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-common.h" 19 #include "block/block_int.h" 20 #include "qemu/module.h" 21 #include "qemu/crc32c.h" 22 #include "block/vhdx.h" 23 #include "migration/migration.h" 24 25 #include <uuid/uuid.h> 26 #include <glib.h> 27 28 /* Options for VHDX creation */ 29 30 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size" 31 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size" 32 #define VHDX_BLOCK_OPT_ZERO "block_state_zero" 33 34 typedef enum VHDXImageType { 35 VHDX_TYPE_DYNAMIC = 0, 36 VHDX_TYPE_FIXED, 37 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */ 38 } VHDXImageType; 39 40 /* Several metadata and region table data entries are identified by 41 * guids in a MS-specific GUID format. */ 42 43 44 /* ------- Known Region Table GUIDs ---------------------- */ 45 static const MSGUID bat_guid = { .data1 = 0x2dc27766, 46 .data2 = 0xf623, 47 .data3 = 0x4200, 48 .data4 = { 0x9d, 0x64, 0x11, 0x5e, 49 0x9b, 0xfd, 0x4a, 0x08} }; 50 51 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, 52 .data2 = 0x4790, 53 .data3 = 0x4b9a, 54 .data4 = { 0xb8, 0xfe, 0x57, 0x5f, 55 0x05, 0x0f, 0x88, 0x6e} }; 56 57 58 59 /* ------- Known Metadata Entry GUIDs ---------------------- */ 60 static const MSGUID file_param_guid = { .data1 = 0xcaa16737, 61 .data2 = 0xfa36, 62 .data3 = 0x4d43, 63 .data4 = { 0xb3, 0xb6, 0x33, 0xf0, 64 0xaa, 0x44, 0xe7, 0x6b} }; 65 66 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, 67 .data2 = 0xcd1b, 68 .data3 = 0x4876, 69 .data4 = { 0xb2, 0x11, 0x5d, 0xbe, 70 0xd8, 0x3b, 0xf4, 0xb8} }; 71 72 static const MSGUID page83_guid = { .data1 = 0xbeca12ab, 73 .data2 = 0xb2e6, 74 .data3 = 0x4523, 75 .data4 = { 0x93, 0xef, 0xc3, 0x09, 76 0xe0, 0x00, 0xc7, 0x46} }; 77 78 79 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, 80 .data2 = 0x445d, 81 .data3 = 0x4471, 82 .data4 = { 0x9c, 0xc9, 0xe9, 0x88, 83 0x52, 0x51, 0xc5, 0x56} }; 84 85 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, 86 .data2 = 0xb30b, 87 .data3 = 0x454d, 88 .data4 = { 0xab, 0xf7, 0xd3, 89 0xd8, 0x48, 0x34, 90 0xab, 0x0c} }; 91 92 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, 93 .data2 = 0xa96f, 94 .data3 = 0x4709, 95 .data4 = { 0xba, 0x47, 0xf2, 96 0x33, 0xa8, 0xfa, 97 0xab, 0x5f} }; 98 99 /* Each parent type must have a valid GUID; this is for parent images 100 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would 101 * need to make up our own QCOW2 GUID type */ 102 static const MSGUID parent_vhdx_guid __attribute__((unused)) 103 = { .data1 = 0xb04aefb7, 104 .data2 = 0xd19e, 105 .data3 = 0x4a81, 106 .data4 = { 0xb7, 0x89, 0x25, 0xb8, 107 0xe9, 0x44, 0x59, 0x13} }; 108 109 110 #define META_FILE_PARAMETER_PRESENT 0x01 111 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 112 #define META_PAGE_83_PRESENT 0x04 113 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 114 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10 115 #define META_PARENT_LOCATOR_PRESENT 0x20 116 117 #define META_ALL_PRESENT \ 118 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ 119 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ 120 META_PHYS_SECTOR_SIZE_PRESENT) 121 122 123 typedef struct VHDXSectorInfo { 124 uint32_t bat_idx; /* BAT entry index */ 125 uint32_t sectors_avail; /* sectors available in payload block */ 126 uint32_t bytes_left; /* bytes left in the block after data to r/w */ 127 uint32_t bytes_avail; /* bytes available in payload block */ 128 uint64_t file_offset; /* absolute offset in bytes, in file */ 129 uint64_t block_offset; /* block offset, in bytes */ 130 } VHDXSectorInfo; 131 132 /* Calculates new checksum. 133 * 134 * Zero is substituted during crc calculation for the original crc field 135 * crc_offset: byte offset in buf of the buffer crc 136 * buf: buffer pointer 137 * size: size of buffer (must be > crc_offset+4) 138 * 139 * Note: The buffer should have all multi-byte data in little-endian format, 140 * and the resulting checksum is in little endian format. 141 */ 142 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) 143 { 144 uint32_t crc; 145 146 assert(buf != NULL); 147 assert(size > (crc_offset + sizeof(crc))); 148 149 memset(buf + crc_offset, 0, sizeof(crc)); 150 crc = crc32c(0xffffffff, buf, size); 151 cpu_to_le32s(&crc); 152 memcpy(buf + crc_offset, &crc, sizeof(crc)); 153 154 return crc; 155 } 156 157 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, 158 int crc_offset) 159 { 160 uint32_t crc_new; 161 uint32_t crc_orig; 162 assert(buf != NULL); 163 164 if (crc_offset > 0) { 165 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 166 memset(buf + crc_offset, 0, sizeof(crc_orig)); 167 } 168 169 crc_new = crc32c(crc, buf, size); 170 if (crc_offset > 0) { 171 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); 172 } 173 174 return crc_new; 175 } 176 177 /* Validates the checksum of the buffer, with an in-place CRC. 178 * 179 * Zero is substituted during crc calculation for the original crc field, 180 * and the crc field is restored afterwards. But the buffer will be modifed 181 * during the calculation, so this may not be not suitable for multi-threaded 182 * use. 183 * 184 * crc_offset: byte offset in buf of the buffer crc 185 * buf: buffer pointer 186 * size: size of buffer (must be > crc_offset+4) 187 * 188 * returns true if checksum is valid, false otherwise 189 */ 190 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) 191 { 192 uint32_t crc_orig; 193 uint32_t crc; 194 195 assert(buf != NULL); 196 assert(size > (crc_offset + 4)); 197 198 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); 199 crc_orig = le32_to_cpu(crc_orig); 200 201 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); 202 203 return crc == crc_orig; 204 } 205 206 207 /* 208 * This generates a UUID that is compliant with the MS GUIDs used 209 * in the VHDX spec (and elsewhere). 210 */ 211 void vhdx_guid_generate(MSGUID *guid) 212 { 213 uuid_t uuid; 214 assert(guid != NULL); 215 216 uuid_generate(uuid); 217 memcpy(guid, uuid, sizeof(MSGUID)); 218 } 219 220 /* Check for region overlaps inside the VHDX image */ 221 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) 222 { 223 int ret = 0; 224 uint64_t end; 225 VHDXRegionEntry *r; 226 227 end = start + length; 228 QLIST_FOREACH(r, &s->regions, entries) { 229 if (!((start >= r->end) || (end <= r->start))) { 230 ret = -EINVAL; 231 goto exit; 232 } 233 } 234 235 exit: 236 return ret; 237 } 238 239 /* Register a region for future checks */ 240 static void vhdx_region_register(BDRVVHDXState *s, 241 uint64_t start, uint64_t length) 242 { 243 VHDXRegionEntry *r; 244 245 r = g_malloc0(sizeof(*r)); 246 247 r->start = start; 248 r->end = start + length; 249 250 QLIST_INSERT_HEAD(&s->regions, r, entries); 251 } 252 253 /* Free all registered regions */ 254 static void vhdx_region_unregister_all(BDRVVHDXState *s) 255 { 256 VHDXRegionEntry *r, *r_next; 257 258 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { 259 QLIST_REMOVE(r, entries); 260 g_free(r); 261 } 262 } 263 264 static void vhdx_set_shift_bits(BDRVVHDXState *s) 265 { 266 s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size); 267 s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block); 268 s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio); 269 s->block_size_bits = 31 - clz32(s->block_size); 270 } 271 272 /* 273 * Per the MS VHDX Specification, for every VHDX file: 274 * - The header section is fixed size - 1 MB 275 * - The header section is always the first "object" 276 * - The first 64KB of the header is the File Identifier 277 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") 278 * - The following 512 bytes constitute a UTF-16 string identifiying the 279 * software that created the file, and is optional and diagnostic only. 280 * 281 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" 282 */ 283 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) 284 { 285 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { 286 return 100; 287 } 288 return 0; 289 } 290 291 /* 292 * Writes the header to the specified offset. 