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 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 1005 if (ret < 0) { 1006 return ret; 1007 } 1008 1009 s->bat = NULL; 1010 s->first_visible_write = true; 1011 1012 qemu_co_mutex_init(&s->lock); 1013 QLIST_INIT(&s->regions); 1014 1015 /* validate the file signature */ 1016 ret = bdrv_pread(bs->file, 0, sizeof(uint64_t), &signature, 0); 1017 if (ret < 0) { 1018 goto fail; 1019 } 1020 if (memcmp(&signature, "vhdxfile", 8)) { 1021 ret = -EINVAL; 1022 goto fail; 1023 } 1024 1025 /* This is used for any header updates, for the file_write_guid. 1026 * The spec dictates that a new value should be used for the first 1027 * header update */ 1028 vhdx_guid_generate(&s->session_guid); 1029 1030 vhdx_parse_header(bs, s, &local_err); 1031 if (local_err != NULL) { 1032 error_propagate(errp, local_err); 1033 ret = -EINVAL; 1034 goto fail; 1035 } 1036 1037 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1038 if (ret < 0) { 1039 goto fail; 1040 } 1041 1042 ret = vhdx_open_region_tables(bs, s); 1043 if (ret < 0) { 1044 goto fail; 1045 } 1046 1047 ret = vhdx_parse_metadata(bs, s); 1048 if (ret < 0) { 1049 goto fail; 1050 } 1051 1052 s->block_size = s->params.block_size; 1053 1054 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1055 * logical_sector_size */ 1056 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1057 1058 vhdx_calc_bat_entries(s); 1059 1060 s->bat_offset = s->bat_rt.file_offset; 1061 1062 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1063 /* BAT allocation is not large enough for all entries */ 1064 ret = -EINVAL; 1065 goto fail; 1066 } 1067 1068 /* s->bat is freed in vhdx_close() */ 1069 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1070 if (s->bat == NULL) { 1071 ret = -ENOMEM; 1072 goto fail; 1073 } 1074 1075 ret = bdrv_pread(bs->file, s->bat_offset, s->bat_rt.length, s->bat, 0); 1076 if (ret < 0) { 1077 goto fail; 1078 } 1079 1080 /* endian convert populated BAT field entires */ 1081 for (i = 0; i < s->bat_entries; i++) { 1082 s->bat[i] = le64_to_cpu(s->bat[i]); 1083 } 1084 1085 if (!(flags & BDRV_O_CHECK)) { 1086 ret = vhdx_check_bat_entries(bs, NULL); 1087 if (ret < 0) { 1088 goto fail; 1089 } 1090 } 1091 1092 /* Disable migration when VHDX images are used */ 1093 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1094 "does not support live migration", 1095 bdrv_get_device_or_node_name(bs)); 1096 ret = migrate_add_blocker(s->migration_blocker, errp); 1097 if (ret < 0) { 1098 error_free(s->migration_blocker); 1099 goto fail; 1100 } 1101 1102 /* TODO: differencing files */ 1103 1104 return 0; 1105 fail: 1106 vhdx_close(bs); 1107 return ret; 1108 } 1109 1110 static int vhdx_reopen_prepare(BDRVReopenState *state, 1111 BlockReopenQueue *queue, Error **errp) 1112 { 1113 return 0; 1114 } 1115 1116 1117 /* 1118 * Perform sector to block offset translations, to get various 1119 * sector and file offsets into the image. See VHDXSectorInfo 1120 */ 1121 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1122 int nb_sectors, VHDXSectorInfo *sinfo) 1123 { 1124 uint32_t block_offset; 1125 1126 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1127 /* effectively a modulo - this gives us the offset into the block 1128 * (in sector sizes) for our sector number */ 1129 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1130 /* the chunk ratio gives us the interleaving of the sector 1131 * bitmaps, so we need to advance our page block index by the 1132 * sector bitmaps entry number */ 1133 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1134 1135 /* the number of sectors we can read/write in this cycle */ 1136 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1137 1138 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1139 1140 if (sinfo->sectors_avail > nb_sectors) { 1141 sinfo->sectors_avail = nb_sectors; 1142 } 1143 1144 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1145 1146 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1147 1148 