QMP: Introduce basic asynchronous events

Debug, shutdown, reset, powerdown and stop are all basic events,
as they are very simple they can be added in the same commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/vl.c b/vl.c
index 2e0fb39..e6fcccf 100644
--- a/vl.c
+++ b/vl.c
@@ -4060,9 +4060,12 @@
 #endif
         } while (vm_can_run());
 
-        if (qemu_debug_requested())
+        if (qemu_debug_requested()) {
+            monitor_protocol_event(EVENT_DEBUG, NULL);
             vm_stop(EXCP_DEBUG);
+        }
         if (qemu_shutdown_requested()) {
+            monitor_protocol_event(EVENT_SHUTDOWN, NULL);
             if (no_shutdown) {
                 vm_stop(0);
                 no_shutdown = 0;
@@ -4070,15 +4073,19 @@
                 break;
         }
         if (qemu_reset_requested()) {
+            monitor_protocol_event(EVENT_RESET, NULL);
             pause_all_vcpus();
             qemu_system_reset();
             resume_all_vcpus();
         }
         if (qemu_powerdown_requested()) {
+            monitor_protocol_event(EVENT_POWERDOWN, NULL);
             qemu_irq_raise(qemu_system_powerdown);
         }
-        if ((r = qemu_vmstop_requested()))
+        if ((r = qemu_vmstop_requested())) {
+            monitor_protocol_event(EVENT_STOP, NULL);
             vm_stop(r);
+        }
     }
     pause_all_vcpus();
 }