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 return vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 415 } 416 417 /* opens the specified header block from the VHDX file header section */ 418 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, 419 Error **errp) 420 { 421 int ret; 422 VHDXHeader *header1; 423 VHDXHeader *header2; 424 bool h1_valid = false; 425 bool h2_valid = false; 426 uint64_t h1_seq = 0; 427 uint64_t h2_seq = 0; 428 uint8_t *buffer; 429 430 /* header1 & header2 are freed in vhdx_close() */ 431 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 432 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 433 434 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 435 436 s->headers[0] = header1; 437 s->headers[1] = header2; 438 439 /* We have to read the whole VHDX_HEADER_SIZE instead of 440 * sizeof(VHDXHeader), because the checksum is over the whole 441 * region */ 442 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, 443 VHDX_HEADER_SIZE); 444 if (ret < 0) { 445 goto fail; 446 } 447 /* copy over just the relevant portion that we need */ 448 memcpy(header1, buffer, sizeof(VHDXHeader)); 449 450 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 451 vhdx_header_le_import(header1); 452 if (header1->signature == VHDX_HEADER_SIGNATURE && 453 header1->version == 1) { 454 h1_seq = header1->sequence_number; 455 h1_valid = true; 456 } 457 } 458 459 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, 460 VHDX_HEADER_SIZE); 461 if (ret < 0) { 462 goto fail; 463 } 464 /* copy over just the relevant portion that we need */ 465 memcpy(header2, buffer, sizeof(VHDXHeader)); 466 467 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 468 vhdx_header_le_import(header2); 469 if (header2->signature == VHDX_HEADER_SIGNATURE && 470 header2->version == 1) { 471 h2_seq = header2->sequence_number; 472 h2_valid = true; 473 } 474 } 475 476 /* If there is only 1 valid header (or no valid headers), we 477 * don't care what the sequence numbers are */ 478 if (h1_valid && !h2_valid) { 479 s->curr_header = 0; 480 } else if (!h1_valid && h2_valid) { 481 s->curr_header = 1; 482 } else if (!h1_valid && !h2_valid) { 483 goto fail; 484 } else { 485 /* If both headers are valid, then we choose the active one by the 486 * highest sequence number. If the sequence numbers are equal, that is 487 * invalid */ 488 if (h1_seq > h2_seq) { 489 s->curr_header = 0; 490 } else if (h2_seq > h1_seq) { 491 s->curr_header = 1; 492 } else { 493 /* The Microsoft Disk2VHD tool will create 2 identical 494 * headers, with identical sequence numbers. If the headers are 495 * identical, don't consider the file corrupt */ 496 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 497 s->curr_header = 0; 498 } else { 499 goto fail; 500 } 501 } 502 } 503 504 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 505 s->headers[s->curr_header]->log_length); 506 goto exit; 507 508 fail: 509 error_setg_errno(errp, -ret, "No valid VHDX header found"); 510 qemu_vfree(header1); 511 qemu_vfree(header2); 512 s->headers[0] = NULL; 513 s->headers[1] = NULL; 514 exit: 515 qemu_vfree(buffer); 516 } 517 518 519 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 520 { 521 int ret = 0; 522 uint8_t *buffer; 523 int offset = 0; 524 VHDXRegionTableEntry rt_entry; 525 uint32_t i; 526 bool bat_rt_found = false; 527 bool metadata_rt_found = false; 528 529 /* We have to read the whole 64KB block, because the crc32 is over the 530 * whole block */ 531 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 532 533 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 534 VHDX_HEADER_BLOCK_SIZE); 535 if (ret < 0) { 536 goto fail; 537 } 538 memcpy(&s->rt, buffer, sizeof(s->rt)); 539 offset += sizeof(s->rt); 540 541 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 542 ret = -EINVAL; 543 goto fail; 544 } 545 546 vhdx_region_header_le_import(&s->rt); 547 548 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 549 ret = -EINVAL; 550 goto fail; 551 } 552 553 554 /* Per spec, maximum region table entry count is 2047 */ 555 if (s->rt.entry_count > 2047) { 556 ret = -EINVAL; 557 goto fail; 558 } 559 560 for (i = 0; i < s->rt.entry_count; i++) { 561 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 562 offset += sizeof(rt_entry); 563 564 vhdx_region_entry_le_import(&rt_entry); 565 566 /* check for region overlap between these entries, and any 567 * other memory regions in the file */ 568 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 569 if (ret < 0) { 570 goto fail; 571 } 572 573 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 574 575 /* see if we recognize the entry */ 576 if (guid_eq(rt_entry.guid, bat_guid)) { 577 /* must be unique; if we have already found it this is invalid */ 578 if (bat_rt_found) { 579 ret = -EINVAL; 580 goto fail; 581 } 582 bat_rt_found = true; 583 s->bat_rt = rt_entry; 584 continue; 585 } 586 587 if (guid_eq(rt_entry.guid, metadata_guid)) { 588 /* must be unique; if we have already found it this is invalid */ 589 if (metadata_rt_found) { 590 ret = -EINVAL; 591 goto fail; 592 } 593 metadata_rt_found = true; 594 s->metadata_rt = rt_entry; 595 continue; 596 } 597 598 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 599 /* cannot read vhdx file - required region table entry that 600 * we do not understand. per spec, we must fail to open */ 601 ret = -ENOTSUP; 602 goto fail; 603 } 604 } 605 606 if (!bat_rt_found || !metadata_rt_found) { 607 ret = -EINVAL; 608 goto fail; 609 } 610 611 ret = 0; 612 613 fail: 614 qemu_vfree(buffer); 615 return ret; 616 } 617 618 619 620 /* Metadata initial parser 621 * 622 * This loads all the metadata entry fields. This may cause additional 623 * fields to be processed (e.g. parent locator, etc..). 624 * 625 * There are 5 Metadata items that are always required: 626 * - File Parameters (block size, has a parent) 627 * - Virtual Disk Size (size, in bytes, of the virtual drive) 628 * - Page 83 Data (scsi page 83 guid) 629 * - Logical Sector Size (logical sector size in bytes, either 512 or 630 * 4096. We only support 512 currently) 631 * - Physical Sector Size (512 or 4096) 632 * 633 * Also, if the File Parameters indicate this is a differencing file, 634 * we must also look for the Parent Locator metadata item. 635 */ 636 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 637 { 638 int ret = 0; 639 uint8_t *buffer; 640 int offset = 0; 641 uint32_t i = 0; 642 VHDXMetadataTableEntry md_entry; 643 644 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 645 646 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 647 VHDX_METADATA_TABLE_MAX_SIZE); 648 if (ret < 0) { 649 goto exit; 650 } 651 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 652 offset += sizeof(s->metadata_hdr); 653 654 vhdx_metadata_header_le_import(&s->metadata_hdr); 655 656 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 