Method process_input_queue

virtio-devices/src/console.rs:193–243

* Each port of virtio console device has one receive * queue. One or more empty buffers are placed by the * driver in the receive queue for incoming data. Here, * we place the input data to these empty buffers. */

(&mut self)

     * we place the input data to these empty buffers.
     */
    fn process_input_queue(&mut self) -> Result<bool, Error> {
        let mut in_buffer = self.in_buffer.lock().unwrap();
        let recv_queue = &mut self.input_queue; //receiveq
        let mut used_descs = false;

        if in_buffer.is_empty() {
            return Ok(false);
        }

        while let Some(mut desc_chain) = recv_queue.pop_descriptor_chain(self.mem.memory()) {
            let mut total_len = 0;
            while let Some(desc) = desc_chain.next() {
                if in_buffer.is_empty() {
                    break;
                }
                if !desc.is_write_only() {
                    warn!("Skipping device-readable descriptor on receiveq");
                    continue;
                }
                let len = cmp::min(desc.len() as usize, in_buffer.len());
                let addr = match desc
                    .addr()
                    .translate_gva(self.access_platform.as_deref(), desc.len() as usize)
                {
                    Ok(a) => a,
                    Err(e) => {
                        warn!("Failed to translate receiveq descriptor address: {e}");
                        break;
                    }
                };
                let source: Vec<u8> = in_buffer.range(..len).copied().collect();
                if let Err(e) = desc_chain.memory().write_slice(&source, addr) {
                    warn!("Failed to write to receiveq descriptor: {e}");
                    break;
                }
                in_buffer.drain(..len);
                total_len += len as u32;
            }

            recv_queue
                .add_used(desc_chain.memory(), desc_chain.head_index(), total_len)
                .map_err(Error::QueueAddUsed)?;
            used_descs = true;

            if in_buffer.is_empty() {
                break;
            }
        }

        Ok(used_descs)
    }

    /*
     * Each port of virtio console device has one transmit