1 /* 2 * Block driver for the Virtual Disk Image (VDI) format 3 * 4 * Copyright (c) 2009, 2012 Stefan Weil 5 * 6 * This program is free software: you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation, either version 2 of the License, or 9 * (at your option) version 3 or any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 * 19 * Reference: 20 * http://forums.virtualbox.org/viewtopic.php?t=8046 21 * 22 * This driver supports create / read / write operations on VDI images. 23 * 24 * Todo (see also TODO in code): 25 * 26 * Some features like snapshots are still missing. 27 * 28 * Deallocation of zero-filled blocks and shrinking images are missing, too 29 * (might be added to common block layer). 30 * 31 * Allocation of blocks could be optimized (less writes to block map and 32 * header). 33 * 34 * Read and write of adjacents blocks could be done in one operation 35 * (current code uses one operation per block (1 MiB). 36 * 37 * The code is not thread safe (missing locks for changes in header and 38 * block table, no problem with current QEMU). 39 * 40 * Hints: 41 * 42 * Blocks (VDI documentation) correspond to clusters (QEMU). 43 * QEMU's backing files could be implemented using VDI snapshot files (TODO). 44 * VDI snapshot files may also contain the complete machine state. 45 * Maybe this machine state can be converted to QEMU PC machine snapshot data. 46 * 47 * The driver keeps a block cache (little endian entries) in memory. 48 * For the standard block size (1 MiB), a 1 TiB disk will use 4 MiB RAM, 49 * so this seems to be reasonable. 50 */ 51 52 #include "qemu-common.h" 53 #include "block_int.h" 54 #include "module.h" 55 #include "migration.h" 56 57 #if defined(CONFIG_UUID) 58 #include <uuid/uuid.h> 59 #else 60 /* TODO: move uuid emulation to some central place in QEMU. */ 61 #include "sysemu.h" /* UUID_FMT */ 62 typedef unsigned char uuid_t[16]; 63 void uuid_generate(uuid_t out); 64 int uuid_is_null(const uuid_t uu); 65 void uuid_unparse(const uuid_t uu, char *out); 66 #endif 67 68 /* Code configuration options. */ 69 70 /* Enable debug messages. */ 71 //~ #define CONFIG_VDI_DEBUG 72 73 /* Support write operations on VDI images. */ 74 #define CONFIG_VDI_WRITE 75 76 /* Support non-standard block (cluster) size. This is untested. 77 * Maybe it will be needed for very large images. 78 */ 79 //~ #define CONFIG_VDI_BLOCK_SIZE 80 81 /* Support static (fixed, pre-allocated) images. */ 82 #define CONFIG_VDI_STATIC_IMAGE 83 84 /* Command line option for static images. */ 85 #define BLOCK_OPT_STATIC "static" 86 87 #define KiB 1024 88 #define MiB (KiB * KiB) 89 90 #define SECTOR_SIZE 512 91 #define DEFAULT_CLUSTER_SIZE (1 * MiB) 92 93 #if defined(CONFIG_VDI_DEBUG) 94 #define logout(fmt, ...) \ 95 fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__) 96 #else 97 #define logout(fmt, ...) ((void)0) 98 #endif 99 100 /* Image signature. */ 101 #define VDI_SIGNATURE 0xbeda107f 102 103 /* Image version. */ 104 #define VDI_VERSION_1_1 0x00010001 105 106 /* Image type. */ 107 #define VDI_TYPE_DYNAMIC 1 108 #define VDI_TYPE_STATIC 2 109 110 /* Innotek / SUN images use these strings in header.text: 111 * "<<< innotek VirtualBox Disk Image >>>\n" 112 * "<<< Sun xVM VirtualBox Disk Image >>>\n" 113 * "<<< Sun VirtualBox Disk Image >>>\n" 114 * The value does not matter, so QEMU created images use a different text. 115 */ 116 #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n" 117 118 /* A never-allocated block; semantically arbitrary content. */ 119 #define VDI_UNALLOCATED 0xffffffffU 120 121 /* A discarded (no longer allocated) block; semantically zero-filled. */ 122 #define VDI_DISCARDED 0xfffffffeU 123 124 #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED) 125 126 #if !defined(CONFIG_UUID) 127 void uuid_generate(uuid_t out) 128 { 129 memset(out, 0, sizeof(uuid_t)); 130 } 131 132 int uuid_is_null(const uuid_t uu) 133 { 134 uuid_t null_uuid = { 0 }; 135 return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0; 136 } 137 138 void uuid_unparse(const uuid_t uu, char *out) 139 { 140 snprintf(out, 37, UUID_FMT, 141 uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7], 142 uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]); 143 } 144 #endif 145 146 typedef struct { 147 BlockDriverAIOCB common; 148 int64_t sector_num; 149 QEMUIOVector *qiov; 150 uint8_t *buf; 151 /* Total number of sectors. */ 152 int nb_sectors; 153 /* Number of sectors for current AIO. */ 154 int n_sectors; 155 /* New allocated block map entry. */ 156 uint32_t bmap_first; 157 uint32_t bmap_last; 158 /* Buffer for new allocated block. */ 159 void *block_buffer; 160 void *orig_buf; 161 bool is_write; 162 int header_modified; 163 BlockDriverAIOCB *hd_aiocb; 164 struct iovec hd_iov; 165 QEMUIOVector hd_qiov; 166 QEMUBH *bh; 167 } VdiAIOCB; 168 169 typedef struct { 170 char text[0x40]; 171 uint32_t signature; 172 uint32_t version; 173 uint32_t header_size; 174 uint32_t image_type; 175 uint32_t image_flags; 176 char description[256]; 177 uint32_t offset_bmap; 178 uint32_t offset_data; 179 uint32_t cylinders; /* disk geometry, unused here */ 180 uint32_t heads; /* disk geometry, unused here */ 181 uint32_t sectors; /* disk geometry, unused here */ 182 uint32_t sector_size; 183 uint32_t unused1; 184 uint64_t disk_size; 185 uint32_t block_size; 186 uint32_t block_extra; /* unused here */ 187 uint32_t blocks_in_image; 188 uint32_t blocks_allocated; 189 uuid_t uuid_image; 190 uuid_t uuid_last_snap; 191 uuid_t uuid_link; 192 uuid_t uuid_parent; 193 uint64_t unused2[7]; 194 } VdiHeader; 195 196 typedef struct { 197 /* The block map entries are little endian (even in memory). */ 198 uint32_t *bmap; 199 /* Size of block (bytes). */ 200 uint32_t block_size; 201 /* Size of block (sectors). */ 202 uint32_t block_sectors; 203 /* First sector of block map. */ 204 uint32_t bmap_sector; 205 /* VDI header (converted to host endianness). */ 206 VdiHeader header; 207 208 Error *migration_blocker; 209 } BDRVVdiState; 210 211 /* Change UUID from little endian (IPRT = VirtualBox format) to big endian 212 * format (network byte order, standard, see RFC 4122) and vice versa. 213 */ 214 static void uuid_convert(uuid_t uuid) 215 { 216 bswap32s((uint32_t *)&uuid[0]); 217 bswap16s((uint16_t *)&uuid[4]); 218 bswap16s((uint16_t *)&uuid[6]); 219 } 220 221 static void vdi_header_to_cpu(VdiHeader *header) 222 { 223 le32_to_cpus(&header->signature); 224 le32_to_cpus(&header->version); 225 le32_to_cpus(&header->header_size); 226 le32_to_cpus(&header->image_type); 227 le32_to_cpus(&header->image_flags); 228 le32_to_cpus(&header->offset_bmap); 229 le32_to_cpus(&header->offset_data); 230 le32_to_cpus(&header->cylinders); 231 le32_to_cpus(&header->heads); 232 le32_to_cpus(&header->sectors); 233 le32_to_cpus(&header->sector_size); 234 le64_to_cpus(&header->disk_size); 235 le32_to_cpus(&header->block_size); 236 le32_to_cpus(&header->block_extra); 237 le32_to_cpus(&header->blocks_in_image); 238 le32_to_cpus(&header->blocks_allocated); 239 uuid_convert(header->uuid_image); 240 uuid_convert(header->uuid_last_snap); 241 uuid_convert(header->uuid_link); 242 uuid_convert(header->uuid_parent); 243 } 244 245 static void vdi_header_to_le(VdiHeader *header) 246 { 247 cpu_to_le32s(&header->signature); 248 cpu_to_le32s(&header->version); 249 cpu_to_le32s(&header->header_size); 250 cpu_to_le32s(&header->image_type); 251 cpu_to_le32s(&header->image_flags); 