static int vpc_open(BlockDriverState *bs, int flags) { BDRVVPCState *s = bs->opaque; int i; struct vhd_footer* footer; struct vhd_dyndisk_header* dyndisk_header; uint8_t buf[HEADER_SIZE]; uint32_t checksum; int err = -1; int disk_type = VHD_DYNAMIC; if (bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) goto fail; footer = (struct vhd_footer*) s->footer_buf; if (strncmp(footer->creator, "conectix", 8)) { int64_t offset = bdrv_getlength(bs->file); if (offset < HEADER_SIZE) { goto fail; } /* If a fixed disk, the footer is found only at the end of the file */ if (bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) { goto fail; } if (strncmp(footer->creator, "conectix", 8)) { 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; /* Allow a maximum disk size of approximately 2 TB */ if (bs->total_sectors >= 65535LL * 255 * 255) { err = -EFBIG; goto fail; } if (disk_type == VHD_DYNAMIC) { if (bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE) != HEADER_SIZE) { goto fail; } dyndisk_header = (struct vhd_dyndisk_header *) buf; if (strncmp(dyndisk_header->magic, "cxsparse", 8)) { 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); if (bdrv_pread(bs->file, s->bat_offset, s->pagetable, s->max_table_entries * 4) != s->max_table_entries * 4) { 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; } } } 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: return err; }