VIRTIO_NET_RSS_HASH_TYPE_UDPv4
if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
new_hashtypes &= ~(VIRTIO_NET_RSS_HASH_TYPE_IPv4 | VIRTIO_NET_RSS_HASH_TYPE_UDPv4);
| (is_l4 ? VIRTIO_NET_RSS_HASH_TYPE_UDPv4 : 0);