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 "block/block_int.h" 21 #include "block/qdict.h" 22 #include "sysemu/block-backend.h" 23 #include "qemu/module.h" 24 #include "qemu/option.h" 25 #include "qemu/crc32c.h" 26 #include "qemu/bswap.h" 27 #include "qemu/error-report.h" 28 #include "vhdx.h" 29 #include "migration/blocker.h" 30 #include "qemu/uuid.h" 31 #include "qapi/qmp/qdict.h" 32 #include "qapi/qobject-input-visitor.h" 33 #include "qapi/qapi-visit-block-core.h" 34 35 /* Options for VHDX creation */ 36 37 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size" 38 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size" 39 #define VHDX_BLOCK_OPT_ZERO "block_state_zero" 40 41 typedef enum VHDXImageType { 42 VHDX_TYPE_DYNAMIC = 0, 43 VHDX_TYPE_FIXED, 44 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */ 45 } VHDXImageType; 46 47 static QemuOptsList vhdx_create_opts; 48 49 /* Several metadata and region table data entries are identified by 50 * guids in a MS-specific GUID format. */ 51 52 53 /* ------- Known Region Table GUIDs ---------------------- */ 54 static const MSGUID bat_guid = { .data1 = 0x2dc27766, 55 .data2 = 0xf623, 56 .data3 = 0x4200, 57 .data4 = { 0x9d, 0x64, 0x11, 0x5e, 58 0x9b, 0xfd, 0x4a, 0x08} }; 59 60 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, 61 .data2 = 0x4790, 62 .data3 = 0x4b9a, 63 .data4 = { 0xb8, 0xfe, 0x57, 0x5f, 64 0x05, 0x0f, 0x88, 0x6e} }; 65 66 67 68 /* ------- Known Metadata Entry GUIDs ---------------------- */ 69 static const MSGUID file_param_guid = { .data1 = 0xcaa16737, 70 .data2 = 0xfa36, 71 .data3 = 0x4d43, 72 .data4 = { 0xb3, 0xb6, 0x33, 0xf0, 73 0xaa, 0x44, 0xe7, 0x6b} }; 74 75 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, 76 .data2 = 0xcd1b, 77 .data3 = 0x4876, 78 .data4 = { 0xb2, 0x11, 0x5d, 0xbe, 79 0xd8, 0x3b, 0xf4, 0xb8} }; 80 81 static const MSGUID page83_guid = { .data1 = 0xbeca12ab, 82 .data2 = 0xb2e6, 83 .data3 = 0x4523, 84 .data4 = { 0x93, 0xef, 0xc3, 0x09, 85 0xe0, 0x00, 0xc7, 0x46} }; 86 87 88 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, 89 .data2 = 0x445d, 90 .data3 = 0x4471, 91 .data4 = { 0x9c, 0xc9, 0xe9, 0x88, 92 0x52, 0x51, 0xc5, 0x56} }; 93 94 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, 95 .data2 = 0xb30b, 96 .data3 = 0x454d, 97 .data4 = { 0xab, 0xf7, 0xd3, 98 0xd8, 0x48, 0x34, 99 0xab, 0x0c} }; 100 101 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, 102 .data2 = 0xa96f, 103 .data3 = 0x4709, 104 .data4 = { 0xba, 0x47, 0xf2, 105 0x33, 0xa8, 0xfa, 106 0xab, 0x5f} }; 107 108 /* Each parent type must have a valid GUID; this is for parent images 109 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would 110 * need to make up our own QCOW2 GUID type */ 111 static const MSGUID parent_vhdx_guid __attribute__((unused)) 112 = { .data1 = 0xb04aefb7, 113 .data2 = 0xd19e, 114 .data3 = 0x4a81, 115 .data4 = { 0xb7, 0x89, 0x25, 0xb8, 116 0xe9, 0x44, 0x59, 0x13} }; 117 118 119 #define META_FILE_PARAMETER_PRESENT 0x01 120 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 121 #define META_PAGE_83_PRESENT 0x04 122 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 123 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 124 #define META_PARENT_LOCATOR_PRESENT 0x20 125 126 #define META_ALL_PRESENT \ 127 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ 128 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ 129 META_PHYS_SECTOR_SIZE_PRESENT) 130 131 132 typedef struct VHDXSectorInfo { 133 uint32_t bat_idx; /* BAT entry index */ 134 uint32_t sectors_avail; /* sectors available in payload block */ 135 uint32_t bytes_left; /* bytes left in the block after data to r/w */ 136 uint32_t bytes_avail; /* bytes available in payload block */ 137 uint64_t file_offset; /* absolute offset in bytes, in file */ 138 uint64_t block_offset; /* block offset, in bytes */ 139 } VHDXSectorInfo; 140 141 /* Calculates new checksum. 142 * 143 * Zero is substituted during crc calculation for the original crc field 144 * crc_offset: byte offset in buf of the buffer crc 145 * buf: buffer pointer 146 * size: size of buffer (must be > crc_offset+4) 147 * 148 * Note: The buffer should have all multi-byte data in little-endian format, 149 * and the resulting checksum is in little endian format. 150 */ 151 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) 152 { 153 uint32_t crc; 154 155 assert(buf != NULL); 156 assert(size > (crc_offset + sizeof(crc))); 157 158 memset(buf + crc_offset, 0, sizeof(crc)); 159 crc = crc32c(0xffffffff, buf, size); 160 crc = cpu_to_le32(crc); 161 memcpy(buf + crc_offset, &crc, sizeof(crc)); 162 163 return crc; 164 } 165 166 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, 167 int crc_offset) 168 { 169 uint32_t crc_new; 170 uint32_t crc_orig; 171 assert(buf != NULL); 172 173 if (crc_offset > 0) { 174 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 175 memset(buf + crc_offset, 0, sizeof(crc_orig)); 176 } 177 178 crc_new = crc32c(crc, buf, size); 179 if (crc_offset > 0) { 180 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); 181 } 182 183 return crc_new; 184 } 185 186 /* Validates the checksum of the buffer, with an in-place CRC. 187 * 188 * Zero is substituted during crc calculation for the original crc field, 189 * and the crc field is restored afterwards. But the buffer will be modified 190 * during the calculation, so this may not be not suitable for multi-threaded 191 * use. 192 * 193 * crc_offset: byte offset in buf of the buffer crc 194 * buf: buffer pointer 195 * size: size of buffer (must be > crc_offset+4) 196 * 197 * returns true if checksum is valid, false otherwise 198 */ 199 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) 200 { 201 uint32_t crc_orig; 202 uint32_t crc; 203 204 assert(buf != NULL); 205 assert(size > (crc_offset + 4)); 206 207 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 208 crc_orig = le32_to_cpu(crc_orig); 209 210 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); 211 212 return crc == crc_orig; 213 } 214 215 216 /* 217 * This generates a UUID that is compliant with the MS GUIDs used 218 * in the VHDX spec (and elsewhere). 219 */ 220 void vhdx_guid_generate(MSGUID *guid) 221 { 222 QemuUUID uuid; 223 assert(guid != NULL); 224 225 qemu_uuid_generate(&uuid); 226 memcpy(guid, &uuid, sizeof(MSGUID)); 227 } 228 229 /* Check for region overlaps inside the VHDX image */ 230 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) 231 { 232 int ret = 0; 233 uint64_t end; 234 VHDXRegionEntry *r; 235 236 end = start + length; 237 QLIST_FOREACH(r, &s->regions, entries) { 238 if (!((start >= r->end) || (end <= r->start))) { 239 error_report("VHDX region %" PRIu64 "-%" PRIu64 " overlaps with " 240 "region %" PRIu64 "-%." PRIu64, start, end, r->start, 241 r->end); 242 ret = -EINVAL; 243 goto exit; 244 } 245 } 246 247 exit: 248 return ret; 249 } 250 251 /* Register a region for future checks */ 252 static void vhdx_region_register(BDRVVHDXState *s, 253 uint64_t start, uint64_t length) 254 { 255 VHDXRegionEntry *r; 256 257 r = g_malloc0(sizeof(*r)); 258 259 r->start = start; 260 r->end = start + length; 261 262 QLIST_INSERT_HEAD(&s->regions, r, entries); 263 } 264 265 /* Free all registered regions */ 266 static void vhdx_region_unregister_all(BDRVVHDXState *s) 267 { 268 VHDXRegionEntry *r, *r_next; 269 270 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { 271 QLIST_REMOVE(r, entries); 272 g_free(r); 273 } 274 } 275 276 static void vhdx_set_shift_bits(BDRVVHDXState *s) 277 { 278 s->logical_sector_size_bits = ctz32(s->logical_sector_size); 279 s->sectors_per_block_bits = ctz32(s->sectors_per_block); 280 s->chunk_ratio_bits = ctz64(s->chunk_ratio); 281 s->block_size_bits = ctz32(s->block_size); 282 } 283 284 /* 285 * Per the MS VHDX Specification, for every VHDX file: 286 * - The header section is fixed size - 1 MB 287 * - The header section is always the first "object" 288 * - The first 64KB of the header is the File Identifier 289 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") 290 * - The following 512 bytes constitute a UTF-16 string identifiying the 291 * software that created the file, and is optional and diagnostic only. 292 * 293 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" 294 */ 295 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) 296 { 297 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { 298 return 100; 299 } 300 return 0; 301 } 302 303 /* 304 * Writes the header to the specified offset. 