293 * 294 * This will optionally read in buffer data from disk (otherwise zero-fill), 295 * and then update the header checksum. Header is converted to proper 296 * endianness before being written to the specified file offset 297 */ 298 static int vhdx_write_header(BlockDriverState *bs_file, VHDXHeader *hdr, 299 uint64_t offset, bool read) 300 { 301 uint8_t *buffer = NULL; 302 int ret; 303 VHDXHeader *header_le; 304 305 assert(bs_file != NULL); 306 assert(hdr != NULL); 307 308 /* the header checksum is not over just the packed size of VHDXHeader, 309 * but rather over the entire 'reserved' range for the header, which is 310 * 4KB (VHDX_HEADER_SIZE). */ 311 312 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); 313 if (read) { 314 /* if true, we can't assume the extra reserved bytes are 0 */ 315 ret = bdrv_pread(bs_file, offset, buffer, VHDX_HEADER_SIZE); 316 if (ret < 0) { 317 goto exit; 318 } 319 } else { 320 memset(buffer, 0, VHDX_HEADER_SIZE); 321 } 322 323 /* overwrite the actual VHDXHeader portion */ 324 header_le = (VHDXHeader *)buffer; 325 memcpy(header_le, hdr, sizeof(VHDXHeader)); 326 vhdx_header_le_export(hdr, header_le); 327 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, 328 offsetof(VHDXHeader, checksum)); 329 ret = bdrv_pwrite_sync(bs_file, offset, header_le, sizeof(VHDXHeader)); 330 331 exit: 332 qemu_vfree(buffer); 333 return ret; 334 } 335 336 /* Update the VHDX headers 337 * 338 * This follows the VHDX spec procedures for header updates. 339 * 340 * - non-current header is updated with largest sequence number 341 */ 342 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, 343 bool generate_data_write_guid, MSGUID *log_guid) 344 { 345 int ret = 0; 346 int hdr_idx = 0; 347 uint64_t header_offset = VHDX_HEADER1_OFFSET; 348 349 VHDXHeader *active_header; 350 VHDXHeader *inactive_header; 351 352 /* operate on the non-current header */ 353 if (s->curr_header == 0) { 354 hdr_idx = 1; 355 header_offset = VHDX_HEADER2_OFFSET; 356 } 357 358 active_header = s->headers[s->curr_header]; 359 inactive_header = s->headers[hdr_idx]; 360 361 inactive_header->sequence_number = active_header->sequence_number + 1; 362 363 /* a new file guid must be generated before any file write, including 364 * headers */ 365 inactive_header->file_write_guid = s->session_guid; 366 367 /* a new data guid only needs to be generated before any guest-visible 368 * writes (i.e. something observable via virtual disk read) */ 369 if (generate_data_write_guid) { 370 vhdx_guid_generate(&inactive_header->data_write_guid); 371 } 372 373 /* update the log guid if present */ 374 if (log_guid) { 375 inactive_header->log_guid = *log_guid; 376 } 377 378 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); 379 if (ret < 0) { 380 goto exit; 381 } 382 s->curr_header = hdr_idx; 383 384 exit: 385 return ret; 386 } 387 388 /* 389 * The VHDX spec calls for header updates to be performed twice, so that both 390 * the current and non-current header have valid info 391 */ 392 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, 393 bool generate_data_write_guid, MSGUID *log_guid) 394 { 395 int ret; 396 397 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 398 if (ret < 0) { 399 return ret; 400 } 401 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); 402 return ret; 403 } 404 405 /* opens the specified header block from the VHDX file header section */ 406 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, 407 Error **errp) 408 { 409 int ret; 410 VHDXHeader *header1; 411 VHDXHeader *header2; 412 bool h1_valid = false; 413 bool h2_valid = false; 414 uint64_t h1_seq = 0; 415 uint64_t h2_seq = 0; 416 uint8_t *buffer; 417 418 /* header1 & header2 are freed in vhdx_close() */ 419 header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); 420 header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); 421 422 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); 423 424 s->headers[0] = header1; 425 s->headers[1] = header2; 426 427 /* We have to read the whole VHDX_HEADER_SIZE instead of 428 * sizeof(VHDXHeader), because the checksum is over the whole 429 * region */ 430 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE); 431 if (ret < 0) { 432 goto fail; 433 } 434 /* copy over just the relevant portion that we need */ 435 memcpy(header1, buffer, sizeof(VHDXHeader)); 436 437 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 438 vhdx_header_le_import(header1); 439 if (header1->signature == VHDX_HEADER_SIGNATURE && 440 header1->version == 1) { 441 h1_seq = header1->sequence_number; 442 h1_valid = true; 443 } 444 } 445 446 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE); 447 if (ret < 0) { 448 goto fail; 449 } 450 /* copy over just the relevant portion that we need */ 451 memcpy(header2, buffer, sizeof(VHDXHeader)); 452 453 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { 454 vhdx_header_le_import(header2); 455 if (header2->signature == VHDX_HEADER_SIGNATURE && 456 header2->version == 1) { 457 h2_seq = header2->sequence_number; 458 h2_valid = true; 459 } 460 } 461 462 /* If there is only 1 valid header (or no valid headers), we 463 * don't care what the sequence numbers are */ 464 if (h1_valid && !h2_valid) { 465 s->curr_header = 0; 466 } else if (!h1_valid && h2_valid) { 467 s->curr_header = 1; 468 } else if (!h1_valid && !h2_valid) { 469 goto fail; 470 } else { 471 /* If both headers are valid, then we choose the active one by the 472 * highest sequence number. If the sequence numbers are equal, that is 473 * invalid */ 474 if (h1_seq > h2_seq) { 475 s->curr_header = 0; 476 } else if (h2_seq > h1_seq) { 477 s->curr_header = 1; 478 } else { 479 /* The Microsoft Disk2VHD tool will create 2 identical 480 * headers, with identical sequence numbers. If the headers are 481 * identical, don't consider the file corrupt */ 482 if (!memcmp(header1, header2, sizeof(VHDXHeader))) { 483 s->curr_header = 0; 484 } else { 485 goto fail; 486 } 487 } 488 } 489 490 vhdx_region_register(s, s->headers[s->curr_header]->log_offset, 491 s->headers[s->curr_header]->log_length); 492 goto exit; 493 494 fail: 495 error_setg_errno(errp, -ret, "No valid VHDX header found"); 496 qemu_vfree(header1); 497 qemu_vfree(header2); 498 s->headers[0] = NULL; 499 s->headers[1] = NULL; 500 exit: 501 qemu_vfree(buffer); 502 } 503 504 505 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) 506 { 507 int ret = 0; 508 uint8_t *buffer; 509 int offset = 0; 510 VHDXRegionTableEntry