2 * Block driver for Connectix / Microsoft Virtual PC images
4 * Copyright (c) 2005 Alex Beregszaszi
5 * Copyright (c) 2009 Kevin Wolf <kwolf@suse.de>
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "block/block_int.h"
28 #include "sysemu/block-backend.h"
29 #include "qemu/module.h"
30 #include "migration/migration.h"
31 #if defined(CONFIG_UUID)
32 #include <uuid/uuid.h>
35 /**************************************************************/
37 #define HEADER_SIZE 512
47 // Seconds since Jan 1, 2000 0:00:00 (UTC)
48 #define VHD_TIMESTAMP_BASE 946684800
50 #define VHD_CHS_MAX_C 65535LL
51 #define VHD_CHS_MAX_H 16
52 #define VHD_CHS_MAX_S 255
54 #define VHD_MAX_SECTORS (65535LL * 255 * 255)
55 #define VHD_MAX_GEOMETRY (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S)
57 #define VPC_OPT_FORCE_SIZE "force_size"
60 typedef struct vhd_footer
{
61 char creator
[8]; // "conectix"
65 // Offset of next header structure, 0xFFFFFFFF if none
68 // Seconds since Jan 1, 2000 0:00:00 (UTC)
71 char creator_app
[4]; // "vpc "
74 char creator_os
[4]; // "Wi2k"
77 uint64_t current_size
;
85 // Checksum of the Hard Disk Footer ("one's complement of the sum of all
86 // the bytes in the footer without the checksum field")
89 // UUID used to identify a parent hard disk (backing file)
92 uint8_t in_saved_state
;
93 } QEMU_PACKED VHDFooter
;
95 typedef struct vhd_dyndisk_header
{
96 char magic
[8]; // "cxsparse"
98 // Offset of next header structure, 0xFFFFFFFF if none
101 // Offset of the Block Allocation Table (BAT)
102 uint64_t table_offset
;
105 uint32_t max_table_entries
; // 32bit/entry
107 // 2 MB by default, must be a power of two
111 uint8_t parent_uuid
[16];
112 uint32_t parent_timestamp
;
115 // Backing file name (in UTF-16)
116 uint8_t parent_name
[512];
121 uint32_t data_length
;
123 uint64_t data_offset
;
125 } QEMU_PACKED VHDDynDiskHeader
;
127 typedef struct BDRVVPCState
{
129 uint8_t footer_buf
[HEADER_SIZE
];
130 uint64_t free_data_block_offset
;
131 int max_table_entries
;
134 uint64_t last_bitmap_offset
;
137 uint32_t bitmap_size
;
142 uint8_t *pageentry_u8
;
143 uint32_t *pageentry_u32
;
144 uint16_t *pageentry_u16
;
146 uint64_t last_bitmap
;
149 Error
*migration_blocker
;
152 #define VPC_OPT_SIZE_CALC "force_size_calc"
153 static QemuOptsList vpc_runtime_opts
= {
154 .name
= "vpc-runtime-opts",
155 .head
= QTAILQ_HEAD_INITIALIZER(vpc_runtime_opts
.head
),
158 .name
= VPC_OPT_SIZE_CALC
,
159 .type
= QEMU_OPT_STRING
,
160 .help
= "Force disk size calculation to use either CHS geometry, "
161 "or use the disk current_size specified in the VHD footer. "
162 "{chs, current_size}"
164 { /* end of list */ }
168 static uint32_t vpc_checksum(uint8_t* buf
, size_t size
)
173 for (i
= 0; i
< size
; i
++)
180 static int vpc_probe(const uint8_t *buf
, int buf_size
, const char *filename
)
182 if (buf_size
>= 8 && !strncmp((char *)buf
, "conectix", 8))
187 static void vpc_parse_options(BlockDriverState
*bs
, QemuOpts
*opts
,
190 BDRVVPCState
*s
= bs
->opaque
;
191 const char *size_calc
;
193 size_calc
= qemu_opt_get(opts
, VPC_OPT_SIZE_CALC
);
