VTNET_CSUM_OFFLOAD
if_togglehwassist(ifp, VTNET_CSUM_OFFLOAD);
if (flags & (VTNET_CSUM_OFFLOAD | VTNET_CSUM_OFFLOAD_IPV6)) {
if (__predict_false((flags & VTNET_CSUM_OFFLOAD &&
if_sethwassistbits(ifp, VTNET_CSUM_OFFLOAD, 0);
(VTNET_CSUM_OFFLOAD | VTNET_CSUM_OFFLOAD_IPV6 | CSUM_TSO)