Annotation of qemu/block-vmdk.c, revision 1.1.1.3

1.1       root        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;
1.1.1.2   root      126:         bs->total_sectors = le64_to_cpu(header.capacity);
                    127:         s->cluster_sectors = le64_to_cpu(header.granularity);
1.1       root      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: 
1.1.1.3 ! root      429: static void vmdk_flush(BlockDriverState *bs)
        !           430: {
        !           431:     BDRVVmdkState *s = bs->opaque;
        !           432:     fsync(s->fd);
        !           433: }
        !           434: 
1.1       root      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,
1.1.1.3 ! root      444:     vmdk_flush,
1.1       root      445:     vmdk_is_allocated,
                    446: };

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