David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 1 | /* |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 2 | * Block driver for Connectix / Microsoft Virtual PC images |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 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 | #include "module.h" |
| 28 | |
| 29 | /**************************************************************/ |
| 30 | |
| 31 | #define HEADER_SIZE 512 |
| 32 | |
| 33 | //#define CACHE |
| 34 | |
| 35 | enum vhd_type { |
| 36 | VHD_FIXED = 2, |
| 37 | VHD_DYNAMIC = 3, |
| 38 | VHD_DIFFERENCING = 4, |
| 39 | }; |
| 40 | |
| 41 | // Seconds since Jan 1, 2000 0:00:00 (UTC) |
| 42 | #define VHD_TIMESTAMP_BASE 946684800 |
| 43 | |
| 44 | // always big-endian |
| 45 | struct vhd_footer { |
| 46 | char creator[8]; // "conectix" |
| 47 | uint32_t features; |
| 48 | uint32_t version; |
| 49 | |
| 50 | // Offset of next header structure, 0xFFFFFFFF if none |
| 51 | uint64_t data_offset; |
| 52 | |
| 53 | // Seconds since Jan 1, 2000 0:00:00 (UTC) |
| 54 | uint32_t timestamp; |
| 55 | |
| 56 | char creator_app[4]; // "vpc " |
| 57 | uint16_t major; |
| 58 | uint16_t minor; |
| 59 | char creator_os[4]; // "Wi2k" |
| 60 | |
| 61 | uint64_t orig_size; |
| 62 | uint64_t size; |
| 63 | |
| 64 | uint16_t cyls; |
| 65 | uint8_t heads; |
| 66 | uint8_t secs_per_cyl; |
| 67 | |
| 68 | uint32_t type; |
| 69 | |
| 70 | // Checksum of the Hard Disk Footer ("one's complement of the sum of all |
| 71 | // the bytes in the footer without the checksum field") |
| 72 | uint32_t checksum; |
| 73 | |
| 74 | // UUID used to identify a parent hard disk (backing file) |
| 75 | uint8_t uuid[16]; |
| 76 | |
| 77 | uint8_t in_saved_state; |
| 78 | }; |
| 79 | |
| 80 | struct vhd_dyndisk_header { |
| 81 | char magic[8]; // "cxsparse" |
| 82 | |
| 83 | // Offset of next header structure, 0xFFFFFFFF if none |
| 84 | uint64_t data_offset; |
| 85 | |
| 86 | // Offset of the Block Allocation Table (BAT) |
| 87 | uint64_t table_offset; |
| 88 | |
| 89 | uint32_t version; |
| 90 | uint32_t max_table_entries; // 32bit/entry |
| 91 | |
| 92 | // 2 MB by default, must be a power of two |
| 93 | uint32_t block_size; |
| 94 | |
| 95 | uint32_t checksum; |
| 96 | uint8_t parent_uuid[16]; |
| 97 | uint32_t parent_timestamp; |
| 98 | uint32_t reserved; |
| 99 | |
| 100 | // Backing file name (in UTF-16) |
| 101 | uint8_t parent_name[512]; |
| 102 | |
| 103 | struct { |
| 104 | uint32_t platform; |
| 105 | uint32_t data_space; |
| 106 | uint32_t data_length; |
| 107 | uint32_t reserved; |
| 108 | uint64_t data_offset; |
| 109 | } parent_locator[8]; |
| 110 | }; |
| 111 | |
| 112 | typedef struct BDRVVPCState { |
| 113 | BlockDriverState *hd; |
| 114 | |
| 115 | uint8_t footer_buf[HEADER_SIZE]; |
| 116 | uint64_t free_data_block_offset; |
| 117 | int max_table_entries; |
| 118 | uint32_t *pagetable; |
| 119 | uint64_t bat_offset; |
| 120 | uint64_t last_bitmap_offset; |
| 121 | |
| 122 | uint32_t block_size; |
| 123 | uint32_t bitmap_size; |
| 124 | |
| 125 | #ifdef CACHE |
| 126 | uint8_t *pageentry_u8; |
| 127 | uint32_t *pageentry_u32; |
| 128 | uint16_t *pageentry_u16; |
| 129 | |
| 130 | uint64_t last_bitmap; |
| 131 | #endif |
| 132 | } BDRVVPCState; |
| 133 | |
| 134 | static uint32_t vpc_checksum(uint8_t* buf, size_t size) |
| 135 | { |
| 136 | uint32_t res = 0; |
| 137 | int i; |
| 138 | |
| 139 | for (i = 0; i < size; i++) |
| 140 | res += buf[i]; |
| 141 | |
| 142 | return ~res; |
| 143 | } |
| 144 | |
| 145 | |
| 146 | static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) |
| 147 | { |
| 148 | if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) |
| 149 | return 100; |
| 150 | return 0; |
| 151 | } |
| 152 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 153 | static int vpc_open(BlockDriverState *bs, int flags) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 154 | { |
