Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu/ar7.git] / block / vhdx.c
blob356ec4c455a42be6e5f68b62c712536e9f2f6310
1 /*
2 * Block driver for Hyper-V VHDX Images
4 * Copyright (c) 2013 Red Hat, Inc.,
6 * Authors:
7 * Jeff Cody <jcody@redhat.com>
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
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.
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 "vhdx.h"
29 #include "migration/blocker.h"
30 #include "qemu/uuid.h"
31 #include "qapi/qmp/qdict.h"
32 #include "qapi/qobject-input-visitor.h"
33 #include "qapi/qapi-visit-block-core.h"
35 /* Options for VHDX creation */
37 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size"
38 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size"
39 #define VHDX_BLOCK_OPT_ZERO "block_state_zero"
41 typedef enum VHDXImageType {
42 VHDX_TYPE_DYNAMIC = 0,
43 VHDX_TYPE_FIXED,
44 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */
45 } VHDXImageType;
47 static QemuOptsList vhdx_create_opts;
49 /* Several metadata and region table data entries are identified by
50 * guids in a MS-specific GUID format. */
53 /* ------- Known Region Table GUIDs ---------------------- */
54 static const MSGUID bat_guid = { .data1 = 0x2dc27766,
55 .data2 = 0xf623,
56 .data3 = 0x4200,
57 .data4 = { 0x9d, 0x64, 0x11, 0x5e,
58 0x9b, 0xfd, 0x4a, 0x08} };
60 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206,
61 .data2 = 0x4790,
62 .data3 = 0x4b9a,
63 .data4 = { 0xb8, 0xfe, 0x57, 0x5f,
64 0x05, 0x0f, 0x88, 0x6e} };
68 /* ------- Known Metadata Entry GUIDs ---------------------- */
69 static const MSGUID file_param_guid = { .data1 = 0xcaa16737,
70 .data2 = 0xfa36,
71 .data3 = 0x4d43,
72 .data4 = { 0xb3, 0xb6, 0x33, 0xf0,
73 0xaa, 0x44, 0xe7, 0x6b} };
75 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224,
76 .data2 = 0xcd1b,
77 .data3 = 0x4876,
78 .data4 = { 0xb2, 0x11, 0x5d, 0xbe,
79 0xd8, 0x3b, 0xf4, 0xb8} };
81 static const MSGUID page83_guid = { .data1 = 0xbeca12ab,
82 .data2 = 0xb2e6,
83 .data3 = 0x4523,
84 .data4 = { 0x93, 0xef, 0xc3, 0x09,
85 0xe0, 0x00, 0xc7, 0x46} };
88 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7,
89 .data2 = 0x445d,
90 .data3 = 0x4471,
91 .data4 = { 0x9c, 0xc9, 0xe9, 0x88,
92 0x52, 0x51, 0xc5, 0x56} };
94 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d,
95 .data2 = 0xb30b,
96 .data3 = 0x454d,
97 .data4 = { 0xab, 0xf7, 0xd3,
98 0xd8, 0x48, 0x34,
99 0xab, 0x0c} };
101 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d,
102 .data2 = 0xa96f,
103 .data3 = 0x4709,
104 .data4 = { 0xba, 0x47, 0xf2,
105 0x33, 0xa8, 0xfa,
106 0xab, 0x5f} };
108 /* Each parent type must have a valid GUID; this is for parent images
109 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would
110 * need to make up our own QCOW2 GUID type */
111 static const MSGUID parent_vhdx_guid __attribute__((unused))
112 = { .data1 = 0xb04aefb7,
113 .data2 = 0xd19e,
114 .data3 = 0x4a81,
115 .data4 = { 0xb7, 0x89, 0x25, 0xb8,
116 0xe9, 0x44, 0x59, 0x13} };
119 #define META_FILE_PARAMETER_PRESENT 0x01
120 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02
121 #define META_PAGE_83_PRESENT 0x04
122 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08
123 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10
124 #define META_PARENT_LOCATOR_PRESENT 0x20
126 #define META_ALL_PRESENT \
127 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \
128 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \
129 META_PHYS_SECTOR_SIZE_PRESENT)
132 typedef struct VHDXSectorInfo {
133 uint32_t bat_idx; /* BAT entry index */
134 uint32_t sectors_avail; /* sectors available in payload block */
135 uint32_t bytes_left; /* bytes left in the block after data to r/w */
136 uint32_t bytes_avail; /* bytes available in payload block */
137 uint64_t file_offset; /* absolute offset in bytes, in file */
138 uint64_t block_offset; /* block offset, in bytes */
139 } VHDXSectorInfo;
141 /* Calculates new checksum.
143 * Zero is substituted during crc calculation for the original crc field
144 * crc_offset: byte offset in buf of the buffer crc
145 * buf: buffer pointer
146 * size: size of buffer (must be > crc_offset+4)
148 * Note: The buffer should have all multi-byte data in little-endian format,
149 * and the resulting checksum is in little endian format.
151 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset)
153 uint32_t crc;
155 assert(buf != NULL);
156 assert(size > (crc_offset + sizeof(crc)));
158 memset(buf + crc_offset, 0, sizeof(crc));
159 crc = crc32c(0xffffffff, buf, size);
160 crc = cpu_to_le32(crc);
161 memcpy(buf + crc_offset, &crc, sizeof(crc));
163 return crc;
166 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
167 int crc_offset)
169 uint32_t crc_new;
170 uint32_t crc_orig;
171 assert(buf != NULL);
173 if (crc_offset > 0) {
174 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
175 memset(buf + crc_offset, 0, sizeof(crc_orig));
178 crc_new = crc32c(crc, buf, size);
179 if (crc_offset > 0) {
180 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig));
183 return crc_new;
186 /* Validates the checksum of the buffer, with an in-place CRC.
188 * Zero is substituted during crc calculation for the original crc field,
189 * and the crc field is restored afterwards. But the buffer will be modified
190 * during the calculation, so this may not be not suitable for multi-threaded
191 * use.
193 * crc_offset: byte offset in buf of the buffer crc
194 * buf: buffer pointer
195 * size: size of buffer (must be > crc_offset+4)
197 * returns true if checksum is valid, false otherwise
199 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset)
201 uint32_t crc_orig;
202 uint32_t crc;
204 assert(buf != NULL);
205 assert(size > (crc_offset + 4));
207 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
208 crc_orig = le32_to_cpu(crc_orig);
210 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset);
212 return crc == crc_orig;
217 * This generates a UUID that is compliant with the MS GUIDs used
218 * in the VHDX spec (and elsewhere).
220 void vhdx_guid_generate(MSGUID *guid)
222 QemuUUID uuid;
223 assert(guid != NULL);
225 qemu_uuid_generate(&uuid);
226 memcpy(guid, &uuid, sizeof(MSGUID));
229 /* Check for region overlaps inside the VHDX image */
230 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length)
232 int ret = 0;
233 uint64_t end;
234 VHDXRegionEntry *r;
236 end = start + length;
237 QLIST_FOREACH(r, &s->regions, entries) {
238 if (!((start >= r->end) || (end <= r->start))) {
239 error_report("VHDX region %" PRIu64 "-%" PRIu64 " overlaps with "
240 "region %" PRIu64 "-%." PRIu64, start, end, r->start,
241 r->end);
242 ret = -EINVAL;
243 goto exit;
247 exit:
248 return ret;
251 /* Register a region for future checks */
252 static void vhdx_region_register(BDRVVHDXState *s,
253 uint64_t start, uint64_t length)
255 VHDXRegionEntry *r;
257 r = g_malloc0(sizeof(*r));
259 r->start = start;
260 r->end = start + length;
262 QLIST_INSERT_HEAD(&s->regions, r, entries);
265 /* Free all registered regions */
266 static void vhdx_region_unregister_all(BDRVVHDXState *s)
268 VHDXRegionEntry *r, *r_next;
270 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) {
271 QLIST_REMOVE(r, entries);
272 g_free(r);
276 static void vhdx_set_shift_bits(BDRVVHDXState *s)
278 s->logical_sector_size_bits = ctz32(s->logical_sector_size);
279 s->sectors_per_block_bits = ctz32(s->sectors_per_block);
280 s->chunk_ratio_bits = ctz64(s->chunk_ratio);
281 s->block_size_bits = ctz32(s->block_size);
285 * Per the MS VHDX Specification, for every VHDX file:
286 * - The header section is fixed size - 1 MB
287 * - The header section is always the first "object"
288 * - The first 64KB of the header is the File Identifier
289 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile")
290 * - The following 512 bytes constitute a UTF-16 string identifiying the
291 * software that created the file, and is optional and diagnostic only.
