forked from xemu-project/xemu
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathvpc.c
1256 lines (1051 loc) · 37 KB
/
vpc.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Block driver for Connectix / Microsoft Virtual PC images
*
* Copyright (c) 2005 Alex Beregszaszi
* Copyright (c) 2009 Kevin Wolf <[email protected]>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "block/block_int.h"
#include "block/qdict.h"
#include "sysemu/block-backend.h"
#include "qemu/module.h"
#include "qemu/option.h"
#include "migration/blocker.h"
#include "qemu/bswap.h"
#include "qemu/uuid.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qobject-input-visitor.h"
#include "qapi/qapi-visit-block-core.h"
/**************************************************************/
#define HEADER_SIZE 512
//#define CACHE
enum vhd_type {
VHD_FIXED = 2,
VHD_DYNAMIC = 3,
VHD_DIFFERENCING = 4,
};
/* Seconds since Jan 1, 2000 0:00:00 (UTC) */
#define VHD_TIMESTAMP_BASE 946684800
#define VHD_CHS_MAX_C 65535LL
#define VHD_CHS_MAX_H 16
#define VHD_CHS_MAX_S 255
#define VHD_MAX_SECTORS 0xff000000 /* 2040 GiB max image size */
#define VHD_MAX_GEOMETRY (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S)
#define VPC_OPT_FORCE_SIZE "force_size"
/* always big-endian */
typedef struct vhd_footer {
char creator[8]; /* "conectix" */
uint32_t features;
uint32_t version;
/* Offset of next header structure, 0xFFFFFFFF if none */
uint64_t data_offset;
/* Seconds since Jan 1, 2000 0:00:00 (UTC) */
uint32_t timestamp;
char creator_app[4]; /* e.g., "vpc " */
uint16_t major;
uint16_t minor;
char creator_os[4]; /* "Wi2k" */
uint64_t orig_size;
uint64_t current_size;
uint16_t cyls;
uint8_t heads;
uint8_t secs_per_cyl;
uint32_t type;
/* Checksum of the Hard Disk Footer ("one's complement of the sum of all
the bytes in the footer without the checksum field") */
uint32_t checksum;
/* UUID used to identify a parent hard disk (backing file) */
QemuUUID uuid;
uint8_t in_saved_state;
} QEMU_PACKED VHDFooter;
typedef struct vhd_dyndisk_header {
char magic[8]; /* "cxsparse" */
/* Offset of next header structure, 0xFFFFFFFF if none */
uint64_t data_offset;
/* Offset of the Block Allocation Table (BAT) */
uint64_t table_offset;
uint32_t version;
uint32_t max_table_entries; /* 32bit/entry */
/* 2 MB by default, must be a power of two */
uint32_t block_size;
uint32_t checksum;
uint8_t parent_uuid[16];
uint32_t parent_timestamp;
uint32_t reserved;
/* Backing file name (in UTF-16) */
uint8_t parent_name[512];
struct {
uint32_t platform;
uint32_t data_space;
uint32_t data_length;
uint32_t reserved;
uint64_t data_offset;
} parent_locator[8];
} QEMU_PACKED VHDDynDiskHeader;
typedef struct BDRVVPCState {
CoMutex lock;
uint8_t footer_buf[HEADER_SIZE];
uint64_t free_data_block_offset;
int max_table_entries;
uint32_t *pagetable;
uint64_t bat_offset;
uint64_t last_bitmap_offset;
uint32_t block_size;
uint32_t bitmap_size;
bool force_use_chs;
bool force_use_sz;
#ifdef CACHE
uint8_t *pageentry_u8;
uint32_t *pageentry_u32;
uint16_t *pageentry_u16;
uint64_t last_bitmap;
#endif
Error *migration_blocker;
} BDRVVPCState;
#define VPC_OPT_SIZE_CALC "force_size_calc"
static QemuOptsList vpc_runtime_opts = {
.name = "vpc-runtime-opts",
.head = QTAILQ_HEAD_INITIALIZER(vpc_runtime_opts.head),
.desc = {
{
.name = VPC_OPT_SIZE_CALC,
.type = QEMU_OPT_STRING,
