1 /*
2 * Block driver for Hyper-V VHDX Images
3 *
4 * Copyright (c) 2013 Red Hat, Inc.,
5 *
6 * Authors:
7 * Jeff Cody <jcody@redhat.com>
8 *
9 * This is based on the "VHDX Format Specification v1.00", published 8/25/2012
10 * by Microsoft:
11 * https://www.microsoft.com/en-us/download/details.aspx?id=34750
12 *
13 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
14 * See the COPYING.LIB file in the top-level directory.
15 *
16 */
17
18 #include "qemu/osdep.h"
19 #include "qapi/error.h"
20 #include "block/block_int.h"
21 #include "block/qdict.h"
22 #include "sysemu/block-backend.h"
23 #include "qemu/module.h"
24 #include "qemu/option.h"
25 #include "qemu/crc32c.h"
26 #include "qemu/bswap.h"
27 #include "vhdx.h"
28 #include "migration/blocker.h"
29 #include "qemu/uuid.h"
30 #include "qapi/qmp/qdict.h"
31 #include "qapi/qobject-input-visitor.h"
32 #include "qapi/qapi-visit-block-core.h"
33
34 /* Options for VHDX creation */
35
36 #define VHDX_BLOCK_OPT_LOG_SIZE "log_size"
37 #define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size"
38 #define VHDX_BLOCK_OPT_ZERO "block_state_zero"
39
40 typedef enum VHDXImageType {
41 VHDX_TYPE_DYNAMIC = 0,
42 VHDX_TYPE_FIXED,
43 VHDX_TYPE_DIFFERENCING, /* Currently unsupported */
44 } VHDXImageType;
45
46 static QemuOptsList vhdx_create_opts;
47
48 /* Several metadata and region table data entries are identified by
49 * guids in a MS-specific GUID format. */
50
51
52 /* ------- Known Region Table GUIDs ---------------------- */
53 static const MSGUID bat_guid = { .data1 = 0x2dc27766,
54 .data2 = 0xf623,
55 .data3 = 0x4200,
56 .data4 = { 0x9d, 0x64, 0x11, 0x5e,
57 0x9b, 0xfd, 0x4a, 0x08} };
58
59 static const MSGUID metadata_guid = { .data1 = 0x8b7ca206,
60 .data2 = 0x4790,
61 .data3 = 0x4b9a,
62 .data4 = { 0xb8, 0xfe, 0x57, 0x5f,
63 0x05, 0x0f, 0x88, 0x6e} };
64
65
66
67 /* ------- Known Metadata Entry GUIDs ---------------------- */
68 static const MSGUID file_param_guid = { .data1 = 0xcaa16737,
69 .data2 = 0xfa36,
70 .data3 = 0x4d43,
71 .data4 = { 0xb3, 0xb6, 0x33, 0xf0,
72 0xaa, 0x44, 0xe7, 0x6b} };
73
74 static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224,
75 .data2 = 0xcd1b,
76 .data3 = 0x4876,
77 .data4 = { 0xb2, 0x11, 0x5d, 0xbe,
78 0xd8, 0x3b, 0xf4, 0xb8} };
79
80 static const MSGUID page83_guid = { .data1 = 0xbeca12ab,
81 .data2 = 0xb2e6,
82 .data3 = 0x4523,
83 .data4 = { 0x93, 0xef, 0xc3, 0x09,
84 0xe0, 0x00, 0xc7, 0x46} };
85
86
87 static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7,
88 .data2 = 0x445d,
89 .data3 = 0x4471,
90 .data4 = { 0x9c, 0xc9, 0xe9, 0x88,
91 0x52, 0x51, 0xc5, 0x56} };
92
93 static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d,
94 .data2 = 0xb30b,
95 .data3 = 0x454d,
96 .data4 = { 0xab, 0xf7, 0xd3,
97 0xd8, 0x48, 0x34,
98 0xab, 0x0c} };
99
100 static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d,
101 .data2 = 0xa96f,
102 .data3 = 0x4709,
103 .data4 = { 0xba, 0x47, 0xf2,
104 0x33, 0xa8, 0xfa,
105 0xab, 0x5f} };
106
107 /* Each parent type must have a valid GUID; this is for parent images
108 * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would
109 * need to make up our own QCOW2 GUID type */
110 static const MSGUID parent_vhdx_guid __attribute__((unused))
111 = { .data1 = 0xb04aefb7,
112 .data2 = 0xd19e,
113 .data3 = 0x4a81,
114 .data4 = { 0xb7, 0x89, 0x25, 0xb8,
115 0xe9, 0x44, 0x59, 0x13} };
116
117
118 #define META_FILE_PARAMETER_PRESENT 0x01
119 #define META_VIRTUAL_DISK_SIZE_PRESENT 0x02
120 #define META_PAGE_83_PRESENT 0x04
121 #define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08
122 #define META_PHYS_SECTOR_SIZE_PRESENT 0x10
123 #define META_PARENT_LOCATOR_PRESENT 0x20
124
125 #define META_ALL_PRESENT \
126 (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \
127 META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \
128 META_PHYS_SECTOR_SIZE_PRESENT)
129
130
131 typedef struct VHDXSectorInfo {
132 uint32_t bat_idx; /* BAT entry index */
133 uint32_t sectors_avail; /* sectors available in payload block */
134 uint32_t bytes_left; /* bytes left in the block after data to r/w */
135 uint32_t bytes_avail; /* bytes available in payload block */
136 uint64_t file_offset; /* absolute offset in bytes, in file */
137 uint64_t block_offset; /* block offset, in bytes */
138 } VHDXSectorInfo;
139
140 /* Calculates new checksum.
141 *
142 * Zero is substituted during crc calculation for the original crc field
143 * crc_offset: byte offset in buf of the buffer crc
144 * buf: buffer pointer
145 * size: size of buffer (must be > crc_offset+4)
146 *
147 * Note: The buffer should have all multi-byte data in little-endian format,
148 * and the resulting checksum is in little endian format.
149 */
vhdx_update_checksum(uint8_t * buf,size_t size,int crc_offset)150 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset)
151 {
152 uint32_t crc;
153
154 assert(buf != NULL);
155 assert(size > (crc_offset + sizeof(crc)));
156
157 memset(buf + crc_offset, 0, sizeof(crc));
158 crc = crc32c(0xffffffff, buf, size);
159 cpu_to_le32s(&crc);
160 memcpy(buf + crc_offset, &crc, sizeof(crc));
161
162 return crc;
163 }
164
vhdx_checksum_calc(uint32_t crc,uint8_t * buf,size_t size,int crc_offset)165 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
166 int crc_offset)
167 {
168 uint32_t crc_new;
169 uint32_t crc_orig;
170 assert(buf != NULL);
171
172 if (crc_offset > 0) {
173 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
174 memset(buf + crc_offset, 0, sizeof(crc_orig));
175 }
176
177 crc_new = crc32c(crc, buf, size);
178 if (crc_offset > 0) {
179 memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig));
180 }
181
182 return crc_new;
183 }
184
185 /* Validates the checksum of the buffer, with an in-place CRC.
186 *
187 * Zero is substituted during crc calculation for the original crc field,
188 * and the crc field is restored afterwards. But the buffer will be modified
189 * during the calculation, so this may not be not suitable for multi-threaded
190 * use.
191 *
192 * crc_offset: byte offset in buf of the buffer crc
193 * buf: buffer pointer
194 * size: size of buffer (must be > crc_offset+4)
195 *
196 * returns true if checksum is valid, false otherwise
197 */
vhdx_checksum_is_valid(uint8_t * buf,size_t size,int crc_offset)198 bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset)
199 {
200 uint32_t crc_orig;
201 uint32_t crc;
202
203 assert(buf != NULL);
204 assert(size > (crc_offset + 4));
205
206 memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig));
207 crc_orig = le32_to_cpu(crc_orig);
208
209 crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset);
210
211 return crc == crc_orig;
212 }
213
214
215 /*
216 * This generates a UUID that is compliant with the MS GUIDs used
217 * in the VHDX spec (and elsewhere).
218 */
vhdx_guid_generate(MSGUID * guid)219 void vhdx_guid_generate(MSGUID *guid)
220 {
221 QemuUUID uuid;
222 assert(guid != NULL);
223
224 qemu_uuid_generate(&uuid);
225 memcpy(guid, &uuid, sizeof(MSGUID));
226 }
227
228 /* Check for region overlaps inside the VHDX image */
vhdx_region_check(BDRVVHDXState * s,uint64_t start,uint64_t length)229 static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length)
230 {
231 int ret = 0;
232 uint64_t end;
233 VHDXRegionEntry *r;
234
235 end = start + length;
236 QLIST_FOREACH(r, &s->regions, entries) {
237 if (!((start >= r->end) || (end <= r->start))) {
238 ret = -EINVAL;
239 goto exit;
240 }
241 }
242
243 exit:
244 return ret;
245 }
246
247 /* Register a region for future checks */
vhdx_region_register(BDRVVHDXState * s,uint64_t start,uint64_t length)248 static void vhdx_region_register(BDRVVHDXState *s,
249 uint64_t start, uint64_t length)
250 {
251 VHDXRegionEntry *r;
252
253 r = g_malloc0(sizeof(*r));
254
255 r->start = start;
256 r->end = start + length;
257
258 QLIST_INSERT_HEAD(&s->regions, r, entries);
259 }
260
261 /* Free all registered regions */
vhdx_region_unregister_all(BDRVVHDXState * s)262 static void vhdx_region_unregister_all(BDRVVHDXState *s)
263 {
264 VHDXRegionEntry *r, *r_next;
265
266 QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) {
267 QLIST_REMOVE(r, entries);
268 g_free(r);
269 }
270 }
271
vhdx_set_shift_bits(BDRVVHDXState * s)272 static void vhdx_set_shift_bits(BDRVVHDXState *s)
273 {
274 s->logical_sector_size_bits = ctz32(s->logical_sector_size);
275 s->sectors_per_block_bits = ctz32(s->sectors_per_block);
276 s->chunk_ratio_bits = ctz64(s->chunk_ratio);
277 s->block_size_bits = ctz32(s->block_size);
278 }
279
280 /*
281 * Per the MS VHDX Specification, for every VHDX file:
282 * - The header section is fixed size - 1 MB
283 * - The header section is always the first "object"
284 * - The first 64KB of the header is the File Identifier
285 * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile")
286 * - The following 512 bytes constitute a UTF-16 string identifiying the
287 * software that created the file, and is optional and diagnostic only.
