vhdx: Bounds checking for block_size and logical_sector_size (CVE-2014-0148)
[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->params.block_size < VHDX_BLOCK_SIZE_MIN ||
784 s->params.block_size > VHDX_BLOCK_SIZE_MAX) {
785 ret = -EINVAL;
786 goto exit;
787 }
788
789 /* only 2 supported sector sizes */
790 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) {
791 ret = -EINVAL;
792 goto exit;
793 }
794
795 /* Both block_size and sector_size are guaranteed powers of 2, below.
796 Due to range checks above, s->sectors_per_block can never be < 256 */
797 s->sectors_per_block = s->params.block_size / s->logical_sector_size;
798 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
799 (uint64_t)s->logical_sector_size /
800 (uint64_t)s->params.block_size;
801
802 /* These values are ones we will want to use for division / multiplication
803 * later on, and they are all guaranteed (per the spec) to be powers of 2,
804 * so we can take advantage of that for shift operations during
805 * reads/writes */
806 if (s->logical_sector_size & (s->logical_sector_size - 1)) {
807 ret = -EINVAL;
808 goto exit;
809 }
810 if (s->sectors_per_block & (s->sectors_per_block - 1)) {
811 ret = -EINVAL;
812 goto exit;
813 }
814 if (s->chunk_ratio & (s->chunk_ratio - 1)) {
815 ret = -EINVAL;
816 goto exit;
817 }
818 s->block_size = s->params.block_size;
819 if (s->block_size & (s->block_size - 1)) {
820 ret = -EINVAL;
821 goto exit;
822 }
823
824 vhdx_set_shift_bits(s);
825
826 ret = 0;
827
828 exit:
829 qemu_vfree(buffer);
830 return ret;
831 }
832
833 /*
834 * Calculate the number of BAT entries, including sector
835 * bitmap entries.
836 */
837 static void vhdx_calc_bat_entries(BDRVVHDXState *s)
838 {
839 uint32_t data_blocks_cnt, bitmap_blocks_cnt;
840
841 data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits;
842 if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) {
843 data_blocks_cnt++;
844 }
845 bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits;
846 if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) {
847 bitmap_blocks_cnt++;
848 }
849
850 if (s->parent_entries) {
851 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1);
852 } else {
853 s->bat_entries = data_blocks_cnt +
854 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits);
855 }
856
857 }
858
859 static void vhdx_close(BlockDriverState *bs)
860 {
861 BDRVVHDXState *s = bs->opaque;
862 qemu_vfree(s->headers[0]);
863 s->headers[0] = NULL;
864 qemu_vfree(s->headers[1]);
865 s->headers[1] = NULL;
866 qemu_vfree(s->bat);
867 s->bat = NULL;
868 qemu_vfree(s->parent_entries);
869 s->parent_entries = NULL;
870 migrate_del_blocker(s->migration_blocker);
871 error_free(s->migration_blocker);
872 qemu_vfree(s->log.hdr);
873 s->log.hdr = NULL;
874 vhdx_region_unregister_all(s);
875 }
876
877 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
878 Error **errp)
879 {
880 BDRVVHDXState *s = bs->opaque;
881 int ret = 0;
882 uint32_t i;
883 uint64_t signature;
884 Error *local_err = NULL;
885
886 s->bat = NULL;
887 s->first_visible_write = true;
888
889 qemu_co_mutex_init(&s->lock);
890 QLIST_INIT(&s->regions);
891
892 /* validate the file signature */
893 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t));
894 if (ret < 0) {
895 goto fail;
896 }
897 if (memcmp(&signature, "vhdxfile", 8)) {
898 ret = -EINVAL;
899 goto fail;
900 }
901
902 /* This is used for any header updates, for the file_write_guid.
