1 /* 2 * Block driver for Hyper-V VHDX Images 3 * 4 * Copyright (c) 2013 Red Hat, Inc., 5 * 6 * Authors: 7 * Jeff Cody <jcody@redhat.com> 8 * 9 * This is based on the "VHDX Format Specification v1.00", published 8/25/2012 10 * by Microsoft: 11 * https://www.microsoft.com/en-us/download/details.aspx?id=34750 12 * 13 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 14 * See the COPYING.LIB file in the top-level directory. 15 * 16 */ 17 18 #include "qemu/osdep.h" 19 #include "qapi/error.h" 20 #include "qemu-common.h" 21 #include "block/block_int.h" 22 #include "sysemu/block-backend.h" 23 #include "qemu/module.h" 24 #include "qemu/crc32c.h" 25 #include "qemu/bswap.h" 26 #include "block/vhdx.h" 27 #include "migration/migration.h" 28 #include "qemu/uuid.h" 29 30 /* Options for VHDX creation */ 31 32 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size" 33 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size" 34 #define VHDX_BLOCK_OPT_ZERO "block_state_zero" 35 36 typedef enum VHDXImageType { 37 VHDX_TYPE_DYNAMIC = 0, 38 VHDX_TYPE_FIXED, 39 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */ 40 } VHDXImageType; 41 42 /* Several metadata and region table data entries are identified by 43 * guids in a MS-specific GUID format. */ 44 45 46 /* ------- Known Region Table GUIDs ---------------------- */ 47 static const MSGUID bat_guid = { .data1 = 0x2dc27766, 48 .data2 = 0xf623, 49 .data3 = 0x4200, 50 .data4 = { 0x9d, 0x64, 0x11, 0x5e, 51 0x9b, 0xfd, 0x4a, 0x08} }; 52 53 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, 54 .data2 = 0x4790, 55 .data3 = 0x4b9a, 56 .data4 = { 0xb8, 0xfe, 0x57, 0x5f, 57 0x05, 0x0f, 0x88, 0x6e} }; 58 59 60 61 /* ------- Known Metadata Entry GUIDs ---------------------- */ 62 static const MSGUID file_param_guid = { .data1 = 0xcaa16737, 63 .data2 = 0xfa36, 64 .data3 = 0x4d43, 65 .data4 = { 0xb3, 0xb6, 0x33, 0xf0, 66 0xaa, 0x44, 0xe7, 0x6b} }; 67 68 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, 69 .data2 = 0xcd1b, 70 .data3 = 0x4876, 71 .data4 = { 0xb2, 0x11, 0x5d, 0xbe, 72 0xd8, 0x3b, 0xf4, 0xb8} }; 73 74 static const MSGUID page83_guid = { .data1 = 0xbeca12ab, 75 .data2 = 0xb2e6, 76 .data3 = 0x4523, 77 .data4 = { 0x93, 0xef, 0xc3, 0x09, 78 0xe0, 0x00, 0xc7, 0x46} }; 79 80 81 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, 82 .data2 = 0x445d, 83 .data3 = 0x4471, 84 .data4 = { 0x9c, 0xc9, 0xe9, 0x88, 85 0x52, 0x51, 0xc5, 0x56} }; 86 87 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, 88 .data2 = 0xb30b, 89 .data3 = 0x454d, 90 .data4 = { 0xab, 0xf7, 0xd3, 91 0xd8, 0x48, 0x34, 92 0xab, 0x0c} }; 93 94 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, 95 .data2 = 0xa96f, 96 .data3 = 0x4709, 97 .data4 = { 0xba, 0x47, 0xf2, 98 0x33, 0xa8, 0xfa, 99 0xab, 0x5f} }; 100 101 /* Each parent type must have a valid GUID; this is for parent images 102 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would 103 * need to make up our own QCOW2 GUID type */ 104 static const MSGUID parent_vhdx_guid __attribute__((unused)) 105 = { .data1 = 0xb04aefb7, 106 .data2 = 0xd19e, 107 .data3 = 0x4a81, 108 .data4 = { 0xb7, 0x89, 0x25, 0xb8, 109 0xe9, 0x44, 0x59, 0x13} }; 110 111 112 #define META_FILE_PARAMETER_PRESENT 0x01 113 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 114 #define META_PAGE_83_PRESENT 0x04 115 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 116 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 117 #define META_PARENT_LOCATOR_PRESENT 0x20 118 119 #define META_ALL_PRESENT \ 120 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ 121 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ 122 META_PHYS_SECTOR_SIZE_PRESENT) 123 124 125 typedef struct VHDXSectorInfo { 126 uint32_t bat_idx; /* BAT entry index */ 127 uint32_t sectors_avail; /* sectors available in payload block */ 128 uint32_t bytes_left; /* bytes left in the block after data to r/w */ 129 uint32_t bytes_avail; /* bytes available in payload block */ 130 uint64_t file_offset; /* absolute offset in bytes, in file */ 131 uint64_t block_offset; /* block offset, in bytes */ 132 } VHDXSectorInfo; 133 134 /* Calculates new checksum. 135 * 136 * Zero is substituted during crc calculation for the original crc field 137 * crc_offset: byte offset in buf of the buffer crc 138 * buf: buffer pointer 139 * size: size of buffer (must be > crc_offset+4) 140 * 141 * Note: The buffer should have all multi-byte data in little-endian format, 142 * and the resulting checksum is in little endian format. 143 */ 144 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) 145 { 146 uint32_t crc; 147 148 assert(buf != NULL); 149 assert(size > (crc_offset + sizeof(crc))); 150 151 memset(buf + crc_offset, 0, sizeof(crc)); 152 crc = crc32c(0xffffffff, buf, size); 153 cpu_to_le32s(&crc); 154 memcpy(buf + crc_offset, &crc, sizeof(crc)); 155 156 return crc; 157 } 158 159 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, 160 int crc_offset) 161 { 162 uint32_t crc_new; 163 uint32_t crc_orig; 164 assert(buf != NULL); 165 166 if (crc_offset > 0) { 167 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 168 memset(buf + crc_offset, 0, sizeof(crc_orig)); 169 } 170 171 crc_new = crc32c(crc, buf, size); 172 if (crc_offset > 0) { 173 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); 174 } 175 176 return crc_new; 177 } 178 179 /* Validates the checksum of the buffer, with an in-place CRC. 180 * 181 * Zero is substituted during crc calculation for the original crc field, 182 * and the crc field is restored afterwards. But the buffer will be modifed 183 * during the calculation, so this may not be not suitable for multi-threaded 184 * use. 185 * 186 * crc_offset: byte offset in buf of the buffer crc 187 * buf: buffer pointer 188 * size: size of buffer (must be > crc_offset+4) 189 * 190 * returns true if checksum is valid, false otherwise 191 */ 192 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) 193 { 194 uint32_t crc_orig; 195 uint32_t crc; 196 197 assert(buf != NULL); 198 assert(size > (crc_offset + 4)); 199 200 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 201 crc_orig = le32_to_cpu(crc_orig); 202 203 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); 204 205 return crc == crc_orig; 206 } 207 208 209 /* 210 * This generates a UUID that is compliant with the MS GUIDs used 211 * in the VHDX spec (and elsewhere). 212 */ 213 void vhdx_guid_generate(MSGUID *guid) 214 { 215 QemuUUID uuid; 216 assert(guid != NULL); 217 218 qemu_uuid_generate(&uuid); 219 memcpy(guid, &uuid, sizeof(MSGUID)); 220 } 221 222 /* Check for region overlaps inside the VHDX image */ 223 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) 224 { 225 int ret = 0; 226 uint64_t end; 227 VHDXRegionEntry *r; 228 229 end = start + length; 230 QLIST_FOREACH(r, &s->regions, entries) { 231 if (!