288 *
289 * Therefore, we probe by looking for the vhdxfile signature "vhdxfile"
290 */
vhdx_probe(const uint8_t * buf,int buf_size,const char * filename)291 static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename)
292 {
293 if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) {
294 return 100;
295 }
296 return 0;
297 }
298
299 /*
300 * Writes the header to the specified offset.
301 *
302 * This will optionally read in buffer data from disk (otherwise zero-fill),
303 * and then update the header checksum. Header is converted to proper
304 * endianness before being written to the specified file offset
305 */
vhdx_write_header(BdrvChild * file,VHDXHeader * hdr,uint64_t offset,bool read)306 static int vhdx_write_header(BdrvChild *file, VHDXHeader *hdr,
307 uint64_t offset, bool read)
308 {
309 BlockDriverState *bs_file = file->bs;
310 uint8_t *buffer = NULL;
311 int ret;
312 VHDXHeader *header_le;
313
314 assert(bs_file != NULL);
315 assert(hdr != NULL);
316
317 /* the header checksum is not over just the packed size of VHDXHeader,
318 * but rather over the entire 'reserved' range for the header, which is
319 * 4KB (VHDX_HEADER_SIZE). */
320
321 buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE);
322 if (read) {
323 /* if true, we can't assume the extra reserved bytes are 0 */
324 ret = bdrv_pread(file, offset, buffer, VHDX_HEADER_SIZE);
325 if (ret < 0) {
326 goto exit;
327 }
328 } else {
329 memset(buffer, 0, VHDX_HEADER_SIZE);
330 }
331
332 /* overwrite the actual VHDXHeader portion */
333 header_le = (VHDXHeader *)buffer;
334 memcpy(header_le, hdr, sizeof(VHDXHeader));
335 vhdx_header_le_export(hdr, header_le);
336 vhdx_update_checksum(buffer, VHDX_HEADER_SIZE,
337 offsetof(VHDXHeader, checksum));
338 ret = bdrv_pwrite_sync(file, offset, header_le, sizeof(VHDXHeader));
339
340 exit:
341 qemu_vfree(buffer);
342 return ret;
343 }
344
345 /* Update the VHDX headers
346 *
347 * This follows the VHDX spec procedures for header updates.
348 *
349 * - non-current header is updated with largest sequence number
350 */
vhdx_update_header(BlockDriverState * bs,BDRVVHDXState * s,bool generate_data_write_guid,MSGUID * log_guid)351 static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s,
352 bool generate_data_write_guid, MSGUID *log_guid)
353 {
354 int ret = 0;
355 int hdr_idx = 0;
356 uint64_t header_offset = VHDX_HEADER1_OFFSET;
357
358 VHDXHeader *active_header;
359 VHDXHeader *inactive_header;
360
361 /* operate on the non-current header */
362 if (s->curr_header == 0) {
363 hdr_idx = 1;
364 header_offset = VHDX_HEADER2_OFFSET;
365 }
366
367 active_header = s->headers[s->curr_header];
368 inactive_header = s->headers[hdr_idx];
369
370 inactive_header->sequence_number = active_header->sequence_number + 1;
371
372 /* a new file guid must be generated before any file write, including
373 * headers */
374 inactive_header->file_write_guid = s->session_guid;
375
376 /* a new data guid only needs to be generated before any guest-visible
377 * writes (i.e. something observable via virtual disk read) */
378 if (generate_data_write_guid) {
379 vhdx_guid_generate(&inactive_header->data_write_guid);
380 }
381
382 /* update the log guid if present */
383 if (log_guid) {
384 inactive_header->log_guid = *log_guid;
385 }
386
387 ret = vhdx_write_header(bs->file, inactive_header, header_offset, true);
388 if (ret < 0) {
389 goto exit;
390 }
391 s->curr_header = hdr_idx;
392
393 exit:
394 return ret;
395 }
396
397 /*
398 * The VHDX spec calls for header updates to be performed twice, so that both
399 * the current and non-current header have valid info
400 */
vhdx_update_headers(BlockDriverState * bs,BDRVVHDXState * s,bool generate_data_write_guid,MSGUID * log_guid)401 int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s,
402 bool generate_data_write_guid, MSGUID *log_guid)
403 {
404 int ret;
405
406 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
407 if (ret < 0) {
408 return ret;
409 }
410 ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid);
411 return ret;
412 }
413
414 /* opens the specified header block from the VHDX file header section */
vhdx_parse_header(BlockDriverState * bs,BDRVVHDXState * s,Error ** errp)415 static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s,
416 Error **errp)
417 {
418 int ret;
419 VHDXHeader *header1;
420 VHDXHeader *header2;
421 bool h1_valid = false;
422 bool h2_valid = false;
423 uint64_t h1_seq = 0;
424 uint64_t h2_seq = 0;
425 uint8_t *buffer;
426
427 /* header1 & header2 are freed in vhdx_close() */
428 header1 = qemu_blockalign(bs, sizeof(VHDXHeader));
429 header2 = qemu_blockalign(bs, sizeof(VHDXHeader));
430
431 buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE);
432
433 s->headers[0] = header1;
434 s->headers[1] = header2;
435
436 /* We have to read the whole VHDX_HEADER_SIZE instead of
437 * sizeof(VHDXHeader), because the checksum is over the whole
438 * region */
439 ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer,
440 VHDX_HEADER_SIZE);
441 if (ret < 0) {
442 goto fail;
443 }
444 /* copy over just the relevant portion that we need */
445 memcpy(header1, buffer, sizeof(VHDXHeader));
446
447 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
448 vhdx_header_le_import(header1);
449 if (header1->signature == VHDX_HEADER_SIGNATURE &&
450 header1->version == 1) {
451 h1_seq = header1->sequence_number;
452 h1_valid = true;
453 }
454 }
455
456 ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer,
457 VHDX_HEADER_SIZE);
458 if (ret < 0) {
459 goto fail;
460 }
461 /* copy over just the relevant portion that we need */
462 memcpy(header2, buffer, sizeof(VHDXHeader));
463
464 if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) {
465 vhdx_header_le_import(header2);
466 if (header2->signature == VHDX_HEADER_SIGNATURE &&
467 header2->version == 1) {
468 h2_seq = header2->sequence_number;
469 h2_valid = true;
470 }
471 }
472
473 /* If there is only 1 valid header (or no valid headers), we
474 * don't care what the sequence numbers are */
475 if (h1_valid && !h2_valid) {
476 s->curr_header = 0;
477 } else if (!h1_valid && h2_valid) {
478 s->curr_header = 1;
479 } else if (!h1_valid && !h2_valid) {
480 goto fail;
481 } else {
482 /* If both headers are valid, then we choose the active one by the
483 * highest sequence number. If the sequence numbers are equal, that is
484 * invalid */
485 if (h1_seq > h2_seq) {
486 s->curr_header = 0;
487 } else if (h2_seq > h1_seq) {
488 s->curr_header = 1;
489 } else {
490 /* The Microsoft Disk2VHD tool will create 2 identical
491 * headers, with identical sequence numbers. If the headers are
492 * identical, don't consider the file corrupt */
493 if (!memcmp(header1, header2, sizeof(VHDXHeader))) {
494 s->curr_header = 0;
495 } else {
496 goto fail;
497 }
498 }
499 }
500
501 vhdx_region_register(s, s->headers[s->curr_header]->log_offset,
502 s->headers[s->curr_header]->log_length);
503 goto exit;
504
505 fail:
506 error_setg_errno(errp, -ret, "No valid VHDX header found");
507 qemu_vfree(header1);
508 qemu_vfree(header2);
509 s->headers[0] = NULL;
510 s->headers[1] = NULL;
511 exit:
512 qemu_vfree(buffer);
513 }
514
515
vhdx_open_region_tables(BlockDriverState * bs,BDRVVHDXState * s)516 static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s)
517 {
518 int ret = 0;
519 uint8_t *buffer;
520 int offset = 0;
521 VHDXRegionTableEntry rt_entry;
522 uint32_t i;
523 bool bat_rt_found = false;
524 bool metadata_rt_found = false;
525
526 /* We have to read the whole 64KB block, because the crc32 is over the
527 * whole block */
528 buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE);
529
530 ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer,
531 VHDX_HEADER_BLOCK_SIZE);
532 if (ret < 0) {
533 goto fail;
534 }
535 memcpy(&s->rt, buffer, sizeof(s->rt));
536 offset += sizeof(s->rt);
537
538 if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) {
539 ret = -EINVAL;
540 goto fail;
541 }
542
543 vhdx_region_header_le_import(&s->rt);
544
545 if (s->rt.signature != VHDX_REGION_SIGNATURE) {
546 ret = -EINVAL;
547 goto fail;
548 }
549
550
551 /* Per spec, maximum region table entry count is 2047 */
552 if (s->rt.entry_count > 2047) {
553 ret = -EINVAL;
554 goto fail;
555 }
556
557 for (i = 0; i < s->rt.entry_count; i++) {
558 memcpy(&rt_entry, buffer + offset, sizeof(rt_entry));
559 offset += sizeof(rt_entry);
560
561 vhdx_region_entry_le_import(&rt_entry);
562
563 /* check for region overlap between these entries, and any
564 * other memory regions in the file */
565 ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length);
566 if (ret < 0) {
567 goto fail;
568 }
569
570 vhdx_region_register(s, rt_entry.file_offset, rt_entry.length);
571
572 /* see if we recognize the entry */
573 if (guid_eq(rt_entry.guid, bat_guid)) {
574 /* must be unique; if we have already found it this is invalid */
575 if (bat_rt_found) {
576 ret = -EINVAL;
577 goto fail;
578 }
579 bat_rt_found = true;
580 s->bat_rt = rt_entry;
581 continue;
582 }
583
584 if (guid_eq(rt_entry.guid, metadata_guid)) {
585 /* must be unique; if we have already found it this is invalid */
586 if (metadata_rt_found) {
587 ret = -EINVAL;
588 goto fail;
589 }
590 metadata_rt_found = true;
591 s->metadata_rt = rt_entry;
592 continue;
593 }
594
595 if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) {
596 /* cannot read vhdx file - required region table entry that
597 * we do not understand. per spec, we must fail to open */
598 ret = -ENOTSUP;
599 goto fail;
600 }
601 }
602
603 if (!bat_rt_found || !metadata_rt_found) {
604 ret = -EINVAL;
605 goto fail;
606 }
607
608 ret = 0;
609
610 fail:
611 qemu_vfree(buffer);
612 return ret;
613 }
614
615
616
617 /* Metadata initial parser
618 *
619 * This loads all the metadata entry fields. This may cause additional
620 * fields to be processed (e.g. parent locator, etc..).
