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, buffer, VHDX_HEADER_SIZE); 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, header_le, sizeof(VHDXHeader)); 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, buffer, 444 VHDX_HEADER_SIZE); 445 if (ret < 0) { 446 goto fail; 447 } 448 /* copy over just the relevant portion that we need */ 449 memcpy(header1, buffer, sizeof(VHDXHeader)); 450 451 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 452 vhdx_header_le_import(header1); 453 if (header1->signature == VHDX_HEADER_SIGNATURE && 454 header1->version == 1) { 455 h1_seq = header1->sequence_number; 456 h1_valid = true; 457 } 458 } 459 460 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, 461 VHDX_HEADER_SIZE); 462 if (ret < 0) { 463 goto fail; 464 } 465 /* copy over just the relevant portion that we need */ 466 memcpy(header2, buffer, sizeof(VHDXHeader)); 467 468 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 469 vhdx_header_le_import(header2); 470 if (header2->signature == VHDX_HEADER_SIGNATURE && 471 header2->version == 1) { 472 h2_seq = header2->sequence_number; 473 h2_valid = true; 474 } 475 } 476 477 /* If there is only 1 valid header (or no valid headers), we 478 * don't care what the sequence numbers are */ 479 if (h1_valid && !h2_valid) { 480 s->curr_header = 0; 481 } else if (!h1_valid && h2_valid) { 482 s->curr_header = 1; 483 } else if (!h1_valid && !h2_valid) { 484 goto fail; 485 } else { 486 /* If both headers are valid, then we choose the active one by the 487 * highest sequence number. If the sequence numbers are equal, that is 488 * invalid */ 489 if (h1_seq > h2_seq) { 490 s->curr_header = 0; 491 } else if (h2_seq > h1_seq) { 492 s->curr_header = 1; 493 } else { 494 /* The Microsoft Disk2VHD tool will create 2 identical 495 * headers, with identical sequence numbers. If the headers are 496 * identical, don't consider the file corrupt */ 497 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 498 s->curr_header = 0; 499 } else { 500 goto fail; 501 } 502 } 503 } 504 505 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 506 s->headers[s->curr_header]->log_length); 507 goto exit; 508 509 fail: 510 error_setg_errno(errp, -ret, "No valid VHDX header found"); 511 qemu_vfree(header1); 512 qemu_vfree(header2); 513 s->headers[0] = NULL; 514 s->headers[1] = NULL; 515 exit: 516 qemu_vfree(buffer); 517 } 518 519 520 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 521 { 522 int ret = 0; 523 uint8_t *buffer; 524 int offset = 0; 525 VHDXRegionTableEntry rt_entry; 526 uint32_t i; 527 bool bat_rt_found = false; 528 bool metadata_rt_found = false; 529 530 /* We have to read the whole 64KB block, because the crc32 is over the 531 * whole block */ 532 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 533 534 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 535 VHDX_HEADER_BLOCK_SIZE); 536 if (ret < 0) { 537 goto fail; 538 } 539 memcpy(&s->rt, buffer, sizeof(s->rt)); 540 offset += sizeof(s->rt); 541 542 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 543 ret = -EINVAL; 544 goto fail; 545 } 546 547 vhdx_region_header_le_import(&s->rt); 548 549 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 550 ret = -EINVAL; 551 goto fail; 552 } 553 554 555 /* Per spec, maximum region table entry count is 2047 */ 556 if (s->rt.entry_count > 2047) { 557 ret = -EINVAL; 558 goto fail; 559 } 560 561 for (i = 0; i < s->rt.entry_count; i++) { 562 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 563 offset += sizeof(rt_entry); 564 565 vhdx_region_entry_le_import(&rt_entry); 566 567 /* check for region overlap between these entries, and any 568 * other memory regions in the file */ 569 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 570 if (ret < 0) { 571 goto fail; 572 } 573 574 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 575 576 /* see if we recognize the entry */ 577 if (guid_eq(rt_entry.guid, bat_guid)) { 578 /* must be unique; if we have already found it this is invalid */ 579 if (bat_rt_found) { 580 ret = -EINVAL; 581 goto fail; 582 } 583 bat_rt_found = true; 584 s->bat_rt = rt_entry; 585 continue; 586 } 587 588 if (guid_eq(rt_entry.guid, metadata_guid)) { 589 /* must be unique; if we have already found it this is invalid */ 590 if (metadata_rt_found) { 591 ret = -EINVAL; 592 goto fail; 593 } 594 metadata_rt_found = true; 595 s->metadata_rt = rt_entry; 596 continue; 597 } 598 599 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 600 /* cannot read vhdx file - required region table entry that 601 * we do not understand. per spec, we must fail to open */ 602 ret = -ENOTSUP; 603 goto fail; 604 } 605 } 606 607 if (!bat_rt_found || !metadata_rt_found) { 608 ret = -EINVAL; 609 goto fail; 610 } 611 612 ret = 0; 613 614 fail: 615 qemu_vfree(buffer); 616 return ret; 617 } 618 619 620 621 /* Metadata initial parser 622 * 623 * This loads all the metadata entry fields. This may cause additional 624 * fields to be processed (e.g. parent locator, etc..). 625 * 626 * There are 5 Metadata items that are always required: 627 * - File Parameters (block size, has a parent) 628 * - Virtual Disk Size (size, in bytes, of the virtual drive) 629 * - Page 83 Data (scsi page 83 guid) 630 * - Logical Sector Size (logical sector size in bytes, either 512 or 631 * 4096. We only support 512 currently) 632 * - Physical Sector Size (512 or 4096) 633 * 634 * Also, if the File Parameters indicate this is a differencing file, 635 * we must also look for the Parent Locator metadata item. 636 */ 637 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 638 { 639 int ret = 0; 640 uint8_t *buffer; 641 int offset = 0; 642 uint32_t i = 0; 643 VHDXMetadataTableEntry md_entry; 644 645 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 646 647 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 648 VHDX_METADATA_TABLE_MAX_SIZE); 649 if (ret < 0) { 650 goto exit; 651 } 652 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 653 offset += sizeof(s->metadata_hdr); 654 655 vhdx_metadata_header_le_import(&s->metadata_hdr); 656 657 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 658 ret = -EINVAL; 659 goto exit; 660 } 661 662 s->metadata_entries.present = 0; 663 664 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 665 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 666 ret = -EINVAL; 667 goto exit; 668 } 669 670 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 671 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 672 offset += sizeof(md_entry); 673 674 vhdx_metadata_entry_le_import(&md_entry); 675 676 if (guid_eq(md_entry.item_id, file_param_guid)) { 677 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 678 ret = -EINVAL; 679 goto exit; 680 } 681 s->metadata_entries.file_parameters_entry = md_entry; 682 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 683 continue; 684 } 685 686 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 687 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 688 ret = -EINVAL; 689 goto exit; 690 } 691 s->metadata_entries.virtual_disk_size_entry = md_entry; 692 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 693 continue; 694 } 695 696 if (guid_eq(md_entry.item_id, page83_guid)) { 697 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 698 ret = -EINVAL; 699 goto exit; 700 } 701 s->metadata_entries.page83_data_entry = md_entry; 702 s->metadata_entries.present |= META_PAGE_83_PRESENT; 703 continue; 704 } 705 706 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 707 if (s->metadata_entries.present & 708 META_LOGICAL_SECTOR_SIZE_PRESENT) { 709 ret = -EINVAL; 710 goto exit; 711 } 712 s->metadata_entries.logical_sector_size_entry = md_entry; 713 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 714 continue; 715 } 716 717 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 718 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 719 ret = -EINVAL; 720 goto exit; 721 } 722 s->metadata_entries.phys_sector_size_entry = md_entry; 723 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 724 continue; 725 } 726 727 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 728 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 729 ret = -EINVAL; 730 goto exit; 731 } 732 s->metadata_entries.parent_locator_entry = md_entry; 733 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 734 continue; 735 } 736 737 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 738 /* cannot read vhdx file - required region table entry that 739 * we do not understand. per spec, we must fail to open */ 740 ret = -ENOTSUP; 741 goto exit; 742 } 743 } 744 745 if (s->metadata_entries.present != META_ALL_PRESENT) { 746 ret = -ENOTSUP; 747 goto exit; 748 } 749 750 ret = bdrv_pread(bs->file, 751 s->metadata_entries.file_parameters_entry.offset 752 + s->metadata_rt.file_offset, 753 &s->params, 754 sizeof(s->params)); 755 756 if (ret < 0) { 757 goto exit; 758 } 759 760 s->params.block_size = le32_to_cpu(s->params.block_size); 761 s->params.data_bits = le32_to_cpu(s->params.data_bits); 762 763 764 /* We now have the file parameters, so we can tell if this is a 765 * differencing file (i.e.. has_parent), is dynamic or fixed 766 * sized (leave_blocks_allocated), and the block size */ 767 768 /* The parent locator required iff the file parameters has_parent set */ 769 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 770 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 771 /* TODO: parse parent locator fields */ 772 ret = -ENOTSUP; /* temp, until differencing files are supported */ 773 goto exit; 774 } else { 775 /* if has_parent is set, but there is not parent locator present, 776 * then that is an invalid combination */ 777 ret = -EINVAL; 778 goto exit; 779 } 780 } 781 782 /* determine virtual disk size, logical sector size, 783 * and phys sector size */ 784 785 ret = bdrv_pread(bs->file, 786 s->metadata_entries.virtual_disk_size_entry.offset 787 + s->metadata_rt.file_offset, 788 &s->virtual_disk_size, 789 sizeof(uint64_t)); 790 if (ret < 0) { 791 goto exit; 792 } 793 ret = bdrv_pread(bs->file, 794 s->metadata_entries.logical_sector_size_entry.offset 795 + s->metadata_rt.file_offset, 796 &s->logical_sector_size, 797 sizeof(uint32_t)); 798 if (ret < 0) { 799 goto exit; 800 } 801 ret = bdrv_pread(bs->file, 802 s->metadata_entries.phys_sector_size_entry.offset 803 + s->metadata_rt.file_offset, 804 &s->physical_sector_size, 805 sizeof(uint32_t)); 806 if (ret < 0) { 807 goto exit; 808 } 809 810 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size); 811 s->logical_sector_size = le32_to_cpu(s->logical_sector_size); 812 s->physical_sector_size = le32_to_cpu(s->physical_sector_size); 813 814 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 815 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 816 ret = -EINVAL; 817 goto exit; 818 } 819 820 /* Currently we only support 512 */ 821 if (s->logical_sector_size != 512) { 822 ret = -ENOTSUP; 823 goto exit; 824 } 825 826 /* Both block_size and sector_size are guaranteed powers of 2, below. 827 Due to range checks above, s->sectors_per_block can never be < 256 */ 828 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 829 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 830 (uint64_t)s->logical_sector_size / 831 (uint64_t)s->params.block_size; 832 833 /* These values are ones we will want to use for division / multiplication 834 * later on, and they are all guaranteed (per the spec) to be powers of 2, 835 * so we can take advantage of that for shift operations during 836 * reads/writes */ 837 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 838 ret = -EINVAL; 839 goto exit; 840 } 841 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 842 ret = -EINVAL; 843 goto exit; 844 } 845 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 846 ret = -EINVAL; 847 goto exit; 848 } 849 s->block_size = s->params.block_size; 850 if (s->block_size & (s->block_size - 1)) { 851 ret = -EINVAL; 852 goto exit; 853 } 854 855 vhdx_set_shift_bits(s); 856 857 ret = 0; 858 859 exit: 860 qemu_vfree(buffer); 861 return ret; 862 } 863 864 /* 865 * Calculate the number of BAT entries, including sector 866 * bitmap entries. 867 */ 868 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 869 { 870 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 871 872 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 873 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 874 875 if (s->parent_entries) { 876 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 877 } else { 878 s->bat_entries = data_blocks_cnt + 879 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 880 } 881 882 } 883 884 static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) 885 { 886 BDRVVHDXState *s = bs->opaque; 887 int64_t image_file_size = bdrv_getlength(bs->file->bs); 888 uint64_t payblocks = s->chunk_ratio; 889 uint64_t i; 890 int ret = 0; 891 892 if (image_file_size < 0) { 893 error_report("Could not determinate VHDX image file size."); 894 return image_file_size; 895 } 896 897 for (i = 0; i < s->bat_entries; i++) { 898 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 899 PAYLOAD_BLOCK_FULLY_PRESENT) { 900 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; 901 /* 902 * Allow that the last block exists only partially. The VHDX spec 903 * states that the image file can only grow in blocksize increments, 904 * but QEMU created images with partial last blocks in the past. 905 */ 906 uint32_t block_length = MIN(s->block_size, 907 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); 908 /* 909 * Check for BAT entry overflow. 