903 * The spec dictates that a new value should be used for the first
904 * header update */
905 vhdx_guid_generate(&s->session_guid);
906
907 vhdx_parse_header(bs, s, &local_err);
908 if (local_err != NULL) {
909 error_propagate(errp, local_err);
910 ret = -EINVAL;
911 goto fail;
912 }
913
914 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp);
915 if (ret < 0) {
916 goto fail;
917 }
918
919 ret = vhdx_open_region_tables(bs, s);
920 if (ret < 0) {
921 goto fail;
922 }
923
924 ret = vhdx_parse_metadata(bs, s);
925 if (ret < 0) {
926 goto fail;
927 }
928
929 s->block_size = s->params.block_size;
930
931 /* the VHDX spec dictates that virtual_disk_size is always a multiple of
932 * logical_sector_size */
933 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits;
934
935 vhdx_calc_bat_entries(s);
936
937 s->bat_offset = s->bat_rt.file_offset;
938
939 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) {
940 /* BAT allocation is not large enough for all entries */
941 ret = -EINVAL;
942 goto fail;
943 }
944
945 /* s->bat is freed in vhdx_close() */
946 s->bat = qemu_blockalign(bs, s->bat_rt.length);
947
948 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
949 if (ret < 0) {
950 goto fail;
951 }
952
953 uint64_t payblocks = s->chunk_ratio;
954 /* endian convert, and verify populated BAT field file offsets against
955 * region table and log entries */
956 for (i = 0; i < s->bat_entries; i++) {
957 le64_to_cpus(&s->bat[i]);
958 if (payblocks--) {
959 /* payload bat entries */
960 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) ==
961 PAYLOAD_BLOCK_FULLY_PRESENT) {
962 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK,
963 s->block_size);
964 if (ret < 0) {
965 goto fail;
966 }
967 }
968 } else {
969 payblocks = s->chunk_ratio;
970 /* Once differencing files are supported, verify sector bitmap
971 * blocks here */
972 }
973 }
974
975 if (flags & BDRV_O_RDWR) {
976 ret = vhdx_update_headers(bs, s, false, NULL);
977 if (ret < 0) {
978 goto fail;
979 }
980 }
981
982 /* TODO: differencing files */
983
984 /* Disable migration when VHDX images are used */
985 error_set(&s->migration_blocker,
986 QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
987 "vhdx", bs->device_name, "live migration");
988 migrate_add_blocker(s->migration_blocker);
989
990 return 0;
991 fail:
992 vhdx_close(bs);
993 return ret;
994 }
995
996 static int vhdx_reopen_prepare(BDRVReopenState *state,
997 BlockReopenQueue *queue, Error **errp)
998 {
999 return 0;
1000 }
1001
1002
1003 /*
1004 * Perform sector to block offset translations, to get various
1005 * sector and file offsets into the image. See VHDXSectorInfo
1006 */
1007 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num,
1008 int nb_sectors, VHDXSectorInfo *sinfo)
1009 {
1010 uint32_t block_offset;
1011
1012 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits;
1013 /* effectively a modulo - this gives us the offset into the block
1014 * (in sector sizes) for our sector number */
1015 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits);
1016 /* the chunk ratio gives us the interleaving of the sector
1017 * bitmaps, so we need to advance our page block index by the
1018 * sector bitmaps entry number */
1019 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits;
1020
1021 /* the number of sectors we can read/write in this cycle */
1022 sinfo->sectors_avail = s->sectors_per_block - block_offset;
1023
1024 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits;
1025
1026 if (sinfo->sectors_avail > nb_sectors) {
1027 sinfo->sectors_avail = nb_sectors;
1028 }
1029
1030 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits;
1031
1032 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK;
1033
1034 sinfo->block_offset = block_offset << s->logical_sector_size_bits;
1035
1036 /* The file offset must be past the header section, so must be > 0 */
1037 if (sinfo->file_offset == 0) {
1038 return;
1039 }
1040
1041 /* block offset is the offset in vhdx logical sectors, in
1042 * the payload data block. Convert that to a byte offset
1043 * in the block, and add in the payload data block offset
1044 * in the file, in bytes, to get the final read address */
1045
1046 sinfo->file_offset += sinfo->block_offset;
1047 }
1048
1049
1050 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1051 {
1052 BDRVVHDXState *s = bs->opaque;
1053
1054 bdi->cluster_size = s->block_size;
1055
1056 bdi->unallocated_blocks_are_zero =
1057 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0;
1058
1059 return 0;
1060 }
1061
1062
1063 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num,
1064 int nb_sectors, QEMUIOVector *qiov)
1065 {
1066 BDRVVHDXState *s = bs->opaque;
1067 int ret = 0;
1068 VHDXSectorInfo sinfo;
1069 uint64_t bytes_done = 0;
1070 QEMUIOVector hd_qiov;
1071
1072 qemu_iovec_init(&hd_qiov, qiov->niov);
1073
1074 qemu_co_mutex_lock(&s->lock);
1075
1076 while (nb_sectors > 0) {
1077 /* We are a differencing file, so we need to inspect the sector bitmap
1078 * to see if we have the data or not */
1079 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1080 /* not supported yet */
1081 ret = -ENOTSUP;
1082 goto exit;
1083 } else {
1084 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1085
1086 qemu_iovec_reset(&hd_qiov);
1087 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail);
1088
1089 /* check the payload block state */
1090 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) {
1091 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1092 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */
1093 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */
1094 case PAYLOAD_BLOCK_ZERO:
1095 /* return zero */
1096 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail);
1097 break;
1098 case PAYLOAD_BLOCK_FULLY_PRESENT:
1099 qemu_co_mutex_unlock(&s->lock);
1100 ret = bdrv_co_readv(bs->file,
1101 sinfo.file_offset >> BDRV_SECTOR_BITS,
1102 sinfo.sectors_avail, &hd_qiov);
1103 qemu_co_mutex_lock(&s->lock);
1104 if (ret < 0) {
1105 goto exit;
1106 }
1107 break;
1108 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1109 /* we don't yet support difference files, fall through
1110 * to error */
1111 default:
1112 ret = -EIO;
1113 goto exit;
1114 break;
1115 }
1116 nb_sectors -= sinfo.sectors_avail;
1117 sector_num += sinfo.sectors_avail;
1118 bytes_done += sinfo.bytes_avail;
1119 }
1120 }
1121 ret = 0;
1122 exit:
1123 qemu_co_mutex_unlock(&s->lock);
1124 qemu_iovec_destroy(&hd_qiov);
1125 return ret;
1126 }
1127
1128 /*
1129 * Allocate a new payload block at the end of the file.