657 ret = -EINVAL; 658 goto exit; 659 } 660 661 s->metadata_entries.present = 0; 662 663 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 664 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 665 ret = -EINVAL; 666 goto exit; 667 } 668 669 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 670 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 671 offset += sizeof(md_entry); 672 673 vhdx_metadata_entry_le_import(&md_entry); 674 675 if (guid_eq(md_entry.item_id, file_param_guid)) { 676 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 677 ret = -EINVAL; 678 goto exit; 679 } 680 s->metadata_entries.file_parameters_entry = md_entry; 681 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 682 continue; 683 } 684 685 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 686 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 687 ret = -EINVAL; 688 goto exit; 689 } 690 s->metadata_entries.virtual_disk_size_entry = md_entry; 691 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 692 continue; 693 } 694 695 if (guid_eq(md_entry.item_id, page83_guid)) { 696 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 697 ret = -EINVAL; 698 goto exit; 699 } 700 s->metadata_entries.page83_data_entry = md_entry; 701 s->metadata_entries.present |= META_PAGE_83_PRESENT; 702 continue; 703 } 704 705 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 706 if (s->metadata_entries.present & 707 META_LOGICAL_SECTOR_SIZE_PRESENT) { 708 ret = -EINVAL; 709 goto exit; 710 } 711 s->metadata_entries.logical_sector_size_entry = md_entry; 712 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 713 continue; 714 } 715 716 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 717 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 718 ret = -EINVAL; 719 goto exit; 720 } 721 s->metadata_entries.phys_sector_size_entry = md_entry; 722 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 723 continue; 724 } 725 726 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 727 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 728 ret = -EINVAL; 729 goto exit; 730 } 731 s->metadata_entries.parent_locator_entry = md_entry; 732 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 733 continue; 734 } 735 736 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 737 /* cannot read vhdx file - required region table entry that 738 * we do not understand. per spec, we must fail to open */ 739 ret = -ENOTSUP; 740 goto exit; 741 } 742 } 743 744 if (s->metadata_entries.present != META_ALL_PRESENT) { 745 ret = -ENOTSUP; 746 goto exit; 747 } 748 749 ret = bdrv_pread(bs->file, 750 s->metadata_entries.file_parameters_entry.offset 751 + s->metadata_rt.file_offset, 752 &s->params, 753 sizeof(s->params)); 754 755 if (ret < 0) { 756 goto exit; 757 } 758 759 s->params.block_size = le32_to_cpu(s->params.block_size); 760 s->params.data_bits = le32_to_cpu(s->params.data_bits); 761 762 763 /* We now have the file parameters, so we can tell if this is a 764 * differencing file (i.e.. has_parent), is dynamic or fixed 765 * sized (leave_blocks_allocated), and the block size */ 766 767 /* The parent locator required iff the file parameters has_parent set */ 768 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 769 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 770 /* TODO: parse parent locator fields */ 771 ret = -ENOTSUP; /* temp, until differencing files are supported */ 772 goto exit; 773 } else { 774 /* if has_parent is set, but there is not parent locator present, 775 * then that is an invalid combination */ 776 ret = -EINVAL; 777 goto exit; 778 } 779 } 780 781 /* determine virtual disk size, logical sector size, 782 * and phys sector size */ 783 784 ret = bdrv_pread(bs->file, 785 s->metadata_entries.virtual_disk_size_entry.offset 786 + s->metadata_rt.file_offset, 787 &s->virtual_disk_size, 788 sizeof(uint64_t)); 789 if (ret < 0) { 790 goto exit; 791 } 792 ret = bdrv_pread(bs->file, 793 s->metadata_entries.logical_sector_size_entry.offset 794 + s->metadata_rt.file_offset, 795 &s->logical_sector_size, 796 sizeof(uint32_t)); 797 if (ret < 0) { 798 goto exit; 799 } 800 ret = bdrv_pread(bs->file, 801 s->metadata_entries.phys_sector_size_entry.offset 802 + s->metadata_rt.file_offset, 803 &s->physical_sector_size, 804 sizeof(uint32_t)); 805 if (ret < 0) { 806 goto exit; 807 } 808 809 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size); 810 s->logical_sector_size = le32_to_cpu(s->logical_sector_size); 811 s->physical_sector_size = le32_to_cpu(s->physical_sector_size); 812 813 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 814 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 815 ret = -EINVAL; 816 goto exit; 817 } 818 819 /* only 2 supported sector sizes */ 820 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { 821 ret = -EINVAL; 822 goto exit; 823 } 824 825 /* Both block_size and sector_size are guaranteed powers of 2, below. 826 Due to range checks above, s->sectors_per_block can never be < 256 */ 827 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 828 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 829 (uint64_t)s->logical_sector_size / 830 (uint64_t)s->params.block_size; 831 832 /* These values are ones we will want to use for division / multiplication 833 * later on, and they are all guaranteed (per the spec) to be powers of 2, 834 * so we can take advantage of that for shift operations during 835 * reads/writes */ 836 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 837 ret = -EINVAL; 838 goto exit; 839 } 840 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 841 ret = -EINVAL; 842 goto exit; 843 } 844 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 845 ret = -EINVAL; 846 goto exit; 847 } 848 s->block_size = s->params.block_size; 849 if (s->block_size & (s->block_size - 1)) { 850 ret = -EINVAL; 851 goto exit; 852 } 853 854 vhdx_set_shift_bits(s); 855 856 ret = 0; 857 858 exit: 859 qemu_vfree(buffer); 860 return ret; 861 } 862 863 /* 864 * Calculate the number of BAT entries, including sector 865 * bitmap entries. 866 */ 867 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 868 { 869 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 870 871 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 872 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 873 874 if (s->parent_entries) { 875 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 876 } else { 877 s->bat_entries = data_blocks_cnt + 878 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 879 } 880 881 } 882 883 static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) 884 { 885 BDRVVHDXState *s = bs->opaque; 886 int64_t image_file_size = bdrv_getlength(bs->file->bs); 887 uint64_t payblocks = s->chunk_ratio; 888 uint64_t i; 889 int ret = 0; 890 891 if (image_file_size < 0) { 892 error_report("Could not determinate VHDX image file size."); 893 return image_file_size; 894 } 895 896 for (i = 0; i < s->bat_entries; i++) { 897 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 898 PAYLOAD_BLOCK_FULLY_PRESENT) { 899 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; 900 /* 901 * Allow that the last block exists only partially. The VHDX spec 902 * states that the image file can only grow in blocksize increments, 903 * but QEMU created images with partial last blocks in the past. 904 */ 905 uint32_t block_length = MIN(s->block_size, 906 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); 907 /* 908 * Check for BAT entry overflow. 