621 *
622 * There are 5 Metadata items that are always required:
623 * - File Parameters (block size, has a parent)
624 * - Virtual Disk Size (size, in bytes, of the virtual drive)
625 * - Page 83 Data (scsi page 83 guid)
626 * - Logical Sector Size (logical sector size in bytes, either 512 or
627 * 4096. We only support 512 currently)
628 * - Physical Sector Size (512 or 4096)
629 *
630 * Also, if the File Parameters indicate this is a differencing file,
631 * we must also look for the Parent Locator metadata item.
632 */
vhdx_parse_metadata(BlockDriverState * bs,BDRVVHDXState * s)633 static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s)
634 {
635 int ret = 0;
636 uint8_t *buffer;
637 int offset = 0;
638 uint32_t i = 0;
639 VHDXMetadataTableEntry md_entry;
640
641 buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE);
642
643 ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer,
644 VHDX_METADATA_TABLE_MAX_SIZE);
645 if (ret < 0) {
646 goto exit;
647 }
648 memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr));
649 offset += sizeof(s->metadata_hdr);
650
651 vhdx_metadata_header_le_import(&s->metadata_hdr);
652
653 if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) {
654 ret = -EINVAL;
655 goto exit;
656 }
657
658 s->metadata_entries.present = 0;
659
660 if ((s->metadata_hdr.entry_count * sizeof(md_entry)) >
661 (VHDX_METADATA_TABLE_MAX_SIZE - offset)) {
662 ret = -EINVAL;
663 goto exit;
664 }
665
666 for (i = 0; i < s->metadata_hdr.entry_count; i++) {
667 memcpy(&md_entry, buffer + offset, sizeof(md_entry));
668 offset += sizeof(md_entry);
669
670 vhdx_metadata_entry_le_import(&md_entry);
671
672 if (guid_eq(md_entry.item_id, file_param_guid)) {
673 if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) {
674 ret = -EINVAL;
675 goto exit;
676 }
677 s->metadata_entries.file_parameters_entry = md_entry;
678 s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT;
679 continue;
680 }
681
682 if (guid_eq(md_entry.item_id, virtual_size_guid)) {
683 if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) {
684 ret = -EINVAL;
685 goto exit;
686 }
687 s->metadata_entries.virtual_disk_size_entry = md_entry;
688 s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT;
689 continue;
690 }
691
692 if (guid_eq(md_entry.item_id, page83_guid)) {
693 if (s->metadata_entries.present & META_PAGE_83_PRESENT) {
694 ret = -EINVAL;
695 goto exit;
696 }
697 s->metadata_entries.page83_data_entry = md_entry;
698 s->metadata_entries.present |= META_PAGE_83_PRESENT;
699 continue;
700 }
701
702 if (guid_eq(md_entry.item_id, logical_sector_guid)) {
703 if (s->metadata_entries.present &
704 META_LOGICAL_SECTOR_SIZE_PRESENT) {
705 ret = -EINVAL;
706 goto exit;
707 }
708 s->metadata_entries.logical_sector_size_entry = md_entry;
709 s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT;
710 continue;
711 }
712
713 if (guid_eq(md_entry.item_id, phys_sector_guid)) {
714 if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) {
715 ret = -EINVAL;
716 goto exit;
717 }
718 s->metadata_entries.phys_sector_size_entry = md_entry;
719 s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT;
720 continue;
721 }
722
723 if (guid_eq(md_entry.item_id, parent_locator_guid)) {
724 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
725 ret = -EINVAL;
726 goto exit;
727 }
728 s->metadata_entries.parent_locator_entry = md_entry;
729 s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT;
730 continue;
731 }
732
733 if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) {
734 /* cannot read vhdx file - required region table entry that
735 * we do not understand. per spec, we must fail to open */
736 ret = -ENOTSUP;
737 goto exit;
738 }
739 }
740
741 if (s->metadata_entries.present != META_ALL_PRESENT) {
742 ret = -ENOTSUP;
743 goto exit;
744 }
745
746 ret = bdrv_pread(bs->file,
747 s->metadata_entries.file_parameters_entry.offset
748 + s->metadata_rt.file_offset,
749 &s->params,
750 sizeof(s->params));
751
752 if (ret < 0) {
753 goto exit;
754 }
755
756 le32_to_cpus(&s->params.block_size);
757 le32_to_cpus(&s->params.data_bits);
758
759
760 /* We now have the file parameters, so we can tell if this is a
761 * differencing file (i.e.. has_parent), is dynamic or fixed
762 * sized (leave_blocks_allocated), and the block size */
763
764 /* The parent locator required iff the file parameters has_parent set */
765 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
766 if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) {
767 /* TODO: parse parent locator fields */
768 ret = -ENOTSUP; /* temp, until differencing files are supported */
769 goto exit;
770 } else {
771 /* if has_parent is set, but there is not parent locator present,
772 * then that is an invalid combination */
773 ret = -EINVAL;
774 goto exit;
775 }
776 }
777
778 /* determine virtual disk size, logical sector size,
779 * and phys sector size */
780
781 ret = bdrv_pread(bs->file,
782 s->metadata_entries.virtual_disk_size_entry.offset
783 + s->metadata_rt.file_offset,
784 &s->virtual_disk_size,
785 sizeof(uint64_t));
786 if (ret < 0) {
787 goto exit;
788 }
789 ret = bdrv_pread(bs->file,
790 s->metadata_entries.logical_sector_size_entry.offset
791 + s->metadata_rt.file_offset,
792 &s->logical_sector_size,
793 sizeof(uint32_t));
794 if (ret < 0) {
795 goto exit;
796 }
797 ret = bdrv_pread(bs->file,
798 s->metadata_entries.phys_sector_size_entry.offset
799 + s->metadata_rt.file_offset,
800 &s->physical_sector_size,
801 sizeof(uint32_t));
802 if (ret < 0) {
803 goto exit;
804 }
805
806 le64_to_cpus(&s->virtual_disk_size);
807 le32_to_cpus(&s->logical_sector_size);
808 le32_to_cpus(&s->physical_sector_size);
809
810 if (s->params.block_size < VHDX_BLOCK_SIZE_MIN ||
811 s->params.block_size > VHDX_BLOCK_SIZE_MAX) {
812 ret = -EINVAL;
813 goto exit;
814 }
815
816 /* only 2 supported sector sizes */
817 if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) {
818 ret = -EINVAL;
819 goto exit;
820 }
821
822 /* Both block_size and sector_size are guaranteed powers of 2, below.
823 Due to range checks above, s->sectors_per_block can never be < 256 */
824 s->sectors_per_block = s->params.block_size / s->logical_sector_size;
825 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
826 (uint64_t)s->logical_sector_size /
827 (uint64_t)s->params.block_size;
828
829 /* These values are ones we will want to use for division / multiplication
830 * later on, and they are all guaranteed (per the spec) to be powers of 2,
831 * so we can take advantage of that for shift operations during
832 * reads/writes */
833 if (s->logical_sector_size & (s->logical_sector_size - 1)) {
834 ret = -EINVAL;
835 goto exit;
836 }
837 if (s->sectors_per_block & (s->sectors_per_block - 1)) {
838 ret = -EINVAL;
839 goto exit;
840 }
841 if (s->chunk_ratio & (s->chunk_ratio - 1)) {
842 ret = -EINVAL;
843 goto exit;
844 }
845 s->block_size = s->params.block_size;
846 if (s->block_size & (s->block_size - 1)) {
847 ret = -EINVAL;
848 goto exit;
849 }
850
851 vhdx_set_shift_bits(s);
852
853 ret = 0;
854
855 exit:
856 qemu_vfree(buffer);
857 return ret;
858 }
859
860 /*
861 * Calculate the number of BAT entries, including sector
862 * bitmap entries.
