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-common.h" 19 #include "block/block_int.h" 20 #include "qemu/module.h" 21 #include "qemu/crc32c.h" 22 #include "block/vhdx.h" 23 #include "migration/migration.h" 24 25 #include <uuid/uuid.h> 26 #include <glib.h> 27 28 /* Options for VHDX creation */ 29 30 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size" 31 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size" 32 #define VHDX_BLOCK_OPT_ZERO "block_state_zero" 33 34 typedef enum VHDXImageType { 35 VHDX_TYPE_DYNAMIC = 0, 36 VHDX_TYPE_FIXED, 37 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */ 38 } VHDXImageType; 39 40 /* Several metadata and region table data entries are identified by 41 * guids in a MS-specific GUID format. */ 42 43 44 /* ------- Known Region Table GUIDs ---------------------- */ 45 static const MSGUID bat_guid = { .data1 = 0x2dc27766, 46 .data2 = 0xf623, 47 .data3 = 0x4200, 48 .data4 = { 0x9d, 0x64, 0x11, 0x5e, 49 0x9b, 0xfd, 0x4a, 0x08} }; 50 51 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, 52 .data2 = 0x4790, 53 .data3 = 0x4b9a, 54 .data4 = { 0xb8, 0xfe, 0x57, 0x5f, 55 0x05, 0x0f, 0x88, 0x6e} }; 56 57 58 59 /* ------- Known Metadata Entry GUIDs ---------------------- */ 60 static const MSGUID file_param_guid = { .data1 = 0xcaa16737, 61 .data2 = 0xfa36, 62 .data3 = 0x4d43, 63 .data4 = { 0xb3, 0xb6, 0x33, 0xf0, 64 0xaa, 0x44, 0xe7, 0x6b} }; 65 66 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, 67 .data2 = 0xcd1b, 68 .data3 = 0x4876, 69 .data4 = { 0xb2, 0x11, 0x5d, 0xbe, 70 0xd8, 0x3b, 0xf4, 0xb8} }; 71 72 static const MSGUID page83_guid = { .data1 = 0xbeca12ab, 73 .data2 = 0xb2e6, 74 .data3 = 0x4523, 75 .data4 = { 0x93, 0xef, 0xc3, 0x09, 76 0xe0, 0x00, 0xc7, 0x46} }; 77 78 79 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, 80 .data2 = 0x445d, 81 .data3 = 0x4471, 82 .data4 = { 0x9c, 0xc9, 0xe9, 0x88, 83 0x52, 0x51, 0xc5, 0x56} }; 84 85 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, 86 .data2 = 0xb30b, 87 .data3 = 0x454d, 88 .data4 = { 0xab, 0xf7, 0xd3, 89 0xd8, 0x48, 0x34, 90 0xab, 0x0c} }; 91 92 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, 93 .data2 = 0xa96f, 94 .data3 = 0x4709, 95 .data4 = { 0xba, 0x47, 0xf2, 96 0x33, 0xa8, 0xfa, 97 0xab, 0x5f} }; 98 99 /* Each parent type must have a valid GUID; this is for parent images 100 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would 101 * need to make up our own QCOW2 GUID type */ 102 static const MSGUID parent_vhdx_guid = { .data1 = 0xb04aefb7, 103 .data2 = 0xd19e, 104 .data3 = 0x4a81, 105 .data4 = { 0xb7, 0x89, 0x25, 0xb8, 106 0xe9, 0x44, 0x59, 0x13} }; 107 108 109 #define META_FILE_PARAMETER_PRESENT 0x01 110 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 111 #define META_PAGE_83_PRESENT 0x04 112 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 113 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 114 #define META_PARENT_LOCATOR_PRESENT 0x20 115 116 #define META_ALL_PRESENT \ 117 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ 118 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ 119 META_PHYS_SECTOR_SIZE_PRESENT) 120 121 122 typedef struct VHDXSectorInfo { 123 uint32_t bat_idx; /* BAT entry index */ 124 uint32_t sectors_avail; /* sectors available in payload block */ 125 uint32_t bytes_left; /* bytes left in the block after data to r/w */ 126 uint32_t bytes_avail; /* bytes available in payload block */ 127 uint64_t file_offset; /* absolute offset in bytes, in file */ 128 uint64_t block_offset; /* block offset, in bytes */ 129 } VHDXSectorInfo; 130 131 /* Calculates new checksum. 132 * 133 * Zero is substituted during crc calculation for the original crc field 134 * crc_offset: byte offset in buf of the buffer crc 135 * buf: buffer pointer 136 * size: size of buffer (must be > crc_offset+4) 137 * 138 * Note: The resulting checksum is in the CPU endianness, not necessarily 139 * in the file format endianness (LE). Any header export to disk should 140 * make sure that vhdx_header_le_export() is used to convert to the 141 * correct endianness 142 */ 143 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) 144 { 145 uint32_t crc; 146 147 assert(buf != NULL); 148 assert(size > (crc_offset + sizeof(crc))); 149 150 memset(buf + crc_offset, 0, sizeof(crc)); 151 crc = crc32c(0xffffffff, buf, size); 152 memcpy(buf + crc_offset, &crc, sizeof(crc)); 153 154 return crc; 155 } 156 157 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, 158 int crc_offset) 159 { 160 uint32_t crc_new; 161 uint32_t crc_orig; 162 assert(buf != NULL); 163 164 if (crc_offset > 0) { 165 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 166 memset(buf + crc_offset, 0, sizeof(crc_orig)); 167 } 168 169 crc_new = crc32c(crc, buf, size); 170 if (crc_offset > 0) { 171 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); 172 } 173 174 return crc_new; 175 } 176 177 /* Validates the checksum of the buffer, with an in-place CRC. 178 * 179 * Zero is substituted during crc calculation for the original crc field, 180 * and the crc field is restored afterwards. But the buffer will be modifed 181 * during the calculation, so this may not be not suitable for multi-threaded 182 * use. 183 * 184 * crc_offset: byte offset in buf of the buffer crc 185 * buf: buffer pointer 186 * size: size of buffer (must be > crc_offset+4) 187 * 188 * returns true if checksum is valid, false otherwise 189 */ 190 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) 191 { 192 uint32_t crc_orig; 193 uint32_t crc; 194 195 assert(buf != NULL); 196 assert(size > (crc_offset + 4)); 197 198 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 199 crc_orig = le32_to_cpu(crc_orig); 200 201 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); 202 203 return crc == crc_orig; 204 } 205 206 207 /* 208 * This generates a UUID that is compliant with the MS GUIDs used 209 * in the VHDX spec (and elsewhere). 210 */ 211 void vhdx_guid_generate(MSGUID *guid) 212 { 213 uuid_t uuid; 214 assert(guid != NULL); 215 216 uuid_generate(uuid); 217 memcpy(guid, uuid, sizeof(MSGUID)); 218 } 219 220 /* Check for region overlaps inside the VHDX image */ 221 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) 222 { 223 int ret = 0; 224 uint64_t end; 225 VHDXRegionEntry *r; 226 227 end = start + length; 228 QLIST_FOREACH(r, &s->regions, entries) { 229 if (!