252 cpu_to_le32s(&header->offset_bmap); 253 cpu_to_le32s(&header->offset_data); 254 cpu_to_le32s(&header->cylinders); 255 cpu_to_le32s(&header->heads); 256 cpu_to_le32s(&header->sectors); 257 cpu_to_le32s(&header->sector_size); 258 cpu_to_le64s(&header->disk_size); 259 cpu_to_le32s(&header->block_size); 260 cpu_to_le32s(&header->block_extra); 261 cpu_to_le32s(&header->blocks_in_image); 262 cpu_to_le32s(&header->blocks_allocated); 263 cpu_to_le32s(&header->blocks_allocated); 264 uuid_convert(header->uuid_image); 265 uuid_convert(header->uuid_last_snap); 266 uuid_convert(header->uuid_link); 267 uuid_convert(header->uuid_parent); 268 } 269 270 #if defined(CONFIG_VDI_DEBUG) 271 static void vdi_header_print(VdiHeader *header) 272 { 273 char uuid[37]; 274 logout("text %s", header->text); 275 logout("signature 0x%04x\n", header->signature); 276 logout("header size 0x%04x\n", header->header_size); 277 logout("image type 0x%04x\n", header->image_type); 278 logout("image flags 0x%04x\n", header->image_flags); 279 logout("description %s\n", header->description); 280 logout("offset bmap 0x%04x\n", header->offset_bmap); 281 logout("offset data 0x%04x\n", header->offset_data); 282 logout("cylinders 0x%04x\n", header->cylinders); 283 logout("heads 0x%04x\n", header->heads); 284 logout("sectors 0x%04x\n", header->sectors); 285 logout("sector size 0x%04x\n", header->sector_size); 286 logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n", 287 header->disk_size, header->disk_size / MiB); 288 logout("block size 0x%04x\n", header->block_size); 289 logout("block extra 0x%04x\n", header->block_extra); 290 logout("blocks tot. 0x%04x\n", header->blocks_in_image); 291 logout("blocks all. 0x%04x\n", header->blocks_allocated); 292 uuid_unparse(header->uuid_image, uuid); 293 logout("uuid image %s\n", uuid); 294 uuid_unparse(header->uuid_last_snap, uuid); 295 logout("uuid snap %s\n", uuid); 296 uuid_unparse(header->uuid_link, uuid); 297 logout("uuid link %s\n", uuid); 298 uuid_unparse(header->uuid_parent, uuid); 299 logout("uuid parent %s\n", uuid); 300 } 301 #endif 302 303 static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res) 304 { 305 /* TODO: additional checks possible. */ 306 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 307 uint32_t blocks_allocated = 0; 308 uint32_t block; 309 uint32_t *bmap; 310 logout("\n"); 311 312 bmap = g_malloc(s->header.blocks_in_image * sizeof(uint32_t)); 313 memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t)); 314 315 /* Check block map and value of blocks_allocated. */ 316 for (block = 0; block < s->header.blocks_in_image; block++) { 317 uint32_t bmap_entry = le32_to_cpu(s->bmap[block]); 318 if (VDI_IS_ALLOCATED(bmap_entry)) { 319 if (bmap_entry < s->header.blocks_in_image) { 320 blocks_allocated++; 321 if (!VDI_IS_ALLOCATED(bmap[bmap_entry])) { 322 bmap[bmap_entry] = bmap_entry; 323 } else { 324 fprintf(stderr, "ERROR: block index %" PRIu32 325 " also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry); 326 res->corruptions++; 327 } 328 } else { 329 fprintf(stderr, "ERROR: block index %" PRIu32 330 " too large, is %" PRIu32 "\n", block, bmap_entry); 331 res->corruptions++; 332 } 333 } 334 } 335 if (blocks_allocated != s->header.blocks_allocated) { 336 fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32 337 ", should be %" PRIu32 "\n", 338 blocks_allocated, s->header.blocks_allocated); 339 res->corruptions++; 340 } 341 342 g_free(bmap); 343 344 return 0; 345 } 346 347 static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 348 { 349 /* TODO: vdi_get_info would be needed for machine snapshots. 