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