event: Add guest agent lifecycle event

As qemu is now able to notify us about change of the channel state used
for communication with the guest agent we now can more precisely track
the state of the guest agent.

To allow notifying management apps this patch implements a new event
that will be triggered on changes of the guest agent state.

daemon/remote.c

@@ -1008,6 +1008,41 @@ remoteRelayDomainEventTunable(virConnectPtr conn,
 }
 
 
+static int
+remoteRelayDomainEventAgentLifecycle(virConnectPtr conn,
+                                     virDomainPtr dom,
+                                     int state,
+                                     int reason,
+                                     void *opaque)
+{
+    daemonClientEventCallbackPtr callback = opaque;
+    remote_domain_event_callback_agent_lifecycle_msg data;
+
+    if (callback->callbackID < 0 ||
+        !remoteRelayDomainEventCheckACL(callback->client, conn, dom))
+        return -1;
+
+    VIR_DEBUG("Relaying domain agent lifecycle event %s %d, callback %d, "
+              " state %d, reason %d",
+              dom->name, dom->id, callback->callbackID, state, reason);
+
+    /* build return data */
+    memset(&data, 0, sizeof(data));
+    data.callbackID = callback->callbackID;
+    make_nonnull_domain(&data.dom, dom);
+
+    data.state = state;
+    data.reason = reason;
+
+    remoteDispatchObjectEventSend(callback->client, remoteProgram,
+                                  REMOTE_PROC_DOMAIN_EVENT_CALLBACK_AGENT_LIFECYCLE,
+                                  (xdrproc_t)xdr_remote_domain_event_callback_agent_lifecycle_msg,
+                                  &data);
+
+    return 0;
+}
+
+
 static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventLifecycle),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventReboot),
@@ -1027,6 +1062,7 @@ static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventDeviceRemoved),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventBlockJob2),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventTunable),
+    VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventAgentLifecycle),
 };
 
 verify(ARRAY_CARDINALITY(domainEventCallbacks) == VIR_DOMAIN_EVENT_ID_LAST);

include/libvirt/libvirt-domain.h

@@ -3332,6 +3332,46 @@ typedef void (*virConnectDomainEventTunableCallback)(virConnectPtr conn,
                                                      void *opaque);
 
 
+typedef enum {
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_STATE_CONNECTED = 1, /* agent connected */
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_STATE_DISCONNECTED = 2, /* agent disconnected */
+
+# ifdef VIR_ENUM_SENTINELS
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_STATE_LAST
+# endif
+} virConnectDomainEventAgentLifecycleState;
+
+typedef enum {
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_UNKNOWN = 0, /* unknown state change reason */
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_DOMAIN_STARTED = 1, /* state changed due to domain start */
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_CHANNEL = 2, /* channel state changed */
+
+# ifdef VIR_ENUM_SENTINELS
+    VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_LAST
+# endif
+} virConnectDomainEventAgentLifecycleReason;
+
+/**
+ * virConnectDomainEventAgentLifecycleCallback:
+ * @conn: connection object
+ * @dom: domain on which the event occurred
+ * @state: new state of the guest agent, one of virConnectDomainEventAgentLifecycleState
+ * @reason: reason for state change; one of virConnectDomainEventAgentLifecycleReason
+ * @opaque: application specified data
+ *
+ * This callback occurs when libvirt detects a change in the state of a guest
+ * agent.
+ *
+ * The callback signature to use when registering for an event of type
+ * VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE with virConnectDomainEventRegisterAny()
+ */
+typedef void (*virConnectDomainEventAgentLifecycleCallback)(virConnectPtr conn,
+                                                            virDomainPtr dom,
+                                                            int state,
+                                                            int reason,
+                                                            void *opaque);
+
+
 /**
  * VIR_DOMAIN_EVENT_CALLBACK:
  *
@@ -3367,6 +3407,7 @@ typedef enum {
     VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED = 15, /* virConnectDomainEventDeviceRemovedCallback */
     VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2 = 16,    /* virConnectDomainEventBlockJobCallback */
     VIR_DOMAIN_EVENT_ID_TUNABLE = 17,        /* virConnectDomainEventTunableCallback */
+    VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE = 18,/* virConnectDomainEventAgentLifecycleCallback */
 