305 * 306 * This will optionally read in buffer data from disk (otherwise zero-fill), 307 * and then update the header checksum. Header is converted to proper 308 * endianness before being written to the specified file offset 309 */ 310 static int vhdx_write_header(BdrvChild *file, VHDXHeader *hdr, 311 uint64_t offset, bool read) 312 { 313 BlockDriverState *bs_file = file->bs; 314 uint8_t *buffer = NULL; 315 int ret; 316 VHDXHeader *header_le; 317 318 assert(bs_file != NULL); 319 assert(hdr != NULL); 320 321 /* the header checksum is not over just the packed size of VHDXHeader, 322 * but rather over the entire 'reserved' range for the header, which is 323 * 4KB (VHDX_HEADER_SIZE). */ 324 325 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); 326 if (read) { 327 /* if true, we can't assume the extra reserved bytes are 0 */ 328 ret = bdrv_pread(file, offset, buffer, VHDX_HEADER_SIZE); 329 if (ret < 0) { 330 goto exit; 331 } 332 } else { 333 memset(buffer, 0, VHDX_HEADER_SIZE); 334 } 335 336 /* overwrite the actual VHDXHeader portion */ 337 header_le = (VHDXHeader *)buffer; 338 memcpy(header_le, hdr, sizeof(VHDXHeader)); 339 vhdx_header_le_export(hdr, header_le); 340 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, 341 offsetof(VHDXHeader, checksum)); 342 ret = bdrv_pwrite_sync(file, offset, header_le, sizeof(VHDXHeader)); 343 344 exit: 345 qemu_vfree(buffer); 346 return ret; 347 } 348 349 /* Update the VHDX headers 350 * 351 * This follows the VHDX spec procedures for header updates. 352 * 353 * - non-current header is updated with largest sequence number 354 */ 355 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 356 bool generate_data_write_guid, MSGUID *log_guid) 357 { 358 int ret = 0; 359 int hdr_idx = 0; 360 uint64_t header_offset = VHDX_HEADER1_OFFSET; 361 362 VHDXHeader *active_header; 363 VHDXHeader *inactive_header; 364 365 /* operate on the non-current header */ 366 if (s->curr_header == 0) { 367 hdr_idx = 1; 368 header_offset = VHDX_HEADER2_OFFSET; 369 } 370 371 active_header = s->headers[s->curr_header]; 372 inactive_header = s->headers[hdr_idx]; 373 374 inactive_header->sequence_number = active_header->sequence_number + 1; 375 376 /* a new file guid must be generated before any file write, including 377 * headers */ 378 inactive_header->file_write_guid = s->session_guid; 379 380 /* a new data guid only needs to be generated before any guest-visible 381 * writes (i.e. something observable via virtual disk read) */ 382 if (generate_data_write_guid) { 383 vhdx_guid_generate(&inactive_header->data_write_guid); 384 } 385 386 /* update the log guid if present */ 387 if (log_guid) { 388 inactive_header->log_guid = *log_guid; 389 } 390 391 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 392 if (ret < 0) { 393 goto exit; 394 } 395 s->curr_header = hdr_idx; 396 397 exit: 398 return ret; 399 } 400 401 /* 402 * The VHDX spec calls for header updates to be performed twice, so that both 403 * the current and non-current header have valid info 404 */ 405 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 406 bool generate_data_write_guid, MSGUID *log_guid) 407 { 408 int ret; 409 410 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 411 if (ret < 0) { 412 return ret; 413 } 414 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 415 return ret; 416 } 417 418 /* opens the specified header block from the VHDX file header section */ 419 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, 420 Error **errp) 421 { 422 int ret; 423 VHDXHeader *header1; 424 VHDXHeader *header2; 425 bool h1_valid = false; 426 bool h2_valid = false; 427 uint64_t h1_seq = 0; 428 uint64_t h2_seq = 0; 429 uint8_t *buffer; 430 431 /* header1 & header2 are freed in vhdx_close() */ 432 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 433 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 434 435 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 436 437 s->headers[0] = header1; 438 s->headers[1] = header2; 439 440 /* We have to read the whole VHDX_HEADER_SIZE instead of 441 * sizeof(VHDXHeader), because the checksum is over the whole 442 * region */ 443 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, 444 VHDX_HEADER_SIZE); 445 if (ret < 0) { 446 goto fail; 447 } 448 /* copy over just the relevant portion that we need */ 449 memcpy(header1, buffer, sizeof(VHDXHeader)); 450 451 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 452 vhdx_header_le_import(header1); 453 if (header1->signature == VHDX_HEADER_SIGNATURE && 454 header1->version == 1) { 455 h1_seq = header1->sequence_number; 456 h1_valid = true; 457 } 458 } 459 460 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, 461 VHDX_HEADER_SIZE); 462 if (ret < 0) { 463 goto fail; 464 } 465 /* copy over just the relevant portion that we need */ 466 memcpy(header2, buffer, sizeof(VHDXHeader)); 467 468 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 469 vhdx_header_le_import(header2); 470 if (header2->signature == VHDX_HEADER_SIGNATURE && 471 header2->version == 1) { 472 h2_seq = header2->sequence_number; 473 h2_valid = true; 474 } 475 } 476 477 /* If there is only 1 valid header (or no valid headers), we 478 * don't care what the sequence numbers are */ 479 if (h1_valid && !h2_valid) { 480 s->curr_header = 0; 481 } else if (!h1_valid && h2_valid) { 482 s->curr_header = 1; 483 } else if (!h1_valid && !h2_valid) { 484 goto fail; 485 } else { 486 /* If both headers are valid, then we choose the active one by the 487 * highest sequence number. If the sequence numbers are equal, that is 488 * invalid */ 489 if (h1_seq > h2_seq) { 490 s->curr_header = 0; 491 } else if (h2_seq > h1_seq) { 492 s->curr_header = 1; 493 } else { 494 /* The Microsoft Disk2VHD tool will create 2 identical 495 * headers, with identical sequence numbers. If the headers are 496 * identical, don't consider the file corrupt */ 497 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 498 s->curr_header = 0; 499 } else { 500 goto fail; 501 } 502 } 503 } 504 505 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 506 s->headers[s->curr_header]->log_length); 507 goto exit; 508 509 fail: 510 error_setg_errno(errp, -ret, "No valid VHDX header found"); 511 qemu_vfree(header1); 512 qemu_vfree(header2); 513 s->headers[0] = NULL; 514 s->headers[1] = NULL; 515 exit: 516 qemu_vfree(buffer); 517 } 518 519 520 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 521 { 522 int ret = 0; 523 uint8_t *buffer; 524 int offset = 0; 525 VHDXRegionTableEntry rt_entry; 526 uint32_t i; 527 bool bat_rt_found = false; 528 bool metadata_rt_found = false; 529 530 /* We have to read the whole 64KB block, because the crc32 is over the 531 * whole block */ 532 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 533 534 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 535 VHDX_HEADER_BLOCK_SIZE); 536 if (ret < 0) { 537 goto fail; 538 } 539 memcpy(&s->rt, buffer, sizeof(s->rt)); 540 offset += sizeof(s->rt); 541 542 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 543 ret = -EINVAL; 544 goto fail; 545 } 546 547 vhdx_region_header_le_import(&s->rt); 548 549 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 550 ret = -EINVAL; 551 goto fail; 552 } 553 554 555 /* Per spec, maximum region table entry count is 2047 */ 556 if (s->rt.entry_count > 2047) { 557 ret = -EINVAL; 558 goto fail; 559 } 560 561 for (i = 0; i < s->rt.entry_count; i++) { 562 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 563 offset += sizeof(rt_entry); 564 565 vhdx_region_entry_le_import(&rt_entry); 566 567 /* check for region overlap between these entries, and any 568 * other memory regions in the file */ 569 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 570 if (ret < 0) { 571 goto fail; 572 } 573 574 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 575 576 /* see if we recognize the entry */ 577 if (guid_eq(rt_entry.guid, bat_guid)) { 578 /* must be unique; if we have already found it this is invalid */ 579 if (bat_rt_found) { 580 ret = -EINVAL; 581 goto fail; 582 } 583 bat_rt_found = true; 584 s->bat_rt = rt_entry; 585 continue; 586 } 587 588 if (guid_eq(rt_entry.guid, metadata_guid)) { 589 /* must be unique; if we have already found it this is invalid */ 590 if (metadata_rt_found) { 591 ret = -EINVAL; 592 goto fail; 593 } 594 metadata_rt_found = true; 595 s->metadata_rt = rt_entry; 596 continue; 597 } 598 599 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 600 /* cannot read vhdx file - required region table entry that 601 * we do not understand. per spec, we must fail to open */ 602 ret = -ENOTSUP; 603 goto fail; 604 } 605 } 606 607 if (!bat_rt_found || !metadata_rt_found) { 608 ret = -EINVAL; 609 goto fail; 610 } 611 612 ret = 0; 613 614 fail: 615 qemu_vfree(buffer); 616 return ret; 617 } 618 619 620 621 /* Metadata initial parser 622 * 623 * This loads all the metadata entry fields. This may cause additional 624 * fields to be processed (e.g. parent locator, etc..). 