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 "qemu/memalign.h" 29 #include "vhdx.h" 30 #include "migration/blocker.h" 31 #include "qemu/uuid.h" 32 #include "qapi/qmp/qdict.h" 33 #include "qapi/qobject-input-visitor.h" 34 #include "qapi/qapi-visit-block-core.h" 35 36 /* Options for VHDX creation */ 37 38 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size" 39 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size" 40 #define VHDX_BLOCK_OPT_ZERO "block_state_zero" 41 42 typedef enum VHDXImageType { 43 VHDX_TYPE_DYNAMIC = 0, 44 VHDX_TYPE_FIXED, 45 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */ 46 } VHDXImageType; 47 48 static QemuOptsList vhdx_create_opts; 49 50 /* Several metadata and region table data entries are identified by 51 * guids in a MS-specific GUID format. */ 52 53 54 /* ------- Known Region Table GUIDs ---------------------- */ 55 static const MSGUID bat_guid = { .data1 = 0x2dc27766, 56 .data2 = 0xf623, 57 .data3 = 0x4200, 58 .data4 = { 0x9d, 0x64, 0x11, 0x5e, 59 0x9b, 0xfd, 0x4a, 0x08} }; 60 61 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, 62 .data2 = 0x4790, 63 .data3 = 0x4b9a, 64 .data4 = { 0xb8, 0xfe, 0x57, 0x5f, 65 0x05, 0x0f, 0x88, 0x6e} }; 66 67 68 69 /* ------- Known Metadata Entry GUIDs ---------------------- */ 70 static const MSGUID file_param_guid = { .data1 = 0xcaa16737, 71 .data2 = 0xfa36, 72 .data3 = 0x4d43, 73 .data4 = { 0xb3, 0xb6, 0x33, 0xf0, 74 0xaa, 0x44, 0xe7, 0x6b} }; 75 76 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, 77 .data2 = 0xcd1b, 78 .data3 = 0x4876, 79 .data4 = { 0xb2, 0x11, 0x5d, 0xbe, 80 0xd8, 0x3b, 0xf4, 0xb8} }; 81 82 static const MSGUID page83_guid = { .data1 = 0xbeca12ab, 83 .data2 = 0xb2e6, 84 .data3 = 0x4523, 85 .data4 = { 0x93, 0xef, 0xc3, 0x09, 86 0xe0, 0x00, 0xc7, 0x46} }; 87 88 89 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, 90 .data2 = 0x445d, 91 .data3 = 0x4471, 92 .data4 = { 0x9c, 0xc9, 0xe9, 0x88, 93 0x52, 0x51, 0xc5, 0x56} }; 94 95 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, 96 .data2 = 0xb30b, 97 .data3 = 0x454d, 98 .data4 = { 0xab, 0xf7, 0xd3, 99 0xd8, 0x48, 0x34, 100 0xab, 0x0c} }; 101 102 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, 103 .data2 = 0xa96f, 104 .data3 = 0x4709, 105 .data4 = { 0xba, 0x47, 0xf2, 106 0x33, 0xa8, 0xfa, 107 0xab, 0x5f} }; 108 109 /* Each parent type must have a valid GUID; this is for parent images 110 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would 111 * need to make up our own QCOW2 GUID type */ 112 static const MSGUID parent_vhdx_guid __attribute__((unused)) 113 = { .data1 = 0xb04aefb7, 114 .data2 = 0xd19e, 115 .data3 = 0x4a81, 116 .data4 = { 0xb7, 0x89, 0x25, 0xb8, 117 0xe9, 0x44, 0x59, 0x13} }; 118 119 120 #define META_FILE_PARAMETER_PRESENT 0x01 121 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 122 #define META_PAGE_83_PRESENT 0x04 123 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 124 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 125 #define META_PARENT_LOCATOR_PRESENT 0x20 126 127 #define META_ALL_PRESENT \ 128 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ 129 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ 130 META_PHYS_SECTOR_SIZE_PRESENT) 131 132 133 typedef struct VHDXSectorInfo { 134 uint32_t bat_idx; /* BAT entry index */ 135 uint32_t sectors_avail; /* sectors available in payload block */ 136 uint32_t bytes_left; /* bytes left in the block after data to r/w */ 137 uint32_t bytes_avail; /* bytes available in payload block */ 138 uint64_t file_offset; /* absolute offset in bytes, in file */ 139 uint64_t block_offset; /* block offset, in bytes */ 140 } VHDXSectorInfo; 141 142 /* Calculates new checksum. 143 * 144 * Zero is substituted during crc calculation for the original crc field 145 * crc_offset: byte offset in buf of the buffer crc 146 * buf: buffer pointer 147 * size: size of buffer (must be > crc_offset+4) 148 * 149 * Note: The buffer should have all multi-byte data in little-endian format, 150 * and the resulting checksum is in little endian format. 151 */ 152 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) 153 { 154 uint32_t crc; 155 156 assert(buf != NULL); 157 assert(size > (crc_offset + sizeof(crc))); 158 159 memset(buf + crc_offset, 0, sizeof(crc)); 160 crc = crc32c(0xffffffff, buf, size); 161 crc = cpu_to_le32(crc); 162 memcpy(buf + crc_offset, &crc, sizeof(crc)); 163 164 return crc; 165 } 166 167 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, 168 int crc_offset) 169 { 170 uint32_t crc_new; 171 uint32_t crc_orig; 172 assert(buf != NULL); 173 174 if (crc_offset > 0) { 175 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 176 memset(buf + crc_offset, 0, sizeof(crc_orig)); 177 } 178 179 crc_new = crc32c(crc, buf, size); 180 if (crc_offset > 0) { 181 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); 182 } 183 184 return crc_new; 185 } 186 187 /* Validates the checksum of the buffer, with an in-place CRC. 188 * 189 * Zero is substituted during crc calculation for the original crc field, 190 * and the crc field is restored afterwards. But the buffer will be modified 191 * during the calculation, so this may not be not suitable for multi-threaded 192 * use. 193 * 194 * crc_offset: byte offset in buf of the buffer crc 195 * buf: buffer pointer 196 * size: size of buffer (must be > crc_offset+4) 197 * 198 * returns true if checksum is valid, false otherwise 199 */ 200 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) 201 { 202 uint32_t crc_orig; 203 uint32_t crc; 204 205 assert(buf != NULL); 206 assert(size > (crc_offset + 4)); 207 208 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 209 crc_orig = le32_to_cpu(crc_orig); 210 211 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); 212 213 return crc == crc_orig; 214 } 215 216 217 /* 218 * This generates a UUID that is compliant with the MS GUIDs used 219 * in the VHDX spec (and elsewhere). 220 */ 221 void vhdx_guid_generate(MSGUID *guid) 222 { 223 QemuUUID uuid; 224 assert(guid != NULL); 225 226 qemu_uuid_generate(&uuid); 227 memcpy(guid, &uuid, sizeof(MSGUID)); 228 } 229 230 /* Check for region overlaps inside the VHDX image */ 231 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) 232 { 233 int ret = 0; 234 uint64_t end; 235 VHDXRegionEntry *r; 236 237 end = start + length; 238 QLIST_FOREACH(r, &s->regions, entries) { 239 if (!