root / block-vpc.c @ 4b16eb9d
History | View | Annotate | Download (16.7 kB)
1 |
/*
|
---|---|
2 |
* Block driver for Conectix/Microsoft Virtual PC images
|
3 |
*
|
4 |
* Copyright (c) 2005 Alex Beregszaszi
|
5 |
* Copyright (c) 2009 Kevin Wolf <kwolf@suse.de>
|
6 |
*
|
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:
|
13 |
*
|
14 |
* The above copyright notice and this permission notice shall be included in
|
15 |
* all copies or substantial portions of the Software.
|
16 |
*
|
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
|
23 |
* THE SOFTWARE.
|
24 |
*/
|
25 |
#include "qemu-common.h" |
26 |
#include "block_int.h" |
27 |
|
28 |
/**************************************************************/
|
29 |
|
30 |
#define HEADER_SIZE 512 |
31 |
|
32 |
//#define CACHE
|
33 |
|
34 |
enum vhd_type {
|
35 |
VHD_FIXED = 2,
|
36 |
VHD_DYNAMIC = 3,
|
37 |
VHD_DIFFERENCING = 4,
|
38 |
}; |
39 |
|
40 |
// Seconds since Jan 1, 2000 0:00:00 (UTC)
|
41 |
#define VHD_TIMESTAMP_BASE 946684800 |
42 |
|
43 |
// always big-endian
|
44 |
struct vhd_footer {
|
45 |
char creator[8]; // "conectix" |
46 |
uint32_t features; |
47 |
uint32_t version; |
48 |
|
49 |
// Offset of next header structure, 0xFFFFFFFF if none
|
50 |
uint64_t data_offset; |
51 |
|
52 |
// Seconds since Jan 1, 2000 0:00:00 (UTC)
|
53 |
uint32_t timestamp; |
54 |
|
55 |
char creator_app[4]; // "vpc " |
56 |
uint16_t major; |
57 |
uint16_t minor; |
58 |
char creator_os[4]; // "Wi2k" |
59 |
|
60 |
uint64_t orig_size; |
61 |
uint64_t size; |
62 |
|
63 |
uint16_t cyls; |
64 |
uint8_t heads; |
65 |
uint8_t secs_per_cyl; |
66 |
|
67 |
uint32_t type; |
68 |
|
69 |
// Checksum of the Hard Disk Footer ("one's complement of the sum of all
|
70 |
// the bytes in the footer without the checksum field")
|
71 |
uint32_t checksum; |
72 |
|
73 |
// UUID used to identify a parent hard disk (backing file)
|
74 |
uint8_t uuid[16];
|
75 |
|
76 |
uint8_t in_saved_state; |
77 |
}; |
78 |
|
79 |
struct vhd_dyndisk_header {
|
80 |
char magic[8]; // "cxsparse" |
81 |
|
82 |
// Offset of next header structure, 0xFFFFFFFF if none
|
83 |
uint64_t data_offset; |
84 |
|
85 |
// Offset of the Block Allocation Table (BAT)
|
86 |
uint64_t table_offset; |
87 |
|
88 |
uint32_t version; |
89 |
uint32_t max_table_entries; // 32bit/entry
|
90 |
|
91 |
// 2 MB by default, must be a power of two
|
92 |
uint32_t block_size; |
93 |
|
94 |
uint32_t checksum; |
95 |
uint8_t parent_uuid[16];
|
96 |
uint32_t parent_timestamp; |
97 |
uint32_t reserved; |
98 |
|
99 |
// Backing file name (in UTF-16)
|
100 |
uint8_t parent_name[512];
|
101 |
|
102 |
struct {
|
103 |
uint32_t platform; |
104 |
uint32_t data_space; |
105 |
uint32_t data_length; |
106 |
uint32_t reserved; |
107 |
uint64_t data_offset; |
108 |
} parent_locator[8];
|
109 |
}; |
110 |
|
111 |
typedef struct BDRVVPCState { |
112 |
BlockDriverState *hd; |
113 |
|
114 |
uint8_t footer_buf[HEADER_SIZE]; |
115 |
uint64_t free_data_block_offset; |
116 |
int max_table_entries;
|
117 |
uint32_t *pagetable; |
118 |
uint64_t bat_offset; |
119 |
uint64_t last_bitmap_offset; |
120 |
|
121 |
uint32_t block_size; |
122 |
uint32_t bitmap_size; |
123 |
|
124 |
#ifdef CACHE
|
125 |
uint8_t *pageentry_u8; |
126 |
uint32_t *pageentry_u32; |
127 |
uint16_t *pageentry_u16; |
128 |
|
129 |
uint64_t last_bitmap; |
130 |
#endif
|
131 |
} BDRVVPCState; |
