event: introduce new event for tunable values

This new event will use typedParameters to expose what has been actually
updated and the reason is that we can in the future extend any tunable
values or add new tunable values. With typedParameters we don't have to
worry about creating some other events, we will just use this universal
event to inform user about updates.
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

daemon/remote.c

@@ -110,6 +110,13 @@ remoteDeserializeTypedParameters(remote_typed_param *args_params_val,
                                  int limit,
                                  int *nparams);
 
+static int
+remoteSerializeTypedParameters(virTypedParameterPtr params,
+                               int nparams,
+                               remote_typed_param **ret_params_val,
+                               u_int *ret_params_len,
+                               unsigned int flags);
+
 static int
 remoteSerializeDomainDiskErrors(virDomainDiskErrorPtr errors,
                                 int nerrors,
@@ -969,6 +976,43 @@ remoteRelayDomainEventBlockJob2(virConnectPtr conn,
 }
 
 
+static int
+remoteRelayDomainEventTunable(virConnectPtr conn,
+                              virDomainPtr dom,
+                              virTypedParameterPtr params,
+                              int nparams,
+                              void *opaque)
+{
+    daemonClientEventCallbackPtr callback = opaque;
+    remote_domain_event_callback_tunable_msg data;
+
+    if (callback->callbackID < 0 ||
+        !remoteRelayDomainEventCheckACL(callback->client, conn, dom))
+        return -1;
+
+    VIR_DEBUG("Relaying domain tunable event %s %d, callback %d",
+              dom->name, dom->id, callback->callbackID);
+
+    /* build return data */
+    memset(&data, 0, sizeof(data));
+    data.callbackID = callback->callbackID;
+    make_nonnull_domain(&data.dom, dom);
+
+    if (remoteSerializeTypedParameters(params, nparams,
+                                       &data.params.params_val,
+                                       &data.params.params_len,
+                                       VIR_TYPED_PARAM_STRING_OKAY) < 0)
+        return -1;
+
+    remoteDispatchObjectEventSend(callback->client, remoteProgram,
+                                  REMOTE_PROC_DOMAIN_EVENT_CALLBACK_TUNABLE,
+                                  (xdrproc_t)xdr_remote_domain_event_callback_tunable_msg,
+                                  &data);
+
+    return 0;
+}
+
+
 static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventLifecycle),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventReboot),
@@ -987,6 +1031,7 @@ static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventPMSuspendDisk),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventDeviceRemoved),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventBlockJob2),
+    VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventTunable),
 };
 
 verify(ARRAY_CARDINALITY(domainEventCallbacks) == VIR_DOMAIN_EVENT_ID_LAST);

include/libvirt/libvirt.h.in

@@ -5203,6 +5203,27 @@ typedef void (*virConnectDomainEventDeviceRemovedCallback)(virConnectPtr conn,
                                                            const char *devAlias,
                                                            void *opaque);
 
+/**
+ * virConnectDomainEventTunableCallback:
+ * @conn: connection object
+ * @dom: domain on which the event occurred
+ * @params: changed tunable values stored as array of virTypedParameter
+ * @nparams: size of the array
+ * @opaque: application specified data
+ *
+ * This callback occurs when tunable values are updated. The params must not
+ * be freed in the callback handler as it's done internally after the callback
+ * handler is executed.
+ *
+ * The callback signature to use when registering for an event of type
+ * VIR_DOMAIN_EVENT_ID_TUNABLE with virConnectDomainEventRegisterAny()
+ */
+typedef void (*virConnectDomainEventTunableCallback)(virConnectPtr conn,
+                                                     virDomainPtr dom,
+                                                     virTypedParameterPtr params,
+                                                     int nparams,
+                                                     void *opaque);
+
 
 /**
  * VIR_DOMAIN_EVENT_CALLBACK:
@@ -5238,6 +5259,7 @@ typedef enum {
     VIR_DOMAIN_EVENT_ID_PMSUSPEND_DISK = 14, /* virConnectDomainEventPMSuspendDiskCallback */
     VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED = 15, /* virConnectDomainEventDeviceRemovedCallback */
     VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2 = 16,    /* virConnectDomainEventBlockJobCallback */
+    VIR_DOMAIN_EVENT_ID_TUNABLE = 17,        /* virConnectDomainEventTunableCallback */
 