| 155 | BDRVVPCState *s = bs->opaque; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 156 | int i; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 157 | struct vhd_footer* footer; |
| 158 | struct vhd_dyndisk_header* dyndisk_header; |
| 159 | uint8_t buf[HEADER_SIZE]; |
| 160 | uint32_t checksum; |
| 161 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 162 | if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 163 | goto fail; |
| 164 | |
| 165 | footer = (struct vhd_footer*) s->footer_buf; |
| 166 | if (strncmp(footer->creator, "conectix", 8)) |
| 167 | goto fail; |
| 168 | |
| 169 | checksum = be32_to_cpu(footer->checksum); |
| 170 | footer->checksum = 0; |
| 171 | if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum) |
| 172 | fprintf(stderr, "block-vpc: The header checksum of '%s' is " |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 173 | "incorrect.\n", bs->filename); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 174 | |
| 175 | // The visible size of a image in Virtual PC depends on the geometry |
| 176 | // rather than on the size stored in the footer (the size in the footer |
| 177 | // is too large usually) |
| 178 | bs->total_sectors = (int64_t) |
| 179 | be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl; |
| 180 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 181 | if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE) |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 182 | != HEADER_SIZE) |
| 183 | goto fail; |
| 184 | |
| 185 | dyndisk_header = (struct vhd_dyndisk_header*) buf; |
| 186 | |
| 187 | if (strncmp(dyndisk_header->magic, "cxsparse", 8)) |
| 188 | goto fail; |
| 189 | |
| 190 | |
| 191 | s->block_size = be32_to_cpu(dyndisk_header->block_size); |
| 192 | s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511; |
| 193 | |
| 194 | s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries); |
| 195 | s->pagetable = qemu_malloc(s->max_table_entries * 4); |
| 196 | |
| 197 | s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 198 | if (bdrv_pread(bs->file, s->bat_offset, s->pagetable, |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 199 | s->max_table_entries * 4) != s->max_table_entries * 4) |
| 200 | goto fail; |
| 201 | |
| 202 | s->free_data_block_offset = |
| 203 | (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; |
| 204 | |
| 205 | for (i = 0; i < s->max_table_entries; i++) { |
| 206 | be32_to_cpus(&s->pagetable[i]); |
| 207 | if (s->pagetable[i] != 0xFFFFFFFF) { |
| 208 | int64_t next = (512 * (int64_t) s->pagetable[i]) + |
| 209 | s->bitmap_size + s->block_size; |
| 210 | |
| 211 | if (next> s->free_data_block_offset) |
| 212 | s->free_data_block_offset = next; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | s->last_bitmap_offset = (int64_t) -1; |
| 217 | |
| 218 | #ifdef CACHE |
| 219 | s->pageentry_u8 = qemu_malloc(512); |
| 220 | s->pageentry_u32 = s->pageentry_u8; |
| 221 | s->pageentry_u16 = s->pageentry_u8; |
| 222 | s->last_pagetable = -1; |
| 223 | #endif |
| 224 | |
| 225 | return 0; |
| 226 | fail: |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 227 | return -1; |
| 228 | } |
| 229 | |
| 230 | /* |
| 231 | * Returns the absolute byte offset of the given sector in the image file. |
| 232 | * If the sector is not allocated, -1 is returned instead. |
| 233 | * |
| 234 | * The parameter write must be 1 if the offset will be used for a write |
| 235 | * operation (the block bitmaps is updated then), 0 otherwise. |
| 236 | */ |
| 237 | static inline int64_t get_sector_offset(BlockDriverState *bs, |
| 238 | int64_t sector_num, int write) |
| 239 | { |
| 240 | BDRVVPCState *s = bs->opaque; |
| 241 | uint64_t offset = sector_num * 512; |
| 242 | uint64_t bitmap_offset, block_offset; |