((start >= r->end) || (end <= r->start))) { 240 error_report("VHDX region %" PRIu64 "-%" PRIu64 " overlaps with " 241 "region %" PRIu64 "-%." PRIu64, start, end, r->start, 242 r->end); 243 ret = -EINVAL; 244 goto exit; 245 } 246 } 247 248 exit: 249 return ret; 250 } 251 252 /* Register a region for future checks */ 253 static void vhdx_region_register(BDRVVHDXState *s, 254 uint64_t start, uint64_t length) 255 { 256 VHDXRegionEntry *r; 257 258 r = g_malloc0(sizeof(*r)); 259 260 r->start = start; 261 r->end = start + length; 262 263 QLIST_INSERT_HEAD(&s->regions, r, entries); 264 } 265 266 /* Free all registered regions */ 267 static void vhdx_region_unregister_all(BDRVVHDXState *s) 268 { 269 VHDXRegionEntry *r, *r_next; 270 271 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { 272 QLIST_REMOVE(r, entries); 273 g_free(r); 274 } 275 } 276 277 static void vhdx_set_shift_bits(BDRVVHDXState *s) 278 { 279 s->logical_sector_size_bits = ctz32(s->logical_sector_size); 280 s->sectors_per_block_bits = ctz32(s->sectors_per_block); 281 s->chunk_ratio_bits = ctz64(s->chunk_ratio); 282 s->block_size_bits = ctz32(s->block_size); 283 } 284 285 /* 286 * Per the MS VHDX Specification, for every VHDX file: 287 * - The header section is fixed size - 1 MB 288 * - The header section is always the first "object" 289 * - The first 64KB of the header is the File Identifier 290 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") 291 * - The following 512 bytes constitute a UTF-16 string identifiying the 292 * software that created the file, and is optional and diagnostic only. 293 * 294 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" 295 */ 296 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) 297 { 298 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { 299 return 100; 300 } 301 return 0; 302 } 303 304 /* 305 * Writes the header to the specified offset. 306 * 307 * This will optionally read in buffer data from disk (otherwise zero-fill), 308 * and then update the header checksum. Header is converted to proper 309 * endianness before being written to the specified file offset 310 */ 311 static int vhdx_write_header(BdrvChild *file, VHDXHeader *hdr, 312 uint64_t offset, bool read) 313 { 314 BlockDriverState *bs_file = file->bs; 315 uint8_t *buffer = NULL; 316 int ret; 317 VHDXHeader *header_le; 318 319 assert(bs_file != NULL); 320 assert(hdr != NULL); 321 322 /* the header checksum is not over just the packed size of VHDXHeader, 323 * but rather over the entire 'reserved' range for the header, which is 324 * 4KB (VHDX_HEADER_SIZE). */ 325 326 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); 327 if (read) { 328 /* if true, we can't assume the extra reserved bytes are 0 */ 329 ret = bdrv_pread(file, offset, VHDX_HEADER_SIZE, buffer, 0); 330 if (ret < 0) { 331 goto exit; 332 } 333 } else { 334 memset(buffer, 0, VHDX_HEADER_SIZE); 335 } 336 337 /* overwrite the actual VHDXHeader portion */ 338 header_le = (VHDXHeader *)buffer; 339 memcpy(header_le, hdr, sizeof(VHDXHeader)); 340 vhdx_header_le_export(hdr, header_le); 341 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, 342 offsetof(VHDXHeader, checksum)); 343 ret = bdrv_pwrite_sync(file, offset, sizeof(VHDXHeader), header_le, 0); 344 345 exit: 346 qemu_vfree(buffer); 347 return ret; 348 } 349 350 /* Update the VHDX headers 351 * 352 * This follows the VHDX spec procedures for header updates. 353 * 354 * - non-current header is updated with largest sequence number 355 */ 356 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 357 bool generate_data_write_guid, MSGUID *log_guid) 358 { 359 int ret = 0; 360 int hdr_idx = 0; 361 uint64_t header_offset = VHDX_HEADER1_OFFSET; 362 363 VHDXHeader *active_header; 364 VHDXHeader *inactive_header; 365 366 /* operate on the non-current header */ 367 if (s->curr_header == 0) { 368 hdr_idx = 1; 369 header_offset = VHDX_HEADER2_OFFSET; 370 } 371 372 active_header = s->headers[s->curr_header]; 373 inactive_header = s->headers[hdr_idx]; 374 375 inactive_header->sequence_number = active_header->sequence_number + 1; 376 377 /* a new file guid must be generated before any file write, including 378 * headers */ 379 inactive_header->file_write_guid = s->session_guid; 380 381 /* a new data guid only needs to be generated before any guest-visible 382 * writes (i.e. something observable via virtual disk read) */ 383 if (generate_data_write_guid) { 384 vhdx_guid_generate(&inactive_header->data_write_guid); 385 } 386 387 /* update the log guid if present */ 388 if (log_guid) { 389 inactive_header->log_guid = *log_guid; 390 } 391 392 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 393 if (ret < 0) { 394 goto exit; 395 } 396 s->curr_header = hdr_idx; 397 398 exit: 399 return ret; 400 } 401 402 /* 403 * The VHDX spec calls for header updates to be performed twice, so that both 404 * the current and non-current header have valid info 405 */ 406 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 407 bool generate_data_write_guid, MSGUID *log_guid) 408 { 409 int ret; 410 411 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 412 if (ret < 0) { 413 return ret; 414 } 415 return vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 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, VHDX_HEADER_SIZE, buffer, 444 0); 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, VHDX_HEADER_SIZE, buffer, 461 0); 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, 535 VHDX_HEADER_BLOCK_SIZE, buffer, 0); 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, 648 VHDX_METADATA_TABLE_MAX_SIZE, buffer, 0); 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 sizeof(s->params), 754 &s->params, 755 0); 756 757 if (ret < 0) { 758 goto exit; 759 } 760 761 s->params.block_size = le32_to_cpu(s->params.block_size); 762 s->params.data_bits = le32_to_cpu(s->params.data_bits); 763 764 765 /* We now have the file parameters, so we can tell if this is a 766 * differencing file (i.e.. has_parent), is dynamic or fixed 767 * sized (leave_blocks_allocated), and the block size */ 768 769 /* The parent locator required iff the file parameters has_parent set */ 770 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 771 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 772 /* TODO: parse parent locator fields */ 773 ret = -ENOTSUP; /* temp, until differencing files are supported */ 774 goto exit; 775 } else { 776 /* if has_parent is set, but there is not parent locator present, 777 * then that is an invalid combination */ 778 ret = -EINVAL; 779 goto exit; 780 } 781 } 782 783 /* determine virtual disk size, logical sector size, 784 * and phys sector size */ 785 786 ret = bdrv_pread(bs->file, 787 s->metadata_entries.virtual_disk_size_entry.offset 788 + s->metadata_rt.file_offset, 789 sizeof(uint64_t), 790 &s->virtual_disk_size, 791 0); 792 if (ret < 0) { 793 goto exit; 794 } 795 ret = bdrv_pread(bs->file, 796 s->metadata_entries.logical_sector_size_entry.offset 797 + s->metadata_rt.file_offset, 798 sizeof(uint32_t), 799 &s->logical_sector_size, 800 0); 801 if (ret < 0) { 802 goto exit; 803 } 804 ret = bdrv_pread(bs->file, 805 s->metadata_entries.phys_sector_size_entry.offset 806 + s->metadata_rt.file_offset, 807 sizeof(uint32_t), 808 &s->physical_sector_size, 809 0); 810 if (ret < 0) { 811 goto exit; 812 } 813 814 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size); 815 s->logical_sector_size = le32_to_cpu(s->logical_sector_size); 816 s->physical_sector_size = le32_to_cpu(s->physical_sector_size); 817 818 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 819 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 820 ret = -EINVAL; 821 goto exit; 822 } 823 824 /* Currently we only support 512 */ 825 if (s->logical_sector_size != 512) { 826 ret = -ENOTSUP; 827 goto exit; 828 } 829 830 /* Both block_size and sector_size are guaranteed powers of 2, below. 