293 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile"
295 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename)
297 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) {
298 return 100;
300 return 0;
304 * Writes the header to the specified offset.
306 * This will optionally read in buffer data from disk (otherwise zero-fill),
307 * and then update the header checksum. Header is converted to proper
308 * endianness before being written to the specified file offset
310 static int vhdx_write_header(BdrvChild *file, VHDXHeader *hdr,
311 uint64_t offset, bool read)
313 BlockDriverState *bs_file = file->bs;
314 uint8_t *buffer = NULL;
315 int ret;
316 VHDXHeader *header_le;
318 assert(bs_file != NULL);
319 assert(hdr != NULL);
321 /* the header checksum is not over just the packed size of VHDXHeader,
322 * but rather over the entire 'reserved' range for the header, which is
323 * 4KB (VHDX_HEADER_SIZE). */
325 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE);
326 if (read) {
327 /* if true, we can't assume the extra reserved bytes are 0 */
328 ret = bdrv_pread(file, offset, buffer, VHDX_HEADER_SIZE);
329 if (ret < 0) {
330 goto exit;
332 } else {
333 memset(buffer, 0, VHDX_HEADER_SIZE);
336 /* overwrite the actual VHDXHeader portion */
337 header_le = (VHDXHeader *)buffer;
338 memcpy(header_le, hdr, sizeof(VHDXHeader));
339 vhdx_header_le_export(hdr, header_le);
340 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE,
341 offsetof(VHDXHeader, checksum));
342 ret = bdrv_pwrite_sync(file, offset, header_le, sizeof(VHDXHeader));
344 exit:
345 qemu_vfree(buffer);
346 return ret;
349 /* Update the VHDX headers
351 * This follows the VHDX spec procedures for header updates.
353 * - non-current header is updated with largest sequence number
355 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s,
356 bool generate_data_write_guid, MSGUID *log_guid)
358 int ret = 0;
359 int hdr_idx = 0;
360 uint64_t header_offset = VHDX_HEADER1_OFFSET;
362 VHDXHeader *active_header;
363 VHDXHeader *inactive_header;
365 /* operate on the non-current header */
366 if (s->curr_header == 0) {
367 hdr_idx = 1;
368 header_offset = VHDX_HEADER2_OFFSET;
371 active_header = s->headers[s->curr_header];
372 inactive_header = s->headers[hdr_idx];
374 inactive_header->sequence_number = active_header->sequence_number + 1;
376 /* a new file guid must be generated before any file write, including
377 * headers */
378 inactive_header->file_write_guid = s->session_guid;
380 /* a new data guid only needs to be generated before any guest-visible
381 * writes (i.e. something observable via virtual disk read) */
382 if (generate_data_write_guid) {
383 vhdx_guid_generate(&inactive_header->data_write_guid);
386 /* update the log guid if present */
387 if (log_guid) {
388 inactive_header->log_guid = *log_guid;
391 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true);
392 if (ret < 0) {
393 goto exit;
395 s->curr_header = hdr_idx;
397 exit:
398 return ret;
402 * The VHDX spec calls for header updates to be performed twice, so that both
403 * the current and non-current header have valid info
405 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s,
406 bool generate_data_write_guid, MSGUID *log_guid)
408 int ret;
410 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
411 if (ret < 0) {
412 return ret;
414 return vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
417 /* opens the specified header block from the VHDX file header section */
418 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s,
419 Error **errp)
421 int ret;
422 VHDXHeader *header1;
423 VHDXHeader *header2;
424 bool h1_valid = false;
425 bool h2_valid = false;
426 uint64_t h1_seq = 0;
427 uint64_t h2_seq = 0;
428 uint8_t *buffer;
430 /* header1 & header2 are freed in vhdx_close() */
431 header1 = qemu_blockalign(bs, sizeof(VHDXHeader));
432 header2 = qemu_blockalign(bs, sizeof(VHDXHeader));
434 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE);
436 s->headers[0] = header1;
437 s->headers[1] = header2;
439 /* We have to read the whole VHDX_HEADER_SIZE instead of
440 * sizeof(VHDXHeader), because the checksum is over the whole
441 * region */
442 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer,
443 VHDX_HEADER_SIZE);
444 if (ret < 0) {
445 goto fail;
447 /* copy over just the relevant portion that we need */
448 memcpy(header1, buffer, sizeof(VHDXHeader));
450 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
451 vhdx_header_le_import(header1);
452 if (header1->signature == VHDX_HEADER_SIGNATURE &&
453 header1->version == 1) {
454 h1_seq = header1->sequence_number;
455 h1_valid = true;
459 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer,
460 VHDX_HEADER_SIZE);
461 if (ret < 0) {
462 goto fail;
464 /* copy over just the relevant portion that we need */
465 memcpy(header2, buffer, sizeof(VHDXHeader));
467 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
468 vhdx_header_le_import(header2);
469 if (header2->signature == VHDX_HEADER_SIGNATURE &&
470 header2->version == 1) {
471 h2_seq = header2->sequence_number;
472 h2_valid = true;
476 /* If there is only 1 valid header (or no valid headers), we
477 * don't care what the sequence numbers are */
478 if (h1_valid && !h2_valid) {
479 s->curr_header = 0;
480 } else if (!h1_valid && h2_valid) {
481 s->curr_header = 1;
482 } else if (!h1_valid && !h2_valid) {
483 goto fail;
484 } else {
485 /* If both headers are valid, then we choose the active one by the
486 * highest sequence number. If the sequence numbers are equal, that is
487 * invalid */
488 if (h1_seq > h2_seq) {
489 s->curr_header = 0;
490 } else if (h2_seq > h1_seq) {
491 s->curr_header = 1;
492 } else {
493 /* The Microsoft Disk2VHD tool will create 2 identical
494 * headers, with identical sequence numbers. If the headers are
495 * identical, don't consider the file corrupt */
496 if (!memcmp(header1, header2, sizeof(VHDXHeader))) {
497 s->curr_header = 0;
498 } else {
499 goto fail;
504 vhdx_region_register(s, s->headers[s->curr_header]->log_offset,
505 s->headers[s->curr_header]->log_length);
506 goto exit;
508 fail:
509 error_setg_errno(errp, -ret, "No valid VHDX header found");
510 qemu_vfree(header1);
511 qemu_vfree(header2);
512 s->headers[0] = NULL;
513 s->headers[1] = NULL;
514 exit:
515 qemu_vfree(buffer);
519 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s)
521 int ret = 0;
522 uint8_t *buffer;
523 int offset = 0;
524 VHDXRegionTableEntry rt_entry;
525 uint32_t i;
526 bool bat_rt_found = false;
527 bool metadata_rt_found = false;
529 /* We have to read the whole 64KB block, because the crc32 is over the
530 * whole block */
531 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE);
533 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer,
534 VHDX_HEADER_BLOCK_SIZE);
535 if (ret < 0) {
536 goto fail;
538 memcpy(&s->rt, buffer, sizeof(s->rt));
539 offset += sizeof(s->rt);
541 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) {
542 ret = -EINVAL;
543 goto fail;
546 vhdx_region_header_le_import(&s->rt);
548 if (s->rt.signature != VHDX_REGION_SIGNATURE) {
549 ret = -EINVAL;
550 goto fail;
554 /* Per spec, maximum region table entry count is 2047 */
555 if (s->rt.entry_count > 2047) {
556 ret = -EINVAL;
557 goto fail;
560 for (i = 0; i < s->rt.entry_count; i++) {
561 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry));
562 offset += sizeof(rt_entry);
564 vhdx_region_entry_le_import(&rt_entry);
566 /* check for region overlap between these entries, and any
567 * other memory regions in the file */
568 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length);
569 if (ret < 0) {
570 goto fail;
573 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length);
575 /* see if we recognize the entry */
576 if (guid_eq(rt_entry.guid, bat_guid)) {
577 /* must be unique; if we have already found it this is invalid */
578 if (bat_rt_found) {
579 ret = -EINVAL;
580 goto fail;
582 bat_rt_found = true;
583 s->bat_rt = rt_entry;
584 continue;
587 if (guid_eq(rt_entry.guid, metadata_guid)) {
588 /* must be unique; if we have already found it this is invalid */
589 if (metadata_rt_found) {
590 ret = -EINVAL;
591 goto fail;
593 metadata_rt_found = true;
594 s->metadata_rt = rt_entry;
595 continue;
598 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) {
599 /* cannot read vhdx file - required region table entry that
600 * we do not understand. per spec, we must fail to open */
601 ret = -ENOTSUP;
602 goto fail;
606 if (!bat_rt_found || !metadata_rt_found) {
607 ret = -EINVAL;
608 goto fail;
611 ret = 0;
613 fail:
614 qemu_vfree(buffer);
615 return ret;
620 /* Metadata initial parser
622 * This loads all the metadata entry fields. This may cause additional
623 * fields to be processed (e.g. parent locator, etc..).
