[libvirt] [PATCH 1/2] Introduce a new event emitted when a virtualization failure occurs

Daniel P. Berrange berrange at redhat.com
Wed May 11 11:59:06 UTC 2011


This introduces a new domain

  VIR_DOMAIN_EVENT_ID_VMM_ERROR

With a callback

 typedef void (*virConnectDomainEventVMMErrorCallback)(virConnectPtr conn,
                                                       virDomainPtr dom,
                                                       int type,
                                                       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.

Currently the event has one 'type' defined

  VIR_DOMAIN_EVENT_VMM_ERROR_CONTROL

which indicates that the primary VM control capabilities have
failed (ie the QEMU monitor).

Other failure types may perhaps include failures of SPICE/VNC
remote desktop, host audio attachment, network attachment,
etc.

* 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                              |   31 +++++++++++++++++++++
 examples/domain-events/events-c/event-test.c |   20 ++++++++++++++
 include/libvirt/libvirt.h.in                 |   26 ++++++++++++++++++
 src/conf/domain_event.c                      |   37 ++++++++++++++++++++++++++
 src/conf/domain_event.h                      |    4 +++
 src/libvirt_private.syms                     |    2 +
 src/remote/remote_driver.c                   |   32 ++++++++++++++++++++++
 src/remote/remote_protocol.x                 |    9 +++++-
 8 files changed, 160 insertions(+), 1 deletions(-)

diff --git a/daemon/remote.c b/daemon/remote.c
index 2220655..b4cf2fe 100644
--- a/daemon/remote.c
+++ b/daemon/remote.c
@@ -379,6 +379,36 @@ static int remoteRelayDomainEventGraphics(virConnectPtr conn ATTRIBUTE_UNUSED,
 }
 
 
+static int remoteRelayDomainEventVMMError(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                          virDomainPtr dom,
+                                          int type,
+                                          void *opaque)
+{
+    struct qemud_client *client = opaque;
+    remote_domain_event_vmm_error_msg data;
+
+    if (!client)
+        return -1;
+
+    VIR_DEBUG("Relaying domain VMM error %s %d %d", dom->name, dom->id, type);
+
+    virMutexLock(&client->lock);
+
+    /* build return data */
+    memset(&data, 0, sizeof data);
+    make_nonnull_domain(&data.dom, dom);
+    data.type = type;
+
+    remoteDispatchDomainEventSend(client,
+                                  REMOTE_PROC_DOMAIN_EVENT_VMM_ERROR,
+                                  (xdrproc_t)xdr_remote_domain_event_vmm_error_msg, &data);
+
+    virMutexUnlock(&client->lock);
+
+    return 0;
+}
+
+
 static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventLifecycle),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventReboot),
@@ -387,6 +417,7 @@ static virConnectDomainEventGenericCallback domainEventCallbacks[] = {
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventIOError),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventGraphics),
     VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventIOErrorReason),
+    VIR_DOMAIN_EVENT_CALLBACK(remoteRelayDomainEventVMMError),
 };
 
 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 1f46d42..678e510 100644
--- a/examples/domain-events/events-c/event-test.c
+++ b/examples/domain-events/events-c/event-test.c
@@ -248,6 +248,18 @@ static int myDomainEventGraphicsCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
     return 0;
 }
 
+static int myDomainEventVMMErrorCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                         virDomainPtr dom,
+                                         int type,
+                                         void *opaque ATTRIBUTE_UNUSED)
+{
+    printf("%s EVENT: Domain %s(%d) vmm error type=%d\n", __func__, virDomainGetName(dom),
+           virDomainGetID(dom), type);
+
+    return 0;
+}
+
+
 static void myFreeFunc(void *opaque)
 {
     char *str = opaque;
@@ -281,6 +293,7 @@ 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);
@@ -339,6 +352,11 @@ 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_VMM_ERROR,
+                                                    VIR_DOMAIN_EVENT_CALLBACK(myDomainEventVMMErrorCallback),
+                                                    strdup("callback VMM error"), myFreeFunc);
 
     if ((callback1ret != -1) &&
         (callback2ret != -1) &&
@@ -363,6 +381,8 @@ int main(int argc, char **argv)
         virConnectDomainEventDeregisterAny(dconn, callback5ret);
         virConnectDomainEventDeregisterAny(dconn, callback6ret);
         virConnectDomainEventDeregisterAny(dconn, callback7ret);
+        if (callback8ret != -1)
+            virConnectDomainEventDeregisterAny(dconn, callback8ret);
     }
 
     VIR_DEBUG0("Closing connection");
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 0e1e27a..7caf828 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -2413,6 +2413,31 @@ typedef void (*virConnectDomainEventGraphicsCallback)(virConnectPtr conn,
                                                       void *opaque);
 
 /**
+ * virDomainEventVMMErrorType:
+ *
+ * The reason for the VMM error
+ */
+typedef enum {
+    VIR_DOMAIN_EVENT_VMM_ERROR_CONTROL = 0,  /* Control channel is broken */
+} virDomainEventVMMErrorReason;
+
+
+/**
+ * virConnectDomainEventVMMErrorCallback:
+ * @conn: connection object
+ * @dom: domain on which the event occurred
+ * @type: the type of the error
+ * @opaque: application specified data
+ *
+ * The callback signature to use when registering for an event of type
+ * VIR_DOMAIN_EVENT_ID_VMM_ERROR with virConnectDomainEventRegisterAny()
+ */
+typedef void (*virConnectDomainEventVMMErrorCallback)(virConnectPtr conn,
+                                                      virDomainPtr dom,
+                                                      int type,
+                                                      void *opaque);
+
+/**
  * VIR_DOMAIN_EVENT_CALLBACK:
  *
  * Used to cast the event specific callback into the generic one
@@ -2429,6 +2454,7 @@ 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_VMM_ERROR = 7,       /* virConnectDomainEventVMMErrorCallback */
 