((start >= r->end) || (end <= r->start))) { 232 ret = -EINVAL; 233 goto exit; 234 } 235 } 236 237 exit: 238 return ret; 239 } 240 241 /* Register a region for future checks */ 242 static void vhdx_region_register(BDRVVHDXState *s, 243 uint64_t start, uint64_t length) 244 { 245 VHDXRegionEntry *r; 246 247 r = g_malloc0(sizeof(*r)); 248 249 r->start = start; 250 r->end = start + length; 251 252 QLIST_INSERT_HEAD(&s->regions, r, entries); 253 } 254 255 /* Free all registered regions */ 256 static void vhdx_region_unregister_all(BDRVVHDXState *s) 257 { 258 VHDXRegionEntry *r, *r_next; 259 260 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { 261 QLIST_REMOVE(r, entries); 262 g_free(r); 263 } 264 } 265 266 static void vhdx_set_shift_bits(BDRVVHDXState *s) 267 { 268 s->logical_sector_size_bits = ctz32(s->logical_sector_size); 269 s->sectors_per_block_bits = ctz32(s->sectors_per_block); 270 s->chunk_ratio_bits = ctz64(s->chunk_ratio); 271 s->block_size_bits = ctz32(s->block_size); 272 } 273 274 /* 275 * Per the MS VHDX Specification, for every VHDX file: 276 * - The header section is fixed size - 1 MB 277 * - The header section is always the first "object" 278 * - The first 64KB of the header is the File Identifier 279 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") 280 * - The following 512 bytes constitute a UTF-16 string identifiying the 281 * software that created the file, and is optional and diagnostic only. 282 * 283 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" 284 */ 285 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) 286 { 287 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { 288 return 100; 289 } 290 return 0; 291 } 292 293 /* 294 * Writes the header to the specified offset. 295 * 296 * This will optionally read in buffer data from disk (otherwise zero-fill), 297 * and then update the header checksum. Header is converted to proper 298 * endianness before being written to the specified file offset 299 */ 300 static int vhdx_write_header(BdrvChild *file, VHDXHeader *hdr, 301 uint64_t offset, bool read) 302 { 303 BlockDriverState *bs_file = file->bs; 304 uint8_t *buffer = NULL; 305 int ret; 306 VHDXHeader *header_le; 307 308 assert(bs_file != NULL); 309 assert(hdr != NULL); 310 311 /* the header checksum is not over just the packed size of VHDXHeader, 312 * but rather over the entire 'reserved' range for the header, which is 313 * 4KB (VHDX_HEADER_SIZE). */ 314 315 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); 316 if (read) { 317 /* if true, we can't assume the extra reserved bytes are 0 */ 318 ret = bdrv_pread(file, offset, buffer, VHDX_HEADER_SIZE); 319 if (ret < 0) { 320 goto exit; 321 } 322 } else { 323 memset(buffer, 0, VHDX_HEADER_SIZE); 324 } 325 326 /* overwrite the actual VHDXHeader portion */ 327 header_le = (VHDXHeader *)buffer; 328 memcpy(header_le, hdr, sizeof(VHDXHeader)); 329 vhdx_header_le_export(hdr, header_le); 330 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, 331 offsetof(VHDXHeader, checksum)); 332 ret = bdrv_pwrite_sync(file, offset, header_le, sizeof(VHDXHeader)); 333 334 exit: 335 qemu_vfree(buffer); 336 return ret; 337 } 338 339 /* Update the VHDX headers 340 * 341 * This follows the VHDX spec procedures for header updates. 342 * 343 * - non-current header is updated with largest sequence number 344 */ 345 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 346 bool generate_data_write_guid, MSGUID *log_guid) 347 { 348 int ret = 0; 349 int hdr_idx = 0; 350 uint64_t header_offset = VHDX_HEADER1_OFFSET; 351 352 VHDXHeader *active_header; 353 VHDXHeader *inactive_header; 354 355 /* operate on the non-current header */ 356 if (s->curr_header == 0) { 357 hdr_idx = 1; 358 header_offset = VHDX_HEADER2_OFFSET; 359 } 360 361 active_header = s->headers[s->curr_header]; 362 inactive_header = s->headers[hdr_idx]; 363 364 inactive_header->sequence_number = active_header->sequence_number + 1; 365 366 /* a new file guid must be generated before any file write, including 367 * headers */ 368 inactive_header->file_write_guid = s->session_guid; 369 370 /* a new data guid only needs to be generated before any guest-visible 371 * writes (i.e. something observable via virtual disk read) */ 372 if (generate_data_write_guid) { 373 vhdx_guid_generate(&inactive_header->data_write_guid); 374 } 375 376 /* update the log guid if present */ 377 if (log_guid) { 378 inactive_header->log_guid = *log_guid; 379 } 380 381 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 382 if (ret < 0) { 383 goto exit; 384 } 385 s->curr_header = hdr_idx; 386 387 exit: 388 return ret; 389 } 390 391 /* 392 * The VHDX spec calls for header updates to be performed twice, so that both 393 * the current and non-current header have valid info 394 */ 395 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 396 bool generate_data_write_guid, MSGUID *log_guid) 397 { 398 int ret; 399 400 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 401 if (ret < 0) { 402 return ret; 403 } 404 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 405 return ret; 406 } 407 408 /* opens the specified header block from the VHDX file header section */ 409 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, 410 Error **errp) 411 { 412 int ret; 413 VHDXHeader *header1; 414 VHDXHeader *header2; 415 bool h1_valid = false; 416 bool h2_valid = false; 417 uint64_t h1_seq = 0; 418 uint64_t h2_seq = 0; 419 uint8_t *buffer; 420 421 /* header1 & header2 are freed in vhdx_close() */ 422 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 423 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 424 425 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 426 427 s->headers[0] = header1; 428 s->headers[1] = header2; 429 430 /* We have to read the whole VHDX_HEADER_SIZE instead of 431 * sizeof(VHDXHeader), because the checksum is over the whole 432 * region */ 433 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, 434 VHDX_HEADER_SIZE); 435 if (ret < 0) { 436 goto fail; 437 } 438 /* copy over just the relevant portion that we need */ 439 memcpy(header1, buffer, sizeof(VHDXHeader)); 440 441 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 442 vhdx_header_le_import(header1); 443 if (header1->signature == VHDX_HEADER_SIGNATURE && 444 header1->version == 1) { 445 h1_seq = header1->sequence_number; 446 h1_valid = true; 447 } 448 } 449 450 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, 451 VHDX_HEADER_SIZE); 452 if (ret < 0) { 453 goto fail; 454 } 455 /* copy over just the relevant portion that we need */ 456 memcpy(header2, buffer, sizeof(VHDXHeader)); 457 458 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 459 vhdx_header_le_import(header2); 460 if (header2->signature == VHDX_HEADER_SIGNATURE && 461 header2->version == 1) { 462 h2_seq = header2->sequence_number; 463 h2_valid = true; 464 } 465 } 466 467 /* If there is only 1 valid header (or no valid headers), we 468 * don't care what the sequence numbers are */ 469 if (h1_valid && !h2_valid) { 470 s->curr_header = 0; 471 } else if (!h1_valid && h2_valid) { 472 s->curr_header = 1; 473 } else if (!h1_valid && !h2_valid) { 474 goto fail; 475 } else { 476 /* If both headers are valid, then we choose the active one by the 477 * highest sequence number. If the sequence numbers are equal, that is 478 * invalid */ 479 if (h1_seq > h2_seq) { 480 s->curr_header = 0; 481 } else if (h2_seq > h1_seq) { 482 s->curr_header = 1; 483 } else { 484 /* The Microsoft Disk2VHD tool will create 2 identical 485 * headers, with identical sequence numbers. If the headers are 486 * identical, don't consider the file corrupt */ 487 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 488 s->curr_header = 0; 489 } else { 490 goto fail; 491 } 492 } 493 } 494 495 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 496 s->headers[s->curr_header]->log_length); 497 goto exit; 498 499 fail: 500 error_setg_errno(errp, -ret, "No valid VHDX header found"); 501 qemu_vfree(header1); 502 qemu_vfree(header2); 503 s->headers[0] = NULL; 504 s->headers[1] = NULL; 505 