| 243 | uint32_t pagetable_index, pageentry_index; |
| 244 | |
| 245 | pagetable_index = offset / s->block_size; |
| 246 | pageentry_index = (offset % s->block_size) / 512; |
| 247 | |
| 248 | if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff) |
| 249 | return -1; // not allocated |
| 250 | |
| 251 | bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; |
| 252 | block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index); |
| 253 | |
| 254 | // We must ensure that we don't write to any sectors which are marked as |
| 255 | // unused in the bitmap. We get away with setting all bits in the block |
| 256 | // bitmap each time we write to a new block. This might cause Virtual PC to |
| 257 | // miss sparse read optimization, but it's not a problem in terms of |
| 258 | // correctness. |
| 259 | if (write && (s->last_bitmap_offset != bitmap_offset)) { |
| 260 | uint8_t bitmap[s->bitmap_size]; |
| 261 | |
| 262 | s->last_bitmap_offset = bitmap_offset; |
| 263 | memset(bitmap, 0xff, s->bitmap_size); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 264 | bdrv_pwrite_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 265 | } |
| 266 | |
| 267 | // printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", |
| 268 | // sector_num, pagetable_index, pageentry_index, |
| 269 | // bitmap_offset, block_offset); |
| 270 | |
| 271 | // disabled by reason |
| 272 | #if 0 |
| 273 | #ifdef CACHE |
| 274 | if (bitmap_offset != s->last_bitmap) |
| 275 | { |
| 276 | lseek(s->fd, bitmap_offset, SEEK_SET); |
| 277 | |
| 278 | s->last_bitmap = bitmap_offset; |
| 279 | |
| 280 | // Scary! Bitmap is stored as big endian 32bit entries, |
| 281 | // while we used to look it up byte by byte |
| 282 | read(s->fd, s->pageentry_u8, 512); |
| 283 | for (i = 0; i < 128; i++) |
| 284 | be32_to_cpus(&s->pageentry_u32[i]); |
| 285 | } |
| 286 | |
| 287 | if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1) |
| 288 | return -1; |
| 289 | #else |
| 290 | lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET); |
| 291 | |
| 292 | read(s->fd, &bitmap_entry, 1); |
| 293 | |
| 294 | if ((bitmap_entry >> (pageentry_index % 8)) & 1) |
| 295 | return -1; // not allocated |
| 296 | #endif |
| 297 | #endif |
| 298 | |
| 299 | return block_offset; |
| 300 | } |
| 301 | |
| 302 | /* |
| 303 | * Writes the footer to the end of the image file. This is needed when the |
| 304 | * file grows as it overwrites the old footer |
| 305 | * |
| 306 | * Returns 0 on success and < 0 on error |
| 307 | */ |
| 308 | static int rewrite_footer(BlockDriverState* bs) |
| 309 | { |
| 310 | int ret; |
| 311 | BDRVVPCState *s = bs->opaque; |
| 312 | int64_t offset = s->free_data_block_offset; |
| 313 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 314 | ret = bdrv_pwrite_sync(bs->file, offset, s->footer_buf, HEADER_SIZE); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 315 | if (ret < 0) |
| 316 | return ret; |
| 317 | |
| 318 | return 0; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | * Allocates a new block. This involves writing a new footer and updating |
| 323 | * the Block Allocation Table to use the space at the old end of the image |
| 324 | * file (overwriting the old footer) |
| 325 | * |
| 326 | * Returns the sectors' offset in the image file on success and < 0 on error |
| 327 | */ |
| 328 | static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) |
| 329 | { |
| 330 | BDRVVPCState *s = bs->opaque; |
| 331 | int64_t bat_offset; |
| 332 | uint32_t index, bat_value; |
| 333 | int ret; |
| 334 | uint8_t bitmap[s->bitmap_size]; |
| 335 | |
| 336 | // Check if sector_num is valid |
| 337 | if ((sector_num < 0) || (sector_num > bs->total_sectors)) |
| 338 | return -1; |
| 339 | |
| 340 | // Write entry into in-memory BAT |
| 341 | index = (sector_num * 512) / s->block_size; |
| 342 | if (s->pagetable[index] != 0xFFFFFFFF) |