625 * 626 * There are 5 Metadata items that are always required: 627 * - File Parameters (block size, has a parent) 628 * - Virtual Disk Size (size, in bytes, of the virtual drive) 629 * - Page 83 Data (scsi page 83 guid) 630 * - Logical Sector Size (logical sector size in bytes, either 512 or 631 * 4096. We only support 512 currently) 632 * - Physical Sector Size (512 or 4096) 633 * 634 * Also, if the File Parameters indicate this is a differencing file, 635 * we must also look for the Parent Locator metadata item. 636 */ 637 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 638 { 639 int ret = 0; 640 uint8_t *buffer; 641 int offset = 0; 642 uint32_t i = 0; 643 VHDXMetadataTableEntry md_entry; 644 645 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 646 647 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 648 VHDX_METADATA_TABLE_MAX_SIZE); 649 if (ret < 0) { 650 goto exit; 651 } 652 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 653 offset += sizeof(s->metadata_hdr); 654 655 vhdx_metadata_header_le_import(&s->metadata_hdr); 656 657 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 658 ret = -EINVAL; 659 goto exit; 660 } 661 662 s->metadata_entries.present = 0; 663 664 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 665 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 666 ret = -EINVAL; 667 goto exit; 668 } 669 670 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 671 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 672 offset += sizeof(md_entry); 673 674 vhdx_metadata_entry_le_import(&md_entry); 675 676 if (guid_eq(md_entry.item_id, file_param_guid)) { 677 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 678 ret = -EINVAL; 679 goto exit; 680 } 681 s->metadata_entries.file_parameters_entry = md_entry; 682 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 683 continue; 684 } 685 686 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 687 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 688 ret = -EINVAL; 689 goto exit; 690 } 691 s->metadata_entries.virtual_disk_size_entry = md_entry; 692 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 693 continue; 694 } 695 696 if (guid_eq(md_entry.item_id, page83_guid)) { 697 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 698 ret = -EINVAL; 699 goto exit; 700 } 701 s->metadata_entries.page83_data_entry = md_entry; 702 s->metadata_entries.present |= META_PAGE_83_PRESENT; 703 continue; 704 } 705 706 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 707 if (s->metadata_entries.present & 708 META_LOGICAL_SECTOR_SIZE_PRESENT) { 709 ret = -EINVAL; 710 goto exit; 711 } 712 s->metadata_entries.logical_sector_size_entry = md_entry; 713 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 714 continue; 715 } 716 717 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 718 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 719 ret = -EINVAL; 720 goto exit; 721 } 722 s->metadata_entries.phys_sector_size_entry = md_entry; 723 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 724 continue; 725 } 726 727 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 728 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 729 ret = -EINVAL; 730 goto exit; 731 } 732 s->metadata_entries.parent_locator_entry = md_entry; 733 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 734 continue; 735 } 736 737 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 738 /* cannot read vhdx file - required region table entry that 739 * we do not understand. per spec, we must fail to open */ 740 ret = -ENOTSUP; 741 goto exit; 742 } 743 } 744 745 if (s->metadata_entries.present != META_ALL_PRESENT) { 746 ret = -ENOTSUP; 747 goto exit; 748 } 749 750 ret = bdrv_pread(bs->file, 751 s->metadata_entries.file_parameters_entry.offset 752 + s->metadata_rt.file_offset, 753 &s->params, 754 sizeof(s->params)); 755 756 if (ret < 0) { 757 goto exit; 758 } 759 760 s->params.block_size = le32_to_cpu(s->params.block_size); 761 s->params.data_bits = le32_to_cpu(s->params.data_bits); 762 763 764 /* We now have the file parameters, so we can tell if this is a 765 * differencing file (i.e.. has_parent), is dynamic or fixed 766 * sized (leave_blocks_allocated), and the block size */ 767 768 /* The parent locator required iff the file parameters has_parent set */ 769 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 770 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 771 /* TODO: parse parent locator fields */ 772 ret = -ENOTSUP; /* temp, until differencing files are supported */ 773 goto exit; 774 } else { 775 /* if has_parent is set, but there is not parent locator present, 776 * then that is an invalid combination */ 777 ret = -EINVAL; 778 goto exit; 779 } 780 } 781 782 /* determine virtual disk size, logical sector size, 783 * and phys sector size */ 784 785 ret = bdrv_pread(bs->file, 786 s->metadata_entries.virtual_disk_size_entry.offset 787 + s->metadata_rt.file_offset, 788 &s->virtual_disk_size, 789 sizeof(uint64_t)); 790 if (ret < 0) { 791 goto exit; 792 } 793 ret = bdrv_pread(bs->file, 794 s->metadata_entries.logical_sector_size_entry.offset 795 + s->metadata_rt.file_offset, 796 &s->logical_sector_size, 797 sizeof(uint32_t)); 798 if (ret < 0) { 799 goto exit; 800 } 801 ret = bdrv_pread(bs->file, 802 s->metadata_entries.phys_sector_size_entry.offset 803 + s->metadata_rt.file_offset, 804 &s->physical_sector_size, 805 sizeof(uint32_t)); 806 if (ret < 0) { 807 goto exit; 808 } 809 810 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size); 811 s->logical_sector_size = le32_to_cpu(s->logical_sector_size); 812 s->physical_sector_size = le32_to_cpu(s->physical_sector_size); 813 814 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 815 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 816 ret = -EINVAL; 817 goto exit; 818 } 819 820 /* only 2 supported sector sizes */ 821 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { 822 ret = -EINVAL; 823 goto exit; 824 } 825 826 /* Both block_size and sector_size are guaranteed powers of 2, below. 827 Due to range checks above, s->sectors_per_block can never be < 256 */ 828 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 829 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 830 (uint64_t)s->logical_sector_size / 831 (uint64_t)s->params.block_size; 832 833 /* These values are ones we will want to use for division / multiplication 834 * later on, and they are all guaranteed (per the spec) to be powers of 2, 835 * so we can take advantage of that for shift operations during 836 * reads/writes */ 837 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 838 ret = -EINVAL; 839 goto exit; 840 } 841 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 842 ret = -EINVAL; 843 goto exit; 844 } 845 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 846 ret = -EINVAL; 847 goto exit; 848 } 849 s->block_size = s->params.block_size; 850 if (s->block_size & (s->block_size - 1)) { 851 ret = -EINVAL; 852 goto exit; 853 } 854 855 vhdx_set_shift_bits(s); 856 857 ret = 0; 858 859 exit: 860 qemu_vfree(buffer); 861 return ret; 862 } 863 864 /* 865 * Calculate the number of BAT entries, including sector 866 * bitmap entries. 