 # ifdef VIR_ENUM_SENTINELS
     VIR_DOMAIN_EVENT_ID_LAST

src/conf/domain_event.c

@@ -54,6 +54,7 @@ static virClassPtr virDomainEventDeviceRemovedClass;
 static virClassPtr virDomainEventPMClass;
 static virClassPtr virDomainQemuMonitorEventClass;
 static virClassPtr virDomainEventTunableClass;
+static virClassPtr virDomainEventAgentLifecycleClass;
 
 
 static void virDomainEventDispose(void *obj);
@@ -70,6 +71,7 @@ static void virDomainEventDeviceRemovedDispose(void *obj);
 static void virDomainEventPMDispose(void *obj);
 static void virDomainQemuMonitorEventDispose(void *obj);
 static void virDomainEventTunableDispose(void *obj);
+static void virDomainEventAgentLifecycleDispose(void *obj);
 
 static void
 virDomainEventDispatchDefaultFunc(virConnectPtr conn,
@@ -215,6 +217,15 @@ struct _virDomainEventTunable {
 typedef struct _virDomainEventTunable virDomainEventTunable;
 typedef virDomainEventTunable *virDomainEventTunablePtr;
 
+struct _virDomainEventAgentLifecycle {
+    virDomainEvent parent;
+
+    int state;
+    int reason;
+};
+typedef struct _virDomainEventAgentLifecycle virDomainEventAgentLifecycle;
+typedef virDomainEventAgentLifecycle *virDomainEventAgentLifecyclePtr;
+
 
 static int
 virDomainEventsOnceInit(void)
@@ -303,6 +314,12 @@ virDomainEventsOnceInit(void)
                       sizeof(virDomainEventTunable),
                       virDomainEventTunableDispose)))
         return -1;
+    if (!(virDomainEventAgentLifecycleClass =
+          virClassNew(virDomainEventClass,
+                      "virDomainEventAgentLifecycle",
+                      sizeof(virDomainEventAgentLifecycle),
+                      virDomainEventAgentLifecycleDispose)))
+        return -1;
     return 0;
 }
 
@@ -447,6 +464,13 @@ virDomainEventTunableDispose(void *obj)
     virTypedParamsFree(event->params, event->nparams);
 }
 
+static void
+virDomainEventAgentLifecycleDispose(void *obj)
+{
+    virDomainEventAgentLifecyclePtr event = obj;
+    VIR_DEBUG("obj=%p", event);
+};
+
 
 static void *
 virDomainEventNew(virClassPtr klass,
@@ -1202,6 +1226,49 @@ virDomainEventDeviceRemovedNewFromDom(virDomainPtr dom,
                                           devAlias);
 }
 
+
+static virObjectEventPtr
+virDomainEventAgentLifecycleNew(int id,
+                                const char *name,
+                                const unsigned char *uuid,
+                                int state,
+                                int reason)
+{
+    virDomainEventAgentLifecyclePtr ev;
+
+    if (virDomainEventsInitialize() < 0)
+        return NULL;
+
+    if (!(ev = virDomainEventNew(virDomainEventAgentLifecycleClass,
+                                 VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE,
+                                 id, name, uuid)))
+        return NULL;
+
+    ev->state = state;
+    ev->reason = reason;
+
+    return (virObjectEventPtr)ev;
+}
+
+virObjectEventPtr
+virDomainEventAgentLifecycleNewFromObj(virDomainObjPtr obj,
+                                       int state,
+                                       int reason)
+{
+    return virDomainEventAgentLifecycleNew(obj->def->id, obj->def->name,
+                                           obj->def->uuid, state, reason);
+}
+
+virObjectEventPtr
+virDomainEventAgentLifecycleNewFromDom(virDomainPtr dom,
+                                       int state,
+                                       int reason)
+{
+    return virDomainEventAgentLifecycleNew(dom->id, dom->name, dom->uuid,
+                                           state, reason);
+}
+
+
 /* This function consumes the params so caller don't have to care about
  * freeing it even if error occurs. The reason is to not have to do deep
  * copy of params.
@@ -1459,6 +1526,17 @@ virDomainEventDispatchDefaultFunc(virConnectPtr conn,
             goto cleanup;
         }
 
