bits; 235 bs->total_sectors = header.size / 512; 236 s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; 237 238 /* read the level 1 table */ 239 shift = s->cluster_bits + s->l2_bits; 240 if (header.size > UINT64_MAX - (1LL << shift)) { 241 error_setg(errp, "Image too large"); 242 ret = -EINVAL; 243 goto fail; 244 } else { 245 uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift; 246 if (l1_size > INT_MAX / sizeof(uint64_t)) { 247 error_setg(errp, "Image too large"); 248 ret = -EINVAL; 249 goto fail; 250 } 251 s->l1_size = l1_size; 252 } 253 254 s->l1_table_offset = header.l1_table_offset; 255 s->l1_table = g_try_new(uint64_t, s->l1_size); 256 if (s->l1_table == NULL) { 257 error_setg(errp, "Could not allocate memory for L1 table"); 258 ret = -ENOMEM; 259 goto fail; 260 } 261 262 ret = bdrv_pread(bs->file, s->l1_table_offset, 263 s->l1_size * sizeof(uint64_t), s->l1_table, 0); 264 if (ret < 0) { 265 goto fail; 266 } 267 268 for(i = 0;i < s->l1_size; i++) { 269 s->l1_table[i] = be64_to_cpu(s->l1_table[i]); 270 } 271 272 /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */ 273 s->l2_cache = 274 qemu_try_blockalign(bs->file->bs, 275 s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); 276 if (s->l2_cache == NULL) { 277 error_setg(errp, "Could not allocate L2 table cache"); 278 ret = -ENOMEM; 279 goto fail; 280 } 281 s->cluster_cache = g_malloc(s->cluster_size); 282 s->cluster_data = g_malloc(s->cluster_size); 283 s->cluster_cache_offset = -1; 284 285 /* read the backing file name */ 286 if (header.backing_file_offset != 0) { 287 len = header.backing_file_size; 288 if (len > 1023 || len >= sizeof(bs->backing_file)) { 289 error_setg(errp, "Backing file name too long"); 290 ret = -EINVAL; 291 goto fail; 292 } 293 ret = bdrv_pread(bs->file, header.backing_file_offset, len, 294 bs->auto_backing_file, 0); 295 if (ret < 0) { 296 goto fail; 297 } 298 bs->auto_backing_file[len] = '\0'; 299 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 300 bs->auto_backing_file); 301 } 302 303 /* Disable migration when qcow images are used */ 304 bdrv_graph_rdlock_main_loop(); 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 bdrv_graph_rdunlock_main_loop(); 309 310 ret = migrate_add_blocker(s->migration_blocker, errp); 311 if (ret < 0) { 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 coroutine_fn GRAPH_RDLOCK 357 get_cluster_offset(BlockDriverState *bs, uint64_t offset, int allocate, 358 int compressed_size, int n_start, int n_end, 359 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_co_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_CO_EVENT(bs->file, BLKDBG_L1_UPDATE); 386 ret = bdrv_co_pwrite_sync(bs->file, 387 s->l1_table_offset + l1_index * sizeof(tmp), 388 sizeof(tmp), &tmp, 0); 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_CO_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_co_pwrite_sync(bs->file, l2_offset, 420 s->l2_size * sizeof(uint64_t), l2_table, 0); 421 if (ret < 0) { 422 return ret; 423 } 424 } else { 425 ret = bdrv_co_pread(bs->file, l2_offset, 426 s->l2_size * sizeof(uint64_t), l2_table, 0); 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_CO_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_co_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_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 458 ret = bdrv_co_pwrite(bs->file, cluster_offset, s->cluster_size, 459 s->cluster_cache, 0); 460 if (ret < 0) { 461 return ret; 462 } 463 } else { 464 cluster_offset = bdrv_co_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_co_truncate(bs->file, 475 cluster_offset + s->cluster_size, 476 false, PREALLOC_MODE_OFF, 0, NULL); 477 if (ret < 0) { 478 return ret; 479 } 480 /* if encrypted, we must initialize the cluster 481 content which won't be written */ 482 if (bs->encrypted && 483 (n_end - n_start) < s->cluster_size) { 484 uint64_t start_offset; 485 assert(s->crypto); 486 start_offset = offset & ~(s->cluster_size - 1); 487 for (i = 0; i < s->cluster_size; i += BDRV_SECTOR_SIZE) { 488 if (i < n_start || i >= n_end) { 489 memset(s->cluster_data, 0x00, BDRV_SECTOR_SIZE); 490 if (qcrypto_block_encrypt(s->crypto, 491 start_offset + i, 492 s->cluster_data, 493 BDRV_SECTOR_SIZE, 494 NULL) < 0) { 495 return -EIO; 496 } 497 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 498 ret = bdrv_co_pwrite(bs->file, cluster_offset + i, 499 BDRV_SECTOR_SIZE, 500 s->cluster_data, 0); 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_CO_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED); 517 } else { 518 BLKDBG_CO_EVENT(bs->file, BLKDBG_L2_UPDATE); 519 } 520 ret = bdrv_co_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp), 521 sizeof(tmp), &tmp, 0); 522 if (ret < 0) { 523 return ret; 524 } 525 } 526 *result = cluster_offset; 527 return 1; 528 } 529 530 static int coroutine_fn GRAPH_RDLOCK 531 qcow_co_block_status(BlockDriverState *bs, bool want_zero, 532 int64_t offset, int64_t bytes, int64_t *pnum, 533 int64_t *map, BlockDriverState **file) 534 { 535 BDRVQcowState *s = bs->opaque; 536 int index_in_cluster, ret; 537 int64_t n; 538 uint64_t cluster_offset; 539 540 qemu_co_mutex_lock(&s->lock); 541 ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset); 542 qemu_co_mutex_unlock(&s->lock); 543 if (ret < 0) { 544 return ret; 545 } 546 index_in_cluster = offset & (s->cluster_size - 1); 547 n = s->cluster_size - index_in_cluster; 548 if (n > bytes) { 549 n = bytes; 550 } 551 *pnum = n; 552 if (!cluster_offset) { 553 return 0; 554 } 555 if (cluster_offset & QCOW_OFLAG_COMPRESSED) { 556 return BDRV_BLOCK_DATA | BDRV_BLOCK_COMPRESSED; 557 } 558 if (s->crypto) { 559 return BDRV_BLOCK_DATA; 560 } 561 *map = cluster_offset | index_in_cluster; 562 *file = bs->file->bs; 563 return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 564 } 565 566 static int decompress_buffer(uint8_t *out_buf, int out_buf_size, 567 const uint8_t *buf, int buf_size) 568 { 569 z_stream strm1, *strm = &strm1; 570 int ret, out_len; 571 572 memset(strm, 0, sizeof(*strm)); 573 574 strm->next_in = (uint8_t *)buf; 575 strm->avail_in = buf_size; 576 strm->next_out = out_buf; 577 strm->avail_out = out_buf_size; 578 579 ret = inflateInit2(strm, -12); 580 if (ret != Z_OK) 581 return -1; 582 ret = inflate(strm, Z_FINISH); 583 out_len = strm->next_out - out_buf; 584 if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) || 585 out_len != out_buf_size) { 586 inflateEnd(strm); 587 return -1; 588 } 589 inflateEnd(strm); 590 return 0; 591 } 592 593 static int coroutine_fn GRAPH_RDLOCK 594 decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset) 595 { 596 BDRVQcowState *s = bs->opaque; 597 int ret, csize; 598 uint64_t coffset; 599 600 coffset = cluster_offset & s->cluster_offset_mask; 601 if (s->cluster_cache_offset != coffset) { 602 csize = cluster_offset >> (63 - s->cluster_bits); 603 csize &= (s->cluster_size - 1); 604 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_COMPRESSED); 605 ret = bdrv_co_pread(bs->file, coffset, csize, s->cluster_data, 0); 606 if (ret < 0) 607 return -1; 608 if (decompress_buffer(s->cluster_cache, s->cluster_size, 609 s->cluster_data, csize) < 0) { 610 return -1; 611 } 612 s->cluster_cache_offset = coffset; 613 } 614 return 0; 615 } 616 617 static void qcow_refresh_limits(BlockDriverState *bs, Error **errp) 618 { 619 /* At least encrypted images require 512-byte alignment. Apply the 620 * limit universally, rather than just on encrypted images, as 621 * it's easier to let the block layer handle rounding than to 622 * audit this code further. */ 623 bs->bl.request_alignment = BDRV_SECTOR_SIZE; 624 } 625 626 static int coroutine_fn GRAPH_RDLOCK 627 