196 /* no override, use autodetect only */
197 } else if (!strcmp(size_calc
, "current_size")) {
198 s
->force_use_sz
= true;
199 } else if (!strcmp(size_calc
, "chs")) {
200 s
->force_use_chs
= true;
202 error_setg(errp
, "Invalid size calculation mode: '%s'", size_calc
);
206 static int vpc_open(BlockDriverState
*bs
, QDict
*options
, int flags
,
209 BDRVVPCState
*s
= bs
->opaque
;
212 VHDDynDiskHeader
*dyndisk_header
;
213 QemuOpts
*opts
= NULL
;
214 Error
*local_err
= NULL
;
216 uint8_t buf
[HEADER_SIZE
];
218 uint64_t computed_size
;
219 uint64_t pagetable_size
;
220 int disk_type
= VHD_DYNAMIC
;
223 opts
= qemu_opts_create(&vpc_runtime_opts
, NULL
, 0, &error_abort
);
224 qemu_opts_absorb_qdict(opts
, options
, &local_err
);
226 error_propagate(errp
, local_err
);
231 vpc_parse_options(bs
, opts
, &local_err
);
233 error_propagate(errp
, local_err
);
238 ret
= bdrv_pread(bs
->file
->bs
, 0, s
->footer_buf
, HEADER_SIZE
);
243 footer
= (VHDFooter
*) s
->footer_buf
;
244 if (strncmp(footer
->creator
, "conectix", 8)) {
245 int64_t offset
= bdrv_getlength(bs
->file
->bs
);
249 } else if (offset
< HEADER_SIZE
) {
254 /* If a fixed disk, the footer is found only at the end of the file */
255 ret
= bdrv_pread(bs
->file
->bs
, offset
-HEADER_SIZE
, s
->footer_buf
,
260 if (strncmp(footer
->creator
, "conectix", 8)) {
261 error_setg(errp
, "invalid VPC image");
265 disk_type
= VHD_FIXED
;
268 checksum
= be32_to_cpu(footer
->checksum
);
269 footer
->checksum
= 0;
270 if (vpc_checksum(s
->footer_buf
, HEADER_SIZE
) != checksum
)
271 fprintf(stderr
, "block-vpc: The header checksum of '%s' is "
272 "incorrect.\n", bs
->filename
);
274 /* Write 'checksum' back to footer, or else will leave it with zero. */
275 footer
->checksum
= cpu_to_be32(checksum
);
277 // The visible size of a image in Virtual PC depends on the geometry
278 // rather than on the size stored in the footer (the size in the footer
279 // is too large usually)
280 bs
->total_sectors
= (int64_t)
281 be16_to_cpu(footer
->cyls
) * footer
->heads
* footer
->secs_per_cyl
;
283 /* Microsoft Virtual PC and Microsoft Hyper-V produce and read
284 * VHD image sizes differently. VPC will rely on CHS geometry,
285 * while Hyper-V and disk2vhd use the size specified in the footer.
287 * We use a couple of approaches to try and determine the correct method:
288 * look at the Creator App field, and look for images that have CHS
289 * geometry that is the maximum value.
291 * If the CHS geometry is the maximum CHS geometry, then we assume that
292 * the size is the footer->current_size to avoid truncation. Otherwise,
293 * we follow the table based on footer->creator_app:
295 * Known creator apps:
296 * 'vpc ' : CHS Virtual PC (uses disk geometry)
297 * 'qemu' : CHS QEMU (uses disk geometry)
298 * 'qem2' : current_size QEMU (uses current_size)
299 * 'win ' : current_size Hyper-V
300 * 'd2v ' : current_size Disk2vhd
302 * The user can override the table values via drive options, however
303 * even with an override we will still use current_size for images
304 * that have CHS geometry of the maximum size.