rt_entry; 511 uint32_t i; 512 bool bat_rt_found = false; 513 bool metadata_rt_found = false; 514 515 /* We have to read the whole 64KB block, because the crc32 is over the 516 * whole block */ 517 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); 518 519 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, 520 VHDX_HEADER_BLOCK_SIZE); 521 if (ret < 0) { 522 goto fail; 523 } 524 memcpy(&s->rt, buffer, sizeof(s->rt)); 525 offset += sizeof(s->rt); 526 527 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { 528 ret = -EINVAL; 529 goto fail; 530 } 531 532 vhdx_region_header_le_import(&s->rt); 533 534 if (s->rt.signature != VHDX_REGION_SIGNATURE) { 535 ret = -EINVAL; 536 goto fail; 537 } 538 539 540 /* Per spec, maximum region table entry count is 2047 */ 541 if (s->rt.entry_count > 2047) { 542 ret = -EINVAL; 543 goto fail; 544 } 545 546 for (i = 0; i < s->rt.entry_count; i++) { 547 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); 548 offset += sizeof(rt_entry); 549 550 vhdx_region_entry_le_import(&rt_entry); 551 552 /* check for region overlap between these entries, and any 553 * other memory regions in the file */ 554 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); 555 if (ret < 0) { 556 goto fail; 557 } 558 559 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); 560 561 /* see if we recognize the entry */ 562 if (guid_eq(rt_entry.guid, bat_guid)) { 563 /* must be unique; if we have already found it this is invalid */ 564 if (bat_rt_found) { 565 ret = -EINVAL; 566 goto fail; 567 } 568 bat_rt_found = true; 569 s->bat_rt = rt_entry; 570 continue; 571 } 572 573 if (guid_eq(rt_entry.guid, metadata_guid)) { 574 /* must be unique; if we have already found it this is invalid */ 575 if (metadata_rt_found) { 576 ret = -EINVAL; 577 goto fail; 578 } 579 metadata_rt_found = true; 580 s->metadata_rt = rt_entry; 581 continue; 582 } 583 584 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { 585 /* cannot read vhdx file - required region table entry that 586 * we do not understand. per spec, we must fail to open */ 587 ret = -ENOTSUP; 588 goto fail; 589 } 590 } 591 592 if (!bat_rt_found || !metadata_rt_found) { 593 ret = -EINVAL; 594 goto fail; 595 } 596 597 ret = 0; 598 599 fail: 600 qemu_vfree(buffer); 601 return ret; 602 } 603 604 605 606 /* Metadata initial parser 607 * 608 * This loads all the metadata entry fields. This may cause additional 609 * fields to be processed (e.g. parent locator, etc..). 610 * 611 * There are 5 Metadata items that are always required: 612 * - File Parameters (block size, has a parent) 613 * - Virtual Disk Size (size, in bytes, of the virtual drive) 614 * - Page 83 Data (scsi page 83 guid) 615 * - Logical Sector Size (logical sector size in bytes, either 512 or 616 * 4096. We only support 512 currently) 617 * - Physical Sector Size (512 or 4096) 618 * 619 * Also, if the File Parameters indicate this is a differencing file, 620 * we must also look for the Parent Locator metadata item. 621 */ 622 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) 623 { 624 int ret = 0; 625 uint8_t *buffer; 626 int offset = 0; 627 uint32_t i = 0; 628 VHDXMetadataTableEntry md_entry; 629 630 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); 631 632 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, 633 VHDX_METADATA_TABLE_MAX_SIZE); 634 if (ret < 0) { 635 goto exit; 636 } 637 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); 638 offset += sizeof(s->metadata_hdr); 639 640 vhdx_metadata_header_le_import(&s->metadata_hdr); 641 642 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { 643 ret = -EINVAL; 644 goto exit; 645 } 646 647 s->metadata_entries.present = 0; 648 649 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > 650 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { 651 ret = -EINVAL; 652 goto exit; 653 } 654 655 for (i = 0; i < s->metadata_hdr.entry_count; i++) { 656 memcpy(&md_entry, buffer + offset, sizeof(md_entry)); 657 offset += sizeof(md_entry); 658 659 vhdx_metadata_entry_le_import(&md_entry); 660 661 if (guid_eq(md_entry.item_id, file_param_guid)) { 662 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { 663 ret = -EINVAL; 664 goto exit; 665 } 666 s->metadata_entries.file_parameters_entry = md_entry; 667 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; 668 continue; 669 } 670 671 if (guid_eq(md_entry.item_id, virtual_size_guid)) { 672 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { 673 ret = -EINVAL; 674 goto exit; 675 } 676 s->metadata_entries.virtual_disk_size_entry = md_entry; 677 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; 678 continue; 679 } 680 681 if (guid_eq(md_entry.item_id, page83_guid)) { 682 if (s->metadata_entries.present & META_PAGE_83_PRESENT) { 683 ret = -EINVAL; 684 goto exit; 685 } 686 s->metadata_entries.page83_data_entry = md_entry; 687 s->metadata_entries.present |= META_PAGE_83_PRESENT; 688 continue; 689 } 690 691 if (guid_eq(md_entry.item_id, logical_sector_guid)) { 692 if (s->metadata_entries.present & 693 META_LOGICAL_SECTOR_SIZE_PRESENT) { 694 ret = -EINVAL; 695 goto exit; 696 } 697 s->metadata_entries.logical_sector_size_entry = md_entry; 698 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; 699 continue; 700 } 701 702 if (guid_eq(md_entry.item_id, phys_sector_guid)) { 703 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { 704 ret = -EINVAL; 705 goto exit; 706 } 707 s->metadata_entries.phys_sector_size_entry = md_entry; 708 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; 709 continue; 710 } 711 712 if (guid_eq(md_entry.item_id, parent_locator_guid)) { 713 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 714 ret = -EINVAL; 715 goto exit; 716 } 717 s->metadata_entries.parent_locator_entry = md_entry; 718 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; 719 continue; 720 } 721 722 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { 723 /* cannot read vhdx file - required region table entry that 724 * we do not understand. per spec, we must fail to open */ 725 ret = -ENOTSUP; 726 goto exit; 727 } 728 } 729 730 if (s->metadata_entries.present != META_ALL_PRESENT) { 731 ret = -ENOTSUP; 732 goto exit; 733 } 734 735 ret = bdrv_pread(bs->file, 736 s->metadata_entries.file_parameters_entry.offset 737 + s->metadata_rt.file_offset, 738 &s->params, 739 sizeof(s->params)); 740 741 if (ret < 0) { 742 goto exit; 743 } 744 745 le32_to_cpus(&s->params.block_size); 746 le32_to_cpus(&s->params.data_bits); 747 748 749 /* We now have the file parameters, so we can tell if this is a 750 * differencing file (i.e.. has_parent), is dynamic or fixed 751 * sized (leave_blocks_allocated), and the block size */ 752 753 /* The parent locator required iff the file parameters has_parent set */ 754 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 755 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { 756 /* TODO: parse parent locator fields */ 757 ret = -ENOTSUP; /* temp, until differencing files are supported */ 758 goto exit; 759 } else { 760 /* if has_parent is set, but there is not parent locator present, 761 * then that is an invalid combination */ 762 ret = -EINVAL; 763 goto exit; 764 } 765 } 766 767 /* determine virtual disk size, logical sector size, 768 * and phys sector size */ 769 770 ret = bdrv_pread(bs->file, 771 s->metadata_entries.virtual_disk_size_entry.offset 772 + s->metadata_rt.file_offset, 773 &s->virtual_disk_size, 774 sizeof(uint64_t)); 775 if (ret < 0) { 776 goto exit; 777 } 778 ret = bdrv_pread(bs->file, 779 s->metadata_entries.logical_sector_size_entry.offset 780 + s->metadata_rt.file_offset, 781 &s->logical_sector_size, 782 sizeof(uint32_t)); 783 if (ret < 0) { 784 goto exit; 785 } 786 ret = bdrv_pread(bs->file, 787 s->metadata_entries.phys_sector_size_entry.offset 788 + s->metadata_rt.file_offset, 789 &s->physical_sector_size, 790 sizeof(uint32_t)); 791 if (ret < 0) { 792 goto exit; 793 } 794 795 le64_to_cpus(&s->virtual_disk_size); 796 le32_to_cpus(&s->logical_sector_size); 797 le32_to_cpus(&s->physical_sector_size); 798 799 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || 800 s->params.block_size > VHDX_BLOCK_SIZE_MAX) { 801 ret = -EINVAL; 802 goto exit; 803 } 804 805 /* only 2 supported sector sizes */ 806 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { 807 ret = -EINVAL; 808 goto exit; 809 } 810 811 /* Both block_size and sector_size are guaranteed powers of 2, below. 812 Due to range checks above, s->sectors_per_block can never be < 256 */ 813 s->sectors_per_block = s->params.block_size / s->logical_sector_size; 814 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 815 (uint64_t)s->logical_sector_size / 816 (uint64_t)s->params.block_size; 817 818 /* These values are ones we will want to use for division / multiplication 819 * later on, and they are all guaranteed (per the spec) to be powers of 2, 820 * so we can take advantage of that for shift operations during 821 * reads/writes */ 822 if (s->logical_sector_size & (s->logical_sector_size - 1)) { 823 ret = -EINVAL; 824 goto exit; 825 } 826 if (s->sectors_per_block & (s->sectors_per_block - 1)) { 827 ret = -EINVAL; 828 goto exit; 829 } 830 if (s->chunk_ratio & (s->chunk_ratio - 1)) { 831 ret = -EINVAL; 832 goto exit; 833 } 834 s->block_size = s->params.block_size; 835 if (s->block_size & (s->block_size - 1)) { 836 ret = -EINVAL; 837 goto exit; 838 } 839 840 vhdx_set_shift_bits(s); 841 842 ret = 0; 843 844 exit: 845 qemu_vfree(buffer); 846 return ret; 847 } 848 849 /* 850 * Calculate the number of BAT entries, including sector 851 * bitmap entries. 852 */ 853 static void vhdx_calc_bat_entries(BDRVVHDXState *s) 854 { 855 uint32_t data_blocks_cnt, bitmap_blocks_cnt; 856 857 data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits; 858 if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) { 859 data_blocks_cnt++; 860 } 861 bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits; 862 if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) { 863 bitmap_blocks_cnt++; 864 } 865 866 if (s->parent_entries) { 867 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); 868 } else { 869 s->bat_entries = data_blocks_cnt + 870 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); 871 } 872 873 } 874 875 static void vhdx_close(BlockDriverState *bs) 876 { 877 BDRVVHDXState *s = bs->opaque; 878 qemu_vfree(s->headers[0]); 879 s->headers[0] = NULL; 880 qemu_vfree(s->headers[1]); 881 s->headers[1] = NULL; 882 qemu_vfree(s->bat); 883 s->bat = NULL; 884 qemu_vfree(s->parent_entries); 885 s->parent_entries = NULL; 886 migrate_del_blocker(s->migration_blocker); 887 error_free(s->migration_blocker); 888 qemu_vfree(s->log.hdr); 889 s->log.hdr = NULL; 890 vhdx_region_unregister_all(s); 891 } 892 893 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, 894 Error **errp) 895 { 896 BDRVVHDXState *s = bs->opaque; 897 int ret = 0; 898 uint32_t i; 899 uint64_t signature; 900 Error *local_err = NULL; 901 902 s->bat = NULL; 903 s->first_visible_write = true; 904 905 qemu_co_mutex_init(&s->lock); 906 QLIST_INIT(&s->regions); 907 908 /* validate the file signature */ 909 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); 910 if (ret < 0) { 911 goto fail; 912 } 913 if (memcmp(&signature, "vhdxfile", 8)) { 914 ret = -EINVAL; 915 goto fail; 916 } 917 918 /* This is used for any header updates, for the file_write_guid. 919 * The spec dictates that a new value should be used for the first 920 * header update */ 921 vhdx_guid_generate(&s->session_guid); 922 923 vhdx_parse_header(bs, s, &local_err); 924 if (local_err != NULL) { 925 error_propagate(errp, local_err); 926 ret = -EINVAL; 927 goto fail; 928 } 929 930 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); 931 if (ret < 0) { 932 goto fail; 933 } 934 935 ret = vhdx_open_region_tables(bs, s); 936 if (ret < 0) { 937 goto fail; 938 } 939 940 ret = vhdx_parse_metadata(bs, s); 941 if (ret < 0) { 942 goto fail; 943 } 944 945 s->block_size = s->params.block_size; 946 947 /* the VHDX spec dictates that virtual_disk_size is always a multiple of 948 * logical_sector_size */ 949 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; 950 951 vhdx_calc_bat_entries(s); 952 953 s->bat_offset = s->bat_rt.file_offset; 954 955 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { 956 /* BAT allocation is not large enough for all entries */ 957 ret = -EINVAL; 958 goto fail; 959 } 960 961 /* s->bat is freed in vhdx_close() */ 962 s->bat = qemu_try_blockalign(bs->file, s->bat_rt.length); 963 if (s->bat == NULL) { 964 ret = -ENOMEM; 965 goto fail; 966 } 967 968 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); 969 if (ret < 0) { 970 goto fail; 971 } 972 973 uint64_t payblocks = s->chunk_ratio; 974 /* endian convert, and verify populated BAT field file offsets against 975 * region table and log entries */ 976 for (i = 0; i < s->bat_entries; i++) { 977 le64_to_cpus(&s->bat[i]); 978 if (payblocks--) { 979 /* payload bat entries */ 980 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == 981 PAYLOAD_BLOCK_FULLY_PRESENT) { 982 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, 983 s->block_size); 984 if (ret < 0) { 985 goto fail; 986 } 987 } 988 } else { 989 payblocks = s->chunk_ratio; 990 /* Once differencing files are supported, verify sector bitmap 991 * blocks here */ 992 } 993 } 994 995 if (flags & BDRV_O_RDWR) { 996 ret = vhdx_update_headers(bs, s, false, NULL); 997 if (ret < 0) { 998 goto fail; 999 } 1000 } 1001 1002 /* TODO: differencing files */ 1003 1004 /* Disable migration when VHDX images are used */ 1005 error_set(&s->migration_blocker, 1006 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 1007 "vhdx", bs->device_name, "live migration"); 1008 migrate_add_blocker(s->migration_blocker); 1009 1010 return 0; 1011 fail: 1012 vhdx_close(bs); 1013 return ret; 1014 } 1015 1016 static int vhdx_reopen_prepare(BDRVReopenState *state, 1017 BlockReopenQueue *queue, Error **errp) 1018 { 1019 return 0; 1020 } 1021 1022 1023 /* 1024 * Perform sector to block offset translations, to get various 1025 * sector and file offsets into the image. See VHDXSectorInfo 1026 */ 1027 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, 1028 int nb_sectors, VHDXSectorInfo *sinfo) 1029 { 1030 uint32_t block_offset; 1031 1032 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; 1033 /* effectively a modulo - this gives us the offset into the block 1034 * (in sector sizes) for our sector number */ 1035 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); 1036 /* the chunk ratio gives us the interleaving of the sector 