[libvirt] [PATCH 1/3] Introduce a new event emitted when a virtualization failure occurs

Daniel P. Berrange berrange at redhat.com
Tue May 24 17:06:41 UTC 2011


This introduces a new domain

  VIR_DOMAIN_EVENT_ID_CONTROL_ERROR

Which uses the existing generic callback

typedef void (*virConnectDomainEventGenericCallback)(virConnectPtr conn,
                                                     virDomainPtr dom,
                                                     void *opaque);

This event is intended to be emitted when there is a failure in
some part of the domain virtualization system. Whether the domain
continues to run/exist after the failure is an implementation
detail specific to the hypervisor.

The idea is that with some types of failure, hypervisors may
prefer to leave the domain running in a "degraded" mode of
operation. For example, if something goes wrong with the QEMU
monitor, it is possible to leave the guest OS running quite
happily. The mgmt app will simply loose the ability todo various
tasks. The mgmt app can then choose how/when to deal with the
failure that occured.

* daemon/remote.c: Dispatch of new event
* examples/domain-events/events-c/event-test.c: Demo catch
  of event
* include/libvirt/libvirt.h.in: Define event ID and callback
* src/conf/domain_event.c, src/conf/domain_event.h: Internal
  event handling
* src/remote/remote_driver.c: Receipt of new event from daemon
* src/remote/remote_protocol.x: Wire protocol for new event
---
 daemon/remote.c                              |   29 ++++++++++++++++++++++++
 examples/domain-events/events-c/event-test.c |   19 ++++++++++++++++
 include/libvirt/libvirt.h.in                 |    1 +
 python/libvirt-override.c                    |    3 ++
 src/conf/domain_event.c                      |   23 +++++++++++++++++++
 src/conf/domain_event.h                      |    2 +
 src/libvirt_private.syms                     |    2 +
 src/remote/remote_driver.c                   |   31 ++++++++++++++++++++++++++
 src/remote/remote_protocol.x                 |    7 +++++-
 9 files changed, 116 insertions(+), 1 deletions(-)

diff --git a/daemon/remote.c b/daemon/remote.c
index 80783b3..59a7377 100644
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -380,6 +380,34 @@ static int remoteRelayDomainEventGraphics(virConnectPtr conn ATTRIBUTE_UNUSED,
 }
 
 
+static int remoteRelayDomainEventControlError(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                              virDomainPtr dom,
+                                              void *opaque)
+{
+    struct qemud_client *client = opaque;
+    remote_domain_event_control_error_msg data;
+
+    if (!client)
+        return -1;
+
+    VIR_DEBUG("Relaying domain control error %s %d", dom->name, dom->id);
+
+    virMutexLock(&client->lock);
+
+    /* build return data */
+    memset(&data, 0, sizeof data);
+    make_nonnull_domain(&data.dom, dom);
+
+    remoteDispatchDomainEventSend(client,
+                                  REMOTE_PROC_DOMAIN_EVENT_CONTROL_ERROR,
+                                  (xdrproc_t)xdr_remote_domain_event_control_error_msg, &data);
+
+    virMutexUnlock(&client->lock);
+
+    return 0;
+}
+
+
 static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventLifecycle),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventReboot),
@@ -388,6 +416,7 @@ static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventIOError),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventGraphics),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventIOErrorReason),
+    VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventControlError),
 };
 
 verify(ARRAY_CARDINALITY(domainEventCallbacks) == VIR_DOMAIN_EVENT_ID_LAST);
diff --git a/examples/domain-events/events-c/event-test.c b/examples/domain-events/events-c/event-test.c
index 2da58b8..4766a0d 100644
--- a/examples/domain-events/events-c/event-test.c
+++ b/examples/domain-events/events-c/event-test.c
@@ -245,6 +245,17 @@ static int myDomainEventGraphicsCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
     return 0;
 }
 
