block-vmdk.c

   1 /*
   2  * Block driver for the VMDK format
   3  *
   4  * Copyright (c) 2004 Fabrice Bellard
   5  * Copyright (c) 2005 Filip Navara
   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 "vl.h"
  26 #include "block_int.h"
  27
  28 #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
  29 #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
  30
  31 typedef struct {
  32     uint32_t version;
  33     uint32_t flags;
  34     uint32_t disk_sectors;
  35     uint32_t granularity;
  36     uint32_t l1dir_offset;
  37     uint32_t l1dir_size;
  38     uint32_t file_sectors;
  39     uint32_t cylinders;
  40     uint32_t heads;
  41     uint32_t sectors_per_track;
  42 } VMDK3Header;
  43
  44 typedef struct {
  45     uint32_t version;
  46     uint32_t flags;
  47     int64_t capacity;
  48     int64_t granularity;
  49     int64_t desc_offset;
  50     int64_t desc_size;
  51     int32_t num_gtes_per_gte;
  52     int64_t rgd_offset;
  53     int64_t gd_offset;
  54     int64_t grain_offset;
  55     char filler[1];
  56     char check_bytes[4];
  57 } __attribute__((packed)) VMDK4Header;
  58
  59 #define L2_CACHE_SIZE 16
  60
  61 typedef struct BDRVVmdkState {
  62     int fd;
  63     int64_t l1_table_offset;
  64     int64_t l1_backup_table_offset;
  65     uint32_t *l1_table;
  66     uint32_t *l1_backup_table;
  67     unsigned int l1_size;
  68     uint32_t l1_entry_sectors;
  69
  70     unsigned int l2_size;
  71     uint32_t *l2_cache;
  72     uint32_t l2_cache_offsets[L2_CACHE_SIZE];
  73     uint32_t l2_cache_counts[L2_CACHE_SIZE];
  74
  75     unsigned int cluster_sectors;
  76 } BDRVVmdkState;
  77
  78 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
  79 {
  80     uint32_t magic;
  81
  82     if (buf_size < 4)
  83         return 0;
  84     magic = be32_to_cpu(*(uint32_t *)buf);
  85     if (magic == VMDK3_MAGIC ||
  86         magic == VMDK4_MAGIC)
  87         return 100;
  88     else
  89         return 0;
  90 }
  91
  92 static int vmdk_open(BlockDriverState *bs, const char *filename)
  93 {
  94     BDRVVmdkState *s = bs->opaque;
  95     int fd, i;
  96     uint32_t magic;
  97     int l1_size;
  98
  99     fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
 100     if (fd < 0) {
 101         fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
 102         if (fd < 0)
 103             return -1;
 104         bs->read_only = 1;
 105     }
 106     if (read(fd, &magic, sizeof(magic)) != sizeof(magic))
 107         goto fail;
 108     magic = be32_to_cpu(magic);
 109     if (magic == VMDK3_MAGIC) {
 110         VMDK3Header header;
 111         if (read(fd, &header, sizeof(header)) !=
 112             sizeof(header))
 113             goto fail;
 114         s->cluster_sectors = le32_to_cpu(header.granularity);
 115         s->l2_size = 1 << 9;
 116         s->l1_size = 1 << 6;
 117         bs->total_sectors = le32_to_cpu(header.disk_sectors);
 118         s->l1_table_offset = le32_to_cpu(header.l1dir_offset) << 9;
 119         s->l1_backup_table_offset = 0;
 120         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 121     } else if (magic == VMDK4_MAGIC) {
 122         VMDK4Header header;
 123
 124         if (read(fd, &header, sizeof(header)) != sizeof(header))
 125             goto fail;
 126         bs->total_sectors = le64_to_cpu(header.capacity);
 127         s->cluster_sectors = le64_to_cpu(header.granularity);
 128         s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
 129         s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
 130         if (s->l1_entry_sectors <= 0)
 131             goto fail;
 132         s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
 133             / s->l1_entry_sectors;
 134         s->l1_table_offset = le64_to_cpu(header.rgd_offset) << 9;
