Struct VirtioNetworkDevice 

pub struct VirtioNetworkDevice { /* private fields */ }

smoltcp Device backed by shared frame queues.

staged_guest_frame exists because the poll loop sometimes needs to inspect a frame before handing it to smoltcp. In particular, the stack wants to classify guest TCP SYN and DNS packets before consumption so it can prepare relay/socket state.

The staging pattern looks like:

queue -> staged_guest_frame -> RxToken -> smoltcp

Implementations

impl VirtioNetworkDevice

pub fn new(queues: Arc<NetworkFrameQueues>, mtu: usize) -> Self

Create a new device for the given queues and MTU.

mtu here is the guest IP MTU, not the full Ethernet frame size. capabilities() translates it to the Ethernet-frame convention expected by smoltcp.

pub fn stage_next_frame(&mut self) -> Option<&[u8]>

Stage one guest frame so the poll loop can inspect it before smoltcp consumes it.

Why staging exists:

• the frame arrives first in guest_to_host
• the poll loop may need to classify it before calling Interface::poll_ingress_single
• once smoltcp calls receive(), ownership moves into an RX token

So staging gives the poll loop a temporary peek at the next frame without losing the normal smoltcp Device flow.

This is the key reason the adapter is not just a direct queue.pop() inside receive().

pub fn drop_staged_frame(&mut self)

Drop the currently staged guest frame.

This is used when the poll loop decides not to pass a frame into smoltcp, for example when the MVP intentionally drops unsupported UDP.

Trait Implementations

impl Device for VirtioNetworkDevice

type RxToken<'a> = DeviceRxToken

type TxToken<'a> = DeviceTxToken<'a>

fn receive( &mut self, _timestamp: Instant, ) -> Option<(Self::RxToken<'_>, Self::TxToken<'_>)>

Construct a token pair consisting of one receive token and one transmit token.

fn transmit(&mut self, _timestamp: Instant) -> Option<Self::TxToken<'_>>

Construct a transmit token.

fn capabilities(&self) -> DeviceCapabilities

Get a description of device capabilities.