306 use_chs
= (!!strncmp(footer
->creator_app
, "win ", 4) &&
307 !!strncmp(footer
->creator_app
, "qem2", 4) &&
308 !!strncmp(footer
->creator_app
, "d2v ", 4)) || s
->force_use_chs
;
310 if (!use_chs
|| bs
->total_sectors
== VHD_MAX_GEOMETRY
|| s
->force_use_sz
) {
311 bs
->total_sectors
= be64_to_cpu(footer
->current_size
) /
315 /* Allow a maximum disk size of approximately 2 TB */
316 if (bs
->total_sectors
>= VHD_MAX_SECTORS
) {
321 if (disk_type
== VHD_DYNAMIC
) {
322 ret
= bdrv_pread(bs
->file
->bs
, be64_to_cpu(footer
->data_offset
), buf
,
328 dyndisk_header
= (VHDDynDiskHeader
*) buf
;
330 if (strncmp(dyndisk_header
->magic
, "cxsparse", 8)) {
335 s
->block_size
= be32_to_cpu(dyndisk_header
->block_size
);
336 if (!is_power_of_2(s
->block_size
) || s
->block_size
< BDRV_SECTOR_SIZE
) {
337 error_setg(errp
, "Invalid block size %" PRIu32
, s
->block_size
);
341 s
->bitmap_size
= ((s
->block_size
/ (8 * 512)) + 511) & ~511;
343 s
->max_table_entries
= be32_to_cpu(dyndisk_header
->max_table_entries
);
345 if ((bs
->total_sectors
* 512) / s
->block_size
> 0xffffffffU
) {
349 if (s
->max_table_entries
> (VHD_MAX_SECTORS
* 512) / s
->block_size
) {
354 computed_size
= (uint64_t) s
->max_table_entries
* s
->block_size
;
355 if (computed_size
< bs
->total_sectors
* 512) {
360 if (s
->max_table_entries
> SIZE_MAX
/ 4 ||
361 s
->max_table_entries
> (int) INT_MAX
/ 4) {
362 error_setg(errp
, "Max Table Entries too large (%" PRId32
")",
363 s
->max_table_entries
);
368 pagetable_size
= (uint64_t) s
->max_table_entries
* 4;
370 s
->pagetable
= qemu_try_blockalign(bs
->file
->bs
, pagetable_size
);
371 if (s
->pagetable
== NULL
) {
376 s
->bat_offset
= be64_to_cpu(dyndisk_header
->table_offset
);
378 ret
= bdrv_pread(bs
->file
->bs
, s
->bat_offset
, s
->pagetable
,
384 s
->free_data_block_offset
=
385 ROUND_UP(s
->bat_offset
+ pagetable_size
, 512);
387 for (i
= 0; i
< s
->max_table_entries
; i
++) {
388 be32_to_cpus(&s
->pagetable
[i
]);
389 if (s
->pagetable
[i
] != 0xFFFFFFFF) {
390 int64_t next
= (512 * (int64_t) s
->pagetable
[i
]) +
391 s
->bitmap_size
+ s
->block_size
;
393 if (next
> s
->free_data_block_offset
) {
394 s
->free_data_block_offset
= next
;
399 if (s
->free_data_block_offset
> bdrv_getlength(bs
->file
->bs
)) {
400 error_setg(errp
, "block-vpc: free_data_block_offset points after "
401 "the end of file. The image has been truncated.");
406 s
->last_bitmap_offset
= (int64_t) -1;
409 s
->pageentry_u8
= g_malloc(512);
410 s
->pageentry_u32
= s
->pageentry_u8
;
411 s
->pageentry_u16
= s
->pageentry_u8
;
412 s
->last_pagetable
= -1;
416 qemu_co_mutex_init(&s
->lock
);
418 /* Disable migration when VHD images are used */
419 error_setg(&s
->migration_blocker
, "The vpc format used by node '%s' "
420 "does not support live migration",
421 bdrv_get_device_or_node_name(bs
));
422 migrate_add_blocker(s
->migration_blocker
);
427 qemu_vfree(s
->pagetable
);
429 g_free(s
->pageentry_u8
);
434 static int vpc_reopen_prepare(BDRVReopenState
*state
,
435 BlockReopenQueue
*queue
, Error
**errp
)
441 * Returns the absolute byte offset of the given sector in the image file.
442 * If the sector is not allocated, -1 is returned instead.
444 * The parameter write must be 1 if the offset will be used for a write
445 * operation (the block bitmaps is updated then), 0 otherwise.