909 */ 910 if (offset > INT64_MAX - s->block_size) { 911 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); 912 ret = -EINVAL; 913 if (!errcnt) { 914 break; 915 } 916 (*errcnt)++; 917 } 918 /* 919 * Check if fully allocated BAT entries do not reside after 920 * end of the image file. 921 */ 922 if (offset >= image_file_size) { 923 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 924 " points after end of file (%" PRIi64 "). Image" 925 " has probably been truncated.", 926 i, offset, image_file_size); 927 ret = -EINVAL; 928 if (!errcnt) { 929 break; 930 } 931 (*errcnt)++; 932 } else if (offset + block_length > image_file_size) { 933 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 934 " points after end of file (%" PRIi64 "). Image" 935 " has probably been truncated.", 936 i, offset + block_length - 1, image_file_size); 937 ret = -EINVAL; 938 if (!errcnt) { 939 break; 940 } 941 (*errcnt)++; 942 } 943 944 /* 945 * verify populated BAT field file offsets against 946 * region table and log entries 947 */ 948 if (payblocks--) { 949 /* payload bat entries */ 950 int ret2; 951 ret2 = vhdx_region_check(s, offset, s->block_size); 952 if (ret2 < 0) { 953 ret = -EINVAL; 954 if (!errcnt) { 955 break; 956 } 957 (*errcnt)++; 958 } 959 } else { 960 payblocks = s->chunk_ratio; 961 /* 962 * Once differencing files are supported, verify sector bitmap 963 * blocks here 964 */ 965 } 966 } 967 } 968 969 return ret; 970 } 971 972 static void vhdx_close(BlockDriverState *bs) 973 { 974 BDRVVHDXState *s = bs->opaque; 975 qemu_vfree(s->headers[0]); 976 s->headers[0] = NULL; 977 qemu_vfree(s->headers[1]); 978 s->headers[1] = NULL; 979 qemu_vfree(s->bat); 980 s->bat = NULL; 981 qemu_vfree(s->parent_entries); 982 s->parent_entries = NULL; 983 migrate_del_blocker(s->migration_blocker); 984 error_free(s->migration_blocker); 985 qemu_vfree(s->log.hdr); 986 s->log.hdr = NULL; 987 vhdx_region_unregister_all(s); 988 } 989 990 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 991 Error **errp) 992 { 993 BDRVVHDXState *s = bs->opaque; 994 int ret = 0; 995 uint32_t i; 996 uint64_t signature; 997 Error *local_err = NULL; 998 999 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 1000 BDRV_CHILD_IMAGE, false, errp); 1001 if (!bs->file) { 1002 return -EINVAL; 1003 } 1004 1005 s->bat = NULL; 1006 s->first_visible_write = true; 1007 1008 qemu_co_mutex_init(&s->lock); 1009 QLIST_INIT(&s->regions); 1010 1011 /* validate the file signature */ 1012 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 1013 if (ret < 0) { 1014 goto fail; 1015 } 1016 if (memcmp(&signature, "vhdxfile", 8)) { 1017 ret = -EINVAL; 1018 goto fail; 1019 } 1020 1021 /* This is used for any header updates, for the file_write_guid. 1022 * The spec dictates that a new value should be used for the first 1023 * header update */ 1024 vhdx_guid_generate(&s->session_guid); 1025 1026 vhdx_parse_header(bs, s, &local_err); 1027 if (local_err != NULL) { 1028 error_propagate(errp, local_err); 1029 ret = -EINVAL; 1030 goto fail; 1031 } 1032 1033 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1034 if (ret < 0) { 1035 goto fail; 1036 } 1037 1038 ret = vhdx_open_region_tables(bs, s); 1039 if (ret < 0) { 1040 goto fail; 1041 } 1042 1043 ret = vhdx_parse_metadata(bs, s); 1044 if (ret < 0) { 1045 goto fail; 1046 } 1047 1048 s->block_size = s->params.block_size; 1049 1050 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1051 * logical_sector_size */ 1052 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1053 1054 vhdx_calc_bat_entries(s); 1055 1056 s->bat_offset = s->bat_rt.file_offset; 1057 1058 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1059 /* BAT allocation is not large enough for all entries */ 1060 ret = -EINVAL; 1061 goto fail; 1062 } 1063 1064 /* s->bat is freed in vhdx_close() */ 1065 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1066 if (s->bat == NULL) { 1067 ret = -ENOMEM; 1068 goto fail; 1069 } 1070 1071 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 1072 if (ret < 0) { 1073 goto fail; 1074 } 1075 1076 /* endian convert populated BAT field entires */ 1077 for (i = 0; i < s->bat_entries; i++) { 1078 s->bat[i] = le64_to_cpu(s->bat[i]); 1079 } 1080 1081 if (!(flags & BDRV_O_CHECK)) { 1082 ret = vhdx_check_bat_entries(bs, NULL); 1083 if (ret < 0) { 1084 goto fail; 1085 } 1086 } 1087 1088 /* Disable migration when VHDX images are used */ 1089 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1090 "does not support live migration", 1091 bdrv_get_device_or_node_name(bs)); 1092 ret = migrate_add_blocker(s->migration_blocker, errp); 1093 if (ret < 0) { 1094 error_free(s->migration_blocker); 1095 goto fail; 1096 } 1097 1098 /* TODO: differencing files */ 1099 1100 return 0; 1101 fail: 1102 vhdx_close(bs); 1103 return ret; 1104 } 1105 1106 static int vhdx_reopen_prepare(BDRVReopenState *state, 1107 BlockReopenQueue *queue, Error **errp) 1108 { 1109 return 0; 1110 } 1111 1112 1113 /* 1114 * Perform sector to block offset translations, to get various 1115 * sector and file offsets into the image. See VHDXSectorInfo 1116 */ 1117 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1118 int nb_sectors, VHDXSectorInfo *sinfo) 1119 { 1120 uint32_t block_offset; 1121 1122 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1123 /* effectively a modulo - this gives us the offset into the block 1124 * (in sector sizes) for our sector number */ 1125 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1126 /* the chunk ratio gives us the interleaving of the sector 1127 * bitmaps, so we need to advance our page block index by the 1128 * sector bitmaps entry number */ 1129 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1130 1131 /* the number of sectors we can read/write in this cycle */ 1132 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1133 1134 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1135 1136 if (sinfo->sectors_avail > nb_sectors) { 1137 sinfo->sectors_avail = nb_sectors; 1138 } 1139 1140 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1141 1142 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1143 1144 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1145 1146 /* The file offset must be past the header section, so must be > 0 */ 1147 if (sinfo->file_offset == 0) { 1148 return; 1149 } 1150 1151 /* block offset is the offset in vhdx logical sectors, in 1152 * the payload data block. Convert that to a byte offset 1153 * in the block, and add in the payload data block offset 1154 * in the file, in bytes, to get the final read address */ 1155 1156 sinfo->file_offset += sinfo->block_offset; 1157 } 1158 1159 1160 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1161 { 1162 BDRVVHDXState *s = bs->opaque; 1163 1164 bdi->cluster_size = s->block_size; 1165 1166 return 0; 1167 } 1168 1169 1170 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1171 int nb_sectors, QEMUIOVector *qiov) 1172 { 1173 BDRVVHDXState *s = bs->opaque; 1174 int ret = 0; 1175 VHDXSectorInfo sinfo; 1176 uint64_t bytes_done = 0; 1177 QEMUIOVector hd_qiov; 1178 1179 qemu_iovec_init(&hd_qiov, qiov->niov); 1180 1181 qemu_co_mutex_lock(&s->lock); 1182 1183 while (nb_sectors > 0) { 1184 /* We are a differencing file, so we need to inspect the sector bitmap 1185 * to see if we have the data or not */ 1186 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1187 /* not supported yet */ 1188 ret = -ENOTSUP; 1189 goto exit; 1190 } else { 1191 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1192 1193 qemu_iovec_reset(&hd_qiov); 1194 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1195 1196 /* check the payload block state */ 1197 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1198 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1199 case PAYLOAD_BLOCK_UNDEFINED: 1200 case PAYLOAD_BLOCK_UNMAPPED: 1201 case PAYLOAD_BLOCK_UNMAPPED_v095: 1202 case PAYLOAD_BLOCK_ZERO: 1203 /* return zero */ 1204 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1205 break; 1206 case PAYLOAD_BLOCK_FULLY_PRESENT: 1207 qemu_co_mutex_unlock(&s->lock); 1208 ret = bdrv_co_preadv(bs->file, sinfo.file_offset, 1209 sinfo.sectors_avail * BDRV_SECTOR_SIZE, 1210 &hd_qiov, 0); 1211 qemu_co_mutex_lock(&s->lock); 1212 if (ret < 0) { 1213 goto exit; 1214 } 1215 break; 1216 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1217 /* we don't yet support difference files, fall through 1218 * to error */ 1219 default: 1220 ret = -EIO; 1221 goto exit; 1222 break; 1223 } 1224 nb_sectors -= sinfo.sectors_avail; 1225 sector_num += sinfo.sectors_avail; 1226 bytes_done += sinfo.bytes_avail; 1227 } 1228 } 1229 ret = 0; 1230 exit: 1231 qemu_co_mutex_unlock(&s->lock); 1232 qemu_iovec_destroy(&hd_qiov); 1233 return ret; 1234 } 1235 1236 /* 1237 * Allocate a new payload block at the end of the file. 1238 * 1239 * Allocation will happen at 1MB alignment inside the file. 1240 * 1241 * If @need_zero is set on entry but not cleared on return, then truncation 1242 * could not guarantee that the new portion reads as zero, and the caller 1243 * will take care of it instead. 1244 * 1245 * Returns the file offset start of the new payload block 1246 */ 1247 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1248 uint64_t *new_offset, bool *need_zero) 1249 { 1250 int64_t current_len; 1251 1252 current_len = bdrv_getlength(bs->file->bs); 1253 if (current_len < 0) { 1254 return current_len; 1255 } 1256 1257 *new_offset = current_len; 1258 1259 /* per the spec, the address for a block is in units of 1MB */ 1260 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1261 if (*new_offset > INT64_MAX) { 1262 return -EINVAL; 1263 } 1264 1265 if (*need_zero) { 1266 int ret; 1267 1268 ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1269 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL); 1270 if (ret != -ENOTSUP) { 1271 *need_zero = false; 1272 return ret; 1273 } 1274 } 1275 1276 return bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1277 PREALLOC_MODE_OFF, 0, NULL); 1278 } 1279 1280 /* 1281 * Update the BAT table entry with the new file offset, and the new entry 1282 * state */ 1283 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1284 VHDXSectorInfo *sinfo, 1285 uint64_t *bat_entry_le, 1286 uint64_t *bat_offset, int state) 1287 { 1288 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1289 * 1MB, and 3 bits for the block state. */ 1290 if ((state == PAYLOAD_BLOCK_ZERO) || 1291 (state == PAYLOAD_BLOCK_UNDEFINED) || 1292 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1293 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1294 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1295 FileOffsetMB field is denoted as 1296 'reserved' in the v1.0 spec. If it is 1297 non-zero, MS Hyper-V will fail to read 1298 the disk image */ 1299 } else { 1300 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1301 } 1302 1303 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1304 1305 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1306 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1307 1308 } 1309 1310 /* Per the spec, on the first write of guest-visible data to the file the 1311 * data write guid must be updated in the header */ 1312 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1313 { 1314 int ret = 0; 1315 if (s->first_visible_write) { 1316 s->first_visible_write = false; 1317 ret = vhdx_update_headers(bs, s, true, NULL); 1318 } 1319 return ret; 1320 } 1321 1322 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1323 int nb_sectors, QEMUIOVector *qiov, 1324 int flags) 1325 { 1326 int ret = -ENOTSUP; 1327 BDRVVHDXState *s = bs->opaque; 1328 VHDXSectorInfo sinfo; 1329 uint64_t bytes_done = 0; 1330 uint64_t bat_entry = 0; 1331 uint64_t bat_entry_offset = 0; 1332 QEMUIOVector hd_qiov; 1333 struct iovec iov1 = { 0 }; 1334 struct iovec iov2 = { 0 }; 1335 int sectors_to_write; 1336 int bat_state; 1337 uint64_t bat_prior_offset = 0; 1338 bool bat_update = false; 1339 1340 assert(!flags); 1341 qemu_iovec_init(&hd_qiov, qiov->niov); 1342 1343 qemu_co_mutex_lock(&s->lock); 1344 1345 ret = vhdx_user_visible_write(bs, s); 1346 if (ret < 0) { 1347 goto exit; 1348 } 1349 1350 while (nb_sectors > 0) { 1351 bool use_zero_buffers = false; 1352 bat_update = false; 1353 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1354 /* not supported yet */ 1355 ret = -ENOTSUP; 1356 goto exit; 1357 } else { 1358 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1359 sectors_to_write = sinfo.sectors_avail; 1360 1361 qemu_iovec_reset(&hd_qiov); 1362 /* check the payload block state */ 1363 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1364 switch (bat_state) { 1365 case PAYLOAD_BLOCK_ZERO: 1366 /* in this case, we need to preserve zero writes for 1367 * data that is not part of this write, so we must pad 1368 * the rest of the buffer to zeroes */ 1369 use_zero_buffers = true; 1370 /* fall through */ 1371 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1372 case PAYLOAD_BLOCK_UNMAPPED: 1373 case PAYLOAD_BLOCK_UNMAPPED_v095: 1374 case PAYLOAD_BLOCK_UNDEFINED: 1375 bat_prior_offset = sinfo.file_offset; 1376 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset, 