132 |
|
133 |
static uint32_t vpc_checksum(uint8_t* buf, size_t size)
|
134 |
{ |
135 |
uint32_t res = 0;
|
136 |
int i;
|
137 |
|
138 |
for (i = 0; i < size; i++) |
139 |
res += buf[i]; |
140 |
|
141 |
return ~res;
|
142 |
} |
143 |
|
144 |
|
145 |
static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) |
146 |
{ |
147 |
if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) |
148 |
return 100; |
149 |
return 0; |
150 |
} |
151 |
|
152 |
static int vpc_open(BlockDriverState *bs, const char *filename, int flags) |
153 |
{ |
154 |
BDRVVPCState *s = bs->opaque; |
155 |
int ret, i;
|
156 |
struct vhd_footer* footer;
|
157 |
struct vhd_dyndisk_header* dyndisk_header;
|
158 |
uint8_t buf[HEADER_SIZE]; |
159 |
uint32_t checksum; |
160 |
|
161 |
ret = bdrv_file_open(&s->hd, filename, flags); |
162 |
if (ret < 0) |
163 |
return ret;
|
164 |
|
165 |
if (bdrv_pread(s->hd, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) |
166 |
goto fail;
|
167 |
|
168 |
footer = (struct vhd_footer*) s->footer_buf;
|
169 |
if (strncmp(footer->creator, "conectix", 8)) |
170 |
goto fail;
|
171 |
|
172 |
checksum = be32_to_cpu(footer->checksum); |
173 |
footer->checksum = 0;
|
174 |
if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum)
|
175 |
fprintf(stderr, "block-vpc: The header checksum of '%s' is "
|
176 |
"incorrect.\n", filename);
|
177 |
|
178 |
// The visible size of a image in Virtual PC depends on the geometry
|
179 |
// rather than on the size stored in the footer (the size in the footer
|
180 |
// is too large usually)
|
181 |
bs->total_sectors = (int64_t) |
182 |
be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl; |
183 |
|
184 |
if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE)
|
185 |
!= HEADER_SIZE) |
186 |
goto fail;
|
187 |
|
188 |
dyndisk_header = (struct vhd_dyndisk_header*) buf;
|
189 |
|
190 |
if (strncmp(dyndisk_header->magic, "cxsparse", 8)) |
191 |
goto fail;
|
192 |
|
193 |
|
194 |
s->block_size = be32_to_cpu(dyndisk_header->block_size); |
195 |
s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511; |
196 |
|
197 |
s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries); |
198 |
s->pagetable = qemu_malloc(s->max_table_entries * 4);
|
199 |
|
200 |
s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); |
201 |
if (bdrv_pread(s->hd, s->bat_offset, s->pagetable,
|
202 |
s->max_table_entries * 4) != s->max_table_entries * 4) |
203 |
goto fail;
|
204 |
|
205 |
s->free_data_block_offset = |
206 |
(s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; |
207 |
|
208 |
for (i = 0; i < s->max_table_entries; i++) { |
209 |
be32_to_cpus(&s->pagetable[i]); |
210 |
if (s->pagetable[i] != 0xFFFFFFFF) { |
211 |
int64_t next = (512 * (int64_t) s->pagetable[i]) +
|
212 |
s->bitmap_size + s->block_size; |
213 |
|
214 |
if (next> s->free_data_block_offset)
|
215 |
s->free_data_block_offset = next; |
216 |
} |
217 |
} |
218 |
|
219 |
s->last_bitmap_offset = (int64_t) -1;
|
220 |
|
221 |
#ifdef CACHE
|
222 |
s->pageentry_u8 = qemu_malloc(512);
|
223 |
s->pageentry_u32 = s->pageentry_u8; |
224 |
s->pageentry_u16 = s->pageentry_u8; |
225 |
s->last_pagetable = -1;
|
226 |
#endif
|
227 |
|
228 |
return 0; |
229 |
fail:
|
230 |
bdrv_delete(s->hd); |
231 |
return -1; |
232 |
} |
233 |
|
234 |
/*
|
235 |
* Returns the absolute byte offset of the given sector in the image file.
