1 /* 2 * Block driver for the Virtual Disk Image (VDI) format 3 * 4 * Copyright (c) 2009 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 56 #if defined(CONFIG_UUID) 57 #include <uuid/uuid.h> 58 #else 59 /* TODO: move uuid emulation to some central place in QEMU. */ 60 #include "sysemu.h" /* UUID_FMT */ 61 typedef unsigned char uuid_t[16]; 62 void uuid_generate(uuid_t out); 63 int uuid_is_null(const uuid_t uu); 64 void uuid_unparse(const uuid_t uu, char *out); 65 #endif 66 67 /* Code configuration options. */ 68 69 /* Enable debug messages. */ 70 //~ #define CONFIG_VDI_DEBUG 71 72 /* Support write operations on VDI images. */ 73 #define CONFIG_VDI_WRITE 74 75 /* Support non-standard block (cluster) size. This is untested. 76 * Maybe it will be needed for very large images. 77 */ 78 //~ #define CONFIG_VDI_BLOCK_SIZE 79 80 /* Support static (fixed, pre-allocated) images. */ 81 #define CONFIG_VDI_STATIC_IMAGE 82 83 /* Command line option for static images. */ 84 #define BLOCK_OPT_STATIC "static" 85 86 #define KiB 1024 87 #define MiB (KiB * KiB) 88 89 #define SECTOR_SIZE 512 90 #define DEFAULT_CLUSTER_SIZE (1 * MiB) 91 92 #if defined(CONFIG_VDI_DEBUG) 93 #define logout(fmt, ...) \ 94 fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__) 95 #else 96 #define logout(fmt, ...) ((void)0) 97 #endif 98 99 /* Image signature. */ 100 #define VDI_SIGNATURE 0xbeda107f 101 102 /* Image version. */ 103 #define VDI_VERSION_1_1 0x00010001 104 105 /* Image type. */ 106 #define VDI_TYPE_DYNAMIC 1 107 #define VDI_TYPE_STATIC 2 108 109 /* Innotek / SUN images use these strings in header.text: 110 * "<<< innotek VirtualBox Disk Image >>>\n" 111 * "<<< Sun xVM VirtualBox Disk Image >>>\n" 112 * "<<< Sun VirtualBox Disk Image >>>\n" 113 * The value does not matter, so QEMU created images use a different text. 114 */ 115 #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n" 116 117 /* Unallocated blocks use this index (no need to convert endianness). */ 118 #define VDI_UNALLOCATED UINT32_MAX 119 120 #if !defined(CONFIG_UUID) 121 void uuid_generate(uuid_t out) 122 { 123 memset(out, 0, sizeof(uuid_t)); 124 } 125 126 int uuid_is_null(const uuid_t uu) 127 { 128 uuid_t null_uuid = { 0 }; 129 return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0; 130 } 131 132 void uuid_unparse(const uuid_t uu, char *out) 133 { 134 snprintf(out, 37, UUID_FMT, 135 uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7], 136 uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]); 137 } 138 #endif 139 140 typedef struct { 141 BlockDriverAIOCB common; 142 int64_t sector_num; 143 QEMUIOVector *qiov; 144 uint8_t *buf; 145 /* Total number of sectors. */ 146 int nb_sectors; 147 /* Number of sectors for current AIO. */ 148 int n_sectors; 149 /* New allocated block map entry. */ 150 uint32_t bmap_first; 151 uint32_t bmap_last; 152 /* Buffer for new allocated block. */ 153 void *block_buffer; 154 void *orig_buf; 155 bool is_write; 156 int header_modified; 157 BlockDriverAIOCB *hd_aiocb; 158 struct iovec hd_iov; 159 QEMUIOVector hd_qiov; 160 QEMUBH *bh; 161 } VdiAIOCB; 162 163 typedef struct { 164 char text[0x40]; 165 uint32_t signature; 166 uint32_t version; 167 uint32_t header_size; 168 uint32_t image_type; 169 uint32_t image_flags; 170 char description[256]; 171 uint32_t offset_bmap; 172 uint32_t