net: setup the loopback iface in a thread

Now that setup_network() returns a vector of threads, it is easy to add
an extra one.

Setting up the loopback interface should be quick. Still, it can be done
in parallel if there is nothing else depending on it.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

src/main.rs

@@ -670,10 +670,15 @@ fn get_network_handle(network_dev: Option<String>, guest_tools_dir: Option<Strin
     }));
 }
 
+fn setup_network_lo() -> Option<thread::JoinHandle<()>> {
+    return Some(thread::spawn(move || {
+        utils::run_cmd("ip", &["link", "set", "dev", "lo", "up"]);
+    }));
+}
+
 fn setup_network() -> Vec<Option<thread::JoinHandle<()>>> {
-    let mut vec = Vec::new();
+    let mut vec = vec![setup_network_lo()];
 
-    utils::run_cmd("ip", &["link", "set", "dev", "lo", "up"]);
     let cmdline = std::fs::read_to_string("/proc/cmdline").unwrap();
     if cmdline.contains("virtme.dhcp") {
         if let Some(guest_tools_dir) = get_guest_tools_dir() {