+    case VIR_DOMAIN_EVENT_ID_AGENT_LIFECYCLE:
+        {
+            virDomainEventAgentLifecyclePtr agentLifecycleEvent;
+            agentLifecycleEvent = (virDomainEventAgentLifecyclePtr)event;
+            ((virConnectDomainEventAgentLifecycleCallback)cb)(conn, dom,
+                                                              agentLifecycleEvent->state,
+                                                              agentLifecycleEvent->reason,
+                                                              cbopaque);
+            goto cleanup;
+        }
+
     case VIR_DOMAIN_EVENT_ID_LAST:
         break;
     }

src/conf/domain_event.h

@@ -193,6 +193,15 @@ virDomainEventTunableNewFromDom(virDomainPtr dom,
                                 virTypedParameterPtr params,
                                 int nparams);
 
+virObjectEventPtr
+virDomainEventAgentLifecycleNewFromObj(virDomainObjPtr obj,
+                                       int state,
+                                       int reason);
+
+virObjectEventPtr
+virDomainEventAgentLifecycleNewFromDom(virDomainPtr dom,
+                                       int state,
+                                       int reason);
 
 int
 virDomainEventStateRegister(virConnectPtr conn,

src/libvirt_private.syms

@@ -437,6 +437,8 @@ virDomainXMLOptionNew;
 
 
 # conf/domain_event.h
+virDomainEventAgentLifecycleNewFromDom;
+virDomainEventAgentLifecycleNewFromObj;
 virDomainEventBalloonChangeNewFromDom;
 virDomainEventBalloonChangeNewFromObj;
 virDomainEventBlockJob2NewFromDom;

src/remote/remote_driver.c

@@ -334,6 +334,11 @@ remoteDomainBuildEventCallbackTunable(virNetClientProgramPtr prog,
                                       virNetClientPtr client,
                                       void *evdata, void *opaque);
 
+static void
+remoteDomainBuildEventCallbackAgentLifecycle(virNetClientProgramPtr prog,
+                                             virNetClientPtr client,
+                                             void *evdata, void *opaque);
+
 static void
 remoteNetworkBuildEventLifecycle(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
                                  virNetClientPtr client ATTRIBUTE_UNUSED,
@@ -489,6 +494,10 @@ static virNetClientProgramEvent remoteEvents[] = {
       remoteDomainBuildEventCallbackTunable,
       sizeof(remote_domain_event_callback_tunable_msg),
       (xdrproc_t)xdr_remote_domain_event_callback_tunable_msg },
+    { REMOTE_PROC_DOMAIN_EVENT_CALLBACK_AGENT_LIFECYCLE,
+      remoteDomainBuildEventCallbackAgentLifecycle,
+      sizeof(remote_domain_event_callback_agent_lifecycle_msg),
+      (xdrproc_t)xdr_remote_domain_event_callback_agent_lifecycle_msg },
 };
 
 
@@ -5482,6 +5491,28 @@ remoteDomainBuildEventCallbackTunable(virNetClientProgramPtr prog ATTRIBUTE_UNUS
 }
 
 
+static void
+remoteDomainBuildEventCallbackAgentLifecycle(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
+                                             virNetClientPtr client ATTRIBUTE_UNUSED,
+                                             void *evdata, void *opaque)
+{
+    virConnectPtr conn = opaque;
+    remote_domain_event_callback_agent_lifecycle_msg *msg = evdata;
+    struct private_data *priv = conn->privateData;
+    virDomainPtr dom;
+    virObjectEventPtr event = NULL;
+
+    if (!(dom = get_nonnull_domain(conn, msg->dom)))
+        return;
+
+    event = virDomainEventAgentLifecycleNewFromDom(dom, msg->state,
+                                                   msg->reason);
+
+    virDomainFree(dom);
+
+    remoteEventQueue(priv, event, msg->callbackID);
+}
+
 static void
 remoteNetworkBuildEventLifecycle(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
                                  virNetClientPtr client ATTRIBUTE_UNUSED,

src/remote/remote_protocol.x

@@ -3108,6 +3108,14 @@ struct remote_connect_get_all_domain_stats_args {
     unsigned int flags;
 };
 