+static int myDomainEventControlErrorCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                             virDomainPtr dom,
+                                             void *opaque ATTRIBUTE_UNUSED)
+{
+    printf("%s EVENT: Domain %s(%d) control error\n", __func__, virDomainGetName(dom),
+           virDomainGetID(dom));
+
+    return 0;
+}
+
+
 static void myFreeFunc(void *opaque)
 {
     char *str = opaque;
@@ -278,6 +289,7 @@ int main(int argc, char **argv)
     int callback5ret = -1;
     int callback6ret = -1;
     int callback7ret = -1;
+    int callback8ret = -1;
     struct sigaction action_stop;
 
     memset(&action_stop, 0, sizeof action_stop);
@@ -336,6 +348,11 @@ int main(int argc, char **argv)
                                                     VIR_DOMAIN_EVENT_ID_GRAPHICS,
                                                     VIR_DOMAIN_EVENT_CALLBACK(myDomainEventGraphicsCallback),
                                                     strdup("callback graphics"), myFreeFunc);
+    callback8ret = virConnectDomainEventRegisterAny(dconn,
+                                                    NULL,
+                                                    VIR_DOMAIN_EVENT_ID_CONTROL_ERROR,
+                                                    VIR_DOMAIN_EVENT_CALLBACK(myDomainEventControlErrorCallback),
+                                                    strdup("callback control error"), myFreeFunc);
 
     if ((callback1ret != -1) &&
         (callback2ret != -1) &&
@@ -360,6 +377,8 @@ int main(int argc, char **argv)
         virConnectDomainEventDeregisterAny(dconn, callback5ret);
         virConnectDomainEventDeregisterAny(dconn, callback6ret);
         virConnectDomainEventDeregisterAny(dconn, callback7ret);
+        if (callback8ret != -1)
+            virConnectDomainEventDeregisterAny(dconn, callback8ret);
     }
 
     VIR_DEBUG("Closing connection");
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 7cd6e13..448951f 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -2525,6 +2525,7 @@ typedef enum {
     VIR_DOMAIN_EVENT_ID_IO_ERROR = 4,        /* virConnectDomainEventIOErrorCallback */
     VIR_DOMAIN_EVENT_ID_GRAPHICS = 5,        /* virConnectDomainEventGraphicsCallback */
     VIR_DOMAIN_EVENT_ID_IO_ERROR_REASON = 6, /* virConnectDomainEventIOErrorReasonCallback */
+    VIR_DOMAIN_EVENT_ID_CONTROL_ERROR = 7,   /* virConnectDomainEventGenericCallback */
 
     /*
      * NB: this enum value will increase over time as new events are
diff --git a/python/libvirt-override.c b/python/libvirt-override.c
index a151e78..d15a865 100644
--- a/python/libvirt-override.c
+++ b/python/libvirt-override.c
@@ -3485,6 +3485,9 @@ libvirt_virConnectDomainEventRegisterAny(ATTRIBUTE_UNUSED PyObject * self,
     case VIR_DOMAIN_EVENT_ID_GRAPHICS:
         cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventGraphicsCallback);
         break;
+    case VIR_DOMAIN_EVENT_ID_CONTROL_ERROR:
+        cb = VIR_DOMAIN_EVENT_CALLBACK(libvirt_virConnectDomainEventGenericCallback);
+        break;
     }
 
     if (!cb) {
diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index b85765e..34a9d91 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -875,6 +875,24 @@ virDomainEventPtr virDomainEventGraphicsNewFromObj(virDomainObjPtr obj,
 }
 
 
+virDomainEventPtr virDomainEventControlErrorNewFromDom(virDomainPtr dom)
+{
+    virDomainEventPtr ev =
+        virDomainEventNewInternal(VIR_DOMAIN_EVENT_ID_CONTROL_ERROR,
+                                  dom->id, dom->name, dom->uuid);
+    return ev;
+}
+
+
+virDomainEventPtr virDomainEventControlErrorNewFromObj(virDomainObjPtr obj)
+{
+    virDomainEventPtr ev =
+        virDomainEventNewInternal(VIR_DOMAIN_EVENT_ID_CONTROL_ERROR,
+                                  obj->def->id, obj->def->name, obj->def->uuid);
+    return ev;
+}
+
+
 /**
  * virDomainEventQueuePop:
  * @evtQueue: the queue of events
@@ -1004,6 +1022,11 @@ void virDomainEventDispatchDefaultFunc(virConnectPtr conn,
                                                     cbopaque);
         break;
 
