I40E_PACKET_HDR_PAD
if (vsi->netdev->mtu > frame_size - I40E_PACKET_HDR_PAD) {
netdev->max_mtu = I40E_MAX_RXBUFFER - I40E_PACKET_HDR_PAD;
if (new_mtu > frame_size - I40E_PACKET_HDR_PAD) {
new_mtu, frame_size - I40E_PACKET_HDR_PAD);
mfs_tc[i] += I40E_PACKET_HDR_PAD;