exit: 506 qemu_vfree(buffer); 507 } 508 509 510 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 511 { 512 int ret = 0; 513 uint8_t *buffer; 514 int offset = 0; 515 VHDXRegionTableEntry rt_entry; 516 uint32_t i; 517 bool bat_rt_found = false; 518 bool metadata_rt_found = false; 519 520 /* We have to read the whole 64KB block, because the crc32 is over the 521 * whole block */ 522 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 523 524 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 525 VHDX_HEADER_BLOCK_SIZE); 526 if (ret < 0) { 527 goto fail; 528 } 529 memcpy(&s->rt, buffer, sizeof(s->rt)); 530 offset += sizeof(s->rt); 531 532 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 533 ret = -EINVAL; 534 goto fail; 535 } 536 537 vhdx_region_header_le_import(&s->rt); 538 539 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 540 ret = -EINVAL; 541 goto fail; 542 } 543 544 545 /* Per spec, maximum region table entry count is 2047 */ 546 if (s->rt.entry_count > 2047) { 547 ret = -EINVAL; 548 goto fail; 549 } 550 551 for (i = 0; i < s->rt.entry_count; i++) { 552 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 553 offset += sizeof(rt_entry); 554 555 vhdx_region_entry_le_import(&rt_entry); 556 557 /* check for region overlap between these entries, and any 558 * other memory regions in the file */ 559 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 560 if (ret < 0) { 561 goto fail; 562 } 563 564 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 565 566 /* see if we recognize the entry */ 567 if (guid_eq(rt_entry.guid, bat_guid)) { 568 /* must be unique; if we have already found it this is invalid */ 569 if (bat_rt_found) { 570 ret = -EINVAL; 571 goto fail; 572 } 573 bat_rt_found = true; 574 s->bat_rt = rt_entry; 575 continue; 576 } 577 578 if (guid_eq(rt_entry.guid, metadata_guid)) { 579 /* must be unique; if we have already found it this is invalid */ 580 if (metadata_rt_found) { 581 ret = -EINVAL; 582 goto fail; 583 } 584 metadata_rt_found = true; 585 s->metadata_rt = rt_entry; 586 continue; 587 } 588 589 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 590 /* cannot read vhdx file - required region table entry that 591 * we do not understand. per spec, we must fail to open */ 592 ret = -ENOTSUP; 593 goto fail; 594 } 595 } 596 597 if (!bat_rt_found || !metadata_rt_found) { 598 ret = -EINVAL; 599 goto fail; 600 } 601 602 ret = 0; 603 604 fail: 605 qemu_vfree(buffer); 606 return ret; 607 } 608 609 610 611 /* Metadata initial parser 612 * 613 * This loads all the metadata entry fields. This may cause additional 614 * fields to be processed (e.g. parent locator, etc..). 615 * 616 * There are 5 Metadata items that are always required: 617 * - File Parameters (block size, has a parent) 618 * - Virtual Disk Size (size, in bytes, of the virtual drive) 619 * - Page 83 Data (scsi page 83 guid) 620 * - Logical Sector Size (logical sector size in bytes, either 512 or 621 * 4096. We only support 512 currently) 622 * - Physical Sector Size (512 or 4096) 623 * 624 * Also, if the File Parameters indicate this is a differencing file, 625 * we must also look for the Parent Locator metadata item. 626 */ 627 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 628 { 629 int ret = 0; 630 uint8_t *buffer; 631 int offset = 0; 632 uint32_t i = 0; 633 VHDXMetadataTableEntry md_entry; 634 635 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 636 637 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 638 VHDX_METADATA_TABLE_MAX_SIZE); 639 if (ret < 0) { 640 goto exit; 641 } 642 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 643 offset += sizeof(s->metadata_hdr); 644 645 vhdx_metadata_header_le_import(&s->metadata_hdr); 646 647 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 648 ret = -EINVAL; 649 goto exit; 650 } 651 652 s->metadata_entries.present = 0; 653 654 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 655 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 656 ret = -EINVAL; 657 goto exit; 658 } 659 660 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 661 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 662 offset += sizeof(md_entry); 663 664 vhdx_metadata_entry_le_import(&md_entry); 665 666 if (guid_eq(md_entry.item_id, file_param_guid)) { 667 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 668 ret = -EINVAL; 669 goto exit; 670 } 671 s->metadata_entries.file_parameters_entry = md_entry; 672 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 673 continue; 674 } 675 676 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 677 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 678 ret = -EINVAL; 679 goto exit; 680 } 681 s->metadata_entries.virtual_disk_size_entry = md_entry; 682 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 683 continue; 684 } 685 686 if (guid_eq(md_entry.item_id, page83_guid)) { 687 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 688 ret = -EINVAL; 689 goto exit; 690 } 691 s->metadata_entries.page83_data_entry = md_entry; 692 s->metadata_entries.present |= META_PAGE_83_PRESENT; 693 continue; 694 } 695 696 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 697 if (s->metadata_entries.present & 698 META_LOGICAL_SECTOR_SIZE_PRESENT) { 699 ret = -EINVAL; 700 goto exit; 701 } 702 s->metadata_entries.logical_sector_size_entry = md_entry; 703 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 704 continue; 705 } 706 707 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 708 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 709 ret = -EINVAL; 710 goto exit; 711 } 712 s->metadata_entries.phys_sector_size_entry = md_entry; 713 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 714 continue; 715 } 716 717 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 718 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 719 ret = -EINVAL; 720 goto exit; 721 } 722 s->metadata_entries.parent_locator_entry = md_entry; 723 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 724 continue; 725 } 726 727 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 728 /* cannot read vhdx file - required region table entry that 729 * we do not understand. per spec, we must fail to open */ 730 ret = -ENOTSUP; 731 goto exit; 732 } 733 } 734 735 if (s->metadata_entries.present != META_ALL_PRESENT) { 736 ret = -ENOTSUP; 737 goto exit; 738 } 739 740 ret = bdrv_pread(bs->file, 741 s->metadata_entries.file_parameters_entry.offset 742 + s->metadata_rt.file_offset, 743 &s->params, 744 sizeof(s->params)); 745 746 if (ret < 0) { 747 goto exit; 748 } 749 750 le32_to_cpus(&s->params.block_size); 751 le32_to_cpus(&s->params.data_bits); 752 753 754 /* We now have the file parameters, so we can tell if this is a 755 * differencing file (i.e.. has_parent), is dynamic or fixed 756 * sized (leave_blocks_allocated), and the block size */ 757 758 /* The parent locator required iff the file parameters has_parent set */ 759 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 760 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 761 /* TODO: parse parent locator fields */ 762 ret = -ENOTSUP; /* temp, until differencing files are supported */ 763 goto exit; 764 } else { 765 /* if has_parent is set, but there is not parent locator present, 766 * then that is an invalid combination */ 767 ret = -EINVAL; 768 goto exit; 769 } 770 } 771 772 /* determine virtual disk size, logical sector size, 773 * and phys sector size */ 774 775 