|
236 |
* If the sector is not allocated, -1 is returned instead.
|
237 |
*
|
238 |
* The parameter write must be 1 if the offset will be used for a write
|
239 |
* operation (the block bitmaps is updated then), 0 otherwise.
|
240 |
*/
|
241 |
static inline int64_t get_sector_offset(BlockDriverState *bs, |
242 |
int64_t sector_num, int write)
|
243 |
{ |
244 |
BDRVVPCState *s = bs->opaque; |
245 |
uint64_t offset = sector_num * 512;
|
246 |
uint64_t bitmap_offset, block_offset; |
247 |
uint32_t pagetable_index, pageentry_index; |
248 |
|
249 |
pagetable_index = offset / s->block_size; |
250 |
pageentry_index = (offset % s->block_size) / 512;
|
251 |
|
252 |
if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff) |
253 |
return -1; // not allocated |
254 |
|
255 |
bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index];
|
256 |
block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index);
|
257 |
|
258 |
// We must ensure that we don't write to any sectors which are marked as
|
259 |
// unused in the bitmap. We get away with setting all bits in the block
|
260 |
// bitmap each time we write to a new block. This might cause Virtual PC to
|
261 |
// miss sparse read optimization, but it's not a problem in terms of
|
262 |
// correctness.
|
263 |
if (write && (s->last_bitmap_offset != bitmap_offset)) {
|
264 |
uint8_t bitmap[s->bitmap_size]; |
265 |
|
266 |
s->last_bitmap_offset = bitmap_offset; |
267 |
memset(bitmap, 0xff, s->bitmap_size);
|
268 |
bdrv_pwrite(s->hd, bitmap_offset, bitmap, s->bitmap_size); |
269 |
} |
270 |
|
271 |
// printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
|
272 |
// sector_num, pagetable_index, pageentry_index,
|
273 |
// bitmap_offset, block_offset);
|
274 |
|
275 |
// disabled by reason
|
276 |
#if 0
|
277 |
#ifdef CACHE
|
278 |
if (bitmap_offset != s->last_bitmap)
|
279 |
{
|
280 |
lseek(s->fd, bitmap_offset, SEEK_SET);
|
281 |
|
282 |
s->last_bitmap = bitmap_offset;
|
283 |
|
284 |
// Scary! Bitmap is stored as big endian 32bit entries,
|
285 |
// while we used to look it up byte by byte
|
286 |
read(s->fd, s->pageentry_u8, 512);
|
287 |
for (i = 0; i < 128; i++)
|
288 |
be32_to_cpus(&s->pageentry_u32[i]);
|
289 |
}
|
290 |
|
291 |
if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
|
292 |
return -1;
|
293 |
#else
|
294 |
lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
|
295 |
|
296 |
read(s->fd, &bitmap_entry, 1);
|
297 |
|
298 |
if ((bitmap_entry >> (pageentry_index % 8)) & 1) |
299 |
return -1; // not allocated |
300 |
#endif
|
301 |
#endif
|
302 |
|
303 |
return block_offset;
|
304 |
} |
305 |
|
306 |
/*
|
307 |
* Writes the footer to the end of the image file. This is needed when the
|
308 |
* file grows as it overwrites the old footer
|
309 |
*
|
310 |
* Returns 0 on success and < 0 on error
|
311 |
*/
|
312 |
static int rewrite_footer(BlockDriverState* bs) |
313 |
{ |
314 |
int ret;
|
315 |
BDRVVPCState *s = bs->opaque; |
316 |
int64_t offset = s->free_data_block_offset; |
317 |
|
318 |
ret = bdrv_pwrite(s->hd, offset, s->footer_buf, HEADER_SIZE); |
319 |
if (ret < 0) |
320 |
return ret;
|
321 |
|
322 |
return 0; |
323 |
} |
324 |
|
325 |
/*
|
326 |