625 * There are 5 Metadata items that are always required:
626 * - File Parameters (block size, has a parent)
627 * - Virtual Disk Size (size, in bytes, of the virtual drive)
628 * - Page 83 Data (scsi page 83 guid)
629 * - Logical Sector Size (logical sector size in bytes, either 512 or
630 * 4096. We only support 512 currently)
631 * - Physical Sector Size (512 or 4096)
633 * Also, if the File Parameters indicate this is a differencing file,
634 * we must also look for the Parent Locator metadata item.
636 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s)
638 int ret = 0;
639 uint8_t *buffer;
640 int offset = 0;
641 uint32_t i = 0;
642 VHDXMetadataTableEntry md_entry;
644 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE);
646 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer,
647 VHDX_METADATA_TABLE_MAX_SIZE);
648 if (ret < 0) {
649 goto exit;
651 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr));
652 offset += sizeof(s->metadata_hdr);
654 vhdx_metadata_header_le_import(&s->metadata_hdr);
656 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) {
657 ret = -EINVAL;
658 goto exit;
661 s->metadata_entries.present = 0;
663 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) >
664 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) {
665 ret = -EINVAL;
666 goto exit;
669 for (i = 0; i < s->metadata_hdr.entry_count; i++) {
670 memcpy(&md_entry, buffer + offset, sizeof(md_entry));
671 offset += sizeof(md_entry);
673 vhdx_metadata_entry_le_import(&md_entry);
675 if (guid_eq(md_entry.item_id, file_param_guid)) {
676 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) {
677 ret = -EINVAL;
678 goto exit;
680 s->metadata_entries.file_parameters_entry = md_entry;
681 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT;
682 continue;
685 if (guid_eq(md_entry.item_id, virtual_size_guid)) {
686 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) {
687 ret = -EINVAL;
688 goto exit;
690 s->metadata_entries.virtual_disk_size_entry = md_entry;
691 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT;
692 continue;
695 if (guid_eq(md_entry.item_id, page83_guid)) {
696 if (s->metadata_entries.present & META_PAGE_83_PRESENT) {
697 ret = -EINVAL;
698 goto exit;
700 s->metadata_entries.page83_data_entry = md_entry;
701 s->metadata_entries.present |= META_PAGE_83_PRESENT;
702 continue;
705 if (guid_eq(md_entry.item_id, logical_sector_guid)) {
706 if (s->metadata_entries.present &
707 META_LOGICAL_SECTOR_SIZE_PRESENT) {
708 ret = -EINVAL;
709 goto exit;
711 s->metadata_entries.logical_sector_size_entry = md_entry;
712 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT;
713 continue;
716 if (guid_eq(md_entry.item_id, phys_sector_guid)) {
717 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) {
718 ret = -EINVAL;
719 goto exit;
721 s->metadata_entries.phys_sector_size_entry = md_entry;
722 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT;
723 continue;
726 if (guid_eq(md_entry.item_id, parent_locator_guid)) {
727 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
728 ret = -EINVAL;
729 goto exit;
731 s->metadata_entries.parent_locator_entry = md_entry;
732 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT;
733 continue;
736 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) {
737 /* cannot read vhdx file - required region table entry that
738 * we do not understand. per spec, we must fail to open */
739 ret = -ENOTSUP;
740 goto exit;
744 if (s->metadata_entries.present != META_ALL_PRESENT) {
745 ret = -ENOTSUP;
746 goto exit;
749 ret = bdrv_pread(bs->file,
750 s->metadata_entries.file_parameters_entry.offset
751 + s->metadata_rt.file_offset,
752 &s->params,
753 sizeof(s->params));
755 if (ret < 0) {
756 goto exit;
759 s->params.block_size = le32_to_cpu(s->params.block_size);
760 s->params.data_bits = le32_to_cpu(s->params.data_bits);
763 /* We now have the file parameters, so we can tell if this is a
764 * differencing file (i.e.. has_parent), is dynamic or fixed
765 * sized (leave_blocks_allocated), and the block size */
767 /* The parent locator required iff the file parameters has_parent set */
768 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
769 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
770 /* TODO: parse parent locator fields */
771 ret = -ENOTSUP; /* temp, until differencing files are supported */
772 goto exit;
773 } else {
774 /* if has_parent is set, but there is not parent locator present,
775 * then that is an invalid combination */
776 ret = -EINVAL;
777 goto exit;
781 /* determine virtual disk size, logical sector size,
782 * and phys sector size */
784 ret = bdrv_pread(bs->file,
785 s->metadata_entries.virtual_disk_size_entry.offset
786 + s->metadata_rt.file_offset,
787 &s->virtual_disk_size,
788 sizeof(uint64_t));
789 if (ret < 0) {
790 goto exit;
792 ret = bdrv_pread(bs->file,
793 s->metadata_entries.logical_sector_size_entry.offset
794 + s->metadata_rt.file_offset,
795 &s->logical_sector_size,
796 sizeof(uint32_t));
797 if (ret < 0) {
798 goto exit;
800 ret = bdrv_pread(bs->file,
801 s->metadata_entries.phys_sector_size_entry.offset
802 + s->metadata_rt.file_offset,
803 &s->physical_sector_size,
804 sizeof(uint32_t));
805 if (ret < 0) {
806 goto exit;
809 s->virtual_disk_size = le64_to_cpu(s->virtual_disk_size);
810 s->logical_sector_size = le32_to_cpu(s->logical_sector_size);
811 s->physical_sector_size = le32_to_cpu(s->physical_sector_size);
813 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN ||
814 s->params.block_size > VHDX_BLOCK_SIZE_MAX) {
815 ret = -EINVAL;
816 goto exit;
819 /* Currently we only support 512 */
820 if (s->logical_sector_size != 512) {
821 ret = -ENOTSUP;
822 goto exit;
825 /* Both block_size and sector_size are guaranteed powers of 2, below.
826 Due to range checks above, s->sectors_per_block can never be < 256 */
827 s->sectors_per_block = s->params.block_size / s->logical_sector_size;
828 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
829 (uint64_t)s->logical_sector_size /
830 (uint64_t)s->params.block_size;
832 /* These values are ones we will want to use for division / multiplication
833 * later on, and they are all guaranteed (per the spec) to be powers of 2,
834 * so we can take advantage of that for shift operations during
835 * reads/writes */
836 if (s->logical_sector_size & (s->logical_sector_size - 1)) {
837 ret = -EINVAL;
838 goto exit;
840 if (s->sectors_per_block & (s->sectors_per_block - 1)) {
841 ret = -EINVAL;
842 goto exit;
844 if (s->chunk_ratio & (s->chunk_ratio - 1)) {
845 ret = -EINVAL;
846 goto exit;
848 s->block_size = s->params.block_size;
849 if (s->block_size & (s->block_size - 1)) {
850 ret = -EINVAL;
851 goto exit;
854 vhdx_set_shift_bits(s);
856 ret = 0;
858 exit:
859 qemu_vfree(buffer);
860 return ret;
864 * Calculate the number of BAT entries, including sector
865 * bitmap entries.