831 Due to range checks above, s->sectors_per_block can never be < 256 */ 832 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 833 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 834 (uint64_t)s->logical_sector_size / 835 (uint64_t)s->params.block_size; 836 837 /* These values are ones we will want to use for division / multiplication 838 * later on, and they are all guaranteed (per the spec) to be powers of 2, 839 * so we can take advantage of that for shift operations during 840 * reads/writes */ 841 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 842 ret = -EINVAL; 843 goto exit; 844 } 845 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 846 ret = -EINVAL; 847 goto exit; 848 } 849 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 850 ret = -EINVAL; 851 goto exit; 852 } 853 s->block_size = s->params.block_size; 854 if (s->block_size & (s->block_size - 1)) { 855 ret = -EINVAL; 856 goto exit; 857 } 858 859 vhdx_set_shift_bits(s); 860 861 ret = 0; 862 863 exit: 864 qemu_vfree(buffer); 865 return ret; 866 } 867 868 /* 869 * Calculate the number of BAT entries, including sector 870 * bitmap entries. 871 */ 872 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 873 { 874 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 875 876 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 877 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 878 879 if (s->parent_entries) { 880 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 881 } else { 882 s->bat_entries = data_blocks_cnt + 883 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 884 } 885 886 } 887 888 static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) 889 { 890 BDRVVHDXState *s = bs->opaque; 891 int64_t image_file_size = bdrv_getlength(bs->file->bs); 892 uint64_t payblocks = s->chunk_ratio; 893 uint64_t i; 894 int ret = 0; 895 896 if (image_file_size < 0) { 897 error_report("Could not determinate VHDX image file size."); 898 return image_file_size; 899 } 900 901 for (i = 0; i < s->bat_entries; i++) { 902 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 903 PAYLOAD_BLOCK_FULLY_PRESENT) { 904 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; 905 /* 906 * Allow that the last block exists only partially. The VHDX spec 907 * states that the image file can only grow in blocksize increments, 908 * but QEMU created images with partial last blocks in the past. 909 */ 910 uint32_t block_length = MIN(s->block_size, 911 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); 912 /* 913 * Check for BAT entry overflow. 914 */ 915 if (offset > INT64_MAX - s->block_size) { 916 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); 917 ret = -EINVAL; 918 if (!errcnt) { 919 break; 920 } 921 (*errcnt)++; 922 } 923 /* 924 * Check if fully allocated BAT entries do not reside after 925 * end of the image file. 926 */ 927 if (offset >= image_file_size) { 928 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 929 " points after end of file (%" PRIi64 "). Image" 930 " has probably been truncated.", 931 i, offset, image_file_size); 932 ret = -EINVAL; 933 if (!errcnt) { 934 break; 935 } 936 (*errcnt)++; 937 } else if (offset + block_length > image_file_size) { 938 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 939 " points after end of file (%" PRIi64 "). Image" 940 " has probably been truncated.", 941 i, offset + block_length - 1, image_file_size); 942 ret = -EINVAL; 943 if (!errcnt) { 944 break; 945 } 946 (*errcnt)++; 947 } 948 949 /* 950 * verify populated BAT field file offsets against 951 * region table and log entries 952 */ 953 if (payblocks--) { 954 /* payload bat entries */ 955 int ret2; 956 ret2 = vhdx_region_check(s, offset, s->block_size); 957 if (ret2 < 0) { 958 ret = -EINVAL; 959 if (!errcnt) { 960 break; 961 } 962 (*errcnt)++; 963 } 964 } else { 965 payblocks = s->chunk_ratio; 966 /* 967 * Once differencing files are supported, verify sector bitmap 968 * blocks here 969 */ 970 } 971 } 972 } 973 974 return ret; 975 } 976 977 static void vhdx_close(BlockDriverState *bs) 978 { 979 BDRVVHDXState *s = bs->opaque; 980 qemu_vfree(s->headers[0]); 981 s->headers[0] = NULL; 982 qemu_vfree(s->headers[1]); 983 s->headers[1] = NULL; 984 qemu_vfree(s->bat); 985 s->bat = NULL; 986 qemu_vfree(s->parent_entries); 987 s->parent_entries = NULL; 988 migrate_del_blocker(s->migration_blocker); 989 error_free(s->migration_blocker); 990 qemu_vfree(s->log.hdr); 991 s->log.hdr = NULL; 992 vhdx_region_unregister_all(s); 993 } 994 995 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 996 Error **errp) 997 { 998 BDRVVHDXState *s = bs->opaque; 999 int ret = 0; 1000 uint32_t i; 1001 uint64_t signature; 1002 Error *local_err = NULL; 1003 1004 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 1005 BDRV_CHILD_IMAGE, false, errp); 1006 if (!bs->file) { 1007 return -EINVAL; 1008 } 1009 1010 s->bat = NULL; 1011 s->first_visible_write = true; 1012 1013 qemu_co_mutex_init(&s->lock); 1014 QLIST_INIT(&s->regions); 1015 1016 /* validate the file signature */ 1017 ret = bdrv_pread(bs->file, 0, sizeof(uint64_t), &signature, 0); 1018 if (ret < 0) { 1019 goto fail; 1020 } 1021 if (memcmp(&signature, "vhdxfile", 8)) { 1022 ret = -EINVAL; 1023 goto fail; 1024 } 1025 1026 /* This is used for any header updates, for the file_write_guid. 1027 * The spec dictates that a new value should be used for the first 1028 * header update */ 1029 vhdx_guid_generate(&s->session_guid); 1030 1031 vhdx_parse_header(bs, s, &local_err); 1032 if (local_err != NULL) { 1033 error_propagate(errp, local_err); 1034 ret = -EINVAL; 1035 goto fail; 1036 } 1037 1038 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1039 if (ret < 0) { 1040 goto fail; 1041 } 1042 1043 ret = vhdx_open_region_tables(bs, s); 1044 if (ret < 0) { 1045 goto fail; 1046 } 1047 1048 ret = vhdx_parse_metadata(bs, s); 1049 if (ret < 0) { 1050 goto fail; 1051 } 1052 1053 s->block_size = s->params.block_size; 1054 1055 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1056 * logical_sector_size */ 1057 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1058 1059 vhdx_calc_bat_entries(s); 1060 1061 s->bat_offset = s->bat_rt.file_offset; 1062 1063 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1064 /* BAT allocation is not large enough for all entries */ 1065 ret = -EINVAL; 1066 goto fail; 1067 } 1068 1069 /* s->bat is freed in vhdx_close() */ 1070 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1071 if (s->bat == NULL) { 1072 ret = -ENOMEM; 1073 goto fail; 1074 } 1075 1076 ret = bdrv_pread(bs->file, s->bat_offset, s->bat_rt.length, s->bat, 0); 1077 if (ret < 0) { 1078 goto fail; 1079 } 1080 1081 /* endian convert populated BAT field entires */ 1082 for (i = 0; i < s->bat_entries; i++) { 1083 s->bat[i] = le64_to_cpu(s->bat[i]); 1084 } 1085 1086 if (!