1377 &use_zero_buffers); 1378 if (ret < 0) { 1379 goto exit; 1380 } 1381 /* 1382 * once we support differencing files, this may also be 1383 * partially present 1384 */ 1385 /* update block state to the newly specified state */ 1386 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1387 &bat_entry_offset, 1388 PAYLOAD_BLOCK_FULLY_PRESENT); 1389 bat_update = true; 1390 /* 1391 * Since we just allocated a block, file_offset is the 1392 * beginning of the payload block. It needs to be the 1393 * write address, which includes the offset into the 1394 * block, unless the entire block needs to read as 1395 * zeroes but truncation was not able to provide them, 1396 * in which case we need to fill in the rest. 1397 */ 1398 if (!use_zero_buffers) { 1399 sinfo.file_offset += sinfo.block_offset; 1400 } else { 1401 /* zero fill the front, if any */ 1402 if (sinfo.block_offset) { 1403 iov1.iov_len = sinfo.block_offset; 1404 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1405 memset(iov1.iov_base, 0, iov1.iov_len); 1406 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1407 iov1.iov_len); 1408 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1409 } 1410 1411 /* our actual data */ 1412 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1413 sinfo.bytes_avail); 1414 1415 /* zero fill the back, if any */ 1416 if ((sinfo.bytes_avail - sinfo.block_offset) < 1417 s->block_size) { 1418 iov2.iov_len = s->block_size - 1419 (sinfo.bytes_avail + sinfo.block_offset); 1420 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1421 memset(iov2.iov_base, 0, iov2.iov_len); 1422 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1423 iov2.iov_len); 1424 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1425 } 1426 } 1427 1428 /* fall through */ 1429 case PAYLOAD_BLOCK_FULLY_PRESENT: 1430 /* if the file offset address is in the header zone, 1431 * there is a problem */ 1432 if (sinfo.file_offset < (1 * MiB)) { 1433 ret = -EFAULT; 1434 goto error_bat_restore; 1435 } 1436 1437 if (!use_zero_buffers) { 1438 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1439 sinfo.bytes_avail); 1440 } 1441 /* block exists, so we can just overwrite it */ 1442 qemu_co_mutex_unlock(&s->lock); 1443 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset, 1444 sectors_to_write * BDRV_SECTOR_SIZE, 1445 &hd_qiov, 0); 1446 qemu_co_mutex_lock(&s->lock); 1447 if (ret < 0) { 1448 goto error_bat_restore; 1449 } 1450 break; 1451 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1452 /* we don't yet support difference files, fall through 1453 * to error */ 1454 default: 1455 ret = -EIO; 1456 goto exit; 1457 break; 1458 } 1459 1460 if (bat_update) { 1461 /* this will update the BAT entry into the log journal, and 1462 * then flush the log journal out to disk */ 1463 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1464 sizeof(VHDXBatEntry), 1465 bat_entry_offset); 1466 if (ret < 0) { 1467 goto exit; 1468 } 1469 } 1470 1471 nb_sectors -= sinfo.sectors_avail; 1472 sector_num += sinfo.sectors_avail; 1473 bytes_done += sinfo.bytes_avail; 1474 1475 } 1476 } 1477 1478 goto exit; 1479 1480 error_bat_restore: 1481 if (bat_update) { 1482 /* keep metadata in sync, and restore the bat entry state 1483 * if error. */ 1484 sinfo.file_offset = bat_prior_offset; 1485 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1486 &bat_entry_offset, bat_state); 1487 } 1488 exit: 1489 qemu_vfree(iov1.iov_base); 1490 qemu_vfree(iov2.iov_base); 1491 qemu_co_mutex_unlock(&s->lock); 1492 qemu_iovec_destroy(&hd_qiov); 1493 return ret; 1494 } 1495 1496 1497 1498 /* 1499 * Create VHDX Headers 1500 * 1501 * There are 2 headers, and the highest sequence number will represent 1502 * the active header 1503 */ 1504 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1505 uint32_t log_size) 1506 { 1507 BlockDriverState *bs = blk_bs(blk); 1508 BdrvChild *child; 1509 int ret = 0; 1510 VHDXHeader *hdr = NULL; 1511 1512 hdr = g_new0(VHDXHeader, 1); 1513 1514 hdr->signature = VHDX_HEADER_SIGNATURE; 1515 hdr->sequence_number = g_random_int(); 1516 hdr->log_version = 0; 1517 hdr->version = 1; 1518 hdr->log_length = log_size; 1519 hdr->log_offset = VHDX_HEADER_SECTION_END; 1520 vhdx_guid_generate(&hdr->file_write_guid); 1521 vhdx_guid_generate(&hdr->data_write_guid); 1522 1523 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1524 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1525 * here, which it really shouldn't be doing. */ 1526 child = QLIST_FIRST(&bs->parents); 1527 assert(!QLIST_NEXT(child, next_parent)); 1528 1529 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1530 if (ret < 0) { 1531 goto exit; 1532 } 1533 hdr->sequence_number++; 1534 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1535 if (ret < 0) { 1536 goto exit; 1537 } 1538 1539 exit: 1540 g_free(hdr); 1541 return ret; 1542 } 1543 1544 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1545 (sizeof(VHDXFileParameters) +\ 1546 sizeof(VHDXVirtualDiskSize) +\ 1547 sizeof(VHDXPage83Data) +\ 1548 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1549 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1550 1551 /* 1552 * Create the Metadata entries. 1553 * 1554 * For more details on the entries, see section 3.5 (pg 29) in the 1555 * VHDX 1.00 specification. 1556 * 1557 * We support 5 metadata entries (all required by spec): 1558 * File Parameters, 1559 * Virtual Disk Size, 1560 * Page 83 Data, 1561 * Logical Sector Size, 1562 * Physical Sector Size 1563 * 1564 * The first 64KB of the Metadata section is reserved for the metadata 1565 * header and entries; beyond that, the metadata items themselves reside. 1566 */ 1567 static int vhdx_create_new_metadata(BlockBackend *blk, 1568 uint64_t image_size, 1569 uint32_t block_size, 1570 uint32_t sector_size, 1571 uint64_t metadata_offset, 1572 VHDXImageType type) 1573 { 1574 int ret = 0; 1575 uint32_t offset = 0; 1576 void *buffer = NULL; 1577 void *entry_buffer; 1578 VHDXMetadataTableHeader *md_table; 1579 VHDXMetadataTableEntry *md_table_entry; 1580 1581 /* Metadata entries */ 1582 VHDXFileParameters *mt_file_params; 1583 VHDXVirtualDiskSize *mt_virtual_size; 1584 VHDXPage83Data *mt_page83; 1585 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1586 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1587 1588 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1589 1590 mt_file_params = entry_buffer; 1591 offset += sizeof(VHDXFileParameters); 1592 mt_virtual_size = entry_buffer + offset; 1593 offset += sizeof(VHDXVirtualDiskSize); 1594 mt_page83 = entry_buffer + offset; 1595 offset += sizeof(VHDXPage83Data); 1596 mt_log_sector_size = entry_buffer + offset; 1597 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1598 mt_phys_sector_size = entry_buffer + offset; 1599 1600 mt_file_params->block_size = cpu_to_le32(block_size); 1601 if (type == VHDX_TYPE_FIXED) { 