chardev: introduce chr_machine_done hook

Introduce ChardevClass.chr_machine_done() hook so that chardevs can run
customized procedures after machine init.

There was an existing mux user already that did similar thing but used a
raw machine done notifier.  Generalize it into a framework, and let the
mux chardevs provide such a class-specific hook to achieve the same
thing.  Then we can move the mux related code to the char-mux.c file.

Since at it, replace the mux_realized variable with the global
machine_init_done varible.

This notifier framework will be further leverged by other type of
chardevs soon.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180306053320.15401-6-peterx@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 17 insertions, 26 deletions

diff --git a/chardev/char.c b/chardev/char.c
index 5d7b079ef0..a6250cac80 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -281,40 +281,31 @@ static const TypeInfo char_type_info = {
     .class_init = char_class_init,
 };
 
-/**
- * Called after processing of default and command-line-specified
- * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
- * to a mux chardev. This is done here to ensure that
- * output/prompts/banners are only displayed for the FE that has
- * focus when initial command-line processing/machine init is
- * completed.
- *
- * After this point, any new FE attached to any new or existing
- * mux will receive CHR_EVENT_OPENED notifications for the BE
- * immediately.
- */
-static int open_muxes(Object *child, void *opaque)
+static int chardev_machine_done_notify_one(Object *child, void *opaque)
 {
-    if (CHARDEV_IS_MUX(child)) {
-        /* send OPENED to all already-attached FEs */
-        mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
-        /* mark mux as OPENED so any new FEs will immediately receive
-         * OPENED event
-         */
-        qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
+    Chardev *chr = (Chardev *)child;
+    ChardevClass *class = CHARDEV_GET_CLASS(chr);
+
+    if (class->chr_machine_done) {
+        return class->chr_machine_done(chr);
     }
 
     return 0;
 }
 
-static void muxes_realize_done(Notifier *notifier, void *unused)
+static void chardev_machine_done_hook(Notifier *notifier, void *unused)
 {
-    muxes_realized = true;
-    object_child_foreach(get_chardevs_root(), open_muxes, NULL);
+    int ret = object_child_foreach(get_chardevs_root(),
+                                   chardev_machine_done_notify_one, NULL);
+
+    if (ret) {
+        error_report("Failed to call chardev machine_done hooks");
+        exit(1);
+    }
 }
 
-static Notifier muxes_realize_notify = {
-    .notify = muxes_realize_done,
+static Notifier chardev_machine_done_notify = {
+    .notify = chardev_machine_done_hook,
 };
 
 static bool qemu_chr_is_busy(Chardev *s)
@@ -1118,7 +1109,7 @@ static void register_types(void)
      * as part of realize functions like serial_isa_realizefn when -nographic
      * is specified
      */
-    qemu_add_machine_init_done_notifier(&muxes_realize_notify);
+    qemu_add_machine_init_done_notifier(&chardev_machine_done_notify);
 }
 
 type_init(register_types);