| 343 | return -1; |
| 344 | |
| 345 | s->pagetable[index] = s->free_data_block_offset / 512; |
| 346 | |
| 347 | // Initialize the block's bitmap |
| 348 | memset(bitmap, 0xff, s->bitmap_size); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 349 | bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap, |
| 350 | s->bitmap_size); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 351 | |
| 352 | // Write new footer (the old one will be overwritten) |
| 353 | s->free_data_block_offset += s->block_size + s->bitmap_size; |
| 354 | ret = rewrite_footer(bs); |
| 355 | if (ret < 0) |
| 356 | goto fail; |
| 357 | |
| 358 | // Write BAT entry to disk |
| 359 | bat_offset = s->bat_offset + (4 * index); |
| 360 | bat_value = be32_to_cpu(s->pagetable[index]); |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 361 | ret = bdrv_pwrite_sync(bs->file, bat_offset, &bat_value, 4); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 362 | if (ret < 0) |
| 363 | goto fail; |
| 364 | |
| 365 | return get_sector_offset(bs, sector_num, 0); |
| 366 | |
| 367 | fail: |
| 368 | s->free_data_block_offset -= (s->block_size + s->bitmap_size); |
| 369 | return -1; |
| 370 | } |
| 371 | |
| 372 | static int vpc_read(BlockDriverState *bs, int64_t sector_num, |
| 373 | uint8_t *buf, int nb_sectors) |
| 374 | { |
| 375 | BDRVVPCState *s = bs->opaque; |
| 376 | int ret; |
| 377 | int64_t offset; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 378 | int64_t sectors, sectors_per_block; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 379 | |
| 380 | while (nb_sectors > 0) { |
| 381 | offset = get_sector_offset(bs, sector_num, 0); |
| 382 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 383 | sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; |
| 384 | sectors = sectors_per_block - (sector_num % sectors_per_block); |
| 385 | if (sectors > nb_sectors) { |
| 386 | sectors = nb_sectors; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 387 | } |
| 388 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 389 | if (offset == -1) { |
| 390 | memset(buf, 0, sectors * BDRV_SECTOR_SIZE); |
| 391 | } else { |
| 392 | ret = bdrv_pread(bs->file, offset, buf, |
| 393 | sectors * BDRV_SECTOR_SIZE); |
| 394 | if (ret != sectors * BDRV_SECTOR_SIZE) { |
| 395 | return -1; |
| 396 | } |
| 397 | } |
| 398 | |
| 399 | nb_sectors -= sectors; |
| 400 | sector_num += sectors; |
| 401 | buf += sectors * BDRV_SECTOR_SIZE; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 402 | } |
| 403 | return 0; |
| 404 | } |
| 405 | |
| 406 | static int vpc_write(BlockDriverState *bs, int64_t sector_num, |
| 407 | const uint8_t *buf, int nb_sectors) |
| 408 | { |
| 409 | BDRVVPCState *s = bs->opaque; |
| 410 | int64_t offset; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 411 | int64_t sectors, sectors_per_block; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 412 | int ret; |
| 413 | |
| 414 | while (nb_sectors > 0) { |
| 415 | offset = get_sector_offset(bs, sector_num, 1); |
| 416 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 417 | sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; |
| 418 | sectors = sectors_per_block - (sector_num % sectors_per_block); |
| 419 | if (sectors > nb_sectors) { |
| 420 | sectors = nb_sectors; |
| 421 | } |
| 422 | |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 423 | if (offset == -1) { |
| 424 | offset = alloc_block(bs, sector_num); |
| 425 | if (offset < 0) |
| 426 | return -1; |
| 427 | } |
| 428 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 429 | ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE); |
| 430 | if (ret != sectors * BDRV_SECTOR_SIZE) { |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 431 | return -1; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 432 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 433 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 434 | nb_sectors -= sectors; |
