demo: learn to connect to a specific VM

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

qemu-display/src/display.rs

@@ -1,10 +1,17 @@
 use futures::stream::{self, StreamExt};
+use std::collections::HashMap;
 use std::convert::TryFrom;
+use std::convert::TryInto;
 use zbus::azync::Connection;
+use zbus::fdo;
 use zbus::fdo::ManagedObjects;
+use zbus::names::BusName;
+use zbus::names::OwnedUniqueName;
+use zbus::names::UniqueName;
+use zbus::names::WellKnownName;
 use zvariant::OwnedObjectPath;
 
-use crate::{Audio, Chardev, Clipboard, Result, UsbRedir};
+use crate::{AsyncVMProxy, Audio, Chardev, Clipboard, Error, Result, UsbRedir};
 
 pub struct Display {
     conn: Connection,
@@ -12,9 +19,36 @@ pub struct Display {
 }
 
 impl Display {
-    pub async fn new(conn: &Connection) -> Result<Self> {
-        let objects = zbus::fdo::AsyncObjectManagerProxy::builder(&conn)
-            .destination("org.qemu")?
+    pub async fn by_name(conn: &Connection) -> Result<HashMap<String, OwnedUniqueName>> {
+        let mut hm = HashMap::new();
+        let list = fdo::AsyncDBusProxy::new(conn)
+            .await?
+            .list_queued_owners(WellKnownName::from_str_unchecked("org.qemu"))
+            .await?;
+        for dest in list.into_iter() {
+            let name = AsyncVMProxy::builder(conn)
+                .destination(UniqueName::from(&dest))?
+                .build()
+                .await?
+                .name()
+                .await?;
+            hm.insert(name, dest);
+        }
+        Ok(hm)
+    }
+
+    pub async fn new<'d, D>(conn: &Connection, dest: Option<D>) -> Result<Self>
+    where
+        D: TryInto<BusName<'d>>,
+        D::Error: Into<Error>,
+    {
+        let dest: BusName = if let Some(dest) = dest {
+            dest.try_into().map_err(Into::into)?
+        } else {
+            "org.qemu".try_into().unwrap()
+        };
+        let objects = fdo::AsyncObjectManagerProxy::builder(&conn)
+            .destination(dest)?
             .path("/org/qemu/Display1")?
             .build()
             .await?

qemu-display/src/error.rs

@@ -1,5 +1,6 @@
 use usbredirhost::rusb;
 
+use std::convert::Infallible;
 use std::error;
 use std::fmt;
 use std::io;
@@ -61,6 +62,12 @@ impl From<zvariant::Error> for Error {
     }
 }
 
+impl From<zbus::names::Error> for Error {
+    fn from(e: zbus::names::Error) -> Self {
+        Error::Zbus(e.into())
+    }
+}
+
 impl From<rusb::Error> for Error {
     fn from(e: rusb::Error) -> Self {
         Error::Rusb(e)
@@ -73,4 +80,10 @@ impl From<usbredirhost::Error> for Error {
     }
 }
 
+impl From<Infallible> for Error {
+    fn from(_: Infallible) -> Self {
+        unreachable!()
+    }
+}
+
 pub type Result<T> = std::result::Result<T, Error>;

qemu-display/src/usbredir.rs

@@ -252,11 +252,7 @@ impl UsbRedir {
         }
 
         // We should do better and watch for owner properties changes, but this would require tasks
-        let _ = inner
-            .channel
-            .0
-            .broadcast(Event::NFreeChannels(nfree))
-            .await;
+        let _ = inner.channel.0.broadcast(Event::NFreeChannels(nfree)).await;
 
         Ok(state)
     }

qemu-rdw/src/main.rs

@@ -27,6 +27,37 @@ struct App {
 impl App {
     fn new() -> Self {
         let app = gtk::Application::new(Some("org.qemu.rdw.demo"), ApplicationFlags::NON_UNIQUE);
+        app.add_main_option(
+            &glib::OPTION_REMAINING,
+            glib::Char(0),
+            glib::OptionFlags::NONE,
+            glib::OptionArg::StringArray,
+            "VM-NAME",
+            Some("VM name"),
+        );
+        app.add_main_option(
+            "version",
+            glib::Char(0),
+            glib::OptionFlags::NONE,
+            glib::OptionArg::None,
+            "Show program version",
+            None,
+        );
+
+        let opt_name: Arc<RefCell<Option<String>>> = Default::default();
+        let name = opt_name.clone();
+        app.connect_handle_local_options(move |_, opt| {
+            if opt.lookup_value("version", None).is_some() {
+                println!("Version: {}", env!("CARGO_PKG_VERSION"));
+                return 0;
+            }
+            name.replace(
+                opt.lookup_value(&glib::OPTION_REMAINING, None)
+                    .and_then(|args| args.child_value(0).get::<String>()),
+            );
+            -1
+        });
+
         let conn = Connection::session()
             .expect("Failed to connect to DBus")
             .into();
@@ -53,8 +84,21 @@ impl App {
             window.set_application(Some(app));
 
             let app_clone = app_clone.clone();
+            let opt_name = opt_name.clone();
             MainContext::default().spawn_local(async move {
-                let display = Display::new(app_clone.connection()).await.unwrap();
+                let name = if let Some(name) = opt_name.borrow().as_ref() {
+                    let list = Display::by_name(app_clone.connection()).await.unwrap();
+                    Some(
+                        list.get(name)
+                            .expect(&format!("Can't find VM name: {}", name))
+                            .clone(),
+                    )
+                } else {
+                    None
+                };
+                let display = Display::new(app_clone.connection(), name.as_ref())
+                    .await
+                    .unwrap();
 
                 let console = Console::new(app_clone.connection(), 0)
                     .await