1130 *
1131 * Allocation will happen at 1MB alignment inside the file
1132 *
1133 * Returns the file offset start of the new payload block
1134 */
1135 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
1136 uint64_t *new_offset)
1137 {
1138 *new_offset = bdrv_getlength(bs->file);
1139
1140 /* per the spec, the address for a block is in units of 1MB */
1141 *new_offset = ROUND_UP(*new_offset, 1024 * 1024);
1142
1143 return bdrv_truncate(bs->file, *new_offset + s->block_size);
1144 }
1145
1146 /*
1147 * Update the BAT table entry with the new file offset, and the new entry
1148 * state */
1149 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s,
1150 VHDXSectorInfo *sinfo,
1151 uint64_t *bat_entry_le,
1152 uint64_t *bat_offset, int state)
1153 {
1154 /* The BAT entry is a uint64, with 44 bits for the file offset in units of
1155 * 1MB, and 3 bits for the block state. */
1156 s->bat[sinfo->bat_idx] = sinfo->file_offset;
1157
1158 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK;
1159
1160 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]);
1161 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry);
1162
1163 }
1164
1165 /* Per the spec, on the first write of guest-visible data to the file the
1166 * data write guid must be updated in the header */
1167 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s)
1168 {
1169 int ret = 0;
1170 if (s->first_visible_write) {
1171 s->first_visible_write = false;
1172 ret = vhdx_update_headers(bs, s, true, NULL);
1173 }
1174 return ret;
1175 }
1176
1177 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
1178 int nb_sectors, QEMUIOVector *qiov)
1179 {
1180 int ret = -ENOTSUP;
1181 BDRVVHDXState *s = bs->opaque;
1182 VHDXSectorInfo sinfo;
1183 uint64_t bytes_done = 0;
1184 uint64_t bat_entry = 0;
1185 uint64_t bat_entry_offset = 0;
1186 QEMUIOVector hd_qiov;
1187 struct iovec iov1 = { 0 };
1188 struct iovec iov2 = { 0 };
1189 int sectors_to_write;
1190 int bat_state;
1191 uint64_t bat_prior_offset = 0;
1192 bool bat_update = false;
1193
1194 qemu_iovec_init(&hd_qiov, qiov->niov);
1195
1196 qemu_co_mutex_lock(&s->lock);
1197
1198 ret = vhdx_user_visible_write(bs, s);
1199 if (ret < 0) {
1200 goto exit;
1201 }
1202
1203 while (nb_sectors > 0) {
1204 bool use_zero_buffers = false;
1205 bat_update = false;
1206 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1207 /* not supported yet */
1208 ret = -ENOTSUP;
1209 goto exit;
1210 } else {
1211 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1212 sectors_to_write = sinfo.sectors_avail;
1213
1214 qemu_iovec_reset(&hd_qiov);
1215 /* check the payload block state */
1216 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK;
1217 switch (bat_state) {
1218 case PAYLOAD_BLOCK_ZERO:
1219 /* in this case, we need to preserve zero writes for
1220 * data that is not part of this write, so we must pad
1221 * the rest of the buffer to zeroes */
1222
1223 /* if we are on a posix system with ftruncate() that extends
1224 * a file, then it is zero-filled for us. On Win32, the raw
1225 * layer uses SetFilePointer and SetFileEnd, which does not
1226 * zero fill AFAIK */
1227
1228 /* Queue another write of zero buffers if the underlying file
1229 * does not zero-fill on file extension */
1230
1231 if (bdrv_has_zero_init(bs->file) == 0) {
1232 use_zero_buffers = true;
1233
1234 /* zero fill the front, if any */
1235 if (sinfo.block_offset) {
1236 iov1.iov_len = sinfo.block_offset;
1237 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len);
1238 memset(iov1.iov_base, 0, iov1.iov_len);
1239 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0,
1240 sinfo.block_offset);
1241 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS;
1242 }
1243
1244 /* our actual data */
1245 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1246 sinfo.bytes_avail);
1247
1248 /* zero fill the back, if any */
1249 if ((sinfo.bytes_avail - sinfo.block_offset) <
1250 s->block_size) {
1251 iov2.iov_len = s->block_size -
1252 (sinfo.bytes_avail + sinfo.block_offset);