.help = "Force disk size calculation to use either CHS geometry, "
"or use the disk current_size specified in the VHD footer. "
"{chs, current_size}"
},
{ /* end of list */ }
}
};
static QemuOptsList vpc_create_opts;
static uint32_t vpc_checksum(uint8_t* buf, size_t size)
{
uint32_t res = 0;
int i;
for (i = 0; i < size; i++)
res += buf[i];
return ~res;
}
static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
{
if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8))
return 100;
return 0;
}
static void vpc_parse_options(BlockDriverState *bs, QemuOpts *opts,
Error **errp)
{
BDRVVPCState *s = bs->opaque;
const char *size_calc;
size_calc = qemu_opt_get(opts, VPC_OPT_SIZE_CALC);
if (!size_calc) {
/* no override, use autodetect only */
} else if (!strcmp(size_calc, "current_size")) {
s->force_use_sz = true;
} else if (!strcmp(size_calc, "chs")) {
s->force_use_chs = true;
} else {
error_setg(errp, "Invalid size calculation mode: '%s'", size_calc);
}
}
static int vpc_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
BDRVVPCState *s = bs->opaque;
int i;
VHDFooter *footer;
VHDDynDiskHeader *dyndisk_header;
QemuOpts *opts = NULL;
Error *local_err = NULL;
bool use_chs;
uint8_t buf[HEADER_SIZE];
uint32_t checksum;
uint64_t computed_size;
uint64_t pagetable_size;
int disk_type = VHD_DYNAMIC;
int ret;
int64_t bs_size;
bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
BDRV_CHILD_IMAGE, false, errp);
if (!bs->file) {
return -EINVAL;
}
opts = qemu_opts_create(&vpc_runtime_opts, NULL, 0, &error_abort);
if (!qemu_opts_absorb_qdict(opts, options, errp)) {
ret = -EINVAL;
goto fail;
}
vpc_parse_options(bs, opts, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE);
if (ret < 0) {
error_setg(errp, "Unable to read VHD header");
goto fail;
}
footer = (VHDFooter *) s->footer_buf;
if (strncmp(footer->creator, "conectix", 8)) {
int64_t offset = bdrv_getlength(bs->file->bs);
if (offset < 0) {
ret = offset;
error_setg(errp, "Invalid file size");
goto fail;
} else if (offset < HEADER_SIZE) {
ret = -EINVAL;
error_setg(errp, "File too small for a VHD header");
goto fail;
}
/* If a fixed disk, the footer is found only at the end of the file */
ret = bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf,
HEADER_SIZE);
if (ret < 0) {
goto fail;
}
if (strncmp(footer->creator, "conectix", 8)) {
error_setg(errp, "invalid VPC image");
ret = -EINVAL;
goto fail;
}
disk_type = VHD_FIXED;
}
checksum = be32_to_cpu(footer->checksum);
footer->checksum = 0;
if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum) {
error_setg(errp, "Incorrect header checksum");
ret = -EINVAL;
goto fail;
}
/* Write 'checksum' back to footer, or else will leave it with zero. */
footer->checksum = cpu_to_be32(checksum);
/* The visible size of a image in Virtual PC depends on the geometry
rather than on the size stored in the footer (the size in the footer
is too large usually) */
bs->total_sectors = (int64_t)
be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl;
/* Microsoft Virtual PC and Microsoft Hyper-V produce and read
* VHD image sizes differently. VPC will rely on CHS geometry,
* while Hyper-V and disk2vhd use the size specified in the footer.
*
* We use a couple of approaches to try and determine the correct method:
* look at the Creator App field, and look for images that have CHS
* geometry that is the maximum value.