867 */ 868 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 869 { 870 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 871 872 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 873 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 874 875 if (s->parent_entries) { 876 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 877 } else { 878 s->bat_entries = data_blocks_cnt + 879 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 880 } 881 882 } 883 884 static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) 885 { 886 BDRVVHDXState *s = bs->opaque; 887 int64_t image_file_size = bdrv_getlength(bs->file->bs); 888 uint64_t payblocks = s->chunk_ratio; 889 uint64_t i; 890 int ret = 0; 891 892 if (image_file_size < 0) { 893 error_report("Could not determinate VHDX image file size."); 894 return image_file_size; 895 } 896 897 for (i = 0; i < s->bat_entries; i++) { 898 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 899 PAYLOAD_BLOCK_FULLY_PRESENT) { 900 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; 901 /* 902 * Allow that the last block exists only partially. The VHDX spec 903 * states that the image file can only grow in blocksize increments, 904 * but QEMU created images with partial last blocks in the past. 905 */ 906 uint32_t block_length = MIN(s->block_size, 907 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); 908 /* 909 * Check for BAT entry overflow. 910 */ 911 if (offset > INT64_MAX - s->block_size) { 912 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); 913 ret = -EINVAL; 914 if (!errcnt) { 915 break; 916 } 917 (*errcnt)++; 918 } 919 /* 920 * Check if fully allocated BAT entries do not reside after 921 * end of the image file. 922 */ 923 if (offset >= image_file_size) { 924 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 925 " points after end of file (%" PRIi64 "). Image" 926 " has probably been truncated.", 927 i, offset, image_file_size); 928 ret = -EINVAL; 929 if (!errcnt) { 930 break; 931 } 932 (*errcnt)++; 933 } else if (offset + block_length > image_file_size) { 934 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 935 " points after end of file (%" PRIi64 "). Image" 936 " has probably been truncated.", 937 i, offset + block_length - 1, image_file_size); 938 ret = -EINVAL; 939 if (!errcnt) { 940 break; 941 } 942 (*errcnt)++; 943 } 944 945 /* 946 * verify populated BAT field file offsets against 947 * region table and log entries 948 */ 949 if (payblocks--) { 950 /* payload bat entries */ 951 int ret2; 952 ret2 = vhdx_region_check(s, offset, s->block_size); 953 if (ret2 < 0) { 954 ret = -EINVAL; 955 if (!errcnt) { 956 break; 957 } 958 (*errcnt)++; 959 } 960 } else { 961 payblocks = s->chunk_ratio; 962 /* 963 * Once differencing files are supported, verify sector bitmap 964 * blocks here 965 */ 966 } 967 } 968 } 969 970 return ret; 971 } 972 973 static void vhdx_close(BlockDriverState *bs) 974 { 975 BDRVVHDXState *s = bs->opaque; 976 qemu_vfree(s->headers[0]); 977 s->headers[0] = NULL; 978 qemu_vfree(s->headers[1]); 979 s->headers[1] = NULL; 980 qemu_vfree(s->bat); 981 s->bat = NULL; 982 qemu_vfree(s->parent_entries); 983 s->parent_entries = NULL; 984 migrate_del_blocker(s->migration_blocker); 985 error_free(s->migration_blocker); 986 qemu_vfree(s->log.hdr); 987 s->log.hdr = NULL; 988 vhdx_region_unregister_all(s); 989 } 990 991 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 992 Error **errp) 993 { 994 BDRVVHDXState *s = bs->opaque; 995 int ret = 0; 996 uint32_t i; 997 uint64_t signature; 998 Error *local_err = NULL; 999 1000 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 1001 false, errp); 1002 if (!bs->file) { 1003 return -EINVAL; 1004 } 1005 1006 s->bat = NULL; 1007 s->first_visible_write = true; 1008 1009 qemu_co_mutex_init(&s->lock); 1010 QLIST_INIT(&s->regions); 1011 1012 /* validate the file signature */ 1013 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 1014 if (ret < 0) { 1015 goto fail; 1016 } 1017 if (memcmp(&signature, "vhdxfile", 8)) { 1018 ret = -EINVAL; 1019 goto fail; 1020 } 1021 1022 /* This is used for any header updates, for the file_write_guid. 1023 * The spec dictates that a new value should be used for the first 1024 * header update */ 1025 vhdx_guid_generate(&s->session_guid); 1026 1027 vhdx_parse_header(bs, s, &local_err); 1028 if (local_err != NULL) { 1029 error_propagate(errp, local_err); 1030 ret = -EINVAL; 1031 goto fail; 1032 } 1033 1034 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1035 if (ret < 0) { 1036 goto fail; 1037 } 1038 1039 ret = vhdx_open_region_tables(bs, s); 1040 if (ret < 0) { 1041 goto fail; 1042 } 1043 1044 ret = vhdx_parse_metadata(bs, s); 1045 if (ret < 0) { 1046 goto fail; 1047 } 1048 1049 s->block_size = s->params.block_size; 1050 1051 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1052 * logical_sector_size */ 1053 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1054 1055 vhdx_calc_bat_entries(s); 1056 1057 s->bat_offset = s->bat_rt.file_offset; 1058 1059 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1060 /* BAT allocation is not large enough for all entries */ 1061 ret = -EINVAL; 1062 goto fail; 1063 } 1064 1065 /* s->bat is freed in vhdx_close() */ 1066 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1067 if (s->bat == NULL) { 1068 ret = -ENOMEM; 1069 goto fail; 1070 } 1071 1072 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 1073 if (ret < 0) { 1074 goto fail; 1075 } 1076 1077 /* endian convert populated BAT field entires */ 1078 for (i = 0; i < s->bat_entries; i++) { 1079 s->bat[i] = le64_to_cpu(s->bat[i]); 1080 } 1081 1082 if (!(flags & BDRV_O_CHECK)) { 1083 ret = vhdx_check_bat_entries(bs, NULL); 1084 if (ret < 0) { 1085 goto fail; 1086 } 1087 } 1088 1089 /* Disable migration when VHDX images are used */ 1090 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1091 "does not support live migration", 1092 bdrv_get_device_or_node_name(bs)); 1093 ret = migrate_add_blocker(s->migration_blocker, &local_err); 1094 if (local_err) { 1095 error_propagate(errp, local_err); 1096 error_free(s->migration_blocker); 1097 goto fail; 1098 } 1099 1100 /* TODO: differencing files */ 1101 1102 return 0; 1103 fail: 1104 vhdx_close(bs); 1105 return ret; 1106 } 1107 1108 static int vhdx_reopen_prepare(BDRVReopenState *state, 1109 BlockReopenQueue *queue, Error **errp) 1110 { 1111 return 0; 1112 } 1113 1114 1115 /* 1116 * Perform sector to block offset translations, to get various 1117 * sector and file offsets into the image. See VHDXSectorInfo 1118 */ 1119 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1120 int nb_sectors, VHDXSectorInfo *sinfo) 1121 { 1122 uint32_t block_offset; 1123 1124 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1125 /* effectively a modulo - this gives us the offset into the block 1126 * (in sector sizes) for our sector number */ 1127 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1128 /* the chunk ratio gives us the interleaving of the sector 1129 * bitmaps, so we need to advance our page block index by the 1130 * sector bitmaps entry number */ 1131 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1132 1133 /* the number of sectors we can read/write in this cycle */ 1134 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1135 1136 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1137 1138 if (sinfo->sectors_avail > nb_sectors) { 1139 sinfo->sectors_avail = nb_sectors; 1140 } 1141 1142 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1143 1144 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1145 1146 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1147 1148 /* The file offset must be past the header section, so must be > 0 */ 1149 if (sinfo->file_offset == 0) { 1150 return; 1151 } 1152 1153 /* block offset is the offset in vhdx logical sectors, in 1154 * the payload data block. Convert that to a byte offset 1155 * in the block, and add in the payload data block offset 1156 * in the file, in bytes, to get the final read address */ 1157 1158 sinfo->file_offset += sinfo->block_offset; 1159 } 1160 1161 1162 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1163 { 1164 BDRVVHDXState *s = bs->opaque; 1165 1166 bdi->cluster_size = s->block_size; 1167 1168 bdi->unallocated_blocks_are_zero = 1169 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; 1170 1171 return 0; 1172 } 1173 1174 1175 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1176 int nb_sectors, QEMUIOVector *qiov) 1177 { 1178 BDRVVHDXState *s = bs->opaque; 1179 int ret = 0; 1180 VHDXSectorInfo sinfo; 1181 uint64_t bytes_done = 0; 1182 QEMUIOVector hd_qiov; 1183 1184 qemu_iovec_init(&hd_qiov, qiov->niov); 1185 1186 qemu_co_mutex_lock(&s->lock); 