863 */
vhdx_calc_bat_entries(BDRVVHDXState * s)864 static void vhdx_calc_bat_entries(BDRVVHDXState *s)
865 {
866 uint32_t data_blocks_cnt, bitmap_blocks_cnt;
867
868 data_blocks_cnt = DIV_ROUND_UP(s->virtual_disk_size, s->block_size);
869 bitmap_blocks_cnt = DIV_ROUND_UP(data_blocks_cnt, s->chunk_ratio);
870
871 if (s->parent_entries) {
872 s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1);
873 } else {
874 s->bat_entries = data_blocks_cnt +
875 ((data_blocks_cnt - 1) >> s->chunk_ratio_bits);
876 }
877
878 }
879
vhdx_close(BlockDriverState * bs)880 static void vhdx_close(BlockDriverState *bs)
881 {
882 BDRVVHDXState *s = bs->opaque;
883 qemu_vfree(s->headers[0]);
884 s->headers[0] = NULL;
885 qemu_vfree(s->headers[1]);
886 s->headers[1] = NULL;
887 qemu_vfree(s->bat);
888 s->bat = NULL;
889 qemu_vfree(s->parent_entries);
890 s->parent_entries = NULL;
891 migrate_del_blocker(s->migration_blocker);
892 error_free(s->migration_blocker);
893 qemu_vfree(s->log.hdr);
894 s->log.hdr = NULL;
895 vhdx_region_unregister_all(s);
896 }
897
vhdx_open(BlockDriverState * bs,QDict * options,int flags,Error ** errp)898 static int vhdx_open(BlockDriverState *bs, QDict *options, int flags,
899 Error **errp)
900 {
901 BDRVVHDXState *s = bs->opaque;
902 int ret = 0;
903 uint32_t i;
904 uint64_t signature;
905 Error *local_err = NULL;
906
907 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
908 false, errp);
909 if (!bs->file) {
910 return -EINVAL;
911 }
912
913 s->bat = NULL;
914 s->first_visible_write = true;
915
916 qemu_co_mutex_init(&s->lock);
917 QLIST_INIT(&s->regions);
918
919 /* validate the file signature */
920 ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t));
921 if (ret < 0) {
922 goto fail;
923 }
924 if (memcmp(&signature, "vhdxfile", 8)) {
925 ret = -EINVAL;
926 goto fail;
927 }
928
929 /* This is used for any header updates, for the file_write_guid.
930 * The spec dictates that a new value should be used for the first
931 * header update */
932 vhdx_guid_generate(&s->session_guid);
933
934 vhdx_parse_header(bs, s, &local_err);
935 if (local_err != NULL) {
936 error_propagate(errp, local_err);
937 ret = -EINVAL;
938 goto fail;
939 }
940
941 ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp);
942 if (ret < 0) {
943 goto fail;
944 }
945
946 ret = vhdx_open_region_tables(bs, s);
947 if (ret < 0) {
948 goto fail;
949 }
950
951 ret = vhdx_parse_metadata(bs, s);
952 if (ret < 0) {
953 goto fail;
954 }
955
956 s->block_size = s->params.block_size;
957
958 /* the VHDX spec dictates that virtual_disk_size is always a multiple of
959 * logical_sector_size */
960 bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits;
961
962 vhdx_calc_bat_entries(s);
963
964 s->bat_offset = s->bat_rt.file_offset;
965
966 if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) {
967 /* BAT allocation is not large enough for all entries */
968 ret = -EINVAL;
969 goto fail;
970 }
971
972 /* s->bat is freed in vhdx_close() */
973 s->bat = qemu_try_blockalign(bs->file->bs, s->bat_rt.length);
974 if (s->bat == NULL) {
975 ret = -ENOMEM;
976 goto fail;
977 }
978
979 ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length);
980 if (ret < 0) {
981 goto fail;
982 }
983
984 uint64_t payblocks = s->chunk_ratio;
985 /* endian convert, and verify populated BAT field file offsets against
986 * region table and log entries */
987 for (i = 0; i < s->bat_entries; i++) {
988 le64_to_cpus(&s->bat[i]);
989 if (payblocks--) {
990 /* payload bat entries */
991 if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) ==
992 PAYLOAD_BLOCK_FULLY_PRESENT) {
993 ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK,
994 s->block_size);
995 if (ret < 0) {
996 goto fail;
997 }
998 }
999 } else {
1000 payblocks = s->chunk_ratio;
1001 /* Once differencing files are supported, verify sector bitmap
1002 * blocks here */
1003 }
1004 }
1005
1006 /* Disable migration when VHDX images are used */
1007 error_setg(&s->migration_blocker, "The vhdx format used by node '%s' "
1008 "does not support live migration",
1009 bdrv_get_device_or_node_name(bs));
1010 ret = migrate_add_blocker(s->migration_blocker, &local_err);
1011 if (local_err) {
1012 error_propagate(errp, local_err);
1013 error_free(s->migration_blocker);
1014 goto fail;
1015 }
1016
1017 /* TODO: differencing files */
1018
1019 return 0;
1020 fail:
1021 vhdx_close(bs);
1022 return ret;
1023 }
1024
vhdx_reopen_prepare(BDRVReopenState * state,BlockReopenQueue * queue,Error ** errp)1025 static int vhdx_reopen_prepare(BDRVReopenState *state,
1026 BlockReopenQueue *queue, Error **errp)
1027 {
1028 return 0;
1029 }
1030
1031
1032 /*
1033 * Perform sector to block offset translations, to get various
1034 * sector and file offsets into the image. See VHDXSectorInfo
1035 */
vhdx_block_translate(BDRVVHDXState * s,int64_t sector_num,int nb_sectors,VHDXSectorInfo * sinfo)1036 static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num,
1037 int nb_sectors, VHDXSectorInfo *sinfo)
1038 {
1039 uint32_t block_offset;
1040
1041 sinfo->bat_idx = sector_num >> s->sectors_per_block_bits;
1042 /* effectively a modulo - this gives us the offset into the block
1043 * (in sector sizes) for our sector number */
1044 block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits);
1045 /* the chunk ratio gives us the interleaving of the sector
1046 * bitmaps, so we need to advance our page block index by the
1047 * sector bitmaps entry number */
1048 sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits;
1049
1050 /* the number of sectors we can read/write in this cycle */
1051 sinfo->sectors_avail = s->sectors_per_block - block_offset;
1052
1053 sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits;
1054
1055 if (sinfo->sectors_avail > nb_sectors) {
1056 sinfo->sectors_avail = nb_sectors;
1057 }
1058
1059 sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits;
1060
1061 sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK;
1062
1063 sinfo->block_offset = block_offset << s->logical_sector_size_bits;
1064
1065 /* The file offset must be past the header section, so must be > 0 */
1066 if (sinfo->file_offset == 0) {
1067 return;
1068 }
1069
1070 /* block offset is the offset in vhdx logical sectors, in
1071 * the payload data block. Convert that to a byte offset
1072 * in the block, and add in the payload data block offset
1073 * in the file, in bytes, to get the final read address */
1074
1075 sinfo->file_offset += sinfo->block_offset;
1076 }
1077
1078
vhdx_get_info(BlockDriverState * bs,BlockDriverInfo * bdi)1079 static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1080 {
1081 BDRVVHDXState *s = bs->opaque;
1082
1083 bdi->cluster_size = s->block_size;
1084
1085 bdi->unallocated_blocks_are_zero =
1086 (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0;
1087
1088 return 0;
1089 }
1090
1091
vhdx_co_readv(BlockDriverState * bs,int64_t sector_num,int nb_sectors,QEMUIOVector * qiov)1092 static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num,
1093 int nb_sectors, QEMUIOVector *qiov)
1094 {
1095 BDRVVHDXState *s = bs->opaque;
1096 int ret = 0;
1097 VHDXSectorInfo sinfo;
1098 uint64_t bytes_done = 0;
1099 QEMUIOVector hd_qiov;
1100
1101 qemu_iovec_init(&hd_qiov, qiov->niov);
1102
1103 qemu_co_mutex_lock(&s->lock);
1104
1105 while (nb_sectors > 0) {
1106 /* We are a differencing file, so we need to inspect the sector bitmap
1107 * to see if we have the data or not */
1108 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1109 /* not supported yet */
1110 ret = -ENOTSUP;
1111 goto exit;
1112 } else {
1113 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1114
1115 qemu_iovec_reset(&hd_qiov);
1116 qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail);
1117
1118 /* check the payload block state */
1119 switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) {
1120 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1121 case PAYLOAD_BLOCK_UNDEFINED:
1122 case PAYLOAD_BLOCK_UNMAPPED:
1123 case PAYLOAD_BLOCK_UNMAPPED_v095:
1124 case PAYLOAD_BLOCK_ZERO:
1125 /* return zero */
1126 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail);
1127 break;
1128 case PAYLOAD_BLOCK_FULLY_PRESENT:
1129 qemu_co_mutex_unlock(&s->lock);
1130 ret = bdrv_co_preadv(bs->file, sinfo.file_offset,
1131 sinfo.sectors_avail * BDRV_SECTOR_SIZE,
1132 &hd_qiov, 0);
1133 qemu_co_mutex_lock(&s->lock);
1134 if (ret < 0) {
1135 goto exit;
1136 }
1137 break;
1138 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1139 /* we don't yet support difference files, fall through
1140 * to error */
1141 default:
1142 ret = -EIO;
1143 goto exit;
1144 break;
1145 }
1146 nb_sectors -= sinfo.sectors_avail;
1147 sector_num += sinfo.sectors_avail;
1148 bytes_done += sinfo.bytes_avail;
1149 }
1150 }
1151 ret = 0;
1152 exit:
1153 qemu_co_mutex_unlock(&s->lock);
1154 qemu_iovec_destroy(&hd_qiov);
1155 return ret;
1156 }
1157
1158 /*
1159 * Allocate a new payload block at the end of the file.
