VIRTIO_NET_CONFIG_SPEED_UNKNOWN
if (vif->vif_speed == VIRTIO_NET_CONFIG_SPEED_UNKNOWN)
vif->vif_speed = VIRTIO_NET_CONFIG_SPEED_UNKNOWN;
vif->vif_speed = VIRTIO_NET_CONFIG_SPEED_UNKNOWN;
vif->vif_speed = VIRTIO_NET_CONFIG_SPEED_UNKNOWN;