867 static void vhdx_calc_bat_entries(BDRVVHDXState *s)
869 uint32_t data_blocks_cnt, bitmap_blocks_cnt;
871 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size);
872 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio);
874 if (s->parent_entries) {
875 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1);
876 } else {
877 s->bat_entries = data_blocks_cnt +
878 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits);
883 static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt)
885 BDRVVHDXState *s = bs->opaque;
886 int64_t image_file_size = bdrv_getlength(bs->file->bs);
887 uint64_t payblocks = s->chunk_ratio;
888 uint64_t i;
889 int ret = 0;
891 if (image_file_size < 0) {
892 error_report("Could not determinate VHDX image file size.");
893 return image_file_size;
896 for (i = 0; i < s->bat_entries; i++) {
897 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) ==
898 PAYLOAD_BLOCK_FULLY_PRESENT) {
899 uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK;
901 * Allow that the last block exists only partially. The VHDX spec
902 * states that the image file can only grow in blocksize increments,
903 * but QEMU created images with partial last blocks in the past.
905 uint32_t block_length = MIN(s->block_size,
906 bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size);
908 * Check for BAT entry overflow.
910 if (offset > INT64_MAX - s->block_size) {
911 error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i);
912 ret = -EINVAL;
913 if (!errcnt) {
914 break;
916 (*errcnt)++;
919 * Check if fully allocated BAT entries do not reside after
920 * end of the image file.
922 if (offset >= image_file_size) {
923 error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64
924 " points after end of file (%" PRIi64 "). Image"
925 " has probably been truncated.",
926 i, offset, image_file_size);
927 ret = -EINVAL;
928 if (!errcnt) {
929 break;
931 (*errcnt)++;
932 } else if (offset + block_length > image_file_size) {
933 error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64
934 " points after end of file (%" PRIi64 "). Image"
935 " has probably been truncated.",
936 i, offset + block_length - 1, image_file_size);
937 ret = -EINVAL;
938 if (!errcnt) {
939 break;
941 (*errcnt)++;
945 * verify populated BAT field file offsets against
946 * region table and log entries
948 if (payblocks--) {
949 /* payload bat entries */
950 int ret2;
951 ret2 = vhdx_region_check(s, offset, s->block_size);
952 if (ret2 < 0) {
953 ret = -EINVAL;
954 if (!errcnt) {
955 break;
957 (*errcnt)++;
959 } else {
960 payblocks = s->chunk_ratio;
962 * Once differencing files are supported, verify sector bitmap
963 * blocks here
969 return ret;
972 static void vhdx_close(BlockDriverState *bs)
974 BDRVVHDXState *s = bs->opaque;
975 qemu_vfree(s->headers[0]);
976 s->headers[0] = NULL;
977 qemu_vfree(s->headers[1]);
978 s->headers[1] = NULL;
979 qemu_vfree(s->bat);
980 s->bat = NULL;
981 qemu_vfree(s->parent_entries);
982 s->parent_entries = NULL;
983 migrate_del_blocker(s->migration_blocker);
984 error_free(s->migration_blocker);
985 qemu_vfree(s->log.hdr);
986 s->log.hdr = NULL;
987 vhdx_region_unregister_all(s);
990 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
991 Error **errp)
993 BDRVVHDXState *s = bs->opaque;
994 int ret = 0;
995 uint32_t i;
996 uint64_t signature;
997 Error *local_err = NULL;
999 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
1000 BDRV_CHILD_IMAGE, false, errp);
1001 if (!bs->file) {
1002 return -EINVAL;
1005 s->bat = NULL;
1006 s->first_visible_write = true;
1008 qemu_co_mutex_init(&s->lock);
1009 QLIST_INIT(&s->regions);
1011 /* validate the file signature */
1012 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t));
1013 if (ret < 0) {
1014 goto fail;
1016 if (memcmp(&signature, "vhdxfile", 8)) {
1017 ret = -EINVAL;
1018 goto fail;
1021 /* This is used for any header updates, for the file_write_guid.
1022 * The spec dictates that a new value should be used for the first
1023 * header update */
1024 vhdx_guid_generate(&s->session_guid);
1026 vhdx_parse_header(bs, s, &local_err);
1027 if (local_err != NULL) {
1028 error_propagate(errp, local_err);
1029 ret = -EINVAL;
1030 goto fail;
1033 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp);
1034 if (ret < 0) {
1035 goto fail;
1038 ret = vhdx_open_region_tables(bs, s);
1039 if (ret < 0) {
1040 goto fail;
1043 ret = vhdx_parse_metadata(bs, s);
1044 if (ret < 0) {
1045 goto fail;
1048 s->block_size = s->params.block_size;
1050 /* the VHDX spec dictates that virtual_disk_size is always a multiple of
1051 * logical_sector_size */
1052 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits;
1054 vhdx_calc_bat_entries(s);
1056 s->bat_offset = s->bat_rt.file_offset;
1058 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) {
1059 /* BAT allocation is not large enough for all entries */
1060 ret = -EINVAL;
1061 goto fail;
1064 /* s->bat is freed in vhdx_close() */
1065 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length);
1066 if (s->bat == NULL) {
1067 ret = -ENOMEM;
1068 goto fail;
1071 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
1072 if (ret < 0) {
1073 goto fail;
1076 /* endian convert populated BAT field entires */
1077 for (i = 0; i < s->bat_entries; i++) {
1078 s->bat[i] = le64_to_cpu(s->bat[i]);
1081 if (!(flags & BDRV_O_CHECK)) {
1082 ret = vhdx_check_bat_entries(bs, NULL);
1083 if (ret < 0) {
1084 goto fail;
1088 /* Disable migration when VHDX images are used */
1089 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' "
1090 "does not support live migration",
1091 bdrv_get_device_or_node_name(bs));
1092 ret = migrate_add_blocker(s->migration_blocker, errp);
1093 if (ret < 0) {
1094 error_free(s->migration_blocker);
1095 goto fail;
1098 /* TODO: differencing files */
1100 return 0;
1101 fail:
1102 vhdx_close(bs);
1103 return ret;
1106 static int vhdx_reopen_prepare(BDRVReopenState *state,
1107 BlockReopenQueue *queue, Error **errp)
1109 return 0;
1114 * Perform sector to block offset translations, to get various
1115 * sector and file offsets into the image. See VHDXSectorInfo
1117 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num,
1118 int nb_sectors, VHDXSectorInfo *sinfo)
1120 uint32_t block_offset;
1122 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits;
1123 /* effectively a modulo - this gives us the offset into the block
1124 * (in sector sizes) for our sector number */
1125 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits);
1126 /* the chunk ratio gives us the interleaving of the sector
1127 * bitmaps, so we need to advance our page block index by the
1128 * sector bitmaps entry number */
1129 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits;
1131 /* the number of sectors we can read/write in this cycle */
1132 sinfo->sectors_avail = s->sectors_per_block - block_offset;
1134 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits;
1136 if (sinfo->sectors_avail > nb_sectors) {
1137 sinfo->sectors_avail = nb_sectors;
1140 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits;
1142 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK;
1144 sinfo->block_offset = block_offset << s->logical_sector_size_bits;
1146 /* The file offset must be past the header section, so must be > 0 */
1147 if (sinfo->file_offset == 0) {
1148 return;
1151 /* block offset is the offset in vhdx logical sectors, in
1152 * the payload data block. Convert that to a byte offset
1153 * in the block, and add in the payload data block offset
1154 * in the file, in bytes, to get the final read address */
1156 sinfo->file_offset += sinfo->block_offset;
1160 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1162 BDRVVHDXState *s = bs->opaque;
1164 bdi->cluster_size = s->block_size;
1166 return 0;
1170 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num,
1171 int nb_sectors, QEMUIOVector *qiov)
1173 BDRVVHDXState *s = bs->opaque;
1174 int ret = 0;
1175 VHDXSectorInfo sinfo;
1176 uint64_t bytes_done = 0;
1177 QEMUIOVector hd_qiov;
1179 qemu_iovec_init(&hd_qiov, qiov->niov);
1181 qemu_co_mutex_lock(&s->lock);
1183 while (nb_sectors > 0) {
1184 /* We are a differencing file, so we need to inspect the sector bitmap
1185 * to see if we have the data or not */
1186 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1187 /* not supported yet */
1188 ret = -ENOTSUP;
1189 goto exit;
1190 } else {
1191 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1193 qemu_iovec_reset(&hd_qiov);
1194 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail);
1196 /* check the payload block state */
1197 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) {
1198 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1199 case PAYLOAD_BLOCK_UNDEFINED:
1200 case PAYLOAD_BLOCK_UNMAPPED:
1201 case PAYLOAD_BLOCK_UNMAPPED_v095:
1202 case PAYLOAD_BLOCK_ZERO:
1203 /* return zero */
1204 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail);
1205 break;
1206 case PAYLOAD_BLOCK_FULLY_PRESENT:
1207 qemu_co_mutex_unlock(&s->lock);
1208 ret = bdrv_co_preadv(bs->file, sinfo.file_offset,
1209 sinfo.sectors_avail * BDRV_SECTOR_SIZE,
1210 &hd_qiov, 0);
1211 qemu_co_mutex_lock(&s->lock);
1212 if (ret < 0) {
1213 goto exit;
1215 break;
1216 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1217 /* we don't yet support difference files, fall through
1218 * to error */
1219 default:
1220 ret = -EIO;
1221 goto exit;
1222 break;
1224 nb_sectors -= sinfo.sectors_avail;
1225 sector_num += sinfo.sectors_avail;
1226 bytes_done += sinfo.bytes_avail;
1229 ret = 0;
1230 exit:
1231 qemu_co_mutex_unlock(&s->lock);
1232 qemu_iovec_destroy(&hd_qiov);
1233 return ret;
1237 * Allocate a new payload block at the end of the file.