910 */ 911 if (offset > INT64_MAX - s->block_size) { 912 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); 913 ret = -EINVAL; 914 if (!errcnt) { 915 break; 916 } 917 (*errcnt)++; 918 } 919 /* 920 * Check if fully allocated BAT entries do not reside after 921 * end of the image file. 922 */ 923 if (offset >= image_file_size) { 924 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 925 " points after end of file (%" PRIi64 "). Image" 926 " has probably been truncated.", 927 i, offset, image_file_size); 928 ret = -EINVAL; 929 if (!errcnt) { 930 break; 931 } 932 (*errcnt)++; 933 } else if (offset + block_length > image_file_size) { 934 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 935 " points after end of file (%" PRIi64 "). Image" 936 " has probably been truncated.", 937 i, offset + block_length - 1, image_file_size); 938 ret = -EINVAL; 939 if (!errcnt) { 940 break; 941 } 942 (*errcnt)++; 943 } 944 945 /* 946 * verify populated BAT field file offsets against 947 * region table and log entries 948 */ 949 if (payblocks--) { 950 /* payload bat entries */ 951 int ret2; 952 ret2 = vhdx_region_check(s, offset, s->block_size); 953 if (ret2 < 0) { 954 ret = -EINVAL; 955 if (!errcnt) { 956 break; 957 } 958 (*errcnt)++; 959 } 960 } else { 961 payblocks = s->chunk_ratio; 962 /* 963 * Once differencing files are supported, verify sector bitmap 964 * blocks here 965 */ 966 } 967 } 968 } 969 970 return ret; 971 } 972 973 static void vhdx_close(BlockDriverState *bs) 974 { 975 BDRVVHDXState *s = bs->opaque; 976 qemu_vfree(s->headers[0]); 977 s->headers[0] = NULL; 978 qemu_vfree(s->headers[1]); 979 s->headers[1] = NULL; 980 qemu_vfree(s->bat); 981 s->bat = NULL; 982 qemu_vfree(s->parent_entries); 983 s->parent_entries = NULL; 984 migrate_del_blocker(s->migration_blocker); 985 error_free(s->migration_blocker); 986 qemu_vfree(s->log.hdr); 987 s->log.hdr = NULL; 988 vhdx_region_unregister_all(s); 989 } 990 991 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 992 Error **errp) 993 { 994 BDRVVHDXState *s = bs->opaque; 995 int ret = 0; 996 uint32_t i; 997 uint64_t signature; 998 Error *local_err = NULL; 999 1000 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 1001 BDRV_CHILD_IMAGE, false, errp); 1002 if (!bs->file) { 1003 return -EINVAL; 1004 } 1005 1006 s->bat = NULL; 1007 s->first_visible_write = true; 1008 1009 qemu_co_mutex_init(&s->lock); 1010 QLIST_INIT(&s->regions); 1011 1012 /* validate the file signature */ 1013 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 1014 if (ret < 0) { 1015 goto fail; 1016 } 1017 if (memcmp(&signature, "vhdxfile", 8)) { 1018 ret = -EINVAL; 1019 goto fail; 1020 } 1021 1022 /* This is used for any header updates, for the file_write_guid. 1023 * The spec dictates that a new value should be used for the first 1024 * header update */ 1025 vhdx_guid_generate(&s->session_guid); 1026 1027 vhdx_parse_header(bs, s, &local_err); 1028 if (local_err != NULL) { 1029 error_propagate(errp, local_err); 1030 ret = -EINVAL; 1031 goto fail; 1032 } 1033 1034 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1035 if (ret < 0) { 1036 goto fail; 1037 } 1038 1039 ret = vhdx_open_region_tables(bs, s); 1040 if (ret < 0) { 1041 goto fail; 1042 } 1043 1044 ret = vhdx_parse_metadata(bs, s); 1045 if (ret < 0) { 1046 goto fail; 1047 } 1048 1049 s->block_size = s->params.block_size; 1050 1051 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1052 * logical_sector_size */ 1053 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1054 1055 vhdx_calc_bat_entries(s); 1056 1057 s->bat_offset = s->bat_rt.file_offset; 1058 1059 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1060 /* BAT allocation is not large enough for all entries */ 1061 ret = -EINVAL; 1062 goto fail; 1063 } 1064 1065 /* s->bat is freed in vhdx_close() */ 1066 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1067 if (s->bat == NULL) { 1068 ret = -ENOMEM; 1069 goto fail; 1070 } 1071 1072 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 1073 if (ret < 0) { 1074 goto fail; 1075 } 1076 1077 /* endian convert populated BAT field entires */ 1078 for (i = 0; i < s->bat_entries; i++) { 1079 s->bat[i] = le64_to_cpu(s->bat[i]); 1080 } 1081 1082 if (!(flags & BDRV_O_CHECK)) { 1083 ret = vhdx_check_bat_entries(bs, NULL); 1084 if (ret < 0) { 1085 goto fail; 1086 } 1087 } 1088 1089 /* Disable migration when VHDX images are used */ 1090 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1091 "does not support live migration", 1092 bdrv_get_device_or_node_name(bs)); 1093 ret = migrate_add_blocker(s->migration_blocker, errp); 1094 if (ret < 0) { 1095 error_free(s->migration_blocker); 1096 goto fail; 1097 } 1098 1099 /* TODO: differencing files */ 1100 1101 return 0; 1102 fail: 1103 vhdx_close(bs); 1104 return ret; 1105 } 1106 1107 static int vhdx_reopen_prepare(BDRVReopenState *state, 1108 BlockReopenQueue *queue, Error **errp) 1109 { 1110 return 0; 1111 } 1112 1113 1114 /* 1115 * Perform sector to block offset translations, to get various 1116 * sector and file offsets into the image. See VHDXSectorInfo 1117 */ 1118 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1119 int nb_sectors, VHDXSectorInfo *sinfo) 1120 { 1121 uint32_t block_offset; 1122 1123 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1124 /* effectively a modulo - this gives us the offset into the block 1125 * (in sector sizes) for our sector number */ 1126 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1127 /* the chunk ratio gives us the interleaving of the sector 1128 * bitmaps, so we need to advance our page block index by the 1129 * sector bitmaps entry number */ 1130 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1131 1132 /* the number of sectors we can read/write in this cycle */ 1133 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1134 1135 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1136 1137 if (sinfo->sectors_avail > nb_sectors) { 1138 sinfo->sectors_avail = nb_sectors; 1139 } 1140 1141 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1142 1143 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1144 1145 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1146 1147 /* The file offset must be past the header section, so must be > 0 */ 1148 if (sinfo->file_offset == 0) { 1149 return; 1150 } 1151 1152 /* block offset is the offset in vhdx logical sectors, in 1153 * the payload data block. Convert that to a byte offset 1154 * in the block, and add in the payload data block offset 1155 * in the file, in bytes, to get the final read address */ 1156 1157 sinfo->file_offset += sinfo->block_offset; 1158 } 1159 1160 1161 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1162 { 1163 BDRVVHDXState *s = bs->opaque; 1164 1165 