1253 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len);
1254 memset(iov2.iov_base, 0, iov2.iov_len);
1255 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0,
1256 sinfo.block_offset);
1257 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS;
1258 }
1259 }
1260
1261 /* fall through */
1262 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1263 case PAYLOAD_BLOCK_UNMAPPED: /* fall through */
1264 case PAYLOAD_BLOCK_UNDEFINED: /* fall through */
1265 bat_prior_offset = sinfo.file_offset;
1266 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset);
1267 if (ret < 0) {
1268 goto exit;
1269 }
1270 /* once we support differencing files, this may also be
1271 * partially present */
1272 /* update block state to the newly specified state */
1273 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1274 &bat_entry_offset,
1275 PAYLOAD_BLOCK_FULLY_PRESENT);
1276 bat_update = true;
1277 /* since we just allocated a block, file_offset is the
1278 * beginning of the payload block. It needs to be the
1279 * write address, which includes the offset into the block */
1280 if (!use_zero_buffers) {
1281 sinfo.file_offset += sinfo.block_offset;
1282 }
1283 /* fall through */
1284 case PAYLOAD_BLOCK_FULLY_PRESENT:
1285 /* if the file offset address is in the header zone,
1286 * there is a problem */
1287 if (sinfo.file_offset < (1024 * 1024)) {
1288 ret = -EFAULT;
1289 goto error_bat_restore;
1290 }
1291
1292 if (!use_zero_buffers) {
1293 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1294 sinfo.bytes_avail);
1295 }
1296 /* block exists, so we can just overwrite it */
1297 qemu_co_mutex_unlock(&s->lock);
1298 ret = bdrv_co_writev(bs->file,
1299 sinfo.file_offset >> BDRV_SECTOR_BITS,
1300 sectors_to_write, &hd_qiov);
1301 qemu_co_mutex_lock(&s->lock);
1302 if (ret < 0) {
1303 goto error_bat_restore;
1304 }
1305 break;
1306 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1307 /* we don't yet support difference files, fall through
1308 * to error */
1309 default:
1310 ret = -EIO;
1311 goto exit;
1312 break;
1313 }
1314
1315 if (bat_update) {
1316 /* this will update the BAT entry into the log journal, and
1317 * then flush the log journal out to disk */
1318 ret = vhdx_log_write_and_flush(bs, s, &bat_entry,
1319 sizeof(VHDXBatEntry),
1320 bat_entry_offset);
1321 if (ret < 0) {
1322 goto exit;
1323 }
1324 }
1325
1326 nb_sectors -= sinfo.sectors_avail;
1327 sector_num += sinfo.sectors_avail;
1328 bytes_done += sinfo.bytes_avail;
1329
1330 }
1331 }
1332
1333 goto exit;
1334
1335 error_bat_restore:
1336 if (bat_update) {
1337 /* keep metadata in sync, and restore the bat entry state
1338 * if error. */
1339 sinfo.file_offset = bat_prior_offset;
1340 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1341 &bat_entry_offset, bat_state);
1342 }
1343 exit:
1344 qemu_vfree(iov1.iov_base);
1345 qemu_vfree(iov2.iov_base);
1346 qemu_co_mutex_unlock(&s->lock);
1347 qemu_iovec_destroy(&hd_qiov);
1348 return ret;
1349 }
1350
1351
1352
1353 /*
1354 * Create VHDX Headers
1355 *
1356 * There are 2 headers, and the highest sequence number will represent
1357 * the active header
1358 */
1359 static int vhdx_create_new_headers(BlockDriverState *bs, uint64_t image_size,
1360 uint32_t log_size)
1361 {
1362 int ret = 0;
1363 VHDXHeader *hdr = NULL;
1364
1365 hdr = g_malloc0(sizeof(VHDXHeader));
1366
1367 hdr->signature = VHDX_HEADER_SIGNATURE;
1368 hdr->sequence_number = g_random_int();
1369 hdr->log_version = 0;
1370 hdr->version = 1;
1371 hdr->log_length = log_size;
1372 hdr->log_offset = VHDX_HEADER_SECTION_END;
1373 vhdx_guid_generate(&hdr->file_write_guid);
1374 vhdx_guid_generate(&hdr->data_write_guid);
1375
1376 ret = vhdx_write_header(bs, hdr, VHDX_HEADER1_OFFSET, false);
1377 if (ret < 0) {
1378 goto exit;
1379 }
1380 hdr->sequence_number++;
1381 ret = vhdx_write_header(bs, hdr, VHDX_HEADER2_OFFSET, false);
1382 if (ret < 0) {
1383 goto exit;
1384 }
1385
1386 exit:
1387 g_free(hdr);
1388 return ret;
1389 }
1390
1391
1392 /*
1393 * Create the Metadata entries.