447 static inline int64_t get_sector_offset(BlockDriverState
*bs
,
448 int64_t sector_num
, int write
)
450 BDRVVPCState
*s
= bs
->opaque
;
451 uint64_t offset
= sector_num
* 512;
452 uint64_t bitmap_offset
, block_offset
;
453 uint32_t pagetable_index
, pageentry_index
;
455 pagetable_index
= offset
/ s
->block_size
;
456 pageentry_index
= (offset
% s
->block_size
) / 512;
458 if (pagetable_index
>= s
->max_table_entries
|| s
->pagetable
[pagetable_index
] == 0xffffffff)
459 return -1; // not allocated
461 bitmap_offset
= 512 * (uint64_t) s
->pagetable
[pagetable_index
];
462 block_offset
= bitmap_offset
+ s
->bitmap_size
+ (512 * pageentry_index
);
464 // We must ensure that we don't write to any sectors which are marked as
465 // unused in the bitmap. We get away with setting all bits in the block
466 // bitmap each time we write to a new block. This might cause Virtual PC to
467 // miss sparse read optimization, but it's not a problem in terms of
469 if (write
&& (s
->last_bitmap_offset
!= bitmap_offset
)) {
470 uint8_t bitmap
[s
->bitmap_size
];
472 s
->last_bitmap_offset
= bitmap_offset
;
473 memset(bitmap
, 0xff, s
->bitmap_size
);
474 bdrv_pwrite_sync(bs
->file
->bs
, bitmap_offset
, bitmap
, s
->bitmap_size
);
481 * Writes the footer to the end of the image file. This is needed when the
482 * file grows as it overwrites the old footer
484 * Returns 0 on success and < 0 on error
486 static int rewrite_footer(BlockDriverState
* bs
)
489 BDRVVPCState
*s
= bs
->opaque
;
490 int64_t offset
= s
->free_data_block_offset
;
492 ret
= bdrv_pwrite_sync(bs
->file
->bs
, offset
, s
->footer_buf
, HEADER_SIZE
);
500 * Allocates a new block. This involves writing a new footer and updating
501 * the Block Allocation Table to use the space at the old end of the image
502 * file (overwriting the old footer)
504 * Returns the sectors' offset in the image file on success and < 0 on error
506 static int64_t alloc_block(BlockDriverState
* bs
, int64_t sector_num
)
508 BDRVVPCState
*s
= bs
->opaque
;
510 uint32_t index
, bat_value
;
512 uint8_t bitmap
[s
->bitmap_size
];
514 // Check if sector_num is valid
515 if ((sector_num
< 0) || (sector_num
> bs
->total_sectors
))
518 // Write entry into in-memory BAT
519 index
= (sector_num
* 512) / s
->block_size
;
520 if (s
->pagetable
[index
] != 0xFFFFFFFF)
523 s
->pagetable
[index
] = s
->free_data_block_offset
/ 512;
525 // Initialize the block's bitmap
526 memset(bitmap
, 0xff, s
->bitmap_size
);
527 ret
= bdrv_pwrite_sync(bs
->file
->bs
, s
->free_data_block_offset
, bitmap
,
533 // Write new footer (the old one will be overwritten)
534 s
->free_data_block_offset
+= s
->block_size
+ s
->bitmap_size
;
535 ret
= rewrite_footer(bs
);
539 // Write BAT entry to disk
540 bat_offset
= s
->bat_offset
+ (4 * index
);
541 bat_value
= cpu_to_be32(s
->pagetable
[index
]);
542 ret
= bdrv_pwrite_sync(bs
->file
->bs
, bat_offset
, &bat_value
, 4);
546 return get_sector_offset(bs
, sector_num
, 0);
