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 /* The Microsoft Disk2VHD tool will create 2 identical 477 * headers, with identical sequence numbers. If the headers are 478 * identical, don't consider the file corrupt */ 479 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 480 s->curr_header = 0; 481 } else { 482 goto fail; 483 } 484 } 485 } 486 487 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 488 s->headers[s->curr_header]->log_length); 489 goto exit; 490 491 fail: 492 error_setg_errno(errp, -ret, "No valid VHDX header found"); 493 qemu_vfree(header1); 494 qemu_vfree(header2); 495 s->headers[0] = NULL; 496 s->headers[1] = NULL; 497 exit: 498 qemu_vfree(buffer); 499 } 500 501 502 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 503 { 504 int ret = 0; 505 uint8_t *buffer; 506 int offset = 0; 507 VHDXRegionTableEntry rt_entry; 508 uint32_t i; 509 bool bat_rt_found = false; 510 bool metadata_rt_found = false; 511 512 /* We have to read the whole 64KB block, because the crc32 is over the 513 * whole block */ 514 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 515 516 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 517 VHDX_HEADER_BLOCK_SIZE); 518 if (ret < 0) { 519 goto fail; 520 } 521 memcpy(&s->rt, buffer, sizeof(s->rt)); 522 vhdx_region_header_le_import(&s->rt); 523 offset += sizeof(s->rt); 524 525 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4) || 526 memcmp(&s->rt.signature, "regi", 4)) { 527 ret = -EINVAL; 528 goto fail; 529 } 530 531 /* Per spec, maximum region table entry count is 2047 */ 532 if (s->rt.entry_count > 2047) { 533 ret = -EINVAL; 534 goto fail; 535 } 536 537 for (i = 0; i < s->rt.entry_count; i++) { 538 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 539 offset += sizeof(rt_entry); 540 541 vhdx_region_entry_le_import(&rt_entry); 542 543 /* check for region overlap between these entries, and any 544 * other memory regions in the file */ 545 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 546 if (ret < 0) { 547 goto fail; 548 } 549 550 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 551 552 /* see if we recognize the entry */ 553 if (guid_eq(rt_entry.guid, bat_guid)) { 554 /* must be unique; if we have already found it this is invalid */ 555 if (bat_rt_found) { 556 ret = -EINVAL; 557 goto fail; 558 } 559 bat_rt_found = true; 560 s->bat_rt = rt_entry; 561 continue; 562 } 563 564 if (guid_eq(rt_entry.guid, metadata_guid)) { 565 /* must be unique; if we have already found it this is invalid */ 566 if (metadata_rt_found) { 567 ret = -EINVAL; 568 goto fail; 569 } 570 metadata_rt_found = true; 571 s->metadata_rt = rt_entry; 572 continue; 573 } 574 575 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 576 /* cannot read vhdx file - required region table entry that 577 * we do not understand. per spec, we must fail to open */ 578 ret = -ENOTSUP; 579 goto fail; 580 } 581 } 582 583 if (!bat_rt_found || !metadata_rt_found) { 584 ret = -EINVAL; 585 goto fail; 586 } 587 588 ret = 0; 589 590 fail: 591 qemu_vfree(buffer); 592 return ret; 593 } 594 595 596 597 /* Metadata initial parser 598 * 599 * This loads all the metadata entry fields. This may cause additional 600 * fields to be processed (e.g. parent locator, etc..). 601 * 602 * There are 5 Metadata items that are always required: 603 * - File Parameters (block size, has a parent) 604 * - Virtual Disk Size (size, in bytes, of the virtual drive) 605 * - Page 83 Data (scsi page 83 guid) 606 * - Logical Sector Size (logical sector size in bytes, either 512 or 607 * 4096. We only support 512 currently) 608 * - Physical Sector Size (512 or 4096) 609 * 610 * Also, if the File Parameters indicate this is a differencing file, 611 * we must also look for the Parent Locator metadata item. 612 */ 613 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 614 { 615 int ret = 0; 616 uint8_t *buffer; 617 int offset = 0; 618 uint32_t i = 0; 619 VHDXMetadataTableEntry md_entry; 620 621 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 622 623 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 624 VHDX_METADATA_TABLE_MAX_SIZE); 625 if (ret < 0) { 626 goto exit; 627 } 628 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 629 offset += sizeof(s->metadata_hdr); 630 631 vhdx_metadata_header_le_import(&s->metadata_hdr); 632 633 if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) { 634 ret = -EINVAL; 635 goto exit; 636 } 637 638 s->metadata_entries.present = 0; 639 640 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 641 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 642 ret = -EINVAL; 643 goto exit; 644 } 645 646 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 647 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 648 offset += sizeof(md_entry); 649 650 vhdx_metadata_entry_le_import(&md_entry); 651 652 if (guid_eq(md_entry.item_id, file_param_guid)) { 653 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 654 ret = -EINVAL; 655 goto exit; 656 } 657 s->metadata_entries.file_parameters_entry = md_entry; 658 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 659 continue; 660 } 661 662 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 663 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 664 ret = -EINVAL; 665 goto exit; 666 } 667 s->metadata_entries.virtual_disk_size_entry = md_entry; 668 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 669 continue; 670 } 671 672 if (guid_eq(md_entry.item_id, page83_guid)) { 673 