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 GRAPH_RDLOCK 357 vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 358 bool generate_data_write_guid, MSGUID *log_guid) 359 { 360 int ret = 0; 361 int hdr_idx = 0; 362 uint64_t header_offset = VHDX_HEADER1_OFFSET; 363 364 VHDXHeader *active_header; 365 VHDXHeader *inactive_header; 366 367 /* operate on the non-current header */ 368 if (s->curr_header == 0) { 369 hdr_idx = 1; 370 header_offset = VHDX_HEADER2_OFFSET; 371 } 372 373 active_header = s->headers[s->curr_header]; 374 inactive_header = s->headers[hdr_idx]; 375 376 inactive_header->sequence_number = active_header->sequence_number + 1; 377 378 /* a new file guid must be generated before any file write, including 379 * headers */ 380 inactive_header->file_write_guid = s->session_guid; 381 382 /* a new data guid only needs to be generated before any guest-visible 383 * writes (i.e. something observable via virtual disk read) */ 384 if (generate_data_write_guid) { 385 vhdx_guid_generate(&inactive_header->data_write_guid); 386 } 387 388 /* update the log guid if present */ 389 if (log_guid) { 390 inactive_header->log_guid = *log_guid; 391 } 392 393 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 394 if (ret < 0) { 395 goto exit; 396 } 397 s->curr_header = hdr_idx; 398 399 exit: 400 return ret; 401 } 402 403 /* 404 * The VHDX spec calls for header updates to be performed twice, so that both 405 * the current and non-current header have valid info 406 */ 407 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 408 bool generate_data_write_guid, MSGUID *log_guid) 409 { 410 int ret; 411 412 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 413 if (ret < 0) { 414 return ret; 415 } 416 return vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 417 } 418 419 /* opens the specified header block from the VHDX file header section */ 420 static void GRAPH_RDLOCK 421 vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, Error **errp) 422 { 423 int ret; 424 VHDXHeader *header1; 425 VHDXHeader *header2; 426 bool h1_valid = false; 427 bool h2_valid = false; 428 uint64_t h1_seq = 0; 429 uint64_t h2_seq = 0; 430 uint8_t *buffer; 431 432 /* header1 & header2 are freed in vhdx_close() */ 433 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 434 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 435 436 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 437 438 s->headers[0] = header1; 439 s->headers[1] = header2; 440 441 /* We have to read the whole VHDX_HEADER_SIZE instead of 442 * sizeof(VHDXHeader), because the checksum is over the whole 443 * region */ 444 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, VHDX_HEADER_SIZE, buffer, 445 0); 446 if (ret < 0) { 447 goto fail; 448 } 449 /* copy over just the relevant portion that we need */ 450 memcpy(header1, buffer, sizeof(VHDXHeader)); 451 452 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 453 vhdx_header_le_import(header1); 454 if (header1->signature == VHDX_HEADER_SIGNATURE && 455 header1->version == 1) { 456 h1_seq = header1->sequence_number; 457 h1_valid = true; 458 } 459 } 460 461 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, VHDX_HEADER_SIZE, buffer, 462 0); 463 if (ret < 0) { 464 goto fail; 465 } 466 /* copy over just the relevant portion that we need */ 467 memcpy(header2, buffer, sizeof(VHDXHeader)); 468 469 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 470 vhdx_header_le_import(header2); 471 if (header2->signature == VHDX_HEADER_SIGNATURE && 472 header2->version == 1) { 473 h2_seq = header2->sequence_number; 474 h2_valid = true; 475 } 476 } 477 478 /* If there is only 1 valid header (or no valid headers), we 479 * don't care what the sequence numbers are */ 480 if (h1_valid && !h2_valid) { 481 s->curr_header = 0; 482 } else if (!h1_valid && h2_valid) { 483 s->curr_header = 1; 484 } else if (!h1_valid && !h2_valid) { 485 goto fail; 486 } else { 487 /* If both headers are valid, then we choose the active one by the 488 * highest sequence number. If the sequence numbers are equal, that is 489 * invalid */ 490 if (h1_seq > h2_seq) { 491 s->curr_header = 0; 492 } else if (h2_seq > h1_seq) { 493 s->curr_header = 1; 494 } else { 495 /* The Microsoft Disk2VHD tool will create 2 identical 496 * headers, with identical sequence numbers. If the headers are 497 * identical, don't consider the file corrupt */ 498 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 499 s->curr_header = 0; 500 } else { 501 goto fail; 502 } 503 } 504 } 505 506 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 507 s->headers[s->curr_header]->log_length); 508 goto exit; 509 510 fail: 511 error_setg_errno(errp, -ret, "No valid VHDX header found"); 512 qemu_vfree(header1); 513 qemu_vfree(header2); 514 s->headers[0] = NULL; 515 s->headers[1] = NULL; 516 exit: 517 qemu_vfree(buffer); 518 } 519 520 521 static int GRAPH_RDLOCK 522 vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 523 { 524 int ret = 0; 525 uint8_t *buffer; 526 int offset = 0; 527 VHDXRegionTableEntry rt_entry; 528 uint32_t i; 529 bool bat_rt_found = false; 530 bool metadata_rt_found = false; 531 532 /* We have to read the whole 64KB block, because the crc32 is over the 533 * whole block */ 534 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 535 536 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, 537 VHDX_HEADER_BLOCK_SIZE, buffer, 0); 538 if (ret < 0) { 539 goto fail; 540 } 541 memcpy(&s->rt, buffer, sizeof(s->rt)); 542 offset += sizeof(s->rt); 543 544 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 545 ret = -EINVAL; 546 goto fail; 547 } 548 549 vhdx_region_header_le_import(&s->rt); 550 551 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 552 ret = -EINVAL; 553 goto fail; 554 } 555 556 557 /* Per spec, maximum region table entry count is 2047 */ 558 if (s->rt.entry_count > 2047) { 559 ret = -EINVAL; 560 goto fail; 561 } 562 563 for (i = 0; i < s->rt.entry_count; i++) { 564 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 565 offset += sizeof(rt_entry); 566 567 vhdx_region_entry_le_import(&rt_entry); 568 569 /* check for region overlap between these entries, and any 570 * other memory regions in the file */ 571 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 572 if (ret < 0) { 573 goto fail; 574 } 575 576 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 577 578 /* see if we recognize the entry */ 579 if (guid_eq(rt_entry.guid, bat_guid)) { 580 /* must be unique; if we have already found it this is invalid */ 581 if (bat_rt_found) { 582 ret = -EINVAL; 583 goto fail; 584 } 585 bat_rt_found = true; 586 s->bat_rt = rt_entry; 587 continue; 588 } 589 590 if (guid_eq(rt_entry.guid, metadata_guid)) { 591 /* must be unique; if we have already found it this is invalid */ 592 if (metadata_rt_found) { 593 ret = -EINVAL; 594 goto fail; 595 } 596 metadata_rt_found = true; 597 s->metadata_rt = rt_entry; 598 continue; 599 } 600 601 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 602 /* cannot read vhdx file - required region table entry that 603 * we do not understand. per spec, we must fail to open */ 604 ret = -ENOTSUP; 605 goto fail; 606 } 607 } 608 609 if (!bat_rt_found || !metadata_rt_found) { 610 ret = -EINVAL; 611 goto fail; 612 } 613 614 ret = 0; 615 616 fail: 617 qemu_vfree(buffer); 618 return ret; 619 } 620 621 622 623 /* Metadata initial parser 624 * 625 * This loads all the metadata entry fields. This may cause additional 626 * fields to be processed (e.g. parent locator, etc..). 