bdi->cluster_size = s->block_size; 1166 1167 return 0; 1168 } 1169 1170 1171 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1172 int nb_sectors, QEMUIOVector *qiov) 1173 { 1174 BDRVVHDXState *s = bs->opaque; 1175 int ret = 0; 1176 VHDXSectorInfo sinfo; 1177 uint64_t bytes_done = 0; 1178 QEMUIOVector hd_qiov; 1179 1180 qemu_iovec_init(&hd_qiov, qiov->niov); 1181 1182 qemu_co_mutex_lock(&s->lock); 1183 1184 while (nb_sectors > 0) { 1185 /* We are a differencing file, so we need to inspect the sector bitmap 1186 * to see if we have the data or not */ 1187 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1188 /* not supported yet */ 1189 ret = -ENOTSUP; 1190 goto exit; 1191 } else { 1192 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1193 1194 qemu_iovec_reset(&hd_qiov); 1195 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1196 1197 /* check the payload block state */ 1198 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1199 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1200 case PAYLOAD_BLOCK_UNDEFINED: 1201 case PAYLOAD_BLOCK_UNMAPPED: 1202 case PAYLOAD_BLOCK_UNMAPPED_v095: 1203 case PAYLOAD_BLOCK_ZERO: 1204 /* return zero */ 1205 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1206 break; 1207 case PAYLOAD_BLOCK_FULLY_PRESENT: 1208 qemu_co_mutex_unlock(&s->lock); 1209 ret = bdrv_co_preadv(bs->file, sinfo.file_offset, 1210 sinfo.sectors_avail * BDRV_SECTOR_SIZE, 1211 &hd_qiov, 0); 1212 qemu_co_mutex_lock(&s->lock); 1213 if (ret < 0) { 1214 goto exit; 1215 } 1216 break; 1217 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1218 /* we don't yet support difference files, fall through 1219 * to error */ 1220 default: 1221 ret = -EIO; 1222 goto exit; 1223 break; 1224 } 1225 nb_sectors -= sinfo.sectors_avail; 1226 sector_num += sinfo.sectors_avail; 1227 bytes_done += sinfo.bytes_avail; 1228 } 1229 } 1230 ret = 0; 1231 exit: 1232 qemu_co_mutex_unlock(&s->lock); 1233 qemu_iovec_destroy(&hd_qiov); 1234 return ret; 1235 } 1236 1237 /* 1238 * Allocate a new payload block at the end of the file. 1239 * 1240 * Allocation will happen at 1MB alignment inside the file. 1241 * 1242 * If @need_zero is set on entry but not cleared on return, then truncation 1243 * could not guarantee that the new portion reads as zero, and the caller 1244 * will take care of it instead. 1245 * 1246 * Returns the file offset start of the new payload block 1247 */ 1248 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1249 uint64_t *new_offset, bool *need_zero) 1250 { 1251 int64_t current_len; 1252 1253 current_len = bdrv_getlength(bs->file->bs); 1254 if (current_len < 0) { 1255 return current_len; 1256 } 1257 1258 *new_offset = current_len; 1259 1260 /* per the spec, the address for a block is in units of 1MB */ 1261 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1262 if (*new_offset > INT64_MAX) { 1263 return -EINVAL; 1264 } 1265 1266 if (*need_zero) { 1267 int ret; 1268 1269 ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1270 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL); 1271 if (ret != -ENOTSUP) { 1272 *need_zero = false; 1273 return ret; 1274 } 1275 } 1276 1277 return bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1278 PREALLOC_MODE_OFF, 0, NULL); 1279 } 1280 1281 /* 1282 * Update the BAT table entry with the new file offset, and the new entry 1283 * state */ 1284 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1285 VHDXSectorInfo *sinfo, 1286 uint64_t *bat_entry_le, 1287 uint64_t *bat_offset, int state) 1288 { 1289 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1290 * 1MB, and 3 bits for the block state. */ 1291 if ((state == PAYLOAD_BLOCK_ZERO) || 1292 (state == PAYLOAD_BLOCK_UNDEFINED) || 1293 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1294 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1295 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1296 FileOffsetMB field is denoted as 1297 'reserved' in the v1.0 spec. If it is 1298 non-zero, MS Hyper-V will fail to read 1299 the disk image */ 1300 } else { 1301 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1302 } 1303 1304 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1305 1306 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1307 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1308 1309 } 1310 1311 /* Per the spec, on the first write of guest-visible data to the file the 1312 * data write guid must be updated in the header */ 1313 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1314 { 1315 int ret = 0; 1316 if (s->first_visible_write) { 1317 s->first_visible_write = false; 1318 ret = vhdx_update_headers(bs, s, true, NULL); 1319 } 1320 return ret; 1321 } 1322 1323 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1324 int nb_sectors, QEMUIOVector *qiov, 1325 int flags) 1326 { 1327 int ret = -ENOTSUP; 1328 BDRVVHDXState *s = bs->opaque; 1329 VHDXSectorInfo sinfo; 1330 uint64_t bytes_done = 0; 1331 uint64_t bat_entry = 0; 1332 uint64_t bat_entry_offset = 0; 1333 QEMUIOVector hd_qiov; 1334 struct iovec iov1 = { 0 }; 1335 struct iovec iov2 = { 0 }; 1336 int sectors_to_write; 1337 int bat_state; 1338 uint64_t bat_prior_offset = 0; 1339 bool bat_update = false; 1340 1341 assert(!flags); 1342 qemu_iovec_init(&hd_qiov, qiov->niov); 1343 1344 qemu_co_mutex_lock(&s->lock); 1345 1346 ret = vhdx_user_visible_write(bs, s); 1347 if (ret < 0) { 1348 goto exit; 1349 } 1350 1351 while (nb_sectors > 0) { 1352 bool use_zero_buffers = false; 1353 bat_update = false; 1354 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1355 /* not supported yet */ 1356 ret = -ENOTSUP; 1357 goto exit; 1358 } else { 1359 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1360 sectors_to_write = sinfo.sectors_avail; 1361 1362 qemu_iovec_reset(&hd_qiov); 1363 /* check the payload block state */ 1364 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1365 switch (bat_state) { 1366 case PAYLOAD_BLOCK_ZERO: 1367 /* in this case, we need to preserve zero writes for 1368 * data that is not part of this write, so we must pad 1369 * the rest of the buffer to zeroes */ 1370 use_zero_buffers = true; 1371 /* fall through */ 1372 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1373 case PAYLOAD_BLOCK_UNMAPPED: 1374 case PAYLOAD_BLOCK_UNMAPPED_v095: 1375 case PAYLOAD_BLOCK_UNDEFINED: 1376 bat_prior_offset = sinfo.file_offset; 1377 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset, 1378 &use_zero_buffers); 1379 if (ret < 0) { 1380 goto exit; 1381 } 1382 /* 1383 * once we support differencing files, this may also be 1384 * partially present 1385 */ 1386 /* update block state to the newly specified state */ 1387 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1388 &bat_entry_offset, 1389 PAYLOAD_BLOCK_FULLY_PRESENT); 1390 