 #ifdef VIR_ENUM_SENTINELS
     VIR_DOMAIN_EVENT_ID_LAST

src/conf/domain_event.c

@@ -34,6 +34,7 @@
 #include "viralloc.h"
 #include "virerror.h"
 #include "virstring.h"
+#include "virtypedparam.h"
 
 #define VIR_FROM_THIS VIR_FROM_NONE
 
@@ -52,6 +53,7 @@ static virClassPtr virDomainEventBalloonChangeClass;
 static virClassPtr virDomainEventDeviceRemovedClass;
 static virClassPtr virDomainEventPMClass;
 static virClassPtr virDomainQemuMonitorEventClass;
+static virClassPtr virDomainEventTunableClass;
 
 
 static void virDomainEventDispose(void *obj);
@@ -67,6 +69,7 @@ static void virDomainEventBalloonChangeDispose(void *obj);
 static void virDomainEventDeviceRemovedDispose(void *obj);
 static void virDomainEventPMDispose(void *obj);
 static void virDomainQemuMonitorEventDispose(void *obj);
+static void virDomainEventTunableDispose(void *obj);
 
 static void
 virDomainEventDispatchDefaultFunc(virConnectPtr conn,
@@ -203,6 +206,15 @@ struct _virDomainQemuMonitorEvent {
 typedef struct _virDomainQemuMonitorEvent virDomainQemuMonitorEvent;
 typedef virDomainQemuMonitorEvent *virDomainQemuMonitorEventPtr;
 
+struct _virDomainEventTunable {
+    virDomainEvent parent;
+
+    virTypedParameterPtr params;
+    int nparams;
+};
+typedef struct _virDomainEventTunable virDomainEventTunable;
+typedef virDomainEventTunable *virDomainEventTunablePtr;
+
 
 static int
 virDomainEventsOnceInit(void)
@@ -285,6 +297,12 @@ virDomainEventsOnceInit(void)
                       sizeof(virDomainQemuMonitorEvent),
                       virDomainQemuMonitorEventDispose)))
         return -1;
+    if (!(virDomainEventTunableClass =
+          virClassNew(virDomainEventClass,
+                      "virDomainEventTunable",
+                      sizeof(virDomainEventTunable),
+                      virDomainEventTunableDispose)))
+        return -1;
     return 0;
 }
 
@@ -420,6 +438,15 @@ virDomainQemuMonitorEventDispose(void *obj)
     VIR_FREE(event->details);
 }
 
+static void
+virDomainEventTunableDispose(void *obj)
+{
+    virDomainEventTunablePtr event = obj;
+    VIR_DEBUG("obj=%p", event);
+
+    virTypedParamsFree(event->params, event->nparams);
+}
+
 
 static void *
 virDomainEventNew(virClassPtr klass,
@@ -1175,6 +1202,61 @@ virDomainEventDeviceRemovedNewFromDom(virDomainPtr dom,
                                           devAlias);
 }
 
+/* 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.
+ */
+static virObjectEventPtr
+virDomainEventTunableNew(int id,
+                         const char *name,
+                         unsigned char *uuid,
+                         virTypedParameterPtr params,
+                         int nparams)
+{
+    virDomainEventTunablePtr ev;
+
+    if (virDomainEventsInitialize() < 0)
+        goto error;
+
+    if (!(ev = virDomainEventNew(virDomainEventTunableClass,
+                                 VIR_DOMAIN_EVENT_ID_TUNABLE,
+                                 id, name, uuid)))
+        goto error;
+
+    ev->params = params;
+    ev->nparams = nparams;
+
+    return (virObjectEventPtr)ev;
+
+ error:
+    virTypedParamsFree(params, nparams);
+    return NULL;
+}
+
+virObjectEventPtr
+virDomainEventTunableNewFromObj(virDomainObjPtr obj,
+                                virTypedParameterPtr params,
+                                int nparams)
+{
+    return virDomainEventTunableNew(obj->def->id,
+                                    obj->def->name,
+                                    obj->def->uuid,
+                                    params,
+                                    nparams);
+}
+
+virObjectEventPtr
+virDomainEventTunableNewFromDom(virDomainPtr dom,
+                                virTypedParameterPtr params,
+                                int nparams)
+{
+    return virDomainEventTunableNew(dom->id,
+                                    dom->name,
+                                    dom->uuid,
+                                    params,
+                                    nparams);
+}
+
 
 static void
 virDomainEventDispatchDefaultFunc(virConnectPtr conn,
@@ -1366,6 +1448,17 @@ virDomainEventDispatchDefaultFunc(virConnectPtr conn,
             goto cleanup;
         }
 