(flags & BDRV_O_CHECK)) { 1087 ret = vhdx_check_bat_entries(bs, NULL); 1088 if (ret < 0) { 1089 goto fail; 1090 } 1091 } 1092 1093 /* Disable migration when VHDX images are used */ 1094 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1095 "does not support live migration", 1096 bdrv_get_device_or_node_name(bs)); 1097 ret = migrate_add_blocker(s->migration_blocker, errp); 1098 if (ret < 0) { 1099 error_free(s->migration_blocker); 1100 goto fail; 1101 } 1102 1103 /* TODO: differencing files */ 1104 1105 return 0; 1106 fail: 1107 vhdx_close(bs); 1108 return ret; 1109 } 1110 1111 static int vhdx_reopen_prepare(BDRVReopenState *state, 1112 BlockReopenQueue *queue, Error **errp) 1113 { 1114 return 0; 1115 } 1116 1117 1118 /* 1119 * Perform sector to block offset translations, to get various 1120 * sector and file offsets into the image. See VHDXSectorInfo 1121 */ 1122 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1123 int nb_sectors, VHDXSectorInfo *sinfo) 1124 { 1125 uint32_t block_offset; 1126 1127 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1128 /* effectively a modulo - this gives us the offset into the block 1129 * (in sector sizes) for our sector number */ 1130 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1131 /* the chunk ratio gives us the interleaving of the sector 1132 * bitmaps, so we need to advance our page block index by the 1133 * sector bitmaps entry number */ 1134 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1135 1136 /* the number of sectors we can read/write in this cycle */ 1137 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1138 1139 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1140 1141 if (sinfo->sectors_avail > nb_sectors) { 1142 sinfo->sectors_avail = nb_sectors; 1143 } 1144 1145 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1146 1147 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1148 1149 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1150 1151 /* The file offset must be past the header section, so must be > 0 */ 1152 if (sinfo->file_offset == 0) { 1153 return; 1154 } 1155 1156 /* block offset is the offset in vhdx logical sectors, in 1157 * the payload data block. Convert that to a byte offset 1158 * in the block, and add in the payload data block offset 1159 * in the file, in bytes, to get the final read address */ 1160 1161 sinfo->file_offset += sinfo->block_offset; 1162 } 1163 1164 1165 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1166 { 1167 BDRVVHDXState *s = bs->opaque; 1168 1169 bdi->cluster_size = s->block_size; 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 * If @need_zero is set on entry but not cleared on return, then truncation 1247 * could not guarantee that the new portion reads as zero, and the caller 1248 * will take care of it instead. 1249 * 1250 * Returns the file offset start of the new payload block 1251 */ 1252 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1253 uint64_t *new_offset, bool *need_zero) 1254 { 1255 int64_t current_len; 1256 1257 current_len = bdrv_getlength(bs->file->bs); 1258 if (current_len < 0) { 1259 return current_len; 1260 } 1261 1262 *new_offset = current_len; 1263 1264 /* per the spec, the address for a block is in units of 1MB */ 1265 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1266 if (*new_offset > INT64_MAX) { 1267 return -EINVAL; 1268 } 1269 1270 if (*need_zero) { 1271 int ret; 1272 1273 ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1274 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL); 1275 if (ret != -ENOTSUP) { 1276 *need_zero = false; 1277 return ret; 1278 } 1279 } 1280 1281 return bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1282 PREALLOC_MODE_OFF, 0, NULL); 1283 } 1284 1285 /* 1286 * Update the BAT table entry with the new file offset, and the new entry 1287 * state */ 1288 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1289 VHDXSectorInfo *sinfo, 1290 uint64_t *bat_entry_le, 1291 uint64_t *bat_offset, int state) 1292 { 1293 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1294 * 1MB, and 3 bits for the block state. */ 1295 if ((state == PAYLOAD_BLOCK_ZERO) || 1296 (state == PAYLOAD_BLOCK_UNDEFINED) || 1297 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1298 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1299 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1300 FileOffsetMB field is denoted as 1301 'reserved' in the v1.0 spec. If it is 1302 non-zero, MS Hyper-V will fail to read 1303 the disk image */ 1304 } else { 1305 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1306 } 1307 1308 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1309 1310 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1311 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1312 1313 } 1314 1315 /* Per the spec, on the first write of guest-visible data to the file the 1316 * data write guid must be updated in the header */ 1317 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1318 { 1319 int ret = 0; 1320 if (s->first_visible_write) { 1321 s->first_visible_write = false; 1322 ret = vhdx_update_headers(bs, s, true, NULL); 1323 } 1324 return ret; 1325 } 1326 1327 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1328 int nb_sectors, QEMUIOVector *qiov, 1329 int flags) 1330 { 1331 int ret = -ENOTSUP; 1332 BDRVVHDXState *s = bs->opaque; 1333 VHDXSectorInfo sinfo; 1334 uint64_t bytes_done = 0; 1335 uint64_t bat_entry = 0; 1336 uint64_t bat_entry_offset = 0; 1337 QEMUIOVector hd_qiov; 1338 struct iovec iov1 = { 0 }; 1339 struct iovec iov2 = { 0 }; 1340 int sectors_to_write; 1341 int bat_state; 1342 uint64_t bat_prior_offset = 0; 1343 bool bat_update = false; 1344 1345 assert(!flags); 1346 qemu_iovec_init(&hd_qiov, qiov->niov); 1347 1348 qemu_co_mutex_lock(&s->lock); 1349 1350 ret = vhdx_user_visible_write(bs, s); 1351 if (ret < 0) { 1352 goto exit; 1353 } 1354 1355 while (nb_sectors > 0) { 1356 bool use_zero_buffers = false; 1357 bat_update = false; 1358 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1359 /* not supported yet */ 1360 ret = -ENOTSUP; 1361 goto exit; 1362 } else { 1363 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1364 sectors_to_write = sinfo.sectors_avail; 1365 1366 qemu_iovec_reset(&hd_qiov); 1367 /* check the payload block state */ 1368 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1369 switch (bat_state) { 1370 case PAYLOAD_BLOCK_ZERO: 1371 /* in this case, we need to preserve zero writes for 1372 * data that is not part of this write, so we must pad 1373 * the rest of the buffer to zeroes */ 1374 use_zero_buffers = true; 1375 /* fall through */ 1376 