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 674 ret = -EINVAL; 675 goto exit; 676 } 677 s->metadata_entries.page83_data_entry = md_entry; 678 s->metadata_entries.present |= META_PAGE_83_PRESENT; 679 continue; 680 } 681 682 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 683 if (s->metadata_entries.present & 684 META_LOGICAL_SECTOR_SIZE_PRESENT) { 685 ret = -EINVAL; 686 goto exit; 687 } 688 s->metadata_entries.logical_sector_size_entry = md_entry; 689 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 690 continue; 691 } 692 693 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 694 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 695 ret = -EINVAL; 696 goto exit; 697 } 698 s->metadata_entries.phys_sector_size_entry = md_entry; 699 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 700 continue; 701 } 702 703 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 704 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 705 ret = -EINVAL; 706 goto exit; 707 } 708 s->metadata_entries.parent_locator_entry = md_entry; 709 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 710 continue; 711 } 712 713 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 714 /* cannot read vhdx file - required region table entry that 715 * we do not understand. per spec, we must fail to open */ 716 ret = -ENOTSUP; 717 goto exit; 718 } 719 } 720 721 if (s->metadata_entries.present != META_ALL_PRESENT) { 722 ret = -ENOTSUP; 723 goto exit; 724 } 725 726 ret = bdrv_pread(bs->file, 727 s->metadata_entries.file_parameters_entry.offset 728 + s->metadata_rt.file_offset, 729 &s->params, 730 sizeof(s->params)); 731 732 if (ret < 0) { 733 goto exit; 734 } 735 736 le32_to_cpus(&s->params.block_size); 737 le32_to_cpus(&s->params.data_bits); 738 739 740 /* We now have the file parameters, so we can tell if this is a 741 * differencing file (i.e.. has_parent), is dynamic or fixed 742 * sized (leave_blocks_allocated), and the block size */ 743 744 /* The parent locator required iff the file parameters has_parent set */ 745 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 746 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 747 /* TODO: parse parent locator fields */ 748 ret = -ENOTSUP; /* temp, until differencing files are supported */ 749 goto exit; 750 } else { 751 /* if has_parent is set, but there is not parent locator present, 752 * then that is an invalid combination */ 753 ret = -EINVAL; 754 goto exit; 755 } 756 } 757 758 /* determine virtual disk size, logical sector size, 759 * and phys sector size */ 760 761 ret = bdrv_pread(bs->file, 762 s->metadata_entries.virtual_disk_size_entry.offset 763 + s->metadata_rt.file_offset, 764 &s->virtual_disk_size, 765 sizeof(uint64_t)); 766 if (ret < 0) { 767 goto exit; 768 } 769 ret = bdrv_pread(bs->file, 770 s->metadata_entries.logical_sector_size_entry.offset 771 + s->metadata_rt.file_offset, 772 &s->logical_sector_size, 773 sizeof(uint32_t)); 774 if (ret < 0) { 775 goto exit; 776 } 777 ret = bdrv_pread(bs->file, 778 s->metadata_entries.phys_sector_size_entry.offset 779 + s->metadata_rt.file_offset, 780 &s->physical_sector_size, 781 sizeof(uint32_t)); 782 if (ret < 0) { 783 goto exit; 784 } 785 786 le64_to_cpus(&s->virtual_disk_size); 787 le32_to_cpus(&s->logical_sector_size); 788 le32_to_cpus(&s->physical_sector_size); 789 790 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 791 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 792 ret = -EINVAL; 793 goto exit; 794 } 795 796 /* only 2 supported sector sizes */ 797 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { 798 ret = -EINVAL; 799 goto exit; 800 } 801 802 /* Both block_size and sector_size are guaranteed powers of 2, below. 803 Due to range checks above, s->sectors_per_block can never be < 256 */ 804 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 805 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 806 (uint64_t)s->logical_sector_size / 807 (uint64_t)s->params.block_size; 808 809 /* These values are ones we will want to use for division / multiplication 810 * later on, and they are all guaranteed (per the spec) to be powers of 2, 811 * so we can take advantage of that for shift operations during 812 * reads/writes */ 813 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 814 ret = -EINVAL; 815 goto exit; 816 } 817 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 818 ret = -EINVAL; 819 goto exit; 820 } 821 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 822 ret = -EINVAL; 823 goto exit; 824 } 825 s->block_size = s->params.block_size; 826 if (s->block_size & (s->block_size - 1)) { 827 ret = -EINVAL; 828 goto exit; 829 } 830 831 vhdx_set_shift_bits(s); 832 833 ret = 0; 834 835 exit: 836 qemu_vfree(buffer); 837 return ret; 838 } 839 840 /* 841 * Calculate the number of BAT entries, including sector 842 * bitmap entries. 