vm-virtio: vhost_user: net: On shutdown() drop the socket

This causes the vhost-user-net backend to shutdown.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

vm-virtio/src/vhost_user/net.rs

@@ -17,6 +17,7 @@ use libc::EFD_NONBLOCK;
 use net_util::MacAddr;
 use std::cmp;
 use std::io::Write;
+use std::os::unix::io::AsRawFd;
 use std::result;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
@@ -354,6 +355,10 @@ impl VirtioDevice for Net {
             self.queue_evts.take().unwrap(),
         ))
     }
+
+    fn shutdown(&mut self) {
+        let _ = unsafe { libc::close(self.vhost_user_net.as_raw_fd()) };
+    }
 }
 
 virtio_ctrl_q_pausable!(Net);