*
* If the CHS geometry is the maximum CHS geometry, then we assume that
* the size is the footer->current_size to avoid truncation. Otherwise,
* we follow the table based on footer->creator_app:
*
* Known creator apps:
* 'vpc ' : CHS Virtual PC (uses disk geometry)
* 'qemu' : CHS QEMU (uses disk geometry)
* 'qem2' : current_size QEMU (uses current_size)
* 'win ' : current_size Hyper-V
* 'd2v ' : current_size Disk2vhd
* 'tap\0' : current_size XenServer
* 'CTXS' : current_size XenConverter
*
* The user can override the table values via drive options, however
* even with an override we will still use current_size for images
* that have CHS geometry of the maximum size.
*/
use_chs = (!!strncmp(footer->creator_app, "win ", 4) &&
!!strncmp(footer->creator_app, "qem2", 4) &&
!!strncmp(footer->creator_app, "d2v ", 4) &&
!!strncmp(footer->creator_app, "CTXS", 4) &&
!!memcmp(footer->creator_app, "tap", 4)) || s->force_use_chs;
if (!use_chs || bs->total_sectors == VHD_MAX_GEOMETRY || s->force_use_sz) {
bs->total_sectors = be64_to_cpu(footer->current_size) /
BDRV_SECTOR_SIZE;
}
/* Allow a maximum disk size of 2040 GiB */
if (bs->total_sectors > VHD_MAX_SECTORS) {
ret = -EFBIG;
goto fail;
}
if (disk_type == VHD_DYNAMIC) {
ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf,
HEADER_SIZE);
if (ret < 0) {
error_setg(errp, "Error reading dynamic VHD header");
goto fail;
}
dyndisk_header = (VHDDynDiskHeader *) buf;
if (strncmp(dyndisk_header->magic, "cxsparse", 8)) {
error_setg(errp, "Invalid header magic");
ret = -EINVAL;
goto fail;
}
s->block_size = be32_to_cpu(dyndisk_header->block_size);
if (!is_power_of_2(s->block_size) || s->block_size < BDRV_SECTOR_SIZE) {
error_setg(errp, "Invalid block size %" PRIu32, s->block_size);
ret = -EINVAL;
goto fail;
}
s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511;
s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries);
if ((bs->total_sectors * 512) / s->block_size > 0xffffffffU) {
error_setg(errp, "Too many blocks");
ret = -EINVAL;
goto fail;
}
computed_size = (uint64_t) s->max_table_entries * s->block_size;
if (computed_size < bs->total_sectors * 512) {
error_setg(errp, "Page table too small");
ret = -EINVAL;
goto fail;
}
if (s->max_table_entries > SIZE_MAX / 4 ||
s->max_table_entries > (int) INT_MAX / 4) {
error_setg(errp, "Max Table Entries too large (%" PRId32 ")",
s->max_table_entries);
ret = -EINVAL;
goto fail;
}
pagetable_size = (uint64_t) s->max_table_entries * 4;
s->pagetable = qemu_try_blockalign(bs->file->bs, pagetable_size);
if (s->pagetable == NULL) {
error_setg(errp, "Unable to allocate memory for page table");
ret = -ENOMEM;
goto fail;
}
s->bat_offset = be64_to_cpu(dyndisk_header->table_offset);
ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable,
pagetable_size);
if (ret < 0) {
error_setg(errp, "Error reading pagetable");
goto fail;
}
s->free_data_block_offset =
ROUND_UP(s->bat_offset + pagetable_size, 512);
for (i = 0; i < s->max_table_entries; i++) {
be32_to_cpus(&s->pagetable[i]);
if (s->pagetable[i] != 0xFFFFFFFF) {
int64_t next = (512 * (int64_t) s->pagetable[i]) +
s->bitmap_size + s->block_size;
if (next > s->free_data_block_offset) {
s->free_data_block_offset = next;
}
}
}
bs_size = bdrv_getlength(bs->file->bs);
if (bs_size < 0) {
error_setg_errno(errp, -bs_size, "Unable to learn image size");
ret = bs_size;
goto fail;
}
if (s->free_data_block_offset > bs_size) {
error_setg(errp, "block-vpc: free_data_block_offset points after "
"the end of file. The image has been truncated.");
ret = -EINVAL;
goto fail;
}
s->last_bitmap_offset = (int64_t) -1;
#ifdef CACHE
s->pageentry_u8 = g_malloc(512);
s->pageentry_u32 = s->pageentry_u8;
s->pageentry_u16 = s->pageentry_u8;
s->last_pagetable = -1;
#endif
}
/* Disable migration when VHD images are used */
error_setg(&s->migration_blocker, "The vpc format used by node '%s' "
"does not support live migration",
bdrv_get_device_or_node_name(bs));
ret = migrate_add_blocker(s->migration_blocker, errp);
if (ret < 0) {
error_free(s->migration_blocker);
goto fail;
}
qemu_co_mutex_init(&s->lock);
qemu_opts_del(opts);
return 0;
fail:
qemu_opts_del(opts);
qemu_vfree(s->pagetable);
#ifdef CACHE
g_free(s->pageentry_u8);
#endif
return ret;
}
static int vpc_reopen_prepare(BDRVReopenState *state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
/*
* Returns the absolute byte offset of the given sector in the image file.