843 */ 844 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 845 { 846 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 847 848 data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits; 849 if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) { 850 data_blocks_cnt++; 851 } 852 bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits; 853 if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) { 854 bitmap_blocks_cnt++; 855 } 856 857 if (s->parent_entries) { 858 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 859 } else { 860 s->bat_entries = data_blocks_cnt + 861 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 862 } 863 864 } 865 866 static void vhdx_close(BlockDriverState *bs) 867 { 868 BDRVVHDXState *s = bs->opaque; 869 qemu_vfree(s->headers[0]); 870 s->headers[0] = NULL; 871 qemu_vfree(s->headers[1]); 872 s->headers[1] = NULL; 873 qemu_vfree(s->bat); 874 s->bat = NULL; 875 qemu_vfree(s->parent_entries); 876 s->parent_entries = NULL; 877 migrate_del_blocker(s->migration_blocker); 878 error_free(s->migration_blocker); 879 qemu_vfree(s->log.hdr); 880 s->log.hdr = NULL; 881 vhdx_region_unregister_all(s); 882 } 883 884 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 885 Error **errp) 886 { 887 BDRVVHDXState *s = bs->opaque; 888 int ret = 0; 889 uint32_t i; 890 uint64_t signature; 891 Error *local_err = NULL; 892 893 s->bat = NULL; 894 s->first_visible_write = true; 895 896 qemu_co_mutex_init(&s->lock); 897 QLIST_INIT(&s->regions); 898 899 /* validate the file signature */ 900 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 901 if (ret < 0) { 902 goto fail; 903 } 904 if (memcmp(&signature, "vhdxfile", 8)) { 905 ret = -EINVAL; 906 goto fail; 907 } 908 909 /* This is used for any header updates, for the file_write_guid. 910 * The spec dictates that a new value should be used for the first 911 * header update */ 912 vhdx_guid_generate(&s->session_guid); 913 914 vhdx_parse_header(bs, s, &local_err); 915 if (local_err != NULL) { 916 error_propagate(errp, local_err); 917 ret = -EINVAL; 918 goto fail; 919 } 920 921 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 922 if (ret < 0) { 923 goto fail; 924 } 925 926 ret = vhdx_open_region_tables(bs, s); 927 if (ret < 0) { 928 goto fail; 929 } 930 931 ret = vhdx_parse_metadata(bs, s); 932 if (ret < 0) { 933 goto fail; 934 } 935 936 s->block_size = s->params.block_size; 937 938 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 939 * logical_sector_size */ 940 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 941 942 vhdx_calc_bat_entries(s); 943 944 s->bat_offset = s->bat_rt.file_offset; 945 946 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 947 /* BAT allocation is not large enough for all entries */ 948 ret = -EINVAL; 949 goto fail; 950 } 951 952 /* s->bat is freed in vhdx_close() */ 953 s->bat = qemu_blockalign(bs, s->bat_rt.length); 954 955 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 956 if (ret < 0) { 957 goto fail; 958 } 959 960 uint64_t payblocks = s->chunk_ratio; 961 /* endian convert, and verify populated BAT field file offsets against 962 * region table and log entries */ 963 for (i = 0; i < s->bat_entries; i++) { 964 le64_to_cpus(&s->bat[i]); 965 if (payblocks--) { 966 /* payload bat entries */ 967 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 968 PAYLOAD_BLOCK_FULLY_PRESENT) { 969 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, 970 s->block_size); 971 if (ret < 0) { 972 goto fail; 973 } 974 } 975 } else { 976 payblocks = s->chunk_ratio; 977 /* Once differencing files are supported, verify sector bitmap 978 * blocks here */ 979 } 980 } 981 982 if (flags & BDRV_O_RDWR) { 983 ret = vhdx_update_headers(bs, s, false, NULL); 984 if (ret < 0) { 985 goto fail; 986 } 987 } 988 989 /* TODO: differencing files */ 990 991 /* Disable migration when VHDX images are used */ 992 error_set(&s->migration_blocker, 993 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 994 "vhdx", bs->device_name, "live migration"); 995 migrate_add_blocker(s->migration_blocker); 996 997 return 0; 998 fail: 999 vhdx_close(bs); 1000 return ret; 1001 } 1002 1003 static int vhdx_reopen_prepare(BDRVReopenState *state, 1004 BlockReopenQueue *queue, Error **errp) 1005 { 1006 return 0; 1007 } 1008 1009 1010 /* 1011 * Perform sector to block offset translations, to get various 1012 * sector and file offsets into the image. See VHDXSectorInfo 1013 */ 1014 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1015 int nb_sectors, VHDXSectorInfo *sinfo) 1016 { 1017 uint32_t block_offset; 1018 1019 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1020 /* effectively a modulo - this gives us the offset into the block 1021 * (in sector sizes) for our sector number */ 1022 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1023 /* the chunk ratio gives us the interleaving of the sector 1024 * bitmaps, so we need to advance our page block index by the 1025 * sector bitmaps entry number */ 1026 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1027 1028 /* the number of sectors we can read/write in this cycle */ 1029 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1030 1031 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1032 1033 if (sinfo->sectors_avail > nb_sectors) { 1034 sinfo->sectors_avail = nb_sectors; 1035 } 1036 1037 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1038 1039 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1040 1041 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1042 1043 /* The file offset must be past the header section, so must be > 0 */ 1044 if (sinfo->file_offset == 0) { 1045 return; 1046 } 1047 1048 /* block offset is the offset in vhdx logical sectors, in 1049 * the payload data block. Convert that to a byte offset 1050 * in the block, and add in the payload data block offset 1051 * in the file, in bytes, to get the final read address */ 1052 1053 sinfo->file_offset += sinfo->block_offset; 1054 } 1055 1056 1057 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1058 { 1059 BDRVVHDXState *s = bs->opaque; 1060 1061 bdi->cluster_size = s->block_size; 1062 1063 bdi->unallocated_blocks_are_zero = 1064 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; 1065 1066 return 0; 1067 } 1068 1069 1070 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1071 int nb_sectors, QEMUIOVector *qiov) 1072 { 1073 BDRVVHDXState *s = bs->opaque; 1074 int ret = 0; 1075 VHDXSectorInfo sinfo; 1076 uint64_t bytes_done = 0; 1077 QEMUIOVector hd_qiov; 1078 1079 qemu_iovec_init(&hd_qiov, qiov->niov); 1080 1081 qemu_co_mutex_lock(&s->lock); 1082 1083 while (nb_sectors > 0) { 1084 /* We are a differencing file, so we need to inspect the sector bitmap 1085 * to see if we have the data or not */ 1086 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1087 /* not supported yet */ 1088 ret = -ENOTSUP; 1089 goto exit; 1090 } else { 1091 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1092 1093 qemu_iovec_reset(&hd_qiov); 1094 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1095 1096 /* check the payload block state */ 1097 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1098 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1099 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1100 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1101 case PAYLOAD_BLOCK_ZERO: 1102 /* return zero */ 1103 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1104 break; 1105 case PAYLOAD_BLOCK_FULLY_PRESENT: 1106 qemu_co_mutex_unlock(&s->lock); 1107 ret = bdrv_co_readv(bs->file, 1108 sinfo.file_offset >> BDRV_SECTOR_BITS, 1109 sinfo.sectors_avail, &hd_qiov); 1110 qemu_co_mutex_lock(&s->lock); 1111 if (ret < 0) { 1112 goto exit; 1113 } 1114 break; 1115 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1116 /* we don't yet support difference files, fall through 1117 * to error */ 1118 default: 1119 ret = -EIO; 1120 goto exit; 1121 break; 1122 } 1123 nb_sectors -= sinfo.sectors_avail; 1124 sector_num += sinfo.sectors_avail; 1125 bytes_done += sinfo.bytes_avail; 1126 } 1127 } 1128 ret = 0; 1129 exit: 1130 qemu_co_mutex_unlock(&s->lock); 1131 qemu_iovec_destroy(&hd_qiov); 1132 return ret; 1133 } 1134 1135 /* 1136 * Allocate a new payload block at the end of the file. 1137 * 1138 * Allocation will happen at 1MB alignment inside the file 1139 * 1140 * Returns the file offset start of the new payload block 1141 */ 1142 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1143 uint64_t *new_offset) 1144 { 1145 *new_offset = bdrv_getlength(bs->file); 1146 1147 /* per the spec, the address for a block is in units of 1MB */ 1148 *new_offset = ROUND_UP(*new_offset, 1024 * 1024); 1149 1150 return bdrv_truncate(bs->file, *new_offset + s->block_size); 1151 } 1152 1153 /* 1154 * Update the BAT table entry with the new file offset, and the new entry 1155 * state */ 1156 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1157 VHDXSectorInfo *sinfo, 1158 uint64_t *bat_entry_le, 1159 uint64_t *bat_offset, int state) 1160 { 1161 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1162 * 1MB, and 3 bits for the block state. */ 1163 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1164 1165 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1166 1167 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1168 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1169 1170 } 1171 1172 /* Per the spec, on the first write of guest-visible data to the file the 1173 * data write guid must be updated in the header */ 1174 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1175 { 1176 int ret = 0; 1177 if (s->first_visible_write) { 1178 s->first_visible_write = false; 1179 ret = vhdx_update_headers(bs, s, true, NULL); 1180 } 1181 return ret; 1182 } 1183 1184 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1185 int nb_sectors, QEMUIOVector *qiov) 1186 { 1187 int ret = -ENOTSUP; 1188 BDRVVHDXState *s = bs->opaque; 1189 VHDXSectorInfo sinfo; 1190 uint64_t bytes_done = 0; 1191 uint64_t bat_entry = 0; 1192 uint64_t bat_entry_offset = 0; 1193 QEMUIOVector hd_qiov; 1194 struct iovec iov1 = { 0 }; 1195 struct iovec iov2 = { 0 }; 1196 int sectors_to_write; 1197 int bat_state; 1198 uint64_t bat_prior_offset = 0; 1199 bool bat_update = false; 1200 1201 qemu_iovec_init(&hd_qiov, qiov->niov); 1202 1203 qemu_co_mutex_lock(&s->lock); 1204 1205 ret = vhdx_user_visible_write(bs, s); 1206 if (ret < 0) { 1207 goto exit; 1208 } 1209 1210 while (nb_sectors > 0) { 1211 bool use_zero_buffers = false; 1212 bat_update = false; 1213 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1214 /* not supported yet */ 1215 ret = -ENOTSUP; 1216 goto exit; 1217 } else { 1218 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1219 sectors_to_write = sinfo.sectors_avail; 1220 1221 qemu_iovec_reset(&hd_qiov); 1222 /* check the payload block state */ 1223 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1224 switch (bat_state) { 1225 case PAYLOAD_BLOCK_ZERO: 1226 /* in this case, we need to preserve zero writes for 1227 * data that is not part of this write, so we must pad 1228 * the rest of the buffer to zeroes */ 1229 1230 /* if we are on a posix system with ftruncate() that extends 1231 * a file, then it is zero-filled for us. On Win32, the raw 1232 * layer uses SetFilePointer and SetFileEnd, which does not 1233 * zero fill AFAIK */ 1234 1235 /* Queue another write of zero buffers if the underlying file 1236 * does not zero-fill on file extension */ 1237 1238 if (bdrv_has_zero_init(bs->file) == 0) { 1239 use_zero_buffers = true; 1240 1241 /* zero fill the