| 435 | sector_num += sectors; |
| 436 | buf += sectors * BDRV_SECTOR_SIZE; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 437 | } |
| 438 | |
| 439 | return 0; |
| 440 | } |
| 441 | |
| 442 | |
| 443 | /* |
| 444 | * Calculates the number of cylinders, heads and sectors per cylinder |
| 445 | * based on a given number of sectors. This is the algorithm described |
| 446 | * in the VHD specification. |
| 447 | * |
| 448 | * Note that the geometry doesn't always exactly match total_sectors but |
| 449 | * may round it down. |
| 450 | * |
| 451 | * Returns 0 on success, -EFBIG if the size is larger than 127 GB |
| 452 | */ |
| 453 | static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, |
| 454 | uint8_t* heads, uint8_t* secs_per_cyl) |
| 455 | { |
| 456 | uint32_t cyls_times_heads; |
| 457 | |
| 458 | if (total_sectors > 65535 * 16 * 255) |
| 459 | return -EFBIG; |
| 460 | |
| 461 | if (total_sectors > 65535 * 16 * 63) { |
| 462 | *secs_per_cyl = 255; |
| 463 | *heads = 16; |
| 464 | cyls_times_heads = total_sectors / *secs_per_cyl; |
| 465 | } else { |
| 466 | *secs_per_cyl = 17; |
| 467 | cyls_times_heads = total_sectors / *secs_per_cyl; |
| 468 | *heads = (cyls_times_heads + 1023) / 1024; |
| 469 | |
| 470 | if (*heads < 4) |
| 471 | *heads = 4; |
| 472 | |
| 473 | if (cyls_times_heads >= (*heads * 1024) || *heads > 16) { |
| 474 | *secs_per_cyl = 31; |
| 475 | *heads = 16; |
| 476 | cyls_times_heads = total_sectors / *secs_per_cyl; |
| 477 | } |
| 478 | |
| 479 | if (cyls_times_heads >= (*heads * 1024)) { |
| 480 | *secs_per_cyl = 63; |
| 481 | *heads = 16; |
| 482 | cyls_times_heads = total_sectors / *secs_per_cyl; |
| 483 | } |
| 484 | } |
| 485 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 486 | *cyls = cyls_times_heads / *heads; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 487 | |
| 488 | return 0; |
| 489 | } |
| 490 | |
| 491 | static int vpc_create(const char *filename, QEMUOptionParameter *options) |
| 492 | { |
| 493 | uint8_t buf[1024]; |
| 494 | struct vhd_footer* footer = (struct vhd_footer*) buf; |
| 495 | struct vhd_dyndisk_header* dyndisk_header = |
| 496 | (struct vhd_dyndisk_header*) buf; |
| 497 | int fd, i; |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 498 | uint16_t cyls = 0; |
| 499 | uint8_t heads = 0; |
| 500 | uint8_t secs_per_cyl = 0; |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 501 | size_t block_size, num_bat_entries; |
| 502 | int64_t total_sectors = 0; |
| 503 | |
| 504 | // Read out options |
| 505 | while (options && options->name) { |
| 506 | if (!strcmp(options->name, "size")) { |
| 507 | total_sectors = options->value.n / 512; |
| 508 | } |
| 509 | options++; |
| 510 | } |
| 511 | |
| 512 | // Create the file |
| 513 | fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); |
| 514 | if (fd < 0) |
| 515 | return -EIO; |
| 516 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 517 | /* Calculate matching total_size and geometry. Increase the number of |
| 518 | sectors requested until we get enough (or fail). */ |
| 519 | for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) { |
| 520 | if (calculate_geometry(total_sectors + i, |
| 521 | &cyls, &heads, &secs_per_cyl)) { |
| 522 | return -EFBIG; |
| 523 | } |
| 524 | } |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 525 | total_sectors = (int64_t) cyls * heads * secs_per_cyl; |
| 526 | |
| 527 | // Prepare the Hard Disk Footer |
| 528 | memset(buf, 0, 1024); |
| 529 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 530 | memcpy(footer->creator, "conectix", 8); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 531 | // TODO Check if "qemu" creator_app is ok for VPC |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 532 | memcpy(footer->creator_app, "qemu", 4); |