1394 *
1395 * For more details on the entries, see section 3.5 (pg 29) in the
1396 * VHDX 1.00 specification.
1397 *
1398 * We support 5 metadata entries (all required by spec):
1399 * File Parameters,
1400 * Virtual Disk Size,
1401 * Page 83 Data,
1402 * Logical Sector Size,
1403 * Physical Sector Size
1404 *
1405 * The first 64KB of the Metadata section is reserved for the metadata
1406 * header and entries; beyond that, the metadata items themselves reside.
1407 */
1408 static int vhdx_create_new_metadata(BlockDriverState *bs,
1409 uint64_t image_size,
1410 uint32_t block_size,
1411 uint32_t sector_size,
1412 uint64_t metadata_offset,
1413 VHDXImageType type)
1414 {
1415 int ret = 0;
1416 uint32_t offset = 0;
1417 void *buffer = NULL;
1418 void *entry_buffer;
1419 VHDXMetadataTableHeader *md_table;;
1420 VHDXMetadataTableEntry *md_table_entry;
1421
1422 /* Metadata entries */
1423 VHDXFileParameters *mt_file_params;
1424 VHDXVirtualDiskSize *mt_virtual_size;
1425 VHDXPage83Data *mt_page83;
1426 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size;
1427 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
1428
1429 entry_buffer = g_malloc0(sizeof(VHDXFileParameters) +
1430 sizeof(VHDXVirtualDiskSize) +
1431 sizeof(VHDXPage83Data) +
1432 sizeof(VHDXVirtualDiskLogicalSectorSize) +
1433 sizeof(VHDXVirtualDiskPhysicalSectorSize));
1434
1435 mt_file_params = entry_buffer;
1436 offset += sizeof(VHDXFileParameters);
1437 mt_virtual_size = entry_buffer + offset;
1438 offset += sizeof(VHDXVirtualDiskSize);
1439 mt_page83 = entry_buffer + offset;
1440 offset += sizeof(VHDXPage83Data);
1441 mt_log_sector_size = entry_buffer + offset;
1442 offset += sizeof(VHDXVirtualDiskLogicalSectorSize);
1443 mt_phys_sector_size = entry_buffer + offset;
1444
1445 mt_file_params->block_size = cpu_to_le32(block_size);
1446 if (type == VHDX_TYPE_FIXED) {
1447 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED;
1448 cpu_to_le32s(&mt_file_params->data_bits);
1449 }
1450
1451 vhdx_guid_generate(&mt_page83->page_83_data);
1452 cpu_to_leguids(&mt_page83->page_83_data);
1453 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size);
1454 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size);
1455 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size);
1456
1457 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1458 md_table = buffer;
1459
1460 md_table->signature = VHDX_METADATA_SIGNATURE;
1461 md_table->entry_count = 5;
1462 vhdx_metadata_header_le_export(md_table);
1463
1464
1465 /* This will reference beyond the reserved table portion */
1466 offset = 64 * KiB;
1467
1468 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader);
1469
1470 md_table_entry[0].item_id = file_param_guid;
1471 md_table_entry[0].offset = offset;
1472 md_table_entry[0].length = sizeof(VHDXFileParameters);
1473 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED;
1474 offset += md_table_entry[0].length;
1475 vhdx_metadata_entry_le_export(&md_table_entry[0]);
1476
1477 md_table_entry[1].item_id = virtual_size_guid;
1478 md_table_entry[1].offset = offset;
1479 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize);
1480 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1481 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1482 offset += md_table_entry[1].length;
1483 vhdx_metadata_entry_le_export(&md_table_entry[1]);
1484
1485 md_table_entry[2].item_id = page83_guid;
1486 md_table_entry[2].offset = offset;
1487 md_table_entry[2].length = sizeof(VHDXPage83Data);
1488 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1489 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1490 offset += md_table_entry[2].length;
1491 vhdx_metadata_entry_le_export(&md_table_entry[2]);
1492
1493 md_table_entry[3].item_id = logical_sector_guid;
1494 md_table_entry[3].offset = offset;
1495 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize);
1496 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1497 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1498 offset += md_table_entry[3].length;
1499 vhdx_metadata_entry_le_export(&md_table_entry[3]);
1500
1501 md_table_entry[4].item_id = phys_sector_guid;
1502 md_table_entry[4].offset = offset;
1503 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize);
1504 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1505 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1506 vhdx_metadata_entry_le_export(&md_table_entry[4]);
1507
1508 ret = bdrv_pwrite(bs, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE);
1509 if (ret < 0) {
1510 goto exit;
1511 }
1512
1513 ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer,
1514 VHDX_HEADER_BLOCK_SIZE);
1515 if (ret < 0) {
1516 goto exit;
1517 }
1518
1519
1520 exit:
1521 g_free(buffer);
1522 g_free(entry_buffer);
1523 return ret;
1524 }
1525
1526 /* This create the actual BAT itself. We currently only support
1527 * 'Dynamic' and 'Fixed' image types.
