diff options
Diffstat (limited to 'block-vmdk.c')
| -rw-r--r-- | block-vmdk.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/block-vmdk.c b/block-vmdk.c new file mode 100644 index 0000000000..d1414e4309 --- /dev/null +++ b/block-vmdk.c @@ -0,0 +1,278 @@ +/* + * Block driver for the VMDK format + * + * Copyright (c) 2004 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "vl.h" +#include "block_int.h" + +/* XXX: this code is untested */ +/* XXX: add write support */ + +#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D') +#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V') + +typedef struct { + uint32_t version; + uint32_t flags; + uint32_t disk_sectors; + uint32_t granularity; + uint32_t l1dir_offset; + uint32_t l1dir_size; + uint32_t file_sectors; + uint32_t cylinders; + uint32_t heads; + uint32_t sectors_per_track; +} VMDK3Header; + +typedef struct { + uint32_t version; + uint32_t flags; + int64_t capacity; + int64_t granularity; + int64_t desc_offset; + int64_t desc_size; + int32_t num_gtes_per_gte; + int64_t rgd_offset; + int64_t gd_offset; + int64_t grain_offset; + char filler[1]; + char check_bytes[4]; +} VMDK4Header; + +#define L2_CACHE_SIZE 16 + +typedef struct BDRVVmdkState { + int fd; + int64_t l1_table_offset; + uint32_t *l1_table; + unsigned int l1_size; + uint32_t l1_entry_sectors; + + unsigned int l2_size; + uint32_t *l2_cache; + uint32_t l2_cache_offsets[L2_CACHE_SIZE]; + uint32_t l2_cache_counts[L2_CACHE_SIZE]; + + unsigned int cluster_sectors; +} BDRVVmdkState; + +static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename) +{ + uint32_t magic; + + if (buf_size < 4) + return 0; + magic = be32_to_cpu(*(uint32_t *)buf); + if (magic == VMDK3_MAGIC || + magic == VMDK4_MAGIC) + return 100; + else + return 0; +} + +static int vmdk_open(BlockDriverState *bs, const char *filename) +{ + BDRVVmdkState *s = bs->opaque; + int fd, i; + uint32_t magic; + int l1_size; + + fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); + if (fd < 0) + return -1; + if (read(fd, &magic, sizeof(magic)) != sizeof(magic)) + goto fail; + magic = le32_to_cpu(magic); + + if (magic == VMDK3_MAGIC) { + VMDK3Header header; + if (read(fd, &header, sizeof(header)) != + sizeof(header)) + goto fail; + s->cluster_sectors = le32_to_cpu(header.granularity); + s->l2_size = 1 << 9; + s->l1_size = 1 << 6; + bs->total_sectors = le32_to_cpu(header.disk_sectors); + s->l1_table_offset = le32_to_cpu(header.l1dir_offset) * 512; + s->l1_entry_sectors = s->l2_size * s->cluster_sectors; + } else if (magic == VMDK4_MAGIC) { + VMDK4Header header; + + if (read(fd, &header, sizeof(header)) != sizeof(header)) + goto fail; + bs->total_sectors = le32_to_cpu(header.capacity); + s->cluster_sectors = le32_to_cpu(header.granularity); + s->l2_size = le32_to_cpu(header.num_gtes_per_gte); + s->l1_entry_sectors = s->l2_size * s->cluster_sectors; + if (s->l1_entry_sectors <= 0) + goto fail; + s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1) + / s->l1_entry_sectors; + s->l1_table_offset = le64_to_cpu(header.rgd_offset) * 512; + } else { + goto fail; + } + /* read the L1 table */ + l1_size = s->l1_size * sizeof(uint32_t); + s->l1_table = qemu_malloc(l1_size); + if (!s->l1_table) + goto fail; + if (read(s->fd, s->l1_table, l1_size) != l1_size) + goto fail; + for(i = 0; i < s->l1_size; i++) { + le32_to_cpus(&s->l1_table[i]); + } + + s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t)); + if (!s->l2_cache) + goto fail; + s->fd = fd; + /* XXX: currently only read only */ + bs->read_only = 1; + return 0; + fail: + qemu_free(s->l1_table); + qemu_free(s->l2_cache); + close(fd); + return -1; +} + +static uint64_t get_cluster_offset(BlockDriverState *bs, + uint64_t offset) +{ + BDRVVmdkState *s = bs->opaque; + unsigned int l1_index, l2_offset, l2_index; + int min_index, i, j; + uint32_t min_count, *l2_table; + uint64_t cluster_offset; + + l1_index = (offset >> 9) / s->l1_entry_sectors; + if (l1_index >= s->l1_size) + return 0; + l2_offset = s->l1_table[l1_index]; + if (!l2_offset) + return 0; + + for(i = 0; i < L2_CACHE_SIZE; i++) { + if (l2_offset == s->l2_cache_offsets[i]) { + /* increment the hit count */ + if (++s->l2_cache_counts[i] == 0xffffffff) { + for(j = 0; j < L2_CACHE_SIZE; j++) { + s->l2_cache_counts[j] >>= 1; + } + } + l2_table = s->l2_cache + (i * s->l2_size); + goto found; + } + } + /* not found: load a new entry in the least used one */ + min_index = 0; + min_count = 0xffffffff; + for(i = 0; i < L2_CACHE_SIZE; i++) { + if (s->l2_cache_counts[i] < min_count) { + min_count = s->l2_cache_counts[i]; + min_index = i; + } + } + l2_table = s->l2_cache + (min_index * s->l2_size); + lseek(s->fd, (int64_t)l2_offset * 512, SEEK_SET); + if (read(s->fd, l2_table, s->l2_size * sizeof(uint32_t)) != + s->l2_size * sizeof(uint32_t)) + return 0; + s->l2_cache_offsets[min_index] = l2_offset; + s->l2_cache_counts[min_index] = 1; + found: + l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size; + cluster_offset = le32_to_cpu(l2_table[l2_index]); + cluster_offset <<= 9; + return cluster_offset; +} + +static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, int *pnum) +{ + BDRVVmdkState *s = bs->opaque; + int index_in_cluster, n; + uint64_t cluster_offset; + + cluster_offset = get_cluster_offset(bs, sector_num << 9); + index_in_cluster = sector_num % s->cluster_sectors; + n = s->cluster_sectors - index_in_cluster; + if (n > nb_sectors) + n = nb_sectors; + *pnum = n; + return (cluster_offset != 0); +} + +static int vmdk_read(BlockDriverState *bs, int64_t sector_num, + uint8_t *buf, int nb_sectors) +{ + BDRVVmdkState *s = bs->opaque; + int ret, index_in_cluster, n; + uint64_t cluster_offset; + + while (nb_sectors > 0) { + cluster_offset = get_cluster_offset(bs, sector_num << 9); + index_in_cluster = sector_num % s->cluster_sectors; + n = s->cluster_sectors - index_in_cluster; + if (n > nb_sectors) + n = nb_sectors; + if (!cluster_offset) { + memset(buf, 0, 512 * n); + } else { + lseek64(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET); + ret = read(s->fd, buf, n * 512); + if (ret != n * 512) + return -1; + } + nb_sectors -= n; + sector_num += n; + buf += n * 512; + } + return 0; +} + +static int vmdk_write(BlockDriverState *bs, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + return -1; +} + +static int vmdk_close(BlockDriverState *bs) +{ + BDRVVmdkState *s = bs->opaque; + qemu_free(s->l1_table); + qemu_free(s->l2_cache); + close(s->fd); +} + +BlockDriver bdrv_vmdk = { + "vmdk", + sizeof(BDRVVmdkState), + vmdk_probe, + vmdk_open, + vmdk_read, + vmdk_write, + vmdk_close, + NULL, /* no create yet */ + vmdk_is_allocated, +}; |