1239 * Allocation will happen at 1MB alignment inside the file.
1241 * If @need_zero is set on entry but not cleared on return, then truncation
1242 * could not guarantee that the new portion reads as zero, and the caller
1243 * will take care of it instead.
1245 * Returns the file offset start of the new payload block
1247 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
1248 uint64_t *new_offset, bool *need_zero)
1250 int64_t current_len;
1252 current_len = bdrv_getlength(bs->file->bs);
1253 if (current_len < 0) {
1254 return current_len;
1257 *new_offset = current_len;
1259 /* per the spec, the address for a block is in units of 1MB */
1260 *new_offset = ROUND_UP(*new_offset, 1 * MiB);
1261 if (*new_offset > INT64_MAX) {
1262 return -EINVAL;
1265 if (*need_zero) {
1266 int ret;
1268 ret = bdrv_truncate(bs->file, *new_offset + s->block_size, false,
1269 PREALLOC_MODE_OFF, BDRV_REQ_ZERO_WRITE, NULL);
1270 if (ret != -ENOTSUP) {
1271 *need_zero = false;
1272 return ret;
1276 return bdrv_truncate(bs->file, *new_offset + s->block_size, false,
1277 PREALLOC_MODE_OFF, 0, NULL);
1281 * Update the BAT table entry with the new file offset, and the new entry
1282 * state */
1283 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s,
1284 VHDXSectorInfo *sinfo,
1285 uint64_t *bat_entry_le,
1286 uint64_t *bat_offset, int state)
1288 /* The BAT entry is a uint64, with 44 bits for the file offset in units of
1289 * 1MB, and 3 bits for the block state. */
1290 if ((state == PAYLOAD_BLOCK_ZERO) ||
1291 (state == PAYLOAD_BLOCK_UNDEFINED) ||
1292 (state == PAYLOAD_BLOCK_NOT_PRESENT) ||
1293 (state == PAYLOAD_BLOCK_UNMAPPED)) {
1294 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the
1295 FileOffsetMB field is denoted as
1296 'reserved' in the v1.0 spec. If it is
1297 non-zero, MS Hyper-V will fail to read
1298 the disk image */
1299 } else {
1300 s->bat[sinfo->bat_idx] = sinfo->file_offset;
1303 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK;
1305 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]);
1306 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry);
1310 /* Per the spec, on the first write of guest-visible data to the file the
1311 * data write guid must be updated in the header */
1312 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s)
1314 int ret = 0;
1315 if (s->first_visible_write) {
1316 s->first_visible_write = false;
1317 ret = vhdx_update_headers(bs, s, true, NULL);
1319 return ret;
1322 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
1323 int nb_sectors, QEMUIOVector *qiov,
1324 int flags)
1326 int ret = -ENOTSUP;
1327 BDRVVHDXState *s = bs->opaque;
1328 VHDXSectorInfo sinfo;
1329 uint64_t bytes_done = 0;
1330 uint64_t bat_entry = 0;
1331 uint64_t bat_entry_offset = 0;
1332 QEMUIOVector hd_qiov;
1333 struct iovec iov1 = { 0 };
1334 struct iovec iov2 = { 0 };
1335 int sectors_to_write;
1336 int bat_state;
1337 uint64_t bat_prior_offset = 0;
1338 bool bat_update = false;
1340 assert(!flags);
1341 qemu_iovec_init(&hd_qiov, qiov->niov);
1343 qemu_co_mutex_lock(&s->lock);
1345 ret = vhdx_user_visible_write(bs, s);
1346 if (ret < 0) {
1347 goto exit;
1350 while (nb_sectors > 0) {
1351 bool use_zero_buffers = false;
1352 bat_update = false;
1353 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1354 /* not supported yet */
1355 ret = -ENOTSUP;
1356 goto exit;
1357 } else {
1358 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1359 sectors_to_write = sinfo.sectors_avail;
1361 qemu_iovec_reset(&hd_qiov);
1362 /* check the payload block state */
1363 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK;
1364 switch (bat_state) {
1365 case PAYLOAD_BLOCK_ZERO:
1366 /* in this case, we need to preserve zero writes for
1367 * data that is not part of this write, so we must pad
1368 * the rest of the buffer to zeroes */
1369 use_zero_buffers = true;
1370 /* fall through */
1371 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1372 case PAYLOAD_BLOCK_UNMAPPED:
1373 case PAYLOAD_BLOCK_UNMAPPED_v095:
1374 case PAYLOAD_BLOCK_UNDEFINED:
1375 bat_prior_offset = sinfo.file_offset;
1376 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset,
1377 &use_zero_buffers);
1378 if (ret < 0) {
1379 goto exit;
1382 * once we support differencing files, this may also be
1383 * partially present
1385 /* update block state to the newly specified state */
1386 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1387 &bat_entry_offset,
1388 PAYLOAD_BLOCK_FULLY_PRESENT);
1389 bat_update = true;
1391 * Since we just allocated a block, file_offset is the
1392 * beginning of the payload block. It needs to be the
1393 * write address, which includes the offset into the
1394 * block, unless the entire block needs to read as
1395 * zeroes but truncation was not able to provide them,
1396 * in which case we need to fill in the rest.