1528 *
1529 * Dynamic images: default state of the BAT is all zeroes.
1530 *
1531 * Fixed images: default state of the BAT is fully populated, with
1532 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT.
1533 */
1534 static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
1535 uint64_t image_size, VHDXImageType type,
1536 bool use_zero_blocks, VHDXRegionTableEntry *rt_bat)
1537 {
1538 int ret = 0;
1539 uint64_t data_file_offset;
1540 uint64_t total_sectors = 0;
1541 uint64_t sector_num = 0;
1542 uint64_t unused;
1543 int block_state;
1544 VHDXSectorInfo sinfo;
1545
1546 assert(s->bat == NULL);
1547
1548 /* this gives a data start after BAT/bitmap entries, and well
1549 * past any metadata entries (with a 4 MB buffer for future
1550 * expansion */
1551 data_file_offset = rt_bat->file_offset + rt_bat->length + 5 * MiB;
1552 total_sectors = image_size >> s->logical_sector_size_bits;
1553
1554 if (type == VHDX_TYPE_DYNAMIC) {
1555 /* All zeroes, so we can just extend the file - the end of the BAT
1556 * is the furthest thing we have written yet */
1557 ret = bdrv_truncate(bs, data_file_offset);
1558 if (ret < 0) {
1559 goto exit;
1560 }
1561 } else if (type == VHDX_TYPE_FIXED) {
1562 ret = bdrv_truncate(bs, data_file_offset + image_size);
1563 if (ret < 0) {
1564 goto exit;
1565 }
1566 } else {
1567 ret = -ENOTSUP;
1568 goto exit;
1569 }
1570
1571 if (type == VHDX_TYPE_FIXED ||
1572 use_zero_blocks ||
1573 bdrv_has_zero_init(bs) == 0) {
1574 /* for a fixed file, the default BAT entry is not zero */
1575 s->bat = g_malloc0(rt_bat->length);
1576 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
1577 PAYLOAD_BLOCK_NOT_PRESENT;
1578 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
1579 /* fill the BAT by emulating sector writes of sectors_per_block size */
1580 while (sector_num < total_sectors) {
1581 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo);
1582 sinfo.file_offset = data_file_offset +
1583 (sector_num << s->logical_sector_size_bits);
1584 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB);
1585 vhdx_update_bat_table_entry(bs, s, &sinfo, &unused, &unused,
1586 block_state);
1587 cpu_to_le64s(&s->bat[sinfo.bat_idx]);
1588 sector_num += s->sectors_per_block;
1589 }
1590 ret = bdrv_pwrite(bs, rt_bat->file_offset, s->bat, rt_bat->length);
1591 if (ret < 0) {
1592 goto exit;
1593 }
1594 }
1595
1596
1597
1598 exit:
1599 g_free(s->bat);
1600 return ret;
1601 }
1602
1603 /* Creates the region table header, and region table entries.
1604 * There are 2 supported region table entries: BAT, and Metadata/
1605 *
1606 * As the calculations for the BAT region table are also needed
1607 * to create the BAT itself, we will also cause the BAT to be
1608 * created.
1609 */
1610 static int vhdx_create_new_region_table(BlockDriverState *bs,
1611 uint64_t image_size,
1612 uint32_t block_size,
1613 uint32_t sector_size,
1614 uint32_t log_size,
1615 bool use_zero_blocks,
1616 VHDXImageType type,
1617 uint64_t *metadata_offset)
1618 {
1619 int ret = 0;
1620 uint32_t offset = 0;
1621 void *buffer = NULL;
1622 BDRVVHDXState *s = NULL;
1623 VHDXRegionTableHeader *region_table;
1624 VHDXRegionTableEntry *rt_bat;
1625 VHDXRegionTableEntry *rt_metadata;
1626
1627 assert(metadata_offset != NULL);
1628
1629 /* Populate enough of the BDRVVHDXState to be able to use the
1630 * pre-existing BAT calculation, translation, and update functions */
1631 s = g_malloc0(sizeof(BDRVVHDXState));
1632
1633 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
1634 (uint64_t) sector_size / (uint64_t) block_size;
1635
1636 s->sectors_per_block = block_size / sector_size;
1637 s->virtual_disk_size = image_size;
1638 s->block_size = block_size;
1639 s->logical_sector_size = sector_size;
1640
1641 vhdx_set_shift_bits(s);
1642
1643 vhdx_calc_bat_entries(s);
1644
1645 /* At this point the VHDX state is populated enough for creation */
1646
1647 /* a single buffer is used so we can calculate the checksum over the
1648 * entire 64KB block */
1649 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1650 region_table = buffer;
1651 offset += sizeof(VHDXRegionTableHeader);