 135         s->l1_backup_table_offset = le64_to_cpu(header.gd_offset) << 9;
 136     } else {
 137         goto fail;
 138     }
 139     /* read the L1 table */
 140     l1_size = s->l1_size * sizeof(uint32_t);
 141     s->l1_table = qemu_malloc(l1_size);
 142     if (!s->l1_table)
 143         goto fail;
 144     if (lseek(fd, s->l1_table_offset, SEEK_SET) == -1)
 145         goto fail;
 146     if (read(fd, s->l1_table, l1_size) != l1_size)
 147         goto fail;
 148     for(i = 0; i < s->l1_size; i++) {
 149         le32_to_cpus(&s->l1_table[i]);
 150     }
 151
 152     if (s->l1_backup_table_offset) {
 153         s->l1_backup_table = qemu_malloc(l1_size);
 154         if (!s->l1_backup_table)
 155             goto fail;
 156         if (lseek(fd, s->l1_backup_table_offset, SEEK_SET) == -1)
 157             goto fail;
 158         if (read(fd, s->l1_backup_table, l1_size) != l1_size)
 159             goto fail;
 160         for(i = 0; i < s->l1_size; i++) {
 161             le32_to_cpus(&s->l1_backup_table[i]);
 162         }
 163     }
 164
 165     s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
 166     if (!s->l2_cache)
 167         goto fail;
 168     s->fd = fd;
 169     return 0;
 170  fail:
 171     qemu_free(s->l1_backup_table);
 172     qemu_free(s->l1_table);
 173     qemu_free(s->l2_cache);
 174     close(fd);
 175     return -1;
 176 }
 177
 178 static uint64_t get_cluster_offset(BlockDriverState *bs,
 179                                    uint64_t offset, int allocate)
 180 {
 181     BDRVVmdkState *s = bs->opaque;
 182     unsigned int l1_index, l2_offset, l2_index;
 183     int min_index, i, j;
 184     uint32_t min_count, *l2_table, tmp;
 185     uint64_t cluster_offset;
 186
 187     l1_index = (offset >> 9) / s->l1_entry_sectors;
 188     if (l1_index >= s->l1_size)
 189         return 0;
 190     l2_offset = s->l1_table[l1_index];
 191     if (!l2_offset)
 192         return 0;
 193     for(i = 0; i < L2_CACHE_SIZE; i++) {
 194         if (l2_offset == s->l2_cache_offsets[i]) {
 195             /* increment the hit count */
 196             if (++s->l2_cache_counts[i] == 0xffffffff) {
 197                 for(j = 0; j < L2_CACHE_SIZE; j++) {
 198                     s->l2_cache_counts[j] >>= 1;
 199                 }
 200             }
 201             l2_table = s->l2_cache + (i * s->l2_size);
 202             goto found;
 203         }
 204     }
 205     /* not found: load a new entry in the least used one */
 206     min_index = 0;
 207     min_count = 0xffffffff;
 208     for(i = 0; i < L2_CACHE_SIZE; i++) {
 209         if (s->l2_cache_counts[i] < min_count) {
 210             min_count = s->l2_cache_counts[i];
 211             min_index = i;
 212         }
 213     }
 214     l2_table = s->l2_cache + (min_index * s->l2_size);
 215     lseek(s->fd, (int64_t)l2_offset * 512, SEEK_SET);
 216     if (read(s->fd, l2_table, s->l2_size * sizeof(uint32_t)) !=
 217         s->l2_size * sizeof(uint32_t))
 218         return 0;
 219     s->l2_cache_offsets[min_index] = l2_offset;
 220     s->l2_cache_counts[min_index] = 1;
 221  found:
 222     l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
 223     cluster_offset = le32_to_cpu(l2_table[l2_index]);
 224     if (!cluster_offset) {
 225         if (!allocate)
 226             return 0;
 227         cluster_offset = lseek(s->fd, 0, SEEK_END);
 228         ftruncate(s->fd, cluster_offset + (s->cluster_sectors << 9));
 229         cluster_offset >>= 9;
 230         /* update L2 table */
 231         tmp = cpu_to_le32(cluster_offset);
 232         l2_table[l2_index] = tmp;
 233         lseek(s->fd, ((int64_t)l2_offset * 512) + (l2_index * sizeof(tmp)), SEEK_SET);
 234         if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp))