+    case VIR_DOMAIN_EVENT_ID_CONTROL_ERROR:
+        (cb)(conn, dom,
+             cbopaque);
+        break;
+
     default:
         VIR_WARN("Unexpected event ID %d", event->eventID);
         break;
diff --git a/src/conf/domain_event.h b/src/conf/domain_event.h
index efc05f9..68dc8a8 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -167,6 +167,8 @@ virDomainEventPtr virDomainEventGraphicsNewFromObj(virDomainObjPtr obj,
                                                    virDomainEventGraphicsAddressPtr remote,
                                                    const char *authScheme,
                                                    virDomainEventGraphicsSubjectPtr subject);
+virDomainEventPtr virDomainEventControlErrorNewFromDom(virDomainPtr dom);
+virDomainEventPtr virDomainEventControlErrorNewFromObj(virDomainObjPtr obj);
 
 
 
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 7b6151c..6036afe 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -370,6 +370,8 @@ virDomainEventCallbackListPurgeMarked;
 virDomainEventCallbackListRemove;
 virDomainEventCallbackListRemoveConn;
 virDomainEventCallbackListRemoveID;
+virDomainEventControlErrorNewFromDom;
+virDomainEventControlErrorNewFromObj;
 virDomainEventDispatch;
 virDomainEventDispatchDefaultFunc;
 virDomainEventFree;
diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
index 8c69743..97e9e2f 100644
--- a/src/remote/remote_driver.c
+++ b/src/remote/remote_driver.c
@@ -4093,6 +4093,33 @@ no_memory:
 }
 
 
+static virDomainEventPtr
+remoteDomainReadEventControlError(virConnectPtr conn, XDR *xdr)
+{
+    remote_domain_event_control_error_msg msg;
+    virDomainPtr dom;
+    virDomainEventPtr event = NULL;
+    memset (&msg, 0, sizeof msg);
+
+    /* unmarshall parameters, and process it*/
+    if (! xdr_remote_domain_event_control_error_msg(xdr, &msg) ) {
+        remoteError(VIR_ERR_RPC, "%s",
+                    _("unable to demarshall reboot event"));
+        return NULL;
+    }
+
+    dom = get_nonnull_domain(conn,msg.dom);
+    if (!dom)
+        return NULL;
+
+    event = virDomainEventControlErrorNewFromDom(dom);
+    xdr_free ((xdrproc_t) &xdr_remote_domain_event_control_error_msg, (char *) &msg);
+
+    virDomainFree(dom);
+    return event;
+}
+
+
 static virDrvOpenStatus ATTRIBUTE_NONNULL (1)
 remoteSecretOpen(virConnectPtr conn, virConnectAuthPtr auth, int flags)
 {
@@ -5903,6 +5930,10 @@ processCallDispatchMessage(virConnectPtr conn, struct private_data *priv,
         event = remoteDomainReadEventGraphics(conn, xdr);
         break;
 
+    case REMOTE_PROC_DOMAIN_EVENT_CONTROL_ERROR:
+        event = remoteDomainReadEventControlError(conn, xdr);
+        break;
+
     default:
         VIR_DEBUG("Unexpected event proc %d", hdr->proc);
         break;
diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x
index f0da95d..61f994f 100644
--- a/src/remote/remote_protocol.x
+++ b/src/remote/remote_protocol.x
@@ -2042,6 +2042,10 @@ struct remote_domain_migrate_confirm3_args {
     int cancelled;
 };
 
+struct remote_domain_event_control_error_msg {
+    remote_nonnull_domain dom;
+};
+
 /*----- Protocol. -----*/
 
 /* Define the program number, protocol version and procedure numbers here. */
@@ -2291,7 +2295,8 @@ enum remote_procedure {
     REMOTE_PROC_DOMAIN_MIGRATE_PERFORM3 = 216, /* skipgen skipgen */
     REMOTE_PROC_DOMAIN_MIGRATE_FINISH3 = 217, /* skipgen skipgen */
     REMOTE_PROC_DOMAIN_MIGRATE_CONFIRM3 = 218, /* skipgen skipgen */
-    REMOTE_PROC_DOMAIN_SET_SCHEDULER_PARAMETERS_FLAGS = 219 /* skipgen skipgen */
+    REMOTE_PROC_DOMAIN_SET_SCHEDULER_PARAMETERS_FLAGS = 219, /* skipgen skipgen */
+    REMOTE_PROC_DOMAIN_EVENT_CONTROL_ERROR = 220 /* skipgen skipgen */
 
     /*
      * Notice how the entries are grouped in sets of 10 ?
-- 
1.7.4.4




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