qcow_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 628 QEMUIOVector *qiov, BdrvRequestFlags flags) 629 { 630 BDRVQcowState *s = bs->opaque; 631 int offset_in_cluster; 632 int ret = 0, n; 633 uint64_t cluster_offset; 634 uint8_t *buf; 635 void *orig_buf; 636 637 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 qemu_co_mutex_unlock(&s->lock); 665 /* qcow2 emits this on bs->file instead of bs->backing */ 666 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); 667 ret = bdrv_co_pread(bs->backing, offset, n, buf, 0); 668 qemu_co_mutex_lock(&s->lock); 669 if (ret < 0) { 670 break; 671 } 672 } else { 673 /* Note: in this case, no need to wait */ 674 memset(buf, 0, n); 675 } 676 } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { 677 /* add AIO support for compressed blocks ? */ 678 if (decompress_cluster(bs, cluster_offset) < 0) { 679 ret = -EIO; 680 break; 681 } 682 memcpy(buf, s->cluster_cache + offset_in_cluster, n); 683 } else { 684 if ((cluster_offset & 511) != 0) { 685 ret = -EIO; 686 break; 687 } 688 qemu_co_mutex_unlock(&s->lock); 689 BLKDBG_CO_EVENT(bs->file, BLKDBG_READ_AIO); 690 ret = bdrv_co_pread(bs->file, cluster_offset + offset_in_cluster, 691 n, buf, 0); 692 qemu_co_mutex_lock(&s->lock); 693 if (ret < 0) { 694 break; 695 } 696 if (bs->encrypted) { 697 assert(s->crypto); 698 if (qcrypto_block_decrypt(s->crypto, 699 offset, buf, n, NULL) < 0) { 700 ret = -EIO; 701 break; 702 } 703 } 704 } 705 ret = 0; 706 707 bytes -= n; 708 offset += n; 709 buf += n; 710 } 711 712 qemu_co_mutex_unlock(&s->lock); 713 714 if (qiov->niov > 1) { 715 qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size); 716 qemu_vfree(orig_buf); 717 } 718 719 return ret; 720 } 721 722 static int coroutine_fn GRAPH_RDLOCK 723 qcow_co_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes, 724 QEMUIOVector *qiov, BdrvRequestFlags flags) 725 { 726 BDRVQcowState *s = bs->opaque; 727 int offset_in_cluster; 728 uint64_t cluster_offset; 729 int ret = 0, n; 730 uint8_t *buf; 731 void *orig_buf; 732 733 s->cluster_cache_offset = -1; /* disable compressed cache */ 734 735 /* We must always copy the iov when encrypting, so we 736 * don't modify the original data buffer during encryption */ 737 if (bs->encrypted || qiov->niov > 1) { 738 buf = orig_buf = qemu_try_blockalign(bs, qiov->size); 739 if (buf == NULL) { 740 return -ENOMEM; 741 } 742 qemu_iovec_to_buf(qiov, 0, buf, qiov->size); 743 } else { 744 orig_buf = NULL; 745 buf = (uint8_t *)qiov->iov->iov_base; 746 } 747 748 qemu_co_mutex_lock(&s->lock); 749 750 while (bytes != 0) { 751 offset_in_cluster = offset & (s->cluster_size - 1); 752 n = s->cluster_size - offset_in_cluster; 753 if (n > bytes) { 754 n = bytes; 755 } 756 ret = get_cluster_offset(bs, offset, 1, 0, offset_in_cluster, 757 offset_in_cluster + n, &cluster_offset); 758 if (ret < 0) { 759 break; 760 } 761 if (!cluster_offset || (cluster_offset & 511) != 0) { 762 ret = -EIO; 763 break; 764 } 765 if (bs->encrypted) { 766 assert(s->crypto); 767 if (qcrypto_block_encrypt(s->crypto, offset, buf, n, NULL) < 0) { 768 ret = -EIO; 769 break; 770 } 771 } 772 773 qemu_co_mutex_unlock(&s->lock); 774 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_AIO); 775 ret = bdrv_co_pwrite(bs->file, cluster_offset + offset_in_cluster, 776 n, buf, 0); 777 qemu_co_mutex_lock(&s->lock); 778 if (ret < 0) { 779 break; 780 } 781 ret = 0; 782 783 bytes -= n; 784 offset += n; 785 buf += n; 786 } 787 qemu_co_mutex_unlock(&s->lock); 788 789 qemu_vfree(orig_buf); 790 791 return ret; 792 } 793 794 static void qcow_close(BlockDriverState *bs) 795 { 796 BDRVQcowState *s = bs->opaque; 797 798 qcrypto_block_free(s->crypto); 799 s->crypto = NULL; 800 g_free(s->l1_table); 801 qemu_vfree(s->l2_cache); 802 g_free(s->cluster_cache); 803 g_free(s->cluster_data); 804 805 migrate_del_blocker(s->migration_blocker); 806 