ret = bdrv_pread(bs->file, 776 s->metadata_entries.virtual_disk_size_entry.offset 777 + s->metadata_rt.file_offset, 778 &s->virtual_disk_size, 779 sizeof(uint64_t)); 780 if (ret < 0) { 781 goto exit; 782 } 783 ret = bdrv_pread(bs->file, 784 s->metadata_entries.logical_sector_size_entry.offset 785 + s->metadata_rt.file_offset, 786 &s->logical_sector_size, 787 sizeof(uint32_t)); 788 if (ret < 0) { 789 goto exit; 790 } 791 ret = bdrv_pread(bs->file, 792 s->metadata_entries.phys_sector_size_entry.offset 793 + s->metadata_rt.file_offset, 794 &s->physical_sector_size, 795 sizeof(uint32_t)); 796 if (ret < 0) { 797 goto exit; 798 } 799 800 le64_to_cpus(&s->virtual_disk_size); 801 le32_to_cpus(&s->logical_sector_size); 802 le32_to_cpus(&s->physical_sector_size); 803 804 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 805 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 806 ret = -EINVAL; 807 goto exit; 808 } 809 810 /* only 2 supported sector sizes */ 811 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { 812 ret = -EINVAL; 813 goto exit; 814 } 815 816 /* Both block_size and sector_size are guaranteed powers of 2, below. 817 Due to range checks above, s->sectors_per_block can never be < 256 */ 818 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 819 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 820 (uint64_t)s->logical_sector_size / 821 (uint64_t)s->params.block_size; 822 823 /* These values are ones we will want to use for division / multiplication 824 * later on, and they are all guaranteed (per the spec) to be powers of 2, 825 * so we can take advantage of that for shift operations during 826 * reads/writes */ 827 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 828 ret = -EINVAL; 829 goto exit; 830 } 831 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 832 ret = -EINVAL; 833 goto exit; 834 } 835 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 836 ret = -EINVAL; 837 goto exit; 838 } 839 s->block_size = s->params.block_size; 840 if (s->block_size & (s->block_size - 1)) { 841 ret = -EINVAL; 842 goto exit; 843 } 844 845 vhdx_set_shift_bits(s); 846 847 ret = 0; 848 849 exit: 850 qemu_vfree(buffer); 851 return ret; 852 } 853 854 /* 855 * Calculate the number of BAT entries, including sector 856 * bitmap entries. 857 */ 858 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 859 { 860 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 861 862 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 863 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 864 865 if (s->parent_entries) { 866 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 867 } else { 868 s->bat_entries = data_blocks_cnt + 869 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 870 } 871 872 } 873 874 static void vhdx_close(BlockDriverState *bs) 875 { 876 BDRVVHDXState *s = bs->opaque; 877 qemu_vfree(s->headers[0]); 878 s->headers[0] = NULL; 879 qemu_vfree(s->headers[1]); 880 s->headers[1] = NULL; 881 qemu_vfree(s->bat); 882 s->bat = NULL; 883 qemu_vfree(s->parent_entries); 884 s->parent_entries = NULL; 885 migrate_del_blocker(s->migration_blocker); 886 error_free(s->migration_blocker); 887 qemu_vfree(s->log.hdr); 888 s->log.hdr = NULL; 889 vhdx_region_unregister_all(s); 890 } 891 892 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 893 Error **errp) 894 { 895 BDRVVHDXState *s = bs->opaque; 896 int ret = 0; 897 uint32_t i; 898 uint64_t signature; 899 Error *local_err = NULL; 900 901 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 902 false, errp); 903 if (!bs->file) { 904 return -EINVAL; 905 } 906 907 s->bat = NULL; 908 s->first_visible_write = true; 909 910 qemu_co_mutex_init(&s->lock); 911 QLIST_INIT(&s->regions); 912 913 /* validate the file signature */ 914 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 915 if (ret < 0) { 916 goto fail; 917 } 918 if (memcmp(&signature, "vhdxfile", 8)) { 919 ret = -EINVAL; 920 goto fail; 921 } 922 923 /* This is used for any header updates, for the file_write_guid. 924 * The spec dictates that a new value should be used for the first 925 * header update */ 926 vhdx_guid_generate(&s->session_guid); 927 928 vhdx_parse_header(bs, s, &local_err); 929 if (local_err != NULL) { 930 error_propagate(errp, local_err); 931 ret = -EINVAL; 932 goto fail; 933 } 934 935 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 936 if (ret < 0) { 937 goto fail; 938 } 939 940 ret = vhdx_open_region_tables(bs, s); 941 if (ret < 0) { 942 goto fail; 943 } 944 945 ret = vhdx_parse_metadata(bs, s); 946 if (ret < 0) { 947 goto fail; 948 } 949 950 s->block_size = s->params.block_size; 951 952 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 953 * logical_sector_size */ 954 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 955 956 vhdx_calc_bat_entries(s); 957 958 s->bat_offset = s->bat_rt.file_offset; 959 960 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 961 /* BAT allocation is not large enough for all entries */ 962 ret = -EINVAL; 963 goto fail; 964 } 965 966 /* s->bat is freed in vhdx_close() */ 967 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 968 if (s->bat == NULL) { 969 ret = -ENOMEM; 970 goto fail; 971 } 972 973 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 974 if (ret < 0) { 975 goto fail; 976 } 977 978 uint64_t payblocks = s->chunk_ratio; 979 /* endian convert, and verify populated BAT field file offsets against 980 * region table and log entries */ 981 for (i = 0; i < s->bat_entries; i++) { 982 le64_to_cpus(&s->bat[i]); 983 if (payblocks--) { 984 /* payload bat entries */ 985 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 986 PAYLOAD_BLOCK_FULLY_PRESENT) { 987 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, 988 s->block_size); 989 if (ret < 0) { 990 goto fail; 991 } 992 } 993 } else { 994 payblocks = s->chunk_ratio; 995 /* Once differencing files are supported, verify sector bitmap 996 * blocks here */ 997 } 998 } 999 1000 /* Disable migration when VHDX images are used */ 1001 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1002 "does not support live migration", 1003 bdrv_get_device_or_node_name(bs)); 1004 ret = migrate_add_blocker(s->migration_blocker, &local_err); 1005 if (local_err) { 1006 error_propagate(errp, local_err); 1007 error_free(s->migration_blocker); 1008 goto fail; 1009 } 1010 1011 if (flags & BDRV_O_RDWR) { 1012 ret = vhdx_update_headers(bs, s, false, NULL); 1013 if (ret < 0) { 1014 goto fail; 1015 } 1016 } 1017 1018 /* TODO: differencing files */ 1019 1020 return 0; 1021 fail: 1022 vhdx_close(bs); 1023 return ret; 1024 } 1025 1026 static int vhdx_reopen_prepare(BDRVReopenState *state, 1027 BlockReopenQueue *queue, Error **errp) 1028 { 1029 return 0; 1030 } 1031 1032 1033 /* 1034 * Perform sector to block offset translations, to get various 1035 * sector and file offsets into the image. See VHDXSectorInfo 1036 */ 1037 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1038 int nb_sectors, VHDXSectorInfo *sinfo) 1039 { 1040 uint32_t block_offset; 1041 1042 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1043 /* effectively a modulo - this gives us the offset into the block 1044 * (in sector sizes) for our sector number */ 1045 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1046 /* the chunk ratio gives us the interleaving of the sector 1047 * bitmaps, so we need to advance our page block index by the 1048 * sector bitmaps entry number */ 1049 