350 vm_state_offset is still missing. */ 351 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 352 logout("\n"); 353 bdi->cluster_size = s->block_size; 354 bdi->vm_state_offset = 0; 355 return 0; 356 } 357 358 static int vdi_make_empty(BlockDriverState *bs) 359 { 360 /* TODO: missing code. */ 361 logout("\n"); 362 /* The return value for missing code must be 0, see block.c. */ 363 return 0; 364 } 365 366 static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename) 367 { 368 const VdiHeader *header = (const VdiHeader *)buf; 369 int result = 0; 370 371 logout("\n"); 372 373 if (buf_size < sizeof(*header)) { 374 /* Header too small, no VDI. */ 375 } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) { 376 result = 100; 377 } 378 379 if (result == 0) { 380 logout("no vdi image\n"); 381 } else { 382 logout("%s", header->text); 383 } 384 385 return result; 386 } 387 388 static int vdi_open(BlockDriverState *bs, int flags) 389 { 390 BDRVVdiState *s = bs->opaque; 391 VdiHeader header; 392 size_t bmap_size; 393 394 logout("\n"); 395 396 if (bdrv_read(bs->file, 0, (uint8_t *)&header, 1) < 0) { 397 goto fail; 398 } 399 400 vdi_header_to_cpu(&header); 401 #if defined(CONFIG_VDI_DEBUG) 402 vdi_header_print(&header); 403 #endif 404 405 if (header.disk_size % SECTOR_SIZE != 0) { 406 /* 'VBoxManage convertfromraw' can create images with odd disk sizes. 407 We accept them but round the disk size to the next multiple of 408 SECTOR_SIZE. */ 409 logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size); 410 header.disk_size += SECTOR_SIZE - 1; 411 header.disk_size &= ~(SECTOR_SIZE - 1); 412 } 413 414 if (header.version != VDI_VERSION_1_1) { 415 logout("unsupported version %u.%u\n", 416 header.version >> 16, header.version & 0xffff); 417 goto fail; 418 } else if (header.offset_bmap % SECTOR_SIZE != 0) { 419 /* We only support block maps which start on a sector boundary. */ 420 logout("unsupported block map offset 0x%x B\n", header.offset_bmap); 421 goto fail; 422 } else if (header.offset_data % SECTOR_SIZE != 0) { 423 /* We only support data blocks which start on a sector boundary. */ 424 logout("unsupported data offset 0x%x B\n", header.offset_data); 425 goto fail; 426 } else if (header.sector_size != SECTOR_SIZE) { 427 logout("unsupported sector size %u B\n", header.sector_size); 428 goto fail; 429 } else if (header.block_size != 1 * MiB) { 430 logout("unsupported block size %u B\n", header.block_size); 431 goto fail; 432 } else if (header.disk_size > 433 (uint64_t)header.blocks_in_image * header.block_size) { 434 logout("unsupported disk size %" PRIu64 " B\n", header.disk_size); 435 goto fail; 436 } else if (!uuid_is_null(header.uuid_link)) { 437 logout("link uuid != 0, unsupported\n"); 438 goto fail; 439 } else if (!uuid_is_null(header.uuid_parent)) { 440 logout("parent uuid != 0, unsupported\n"); 441 goto fail; 442 } 443 444 bs->total_sectors = header.disk_size / SECTOR_SIZE; 445 446 s->block_size = header.block_size; 447 s->block_sectors = header.block_size / SECTOR_SIZE; 448 s->bmap_sector = header.offset_bmap / SECTOR_SIZE; 449 s->header = header; 450 451 bmap_size = header.blocks_in_image * sizeof(uint32_t); 452 bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE; 453 if (bmap_size > 0) { 454 s->bmap = g_malloc(bmap_size * SECTOR_SIZE); 455 } 456 if (bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size) < 0) { 457 goto fail_free_bmap; 458 } 459 460 /* Disable migration when vdi images are used */ 461 error_set(&s->migration_blocker, 462 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 463 "vdi", bs->device_name, "live migration"); 464 migrate_add_blocker(s->migration_blocker); 465 466 return 0; 467 468 fail_free_bmap: 469 g_free(s->bmap); 470 471 fail: 472 return -1; 473 } 474 475 static int