549 s
->free_data_block_offset
-= (s
->block_size
+ s
->bitmap_size
);
553 static int vpc_get_info(BlockDriverState
*bs
, BlockDriverInfo
*bdi
)
555 BDRVVPCState
*s
= (BDRVVPCState
*)bs
->opaque
;
556 VHDFooter
*footer
= (VHDFooter
*) s
->footer_buf
;
558 if (be32_to_cpu(footer
->type
) != VHD_FIXED
) {
559 bdi
->cluster_size
= s
->block_size
;
562 bdi
->unallocated_blocks_are_zero
= true;
566 static int vpc_read(BlockDriverState
*bs
, int64_t sector_num
,
567 uint8_t *buf
, int nb_sectors
)
569 BDRVVPCState
*s
= bs
->opaque
;
572 int64_t sectors
, sectors_per_block
;
573 VHDFooter
*footer
= (VHDFooter
*) s
->footer_buf
;
575 if (be32_to_cpu(footer
->type
) == VHD_FIXED
) {
576 return bdrv_read(bs
->file
->bs
, sector_num
, buf
, nb_sectors
);
578 while (nb_sectors
> 0) {
579 offset
= get_sector_offset(bs
, sector_num
, 0);
581 sectors_per_block
= s
->block_size
>> BDRV_SECTOR_BITS
;
582 sectors
= sectors_per_block
- (sector_num
% sectors_per_block
);
583 if (sectors
> nb_sectors
) {
584 sectors
= nb_sectors
;
588 memset(buf
, 0, sectors
* BDRV_SECTOR_SIZE
);
590 ret
= bdrv_pread(bs
->file
->bs
, offset
, buf
,
591 sectors
* BDRV_SECTOR_SIZE
);
592 if (ret
!= sectors
* BDRV_SECTOR_SIZE
) {
597 nb_sectors
-= sectors
;
598 sector_num
+= sectors
;
599 buf
+= sectors
* BDRV_SECTOR_SIZE
;
604 static coroutine_fn
int vpc_co_read(BlockDriverState
*bs
, int64_t sector_num
,
605 uint8_t *buf
, int nb_sectors
)
608 BDRVVPCState
*s
= bs
->opaque
;
609 qemu_co_mutex_lock(&s
->lock
);
610 ret
= vpc_read(bs
, sector_num
, buf
, nb_sectors
);
611 qemu_co_mutex_unlock(&s
->lock
);
615 static int vpc_write(BlockDriverState
*bs
, int64_t sector_num
,
616 const uint8_t *buf
, int nb_sectors
)
618 BDRVVPCState
*s
= bs
->opaque
;
620 int64_t sectors
, sectors_per_block
;
622 VHDFooter
*footer
= (VHDFooter
*) s
->footer_buf
;
624 if (be32_to_cpu(footer
->type
) == VHD_FIXED
) {
625 return bdrv_write(bs
->file
->bs
, sector_num
, buf
, nb_sectors
);
627 while (nb_sectors
> 0) {
628 offset
= get_sector_offset(bs
, sector_num
, 1);
630 sectors_per_block
= s
->block_size
>> BDRV_SECTOR_BITS
;
631 sectors
= sectors_per_block
- (sector_num
% sectors_per_block
);
632 if (sectors
> nb_sectors
) {
633 sectors
= nb_sectors
;
637 offset
= alloc_block(bs
, sector_num
);
642 ret
= bdrv_pwrite(bs
->file
->bs
, offset
, buf
,
643 sectors
* BDRV_SECTOR_SIZE
);
644 if (ret
!= sectors
* BDRV_SECTOR_SIZE
) {
648 nb_sectors
-= sectors
;
649 sector_num
+= sectors
;
650 buf
+= sectors
* BDRV_SECTOR_SIZE
;
656 static coroutine_fn
int vpc_co_write(BlockDriverState
*bs
, int64_t sector_num
,
657 const uint8_t *buf
, int nb_sectors
)
660 BDRVVPCState
*s
= bs
->opaque
;
661 qemu_co_mutex_lock(&s
->lock
);
662 ret
= vpc_write(bs
, sector_num
, buf
, nb_sectors
);
663 qemu_co_mutex_unlock(&s
->lock
);
667 static int64_t coroutine_fn
vpc_co_get_block_status(BlockDriverState
*bs
,
668 int64_t sector_num
, int nb_sectors
, int *pnum
, BlockDriverState
**file
)