 235             return 0;
 236         /* update backup L2 table */
 237         if (s->l1_backup_table_offset != 0) {
 238             l2_offset = s->l1_backup_table[l1_index];
 239             lseek(s->fd, ((int64_t)l2_offset * 512) + (l2_index * sizeof(tmp)), SEEK_SET);
 240             if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp))
 241                 return 0;
 242         }
 243     }
 244     cluster_offset <<= 9;
 245     return cluster_offset;
 246 }
 247
 248 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
 249                              int nb_sectors, int *pnum)
 250 {
 251     BDRVVmdkState *s = bs->opaque;
 252     int index_in_cluster, n;
 253     uint64_t cluster_offset;
 254
 255     cluster_offset = get_cluster_offset(bs, sector_num << 9, 0);
 256     index_in_cluster = sector_num % s->cluster_sectors;
 257     n = s->cluster_sectors - index_in_cluster;
 258     if (n > nb_sectors)
 259         n = nb_sectors;
 260     *pnum = n;
 261     return (cluster_offset != 0);
 262 }
 263
 264 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
 265                     uint8_t *buf, int nb_sectors)
 266 {
 267     BDRVVmdkState *s = bs->opaque;
 268     int ret, index_in_cluster, n;
 269     uint64_t cluster_offset;
 270
 271     while (nb_sectors > 0) {
 272         cluster_offset = get_cluster_offset(bs, sector_num << 9, 0);
 273         index_in_cluster = sector_num % s->cluster_sectors;
 274         n = s->cluster_sectors - index_in_cluster;
 275         if (n > nb_sectors)
 276             n = nb_sectors;
 277         if (!cluster_offset) {
 278             memset(buf, 0, 512 * n);
 279         } else {
 280             lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
 281             ret = read(s->fd, buf, n * 512);
 282             if (ret != n * 512)
 283                 return -1;
 284         }
 285         nb_sectors -= n;
 286         sector_num += n;
 287         buf += n * 512;
 288     }
 289     return 0;
 290 }
 291
 292 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
 293                      const uint8_t *buf, int nb_sectors)
 294 {
 295     BDRVVmdkState *s = bs->opaque;
 296     int ret, index_in_cluster, n;
 297     uint64_t cluster_offset;
 298
 299     while (nb_sectors > 0) {
 300         index_in_cluster = sector_num & (s->cluster_sectors - 1);
 301         n = s->cluster_sectors - index_in_cluster;
 302         if (n > nb_sectors)
 303             n = nb_sectors;
 304         cluster_offset = get_cluster_offset(bs, sector_num << 9, 1);
 305         if (!cluster_offset)
 306             return -1;
 307         lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
 308         ret = write(s->fd, buf, n * 512);
 309         if (ret != n * 512)
 310             return -1;
 311         nb_sectors -= n;
 312         sector_num += n;
 313         buf += n * 512;
 314     }
 315     return 0;
 316 }
 317
 318 static int vmdk_create(const char *filename, int64_t total_size,
 319                        const char *backing_file, int flags)
 320 {
 321     int fd, i;
 322     VMDK4Header header;
 323     uint32_t tmp, magic, grains, gd_size, gt_size, gt_count;
 324     char *desc_template =
 325         "# Disk DescriptorFile\n"
 326         "version=1\n"
 327         "CID=%x\n"
 328         "parentCID=ffffffff\n"
 329         "createType=\"monolithicSparse\"\n"
 330         "\n"
 331         "# Extent description\n"
 332         "RW %lu SPARSE \"%s\"\n"
 333         "\n"
 334         "# The Disk Data Base \n"
 335         "#DDB\n"
 336         "\n"
 337         "ddb.virtualHWVersion = \"3\"\n"
 338         "ddb.geometry.cylinders = \"%lu\"\n"
 339         "ddb.geometry.heads = \"16\"\n"
 340         "ddb.geometry.sectors = \"63\"\n"
 341         "ddb.adapterType = \"ide\"\n";