front, if any */ 1242 if (sinfo.block_offset) { 1243 iov1.iov_len = sinfo.block_offset; 1244 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1245 memset(iov1.iov_base, 0, iov1.iov_len); 1246 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1247 sinfo.block_offset); 1248 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1249 } 1250 1251 /* our actual data */ 1252 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1253 sinfo.bytes_avail); 1254 1255 /* zero fill the back, if any */ 1256 if ((sinfo.bytes_avail - sinfo.block_offset) < 1257 s->block_size) { 1258 iov2.iov_len = s->block_size - 1259 (sinfo.bytes_avail + sinfo.block_offset); 1260 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1261 memset(iov2.iov_base, 0, iov2.iov_len); 1262 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1263 sinfo.block_offset); 1264 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1265 } 1266 } 1267 1268 /* fall through */ 1269 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1270 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1271 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1272 bat_prior_offset = sinfo.file_offset; 1273 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); 1274 if (ret < 0) { 1275 goto exit; 1276 } 1277 /* once we support differencing files, this may also be 1278 * partially present */ 1279 /* update block state to the newly specified state */ 1280 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1281 &bat_entry_offset, 1282 PAYLOAD_BLOCK_FULLY_PRESENT); 1283 bat_update = true; 1284 /* since we just allocated a block, file_offset is the 1285 * beginning of the payload block. It needs to be the 1286 * write address, which includes the offset into the block */ 1287 if (!use_zero_buffers) { 1288 sinfo.file_offset += sinfo.block_offset; 1289 } 1290 /* fall through */ 1291 case PAYLOAD_BLOCK_FULLY_PRESENT: 1292 /* if the file offset address is in the header zone, 1293 * there is a problem */ 1294 if (sinfo.file_offset < (1024 * 1024)) { 1295 ret = -EFAULT; 1296 goto error_bat_restore; 1297 } 1298 1299 if (!use_zero_buffers) { 1300 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1301 sinfo.bytes_avail); 1302 } 1303 /* block exists, so we can just overwrite it */ 1304 qemu_co_mutex_unlock(&s->lock); 1305 ret = bdrv_co_writev(bs->file, 1306 sinfo.file_offset >> BDRV_SECTOR_BITS, 1307 sectors_to_write, &hd_qiov); 1308 qemu_co_mutex_lock(&s->lock); 1309 if (ret < 0) { 1310 goto error_bat_restore; 1311 } 1312 break; 1313 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1314 /* we don't yet support difference files, fall through 1315 * to error */ 1316 default: 1317 ret = -EIO; 1318 goto exit; 1319 break; 1320 } 1321 1322 if (bat_update) { 1323 /* this will update the BAT entry into the log journal, and 1324 * then flush the log journal out to disk */ 1325 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1326 sizeof(VHDXBatEntry), 1327 bat_entry_offset); 1328 if (ret < 0) { 1329 goto exit; 1330 } 1331 } 1332 1333 nb_sectors -= sinfo.sectors_avail; 1334 sector_num += sinfo.sectors_avail; 1335 bytes_done += sinfo.bytes_avail; 1336 1337 } 1338 } 1339 1340 goto exit; 1341 1342 error_bat_restore: 1343 if (bat_update) { 1344 /* keep metadata in sync, and restore the bat entry state 1345 * if error. */ 1346 sinfo.file_offset = bat_prior_offset; 1347 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1348 &bat_entry_offset, bat_state); 1349 } 1350 exit: 1351 qemu_vfree(iov1.iov_base); 1352 qemu_vfree(iov2.iov_base); 1353 qemu_co_mutex_unlock(&s->lock); 1354 qemu_iovec_destroy(&hd_qiov); 1355 return ret; 1356 } 1357 1358 1359 1360 /* 1361 * Create VHDX Headers 1362 * 1363 * There are 2 headers, and the highest sequence number will represent 1364 * the active header 1365 */ 1366 static int vhdx_create_new_headers(BlockDriverState *bs, uint64_t image_size, 1367 uint32_t log_size) 1368 { 1369 int ret = 0; 1370 VHDXHeader *hdr = NULL; 1371 1372 hdr = g_malloc0(sizeof(VHDXHeader)); 1373 1374 hdr->signature = VHDX_HEADER_SIGNATURE; 1375 hdr->sequence_number = g_random_int(); 1376 hdr->log_version = 0; 1377 hdr->version = 1; 1378 hdr->log_length = log_size; 1379 hdr->log_offset = VHDX_HEADER_SECTION_END; 1380 vhdx_guid_generate(&hdr->file_write_guid); 1381 vhdx_guid_generate(&hdr->data_write_guid); 1382 1383 ret = vhdx_write_header(bs, hdr, VHDX_HEADER1_OFFSET, false); 1384 if (ret < 0) { 1385 goto exit; 1386 } 1387 hdr->sequence_number++; 1388 ret = vhdx_write_header(bs, hdr, VHDX_HEADER2_OFFSET, false); 1389 if (ret < 0) { 1390 goto exit; 1391 } 1392 1393 exit: 1394 g_free(hdr); 1395 return ret; 1396 } 1397 1398 1399 /* 1400 * Create the Metadata entries. 1401 * 1402 * For more details on the entries, see section 3.5 (pg 29) in the 1403 * VHDX 1.00 specification. 1404 * 1405 * We support 5 metadata entries (all required by spec): 1406 * File Parameters, 1407 * Virtual Disk Size, 1408 * Page 83 Data, 1409 * Logical Sector Size, 1410 * Physical Sector Size 1411 * 1412 * The first 64KB of the Metadata section is reserved for the metadata 1413 * header and entries; beyond that, the metadata items themselves reside. 