670 BDRVVPCState
*s
= bs
->opaque
;
671 VHDFooter
*footer
= (VHDFooter
*) s
->footer_buf
;
672 int64_t start
, offset
;
676 if (be32_to_cpu(footer
->type
) == VHD_FIXED
) {
678 *file
= bs
->file
->bs
;
679 return BDRV_BLOCK_RAW
| BDRV_BLOCK_OFFSET_VALID
| BDRV_BLOCK_DATA
|
680 (sector_num
<< BDRV_SECTOR_BITS
);
683 offset
= get_sector_offset(bs
, sector_num
, 0);
685 allocated
= (offset
!= -1);
689 /* All sectors in a block are contiguous (without using the bitmap) */
690 n
= ROUND_UP(sector_num
+ 1, s
->block_size
/ BDRV_SECTOR_SIZE
)
692 n
= MIN(n
, nb_sectors
);
697 /* *pnum can't be greater than one block for allocated
698 * sectors since there is always a bitmap in between. */
700 *file
= bs
->file
->bs
;
701 return BDRV_BLOCK_DATA
| BDRV_BLOCK_OFFSET_VALID
| start
;
703 if (nb_sectors
== 0) {
706 offset
= get_sector_offset(bs
, sector_num
, 0);
707 } while (offset
== -1);
713 * Calculates the number of cylinders, heads and sectors per cylinder
714 * based on a given number of sectors. This is the algorithm described
715 * in the VHD specification.
717 * Note that the geometry doesn't always exactly match total_sectors but
720 * Returns 0 on success, -EFBIG if the size is larger than ~2 TB. Override
721 * the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB)
722 * and instead allow up to 255 heads.
724 static int calculate_geometry(int64_t total_sectors
, uint16_t* cyls
,
725 uint8_t* heads
, uint8_t* secs_per_cyl
)
727 uint32_t cyls_times_heads
;
729 total_sectors
= MIN(total_sectors
, VHD_MAX_GEOMETRY
);
731 if (total_sectors
>= 65535LL * 16 * 63) {
734 cyls_times_heads
= total_sectors
/ *secs_per_cyl
;
737 cyls_times_heads
= total_sectors
/ *secs_per_cyl
;
738 *heads
= (cyls_times_heads
+ 1023) / 1024;
744 if (cyls_times_heads
>= (*heads
* 1024) || *heads
> 16) {
747 cyls_times_heads
= total_sectors
/ *secs_per_cyl
;
750 if (cyls_times_heads
>= (*heads
* 1024)) {
753 cyls_times_heads
= total_sectors
/ *secs_per_cyl
;
757 *cyls
= cyls_times_heads
/ *heads
;
762 static int create_dynamic_disk(BlockBackend
*blk
, uint8_t *buf
,
763 int64_t total_sectors
)
765 VHDDynDiskHeader
*dyndisk_header
=
766 (VHDDynDiskHeader
*) buf
;
767 size_t block_size
, num_bat_entries
;
772 // Write the footer (twice: at the beginning and at the end)
773 block_size
= 0x200000;
774 num_bat_entries
= (total_sectors
+ block_size
/ 512) / (block_size
/ 512);
776 ret
= blk_pwrite(blk
, offset
, buf
, HEADER_SIZE
);
781 offset
= 1536 + ((num_bat_entries
* 4 + 511) & ~511);
782 ret
= blk_pwrite(blk
, offset
, buf
, HEADER_SIZE
);
787 // Write the initial BAT
790 memset(buf
, 0xFF, 512);
791 for (i
= 0; i
< (num_bat_entries
* 4 + 511) / 512; i
++) {
792 ret
= blk_pwrite(blk
, offset
, buf
, 512);
799 // Prepare the Dynamic Disk Header
800 memset(buf
, 0, 1024);
802 memcpy(dyndisk_header
->magic
, "cxsparse", 8);
805 * Note: The spec is actually wrong here for data_offset, it says
806 * 0xFFFFFFFF, but MS tools expect all 64 bits to be set.
