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