1398 if (!use_zero_buffers) {
1399 sinfo.file_offset += sinfo.block_offset;
1400 } else {
1401 /* zero fill the front, if any */
1402 if (sinfo.block_offset) {
1403 iov1.iov_len = sinfo.block_offset;
1404 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len);
1405 memset(iov1.iov_base, 0, iov1.iov_len);
1406 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0,
1407 iov1.iov_len);
1408 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS;
1411 /* our actual data */
1412 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1413 sinfo.bytes_avail);
1415 /* zero fill the back, if any */
1416 if ((sinfo.bytes_avail - sinfo.block_offset) <
1417 s->block_size) {
1418 iov2.iov_len = s->block_size -
1419 (sinfo.bytes_avail + sinfo.block_offset);
1420 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len);
1421 memset(iov2.iov_base, 0, iov2.iov_len);
1422 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0,
1423 iov2.iov_len);
1424 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS;
1428 /* fall through */
1429 case PAYLOAD_BLOCK_FULLY_PRESENT:
1430 /* if the file offset address is in the header zone,
1431 * there is a problem */
1432 if (sinfo.file_offset < (1 * MiB)) {
1433 ret = -EFAULT;
1434 goto error_bat_restore;
1437 if (!use_zero_buffers) {
1438 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1439 sinfo.bytes_avail);
1441 /* block exists, so we can just overwrite it */
1442 qemu_co_mutex_unlock(&s->lock);
1443 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset,
1444 sectors_to_write * BDRV_SECTOR_SIZE,
1445 &hd_qiov, 0);
1446 qemu_co_mutex_lock(&s->lock);
1447 if (ret < 0) {
1448 goto error_bat_restore;
1450 break;
1451 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1452 /* we don't yet support difference files, fall through
1453 * to error */
1454 default:
1455 ret = -EIO;
1456 goto exit;
1457 break;
1460 if (bat_update) {
1461 /* this will update the BAT entry into the log journal, and
1462 * then flush the log journal out to disk */
1463 ret = vhdx_log_write_and_flush(bs, s, &bat_entry,
1464 sizeof(VHDXBatEntry),
1465 bat_entry_offset);
1466 if (ret < 0) {
1467 goto exit;
1471 nb_sectors -= sinfo.sectors_avail;
1472 sector_num += sinfo.sectors_avail;
1473 bytes_done += sinfo.bytes_avail;
1478 goto exit;
1480 error_bat_restore:
1481 if (bat_update) {
1482 /* keep metadata in sync, and restore the bat entry state
1483 * if error. */
1484 sinfo.file_offset = bat_prior_offset;
1485 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1486 &bat_entry_offset, bat_state);
1488 exit:
1489 qemu_vfree(iov1.iov_base);
1490 qemu_vfree(iov2.iov_base);
1491 qemu_co_mutex_unlock(&s->lock);
1492 qemu_iovec_destroy(&hd_qiov);
1493 return ret;
1499 * Create VHDX Headers
1501 * There are 2 headers, and the highest sequence number will represent
1502 * the active header
1504 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size,
1505 uint32_t log_size)
1507 BlockDriverState *bs = blk_bs(blk);
1508 BdrvChild *child;
1509 int ret = 0;
1510 VHDXHeader *hdr = NULL;
1512 hdr = g_new0(VHDXHeader, 1);
1514 hdr->signature = VHDX_HEADER_SIGNATURE;
1515 hdr->sequence_number = g_random_int();
1516 hdr->log_version = 0;
1517 hdr->version = 1;
1518 hdr->log_length = log_size;
1519 hdr->log_offset = VHDX_HEADER_SECTION_END;
1520 vhdx_guid_generate(&hdr->file_write_guid);
1521 vhdx_guid_generate(&hdr->data_write_guid);
1523 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This
1524 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend
1525 * here, which it really shouldn't be doing. */
1526 child = QLIST_FIRST(&bs->parents);
1527 assert(!QLIST_NEXT(child, next_parent));
1529 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false);
1530 if (ret < 0) {
1531 goto exit;
1533 hdr->sequence_number++;
1534 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false);
1535 if (ret < 0) {
1536 goto exit;
1539 exit:
1540 g_free(hdr);
1541 return ret;
1544 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \
1545 (sizeof(VHDXFileParameters) +\
1546 sizeof(VHDXVirtualDiskSize) +\
1547 sizeof(VHDXPage83Data) +\
1548 sizeof(VHDXVirtualDiskLogicalSectorSize) +\
1549 sizeof(VHDXVirtualDiskPhysicalSectorSize))
1552 * Create the Metadata entries.
1554 * For more details on the entries, see section 3.5 (pg 29) in the
1555 * VHDX 1.00 specification.
1557 * We support 5 metadata entries (all required by spec):
1558 * File Parameters,
1559 * Virtual Disk Size,
1560 * Page 83 Data,
1561 * Logical Sector Size,
1562 * Physical Sector Size
1564 * The first 64KB of the Metadata section is reserved for the metadata
1565 * header and entries; beyond that, the metadata items themselves reside.
1567 static int vhdx_create_new_metadata(BlockBackend *blk,
1568 uint64_t image_size,
1569 uint32_t block_size,
1570 uint32_t sector_size,
1571 uint64_t metadata_offset,
1572 VHDXImageType type)
1574 int ret = 0;
1575 uint32_t offset = 0;
1576 void *buffer = NULL;
1577 void *entry_buffer;
1578 VHDXMetadataTableHeader *md_table;
1579 VHDXMetadataTableEntry *md_table_entry;
1581 /* Metadata entries */
1582 VHDXFileParameters *mt_file_params;
1583 VHDXVirtualDiskSize *mt_virtual_size;
1584 VHDXPage83Data *mt_page83;
1585 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size;
1586 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
1588 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE);
1590 mt_file_params = entry_buffer;
1591 offset += sizeof(VHDXFileParameters);
1592 mt_virtual_size = entry_buffer + offset;
1593 offset += sizeof(VHDXVirtualDiskSize);
1594 mt_page83 = entry_buffer + offset;
1595 offset += sizeof(VHDXPage83Data);
1596 mt_log_sector_size = entry_buffer + offset;
1597 offset += sizeof(VHDXVirtualDiskLogicalSectorSize);
1598 mt_phys_sector_size = entry_buffer + offset;
1600 mt_file_params->block_size = cpu_to_le32(block_size);
1601 if (type == VHDX_TYPE_FIXED) {
1602 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED;
1603 mt_file_params->data_bits = cpu_to_le32(mt_file_params->data_bits);
1606 vhdx_guid_generate(&mt_page83->page_83_data);
1607 cpu_to_leguids(&mt_page83->page_83_data);
1608 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size);
1609 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size);
1610 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size);
1612 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1613 md_table = buffer;
1615 md_table->signature = VHDX_METADATA_SIGNATURE;
1616 md_table->entry_count = 5;
1617 vhdx_metadata_header_le_export(md_table);
1620 /* This will reference beyond the reserved table portion */
1621 offset = 64 * KiB;
1623 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader);
1625 md_table_entry[0].item_id = file_param_guid;
1626 md_table_entry[0].offset = offset;
1627 md_table_entry[0].length = sizeof(VHDXFileParameters);
1628 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED;
1629 offset += md_table_entry[0].length;
1630 vhdx_metadata_entry_le_export(&md_table_entry[0]);
1632 md_table_entry[1].item_id = virtual_size_guid;
1633 md_table_entry[1].offset = offset;
1634 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize);
1635 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1636 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1637 offset += md_table_entry[1].length;
1638 vhdx_metadata_entry_le_export(&md_table_entry[1]);
1640 md_table_entry[2].item_id = page83_guid;
1641 md_table_entry[2].offset = offset;
1642 md_table_entry[2].length = sizeof(VHDXPage83Data);
1643 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1644 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1645 offset += md_table_entry[2].length;
1646 vhdx_metadata_entry_le_export(&md_table_entry[2]);
1648 md_table_entry[3].item_id = logical_sector_guid;
1649 md_table_entry[3].offset = offset;
1650 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize);
1651 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1652 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1653 offset += md_table_entry[3].length;
1654 vhdx_metadata_entry_le_export(&md_table_entry[3]);
1656 md_table_entry[4].item_id = phys_sector_guid;
1657 md_table_entry[4].offset = offset;
1658 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize);
1659 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1660 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1661 vhdx_metadata_entry_le_export(&md_table_entry[4]);
1663 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0);
1664 if (ret < 0) {
1665 goto exit;
1668 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer,
1669 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0);
1670 if (ret < 0) {
1671 goto exit;
1675 exit:
1676 g_free(buffer);
1677 g_free(entry_buffer);
1678 return ret;
1681 /* This create the actual BAT itself. We currently only support
1682 * 'Dynamic' and 'Fixed' image types.
1684 * Dynamic images: default state of the BAT is all zeroes.
1686 * Fixed images: default state of the BAT is fully populated, with
1687 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT.
1689 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
1690 uint64_t image_size, VHDXImageType type,
1691 bool use_zero_blocks, uint64_t file_offset,
1692 uint32_t length, Error **errp)
1694 int ret = 0;
1695 uint64_t data_file_offset;
1696 uint64_t total_sectors = 0;
1697 uint64_t sector_num = 0;
1698 uint64_t unused;
1699 int block_state;
1700 VHDXSectorInfo sinfo;
1702 assert(s->bat == NULL);
1704 /* this gives a data start after BAT/bitmap entries, and well
1705 * past any metadata entries (with a 4 MB buffer for future
1706 * expansion */
1707 data_file_offset = file_offset + length + 5 * MiB;
1708 total_sectors = image_size >> s->logical_sector_size_bits;
1710 if (type == VHDX_TYPE_DYNAMIC) {
1711 /* All zeroes, so we can just extend the file - the end of the BAT
1712 * is the furthest thing we have written yet */
1713 ret = blk_truncate(blk, data_file_offset, false, PREALLOC_MODE_OFF,
1714 0, errp);
1715 if (ret < 0) {
1716 goto exit;
1718 } else if (type == VHDX_TYPE_FIXED) {
1719 ret = blk_truncate(blk, data_file_offset + image_size, false,
1720 PREALLOC_MODE_OFF, 0, errp);
1721 if (ret < 0) {
1722 goto exit;
1724 } else {
1725 error_setg(errp, "Unsupported image type");
1726 ret = -ENOTSUP;
1727 goto exit;
1730 if (type == VHDX_TYPE_FIXED ||
1731 use_zero_blocks ||
1732 bdrv_has_zero_init(blk_bs(blk)) == 0) {
1733 /* for a fixed file, the default BAT entry is not zero */
1734 s->bat = g_try_malloc0(length);
1735 if (length && s->bat == NULL) {
1736 error_setg(errp, "Failed to allocate memory for the BAT");
1737 ret = -ENOMEM;
1738 goto exit;
1740 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
1741 PAYLOAD_BLOCK_NOT_PRESENT;
1742 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
1743 /* fill the BAT by emulating sector writes of sectors_per_block size */
1744 while (sector_num < total_sectors) {
1745 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo);
1746 sinfo.file_offset = data_file_offset +
1747 (sector_num << s->logical_sector_size_bits);
1748 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB);
1749 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused,
1750 block_state);
1751 s->bat[sinfo.bat_idx] = cpu_to_le64(s->bat[sinfo.bat_idx]);
1752 sector_num += s->sectors_per_block;
1754 ret = blk_pwrite(blk, file_offset, s->bat, length, 0);
1755 if (ret < 0) {
1756 error_setg_errno(errp, -ret, "Failed to write the BAT");
1757 goto exit;
1763 exit:
1764 g_free(s->bat);
1765 return ret;
1768 /* Creates the region table header, and region table entries.