 342     char desc[1024];
 343     const char *real_filename, *temp_str;
 344
 345     /* XXX: add support for backing file */
 346
 347     fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
 348               0644);
 349     if (fd < 0)
 350         return -1;
 351     magic = cpu_to_be32(VMDK4_MAGIC);
 352     memset(&header, 0, sizeof(header));
 353     header.version = cpu_to_le32(1);
 354     header.flags = cpu_to_le32(3); /* ?? */
 355     header.capacity = cpu_to_le64(total_size);
 356     header.granularity = cpu_to_le64(128);
 357     header.num_gtes_per_gte = cpu_to_le32(512);
 358
 359     grains = (total_size + header.granularity - 1) / header.granularity;
 360     gt_size = ((header.num_gtes_per_gte * sizeof(uint32_t)) + 511) >> 9;
 361     gt_count = (grains + header.num_gtes_per_gte - 1) / header.num_gtes_per_gte;
 362     gd_size = (gt_count * sizeof(uint32_t) + 511) >> 9;
 363
 364     header.desc_offset = 1;
 365     header.desc_size = 20;
 366     header.rgd_offset = header.desc_offset + header.desc_size;
 367     header.gd_offset = header.rgd_offset + gd_size + (gt_size * gt_count);
 368     header.grain_offset =
 369        ((header.gd_offset + gd_size + (gt_size * gt_count) +
 370          header.granularity - 1) / header.granularity) *
 371         header.granularity;
 372
 373     header.desc_offset = cpu_to_le64(header.desc_offset);
 374     header.desc_size = cpu_to_le64(header.desc_size);
 375     header.rgd_offset = cpu_to_le64(header.rgd_offset);
 376     header.gd_offset = cpu_to_le64(header.gd_offset);
 377     header.grain_offset = cpu_to_le64(header.grain_offset);
 378
 379     header.check_bytes[0] = 0xa;
 380     header.check_bytes[1] = 0x20;
 381     header.check_bytes[2] = 0xd;
 382     header.check_bytes[3] = 0xa;
 383
 384     /* write all the data */
 385     write(fd, &magic, sizeof(magic));
 386     write(fd, &header, sizeof(header));
 387
 388     ftruncate(fd, header.grain_offset << 9);
 389
 390     /* write grain directory */
 391     lseek(fd, le64_to_cpu(header.rgd_offset) << 9, SEEK_SET);
 392     for (i = 0, tmp = header.rgd_offset + gd_size;
 393          i < gt_count; i++, tmp += gt_size)
 394         write(fd, &tmp, sizeof(tmp));
 395
 396     /* write backup grain directory */
 397     lseek(fd, le64_to_cpu(header.gd_offset) << 9, SEEK_SET);
 398     for (i = 0, tmp = header.gd_offset + gd_size;
 399          i < gt_count; i++, tmp += gt_size)
 400         write(fd, &tmp, sizeof(tmp));
 401
 402     /* compose the descriptor */
 403     real_filename = filename;
 404     if ((temp_str = strrchr(real_filename, '\\')) != NULL)
 405         real_filename = temp_str + 1;
 406     if ((temp_str = strrchr(real_filename, '/')) != NULL)
 407         real_filename = temp_str + 1;
 408     if ((temp_str = strrchr(real_filename, ':')) != NULL)
 409         real_filename = temp_str + 1;
 410     sprintf(desc, desc_template, time(NULL), (unsigned long)total_size,
 411             real_filename, total_size / (63 * 16));
 412
 413     /* write the descriptor */
 414     lseek(fd, le64_to_cpu(header.desc_offset) << 9, SEEK_SET);
 415     write(fd, desc, strlen(desc));
 416
 417     close(fd);
 418     return 0;
 419 }
 420
 421 static void vmdk_close(BlockDriverState *bs)
 422 {
 423     BDRVVmdkState *s = bs->opaque;
 424     qemu_free(s->l1_table);
 425     qemu_free(s->l2_cache);
 426     close(s->fd);
 427 }
 428
 429 static void vmdk_flush(BlockDriverState *bs)
 430 {
 431     BDRVVmdkState *s = bs->opaque;
 432     fsync(s->fd);
 433 }
 434
 435 BlockDriver bdrv_vmdk = {
 436     "vmdk",
 437     sizeof(BDRVVmdkState),
 438     vmdk_probe,
 439     vmdk_open,
 440     vmdk_read,
 441     vmdk_write,
 442     vmdk_close,
 443     vmdk_create,
 444     vmdk_flush,
 445     vmdk_is_allocated,
 446 };