((start >= r->end) || (end <= r->start))) { 230 ret = -EINVAL; 231 goto exit; 232 } 233 } 234 235 exit: 236 return ret; 237 } 238 239 /* Register a region for future checks */ 240 static void vhdx_region_register(BDRVVHDXState *s, 241 uint64_t start, uint64_t length) 242 { 243 VHDXRegionEntry *r; 244 245 r = g_malloc0(sizeof(*r)); 246 247 r->start = start; 248 r->end = start + length; 249 250 QLIST_INSERT_HEAD(&s->regions, r, entries); 251 } 252 253 /* Free all registered regions */ 254 static void vhdx_region_unregister_all(BDRVVHDXState *s) 255 { 256 VHDXRegionEntry *r, *r_next; 257 258 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { 259 QLIST_REMOVE(r, entries); 260 g_free(r); 261 } 262 } 263 264 static void vhdx_set_shift_bits(BDRVVHDXState *s) 265 { 266 s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size); 267 s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block); 268 s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio); 269 s->block_size_bits = 31 - clz32(s->block_size); 270 } 271 272 /* 273 * Per the MS VHDX Specification, for every VHDX file: 274 * - The header section is fixed size - 1 MB 275 * - The header section is always the first "object" 276 * - The first 64KB of the header is the File Identifier 277 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") 278 * - The following 512 bytes constitute a UTF-16 string identifiying the 279 * software that created the file, and is optional and diagnostic only. 280 * 281 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" 282 */ 283 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) 284 { 285 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { 286 return 100; 287 } 288 return 0; 289 } 290 291 /* 292 * Writes the header to the specified offset. 293 * 294 * This will optionally read in buffer data from disk (otherwise zero-fill), 295 * and then update the header checksum. Header is converted to proper 296 * endianness before being written to the specified file offset 297 */ 298 static int vhdx_write_header(BlockDriverState *bs_file, VHDXHeader *hdr, 299 uint64_t offset, bool read) 300 { 301 uint8_t *buffer = NULL; 302 int ret; 303 VHDXHeader header_le; 304 305 assert(bs_file != NULL); 306 assert(hdr != NULL); 307 308 /* the header checksum is not over just the packed size of VHDXHeader, 309 * but rather over the entire 'reserved' range for the header, which is 310 * 4KB (VHDX_HEADER_SIZE). */ 311 312 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); 313 if (read) { 314 /* if true, we can't assume the extra reserved bytes are 0 */ 315 ret = bdrv_pread(bs_file, offset, buffer, VHDX_HEADER_SIZE); 316 if (ret < 0) { 317 goto exit; 318 } 319 } else { 320 memset(buffer, 0, VHDX_HEADER_SIZE); 321 } 322 323 /* overwrite the actual VHDXHeader portion */ 324 memcpy(buffer, hdr, sizeof(VHDXHeader)); 325 hdr->checksum = vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, 326 offsetof(VHDXHeader, checksum)); 327 vhdx_header_le_export(hdr, &header_le); 328 ret = bdrv_pwrite_sync(bs_file, offset, &header_le, sizeof(VHDXHeader)); 329 330 exit: 331 qemu_vfree(buffer); 332 return ret; 333 } 334 335 /* Update the VHDX headers 336 * 337 * This follows the VHDX spec procedures for header updates. 338 * 339 * - non-current header is updated with largest sequence number 340 */ 341 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 342 bool generate_data_write_guid, MSGUID *log_guid) 343 { 344 int ret = 0; 345 int hdr_idx = 0; 346 uint64_t header_offset = VHDX_HEADER1_OFFSET; 347 348 VHDXHeader *active_header; 349 VHDXHeader *inactive_header; 350 351 /* operate on the non-current header */ 352 if (s->curr_header == 0) { 353 hdr_idx = 1; 354 header_offset = VHDX_HEADER2_OFFSET; 355 } 356 357 active_header = s->headers[s->curr_header]; 358 inactive_header = s->headers[hdr_idx]; 359 360 inactive_header->sequence_number = active_header->sequence_number + 1; 361 362 /* a new file guid must be generated before any file write, including 363 * headers */ 364 inactive_header->file_write_guid = s->session_guid; 365 366 /* a new data guid only needs to be generated before any guest-visible 367 * writes (i.e. something observable via virtual disk read) */ 368 if (generate_data_write_guid) { 369 vhdx_guid_generate(&inactive_header->data_write_guid); 370 } 371 372 /* update the log guid if present */ 373 if (log_guid) { 374 inactive_header->log_guid = *log_guid; 375 } 376 377 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 378 if (ret < 0) { 379 goto exit; 380 } 381 s->curr_header = hdr_idx; 382 383 exit: 384 return ret; 385 } 386 387 /* 388 * The VHDX spec calls for header updates to be performed twice, so that both 389 * the current and non-current header have valid info 390 */ 391 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 392 bool generate_data_write_guid, MSGUID *log_guid) 393 { 394 int ret; 395 396 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 397 if (ret < 0) { 398 return ret; 399 } 400 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 401 return ret; 402 } 403 404 /* opens the specified header block from the VHDX file header section */ 405 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, 406 Error **errp) 407 { 408 int ret; 409 VHDXHeader *header1; 410 VHDXHeader *header2; 411 bool h1_valid = false; 412 bool h2_valid = false; 413 uint64_t h1_seq = 0; 414 uint64_t h2_seq = 0; 415 uint8_t *buffer; 416 417 /* header1 & header2 are freed in vhdx_close() */ 418 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 419 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 420 421 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 422 423 s->headers[0] = header1; 424 s->headers[1] = header2; 425 426 /* We have to read the whole VHDX_HEADER_SIZE instead of 427 * sizeof(VHDXHeader), because the checksum is over the whole 428 * region */ 429 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE); 430 if (ret < 0) { 431 goto fail; 432 } 433 /* copy over just the relevant portion that we need */ 434 memcpy(header1, buffer, sizeof(VHDXHeader)); 435 vhdx_header_le_import(header1); 436 437 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && 438 !memcmp(&header1->signature, "head", 4) && 439 header1->version == 1) { 440 h1_seq = header1->sequence_number; 441 h1_valid = true; 442 } 443 444 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE); 445 if (ret < 0) { 446 goto fail; 447 } 448 /* copy over just the relevant portion that we need */ 449 memcpy(header2, buffer, sizeof(VHDXHeader)); 450 vhdx_header_le_import(header2); 451 452 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4) && 453 !memcmp(&header2->signature, "head", 4) && 454 header2->version == 1) { 455 h2_seq = header2->sequence_number; 456 h2_valid = true; 457 } 458 459 /* If there is only 1 valid header (or no valid headers), we 460 * don't care what the sequence numbers are */ 461 if (h1_valid && !h2_valid) { 462 s->curr_header = 0; 463 } else if (!h1_valid && h2_valid) { 464 s->curr_header = 1; 465 } else if (!h1_valid && !h2_valid) { 466 goto fail; 467 } else { 468 /* If both headers are valid, then we choose the active one by the 469 * highest sequence number. If the sequence numbers are equal, that is 470 * invalid */ 471 if (h1_seq > h2_seq) { 472 s->curr_header = 0; 473 } else if (h2_seq > h1_seq) { 474 s->curr_header = 1; 475 } else { 476 goto fail; 477 } 478 } 479 480 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 481 s->headers[s->curr_header]->log_length); 482 goto exit; 483 484 fail: 485 error_setg_errno(errp, -ret, "No valid VHDX header found"); 486 qemu_vfree(header1); 487 qemu_vfree(header2); 488 s->headers[0] = NULL; 489 s->headers[1] = NULL; 490 exit: 491 qemu_vfree(buffer); 492 } 493 494 495 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 496 { 497 int ret = 0; 498 uint8_t *buffer; 499 int offset = 0; 500 