static int add_old_style_options(const char *fmt, QemuOpts *opts, const char *base_filename, const char *base_fmt) { if (base_filename) { if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename)) { error_report("Backing file not supported for file format '%s'", fmt); return -1; } } if (base_fmt) { if (qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt)) { error_report("Backing file format not supported for file " "format '%s'", fmt); return -1; } } return 0; }