offset_data; 173 uint32_t cylinders; /* disk geometry, unused here */ 174 uint32_t heads; /* disk geometry, unused here */ 175 uint32_t sectors; /* disk geometry, unused here */ 176 uint32_t sector_size; 177 uint32_t unused1; 178 uint64_t disk_size; 179 uint32_t block_size; 180 uint32_t block_extra; /* unused here */ 181 uint32_t blocks_in_image; 182 uint32_t blocks_allocated; 183 uuid_t uuid_image; 184 uuid_t uuid_last_snap; 185 uuid_t uuid_link; 186 uuid_t uuid_parent; 187 uint64_t unused2[7]; 188 } VdiHeader; 189 190 typedef struct { 191 /* The block map entries are little endian (even in memory). */ 192 uint32_t *bmap; 193 /* Size of block (bytes). */ 194 uint32_t block_size; 195 /* Size of block (sectors). */ 196 uint32_t block_sectors; 197 /* First sector of block map. */ 198 uint32_t bmap_sector; 199 /* VDI header (converted to host endianness). */ 200 VdiHeader header; 201 } BDRVVdiState; 202 203 /* Change UUID from little endian (IPRT = VirtualBox format) to big endian 204 * format (network byte order, standard, see RFC 4122) and vice versa. 205 */ 206 static void uuid_convert(uuid_t uuid) 207 { 208 bswap32s((uint32_t *)&uuid[0]); 209 bswap16s((uint16_t *)&uuid[4]); 210 bswap16s((uint16_t *)&uuid[6]); 211 } 212 213 static void vdi_header_to_cpu(VdiHeader *header) 214 { 215 le32_to_cpus(&header->signature); 216 le32_to_cpus(&header->version); 217 le32_to_cpus(&header->header_size); 218 le32_to_cpus(&header->image_type); 219 le32_to_cpus(&header->image_flags); 220 le32_to_cpus(&header->offset_bmap); 221 le32_to_cpus(&header->offset_data); 222 le32_to_cpus(&header->cylinders); 223 le32_to_cpus(&header->heads); 224 le32_to_cpus(&header->sectors); 225 le32_to_cpus(&header->sector_size); 226 le64_to_cpus(&header->disk_size); 227 le32_to_cpus(&header->block_size); 228 le32_to_cpus(&header->block_extra); 229 le32_to_cpus(&header->blocks_in_image); 230 le32_to_cpus(&header->blocks_allocated); 231 uuid_convert(header->uuid_image); 232 uuid_convert(header->uuid_last_snap); 233 uuid_convert(header->uuid_link); 234 uuid_convert(header->uuid_parent); 235 } 236 237 static void vdi_header_to_le(VdiHeader *header) 238 { 239 cpu_to_le32s(&header->signature); 240 cpu_to_le32s(&header->version); 241 cpu_to_le32s(&header->header_size); 242 cpu_to_le32s(&header->image_type); 243 cpu_to_le32s(&header->image_flags); 244 cpu_to_le32s(&header->offset_bmap); 245 cpu_to_le32s(&header->offset_data); 246 cpu_to_le32s(&header->cylinders); 247 cpu_to_le32s(&header->heads); 248 cpu_to_le32s(&header->sectors); 249 cpu_to_le32s(&header->sector_size); 250 cpu_to_le64s(&header->disk_size); 251 cpu_to_le32s(&header->block_size); 252 cpu_to_le32s(&header->block_extra); 253 cpu_to_le32s(&header->blocks_in_image); 254 cpu_to_le32s(&header->blocks_allocated); 255 cpu_to_le32s(&header->blocks_allocated); 256 uuid_convert(header->uuid_image); 257 uuid_convert(header->uuid_last_snap); 258 uuid_convert(header->uuid_link); 259 uuid_convert(header->uuid_parent); 260 } 261 262 #if defined(CONFIG_VDI_DEBUG) 263 static void vdi_header_print(VdiHeader *header) 264 { 265 char uuid[37]; 266 logout("text %s", header->text); 267 logout("signature 0x%04x\n", header->signature); 268 logout("header size 0x%04x\n", header->header_size); 269 logout("image type 0x%04x\n", header->image_type); 270 logout("image