1414 */ 1415 static int vhdx_create_new_metadata(BlockDriverState *bs, 1416 uint64_t image_size, 1417 uint32_t block_size, 1418 uint32_t sector_size, 1419 uint64_t metadata_offset, 1420 VHDXImageType type) 1421 { 1422 int ret = 0; 1423 uint32_t offset = 0; 1424 void *buffer = NULL; 1425 void *entry_buffer; 1426 VHDXMetadataTableHeader *md_table;; 1427 VHDXMetadataTableEntry *md_table_entry; 1428 1429 /* Metadata entries */ 1430 VHDXFileParameters *mt_file_params; 1431 VHDXVirtualDiskSize *mt_virtual_size; 1432 VHDXPage83Data *mt_page83; 1433 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1434 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1435 1436 entry_buffer = g_malloc0(sizeof(VHDXFileParameters) + 1437 sizeof(VHDXVirtualDiskSize) + 1438 sizeof(VHDXPage83Data) + 1439 sizeof(VHDXVirtualDiskLogicalSectorSize) + 1440 sizeof(VHDXVirtualDiskPhysicalSectorSize)); 1441 1442 mt_file_params = entry_buffer; 1443 offset += sizeof(VHDXFileParameters); 1444 mt_virtual_size = entry_buffer + offset; 1445 offset += sizeof(VHDXVirtualDiskSize); 1446 mt_page83 = entry_buffer + offset; 1447 offset += sizeof(VHDXPage83Data); 1448 mt_log_sector_size = entry_buffer + offset; 1449 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1450 mt_phys_sector_size = entry_buffer + offset; 1451 1452 mt_file_params->block_size = cpu_to_le32(block_size); 1453 if (type == VHDX_TYPE_FIXED) { 1454 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1455 cpu_to_le32s(&mt_file_params->data_bits); 1456 } 1457 1458 vhdx_guid_generate(&mt_page83->page_83_data); 1459 cpu_to_leguids(&mt_page83->page_83_data); 1460 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1461 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1462 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1463 1464 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1465 md_table = buffer; 1466 1467 md_table->signature = VHDX_METADATA_SIGNATURE; 1468 md_table->entry_count = 5; 1469 vhdx_metadata_header_le_export(md_table); 1470 1471 1472 /* This will reference beyond the reserved table portion */ 1473 offset = 64 * KiB; 1474 1475 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1476 1477 md_table_entry[0].item_id = file_param_guid; 1478 md_table_entry[0].offset = offset; 1479 md_table_entry[0].length = sizeof(VHDXFileParameters); 1480 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1481 offset += md_table_entry[0].length; 1482 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1483 1484 md_table_entry[1].item_id = virtual_size_guid; 1485 md_table_entry[1].offset = offset; 1486 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1487 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1488 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1489 offset += md_table_entry[1].length; 1490 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1491 1492 md_table_entry[2].item_id = page83_guid; 1493 md_table_entry[2].offset = offset; 1494 md_table_entry[2].length = sizeof(VHDXPage83Data); 1495 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1496 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1497 offset += md_table_entry[2].length; 1498 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1499 1500 md_table_entry[3].item_id = logical_sector_guid; 1501 md_table_entry[3].offset = offset; 1502 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1503 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1504 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1505 offset += md_table_entry[3].length; 1506 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1507 1508 md_table_entry[4].item_id = phys_sector_guid; 1509 md_table_entry[4].offset = offset; 1510 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1511 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1512 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1513 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1514 1515 ret = bdrv_pwrite(bs, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE); 1516 if (ret < 0) { 1517 goto exit; 1518 } 1519 1520 ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer, 1521 VHDX_HEADER_BLOCK_SIZE); 1522 if (ret < 0) { 1523 goto exit; 1524 } 1525 1526 1527 exit: 1528 g_free(buffer); 1529 g_free(entry_buffer); 1530 return ret; 1531 } 1532 1533 /* This create the actual BAT itself. We currently only support 1534 * 'Dynamic' and 'Fixed' image types. 1535 * 1536 * Dynamic images: default state of the BAT is all zeroes. 1537 * 1538 * Fixed images: default state of the BAT is fully populated, with 1539 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1540 */ 1541 static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s, 1542 uint64_t image_size, VHDXImageType type, 1543 bool use_zero_blocks, VHDXRegionTableEntry *rt_bat) 1544 { 1545 int ret = 0; 1546 uint64_t data_file_offset; 1547 uint64_t total_sectors = 0; 1548 uint64_t sector_num = 0; 1549 uint64_t unused; 1550 int block_state; 1551 VHDXSectorInfo sinfo; 1552 1553 assert(s->bat == NULL); 1554 1555 /* this gives a data start after BAT/bitmap entries, and well 1556 * past any metadata entries (with a 4 MB buffer for future 1557 * expansion */ 1558 data_file_offset = rt_bat->file_offset + rt_bat->length + 5 * MiB; 1559 total_sectors = image_size >> s->logical_sector_size_bits; 1560 1561 if (type == VHDX_TYPE_DYNAMIC) { 1562 /* All zeroes, so we can just extend the file - the end of the BAT 1563 * is the furthest thing we have written yet */ 1564 ret = bdrv_truncate(bs, data_file_offset); 1565 if (ret < 0) { 1566 goto exit; 1567 } 1568 } else if (type == VHDX_TYPE_FIXED) { 1569 ret = bdrv_truncate(bs, data_file_offset + image_size); 1570 if (ret < 0) { 1571 goto exit; 1572 } 1573 } else { 1574 ret = -ENOTSUP; 1575 goto exit; 1576 } 1577 1578 if (type == VHDX_TYPE_FIXED || 