1160 *
1161 * Allocation will happen at 1MB alignment inside the file
1162 *
1163 * Returns the file offset start of the new payload block
1164 */
vhdx_allocate_block(BlockDriverState * bs,BDRVVHDXState * s,uint64_t * new_offset)1165 static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s,
1166 uint64_t *new_offset)
1167 {
1168 int64_t current_len;
1169
1170 current_len = bdrv_getlength(bs->file->bs);
1171 if (current_len < 0) {
1172 return current_len;
1173 }
1174
1175 *new_offset = current_len;
1176
1177 /* per the spec, the address for a block is in units of 1MB */
1178 *new_offset = ROUND_UP(*new_offset, 1024 * 1024);
1179 if (*new_offset > INT64_MAX) {
1180 return -EINVAL;
1181 }
1182
1183 return bdrv_truncate(bs->file, *new_offset + s->block_size,
1184 PREALLOC_MODE_OFF, NULL);
1185 }
1186
1187 /*
1188 * Update the BAT table entry with the new file offset, and the new entry
1189 * state */
vhdx_update_bat_table_entry(BlockDriverState * bs,BDRVVHDXState * s,VHDXSectorInfo * sinfo,uint64_t * bat_entry_le,uint64_t * bat_offset,int state)1190 static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s,
1191 VHDXSectorInfo *sinfo,
1192 uint64_t *bat_entry_le,
1193 uint64_t *bat_offset, int state)
1194 {
1195 /* The BAT entry is a uint64, with 44 bits for the file offset in units of
1196 * 1MB, and 3 bits for the block state. */
1197 if ((state == PAYLOAD_BLOCK_ZERO) ||
1198 (state == PAYLOAD_BLOCK_UNDEFINED) ||
1199 (state == PAYLOAD_BLOCK_NOT_PRESENT) ||
1200 (state == PAYLOAD_BLOCK_UNMAPPED)) {
1201 s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the
1202 FileOffsetMB field is denoted as
1203 'reserved' in the v1.0 spec. If it is
1204 non-zero, MS Hyper-V will fail to read
1205 the disk image */
1206 } else {
1207 s->bat[sinfo->bat_idx] = sinfo->file_offset;
1208 }
1209
1210 s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK;
1211
1212 *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]);
1213 *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry);
1214
1215 }
1216
1217 /* Per the spec, on the first write of guest-visible data to the file the
1218 * data write guid must be updated in the header */
vhdx_user_visible_write(BlockDriverState * bs,BDRVVHDXState * s)1219 int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s)
1220 {
1221 int ret = 0;
1222 if (s->first_visible_write) {
1223 s->first_visible_write = false;
1224 ret = vhdx_update_headers(bs, s, true, NULL);
1225 }
1226 return ret;
1227 }
1228
vhdx_co_writev(BlockDriverState * bs,int64_t sector_num,int nb_sectors,QEMUIOVector * qiov,int flags)1229 static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num,
1230 int nb_sectors, QEMUIOVector *qiov,
1231 int flags)
1232 {
1233 int ret = -ENOTSUP;
1234 BDRVVHDXState *s = bs->opaque;
1235 VHDXSectorInfo sinfo;
1236 uint64_t bytes_done = 0;
1237 uint64_t bat_entry = 0;
1238 uint64_t bat_entry_offset = 0;
1239 QEMUIOVector hd_qiov;
1240 struct iovec iov1 = { 0 };
1241 struct iovec iov2 = { 0 };
1242 int sectors_to_write;
1243 int bat_state;
1244 uint64_t bat_prior_offset = 0;
1245 bool bat_update = false;
1246
1247 assert(!flags);
1248 qemu_iovec_init(&hd_qiov, qiov->niov);
1249
1250 qemu_co_mutex_lock(&s->lock);
1251
1252 ret = vhdx_user_visible_write(bs, s);
1253 if (ret < 0) {
1254 goto exit;
1255 }
1256
1257 while (nb_sectors > 0) {
1258 bool use_zero_buffers = false;
1259 bat_update = false;
1260 if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) {
1261 /* not supported yet */
1262 ret = -ENOTSUP;
1263 goto exit;
1264 } else {
1265 vhdx_block_translate(s, sector_num, nb_sectors, &sinfo);
1266 sectors_to_write = sinfo.sectors_avail;
1267
1268 qemu_iovec_reset(&hd_qiov);
1269 /* check the payload block state */
1270 bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK;
1271 switch (bat_state) {
1272 case PAYLOAD_BLOCK_ZERO:
1273 /* in this case, we need to preserve zero writes for
1274 * data that is not part of this write, so we must pad
1275 * the rest of the buffer to zeroes */
1276
1277 /* if we are on a posix system with ftruncate() that extends
1278 * a file, then it is zero-filled for us. On Win32, the raw
1279 * layer uses SetFilePointer and SetFileEnd, which does not
1280 * zero fill AFAIK */
1281
1282 /* Queue another write of zero buffers if the underlying file
1283 * does not zero-fill on file extension */
1284
1285 if (bdrv_has_zero_init(bs->file->bs) == 0) {
1286 use_zero_buffers = true;
1287
1288 /* zero fill the front, if any */
1289 if (sinfo.block_offset) {
1290 iov1.iov_len = sinfo.block_offset;
1291 iov1.iov_base = qemu_blockalign(bs, iov1.iov_len);
1292 memset(iov1.iov_base, 0, iov1.iov_len);
1293 qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0,
1294 iov1.iov_len);
1295 sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS;
1296 }
1297
1298 /* our actual data */
1299 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1300 sinfo.bytes_avail);
1301
1302 /* zero fill the back, if any */
1303 if ((sinfo.bytes_avail - sinfo.block_offset) <
1304 s->block_size) {
1305 iov2.iov_len = s->block_size -
1306 (sinfo.bytes_avail + sinfo.block_offset);
1307 iov2.iov_base = qemu_blockalign(bs, iov2.iov_len);
1308 memset(iov2.iov_base, 0, iov2.iov_len);
1309 qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0,
1310 iov2.iov_len);
1311 sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS;
1312 }
1313 }
1314 /* fall through */
1315 case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
1316 case PAYLOAD_BLOCK_UNMAPPED:
1317 case PAYLOAD_BLOCK_UNMAPPED_v095:
1318 case PAYLOAD_BLOCK_UNDEFINED:
1319 bat_prior_offset = sinfo.file_offset;
1320 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset);
1321 if (ret < 0) {
1322 goto exit;
1323 }
1324 /* once we support differencing files, this may also be
1325 * partially present */
1326 /* update block state to the newly specified state */
1327 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1328 &bat_entry_offset,
1329 PAYLOAD_BLOCK_FULLY_PRESENT);
1330 bat_update = true;
1331 /* since we just allocated a block, file_offset is the
1332 * beginning of the payload block. It needs to be the
1333 * write address, which includes the offset into the block */
1334 if (!use_zero_buffers) {
1335 sinfo.file_offset += sinfo.block_offset;
1336 }
1337 /* fall through */
1338 case PAYLOAD_BLOCK_FULLY_PRESENT:
1339 /* if the file offset address is in the header zone,
1340 * there is a problem */
1341 if (sinfo.file_offset < (1024 * 1024)) {
1342 ret = -EFAULT;
1343 goto error_bat_restore;
1344 }
1345
1346 if (!use_zero_buffers) {
1347 qemu_iovec_concat(&hd_qiov, qiov, bytes_done,
1348 sinfo.bytes_avail);
1349 }
1350 /* block exists, so we can just overwrite it */
1351 qemu_co_mutex_unlock(&s->lock);
1352 ret = bdrv_co_pwritev(bs->file, sinfo.file_offset,
1353 sectors_to_write * BDRV_SECTOR_SIZE,
1354 &hd_qiov, 0);
1355 qemu_co_mutex_lock(&s->lock);
1356 if (ret < 0) {
1357 goto error_bat_restore;
1358 }
1359 break;
1360 case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
1361 /* we don't yet support difference files, fall through
1362 * to error */
1363 default:
1364 ret = -EIO;
1365 goto exit;
1366 break;
1367 }
1368
1369 if (bat_update) {
1370 /* this will update the BAT entry into the log journal, and
1371 * then flush the log journal out to disk */
1372 ret = vhdx_log_write_and_flush(bs, s, &bat_entry,
1373 sizeof(VHDXBatEntry),
1374 bat_entry_offset);
1375 if (ret < 0) {
1376 goto exit;
1377 }
1378 }
1379
1380 nb_sectors -= sinfo.sectors_avail;
1381 sector_num += sinfo.sectors_avail;
1382 bytes_done += sinfo.bytes_avail;
1383
1384 }
1385 }
1386
1387 goto exit;
1388
1389 error_bat_restore:
1390 if (bat_update) {
1391 /* keep metadata in sync, and restore the bat entry state
1392 * if error. */
1393 sinfo.file_offset = bat_prior_offset;
1394 vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry,
1395 &bat_entry_offset, bat_state);
1396 }
1397 exit:
1398 qemu_vfree(iov1.iov_base);
1399 qemu_vfree(iov2.iov_base);
1400 qemu_co_mutex_unlock(&s->lock);
1401 qemu_iovec_destroy(&hd_qiov);
1402 return ret;
1403 }
1404
1405
1406
1407 /*
1408 * Create VHDX Headers
1409 *
1410 * There are 2 headers, and the highest sequence number will represent
1411 * the active header
1412 */
vhdx_create_new_headers(BlockBackend * blk,uint64_t image_size,uint32_t log_size)1413 static int vhdx_create_new_headers(BlockBackend *blk, uint64_t image_size,
1414 uint32_t log_size)
1415 {
1416 BlockDriverState *bs = blk_bs(blk);
1417 BdrvChild *child;
1418 int ret = 0;
1419 VHDXHeader *hdr = NULL;
1420
1421 hdr = g_new0(VHDXHeader, 1);
1422
1423 hdr->signature = VHDX_HEADER_SIGNATURE;
1424 hdr->sequence_number = g_random_int();
1425 hdr->log_version = 0;
1426 hdr->version = 1;
1427 hdr->log_length = log_size;
1428 hdr->log_offset = VHDX_HEADER_SECTION_END;
1429 vhdx_guid_generate(&hdr->file_write_guid);
1430 vhdx_guid_generate(&hdr->data_write_guid);
1431
1432 /* XXX Ugly way to get blk->root, but that's a feature, not a bug. This
1433 * hack makes it obvious that vhdx_write_header() bypasses the BlockBackend
1434 * here, which it really shouldn't be doing. */
1435 child = QLIST_FIRST(&bs->parents);
1436 assert(!QLIST_NEXT(child, next_parent));
1437
1438 ret = vhdx_write_header(child, hdr, VHDX_HEADER1_OFFSET, false);
1439 if (ret < 0) {
1440 goto exit;
1441 }
1442 hdr->sequence_number++;
1443 ret = vhdx_write_header(child, hdr, VHDX_HEADER2_OFFSET, false);
1444 if (ret < 0) {
1445 goto exit;
1446 }
1447
1448 exit:
1449 g_free(hdr);
1450 return ret;
1451 }
1452
1453 #define VHDX_METADATA_ENTRY_BUFFER_SIZE \
1454 (sizeof(VHDXFileParameters) +\
1455 sizeof(VHDXVirtualDiskSize) +\
1456 sizeof(VHDXPage83Data) +\
1457 sizeof(VHDXVirtualDiskLogicalSectorSize) +\
1458 sizeof(VHDXVirtualDiskPhysicalSectorSize))
1459
1460 /*
1461 * Create the Metadata entries.