627 * 628 * There are 5 Metadata items that are always required: 629 * - File Parameters (block size, has a parent) 630 * - Virtual Disk Size (size, in bytes, of the virtual drive) 631 * - Page 83 Data (scsi page 83 guid) 632 * - Logical Sector Size (logical sector size in bytes, either 512 or 633 * 4096. We only support 512 currently) 634 * - Physical Sector Size (512 or 4096) 635 * 636 * Also, if the File Parameters indicate this is a differencing file, 637 * we must also look for the Parent Locator metadata item. 638 */ 639 static int GRAPH_RDLOCK 640 vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 641 { 642 int ret = 0; 643 uint8_t *buffer; 644 int offset = 0; 645 uint32_t i = 0; 646 VHDXMetadataTableEntry md_entry; 647 648 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 649 650 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, 651 VHDX_METADATA_TABLE_MAX_SIZE, buffer, 0); 652 if (ret < 0) { 653 goto exit; 654 } 655 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 656 offset += sizeof(s->metadata_hdr); 657 658 vhdx_metadata_header_le_import(&s->metadata_hdr); 659 660 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 661 ret = -EINVAL; 662 goto exit; 663 } 664 665 s->metadata_entries.present = 0; 666 667 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 668 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 669 ret = -EINVAL; 670 goto exit; 671 } 672 673 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 674 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 675 offset += sizeof(md_entry); 676 677 vhdx_metadata_entry_le_import(&md_entry); 678 679 if (guid_eq(md_entry.item_id, file_param_guid)) { 680 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 681 ret = -EINVAL; 682 goto exit; 683 } 684 s->metadata_entries.file_parameters_entry = md_entry; 685 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 686 continue; 687 } 688 689 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 690 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 691 ret = -EINVAL; 692 goto exit; 693 } 694 s->metadata_entries.virtual_disk_size_entry = md_entry; 695 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 696 continue; 697 } 698 699 if (guid_eq(md_entry.item_id, page83_guid)) { 700 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 701 ret = -EINVAL; 702 goto exit; 703 } 704 s->metadata_entries.page83_data_entry = md_entry; 705 s->metadata_entries.present |= META_PAGE_83_PRESENT; 706 continue; 707 } 708 709 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 710 if (s->metadata_entries.present & 711 META_LOGICAL_SECTOR_SIZE_PRESENT) { 712 ret = -EINVAL; 713 goto exit; 714 } 715 s->metadata_entries.logical_sector_size_entry = md_entry; 716 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 717 continue; 718 } 719 720 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 721 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 722 ret = -EINVAL; 723 goto exit; 724 } 725 s->metadata_entries.phys_sector_size_entry = md_entry; 726 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 727 continue; 728 } 729 730 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 731 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 732 ret = -EINVAL; 733 goto exit; 734 } 735 s->metadata_entries.parent_locator_entry = md_entry; 736 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 737 continue; 738 } 739 740 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 741 /* cannot read vhdx file - required region table entry that 742 * we do not understand. per spec, we must fail to open */ 743 ret = -ENOTSUP; 744 goto exit; 745 } 746 } 747 748 if (s->metadata_entries.present != META_ALL_PRESENT) { 749 ret = -ENOTSUP; 750 goto exit; 751 } 752 753 ret = bdrv_pread(bs->file, 754 s->metadata_entries.file_parameters_entry.offset 755 + s->metadata_rt.file_offset, 756 sizeof(s->params), 757 &s->params, 758 0); 759 760 if (ret < 0) { 761 goto exit; 762 } 763 764 s->params.block_size = le32_to_cpu(s->params.block_size); 765 s->params.data_bits = le32_to_cpu(s->params.data_bits); 766 767 768 /* We now have the file parameters, so we can tell if this is a 769 * differencing file (i.e.. has_parent), is dynamic or fixed 770 * sized (leave_blocks_allocated), and the block size */ 771 772 /* The parent locator required iff the file parameters has_parent set */ 773 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 774 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 775 /* TODO: parse parent locator fields */ 776 ret = -ENOTSUP; /* temp, until differencing files are supported */ 777 goto exit; 778 } else { 779 /* if has_parent is set, but there is not parent locator present, 780 * then that is an invalid combination */ 781 ret = -EINVAL; 782 goto exit; 783 } 784 } 785 786 /* determine virtual disk size, logical sector size, 787 * and phys sector size */ 788 789 ret = bdrv_pread(bs->file, 790 s->metadata_entries.virtual_disk_size_entry.offset 791 + s->metadata_rt.file_offset, 792 sizeof(uint64_t), 793 &s->virtual_disk_size, 794 0); 795 if (ret < 0) { 796 goto exit; 797 } 798 ret = bdrv_pread(bs->file, 799 s->metadata_entries.logical_sector_size_entry.offset 800 + s->metadata_rt.file_offset, 801 sizeof(uint32_t), 802 &s->logical_sector_size, 803 0); 804 if (ret < 0) { 805 goto exit; 806 } 807 ret = bdrv_pread(bs->file, 808 s->metadata_entries.phys_sector_size_entry.offset 809 + s->metadata_rt.file_offset, 810 sizeof(uint32_t), 811 &s->physical_sector_size, 812 0); 813 if (ret < 0) { 814 goto exit; 815 } 816 817 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size); 818 s->logical_sector_size = le32_to_cpu(s->logical_sector_size); 819 s->physical_sector_size = le32_to_cpu(s->physical_sector_size); 820 821 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 822 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 823 ret = -EINVAL; 824 goto exit; 825 } 826 827 /* Currently we only support 512 */ 828 if (s->logical_sector_size != 512) { 829 ret = -ENOTSUP; 830 goto exit; 831 } 832 833 /* Both block_size and sector_size are guaranteed powers of 2, below. 834 Due to range checks above, s->sectors_per_block can never be < 256 */ 835 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 836 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 837 (uint64_t)s->logical_sector_size / 838 (uint64_t)s->params.block_size; 839 840 /* These values are ones we will want to use for division / multiplication 841 * later on, and they are all guaranteed (per the spec) to be powers of 2, 842 * so we can take advantage of that for shift operations during 843 * reads/writes */ 844 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 845 ret = -EINVAL; 846 goto exit; 847 } 848 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 849 ret = -EINVAL; 850 goto exit; 851 } 852 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 853 ret = -EINVAL; 854 goto exit; 855 } 856 s->block_size = s->params.block_size; 857 if (s->block_size & (s->block_size - 1)) { 858 ret = -EINVAL; 859 goto exit; 860 } 861 862 vhdx_set_shift_bits(s); 863 864 ret = 0; 865 866 exit: 867 qemu_vfree(buffer); 868 return ret; 869 } 870 871 /* 872 * Calculate the number of BAT entries, including sector 873 * bitmap entries. 