1602 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1603 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1604 } 1605 1606 vhdx_guid_generate(&mt_page83->page_83_data); 1607 cpu_to_leguids(&mt_page83->page_83_data); 1608 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1609 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1610 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1611 1612 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1613 md_table = buffer; 1614 1615 md_table->signature = VHDX_METADATA_SIGNATURE; 1616 md_table->entry_count = 5; 1617 vhdx_metadata_header_le_export(md_table); 1618 1619 1620 /* This will reference beyond the reserved table portion */ 1621 offset = 64 * KiB; 1622 1623 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1624 1625 md_table_entry[0].item_id = file_param_guid; 1626 md_table_entry[0].offset = offset; 1627 md_table_entry[0].length = sizeof(VHDXFileParameters); 1628 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1629 offset += md_table_entry[0].length; 1630 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1631 1632 md_table_entry[1].item_id = virtual_size_guid; 1633 md_table_entry[1].offset = offset; 1634 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1635 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1636 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1637 offset += md_table_entry[1].length; 1638 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1639 1640 md_table_entry[2].item_id = page83_guid; 1641 md_table_entry[2].offset = offset; 1642 md_table_entry[2].length = sizeof(VHDXPage83Data); 1643 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1644 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1645 offset += md_table_entry[2].length; 1646 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1647 1648 md_table_entry[3].item_id = logical_sector_guid; 1649 md_table_entry[3].offset = offset; 1650 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1651 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1652 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1653 offset += md_table_entry[3].length; 1654 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1655 1656 md_table_entry[4].item_id = phys_sector_guid; 1657 md_table_entry[4].offset = offset; 1658 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1659 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1660 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1661 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1662 1663 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0); 1664 if (ret < 0) { 1665 goto exit; 1666 } 1667 1668 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer, 1669 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0); 1670 if (ret < 0) { 1671 goto exit; 1672 } 1673 1674 1675 exit: 1676 g_free(buffer); 1677 g_free(entry_buffer); 1678 return ret; 1679 } 1680 1681 /* This create the actual BAT itself. We currently only support 1682 * 'Dynamic' and 'Fixed' image types. 1683 * 1684 * Dynamic images: default state of the BAT is all zeroes. 1685 * 1686 * Fixed images: default state of the BAT is fully populated, with 1687 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1688 */ 1689 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1690 uint64_t image_size, VHDXImageType type, 1691 bool use_zero_blocks, uint64_t file_offset, 1692 uint32_t length, Error **errp) 1693 { 1694 int ret = 0; 1695 uint64_t data_file_offset; 1696 uint64_t total_sectors = 0; 1697 uint64_t sector_num = 0; 1698 uint64_t unused; 1699 int block_state; 1700 VHDXSectorInfo sinfo; 1701 1702 assert(s->bat == NULL); 1703 1704 /* this gives a data start after BAT/bitmap entries, and well 1705 * past any metadata entries (with a 4 MB buffer for future 1706 * expansion */ 1707 data_file_offset = file_offset + length + 5 * MiB; 1708 total_sectors = image_size >> s->logical_sector_size_bits; 1709 1710 if (type == VHDX_TYPE_DYNAMIC) { 1711 /* All zeroes, so we can just extend the file - the end of the BAT 1712 * is the furthest thing we have written yet */ 1713 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1714 0, errp); 1715 if (ret < 0) { 1716 goto exit; 1717 } 1718 } else if (type == VHDX_TYPE_FIXED) { 1719 ret = blk_truncate(blk, data_file_offset + image_size, false, 1720 PREALLOC_MODE_OFF, 0, errp); 1721 if (ret < 0) { 1722 goto exit; 1723 } 1724 } else { 1725 error_setg(errp, "Unsupported image type"); 1726 ret = -ENOTSUP; 1727 goto exit; 1728 } 1729 1730 if (type == VHDX_TYPE_FIXED || 1731 use_zero_blocks || 1732 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1733 /* for a fixed file, the default BAT entry is not zero */ 1734 s->bat = g_try_malloc0(length); 1735 if (length && s->bat == NULL) { 1736 error_setg(errp, "Failed to allocate memory for the BAT"); 1737 ret = -ENOMEM; 1738 goto exit; 1739 } 1740 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1741 PAYLOAD_BLOCK_NOT_PRESENT; 1742 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1743 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1744 while (sector_num < total_sectors) { 1745 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1746 sinfo.file_offset = data_file_offset + 1747 (sector_num << s->logical_sector_size_bits); 1748 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1749 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1750 block_state); 1751 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1752 sector_num += s->sectors_per_block; 1753 } 1754 ret = blk_pwrite(blk, file_offset, s->bat, length, 0); 1755 if (ret < 0) { 1756 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1757 goto exit; 1758 } 1759 } 1760 1761 1762 1763 exit: 1764 g_free(s->bat); 1765 return ret; 1766 } 1767 1768 /* Creates the region table header, and region table entries. 1769 * There are 2 supported region table entries: BAT, and Metadata/ 1770 * 1771 * As the calculations for the BAT region table are also needed 1772 * to create the BAT itself, we will also cause the BAT to be 1773 * created. 