1462 *
1463 * For more details on the entries, see section 3.5 (pg 29) in the
1464 * VHDX 1.00 specification.
1465 *
1466 * We support 5 metadata entries (all required by spec):
1467 * File Parameters,
1468 * Virtual Disk Size,
1469 * Page 83 Data,
1470 * Logical Sector Size,
1471 * Physical Sector Size
1472 *
1473 * The first 64KB of the Metadata section is reserved for the metadata
1474 * header and entries; beyond that, the metadata items themselves reside.
1475 */
vhdx_create_new_metadata(BlockBackend * blk,uint64_t image_size,uint32_t block_size,uint32_t sector_size,uint64_t metadata_offset,VHDXImageType type)1476 static int vhdx_create_new_metadata(BlockBackend *blk,
1477 uint64_t image_size,
1478 uint32_t block_size,
1479 uint32_t sector_size,
1480 uint64_t metadata_offset,
1481 VHDXImageType type)
1482 {
1483 int ret = 0;
1484 uint32_t offset = 0;
1485 void *buffer = NULL;
1486 void *entry_buffer;
1487 VHDXMetadataTableHeader *md_table;
1488 VHDXMetadataTableEntry *md_table_entry;
1489
1490 /* Metadata entries */
1491 VHDXFileParameters *mt_file_params;
1492 VHDXVirtualDiskSize *mt_virtual_size;
1493 VHDXPage83Data *mt_page83;
1494 VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size;
1495 VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
1496
1497 entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE);
1498
1499 mt_file_params = entry_buffer;
1500 offset += sizeof(VHDXFileParameters);
1501 mt_virtual_size = entry_buffer + offset;
1502 offset += sizeof(VHDXVirtualDiskSize);
1503 mt_page83 = entry_buffer + offset;
1504 offset += sizeof(VHDXPage83Data);
1505 mt_log_sector_size = entry_buffer + offset;
1506 offset += sizeof(VHDXVirtualDiskLogicalSectorSize);
1507 mt_phys_sector_size = entry_buffer + offset;
1508
1509 mt_file_params->block_size = cpu_to_le32(block_size);
1510 if (type == VHDX_TYPE_FIXED) {
1511 mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED;
1512 cpu_to_le32s(&mt_file_params->data_bits);
1513 }
1514
1515 vhdx_guid_generate(&mt_page83->page_83_data);
1516 cpu_to_leguids(&mt_page83->page_83_data);
1517 mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size);
1518 mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size);
1519 mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size);
1520
1521 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1522 md_table = buffer;
1523
1524 md_table->signature = VHDX_METADATA_SIGNATURE;
1525 md_table->entry_count = 5;
1526 vhdx_metadata_header_le_export(md_table);
1527
1528
1529 /* This will reference beyond the reserved table portion */
1530 offset = 64 * KiB;
1531
1532 md_table_entry = buffer + sizeof(VHDXMetadataTableHeader);
1533
1534 md_table_entry[0].item_id = file_param_guid;
1535 md_table_entry[0].offset = offset;
1536 md_table_entry[0].length = sizeof(VHDXFileParameters);
1537 md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED;
1538 offset += md_table_entry[0].length;
1539 vhdx_metadata_entry_le_export(&md_table_entry[0]);
1540
1541 md_table_entry[1].item_id = virtual_size_guid;
1542 md_table_entry[1].offset = offset;
1543 md_table_entry[1].length = sizeof(VHDXVirtualDiskSize);
1544 md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1545 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1546 offset += md_table_entry[1].length;
1547 vhdx_metadata_entry_le_export(&md_table_entry[1]);
1548
1549 md_table_entry[2].item_id = page83_guid;
1550 md_table_entry[2].offset = offset;
1551 md_table_entry[2].length = sizeof(VHDXPage83Data);
1552 md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1553 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1554 offset += md_table_entry[2].length;
1555 vhdx_metadata_entry_le_export(&md_table_entry[2]);
1556
1557 md_table_entry[3].item_id = logical_sector_guid;
1558 md_table_entry[3].offset = offset;
1559 md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize);
1560 md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1561 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1562 offset += md_table_entry[3].length;
1563 vhdx_metadata_entry_le_export(&md_table_entry[3]);
1564
1565 md_table_entry[4].item_id = phys_sector_guid;
1566 md_table_entry[4].offset = offset;
1567 md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize);
1568 md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
1569 VHDX_META_FLAGS_IS_VIRTUAL_DISK;
1570 vhdx_metadata_entry_le_export(&md_table_entry[4]);
1571
1572 ret = blk_pwrite(blk, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE, 0);
1573 if (ret < 0) {
1574 goto exit;
1575 }
1576
1577 ret = blk_pwrite(blk, metadata_offset + (64 * KiB), entry_buffer,
1578 VHDX_METADATA_ENTRY_BUFFER_SIZE, 0);
1579 if (ret < 0) {
1580 goto exit;
1581 }
1582
1583
1584 exit:
1585 g_free(buffer);
1586 g_free(entry_buffer);
1587 return ret;
1588 }
1589
1590 /* This create the actual BAT itself. We currently only support
1591 * 'Dynamic' and 'Fixed' image types.
1592 *
1593 * Dynamic images: default state of the BAT is all zeroes.
1594 *
1595 * Fixed images: default state of the BAT is fully populated, with
1596 * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT.
1597 */
vhdx_create_bat(BlockBackend * blk,BDRVVHDXState * s,uint64_t image_size,VHDXImageType type,bool use_zero_blocks,uint64_t file_offset,uint32_t length,Error ** errp)1598 static int vhdx_create_bat(BlockBackend *blk, BDRVVHDXState *s,
1599 uint64_t image_size, VHDXImageType type,
1600 bool use_zero_blocks, uint64_t file_offset,
1601 uint32_t length, Error **errp)
1602 {
1603 int ret = 0;
1604 uint64_t data_file_offset;
1605 uint64_t total_sectors = 0;
1606 uint64_t sector_num = 0;
1607 uint64_t unused;
1608 int block_state;
1609 VHDXSectorInfo sinfo;
1610
1611 assert(s->bat == NULL);
1612
1613 /* this gives a data start after BAT/bitmap entries, and well
1614 * past any metadata entries (with a 4 MB buffer for future
1615 * expansion */
1616 data_file_offset = file_offset + length + 5 * MiB;
1617 total_sectors = image_size >> s->logical_sector_size_bits;
1618
1619 if (type == VHDX_TYPE_DYNAMIC) {
1620 /* All zeroes, so we can just extend the file - the end of the BAT
1621 * is the furthest thing we have written yet */
1622 ret = blk_truncate(blk, data_file_offset, PREALLOC_MODE_OFF, errp);
1623 if (ret < 0) {
1624 goto exit;
1625 }
1626 } else if (type == VHDX_TYPE_FIXED) {
1627 ret = blk_truncate(blk, data_file_offset + image_size,
1628 PREALLOC_MODE_OFF, errp);
1629 if (ret < 0) {
1630 goto exit;
1631 }
1632 } else {
1633 error_setg(errp, "Unsupported image type");
1634 ret = -ENOTSUP;
1635 goto exit;
1636 }
1637
1638 if (type == VHDX_TYPE_FIXED ||
1639 use_zero_blocks ||
1640 bdrv_has_zero_init(blk_bs(blk)) == 0) {
1641 /* for a fixed file, the default BAT entry is not zero */
1642 s->bat = g_try_malloc0(length);
1643 if (length && s->bat == NULL) {
1644 error_setg(errp, "Failed to allocate memory for the BAT");
1645 ret = -ENOMEM;
1646 goto exit;
1647 }
1648 block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
1649 PAYLOAD_BLOCK_NOT_PRESENT;
1650 block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
1651 /* fill the BAT by emulating sector writes of sectors_per_block size */
1652 while (sector_num < total_sectors) {
1653 vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo);
1654 sinfo.file_offset = data_file_offset +
1655 (sector_num << s->logical_sector_size_bits);
1656 sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB);
1657 vhdx_update_bat_table_entry(blk_bs(blk), s, &sinfo, &unused, &unused,
1658 block_state);
1659 cpu_to_le64s(&s->bat[sinfo.bat_idx]);
1660 sector_num += s->sectors_per_block;
1661 }
1662 ret = blk_pwrite(blk, file_offset, s->bat, length, 0);
1663 if (ret < 0) {
1664 error_setg_errno(errp, -ret, "Failed to write the BAT");
1665 goto exit;
1666 }
1667 }
1668
1669
1670
1671 exit:
1672 g_free(s->bat);
1673 return ret;
1674 }
1675
1676 /* Creates the region table header, and region table entries.