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1050 1051 /* the number of sectors we can read/write in this cycle */ 1052 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1053 1054 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1055 1056 if (sinfo->sectors_avail > nb_sectors) { 1057 sinfo->sectors_avail = nb_sectors; 1058 } 1059 1060 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1061 1062 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1063 1064 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1065 1066 /* The file offset must be past the header section, so must be > 0 */ 1067 if (sinfo->file_offset == 0) { 1068 return; 1069 } 1070 1071 /* block offset is the offset in vhdx logical sectors, in 1072 * the payload data block. Convert that to a byte offset 1073 * in the block, and add in the payload data block offset 1074 * in the file, in bytes, to get the final read address */ 1075 1076 sinfo->file_offset += sinfo->block_offset; 1077 } 1078 1079 1080 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1081 { 1082 BDRVVHDXState *s = bs->opaque; 1083 1084 bdi->cluster_size = s->block_size; 1085 1086 bdi->unallocated_blocks_are_zero = 1087 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; 1088 1089 return 0; 1090 } 1091 1092 1093 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1094 int nb_sectors, QEMUIOVector *qiov) 1095 { 1096 BDRVVHDXState *s = bs->opaque; 1097 int ret = 0; 1098 VHDXSectorInfo sinfo; 1099 uint64_t bytes_done = 0; 1100 QEMUIOVector hd_qiov; 1101 1102 qemu_iovec_init(&hd_qiov, qiov->niov); 1103 1104 qemu_co_mutex_lock(&s->lock); 1105 1106 while (nb_sectors > 0) { 1107 /* We are a differencing file, so we need to inspect the sector bitmap 1108 * to see if we have the data or not */ 1109 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1110 /* not supported yet */ 1111 ret = -ENOTSUP; 1112 goto exit; 1113 } else { 1114 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1115 1116 qemu_iovec_reset(&hd_qiov); 1117 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1118 1119 /* check the payload block state */ 1120 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1121 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1122 case PAYLOAD_BLOCK_UNDEFINED: 1123 case PAYLOAD_BLOCK_UNMAPPED: 1124 case PAYLOAD_BLOCK_UNMAPPED_v095: 1125 case PAYLOAD_BLOCK_ZERO: 1126 /* return zero */ 1127 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1128 break; 1129 case PAYLOAD_BLOCK_FULLY_PRESENT: 1130 qemu_co_mutex_unlock(&s->lock); 1131 ret = bdrv_co_readv(bs->file, 1132 sinfo.file_offset >> BDRV_SECTOR_BITS, 1133 sinfo.sectors_avail, &hd_qiov); 1134 qemu_co_mutex_lock(&s->lock); 1135 if (ret < 0) { 1136 goto exit; 1137 } 1138 break; 1139 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1140 /* we don't yet support difference files, fall through 1141 * to error */ 1142 default: 1143 ret = -EIO; 1144 goto exit; 1145 break; 1146 } 1147 nb_sectors -= sinfo.sectors_avail; 1148 sector_num += sinfo.sectors_avail; 1149 bytes_done += sinfo.bytes_avail; 1150 } 1151 } 1152 ret = 0; 1153 exit: 1154 qemu_co_mutex_unlock(&s->lock); 1155 qemu_iovec_destroy(&hd_qiov); 1156 return ret; 1157 } 1158 1159 /* 1160 * Allocate a new payload block at the end of the file. 1161 * 1162 * Allocation will happen at 1MB alignment inside the file 1163 * 1164 * Returns the file offset start of the new payload block 1165 */ 1166 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1167 uint64_t *new_offset) 1168 { 1169 *new_offset = bdrv_getlength(bs->file->bs); 1170 1171 /* per the spec, the address for a block is in units of 1MB */ 1172 *new_offset = ROUND_UP(*new_offset, 1024 * 1024); 1173 1174 return bdrv_truncate(bs->file, *new_offset + s->block_size); 1175 } 1176 1177 /* 1178 * Update the BAT table entry with the new file offset, and the new entry 1179 * state */ 1180 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1181 VHDXSectorInfo *sinfo, 1182 uint64_t *bat_entry_le, 1183 uint64_t *bat_offset, int state) 1184 { 1185 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1186 * 1MB, and 3 bits for the block state. */ 1187 if ((state == PAYLOAD_BLOCK_ZERO) || 1188 (state == PAYLOAD_BLOCK_UNDEFINED) || 1189 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1190 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1191 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1192 FileOffsetMB field is denoted as 1193 'reserved' in the v1.0 spec. If it is 1194 non-zero, MS Hyper-V will fail to read 1195 the disk image */ 1196 } else { 1197 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1198 } 1199 1200 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1201 1202 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1203 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1204 1205 } 1206 1207 /* Per the spec, on the first write of guest-visible data to the file the 1208 * data write guid must be updated in the header */ 1209 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1210 { 1211 int ret = 0; 1212 if (s->first_visible_write) { 1213 s->first_visible_write = false; 1214 ret = vhdx_update_headers(bs, s, true, NULL); 1215 } 1216 return ret; 1217 } 1218 1219 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1220 int nb_sectors, QEMUIOVector *qiov) 1221 { 1222 int ret = -ENOTSUP; 1223 BDRVVHDXState *s = bs->opaque; 1224 VHDXSectorInfo sinfo; 1225 uint64_t bytes_done = 0; 1226 uint64_t bat_entry = 0; 1227 uint64_t bat_entry_offset = 0; 1228 QEMUIOVector hd_qiov; 1229 struct iovec iov1 = { 0 }; 1230 struct iovec iov2 = { 0 }; 1231 int sectors_to_write; 1232 int bat_state; 1233 uint64_t bat_prior_offset = 0; 1234 bool bat_update = false; 1235 1236 qemu_iovec_init(&hd_qiov, qiov->niov); 1237 1238 qemu_co_mutex_lock(&s->lock); 1239 1240 ret = vhdx_user_visible_write(bs, s); 1241 if (ret < 0) { 1242 goto exit; 1243 } 1244 1245 while (nb_sectors > 0) { 1246 bool use_zero_buffers = false; 1247 bat_update = false; 1248 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1249 /* not supported yet */ 1250 ret = -ENOTSUP; 1251 goto exit; 1252 } else { 1253 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1254 sectors_to_write = sinfo.sectors_avail; 1255 1256 qemu_iovec_reset(&hd_qiov); 1257 /* check the payload block state */ 1258 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1259 switch (bat_state) { 1260 case PAYLOAD_BLOCK_ZERO: 1261 /* in this case, we need to preserve zero writes for 1262 * data that is not part of this write, so we must pad 1263 * the rest of the buffer to zeroes */ 1264 1265 /* if we are on a posix system with ftruncate() that extends 1266 * a file, then it is zero-filled for us. On Win32, the raw 1267 * layer uses SetFilePointer and SetFileEnd, which does not 1268 * zero fill AFAIK */ 1269 1270 /* Queue another write of zero buffers if the underlying file 1271 * does not zero-fill on file extension */ 1272 1273 if (bdrv_has_zero_init(bs->file->bs) == 0) { 1274 use_zero_buffers = true; 1275 1276 /* zero fill the front, if any */ 1277 if (sinfo.block_offset) { 1278 iov1.iov_len = sinfo.block_offset; 1279 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1280 memset(iov1.iov_base, 0, iov1.iov_len); 1281 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1282 iov1.iov_len); 1283 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1284 } 1285 1286 /* our actual data */ 1287 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1288 