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1149 1150 /* The file offset must be past the header section, so must be > 0 */ 1151 if (sinfo->file_offset == 0) { 1152 return; 1153 } 1154 1155 /* block offset is the offset in vhdx logical sectors, in 1156 * the payload data block. Convert that to a byte offset 1157 * in the block, and add in the payload data block offset 1158 * in the file, in bytes, to get the final read address */ 1159 1160 sinfo->file_offset += sinfo->block_offset; 1161 } 1162 1163 1164 static int coroutine_fn 1165 vhdx_co_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 int coroutine_fn GRAPH_RDLOCK 1176 vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 1177 QEMUIOVector *qiov) 1178 { 1179 BDRVVHDXState *s = bs->opaque; 1180 int ret = 0; 1181 VHDXSectorInfo sinfo; 1182 uint64_t bytes_done = 0; 1183 QEMUIOVector hd_qiov; 1184 1185 qemu_iovec_init(&hd_qiov, qiov->niov); 1186 1187 qemu_co_mutex_lock(&s->lock); 1188 1189 while (nb_sectors > 0) { 1190 /* We are a differencing file, so we need to inspect the sector bitmap 1191 * to see if we have the data or not */ 1192 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1193 /* not supported yet */ 1194 ret = -ENOTSUP; 1195 goto exit; 1196 } else { 1197 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1198 1199 qemu_iovec_reset(&hd_qiov); 1200 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1201 1202 /* check the payload block state */ 1203 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1204 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1205 case PAYLOAD_BLOCK_UNDEFINED: 1206 case PAYLOAD_BLOCK_UNMAPPED: 1207 case PAYLOAD_BLOCK_UNMAPPED_v095: 1208 case PAYLOAD_BLOCK_ZERO: 1209 /* return zero */ 1210 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1211 break; 1212 case PAYLOAD_BLOCK_FULLY_PRESENT: 1213 qemu_co_mutex_unlock(&s->lock); 1214 ret = bdrv_co_preadv(bs->file, sinfo.file_offset, 1215 sinfo.sectors_avail * BDRV_SECTOR_SIZE, 1216 &hd_qiov, 0); 1217 qemu_co_mutex_lock(&s->lock); 1218 if (ret < 0) { 1219 goto exit; 1220 } 1221 break; 1222 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1223 /* we don't yet support difference files, fall through 1224 * to error */ 1225 default: 1226 ret = -EIO; 1227 goto exit; 1228 break; 1229 } 1230 nb_sectors -= sinfo.sectors_avail; 1231 sector_num += sinfo.sectors_avail; 1232 bytes_done += sinfo.bytes_avail; 1233 } 1234 } 1235 ret = 0; 1236 exit: 1237 qemu_co_mutex_unlock(&s->lock); 1238 qemu_iovec_destroy(&hd_qiov); 1239 return ret; 1240 } 1241 1242 /* 1243 * Allocate a new payload block at the end of the file. 1244 * 1245 * Allocation will happen at 1MB alignment inside the file. 1246 * 1247 * If @need_zero is set on entry but not cleared on return, then truncation 1248 * could not guarantee that the new portion reads as zero, and the caller 1249 * will take care of it instead. 1250 * 1251 * Returns the file offset start of the new payload block 1252 */ 1253 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1254 uint64_t *new_offset, bool *need_zero) 1255 { 1256 int64_t current_len; 1257 1258 current_len = bdrv_getlength(bs->file->bs); 1259 if (current_len < 0) { 1260 return current_len; 1261 } 1262 1263 *new_offset = current_len; 1264 1265 /* per the spec, the address for a block is in units of 1MB */ 1266 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1267 if (*new_offset > INT64_MAX) { 1268 return -EINVAL; 1269 } 1270 1271 if (*need_zero) { 1272 int ret; 1273 1274 ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1275 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL); 1276 if (ret != -ENOTSUP) { 1277 *need_zero = false; 1278 return ret; 1279 } 1280 } 1281 1282 return bdrv_truncate(bs->file, *new_offset + s->block_size, false, 1283 PREALLOC_MODE_OFF, 0, NULL); 1284 } 1285 1286 /* 1287 * Update the BAT table entry with the new file offset, and the new entry 1288 * state */ 1289 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1290 VHDXSectorInfo *sinfo, 