1677 * There are 2 supported region table entries: BAT, and Metadata/
1678 *
1679 * As the calculations for the BAT region table are also needed
1680 * to create the BAT itself, we will also cause the BAT to be
1681 * created.
1682 */
vhdx_create_new_region_table(BlockBackend * blk,uint64_t image_size,uint32_t block_size,uint32_t sector_size,uint32_t log_size,bool use_zero_blocks,VHDXImageType type,uint64_t * metadata_offset,Error ** errp)1683 static int vhdx_create_new_region_table(BlockBackend *blk,
1684 uint64_t image_size,
1685 uint32_t block_size,
1686 uint32_t sector_size,
1687 uint32_t log_size,
1688 bool use_zero_blocks,
1689 VHDXImageType type,
1690 uint64_t *metadata_offset,
1691 Error **errp)
1692 {
1693 int ret = 0;
1694 uint32_t offset = 0;
1695 void *buffer = NULL;
1696 uint64_t bat_file_offset;
1697 uint32_t bat_length;
1698 BDRVVHDXState *s = NULL;
1699 VHDXRegionTableHeader *region_table;
1700 VHDXRegionTableEntry *rt_bat;
1701 VHDXRegionTableEntry *rt_metadata;
1702
1703 assert(metadata_offset != NULL);
1704
1705 /* Populate enough of the BDRVVHDXState to be able to use the
1706 * pre-existing BAT calculation, translation, and update functions */
1707 s = g_new0(BDRVVHDXState, 1);
1708
1709 s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
1710 (uint64_t) sector_size / (uint64_t) block_size;
1711
1712 s->sectors_per_block = block_size / sector_size;
1713 s->virtual_disk_size = image_size;
1714 s->block_size = block_size;
1715 s->logical_sector_size = sector_size;
1716
1717 vhdx_set_shift_bits(s);
1718
1719 vhdx_calc_bat_entries(s);
1720
1721 /* At this point the VHDX state is populated enough for creation */
1722
1723 /* a single buffer is used so we can calculate the checksum over the
1724 * entire 64KB block */
1725 buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
1726 region_table = buffer;
1727 offset += sizeof(VHDXRegionTableHeader);
1728 rt_bat = buffer + offset;
1729 offset += sizeof(VHDXRegionTableEntry);
1730 rt_metadata = buffer + offset;
1731
1732 region_table->signature = VHDX_REGION_SIGNATURE;
1733 region_table->entry_count = 2; /* BAT and Metadata */
1734
1735 rt_bat->guid = bat_guid;
1736 rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB);
1737 rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB);
1738 s->bat_offset = rt_bat->file_offset;
1739
1740 rt_metadata->guid = metadata_guid;
1741 rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length,
1742 MiB);
1743 rt_metadata->length = 1 * MiB; /* min size, and more than enough */
1744 *metadata_offset = rt_metadata->file_offset;
1745
1746 bat_file_offset = rt_bat->file_offset;
1747 bat_length = rt_bat->length;
1748
1749 vhdx_region_header_le_export(region_table);
1750 vhdx_region_entry_le_export(rt_bat);
1751 vhdx_region_entry_le_export(rt_metadata);
1752
1753 vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE,
1754 offsetof(VHDXRegionTableHeader, checksum));
1755
1756
1757 /* The region table gives us the data we need to create the BAT,
1758 * so do that now */
1759 ret = vhdx_create_bat(blk, s, image_size, type, use_zero_blocks,
1760 bat_file_offset, bat_length, errp);
1761 if (ret < 0) {
1762 goto exit;
1763 }
1764
1765 /* Now write out the region headers to disk */
1766 ret = blk_pwrite(blk, VHDX_REGION_TABLE_OFFSET, buffer,
1767 VHDX_HEADER_BLOCK_SIZE, 0);
1768 if (ret < 0) {
1769 error_setg_errno(errp, -ret, "Failed to write first region table");
1770 goto exit;
1771 }
1772
1773 ret = blk_pwrite(blk, VHDX_REGION_TABLE2_OFFSET, buffer,
1774 VHDX_HEADER_BLOCK_SIZE, 0);
1775 if (ret < 0) {
1776 error_setg_errno(errp, -ret, "Failed to write second region table");
1777 goto exit;
1778 }
1779
1780 exit:
1781 g_free(s);
1782 g_free(buffer);
1783 return ret;
1784 }
1785
1786 /* We need to create the following elements:
1787 *
1788 * .-----------------------------------------------------------------.
1789 * | (A) | (B) | (C) | (D) | (E) |
1790 * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 |
1791 * | | | | | |
1792 * .-----------------------------------------------------------------.
1793 * 0 64KB 128KB 192KB 256KB 320KB
1794 *
1795 *
1796 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1797 * | (F) | (G) | (H) | |
1798 * | Journal Log | BAT / Bitmap | Metadata | .... data ...... |
1799 * | | | | |
1800 * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
1801 * 1MB
1802 */
vhdx_co_create(BlockdevCreateOptions * opts,Error ** errp)1803 static int coroutine_fn vhdx_co_create(BlockdevCreateOptions *opts,
1804 Error **errp)
1805 {
1806 BlockdevCreateOptionsVhdx *vhdx_opts;
1807 BlockBackend *blk = NULL;
1808 BlockDriverState *bs = NULL;
1809
1810 int ret = 0;
1811 uint64_t image_size;
1812 uint32_t log_size;
1813 uint32_t block_size;
1814 uint64_t signature;
1815 uint64_t metadata_offset;
1816 bool use_zero_blocks = false;
1817
1818 gunichar2 *creator = NULL;
1819 glong creator_items;
1820 VHDXImageType image_type;
1821
1822 assert(opts->driver == BLOCKDEV_DRIVER_VHDX);
1823 vhdx_opts = &opts->u.vhdx;
1824
1825 /* Validate options and set default values */
1826 image_size = vhdx_opts->size;
1827 if (image_size > VHDX_MAX_IMAGE_SIZE) {
1828 error_setg(errp, "Image size too large; max of 64TB");
1829 return -EINVAL;
1830 }
1831
1832 if (!vhdx_opts->has_log_size) {
1833 log_size = DEFAULT_LOG_SIZE;
1834 } else {
1835 if (vhdx_opts->log_size > UINT32_MAX) {
1836 error_setg(errp, "Log size must be smaller than 4 GB");
1837 return -EINVAL;
1838 }
1839 log_size = vhdx_opts->log_size;
1840 }
1841 if (log_size < MiB || (log_size % MiB) != 0) {
1842 error_setg(errp, "Log size must be a multiple of 1 MB");
1843 return -EINVAL;
1844 }
1845
1846 if (!vhdx_opts->has_block_state_zero) {
1847 use_zero_blocks = true;
1848 } else {
1849 use_zero_blocks = vhdx_opts->block_state_zero;
1850 }
1851
1852 if (!vhdx_opts->has_subformat) {
1853 vhdx_opts->subformat = BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC;
1854 }
1855
1856 switch (vhdx_opts->subformat) {
1857 case BLOCKDEV_VHDX_SUBFORMAT_DYNAMIC:
1858 image_type = VHDX_TYPE_DYNAMIC;
1859 break;
1860 case BLOCKDEV_VHDX_SUBFORMAT_FIXED:
1861 image_type = VHDX_TYPE_FIXED;
1862 break;
1863 default:
1864 g_assert_not_reached();
1865 }
1866
1867 /* These are pretty arbitrary, and mainly designed to keep the BAT
1868 * size reasonable to load into RAM */
1869 if (vhdx_opts->has_block_size) {
1870 block_size = vhdx_opts->block_size;
1871 } else {
1872 if (image_size > 32 * TiB) {
1873 block_size = 64 * MiB;
1874 } else if (image_size > (uint64_t) 100 * GiB) {
1875 block_size = 32 * MiB;
1876 } else if (image_size > 1 * GiB) {
1877 block_size = 16 * MiB;
1878 } else {
1879 block_size = 8 * MiB;
1880 }
1881 }
1882
1883 if (block_size < MiB || (block_size % MiB) != 0) {
1884 error_setg(errp, "Block size must be a multiple of 1 MB");
1885 return -EINVAL;
1886 }
1887 if (!is_power_of_2(block_size)) {
1888 error_setg(errp, "Block size must be a power of two");
1889 return -EINVAL;
1890 }
1891 if (block_size > VHDX_BLOCK_SIZE_MAX) {
1892 error_setg(errp, "Block size must not exceed %d", VHDX_BLOCK_SIZE_MAX);
1893 return -EINVAL;
1894 }
1895
1896 /* Create BlockBackend to write to the image */
1897 bs = bdrv_open_blockdev_ref(vhdx_opts->file, errp);
1898 if (bs == NULL) {
1899 return -EIO;
1900 }
1901
1902 blk = blk_new(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