* Allocates a new block. This involves writing a new footer and updating
|
327 |
* the Block Allocation Table to use the space at the old end of the image
|
328 |
* file (overwriting the old footer)
|
329 |
*
|
330 |
* Returns the sectors' offset in the image file on success and < 0 on error
|
331 |
*/
|
332 |
static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num)
|
333 |
{ |
334 |
BDRVVPCState *s = bs->opaque; |
335 |
int64_t bat_offset; |
336 |
uint32_t index, bat_value; |
337 |
int ret;
|
338 |
uint8_t bitmap[s->bitmap_size]; |
339 |
|
340 |
// Check if sector_num is valid
|
341 |
if ((sector_num < 0) || (sector_num > bs->total_sectors)) |
342 |
return -1; |
343 |
|
344 |
// Write entry into in-memory BAT
|
345 |
index = (sector_num * 512) / s->block_size;
|
346 |
if (s->pagetable[index] != 0xFFFFFFFF) |
347 |
return -1; |
348 |
|
349 |
s->pagetable[index] = s->free_data_block_offset / 512;
|
350 |
|
351 |
// Initialize the block's bitmap
|
352 |
memset(bitmap, 0xff, s->bitmap_size);
|
353 |
bdrv_pwrite(s->hd, s->free_data_block_offset, bitmap, s->bitmap_size); |
354 |
|
355 |
// Write new footer (the old one will be overwritten)
|
356 |
s->free_data_block_offset += s->block_size + s->bitmap_size; |
357 |
ret = rewrite_footer(bs); |
358 |
if (ret < 0) |
359 |
goto fail;
|
360 |
|
361 |
// Write BAT entry to disk
|
362 |
bat_offset = s->bat_offset + (4 * index);
|
363 |
bat_value = be32_to_cpu(s->pagetable[index]); |
364 |
ret = bdrv_pwrite(s->hd, bat_offset, &bat_value, 4);
|
365 |
if (ret < 0) |
366 |
goto fail;
|
367 |
|
368 |
return get_sector_offset(bs, sector_num, 0); |
369 |
|
370 |
fail:
|
371 |
s->free_data_block_offset -= (s->block_size + s->bitmap_size); |
372 |
return -1; |
373 |
} |
374 |
|
375 |
static int vpc_read(BlockDriverState *bs, int64_t sector_num, |
376 |
uint8_t *buf, int nb_sectors)
|
377 |
{ |
378 |
BDRVVPCState *s = bs->opaque; |
379 |
int ret;
|
380 |
int64_t offset; |
381 |
|
382 |
while (nb_sectors > 0) { |
383 |
offset = get_sector_offset(bs, sector_num, 0);
|
384 |
|
385 |
if (offset == -1) { |
386 |
memset(buf, 0, 512); |
387 |
} else {
|
388 |
ret = bdrv_pread(s->hd, offset, buf, 512);
|
389 |
if (ret != 512) |
390 |
return -1; |
391 |
} |
392 |
|
393 |
nb_sectors--; |
394 |
sector_num++; |
395 |
buf += 512;
|
396 |
} |
397 |
return 0; |
398 |
} |
399 |
|
400 |
static int vpc_write(BlockDriverState *bs, int64_t sector_num, |
401 |
const uint8_t *buf, int nb_sectors) |
402 |
{ |
403 |
BDRVVPCState *s = bs->opaque; |
404 |
int64_t offset; |
405 |
int ret;
|
406 |
|
407 |
while (nb_sectors > 0) { |
408 |
offset = get_sector_offset(bs, sector_num, 1);
|
409 |
|
410 |
if (offset == -1) { |
411 |
offset = alloc_block(bs, sector_num); |
412 |
if (offset < 0) |
413 |
return -1; |
414 |
} |
415 |
|
416 |
ret = bdrv_pwrite(s->hd, offset, buf, 512);
|
417 |
if (ret != 512) |
418 |
return -1; |
419 |
|
420 |
nb_sectors--; |
421 |
sector_num++; |
422 |
buf += 512;
|
423 |
} |
424 |
|
425 |
return 0; |
426 |
} |
427 |
|
428 |
|
429 |
/*
|
430 |
* Calculates the number of cylinders, heads and sectors per cylinder
|
431 |
* based on a given number of sectors. This is the algorithm described
|
432 |
* in the VHD specification.