VHDXRegionTableEntry rt_entry; 501 uint32_t i; 502 bool bat_rt_found = false; 503 bool metadata_rt_found = false; 504 505 /* We have to read the whole 64KB block, because the crc32 is over the 506 * whole block */ 507 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 508 509 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 510 VHDX_HEADER_BLOCK_SIZE); 511 if (ret < 0) { 512 goto fail; 513 } 514 memcpy(&s->rt, buffer, sizeof(s->rt)); 515 vhdx_region_header_le_import(&s->rt); 516 offset += sizeof(s->rt); 517 518 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) || 519 memcmp(&s->rt.signature, "regi", 4)) { 520 ret = -EINVAL; 521 goto fail; 522 } 523 524 /* Per spec, maximum region table entry count is 2047 */ 525 if (s->rt.entry_count > 2047) { 526 ret = -EINVAL; 527 goto fail; 528 } 529 530 for (i = 0; i < s->rt.entry_count; i++) { 531 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 532 offset += sizeof(rt_entry); 533 534 vhdx_region_entry_le_import(&rt_entry); 535 536 /* check for region overlap between these entries, and any 537 * other memory regions in the file */ 538 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 539 if (ret < 0) { 540 goto fail; 541 } 542 543 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 544 545 /* see if we recognize the entry */ 546 if (guid_eq(rt_entry.guid, bat_guid)) { 547 /* must be unique; if we have already found it this is invalid */ 548 if (bat_rt_found) { 549 ret = -EINVAL; 550 goto fail; 551 } 552 bat_rt_found = true; 553 s->bat_rt = rt_entry; 554 continue; 555 } 556 557 if (guid_eq(rt_entry.guid, metadata_guid)) { 558 /* must be unique; if we have already found it this is invalid */ 559 if (metadata_rt_found) { 560 ret = -EINVAL; 561 goto fail; 562 } 563 metadata_rt_found = true; 564 s->metadata_rt = rt_entry; 565 continue; 566 } 567 568 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 569 /* cannot read vhdx file - required region table entry that 570 * we do not understand. per spec, we must fail to open */ 571 ret = -ENOTSUP; 572 goto fail; 573 } 574 } 575 576 if (!bat_rt_found || !metadata_rt_found) { 577 ret = -EINVAL; 578 goto fail; 579 } 580 581 ret = 0; 582 583 fail: 584 qemu_vfree(buffer); 585 return ret; 586 } 587 588 589 590 /* Metadata initial parser 591 * 592 * This loads all the metadata entry fields. This may cause additional 593 * fields to be processed (e.g. parent locator, etc..). 594 * 595 * There are 5 Metadata items that are always required: 596 * - File Parameters (block size, has a parent) 597 * - Virtual Disk Size (size, in bytes, of the virtual drive) 598 * - Page 83 Data (scsi page 83 guid) 599 * - Logical Sector Size (logical sector size in bytes, either 512 or 600 * 4096. We only support 512 currently) 601 * - Physical Sector Size (512 or 4096) 602 * 603 * Also, if the File Parameters indicate this is a differencing file, 604 * we must also look for the Parent Locator metadata item. 605 */ 606 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 607 { 608 int ret = 0; 609 uint8_t *buffer; 610 int offset = 0; 611 uint32_t i = 0; 612 VHDXMetadataTableEntry md_entry; 613 614 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 615 616 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 617 VHDX_METADATA_TABLE_MAX_SIZE); 618 if (ret < 0) { 619 goto exit; 620 } 621 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 622 offset += sizeof(s->metadata_hdr); 623 624 vhdx_metadata_header_le_import(&s->metadata_hdr); 625 626 if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) { 627 ret = -EINVAL; 628 goto exit; 629 } 630 631 s->metadata_entries.present = 0; 632 633 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 634 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 635 ret = -EINVAL; 636 goto exit; 637 } 638 639 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 640 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 641 offset += sizeof(md_entry); 642 643 vhdx_metadata_entry_le_import(&md_entry); 644 645 if (guid_eq(md_entry.item_id, file_param_guid)) { 646 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 647 ret = -EINVAL; 648 goto exit; 649 } 650 s->metadata_entries.file_parameters_entry = md_entry; 651 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 652 continue; 653 } 654 655 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 656 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 657 ret = -EINVAL; 658 goto exit; 659 } 660 s->metadata_entries.virtual_disk_size_entry = md_entry; 661 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 662 continue; 663 } 664 665 if (guid_eq(md_entry.item_id, page83_guid)) { 666 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 667 ret = -EINVAL; 668 goto exit; 669 } 670 s->metadata_entries.page83_data_entry = md_entry; 671 s->metadata_entries.present |= META_PAGE_83_PRESENT; 672 continue; 673 } 674 675 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 676 if (s->metadata_entries.present & 677 META_LOGICAL_SECTOR_SIZE_PRESENT) { 678 ret = -EINVAL; 679 goto exit; 680 } 681 s->metadata_entries.logical_sector_size_entry = md_entry; 682 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 683 continue; 684 } 685 686 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 687 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 688 ret = -EINVAL; 689 goto exit; 690 } 691 s->metadata_entries.phys_sector_size_entry = md_entry; 692 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 693 continue; 694 } 695 696 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 697 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 698 ret = -EINVAL; 699 goto exit; 700 } 701 s->metadata_entries.parent_locator_entry = md_entry; 702 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 703 continue; 704 } 705 706 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 707 /* cannot read vhdx file - required region table entry that 708 * we do not understand. per spec, we must fail to open */ 709 ret = -ENOTSUP; 710 goto exit; 711 } 712 } 713 714 if (s->metadata_entries.present != META_ALL_PRESENT) { 715 ret = -ENOTSUP; 716 goto exit; 717 } 718 719 ret = bdrv_pread(bs->file, 720 s->metadata_entries.file_parameters_entry.offset 721 + s->metadata_rt.file_offset, 722 &s->params, 723 sizeof(s->params)); 724 725 if (ret < 0) { 726 goto exit; 727 } 728 729 le32_to_cpus(&s->params.block_size); 730 le32_to_cpus(&s->params.data_bits); 731 732 733 /* We now have the file parameters, so we can tell if this is a 734 * differencing file (i.e.. has_parent), is dynamic or fixed 735 * sized (leave_blocks_allocated), and the block size */ 736 737 /* The parent locator required iff the file parameters has_parent set */ 738 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 739 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 740 /* TODO: parse parent locator fields */ 741 ret = -ENOTSUP; /* temp, until differencing files are supported */ 742 goto exit; 743 } else { 744 /* if has_parent is set, but there is not parent locator present, 745 * then that is an invalid combination */ 746 ret = -EINVAL; 747 goto exit; 748 } 749 } 750 751 /* determine virtual disk size, logical sector size, 752 * and phys sector size */ 753 754 ret = bdrv_pread(bs->file, 755 s->metadata_entries.virtual_disk_size_entry.offset 756 + s->metadata_rt.file_offset, 757 &s->virtual_disk_size, 758 sizeof(uint64_t)); 759 if (ret < 0) { 760 goto exit; 761 } 762 ret = bdrv_pread(bs->file, 763 s->metadata_entries.logical_sector_size_entry.offset 764 + s->metadata_rt.file_offset, 765 &s->logical_sector_size, 766 sizeof(uint32_t)); 767 if (ret < 0) { 768 goto exit; 769 } 770 ret = bdrv_pread(bs->file, 771 s->metadata_entries.phys_sector_size_entry.offset 772 + s->metadata_rt.file_offset, 773 &s->physical_sector_size, 774 sizeof(uint32_t)); 775 if (ret < 0) { 776 goto exit; 777 } 778 779 le64_to_cpus(&s->virtual_disk_size); 780 le32_to_cpus(&s->logical_sector_size); 781 le32_to_cpus(&s->physical_sector_size); 782 783 if (s->logical_sector_size == 0 || s->params.block_size == 0) { 784 ret = -EINVAL; 785 goto exit; 786 } 787 788 /* both block_size and sector_size are guaranteed powers of 2 */ 789 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 790 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 791 (uint64_t)s->logical_sector_size / 792 (uint64_t)s->params.block_size; 793 794 /* These values are ones we will want to use for division / multiplication 795 * later on, and they are all guaranteed (per the spec) to be powers of 2, 796 * so we can take advantage of that for shift operations during 797 * reads/writes */ 798 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 799 ret = -EINVAL; 800 goto exit; 801 } 802 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 803 ret = -EINVAL; 804 goto exit; 805 } 806 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 807 ret = -EINVAL; 808 goto exit; 809 } 810 s->block_size = s->params.block_size; 811 if (s->block_size & (s->block_size - 1)) { 812 ret = -EINVAL; 813 goto exit; 814 } 815 816 vhdx_set_shift_bits(s); 817 818 ret = 0; 819 820 exit: 821 qemu_vfree(buffer); 822 return ret; 823 } 824 825 /* 826 * Calculate the number of BAT entries, including sector 827 * bitmap entries. 828 */ 829 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 830 { 831 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 832 833 data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits; 834 if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) { 835 data_blocks_cnt++; 836 } 837 bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits; 838 if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) { 839 bitmap_blocks_cnt++; 840 } 841 842 if (s->parent_entries) { 843 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 844 } else { 845 s->bat_entries = data_blocks_cnt + 846 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 847 } 848 849 } 850 851 static void vhdx_close(BlockDriverState *bs) 852 { 853 BDRVVHDXState *s = bs->opaque; 854 qemu_vfree(s->headers[0]); 855 s->headers[0] = NULL; 856 qemu_vfree(s->headers[1]); 857 s->headers[1] = NULL; 858 qemu_vfree(s->bat); 859 s->bat = NULL; 860 qemu_vfree(s->parent_entries); 861 s->parent_entries = NULL; 862 migrate_del_blocker(s->migration_blocker); 863 error_free(s->migration_blocker); 864 qemu_vfree(s->log.hdr); 865 s->log.hdr = NULL; 866 vhdx_region_unregister_all(s); 867 } 868 869 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 870 Error **errp) 871 { 872 BDRVVHDXState *s = bs->opaque; 873 int ret = 0; 874 uint32_t i; 875 uint64_t signature; 876 Error *local_err = NULL; 877 878 s->bat = NULL; 879 s->first_visible_write = true; 880 881 qemu_co_mutex_init(&s->lock); 882 QLIST_INIT(&s->regions); 883 884 /* validate the file signature */ 885 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 886 if (ret < 0) { 887 goto fail; 888 } 889 if (memcmp(&signature, "vhdxfile", 8)) { 890 ret = -EINVAL; 891 goto fail; 892 } 893 894 /* This is used for any header updates, for the file_write_guid. 895 * The spec dictates that a new value should be used for the first 896 * header update */ 897 vhdx_guid_generate(&s->session_guid); 898 899 vhdx_parse_header(bs, s, &local_err); 900 if (local_err != NULL) { 901 error_propagate(errp, local_err); 902 ret = -EINVAL; 903 goto fail; 904 } 905 906 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 907 if (ret < 0) { 908 goto fail; 909 } 910 911 ret = vhdx_open_region_tables(bs, s); 912 if (ret < 0) { 913 goto fail; 914 } 915 916 ret = vhdx_parse_metadata(bs, s); 917 if (ret < 0) { 918 goto fail; 919 } 920 921 s->block_size = s->params.block_size; 922 923 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 924 * logical_sector_size */ 925 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 926 927 vhdx_calc_bat_entries(s); 928 929 s->bat_offset = s->bat_rt.file_offset; 930 931 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 932 /* BAT allocation is not large enough for all entries */ 933 ret = -EINVAL; 934 goto fail; 935 } 936 937 /* s->bat is freed in vhdx_close() */ 938 s->bat = qemu_blockalign(bs, s->bat_rt.length); 939 940 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 941 if (ret < 0) { 942 goto fail; 943 } 944 945 uint64_t payblocks = s->chunk_ratio; 946 /* endian convert, and verify populated BAT field file offsets against 947 * region table and log entries */ 948 for (i = 0; i < s->bat_entries; i++) { 949 le64_to_cpus(&s->bat[i]); 950 if (payblocks--) { 951 /* payload bat entries */ 952 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 953 PAYLOAD_BLOCK_FULLY_PRESENT) { 954 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, 955 s->block_size); 956 if (ret < 0) { 957 goto fail; 958 } 959 } 960 } else { 961 payblocks = s->chunk_ratio; 962 /* Once differencing files are supported, verify sector bitmap 963 * blocks here */ 964 } 965 } 966 967 if (flags & BDRV_O_RDWR) { 968 ret = vhdx_update_headers(bs, s, false, NULL); 969 if (ret < 0) { 970 goto fail; 971 } 972 } 973 974 /* TODO: differencing files */ 975 976 /* Disable migration when VHDX images are used */ 977 error_set(&s->migration_blocker, 978 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 979 "vhdx", bs->device_name, "live migration"); 980 migrate_add_blocker(s->migration_blocker); 981 982 return 0; 983 fail: 984 vhdx_close(bs); 985 return ret; 986 } 987 988 static int vhdx_reopen_prepare(BDRVReopenState *state, 989 BlockReopenQueue *queue, Error **errp) 990 { 991 return 0; 992 } 993 994 995 /* 996 * Perform sector to block offset translations, to get various 997 * sector and file offsets into the image. See VHDXSectorInfo 998 */ 999 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1000 int nb_sectors, VHDXSectorInfo *sinfo) 1001 { 1002 uint32_t block_offset; 1003 1004 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1005 /* effectively a modulo - this gives us the offset into the block 1006 * (in sector sizes) for our sector number */ 1007 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1008 /* the chunk ratio gives us the interleaving of the sector 1009 * bitmaps, so we need to advance our page block index by the 1010 * sector bitmaps entry number */ 1011 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1012 