virtio_net: don't kill worker on malformed tx packet

[benhillis]

A single malformed TX packet (e.g. empty payload) caused queue_tx_packet to return an error that propagated through the main_loop, permanently killing the worker for that queue pair. Instead, log a warning and continue processing.

[Copilot]

Pull request overview

This PR prevents the virtio_net TX worker loop from permanently exiting when it encounters a malformed TX descriptor chain (e.g., empty payload). Instead of propagating the error out of main_loop, it logs a warning and continues processing subsequent packets.

Changes:

• Catch queue_tx_packet failures in the TX receive path and continue the worker loop.
• Emit a warning when a malformed TX packet is dropped instead of terminating the queue-pair worker.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

[github-actions]

At least one Petri test failed.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

[Copilot]

This match err { ... } moves err, but the logging line inside the WorkerError::Packet(_) arm still references err (error = &err ...). This should fail to compile with a "use of moved value" error. Restructure to match on &err (or use if let WorkerError::Packet(_) = &err { ... }) so you can borrow for logging and still propagate the owned err in the non-packet case.

Suggested change

	match err {
	WorkerError::Packet(_) => {
	tracelimit::warn_ratelimited!(
	error = &err as &dyn std::error::Error,
	"dropping malformed tx packet"
	);
	continue;
	}
	other => return Err(other),
	}
	if let WorkerError::Packet(_) = &err {
	tracelimit::warn_ratelimited!(
	error = &err as &dyn std::error::Error,
	"dropping malformed tx packet"
	);
	continue;
	}
	return Err(err);