bat_update = true; 1391 /* 1392 * Since we just allocated a block, file_offset is the 1393 * beginning of the payload block. It needs to be the 1394 * write address, which includes the offset into the 1395 * block, unless the entire block needs to read as 1396 * zeroes but truncation was not able to provide them, 1397 * in which case we need to fill in the rest. 1398 */ 1399 if (!use_zero_buffers) { 1400 sinfo.file_offset += sinfo.block_offset; 1401 } else { 1402 /* zero fill the front, if any */ 1403 if (sinfo.block_offset) { 1404 iov1.iov_len = sinfo.block_offset; 1405 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1406 memset(iov1.iov_base, 0, iov1.iov_len); 1407 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1408 iov1.iov_len); 1409 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1410 } 1411 1412 /* our actual data */ 1413 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1414 sinfo.bytes_avail); 1415 1416 /* zero fill the back, if any */ 1417 if ((sinfo.bytes_avail - sinfo.block_offset) < 1418 s->block_size) { 1419 iov2.iov_len = s->block_size - 1420 (sinfo.bytes_avail + sinfo.block_offset); 1421 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1422 memset(iov2.iov_base, 0, iov2.iov_len); 1423 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1424 iov2.iov_len); 1425 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1426 } 1427 } 1428 1429 /* fall through */ 1430 case PAYLOAD_BLOCK_FULLY_PRESENT: 1431 /* if the file offset address is in the header zone, 1432 * there is a problem */ 1433 if (sinfo.file_offset < (1 * MiB)) { 1434 ret = -EFAULT; 1435 goto error_bat_restore; 1436 } 1437 1438 if (!use_zero_buffers) { 1439 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1440 sinfo.bytes_avail); 1441 } 1442 /* block exists, so we can just overwrite it */ 1443 qemu_co_mutex_unlock(&s->lock); 1444 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset, 1445 sectors_to_write * BDRV_SECTOR_SIZE, 1446 &hd_qiov, 0); 1447 qemu_co_mutex_lock(&s->lock); 1448 if (ret < 0) { 1449 goto error_bat_restore; 1450 } 1451 break; 1452 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1453 /* we don't yet support difference files, fall through 1454 * to error */ 1455 default: 1456 ret = -EIO; 1457 goto exit; 1458 break; 1459 } 1460 1461 if (bat_update) { 1462 /* this will update the BAT entry into the log journal, and 1463 * then flush the log journal out to disk */ 1464 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1465 sizeof(VHDXBatEntry), 1466 bat_entry_offset); 1467 if (ret < 0) { 1468 goto exit; 1469 } 1470 } 1471 1472 nb_sectors -= sinfo.sectors_avail; 1473 sector_num += sinfo.sectors_avail; 1474 bytes_done += sinfo.bytes_avail; 1475 1476 } 1477 } 1478 1479 goto exit; 1480 1481 error_bat_restore: 1482 if (bat_update) { 1483 /* keep metadata in sync, and restore the bat entry state 1484 * if error. */ 1485 sinfo.file_offset = bat_prior_offset; 1486 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1487 &bat_entry_offset, bat_state); 1488 } 1489 exit: 1490 qemu_vfree(iov1.iov_base); 1491 qemu_vfree(iov2.iov_base); 1492 qemu_co_mutex_unlock(&s->lock); 1493 qemu_iovec_destroy(&hd_qiov); 1494 return ret; 1495 } 1496 1497 1498 1499 /* 1500 * Create VHDX Headers 1501 * 1502 * There are 2 headers, and the highest sequence number will represent 1503 * the active header 1504 */ 1505 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1506 uint32_t log_size) 1507 { 1508 BlockDriverState *bs = blk_bs(blk); 1509 BdrvChild *child; 1510 int ret = 0; 1511 VHDXHeader *hdr = NULL; 1512 1513 hdr = g_new0(VHDXHeader, 1); 1514 1515 hdr->signature = VHDX_HEADER_SIGNATURE; 1516 hdr->sequence_number = g_random_int(); 1517 hdr->log_version = 0; 1518 hdr->version = 1; 1519 hdr->log_length = log_size; 1520 hdr->log_offset = VHDX_HEADER_SECTION_END; 1521 vhdx_guid_generate(&hdr->file_write_guid); 1522 vhdx_guid_generate(&hdr->data_write_guid); 1523 1524 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1525 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1526 * here, which it really shouldn't be doing. */ 1527 child = QLIST_FIRST(&bs->parents); 1528 assert(!QLIST_NEXT(child, next_parent)); 1529 1530 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1531 if (ret < 0) { 1532 goto exit; 1533 } 1534 hdr->sequence_number++; 1535 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1536 if (ret < 0) { 1537 goto exit; 1538 } 1539 1540 exit: 1541 g_free(hdr); 1542 return ret; 1543 } 1544 1545 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1546 (sizeof(VHDXFileParameters) +\ 1547 sizeof(VHDXVirtualDiskSize) +\ 1548 sizeof(VHDXPage83Data) +\ 1549 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1550 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1551 1552 /* 1553 * Create the Metadata entries. 1554 * 1555 * For more details on the entries, see section 3.5 (pg 29) in the 1556 * VHDX 1.00 specification. 1557 * 1558 * We support 5 metadata entries (all required by spec): 1559 * File Parameters, 1560 * Virtual Disk Size, 1561 * Page 83 Data, 1562 * Logical Sector Size, 1563 * Physical Sector Size 1564 * 1565 * The first 64KB of the Metadata section is reserved for the metadata 1566 * header and entries; beyond that, the metadata items themselves reside. 1567 */ 1568 static int vhdx_create_new_metadata(BlockBackend *blk, 1569 uint64_t image_size, 1570 uint32_t block_size, 1571 uint32_t sector_size, 1572 uint64_t metadata_offset, 1573 VHDXImageType type) 1574 { 1575 int ret = 0; 1576 uint32_t offset = 0; 1577 void *buffer = NULL; 1578 void *entry_buffer; 1579 VHDXMetadataTableHeader *md_table; 1580 VHDXMetadataTableEntry *md_table_entry; 1581 1582 /* Metadata entries */ 1583 VHDXFileParameters *mt_file_params; 1584 VHDXVirtualDiskSize *mt_virtual_size; 1585 VHDXPage83Data *mt_page83; 1586 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1587 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1588 1589 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1590 1591 mt_file_params = entry_buffer; 1592 offset += sizeof(VHDXFileParameters); 1593 mt_virtual_size = entry_buffer + offset; 1594 offset += sizeof(VHDXVirtualDiskSize); 1595 mt_page83 = entry_buffer + offset; 1596 offset += sizeof(VHDXPage83Data); 1597 mt_log_sector_size = entry_buffer + offset; 1598 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1599 mt_phys_sector_size = entry_buffer + offset; 1600 1601 mt_file_params->block_size = cpu_to_le32(block_size); 1602 if (type == VHDX_TYPE_FIXED) { 1603 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1604 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1605 } 1606 1607 vhdx_guid_generate(&mt_page83->page_83_data); 1608 cpu_to_leguids(&mt_page83->page_83_data); 1609 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1610 