1187 1188 while (nb_sectors > 0) { 1189 /* We are a differencing file, so we need to inspect the sector bitmap 1190 * to see if we have the data or not */ 1191 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1192 /* not supported yet */ 1193 ret = -ENOTSUP; 1194 goto exit; 1195 } else { 1196 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1197 1198 qemu_iovec_reset(&hd_qiov); 1199 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1200 1201 /* check the payload block state */ 1202 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1203 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1204 case PAYLOAD_BLOCK_UNDEFINED: 1205 case PAYLOAD_BLOCK_UNMAPPED: 1206 case PAYLOAD_BLOCK_UNMAPPED_v095: 1207 case PAYLOAD_BLOCK_ZERO: 1208 /* return zero */ 1209 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1210 break; 1211 case PAYLOAD_BLOCK_FULLY_PRESENT: 1212 qemu_co_mutex_unlock(&s->lock); 1213 ret = bdrv_co_preadv(bs->file, sinfo.file_offset, 1214 sinfo.sectors_avail * BDRV_SECTOR_SIZE, 1215 &hd_qiov, 0); 1216 qemu_co_mutex_lock(&s->lock); 1217 if (ret < 0) { 1218 goto exit; 1219 } 1220 break; 1221 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1222 /* we don't yet support difference files, fall through 1223 * to error */ 1224 default: 1225 ret = -EIO; 1226 goto exit; 1227 break; 1228 } 1229 nb_sectors -= sinfo.sectors_avail; 1230 sector_num += sinfo.sectors_avail; 1231 bytes_done += sinfo.bytes_avail; 1232 } 1233 } 1234 ret = 0; 1235 exit: 1236 qemu_co_mutex_unlock(&s->lock); 1237 qemu_iovec_destroy(&hd_qiov); 1238 return ret; 1239 } 1240 1241 /* 1242 * Allocate a new payload block at the end of the file. 1243 * 1244 * Allocation will happen at 1MB alignment inside the file 1245 * 1246 * Returns the file offset start of the new payload block 1247 */ 1248 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1249 uint64_t *new_offset) 1250 { 1251 int64_t current_len; 1252 1253 current_len = bdrv_getlength(bs->file->bs); 1254 if (current_len < 0) { 1255 return current_len; 1256 } 1257 1258 *new_offset = current_len; 1259 1260 /* per the spec, the address for a block is in units of 1MB */ 1261 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1262 if (*new_offset > INT64_MAX) { 1263 return -EINVAL; 1264 } 1265 1266 return bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1267 PREALLOC_MODE_OFF, NULL); 1268 } 1269 1270 /* 1271 * Update the BAT table entry with the new file offset, and the new entry 1272 * state */ 1273 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1274 VHDXSectorInfo *sinfo, 1275 uint64_t *bat_entry_le, 1276 uint64_t *bat_offset, int state) 1277 { 1278 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1279 * 1MB, and 3 bits for the block state. */ 1280 if ((state == PAYLOAD_BLOCK_ZERO) || 1281 (state == PAYLOAD_BLOCK_UNDEFINED) || 1282 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1283 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1284 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1285 FileOffsetMB field is denoted as 1286 'reserved' in the v1.0 spec. If it is 1287 non-zero, MS Hyper-V will fail to read 1288 the disk image */ 1289 } else { 1290 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1291 } 1292 1293 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1294 1295 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1296 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1297 1298 } 1299 1300 /* Per the spec, on the first write of guest-visible data to the file the 1301 * data write guid must be updated in the header */ 1302 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1303 { 1304 int ret = 0; 1305 if (s->first_visible_write) { 1306 s->first_visible_write = false; 1307 ret = vhdx_update_headers(bs, s, true, NULL); 1308 } 1309 return ret; 1310 } 1311 1312 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1313 int nb_sectors, QEMUIOVector *qiov, 1314 int flags) 1315 { 1316 int ret = -ENOTSUP; 1317 BDRVVHDXState *s = bs->opaque; 1318 VHDXSectorInfo sinfo; 1319 uint64_t bytes_done = 0; 1320 uint64_t bat_entry = 0; 1321 uint64_t bat_entry_offset = 0; 1322 QEMUIOVector hd_qiov; 1323 struct iovec iov1 = { 0 }; 1324 struct iovec iov2 = { 0 }; 1325 int sectors_to_write; 1326 int bat_state; 1327 uint64_t bat_prior_offset = 0; 1328 bool bat_update = false; 1329 1330 assert(!flags); 1331 qemu_iovec_init(&hd_qiov, qiov->niov); 1332 1333 qemu_co_mutex_lock(&s->lock); 1334 1335 ret = vhdx_user_visible_write(bs, s); 1336 if (ret < 0) { 1337 goto exit; 1338 } 1339 1340 while (nb_sectors > 0) { 1341 bool use_zero_buffers = false; 1342 bat_update = false; 1343 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1344 /* not supported yet */ 1345 ret = -ENOTSUP; 1346 goto exit; 1347 } else { 1348 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1349 sectors_to_write = sinfo.sectors_avail; 1350 1351 qemu_iovec_reset(&hd_qiov); 1352 /* check the payload block state */ 1353 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1354 switch (bat_state) { 1355 case PAYLOAD_BLOCK_ZERO: 1356 /* in this case, we need to preserve zero writes for 1357 * data that is not part of this write, so we must pad 1358 * the rest of the buffer to zeroes */ 1359 1360 /* if we are on a posix system with ftruncate() that extends 1361 * a file, then it is zero-filled for us. On Win32, the raw 1362 * layer uses SetFilePointer and SetFileEnd, which does not 1363 * zero fill AFAIK */ 1364 1365 /* Queue another write of zero buffers if the underlying file 1366 * does not zero-fill on file extension */ 1367 1368 if (bdrv_has_zero_init_truncate(bs->file->bs) == 0) { 1369 use_zero_buffers = true; 1370 1371 /* zero fill the front, if any */ 1372 if (sinfo.block_offset) { 1373 iov1.iov_len = sinfo.block_offset; 1374 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1375 memset(iov1.iov_base, 0, iov1.iov_len); 1376 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1377 iov1.iov_len); 1378 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1379 } 1380 1381 /* our actual data */ 1382 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1383 sinfo.bytes_avail); 1384 1385 /* zero fill the back, if any */ 1386 if ((sinfo.bytes_avail - sinfo.block_offset) < 1387 s->block_size) { 1388 iov2.iov_len = s->block_size - 1389 (sinfo.bytes_avail + sinfo.block_offset); 1390 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1391 memset(iov2.iov_base, 0, iov2.iov_len); 1392 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1393 iov2.iov_len); 1394 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1395 } 1396 } 1397 /* fall through */ 1398 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1399 case PAYLOAD_BLOCK_UNMAPPED: 1400 case PAYLOAD_BLOCK_UNMAPPED_v095: 1401 case PAYLOAD_BLOCK_UNDEFINED: 1402 bat_prior_offset = sinfo.file_offset; 1403 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); 1404 if (ret < 0) { 1405 goto exit; 1406 } 1407 /* once we support differencing files, this may also be 1408 * partially present */ 1409 /* update block state to the newly specified state */ 1410 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1411 &bat_entry_offset, 1412 PAYLOAD_BLOCK_FULLY_PRESENT); 1413 bat_update = true; 1414 /* since we just allocated a block, file_offset is the 1415 * beginning of the payload block. It needs to be the 1416 * write address, which includes the offset into the block */ 1417 if (!use_zero_buffers) { 1418 sinfo.file_offset += sinfo.block_offset; 1419 } 1420 /* fall through */ 1421 case PAYLOAD_BLOCK_FULLY_PRESENT: 1422 /* if the file offset address is in the header zone, 1423 * there is a problem */ 1424 if (sinfo.file_offset < (1 * MiB)) { 1425 ret = -EFAULT; 1426 goto error_bat_restore; 1427 } 1428 1429 if (!use_zero_buffers) { 1430 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1431 sinfo.bytes_avail); 1432 } 1433 /* block exists, so we can just overwrite it */ 1434 qemu_co_mutex_unlock(&s->lock); 1435 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset, 1436 sectors_to_write * BDRV_SECTOR_SIZE, 1437 &hd_qiov, 0); 1438 qemu_co_mutex_lock(&s->lock); 1439 if (ret < 0) { 1440 goto error_bat_restore; 1441 } 1442 break; 1443 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1444 /* we don't yet support difference files, fall through 1445 * to error */ 1446 default: 1447 ret = -EIO; 