QMP: Introduce WATCHDOG event

It's emitted whenever the watchdog device's timer expires. The action
taken is provided in the 'data' member.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

QMP/qmp-events.txt

@@ -169,3 +169,22 @@ Example:
         "client": { "family": "ipv4", "service": "46089",
                     "host": "127.0.0.1", "sasl_username": "luiz" } },
         "timestamp": { "seconds": 1263475302, "microseconds": 150772 } }
+
+WATCHDOG
+--------
+
+Emitted when the watchdog device's timer is expired.
+
+Data:
+
+- "action": Action that has been taken, it's one of the following (json-string):
+            "reset", "shutdown", "poweroff", "pause", "debug", or "none"
+
+Example:
+
+{ "event": "WATCHDOG",
+     "data": { "action": "reset" },
+     "timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
+
+Note: If action is "reset", "shutdown", or "pause" the WATCHDOG event is
+followed respectively by the RESET, SHUTDOWN, or STOP events.

hw/watchdog.c

@@ -23,6 +23,8 @@
 #include "qemu-option.h"
 #include "qemu-config.h"
 #include "qemu-queue.h"
+#include "qemu-objects.h"
+#include "monitor.h"
 #include "sysemu.h"
 #include "hw/watchdog.h"
 
@@ -98,6 +100,15 @@ int select_watchdog_action(const char *p)
     return 0;
 }
 
+static void watchdog_mon_event(const char *action)
+{
+    QObject *data;
+
+    data = qobject_from_jsonf("{ 'action': %s }", action);
+    monitor_protocol_event(QEVENT_WATCHDOG, data);
+    qobject_decref(data);
+}
+
 /* This actually performs the "action" once a watchdog has expired,
  * ie. reboot, shutdown, exit, etc.
  */
@@ -105,26 +116,32 @@ void watchdog_perform_action(void)
 {
     switch(watchdog_action) {
     case WDT_RESET:             /* same as 'system_reset' in monitor */
+        watchdog_mon_event("reset");
         qemu_system_reset_request();
         break;
 
     case WDT_SHUTDOWN:          /* same as 'system_powerdown' in monitor */
+        watchdog_mon_event("shutdown");
         qemu_system_powerdown_request();
         break;
 
     case WDT_POWEROFF:          /* same as 'quit' command in monitor */
+        watchdog_mon_event("poweroff");
         exit(0);
         break;
 
     case WDT_PAUSE:             /* same as 'stop' command in monitor */
+        watchdog_mon_event("pause");
         vm_stop(0);
         break;
 
     case WDT_DEBUG:
+        watchdog_mon_event("debug");
         fprintf(stderr, "watchdog: timer fired\n");
         break;
 
     case WDT_NONE:
+        watchdog_mon_event("none");
         break;
     }
 }

monitor.c

@@ -426,6 +426,9 @@ void monitor_protocol_event(MonitorEvent event, QObject *data)
         case QEVENT_RTC_CHANGE:
             event_name = "RTC_CHANGE";
             break;
+        case QEVENT_WATCHDOG:
+            event_name = "WATCHDOG";
+            break;
         default:
             abort();
             break;

monitor.h

@@ -24,6 +24,7 @@ typedef enum MonitorEvent {
     QEVENT_VNC_DISCONNECTED,
     QEVENT_BLOCK_IO_ERROR,
     QEVENT_RTC_CHANGE,
+    QEVENT_WATCHDOG,
     QEVENT_MAX,
 } MonitorEvent;