1037 * bitmaps, so we need to advance our page block index by the 1038 * sector bitmaps entry number */ 1039 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; 1040 1041 /* the number of sectors we can read/write in this cycle */ 1042 sinfo->sectors_avail = s->sectors_per_block - block_offset; 1043 1044 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; 1045 1046 if (sinfo->sectors_avail > nb_sectors) { 1047 sinfo->sectors_avail = nb_sectors; 1048 } 1049 1050 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; 1051 1052 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; 1053 1054 sinfo->block_offset = block_offset << s->logical_sector_size_bits; 1055 1056 /* The file offset must be past the header section, so must be > 0 */ 1057 if (sinfo->file_offset == 0) { 1058 return; 1059 } 1060 1061 /* block offset is the offset in vhdx logical sectors, in 1062 * the payload data block. Convert that to a byte offset 1063 * in the block, and add in the payload data block offset 1064 * in the file, in bytes, to get the final read address */ 1065 1066 sinfo->file_offset += sinfo->block_offset; 1067 } 1068 1069 1070 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1071 { 1072 BDRVVHDXState *s = bs->opaque; 1073 1074 bdi->cluster_size = s->block_size; 1075 1076 bdi->unallocated_blocks_are_zero = 1077 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; 1078 1079 return 0; 1080 } 1081 1082 1083 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 1084 int nb_sectors, QEMUIOVector *qiov) 1085 { 1086 BDRVVHDXState *s = bs->opaque; 1087 int ret = 0; 1088 VHDXSectorInfo sinfo; 1089 uint64_t bytes_done = 0; 1090 QEMUIOVector hd_qiov; 1091 1092 qemu_iovec_init(&hd_qiov, qiov->niov); 1093 1094 qemu_co_mutex_lock(&s->lock); 1095 1096 while (nb_sectors > 0) { 1097 /* We are a differencing file, so we need to inspect the sector bitmap 1098 * to see if we have the data or not */ 1099 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1100 /* not supported yet */ 1101 ret = -ENOTSUP; 1102 goto exit; 1103 } else { 1104 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1105 1106 qemu_iovec_reset(&hd_qiov); 1107 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); 1108 1109 /* check the payload block state */ 1110 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { 1111 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1112 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1113 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1114 case PAYLOAD_BLOCK_ZERO: 1115 /* return zero */ 1116 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); 1117 break; 1118 case PAYLOAD_BLOCK_FULLY_PRESENT: 1119 qemu_co_mutex_unlock(&s->lock); 1120 ret = bdrv_co_readv(bs->file, 1121 sinfo.file_offset >> BDRV_SECTOR_BITS, 1122 sinfo.sectors_avail, &hd_qiov); 1123 qemu_co_mutex_lock(&s->lock); 1124 if (ret < 0) { 1125 goto exit; 1126 } 1127 break; 1128 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1129 /* we don't yet support difference files, fall through 1130 * to error */ 1131 default: 1132 ret = -EIO; 1133 goto exit; 1134 break; 1135 } 1136 nb_sectors -= sinfo.sectors_avail; 1137 sector_num += sinfo.sectors_avail; 1138 bytes_done += sinfo.bytes_avail; 1139 } 1140 } 1141 ret = 0; 1142 exit: 1143 qemu_co_mutex_unlock(&s->lock); 1144 qemu_iovec_destroy(&hd_qiov); 1145 return ret; 1146 } 1147 1148 /* 1149 * Allocate a new payload block at the end of the file. 1150 * 1151 * Allocation will happen at 1MB alignment inside the file 1152 * 1153 * Returns the file offset start of the new payload block 1154 */ 1155 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, 1156 uint64_t *new_offset) 1157 { 1158 *new_offset = bdrv_getlength(bs->file); 1159 1160 /* per the spec, the address for a block is in units of 1MB */ 1161 *new_offset = ROUND_UP(*new_offset, 1024 * 1024); 1162 1163 return bdrv_truncate(bs->file, *new_offset + s->block_size); 1164 } 1165 1166 /* 1167 * Update the BAT table entry with the new file offset, and the new entry 1168 * state */ 1169 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, 1170 VHDXSectorInfo *sinfo, 1171 uint64_t *bat_entry_le, 1172 uint64_t *bat_offset, int state) 1173 { 1174 /* The BAT entry is a uint64, with 44 bits for the file offset in units of 1175 * 1MB, and 3 bits for the block state. */ 1176 s->bat[sinfo->bat_idx] = sinfo->file_offset; 1177 1178 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; 1179 1180 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); 1181 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); 1182 1183 } 1184 1185 /* Per the spec, on the first write of guest-visible data to the file the 1186 * data write guid must be updated in the header */ 1187 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) 1188 { 1189 int ret = 0; 1190 if (s->first_visible_write) { 1191 s->first_visible_write = false; 1192 ret = vhdx_update_headers(bs, s, true, NULL); 1193 } 1194 return ret; 1195 } 1196 1197 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 1198 int nb_sectors, QEMUIOVector *qiov) 1199 { 1200 int ret = -ENOTSUP; 1201 BDRVVHDXState *s = bs->opaque; 1202 VHDXSectorInfo sinfo; 1203 uint64_t bytes_done = 0; 1204 uint64_t bat_entry = 0; 1205 uint64_t bat_entry_offset = 0; 1206 QEMUIOVector hd_qiov; 1207 struct iovec iov1 = { 0 }; 1208 struct iovec iov2 = { 0 }; 1209 int sectors_to_write; 1210 int bat_state; 1211 uint64_t bat_prior_offset = 0; 1212 bool bat_update = false; 1213 1214 qemu_iovec_init(&hd_qiov, qiov->niov); 1215 1216 qemu_co_mutex_lock(&s->lock); 1217 1218 ret = vhdx_user_visible_write(bs, s); 1219 if (ret < 0) { 1220 goto exit; 1221 } 1222 1223 while (nb_sectors > 0) { 1224 bool use_zero_buffers = false; 1225 bat_update = false; 1226 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { 1227 /* not supported yet */ 1228 ret = -ENOTSUP; 1229 goto exit; 1230 } else { 1231 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); 1232 sectors_to_write = sinfo.sectors_avail; 1233 1234 qemu_iovec_reset(&hd_qiov); 1235 /* check the payload block state */ 1236 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; 1237 switch (bat_state) { 1238 case PAYLOAD_BLOCK_ZERO: 1239 /* in this case, we need to preserve zero writes for 1240 * data that is not part of this write, so we must pad 1241 * the rest of the buffer to zeroes */ 1242 1243 /* if we are on a posix system with ftruncate() that extends 1244 * a file, then it is zero-filled for us. On Win32, the raw 1245 * layer uses SetFilePointer and SetFileEnd, which does not 1246 * zero fill AFAIK */ 1247 1248 /* Queue another write of zero buffers if the underlying file 1249 * does not zero-fill on file extension */ 1250 1251 if (bdrv_has_zero_init(bs->file) == 0) { 1252 use_zero_buffers = true; 1253 1254 /* zero fill the front, if any */ 1255 if (sinfo.block_offset) { 1256 iov1.iov_len = sinfo.block_offset; 1257 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); 1258 memset(iov1.iov_base, 0, iov1.iov_len); 1259 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, 1260 sinfo.block_offset); 1261 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; 1262 } 1263 1264 /* our actual data */ 1265 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1266 sinfo.bytes_avail); 1267 1268 /* zero fill the back, if any */ 1269 if ((sinfo.bytes_avail - sinfo.block_offset) < 1270 s->block_size) { 1271 iov2.iov_len = s->block_size - 1272 (sinfo.bytes_avail + sinfo.block_offset); 1273 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); 1274 memset(iov2.iov_base, 0, iov2.iov_len); 1275 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, 1276 sinfo.block_offset); 1277 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; 1278 } 1279 } 1280 1281 /* fall through */ 1282 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ 1283 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */ 1284 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */ 1285 bat_prior_offset = sinfo.file_offset; 1286 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); 1287 if (ret < 0) { 1288 goto exit; 1289 } 1290 /* once we support differencing files, this may also be 1291 * partially present */ 1292 /* update block state to the newly specified state */ 1293 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1294 &bat_entry_offset, 1295 PAYLOAD_BLOCK_FULLY_PRESENT); 1296 bat_update = true; 1297 /* since we just allocated a block, file_offset is the 1298 * beginning of the payload block. It needs to be the 1299 * write address, which includes the offset into the block */ 1300 if (!use_zero_buffers) { 1301 sinfo.file_offset += sinfo.block_offset; 1302 } 1303 /* fall through */ 1304 case PAYLOAD_BLOCK_FULLY_PRESENT: 1305 /* if the file offset address is in the header zone, 1306 * there is a problem */ 1307 if (sinfo.file_offset < (1024 * 1024)) { 1308 ret = -EFAULT; 1309 goto error_bat_restore; 1310 } 1311 1312 if (!use_zero_buffers) { 1313 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, 1314 sinfo.bytes_avail); 1315 } 1316 /* block exists, so we can just overwrite it */ 1317 qemu_co_mutex_unlock(&s->lock); 1318 ret = bdrv_co_writev(bs->file, 1319 sinfo.file_offset >> BDRV_SECTOR_BITS, 1320 sectors_to_write, &hd_qiov); 1321 qemu_co_mutex_lock(&s->lock); 1322 if (ret < 0) { 1323 goto error_bat_restore; 1324 } 1325 break; 1326 case PAYLOAD_BLOCK_PARTIALLY_PRESENT: 1327 /* we don't yet support difference files, fall through 1328 * to error */ 1329 default: 1330 ret = -EIO; 1331 goto exit; 1332 break; 1333 } 1334 1335 if (bat_update) { 1336 /* this will update the BAT entry into the log journal, and 1337 * then flush the log journal out to disk */ 1338 ret = vhdx_log_write_and_flush(bs, s, &bat_entry, 1339 sizeof(VHDXBatEntry), 1340 bat_entry_offset); 1341 if (ret < 0) { 1342 goto exit; 1343 } 1344 } 1345 1346 nb_sectors -= sinfo.sectors_avail; 1347 sector_num += sinfo.sectors_avail; 1348 bytes_done += sinfo.bytes_avail; 1349 1350 } 1351 } 1352 1353 goto exit; 1354 1355 error_bat_restore: 1356 if (bat_update) { 1357 /* keep metadata in sync, and restore the bat entry state 1358 * if error. */ 1359 sinfo.file_offset = bat_prior_offset; 1360 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, 1361 &bat_entry_offset, bat_state); 1362 } 1363 exit: 1364 qemu_vfree(iov1.iov_base); 1365 qemu_vfree(iov2.iov_base); 1366 qemu_co_mutex_unlock(&s->lock); 1367 qemu_iovec_destroy(&hd_qiov); 1368 return ret; 1369 } 1370 1371 1372 1373 /* 1374 * Create VHDX Headers 1375 * 1376 * There are 2 headers, and the highest sequence number will represent 1377 * the active header 1378 */ 1379 static int vhdx_create_new_headers(BlockDriverState *bs, uint64_t image_size, 1380 uint32_t log_size) 1381 { 1382 int ret = 0; 1383 VHDXHeader *hdr = NULL; 1384 1385 hdr = g_new0(VHDXHeader, 1); 1386 1387 hdr->signature = VHDX_HEADER_SIGNATURE; 1388 hdr->sequence_number = g_random_int(); 1389 hdr->log_version = 0; 1390 hdr->version = 1; 1391 hdr->log_length = log_size; 1392 hdr->log_offset = VHDX_HEADER_SECTION_END; 1393 vhdx_guid_generate(&hdr->file_write_guid); 1394 vhdx_guid_generate(&hdr->data_write_guid); 1395 1396 ret = vhdx_write_header(bs, hdr, VHDX_HEADER1_OFFSET, false); 1397 if (ret < 0) { 1398 goto exit; 1399 } 1400 hdr->sequence_number++; 1401 ret = vhdx_write_header(bs, hdr, VHDX_HEADER2_OFFSET, false); 1402 if (ret < 0) { 1403 goto exit; 1404 } 1405 1406 exit: 1407 g_free(hdr); 1408 return ret; 1409 } 1410 1411 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \ 1412 (sizeof(VHDXFileParameters) +\ 1413 sizeof(VHDXVirtualDiskSize) +\ 1414 sizeof(VHDXPage83Data) +\ 1415 sizeof(VHDXVirtualDiskLogicalSectorSize) +\ 1416 sizeof(VHDXVirtualDiskPhysicalSectorSize)) 1417 1418 /* 1419 * Create the Metadata entries. 1420 * 1421 * For more details on the entries, see section 3.5 (pg 29) in the 1422 * VHDX 1.00 specification. 1423 * 1424 * We support 5 metadata entries (all required by spec): 1425 * File Parameters, 1426 * Virtual Disk Size, 1427 * Page 83 Data, 1428 * Logical Sector Size, 1429 * Physical Sector Size 1430 * 1431 * The first 64KB of the Metadata section is reserved for the metadata 1432 * header and entries; beyond that, the metadata items themselves reside. 1433 */ 1434 static int vhdx_create_new_metadata(BlockDriverState *bs, 1435 uint64_t image_size, 1436 uint32_t block_size, 1437 uint32_t sector_size, 1438 uint64_t metadata_offset, 1439 VHDXImageType type) 1440 { 1441 int ret = 0; 1442 uint32_t offset = 0; 1443 void *buffer = NULL; 1444 void *entry_buffer; 1445 VHDXMetadataTableHeader *md_table;; 1446 VHDXMetadataTableEntry *md_table_entry; 1447 1448 /* Metadata entries */ 1449 VHDXFileParameters *mt_file_params; 1450 VHDXVirtualDiskSize *mt_virtual_size; 1451 VHDXPage83Data *mt_page83; 1452 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; 1453 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; 1454 1455 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); 1456 1457 mt_file_params = entry_buffer; 1458 offset += sizeof(VHDXFileParameters); 1459 mt_virtual_size = entry_buffer + offset; 1460 offset += sizeof(VHDXVirtualDiskSize); 1461 mt_page83 = entry_buffer + offset; 1462 offset += sizeof(VHDXPage83Data); 1463 mt_log_sector_size = entry_buffer + offset; 1464 offset += sizeof(VHDXVirtualDiskLogicalSectorSize); 1465 mt_phys_sector_size = entry_buffer + offset; 1466 1467 mt_file_params->block_size = cpu_to_le32(block_size); 1468 if (type == VHDX_TYPE_FIXED) { 1469 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED; 1470 cpu_to_le32s(&mt_file_params->data_bits); 1471 } 1472 1473 vhdx_guid_generate(&mt_page83->page_83_data); 1474 cpu_to_leguids(&mt_page83->page_83_data); 1475 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size); 1476 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size); 1477 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size); 1478 1479 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1480 md_table = buffer; 1481 1482 md_table->signature = VHDX_METADATA_SIGNATURE; 1483 md_table->entry_count = 5; 1484 vhdx_metadata_header_le_export(md_table); 1485 1486 1487 /* This will reference beyond the reserved table portion */ 1488 offset = 64 * KiB; 1489 1490 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader); 1491 1492 md_table_entry[0].item_id = file_param_guid; 1493 md_table_entry[0].offset = offset; 1494 md_table_entry[0].length = sizeof(VHDXFileParameters); 1495 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED; 1496 offset += md_table_entry[0].length; 1497 vhdx_metadata_entry_le_export(&md_table_entry[0]); 1498 