1448 goto exit; 1449 break; 1450 } 1451 1452 if (bat_update) { 1453 /* this will update the BAT entry into the log journal, and 1454 * then flush the log journal out to disk */ 1455 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1456 sizeof(VHDXBatEntry), 1457 bat_entry_offset); 1458 if (ret < 0) { 1459 goto exit; 1460 } 1461 } 1462 1463 nb_sectors -= sinfo.sectors_avail; 1464 sector_num += sinfo.sectors_avail; 1465 bytes_done += sinfo.bytes_avail; 1466 1467 } 1468 } 1469 1470 goto exit; 1471 1472 error_bat_restore: 1473 if (bat_update) { 1474 /* keep metadata in sync, and restore the bat entry state 1475 * if error. */ 1476 sinfo.file_offset = bat_prior_offset; 1477 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1478 &bat_entry_offset, bat_state); 1479 } 1480 exit: 1481 qemu_vfree(iov1.iov_base); 1482 qemu_vfree(iov2.iov_base); 1483 qemu_co_mutex_unlock(&s->lock); 1484 qemu_iovec_destroy(&hd_qiov); 1485 return ret; 1486 } 1487 1488 1489 1490 /* 1491 * Create VHDX Headers 1492 * 1493 * There are 2 headers, and the highest sequence number will represent 1494 * the active header 1495 */ 1496 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1497 uint32_t log_size) 1498 { 1499 BlockDriverState *bs = blk_bs(blk); 1500 BdrvChild *child; 1501 int ret = 0; 1502 VHDXHeader *hdr = NULL; 1503 1504 hdr = g_new0(VHDXHeader, 1); 1505 1506 hdr->signature = VHDX_HEADER_SIGNATURE; 1507 hdr->sequence_number = g_random_int(); 1508 hdr->log_version = 0; 1509 hdr->version = 1; 1510 hdr->log_length = log_size; 1511 hdr->log_offset = VHDX_HEADER_SECTION_END; 1512 vhdx_guid_generate(&hdr->file_write_guid); 1513 vhdx_guid_generate(&hdr->data_write_guid); 1514 1515 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1516 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1517 * here, which it really shouldn't be doing. */ 1518 child = QLIST_FIRST(&bs->parents); 1519 assert(!QLIST_NEXT(child, next_parent)); 1520 1521 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1522 if (ret < 0) { 1523 goto exit; 1524 } 1525 hdr->sequence_number++; 1526 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1527 if (ret < 0) { 1528 goto exit; 1529 } 1530 1531 exit: 1532 g_free(hdr); 1533 return ret; 1534 } 1535 1536 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1537 (sizeof(VHDXFileParameters) +\ 1538 sizeof(VHDXVirtualDiskSize) +\ 1539 sizeof(VHDXPage83Data) +\ 1540 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1541 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1542 1543 /* 1544 * Create the Metadata entries. 1545 * 1546 * For more details on the entries, see section 3.5 (pg 29) in the 1547 * VHDX 1.00 specification. 1548 * 1549 * We support 5 metadata entries (all required by spec): 1550 * File Parameters, 1551 * Virtual Disk Size, 1552 * Page 83 Data, 1553 * Logical Sector Size, 1554 * Physical Sector Size 1555 * 1556 * The first 64KB of the Metadata section is reserved for the metadata 1557 * header and entries; beyond that, the metadata items themselves reside. 1558 */ 1559 static int vhdx_create_new_metadata(BlockBackend *blk, 1560 uint64_t image_size, 1561 uint32_t block_size, 1562 uint32_t sector_size, 1563 uint64_t metadata_offset, 1564 VHDXImageType type) 1565 { 1566 int ret = 0; 1567 uint32_t offset = 0; 1568 void *buffer = NULL; 1569 void *entry_buffer; 1570 VHDXMetadataTableHeader *md_table; 1571 VHDXMetadataTableEntry *md_table_entry; 1572 1573 /* Metadata entries */ 1574 VHDXFileParameters *mt_file_params; 1575 VHDXVirtualDiskSize *mt_virtual_size; 1576 VHDXPage83Data *mt_page83; 1577 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1578 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1579 1580 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1581 1582 mt_file_params = entry_buffer; 1583 offset += sizeof(VHDXFileParameters); 1584 mt_virtual_size = entry_buffer + offset; 1585 offset += sizeof(VHDXVirtualDiskSize); 1586 mt_page83 = entry_buffer + offset; 1587 offset += sizeof(VHDXPage83Data); 1588 mt_log_sector_size = entry_buffer + offset; 1589 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1590 mt_phys_sector_size = entry_buffer + offset; 1591 1592 mt_file_params->block_size = cpu_to_le32(block_size); 1593 if (type == VHDX_TYPE_FIXED) { 1594 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1595 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1596 } 1597 1598 vhdx_guid_generate(&mt_page83->page_83_data); 1599 cpu_to_leguids(&mt_page83->page_83_data); 1600 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1601 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1602 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1603 1604 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1605 md_table = buffer; 1606 1607 md_table->signature = VHDX_METADATA_SIGNATURE; 1608 md_table->entry_count = 5; 1609 vhdx_metadata_header_le_export(md_table); 1610 1611 1612 /* This will reference beyond the reserved table portion */ 1613 offset = 64 * KiB; 1614 1615 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1616 1617 md_table_entry[0].item_id = file_param_guid; 1618 md_table_entry[0].offset = offset; 1619 md_table_entry[0].length = sizeof(VHDXFileParameters); 1620 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1621 offset += md_table_entry[0].length; 1622 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1623 1624 md_table_entry[1].item_id = virtual_size_guid; 1625 md_table_entry[1].offset = offset; 1626 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1627 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1628 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1629 offset += md_table_entry[1].length; 1630 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1631 1632 md_table_entry[2].item_id = page83_guid; 1633 md_table_entry[2].offset = offset; 1634 md_table_entry[2].length = sizeof(VHDXPage83Data); 1635 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1636 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1637 offset += md_table_entry[2].length; 1638 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1639 1640 md_table_entry[3].item_id = logical_sector_guid; 1641 md_table_entry[3].offset = offset; 1642 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1643 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1644 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1645 offset += md_table_entry[3].length; 1646 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1647 1648 md_table_entry[4].item_id = phys_sector_guid; 1649 md_table_entry[4].offset = offset; 1650 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1651 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1652 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1653 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1654 1655 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0); 1656 if (ret < 0) { 1657 goto exit; 1658 } 1659 1660 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer, 1661 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0); 1662 if (ret < 0) { 1663 goto exit; 1664 } 1665 1666 1667 exit: 1668 g_free(buffer); 1669 g_free(entry_buffer); 1670 return ret; 1671 } 1672 1673 /* This create the actual BAT itself. We currently only support 1674 * 'Dynamic' and 'Fixed' image types. 1675 * 1676 * Dynamic images: default state of the BAT is all zeroes. 