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1611 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1612 1613 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1614 md_table = buffer; 1615 1616 md_table->signature = VHDX_METADATA_SIGNATURE; 1617 md_table->entry_count = 5; 1618 vhdx_metadata_header_le_export(md_table); 1619 1620 1621 /* This will reference beyond the reserved table portion */ 1622 offset = 64 * KiB; 1623 1624 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1625 1626 md_table_entry[0].item_id = file_param_guid; 1627 md_table_entry[0].offset = offset; 1628 md_table_entry[0].length = sizeof(VHDXFileParameters); 1629 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1630 offset += md_table_entry[0].length; 1631 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1632 1633 md_table_entry[1].item_id = virtual_size_guid; 1634 md_table_entry[1].offset = offset; 1635 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1636 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1637 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1638 offset += md_table_entry[1].length; 1639 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1640 1641 md_table_entry[2].item_id = page83_guid; 1642 md_table_entry[2].offset = offset; 1643 md_table_entry[2].length = sizeof(VHDXPage83Data); 1644 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1645 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1646 offset += md_table_entry[2].length; 1647 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1648 1649 md_table_entry[3].item_id = logical_sector_guid; 1650 md_table_entry[3].offset = offset; 1651 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1652 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1653 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1654 offset += md_table_entry[3].length; 1655 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1656 1657 md_table_entry[4].item_id = phys_sector_guid; 1658 md_table_entry[4].offset = offset; 1659 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1660 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1661 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1662 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1663 1664 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0); 1665 if (ret < 0) { 1666 goto exit; 1667 } 1668 1669 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer, 1670 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0); 1671 if (ret < 0) { 1672 goto exit; 1673 } 1674 1675 1676 exit: 1677 g_free(buffer); 1678 g_free(entry_buffer); 1679 return ret; 1680 } 1681 1682 /* This create the actual BAT itself. We currently only support 1683 * 'Dynamic' and 'Fixed' image types. 1684 * 1685 * Dynamic images: default state of the BAT is all zeroes. 1686 * 1687 * Fixed images: default state of the BAT is fully populated, with 1688 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1689 */ 1690 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1691 uint64_t image_size, VHDXImageType type, 1692 bool use_zero_blocks, uint64_t file_offset, 1693 uint32_t length, Error **errp) 1694 { 1695 int ret = 0; 1696 uint64_t data_file_offset; 1697 uint64_t total_sectors = 0; 1698 uint64_t sector_num = 0; 1699 uint64_t unused; 1700 int block_state; 1701 VHDXSectorInfo sinfo; 1702 1703 assert(s->bat == NULL); 1704 1705 /* this gives a data start after BAT/bitmap entries, and well 1706 * past any metadata entries (with a 4 MB buffer for future 1707 * expansion */ 1708 data_file_offset = file_offset + length + 5 * MiB; 1709 total_sectors = image_size >> s->logical_sector_size_bits; 1710 1711 if (type == VHDX_TYPE_DYNAMIC) { 1712 /* All zeroes, so we can just extend the file - the end of the BAT 1713 * is the furthest thing we have written yet */ 1714 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1715 0, errp); 1716 if (ret < 0) { 1717 goto exit; 1718 } 1719 } else if (type == VHDX_TYPE_FIXED) { 1720 ret = blk_truncate(blk, data_file_offset + image_size, false, 1721 PREALLOC_MODE_OFF, 0, errp); 1722 if (ret < 0) { 1723 goto exit; 1724 } 1725 } else { 1726 error_setg(errp, "Unsupported image type"); 1727 ret = -ENOTSUP; 1728 goto exit; 1729 } 1730 1731 if (type == VHDX_TYPE_FIXED || 1732 use_zero_blocks || 1733 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1734 /* for a fixed file, the default BAT entry is not zero */ 1735 s->bat = g_try_malloc0(length); 1736 if (length && s->bat == NULL) { 1737 error_setg(errp, "Failed to allocate memory for the BAT"); 1738 ret = -ENOMEM; 1739 goto exit; 1740 } 1741 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1742 PAYLOAD_BLOCK_NOT_PRESENT; 1743 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1744 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1745 while (sector_num < total_sectors) { 1746 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1747 sinfo.file_offset = data_file_offset + 1748 (sector_num << s->logical_sector_size_bits); 1749 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1750 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1751 block_state); 1752 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1753 sector_num += s->sectors_per_block; 1754 } 1755 ret = blk_pwrite(blk, file_offset, s->bat, length, 0); 1756 if (ret < 0) { 1757 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1758 goto exit; 1759 } 1760 } 1761 1762 1763 1764 exit: 1765 g_free(s->bat); 1766 return ret; 1767 } 1768 1769 /* Creates the region table header, and region table entries. 1770 * There are 2 supported region table entries: BAT, and Metadata/ 1771 * 1772 * As the calculations for the BAT region table are also needed 1773 * to create the BAT itself, we will also cause the BAT to be 1774 * created. 