sinfo.bytes_avail); 1289 1290 /* zero fill the back, if any */ 1291 if ((sinfo.bytes_avail - sinfo.block_offset) < 1292 s->block_size) { 1293 iov2.iov_len = s->block_size - 1294 (sinfo.bytes_avail + sinfo.block_offset); 1295 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1296 memset(iov2.iov_base, 0, iov2.iov_len); 1297 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1298 iov2.iov_len); 1299 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1300 } 1301 } 1302 /* fall through */ 1303 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1304 case PAYLOAD_BLOCK_UNMAPPED: 1305 case PAYLOAD_BLOCK_UNMAPPED_v095: 1306 case PAYLOAD_BLOCK_UNDEFINED: 1307 bat_prior_offset = sinfo.file_offset; 1308 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); 1309 if (ret < 0) { 1310 goto exit; 1311 } 1312 /* once we support differencing files, this may also be 1313 * partially present */ 1314 /* update block state to the newly specified state */ 1315 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1316 &bat_entry_offset, 1317 PAYLOAD_BLOCK_FULLY_PRESENT); 1318 bat_update = true; 1319 /* since we just allocated a block, file_offset is the 1320 * beginning of the payload block. It needs to be the 1321 * write address, which includes the offset into the block */ 1322 if (!use_zero_buffers) { 1323 sinfo.file_offset += sinfo.block_offset; 1324 } 1325 /* fall through */ 1326 case PAYLOAD_BLOCK_FULLY_PRESENT: 1327 /* if the file offset address is in the header zone, 1328 * there is a problem */ 1329 if (sinfo.file_offset < (1024 * 1024)) { 1330 ret = -EFAULT; 1331 goto error_bat_restore; 1332 } 1333 1334 if (!use_zero_buffers) { 1335 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1336 sinfo.bytes_avail); 1337 } 1338 /* block exists, so we can just overwrite it */ 1339 qemu_co_mutex_unlock(&s->lock); 1340 ret = bdrv_co_writev(bs->file, 1341 sinfo.file_offset >> BDRV_SECTOR_BITS, 1342 sectors_to_write, &hd_qiov); 1343 qemu_co_mutex_lock(&s->lock); 1344 if (ret < 0) { 1345 goto error_bat_restore; 1346 } 1347 break; 1348 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1349 /* we don't yet support difference files, fall through 1350 * to error */ 1351 default: 1352 ret = -EIO; 1353 goto exit; 1354 break; 1355 } 1356 1357 if (bat_update) { 1358 /* this will update the BAT entry into the log journal, and 1359 * then flush the log journal out to disk */ 1360 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1361 sizeof(VHDXBatEntry), 1362 bat_entry_offset); 1363 if (ret < 0) { 1364 goto exit; 1365 } 1366 } 1367 1368 nb_sectors -= sinfo.sectors_avail; 1369 sector_num += sinfo.sectors_avail; 1370 bytes_done += sinfo.bytes_avail; 1371 1372 } 1373 } 1374 1375 goto exit; 1376 1377 error_bat_restore: 1378 if (bat_update) { 1379 /* keep metadata in sync, and restore the bat entry state 1380 * if error. */ 1381 sinfo.file_offset = bat_prior_offset; 1382 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1383 &bat_entry_offset, bat_state); 1384 } 1385 exit: 1386 qemu_vfree(iov1.iov_base); 1387 qemu_vfree(iov2.iov_base); 1388 qemu_co_mutex_unlock(&s->lock); 1389 qemu_iovec_destroy(&hd_qiov); 1390 return ret; 1391 } 1392 1393 1394 1395 /* 1396 * Create VHDX Headers 1397 * 1398 * There are 2 headers, and the highest sequence number will represent 1399 * the active header 1400 */ 1401 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1402 uint32_t log_size) 1403 { 1404 BlockDriverState *bs = blk_bs(blk); 1405 BdrvChild *child; 1406 int ret = 0; 1407 VHDXHeader *hdr = NULL; 1408 1409 hdr = g_new0(VHDXHeader, 1); 1410 1411 hdr->signature = VHDX_HEADER_SIGNATURE; 1412 hdr->sequence_number = g_random_int(); 1413 hdr->log_version = 0; 1414 hdr->version = 1; 1415 hdr->log_length = log_size; 1416 hdr->log_offset = VHDX_HEADER_SECTION_END; 1417 vhdx_guid_generate(&hdr->file_write_guid); 1418 vhdx_guid_generate(&hdr->data_write_guid); 1419 1420 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1421 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1422 * here, which it really shouldn't be doing. */ 1423 child = QLIST_FIRST(&bs->parents); 1424 assert(!QLIST_NEXT(child, next_parent)); 1425 1426 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1427 if (ret < 0) { 1428 goto exit; 1429 } 1430 hdr->sequence_number++; 1431 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1432 if (ret < 0) { 1433 goto exit; 1434 } 1435 1436 exit: 1437 g_free(hdr); 1438 return ret; 1439 } 1440 1441 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1442 (sizeof(VHDXFileParameters) +\ 1443 sizeof(VHDXVirtualDiskSize) +\ 1444 sizeof(VHDXPage83Data) +\ 1445 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1446 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1447 1448 /* 1449 * Create the Metadata entries. 1450 * 1451 * For more details on the entries, see section 3.5 (pg 29) in the 1452 * VHDX 1.00 specification. 1453 * 1454 * We support 5 metadata entries (all required by spec): 1455 * File Parameters, 1456 * Virtual Disk Size, 1457 * Page 83 Data, 1458 * Logical Sector Size, 1459 * Physical Sector Size 1460 * 1461 * The first 64KB of the Metadata section is reserved for the metadata 1462 * header and entries; beyond that, the metadata items themselves reside. 1463 */ 1464 static int vhdx_create_new_metadata(BlockBackend *blk, 1465 uint64_t image_size, 1466 uint32_t block_size, 1467 uint32_t sector_size, 1468 uint64_t metadata_offset, 1469 VHDXImageType type) 1470 { 1471 int ret = 0; 1472 uint32_t offset = 0; 1473 void *buffer = NULL; 1474 void *entry_buffer; 1475 VHDXMetadataTableHeader *md_table; 1476 VHDXMetadataTableEntry *md_table_entry; 1477 1478 /* Metadata entries */ 1479 VHDXFileParameters *mt_file_params; 1480 VHDXVirtualDiskSize *mt_virtual_size; 1481 VHDXPage83Data *mt_page83; 1482 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1483 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1484 1485 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1486 1487 mt_file_params = entry_buffer; 1488 offset += sizeof(VHDXFileParameters); 1489 mt_virtual_size = entry_buffer + offset; 1490 offset += sizeof(VHDXVirtualDiskSize); 1491 mt_page83 = entry_buffer + offset; 1492 offset += sizeof(VHDXPage83Data); 1493 mt_log_sector_size = entry_buffer + offset; 1494 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1495 mt_phys_sector_size = entry_buffer + offset; 1496 1497 mt_file_params->block_size = cpu_to_le32(block_size); 1498 if (type == VHDX_TYPE_FIXED) { 1499 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1500 cpu_to_le32s(&mt_file_params->data_bits); 1501 } 1502 1503 vhdx_guid_generate(&mt_page83->page_83_data); 1504 cpu_to_leguids(&mt_page83->page_83_data); 1505 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1506 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1507 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1508 1509 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1510 md_table = buffer; 1511 1512 md_table->signature = VHDX_METADATA_SIGNATURE; 1513 md_table->entry_count = 5; 1514 vhdx_metadata_header_le_export(md_table); 1515 1516 1517 /* This will reference beyond the reserved table portion */ 1518 offset = 64 * KiB; 1519 1520 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1521 1522 md_table_entry[0].item_id = file_param_guid; 1523 md_table_entry[0].offset = offset; 1524 md_table_entry[0].length = sizeof(VHDXFileParameters); 1525 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1526 