1291 uint64_t *bat_entry_le, 1292 uint64_t *bat_offset, int state) 1293 { 1294 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1295 * 1MB, and 3 bits for the block state. */ 1296 if ((state == PAYLOAD_BLOCK_ZERO) || 1297 (state == PAYLOAD_BLOCK_UNDEFINED) || 1298 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1299 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1300 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1301 FileOffsetMB field is denoted as 1302 'reserved' in the v1.0 spec. If it is 1303 non-zero, MS Hyper-V will fail to read 1304 the disk image */ 1305 } else { 1306 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1307 } 1308 1309 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1310 1311 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1312 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1313 1314 } 1315 1316 /* Per the spec, on the first write of guest-visible data to the file the 1317 * data write guid must be updated in the header */ 1318 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1319 { 1320 int ret = 0; 1321 if (s->first_visible_write) { 1322 s->first_visible_write = false; 1323 ret = vhdx_update_headers(bs, s, true, NULL); 1324 } 1325 return ret; 1326 } 1327 1328 static int coroutine_fn GRAPH_RDLOCK 1329 vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 1330 QEMUIOVector *qiov, int flags) 1331 { 1332 int ret = -ENOTSUP; 1333 BDRVVHDXState *s = bs->opaque; 1334 VHDXSectorInfo sinfo; 1335 uint64_t bytes_done = 0; 1336 uint64_t bat_entry = 0; 1337 uint64_t bat_entry_offset = 0; 1338 QEMUIOVector hd_qiov; 1339 struct iovec iov1 = { 0 }; 1340 struct iovec iov2 = { 0 }; 1341 int sectors_to_write; 1342 int bat_state; 1343 uint64_t bat_prior_offset = 0; 1344 bool bat_update = false; 1345 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 coroutine_fn GRAPH_RDLOCK 1510 vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1511 uint32_t log_size) 1512 { 1513 BlockDriverState *bs = blk_bs(blk); 1514 BdrvChild *child; 1515 int ret = 0; 1516 VHDXHeader *hdr = NULL; 1517 1518 hdr = g_new0(VHDXHeader, 1); 1519 1520 hdr->signature = VHDX_HEADER_SIGNATURE; 1521 hdr->sequence_number = g_random_int(); 1522 hdr->log_version = 0; 1523 hdr->version = 1; 1524 hdr->log_length = log_size; 1525 hdr->log_offset = VHDX_HEADER_SECTION_END; 1526 vhdx_guid_generate(&hdr->file_write_guid); 1527 vhdx_guid_generate(&hdr->data_write_guid); 1528 1529 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1530 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1531 * here, which it really shouldn't be doing. */ 1532 child = QLIST_FIRST(&bs->parents); 1533 assert(!QLIST_NEXT(child, next_parent)); 1534 1535 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1536 if (ret < 0) { 1537 goto exit; 1538 } 1539 hdr->sequence_number++; 1540 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1541 if (ret < 0) { 1542 goto exit; 1543 } 1544 1545 exit: 1546 g_free(hdr); 1547 return ret; 1548 } 1549 1550 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1551 (sizeof(VHDXFileParameters) +\ 1552 sizeof(VHDXVirtualDiskSize) +\ 1553 sizeof(VHDXPage83Data) +\ 1554 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1555 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1556 1557 /* 1558 * Create the Metadata entries. 1559 * 1560 * For more details on the entries, see section 3.5 (pg 29) in the 1561 * VHDX 1.00 specification. 1562 * 1563 * We support 5 metadata entries (all required by spec): 1564 * File Parameters, 1565 * Virtual Disk Size, 1566 * Page 83 Data, 1567 * Logical Sector Size, 1568 * Physical Sector Size 1569 * 1570 * The first 64KB of the Metadata section is reserved for the metadata 1571 * header and entries; beyond that, the metadata items themselves reside. 