error_free(s->migration_blocker); 807 } 808 809 static int coroutine_fn GRAPH_UNLOCKED 810 qcow_co_create(BlockdevCreateOptions *opts, Error **errp) 811 { 812 BlockdevCreateOptionsQcow *qcow_opts; 813 int header_size, backing_filename_len, l1_size, shift, i; 814 QCowHeader header; 815 uint8_t *tmp; 816 int64_t total_size = 0; 817 int ret; 818 BlockDriverState *bs; 819 BlockBackend *qcow_blk; 820 QCryptoBlock *crypto = NULL; 821 822 assert(opts->driver == BLOCKDEV_DRIVER_QCOW); 823 qcow_opts = &opts->u.qcow; 824 825 /* Sanity checks */ 826 total_size = qcow_opts->size; 827 if (total_size == 0) { 828 error_setg(errp, "Image size is too small, cannot be zero length"); 829 return -EINVAL; 830 } 831 832 if (qcow_opts->encrypt && 833 qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW) 834 { 835 error_setg(errp, "Unsupported encryption format"); 836 return -EINVAL; 837 } 838 839 /* Create BlockBackend to write to the image */ 840 bs = bdrv_co_open_blockdev_ref(qcow_opts->file, errp); 841 if (bs == NULL) { 842 return -EIO; 843 } 844 845 qcow_blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, 846 BLK_PERM_ALL, errp); 847 if (!qcow_blk) { 848 ret = -EPERM; 849 goto exit; 850 } 851 blk_set_allow_write_beyond_eof(qcow_blk, true); 852 853 /* Create image format */ 854 memset(&header, 0, sizeof(header)); 855 header.magic = cpu_to_be32(QCOW_MAGIC); 856 header.version = cpu_to_be32(QCOW_VERSION); 857 header.size = cpu_to_be64(total_size); 858 header_size = sizeof(header); 859 backing_filename_len = 0; 860 if (qcow_opts->backing_file) { 861 if (strcmp(qcow_opts->backing_file, "fat:")) { 862 header.backing_file_offset = cpu_to_be64(header_size); 863 backing_filename_len = strlen(qcow_opts->backing_file); 864 header.backing_file_size = cpu_to_be32(backing_filename_len); 865 header_size += backing_filename_len; 866 } else { 867 /* special backing file for vvfat */ 868 qcow_opts->backing_file = NULL; 869 } 870 header.cluster_bits = 9; /* 512 byte cluster to avoid copying 871 unmodified sectors */ 872 header.l2_bits = 12; /* 32 KB L2 tables */ 873 } else { 874 header.cluster_bits = 12; /* 4 KB clusters */ 875 header.l2_bits = 9; /* 4 KB L2 tables */ 876 } 877 header_size = (header_size + 7) & ~7; 878 shift = header.cluster_bits + header.l2_bits; 879 l1_size = (total_size + (1LL << shift) - 1) >> shift; 880 881 header.l1_table_offset = cpu_to_be64(header_size); 882 883 if (qcow_opts->encrypt) { 884 header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); 885 886 crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.", 887 NULL, NULL, NULL, errp); 888 if (!crypto) { 889 ret = -EINVAL; 890 goto exit; 891 } 892 } else { 893 header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); 894 } 895 896 /* write all the data */ 897 ret = blk_co_pwrite(qcow_blk, 0, sizeof(header), &header, 0); 898 if (ret < 0) { 899 goto exit; 900 } 901 902 if (qcow_opts->backing_file) { 903 ret = blk_co_pwrite(qcow_blk, sizeof(header), backing_filename_len, 904 qcow_opts->backing_file, 0); 905 if (ret < 0) { 906 goto exit; 907 } 908 } 909 910 tmp = g_malloc0(BDRV_SECTOR_SIZE); 911 for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE); 912 i++) { 913 ret = blk_co_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i, 914 BDRV_SECTOR_SIZE, tmp, 0); 915 if (ret < 0) { 916 g_free(tmp); 917 goto exit; 918 } 919 } 920 921 g_free(tmp); 922 ret = 0; 923 exit: 924 blk_co_unref(qcow_blk); 925 bdrv_co_unref(bs); 926 qcrypto_block_free(crypto); 927 return ret; 928 } 929 930 static int coroutine_fn GRAPH_UNLOCKED 931 qcow_co_create_opts(BlockDriver *drv, const char *filename, 932 QemuOpts *opts, Error **errp) 933 { 934 BlockdevCreateOptions *create_options = NULL; 935 BlockDriverState *bs = NULL; 936 QDict *qdict = NULL; 937 Visitor *v; 938 const char *val; 939 int ret; 940 char *backing_fmt; 941 942 static const QDictRenames opt_renames[] = { 943 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 944 { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT }, 945 { NULL, NULL }, 946 }; 947 948 /* 949 * We can't actually store a backing format, but can check that 950 * the user's request made sense. 