1775 */ 1776 static int vhdx_create_new_region_table(BlockBackend *blk, 1777 uint64_t image_size, 1778 uint32_t block_size, 1779 uint32_t sector_size, 1780 uint32_t log_size, 1781 bool use_zero_blocks, 1782 VHDXImageType type, 1783 uint64_t *metadata_offset, 1784 Error **errp) 1785 { 1786 int ret = 0; 1787 uint32_t offset = 0; 1788 void *buffer = NULL; 1789 uint64_t bat_file_offset; 1790 uint32_t bat_length; 1791 BDRVVHDXState *s = NULL; 1792 VHDXRegionTableHeader *region_table; 1793 VHDXRegionTableEntry *rt_bat; 1794 VHDXRegionTableEntry *rt_metadata; 1795 1796 assert(metadata_offset != NULL); 1797 1798 /* Populate enough of the BDRVVHDXState to be able to use the 1799 * pre-existing BAT calculation, translation, and update functions */ 1800 s = g_new0(BDRVVHDXState, 1); 1801 1802 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1803 (uint64_t) sector_size / (uint64_t) block_size; 1804 1805 s->sectors_per_block = block_size / sector_size; 1806 s->virtual_disk_size = image_size; 1807 s->block_size = block_size; 1808 s->logical_sector_size = sector_size; 1809 1810 vhdx_set_shift_bits(s); 1811 1812 vhdx_calc_bat_entries(s); 1813 1814 /* At this point the VHDX state is populated enough for creation */ 1815 1816 /* a single buffer is used so we can calculate the checksum over the 1817 * entire 64KB block */ 1818 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1819 region_table = buffer; 1820 offset += sizeof(VHDXRegionTableHeader); 1821 rt_bat = buffer + offset; 1822 offset += sizeof(VHDXRegionTableEntry); 1823 rt_metadata = buffer + offset; 1824 1825 region_table->signature = VHDX_REGION_SIGNATURE; 1826 region_table->entry_count = 2; /* BAT and Metadata */ 1827 1828 rt_bat->guid = bat_guid; 1829 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1830 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1831 s->bat_offset = rt_bat->file_offset; 1832 1833 rt_metadata->guid = metadata_guid; 1834 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1835 MiB); 1836 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1837 *metadata_offset = rt_metadata->file_offset; 1838 1839 bat_file_offset = rt_bat->file_offset; 1840 bat_length = rt_bat->length; 1841 1842 vhdx_region_header_le_export(region_table); 1843 vhdx_region_entry_le_export(rt_bat); 1844 vhdx_region_entry_le_export(rt_metadata); 1845 1846 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1847 offsetof(VHDXRegionTableHeader, checksum)); 1848 1849 1850 /* The region table gives us the data we need to create the BAT, 1851 * so do that now */ 1852 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1853 bat_file_offset, bat_length, errp); 1854 if (ret < 0) { 1855 goto exit; 1856 } 1857 1858 /* Now write out the region headers to disk */ 1859 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer, 1860 VHDX_HEADER_BLOCK_SIZE, 0); 1861 if (ret < 0) { 1862 error_setg_errno(errp, -ret, "Failed to write first region table"); 1863 goto exit; 1864 } 1865 1866 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer, 1867 VHDX_HEADER_BLOCK_SIZE, 0); 1868 if (ret < 0) { 1869 error_setg_errno(errp, -ret, "Failed to write second region table"); 1870 goto exit; 1871 } 1872 1873 exit: 1874 g_free(s); 1875 g_free(buffer); 1876 return ret; 1877 } 1878 1879 /* We need to create the following elements: 1880 * 1881 * .-----------------------------------------------------------------. 1882 * | (A) | (B) | (C) | (D) | (E) | 1883 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1884 * | | | | | | 1885 * .-----------------------------------------------------------------. 1886 * 0 64KB 128KB 192KB 256KB 320KB 1887 * 1888 * 1889 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1890 * | (F) | (G) | (H) | | 1891 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1892 * | | | | | 1893 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1894 * 1MB 1895 */ 1896 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts, 1897 Error **errp) 1898 { 1899 BlockdevCreateOptionsVhdx *vhdx_opts; 1900 BlockBackend *blk = NULL; 1901 BlockDriverState *bs = NULL; 1902 1903 int ret = 0; 1904 uint64_t image_size; 1905 uint32_t log_size; 1906 uint32_t block_size; 1907 uint64_t signature; 1908 uint64_t metadata_offset; 1909 bool use_zero_blocks = false; 1910 1911 gunichar2 *creator = NULL; 1912 glong creator_items; 1913 VHDXImageType image_type; 1914 1915 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1916 vhdx_opts = &opts->u.vhdx; 1917 1918 /* Validate options and set default values */ 1919 image_size = vhdx_opts->size; 1920 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1921 error_setg(errp, "Image size too large; max of 64TB"); 1922 return -EINVAL; 1923 } 1924 1925 if (!vhdx_opts->has_log_size) { 1926 log_size = DEFAULT_LOG_SIZE; 1927 } else { 1928 if (vhdx_opts->log_size > UINT32_MAX) { 1929 error_setg(errp, "Log size must be smaller than 4 GB"); 1930 return -EINVAL; 1931 } 1932 log_size = vhdx_opts->log_size; 1933 } 1934 if (log_size < MiB || (log_size % MiB) != 0) { 1935 error_setg(errp, "Log size must be a multiple of 1 MB"); 1936 return -EINVAL; 1937 } 1938 1939 if (!vhdx_opts->has_block_state_zero) { 1940 use_zero_blocks = true; 1941 } else { 1942 use_zero_blocks = vhdx_opts->block_state_zero; 1943 } 1944 1945 if (!vhdx_opts->has_subformat) { 1946 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1947 } 1948 1949 switch (vhdx_opts->subformat) { 1950 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1951 image_type = VHDX_TYPE_DYNAMIC; 1952 break; 1953 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1954 image_type = VHDX_TYPE_FIXED; 1955 break; 1956 default: 1957 g_assert_not_reached(); 1958 } 1959 1960 /* These are pretty arbitrary, and mainly designed to keep the BAT 1961 * size reasonable to load into RAM */ 1962 if (vhdx_opts->has_block_size) { 1963 block_size = vhdx_opts->block_size; 1964 } else { 1965 if (image_size > 32 * TiB) { 1966 block_size = 64 * MiB; 1967 } else if (image_size > (uint64_t) 100 * GiB) { 1968 block_size = 32 * MiB; 1969 } else if (image_size > 1 * GiB) { 1970 block_size = 16 * MiB; 1971 } else { 1972 block_size = 8 * MiB; 1973 } 1974 } 1975 1976 if (block_size < MiB || (block_size % MiB) != 0) { 1977 error_setg(errp, "Block size must be a multiple of 1 MB"); 1978 return -EINVAL; 1979 } 1980 if (!is_power_of_2(block_size)) { 1981 error_setg(errp, "Block size must be a power of two"); 1982 return -EINVAL; 1983 } 1984 if (block_size > VHDX_BLOCK_SIZE_MAX) { 1985 error_setg(errp, "Block size must not exceed %" PRId64, 1986 VHDX_BLOCK_SIZE_MAX); 1987 return -EINVAL; 1988 } 1989 1990 /* Create BlockBackend to write to the image */ 1991 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp); 1992 if (bs == NULL) { 1993 return -EIO; 1994 } 1995 1996 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 1997 errp); 1998 if (!blk) { 1999 ret = -EPERM; 2000 goto delete_and_exit; 2001 } 2002 blk_set_allow_write_beyond_eof(blk, true); 2003 2004 /* Create (A) */ 2005 2006 /* The creator field is optional, but may be useful for 2007 * debugging / diagnostics */ 2008 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2009 &creator_items, NULL); 2010 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2011 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature), 2012 0); 2013 if (ret < 0) { 2014 error_setg_errno(errp, -ret, "Failed to write file signature"); 2015 goto delete_and_exit; 2016 } 2017 if (creator) { 2018 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2019 creator, creator_items * sizeof(gunichar2), 0); 2020 if (ret < 0) { 2021 error_setg_errno(errp, -ret, "Failed to write creator field"); 2022 goto delete_and_exit; 2023 } 2024 } 2025 2026 2027 /* Creates (B),(C) */ 2028 ret = vhdx_create_new_headers(blk, image_size, log_size); 