coroutine_fn vdi_co_is_allocated(BlockDriverState *bs, 476 int64_t sector_num, int nb_sectors, int *pnum) 477 { 478 /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */ 479 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 480 size_t bmap_index = sector_num / s->block_sectors; 481 size_t sector_in_block = sector_num % s->block_sectors; 482 int n_sectors = s->block_sectors - sector_in_block; 483 uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]); 484 logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum); 485 if (n_sectors > nb_sectors) { 486 n_sectors = nb_sectors; 487 } 488 *pnum = n_sectors; 489 return VDI_IS_ALLOCATED(bmap_entry); 490 } 491 492 static void vdi_aio_cancel(BlockDriverAIOCB *blockacb) 493 { 494 /* TODO: This code is untested. How can I get it executed? */ 495 VdiAIOCB *acb = container_of(blockacb, VdiAIOCB, common); 496 logout("\n"); 497 if (acb->hd_aiocb) { 498 bdrv_aio_cancel(acb->hd_aiocb); 499 } 500 qemu_aio_release(acb); 501 } 502 503 static AIOPool vdi_aio_pool = { 504 .aiocb_size = sizeof(VdiAIOCB), 505 .cancel = vdi_aio_cancel, 506 }; 507 508 static VdiAIOCB *vdi_aio_setup(BlockDriverState *bs, int64_t sector_num, 509 QEMUIOVector *qiov, int nb_sectors, 510 BlockDriverCompletionFunc *cb, void *opaque, int is_write) 511 { 512 VdiAIOCB *acb; 513 514 logout("%p, %" PRId64 ", %p, %d, %p, %p, %d\n", 515 bs, sector_num, qiov, nb_sectors, cb, opaque, is_write); 516 517 acb = qemu_aio_get(&vdi_aio_pool, bs, cb, opaque); 518 acb->hd_aiocb = NULL; 519 acb->sector_num = sector_num; 520 acb->qiov = qiov; 521 acb->is_write = is_write; 522 523 if (qiov->niov > 1) { 524 acb->buf = qemu_blockalign(bs, qiov->size); 525 acb->orig_buf = acb->buf; 526 if (is_write) { 527 qemu_iovec_to_buffer(qiov, acb->buf); 528 } 529 } else { 530 acb->buf = (uint8_t *)qiov->iov->iov_base; 531 } 532 acb->nb_sectors = nb_sectors; 533 acb->n_sectors = 0; 534 acb->bmap_first = VDI_UNALLOCATED; 535 acb->bmap_last = VDI_UNALLOCATED; 536 acb->block_buffer = NULL; 537 acb->header_modified = 0; 538 return acb; 539 } 540 541 static int vdi_schedule_bh(QEMUBHFunc *cb, VdiAIOCB *acb) 542 { 543 logout("\n"); 544 545 if (acb->bh) { 546 return -EIO; 547 } 548 549 acb->bh = qemu_bh_new(cb, acb); 550 if (!acb->bh) { 551 return -EIO; 552 } 553 554 qemu_bh_schedule(acb->bh); 555 556 return 0; 557 } 558 559 static void vdi_aio_read_cb(void *opaque, int ret); 560 static void vdi_aio_write_cb(void *opaque, int ret); 561 562 static void vdi_aio_rw_bh(void *opaque) 563 { 564 VdiAIOCB *acb = opaque; 565 logout("\n"); 566 qemu_bh_delete(acb->bh); 567 acb->bh = NULL; 568 569 if (acb->is_write) { 570 vdi_aio_write_cb(opaque, 0); 571 } else { 572 vdi_aio_read_cb(opaque, 0); 573 } 574 } 575 576 static void vdi_aio_read_cb(void *opaque, int ret) 577 { 578 VdiAIOCB *acb = opaque; 579 BlockDriverState *bs = acb->common.bs; 580 BDRVVdiState *s = bs->opaque; 581 uint32_t bmap_entry; 582 uint32_t block_index; 583 uint32_t sector_in_block; 584 uint32_t n_sectors; 585 586 logout("%u sectors read\n", acb->n_sectors); 587 588 acb->hd_aiocb = NULL; 589 590 if (ret < 0) { 591 goto done; 592 } 593 594 acb->nb_sectors -= acb->n_sectors; 595 596 if (acb->nb_sectors == 0) { 597 /* request completed */ 598 ret = 0; 599 goto done; 600 } 601 602 acb->sector_num += acb->n_sectors; 603 acb->buf += acb->n_sectors * SECTOR_SIZE; 604 605 block_index = acb->sector_num / s->block_sectors; 606 sector_in_block = acb->sector_num % s->block_sectors; 607 n_sectors = s->block_sectors - sector_in_block; 608 if (n_sectors > acb->nb_sectors) { 609 n_sectors = acb->nb_sectors; 610 } 611 612 logout("will read %u sectors starting at sector %" PRIu64 "\n", 613 n_sectors, acb->sector_num); 614 615 /* prepare next AIO request */ 616 acb->n_sectors = n_sectors; 617 bmap_entry = le32_to_cpu(s->bmap[block_index]); 618 if (!VDI_IS_ALLOCATED(bmap_entry)) { 619 /* Block not allocated, return zeros, no need to wait. */ 620 memset(acb->buf, 0, n_sectors * SECTOR_SIZE); 621 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 622 if (ret < 0) { 623 goto done; 624 } 625 } else { 626 uint64_t offset = s->header.offset_data / SECTOR_SIZE + 627 (uint64_t)bmap_entry * s->block_sectors + 628 sector_in_block; 629 acb->hd_iov.iov_base = (void *)acb->buf; 630 acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE; 631 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 632 acb->hd_aiocb = bdrv_aio_readv(bs->file, offset, &acb->hd_qiov, 633 n_sectors, vdi_aio_read_cb, acb); 634 } 635 return; 636 done: 637 if (acb->qiov->niov > 1) { 638 qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); 639 qemu_vfree(acb->orig_buf); 640 } 641 acb->common.cb(acb->common.opaque, ret); 642 qemu_aio_release(acb); 643 } 644 645 static BlockDriverAIOCB *vdi_aio_readv(BlockDriverState *bs, 646 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 647 BlockDriverCompletionFunc *cb, void *opaque) 648 { 649 VdiAIOCB *acb; 650 int ret; 651 652 logout("\n"); 653 acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 654 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 655 if (ret < 0) { 656 if (acb->qiov->niov > 1) { 657 qemu_vfree(acb->orig_buf); 658 } 659 qemu_aio_release(acb); 660 return NULL; 661 } 662 663 return &acb->common; 664 } 665 666 static void vdi_aio_write_cb(void *opaque, int ret) 667 { 668 VdiAIOCB *acb = opaque; 669 BlockDriverState *bs = acb->common.bs; 670 BDRVVdiState *s = bs->opaque; 671 uint32_t bmap_entry; 672 uint32_t block_index; 673 uint32_t sector_in_block; 674 uint32_t n_sectors; 675 676 acb->hd_aiocb = NULL; 677 678 if (ret < 0) { 679 goto done; 680 } 681 682 acb->nb_sectors -= acb->n_sectors; 683 acb->sector_num += acb->n_sectors; 684 acb->buf += acb->n_sectors * SECTOR_SIZE; 685 686 if (acb->nb_sectors == 0) { 687 logout("finished data write\n"); 688 acb->n_sectors = 0; 689 if (acb->header_modified) { 690 VdiHeader *header = acb->block_buffer; 691 logout("now writing modified header\n"); 692 assert(VDI_IS_ALLOCATED(acb->bmap_first)); 693 *header = s->header; 694 vdi_header_to_le(header); 695 acb->header_modified = 0; 696 acb->hd_iov.iov_base = acb->block_buffer; 697 acb->hd_iov.iov_len = SECTOR_SIZE; 698 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 699 acb->hd_aiocb = bdrv_aio_writev(bs->file, 0, &acb->hd_qiov, 1, 700 vdi_aio_write_cb, acb); 701 return; 702 } else if (VDI_IS_ALLOCATED(acb->bmap_first)) { 703 /* One or more new blocks were allocated. */ 704 uint64_t offset; 705 uint32_t bmap_first; 706 uint32_t bmap_last; 707 g_free(acb->block_buffer); 708 acb->block_buffer = NULL; 709 bmap_first = acb->bmap_first; 710 bmap_last = acb->bmap_last; 711 logout("now writing modified block map entry %u...%u\n", 712 bmap_first, bmap_last); 713 /* Write modified sectors from block map. */ 714 bmap_first /= (SECTOR_SIZE / sizeof(uint32_t)); 715 bmap_last /= (SECTOR_SIZE / sizeof(uint32_t)); 716 n_sectors = bmap_last - bmap_first + 1; 717 offset = s->bmap_sector + bmap_first; 718 acb->bmap_first = VDI_UNALLOCATED; 719 acb->hd_iov.iov_base = (void *)((uint8_t *)&s->bmap[0] + 720 bmap_first * SECTOR_SIZE); 721 acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE; 722 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 723 logout("will write %u block map sectors starting from entry %u\n", 724 n_sectors, bmap_first); 725 acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov, 726 n_sectors, vdi_aio_write_cb, acb); 727 return; 