1572 */ 1573 static int vhdx_create_new_metadata(BlockBackend *blk, 1574 uint64_t image_size, 1575 uint32_t block_size, 1576 uint32_t sector_size, 1577 uint64_t metadata_offset, 1578 VHDXImageType type) 1579 { 1580 int ret = 0; 1581 uint32_t offset = 0; 1582 void *buffer = NULL; 1583 void *entry_buffer; 1584 VHDXMetadataTableHeader *md_table; 1585 VHDXMetadataTableEntry *md_table_entry; 1586 1587 /* Metadata entries */ 1588 VHDXFileParameters *mt_file_params; 1589 VHDXVirtualDiskSize *mt_virtual_size; 1590 VHDXPage83Data *mt_page83; 1591 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1592 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1593 1594 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1595 1596 mt_file_params = entry_buffer; 1597 offset += sizeof(VHDXFileParameters); 1598 mt_virtual_size = entry_buffer + offset; 1599 offset += sizeof(VHDXVirtualDiskSize); 1600 mt_page83 = entry_buffer + offset; 1601 offset += sizeof(VHDXPage83Data); 1602 mt_log_sector_size = entry_buffer + offset; 1603 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1604 mt_phys_sector_size = entry_buffer + offset; 1605 1606 mt_file_params->block_size = cpu_to_le32(block_size); 1607 if (type == VHDX_TYPE_FIXED) { 1608 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1609 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1610 } 1611 1612 vhdx_guid_generate(&mt_page83->page_83_data); 1613 cpu_to_leguids(&mt_page83->page_83_data); 1614 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1615 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1616 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1617 1618 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1619 md_table = buffer; 1620 1621 md_table->signature = VHDX_METADATA_SIGNATURE; 1622 md_table->entry_count = 5; 1623 vhdx_metadata_header_le_export(md_table); 1624 1625 1626 /* This will reference beyond the reserved table portion */ 1627 offset = 64 * KiB; 1628 1629 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1630 1631 md_table_entry[0].item_id = file_param_guid; 1632 md_table_entry[0].offset = offset; 1633 md_table_entry[0].length = sizeof(VHDXFileParameters); 1634 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1635 offset += md_table_entry[0].length; 1636 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1637 1638 md_table_entry[1].item_id = virtual_size_guid; 1639 md_table_entry[1].offset = offset; 1640 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1641 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1642 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1643 offset += md_table_entry[1].length; 1644 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1645 1646 md_table_entry[2].item_id = page83_guid; 1647 md_table_entry[2].offset = offset; 1648 md_table_entry[2].length = sizeof(VHDXPage83Data); 1649 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1650 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1651 offset += md_table_entry[2].length; 1652 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1653 1654 md_table_entry[3].item_id = logical_sector_guid; 1655 md_table_entry[3].offset = offset; 1656 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1657 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1658 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1659 offset += md_table_entry[3].length; 1660 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1661 1662 md_table_entry[4].item_id = phys_sector_guid; 1663 md_table_entry[4].offset = offset; 1664 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1665 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1666 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1667 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1668 1669 ret = blk_pwrite(blk, metadata_offset, VHDX_HEADER_BLOCK_SIZE, buffer, 0); 1670 if (ret < 0) { 1671 goto exit; 1672 } 1673 1674 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), 1675 VHDX_METADATA_ENTRY_BUFFER_SIZE, entry_buffer, 0); 1676 if (ret < 0) { 1677 goto exit; 1678 } 1679 1680 1681 exit: 1682 g_free(buffer); 1683 g_free(entry_buffer); 1684 return ret; 1685 } 1686 1687 /* This create the actual BAT itself. We currently only support 1688 * 'Dynamic' and 'Fixed' image types. 