1652 rt_bat = buffer + offset;
1653 offset += sizeof(VHDXRegionTableEntry);
1654 rt_metadata = buffer + offset;
1655
1656 region_table->signature = VHDX_REGION_SIGNATURE;
1657 region_table->entry_count = 2; /* BAT and Metadata */
1658
1659 rt_bat->guid = bat_guid;
1660 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB);
1661 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB);
1662 s->bat_offset = rt_bat->file_offset;
1663
1664 rt_metadata->guid = metadata_guid;
1665 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length,
1666 MiB);
1667 rt_metadata->length = 1 * MiB; /* min size, and more than enough */
1668 *metadata_offset = rt_metadata->file_offset;
1669
1670 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE,
1671 offsetof(VHDXRegionTableHeader, checksum));
1672
1673
1674 /* The region table gives us the data we need to create the BAT,
1675 * so do that now */
1676 ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, rt_bat);
1677
1678 /* Now write out the region headers to disk */
1679 vhdx_region_header_le_export(region_table);
1680 vhdx_region_entry_le_export(rt_bat);
1681 vhdx_region_entry_le_export(rt_metadata);
1682
1683 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer,
1684 VHDX_HEADER_BLOCK_SIZE);
1685 if (ret < 0) {
1686 goto exit;
1687 }
1688
1689 ret = bdrv_pwrite(bs, VHDX_REGION_TABLE2_OFFSET, buffer,
1690 VHDX_HEADER_BLOCK_SIZE);
1691 if (ret < 0) {
1692 goto exit;
1693 }
1694
1695
1696 exit:
1697 g_free(s);
1698 g_free(buffer);
1699 return ret;
1700 }
1701
1702 /* We need to create the following elements:
1703 *
1704 * .-----------------------------------------------------------------.
1705 * | (A) | (B) | (C) | (D) | (E) |
1706 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 |
1707 * | | | | | |
1708 * .-----------------------------------------------------------------.
1709 * 0 64KB 128KB 192KB 256KB 320KB
1710 *
1711 *
1712 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1713 * | (F) | (G) | (H) | |
1714 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... |
1715 * | | | | |
1716 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1717 * 1MB
1718 */
1719 static int vhdx_create(const char *filename, QEMUOptionParameter *options,
1720 Error **errp)
1721 {
1722 int ret = 0;
1723 uint64_t image_size = (uint64_t) 2 * GiB;
1724 uint32_t log_size = 1 * MiB;
1725 uint32_t block_size = 0;
1726 uint64_t signature;
1727 uint64_t metadata_offset;
1728 bool use_zero_blocks = false;
1729
1730 gunichar2 *creator = NULL;
1731 glong creator_items;
1732 BlockDriverState *bs;
1733 const char *type = NULL;
1734 VHDXImageType image_type;
1735 Error *local_err = NULL;
1736
1737 while (options && options->name) {
1738 if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
1739 image_size = options->value.n;
1740 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_LOG_SIZE)) {
1741 log_size = options->value.n;
1742 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_BLOCK_SIZE)) {
1743 block_size = options->value.n;
1744 } else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) {
1745 type = options->value.s;
1746 } else if (!strcmp(options->name, VHDX_BLOCK_OPT_ZERO)) {
1747 use_zero_blocks = options->value.n != 0;
1748 }
1749 options++;
1750 }
1751
1752 if (image_size > VHDX_MAX_IMAGE_SIZE) {
1753 error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB");
1754 ret = -EINVAL;
1755 goto exit;
1756 }
1757
1758 if (type == NULL) {
1759 type = "dynamic";
1760 }
1761
1762 if (!strcmp(type, "dynamic")) {
1763 image_type = VHDX_TYPE_DYNAMIC;
1764 } else if (!strcmp(type, "fixed")) {
1765 image_type = VHDX_TYPE_FIXED;
1766 } else if (!strcmp(type, "differencing")) {
1767 error_setg_errno(errp, ENOTSUP,
1768 "Differencing files not yet supported");
1769 ret = -ENOTSUP;
1770 goto exit;
1771 } else {
1772 ret = -EINVAL;
1773 goto exit;
1774 }
1775
1776 /* These are pretty arbitrary, and mainly designed to keep the BAT
1777 * size reasonable to load into RAM */
1778 if (block_size == 0) {
1779 if (image_size > 32 * TiB) {
1780 block_size = 64 * MiB;
1781 } else if (image_size > (uint64_t) 100 * GiB) {