1499 md_table_entry[1].item_id = virtual_size_guid; 1500 md_table_entry[1].offset = offset; 1501 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize); 1502 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1503 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1504 offset += md_table_entry[1].length; 1505 vhdx_metadata_entry_le_export(&md_table_entry[1]); 1506 1507 md_table_entry[2].item_id = page83_guid; 1508 md_table_entry[2].offset = offset; 1509 md_table_entry[2].length = sizeof(VHDXPage83Data); 1510 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1511 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1512 offset += md_table_entry[2].length; 1513 vhdx_metadata_entry_le_export(&md_table_entry[2]); 1514 1515 md_table_entry[3].item_id = logical_sector_guid; 1516 md_table_entry[3].offset = offset; 1517 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize); 1518 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1519 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1520 offset += md_table_entry[3].length; 1521 vhdx_metadata_entry_le_export(&md_table_entry[3]); 1522 1523 md_table_entry[4].item_id = phys_sector_guid; 1524 md_table_entry[4].offset = offset; 1525 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize); 1526 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED | 1527 VHDX_META_FLAGS_IS_VIRTUAL_DISK; 1528 vhdx_metadata_entry_le_export(&md_table_entry[4]); 1529 1530 ret = bdrv_pwrite(bs, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE); 1531 if (ret < 0) { 1532 goto exit; 1533 } 1534 1535 ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer, 1536 VHDX_METADATA_ENTRY_BUFFER_SIZE); 1537 if (ret < 0) { 1538 goto exit; 1539 } 1540 1541 1542 exit: 1543 g_free(buffer); 1544 g_free(entry_buffer); 1545 return ret; 1546 } 1547 1548 /* This create the actual BAT itself. We currently only support 1549 * 'Dynamic' and 'Fixed' image types. 1550 * 1551 * Dynamic images: default state of the BAT is all zeroes. 1552 * 1553 * Fixed images: default state of the BAT is fully populated, with 1554 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT. 1555 */ 1556 static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s, 1557 uint64_t image_size, VHDXImageType type, 1558 bool use_zero_blocks, uint64_t file_offset, 1559 uint32_t length) 1560 { 1561 int ret = 0; 1562 uint64_t data_file_offset; 1563 uint64_t total_sectors = 0; 1564 uint64_t sector_num = 0; 1565 uint64_t unused; 1566 int block_state; 1567 VHDXSectorInfo sinfo; 1568 1569 assert(s->bat == NULL); 1570 1571 /* this gives a data start after BAT/bitmap entries, and well 1572 * past any metadata entries (with a 4 MB buffer for future 1573 * expansion */ 1574 data_file_offset = file_offset + length + 5 * MiB; 1575 total_sectors = image_size >> s->logical_sector_size_bits; 1576 1577 if (type == VHDX_TYPE_DYNAMIC) { 1578 /* All zeroes, so we can just extend the file - the end of the BAT 1579 * is the furthest thing we have written yet */ 1580 ret = bdrv_truncate(bs, data_file_offset); 1581 if (ret < 0) { 1582 goto exit; 1583 } 1584 } else if (type == VHDX_TYPE_FIXED) { 1585 ret = bdrv_truncate(bs, data_file_offset + image_size); 1586 if (ret < 0) { 1587 goto exit; 1588 } 1589 } else { 1590 ret = -ENOTSUP; 1591 goto exit; 1592 } 1593 1594 if (type == VHDX_TYPE_FIXED || 1595 use_zero_blocks || 1596 bdrv_has_zero_init(bs) == 0) { 1597 /* for a fixed file, the default BAT entry is not zero */ 1598 s->bat = g_try_malloc0(length); 1599 if (length && s->bat == NULL) { 1600 ret = -ENOMEM; 1601 goto exit; 1602 } 1603 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT : 1604 PAYLOAD_BLOCK_NOT_PRESENT; 1605 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state; 1606 /* fill the BAT by emulating sector writes of sectors_per_block size */ 1607 while (sector_num < total_sectors) { 1608 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo); 1609 sinfo.file_offset = data_file_offset + 1610 (sector_num << s->logical_sector_size_bits); 1611 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB); 1612 vhdx_update_bat_table_entry(bs, s, &sinfo, &unused, &unused, 1613 block_state); 1614 cpu_to_le64s(&s->bat[sinfo.bat_idx]); 1615 sector_num += s->sectors_per_block; 1616 } 1617 ret = bdrv_pwrite(bs, file_offset, s->bat, length); 1618 if (ret < 0) { 1619 goto exit; 1620 } 1621 } 1622 1623 1624 1625 exit: 1626 g_free(s->bat); 1627 return ret; 1628 } 1629 1630 /* Creates the region table header, and region table entries. 1631 * There are 2 supported region table entries: BAT, and Metadata/ 1632 * 1633 * As the calculations for the BAT region table are also needed 1634 * to create the BAT itself, we will also cause the BAT to be 1635 * created. 1636 */ 1637 static int vhdx_create_new_region_table(BlockDriverState *bs, 1638 uint64_t image_size, 1639 uint32_t block_size, 1640 uint32_t sector_size, 1641 uint32_t log_size, 1642 bool use_zero_blocks, 1643 VHDXImageType type, 1644 uint64_t *metadata_offset) 1645 { 1646 int ret = 0; 1647 uint32_t offset = 0; 1648 void *buffer = NULL; 1649 uint64_t bat_file_offset; 1650 uint32_t bat_length; 1651 BDRVVHDXState *s = NULL; 1652 VHDXRegionTableHeader *region_table; 1653 VHDXRegionTableEntry *rt_bat; 1654 VHDXRegionTableEntry *rt_metadata; 1655 1656 assert(metadata_offset != NULL); 1657 1658 /* Populate enough of the BDRVVHDXState to be able to use the 1659 * pre-existing BAT calculation, translation, and update functions */ 1660 s = g_new0(BDRVVHDXState, 1); 1661 1662 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * 1663 (uint64_t) sector_size / (uint64_t) block_size; 1664 1665 s->sectors_per_block = block_size / sector_size; 1666 s->virtual_disk_size = image_size; 1667 s->block_size = block_size; 1668 s->logical_sector_size = sector_size; 1669 1670 vhdx_set_shift_bits(s); 1671 1672 vhdx_calc_bat_entries(s); 1673 1674 /* At this point the VHDX state is populated enough for creation */ 1675 1676 /* a single buffer is used so we can calculate the checksum over the 1677 * entire 64KB block */ 1678 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE); 1679 region_table = buffer; 1680 offset += sizeof(VHDXRegionTableHeader); 1681 rt_bat = buffer + offset; 1682 offset += sizeof(VHDXRegionTableEntry); 1683 rt_metadata = buffer + offset; 1684 1685 region_table->signature = VHDX_REGION_SIGNATURE; 1686 region_table->entry_count = 2; /* BAT and Metadata */ 1687 1688 rt_bat->guid = bat_guid; 1689 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB); 1690 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB); 1691 s->bat_offset = rt_bat->file_offset; 1692 1693 rt_metadata->guid = metadata_guid; 1694 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length, 1695 MiB); 1696 rt_metadata->length = 1 * MiB; /* min size, and more than enough */ 1697 *metadata_offset = rt_metadata->file_offset; 1698 1699 bat_file_offset = rt_bat->file_offset; 1700 bat_length = rt_bat->length; 1701 1702 vhdx_region_header_le_export(region_table); 1703 vhdx_region_entry_le_export(rt_bat); 1704 vhdx_region_entry_le_export(rt_metadata); 1705 1706 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE, 1707 offsetof(VHDXRegionTableHeader, checksum)); 1708 1709 1710 /* The region table gives us the data we need to create the BAT, 1711 * so do that now */ 1712 ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, 1713 bat_file_offset, bat_length); 1714 if (ret < 0) { 1715 goto exit; 1716 } 1717 1718 /* Now write out the region headers to disk */ 1719 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer, 1720 VHDX_HEADER_BLOCK_SIZE); 1721 if (ret < 0) { 1722 goto exit; 1723 } 1724 1725 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE2_OFFSET, buffer, 1726 VHDX_HEADER_BLOCK_SIZE); 1727 if (ret < 0) { 1728 goto exit; 1729 } 1730 1731 exit: 1732 g_free(s); 1733 g_free(buffer); 1734 return ret; 1735 } 1736 1737 /* We need to create the following elements: 1738 * 1739 * .