808 dyndisk_header
->data_offset
= cpu_to_be64(0xFFFFFFFFFFFFFFFFULL
);
809 dyndisk_header
->table_offset
= cpu_to_be64(3 * 512);
810 dyndisk_header
->version
= cpu_to_be32(0x00010000);
811 dyndisk_header
->block_size
= cpu_to_be32(block_size
);
812 dyndisk_header
->max_table_entries
= cpu_to_be32(num_bat_entries
);
814 dyndisk_header
->checksum
= cpu_to_be32(vpc_checksum(buf
, 1024));
819 ret
= blk_pwrite(blk
, offset
, buf
, 1024);
828 static int create_fixed_disk(BlockBackend
*blk
, uint8_t *buf
,
833 /* Add footer to total size */
834 total_size
+= HEADER_SIZE
;
836 ret
= blk_truncate(blk
, total_size
);
841 ret
= blk_pwrite(blk
, total_size
- HEADER_SIZE
, buf
, HEADER_SIZE
);
849 static int vpc_create(const char *filename
, QemuOpts
*opts
, Error
**errp
)
852 VHDFooter
*footer
= (VHDFooter
*) buf
;
853 char *disk_type_param
;
857 uint8_t secs_per_cyl
= 0;
858 int64_t total_sectors
;
863 Error
*local_err
= NULL
;
864 BlockBackend
*blk
= NULL
;
866 /* Read out options */
867 total_size
= ROUND_UP(qemu_opt_get_size_del(opts
, BLOCK_OPT_SIZE
, 0),
869 disk_type_param
= qemu_opt_get_del(opts
, BLOCK_OPT_SUBFMT
);
870 if (disk_type_param
) {
871 if (!strcmp(disk_type_param
, "dynamic")) {
872 disk_type
= VHD_DYNAMIC
;
873 } else if (!strcmp(disk_type_param
, "fixed")) {
874 disk_type
= VHD_FIXED
;
880 disk_type
= VHD_DYNAMIC
;
883 force_size
= qemu_opt_get_bool_del(opts
, VPC_OPT_FORCE_SIZE
, false);
885 ret
= bdrv_create_file(filename
, opts
, &local_err
);
887 error_propagate(errp
, local_err
);
891 blk
= blk_new_open(filename
, NULL
, NULL
,
892 BDRV_O_RDWR
| BDRV_O_CACHE_WB
| BDRV_O_PROTOCOL
,
895 error_propagate(errp
, local_err
);
900 blk_set_allow_write_beyond_eof(blk
, true);
903 * Calculate matching total_size and geometry. Increase the number of
904 * sectors requested until we get enough (or fail). This ensures that
905 * qemu-img convert doesn't truncate images, but rather rounds up.
907 * If the image size can't be represented by a spec conformant CHS geometry,
908 * we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use
909 * the image size from the VHD footer to calculate total_sectors.
912 /* This will force the use of total_size for sector count, below */
913 cyls
= VHD_CHS_MAX_C
;
914 heads
= VHD_CHS_MAX_H
;
915 secs_per_cyl
= VHD_CHS_MAX_S
;
917 total_sectors
= MIN(VHD_MAX_GEOMETRY
, total_size
/ BDRV_SECTOR_SIZE
);
918 for (i
= 0; total_sectors
> (int64_t)cyls
* heads
* secs_per_cyl
; i
++) {
919 calculate_geometry(total_sectors
+ i
, &cyls
, &heads
, &secs_per_cyl
);
923 if ((int64_t)cyls
* heads
* secs_per_cyl
== VHD_MAX_GEOMETRY
) {
924 total_sectors
= total_size
/ BDRV_SECTOR_SIZE
;
925 /* Allow a maximum disk size of approximately 2 TB */
926 if (total_sectors
> VHD_MAX_SECTORS
) {
931 total_sectors
= (int64_t)cyls
* heads
* secs_per_cyl
;
932 total_size
= total_sectors
* BDRV_SECTOR_SIZE
;
935 /* Prepare the Hard Disk Footer */
936 memset(buf
, 0, 1024);