offset += md_table_entry[0].length; 1527 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1528 1529 md_table_entry[1].item_id = virtual_size_guid; 1530 md_table_entry[1].offset = offset; 1531 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1532 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1533 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1534 offset += md_table_entry[1].length; 1535 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1536 1537 md_table_entry[2].item_id = page83_guid; 1538 md_table_entry[2].offset = offset; 1539 md_table_entry[2].length = sizeof(VHDXPage83Data); 1540 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1541 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1542 offset += md_table_entry[2].length; 1543 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1544 1545 md_table_entry[3].item_id = logical_sector_guid; 1546 md_table_entry[3].offset = offset; 1547 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1548 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1549 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1550 offset += md_table_entry[3].length; 1551 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1552 1553 md_table_entry[4].item_id = phys_sector_guid; 1554 md_table_entry[4].offset = offset; 1555 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1556 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1557 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1558 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1559 1560 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0); 1561 if (ret < 0) { 1562 goto exit; 1563 } 1564 1565 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer, 1566 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0); 1567 if (ret < 0) { 1568 goto exit; 1569 } 1570 1571 1572 exit: 1573 g_free(buffer); 1574 g_free(entry_buffer); 1575 return ret; 1576 } 1577 1578 /* This create the actual BAT itself. We currently only support 1579 * 'Dynamic' and 'Fixed' image types. 1580 * 1581 * Dynamic images: default state of the BAT is all zeroes. 1582 * 1583 * Fixed images: default state of the BAT is fully populated, with 1584 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1585 */ 1586 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1587 uint64_t image_size, VHDXImageType type, 1588 bool use_zero_blocks, uint64_t file_offset, 1589 uint32_t length) 1590 { 1591 int ret = 0; 1592 uint64_t data_file_offset; 1593 uint64_t total_sectors = 0; 1594 uint64_t sector_num = 0; 1595 uint64_t unused; 1596 int block_state; 1597 VHDXSectorInfo sinfo; 1598 1599 assert(s->bat == NULL); 1600 1601 /* this gives a data start after BAT/bitmap entries, and well 1602 * past any metadata entries (with a 4 MB buffer for future 1603 * expansion */ 1604 data_file_offset = file_offset + length + 5 * MiB; 1605 total_sectors = image_size >> s->logical_sector_size_bits; 1606 1607 if (type == VHDX_TYPE_DYNAMIC) { 1608 /* All zeroes, so we can just extend the file - the end of the BAT 1609 * is the furthest thing we have written yet */ 1610 ret = blk_truncate(blk, data_file_offset); 1611 if (ret < 0) { 1612 goto exit; 1613 } 1614 } else if (type == VHDX_TYPE_FIXED) { 1615 ret = blk_truncate(blk, data_file_offset + image_size); 1616 if (ret < 0) { 1617 goto exit; 1618 } 1619 } else { 1620 ret = -ENOTSUP; 1621 goto exit; 1622 } 1623 1624 if (type == VHDX_TYPE_FIXED || 1625 use_zero_blocks || 1626 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1627 /* for a fixed file, the default BAT entry is not zero */ 1628 s->bat = g_try_malloc0(length); 1629 if (length && s->bat == NULL) { 1630 ret = -ENOMEM; 1631 goto exit; 1632 } 1633 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1634 PAYLOAD_BLOCK_NOT_PRESENT; 1635 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1636 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1637 while (sector_num < total_sectors) { 1638 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1639 sinfo.file_offset = data_file_offset + 1640 (sector_num << s->logical_sector_size_bits); 1641 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1642 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1643 block_state); 1644 cpu_to_le64s(&s->bat[sinfo.bat_idx]); 1645 sector_num += s->sectors_per_block; 1646 } 1647 ret = blk_pwrite(blk, file_offset, s->bat, length, 0); 1648 if (ret < 0) { 1649 goto exit; 1650 } 1651 } 1652 1653 1654 1655 exit: 1656 g_free(s->bat); 1657 return ret; 1658 } 1659 1660 /* Creates the region table header, and region table entries. 1661 * There are 2 supported region table entries: BAT, and Metadata/ 1662 * 1663 * As the calculations for the BAT region table are also needed 1664 * to create the BAT itself, we will also cause the BAT to be 1665 * created. 1666 */ 1667 static int vhdx_create_new_region_table(BlockBackend *blk, 1668 uint64_t image_size, 1669 uint32_t block_size, 1670 uint32_t sector_size, 1671 uint32_t log_size, 1672 bool use_zero_blocks, 1673 VHDXImageType type, 1674 uint64_t *metadata_offset) 1675 { 1676 int ret = 0; 1677 uint32_t offset = 0; 1678 void *buffer = NULL; 1679 uint64_t bat_file_offset; 1680 uint32_t bat_length; 1681 BDRVVHDXState *s = NULL; 1682 VHDXRegionTableHeader *region_table; 1683 VHDXRegionTableEntry *rt_bat; 1684 VHDXRegionTableEntry *rt_metadata; 1685 1686 assert(metadata_offset != NULL); 1687 1688 /* Populate enough of the BDRVVHDXState to be able to use the 1689 * pre-existing BAT calculation, translation, and update functions */ 1690 s = g_new0(BDRVVHDXState, 1); 1691 1692 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1693 (uint64_t) sector_size / (uint64_t) block_size; 1694 1695 s->sectors_per_block = block_size / sector_size; 1696 s->virtual_disk_size = image_size; 1697 s->block_size = block_size; 1698 s->logical_sector_size = sector_size; 1699 1700 vhdx_set_shift_bits(s); 1701 1702 vhdx_calc_bat_entries(s); 1703 1704 /* At this point the VHDX state is populated enough for creation */ 1705 1706 /* a single buffer is used so we can calculate the checksum over the 1707 * entire 64KB block */ 1708 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1709 region_table = buffer; 1710 offset += sizeof(VHDXRegionTableHeader); 1711 rt_bat = buffer + offset; 1712 offset += sizeof(VHDXRegionTableEntry); 1713 rt_metadata = buffer + offset; 1714 1715 region_table->signature = VHDX_REGION_SIGNATURE; 1716 region_table->entry_count = 2; /* BAT and Metadata */ 1717 1718 rt_bat->guid = bat_guid; 1719 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1720 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1721 s->bat_offset = rt_bat->file_offset; 1722 1723 rt_metadata->guid = metadata_guid; 1724 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1725 MiB); 1726 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1727 *metadata_offset = rt_metadata->file_offset; 1728 1729 bat_file_offset = rt_bat->file_offset; 1730 bat_length = rt_bat->length; 1731 1732 vhdx_region_header_le_export(region_table); 1733 vhdx_region_entry_le_export(rt_bat); 1734 vhdx_region_entry_le_export(rt_metadata); 1735 1736 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1737 offsetof(VHDXRegionTableHeader, checksum)); 1738 1739 1740 /* The region table gives us the data we need to create the BAT, 1741 * so do that now */ 1742 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1743 bat_file_offset, bat_length); 1744 if (ret < 0) { 1745 goto exit; 1746 } 1747 1748 /* Now write out the region headers to disk */ 1749 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer, 1750 VHDX_HEADER_BLOCK_SIZE, 0); 1751 if (ret < 0) { 1752 goto exit; 1753 } 1754 1755 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer, 1756 VHDX_HEADER_BLOCK_SIZE, 0); 1757 if (ret < 0) { 1758 goto exit; 1759 } 1760 1761 exit: 1762 g_free(s); 1763 g_free(buffer); 1764 return ret; 1765 } 1766 1767 /* We need to create the following elements: 1768 * 1769 * .