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1377 case PAYLOAD_BLOCK_UNMAPPED: 1378 case PAYLOAD_BLOCK_UNMAPPED_v095: 1379 case PAYLOAD_BLOCK_UNDEFINED: 1380 bat_prior_offset = sinfo.file_offset; 1381 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset, 1382 &use_zero_buffers); 1383 if (ret < 0) { 1384 goto exit; 1385 } 1386 /* 1387 * once we support differencing files, this may also be 1388 * partially present 1389 */ 1390 /* update block state to the newly specified state */ 1391 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1392 &bat_entry_offset, 1393 PAYLOAD_BLOCK_FULLY_PRESENT); 1394 bat_update = true; 1395 /* 1396 * Since we just allocated a block, file_offset is the 1397 * beginning of the payload block. It needs to be the 1398 * write address, which includes the offset into the 1399 * block, unless the entire block needs to read as 1400 * zeroes but truncation was not able to provide them, 1401 * in which case we need to fill in the rest. 1402 */ 1403 if (!use_zero_buffers) { 1404 sinfo.file_offset += sinfo.block_offset; 1405 } else { 1406 /* zero fill the front, if any */ 1407 if (sinfo.block_offset) { 1408 iov1.iov_len = sinfo.block_offset; 1409 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1410 memset(iov1.iov_base, 0, iov1.iov_len); 1411 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1412 iov1.iov_len); 1413 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1414 } 1415 1416 /* our actual data */ 1417 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1418 sinfo.bytes_avail); 1419 1420 /* zero fill the back, if any */ 1421 if ((sinfo.bytes_avail - sinfo.block_offset) < 1422 s->block_size) { 1423 iov2.iov_len = s->block_size - 1424 (sinfo.bytes_avail + sinfo.block_offset); 1425 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1426 memset(iov2.iov_base, 0, iov2.iov_len); 1427 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1428 iov2.iov_len); 1429 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1430 } 1431 } 1432 1433 /* fall through */ 1434 case PAYLOAD_BLOCK_FULLY_PRESENT: 1435 /* if the file offset address is in the header zone, 1436 * there is a problem */ 1437 if (sinfo.file_offset < (1 * MiB)) { 1438 ret = -EFAULT; 1439 goto error_bat_restore; 1440 } 1441 1442 if (!use_zero_buffers) { 1443 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1444 sinfo.bytes_avail); 1445 } 1446 /* block exists, so we can just overwrite it */ 1447 qemu_co_mutex_unlock(&s->lock); 1448 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset, 1449 sectors_to_write * BDRV_SECTOR_SIZE, 1450 &hd_qiov, 0); 1451 qemu_co_mutex_lock(&s->lock); 1452 if (ret < 0) { 1453 goto error_bat_restore; 1454 } 1455 break; 1456 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1457 /* we don't yet support difference files, fall through 1458 * to error */ 1459 default: 1460 ret = -EIO; 1461 goto exit; 1462 break; 1463 } 1464 1465 if (bat_update) { 1466 /* this will update the BAT entry into the log journal, and 1467 * then flush the log journal out to disk */ 1468 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1469 sizeof(VHDXBatEntry), 1470 bat_entry_offset); 1471 if (ret < 0) { 1472 goto exit; 1473 } 1474 } 1475 1476 nb_sectors -= sinfo.sectors_avail; 1477 sector_num += sinfo.sectors_avail; 1478 bytes_done += sinfo.bytes_avail; 1479 1480 } 1481 } 1482 1483 goto exit; 1484 1485 error_bat_restore: 1486 if (bat_update) { 1487 /* keep metadata in sync, and restore the bat entry state 1488 * if error. */ 1489 sinfo.file_offset = bat_prior_offset; 1490 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1491 &bat_entry_offset, bat_state); 1492 } 1493 exit: 1494 qemu_vfree(iov1.iov_base); 1495 qemu_vfree(iov2.iov_base); 1496 qemu_co_mutex_unlock(&s->lock); 1497 qemu_iovec_destroy(&hd_qiov); 1498 return ret; 1499 } 1500 1501 1502 1503 /* 1504 * Create VHDX Headers 1505 * 1506 * There are 2 headers, and the highest sequence number will represent 1507 * the active header 1508 */ 1509 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1510 uint32_t log_size) 1511 { 1512 BlockDriverState *bs = blk_bs(blk); 1513 BdrvChild *child; 1514 int ret = 0; 1515 VHDXHeader *hdr = NULL; 1516 1517 hdr = g_new0(VHDXHeader, 1); 1518 1519 hdr->signature = VHDX_HEADER_SIGNATURE; 1520 hdr->sequence_number = g_random_int(); 1521 hdr->log_version = 0; 1522 hdr->version = 1; 1523 hdr->log_length = log_size; 1524 hdr->log_offset = VHDX_HEADER_SECTION_END; 1525 vhdx_guid_generate(&hdr->file_write_guid); 1526 vhdx_guid_generate(&hdr->data_write_guid); 1527 1528 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1529 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1530 * here, which it really shouldn't be doing. */ 1531 child = QLIST_FIRST(&bs->parents); 1532 assert(!QLIST_NEXT(child, next_parent)); 1533 1534 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1535 if (ret < 0) { 1536 goto exit; 1537 } 1538 hdr->sequence_number++; 1539 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1540 if (ret < 0) { 1541 goto exit; 1542 } 1543 1544 exit: 1545 g_free(hdr); 1546 return ret; 1547 } 1548 1549 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1550 (sizeof(VHDXFileParameters) +\ 1551 sizeof(VHDXVirtualDiskSize) +\ 1552 sizeof(VHDXPage83Data) +\ 1553 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1554 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1555 1556 /* 1557 * Create the Metadata entries. 1558 * 1559 * For more details on the entries, see section 3.5 (pg 29) in the 1560 * VHDX 1.00 specification. 1561 * 1562 * We support 5 metadata entries (all required by spec): 1563 * File Parameters, 1564 * Virtual Disk Size, 1565 * Page 83 Data, 1566 * Logical Sector Size, 1567 * Physical Sector Size 1568 * 1569 * The first 64KB of the Metadata section is reserved for the metadata 1570 * header and entries; beyond that, the metadata items themselves reside. 1571 */ 1572 static int vhdx_create_new_metadata(BlockBackend *blk, 1573 uint64_t image_size, 1574 uint32_t block_size, 1575 uint32_t sector_size, 1576 uint64_t metadata_offset, 1577 VHDXImageType type) 1578 { 1579 int ret = 0; 1580 uint32_t offset = 0; 1581 void *buffer = NULL; 1582 void *entry_buffer; 1583 VHDXMetadataTableHeader *md_table; 1584 VHDXMetadataTableEntry *md_table_entry; 1585 1586 /* Metadata entries */ 1587 VHDXFileParameters *mt_file_params; 1588 VHDXVirtualDiskSize *mt_virtual_size; 1589 VHDXPage83Data *mt_page83; 1590 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1591 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1592 1593 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1594 1595 mt_file_params = entry_buffer; 1596 offset += sizeof(VHDXFileParameters); 1597 mt_virtual_size = entry_buffer + offset; 1598 offset += sizeof(VHDXVirtualDiskSize); 1599 mt_page83 = entry_buffer + offset; 1600 offset += sizeof(VHDXPage83Data); 1601 mt_log_sector_size = entry_buffer + offset; 1602 