* If the sector is not allocated, -1 is returned instead.
* If an error occurred trying to write an updated block bitmap back to
* the file, -2 is returned, and the error value is written to *err.
* This can only happen for a write operation.
*
* The parameter write must be 1 if the offset will be used for a write
* operation (the block bitmaps is updated then), 0 otherwise.
* If write is true then err must not be NULL.
*/
static inline int64_t get_image_offset(BlockDriverState *bs, uint64_t offset,
bool write, int *err)
{
BDRVVPCState *s = bs->opaque;
uint64_t bitmap_offset, block_offset;
uint32_t pagetable_index, offset_in_block;
assert(!(write && err == NULL));
pagetable_index = offset / s->block_size;
offset_in_block = offset % s->block_size;
if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff)
return -1; /* not allocated */
bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index];
block_offset = bitmap_offset + s->bitmap_size + offset_in_block;
/* We must ensure that we don't write to any sectors which are marked as
unused in the bitmap. We get away with setting all bits in the block
bitmap each time we write to a new block. This might cause Virtual PC to
miss sparse read optimization, but it's not a problem in terms of
correctness. */
if (write && (s->last_bitmap_offset != bitmap_offset)) {
uint8_t bitmap[s->bitmap_size];
int r;
s->last_bitmap_offset = bitmap_offset;
memset(bitmap, 0xff, s->bitmap_size);
r = bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size);
if (r < 0) {
*err = r;
return -2;
}
}
return block_offset;
}
/*
* Writes the footer to the end of the image file. This is needed when the
* file grows as it overwrites the old footer
*
* Returns 0 on success and < 0 on error
*/
static int rewrite_footer(BlockDriverState* bs)
{
int ret;
BDRVVPCState *s = bs->opaque;
int64_t offset = s->free_data_block_offset;
ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, HEADER_SIZE);
if (ret < 0)
return ret;
return 0;
}
/*
* Allocates a new block. This involves writing a new footer and updating
* the Block Allocation Table to use the space at the old end of the image
* file (overwriting the old footer)
*
* Returns the sectors' offset in the image file on success and < 0 on error
*/
static int64_t alloc_block(BlockDriverState* bs, int64_t offset)
{
BDRVVPCState *s = bs->opaque;
int64_t bat_offset;
uint32_t index, bat_value;
int ret;
uint8_t bitmap[s->bitmap_size];
/* Check if sector_num is valid */
if ((offset < 0) || (offset > bs->total_sectors * BDRV_SECTOR_SIZE)) {
return -EINVAL;
}
/* Write entry into in-memory BAT */
index = offset / s->block_size;
assert(s->pagetable[index] == 0xFFFFFFFF);
s->pagetable[index] = s->free_data_block_offset / 512;
/* Initialize the block's bitmap */
memset(bitmap, 0xff, s->bitmap_size);
ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap,
s->bitmap_size);
if (ret < 0) {
return ret;
}
/* Write new footer (the old one will be overwritten) */
s->free_data_block_offset += s->block_size + s->bitmap_size;
ret = rewrite_footer(bs);
if (ret < 0)
goto fail;
/* Write BAT entry to disk */
bat_offset = s->bat_offset + (4 * index);
bat_value = cpu_to_be32(s->pagetable[index]);
ret = bdrv_pwrite_sync(bs->file, bat_offset, &bat_value, 4);
if (ret < 0)
goto fail;
return get_image_offset(bs, offset, false, NULL);
fail:
s->free_data_block_offset -= (s->block_size + s->bitmap_size);
return ret;
}
static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
{
BDRVVPCState *s = (BDRVVPCState *)bs->opaque;
VHDFooter *footer = (VHDFooter *) s->footer_buf;
if (be32_to_cpu(footer->type) != VHD_FIXED) {
bdi->cluster_size = s->block_size;
}
return 0;
}