1769 * There are 2 supported region table entries: BAT, and Metadata/
1771 * As the calculations for the BAT region table are also needed
1772 * to create the BAT itself, we will also cause the BAT to be
1773 * created.
1775 static int vhdx_create_new_region_table(BlockBackend *blk,
1776 uint64_t image_size,
1777 uint32_t block_size,
1778 uint32_t sector_size,
1779 uint32_t log_size,
1780 bool use_zero_blocks,
1781 VHDXImageType type,
1782 uint64_t *metadata_offset,
1783 Error **errp)
1785 int ret = 0;
1786 uint32_t offset = 0;
1787 void *buffer = NULL;
1788 uint64_t bat_file_offset;
1789 uint32_t bat_length;
1790 BDRVVHDXState *s = NULL;
1791 VHDXRegionTableHeader *region_table;
1792 VHDXRegionTableEntry *rt_bat;
1793 VHDXRegionTableEntry *rt_metadata;
1795 assert(metadata_offset != NULL);
1797 /* Populate enough of the BDRVVHDXState to be able to use the
1798 * pre-existing BAT calculation, translation, and update functions */
1799 s = g_new0(BDRVVHDXState, 1);
1801 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
1802 (uint64_t) sector_size / (uint64_t) block_size;
1804 s->sectors_per_block = block_size / sector_size;
1805 s->virtual_disk_size = image_size;
1806 s->block_size = block_size;
1807 s->logical_sector_size = sector_size;
1809 vhdx_set_shift_bits(s);
1811 vhdx_calc_bat_entries(s);
1813 /* At this point the VHDX state is populated enough for creation */
1815 /* a single buffer is used so we can calculate the checksum over the
1816 * entire 64KB block */
1817 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1818 region_table = buffer;
1819 offset += sizeof(VHDXRegionTableHeader);
1820 rt_bat = buffer + offset;
1821 offset += sizeof(VHDXRegionTableEntry);
1822 rt_metadata = buffer + offset;
1824 region_table->signature = VHDX_REGION_SIGNATURE;
1825 region_table->entry_count = 2; /* BAT and Metadata */
1827 rt_bat->guid = bat_guid;
1828 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB);
1829 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB);
1830 s->bat_offset = rt_bat->file_offset;
1832 rt_metadata->guid = metadata_guid;
1833 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length,
1834 MiB);
1835 rt_metadata->length = 1 * MiB; /* min size, and more than enough */
1836 *metadata_offset = rt_metadata->file_offset;
1838 bat_file_offset = rt_bat->file_offset;
1839 bat_length = rt_bat->length;
1841 vhdx_region_header_le_export(region_table);
1842 vhdx_region_entry_le_export(rt_bat);
1843 vhdx_region_entry_le_export(rt_metadata);
1845 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE,
1846 offsetof(VHDXRegionTableHeader, checksum));
1849 /* The region table gives us the data we need to create the BAT,
1850 * so do that now */
1851 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks,
1852 bat_file_offset, bat_length, errp);
1853 if (ret < 0) {
1854 goto exit;
1857 /* Now write out the region headers to disk */
1858 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer,
1859 VHDX_HEADER_BLOCK_SIZE, 0);
1860 if (ret < 0) {
1861 error_setg_errno(errp, -ret, "Failed to write first region table");
1862 goto exit;
1865 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer,
1866 VHDX_HEADER_BLOCK_SIZE, 0);
1867 if (ret < 0) {
1868 error_setg_errno(errp, -ret, "Failed to write second region table");
1869 goto exit;
1872 exit:
1873 g_free(s);
1874 g_free(buffer);
1875 return ret;
1878 /* We need to create the following elements:
1880 * .-----------------------------------------------------------------.
1881 * | (A) | (B) | (C) | (D) | (E) |
1882 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 |
1883 * | | | | | |
1884 * .-----------------------------------------------------------------.
1885 * 0 64KB 128KB 192KB 256KB 320KB
1888 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1889 * | (F) | (G) | (H) | |
1890 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... |
1891 * | | | | |
1892 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1893 * 1MB
1895 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts,
1896 Error **errp)
1898 BlockdevCreateOptionsVhdx *vhdx_opts;
1899 BlockBackend *blk = NULL;
1900 BlockDriverState *bs = NULL;
1902 int ret = 0;
1903 uint64_t image_size;
1904 uint32_t log_size;
1905 uint32_t block_size;
1906 uint64_t signature;
1907 uint64_t metadata_offset;
1908 bool use_zero_blocks = false;
1910 gunichar2 *creator = NULL;
1911 glong creator_items;
1912 VHDXImageType image_type;
1914 assert(opts->driver == BLOCKDEV_DRIVER_VHDX);
1915 vhdx_opts = &opts->u.vhdx;
1917 /* Validate options and set default values */
1918 image_size = vhdx_opts->size;
1919 if (image_size > VHDX_MAX_IMAGE_SIZE) {
1920 error_setg(errp, "Image size too large; max of 64TB");
1921 return -EINVAL;
1924 if (!vhdx_opts->has_log_size) {
1925 log_size = DEFAULT_LOG_SIZE;
1926 } else {
1927 if (vhdx_opts->log_size > UINT32_MAX) {
1928 error_setg(errp, "Log size must be smaller than 4 GB");
1929 return -EINVAL;
1931 log_size = vhdx_opts->log_size;
1933 if (log_size < MiB || (log_size % MiB) != 0) {
1934 error_setg(errp, "Log size must be a multiple of 1 MB");
1935 return -EINVAL;
1938 if (!vhdx_opts->has_block_state_zero) {
1939 use_zero_blocks = true;
1940 } else {
1941 use_zero_blocks = vhdx_opts->block_state_zero;
1944 if (!vhdx_opts->has_subformat) {
1945 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC;
1948 switch (vhdx_opts->subformat) {
1949 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC:
1950 image_type = VHDX_TYPE_DYNAMIC;
1951 break;
1952 case BLOCKDEV_VHDX_SUBFORMAT_FIXED:
1953 image_type = VHDX_TYPE_FIXED;
1954 break;
1955 default:
1956 g_assert_not_reached();
1959 /* These are pretty arbitrary, and mainly designed to keep the BAT
1960 * size reasonable to load into RAM */
1961 if (vhdx_opts->has_block_size) {
1962 block_size = vhdx_opts->block_size;
1963 } else {
1964 if (image_size > 32 * TiB) {
1965 block_size = 64 * MiB;
1966 } else if (image_size > (uint64_t) 100 * GiB) {
1967 block_size = 32 * MiB;
1968 } else if (image_size > 1 * GiB) {
1969 block_size = 16 * MiB;
1970 } else {
1971 block_size = 8 * MiB;
1975 if (block_size < MiB || (block_size % MiB) != 0) {
1976 error_setg(errp, "Block size must be a multiple of 1 MB");
1977 return -EINVAL;
1979 if (!is_power_of_2(block_size)) {
1980 error_setg(errp, "Block size must be a power of two");
1981 return -EINVAL;
1983 if (block_size > VHDX_BLOCK_SIZE_MAX) {
1984 error_setg(errp, "Block size must not exceed %" PRId64,
1985 VHDX_BLOCK_SIZE_MAX);
1986 return -EINVAL;
1989 /* Create BlockBackend to write to the image */
1990 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp);
1991 if (bs == NULL) {
1992 return -EIO;
1995 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
1996 errp);
1997 if (!blk) {
1998 ret = -EPERM;
1999 goto delete_and_exit;
2001 blk_set_allow_write_beyond_eof(blk, true);
2003 /* Create (A) */
2005 /* The creator field is optional, but may be useful for
2006 * debugging / diagnostics */