874 */ 875 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 876 { 877 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 878 879 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size); 880 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio); 881 882 if (s->parent_entries) { 883 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 884 } else { 885 s->bat_entries = data_blocks_cnt + 886 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 887 } 888 889 } 890 891 static int coroutine_mixed_fn GRAPH_RDLOCK 892 vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) 893 { 894 BDRVVHDXState *s = bs->opaque; 895 int64_t image_file_size = bdrv_getlength(bs->file->bs); 896 uint64_t payblocks = s->chunk_ratio; 897 uint64_t i; 898 int ret = 0; 899 900 if (image_file_size < 0) { 901 error_report("Could not determinate VHDX image file size."); 902 return image_file_size; 903 } 904 905 for (i = 0; i < s->bat_entries; i++) { 906 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 907 PAYLOAD_BLOCK_FULLY_PRESENT) { 908 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; 909 /* 910 * Allow that the last block exists only partially. The VHDX spec 911 * states that the image file can only grow in blocksize increments, 912 * but QEMU created images with partial last blocks in the past. 913 */ 914 uint32_t block_length = MIN(s->block_size, 915 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); 916 /* 917 * Check for BAT entry overflow. 918 */ 919 if (offset > INT64_MAX - s->block_size) { 920 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); 921 ret = -EINVAL; 922 if (!errcnt) { 923 break; 924 } 925 (*errcnt)++; 926 } 927 /* 928 * Check if fully allocated BAT entries do not reside after 929 * end of the image file. 930 */ 931 if (offset >= image_file_size) { 932 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 933 " points after end of file (%" PRIi64 "). Image" 934 " has probably been truncated.", 935 i, offset, image_file_size); 936 ret = -EINVAL; 937 if (!errcnt) { 938 break; 939 } 940 (*errcnt)++; 941 } else if (offset + block_length > image_file_size) { 942 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 943 " points after end of file (%" PRIi64 "). Image" 944 " has probably been truncated.", 945 i, offset + block_length - 1, image_file_size); 946 ret = -EINVAL; 947 if (!errcnt) { 948 break; 949 } 950 (*errcnt)++; 951 } 952 953 /* 954 * verify populated BAT field file offsets against 955 * region table and log entries 956 */ 957 if (payblocks--) { 958 /* payload bat entries */ 959 int ret2; 960 ret2 = vhdx_region_check(s, offset, s->block_size); 961 if (ret2 < 0) { 962 ret = -EINVAL; 963 if (!errcnt) { 964 break; 965 } 966 (*errcnt)++; 967 } 968 } else { 969 payblocks = s->chunk_ratio; 970 /* 971 * Once differencing files are supported, verify sector bitmap 972 * blocks here 973 */ 974 } 975 } 976 } 977 978 return ret; 979 } 980 981 static void vhdx_close(BlockDriverState *bs) 982 { 983 BDRVVHDXState *s = bs->opaque; 984 qemu_vfree(s->headers[0]); 985 s->headers[0] = NULL; 986 qemu_vfree(s->headers[1]); 987 s->headers[1] = NULL; 988 qemu_vfree(s->bat); 989 s->bat = NULL; 990 qemu_vfree(s->parent_entries); 991 s->parent_entries = NULL; 992 migrate_del_blocker(&s->migration_blocker); 993 qemu_vfree(s->log.hdr); 994 s->log.hdr = NULL; 995 vhdx_region_unregister_all(s); 996 } 997 998 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 999 Error **errp) 1000 { 1001 BDRVVHDXState *s = bs->opaque; 1002 int ret = 0; 1003 uint32_t i; 1004 uint64_t signature; 1005 Error *local_err = NULL; 1006 1007 GLOBAL_STATE_CODE(); 1008 1009 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 1010 if (ret < 0) { 1011 return ret; 1012 } 1013 1014 GRAPH_RDLOCK_GUARD_MAINLOOP(); 1015 1016 s->bat = NULL; 1017 s->first_visible_write = true; 1018 1019 qemu_co_mutex_init(&s->lock); 1020 QLIST_INIT(&s->regions); 1021 1022 /* validate the file signature */ 1023 ret = bdrv_pread(bs->file, 0, sizeof(uint64_t), &signature, 0); 1024 if (ret < 0) { 1025 goto fail; 1026 } 1027 if (memcmp(&signature, "vhdxfile", 8)) { 1028 ret = -EINVAL; 1029 goto fail; 1030 } 1031 1032 /* This is used for any header updates, for the file_write_guid. 1033 * The spec dictates that a new value should be used for the first 1034 * header update */ 1035 vhdx_guid_generate(&s->session_guid); 1036 1037 vhdx_parse_header(bs, s, &local_err); 1038 if (local_err != NULL) { 1039 error_propagate(errp, local_err); 1040 ret = -EINVAL; 1041 goto fail; 1042 } 1043 1044 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 1045 if (ret < 0) { 1046 goto fail; 1047 } 1048 1049 ret = vhdx_open_region_tables(bs, s); 1050 if (ret < 0) { 1051 goto fail; 1052 } 1053 1054 ret = vhdx_parse_metadata(bs, s); 1055 if (ret < 0) { 1056 goto fail; 1057 } 1058 1059 s->block_size = s->params.block_size; 1060 1061 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 1062 * logical_sector_size */ 1063 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 1064 1065 vhdx_calc_bat_entries(s); 1066 1067 s->bat_offset = s->bat_rt.file_offset; 1068 1069 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 1070 /* BAT allocation is not large enough for all entries */ 1071 ret = -EINVAL; 1072 goto fail; 1073 } 1074 1075 /* s->bat is freed in vhdx_close() */ 1076 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length); 1077 if (s->bat == NULL) { 1078 ret = -ENOMEM; 1079 goto fail; 1080 } 1081 1082 ret = bdrv_pread(bs->file, s->bat_offset, s->bat_rt.length, s->bat, 0); 1083 if (ret < 0) { 1084 goto fail; 1085 } 1086 1087 /* endian convert populated BAT field entries */ 1088 for (i = 0; i < s->bat_entries; i++) { 1089 s->bat[i] = le64_to_cpu(s->bat[i]); 1090 } 1091 1092 if (!(flags & BDRV_O_CHECK)) { 1093 ret = vhdx_check_bat_entries(bs, NULL); 1094 if (ret < 0) { 1095 goto fail; 1096 } 1097 } 1098 1099 /* Disable migration when VHDX images are used */ 1100 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " 1101 "does not support live migration", 1102 bdrv_get_device_or_node_name(bs)); 1103 ret = migrate_add_blocker_normal(&s->migration_blocker, errp); 1104 if (ret < 0) { 1105 goto fail; 1106 } 1107 1108 /* TODO: differencing files */ 1109 1110 return 0; 1111 fail: 1112 vhdx_close(bs); 1113 return ret; 1114 } 1115 1116 static int vhdx_reopen_prepare(BDRVReopenState *state, 1117 BlockReopenQueue *queue, Error **errp) 1118 { 1119 return 0; 1120 } 1121 1122 1123 /* 1124 * Perform sector to block offset translations, to get various 1125 * sector and file offsets into the image. See VHDXSectorInfo 1126 */ 1127 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1128 int nb_sectors, VHDXSectorInfo *sinfo) 1129 { 1130 uint32_t block_offset; 1131 1132 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1133 /* effectively a modulo - this