1903 ret = blk_insert_bs(blk, bs, errp);
1904 if (ret < 0) {
1905 goto delete_and_exit;
1906 }
1907 blk_set_allow_write_beyond_eof(blk, true);
1908
1909 /* Create (A) */
1910
1911 /* The creator field is optional, but may be useful for
1912 * debugging / diagnostics */
1913 creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL,
1914 &creator_items, NULL);
1915 signature = cpu_to_le64(VHDX_FILE_SIGNATURE);
1916 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature),
1917 0);
1918 if (ret < 0) {
1919 error_setg_errno(errp, -ret, "Failed to write file signature");
1920 goto delete_and_exit;
1921 }
1922 if (creator) {
1923 ret = blk_pwrite(blk, VHDX_FILE_ID_OFFSET + sizeof(signature),
1924 creator, creator_items * sizeof(gunichar2), 0);
1925 if (ret < 0) {
1926 error_setg_errno(errp, -ret, "Failed to write creator field");
1927 goto delete_and_exit;
1928 }
1929 }
1930
1931
1932 /* Creates (B),(C) */
1933 ret = vhdx_create_new_headers(blk, image_size, log_size);
1934 if (ret < 0) {
1935 error_setg_errno(errp, -ret, "Failed to write image headers");
1936 goto delete_and_exit;
1937 }
1938
1939 /* Creates (D),(E),(G) explicitly. (F) created as by-product */
1940 ret = vhdx_create_new_region_table(blk, image_size, block_size, 512,
1941 log_size, use_zero_blocks, image_type,
1942 &metadata_offset, errp);
1943 if (ret < 0) {
1944 goto delete_and_exit;
1945 }
1946
1947 /* Creates (H) */
1948 ret = vhdx_create_new_metadata(blk, image_size, block_size, 512,
1949 metadata_offset, image_type);
1950 if (ret < 0) {
1951 error_setg_errno(errp, -ret, "Failed to initialize metadata");
1952 goto delete_and_exit;
1953 }
1954
1955 ret = 0;
1956 delete_and_exit:
1957 blk_unref(blk);
1958 bdrv_unref(bs);
1959 g_free(creator);
1960 return ret;
1961 }
1962
vhdx_co_create_opts(const char * filename,QemuOpts * opts,Error ** errp)1963 static int coroutine_fn vhdx_co_create_opts(const char *filename,
1964 QemuOpts *opts,
1965 Error **errp)
1966 {
1967 BlockdevCreateOptions *create_options = NULL;
1968 QDict *qdict;
1969 Visitor *v;
1970 BlockDriverState *bs = NULL;
1971 Error *local_err = NULL;
1972 int ret;
1973
1974 static const QDictRenames opt_renames[] = {
1975 { VHDX_BLOCK_OPT_LOG_SIZE, "log-size" },
1976 { VHDX_BLOCK_OPT_BLOCK_SIZE, "block-size" },
1977 { VHDX_BLOCK_OPT_ZERO, "block-state-zero" },
1978 { NULL, NULL },
1979 };
1980
1981 /* Parse options and convert legacy syntax */
1982 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vhdx_create_opts, true);
1983
1984 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
1985 ret = -EINVAL;
1986 goto fail;
1987 }
1988
1989 /* Create and open the file (protocol layer) */
1990 ret = bdrv_create_file(filename, opts, &local_err);
1991 if (ret < 0) {
1992 error_propagate(errp, local_err);
1993 goto fail;
1994 }
1995
1996 bs = bdrv_open(filename, NULL, NULL,
1997 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
1998 if (bs == NULL) {
1999 ret = -EIO;
2000 goto fail;
2001 }
2002
2003 /* Now get the QAPI type BlockdevCreateOptions */
2004 qdict_put_str(qdict, "driver", "vhdx");
2005 qdict_put_str(qdict, "file", bs->node_name);
2006
2007 v = qobject_input_visitor_new_flat_confused(qdict, errp);
2008 if (!v) {
2009 ret = -EINVAL;
2010 goto fail;
2011 }
2012
2013 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
2014 visit_free(v);
2015
2016 if (local_err) {
2017 error_propagate(errp, local_err);
2018 ret = -EINVAL;
2019 goto fail;
2020 }
2021
2022 /* Silently round up sizes:
2023 * The image size is rounded to 512 bytes. Make the block and log size
2024 * close to what was specified, but must be at least 1MB, and a multiple of
2025 * 1 MB. Also respect VHDX_BLOCK_SIZE_MAX for block sizes. block_size = 0
2026 * means auto, which is represented by a missing key in QAPI. */
2027 assert(create_options->driver == BLOCKDEV_DRIVER_VHDX);
2028 create_options->u.vhdx.size =
2029 ROUND_UP(create_options->u.vhdx.size, BDRV_SECTOR_SIZE);
2030
2031 if (create_options->u.vhdx.has_log_size) {
2032 create_options->u.vhdx.log_size =
2033 ROUND_UP(create_options->u.vhdx.log_size, MiB);
2034 }
2035 if (create_options->u.vhdx.has_block_size) {
2036 create_options->u.vhdx.block_size =
2037 ROUND_UP(create_options->u.vhdx.block_size, MiB);
2038
2039 if (create_options->u.vhdx.block_size == 0) {
2040 create_options->u.vhdx.has_block_size = false;
2041 }
2042 if (create_options->u.vhdx.block_size > VHDX_BLOCK_SIZE_MAX) {
2043 create_options->u.vhdx.block_size = VHDX_BLOCK_SIZE_MAX;
2044 }
2045 }
2046
2047 /* Create the vhdx image (format layer) */
2048 ret = vhdx_co_create(create_options, errp);
2049
2050 fail:
2051 qobject_unref(qdict);
2052 bdrv_unref(bs);
2053 qapi_free_BlockdevCreateOptions(create_options);
2054 return ret;
2055 }
2056
2057 /* If opened r/w, the VHDX driver will automatically replay the log,
2058 * if one is present, inside the vhdx_open() call.
2059 *
2060 * If qemu-img check -r all is called, the image is automatically opened
2061 * r/w and any log has already been replayed, so there is nothing (currently)
2062 * for us to do here
2063 */
vhdx_co_check(BlockDriverState * bs,BdrvCheckResult * result,BdrvCheckMode fix)2064 static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
2065 BdrvCheckResult *result,
2066 BdrvCheckMode fix)
2067 {
2068 BDRVVHDXState *s = bs->opaque;
2069
2070 if (s->log_replayed_on_open) {
2071 result->corruptions_fixed++;
2072 }
2073 return 0;
2074 }
2075
2076 static QemuOptsList vhdx_create_opts = {
2077 .name = "vhdx-create-opts",
2078 .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head),
2079 .desc = {
2080 {
2081 .name = BLOCK_OPT_SIZE,
2082 .type = QEMU_OPT_SIZE,
2083 .help = "Virtual disk size; max of 64TB."
2084 },
2085 {
2086 .name = VHDX_BLOCK_OPT_LOG_SIZE,
2087 .type = QEMU_OPT_SIZE,
2088 .def_value_str = stringify(DEFAULT_LOG_SIZE),
2089 .help = "Log size; min 1MB."
2090 },
2091 {
2092 .name = VHDX_BLOCK_OPT_BLOCK_SIZE,
2093 .type = QEMU_OPT_SIZE,
2094 .def_value_str = stringify(0),
2095 .help = "Block Size; min 1MB, max 256MB. " \
2096 "0 means auto-calculate based on image size."
2097 },
2098 {
2099 .name = BLOCK_OPT_SUBFMT,
2100 .type = QEMU_OPT_STRING,
2101 .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\
2102 "Default is 'dynamic'."
2103 },
2104 {
2105 .name = VHDX_BLOCK_OPT_ZERO,
2106 .type = QEMU_OPT_BOOL,
2107 .help = "Force use of payload blocks of type 'ZERO'. "\
2108 "Non-standard, but default. Do not set to 'off' when "\
2109 "using 'qemu-img convert' with subformat=dynamic."
2110 },
2111 { NULL }
2112 }
2113 };
2114
2115 static BlockDriver bdrv_vhdx = {
2116 .format_name = "vhdx",
2117 .instance_size = sizeof(BDRVVHDXState),
2118 .bdrv_probe = vhdx_probe,
2119 .bdrv_open = vhdx_open,
2120 .bdrv_close = vhdx_close,
2121 .bdrv_reopen_prepare = vhdx_reopen_prepare,
2122 .bdrv_child_perm = bdrv_format_default_perms,
2123 .bdrv_co_readv = vhdx_co_readv,
2124 .bdrv_co_writev = vhdx_co_writev,
2125 .bdrv_co_create = vhdx_co_create,
2126 .bdrv_co_create_opts = vhdx_co_create_opts,
2127 .bdrv_get_info = vhdx_get_info,
2128 .bdrv_co_check = vhdx_co_check,
2129 .bdrv_has_zero_init = bdrv_has_zero_init_1,
2130
2131 .create_opts = &vhdx_create_opts,
2132 };
2133
bdrv_vhdx_init(void)2134 static void bdrv_vhdx_init(void)
2135 {
2136 bdrv_register(&bdrv_vhdx);
2137 }
2138
2139 block_init(bdrv_vhdx_init);
2140