728 } 729 ret = 0; 730 goto done; 731 } 732 733 logout("%u sectors written\n", acb->n_sectors); 734 735 block_index = acb->sector_num / s->block_sectors; 736 sector_in_block = acb->sector_num % s->block_sectors; 737 n_sectors = s->block_sectors - sector_in_block; 738 if (n_sectors > acb->nb_sectors) { 739 n_sectors = acb->nb_sectors; 740 } 741 742 logout("will write %u sectors starting at sector %" PRIu64 "\n", 743 n_sectors, acb->sector_num); 744 745 /* prepare next AIO request */ 746 acb->n_sectors = n_sectors; 747 bmap_entry = le32_to_cpu(s->bmap[block_index]); 748 if (!VDI_IS_ALLOCATED(bmap_entry)) { 749 /* Allocate new block and write to it. */ 750 uint64_t offset; 751 uint8_t *block; 752 bmap_entry = s->header.blocks_allocated; 753 s->bmap[block_index] = cpu_to_le32(bmap_entry); 754 s->header.blocks_allocated++; 755 offset = s->header.offset_data / SECTOR_SIZE + 756 (uint64_t)bmap_entry * s->block_sectors; 757 block = acb->block_buffer; 758 if (block == NULL) { 759 block = g_malloc(s->block_size); 760 acb->block_buffer = block; 761 acb->bmap_first = block_index; 762 assert(!acb->header_modified); 763 acb->header_modified = 1; 764 } 765 acb->bmap_last = block_index; 766 /* Copy data to be written to new block and zero unused parts. */ 767 memset(block, 0, sector_in_block * SECTOR_SIZE); 768 memcpy(block + sector_in_block * SECTOR_SIZE, 769 acb->buf, n_sectors * SECTOR_SIZE); 770 memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0, 771 (s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE); 772 acb->hd_iov.iov_base = (void *)block; 773 acb->hd_iov.iov_len = s->block_size; 774 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 775 acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, 776 &acb->hd_qiov, s->block_sectors, 777 vdi_aio_write_cb, acb); 778 } else { 779 uint64_t offset = s->header.offset_data / SECTOR_SIZE + 780 (uint64_t)bmap_entry * s->block_sectors + 781 sector_in_block; 782 acb->hd_iov.iov_base = (void *)acb->buf; 783 acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE; 784 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 785 acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov, 786 n_sectors, vdi_aio_write_cb, acb); 787 } 788 789 return; 790 791 done: 792 if (acb->qiov->niov > 1) { 793 qemu_vfree(acb->orig_buf); 794 } 795 acb->common.cb(acb->common.opaque, ret); 796 qemu_aio_release(acb); 797 } 798 799 static BlockDriverAIOCB *vdi_aio_writev(BlockDriverState *bs, 800 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 801 BlockDriverCompletionFunc *cb, void *opaque) 802 { 803 VdiAIOCB *acb; 804 int ret; 805 806 logout("\n"); 807 acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); 808 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 809 if (ret < 0) { 810 if (acb->qiov->niov > 1) { 811 qemu_vfree(acb->orig_buf); 812 } 813 qemu_aio_release(acb); 814 return NULL; 815 } 816 817 return &acb->common; 818 } 819 820 static int vdi_create(const char *filename, QEMUOptionParameter *options) 821 { 822 int fd; 823 int result = 0; 824 uint64_t bytes = 0; 825 uint32_t blocks; 826 size_t block_size = DEFAULT_CLUSTER_SIZE; 827 uint32_t image_type = VDI_TYPE_DYNAMIC; 828 VdiHeader header; 829 size_t i; 830 size_t bmap_size; 831 uint32_t *bmap; 832 833 logout("\n"); 834 835 /* Read out options. */ 836 while (options && options->name) { 837 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 838 bytes = options->value.n; 839 #if defined(CONFIG_VDI_BLOCK_SIZE) 840 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 841 if (options->value.n) { 842 /* TODO: Additional checks (SECTOR_SIZE * 2^n, ...). */ 843 block_size = options->value.n; 844 } 845 #endif 846 #if defined(CONFIG_VDI_STATIC_IMAGE) 