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1603 mt_phys_sector_size = entry_buffer + offset; 1604 1605 mt_file_params->block_size = cpu_to_le32(block_size); 1606 if (type == VHDX_TYPE_FIXED) { 1607 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1608 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1609 } 1610 1611 vhdx_guid_generate(&mt_page83->page_83_data); 1612 cpu_to_leguids(&mt_page83->page_83_data); 1613 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1614 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1615 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1616 1617 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1618 md_table = buffer; 1619 1620 md_table->signature = VHDX_METADATA_SIGNATURE; 1621 md_table->entry_count = 5; 1622 vhdx_metadata_header_le_export(md_table); 1623 1624 1625 /* This will reference beyond the reserved table portion */ 1626 offset = 64 * KiB; 1627 1628 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1629 1630 md_table_entry[0].item_id = file_param_guid; 1631 md_table_entry[0].offset = offset; 1632 md_table_entry[0].length = sizeof(VHDXFileParameters); 1633 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1634 offset += md_table_entry[0].length; 1635 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1636 1637 md_table_entry[1].item_id = virtual_size_guid; 1638 md_table_entry[1].offset = offset; 1639 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1640 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1641 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1642 offset += md_table_entry[1].length; 1643 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1644 1645 md_table_entry[2].item_id = page83_guid; 1646 md_table_entry[2].offset = offset; 1647 md_table_entry[2].length = sizeof(VHDXPage83Data); 1648 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1649 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1650 offset += md_table_entry[2].length; 1651 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1652 1653 md_table_entry[3].item_id = logical_sector_guid; 1654 md_table_entry[3].offset = offset; 1655 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1656 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1657 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1658 offset += md_table_entry[3].length; 1659 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1660 1661 md_table_entry[4].item_id = phys_sector_guid; 1662 md_table_entry[4].offset = offset; 1663 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1664 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1665 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1666 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1667 1668 ret = blk_pwrite(blk, metadata_offset, VHDX_HEADER_BLOCK_SIZE, buffer, 0); 1669 if (ret < 0) { 1670 goto exit; 1671 } 1672 1673 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), 1674 VHDX_METADATA_ENTRY_BUFFER_SIZE, entry_buffer, 0); 1675 if (ret < 0) { 1676 goto exit; 1677 } 1678 1679 1680 exit: 1681 g_free(buffer); 1682 g_free(entry_buffer); 1683 return ret; 1684 } 1685 1686 /* This create the actual BAT itself. We currently only support 1687 * 'Dynamic' and 'Fixed' image types. 1688 * 1689 * Dynamic images: default state of the BAT is all zeroes. 1690 * 1691 * Fixed images: default state of the BAT is fully populated, with 1692 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1693 */ 1694 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1695 uint64_t image_size, VHDXImageType type, 1696 bool use_zero_blocks, uint64_t file_offset, 1697 uint32_t length, Error **errp) 1698 { 1699 int ret = 0; 1700 uint64_t data_file_offset; 1701 uint64_t total_sectors = 0; 1702 uint64_t sector_num = 0; 1703 uint64_t unused; 1704 int block_state; 1705 VHDXSectorInfo sinfo; 1706 1707 assert(s->bat == NULL); 1708 1709 /* this gives a data start after BAT/bitmap entries, and well 1710 * past any metadata entries (with a 4 MB buffer for future 1711 * expansion */ 1712 data_file_offset = file_offset + length + 5 * MiB; 1713 total_sectors = image_size >> s->logical_sector_size_bits; 1714 1715 if (type == VHDX_TYPE_DYNAMIC) { 1716 /* All zeroes, so we can just extend the file - the end of the BAT 1717 * is the furthest thing we have written yet */ 1718 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1719 0, errp); 1720 if (ret < 0) { 1721 goto exit; 1722 } 1723 } else if (type == VHDX_TYPE_FIXED) { 1724 ret = blk_truncate(blk, data_file_offset + image_size, false, 1725 PREALLOC_MODE_OFF, 0, errp); 1726 if (ret < 0) { 1727 goto exit; 1728 } 1729 } else { 1730 error_setg(errp, "Unsupported image type"); 1731 ret = -ENOTSUP; 1732 goto exit; 1733 } 1734 1735 if (type == VHDX_TYPE_FIXED || 1736 use_zero_blocks || 1737 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1738 /* for a fixed file, the default BAT entry is not zero */ 1739 s->bat = g_try_malloc0(length); 1740 if (length && s->bat == NULL) { 1741 error_setg(errp, "Failed to allocate memory for the BAT"); 1742 ret = -ENOMEM; 1743 goto exit; 1744 } 1745 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1746 PAYLOAD_BLOCK_NOT_PRESENT; 1747 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1748 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1749 while (sector_num < total_sectors) { 1750 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1751 sinfo.file_offset = data_file_offset + 1752 (sector_num << s->logical_sector_size_bits); 1753 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1754 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1755 block_state); 1756 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1757 sector_num += s->sectors_per_block; 1758 } 1759 ret = blk_pwrite(blk, file_offset, length, s->bat, 0); 1760 if (ret < 0) { 1761 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1762 goto exit; 1763 } 1764 } 1765 1766 1767 1768 exit: 1769 g_free(s->bat); 1770 return ret; 1771 } 1772 1773 /* Creates the region table header, and region table entries. 1774 * There are 2 supported region table entries: BAT, and Metadata/ 1775 * 1776 * As the calculations for the BAT region table are also needed 1777 * to create the BAT itself, we will also cause the BAT to be 1778 * created. 