|
433 |
*
|
434 |
* Note that the geometry doesn't always exactly match total_sectors but
|
435 |
* may round it down.
|
436 |
*
|
437 |
* Returns 0 on success, -EFBIG if the size is larger than 127 GB
|
438 |
*/
|
439 |
static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, |
440 |
uint8_t* heads, uint8_t* secs_per_cyl) |
441 |
{ |
442 |
uint32_t cyls_times_heads; |
443 |
|
444 |
if (total_sectors > 65535 * 16 * 255) |
445 |
return -EFBIG;
|
446 |
|
447 |
if (total_sectors > 65535 * 16 * 63) { |
448 |
*secs_per_cyl = 255;
|
449 |
*heads = 16;
|
450 |
cyls_times_heads = total_sectors / *secs_per_cyl; |
451 |
} else {
|
452 |
*secs_per_cyl = 17;
|
453 |
cyls_times_heads = total_sectors / *secs_per_cyl; |
454 |
*heads = (cyls_times_heads + 1023) / 1024; |
455 |
|
456 |
if (*heads < 4) |
457 |
*heads = 4;
|
458 |
|
459 |
if (cyls_times_heads >= (*heads * 1024) || *heads > 16) { |
460 |
*secs_per_cyl = 31;
|
461 |
*heads = 16;
|
462 |
cyls_times_heads = total_sectors / *secs_per_cyl; |
463 |
} |
464 |
|
465 |
if (cyls_times_heads >= (*heads * 1024)) { |
466 |
*secs_per_cyl = 63;
|
467 |
*heads = 16;
|
468 |
cyls_times_heads = total_sectors / *secs_per_cyl; |
469 |
} |
470 |
} |
471 |
|
472 |
// Note: Rounding up deviates from the Virtual PC behaviour
|
473 |
// However, we need this to avoid truncating images in qemu-img convert
|
474 |
*cyls = (cyls_times_heads + *heads - 1) / *heads;
|
475 |
|
476 |
return 0; |
477 |
} |
478 |
|
479 |
static int vpc_create(const char *filename, int64_t total_sectors, |
480 |
const char *backing_file, int flags) |
481 |
{ |
482 |
uint8_t buf[1024];
|
483 |
struct vhd_footer* footer = (struct vhd_footer*) buf; |
484 |
struct vhd_dyndisk_header* dyndisk_header =
|
485 |
(struct vhd_dyndisk_header*) buf;
|
486 |
int fd, i;
|
487 |
uint16_t cyls; |
488 |
uint8_t heads; |
489 |
uint8_t secs_per_cyl; |
490 |
size_t block_size, num_bat_entries; |
491 |
|
492 |
if (backing_file != NULL) |
493 |
return -ENOTSUP;
|
494 |
|
495 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
496 |
if (fd < 0) |
497 |
return -EIO;
|
498 |
|
499 |
// Calculate matching total_size and geometry
|
500 |
if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl))
|
501 |
return -EFBIG;
|
502 |
total_sectors = (int64_t) cyls * heads * secs_per_cyl; |
503 |
|
504 |
// Prepare the Hard Disk Footer
|
505 |
memset(buf, 0, 1024); |
506 |
|
507 |
strncpy(footer->creator, "conectix", 8); |
508 |
// TODO Check if "qemu" creator_app is ok for VPC
|
509 |
strncpy(footer->creator_app, "qemu", 4); |
510 |
strncpy(footer->creator_os, "Wi2k", 4); |
511 |
|
512 |
footer->features = be32_to_cpu(0x02);
|
513 |
footer->version = be32_to_cpu(0x00010000);
|
514 |
footer->data_offset = be64_to_cpu(HEADER_SIZE); |