gives us the offset into the block 1134 * (in sector sizes) for our sector number */ 1135 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1136 /* the chunk ratio gives us the interleaving of the sector 1137 * bitmaps, so we need to advance our page block index by the 1138 * sector bitmaps entry number */ 1139 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1140 1141 /* the number of sectors we can read/write in this cycle */ 1142 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1143 1144 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1145 1146 if (sinfo->sectors_avail > nb_sectors) { 1147 sinfo->sectors_avail = nb_sectors; 1148 } 1149 1150 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1151 1152 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1153 1154 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1155 1156 /* The file offset must be past the header section, so must be > 0 */ 1157 if (sinfo->file_offset == 0) { 1158 return; 1159 } 1160 1161 /* block offset is the offset in vhdx logical sectors, in 1162 * the payload data block. Convert that to a byte offset 1163 * in the block, and add in the payload data block offset 1164 * in the file, in bytes, to get the final read address */ 1165 1166 sinfo->file_offset += sinfo->block_offset; 1167 } 1168 1169 1170 static int coroutine_fn 1171 vhdx_co_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1172 { 1173 BDRVVHDXState *s = bs->opaque; 1174 1175 bdi->cluster_size = s->block_size; 1176 1177 return 0; 1178 } 1179 1180 1181 static int coroutine_fn GRAPH_RDLOCK 1182 vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 1183 QEMUIOVector *qiov) 1184 { 1185 BDRVVHDXState *s = bs->opaque; 1186 int ret = 0; 1187 VHDXSectorInfo sinfo; 1188 uint64_t bytes_done = 0; 1189 QEMUIOVector hd_qiov; 1190 1191 qemu_iovec_init(&hd_qiov, qiov->niov); 1192 1193 qemu_co_mutex_lock(&s->lock); 1194 1195 while (nb_sectors > 0) { 1196 /* We are a differencing file, so we need to inspect the sector bitmap 1197 * to see if we have the data or not */ 1198 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1199 /* not supported yet */ 1200 ret = -ENOTSUP; 1201 goto exit; 1202 } else { 1203 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1204 1205 qemu_iovec_reset(&hd_qiov); 1206 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1207 1208 /* check the payload block state */ 1209 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1210 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1211 case PAYLOAD_BLOCK_UNDEFINED: 1212 case PAYLOAD_BLOCK_UNMAPPED: 1213 case PAYLOAD_BLOCK_UNMAPPED_v095: 1214 case PAYLOAD_BLOCK_ZERO: 1215 /* return zero */ 1216 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1217 break; 1218 case PAYLOAD_BLOCK_FULLY_PRESENT: 1219 qemu_co_mutex_unlock(&s->lock); 1220 ret = bdrv_co_preadv(bs->file, sinfo.file_offset, 1221 sinfo.sectors_avail * BDRV_SECTOR_SIZE, 1222 &hd_qiov, 0); 1223 qemu_co_mutex_lock(&s->lock); 1224 if (ret < 0) { 1225 goto exit; 1226 } 1227 break; 1228 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1229 /* we don't yet support difference files, fall through 1230 * to error */ 1231 default: 1232 ret = -EIO; 1233 goto exit; 1234 break; 1235 } 1236 nb_sectors -= sinfo.sectors_avail; 1237 sector_num += sinfo.sectors_avail; 1238 bytes_done += sinfo.bytes_avail; 1239 } 1240 } 1241 ret = 0; 1242 exit: 1243 qemu_co_mutex_unlock(&s->lock); 1244 qemu_iovec_destroy(&hd_qiov); 1245 return ret; 1246 } 1247 1248 /* 1249 * Allocate a new payload block at the end of the file. 1250 * 1251 * Allocation will happen at 1MB alignment inside the file. 1252 * 1253 * If @need_zero is set on entry but not cleared on return, then truncation 1254 * could not guarantee that the new portion reads as zero, and the caller 1255 * will take care of it instead. 1256 * 1257 * Returns the file offset start of the new payload block 1258 */ 1259 static int coroutine_fn GRAPH_RDLOCK 1260 vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1261 uint64_t *new_offset, bool *need_zero) 1262 { 1263 int64_t current_len; 1264 1265 current_len = bdrv_co_getlength(bs->file->bs); 1266 if (current_len < 0) { 1267 return current_len; 1268 } 1269 1270 *new_offset = current_len; 1271 1272 /* per the spec, the address for a block is in units of 1MB */ 1273 *new_offset = ROUND_UP(*new_offset, 1 * MiB); 1274 if (*new_offset > INT64_MAX) { 1275 return -EINVAL; 1276 } 1277 1278 if (*need_zero) { 1279 int ret; 1280 1281 ret = bdrv_co_truncate(bs->file, *new_offset + s->block_size, false, 1282 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL); 1283 if (ret != -ENOTSUP) { 1284 *need_zero = false; 1285 return ret; 1286 } 1287 } 1288 1289 return bdrv_co_truncate(bs->file, *new_offset + s->block_size, false, 1290 PREALLOC_MODE_OFF, 0, NULL); 1291 } 1292 1293 /* 1294 * Update the BAT table entry with the new file offset, and the new entry 1295 * state */ 1296 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1297 VHDXSectorInfo *sinfo, 1298 uint64_t *bat_entry_le, 1299 uint64_t *bat_offset, int state) 1300 { 1301 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1302 * 1MB, and 3 bits for the block state. */ 1303 if ((state == PAYLOAD_BLOCK_ZERO) || 1304 (state == PAYLOAD_BLOCK_UNDEFINED) || 1305 (state == PAYLOAD_BLOCK_NOT_PRESENT) || 1306 (state == PAYLOAD_BLOCK_UNMAPPED)) { 1307 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the 1308 FileOffsetMB field is denoted as 1309 'reserved' in the v1.0 spec. If it is 1310 non-zero, MS Hyper-V will fail to read 1311 the disk image */ 1312 } else { 1313 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1314 } 1315 1316 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1317 1318 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1319 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1320 1321 } 1322 1323 /* Per the spec, on the first write of guest-visible data to the file the 1324 * data write guid must be updated in the header */ 1325 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1326 { 1327 int ret = 0; 1328 if (s->first_visible_write) { 1329 s->first_visible_write = false; 1330 ret = vhdx_update_headers(bs, s, true, NULL); 1331 } 1332 return ret; 1333 } 1334 1335 static int coroutine_fn GRAPH_RDLOCK 1336 vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 1337 QEMUIOVector *qiov, int flags) 1338 { 1339 int ret = -ENOTSUP; 1340 BDRVVHDXState *s = bs->opaque; 1341 VHDXSectorInfo sinfo; 1342 uint64_t bytes_done = 0; 1343 uint64_t bat_entry = 0; 1344 uint64_t bat_entry_offset = 0; 1345 QEMUIOVector hd_qiov; 1346 struct iovec iov1 = { 0 }; 1347 struct iovec iov2 = { 0 }; 1348 int sectors_to_write; 1349 int bat_state; 1350 uint64_t bat_prior_offset = 0; 1351 bool bat_update = false; 1352 1353 qemu_iovec_init(&hd_qiov, qiov->niov); 1354 1355 qemu_co_mutex_lock(&s->lock); 1356 1357 ret = vhdx_user_visible_write(bs, s); 1358 if (ret < 0) { 1359 goto exit; 1360 } 1361 1362 while (nb_sectors > 0) { 1363 bool use_zero_buffers = false; 1364 bat_update = false; 1365 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1366 /* not supported yet */ 1367 ret = -ENOTSUP; 1368 goto exit; 1369 } else { 1370 