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