Method process_tx

net_util/src/queue_pair.rs:489–537

(
        &mut self,
        mem: &vm_memory::GuestMemoryMmap<B>,
        queue: &mut Queue,
    )

impl NetQueuePair {
    pub fn process_tx<B: Bitmap + 'static>(
        &mut self,
        mem: &vm_memory::GuestMemoryMmap<B>,
        queue: &mut Queue,
    ) -> Result<bool, NetQueuePairError> {
        let tx_tap_retry = self.tx.process_desc_chain(
            mem,
            &self.tap,
            queue,
            &mut self.tx_rate_limiter,
            self.access_platform.as_deref(),
        )?;

        // We got told to try again when writing to the tap. Wait for the TAP to be writable
        if tx_tap_retry && !self.tx_tap_listening {
            register_listener(
                self.epoll_fd.unwrap(),
                self.tap_for_write_epoll.as_raw_fd(),
                epoll::Events::EPOLLOUT,
                u64::from(self.tap_tx_event_id),
            )
            .map_err(NetQueuePairError::RegisterListener)?;
            self.tx_tap_listening = true;
            info!("Writing to TAP returned EAGAIN. Listening for TAP to become writable.");
        } else if !tx_tap_retry && self.tx_tap_listening {
            unregister_listener(
                self.epoll_fd.unwrap(),
                self.tap_for_write_epoll.as_raw_fd(),
                epoll::Events::EPOLLOUT,
                u64::from(self.tap_tx_event_id),
            )
            .map_err(NetQueuePairError::UnregisterListener)?;
            self.tx_tap_listening = false;
            info!("Writing to TAP succeeded. No longer listening for TAP to become writable.");
        }

        self.counters
            .tx_bytes
            .fetch_add(self.tx.counter_bytes.0, Ordering::AcqRel);
        self.counters
            .tx_frames
            .fetch_add(self.tx.counter_frames.0, Ordering::AcqRel);
        self.tx.counter_bytes = Wrapping(0);
        self.tx.counter_frames = Wrapping(0);

        queue
            .needs_notification(mem)
            .map_err(NetQueuePairError::QueueNeedsNotification)
    }

    pub fn process_rx<B: Bitmap + 'static>(
        &mut self,