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1371 sectors_to_write = sinfo.sectors_avail; 1372 1373 qemu_iovec_reset(&hd_qiov); 1374 /* check the payload block state */ 1375 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1376 switch (bat_state) { 1377 case PAYLOAD_BLOCK_ZERO: 1378 /* in this case, we need to preserve zero writes for 1379 * data that is not part of this write, so we must pad 1380 * the rest of the buffer to zeroes */ 1381 use_zero_buffers = true; 1382 /* fall through */ 1383 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1384 case PAYLOAD_BLOCK_UNMAPPED: 1385 case PAYLOAD_BLOCK_UNMAPPED_v095: 1386 case PAYLOAD_BLOCK_UNDEFINED: 1387 bat_prior_offset = sinfo.file_offset; 1388 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset, 1389 &use_zero_buffers); 1390 if (ret < 0) { 1391 goto exit; 1392 } 1393 /* 1394 * once we support differencing files, this may also be 1395 * partially present 1396 */ 1397 /* update block state to the newly specified state */ 1398 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1399 &bat_entry_offset, 1400 PAYLOAD_BLOCK_FULLY_PRESENT); 1401 bat_update = true; 1402 /* 1403 * Since we just allocated a block, file_offset is the 1404 * beginning of the payload block. It needs to be the 1405 * write address, which includes the offset into the 1406 * block, unless the entire block needs to read as 1407 * zeroes but truncation was not able to provide them, 1408 * in which case we need to fill in the rest. 1409 */ 1410 if (!use_zero_buffers) { 1411 sinfo.file_offset += sinfo.block_offset; 1412 } else { 1413 /* zero fill the front, if any */ 1414 if (sinfo.block_offset) { 1415 iov1.iov_len = sinfo.block_offset; 1416 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1417 memset(iov1.iov_base, 0, iov1.iov_len); 1418 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1419 iov1.iov_len); 1420 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1421 } 1422 1423 /* our actual data */ 1424 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1425 sinfo.bytes_avail); 1426 1427 /* zero fill the back, if any */ 1428 if ((sinfo.bytes_avail - sinfo.block_offset) < 1429 s->block_size) { 1430 iov2.iov_len = s->block_size - 1431 (sinfo.bytes_avail + sinfo.block_offset); 1432 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1433 memset(iov2.iov_base, 0, iov2.iov_len); 1434 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1435 iov2.iov_len); 1436 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1437 } 1438 } 1439 1440 /* fall through */ 1441 case PAYLOAD_BLOCK_FULLY_PRESENT: 1442 /* if the file offset address is in the header zone, 1443 * there is a problem */ 1444 if (sinfo.file_offset < (1 * MiB)) { 1445 ret = -EFAULT; 1446 goto error_bat_restore; 1447 } 1448 1449 if (!use_zero_buffers) { 1450 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1451 sinfo.bytes_avail); 1452 } 1453 /* block exists, so we can just overwrite it */ 1454 qemu_co_mutex_unlock(&s->lock); 1455 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset, 1456 sectors_to_write * BDRV_SECTOR_SIZE, 1457 &hd_qiov, 0); 1458 qemu_co_mutex_lock(&s->lock); 1459 if (ret < 0) { 1460 goto error_bat_restore; 1461 } 1462 break; 1463 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1464 /* we don't yet support difference files, fall through 1465 * to error */ 1466 default: 1467 ret = -EIO; 1468 goto exit; 1469 break; 1470 } 1471 1472 if (bat_update) { 1473 /* this will update the BAT entry into the log journal, and 1474 * then flush the log journal out to disk */ 1475 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1476 sizeof(VHDXBatEntry), 1477 bat_entry_offset); 1478 if (ret < 0) { 1479 goto exit; 1480 } 1481 } 1482 1483 nb_sectors -= sinfo.sectors_avail; 1484 sector_num += sinfo.sectors_avail; 1485 bytes_done += sinfo.bytes_avail; 1486 1487 } 1488 } 1489 1490 goto exit; 1491 1492 error_bat_restore: 1493 if (bat_update) { 1494 /* keep metadata in sync, and restore the bat entry state 1495 * if error. */ 1496 sinfo.file_offset = bat_prior_offset; 1497 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1498 &bat_entry_offset, bat_state); 1499 } 1500 exit: 1501 qemu_vfree(iov1.iov_base); 1502 qemu_vfree(iov2.iov_base); 1503 qemu_co_mutex_unlock(&s->lock); 1504 qemu_iovec_destroy(&hd_qiov); 1505 return ret; 1506 } 1507 1508 1509 1510 /* 1511 * Create VHDX Headers 1512 * 1513 * There are 2 headers, and the highest sequence number will represent 1514 * the active header 1515 */ 1516 static int coroutine_fn GRAPH_UNLOCKED 1517 vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size, 1518 uint32_t log_size) 1519 { 1520 BlockDriverState *bs = blk_bs(blk); 1521 BdrvChild *child; 1522 int ret = 0; 1523 VHDXHeader *hdr = NULL; 1524 1525 GRAPH_RDLOCK_GUARD(); 1526 1527 hdr = g_new0(VHDXHeader, 1); 1528 1529 hdr->signature = VHDX_HEADER_SIGNATURE; 1530 hdr->sequence_number = g_random_int(); 1531 hdr->log_version = 0; 1532 hdr->version = 1; 1533 hdr->log_length = log_size; 1534 hdr->log_offset = VHDX_HEADER_SECTION_END; 1535 vhdx_guid_generate(&hdr->file_write_guid); 1536 vhdx_guid_generate(&hdr->data_write_guid); 1537 1538 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This 1539 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend 1540 * here, which it really shouldn't be doing. */ 1541 child = QLIST_FIRST(&bs->parents); 1542 assert(!QLIST_NEXT(child, next_parent)); 1543 1544 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false); 1545 if (ret < 0) { 1546 goto exit; 1547 } 1548 hdr->sequence_number++; 1549 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false); 1550 if (ret < 0) { 1551 goto exit; 1552 } 1553 1554 exit: 1555 g_free(hdr); 1556 return ret; 1557 } 1558 1559 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1560 (sizeof(VHDXFileParameters) +\ 1561 sizeof(VHDXVirtualDiskSize) +\ 1562 sizeof(VHDXPage83Data) +\ 1563 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1564 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1565 1566 /* 1567 * Create the Metadata entries. 1568 * 1569 * For more details on the entries, see section 3.5 (pg 29) in the 1570 * VHDX 1.00 specification. 1571 * 1572 * We support 5 metadata entries (all required by spec): 1573 * File Parameters, 1574 * Virtual Disk Size, 1575 * Page 83 Data, 1576 * Logical Sector Size, 1577 * Physical Sector Size 1578 * 1579 * The first 64KB of the Metadata section is reserved for the metadata 1580 * header and entries; beyond that, the metadata items themselves reside. 