1013 /* the number of sectors we can read/write in this cycle */ 1014 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1015 1016 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1017 1018 if (sinfo->sectors_avail > nb_sectors) { 1019 sinfo->sectors_avail = nb_sectors; 1020 } 1021 1022 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1023 1024 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1025 1026 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1027 1028 /* The file offset must be past the header section, so must be > 0 */ 1029 if (sinfo->file_offset == 0) { 1030 return; 1031 } 1032 1033 /* block offset is the offset in vhdx logical sectors, in 1034 * the payload data block. Convert that to a byte offset 1035 * in the block, and add in the payload data block offset 1036 * in the file, in bytes, to get the final read address */ 1037 1038 sinfo->file_offset += sinfo->block_offset; 1039 } 1040 1041 1042 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1043 { 1044 BDRVVHDXState *s = bs->opaque; 1045 1046 bdi->cluster_size = s->block_size; 1047 1048 bdi->unallocated_blocks_are_zero = 1049 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; 1050 1051 return 0; 1052 } 1053 1054 1055 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1056 int nb_sectors, QEMUIOVector *qiov) 1057 { 1058 BDRVVHDXState *s = bs->opaque; 1059 int ret = 0; 1060 VHDXSectorInfo sinfo; 1061 uint64_t bytes_done = 0; 1062 QEMUIOVector hd_qiov; 1063 1064 qemu_iovec_init(&hd_qiov, qiov->niov); 1065 1066 qemu_co_mutex_lock(&s->lock); 1067 1068 while (nb_sectors > 0) { 1069 /* We are a differencing file, so we need to inspect the sector bitmap 1070 * to see if we have the data or not */ 1071 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1072 /* not supported yet */ 1073 ret = -ENOTSUP; 1074 goto exit; 1075 } else { 1076 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1077 1078 qemu_iovec_reset(&hd_qiov); 1079 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1080 1081 /* check the payload block state */ 1082 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1083 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1084 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1085 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1086 case PAYLOAD_BLOCK_ZERO: 1087 /* return zero */ 1088 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1089 break; 1090 case PAYLOAD_BLOCK_FULLY_PRESENT: 1091 qemu_co_mutex_unlock(&s->lock); 1092 ret = bdrv_co_readv(bs->file, 1093 sinfo.file_offset >> BDRV_SECTOR_BITS, 1094 sinfo.sectors_avail, &hd_qiov); 1095 qemu_co_mutex_lock(&s->lock); 1096 if (ret < 0) { 1097 goto exit; 1098 } 1099 break; 1100 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1101 /* we don't yet support difference files, fall through 1102 * to error */ 1103 default: 1104 ret = -EIO; 1105 goto exit; 1106 break; 1107 } 1108 nb_sectors -= sinfo.sectors_avail; 1109 sector_num += sinfo.sectors_avail; 1110 bytes_done += sinfo.bytes_avail; 1111 } 1112 } 1113 ret = 0; 1114 exit: 1115 qemu_co_mutex_unlock(&s->lock); 1116 qemu_iovec_destroy(&hd_qiov); 1117 return ret; 1118 } 1119 1120 /* 1121 * Allocate a new payload block at the end of the file. 1122 * 1123 * Allocation will happen at 1MB alignment inside the file 1124 * 1125 * Returns the file offset start of the new payload block 1126 */ 1127 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1128 uint64_t *new_offset) 1129 { 1130 *new_offset = bdrv_getlength(bs->file); 1131 1132 /* per the spec, the address for a block is in units of 1MB */ 1133 *new_offset = ROUND_UP(*new_offset, 1024 * 1024); 1134 1135 return bdrv_truncate(bs->file, *new_offset + s->block_size); 1136 } 1137 1138 /* 1139 * Update the BAT table entry with the new file offset, and the new entry 1140 * state */ 1141 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1142 VHDXSectorInfo *sinfo, 1143 uint64_t *bat_entry_le, 1144 uint64_t *bat_offset, int state) 1145 { 1146 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1147 * 1MB, and 3 bits for the block state. */ 1148 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1149 1150 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1151 1152 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1153 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1154 1155 } 1156 1157 /* Per the spec, on the first write of guest-visible data to the file the 1158 * data write guid must be updated in the header */ 1159 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1160 { 1161 int ret = 0; 1162 if (s->first_visible_write) { 1163 s->first_visible_write = false; 1164 ret = vhdx_update_headers(bs, s, true, NULL); 1165 } 1166 return ret; 1167 } 1168 1169 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1170 int nb_sectors, QEMUIOVector *qiov) 1171 { 1172 int ret = -ENOTSUP; 1173 BDRVVHDXState *s = bs->opaque; 1174 VHDXSectorInfo sinfo; 1175 uint64_t bytes_done = 0; 1176 uint64_t bat_entry = 0; 1177 uint64_t bat_entry_offset = 0; 1178 QEMUIOVector hd_qiov; 1179 struct iovec iov1 = { 0 }; 1180 struct iovec iov2 = { 0 }; 1181 int sectors_to_write; 1182 int bat_state; 1183 uint64_t bat_prior_offset = 0; 1184 bool bat_update = false; 1185 1186 qemu_iovec_init(&hd_qiov, qiov->niov); 1187 1188 qemu_co_mutex_lock(&s->lock); 1189 1190 ret = vhdx_user_visible_write(bs, s); 1191 if (ret < 0) { 1192 goto exit; 1193 } 1194 1195 while (nb_sectors > 0) { 1196 bool use_zero_buffers = false; 1197 bat_update = false; 1198 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1199 /* not supported yet */ 1200 ret = -ENOTSUP; 1201 goto exit; 1202 } else { 1203 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1204 sectors_to_write = sinfo.sectors_avail; 1205 1206 qemu_iovec_reset(&hd_qiov); 1207 /* check the payload block state */ 1208 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1209 switch (bat_state) { 1210 case PAYLOAD_BLOCK_ZERO: 1211 /* in this case, we need to preserve zero writes for 1212 * data that is not part of this write, so we must pad 1213 * the rest of the buffer to zeroes */ 1214 1215 /* if we are on a posix system with ftruncate() that extends 1216 * a file, then it is zero-filled for us. On Win32, the raw 1217 * layer uses SetFilePointer and SetFileEnd, which does not 1218 * zero fill AFAIK */ 1219 1220 /* Queue another write of zero buffers if the underlying file 1221 * does not zero-fill on file extension */ 1222 1223 if (bdrv_has_zero_init(bs->file) == 0) { 1224 use_zero_buffers = true; 1225 1226 /* zero fill the front, if any */ 1227 if (sinfo.block_offset) { 1228 iov1.iov_len = sinfo.block_offset; 1229 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1230 memset(iov1.iov_base, 0, iov1.iov_len); 1231 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1232 sinfo.block_offset); 1233 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1234 } 1235 1236 /* our actual data */ 1237 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1238 sinfo.bytes_avail); 1239 1240 /* zero fill the back, if any */ 1241 if ((sinfo.bytes_avail - sinfo.block_offset) < 1242 s->block_size) { 