static int coroutine_fn
vpc_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
BDRVVPCState *s = bs->opaque;
int ret;
int64_t image_offset;
int64_t n_bytes;
int64_t bytes_done = 0;
VHDFooter *footer = (VHDFooter *) s->footer_buf;
QEMUIOVector local_qiov;
if (be32_to_cpu(footer->type) == VHD_FIXED) {
return bdrv_co_preadv(bs->file, offset, bytes, qiov, 0);
}
qemu_co_mutex_lock(&s->lock);
qemu_iovec_init(&local_qiov, qiov->niov);
while (bytes > 0) {
image_offset = get_image_offset(bs, offset, false, NULL);
n_bytes = MIN(bytes, s->block_size - (offset % s->block_size));
if (image_offset == -1) {
qemu_iovec_memset(qiov, bytes_done, 0, n_bytes);
} else {
qemu_iovec_reset(&local_qiov);
qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
qemu_co_mutex_unlock(&s->lock);
ret = bdrv_co_preadv(bs->file, image_offset, n_bytes,
&local_qiov, 0);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
}
bytes -= n_bytes;
offset += n_bytes;
bytes_done += n_bytes;
}
ret = 0;
fail:
qemu_iovec_destroy(&local_qiov);
qemu_co_mutex_unlock(&s->lock);
return ret;
}
static int coroutine_fn
vpc_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
BDRVVPCState *s = bs->opaque;
int64_t image_offset;
int64_t n_bytes;
int64_t bytes_done = 0;
int ret = 0;
VHDFooter *footer = (VHDFooter *) s->footer_buf;
QEMUIOVector local_qiov;
if (be32_to_cpu(footer->type) == VHD_FIXED) {
return bdrv_co_pwritev(bs->file, offset, bytes, qiov, 0);
}
qemu_co_mutex_lock(&s->lock);
qemu_iovec_init(&local_qiov, qiov->niov);
while (bytes > 0) {
image_offset = get_image_offset(bs, offset, true, &ret);
if (image_offset == -2) {
/* Failed to write block bitmap: can't proceed with write */
goto fail;
}
n_bytes = MIN(bytes, s->block_size - (offset % s->block_size));
if (image_offset == -1) {
image_offset = alloc_block(bs, offset);
if (image_offset < 0) {
ret = image_offset;
goto fail;
}
}
qemu_iovec_reset(&local_qiov);
qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes);
qemu_co_mutex_unlock(&s->lock);
ret = bdrv_co_pwritev(bs->file, image_offset, n_bytes,
&local_qiov, 0);
qemu_co_mutex_lock(&s->lock);
if (ret < 0) {
goto fail;
}
bytes -= n_bytes;
offset += n_bytes;
bytes_done += n_bytes;
}
ret = 0;
fail:
qemu_iovec_destroy(&local_qiov);
qemu_co_mutex_unlock(&s->lock);
return ret;
}
static int coroutine_fn vpc_co_block_status(BlockDriverState *bs,
bool want_zero,
int64_t offset, int64_t bytes,
int64_t *pnum, int64_t *map,
BlockDriverState **file)
{
BDRVVPCState *s = bs->opaque;
VHDFooter *footer = (VHDFooter*) s->footer_buf;
int64_t image_offset;
bool allocated;
int ret;
int64_t n;
if (be32_to_cpu(footer->type) == VHD_FIXED) {
*pnum = bytes;
*map = offset;
*file = bs->file->bs;
return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_RECURSE;
}
qemu_co_mutex_lock(&s->lock);
image_offset = get_image_offset(bs, offset, false, NULL);
allocated = (image_offset != -1);
*pnum = 0;
ret = BDRV_BLOCK_ZERO;
do {
/* All sectors in a block are contiguous (without using the bitmap) */
n = ROUND_UP(offset + 1, s->block_size) - offset;
n = MIN(n, bytes);
*pnum += n;
offset += n;
bytes -= n;
/* *pnum can't be greater than one block for allocated
* sectors since there is always a bitmap in between. */
if (allocated) {
*file = bs->file->bs;
*map = image_offset;
ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
break;
}
if (bytes == 0) {
break;
}
image_offset = get_image_offset(bs, offset, false, NULL);
} while (image_offset == -1);
qemu_co_mutex_unlock(&s->lock);
return ret;
}
/*
* Calculates the number of cylinders, heads and sectors per cylinder
* based on a given number of sectors. This is the algorithm described
* in the VHD specification.
