Method new_with_tap

virtio-devices/src/net.rs:422–530

(
        id: String,
        taps: Vec<Tap>,
        guest_mac: Option<MacAddr>,
        access_platform_enabled: bool,
        num_queues: usize,
        queue_size: u16,
        seccomp_action: Sec

    /// Create a new virtio network device with the given TAP interface.
    #[allow(clippy::too_many_arguments)]
    pub fn new_with_tap(
        id: String,
        taps: Vec<Tap>,
        guest_mac: Option<MacAddr>,
        access_platform_enabled: bool,
        num_queues: usize,
        queue_size: u16,
        seccomp_action: SeccompAction,
        rate_limiter_config: Option<RateLimiterConfig>,
        exit_evt: EventFd,
        state: Option<NetState>,
        offload_tso: bool,
        offload_ufo: bool,
        offload_csum: bool,
    ) -> Result<Self> {
        assert!(!taps.is_empty());

        // Skip advertising VIRTIO_NET_F_MTU and let the guest fall back to the Ethernet default if querying failed
        let mtu = match taps[0].mtu() {
            Ok(m) => Some(m as u16),
            Err(e) => {
                warn!("Failed to query tap MTU; not advertising VIRTIO_NET_F_MTU: {e}");
                None
            }
        };

        let (avail_features, acked_features, config, queue_sizes, paused) = if let Some(state) =
            state
        {
            info!("Restoring virtio-net {id}");
            (
                state.avail_features,
                state.acked_features,
                state.config,
                state.queue_size,
                true,
            )
        } else {
            let mut avail_features = (1 << VIRTIO_RING_F_EVENT_IDX) | (1 << VIRTIO_F_VERSION_1);

            if mtu.is_some() {
                avail_features |= 1 << VIRTIO_NET_F_MTU;
            }

            if access_platform_enabled {
                avail_features |= 1u64 << VIRTIO_F_ACCESS_PLATFORM;
            }

            // Configure TSO/UFO features when hardware checksum offload is enabled.
            if offload_csum {
                avail_features |= (1 << VIRTIO_NET_F_CSUM)
                    | (1 << VIRTIO_NET_F_GUEST_CSUM)
                    | (1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS);

                if offload_tso {
                    avail_features |= (1 << VIRTIO_NET_F_HOST_ECN)
                        | (1 << VIRTIO_NET_F_HOST_TSO4)
                        | (1 << VIRTIO_NET_F_HOST_TSO6)