-----------------------------------------------------------------. 1770 * | (A) | (B) | (C) | (D) | (E) | 1771 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1772 * | | | | | | 1773 * .-----------------------------------------------------------------. 1774 * 0 64KB 128KB 192KB 256KB 320KB 1775 * 1776 * 1777 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1778 * | (F) | (G) | (H) | | 1779 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1780 * | | | | | 1781 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1782 * 1MB 1783 */ 1784 static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp) 1785 { 1786 int ret = 0; 1787 uint64_t image_size = (uint64_t) 2 * GiB; 1788 uint32_t log_size = 1 * MiB; 1789 uint32_t block_size = 0; 1790 uint64_t signature; 1791 uint64_t metadata_offset; 1792 bool use_zero_blocks = false; 1793 1794 gunichar2 *creator = NULL; 1795 glong creator_items; 1796 BlockBackend *blk; 1797 char *type = NULL; 1798 VHDXImageType image_type; 1799 Error *local_err = NULL; 1800 1801 image_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), 1802 BDRV_SECTOR_SIZE); 1803 log_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_LOG_SIZE, 0); 1804 block_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_BLOCK_SIZE, 0); 1805 type = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT); 1806 use_zero_blocks = qemu_opt_get_bool_del(opts, VHDX_BLOCK_OPT_ZERO, true); 1807 1808 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1809 error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB"); 1810 ret = -EINVAL; 1811 goto exit; 1812 } 1813 1814 if (type == NULL) { 1815 type = g_strdup("dynamic"); 1816 } 1817 1818 if (!strcmp(type, "dynamic")) { 1819 image_type = VHDX_TYPE_DYNAMIC; 1820 } else if (!strcmp(type, "fixed")) { 1821 image_type = VHDX_TYPE_FIXED; 1822 } else if (!strcmp(type, "differencing")) { 1823 error_setg_errno(errp, ENOTSUP, 1824 "Differencing files not yet supported"); 1825 ret = -ENOTSUP; 1826 goto exit; 1827 } else { 1828 ret = -EINVAL; 1829 goto exit; 1830 } 1831 1832 /* These are pretty arbitrary, and mainly designed to keep the BAT 1833 * size reasonable to load into RAM */ 1834 if (block_size == 0) { 1835 if (image_size > 32 * TiB) { 1836 block_size = 64 * MiB; 1837 } else if (image_size > (uint64_t) 100 * GiB) { 1838 block_size = 32 * MiB; 1839 } else if (image_size > 1 * GiB) { 1840 block_size = 16 * MiB; 1841 } else { 1842 block_size = 8 * MiB; 1843 } 1844 } 1845 1846 1847 /* make the log size close to what was specified, but must be 1848 * min 1MB, and multiple of 1MB */ 1849 log_size = ROUND_UP(log_size, MiB); 1850 1851 block_size = ROUND_UP(block_size, MiB); 1852 block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX : 1853 block_size; 1854 1855 ret = bdrv_create_file(filename, opts, &local_err); 1856 if (ret < 0) { 1857 error_propagate(errp, local_err); 1858 goto exit; 1859 } 1860 1861 blk = blk_new_open(filename, NULL, NULL, 1862 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, 1863 &local_err); 1864 if (blk == NULL) { 1865 error_propagate(errp, local_err); 1866 ret = -EIO; 1867 goto exit; 1868 } 1869 1870 blk_set_allow_write_beyond_eof(blk, true); 1871 1872 /* Create (A) */ 1873 1874 /* The creator field is optional, but may be useful for 1875 * debugging / diagnostics */ 1876 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 1877 &creator_items, NULL); 1878 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 1879 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature), 1880 0); 1881 if (ret < 0) { 1882 goto delete_and_exit; 1883 } 1884 if (creator) { 1885 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 1886 creator, creator_items * sizeof(gunichar2), 0); 1887 if (ret < 0) { 1888 goto delete_and_exit; 1889 } 1890 } 1891 1892 1893 /* Creates (B),(C) */ 1894 ret = vhdx_create_new_headers(blk, image_size, log_size); 1895 if (ret < 0) { 1896 goto delete_and_exit; 1897 } 1898 1899 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 1900 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 1901 log_size, use_zero_blocks, image_type, 1902 &metadata_offset); 1903 if (ret < 0) { 1904 goto delete_and_exit; 1905 } 1906 1907 /* Creates (H) */ 1908 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 1909 metadata_offset, image_type); 1910 if (ret < 0) { 1911 goto delete_and_exit; 1912 } 1913 1914 1915 delete_and_exit: 1916 blk_unref(blk); 1917 exit: 1918 g_free(type); 1919 g_free(creator); 1920 return ret; 1921 } 1922 1923 /* If opened r/w, the VHDX driver will automatically replay the log, 1924 * if one is present, inside the vhdx_open() call. 1925 * 1926 * If qemu-img check -r all is called, the image is automatically opened 1927 * r/w and any log has already been replayed, so there is nothing (currently) 1928 * for us to do here 1929 */ 1930 static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result, 1931 BdrvCheckMode fix) 1932 { 1933 BDRVVHDXState *s = bs->opaque; 1934 1935 if (s->log_replayed_on_open) { 1936 result->corruptions_fixed++; 1937 } 1938 return 0; 1939 } 1940 1941 static QemuOptsList vhdx_create_opts = { 1942 .name = "vhdx-create-opts", 1943 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 1944 .desc = { 1945 { 1946 .name = BLOCK_OPT_SIZE, 1947 .type = QEMU_OPT_SIZE, 1948 .help = "Virtual disk size; max of 64TB." 1949 }, 1950 { 1951 .name = VHDX_BLOCK_OPT_LOG_SIZE, 1952 .type = QEMU_OPT_SIZE, 1953 .def_value_str = stringify(DEFAULT_LOG_SIZE), 1954 .help = "Log size; min 1MB." 1955 }, 1956 { 1957 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 1958 .type = QEMU_OPT_SIZE, 1959 .def_value_str = stringify(0), 1960 .help = "Block Size; min 1MB, max 256MB. " \ 1961 "0 means auto-calculate based on image size." 1962 }, 1963 { 1964 .name = BLOCK_OPT_SUBFMT, 1965 .type = QEMU_OPT_STRING, 1966 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ 1967 "Default is 'dynamic'." 1968 }, 1969 { 1970 .name = VHDX_BLOCK_OPT_ZERO, 1971 .type = QEMU_OPT_BOOL, 1972 .help = "Force use of payload blocks of type 'ZERO'. "\ 1973 "Non-standard, but default. Do not set to 'off' when "\ 1974 "using 'qemu-img convert' with subformat=dynamic." 1975 }, 1976 { NULL } 1977 } 1978 }; 1979 1980 static BlockDriver bdrv_vhdx = { 1981 .format_name = "vhdx", 1982 .instance_size = sizeof(BDRVVHDXState), 1983 .bdrv_probe = vhdx_probe, 1984 .bdrv_open = vhdx_open, 1985 .bdrv_close = vhdx_close, 1986 .bdrv_reopen_prepare = vhdx_reopen_prepare, 1987 .bdrv_child_perm = bdrv_format_default_perms, 1988 .bdrv_co_readv = vhdx_co_readv, 1989 .bdrv_co_writev = vhdx_co_writev, 1990 .bdrv_create = vhdx_create, 1991 .bdrv_get_info = vhdx_get_info, 1992 .bdrv_check = vhdx_check, 1993 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1994 1995 .create_opts = &vhdx_create_opts, 1996 }; 1997 1998 static void bdrv_vhdx_init(void) 1999 { 2000 bdrv_register(&bdrv_vhdx); 2001 } 2002 2003 block_init(bdrv_vhdx_init); 2004