1677 * 1678 * Fixed images: default state of the BAT is fully populated, with 1679 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1680 */ 1681 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1682 uint64_t image_size, VHDXImageType type, 1683 bool use_zero_blocks, uint64_t file_offset, 1684 uint32_t length, Error **errp) 1685 { 1686 int ret = 0; 1687 uint64_t data_file_offset; 1688 uint64_t total_sectors = 0; 1689 uint64_t sector_num = 0; 1690 uint64_t unused; 1691 int block_state; 1692 VHDXSectorInfo sinfo; 1693 1694 assert(s->bat == NULL); 1695 1696 /* this gives a data start after BAT/bitmap entries, and well 1697 * past any metadata entries (with a 4 MB buffer for future 1698 * expansion */ 1699 data_file_offset = file_offset + length + 5 * MiB; 1700 total_sectors = image_size >> s->logical_sector_size_bits; 1701 1702 if (type == VHDX_TYPE_DYNAMIC) { 1703 /* All zeroes, so we can just extend the file - the end of the BAT 1704 * is the furthest thing we have written yet */ 1705 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1706 errp); 1707 if (ret < 0) { 1708 goto exit; 1709 } 1710 } else if (type == VHDX_TYPE_FIXED) { 1711 ret = blk_truncate(blk, data_file_offset + image_size, false, 1712 PREALLOC_MODE_OFF, errp); 1713 if (ret < 0) { 1714 goto exit; 1715 } 1716 } else { 1717 error_setg(errp, "Unsupported image type"); 1718 ret = -ENOTSUP; 1719 goto exit; 1720 } 1721 1722 if (type == VHDX_TYPE_FIXED || 1723 use_zero_blocks || 1724 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1725 /* for a fixed file, the default BAT entry is not zero */ 1726 s->bat = g_try_malloc0(length); 1727 if (length && s->bat == NULL) { 1728 error_setg(errp, "Failed to allocate memory for the BAT"); 1729 ret = -ENOMEM; 1730 goto exit; 1731 } 1732 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1733 PAYLOAD_BLOCK_NOT_PRESENT; 1734 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1735 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1736 while (sector_num < total_sectors) { 1737 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1738 sinfo.file_offset = data_file_offset + 1739 (sector_num << s->logical_sector_size_bits); 1740 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1741 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1742 block_state); 1743 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1744 sector_num += s->sectors_per_block; 1745 } 1746 ret = blk_pwrite(blk, file_offset, s->bat, length, 0); 1747 if (ret < 0) { 1748 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1749 goto exit; 1750 } 1751 } 1752 1753 1754 1755 exit: 1756 g_free(s->bat); 1757 return ret; 1758 } 1759 1760 /* Creates the region table header, and region table entries. 1761 * There are 2 supported region table entries: BAT, and Metadata/ 1762 * 1763 * As the calculations for the BAT region table are also needed 1764 * to create the BAT itself, we will also cause the BAT to be 1765 * created. 1766 */ 1767 static int vhdx_create_new_region_table(BlockBackend *blk, 1768 uint64_t image_size, 1769 uint32_t block_size, 1770 uint32_t sector_size, 1771 uint32_t log_size, 1772 bool use_zero_blocks, 1773 VHDXImageType type, 1774 uint64_t *metadata_offset, 1775 Error **errp) 1776 { 1777 int ret = 0; 1778 uint32_t offset = 0; 1779 void *buffer = NULL; 1780 uint64_t bat_file_offset; 1781 uint32_t bat_length; 1782 BDRVVHDXState *s = NULL; 1783 VHDXRegionTableHeader *region_table; 1784 VHDXRegionTableEntry *rt_bat; 1785 VHDXRegionTableEntry *rt_metadata; 1786 1787 assert(metadata_offset != NULL); 1788 1789 /* Populate enough of the BDRVVHDXState to be able to use the 1790 * pre-existing BAT calculation, translation, and update functions */ 1791 s = g_new0(BDRVVHDXState, 1); 1792 1793 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1794 (uint64_t) sector_size / (uint64_t) block_size; 1795 1796 s->sectors_per_block = block_size / sector_size; 1797 s->virtual_disk_size = image_size; 1798 s->block_size = block_size; 1799 s->logical_sector_size = sector_size; 1800 1801 vhdx_set_shift_bits(s); 1802 1803 vhdx_calc_bat_entries(s); 1804 1805 /* At this point the VHDX state is populated enough for creation */ 1806 1807 /* a single buffer is used so we can calculate the checksum over the 1808 * entire 64KB block */ 1809 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1810 region_table = buffer; 1811 offset += sizeof(VHDXRegionTableHeader); 1812 rt_bat = buffer + offset; 1813 offset += sizeof(VHDXRegionTableEntry); 1814 rt_metadata = buffer + offset; 1815 1816 region_table->signature = VHDX_REGION_SIGNATURE; 1817 region_table->entry_count = 2; /* BAT and Metadata */ 1818 1819 rt_bat->guid = bat_guid; 1820 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1821 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1822 s->bat_offset = rt_bat->file_offset; 1823 1824 rt_metadata->guid = metadata_guid; 1825 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1826 MiB); 1827 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1828 *metadata_offset = rt_metadata->file_offset; 1829 1830 bat_file_offset = rt_bat->file_offset; 1831 bat_length = rt_bat->length; 1832 1833 vhdx_region_header_le_export(region_table); 1834 vhdx_region_entry_le_export(rt_bat); 1835 vhdx_region_entry_le_export(rt_metadata); 1836 1837 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1838 offsetof(VHDXRegionTableHeader, checksum)); 1839 1840 1841 /* The region table gives us the data we need to create the BAT, 1842 * so do that now */ 1843 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1844 bat_file_offset, bat_length, errp); 1845 if (ret < 0) { 1846 goto exit; 1847 } 1848 1849 /* Now write out the region headers to disk */ 1850 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer, 1851 VHDX_HEADER_BLOCK_SIZE, 0); 1852 if (ret < 0) { 1853 error_setg_errno(errp, -ret, "Failed to write first region table"); 1854 goto exit; 1855 } 1856 1857 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer, 1858 VHDX_HEADER_BLOCK_SIZE, 0); 1859 if (ret < 0) { 1860 error_setg_errno(errp, -ret, "Failed to write second region table"); 1861 goto exit; 1862 } 1863 1864 exit: 1865 g_free(s); 1866 g_free(buffer); 1867 return ret; 1868 } 1869 1870 /* We need to create the following elements: 1871 * 1872 * .-----------------------------------------------------------------. 1873 * | (A) | (B) | (C) | (D) | (E) | 1874 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1875 * | | | | | | 1876 * .-----------------------------------------------------------------. 1877 * 0 64KB 128KB 192KB 256KB 320KB 1878 * 1879 * 1880 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1881 * | (F) | (G) | (H) | | 1882 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1883 * | | | | | 1884 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1885 * 1MB 1886 */ 1887 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts, 1888 Error **errp) 1889 { 1890 BlockdevCreateOptionsVhdx *vhdx_opts; 1891 BlockBackend *blk = NULL; 1892 BlockDriverState *bs = NULL; 1893 1894 int ret = 0; 1895 uint64_t image_size; 1896 uint32_t log_size; 1897 uint32_t block_size; 1898 uint64_t signature; 1899 uint64_t metadata_offset; 1900 bool use_zero_blocks = false; 1901 1902 gunichar2 *creator = NULL; 1903 glong creator_items; 1904 VHDXImageType image_type; 1905 1906 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1907 vhdx_opts = &opts->u.vhdx; 1908 1909 /* Validate options and set default values */ 1910 image_size = vhdx_opts->size; 1911 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1912 error_setg(errp, "Image size too large; max of 64TB"); 1913 return -EINVAL; 1914 } 1915 1916 if (!vhdx_opts->has_log_size) { 1917 log_size = DEFAULT_LOG_SIZE; 1918 } else { 1919 if (vhdx_opts->log_size > UINT32_MAX) { 1920 error_setg(errp, "Log size must be smaller than 4 GB"); 1921 return -EINVAL; 1922 } 1923 log_size = vhdx_opts->log_size; 1924 } 1925 if (log_size < MiB || (log_size % MiB) != 0) { 1926 error_setg(errp, "Log size must be a multiple of 1 MB"); 1927 return -EINVAL; 1928 } 1929 1930 if (!vhdx_opts->has_block_state_zero) { 1931 use_zero_blocks = true; 1932 } else { 1933 use_zero_blocks = vhdx_opts->block_state_zero; 1934 } 1935 1936 if (!vhdx_opts->has_subformat) { 1937 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1938 } 1939 1940 switch (vhdx_opts->subformat) { 1941 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1942 image_type = VHDX_TYPE_DYNAMIC; 1943 break; 1944 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1945 image_type = VHDX_TYPE_FIXED; 1946 break; 1947 default: 1948 g_assert_not_reached(); 1949 } 1950 1951 /* These are pretty arbitrary, and mainly designed to keep the BAT 1952 * size reasonable to load into RAM */ 1953 if (vhdx_opts->has_block_size) { 1954 block_size = vhdx_opts->block_size; 1955 } else { 1956 if (image_size > 32 * TiB) { 1957 block_size = 64 * MiB; 1958 } else if (image_size > (uint64_t) 100 * GiB) { 1959 block_size = 32 * MiB; 1960 } else if (image_size > 1 * GiB) { 1961 block_size = 16 * MiB; 1962 } else { 1963 block_size = 8 * MiB; 1964 } 1965 } 1966 1967 if (block_size < MiB || (block_size % MiB) != 0) { 1968 error_setg(errp, "Block size must be a multiple of 1 MB"); 1969 return -EINVAL; 1970 } 1971 if (!is_power_of_2(block_size)) { 1972 error_setg(errp, "Block