2007 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL,
2008 &creator_items, NULL);
2009 signature = cpu_to_le64(VHDX_FILE_SIGNATURE);
2010 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature),
2012 if (ret < 0) {
2013 error_setg_errno(errp, -ret, "Failed to write file signature");
2014 goto delete_and_exit;
2016 if (creator) {
2017 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature),
2018 creator, creator_items * sizeof(gunichar2), 0);
2019 if (ret < 0) {
2020 error_setg_errno(errp, -ret, "Failed to write creator field");
2021 goto delete_and_exit;
2026 /* Creates (B),(C) */
2027 ret = vhdx_create_new_headers(blk, image_size, log_size);
2028 if (ret < 0) {
2029 error_setg_errno(errp, -ret, "Failed to write image headers");
2030 goto delete_and_exit;
2033 /* Creates (D),(E),(G) explicitly. (F) created as by-product */
2034 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512,
2035 log_size, use_zero_blocks, image_type,
2036 &metadata_offset, errp);
2037 if (ret < 0) {
2038 goto delete_and_exit;
2041 /* Creates (H) */
2042 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512,
2043 metadata_offset, image_type);
2044 if (ret < 0) {
2045 error_setg_errno(errp, -ret, "Failed to initialize metadata");
2046 goto delete_and_exit;
2049 ret = 0;
2050 delete_and_exit:
2051 blk_unref(blk);
2052 bdrv_unref(bs);
2053 g_free(creator);
2054 return ret;
2057 static int coroutine_fn vhdx_co_create_opts(BlockDriver *drv,
2058 const char *filename,
2059 QemuOpts *opts,
2060 Error **errp)
2062 BlockdevCreateOptions *create_options = NULL;
2063 QDict *qdict;
2064 Visitor *v;
2065 BlockDriverState *bs = NULL;
2066 int ret;
2068 static const QDictRenames opt_renames[] = {
2069 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" },
2070 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" },
2071 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" },
2072 { NULL, NULL },
2075 /* Parse options and convert legacy syntax */
2076 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true);
2078 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
2079 ret = -EINVAL;
2080 goto fail;
2083 /* Create and open the file (protocol layer) */
2084 ret = bdrv_create_file(filename, opts, errp);
2085 if (ret < 0) {
2086 goto fail;
2089 bs = bdrv_open(filename, NULL, NULL,
2090 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
2091 if (bs == NULL) {
2092 ret = -EIO;
2093 goto fail;
2096 /* Now get the QAPI type BlockdevCreateOptions */
2097 qdict_put_str(qdict, "driver", "vhdx");
2098 qdict_put_str(qdict, "file", bs->node_name);
2100 v = qobject_input_visitor_new_flat_confused(qdict, errp);
2101 if (!v) {
2102 ret = -EINVAL;
2103 goto fail;
2106 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
2107 visit_free(v);
2108 if (!create_options) {
2109 ret = -EINVAL;
2110 goto fail;
2113 /* Silently round up sizes:
2114 * The image size is rounded to 512 bytes. Make the block and log size
2115 * close to what was specified, but must be at least 1MB, and a multiple of
2116 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0
2117 * means auto, which is represented by a missing key in QAPI. */
2118 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX);
2119 create_options->u.vhdx.size =
2120 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE);
2122 if (create_options->u.vhdx.has_log_size) {
2123 create_options->u.vhdx.log_size =
2124 ROUND_UP(create_options->u.vhdx.log_size, MiB);
2126 if (create_options->u.vhdx.has_block_size) {
2127 create_options->u.vhdx.block_size =
2128 ROUND_UP(create_options->u.vhdx.block_size, MiB);
2130 if (create_options->u.vhdx.block_size == 0) {
2131 create_options->u.vhdx.has_block_size = false;
2133 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) {
2134 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX;
2138 /* Create the vhdx image (format layer) */
2139 ret = vhdx_co_create(create_options, errp);
2141 fail:
2142 qobject_unref(qdict);
2143 bdrv_unref(bs);
2144 qapi_free_BlockdevCreateOptions(create_options);
2145 return ret;
2148 /* If opened r/w, the VHDX driver will automatically replay the log,
2149 * if one is present, inside the vhdx_open() call.
2151 * If qemu-img check -r all is called, the image is automatically opened
2152 * r/w and any log has already been replayed, so there is nothing (currently)
2153 * for us to do here
2155 static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
2156 BdrvCheckResult *result,
2157 BdrvCheckMode fix)
2159 BDRVVHDXState *s = bs->opaque;
2161 if (s->log_replayed_on_open) {
2162 result->corruptions_fixed++;
2165 vhdx_check_bat_entries(bs, &result->corruptions);
2167 return 0;
2170 static int vhdx_has_zero_init(BlockDriverState *bs)
2172 BDRVVHDXState *s = bs->opaque;
2173 int state;
2176 * Check the subformat: Fixed images have all BAT entries present,
2177 * dynamic images have none (right after creation). It is
2178 * therefore enough to check the first BAT entry.
2180 if (!s->bat_entries) {
2181 return 1;
2184 state = s->bat[0] & VHDX_BAT_STATE_BIT_MASK;
2185 if (state == PAYLOAD_BLOCK_FULLY_PRESENT) {
2186 /* Fixed subformat */
2187 return bdrv_has_zero_init(bs->file->bs);
2190 /* Dynamic subformat */
2191 return 1;
2194 static QemuOptsList vhdx_create_opts = {
2195 .name = "vhdx-create-opts",
2196 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head),
2197 .desc = {
2199 .name = BLOCK_OPT_SIZE,
2200 .type = QEMU_OPT_SIZE,
2201 .help = "Virtual disk size; max of 64TB."
2204 .name = VHDX_BLOCK_OPT_LOG_SIZE,
2205 .type = QEMU_OPT_SIZE,
2206 .def_value_str = stringify(DEFAULT_LOG_SIZE),
2207 .help = "Log size; min 1MB."
2210 .name = VHDX_BLOCK_OPT_BLOCK_SIZE,
2211 .type = QEMU_OPT_SIZE,
2212 .def_value_str = stringify(0),
2213 .help = "Block Size; min 1MB, max 256MB. "
2214 "0 means auto-calculate based on image size."
2217 .name = BLOCK_OPT_SUBFMT,
2218 .type = QEMU_OPT_STRING,
2219 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "
2220 "Default is 'dynamic'."
2223 .name = VHDX_BLOCK_OPT_ZERO,
2224 .type = QEMU_OPT_BOOL,
2225 .help = "Force use of payload blocks of type 'ZERO'. "
2226 "Non-standard, but default. Do not set to 'off' when "
2227 "using 'qemu-img convert' with subformat=dynamic."
2229 { NULL }
2233 static BlockDriver bdrv_vhdx = {
2234 .format_name = "vhdx",
2235 .instance_size = sizeof(BDRVVHDXState),
2236 .bdrv_probe = vhdx_probe,
2237 .bdrv_open = vhdx_open,
2238 .bdrv_close = vhdx_close,
2239 .bdrv_reopen_prepare = vhdx_reopen_prepare,
2240 .bdrv_child_perm = bdrv_default_perms,
2241 .bdrv_co_readv = vhdx_co_readv,
2242 .bdrv_co_writev = vhdx_co_writev,
2243 .bdrv_co_create = vhdx_co_create,
2244 .bdrv_co_create_opts = vhdx_co_create_opts,
2245 .bdrv_get_info = vhdx_get_info,
2246 .bdrv_co_check = vhdx_co_check,
2247 .bdrv_has_zero_init = vhdx_has_zero_init,
2249 .is_format = true,
2250 .create_opts = &vhdx_create_opts,
2253 static void bdrv_vhdx_init(void)
2255 bdrv_register(&bdrv_vhdx);
2258 block_init(bdrv_vhdx_init);