+    case VIR_DOMAIN_EVENT_ID_TUNABLE:
+        {
+            virDomainEventTunablePtr tunableEvent;
+            tunableEvent = (virDomainEventTunablePtr)event;
+            ((virConnectDomainEventTunableCallback)cb)(conn, dom,
+                                                       tunableEvent->params,
+                                                       tunableEvent->nparams,
+                                                       cbopaque);
+            goto cleanup;
+        }
+
     case VIR_DOMAIN_EVENT_ID_LAST:
         break;
     }

src/conf/domain_event.h

@@ -184,6 +184,15 @@ virDomainEventDeviceRemovedNewFromObj(virDomainObjPtr obj,
 virObjectEventPtr
 virDomainEventDeviceRemovedNewFromDom(virDomainPtr dom,
                                       const char *devAlias);
+virObjectEventPtr
+virDomainEventTunableNewFromObj(virDomainObjPtr obj,
+                                virTypedParameterPtr params,
+                                int nparams);
+virObjectEventPtr
+virDomainEventTunableNewFromDom(virDomainPtr dom,
+                                virTypedParameterPtr params,
+                                int nparams);
+
 
 int
 virDomainEventStateRegister(virConnectPtr conn,

src/libvirt_private.syms

@@ -473,6 +473,8 @@ virDomainEventStateRegister;
 virDomainEventStateRegisterID;
 virDomainEventTrayChangeNewFromDom;
 virDomainEventTrayChangeNewFromObj;
+virDomainEventTunableNewFromDom;
+virDomainEventTunableNewFromObj;
 virDomainEventWatchdogNewFromDom;
 virDomainEventWatchdogNewFromObj;
 virDomainQemuMonitorEventNew;

src/remote/remote_driver.c

@@ -330,6 +330,11 @@ remoteDomainBuildEventBlockJob2(virNetClientProgramPtr prog,
                                 virNetClientPtr client,
                                 void *evdata, void *opaque);
 
+static void
+remoteDomainBuildEventCallbackTunable(virNetClientProgramPtr prog,
+                                      virNetClientPtr client,
+                                      void *evdata, void *opaque);
+
 static void
 remoteNetworkBuildEventLifecycle(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
                                  virNetClientPtr client ATTRIBUTE_UNUSED,
@@ -481,6 +486,10 @@ static virNetClientProgramEvent remoteEvents[] = {
       remoteDomainBuildEventBlockJob2,
       sizeof(remote_domain_event_block_job_2_msg),
       (xdrproc_t)xdr_remote_domain_event_block_job_2_msg },
+    { REMOTE_PROC_DOMAIN_EVENT_CALLBACK_TUNABLE,
+      remoteDomainBuildEventCallbackTunable,
+      sizeof(remote_domain_event_callback_tunable_msg),
+      (xdrproc_t)xdr_remote_domain_event_callback_tunable_msg },
 };
 
 
@@ -5513,6 +5522,39 @@ remoteDomainBuildEventCallbackDeviceRemoved(virNetClientProgramPtr prog ATTRIBUT
 }
 
 
+static void
+remoteDomainBuildEventCallbackTunable(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
+                                      virNetClientPtr client ATTRIBUTE_UNUSED,
+                                      void *evdata, void *opaque)
+{
+    virConnectPtr conn = opaque;
+    remote_domain_event_callback_tunable_msg *msg = evdata;
+    struct private_data *priv = conn->privateData;
+    virDomainPtr dom;
+    virTypedParameterPtr params = NULL;
+    int nparams = 0;
+    virObjectEventPtr event = NULL;
+
+    if (remoteDeserializeTypedParameters(msg->params.params_val,
+                                         msg->params.params_len,
+                                         REMOTE_DOMAIN_EVENT_TUNABLE_MAX,
+                                         &params, &nparams) < 0)
+        return;
+
+    dom = get_nonnull_domain(conn, msg->dom);
+    if (!dom) {
+        virTypedParamsFree(params, nparams);
+        return;
+    }
+
+    event = virDomainEventTunableNewFromDom(dom, params, nparams);
+
+    virDomainFree(dom);
+
+    remoteEventQueue(priv, event, msg->callbackID);
+}
+
+
 static void
 remoteNetworkBuildEventLifecycle(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
                                  virNetClientPtr client ATTRIBUTE_UNUSED,

src/remote/remote_protocol.x

@@ -247,6 +247,9 @@ const REMOTE_NETWORK_DHCP_LEASES_MAX = 65536;
 /* Upper limit on count of parameters returned via bulk stats API */
 const REMOTE_CONNECT_GET_ALL_DOMAIN_STATS_MAX = 4096;
 
