+ if (vtpci_with_feature(hw, VIRTIO_NET_F_MTU)) {
+ vtpci_read_dev_config(hw,
+ offsetof(struct virtio_net_config, mtu),
+ &config->mtu,
+ sizeof(config->mtu));
+
+ /*
+ * MTU value has already been checked at negotiation
+ * time, but check again in case it has changed since
+ * then, which should not happen.
+ */
+ if (config->mtu < ETHER_MIN_MTU) {
+ PMD_INIT_LOG(ERR, "invalid max MTU value (%u)",
+ config->mtu);
+ return -1;
+ }
+
+ hw->max_mtu = config->mtu;
+ /* Set initial MTU to maximum one supported by vhost */
+ eth_dev->data->mtu = config->mtu;
+
+ } else {
+ hw->max_mtu = VIRTIO_MAX_RX_PKTLEN - ETHER_HDR_LEN -
+ VLAN_TAG_LEN - hw->vtnet_hdr_size;
+ }
+