1689 * 1690 * Dynamic images: default state of the BAT is all zeroes. 1691 * 1692 * Fixed images: default state of the BAT is fully populated, with 1693 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1694 */ 1695 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1696 uint64_t image_size, VHDXImageType type, 1697 bool use_zero_blocks, uint64_t file_offset, 1698 uint32_t length, Error **errp) 1699 { 1700 int ret = 0; 1701 uint64_t data_file_offset; 1702 uint64_t total_sectors = 0; 1703 uint64_t sector_num = 0; 1704 uint64_t unused; 1705 int block_state; 1706 VHDXSectorInfo sinfo; 1707 1708 assert(s->bat == NULL); 1709 1710 /* this gives a data start after BAT/bitmap entries, and well 1711 * past any metadata entries (with a 4 MB buffer for future 1712 * expansion */ 1713 data_file_offset = file_offset + length + 5 * MiB; 1714 total_sectors = image_size >> s->logical_sector_size_bits; 1715 1716 if (type == VHDX_TYPE_DYNAMIC) { 1717 /* All zeroes, so we can just extend the file - the end of the BAT 1718 * is the furthest thing we have written yet */ 1719 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1720 0, errp); 1721 if (ret < 0) { 1722 goto exit; 1723 } 1724 } else if (type == VHDX_TYPE_FIXED) { 1725 ret = blk_truncate(blk, data_file_offset + image_size, false, 1726 PREALLOC_MODE_OFF, 0, errp); 1727 if (ret < 0) { 1728 goto exit; 1729 } 1730 } else { 1731 error_setg(errp, "Unsupported image type"); 1732 ret = -ENOTSUP; 1733 goto exit; 1734 } 1735 1736 if (type == VHDX_TYPE_FIXED || 1737 use_zero_blocks || 1738 bdrv_has_zero_init(blk_bs(blk)) == 0) { 1739 /* for a fixed file, the default BAT entry is not zero */ 1740 s->bat = g_try_malloc0(length); 1741 if (length && s->bat == NULL) { 1742 error_setg(errp, "Failed to allocate memory for the BAT"); 1743 ret = -ENOMEM; 1744 goto exit; 1745 } 1746 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1747 PAYLOAD_BLOCK_NOT_PRESENT; 1748 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1749 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1750 while (sector_num < total_sectors) { 1751 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1752 sinfo.file_offset = data_file_offset + 1753 (sector_num << s->logical_sector_size_bits); 1754 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1755 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1756 block_state); 1757 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1758 sector_num += s->sectors_per_block; 1759 } 1760 ret = blk_pwrite(blk, file_offset, length, s->bat, 0); 1761 if (ret < 0) { 1762 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1763 goto exit; 1764 } 1765 } 1766 1767 1768 1769 exit: 1770 g_free(s->bat); 1771 return ret; 1772 } 1773 1774 /* Creates the region table header, and region table entries. 1775 * There are 2 supported region table entries: BAT, and Metadata/ 1776 * 1777 * As the calculations for the BAT region table are also needed 1778 * to create the BAT itself, we will also cause the BAT to be 1779 * created. 1780 */ 1781 static int vhdx_create_new_region_table(BlockBackend *blk, 1782 uint64_t image_size, 1783 uint32_t block_size, 1784 uint32_t sector_size, 1785 uint32_t log_size, 1786 bool use_zero_blocks, 1787 VHDXImageType type, 1788 uint64_t *metadata_offset, 1789 Error **errp) 1790 { 1791 int ret = 0; 1792 uint32_t offset = 0; 1793 void *buffer = NULL; 1794 uint64_t bat_file_offset; 1795 uint32_t bat_length; 1796 BDRVVHDXState *s = NULL; 1797 VHDXRegionTableHeader *region_table; 1798 VHDXRegionTableEntry *rt_bat; 1799 VHDXRegionTableEntry *rt_metadata; 1800 1801 assert(metadata_offset != NULL); 1802 1803 /* Populate enough of the BDRVVHDXState to be able to use the 1804 * pre-existing BAT calculation, translation, and update functions */ 1805 s = g_new0(BDRVVHDXState, 1); 1806 1807 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1808 (uint64_t) sector_size / (uint64_t) block_size; 1809 1810 s->sectors_per_block = block_size / sector_size; 1811 s->virtual_disk_size = image_size; 1812 s->block_size = block_size; 1813 s->logical_sector_size = sector_size; 1814 1815 vhdx_set_shift_bits(s); 1816 1817 vhdx_calc_bat_entries(s); 1818 1819 /* At this point the VHDX state is populated enough for creation */ 1820 1821 /* a single buffer is used so we can calculate the checksum over the 1822 * entire 64KB block */ 1823 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1824 region_table = buffer; 1825 offset += sizeof(VHDXRegionTableHeader); 1826 rt_bat = buffer + offset; 1827 offset += sizeof(VHDXRegionTableEntry); 1828 rt_metadata = buffer + offset; 1829 1830 region_table->signature = VHDX_REGION_SIGNATURE; 1831 region_table->entry_count = 2; /* BAT and Metadata */ 1832 1833 rt_bat->guid = bat_guid; 1834 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1835 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1836 s->bat_offset = rt_bat->file_offset; 1837 1838 rt_metadata->guid = metadata_guid; 1839 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1840 MiB); 1841 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1842 *metadata_offset = rt_metadata->file_offset; 1843 1844 bat_file_offset = rt_bat->file_offset; 1845 bat_length = rt_bat->length; 1846 1847 vhdx_region_header_le_export(region_table); 1848 vhdx_region_entry_le_export(rt_bat); 1849 vhdx_region_entry_le_export(rt_metadata); 1850 1851 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1852 offsetof(VHDXRegionTableHeader, checksum)); 1853 1854 1855 /* The region table gives us the data we need to create the BAT, 1856 * so do that now */ 1857 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1858 bat_file_offset, bat_length, errp); 1859 if (ret < 0) { 1860 goto exit; 1861 } 1862 1863 /* Now write out the region headers to disk */ 1864 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1865 buffer, 0); 1866 if (ret < 0) { 1867 error_setg_errno(errp, -ret, "Failed to write first region table"); 1868 goto exit; 1869 } 1870 1871 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1872 buffer, 0); 1873 if (ret < 0) { 1874 error_setg_errno(errp, -ret, "Failed to write second region table"); 1875 goto exit; 1876 } 1877 1878 exit: 1879 g_free(s); 1880 g_free(buffer); 1881 return ret; 1882 } 1883 1884 /* We need to create the following elements: 1885 * 1886 * .-----------------------------------------------------------------. 1887 * | (A) | (B) | (C) | (D) | (E) | 1888 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1889 * | | | | | | 1890 * .-----------------------------------------------------------------. 1891 * 0 64KB 128KB 192KB 256KB 320KB 1892 * 1893 * 1894 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1895 * | (F) | (G) | (H) | | 1896 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1897 * | | | | | 1898 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1899 * 1MB 1900 */ 1901 static int coroutine_fn GRAPH_RDLOCK 1902 vhdx_co_create(BlockdevCreateOptions *opts, Error **errp) 1903 { 1904 BlockdevCreateOptionsVhdx *vhdx_opts; 1905 BlockBackend *blk = NULL; 1906 BlockDriverState *bs = NULL; 1907 1908 int ret = 0; 1909 uint64_t image_size; 1910 uint32_t log_size; 1911 uint32_t block_size; 1912 uint64_t signature; 1913 uint64_t metadata_offset; 1914 bool use_zero_blocks = false; 1915 1916 gunichar2 *creator = NULL; 1917 glong creator_items; 1918 VHDXImageType image_type; 1919 1920 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1921 vhdx_opts = &opts->u.vhdx; 1922 1923 /* Validate options and set default values */ 1924 image_size = vhdx_opts->size; 1925 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1926 error_setg(errp, "Image size too large; max of 64TB"); 1927 return -EINVAL; 1928 } 1929 1930 if (!vhdx_opts->has_log_size) { 1931 log_size = DEFAULT_LOG_SIZE; 1932 } else { 1933 if (vhdx_opts->log_size > UINT32_MAX) { 1934 error_setg(errp, "Log size must be smaller than 4 GB"); 1935 return -EINVAL; 1936 } 1937 log_size = vhdx_opts->log_size; 1938 } 1939 if (log_size < MiB || (log_size % MiB) != 0) { 