1581 */ 1582 static int coroutine_fn 1583 vhdx_create_new_metadata(BlockBackend *blk, uint64_t image_size, 1584 uint32_t block_size, uint32_t sector_size, 1585 uint64_t metadata_offset, VHDXImageType type) 1586 { 1587 int ret = 0; 1588 uint32_t offset = 0; 1589 void *buffer = NULL; 1590 void *entry_buffer; 1591 VHDXMetadataTableHeader *md_table; 1592 VHDXMetadataTableEntry *md_table_entry; 1593 1594 /* Metadata entries */ 1595 VHDXFileParameters *mt_file_params; 1596 VHDXVirtualDiskSize *mt_virtual_size; 1597 VHDXPage83Data *mt_page83; 1598 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1599 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1600 1601 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1602 1603 mt_file_params = entry_buffer; 1604 offset += sizeof(VHDXFileParameters); 1605 mt_virtual_size = entry_buffer + offset; 1606 offset += sizeof(VHDXVirtualDiskSize); 1607 mt_page83 = entry_buffer + offset; 1608 offset += sizeof(VHDXPage83Data); 1609 mt_log_sector_size = entry_buffer + offset; 1610 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1611 mt_phys_sector_size = entry_buffer + offset; 1612 1613 mt_file_params->block_size = cpu_to_le32(block_size); 1614 if (type == VHDX_TYPE_FIXED) { 1615 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1616 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits); 1617 } 1618 1619 vhdx_guid_generate(&mt_page83->page_83_data); 1620 cpu_to_leguids(&mt_page83->page_83_data); 1621 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1622 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1623 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1624 1625 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1626 md_table = buffer; 1627 1628 md_table->signature = VHDX_METADATA_SIGNATURE; 1629 md_table->entry_count = 5; 1630 vhdx_metadata_header_le_export(md_table); 1631 1632 1633 /* This will reference beyond the reserved table portion */ 1634 offset = 64 * KiB; 1635 1636 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1637 1638 md_table_entry[0].item_id = file_param_guid; 1639 md_table_entry[0].offset = offset; 1640 md_table_entry[0].length = sizeof(VHDXFileParameters); 1641 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1642 offset += md_table_entry[0].length; 1643 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1644 1645 md_table_entry[1].item_id = virtual_size_guid; 1646 md_table_entry[1].offset = offset; 1647 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1648 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1649 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1650 offset += md_table_entry[1].length; 1651 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1652 1653 md_table_entry[2].item_id = page83_guid; 1654 md_table_entry[2].offset = offset; 1655 md_table_entry[2].length = sizeof(VHDXPage83Data); 1656 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1657 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1658 offset += md_table_entry[2].length; 1659 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1660 1661 md_table_entry[3].item_id = logical_sector_guid; 1662 md_table_entry[3].offset = offset; 1663 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1664 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1665 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1666 offset += md_table_entry[3].length; 1667 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1668 1669 md_table_entry[4].item_id = phys_sector_guid; 1670 md_table_entry[4].offset = offset; 1671 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1672 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1673 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1674 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1675 1676 ret = blk_co_pwrite(blk, metadata_offset, VHDX_HEADER_BLOCK_SIZE, buffer, 0); 1677 if (ret < 0) { 1678 goto exit; 1679 } 1680 1681 ret = blk_co_pwrite(blk, metadata_offset + (64 * KiB), 1682 VHDX_METADATA_ENTRY_BUFFER_SIZE, entry_buffer, 0); 1683 if (ret < 0) { 1684 goto exit; 1685 } 1686 1687 1688 exit: 1689 g_free(buffer); 1690 g_free(entry_buffer); 1691 return ret; 1692 } 1693 1694 /* This create the actual BAT itself. We currently only support 1695 * 'Dynamic' and 'Fixed' image types. 1696 * 1697 * Dynamic images: default state of the BAT is all zeroes. 1698 * 1699 * Fixed images: default state of the BAT is fully populated, with 1700 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1701 */ 1702 static int coroutine_fn GRAPH_UNLOCKED 1703 vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s, 1704 uint64_t image_size, VHDXImageType type, 1705 bool use_zero_blocks, uint64_t file_offset, 1706 uint32_t length, Error **errp) 1707 { 1708 int ret = 0; 1709 uint64_t data_file_offset; 1710 uint64_t total_sectors = 0; 1711 uint64_t sector_num = 0; 1712 uint64_t unused; 1713 int block_state; 1714 VHDXSectorInfo sinfo; 1715 bool has_zero_init; 1716 1717 assert(s->bat == NULL); 1718 1719 /* this gives a data start after BAT/bitmap entries, and well 1720 * past any metadata entries (with a 4 MB buffer for future 1721 * expansion */ 1722 data_file_offset = file_offset + length + 5 * MiB; 1723 total_sectors = image_size >> s->logical_sector_size_bits; 1724 1725 if (type == VHDX_TYPE_DYNAMIC) { 1726 /* All zeroes, so we can just extend the file - the end of the BAT 1727 * is the furthest thing we have written yet */ 1728 ret = blk_co_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF, 1729 0, errp); 1730 if (ret < 0) { 1731 goto exit; 1732 } 1733 } else if (type == VHDX_TYPE_FIXED) { 1734 ret = blk_co_truncate(blk, data_file_offset + image_size, false, 1735 PREALLOC_MODE_OFF, 0, errp); 1736 if (ret < 0) { 1737 goto exit; 1738 } 1739 } else { 1740 error_setg(errp, "Unsupported image type"); 1741 ret = -ENOTSUP; 1742 goto exit; 1743 } 1744 1745 bdrv_graph_co_rdlock(); 1746 has_zero_init = bdrv_has_zero_init(blk_bs(blk)); 1747 bdrv_graph_co_rdunlock(); 1748 1749 if (type == VHDX_TYPE_FIXED || 1750 use_zero_blocks || 1751 has_zero_init == 0) { 1752 /* for a fixed file, the default BAT entry is not zero */ 1753 s->bat = g_try_malloc0(length); 1754 if (length && s->bat == NULL) { 1755 error_setg(errp, "Failed to allocate memory for the BAT"); 1756 ret = -ENOMEM; 1757 goto exit; 1758 } 1759 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1760 PAYLOAD_BLOCK_NOT_PRESENT; 1761 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1762 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1763 while (sector_num < total_sectors) { 1764 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1765 sinfo.file_offset = data_file_offset + 1766 (sector_num << s->logical_sector_size_bits); 1767 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1768 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused, 1769 block_state); 1770 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]); 1771 sector_num += s->sectors_per_block; 1772 } 1773 ret = blk_co_pwrite(blk, file_offset, length, s->bat, 0); 1774 if (ret < 0) { 1775 error_setg_errno(errp, -ret, "Failed to write the BAT"); 1776 goto exit; 1777 } 1778 } 1779 1780 1781 1782 exit: 1783 g_free(s->bat); 1784 return ret; 1785 } 1786 1787 /* Creates the region table header, and region table entries. 1788 * There are 2 supported region table entries: BAT, and Metadata/ 1789 * 1790 * As the calculations for the BAT region table are also needed 1791 * to create the BAT itself, we will also cause the BAT to be 1792 * created. 