From 97e16f249f68f7c39a904539a23042598a9b5c9d Mon Sep 17 00:00:00 2001
From: Rob Bradford <rbradford@meta.com>
Date: Wed, 6 May 2026 14:16:59 +0100
Subject: [PATCH] virtio-devices: mem: Respond to unknown request types

An unknown request type caused process_queue to return an error that
killed the device thread. The request/response descriptors are already
parsed at this point, so respond with VIRTIO_MEM_RESP_ERROR and
continue processing.

Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:claude-opus-4-6
---
 virtio-devices/src/mem.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/virtio-devices/src/mem.rs b/virtio-devices/src/mem.rs
index 9f149deeb..06ecb3b7e 100644
--- a/virtio-devices/src/mem.rs
+++ b/virtio-devices/src/mem.rs
@@ -23,7 +23,7 @@ use std::{io, result};
 
 use anyhow::anyhow;
 use event_monitor::event;
-use log::{error, info};
+use log::{error, info, warn};
 use seccompiler::SeccompAction;
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
@@ -654,7 +654,8 @@ impl MemEpollHandler {
                 VIRTIO_MEM_REQ_UNPLUG_ALL => (self.unplug_all(), 0u16),
                 VIRTIO_MEM_REQ_STATE => self.state_request(r.req.addr, r.req.nb_blocks),
                 _ => {
-                    return Err(Error::UnknownRequestType(r.req.req_type));
+                    warn!("Unknown request type: {}", r.req.req_type);
+                    (VIRTIO_MEM_RESP_ERROR, 0u16)
                 }
             };
             let len = r.send_response(desc_chain.memory(), resp_type, resp_state)?;