+/* Upper limit of message size for tunable event. */
+const REMOTE_DOMAIN_EVENT_TUNABLE_MAX = 8388608;
+
 /* UUID.  VIR_UUID_BUFLEN definition comes from libvirt.h */
 typedef opaque remote_uuid[VIR_UUID_BUFLEN];
 
@@ -2990,6 +2993,12 @@ struct remote_domain_event_block_job_2_msg {
     int status;
 };
 
+struct remote_domain_event_callback_tunable_msg {
+    int callbackID;
+    remote_nonnull_domain dom;
+    remote_typed_param params<REMOTE_DOMAIN_EVENT_TUNABLE_MAX>;
+};
+
 struct remote_connect_get_cpu_model_names_args {
     remote_nonnull_string arch;
     int need_results;
@@ -5472,5 +5481,11 @@ enum remote_procedure {
      * @generate: both
      * @acl: domain:block_write
      */
-    REMOTE_PROC_DOMAIN_BLOCK_COPY = 345
+    REMOTE_PROC_DOMAIN_BLOCK_COPY = 345,
+
+    /**
+     * @generate: both
+     * @acl: none
+     */
+    REMOTE_PROC_DOMAIN_EVENT_CALLBACK_TUNABLE = 346
 };

src/remote_protocol-structs

@@ -2445,6 +2445,14 @@ struct remote_domain_event_block_job_2_msg {
         int                        type;
         int                        status;
 };
+struct remote_domain_event_callback_tunable_msg {
+        int                        callbackID;
+        remote_nonnull_domain      dom;
+        struct {
+                u_int              params_len;
+                remote_typed_param * params_val;
+        } params;
+};
 struct remote_connect_get_cpu_model_names_args {
         remote_nonnull_string      arch;
         int                        need_results;
@@ -2901,4 +2909,5 @@ enum remote_procedure {
         REMOTE_PROC_DOMAIN_OPEN_GRAPHICS_FD = 343,
         REMOTE_PROC_CONNECT_GET_ALL_DOMAIN_STATS = 344,
         REMOTE_PROC_DOMAIN_BLOCK_COPY = 345,
+        REMOTE_PROC_DOMAIN_EVENT_CALLBACK_TUNABLE = 346,
 };

tools/virsh-domain.c

@@ -11454,6 +11454,37 @@ vshEventDeviceRemovedPrint(virConnectPtr conn ATTRIBUTE_UNUSED,
         vshEventDone(data->ctl);
 }
 
+static void
+vshEventTunablePrint(virConnectPtr conn ATTRIBUTE_UNUSED,
+                     virDomainPtr dom,
+                     virTypedParameterPtr params,
+                     int nparams,
+                     void *opaque)
+{
+    vshDomEventData *data = opaque;
+    size_t i;
+    char *value = NULL;
+
+    if (!data->loop && *data->count)
+        return;
+
+    vshPrint(data->ctl,
+             _("event 'tunable' for domain %s:\n"),
+             virDomainGetName(dom));
+
+    for (i = 0; i < nparams; i++) {
+        value = virTypedParameterToString(&params[i]);
+        if (value) {
+            vshPrint(data->ctl, _("\t%s: %s\n"), params[i].field, value);
+            VIR_FREE(value);
+        }
+    }
+
+    (*data->count)++;
+    if (!data->loop)
+        vshEventDone(data->ctl);
+}
+
 static vshEventCallback vshEventCallbacks[] = {
     { "lifecycle",
       VIR_DOMAIN_EVENT_CALLBACK(vshEventLifecyclePrint), },
@@ -11487,6 +11518,8 @@ static vshEventCallback vshEventCallbacks[] = {
       VIR_DOMAIN_EVENT_CALLBACK(vshEventDeviceRemovedPrint), },
     { "block-job-2",
       VIR_DOMAIN_EVENT_CALLBACK(vshEventBlockJobPrint), },
+    { "tunable",
+      VIR_DOMAIN_EVENT_CALLBACK(vshEventTunablePrint), },
 };
 verify(VIR_DOMAIN_EVENT_ID_LAST == ARRAY_CARDINALITY(vshEventCallbacks));