1779 */ 1780 static int vhdx_create_new_region_table(BlockBackend *blk, 1781 uint64_t image_size, 1782 uint32_t block_size, 1783 uint32_t sector_size, 1784 uint32_t log_size, 1785 bool use_zero_blocks, 1786 VHDXImageType type, 1787 uint64_t *metadata_offset, 1788 Error **errp) 1789 { 1790 int ret = 0; 1791 uint32_t offset = 0; 1792 void *buffer = NULL; 1793 uint64_t bat_file_offset; 1794 uint32_t bat_length; 1795 BDRVVHDXState *s = NULL; 1796 VHDXRegionTableHeader *region_table; 1797 VHDXRegionTableEntry *rt_bat; 1798 VHDXRegionTableEntry *rt_metadata; 1799 1800 assert(metadata_offset != NULL); 1801 1802 /* Populate enough of the BDRVVHDXState to be able to use the 1803 * pre-existing BAT calculation, translation, and update functions */ 1804 s = g_new0(BDRVVHDXState, 1); 1805 1806 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1807 (uint64_t) sector_size / (uint64_t) block_size; 1808 1809 s->sectors_per_block = block_size / sector_size; 1810 s->virtual_disk_size = image_size; 1811 s->block_size = block_size; 1812 s->logical_sector_size = sector_size; 1813 1814 vhdx_set_shift_bits(s); 1815 1816 vhdx_calc_bat_entries(s); 1817 1818 /* At this point the VHDX state is populated enough for creation */ 1819 1820 /* a single buffer is used so we can calculate the checksum over the 1821 * entire 64KB block */ 1822 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1823 region_table = buffer; 1824 offset += sizeof(VHDXRegionTableHeader); 1825 rt_bat = buffer + offset; 1826 offset += sizeof(VHDXRegionTableEntry); 1827 rt_metadata = buffer + offset; 1828 1829 region_table->signature = VHDX_REGION_SIGNATURE; 1830 region_table->entry_count = 2; /* BAT and Metadata */ 1831 1832 rt_bat->guid = bat_guid; 1833 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1834 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1835 s->bat_offset = rt_bat->file_offset; 1836 1837 rt_metadata->guid = metadata_guid; 1838 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1839 MiB); 1840 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1841 *metadata_offset = rt_metadata->file_offset; 1842 1843 bat_file_offset = rt_bat->file_offset; 1844 bat_length = rt_bat->length; 1845 1846 vhdx_region_header_le_export(region_table); 1847 vhdx_region_entry_le_export(rt_bat); 1848 vhdx_region_entry_le_export(rt_metadata); 1849 1850 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1851 offsetof(VHDXRegionTableHeader, checksum)); 1852 1853 1854 /* The region table gives us the data we need to create the BAT, 1855 * so do that now */ 1856 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1857 bat_file_offset, bat_length, errp); 1858 if (ret < 0) { 1859 goto exit; 1860 } 1861 1862 /* Now write out the region headers to disk */ 1863 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1864 buffer, 0); 1865 if (ret < 0) { 1866 error_setg_errno(errp, -ret, "Failed to write first region table"); 1867 goto exit; 1868 } 1869 1870 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1871 buffer, 0); 1872 if (ret < 0) { 1873 error_setg_errno(errp, -ret, "Failed to write second region table"); 1874 goto exit; 1875 } 1876 1877 exit: 1878 g_free(s); 1879 g_free(buffer); 1880 return ret; 1881 } 1882 1883 /* We need to create the following elements: 1884 * 1885 * .-----------------------------------------------------------------. 1886 * | (A) | (B) | (C) | (D) | (E) | 1887 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1888 * | | | | | | 1889 * .-----------------------------------------------------------------. 1890 * 0 64KB 128KB 192KB 256KB 320KB 1891 * 1892 * 1893 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1894 * | (F) | (G) | (H) | | 1895 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1896 * | | | | | 1897 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1898 * 1MB 1899 */ 1900 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts, 1901 Error **errp) 1902 { 1903 BlockdevCreateOptionsVhdx *vhdx_opts; 1904 BlockBackend *blk = NULL; 1905 BlockDriverState *bs = NULL; 1906 1907 int ret = 0; 1908 uint64_t image_size; 1909 uint32_t log_size; 1910 uint32_t block_size; 1911 uint64_t signature; 1912 uint64_t metadata_offset; 1913 bool use_zero_blocks = false; 1914 1915 gunichar2 *creator = NULL; 1916 glong creator_items; 1917 VHDXImageType image_type; 1918 1919 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1920 vhdx_opts = &opts->u.vhdx; 1921 1922 /* Validate options and set default values */ 1923 image_size = vhdx_opts->size; 1924 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1925 error_setg(errp, "Image size too large; max of 64TB"); 1926 return -EINVAL; 1927 } 1928 1929 if (!vhdx_opts->has_log_size) { 1930 log_size = DEFAULT_LOG_SIZE; 1931 } else { 1932 if (vhdx_opts->log_size > UINT32_MAX) { 1933 error_setg(errp, "Log size must be smaller than 4 GB"); 1934 return -EINVAL; 1935 } 1936 log_size = vhdx_opts->log_size; 1937 } 1938 if (log_size < MiB || (log_size % MiB) != 0) { 1939 error_setg(errp, "Log size must be a multiple of 1 MB"); 1940 return -EINVAL; 1941 } 1942 1943 if (!vhdx_opts->has_block_state_zero) { 1944 use_zero_blocks = true; 1945 } else { 1946 use_zero_blocks = vhdx_opts->block_state_zero; 1947 } 1948 1949 if (!vhdx_opts->has_subformat) { 1950 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1951 } 1952 1953 switch (vhdx_opts->subformat) { 1954 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1955 image_type = VHDX_TYPE_DYNAMIC; 1956 break; 1957 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1958 image_type = VHDX_TYPE_FIXED; 1959 break; 1960 default: 1961 g_assert_not_reached(); 1962 } 1963 1964 /* These are pretty arbitrary, and mainly designed to keep the BAT 1965 * size reasonable to load into RAM */ 1966 if (vhdx_opts->has_block_size) { 1967 block_size = vhdx_opts->block_size; 1968 } else { 1969 if (image_size > 32 * TiB) { 1970 block_size = 64 * MiB; 1971 } else if (image_size > (uint64_t) 100 * GiB) { 1972 block_size = 32 * MiB; 1973 } else if (image_size > 1 * GiB) { 1974 block_size = 16 * MiB; 1975 } else { 1976 block_size = 8 * MiB; 1977 } 1978 } 1979 1980 if (block_size < MiB || (block_size % MiB) != 0) { 1981 error_setg(errp, "Block size must be a multiple of 1 MB"); 1982 return -EINVAL; 1983 } 1984 if (!is_power_of_2(block_size)) { 1985 error_setg(errp, "Block size must be a power of two"); 1986 return -EINVAL; 1987 } 1988 if (block_size > VHDX_BLOCK_SIZE_MAX) { 1989 error_setg(errp, "Block size must not exceed %" PRId64, 1990 VHDX_BLOCK_SIZE_MAX); 1991 return -EINVAL; 1992 } 1993 1994 /* Create BlockBackend to write to the image */ 1995 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp); 1996 if (bs == NULL) { 1997 return -EIO; 1998 } 1999 2000 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 2001 errp); 2002 if (!blk) { 2003 ret = -EPERM; 2004 goto delete_and_exit; 2005 } 2006 blk_set_allow_write_beyond_eof(blk, true); 2007 2008 /* Create (A) */ 2009 2010 /* The creator field is optional, but may be useful for 2011 * debugging / diagnostics */ 2012 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2013 &creator_items, NULL); 2014 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2015 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, sizeof(signature), &signature, 2016 0); 2017 if (ret < 0) { 2018 error_setg_errno(errp, -ret, "Failed to write file signature"); 2019 goto delete_and_exit; 2020 } 2021 if (creator) { 2022 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2023 creator_items * sizeof(gunichar2), creator, 0); 2024 if (ret < 0) { 2025 error_setg_errno(errp, -ret, "Failed to write creator