qapi event: convert BALLOON_CHANGE

Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

balloon.c

@@ -81,19 +81,6 @@ static int qemu_balloon_status(BalloonInfo *info)
     return 1;
 }
 
-void qemu_balloon_changed(int64_t actual)
-{
-    QObject *data;
-
-    data = qobject_from_jsonf("{ 'actual': %" PRId64 " }",
-                              actual);
-
-    monitor_protocol_event(QEVENT_BALLOON_CHANGE, data);
-
-    qobject_decref(data);
-}
-
-
 BalloonInfo *qmp_query_balloon(Error **errp)
 {
     BalloonInfo *info;

docs/qmp/qmp-events.txt

@@ -1,23 +1,6 @@
                    QEMU Machine Protocol Events
                    ============================
 
-BALLOON_CHANGE
---------------
-
-Emitted when the guest changes the actual BALLOON level. This
-value is equivalent to the 'actual' field return by the
-'query-balloon' command
-
-Data:
-
-- "actual": actual level of the guest memory balloon in bytes (json-number)
-
-Example:
-
-{ "event": "BALLOON_CHANGE",
-    "data": { "actual": 944766976 },
-    "timestamp": { "seconds": 1267020223, "microseconds": 435656 } }
-
 GUEST_PANICKED
 --------------
 

hw/virtio/virtio-balloon.c

@@ -24,6 +24,7 @@
 #include "sysemu/kvm.h"
 #include "exec/address-spaces.h"
 #include "qapi/visitor.h"
+#include "qapi-event.h"
 
 #if defined(__linux__)
 #include <sys/mman.h>
@@ -289,8 +290,9 @@ static void virtio_balloon_set_config(VirtIODevice *vdev,
     memcpy(&config, config_data, sizeof(struct virtio_balloon_config));
     dev->actual = le32_to_cpu(config.actual);
     if (dev->actual != oldactual) {
-        qemu_balloon_changed(ram_size -
-                       ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT));
+        qapi_event_send_balloon_change(ram_size -
+                        ((ram_addr_t) dev->actual << VIRTIO_BALLOON_PFN_SHIFT),
+                        &error_abort);
     }
 }
 

include/sysemu/balloon.h

@@ -24,6 +24,4 @@ int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
 			     QEMUBalloonStatus *stat_func, void *opaque);
 void qemu_remove_balloon_handler(void *opaque);
 
-void qemu_balloon_changed(int64_t actual);
-
 #endif

monitor.c

@@ -616,6 +616,7 @@ static void monitor_qapi_event_init(void)
     /* Limit guest-triggerable events to 1 per second */
     monitor_qapi_event_throttle(QAPI_EVENT_RTC_CHANGE, 1000);
     monitor_qapi_event_throttle(QAPI_EVENT_WATCHDOG, 1000);
+    monitor_qapi_event_throttle(QAPI_EVENT_BALLOON_CHANGE, 1000);
 
     qmp_event_set_func_emit(monitor_qapi_event_queue);
 }
@@ -742,8 +743,6 @@ monitor_protocol_event_throttle(MonitorEvent event,
  * and initialize state */
 static void monitor_protocol_event_init(void)
 {
-    /* Limit RTC & BALLOON events to 1 per second */
-    monitor_protocol_event_throttle(QEVENT_BALLOON_CHANGE, 1000);
     /* limit the rate of quorum events to avoid hammering the management */
     monitor_protocol_event_throttle(QEVENT_QUORUM_REPORT_BAD, 1000);
     monitor_protocol_event_throttle(QEVENT_QUORUM_FAILURE, 1000);

qapi-event.json

@@ -253,3 +253,16 @@
 ##
 { 'event': 'ACPI_DEVICE_OST',
      'data': { 'info': 'ACPIOSTInfo' } }
+
+##
+# @BALLOON_CHANGE
+#
+# Emitted when the guest changes the actual BALLOON level. This value is
+# equivalent to the @actual field return by the 'query-balloon' command
+#
+# @actual: actual level of the guest memory balloon in bytes
+#
+# Since: 1.2
+##
+{ 'event': 'BALLOON_CHANGE',
+  'data': { 'actual': 'int' } }