| 533 | memcpy(footer->creator_os, "Wi2k", 4); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 534 | |
| 535 | footer->features = be32_to_cpu(0x02); |
| 536 | footer->version = be32_to_cpu(0x00010000); |
| 537 | footer->data_offset = be64_to_cpu(HEADER_SIZE); |
| 538 | footer->timestamp = be32_to_cpu(time(NULL) - VHD_TIMESTAMP_BASE); |
| 539 | |
| 540 | // Version of Virtual PC 2007 |
| 541 | footer->major = be16_to_cpu(0x0005); |
| 542 | footer->minor =be16_to_cpu(0x0003); |
| 543 | |
| 544 | footer->orig_size = be64_to_cpu(total_sectors * 512); |
| 545 | footer->size = be64_to_cpu(total_sectors * 512); |
| 546 | |
| 547 | footer->cyls = be16_to_cpu(cyls); |
| 548 | footer->heads = heads; |
| 549 | footer->secs_per_cyl = secs_per_cyl; |
| 550 | |
| 551 | footer->type = be32_to_cpu(VHD_DYNAMIC); |
| 552 | |
| 553 | // TODO uuid is missing |
| 554 | |
| 555 | footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE)); |
| 556 | |
| 557 | // Write the footer (twice: at the beginning and at the end) |
| 558 | block_size = 0x200000; |
| 559 | num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512); |
| 560 | |
| 561 | if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) |
| 562 | return -EIO; |
| 563 | |
| 564 | if (lseek(fd, 1536 + ((num_bat_entries * 4 + 511) & ~511), SEEK_SET) < 0) |
| 565 | return -EIO; |
| 566 | if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) |
| 567 | return -EIO; |
| 568 | |
| 569 | // Write the initial BAT |
| 570 | if (lseek(fd, 3 * 512, SEEK_SET) < 0) |
| 571 | return -EIO; |
| 572 | |
| 573 | memset(buf, 0xFF, 512); |
| 574 | for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) |
| 575 | if (write(fd, buf, 512) != 512) |
| 576 | return -EIO; |
| 577 | |
| 578 | |
| 579 | // Prepare the Dynamic Disk Header |
| 580 | memset(buf, 0, 1024); |
| 581 | |
David 'Digit' Turner | cb42a1b | 2010-12-23 02:54:08 +0100 | [diff] [blame] | 582 | memcpy(dyndisk_header->magic, "cxsparse", 8); |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 583 | |
| 584 | dyndisk_header->data_offset = be64_to_cpu(0xFFFFFFFF); |
| 585 | dyndisk_header->table_offset = be64_to_cpu(3 * 512); |
| 586 | dyndisk_header->version = be32_to_cpu(0x00010000); |
| 587 | dyndisk_header->block_size = be32_to_cpu(block_size); |
| 588 | dyndisk_header->max_table_entries = be32_to_cpu(num_bat_entries); |
| 589 | |
| 590 | dyndisk_header->checksum = be32_to_cpu(vpc_checksum(buf, 1024)); |
| 591 | |
| 592 | // Write the header |
| 593 | if (lseek(fd, 512, SEEK_SET) < 0) |
| 594 | return -EIO; |
| 595 | if (write(fd, buf, 1024) != 1024) |
| 596 | return -EIO; |
| 597 | |
| 598 | close(fd); |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | static void vpc_close(BlockDriverState *bs) |
| 603 | { |
| 604 | BDRVVPCState *s = bs->opaque; |
| 605 | qemu_free(s->pagetable); |
| 606 | #ifdef CACHE |
| 607 | qemu_free(s->pageentry_u8); |
| 608 | #endif |
David 'Digit' Turner | 5d8f37a | 2009-09-14 14:32:27 -0700 | [diff] [blame] | 609 | } |
| 610 | |
| 611 | static QEMUOptionParameter vpc_create_options[] = { |
| 612 | { |
| 613 | .name = BLOCK_OPT_SIZE, |
| 614 | .type = OPT_SIZE, |
| 615 | .help = "Virtual disk size" |
| 616 | }, |
| 617 | { NULL } |
| 618 | }; |
| 619 | |
| 620 | static BlockDriver bdrv_vpc = { |
| 621 | .format_name = "vpc", |
| 622 | .instance_size = sizeof(BDRVVPCState), |
| 623 | .bdrv_probe = vpc_probe, |
| 624 | .bdrv_open = vpc_open, |
| 625 | .bdrv_read = vpc_read, |
| 626 | .bdrv_write = vpc_write, |
| 627 | .bdrv_close = vpc_close, |
| 628 | .bdrv_create = vpc_create, |
| 629 | |
| 630 | .create_options = vpc_create_options, |
| 631 | }; |
| 632 | |
| 633 | static void bdrv_vpc_init(void) |
| 634 | { |
| 635 | bdrv_register(&bdrv_vpc); |
| 636 | } |
| 637 | |
| 638 | block_init(bdrv_vpc_init); |