field"); 2026 goto delete_and_exit; 2027 } 2028 } 2029 2030 2031 /* Creates (B),(C) */ 2032 ret = vhdx_create_new_headers(blk, image_size, log_size); 2033 if (ret < 0) { 2034 error_setg_errno(errp, -ret, "Failed to write image headers"); 2035 goto delete_and_exit; 2036 } 2037 2038 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2039 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2040 log_size, use_zero_blocks, image_type, 2041 &metadata_offset, errp); 2042 if (ret < 0) { 2043 goto delete_and_exit; 2044 } 2045 2046 /* Creates (H) */ 2047 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2048 metadata_offset, image_type); 2049 if (ret < 0) { 2050 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2051 goto delete_and_exit; 2052 } 2053 2054 ret = 0; 2055 delete_and_exit: 2056 blk_unref(blk); 2057 bdrv_unref(bs); 2058 g_free(creator); 2059 return ret; 2060 } 2061 2062 static int coroutine_fn vhdx_co_create_opts(BlockDriver *drv, 2063 const char *filename, 2064 QemuOpts *opts, 2065 Error **errp) 2066 { 2067 BlockdevCreateOptions *create_options = NULL; 2068 QDict *qdict; 2069 Visitor *v; 2070 BlockDriverState *bs = NULL; 2071 int ret; 2072 2073 static const QDictRenames opt_renames[] = { 2074 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" }, 2075 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" }, 2076 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" }, 2077 { NULL, NULL }, 2078 }; 2079 2080 /* Parse options and convert legacy syntax */ 2081 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true); 2082 2083 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 2084 ret = -EINVAL; 2085 goto fail; 2086 } 2087 2088 /* Create and open the file (protocol layer) */ 2089 ret = bdrv_create_file(filename, opts, errp); 2090 if (ret < 0) { 2091 goto fail; 2092 } 2093 2094 bs = bdrv_open(filename, NULL, NULL, 2095 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 2096 if (bs == NULL) { 2097 ret = -EIO; 2098 goto fail; 2099 } 2100 2101 /* Now get the QAPI type BlockdevCreateOptions */ 2102 qdict_put_str(qdict, "driver", "vhdx"); 2103 qdict_put_str(qdict, "file", bs->node_name); 2104 2105 v = qobject_input_visitor_new_flat_confused(qdict, errp); 2106 if (!v) { 2107 ret = -EINVAL; 2108 goto fail; 2109 } 2110 2111 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 2112 visit_free(v); 2113 if (!create_options) { 2114 ret = -EINVAL; 2115 goto fail; 2116 } 2117 2118 /* Silently round up sizes: 2119 * The image size is rounded to 512 bytes. Make the block and log size 2120 * close to what was specified, but must be at least 1MB, and a multiple of 2121 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0 2122 * means auto, which is represented by a missing key in QAPI. */ 2123 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX); 2124 create_options->u.vhdx.size = 2125 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE); 2126 2127 if (create_options->u.vhdx.has_log_size) { 2128 create_options->u.vhdx.log_size = 2129 ROUND_UP(create_options->u.vhdx.log_size, MiB); 2130 } 2131 if (create_options->u.vhdx.has_block_size) { 2132 create_options->u.vhdx.block_size = 2133 ROUND_UP(create_options->u.vhdx.block_size, MiB); 2134 2135 if (create_options->u.vhdx.block_size == 0) { 2136 create_options->u.vhdx.has_block_size = false; 2137 } 2138 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) { 2139 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX; 2140 } 2141 } 2142 2143 /* Create the vhdx image (format layer) */ 2144 ret = vhdx_co_create(create_options, errp); 2145 2146 fail: 2147 qobject_unref(qdict); 2148 bdrv_unref(bs); 2149 qapi_free_BlockdevCreateOptions(create_options); 2150 return ret; 2151 } 2152 2153 /* If opened r/w, the VHDX driver will automatically replay the log, 2154 * if one is present, inside the vhdx_open() call. 2155 * 2156 * If qemu-img check -r all is called, the image is automatically opened 2157 * r/w and any log has already been replayed, so there is nothing (currently) 2158 * for us to do here 2159 */ 2160 static int coroutine_fn vhdx_co_check(BlockDriverState *bs, 2161 BdrvCheckResult *result, 2162 BdrvCheckMode fix) 2163 { 2164 BDRVVHDXState *s = bs->opaque; 2165 2166 if (s->log_replayed_on_open) { 2167 result->corruptions_fixed++; 2168 } 2169 2170 vhdx_check_bat_entries(bs, &result->corruptions); 2171 2172 return 0; 2173 } 2174 2175 static int vhdx_has_zero_init(BlockDriverState *bs) 2176 { 2177 BDRVVHDXState *s = bs->opaque; 2178 int state; 2179 2180 /* 2181 * Check the subformat: Fixed images have all BAT entries present, 2182 * dynamic images have none (right after creation). It is 2183 * therefore enough to check the first BAT entry. 2184 */ 2185 if (!s->bat_entries) { 2186 return 1; 2187 } 2188 2189 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK; 2190 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) { 2191 /* Fixed subformat */ 2192 return bdrv_has_zero_init(bs->file->bs); 2193 } 2194 2195 /* Dynamic subformat */ 2196 return 1; 2197 } 2198 2199 static QemuOptsList vhdx_create_opts = { 2200 .name = "vhdx-create-opts", 2201 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 2202 .desc = { 2203 { 2204 .name = BLOCK_OPT_SIZE, 2205 .type = QEMU_OPT_SIZE, 2206 .help = "Virtual disk size; max of 64TB." 2207 }, 2208 { 2209 .name = VHDX_BLOCK_OPT_LOG_SIZE, 2210 .type = QEMU_OPT_SIZE, 2211 .def_value_str = stringify(DEFAULT_LOG_SIZE), 2212 .help = "Log size; min 1MB." 2213 }, 2214 { 2215 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 2216 .type = QEMU_OPT_SIZE, 2217 .def_value_str = stringify(0), 2218 .help = "Block Size; min 1MB, max 256MB. " 2219 "0 means auto-calculate based on image size." 2220 }, 2221 { 2222 .name = BLOCK_OPT_SUBFMT, 2223 .type = QEMU_OPT_STRING, 2224 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. " 2225 "Default is 'dynamic'." 2226 }, 2227 { 2228 .name = VHDX_BLOCK_OPT_ZERO, 2229 .type = QEMU_OPT_BOOL, 2230 .help = "Force use of payload blocks of type 'ZERO'. " 2231 "Non-standard, but default. Do not set to 'off' when " 2232 "using 'qemu-img convert' with subformat=dynamic." 2233 }, 2234 { NULL } 2235 } 2236 }; 2237 2238 static BlockDriver bdrv_vhdx = { 2239 .format_name = "vhdx", 2240 .instance_size = sizeof(BDRVVHDXState), 2241 .bdrv_probe = vhdx_probe, 2242 .bdrv_open = vhdx_open, 2243 .bdrv_close = vhdx_close, 2244 .bdrv_reopen_prepare = vhdx_reopen_prepare, 2245 .bdrv_child_perm = bdrv_default_perms, 2246 .bdrv_co_readv = vhdx_co_readv, 2247 .bdrv_co_writev = vhdx_co_writev, 2248 .bdrv_co_create = vhdx_co_create, 2249 .bdrv_co_create_opts = vhdx_co_create_opts, 2250 .bdrv_get_info = vhdx_get_info, 2251 .bdrv_co_check = vhdx_co_check, 2252 .bdrv_has_zero_init = vhdx_has_zero_init, 2253 2254 .is_format = true, 2255 .create_opts = &vhdx_create_opts, 2256 }; 2257 2258 static void bdrv_vhdx_init(void) 2259 { 2260 bdrv_register(&bdrv_vhdx); 2261 } 2262 2263 block_init(bdrv_vhdx_init); 2264