1774 */ 1775 static int vhdx_create_new_region_table(BlockBackend *blk, 1776 uint64_t image_size, 1777 uint32_t block_size, 1778 uint32_t sector_size, 1779 uint32_t log_size, 1780 bool use_zero_blocks, 1781 VHDXImageType type, 1782 uint64_t *metadata_offset, 1783 Error **errp) 1784 { 1785 int ret = 0; 1786 uint32_t offset = 0; 1787 void *buffer = NULL; 1788 uint64_t bat_file_offset; 1789 uint32_t bat_length; 1790 BDRVVHDXState *s = NULL; 1791 VHDXRegionTableHeader *region_table; 1792 VHDXRegionTableEntry *rt_bat; 1793 VHDXRegionTableEntry *rt_metadata; 1794 1795 assert(metadata_offset != NULL); 1796 1797 /* Populate enough of the BDRVVHDXState to be able to use the 1798 * pre-existing BAT calculation, translation, and update functions */ 1799 s = g_new0(BDRVVHDXState, 1); 1800 1801 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1802 (uint64_t) sector_size / (uint64_t) block_size; 1803 1804 s->sectors_per_block = block_size / sector_size; 1805 s->virtual_disk_size = image_size; 1806 s->block_size = block_size; 1807 s->logical_sector_size = sector_size; 1808 1809 vhdx_set_shift_bits(s); 1810 1811 vhdx_calc_bat_entries(s); 1812 1813 /* At this point the VHDX state is populated enough for creation */ 1814 1815 /* a single buffer is used so we can calculate the checksum over the 1816 * entire 64KB block */ 1817 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1818 region_table = buffer; 1819 offset += sizeof(VHDXRegionTableHeader); 1820 rt_bat = buffer + offset; 1821 offset += sizeof(VHDXRegionTableEntry); 1822 rt_metadata = buffer + offset; 1823 1824 region_table->signature = VHDX_REGION_SIGNATURE; 1825 region_table->entry_count = 2; /* BAT and Metadata */ 1826 1827 rt_bat->guid = bat_guid; 1828 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1829 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1830 s->bat_offset = rt_bat->file_offset; 1831 1832 rt_metadata->guid = metadata_guid; 1833 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1834 MiB); 1835 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1836 *metadata_offset = rt_metadata->file_offset; 1837 1838 bat_file_offset = rt_bat->file_offset; 1839 bat_length = rt_bat->length; 1840 1841 vhdx_region_header_le_export(region_table); 1842 vhdx_region_entry_le_export(rt_bat); 1843 vhdx_region_entry_le_export(rt_metadata); 1844 1845 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1846 offsetof(VHDXRegionTableHeader, checksum)); 1847 1848 1849 /* The region table gives us the data we need to create the BAT, 1850 * so do that now */ 1851 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1852 bat_file_offset, bat_length, errp); 1853 if (ret < 0) { 1854 goto exit; 1855 } 1856 1857 /* Now write out the region headers to disk */ 1858 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer, 1859 VHDX_HEADER_BLOCK_SIZE, 0); 1860 if (ret < 0) { 1861 error_setg_errno(errp, -ret, "Failed to write first region table"); 1862 goto exit; 1863 } 1864 1865 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer, 1866 VHDX_HEADER_BLOCK_SIZE, 0); 1867 if (ret < 0) { 1868 error_setg_errno(errp, -ret, "Failed to write second region table"); 1869 goto exit; 1870 } 1871 1872 exit: 1873 g_free(s); 1874 g_free(buffer); 1875 return ret; 1876 } 1877 1878 /* We need to create the following elements: 1879 * 1880 * .-----------------------------------------------------------------. 1881 * | (A) | (B) | (C) | (D) | (E) | 1882 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1883 * | | | | | | 1884 * .-----------------------------------------------------------------. 1885 * 0 64KB 128KB 192KB 256KB 320KB 1886 * 1887 * 1888 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1889 * | (F) | (G) | (H) | | 1890 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1891 * | | | | | 1892 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1893 * 1MB 1894 */ 1895 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts, 1896 Error **errp) 1897 { 1898 BlockdevCreateOptionsVhdx *vhdx_opts; 1899 BlockBackend *blk = NULL; 1900 BlockDriverState *bs = NULL; 1901 1902 int ret = 0; 1903 uint64_t image_size; 1904 uint32_t log_size; 1905 uint32_t block_size; 1906 uint64_t signature; 1907 uint64_t metadata_offset; 1908 bool use_zero_blocks = false; 1909 1910 gunichar2 *creator = NULL; 1911 glong creator_items; 1912 VHDXImageType image_type; 1913 1914 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1915 vhdx_opts = &opts->u.vhdx; 1916 1917 /* Validate options and set default values */ 1918 image_size = vhdx_opts->size; 1919 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1920 error_setg(errp, "Image size too large; max of 64TB"); 1921 return -EINVAL; 1922 } 1923 1924 if (!vhdx_opts->has_log_size) { 1925 log_size = DEFAULT_LOG_SIZE; 1926 } else { 1927 if (vhdx_opts->log_size > UINT32_MAX) { 1928 error_setg(errp, "Log size must be smaller than 4 GB"); 1929 return -EINVAL; 1930 } 1931 log_size = vhdx_opts->log_size; 1932 } 1933 if (log_size < MiB || (log_size % MiB) != 0) { 1934 error_setg(errp, "Log size must be a multiple of 1 MB"); 1935 return -EINVAL; 1936 } 1937 1938 if (!vhdx_opts->has_block_state_zero) { 1939 use_zero_blocks = true; 1940 } else { 1941 use_zero_blocks = vhdx_opts->block_state_zero; 1942 } 1943 1944 if (!vhdx_opts->has_subformat) { 1945 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1946 } 1947 1948 switch (vhdx_opts->subformat) { 1949 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1950 image_type = VHDX_TYPE_DYNAMIC; 1951 break; 1952 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1953 image_type = VHDX_TYPE_FIXED; 1954 break; 1955 default: 1956 g_assert_not_reached(); 1957 } 1958 1959 /* These are pretty arbitrary, and mainly designed to keep the BAT 1960 * size reasonable to load into RAM */ 1961 if (vhdx_opts->has_block_size) { 1962 block_size = vhdx_opts->block_size; 1963 } else { 1964 if (image_size > 32 * TiB) { 1965 block_size = 64 * MiB; 1966 } else if (image_size > (uint64_t) 100 * GiB) { 1967 block_size = 32 * MiB; 1968 } else if (image_size > 1 * GiB) { 1969 block_size = 16 * MiB; 1970 } else { 1971 block_size = 8 * MiB; 1972 } 1973 } 1974 1975 if (block_size < MiB || (block_size % MiB) != 0) { 1976 error_setg(errp, "Block size must be a multiple of 1 MB"); 1977 return -EINVAL; 1978 } 1979 if (!is_power_of_2(block_size)) { 1980 error_setg(errp, "Block size must be a power of two"); 1981 return -EINVAL; 1982 } 1983 if (block_size > VHDX_BLOCK_SIZE_MAX) { 1984 error_setg(errp, "Block size must not exceed %" PRId64, 1985 VHDX_BLOCK_SIZE_MAX); 1986 return -EINVAL; 1987 } 1988 1989 /* Create BlockBackend to write to the image */ 1990 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp); 1991 if (bs == NULL) { 1992 return -EIO; 1993 } 1994 1995 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 1996 errp); 1997 if (!blk) { 1998 ret = -EPERM; 1999 goto delete_and_exit; 2000 } 2001 blk_set_allow_write_beyond_eof(blk, true); 2002 2003 /* Create (A) */ 2004 2005 /* The creator field is optional, but may be useful for 2006 * debugging / diagnostics */ 2007 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2008 &creator_items, NULL); 2009 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2010 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature), 2011 0); 2012 if (ret < 0) { 2013 error_setg_errno(errp, -ret, "Failed to write file signature"); 2014 goto delete_and_exit; 2015 } 2016 if (creator) { 2017 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2018 creator, creator_items * sizeof(gunichar2), 0); 2019 if (ret < 0) { 2020 error_setg_errno(errp, -ret, "Failed to write creator field"); 2021 goto delete_and_exit; 2022 } 2023 } 2024 