static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) { int ret = 0; uint8_t *buffer; int offset = 0; uint32_t i = 0; VHDXMetadataTableEntry md_entry; buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, VHDX_METADATA_TABLE_MAX_SIZE); if (ret < 0) { goto exit; } memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); offset += sizeof(s->metadata_hdr); vhdx_metadata_header_le_import(&s->metadata_hdr); if (memcmp(&s->metadata_hdr.signature, "metadata", 8)) { ret = -EINVAL; goto exit; } s->metadata_entries.present = 0; if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { ret = -EINVAL; goto exit; } for (i = 0; i < s->metadata_hdr.entry_count; i++) { memcpy(&md_entry, buffer + offset, sizeof(md_entry)); offset += sizeof(md_entry); vhdx_metadata_entry_le_import(&md_entry); if (guid_eq(md_entry.item_id, file_param_guid)) { if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.file_parameters_entry = md_entry; s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; continue; } if (guid_eq(md_entry.item_id, virtual_size_guid)) { if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.virtual_disk_size_entry = md_entry; s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; continue; } if (guid_eq(md_entry.item_id, page83_guid)) { if (s->metadata_entries.present & META_PAGE_83_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.page83_data_entry = md_entry; s->metadata_entries.present |= META_PAGE_83_PRESENT; continue; } if (guid_eq(md_entry.item_id, logical_sector_guid)) { if (s->metadata_entries.present & META_LOGICAL_SECTOR_SIZE_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.logical_sector_size_entry = md_entry; s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; continue; } if (guid_eq(md_entry.item_id, phys_sector_guid)) { if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.phys_sector_size_entry = md_entry; s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; continue; } if (guid_eq(md_entry.item_id, parent_locator_guid)) { if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { ret = -EINVAL; goto exit; } s->metadata_entries.parent_locator_entry = md_entry; s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; continue; } if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { /* cannot read vhdx file - required region table entry that * we do not understand. per spec, we must fail to open */ ret = -ENOTSUP; goto exit; } } if (s->metadata_entries.present != META_ALL_PRESENT) { ret = -ENOTSUP; goto exit; } ret = bdrv_pread(bs->file, s->metadata_entries.file_parameters_entry.offset + s->metadata_rt.file_offset, &s->params, sizeof(s->params)); if (ret < 0) { goto exit; } le32_to_cpus(&s->params.block_size); le32_to_cpus(&s->params.data_bits); /* We now have the file parameters, so we can tell if this is a * differencing file (i.e.. has_parent), is dynamic or fixed * sized (leave_blocks_allocated), and the block size */ /* The parent locator required iff the file parameters has_parent set */ if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { /* TODO: parse parent locator fields */ ret = -ENOTSUP; /* temp, until differencing files are supported */ goto exit; } else { /* if has_parent is set, but there is not parent locator present, * then that is an invalid combination */ ret = -EINVAL; goto exit; } } /* determine virtual disk size, logical sector size, * and phys sector size */ ret = bdrv_pread(bs->file, s->metadata_entries.virtual_disk_size_entry.offset + s->metadata_rt.file_offset, &s->virtual_disk_size, sizeof(uint64_t)); if (ret < 0) { goto exit; } ret = bdrv_pread(bs->file, s->metadata_entries.logical_sector_size_entry.offset + s->metadata_rt.file_offset, &s->logical_sector_size, sizeof(uint32_t)); if (ret < 0) { goto exit; } ret = bdrv_pread(bs->file, s->metadata_entries.phys_sector_size_entry.offset + s->metadata_rt.file_offset, &s->physical_sector_size, sizeof(uint32_t)); if (ret < 0) { goto exit; } le64_to_cpus(&s->virtual_disk_size); le32_to_cpus(&s->logical_sector_size); le32_to_cpus(&s->physical_sector_size); if (s->logical_sector_size == 0 || s->params.block_size == 0) { ret = -EINVAL; goto exit; } /* both block_size and sector_size are guaranteed powers of 2 */ s->sectors_per_block = s->params.block_size / s->logical_sector_size; s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * (uint64_t)s->logical_sector_size / (uint64_t)s->params.block_size; /* These values are ones we will want to use for division / multiplication * later on, and they are all guaranteed (per the spec) to be powers of 2, * so we can take advantage of that for shift operations during * reads/writes */ if (s->logical_sector_size & (s->logical_sector_size - 1)) { ret = -EINVAL; goto exit; } if (s->sectors_per_block & (s->sectors_per_block - 1)) { ret = -EINVAL; goto exit; } if (s->chunk_ratio & (s->chunk_ratio - 1)) { ret = -EINVAL; goto exit; } s->block_size = s->params.block_size; if (s->block_size & (s->block_size - 1)) { ret = -EINVAL; goto exit; } vhdx_set_shift_bits(s); ret = 0; exit: qemu_vfree(buffer); return ret; }