static int vpc_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVVPCState *s = bs->opaque; int i; VHDFooter *footer; VHDDynDiskHeader *dyndisk_header; uint8_t buf[HEADER_SIZE]; uint32_t checksum; int disk_type = VHD_DYNAMIC; int ret; ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); if (ret < 0) { goto fail; } footer = (VHDFooter *) s->footer_buf; if (strncmp(footer->creator, "conectix", 8)) { int64_t offset = bdrv_getlength(bs->file); if (offset < 0) { ret = offset; goto fail; } else if (offset < HEADER_SIZE) { ret = -EINVAL; goto fail; } /* If a fixed disk, the footer is found only at the end of the file */ ret = bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf, HEADER_SIZE); if (ret < 0) { goto fail; } if (strncmp(footer->creator, "conectix", 8)) { error_setg(errp, "invalid VPC image"); ret = -EINVAL; goto fail; } disk_type = VHD_FIXED; } checksum = be32_to_cpu(footer->checksum); footer->checksum = 0; if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum) fprintf(stderr, "block-vpc: The header checksum of '%s' is " "incorrect.\n", bs->filename); /* Write 'checksum' back to footer, or else will leave it with zero. */ footer->checksum = be32_to_cpu(checksum); // The visible size of a image in Virtual PC depends on the geometry // rather than on the size stored in the footer (the size in the footer // is too large usually) bs->total_sectors = (int64_t) be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl; /* images created with disk2vhd report a far higher virtual size * than expected with the cyls * heads * sectors_per_cyl formula. * use the footer->size instead if the image was created with * disk2vhd. */ if (!strncmp(footer->creator_app, "d2v", 4)) { bs->total_sectors = be64_to_cpu(footer->size) / BDRV_SECTOR_SIZE; } /* Allow a maximum disk size of approximately 2 TB */ if (bs->total_sectors >= 65535LL * 255 * 255) { ret = -EFBIG; goto fail; } if (disk_type == VHD_DYNAMIC) { ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE); if (ret < 0) { goto fail; } dyndisk_header = (VHDDynDiskHeader *) buf; if (strncmp(dyndisk_header->magic, "cxsparse", 8)) { ret = -EINVAL; goto fail; } s->block_size = be32_to_cpu(dyndisk_header->block_size); s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511; s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries); s->pagetable = g_malloc(s->max_table_entries * 4); s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable, s->max_table_entries * 4); if (ret < 0) { goto fail; } s->free_data_block_offset = (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; for (i = 0; i < s->max_table_entries; i++) { be32_to_cpus(&s->pagetable[i]); if (s->pagetable[i] != 0xFFFFFFFF) { int64_t next = (512 * (int64_t) s->pagetable[i]) + s->bitmap_size + s->block_size; if (next > s->free_data_block_offset) { s->free_data_block_offset = next; } } } if (s->free_data_block_offset > bdrv_getlength(bs->file)) { error_setg(errp, "block-vpc: free_data_block_offset points after " "the end of file. The image has been truncated."); ret = -EINVAL; goto fail; } s->last_bitmap_offset = (int64_t) -1; #ifdef CACHE s->pageentry_u8 = g_malloc(512); s->pageentry_u32 = s->pageentry_u8; s->pageentry_u16 = s->pageentry_u8; s->last_pagetable = -1; #endif } qemu_co_mutex_init(&s->lock); /* Disable migration when VHD images are used */ error_set(&s->migration_blocker, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, "vpc", bs->device_name, "live migration"); migrate_add_blocker(s->migration_blocker); return 0; fail: g_free(s->pagetable); #ifdef CACHE g_free(s->pageentry_u8); #endif return ret; }