*
* Note that the geometry doesn't always exactly match total_sectors but
* may round it down.
*
* Returns 0 on success, -EFBIG if the size is larger than 2040 GiB. Override
* the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)
* and instead allow up to 255 heads.
*/
static int calculate_geometry(int64_t total_sectors, uint16_t* cyls,
uint8_t* heads, uint8_t* secs_per_cyl)
{
uint32_t cyls_times_heads;
total_sectors = MIN(total_sectors, VHD_MAX_GEOMETRY);
if (total_sectors >= 65535LL * 16 * 63) {
*secs_per_cyl = 255;
*heads = 16;
cyls_times_heads = total_sectors / *secs_per_cyl;
} else {
*secs_per_cyl = 17;
cyls_times_heads = total_sectors / *secs_per_cyl;
*heads = DIV_ROUND_UP(cyls_times_heads, 1024);
if (*heads < 4) {
*heads = 4;
}
if (cyls_times_heads >= (*heads * 1024) || *heads > 16) {
*secs_per_cyl = 31;
*heads = 16;
cyls_times_heads = total_sectors / *secs_per_cyl;
}
if (cyls_times_heads >= (*heads * 1024)) {
*secs_per_cyl = 63;
*heads = 16;
cyls_times_heads = total_sectors / *secs_per_cyl;
}
}
*cyls = cyls_times_heads / *heads;
return 0;
}
static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf,
int64_t total_sectors)
{
VHDDynDiskHeader *dyndisk_header =
(VHDDynDiskHeader *) buf;
size_t block_size, num_bat_entries;
int i;
int ret;
int64_t offset = 0;
/* Write the footer (twice: at the beginning and at the end) */
block_size = 0x200000;
num_bat_entries = DIV_ROUND_UP(total_sectors, block_size / 512);
ret = blk_pwrite(blk, offset, buf, HEADER_SIZE, 0);
if (ret < 0) {
goto fail;
}
offset = 1536 + ((num_bat_entries * 4 + 511) & ~511);
ret = blk_pwrite(blk, offset, buf, HEADER_SIZE, 0);
if (ret < 0) {
goto fail;
}
/* Write the initial BAT */
offset = 3 * 512;
memset(buf, 0xFF, 512);
for (i = 0; i < DIV_ROUND_UP(num_bat_entries * 4, 512); i++) {
ret = blk_pwrite(blk, offset, buf, 512, 0);
if (ret < 0) {
goto fail;
}
offset += 512;
}
/* Prepare the Dynamic Disk Header */
memset(buf, 0, 1024);
memcpy(dyndisk_header->magic, "cxsparse", 8);
/*
* Note: The spec is actually wrong here for data_offset, it says
* 0xFFFFFFFF, but MS tools expect all 64 bits to be set.