951 */ 952 backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT); 953 if (backing_fmt && !bdrv_find_format(backing_fmt)) { 954 error_setg(errp, "unrecognized backing format '%s'", backing_fmt); 955 ret = -EINVAL; 956 goto fail; 957 } 958 959 /* Parse options and convert legacy syntax */ 960 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true); 961 962 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT); 963 if (val && !strcmp(val, "on")) { 964 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow"); 965 } else if (val && !strcmp(val, "off")) { 966 qdict_del(qdict, BLOCK_OPT_ENCRYPT); 967 } 968 969 val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT); 970 if (val && !strcmp(val, "aes")) { 971 qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow"); 972 } 973 974 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 975 ret = -EINVAL; 976 goto fail; 977 } 978 979 /* Create and open the file (protocol layer) */ 980 ret = bdrv_co_create_file(filename, opts, errp); 981 if (ret < 0) { 982 goto fail; 983 } 984 985 bs = bdrv_co_open(filename, NULL, NULL, 986 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 987 if (bs == NULL) { 988 ret = -EIO; 989 goto fail; 990 } 991 992 /* Now get the QAPI type BlockdevCreateOptions */ 993 qdict_put_str(qdict, "driver", "qcow"); 994 qdict_put_str(qdict, "file", bs->node_name); 995 996 v = qobject_input_visitor_new_flat_confused(qdict, errp); 997 if (!v) { 998 ret = -EINVAL; 999 goto fail; 1000 } 1001 1002 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 1003 visit_free(v); 1004 if (!create_options) { 1005 ret = -EINVAL; 1006 goto fail; 1007 } 1008 1009 /* Silently round up size */ 1010 assert(create_options->driver == BLOCKDEV_DRIVER_QCOW); 1011 create_options->u.qcow.size = 1012 ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE); 1013 1014 /* Create the qcow image (format layer) */ 1015 ret = qcow_co_create(create_options, errp); 1016 if (ret < 0) { 1017 goto fail; 1018 } 1019 1020 ret = 0; 1021 fail: 1022 g_free(backing_fmt); 1023 qobject_unref(qdict); 1024 bdrv_co_unref(bs); 1025 qapi_free_BlockdevCreateOptions(create_options); 1026 return ret; 1027 } 1028 1029 static int qcow_make_empty(BlockDriverState *bs) 1030 { 1031 BDRVQcowState *s = bs->opaque; 1032 uint32_t l1_length = s->l1_size * sizeof(uint64_t); 1033 int ret; 1034 1035 memset(s->l1_table, 0, l1_length); 1036 if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, l1_length, s->l1_table, 1037 0) < 0) 1038 return -1; 1039 ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length, false, 1040 PREALLOC_MODE_OFF, 0, NULL); 1041 if (ret < 0) 1042 return ret; 1043 1044 memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); 1045 memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); 1046 memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); 1047 1048 return 0; 1049 } 1050 1051 /* XXX: put compressed sectors first, then all the cluster aligned 1052 tables to avoid losing bytes in alignment */ 1053 static int coroutine_fn GRAPH_RDLOCK 1054 qcow_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes, 1055 QEMUIOVector *qiov) 1056 { 1057 BDRVQcowState *s = bs->opaque; 1058 z_stream strm; 1059 int ret, out_len; 1060 uint8_t *buf, *out_buf; 1061 uint64_t cluster_offset; 1062 1063 buf = qemu_blockalign(bs, s->cluster_size); 1064 if (bytes != s->cluster_size) { 1065 if (bytes > s->cluster_size || 1066 offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS) 1067 { 1068 qemu_vfree(buf); 1069 return -EINVAL; 1070 } 1071 /* Zero-pad