int bdrv_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_info) { BlockDriver *drv = bs->drv; if (!drv) return -ENOMEDIUM; if (drv->bdrv_snapshot_list) return drv->bdrv_snapshot_list(bs, psn_info); if (bs->file) return bdrv_snapshot_list(bs->file, psn_info); return -ENOTSUP; }