847 } else if (!strcmp(options->name, BLOCK_OPT_STATIC)) { 848 if (options->value.n) { 849 image_type = VDI_TYPE_STATIC; 850 } 851 #endif 852 } 853 options++; 854 } 855 856 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 857 0644); 858 if (fd < 0) { 859 return -errno; 860 } 861 862 /* We need enough blocks to store the given disk size, 863 so always round up. */ 864 blocks = (bytes + block_size - 1) / block_size; 865 866 bmap_size = blocks * sizeof(uint32_t); 867 bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1)); 868 869 memset(&header, 0, sizeof(header)); 870 pstrcpy(header.text, sizeof(header.text), VDI_TEXT); 871 header.signature = VDI_SIGNATURE; 872 header.version = VDI_VERSION_1_1; 873 header.header_size = 0x180; 874 header.image_type = image_type; 875 header.offset_bmap = 0x200; 876 header.offset_data = 0x200 + bmap_size; 877 header.sector_size = SECTOR_SIZE; 878 header.disk_size = bytes; 879 header.block_size = block_size; 880 header.blocks_in_image = blocks; 881 if (image_type == VDI_TYPE_STATIC) { 882 header.blocks_allocated = blocks; 883 } 884 uuid_generate(header.uuid_image); 885 uuid_generate(header.uuid_last_snap); 886 /* There is no need to set header.uuid_link or header.uuid_parent here. */ 887 #if defined(CONFIG_VDI_DEBUG) 888 vdi_header_print(&header); 889 #endif 890 vdi_header_to_le(&header); 891 if (write(fd, &header, sizeof(header)) < 0) { 892 result = -errno; 893 } 894 895 bmap = NULL; 896 if (bmap_size > 0) { 897 bmap = (uint32_t *)g_malloc0(bmap_size); 898 } 899 for (i = 0; i < blocks; i++) { 900 if (image_type == VDI_TYPE_STATIC) { 901 bmap[i] = i; 902 } else { 903 bmap[i] = VDI_UNALLOCATED; 904 } 905 } 906 if (write(fd, bmap, bmap_size) < 0) { 907 result = -errno; 908 } 909 g_free(bmap); 910 if (image_type == VDI_TYPE_STATIC) { 911 if (ftruncate(fd, sizeof(header) + bmap_size + blocks * block_size)) { 912 result = -errno; 913 } 914 } 915 916 if (close(fd) < 0) { 917 result = -errno; 918 } 919 920 return result; 921 } 922 923 static void vdi_close(BlockDriverState *bs) 924 { 925 BDRVVdiState *s = bs->opaque; 926 927 g_free(s->bmap); 928 929 migrate_del_blocker(s->migration_blocker); 930 error_free(s->migration_blocker); 931 } 932 933 static coroutine_fn int vdi_co_flush(BlockDriverState *bs) 934 { 935 logout("\n"); 936 return bdrv_co_flush(bs->file); 937 } 938 939 940 static QEMUOptionParameter vdi_create_options[] = { 941 { 942 .name = BLOCK_OPT_SIZE, 943 .type = OPT_SIZE, 944 .help = "Virtual disk size" 945 }, 946 #if defined(CONFIG_VDI_BLOCK_SIZE) 947 { 948 .name = BLOCK_OPT_CLUSTER_SIZE, 949 .type = OPT_SIZE, 950 .help = "VDI cluster (block) size", 951 .value = { .n = DEFAULT_CLUSTER_SIZE }, 952 }, 953 #endif 954 #if defined(CONFIG_VDI_STATIC_IMAGE) 955 { 956 .name = BLOCK_OPT_STATIC, 957 .type = OPT_FLAG, 958 .help = "VDI static (pre-allocated) image" 959 }, 960 #endif 961 /* TODO: An additional option to set UUID values might be useful. */ 962 { NULL } 963 }; 964 965 static BlockDriver bdrv_vdi = { 966 .format_name = "vdi", 967 .instance_size = sizeof(BDRVVdiState), 968 .bdrv_probe = vdi_probe, 969 .bdrv_open = vdi_open, 970 .bdrv_close = vdi_close, 971 .bdrv_create = vdi_create, 972 .bdrv_co_flush_to_disk = vdi_co_flush, 973 .bdrv_co_is_allocated = vdi_co_is_allocated, 974 .bdrv_make_empty = vdi_make_empty, 975 976 .bdrv_aio_readv = vdi_aio_readv, 977 #if defined(CONFIG_VDI_WRITE) 978 .bdrv_aio_writev = vdi_aio_writev, 979 #endif 980 981 .bdrv_get_info = vdi_get_info, 982 983 .create_options = vdi_create_options, 984 .bdrv_check = vdi_check, 985 }; 986 987 static void bdrv_vdi_init(void) 988 { 989 logout("\n"); 990 bdrv_register(&bdrv_vdi); 991 } 992 993 block_init(bdrv_vdi_init); 994