flags 0x%04x\n", header->image_flags); 271 logout("description %s\n", header->description); 272 logout("offset bmap 0x%04x\n", header->offset_bmap); 273 logout("offset data 0x%04x\n", header->offset_data); 274 logout("cylinders 0x%04x\n", header->cylinders); 275 logout("heads 0x%04x\n", header->heads); 276 logout("sectors 0x%04x\n", header->sectors); 277 logout("sector size 0x%04x\n", header->sector_size); 278 logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n", 279 header->disk_size, header->disk_size / MiB); 280 logout("block size 0x%04x\n", header->block_size); 281 logout("block extra 0x%04x\n", header->block_extra); 282 logout("blocks tot. 0x%04x\n", header->blocks_in_image); 283 logout("blocks all. 0x%04x\n", header->blocks_allocated); 284 uuid_unparse(header->uuid_image, uuid); 285 logout("uuid image %s\n", uuid); 286 uuid_unparse(header->uuid_last_snap, uuid); 287 logout("uuid snap %s\n", uuid); 288 uuid_unparse(header->uuid_link, uuid); 289 logout("uuid link %s\n", uuid); 290 uuid_unparse(header->uuid_parent, uuid); 291 logout("uuid parent %s\n", uuid); 292 } 293 #endif 294 295 static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res) 296 { 297 /* TODO: additional checks possible. */ 298 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 299 uint32_t blocks_allocated = 0; 300 uint32_t block; 301 uint32_t *bmap; 302 logout("\n"); 303 304 bmap = qemu_malloc(s->header.blocks_in_image * sizeof(uint32_t)); 305 memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t)); 306 307 /* Check block map and value of blocks_allocated. */ 308 for (block = 0; block < s->header.blocks_in_image; block++) { 309 uint32_t bmap_entry = le32_to_cpu(s->bmap[block]); 310 if (bmap_entry != VDI_UNALLOCATED) { 311 if (bmap_entry < s->header.blocks_in_image) { 312 blocks_allocated++; 313 if (bmap[bmap_entry] == VDI_UNALLOCATED) { 314 bmap[bmap_entry] = bmap_entry; 315 } else { 316 fprintf(stderr, "ERROR: block index %" PRIu32 317 " also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry); 318 res->corruptions++; 319 } 320 } else { 321 fprintf(stderr, "ERROR: block index %" PRIu32 322 " too large, is %" PRIu32 "\n", block, bmap_entry); 323 res->corruptions++; 324 } 325 } 326 } 327 if (blocks_allocated != s->header.blocks_allocated) { 328 fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32 329 ", should be %" PRIu32 "\n", 330 blocks_allocated, s->header.blocks_allocated); 331 res->corruptions++; 332 } 333 334 qemu_free(bmap); 335 336 return 0; 337 } 338 339 static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 340 { 341 /* TODO: vdi_get_info would be needed for machine snapshots. 342 vm_state_offset is still missing. */ 343 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 344 logout("\n"); 345 bdi->cluster_size = s->block_size; 346 bdi->vm_state_offset = 0; 347 return 0; 348 } 349 350 static int vdi_make_empty(BlockDriverState *bs) 351 { 352 /* TODO: missing code. */ 353 logout("\n"); 354 /* The return value for missing code must be 0, see block.c. */ 355 return 0; 356 } 357 358 static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename) 359 { 360 const VdiHeader *header = (const VdiHeader *)buf; 361 int result = 0; 362 363 logout("\n"); 364 365 if (buf_size < sizeof(*header)) { 366 /* Header too small, no VDI. */ 367 } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) { 368 result = 100; 369 } 370 371 if (result == 0) { 372 logout("no vdi image\n"); 373 } else { 374 logout("%s", header->text); 375 } 376 377 return result; 378 } 379 380 static int vdi_open(BlockDriverState *bs, int flags) 381 { 382 BDRVVdiState *s = bs->opaque; 383 VdiHeader header; 384 size_t bmap_size; 385 386 logout("\n"); 387 388 if (bdrv_read(bs->file, 0, (uint8_t *)&header, 1) < 0) { 389 goto fail; 390 } 391 392 vdi_header_to_cpu(&header); 393 #if defined(CONFIG_VDI_DEBUG) 394 vdi_header_print(&header); 395 #endif 396 397 if (header.disk_size % SECTOR_SIZE != 0) { 398 /* 'VBoxManage convertfromraw' can create images with odd disk sizes. 399 We accept them but round the disk size to the next multiple of 400 SECTOR_SIZE. */ 401 logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size); 402 header.disk_size += SECTOR_SIZE - 1; 403 header.disk_size &= ~(SECTOR_SIZE - 1); 404 } 405 406 if (header.version != VDI_VERSION_1_1) { 407 logout("unsupported version %u.%u\n", 408 header.version >> 16, header.version & 0xffff); 409 goto fail; 410 } else if (header.offset_bmap % SECTOR_SIZE != 0) { 411 /* We only support block maps which start on a sector boundary. */ 412 logout("unsupported block map offset 0x%x B\n", header.offset_bmap); 413 goto fail; 414 } else if (header.offset_data % SECTOR_SIZE != 0) { 415 /* We only support data blocks which start on a sector boundary. */ 416 logout("unsupported data offset 0x%x B\n", header.offset_data); 417 goto fail; 418 } else if (header.sector_size != SECTOR_SIZE) { 419 logout("unsupported sector size %u B\n", header.sector_size); 420 goto fail; 421 } else if (header.block_size != 1 * MiB) { 422 logout("unsupported block size %u B\n", header.block_size); 423 goto fail; 424 } else if (header.disk_size > 425 (uint64_t)header.blocks_in_image * header.block_size) { 426 logout("unsupported disk size %" PRIu64 " B\n", header.disk_size); 427 goto fail; 428 } else if (!uuid_is_null(header.uuid_link)) { 429 logout("link uuid != 0, unsupported\n"); 430 goto fail; 431 } else if (!uuid_is_null(header.uuid_parent)) { 432 logout("parent uuid != 0, unsupported\n"); 433 goto fail; 434 } 435 436 bs->total_sectors = header.disk_size / SECTOR_SIZE; 437 438 s->block_size = header.block_size; 439 s->block_sectors = header.block_size / SECTOR_SIZE; 440 s->bmap_sector = header.offset_bmap / SECTOR_SIZE; 441 s->header = header; 442 443 bmap_size = header.blocks_in_image * sizeof(uint32_t); 444 bmap_size = (bmap_size + SECTOR_SIZE - 1) / SECTOR_SIZE; 445 if (bmap_size > 0) { 446 s->bmap = qemu_malloc(bmap_size * SECTOR_SIZE); 447 } 448 if (bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size) < 0) { 449 goto fail_free_bmap; 450 } 451 452 return 0; 453 454 fail_free_bmap: 455 qemu_free(s->bmap); 456 457 fail: 458 return -1; 459 } 460 461 static int vdi_is_allocated(BlockDriverState *bs, int64_t sector_num, 462 int nb_sectors, int *pnum) 463 { 464 /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */ 465 BDRVVdiState *s = (BDRVVdiState *)bs->opaque; 466 size_t bmap_index = sector_num / s->block_sectors; 467 size_t sector_in_block = sector_num % s->block_sectors; 468 int n_sectors = s->block_sectors - sector_in_block; 469 uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]); 470 logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum); 471 if (n_sectors > nb_sectors) { 472 n_sectors = nb_sectors; 473 } 474 *pnum = n_sectors; 475 return bmap_entry != VDI_UNALLOCATED; 476 } 477 478 static void vdi_aio_cancel(BlockDriverAIOCB *blockacb) 479 { 480 /* TODO: This code is untested. How can I get it executed? */ 481 VdiAIOCB *acb = container_of(blockacb, VdiAIOCB, common); 482 logout("\n"); 483 if (acb->hd_aiocb) { 484 bdrv_aio_cancel(acb->hd_aiocb); 485 } 486 qemu_aio_release(acb); 487 } 488 489 static AIOPool vdi_aio_pool = { 490 .aiocb_size = sizeof(VdiAIOCB), 491 .cancel = vdi_aio_cancel, 492 }; 493 494 static VdiAIOCB *vdi_aio_setup(BlockDriverState *bs, int64_t sector_num, 495 QEMUIOVector *qiov, int nb_sectors, 496 BlockDriverCompletionFunc *cb, void *opaque, int is_write) 497 { 498 VdiAIOCB *acb; 499 500 logout("%p, %" PRId64 ", %p, %d, %p, %p, %d\n", 501 bs, sector_num, qiov, nb_sectors, cb, opaque, is_write); 502 503 acb = qemu_aio_get(&vdi_aio_pool, bs, cb, opaque); 504 if (acb) { 505 acb->hd_aiocb = NULL; 506 acb->sector_num = sector_num; 507 acb->qiov = qiov; 508 acb->is_write = is_write; 509 510 if (qiov->niov > 1) { 511 acb->buf = qemu_blockalign(bs, qiov->size); 512 acb->orig_buf = acb->buf; 513 if (is_write) { 514 qemu_iovec_to_buffer(qiov, acb->buf); 515 } 516 } else { 517 acb->buf = (uint8_t *)qiov->iov->iov_base; 518 } 519 acb->nb_sectors = nb_sectors; 520 acb->n_sectors = 0; 521 acb->bmap_first = VDI_UNALLOCATED; 522 acb->bmap_last = VDI_UNALLOCATED; 523 acb->block_buffer = NULL; 524 acb->header_modified = 0; 525 } 526 return acb; 527 } 528 529 static int vdi_schedule_bh(QEMUBHFunc *cb, VdiAIOCB *acb) 530 { 531 logout("\n"); 532 533 if (acb->bh) { 534 return -EIO; 535 } 536 537 acb->bh = qemu_bh_new(cb, acb); 538 if (!acb->bh) { 539 return -EIO; 540 } 541 542 qemu_bh_schedule(acb->bh); 543 544 return 0; 545 } 546 547 static void vdi_aio_read_cb(void *opaque, int ret); 548 static void vdi_aio_write_cb(void *opaque, int ret); 549 550 static void vdi_aio_rw_bh(void *opaque) 551 { 552 VdiAIOCB *acb = opaque; 553 logout("\n"); 554 qemu_bh_delete(acb->bh); 555 acb->bh = NULL; 556 557 if (acb->is_write) { 558 vdi_aio_write_cb(opaque, 0); 559 } else { 560 vdi_aio_read_cb(opaque, 0); 561 } 562 } 563 564 static void vdi_aio_read_cb(void *opaque, int ret) 565 { 566 VdiAIOCB *acb = opaque; 567 BlockDriverState *bs = acb->common.bs; 568 BDRVVdiState *s = bs->opaque; 569 uint32_t bmap_entry; 570 uint32_t block_index; 571 uint32_t sector_in_block; 572 uint32_t n_sectors; 573 574 logout("%u sectors read\n", acb->n_sectors); 575 576 acb->hd_aiocb = NULL; 577 578 if (ret < 0) { 579 goto done; 580 } 581 582 acb->nb_sectors -= acb->n_sectors; 583 584 if (acb->nb_sectors == 0) { 585 /* request completed */ 586 ret = 0; 587 goto done; 588 } 589 590 acb->sector_num += acb->n_sectors; 591 acb->buf += acb->n_sectors * SECTOR_SIZE; 592 593 block_index = acb->sector_num / s->block_sectors; 594 sector_in_block = acb->sector_num % s->block_sectors; 595 n_sectors = s->block_sectors - sector_in_block; 596 if (n_sectors > acb->nb_sectors) { 597 n_sectors = acb->nb_sectors; 598 } 599 600 logout("will read %u sectors starting at sector %" PRIu64 "\n", 601 n_sectors, acb->sector_num); 602 603 /* prepare next AIO request */ 604 acb->n_sectors = n_sectors; 605 bmap_entry = le32_to_cpu(s->bmap[block_index]); 606 if (bmap_entry == VDI_UNALLOCATED) { 607 /* Block not allocated, return zeros, no need to wait. */ 608 memset(acb->buf, 0, n_sectors * SECTOR_SIZE); 609 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 610 if (ret < 0) { 611 goto done; 612 } 613 } else { 614 uint64_t offset = s->header.offset_data / SECTOR_SIZE + 615 (uint64_t)bmap_entry * s->block_sectors + 616 sector_in_block; 617 acb->hd_iov.iov_base = (void *)acb->buf; 618 acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE; 619 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 620 acb->hd_aiocb = bdrv_aio_readv(bs->file, offset, &acb->hd_qiov, 621 n_sectors, vdi_aio_read_cb, acb); 622 if (acb->hd_aiocb == NULL) { 623 ret = -EIO; 624 goto done; 625 } 626 } 627 return; 628 done: 629 if (acb->qiov->niov > 1) { 630 qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size); 631 qemu_vfree(acb->orig_buf); 632 } 633 acb->common.cb(acb->common.opaque, ret); 634 qemu_aio_release(acb); 635 } 636 637 static BlockDriverAIOCB *vdi_aio_readv(BlockDriverState *bs, 638 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 639 BlockDriverCompletionFunc *cb, void *opaque) 640 { 641 VdiAIOCB *acb; 642 int ret; 643 644 logout("\n"); 645 acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 646 if (!acb) { 647 return NULL; 648 } 649 650 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 651 if (ret < 0) { 652 if (acb->qiov->niov > 1) { 653 qemu_vfree(acb->orig_buf); 654 } 655 qemu_aio_release(acb); 656 return NULL; 657 } 658 659 return &acb->common; 660 } 661 662 static void vdi_aio_write_cb(void *opaque, int ret) 663 { 664 VdiAIOCB *acb = opaque; 665 BlockDriverState *bs = acb->common.bs; 666 BDRVVdiState *s = bs->opaque; 667 uint32_t bmap_entry; 668 uint32_t block_index; 669 uint32_t sector_in_block; 670 uint32_t n_sectors; 671 672 acb->hd_aiocb = NULL; 673 674 if (ret < 0) { 675 goto done; 676 } 677 678 acb->nb_sectors -= acb->n_sectors; 679 acb->sector_num += acb->n_sectors; 680 acb->buf += acb->n_sectors * SECTOR_SIZE; 681 682 if (acb->nb_sectors == 0) { 683 logout("finished data write\n"); 684 acb->n_sectors = 0; 685 if (acb->header_modified) { 686 VdiHeader *header = acb->block_buffer; 687 logout("now writing modified header\n"); 688 assert(acb->bmap_first != VDI_UNALLOCATED); 689 *header = s->header; 690 vdi_header_to_le(header); 691 acb->header_modified = 0; 692 acb->hd_iov.iov_base = acb->block_buffer; 693 acb->hd_iov.iov_len = SECTOR_SIZE; 694 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 695 acb->hd_aiocb = bdrv_aio_writev(bs->file, 0, &acb->hd_qiov, 1, 696 vdi_aio_write_cb, acb); 697 if (acb->hd_aiocb == NULL) { 698 ret = -EIO; 699 goto done; 700 } 701 return; 702 } else if (acb->bmap_first != VDI_UNALLOCATED) { 703 /* One or more new blocks were allocated. */ 704 uint64_t offset; 705 uint32_t bmap_first; 706 uint32_t bmap_last; 707 qemu_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 if (acb->hd_aiocb == NULL) { 728 ret = -EIO; 729 goto done; 730 } 731 return; 732 } 733 ret = 0; 734 goto done; 735 } 736 737 logout("%u sectors written\n", acb->n_sectors); 738 739 block_index = acb->sector_num / s->block_sectors; 740 sector_in_block = acb->sector_num % s->block_sectors; 741 n_sectors = s->block_sectors - sector_in_block; 742 if (n_sectors > acb->nb_sectors) { 743 n_sectors = acb->nb_sectors; 744 } 745 746 logout("will write %u sectors starting at sector %" PRIu64 "\n", 747 n_sectors, acb->sector_num); 748 749 /* prepare next AIO request */ 750 acb->n_sectors = n_sectors; 751 bmap_entry = le32_to_cpu(s->bmap[block_index]); 752 if (bmap_entry == VDI_UNALLOCATED) { 753 /* Allocate new block and write to it. */ 754 uint64_t offset; 755 uint8_t *block; 756 bmap_entry = s->header.blocks_allocated; 757 s->bmap[block_index] = cpu_to_le32(bmap_entry); 758 s->header.blocks_allocated++; 759 offset = s->header.offset_data / SECTOR_SIZE + 760 (uint64_t)bmap_entry * s->block_sectors; 761 block = acb->block_buffer; 762 if (block == NULL) { 763 block = qemu_mallocz(s->block_size); 764 acb->block_buffer = block; 765 acb->bmap_first = block_index; 766 assert(!acb->header_modified); 767 acb->header_modified = 1; 768 } 769 acb->bmap_last = block_index; 770 memcpy(block + sector_in_block * SECTOR_SIZE, 771 acb->buf, n_sectors * 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 if (acb->hd_aiocb == NULL) { 779 ret = -EIO; 780 goto done; 781 } 782 } else { 783 uint64_t offset = s->header.offset_data / SECTOR_SIZE + 784 (uint64_t)bmap_entry * s->block_sectors + 785 sector_in_block; 786 acb->hd_iov.iov_base = (void *)acb->buf; 787 acb->hd_iov.iov_len = n_sectors * SECTOR_SIZE; 788 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1); 789 acb->hd_aiocb = bdrv_aio_writev(bs->file, offset, &acb->hd_qiov, 790 n_sectors, vdi_aio_write_cb, acb); 791 if (acb->hd_aiocb == NULL) { 792 ret = -EIO; 793 goto done; 794 } 795 } 796 797 return; 798 799 done: 800 if (acb->qiov->niov > 1) { 801 qemu_vfree(acb->orig_buf); 802 } 803 acb->common.cb(acb->common.opaque, ret); 804 qemu_aio_release(acb); 805 } 806 807 static BlockDriverAIOCB *vdi_aio_writev(BlockDriverState *bs, 808 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 809 BlockDriverCompletionFunc *cb, void *opaque) 810 { 811 VdiAIOCB *acb; 812 int ret; 813 814 logout("\n"); 815 acb = vdi_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); 816 if (!acb) { 817 return NULL; 818 } 819 820 ret = vdi_schedule_bh(vdi_aio_rw_bh, acb); 821 if (ret < 0) { 822 if (acb->qiov->niov > 1) { 823 qemu_vfree(acb->orig_buf); 824 } 825 qemu_aio_release(acb); 826 return NULL; 827 } 828 829 return &acb->common; 830 } 831 832 static int vdi_create(const char *filename, QEMUOptionParameter *options) 833 { 834 int fd; 835 int result = 0; 836 uint64_t bytes = 0; 837 uint32_t blocks; 838 size_t block_size = DEFAULT_CLUSTER_SIZE; 839 uint32_t image_type = VDI_TYPE_DYNAMIC; 840 VdiHeader header; 841 size_t i; 842 size_t bmap_size; 843 uint32_t *bmap; 844 845 logout("\n"); 846 847 /* Read out options. */ 848 while (options && options->name) { 849 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 850 bytes = options->value.n; 851 #if defined(CONFIG_VDI_BLOCK_SIZE) 852 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 853 if (options->value.n) { 854 /* TODO: Additional checks (SECTOR_SIZE * 2^n, ...). */ 855 block_size = options->value.n; 856 } 857 #endif 858 #if defined(CONFIG_VDI_STATIC_IMAGE) 859 } else if (!strcmp(options->name, BLOCK_OPT_STATIC)) { 860 if (options->value.n) { 861 image_type = VDI_TYPE_STATIC; 862 } 863 #endif 864 } 865 options++; 866 } 867 868 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, 