last write if image size is not cluster aligned */ 1072 memset(buf + bytes, 0, s->cluster_size - bytes); 1073 } 1074 qemu_iovec_to_buf(qiov, 0, buf, qiov->size); 1075 1076 out_buf = g_malloc(s->cluster_size); 1077 1078 /* best compression, small window, no zlib header */ 1079 memset(&strm, 0, sizeof(strm)); 1080 ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, 1081 Z_DEFLATED, -12, 1082 9, Z_DEFAULT_STRATEGY); 1083 if (ret != 0) { 1084 ret = -EINVAL; 1085 goto fail; 1086 } 1087 1088 strm.avail_in = s->cluster_size; 1089 strm.next_in = (uint8_t *)buf; 1090 strm.avail_out = s->cluster_size; 1091 strm.next_out = out_buf; 1092 1093 ret = deflate(&strm, Z_FINISH); 1094 if (ret != Z_STREAM_END && ret != Z_OK) { 1095 deflateEnd(&strm); 1096 ret = -EINVAL; 1097 goto fail; 1098 } 1099 out_len = strm.next_out - out_buf; 1100 1101 deflateEnd(&strm); 1102 1103 if (ret != Z_STREAM_END || out_len >= s->cluster_size) { 1104 /* could not compress: write normal cluster */ 1105 ret = qcow_co_pwritev(bs, offset, bytes, qiov, 0); 1106 if (ret < 0) { 1107 goto fail; 1108 } 1109 goto success; 1110 } 1111 qemu_co_mutex_lock(&s->lock); 1112 ret = get_cluster_offset(bs, offset, 2, out_len, 0, 0, &cluster_offset); 1113 qemu_co_mutex_unlock(&s->lock); 1114 if (ret < 0) { 1115 goto fail; 1116 } 1117 if (cluster_offset == 0) { 1118 ret = -EIO; 1119 goto fail; 1120 } 1121 cluster_offset &= s->cluster_offset_mask; 1122 1123 BLKDBG_CO_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); 1124 ret = bdrv_co_pwrite(bs->file, cluster_offset, out_len, out_buf, 0); 1125 if (ret < 0) { 1126 goto fail; 1127 } 1128 success: 1129 ret = 0; 1130 fail: 1131 qemu_vfree(buf); 1132 g_free(out_buf); 1133 return ret; 1134 } 1135 1136 static int coroutine_fn 1137 qcow_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1138 { 1139 BDRVQcowState *s = bs->opaque; 1140 bdi->cluster_size = s->cluster_size; 1141 return 0; 1142 } 1143 1144 static QemuOptsList qcow_create_opts = { 1145 .name = "qcow-create-opts", 1146 .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head), 1147 .desc = { 1148 { 1149 .name = BLOCK_OPT_SIZE, 1150 .type = QEMU_OPT_SIZE, 1151 .help = "Virtual disk size" 1152 }, 1153 { 1154 .name = BLOCK_OPT_BACKING_FILE, 1155 .type = QEMU_OPT_STRING, 1156 .help = "File name of a base image" 1157 }, 1158 { 1159 .name = BLOCK_OPT_BACKING_FMT, 1160 .type = QEMU_OPT_STRING, 1161 .help = "Format of the backing image", 1162 }, 1163 { 1164 .name = BLOCK_OPT_ENCRYPT, 1165 .type = QEMU_OPT_BOOL, 1166 .help = "Encrypt the image with format 'aes'. (Deprecated " 1167 "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", 1168 }, 1169 { 1170 .name = BLOCK_OPT_ENCRYPT_FORMAT, 1171 .type = QEMU_OPT_STRING, 1172 .help = "Encrypt the image, format choices: 'aes'", 1173 }, 1174 BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."), 1175 { /* end of list */ } 1176 } 1177 }; 1178 1179 static const char *const qcow_strong_runtime_opts[] = { 1180 "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET, 1181 1182 NULL 1183 }; 1184 1185 static BlockDriver bdrv_qcow = { 1186 .format_name = "qcow", 1187 .instance_size = sizeof(BDRVQcowState), 1188 .bdrv_probe = qcow_probe, 1189 .bdrv_open = qcow_open, 1190 .bdrv_close = qcow_close, 1191 .bdrv_child_perm = bdrv_default_perms, 1192 .bdrv_reopen_prepare = qcow_reopen_prepare, 1193 .bdrv_co_create = qcow_co_create, 1194 .bdrv_co_create_opts = qcow_co_create_opts, 1195 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1196 .is_format = true, 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_co_get_info = qcow_co_get_info, 1207 1208 .create_opts = &qcow_create_opts, 1209 .strong_runtime_opts = qcow_strong_runtime_opts, 1210 }; 1211 1212 static void bdrv_qcow_init(void) 1213 { 1214 bdrv_register(&bdrv_qcow); 1215 } 1216 1217 block_init(bdrv_qcow_init); 1218