1579 use_zero_blocks || 1580 bdrv_has_zero_init(bs) == 0) { 1581 /* for a fixed file, the default BAT entry is not zero */ 1582 s->bat = g_malloc0(rt_bat->length); 1583 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1584 PAYLOAD_BLOCK_NOT_PRESENT; 1585 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1586 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1587 while (sector_num < total_sectors) { 1588 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1589 sinfo.file_offset = data_file_offset + 1590 (sector_num << s->logical_sector_size_bits); 1591 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1592 vhdx_update_bat_table_entry(bs, s, &sinfo, &unused, &unused, 1593 block_state); 1594 cpu_to_le64s(&s->bat[sinfo.bat_idx]); 1595 sector_num += s->sectors_per_block; 1596 } 1597 ret = bdrv_pwrite(bs, rt_bat->file_offset, s->bat, rt_bat->length); 1598 if (ret < 0) { 1599 goto exit; 1600 } 1601 } 1602 1603 1604 1605 exit: 1606 g_free(s->bat); 1607 return ret; 1608 } 1609 1610 /* Creates the region table header, and region table entries. 1611 * There are 2 supported region table entries: BAT, and Metadata/ 1612 * 1613 * As the calculations for the BAT region table are also needed 1614 * to create the BAT itself, we will also cause the BAT to be 1615 * created. 1616 */ 1617 static int vhdx_create_new_region_table(BlockDriverState *bs, 1618 uint64_t image_size, 1619 uint32_t block_size, 1620 uint32_t sector_size, 1621 uint32_t log_size, 1622 bool use_zero_blocks, 1623 VHDXImageType type, 1624 uint64_t *metadata_offset) 1625 { 1626 int ret = 0; 1627 uint32_t offset = 0; 1628 void *buffer = NULL; 1629 BDRVVHDXState *s = NULL; 1630 VHDXRegionTableHeader *region_table; 1631 VHDXRegionTableEntry *rt_bat; 1632 VHDXRegionTableEntry *rt_metadata; 1633 1634 assert(metadata_offset != NULL); 1635 1636 /* Populate enough of the BDRVVHDXState to be able to use the 1637 * pre-existing BAT calculation, translation, and update functions */ 1638 s = g_malloc0(sizeof(BDRVVHDXState)); 1639 1640 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1641 (uint64_t) sector_size / (uint64_t) block_size; 1642 1643 s->sectors_per_block = block_size / sector_size; 1644 s->virtual_disk_size = image_size; 1645 s->block_size = block_size; 1646 s->logical_sector_size = sector_size; 1647 1648 vhdx_set_shift_bits(s); 1649 1650 vhdx_calc_bat_entries(s); 1651 1652 /* At this point the VHDX state is populated enough for creation */ 1653 1654 /* a single buffer is used so we can calculate the checksum over the 1655 * entire 64KB block */ 1656 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1657 region_table = buffer; 1658 offset += sizeof(VHDXRegionTableHeader); 1659 rt_bat = buffer + offset; 1660 offset += sizeof(VHDXRegionTableEntry); 1661 rt_metadata = buffer + offset; 1662 1663 region_table->signature = VHDX_REGION_SIGNATURE; 1664 region_table->entry_count = 2; /* BAT and Metadata */ 1665 1666 rt_bat->guid = bat_guid; 1667 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1668 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1669 s->bat_offset = rt_bat->file_offset; 1670 1671 rt_metadata->guid = metadata_guid; 1672 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1673 MiB); 1674 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1675 *metadata_offset = rt_metadata->file_offset; 1676 1677 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1678 offsetof(VHDXRegionTableHeader, checksum)); 1679 1680 1681 /* The region table gives us the data we need to create the BAT, 1682 * so do that now */ 1683 ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, rt_bat); 1684 1685 /* Now write out the region headers to disk */ 1686 vhdx_region_header_le_export(region_table); 1687 vhdx_region_entry_le_export(rt_bat); 1688 vhdx_region_entry_le_export(rt_metadata); 1689 1690 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer, 1691 VHDX_HEADER_BLOCK_SIZE); 1692 if (ret < 0) { 1693 goto exit; 1694 } 1695 1696 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE2_OFFSET, buffer, 1697 VHDX_HEADER_BLOCK_SIZE); 1698 if (ret < 0) { 1699 goto exit; 1700 } 1701 1702 1703 exit: 1704 g_free(s); 1705 g_free(buffer); 1706 return ret; 1707 } 1708 1709 /* We need to create the following elements: 1710 * 1711 * .-----------------------------------------------------------------. 1712 * | (A) | (B) | (C) | (D) | (E) | 1713 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1714 * | | | | | | 1715 * .-----------------------------------------------------------------. 1716 * 0 64KB 128KB 192KB 256KB 320KB 1717 * 1718 * 1719 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1720 * | (F) | (G) | (H) | | 1721 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1722 * | | | | | 1723 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1724 * 1MB 1725 */ 1726 static int vhdx_create(const char *filename, QEMUOptionParameter *options, 1727 Error **errp) 1728 { 1729 int ret = 0; 1730 uint64_t image_size = (uint64_t) 2 * GiB; 1731 uint32_t log_size = 1 * MiB; 1732 uint32_t block_size = 0; 1733 uint64_t signature; 1734 uint64_t metadata_offset; 1735 bool use_zero_blocks = false; 1736 1737 gunichar2 *creator = NULL; 1738 glong creator_items; 1739 BlockDriverState *bs; 1740 const char *type = NULL; 1741 VHDXImageType image_type; 1742 Error *local_err = NULL; 1743 1744 while (options && options->name) { 1745 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 1746 image_size = options->value.n; 1747 