869 0644); 870 if (fd < 0) { 871 return -errno; 872 } 873 874 /* We need enough blocks to store the given disk size, 875 so always round up. */ 876 blocks = (bytes + block_size - 1) / block_size; 877 878 bmap_size = blocks * sizeof(uint32_t); 879 bmap_size = ((bmap_size + SECTOR_SIZE - 1) & ~(SECTOR_SIZE -1)); 880 881 memset(&header, 0, sizeof(header)); 882 pstrcpy(header.text, sizeof(header.text), VDI_TEXT); 883 header.signature = VDI_SIGNATURE; 884 header.version = VDI_VERSION_1_1; 885 header.header_size = 0x180; 886 header.image_type = image_type; 887 header.offset_bmap = 0x200; 888 header.offset_data = 0x200 + bmap_size; 889 header.sector_size = SECTOR_SIZE; 890 header.disk_size = bytes; 891 header.block_size = block_size; 892 header.blocks_in_image = blocks; 893 if (image_type == VDI_TYPE_STATIC) { 894 header.blocks_allocated = blocks; 895 } 896 uuid_generate(header.uuid_image); 897 uuid_generate(header.uuid_last_snap); 898 /* There is no need to set header.uuid_link or header.uuid_parent here. */ 899 #if defined(CONFIG_VDI_DEBUG) 900 vdi_header_print(&header); 901 #endif 902 vdi_header_to_le(&header); 903 if (write(fd, &header, sizeof(header)) < 0) { 904 result = -errno; 905 } 906 907 bmap = NULL; 908 if (bmap_size > 0) { 909 bmap = (uint32_t *)qemu_mallocz(bmap_size); 910 } 911 for (i = 0; i < blocks; i++) { 912 if (image_type == VDI_TYPE_STATIC) { 913 bmap[i] = i; 914 } else { 915 bmap[i] = VDI_UNALLOCATED; 916 } 917 } 918 if (write(fd, bmap, bmap_size) < 0) { 919 result = -errno; 920 } 921 qemu_free(bmap); 922 if (image_type == VDI_TYPE_STATIC) { 923 if (ftruncate(fd, sizeof(header) + bmap_size + blocks * block_size)) { 924 result = -errno; 925 } 926 } 927 928 if (close(fd) < 0) { 929 result = -errno; 930 } 931 932 return result; 933 } 934 935 static void vdi_close(BlockDriverState *bs) 936 { 937 } 938 939 static int vdi_flush(BlockDriverState *bs) 940 { 941 logout("\n"); 942 return bdrv_flush(bs->file); 943 } 944 945 946 static QEMUOptionParameter vdi_create_options[] = { 947 { 948 .name = BLOCK_OPT_SIZE, 949 .type = OPT_SIZE, 950 .help = "Virtual disk size" 951 }, 952 #if defined(CONFIG_VDI_BLOCK_SIZE) 953 { 954 .name = BLOCK_OPT_CLUSTER_SIZE, 955 .type = OPT_SIZE, 956 .help = "VDI cluster (block) size", 957 .value = { .n = DEFAULT_CLUSTER_SIZE }, 958 }, 959 #endif 960 #if defined(CONFIG_VDI_STATIC_IMAGE) 961 { 962 .name = BLOCK_OPT_STATIC, 963 .type = OPT_FLAG, 964 .help = "VDI static (pre-allocated) image" 965 }, 966 #endif 967 /* TODO: An additional option to set UUID values might be useful. */ 968 { NULL } 969 }; 970 971 static BlockDriver bdrv_vdi = { 972 .format_name = "vdi", 973 .instance_size = sizeof(BDRVVdiState), 974 .bdrv_probe = vdi_probe, 975 .bdrv_open = vdi_open, 976 .bdrv_close = vdi_close, 977 .bdrv_create = vdi_create, 978 .bdrv_flush = vdi_flush, 979 .bdrv_is_allocated = vdi_is_allocated, 980 .bdrv_make_empty = vdi_make_empty, 981 982 .bdrv_aio_readv = vdi_aio_readv, 983 #if defined(CONFIG_VDI_WRITE) 984 .bdrv_aio_writev = vdi_aio_writev, 985 #endif 986 987 .bdrv_get_info = vdi_get_info, 988 989 .create_options = vdi_create_options, 990 .bdrv_check = vdi_check, 991 }; 992 993 static void bdrv_vdi_init(void) 994 { 995 logout("\n"); 996 bdrv_register(&bdrv_vdi); 997 } 998 999 block_init(bdrv_vdi_init); 1000