1243 iov2.iov_len = s->block_size - 1244 (sinfo.bytes_avail + sinfo.block_offset); 1245 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1246 memset(iov2.iov_base, 0, iov2.iov_len); 1247 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1248 sinfo.block_offset); 1249 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1250 } 1251 } 1252 1253 /* fall through */ 1254 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1255 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1256 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1257 bat_prior_offset = sinfo.file_offset; 1258 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); 1259 if (ret < 0) { 1260 goto exit; 1261 } 1262 /* once we support differencing files, this may also be 1263 * partially present */ 1264 /* update block state to the newly specified state */ 1265 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1266 &bat_entry_offset, 1267 PAYLOAD_BLOCK_FULLY_PRESENT); 1268 bat_update = true; 1269 /* since we just allocated a block, file_offset is the 1270 * beginning of the payload block. It needs to be the 1271 * write address, which includes the offset into the block */ 1272 if (!use_zero_buffers) { 1273 sinfo.file_offset += sinfo.block_offset; 1274 } 1275 /* fall through */ 1276 case PAYLOAD_BLOCK_FULLY_PRESENT: 1277 /* if the file offset address is in the header zone, 1278 * there is a problem */ 1279 if (sinfo.file_offset < (1024 * 1024)) { 1280 ret = -EFAULT; 1281 goto error_bat_restore; 1282 } 1283 1284 if (!use_zero_buffers) { 1285 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1286 sinfo.bytes_avail); 1287 } 1288 /* block exists, so we can just overwrite it */ 1289 qemu_co_mutex_unlock(&s->lock); 1290 ret = bdrv_co_writev(bs->file, 1291 sinfo.file_offset >> BDRV_SECTOR_BITS, 1292 sectors_to_write, &hd_qiov); 1293 qemu_co_mutex_lock(&s->lock); 1294 if (ret < 0) { 1295 goto error_bat_restore; 1296 } 1297 break; 1298 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1299 /* we don't yet support difference files, fall through 1300 * to error */ 1301 default: 1302 ret = -EIO; 1303 goto exit; 1304 break; 1305 } 1306 1307 if (bat_update) { 1308 /* this will update the BAT entry into the log journal, and 1309 * then flush the log journal out to disk */ 1310 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1311 sizeof(VHDXBatEntry), 1312 bat_entry_offset); 1313 if (ret < 0) { 1314 goto exit; 1315 } 1316 } 1317 1318 nb_sectors -= sinfo.sectors_avail; 1319 sector_num += sinfo.sectors_avail; 1320 bytes_done += sinfo.bytes_avail; 1321 1322 } 1323 } 1324 1325 goto exit; 1326 1327 error_bat_restore: 1328 if (bat_update) { 1329 /* keep metadata in sync, and restore the bat entry state 1330 * if error. */ 1331 sinfo.file_offset = bat_prior_offset; 1332 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1333 &bat_entry_offset, bat_state); 1334 } 1335 exit: 1336 qemu_vfree(iov1.iov_base); 1337 qemu_vfree(iov2.iov_base); 1338 qemu_co_mutex_unlock(&s->lock); 1339 qemu_iovec_destroy(&hd_qiov); 1340 return ret; 1341 } 1342 1343 1344 1345 /* 1346 * Create VHDX Headers 1347 * 1348 * There are 2 headers, and the highest sequence number will represent 1349 * the active header 1350 */ 1351 static int vhdx_create_new_headers(BlockDriverState *bs, uint64_t image_size, 1352 uint32_t log_size) 1353 { 1354 int ret = 0; 1355 VHDXHeader *hdr = NULL; 1356 1357 hdr = g_malloc0(sizeof(VHDXHeader)); 1358 1359 hdr->signature = VHDX_HEADER_SIGNATURE; 1360 hdr->sequence_number = g_random_int(); 1361 hdr->log_version = 0; 1362 hdr->version = 1; 1363 hdr->log_length = log_size; 1364 hdr->log_offset = VHDX_HEADER_SECTION_END; 1365 vhdx_guid_generate(&hdr->file_write_guid); 1366 vhdx_guid_generate(&hdr->data_write_guid); 1367 1368 ret = vhdx_write_header(bs, hdr, VHDX_HEADER1_OFFSET, false); 1369 if (ret < 0) { 1370 goto exit; 1371 } 1372 hdr->sequence_number++; 1373 ret = vhdx_write_header(bs, hdr, VHDX_HEADER2_OFFSET, false); 1374 if (ret < 0) { 1375 goto exit; 1376 } 1377 1378 exit: 1379 g_free(hdr); 1380 return ret; 1381 } 1382 1383 1384 /* 1385 * Create the Metadata entries. 1386 * 1387 * For more details on the entries, see section 3.5 (pg 29) in the 1388 * VHDX 1.00 specification. 1389 * 1390 * We support 5 metadata entries (all required by spec): 1391 * File Parameters, 1392 * Virtual Disk Size, 1393 * Page 83 Data, 1394 * Logical Sector Size, 1395 * Physical Sector Size 1396 * 1397 * The first 64KB of the Metadata section is reserved for the metadata 1398 * header and entries; beyond that, the metadata items themselves reside. 1399 */ 1400 static int vhdx_create_new_metadata(BlockDriverState *bs, 1401 uint64_t image_size, 1402 uint32_t block_size, 1403 uint32_t sector_size, 1404 uint64_t metadata_offset, 1405 VHDXImageType type) 1406 { 1407 int ret = 0; 1408 uint32_t offset = 0; 1409 void *buffer = NULL; 1410 void *entry_buffer; 1411 VHDXMetadataTableHeader *md_table;; 1412 VHDXMetadataTableEntry *md_table_entry; 1413 1414 /* Metadata entries */ 1415 VHDXFileParameters *mt_file_params; 1416 VHDXVirtualDiskSize *mt_virtual_size; 1417 VHDXPage83Data *mt_page83; 1418 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1419 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1420 1421 entry_buffer = g_malloc0(sizeof(VHDXFileParameters) + 1422 sizeof(VHDXVirtualDiskSize) + 1423 sizeof(VHDXPage83Data) + 1424 sizeof(VHDXVirtualDiskLogicalSectorSize) + 1425 sizeof(VHDXVirtualDiskPhysicalSectorSize)); 1426 1427 mt_file_params = entry_buffer; 1428 offset += sizeof(VHDXFileParameters); 1429 mt_virtual_size = entry_buffer + offset; 1430 offset += sizeof(VHDXVirtualDiskSize); 1431 mt_page83 = entry_buffer + offset; 1432 offset += sizeof(VHDXPage83Data); 1433 mt_log_sector_size = entry_buffer + offset; 1434 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1435 mt_phys_sector_size = entry_buffer + offset; 1436 1437 mt_file_params->block_size = cpu_to_le32(block_size); 1438 if (type == VHDX_TYPE_FIXED) { 1439 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1440 cpu_to_le32s(&mt_file_params->data_bits); 1441 } 1442 1443 vhdx_guid_generate(&mt_page83->page_83_data); 1444 cpu_to_leguids(&mt_page83->page_83_data); 1445 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1446 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1447 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1448 1449 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1450 md_table = buffer; 1451 1452 md_table->signature = VHDX_METADATA_SIGNATURE; 1453 md_table->entry_count = 5; 1454 vhdx_metadata_header_le_export(md_table); 1455 1456 1457 /* This will reference beyond the reserved table portion */ 1458 offset = 64 * KiB; 1459 1460 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1461 1462 md_table_entry[0].item_id = file_param_guid; 1463 md_table_entry[0].offset = offset; 1464 md_table_entry[0].length = sizeof(VHDXFileParameters); 1465 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1466 offset += md_table_entry[0].length; 1467 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1468 1469 md_table_entry[1].item_id = virtual_size_guid; 1470 md_table_entry[1].offset = offset; 1471 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1472 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1473 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1474 offset += md_table_entry[1].length; 1475 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1476 1477 md_table_entry[2].item_id = page83_guid; 1478 md_table_entry[2].offset = offset; 1479 md_table_entry[2].length = sizeof(VHDXPage83Data); 1480 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1481 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1482 offset += md_table_entry[2].length; 1483 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1484 1485 md_table_entry[3].item_id = logical_sector_guid; 1486 md_table_entry[3].offset = offset; 1487 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1488 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1489 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1490 offset += md_table_entry[3].length; 1491 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1492 1493 md_table_entry[4].item_id = phys_sector_guid; 1494 md_table_entry[4].offset = offset; 1495 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1496 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1497 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1498 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1499 1500 ret = bdrv_pwrite(bs, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE); 1501 if (ret < 0) { 1502 goto exit; 1503 } 1504 1505 ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer, 1506 VHDX_HEADER_BLOCK_SIZE); 1507 if (ret < 0) { 1508 goto exit; 1509 } 1510 1511 1512 exit: 1513 g_free(buffer); 1514 g_free(entry_buffer); 1515 return ret; 1516 } 1517 1518 /* This create the actual BAT itself. We currently only support 1519 * 'Dynamic' and 'Fixed' image types. 1520 * 1521 * Dynamic images: default state of the BAT is all zeroes. 1522 * 1523 * Fixed images: default state of the BAT is fully populated, with 1524 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1525 */ 1526 static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s, 1527 uint64_t image_size, VHDXImageType type, 1528 bool use_zero_blocks, VHDXRegionTableEntry *rt_bat) 1529 { 1530 int ret = 0; 1531 uint64_t data_file_offset; 1532 uint64_t total_sectors = 0; 1533 uint64_t sector_num = 0; 1534 uint64_t unused; 1535 int block_state; 1536 VHDXSectorInfo sinfo; 1537 1538 assert(s->bat == NULL); 1539 1540 /* this gives a data start after BAT/bitmap entries, and well 1541 * past any metadata entries (with a 4 MB buffer for future 1542 * expansion */ 1543 data_file_offset = rt_bat->file_offset + rt_bat->length + 5 * MiB; 1544 total_sectors = image_size >> s->logical_sector_size_bits; 1545 1546 if (type == VHDX_TYPE_DYNAMIC) { 1547 /* All zeroes, so we can just extend the file - the end of the BAT 1548 * is the furthest thing we have written yet */ 1549 ret = bdrv_truncate(bs, data_file_offset); 1550 if (ret < 0) { 1551 goto exit; 1552 } 1553 } else if (type == VHDX_TYPE_FIXED) { 1554 ret = bdrv_truncate(bs, data_file_offset + image_size); 1555 if (ret < 0) { 1556 goto exit; 1557 } 1558 } else { 1559 ret = -ENOTSUP; 1560 goto exit; 1561 } 1562 1563 if (type == VHDX_TYPE_FIXED || 1564 use_zero_blocks || 1565 bdrv_has_zero_init(bs) == 0) { 1566 /* for a fixed file, the default BAT entry is not zero */ 1567 s->bat = g_malloc0(rt_bat->length); 1568 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1569 PAYLOAD_BLOCK_NOT_PRESENT; 1570 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1571 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1572 while (sector_num < total_sectors) { 1573 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1574 sinfo.file_offset = data_file_offset + 1575 (sector_num << s->logical_sector_size_bits); 1576 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1577 vhdx_update_bat_table_entry(bs, s, &sinfo, &unused, &unused, 1578 block_state); 1579 cpu_to_le64s(&s->bat[sinfo.bat_idx]); 1580 sector_num += s->sectors_per_block; 1581 } 1582 ret = bdrv_pwrite(bs, rt_bat->file_offset, s->bat, rt_bat->length); 1583 if (ret < 0) { 1584 goto exit; 1585 } 1586 } 1587 1588 1589 1590 exit: 1591 g_free(s->bat); 1592 return ret; 1593 } 1594 1595 /* Creates the region table header, and region table entries. 1596 * There are 2 supported region table entries: BAT, and Metadata/ 1597 * 1598 * As the calculations for the BAT region table are also needed 1599 * to create the BAT itself, we will also cause the BAT to be 1600 * created. 1601 */ 1602 static int vhdx_create_new_region_table(BlockDriverState *bs, 1603 uint64_t image_size, 1604 uint32_t block_size, 1605 uint32_t sector_size, 1606 uint32_t log_size, 1607 bool use_zero_blocks, 1608 VHDXImageType type, 1609 uint64_t *metadata_offset) 1610 { 1611 int ret = 0; 1612 uint32_t offset = 0; 1613 void *buffer = NULL; 1614 BDRVVHDXState *s = NULL; 1615 VHDXRegionTableHeader *region_table; 1616 VHDXRegionTableEntry *rt_bat; 1617 VHDXRegionTableEntry *rt_metadata; 1618 1619 assert(metadata_offset != NULL); 1620 1621 /* Populate enough of the BDRVVHDXState to be able to use the 1622 * pre-existing BAT calculation, translation, and update functions */ 1623 s = g_malloc0(sizeof(BDRVVHDXState)); 1624 1625 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1626 (uint64_t) sector_size / (uint64_t) block_size; 1627 1628 s->sectors_per_block = block_size / sector_size; 1629 s->virtual_disk_size = image_size; 1630 s->block_size = block_size; 1631 s->logical_sector_size = sector_size; 1632 1633 vhdx_set_shift_bits(s); 1634 1635 vhdx_calc_bat_entries(s); 1636 1637 /* At this point the VHDX state is populated enough for creation */ 1638 1639 /* a single buffer is used so we can calculate the checksum over the 1640 * entire 64KB block */ 1641 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1642 region_table = buffer; 1643 offset += sizeof(VHDXRegionTableHeader); 1644 rt_bat = buffer + offset; 1645 offset += sizeof(VHDXRegionTableEntry); 1646 rt_metadata = buffer + offset; 1647 1648 region_table->signature = VHDX_REGION_SIGNATURE; 1649 region_table->entry_count = 2; /* BAT and Metadata */ 1650 1651 rt_bat->guid = bat_guid; 1652 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1653 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1654 s->bat_offset = rt_bat->file_offset; 1655 1656 rt_metadata->guid = metadata_guid; 1657 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1658 MiB); 1659 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1660 *metadata_offset = rt_metadata->file_offset; 1661 1662 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1663 offsetof(VHDXRegionTableHeader, checksum)); 1664 1665 1666 /* The region table gives us the data we need to create the BAT, 1667 * so do that now */ 1668 ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, rt_bat); 1669 1670 /* Now write out the region headers to disk */ 1671 vhdx_region_header_le_export(region_table); 1672 vhdx_region_entry_le_export(rt_bat); 1673 vhdx_region_entry_le_export(rt_metadata); 1674 1675 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer, 1676 VHDX_HEADER_BLOCK_SIZE); 1677 if (ret < 0) { 1678 goto exit; 1679 } 1680 1681 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE2_OFFSET, buffer, 1682 VHDX_HEADER_BLOCK_SIZE); 1683 if (ret < 0) { 1684 goto exit; 1685 } 1686 1687 1688 exit: 1689 g_free(s); 1690 g_free(buffer); 1691 return ret; 1692 } 1693 1694 /* We need to create the following elements: 1695 * 1696 * .