2025 2026 /* Creates (B),(C) */ 2027 ret = vhdx_create_new_headers(blk, image_size, log_size); 2028 if (ret < 0) { 2029 error_setg_errno(errp, -ret, "Failed to write image headers"); 2030 goto delete_and_exit; 2031 } 2032 2033 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2034 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2035 log_size, use_zero_blocks, image_type, 2036 &metadata_offset, errp); 2037 if (ret < 0) { 2038 goto delete_and_exit; 2039 } 2040 2041 /* Creates (H) */ 2042 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2043 metadata_offset, image_type); 2044 if (ret < 0) { 2045 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2046 goto delete_and_exit; 2047 } 2048 2049 ret = 0; 2050 delete_and_exit: 2051 blk_unref(blk); 2052 bdrv_unref(bs); 2053 g_free(creator); 2054 return ret; 2055 } 2056 2057 static int coroutine_fn vhdx_co_create_opts(BlockDriver *drv, 2058 const char *filename, 2059 QemuOpts *opts, 2060 Error **errp) 2061 { 2062 BlockdevCreateOptions *create_options = NULL; 2063 QDict *qdict; 2064 Visitor *v; 2065 BlockDriverState *bs = NULL; 2066 int ret; 2067 2068 static const QDictRenames opt_renames[] = { 2069 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" }, 2070 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" }, 2071 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" }, 2072 { NULL, NULL }, 2073 }; 2074 2075 /* Parse options and convert legacy syntax */ 2076 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true); 2077 2078 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 2079 ret = -EINVAL; 2080 goto fail; 2081 } 2082 2083 /* Create and open the file (protocol layer) */ 2084 ret = bdrv_create_file(filename, opts, errp); 2085 if (ret < 0) { 2086 goto fail; 2087 } 2088 2089 bs = bdrv_open(filename, NULL, NULL, 2090 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 2091 if (bs == NULL) { 2092 ret = -EIO; 2093 goto fail; 2094 } 2095 2096 /* Now get the QAPI type BlockdevCreateOptions */ 2097 qdict_put_str(qdict, "driver", "vhdx"); 2098 qdict_put_str(qdict, "file", bs->node_name); 2099 2100 v = qobject_input_visitor_new_flat_confused(qdict, errp); 2101 if (!v) { 2102 ret = -EINVAL; 2103 goto fail; 2104 } 2105 2106 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 2107 visit_free(v); 2108 if (!create_options) { 2109 ret = -EINVAL; 2110 goto fail; 2111 } 2112 2113 /* Silently round up sizes: 2114 * The image size is rounded to 512 bytes. Make the block and log size 2115 * close to what was specified, but must be at least 1MB, and a multiple of 2116 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0 2117 * means auto, which is represented by a missing key in QAPI. */ 2118 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX); 2119 create_options->u.vhdx.size = 2120 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE); 2121 2122 if (create_options->u.vhdx.has_log_size) { 2123 create_options->u.vhdx.log_size = 2124 ROUND_UP(create_options->u.vhdx.log_size, MiB); 2125 } 2126 if (create_options->u.vhdx.has_block_size) { 2127 create_options->u.vhdx.block_size = 2128 ROUND_UP(create_options->u.vhdx.block_size, MiB); 2129 2130 if (create_options->u.vhdx.block_size == 0) { 2131 create_options->u.vhdx.has_block_size = false; 2132 } 2133 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) { 2134 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX; 2135 } 2136 } 2137 2138 /* Create the vhdx image (format layer) */ 2139 ret = vhdx_co_create(create_options, errp); 2140 2141 fail: 2142 qobject_unref(qdict); 2143 bdrv_unref(bs); 2144 qapi_free_BlockdevCreateOptions(create_options); 2145 return ret; 2146 } 2147 2148 /* If opened r/w, the VHDX driver will automatically replay the log, 2149 * if one is present, inside the vhdx_open() call. 2150 * 2151 * If qemu-img check -r all is called, the image is automatically opened 2152 * r/w and any log has already been replayed, so there is nothing (currently) 2153 * for us to do here 2154 */ 2155 static int coroutine_fn vhdx_co_check(BlockDriverState *bs, 2156 BdrvCheckResult *result, 2157 BdrvCheckMode fix) 2158 { 2159 BDRVVHDXState *s = bs->opaque; 2160 2161 if (s->log_replayed_on_open) { 2162 result->corruptions_fixed++; 2163 } 2164 2165 vhdx_check_bat_entries(bs, &result->corruptions); 2166 2167 return 0; 2168 } 2169 2170 static int vhdx_has_zero_init(BlockDriverState *bs) 2171 { 2172 BDRVVHDXState *s = bs->opaque; 2173 int state; 2174 2175 /* 2176 * Check the subformat: Fixed images have all BAT entries present, 2177 * dynamic images have none (right after creation). It is 2178 * therefore enough to check the first BAT entry. 2179 */ 2180 if (!s->bat_entries) { 2181 return 1; 2182 } 2183 2184 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK; 2185 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) { 2186 /* Fixed subformat */ 2187 return bdrv_has_zero_init(bs->file->bs); 2188 } 2189 2190 /* Dynamic subformat */ 2191 return 1; 2192 } 2193 2194 static QemuOptsList vhdx_create_opts = { 2195 .name = "vhdx-create-opts", 2196 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 2197 .desc = { 2198 { 2199 .name = BLOCK_OPT_SIZE, 2200 .type = QEMU_OPT_SIZE, 2201 .help = "Virtual disk size; max of 64TB." 2202 }, 2203 { 2204 .name = VHDX_BLOCK_OPT_LOG_SIZE, 2205 .type = QEMU_OPT_SIZE, 2206 .def_value_str = stringify(DEFAULT_LOG_SIZE), 2207 .help = "Log size; min 1MB." 2208 }, 2209 { 2210 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 2211 .type = QEMU_OPT_SIZE, 2212 .def_value_str = stringify(0), 2213 .help = "Block Size; min 1MB, max 256MB. " 2214 "0 means auto-calculate based on image size." 2215 }, 2216 { 2217 .name = BLOCK_OPT_SUBFMT, 2218 .type = QEMU_OPT_STRING, 2219 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. " 2220 "Default is 'dynamic'." 2221 }, 2222 { 2223 .name = VHDX_BLOCK_OPT_ZERO, 2224 .type = QEMU_OPT_BOOL, 2225 .help = "Force use of payload blocks of type 'ZERO'. " 2226 "Non-standard, but default. Do not set to 'off' when " 2227 "using 'qemu-img convert' with subformat=dynamic." 2228 }, 2229 { NULL } 2230 } 2231 }; 2232 2233 static BlockDriver bdrv_vhdx = { 2234 .format_name = "vhdx", 2235 .instance_size = sizeof(BDRVVHDXState), 2236 .bdrv_probe = vhdx_probe, 2237 .bdrv_open = vhdx_open, 2238 .bdrv_close = vhdx_close, 2239 .bdrv_reopen_prepare = vhdx_reopen_prepare, 2240 .bdrv_child_perm = bdrv_default_perms, 2241 .bdrv_co_readv = vhdx_co_readv, 2242 .bdrv_co_writev = vhdx_co_writev, 2243 .bdrv_co_create = vhdx_co_create, 2244 .bdrv_co_create_opts = vhdx_co_create_opts, 2245 .bdrv_get_info = vhdx_get_info, 2246 .bdrv_co_check = vhdx_co_check, 2247 .bdrv_has_zero_init = vhdx_has_zero_init, 2248 2249 .is_format = true, 2250 .create_opts = &vhdx_create_opts, 2251 }; 2252 2253 static void bdrv_vhdx_init(void) 2254 { 2255 bdrv_register(&bdrv_vhdx); 2256 } 2257 2258 block_init(bdrv_vhdx_init); 2259