-----------------------------------------------------------------. 1740 * | (A) | (B) | (C) | (D) | (E) | 1741 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 | 1742 * | | | | | | 1743 * .-----------------------------------------------------------------. 1744 * 0 64KB 128KB 192KB 256KB 320KB 1745 * 1746 * 1747 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1748 * | (F) | (G) | (H) | | 1749 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... | 1750 * | | | | | 1751 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------. 1752 * 1MB 1753 */ 1754 static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp) 1755 { 1756 int ret = 0; 1757 uint64_t image_size = (uint64_t) 2 * GiB; 1758 uint32_t log_size = 1 * MiB; 1759 uint32_t block_size = 0; 1760 uint64_t signature; 1761 uint64_t metadata_offset; 1762 bool use_zero_blocks = false; 1763 1764 gunichar2 *creator = NULL; 1765 glong creator_items; 1766 BlockDriverState *bs; 1767 char *type = NULL; 1768 VHDXImageType image_type; 1769 Error *local_err = NULL; 1770 1771 image_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), 1772 BDRV_SECTOR_SIZE); 1773 log_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_LOG_SIZE, 0); 1774 block_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_BLOCK_SIZE, 0); 1775 type = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT); 1776 use_zero_blocks = qemu_opt_get_bool_del(opts, VHDX_BLOCK_OPT_ZERO, false); 1777 1778 if (image_size > VHDX_MAX_IMAGE_SIZE) { 1779 error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB"); 1780 ret = -EINVAL; 1781 goto exit; 1782 } 1783 1784 if (type == NULL) { 1785 type = g_strdup("dynamic"); 1786 } 1787 1788 if (!strcmp(type, "dynamic")) { 1789 image_type = VHDX_TYPE_DYNAMIC; 1790 } else if (!strcmp(type, "fixed")) { 1791 image_type = VHDX_TYPE_FIXED; 1792 } else if (!strcmp(type, "differencing")) { 1793 error_setg_errno(errp, ENOTSUP, 1794 "Differencing files not yet supported"); 1795 ret = -ENOTSUP; 1796 goto exit; 1797 } else { 1798 ret = -EINVAL; 1799 goto exit; 1800 } 1801 1802 /* These are pretty arbitrary, and mainly designed to keep the BAT 1803 * size reasonable to load into RAM */ 1804 if (block_size == 0) { 1805 if (image_size > 32 * TiB) { 1806 block_size = 64 * MiB; 1807 } else if (image_size > (uint64_t) 100 * GiB) { 1808 block_size = 32 * MiB; 1809 } else if (image_size > 1 * GiB) { 1810 block_size = 16 * MiB; 1811 } else { 1812 block_size = 8 * MiB; 1813 } 1814 } 1815 1816 1817 /* make the log size close to what was specified, but must be 1818 * min 1MB, and multiple of 1MB */ 1819 log_size = ROUND_UP(log_size, MiB); 1820 1821 block_size = ROUND_UP(block_size, MiB); 1822 block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX : 1823 block_size; 1824 1825 ret = bdrv_create_file(filename, opts, &local_err); 1826 if (ret < 0) { 1827 error_propagate(errp, local_err); 1828 goto exit; 1829 } 1830 1831 bs = NULL; 1832 ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, 1833 NULL, &local_err); 1834 if (ret < 0) { 1835 error_propagate(errp, local_err); 1836 goto exit; 1837 } 1838 1839 /* Create (A) */ 1840 1841 /* The creator field is optional, but may be useful for 1842 * debugging / diagnostics */ 1843 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL, 1844 &creator_items, NULL); 1845 signature = cpu_to_le64(VHDX_FILE_SIGNATURE); 1846 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature)); 1847 if (ret < 0) { 1848 goto delete_and_exit; 1849 } 1850 if (creator) { 1851 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET + sizeof(signature), 1852 creator, creator_items * sizeof(gunichar2)); 1853 if (ret < 0) { 1854 goto delete_and_exit; 1855 } 1856 } 1857 1858 1859 /* Creates (B),(C) */ 1860 ret = vhdx_create_new_headers(bs, image_size, log_size); 1861 if (ret < 0) { 1862 goto delete_and_exit; 1863 } 1864 1865 /* Creates (D),(E),(G) explicitly. (F) created as by-product */ 1866 ret = vhdx_create_new_region_table(bs, image_size, block_size, 512, 1867 log_size, use_zero_blocks, image_type, 1868 &metadata_offset); 1869 if (ret < 0) { 1870 goto delete_and_exit; 1871 } 1872 1873 /* Creates (H) */ 1874 ret = vhdx_create_new_metadata(bs, image_size, block_size, 512, 1875 metadata_offset, image_type); 1876 if (ret < 0) { 1877 goto delete_and_exit; 1878 } 1879 1880 1881 delete_and_exit: 1882 bdrv_unref(bs); 1883 exit: 1884 g_free(type); 1885 g_free(creator); 1886 return ret; 1887 } 1888 1889 /* If opened r/w, the VHDX driver will automatically replay the log, 1890 * if one is present, inside the vhdx_open() call. 1891 * 1892 * If qemu-img check -r all is called, the image is automatically opened 1893 * r/w and any log has already been replayed, so there is nothing (currently) 1894 * for us to do here 1895 */ 1896 static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result, 1897 BdrvCheckMode fix) 1898 { 1899 BDRVVHDXState *s = bs->opaque; 1900 1901 if (s->log_replayed_on_open) { 1902 result->corruptions_fixed++; 1903 } 1904 return 0; 1905 } 1906 1907 static QemuOptsList vhdx_create_opts = { 1908 .name = "vhdx-create-opts", 1909 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), 1910 .desc = { 1911 { 1912 .name = BLOCK_OPT_SIZE, 1913 .type = QEMU_OPT_SIZE, 1914 .help = "Virtual disk size; max of 64TB." 1915 }, 1916 { 1917 .name = VHDX_BLOCK_OPT_LOG_SIZE, 1918 .type = QEMU_OPT_SIZE, 1919 .def_value_str = stringify(DEFAULT_LOG_SIZE), 1920 .help = "Log size; min 1MB." 1921 }, 1922 { 1923 .name = VHDX_BLOCK_OPT_BLOCK_SIZE, 1924 .type = QEMU_OPT_SIZE, 1925 .def_value_str = stringify(0), 1926 .help = "Block Size; min 1MB, max 256MB. " \ 1927 "0 means auto-calculate based on image size." 1928 }, 1929 { 1930 .name = BLOCK_OPT_SUBFMT, 1931 .type = QEMU_OPT_STRING, 1932 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ 1933 "Default is 'dynamic'." 1934 }, 1935 { 1936 .name = VHDX_BLOCK_OPT_ZERO, 1937 .type = QEMU_OPT_BOOL, 1938 .help = "Force use of payload blocks of type 'ZERO'. Non-standard." 1939 }, 1940 { NULL } 1941 } 1942 }; 1943 1944 static BlockDriver bdrv_vhdx = { 1945 .format_name = "vhdx", 1946 .instance_size = sizeof(BDRVVHDXState), 1947 .bdrv_probe = vhdx_probe, 1948 .bdrv_open = vhdx_open, 1949 .bdrv_close = vhdx_close, 1950 .bdrv_reopen_prepare = vhdx_reopen_prepare, 1951 .bdrv_co_readv = vhdx_co_readv, 1952 .bdrv_co_writev = vhdx_co_writev, 1953 .bdrv_create = vhdx_create, 1954 .bdrv_get_info = vhdx_get_info, 1955 .bdrv_check = vhdx_check, 1956 1957 .create_opts = &vhdx_create_opts, 1958 }; 1959 1960 static void bdrv_vhdx_init(void) 1961 { 1962 bdrv_register(&bdrv_vhdx); 1963 } 1964 1965 block_init(bdrv_vhdx_init); 1966