vsock: clean up comments and fix log messages

Remove old comments, useless code, and code commented.

Avoid println!() to print messages and replaced with dbg!(), info!(),
or error!().

Also init `env_logger` like other daemons in the main().

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>

Cargo.lock

@@ -675,6 +675,7 @@ version = "0.1.0"
 dependencies = [
  "byteorder",
  "clap 3.2.22",
+ "env_logger",
  "epoll",
  "futures",
  "log",

vsock/Cargo.toml

@@ -12,6 +12,7 @@ edition = "2018"
 [dependencies]
 byteorder = "1"
 clap = { version = ">=3.0",  features = ["derive"] }
+env_logger = ">=0.9"
 epoll = "4.3.1"
 futures = { version = "0.3", features = ["thread-pool"] }
 log = ">=0.4.6"

vsock/src/main.rs

@@ -9,9 +9,9 @@ mod vhu_vsock_thread;
 mod vsock_conn;
 
 use clap::Parser;
+use log::{info, warn};
 use std::{
     convert::TryFrom,
-    process,
     sync::{Arc, RwLock},
 };
 use vhost::{vhost_user, vhost_user::Listener};
@@ -38,48 +38,35 @@ pub(crate) fn start_backend_server(vsock_config: VsockConfig) {
 
         let mut vring_workers = vsock_daemon.get_epoll_handlers();
 
-        if vring_workers.len() != vsock_backend.read().unwrap().threads.len() {
-            println!("Number of vring workers must be identical to number of backend threads");
-        }
-
         for thread in vsock_backend.read().unwrap().threads.iter() {
             thread
                 .lock()
                 .unwrap()
                 .set_vring_worker(Some(vring_workers.remove(0)));
         }
-        if let Err(e) = vsock_daemon.start(listener) {
-            dbg!("Failed to start vsock daemon: {:?}", e);
-            process::exit(1);
-        }
+
+        vsock_daemon.start(listener).unwrap();
 
         match vsock_daemon.wait() {
             Ok(()) => {
-                println!("Stopping cleanly");
-                process::exit(0);
+                info!("Stopping cleanly");
             }
             Err(vhost_user_backend::Error::HandleRequest(vhost_user::Error::PartialMessage)) => {
-                println!("vhost-user connection closed with partial message. If the VM is shutting down, this is expected behavior; otherwise, it might be a bug.");
-                continue;
+                info!("vhost-user connection closed with partial message. If the VM is shutting down, this is expected behavior; otherwise, it might be a bug.");
             }
             Err(e) => {
-                println!("Error running daemon: {:?}", e);
+                warn!("Error running daemon: {:?}", e);
             }
         }
 
-        vsock_backend
-            .read()
-            .unwrap()
-            .exit_event
-            .write(1)
-            .expect("Shutting down worker thread");
-
-        println!("Vsock daemon is finished");
+        // No matter the result, we need to shut down the worker thread.
+        vsock_backend.read().unwrap().exit_event.write(1).unwrap();
     }
 }
 
 fn main() {
-    let vsock_config = VsockConfig::try_from(VsockArgs::parse()).unwrap();
+    env_logger::init();
 
+    let vsock_config = VsockConfig::try_from(VsockArgs::parse()).unwrap();
     start_backend_server(vsock_config);
 }

vsock/src/thread_backend.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: Apache-2.0 or BSD-3-Clause
 
-#![deny(missing_docs)]
-
 use super::{
     rxops::*,
     vhu_vsock::{
@@ -22,7 +20,6 @@ use std::{
 use virtio_vsock::packet::VsockPacket;
 use vm_memory::bitmap::BitmapSlice;
 
-// TODO: convert UnixStream to Arc<Mutex<UnixStream>>
 pub struct VsockThreadBackend {
     /// Map of ConnMapKey objects indexed by raw file descriptors.
     pub listener_map: HashMap<RawFd, ConnMapKey>,

vsock/src/vhu_vsock.rs

@@ -278,10 +278,6 @@ impl VhostUserBackendMut<VringRwLock, ()> for VhostUserVsockBackend {
         let vring_rx = &vrings[0];
         let vring_tx = &vrings[1];
 
-        if evset == EventSet::OUT {
-            dbg!("received epollout");
-        }
-
         if evset != EventSet::IN {
             return Err(Error::HandleEventNotEpollIn.into());
         }

vsock/src/vhu_vsock_thread.rs

@@ -365,7 +365,6 @@ impl VhostUserVsockThread {
             epoll::Events::EPOLLIN,
         )?;
 
-        // self.register_listener(stream_fd, BACKEND_EVENT);
         Ok(())
     }
 
@@ -461,11 +460,6 @@ impl VhostUserVsockThread {
                 if !vring.enable_notification().unwrap() {
                     break;
                 }
-                // TODO: This may not be required because of
-                // previous pending_rx check
-                // if !work {
-                //     break;
-                // }
             }
         } else {
             self.process_rx_queue(vring)?;

vsock/src/vsock_conn.rs

@@ -290,12 +290,12 @@ impl<S: AsRawFd + Read + Write> VsockConnection<S> {
                 if e.kind() == ErrorKind::WouldBlock {
                     0
                 } else {
-                    println!("send_bytes error: {:?}", e);
+                    dbg!("send_bytes error: {:?}", e);
                     return Err(Error::UnixWrite);
                 }
             }
             Err(e) => {
-                println!("send_bytes error: {:?}", e);
+                dbg!("send_bytes error: {:?}", e);
                 return Err(Error::UnixWrite);
             }
         };