+struct remote_domain_event_callback_agent_lifecycle_msg {
+    int callbackID;
+    remote_nonnull_domain dom;
+
+    int state;
+    int reason;
+};
+
 struct remote_connect_get_all_domain_stats_ret {
     remote_domain_stats_record retStats<REMOTE_DOMAIN_LIST_MAX>;
 };
@@ -5506,5 +5514,11 @@ enum remote_procedure {
      * @generate: none
      * @acl: connect:write
      */
-    REMOTE_PROC_NODE_ALLOC_PAGES = 347
+    REMOTE_PROC_NODE_ALLOC_PAGES = 347,
+
+    /**
+     * @generate: both
+     * @acl: none
+     */
+    REMOTE_PROC_DOMAIN_EVENT_CALLBACK_AGENT_LIFECYCLE = 348
 };

src/remote_protocol-structs

@@ -2573,6 +2573,12 @@ struct remote_connect_get_all_domain_stats_args {
         u_int                      stats;
         u_int                      flags;
 };
+struct remote_domain_event_callback_agent_lifecycle_msg {
+        int                        callbackID;
+        remote_nonnull_domain      dom;
+        int                        state;
+        int                        reason;
+};
 struct remote_connect_get_all_domain_stats_ret {
         struct {
                 u_int              retStats_len;
@@ -2927,4 +2933,5 @@ enum remote_procedure {
         REMOTE_PROC_DOMAIN_BLOCK_COPY = 345,
         REMOTE_PROC_DOMAIN_EVENT_CALLBACK_TUNABLE = 346,
         REMOTE_PROC_NODE_ALLOC_PAGES = 347,
+        REMOTE_PROC_DOMAIN_EVENT_CALLBACK_AGENT_LIFECYCLE = 348,
 };

tools/virsh-domain.c

@@ -11672,6 +11672,43 @@ vshEventTunablePrint(virConnectPtr conn ATTRIBUTE_UNUSED,
         vshEventDone(data->ctl);
 }
 
+VIR_ENUM_DECL(vshEventAgentLifecycleState)
+VIR_ENUM_IMPL(vshEventAgentLifecycleState,
+              VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_STATE_LAST,
+              N_("unknown"),
+              N_("connected"),
+              N_("disconnected"))
+
+VIR_ENUM_DECL(vshEventAgentLifecycleReason)
+VIR_ENUM_IMPL(vshEventAgentLifecycleReason,
+              VIR_CONNECT_DOMAIN_EVENT_AGENT_LIFECYCLE_REASON_LAST,
+              N_("unknown"),
+              N_("domain started"),
+              N_("channel event"))
+
+#define UNKNOWNSTR(str) (str ? str : N_("unsupported value"))
+static void
+vshEventAgentLifecyclePrint(virConnectPtr conn ATTRIBUTE_UNUSED,
+                            virDomainPtr dom,
+                            int state,
+                            int reason,
+                            void *opaque)
+{
+    vshDomEventData *data = opaque;
+
+    if (!data->loop && *data->count)
+        return;
+    vshPrint(data->ctl,
+             _("event 'agent-lifecycle' for domain %s: state: '%s' reason: '%s'\n"),
+             virDomainGetName(dom),
+             UNKNOWNSTR(vshEventAgentLifecycleStateTypeToString(state)),
+             UNKNOWNSTR(vshEventAgentLifecycleReasonTypeToString(reason)));
+
+    (*data->count)++;
+    if (!data->loop)
+        vshEventDone(data->ctl);
+}
+
 static vshEventCallback vshEventCallbacks[] = {
     { "lifecycle",
       VIR_DOMAIN_EVENT_CALLBACK(vshEventLifecyclePrint), },
@@ -11707,6 +11744,8 @@ static vshEventCallback vshEventCallbacks[] = {
       VIR_DOMAIN_EVENT_CALLBACK(vshEventBlockJobPrint), },
     { "tunable",
       VIR_DOMAIN_EVENT_CALLBACK(vshEventTunablePrint), },
+    { "agent-lifecycle",
+      VIR_DOMAIN_EVENT_CALLBACK(vshEventAgentLifecyclePrint), },
 };
 verify(VIR_DOMAIN_EVENT_ID_LAST == ARRAY_CARDINALITY(vshEventCallbacks));