-----------------------------------------------------------------. 1697 * | (A) | (B) | (C) | (D) | (E) | 1698 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1699 * | | | | | | 1700 * .-----------------------------------------------------------------. 1701 * 0 64KB 128KB 192KB 256KB 320KB 1702 * 1703 * 1704 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1705 * | (F) | (G) | (H) | | 1706 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1707 * | | | | | 1708 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1709 * 1MB 1710 */ 1711 static int vhdx_create(const char *filename, QEMUOptionParameter *options, 1712 Error **errp) 1713 { 1714 int ret = 0; 1715 uint64_t image_size = (uint64_t) 2 * GiB; 1716 uint32_t log_size = 1 * MiB; 1717 uint32_t block_size = 0; 1718 uint64_t signature; 1719 uint64_t metadata_offset; 1720 bool use_zero_blocks = false; 1721 1722 gunichar2 *creator = NULL; 1723 glong creator_items; 1724 BlockDriverState *bs; 1725 const char *type = NULL; 1726 VHDXImageType image_type; 1727 Error *local_err = NULL; 1728 1729 while (options && options->name) { 1730 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 1731 image_size = options->value.n; 1732 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_LOG_SIZE)) { 1733 log_size = options->value.n; 1734 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_BLOCK_SIZE)) { 1735 block_size = options->value.n; 1736 } else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) { 1737 type = options->value.s; 1738 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_ZERO)) { 1739 use_zero_blocks = options->value.n != 0; 1740 } 1741 options++; 1742 } 1743 1744 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1745 error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB"); 1746 ret = -EINVAL; 1747 goto exit; 1748 } 1749 1750 if (type == NULL) { 1751 type = "dynamic"; 1752 } 1753 1754 if (!strcmp(type, "dynamic")) { 1755 image_type = VHDX_TYPE_DYNAMIC; 1756 } else if (!strcmp(type, "fixed")) { 1757 image_type = VHDX_TYPE_FIXED; 1758 } else if (!strcmp(type, "differencing")) { 1759 error_setg_errno(errp, ENOTSUP, 1760 "Differencing files not yet supported"); 1761 ret = -ENOTSUP; 1762 goto exit; 1763 } else { 1764 ret = -EINVAL; 1765 goto exit; 1766 } 1767 1768 /* These are pretty arbitrary, and mainly designed to keep the BAT 1769 * size reasonable to load into RAM */ 1770 if (block_size == 0) { 1771 if (image_size > 32 * TiB) { 1772 block_size = 64 * MiB; 1773 } else if (image_size > (uint64_t) 100 * GiB) { 1774 block_size = 32 * MiB; 1775 } else if (image_size > 1 * GiB) { 1776 block_size = 16 * MiB; 1777 } else { 1778 block_size = 8 * MiB; 1779 } 1780 } 1781 1782 1783 /* make the log size close to what was specified, but must be 1784 * min 1MB, and multiple of 1MB */ 1785 log_size = ROUND_UP(log_size, MiB); 1786 1787 block_size = ROUND_UP(block_size, MiB); 1788 block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX : 1789 block_size; 1790 1791 ret = bdrv_create_file(filename, options, &local_err); 1792 if (ret < 0) { 1793 error_propagate(errp, local_err); 1794 goto exit; 1795 } 1796 1797 bs = NULL; 1798 ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1799 NULL, &local_err); 1800 if (ret < 0) { 1801 error_propagate(errp, local_err); 1802 goto exit; 1803 } 1804 1805 /* Create (A) */ 1806 1807 /* The creator field is optional, but may be useful for 1808 * debugging / diagnostics */ 1809 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 1810 &creator_items, NULL); 1811 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 1812 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature)); 1813 if (ret < 0) { 1814 goto delete_and_exit; 1815 } 1816 if (creator) { 1817 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET + sizeof(signature), 1818 creator, creator_items * sizeof(gunichar2)); 1819 if (ret < 0) { 1820 goto delete_and_exit; 1821 } 1822 } 1823 1824 1825 /* Creates (B),(C) */ 1826 ret = vhdx_create_new_headers(bs, image_size, log_size); 1827 if (ret < 0) { 1828 goto delete_and_exit; 1829 } 1830 1831 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 1832 ret = vhdx_create_new_region_table(bs, image_size, block_size, 512, 1833 log_size, use_zero_blocks, image_type, 1834 &metadata_offset); 1835 if (ret < 0) { 1836 goto delete_and_exit; 1837 } 1838 1839 /* Creates (H) */ 1840 ret = vhdx_create_new_metadata(bs, image_size, block_size, 512, 1841 metadata_offset, image_type); 1842 if (ret < 0) { 1843 goto delete_and_exit; 1844 } 1845 1846 1847 1848 delete_and_exit: 1849 bdrv_unref(bs); 1850 exit: 1851 g_free(creator); 1852 return ret; 1853 } 1854 1855 /* If opened r/w, the VHDX driver will automatically replay the log, 1856 * if one is present, inside the vhdx_open() call. 1857 * 1858 * If qemu-img check -r all is called, the image is automatically opened 1859 * r/w and any log has already been replayed, so there is nothing (currently) 1860 * for us to do here 1861 */ 1862 static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result, 1863 BdrvCheckMode fix) 1864 { 1865 BDRVVHDXState *s = bs->opaque; 1866 1867 if (s->log_replayed_on_open) { 1868 result->corruptions_fixed++; 1869 } 1870 return 0; 1871 } 1872 1873 static QEMUOptionParameter vhdx_create_options[] = { 1874 { 1875 .name = BLOCK_OPT_SIZE, 1876 .type = OPT_SIZE, 1877 .help = "Virtual disk size; max of 64TB." 1878 }, 1879 { 1880 .name = VHDX_BLOCK_OPT_LOG_SIZE, 1881 .type = OPT_SIZE, 1882 .value.n = 1 * MiB, 1883 .help = "Log size; min 1MB." 1884 }, 1885 { 1886 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 1887 .type = OPT_SIZE, 1888 .value.n = 0, 1889 .help = "Block Size; min 1MB, max 256MB. " \ 1890 "0 means auto-calculate based on image size." 1891 }, 1892 { 1893 .name = BLOCK_OPT_SUBFMT, 1894 .type = OPT_STRING, 1895 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ 1896 "Default is 'dynamic'." 1897 }, 1898 { 1899 .name = VHDX_BLOCK_OPT_ZERO, 1900 .type = OPT_FLAG, 1901 .help = "Force use of payload blocks of type 'ZERO'. Non-standard." 1902 }, 1903 { NULL } 1904 }; 1905 1906 static BlockDriver bdrv_vhdx = { 1907 .format_name = "vhdx", 1908 .instance_size = sizeof(BDRVVHDXState), 1909 .bdrv_probe = vhdx_probe, 1910 .bdrv_open = vhdx_open, 1911 .bdrv_close = vhdx_close, 1912 .bdrv_reopen_prepare = vhdx_reopen_prepare, 1913 .bdrv_co_readv = vhdx_co_readv, 1914 .bdrv_co_writev = vhdx_co_writev, 1915 .bdrv_create = vhdx_create, 1916 .bdrv_get_info = vhdx_get_info, 1917 .bdrv_check = vhdx_check, 1918 1919 .create_options = vhdx_create_options, 1920 }; 1921 1922 static void bdrv_vhdx_init(void) 1923 { 1924 bdrv_register(&bdrv_vhdx); 1925 } 1926 1927 block_init(bdrv_vhdx_init); 1928