2029 if (ret < 0) { 2030 error_setg_errno(errp, -ret, "Failed to write image headers"); 2031 goto delete_and_exit; 2032 } 2033 2034 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2035 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2036 log_size, use_zero_blocks, image_type, 2037 &metadata_offset, errp); 2038 if (ret < 0) { 2039 goto delete_and_exit; 2040 } 2041 2042 /* Creates (H) */ 2043 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2044 metadata_offset, image_type); 2045 if (ret < 0) { 2046 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2047 goto delete_and_exit; 2048 } 2049 2050 ret = 0; 2051 delete_and_exit: 2052 blk_unref(blk); 2053 bdrv_unref(bs); 2054 g_free(creator); 2055 return ret; 2056 } 2057 2058 static int coroutine_fn vhdx_co_create_opts(BlockDriver *drv, 2059 const char *filename, 2060 QemuOpts *opts, 2061 Error **errp) 2062 { 2063 BlockdevCreateOptions *create_options = NULL; 2064 QDict *qdict; 2065 Visitor *v; 2066 BlockDriverState *bs = NULL; 2067 int ret; 2068 2069 static const QDictRenames opt_renames[] = { 2070 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" }, 2071 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" }, 2072 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" }, 2073 { NULL, NULL }, 2074 }; 2075 2076 /* Parse options and convert legacy syntax */ 2077 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true); 2078 2079 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 2080 ret = -EINVAL; 2081 goto fail; 2082 } 2083 2084 /* Create and open the file (protocol layer) */ 2085 ret = bdrv_create_file(filename, opts, errp); 2086 if (ret < 0) { 2087 goto fail; 2088 } 2089 2090 bs = bdrv_open(filename, NULL, NULL, 2091 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 2092 if (bs == NULL) { 2093 ret = -EIO; 2094 goto fail; 2095 } 2096 2097 /* Now get the QAPI type BlockdevCreateOptions */ 2098 qdict_put_str(qdict, "driver", "vhdx"); 2099 qdict_put_str(qdict, "file", bs->node_name); 2100 2101 v = qobject_input_visitor_new_flat_confused(qdict, errp); 2102 if (!v) { 2103 ret = -EINVAL; 2104 goto fail; 2105 } 2106 2107 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 2108 visit_free(v); 2109 if (!create_options) { 2110 ret = -EINVAL; 2111 goto fail; 2112 } 2113 2114 /* Silently round up sizes: 2115 * The image size is rounded to 512 bytes. Make the block and log size 2116 * close to what was specified, but must be at least 1MB, and a multiple of 2117 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0 2118 * means auto, which is represented by a missing key in QAPI. */ 2119 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX); 2120 create_options->u.vhdx.size = 2121 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE); 2122 2123 if (create_options->u.vhdx.has_log_size) { 2124 create_options->u.vhdx.log_size = 2125 ROUND_UP(create_options->u.vhdx.log_size, MiB); 2126 } 2127 if (create_options->u.vhdx.has_block_size) { 2128 create_options->u.vhdx.block_size = 2129 ROUND_UP(create_options->u.vhdx.block_size, MiB); 2130 2131 if (create_options->u.vhdx.block_size == 0) { 2132 create_options->u.vhdx.has_block_size = false; 2133 } 2134 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) { 2135 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX; 2136 } 2137 } 2138 2139 /* Create the vhdx image (format layer) */ 2140 ret = vhdx_co_create(create_options, errp); 2141 2142 fail: 2143 qobject_unref(qdict); 2144 bdrv_unref(bs); 2145 qapi_free_BlockdevCreateOptions(create_options); 2146 return ret; 2147 } 2148 2149 /* If opened r/w, the VHDX driver will automatically replay the log, 2150 * if one is present, inside the vhdx_open() call. 2151 * 2152 * If qemu-img check -r all is called, the image is automatically opened 2153 * r/w and any log has already been replayed, so there is nothing (currently) 2154 * for us to do here 2155 */ 2156 static int coroutine_fn vhdx_co_check(BlockDriverState *bs, 2157 BdrvCheckResult *result, 2158 BdrvCheckMode fix) 2159 { 2160 BDRVVHDXState *s = bs->opaque; 2161 2162 if (s->log_replayed_on_open) { 2163 result->corruptions_fixed++; 2164 } 2165 2166 vhdx_check_bat_entries(bs, &result->corruptions); 2167 2168 return 0; 2169 } 2170 2171 static int vhdx_has_zero_init(BlockDriverState *bs) 2172 { 2173 BDRVVHDXState *s = bs->opaque; 2174 int state; 2175 2176 /* 2177 * Check the subformat: Fixed images have all BAT entries present, 2178 * dynamic images have none (right after creation). It is 2179 * therefore enough to check the first BAT entry. 2180 */ 2181 if (!s->bat_entries) { 2182 return 1; 2183 } 2184 2185 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK; 2186 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) { 2187 /* Fixed subformat */ 2188 return bdrv_has_zero_init(bs->file->bs); 2189 } 2190 2191 /* Dynamic subformat */ 2192 return 1; 2193 } 2194 2195 static QemuOptsList vhdx_create_opts = { 2196 .name = "vhdx-create-opts", 2197 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 2198 .desc = { 2199 { 2200 .name = BLOCK_OPT_SIZE, 2201 .type = QEMU_OPT_SIZE, 2202 .help = "Virtual disk size; max of 64TB." 2203 }, 2204 { 2205 .name = VHDX_BLOCK_OPT_LOG_SIZE, 2206 .type = QEMU_OPT_SIZE, 2207 .def_value_str = stringify(DEFAULT_LOG_SIZE), 2208 .help = "Log size; min 1MB." 2209 }, 2210 { 2211 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 2212 .type = QEMU_OPT_SIZE, 2213 .def_value_str = stringify(0), 2214 .help = "Block Size; min 1MB, max 256MB. " 2215 "0 means auto-calculate based on image size." 2216 }, 2217 { 2218 .name = BLOCK_OPT_SUBFMT, 2219 .type = QEMU_OPT_STRING, 2220 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. " 2221 "Default is 'dynamic'." 2222 }, 2223 { 2224 .name = VHDX_BLOCK_OPT_ZERO, 2225 .type = QEMU_OPT_BOOL, 2226 .help = "Force use of payload blocks of type 'ZERO'. " 2227 "Non-standard, but default. Do not set to 'off' when " 2228 "using 'qemu-img convert' with subformat=dynamic." 2229 }, 2230 { NULL } 2231 } 2232 }; 2233 2234 static BlockDriver bdrv_vhdx = { 2235 .format_name = "vhdx", 2236 .instance_size = sizeof(BDRVVHDXState), 2237 .bdrv_probe = vhdx_probe, 2238 .bdrv_open = vhdx_open, 2239 .bdrv_close = vhdx_close, 2240 .bdrv_reopen_prepare = vhdx_reopen_prepare, 2241 .bdrv_child_perm = bdrv_default_perms, 2242 .bdrv_co_readv = vhdx_co_readv, 2243 .bdrv_co_writev = vhdx_co_writev, 2244 .bdrv_co_create = vhdx_co_create, 2245 .bdrv_co_create_opts = vhdx_co_create_opts, 2246 .bdrv_get_info = vhdx_get_info, 2247 .bdrv_co_check = vhdx_co_check, 2248 .bdrv_has_zero_init = vhdx_has_zero_init, 2249 2250 .is_format = true, 2251 .create_opts = &vhdx_create_opts, 2252 }; 2253 2254 static void bdrv_vhdx_init(void) 2255 { 2256 bdrv_register(&bdrv_vhdx); 2257 } 2258 2259 block_init(bdrv_vhdx_init); 2260