1782 block_size = 32 * MiB;
1783 } else if (image_size > 1 * GiB) {
1784 block_size = 16 * MiB;
1785 } else {
1786 block_size = 8 * MiB;
1787 }
1788 }
1789
1790
1791 /* make the log size close to what was specified, but must be
1792 * min 1MB, and multiple of 1MB */
1793 log_size = ROUND_UP(log_size, MiB);
1794
1795 block_size = ROUND_UP(block_size, MiB);
1796 block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX :
1797 block_size;
1798
1799 ret = bdrv_create_file(filename, options, &local_err);
1800 if (ret < 0) {
1801 error_propagate(errp, local_err);
1802 goto exit;
1803 }
1804
1805 bs = NULL;
1806 ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL,
1807 NULL, &local_err);
1808 if (ret < 0) {
1809 error_propagate(errp, local_err);
1810 goto exit;
1811 }
1812
1813 /* Create (A) */
1814
1815 /* The creator field is optional, but may be useful for
1816 * debugging / diagnostics */
1817 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL,
1818 &creator_items, NULL);
1819 signature = cpu_to_le64(VHDX_FILE_SIGNATURE);
1820 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature));
1821 if (ret < 0) {
1822 goto delete_and_exit;
1823 }
1824 if (creator) {
1825 ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET + sizeof(signature),
1826 creator, creator_items * sizeof(gunichar2));
1827 if (ret < 0) {
1828 goto delete_and_exit;
1829 }
1830 }
1831
1832
1833 /* Creates (B),(C) */
1834 ret = vhdx_create_new_headers(bs, image_size, log_size);
1835 if (ret < 0) {
1836 goto delete_and_exit;
1837 }
1838
1839 /* Creates (D),(E),(G) explicitly. (F) created as by-product */
1840 ret = vhdx_create_new_region_table(bs, image_size, block_size, 512,
1841 log_size, use_zero_blocks, image_type,
1842 &metadata_offset);
1843 if (ret < 0) {
1844 goto delete_and_exit;
1845 }
1846
1847 /* Creates (H) */
1848 ret = vhdx_create_new_metadata(bs, image_size, block_size, 512,
1849 metadata_offset, image_type);
1850 if (ret < 0) {
1851 goto delete_and_exit;
1852 }
1853
1854
1855
1856 delete_and_exit:
1857 bdrv_unref(bs);
1858 exit:
1859 g_free(creator);
1860 return ret;
1861 }
1862
1863 /* If opened r/w, the VHDX driver will automatically replay the log,
1864 * if one is present, inside the vhdx_open() call.
1865 *
1866 * If qemu-img check -r all is called, the image is automatically opened
1867 * r/w and any log has already been replayed, so there is nothing (currently)
1868 * for us to do here
1869 */
1870 static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result,
1871 BdrvCheckMode fix)
1872 {
1873 BDRVVHDXState *s = bs->opaque;
1874
1875 if (s->log_replayed_on_open) {
1876 result->corruptions_fixed++;
1877 }
1878 return 0;
1879 }
1880
1881 static QEMUOptionParameter vhdx_create_options[] = {
1882 {
1883 .name = BLOCK_OPT_SIZE,
1884 .type = OPT_SIZE,
1885 .help = "Virtual disk size; max of 64TB."
1886 },
1887 {
1888 .name = VHDX_BLOCK_OPT_LOG_SIZE,
1889 .type = OPT_SIZE,
1890 .value.n = 1 * MiB,
1891 .help = "Log size; min 1MB."
1892 },
1893 {
1894 .name = VHDX_BLOCK_OPT_BLOCK_SIZE,
1895 .type = OPT_SIZE,
1896 .value.n = 0,
1897 .help = "Block Size; min 1MB, max 256MB. " \
1898 "0 means auto-calculate based on image size."
1899 },
1900 {
1901 .name = BLOCK_OPT_SUBFMT,
1902 .type = OPT_STRING,
1903 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\
1904 "Default is 'dynamic'."
1905 },
1906 {
1907 .name = VHDX_BLOCK_OPT_ZERO,
1908 .type = OPT_FLAG,
1909 .help = "Force use of payload blocks of type 'ZERO'. Non-standard."
1910 },
1911 { NULL }
1912 };
1913
1914 static BlockDriver bdrv_vhdx = {
1915 .format_name = "vhdx",
1916 .instance_size = sizeof(BDRVVHDXState),
1917 .bdrv_probe = vhdx_probe,
1918 .bdrv_open = vhdx_open,
1919 .bdrv_close = vhdx_close,
1920 .bdrv_reopen_prepare = vhdx_reopen_prepare,
1921 .bdrv_co_readv = vhdx_co_readv,
1922 .bdrv_co_writev = vhdx_co_writev,
1923 .bdrv_create = vhdx_create,
1924 .bdrv_get_info = vhdx_get_info,
1925 .bdrv_check = vhdx_check,
1926
1927 .create_options = vhdx_create_options,
1928 };
1929
1930 static void bdrv_vhdx_init(void)
1931 {
1932 bdrv_register(&bdrv_vhdx);
1933 }
1934
1935 block_init(bdrv_vhdx_init);