*/
dyndisk_header->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL);
dyndisk_header->table_offset = cpu_to_be64(3 * 512);
dyndisk_header->version = cpu_to_be32(0x00010000);
dyndisk_header->block_size = cpu_to_be32(block_size);
dyndisk_header->max_table_entries = cpu_to_be32(num_bat_entries);
dyndisk_header->checksum = cpu_to_be32(vpc_checksum(buf, 1024));
/* Write the header */
offset = 512;
ret = blk_pwrite(blk, offset, buf, 1024, 0);
if (ret < 0) {
goto fail;
}
ret = 0;
fail:
return ret;
}
static int create_fixed_disk(BlockBackend *blk, uint8_t *buf,
int64_t total_size, Error **errp)
{
int ret;
/* Add footer to total size */
total_size += HEADER_SIZE;
ret = blk_truncate(blk, total_size, false, PREALLOC_MODE_OFF, 0, errp);
if (ret < 0) {
return ret;
}
ret = blk_pwrite(blk, total_size - HEADER_SIZE, buf, HEADER_SIZE, 0);
if (ret < 0) {
error_setg_errno(errp, -ret, "Unable to write VHD header");
return ret;
}
return 0;
}
static int calculate_rounded_image_size(BlockdevCreateOptionsVpc *vpc_opts,
uint16_t *out_cyls,
uint8_t *out_heads,
uint8_t *out_secs_per_cyl,
int64_t *out_total_sectors,
Error **errp)
{
int64_t total_size = vpc_opts->size;
uint16_t cyls = 0;
uint8_t heads = 0;
uint8_t secs_per_cyl = 0;
int64_t total_sectors;
int i;
/*
* Calculate matching total_size and geometry. Increase the number of
* sectors requested until we get enough (or fail). This ensures that
* qemu-img convert doesn't truncate images, but rather rounds up.
*
* If the image size can't be represented by a spec conformant CHS geometry,
* we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use
* the image size from the VHD footer to calculate total_sectors.
*/
if (vpc_opts->force_size) {
/* This will force the use of total_size for sector count, below */
cyls = VHD_CHS_MAX_C;
heads = VHD_CHS_MAX_H;
secs_per_cyl = VHD_CHS_MAX_S;
} else {
total_sectors = MIN(VHD_MAX_GEOMETRY, total_size / BDRV_SECTOR_SIZE);
for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl);
}
}
if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) {
total_sectors = total_size / BDRV_SECTOR_SIZE;
/* Allow a maximum disk size of 2040 GiB */
if (total_sectors > VHD_MAX_SECTORS) {
error_setg(errp, "Disk size is too large, max size is 2040 GiB");
return -EFBIG;
}
} else {
total_sectors = (int64_t) cyls * heads * secs_per_cyl;
}
*out_total_sectors = total_sectors;
if (out_cyls) {
*out_cyls = cyls;
*out_heads = heads;
*out_secs_per_cyl = secs_per_cyl;
}
return 0;
}
static int coroutine_fn vpc_co_create(BlockdevCreateOptions *opts,
Error **errp)
{
BlockdevCreateOptionsVpc *vpc_opts;
BlockBackend *blk = NULL;
BlockDriverState *bs = NULL;
uint8_t buf[1024];
VHDFooter *footer = (VHDFooter *) buf;
uint16_t cyls = 0;
uint8_t heads = 0;
uint8_t secs_per_cyl = 0;
int64_t total_sectors;
int64_t total_size;
int disk_type;
int ret = -EIO;
QemuUUID uuid;
assert(opts->driver == BLOCKDEV_DRIVER_VPC);
vpc_opts = &opts->u.vpc;
/* Validate options and set default values */
total_size = vpc_opts->size;
if (!vpc_opts->has_subformat) {
vpc_opts->subformat = BLOCKDEV_VPC_SUBFORMAT_DYNAMIC;
}
switch (vpc_opts->subformat) {
case BLOCKDEV_VPC_SUBFORMAT_DYNAMIC:
disk_type = VHD_DYNAMIC;
break;
case BLOCKDEV_VPC_SUBFORMAT_FIXED:
disk_type = VHD_FIXED;
break;