515 |
footer->timestamp = be32_to_cpu(time(NULL) - VHD_TIMESTAMP_BASE);
|
516 |
|
517 |
// Version of Virtual PC 2007
|
518 |
footer->major = be16_to_cpu(0x0005);
|
519 |
footer->minor =be16_to_cpu(0x0003);
|
520 |
|
521 |
footer->orig_size = be64_to_cpu(total_sectors * 512);
|
522 |
footer->size = be64_to_cpu(total_sectors * 512);
|
523 |
|
524 |
footer->cyls = be16_to_cpu(cyls); |
525 |
footer->heads = heads; |
526 |
footer->secs_per_cyl = secs_per_cyl; |
527 |
|
528 |
footer->type = be32_to_cpu(VHD_DYNAMIC); |
529 |
|
530 |
// TODO uuid is missing
|
531 |
|
532 |
footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE)); |
533 |
|
534 |
// Write the footer (twice: at the beginning and at the end)
|
535 |
block_size = 0x200000;
|
536 |
num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512); |
537 |
|
538 |
if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE)
|
539 |
return -EIO;
|
540 |
|
541 |
if (lseek(fd, 1536 + ((num_bat_entries * 4 + 511) & ~511), SEEK_SET) < 0) |
542 |
return -EIO;
|
543 |
if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE)
|
544 |
return -EIO;
|
545 |
|
546 |
// Write the initial BAT
|
547 |
if (lseek(fd, 3 * 512, SEEK_SET) < 0) |
548 |
return -EIO;
|
549 |
|
550 |
memset(buf, 0xFF, 512); |
551 |
for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) |
552 |
if (write(fd, buf, 512) != 512) |
553 |
return -EIO;
|
554 |
|
555 |
|
556 |
// Prepare the Dynamic Disk Header
|
557 |
memset(buf, 0, 1024); |
558 |
|
559 |
strncpy(dyndisk_header->magic, "cxsparse", 8); |
560 |
|
561 |
dyndisk_header->data_offset = be64_to_cpu(0xFFFFFFFF);
|
562 |
dyndisk_header->table_offset = be64_to_cpu(3 * 512); |
563 |
dyndisk_header->version = be32_to_cpu(0x00010000);
|
564 |
dyndisk_header->block_size = be32_to_cpu(block_size); |
565 |
dyndisk_header->max_table_entries = be32_to_cpu(num_bat_entries); |
566 |
|
567 |
dyndisk_header->checksum = be32_to_cpu(vpc_checksum(buf, 1024));
|
568 |
|
569 |
// Write the header
|
570 |
if (lseek(fd, 512, SEEK_SET) < 0) |
571 |
return -EIO;
|
572 |
if (write(fd, buf, 1024) != 1024) |
573 |
return -EIO;
|
574 |
|
575 |
close(fd); |
576 |
return 0; |
577 |
} |
578 |
|
579 |
static void vpc_close(BlockDriverState *bs) |
580 |
{ |
581 |
BDRVVPCState *s = bs->opaque; |
582 |
qemu_free(s->pagetable); |
583 |
#ifdef CACHE
|
584 |
qemu_free(s->pageentry_u8); |
585 |
#endif
|
586 |
bdrv_delete(s->hd); |
587 |
} |
588 |
|
589 |
BlockDriver bdrv_vpc = { |
590 |
.format_name = "vpc",
|
591 |
.instance_size = sizeof(BDRVVPCState),
|
592 |
.bdrv_probe = vpc_probe, |
593 |
.bdrv_open = vpc_open, |
594 |
.bdrv_read = vpc_read, |
595 |
.bdrv_write = vpc_write, |
596 |
.bdrv_close = vpc_close, |
597 |
.bdrv_create = vpc_create, |
598 |
}; |