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_LOG_SIZE)) { 1748 log_size = options->value.n; 1749 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_BLOCK_SIZE)) { 1750 block_size = options->value.n; 1751 } else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) { 1752 type = options->value.s; 1753 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_ZERO)) { 1754 use_zero_blocks = options->value.n != 0; 1755 } 1756 options++; 1757 } 1758 1759 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1760 error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB"); 1761 ret = -EINVAL; 1762 goto exit; 1763 } 1764 1765 if (type == NULL) { 1766 type = "dynamic"; 1767 } 1768 1769 if (!strcmp(type, "dynamic")) { 1770 image_type = VHDX_TYPE_DYNAMIC; 1771 } else if (!strcmp(type, "fixed")) { 1772 image_type = VHDX_TYPE_FIXED; 1773 } else if (!strcmp(type, "differencing")) { 1774 error_setg_errno(errp, ENOTSUP, 1775 "Differencing files not yet supported"); 1776 ret = -ENOTSUP; 1777 goto exit; 1778 } else { 1779 ret = -EINVAL; 1780 goto exit; 1781 } 1782 1783 /* These are pretty arbitrary, and mainly designed to keep the BAT 1784 * size reasonable to load into RAM */ 1785 if (block_size == 0) { 1786 if (image_size > 32 * TiB) { 1787 block_size = 64 * MiB; 1788 } else if (image_size > (uint64_t) 100 * GiB) { 1789 block_size = 32 * MiB; 1790 } else if (image_size > 1 * GiB) { 1791 block_size = 16 * MiB; 1792 } else { 1793 block_size = 8 * MiB; 1794 } 1795 } 1796 1797 1798 /* make the log size close to what was specified, but must be 1799 * min 1MB, and multiple of 1MB */ 1800 log_size = ROUND_UP(log_size, MiB); 1801 1802 block_size = ROUND_UP(block_size, MiB); 1803 block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX : 1804 block_size; 1805 1806 ret = bdrv_create_file(filename, options, &local_err); 1807 if (ret < 0) { 1808 error_propagate(errp, local_err); 1809 goto exit; 1810 } 1811 1812 bs = NULL; 1813 ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1814 NULL, &local_err); 1815 if (ret < 0) { 1816 error_propagate(errp, local_err); 1817 goto exit; 1818 } 1819 1820 /* Create (A) */ 1821 1822 /* The creator field is optional, but may be useful for 1823 * debugging / diagnostics */ 1824 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 1825 &creator_items, NULL); 1826 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 1827 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature)); 1828 if (ret < 0) { 1829 goto delete_and_exit; 1830 } 1831 if (creator) { 1832 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET + sizeof(signature), 1833 creator, creator_items * sizeof(gunichar2)); 1834 if (ret < 0) { 1835 goto delete_and_exit; 1836 } 1837 } 1838 1839 1840 /* Creates (B),(C) */ 1841 ret = vhdx_create_new_headers(bs, image_size, log_size); 1842 if (ret < 0) { 1843 goto delete_and_exit; 1844 } 1845 1846 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 1847 ret = vhdx_create_new_region_table(bs, image_size, block_size, 512, 1848 log_size, use_zero_blocks, image_type, 1849 &metadata_offset); 1850 if (ret < 0) { 1851 goto delete_and_exit; 1852 } 1853 1854 /* Creates (H) */ 1855 ret = vhdx_create_new_metadata(bs, image_size, block_size, 512, 1856 metadata_offset, image_type); 1857 if (ret < 0) { 1858 goto delete_and_exit; 1859 } 1860 1861 1862 1863 delete_and_exit: 1864 bdrv_unref(bs); 1865 exit: 1866 g_free(creator); 1867 return ret; 1868 } 1869 1870 /* If opened r/w, the VHDX driver will automatically replay the log, 1871 * if one is present, inside the vhdx_open() call. 1872 * 1873 * If qemu-img check -r all is called, the image is automatically opened 1874 * r/w and any log has already been replayed, so there is nothing (currently) 1875 * for us to do here 1876 */ 1877 static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result, 1878 BdrvCheckMode fix) 1879 { 1880 BDRVVHDXState *s = bs->opaque; 1881 1882 if (s->log_replayed_on_open) { 1883 result->corruptions_fixed++; 1884 } 1885 return 0; 1886 } 1887 1888 static QEMUOptionParameter vhdx_create_options[] = { 1889 { 1890 .name = BLOCK_OPT_SIZE, 1891 .type = OPT_SIZE, 1892 .help = "Virtual disk size; max of 64TB." 1893 }, 1894 { 1895 .name = VHDX_BLOCK_OPT_LOG_SIZE, 1896 .type = OPT_SIZE, 1897 .value.n = 1 * MiB, 1898 .help = "Log size; min 1MB." 1899 }, 1900 { 1901 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 1902 .type = OPT_SIZE, 1903 .value.n = 0, 1904 .help = "Block Size; min 1MB, max 256MB. " \ 1905 "0 means auto-calculate based on image size." 1906 }, 1907 { 1908 .name = BLOCK_OPT_SUBFMT, 1909 .type = OPT_STRING, 1910 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ 1911 "Default is 'dynamic'." 1912 }, 1913 { 1914 .name = VHDX_BLOCK_OPT_ZERO, 1915 .type = OPT_FLAG, 1916 .help = "Force use of payload blocks of type 'ZERO'. Non-standard." 1917 }, 1918 { NULL } 1919 }; 1920 1921 static BlockDriver bdrv_vhdx = { 1922 .format_name = "vhdx", 1923 .instance_size = sizeof(BDRVVHDXState), 1924 .bdrv_probe = vhdx_probe, 1925 .bdrv_open = vhdx_open, 1926 .bdrv_close = vhdx_close, 1927 .bdrv_reopen_prepare = vhdx_reopen_prepare, 1928 .bdrv_co_readv = vhdx_co_readv, 1929 .bdrv_co_writev = vhdx_co_writev, 1930 .bdrv_create = vhdx_create, 1931 .bdrv_get_info = vhdx_get_info, 1932 .bdrv_check = vhdx_check, 1933 1934 .create_options = vhdx_create_options, 1935 }; 1936 1937 static void bdrv_vhdx_init(void) 1938 { 1939 bdrv_register(&bdrv_vhdx); 1940 } 1941 1942 block_init(bdrv_vhdx_init); 1943