1793 */ 1794 static int coroutine_fn GRAPH_UNLOCKED 1795 vhdx_create_new_region_table(BlockBackend *blk, uint64_t image_size, 1796 uint32_t block_size, uint32_t sector_size, 1797 uint32_t log_size, bool use_zero_blocks, 1798 VHDXImageType type, uint64_t *metadata_offset, 1799 Error **errp) 1800 { 1801 int ret = 0; 1802 uint32_t offset = 0; 1803 void *buffer = NULL; 1804 uint64_t bat_file_offset; 1805 uint32_t bat_length; 1806 BDRVVHDXState *s = NULL; 1807 VHDXRegionTableHeader *region_table; 1808 VHDXRegionTableEntry *rt_bat; 1809 VHDXRegionTableEntry *rt_metadata; 1810 1811 assert(metadata_offset != NULL); 1812 1813 /* Populate enough of the BDRVVHDXState to be able to use the 1814 * pre-existing BAT calculation, translation, and update functions */ 1815 s = g_new0(BDRVVHDXState, 1); 1816 1817 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1818 (uint64_t) sector_size / (uint64_t) block_size; 1819 1820 s->sectors_per_block = block_size / sector_size; 1821 s->virtual_disk_size = image_size; 1822 s->block_size = block_size; 1823 s->logical_sector_size = sector_size; 1824 1825 vhdx_set_shift_bits(s); 1826 1827 vhdx_calc_bat_entries(s); 1828 1829 /* At this point the VHDX state is populated enough for creation */ 1830 1831 /* a single buffer is used so we can calculate the checksum over the 1832 * entire 64KB block */ 1833 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1834 region_table = buffer; 1835 offset += sizeof(VHDXRegionTableHeader); 1836 rt_bat = buffer + offset; 1837 offset += sizeof(VHDXRegionTableEntry); 1838 rt_metadata = buffer + offset; 1839 1840 region_table->signature = VHDX_REGION_SIGNATURE; 1841 region_table->entry_count = 2; /* BAT and Metadata */ 1842 1843 rt_bat->guid = bat_guid; 1844 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1845 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1846 s->bat_offset = rt_bat->file_offset; 1847 1848 rt_metadata->guid = metadata_guid; 1849 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1850 MiB); 1851 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1852 *metadata_offset = rt_metadata->file_offset; 1853 1854 bat_file_offset = rt_bat->file_offset; 1855 bat_length = rt_bat->length; 1856 1857 vhdx_region_header_le_export(region_table); 1858 vhdx_region_entry_le_export(rt_bat); 1859 vhdx_region_entry_le_export(rt_metadata); 1860 1861 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1862 offsetof(VHDXRegionTableHeader, checksum)); 1863 1864 1865 /* The region table gives us the data we need to create the BAT, 1866 * so do that now */ 1867 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks, 1868 bat_file_offset, bat_length, errp); 1869 if (ret < 0) { 1870 goto exit; 1871 } 1872 1873 /* Now write out the region headers to disk */ 1874 ret = blk_co_pwrite(blk, VHDX_REGION_TABLE_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1875 buffer, 0); 1876 if (ret < 0) { 1877 error_setg_errno(errp, -ret, "Failed to write first region table"); 1878 goto exit; 1879 } 1880 1881 ret = blk_co_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, VHDX_HEADER_BLOCK_SIZE, 1882 buffer, 0); 1883 if (ret < 0) { 1884 error_setg_errno(errp, -ret, "Failed to write second region table"); 1885 goto exit; 1886 } 1887 1888 exit: 1889 g_free(s); 1890 g_free(buffer); 1891 return ret; 1892 } 1893 1894 /* We need to create the following elements: 1895 * 1896 * .-----------------------------------------------------------------. 1897 * | (A) | (B) | (C) | (D) | (E) | 1898 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1899 * | | | | | | 1900 * .-----------------------------------------------------------------. 1901 * 0 64KB 128KB 192KB 256KB 320KB 1902 * 1903 * 1904 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1905 * | (F) | (G) | (H) | | 1906 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1907 * | | | | | 1908 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1909 * 1MB 1910 */ 1911 static int coroutine_fn GRAPH_UNLOCKED 1912 vhdx_co_create(BlockdevCreateOptions *opts, Error **errp) 1913 { 1914 BlockdevCreateOptionsVhdx *vhdx_opts; 1915 BlockBackend *blk = NULL; 1916 BlockDriverState *bs = NULL; 1917 1918 int ret = 0; 1919 uint64_t image_size; 1920 uint32_t log_size; 1921 uint32_t block_size; 1922 uint64_t signature; 1923 uint64_t metadata_offset; 1924 bool use_zero_blocks = false; 1925 1926 gunichar2 *creator = NULL; 1927 glong creator_items; 1928 VHDXImageType image_type; 1929 1930 assert(opts->driver == BLOCKDEV_DRIVER_VHDX); 1931 vhdx_opts = &opts->u.vhdx; 1932 1933 /* Validate options and set default values */ 1934 image_size = vhdx_opts->size; 1935 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1936 error_setg(errp, "Image size too large; max of 64TB"); 1937 return -EINVAL; 1938 } 1939 1940 if (!vhdx_opts->has_log_size) { 1941 log_size = DEFAULT_LOG_SIZE; 1942 } else { 1943 if (vhdx_opts->log_size > UINT32_MAX) { 1944 error_setg(errp, "Log size must be smaller than 4 GB"); 1945 return -EINVAL; 1946 } 1947 log_size = vhdx_opts->log_size; 1948 } 1949 if (log_size < MiB || (log_size % MiB) != 0) { 1950 error_setg(errp, "Log size must be a multiple of 1 MB"); 1951 return -EINVAL; 1952 } 1953 1954 if (!vhdx_opts->has_block_state_zero) { 1955 use_zero_blocks = true; 1956 } else { 1957 use_zero_blocks = vhdx_opts->block_state_zero; 1958 } 1959 1960 if (!vhdx_opts->has_subformat) { 1961 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC; 1962 } 1963 1964 switch (vhdx_opts->subformat) { 1965 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC: 1966 image_type = VHDX_TYPE_DYNAMIC; 1967 break; 1968 case BLOCKDEV_VHDX_SUBFORMAT_FIXED: 1969 image_type = VHDX_TYPE_FIXED; 1970 break; 1971 default: 1972 g_assert_not_reached(); 1973 } 1974 1975 /* These are pretty arbitrary, and mainly designed to keep the BAT 1976 * size reasonable to load into RAM */ 1977 if (vhdx_opts->has_block_size) { 1978 block_size = vhdx_opts->block_size; 1979 } else { 1980 if (image_size > 32 * TiB) { 1981 block_size = 64 * MiB; 1982 } else if (image_size > (uint64_t) 100 * GiB) { 1983 block_size = 32 * MiB; 1984 } else if (image_size > 1 * GiB) { 1985 block_size = 16 * MiB; 1986 } else { 1987 block_size = 8 * MiB; 1988 } 1989 } 1990 1991 if (block_size < MiB || (block_size % MiB) != 0) { 1992 error_setg(errp, "Block size must be a multiple of 1 MB"); 1993 return -EINVAL; 1994 } 1995 if (!is_power_of_2(block_size)) { 1996 error_setg(errp, "Block size must be a power of two"); 1997 return -EINVAL; 1998 } 1999 if (block_size > VHDX_BLOCK_SIZE_MAX) { 2000 error_setg(errp, "Block size must not exceed %" PRId64, 2001 VHDX_BLOCK_SIZE_MAX); 2002 return -EINVAL; 2003 } 2004 2005 /* Create BlockBackend to write to the image */ 2006 bs = bdrv_co_open_blockdev_ref(vhdx_opts->file, errp); 2007 if (bs == NULL) { 2008 return -EIO; 2009 } 2010 2011 blk = blk_co_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 2012 errp); 2013 if (!blk) { 2014 ret = -EPERM; 2015 goto delete_and_exit; 2016 } 2017 blk_set_allow_write_beyond_eof(blk, true); 2018 2019 /* Create (A) */ 2020 2021 /* The creator field is optional, but may be useful for 2022 * debugging / diagnostics */ 2023 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 2024 &creator_items, NULL); 2025 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 2026 ret = blk_co_pwrite(blk, VHDX_FILE_ID_OFFSET, sizeof(signature), &signature, 2027 0); 2028 if (ret < 0) { 2029 error_setg_errno(errp, -ret, "Failed to write file signature"); 2030 goto delete_and_exit; 2031 } 2032 if (creator) { 2033 ret = blk_co_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature), 2034 creator_items * sizeof(gunichar2), creator, 0); 2035 if (ret < 0) { 2036 error_setg_errno(errp, -ret, "Failed to write creator field"); 2037 goto delete_and_exit; 2038 } 2039 } 2040 2041 2042 /* Creates (B),(C) */ 2043 ret = vhdx_create_new_headers(blk, image_size, log_size); 2044 if (ret < 0) { 2045 error_setg_errno(errp, -ret, "Failed to write image headers"); 2046 goto delete_and_exit; 2047 } 2048 2049 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 2050 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512, 2051 log_size, use_zero_blocks, image_type, 2052 &metadata_offset, errp); 2053 if (ret < 0) { 2054 goto delete_and_exit; 2055 } 2056 2057 /* Creates (H) */ 2058 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512, 2059 metadata_offset, image_type); 2060 if (ret < 0) { 2061 error_setg_errno(errp, -ret, "Failed to initialize metadata"); 2062 goto delete_and_exit; 2063 } 2064 2065 ret = 0; 2066 delete_and_exit: 2067 blk_co_unref(blk); 2068 bdrv_co_unref(bs); 2069 g_free(creator); 2070 return ret; 2071 } 2072 2073 static int coroutine_fn GRAPH_UNLOCKED 2074 vhdx_co_create_opts(BlockDriver *drv, const char *filename, 2075 QemuOpts *opts, Error **errp) 2076 { 2077 BlockdevCreateOptions *create_options = NULL; 2078 QDict *qdict; 2079 Visitor *v; 2080 BlockDriverState *bs = NULL; 2081 int ret; 2082 2083 static const QDictRenames opt_renames[] = { 2084 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" }, 2085 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" }, 2086 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" }, 2087 { NULL, NULL }, 2088 }; 2089 2090 /* Parse options and convert legacy syntax */ 2091 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true); 2092 2093 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 2094 ret = -EINVAL; 2095 goto fail; 2096 } 2097 2098 /* Create and open the file (protocol layer) */ 2099 ret = bdrv_co_create_file(filename, opts, errp); 2100 if (ret < 0) { 2101 goto fail; 2102 } 2103 2104 bs = bdrv_co_open(filename, NULL, NULL, 2105 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 2106 if (bs == NULL) { 2107 ret = -EIO; 2108 goto fail; 2109 } 2110 2111 /* Now get the QAPI type BlockdevCreateOptions */ 2112 qdict_put_str(qdict, "driver", "vhdx"); 2113 qdict_put_str(qdict, "file", bs->node_name); 2114 2115 v = qobject_input_visitor_new_flat_confused(qdict, errp); 2116 if (!v) { 2117 ret = -EINVAL; 2118 goto fail; 2119 } 2120 2121 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 2122 visit_free(v); 2123 if (!create_options) { 2124 ret = -EINVAL; 2125 goto fail; 2126 } 2127 2128 /* Silently round up sizes: 2129 * The image size is rounded to 512 bytes. Make the block and log size 2130 * close to what was specified, but must be at least 1MB, and a multiple of 2131 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0 2132 * means auto, which is represented by a missing key in QAPI. */ 2133 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX); 2134 create_options->u.vhdx.size = 2135 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE); 2136 2137 if (create_options->u.vhdx.has_log_size) { 2138 create_options->u.vhdx.log_size = 2139 ROUND_UP(create_options->u.vhdx.log_size, MiB); 2140 } 2141 if (create_options->u.vhdx.has_block_size) { 2142 create_options->u.vhdx.block_size = 2143 ROUND_UP(create_options->u.vhdx.block_size, MiB); 2144 2145 if (create_options->u.vhdx.block_size == 0) { 2146 create_options->u.vhdx.has_block_size = false; 2147 } 2148 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) { 2149 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX; 2150 } 2151 } 2152 2153 /* Create the vhdx image (format layer) */ 2154 ret = vhdx_co_create(create_options, errp); 2155 2156 fail: 2157 qobject_unref(qdict); 2158 bdrv_co_unref(bs); 2159 qapi_free_BlockdevCreateOptions(create_options); 2160 return ret; 2161 } 2162 2163 /* If opened r/w, the VHDX driver will automatically replay the log, 2164 * if one is present, inside the vhdx_open() call. 2165 * 2166 * If qemu-img check -r all is called, the image is automatically opened 2167 * r/w and any log has already been replayed, so there is nothing (currently) 2168 * for us to do here 2169 */ 2170 static int coroutine_fn GRAPH_RDLOCK 2171 vhdx_co_check(BlockDriverState *bs, BdrvCheckResult *result, 2172 BdrvCheckMode fix) 2173 { 2174 BDRVVHDXState *s = bs->opaque; 2175 2176 if (s->log_replayed_on_open) { 2177 result->corruptions_fixed++; 2178 } 2179 2180 vhdx_check_bat_entries(bs, &result->corruptions); 2181 2182 return 0; 2183 } 2184 2185 static int GRAPH_RDLOCK vhdx_has_zero_init(BlockDriverState *bs) 2186 { 2187 BDRVVHDXState *s = bs->opaque; 2188 int state; 2189 2190 /* 2191 * Check the subformat: Fixed images have all BAT entries present, 2192 * dynamic images have none (right after creation). It is 2193 * therefore enough to check the first BAT entry. 2194 */ 2195 if (!s->bat_entries) { 2196 return 1; 2197 } 2198 2199 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK; 2200 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) { 2201 /* Fixed subformat */ 2202 return bdrv_has_zero_init(bs->file->bs); 2203 } 2204 2205 /* Dynamic subformat */ 2206 return 1; 2207 } 2208 2209 static QemuOptsList vhdx_create_opts = { 2210 .name = "vhdx-create-opts", 2211 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 2212 .desc = { 2213 { 2214 .name = BLOCK_OPT_SIZE, 2215 .type = QEMU_OPT_SIZE, 2216 .help = "Virtual disk size; max of 64TB." 2217 }, 2218 { 2219 .name = VHDX_BLOCK_OPT_LOG_SIZE, 2220 .type = QEMU_OPT_SIZE, 2221 .def_value_str = stringify(DEFAULT_LOG_SIZE), 2222 .help = "Log size; min 1MB." 2223 }, 2224 { 2225 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 2226 .type = QEMU_OPT_SIZE, 2227 .def_value_str = stringify(0), 2228 .help = "Block Size; min 1MB, max 256MB. " 2229 "0 means auto-calculate based on image size." 2230 }, 2231 { 2232 .name = BLOCK_OPT_SUBFMT, 2233 .type = QEMU_OPT_STRING, 2234 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. " 2235 "Default is 'dynamic'." 2236 }, 2237 { 2238 .name = VHDX_BLOCK_OPT_ZERO, 2239 .type = QEMU_OPT_BOOL, 2240 .help = "Force use of payload blocks of type 'ZERO'. " 2241 "Non-standard, but default. Do not set to 'off' when " 2242 "using 'qemu-img convert' with subformat=dynamic." 2243 }, 2244 { NULL } 2245 } 2246 }; 2247 2248 static BlockDriver bdrv_vhdx = { 2249 .format_name = "vhdx", 2250 .instance_size = sizeof(BDRVVHDXState), 2251 .bdrv_probe = vhdx_probe, 2252 .bdrv_open = vhdx_open, 2253 .bdrv_close = vhdx_close, 2254 .bdrv_reopen_prepare = vhdx_reopen_prepare, 2255 .bdrv_child_perm = bdrv_default_perms, 2256 .bdrv_co_readv = vhdx_co_readv, 2257 .bdrv_co_writev = vhdx_co_writev, 2258 .bdrv_co_create = vhdx_co_create, 2259 .bdrv_co_create_opts = vhdx_co_create_opts, 2260 .bdrv_co_get_info = vhdx_co_get_info, 2261 .bdrv_co_check = vhdx_co_check, 2262 .bdrv_has_zero_init = vhdx_has_zero_init, 2263 2264 .is_format = true, 2265 .create_opts = &vhdx_create_opts, 2266 }; 2267 2268 static void bdrv_vhdx_init(void) 2269 { 2270 bdrv_register(&bdrv_vhdx); 2271 } 2272 2273 block_init(bdrv_vhdx_init); 2274