938 memcpy(footer
->creator
, "conectix", 8);
940 memcpy(footer
->creator_app
, "qem2", 4);
942 memcpy(footer
->creator_app
, "qemu", 4);
944 memcpy(footer
->creator_os
, "Wi2k", 4);
946 footer
->features
= cpu_to_be32(0x02);
947 footer
->version
= cpu_to_be32(0x00010000);
948 if (disk_type
== VHD_DYNAMIC
) {
949 footer
->data_offset
= cpu_to_be64(HEADER_SIZE
);
951 footer
->data_offset
= cpu_to_be64(0xFFFFFFFFFFFFFFFFULL
);
953 footer
->timestamp
= cpu_to_be32(time(NULL
) - VHD_TIMESTAMP_BASE
);
955 /* Version of Virtual PC 2007 */
956 footer
->major
= cpu_to_be16(0x0005);
957 footer
->minor
= cpu_to_be16(0x0003);
958 footer
->orig_size
= cpu_to_be64(total_size
);
959 footer
->current_size
= cpu_to_be64(total_size
);
960 footer
->cyls
= cpu_to_be16(cyls
);
961 footer
->heads
= heads
;
962 footer
->secs_per_cyl
= secs_per_cyl
;
964 footer
->type
= cpu_to_be32(disk_type
);
966 #if defined(CONFIG_UUID)
967 uuid_generate(footer
->uuid
);
970 footer
->checksum
= cpu_to_be32(vpc_checksum(buf
, HEADER_SIZE
));
972 if (disk_type
== VHD_DYNAMIC
) {
973 ret
= create_dynamic_disk(blk
, buf
, total_sectors
);
975 ret
= create_fixed_disk(blk
, buf
, total_size
);
980 g_free(disk_type_param
);
984 static int vpc_has_zero_init(BlockDriverState
*bs
)
986 BDRVVPCState
*s
= bs
->opaque
;
987 VHDFooter
*footer
= (VHDFooter
*) s
->footer_buf
;
989 if (be32_to_cpu(footer
->type
) == VHD_FIXED
) {
990 return bdrv_has_zero_init(bs
->file
->bs
);
996 static void vpc_close(BlockDriverState
*bs
)
998 BDRVVPCState
*s
= bs
->opaque
;
999 qemu_vfree(s
->pagetable
);
1001 g_free(s
->pageentry_u8
);
1004 migrate_del_blocker(s
->migration_blocker
);
1005 error_free(s
->migration_blocker
);
1008 static QemuOptsList vpc_create_opts
= {
1009 .name
= "vpc-create-opts",
1010 .head
= QTAILQ_HEAD_INITIALIZER(vpc_create_opts
.head
),
1013 .name
= BLOCK_OPT_SIZE
,
1014 .type
= QEMU_OPT_SIZE
,
1015 .help
= "Virtual disk size"
1018 .name
= BLOCK_OPT_SUBFMT
,
1019 .type
= QEMU_OPT_STRING
,
1021 "Type of virtual hard disk format. Supported formats are "
1022 "{dynamic (default) | fixed} "
1025 .name
= VPC_OPT_FORCE_SIZE
,
1026 .type
= QEMU_OPT_BOOL
,
1027 .help
= "Force disk size calculation to use the actual size "
1028 "specified, rather than using the nearest CHS-based "
1031 { /* end of list */ }
1035 static BlockDriver bdrv_vpc
= {
1036 .format_name
= "vpc",
1037 .instance_size
= sizeof(BDRVVPCState
),
1039 .bdrv_probe
= vpc_probe
,
1040 .bdrv_open
= vpc_open
,
1041 .bdrv_close
= vpc_close
,
1042 .bdrv_reopen_prepare
= vpc_reopen_prepare
,
1043 .bdrv_create
= vpc_create
,
1045 .bdrv_read
= vpc_co_read
,
1046 .bdrv_write
= vpc_co_write
,
1047 .bdrv_co_get_block_status
= vpc_co_get_block_status
,
1049 .bdrv_get_info
= vpc_get_info
,
1051 .create_opts
= &vpc_create_opts
,
1052 .bdrv_has_zero_init
= vpc_has_zero_init
,
1055 static void bdrv_vpc_init(void)
1057 bdrv_register(&bdrv_vpc
);
1060 block_init(bdrv_vpc_init
);