size must be a power of two"); 1973 return -EINVAL; 1974 } 1975 if (block_size > VHDX_BLOCK_SIZE_MAX) { 1976 error_setg(errp, "Block size must not exceed %" PRId64, 1977 VHDX_BLOCK_SIZE_MAX); 1978 return -EINVAL; 1979 } 1980 1981 /* Create BlockBackend to write to the image */ 1982 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp); 1983 if (bs == NULL) { 1984 return -EIO; 1985 } 1986 1987 blk = blk_new(bdrv_get_aio_context(bs), 1988 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 1989 ret = blk_insert_bs(blk, bs, errp); 1990 if (ret < 0) { 1991 goto delete_and_exit; 1992 } 1993 blk_set_allow_write_beyond_eof(blk, true); 1994 1995 /* Create (A) */ 1996 1997 /* The creator field is optional, but may be useful for 1998 * debugging / diagnostics */ 1999 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2000 &creator_items, NULL); 2001 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2002 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature), 2003 0); 2004 if (ret < 0) { 2005 error_setg_errno(errp, -ret, "Failed to write file signature"); 2006 goto delete_and_exit; 2007 } 2008 if (creator) { 2009 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2010 creator, creator_items * sizeof(gunichar2), 0); 2011 if (ret < 0) { 2012 error_setg_errno(errp, -ret, "Failed to write creator field"); 2013 goto delete_and_exit; 2014 } 2015 } 2016 2017 2018 /* Creates (B),(C) */ 2019 ret = vhdx_create_new_headers(blk, image_size, log_size); 2020 if (ret < 0) { 2021 error_setg_errno(errp, -ret, "Failed to write image headers"); 2022 goto delete_and_exit; 2023 } 2024 2025 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2026 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2027 log_size, use_zero_blocks, image_type, 2028 &metadata_offset, errp); 2029 if (ret < 0) { 2030 goto delete_and_exit; 2031 } 2032 2033 /* Creates (H) */ 2034 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2035 metadata_offset, image_type); 2036 if (ret < 0) { 2037 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2038 goto delete_and_exit; 2039 } 2040 2041 ret = 0; 2042 delete_and_exit: 2043 blk_unref(blk); 2044 bdrv_unref(bs); 2045 g_free(creator); 2046 return ret; 2047 } 2048 2049 static int coroutine_fn vhdx_co_create_opts(const char *filename, 2050 QemuOpts *opts, 2051 Error **errp) 2052 { 2053 BlockdevCreateOptions *create_options = NULL; 2054 QDict *qdict; 2055 Visitor *v; 2056 BlockDriverState *bs = NULL; 2057 Error *local_err = NULL; 2058 int ret; 2059 2060 static const QDictRenames opt_renames[] = { 2061 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" }, 2062 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" }, 2063 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" }, 2064 { NULL, NULL }, 2065 }; 2066 2067 /* Parse options and convert legacy syntax */ 2068 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true); 2069 2070 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 2071 ret = -EINVAL; 2072 goto fail; 2073 } 2074 2075 /* Create and open the file (protocol layer) */ 2076 ret = bdrv_create_file(filename, opts, &local_err); 2077 if (ret < 0) { 2078 error_propagate(errp, local_err); 2079 goto fail; 2080 } 2081 2082 bs = bdrv_open(filename, NULL, NULL, 2083 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 2084 if (bs == NULL) { 2085 ret = -EIO; 2086 goto fail; 2087 } 2088 2089 /* Now get the QAPI type BlockdevCreateOptions */ 2090 qdict_put_str(qdict, "driver", "vhdx"); 2091 qdict_put_str(qdict, "file", bs->node_name); 2092 2093 v = qobject_input_visitor_new_flat_confused(qdict, errp); 2094 if (!v) { 2095 ret = -EINVAL; 2096 goto fail; 2097 } 2098 2099 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 2100 visit_free(v); 2101 2102 if (local_err) { 2103 error_propagate(errp, local_err); 2104 ret = -EINVAL; 2105 goto fail; 2106 } 2107 2108 /* Silently round up sizes: 2109 * The image size is rounded to 512 bytes. Make the block and log size 2110 * close to what was specified, but must be at least 1MB, and a multiple of 2111 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0 2112 * means auto, which is represented by a missing key in QAPI. */ 2113 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX); 2114 create_options->u.vhdx.size = 2115 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE); 2116 2117 if (create_options->u.vhdx.has_log_size) { 2118 create_options->u.vhdx.log_size = 2119 ROUND_UP(create_options->u.vhdx.log_size, MiB); 2120 } 2121 if (create_options->u.vhdx.has_block_size) { 2122 create_options->u.vhdx.block_size = 2123 ROUND_UP(create_options->u.vhdx.block_size, MiB); 2124 2125 if (create_options->u.vhdx.block_size == 0) { 2126 create_options->u.vhdx.has_block_size = false; 2127 } 2128 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) { 2129 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX; 2130 } 2131 } 2132 2133 /* Create the vhdx image (format layer) */ 2134 ret = vhdx_co_create(create_options, errp); 2135 2136 fail: 2137 qobject_unref(qdict); 2138 bdrv_unref(bs); 2139 qapi_free_BlockdevCreateOptions(create_options); 2140 return ret; 2141 } 2142 2143 /* If opened r/w, the VHDX driver will automatically replay the log, 2144 * if one is present, inside the vhdx_open() call. 2145 * 2146 * If qemu-img check -r all is called, the image is automatically opened 2147 * r/w and any log has already been replayed, so there is nothing (currently) 2148 * for us to do here 2149 */ 2150 static int coroutine_fn vhdx_co_check(BlockDriverState *bs, 2151 BdrvCheckResult *result, 2152 BdrvCheckMode fix) 2153 { 2154 BDRVVHDXState *s = bs->opaque; 2155 2156 if (s->log_replayed_on_open) { 2157 result->corruptions_fixed++; 2158 } 2159 2160 vhdx_check_bat_entries(bs, &result->corruptions); 2161 2162 return 0; 2163 } 2164 2165 static int vhdx_has_zero_init(BlockDriverState *bs) 2166 { 2167 BDRVVHDXState *s = bs->opaque; 2168 int state; 2169 2170 /* 2171 * Check the subformat: Fixed images have all BAT entries present, 2172 * dynamic images have none (right after creation). It is 2173 * therefore enough to check the first BAT entry. 2174 */ 2175 if (!s->bat_entries) { 2176 return 1; 2177 } 2178 2179 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK; 2180 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) { 2181 /* Fixed subformat */ 2182 return bdrv_has_zero_init(bs->file->bs); 2183 } 2184 2185 /* Dynamic subformat */ 2186 return 1; 2187 } 2188 2189 static QemuOptsList vhdx_create_opts = { 2190 .name = "vhdx-create-opts", 2191 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 2192 .desc = { 2193 { 2194 .name = BLOCK_OPT_SIZE, 2195 .type = QEMU_OPT_SIZE, 2196 .help = "Virtual disk size; max of 64TB." 2197 }, 2198 { 2199 .name = VHDX_BLOCK_OPT_LOG_SIZE, 2200 .type = QEMU_OPT_SIZE, 2201 .def_value_str = stringify(DEFAULT_LOG_SIZE), 2202 .help = "Log size; min 1MB." 2203 }, 2204 { 2205 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 2206 .type = QEMU_OPT_SIZE, 2207 .def_value_str = stringify(0), 2208 .help = "Block Size; min 1MB, max 256MB. " \ 2209 "0 means auto-calculate based on image size." 2210 }, 2211 { 2212 .name = BLOCK_OPT_SUBFMT, 2213 .type = QEMU_OPT_STRING, 2214 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ 2215 "Default is 'dynamic'." 2216 }, 2217 { 2218 .name = VHDX_BLOCK_OPT_ZERO, 2219 .type = QEMU_OPT_BOOL, 2220 .help = "Force use of payload blocks of type 'ZERO'. "\ 2221 "Non-standard, but default. Do not set to 'off' when "\ 2222 "using 'qemu-img convert' with subformat=dynamic." 2223 }, 2224 { NULL } 2225 } 2226 }; 2227 2228 static BlockDriver bdrv_vhdx = { 2229 .format_name = "vhdx", 2230 .instance_size = sizeof(BDRVVHDXState), 2231 .bdrv_probe = vhdx_probe, 2232 .bdrv_open = vhdx_open, 2233 .bdrv_close = vhdx_close, 2234 .bdrv_reopen_prepare = vhdx_reopen_prepare, 2235 .bdrv_child_perm = bdrv_format_default_perms, 2236 .bdrv_co_readv = vhdx_co_readv, 2237 .bdrv_co_writev = vhdx_co_writev, 2238 .bdrv_co_create = vhdx_co_create, 2239 .bdrv_co_create_opts = vhdx_co_create_opts, 2240 .bdrv_get_info = vhdx_get_info, 2241 .bdrv_co_check = vhdx_co_check, 2242 .bdrv_has_zero_init = vhdx_has_zero_init, 2243 2244 .create_opts = &vhdx_create_opts, 2245 }; 2246 2247 static void bdrv_vhdx_init(void) 2248 { 2249 bdrv_register(&bdrv_vhdx); 2250 } 2251 2252 block_init(bdrv_vhdx_init); 2253