1940 error_setg(errp, "Log size must be a multiple of 1 MB"); 1941 return -EINVAL; 1942 } 1943 1944 if (!vhdx_opts->has_block_state_zero) { 1945 use_zero_blocks = true; 1946 } else { 1947 use_zero_blocks = vhdx_opts->block_state_zero; 1948 } 1949 1950 if (!vhdx_opts->has_subformat) { 1951 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1952 } 1953 1954 switch (vhdx_opts->subformat) { 1955 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1956 image_type = VHDX_TYPE_DYNAMIC; 1957 break; 1958 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1959 image_type = VHDX_TYPE_FIXED; 1960 break; 1961 default: 1962 g_assert_not_reached(); 1963 } 1964 1965 /* These are pretty arbitrary, and mainly designed to keep the BAT 1966 * size reasonable to load into RAM */ 1967 if (vhdx_opts->has_block_size) { 1968 block_size = vhdx_opts->block_size; 1969 } else { 1970 if (image_size > 32 * TiB) { 1971 block_size = 64 * MiB; 1972 } else if (image_size > (uint64_t) 100 * GiB) { 1973 block_size = 32 * MiB; 1974 } else if (image_size > 1 * GiB) { 1975 block_size = 16 * MiB; 1976 } else { 1977 block_size = 8 * MiB; 1978 } 1979 } 1980 1981 if (block_size < MiB || (block_size % MiB) != 0) { 1982 error_setg(errp, "Block size must be a multiple of 1 MB"); 1983 return -EINVAL; 1984 } 1985 if (!is_power_of_2(block_size)) { 1986 error_setg(errp, "Block size must be a power of two"); 1987 return -EINVAL; 1988 } 1989 if (block_size > VHDX_BLOCK_SIZE_MAX) { 1990 error_setg(errp, "Block size must not exceed %" PRId64, 1991 VHDX_BLOCK_SIZE_MAX); 1992 return -EINVAL; 1993 } 1994 1995 /* Create BlockBackend to write to the image */ 1996 bs = bdrv_co_open_blockdev_ref(vhdx_opts->file, errp); 1997 if (bs == NULL) { 1998 return -EIO; 1999 } 2000 2001 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 2002 errp); 2003 if (!blk) { 2004 ret = -EPERM; 2005 goto delete_and_exit; 2006 } 2007 blk_set_allow_write_beyond_eof(blk, true); 2008 2009 /* Create (A) */ 2010 2011 /* The creator field is optional, but may be useful for 2012 * debugging / diagnostics */ 2013 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2014 &creator_items, NULL); 2015 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2016 ret = blk_co_pwrite(blk, VHDX_FILE_ID_OFFSET, sizeof(signature), &signature, 2017 0); 2018 if (ret < 0) { 2019 error_setg_errno(errp, -ret, "Failed to write file signature"); 2020 goto delete_and_exit; 2021 } 2022 if (creator) { 2023 ret = blk_co_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2024 creator_items * sizeof(gunichar2), creator, 0); 2025 if (ret < 0) { 2026 error_setg_errno(errp, -ret, "Failed to write creator field"); 2027 goto delete_and_exit; 2028 } 2029 } 2030 2031 2032 /* Creates (B),(C) */ 2033 ret = vhdx_create_new_headers(blk, image_size, log_size); 2034 if (ret < 0) { 2035 error_setg_errno(errp, -ret, "Failed to write image headers"); 2036 goto delete_and_exit; 2037 } 2038 2039 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2040 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2041 log_size, use_zero_blocks, image_type, 2042 &metadata_offset, errp); 2043 if (ret < 0) { 2044 goto delete_and_exit; 2045 } 2046 2047 /* Creates (H) */ 2048 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2049 metadata_offset, image_type); 2050 if (ret < 0) { 2051 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2052 goto delete_and_exit; 2053 } 2054 2055 ret = 0; 2056 delete_and_exit: 2057 blk_co_unref(blk); 2058 bdrv_co_unref(bs); 2059 g_free(creator); 2060 return ret; 2061 } 2062 2063 static int coroutine_fn GRAPH_RDLOCK 2064 vhdx_co_create_opts(BlockDriver *drv, const char *filename, 2065 QemuOpts *opts, 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_co_create_file(filename, opts, errp); 2090 if (ret < 0) { 2091 goto fail; 2092 } 2093 2094 bs = bdrv_co_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_co_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_co_get_info = vhdx_co_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