     /*
      * NB: this enum value will increase over time as new events are
diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
index 688bf6c..fdbe630 100644
--- a/src/conf/domain_event.c
+++ b/src/conf/domain_event.c
@@ -83,6 +83,9 @@ struct _virDomainEvent {
             char *authScheme;
             virDomainEventGraphicsSubjectPtr subject;
         } graphics;
+        struct {
+            int type;
+        } vmmError;
     } data;
 };
 
@@ -783,6 +786,34 @@ virDomainEventPtr virDomainEventGraphicsNewFromObj(virDomainObjPtr obj,
 }
 
 
+virDomainEventPtr virDomainEventVMMErrorNewFromDom(virDomainPtr dom,
+                                                   int type)
+{
+    virDomainEventPtr ev =
+        virDomainEventNewInternal(VIR_DOMAIN_EVENT_ID_VMM_ERROR,
+                                  dom->id, dom->name, dom->uuid);
+
+    if (ev)
+        ev->data.vmmError.type = type;
+
+    return ev;
+}
+
+
+virDomainEventPtr virDomainEventVMMErrorNewFromObj(virDomainObjPtr obj,
+                                                   int type)
+{
+    virDomainEventPtr ev =
+        virDomainEventNewInternal(VIR_DOMAIN_EVENT_ID_VMM_ERROR,
+                                  obj->def->id, obj->def->name, obj->def->uuid);
+
+    if (ev)
+        ev->data.vmmError.type = type;
+
+    return ev;
+}
+
+
 /**
  * virDomainEventQueueFree:
  * @queue: pointer to the queue
@@ -932,6 +963,12 @@ void virDomainEventDispatchDefaultFunc(virConnectPtr conn,
                                                     cbopaque);
         break;
 
+    case VIR_DOMAIN_EVENT_ID_VMM_ERROR:
+        ((virConnectDomainEventVMMErrorCallback)cb)(conn, dom,
+                                                    event->data.vmmError.type,
+                                                    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 c03a159..c1ff871 100644
--- a/src/conf/domain_event.h
+++ b/src/conf/domain_event.h
@@ -153,6 +153,10 @@ virDomainEventPtr virDomainEventGraphicsNewFromObj(virDomainObjPtr obj,
                                                    virDomainEventGraphicsAddressPtr remote,
                                                    const char *authScheme,
                                                    virDomainEventGraphicsSubjectPtr subject);
+virDomainEventPtr virDomainEventVMMErrorNewFromDom(virDomainPtr dom,
+                                                   int reason);
+virDomainEventPtr virDomainEventVMMErrorNewFromObj(virDomainObjPtr obj,
+                                                   int reason);
 
 
 
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 7e5b1d7..e3e4a34 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -389,6 +389,8 @@ virDomainEventRTCChangeNewFromObj;
 virDomainEventRebootNew;
 virDomainEventRebootNewFromDom;
 virDomainEventRebootNewFromObj;
+virDomainEventVMMErrorNewFromDom;
+virDomainEventVMMErrorNewFromObj;
 virDomainEventWatchdogNewFromDom;
 virDomainEventWatchdogNewFromObj;
 
diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
index 37940f3..11ab095 100644
--- a/src/remote/remote_driver.c
+++ b/src/remote/remote_driver.c
@@ -4121,6 +4121,34 @@ no_memory:
 }
 
 
+static virDomainEventPtr
+remoteDomainReadEventVMMError(virConnectPtr conn, XDR *xdr)
+{
+    remote_domain_event_vmm_error_msg msg;
+    virDomainPtr dom;
+    virDomainEventPtr event = NULL;
+    memset (&msg, 0, sizeof msg);
+
+    /* unmarshall parameters, and process it*/
+    if (! xdr_remote_domain_event_vmm_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 = virDomainEventVMMErrorNewFromDom(dom,
+                                             msg.type);
+    xdr_free ((xdrproc_t) &xdr_remote_domain_event_vmm_error_msg, (char *) &msg);
+
+    virDomainFree(dom);
+    return event;
+}
+
+
 static virDrvOpenStatus ATTRIBUTE_NONNULL (1)
 remoteSecretOpen(virConnectPtr conn, virConnectAuthPtr auth, int flags)
 {
@@ -5544,6 +5572,10 @@ processCallDispatchMessage(virConnectPtr conn, struct private_data *priv,
         event = remoteDomainReadEventGraphics(conn, xdr);
         break;
 
+    case REMOTE_PROC_DOMAIN_EVENT_VMM_ERROR:
+        event = remoteDomainReadEventVMMError(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 2cf6022..d12438a 100644
--- a/src/remote/remote_protocol.x
+++ b/src/remote/remote_protocol.x
@@ -1945,6 +1945,11 @@ struct remote_storage_vol_download_args {
     unsigned int flags;
 };
 
+struct remote_domain_event_vmm_error_msg {
+    remote_nonnull_domain dom;
+    int type;
+};
+
 
 /*----- Protocol. -----*/
 
@@ -2182,7 +2187,9 @@ enum remote_procedure {
     REMOTE_PROC_DOMAIN_MIGRATE_SET_MAX_SPEED = 207,
     REMOTE_PROC_STORAGE_VOL_UPLOAD = 208,
     REMOTE_PROC_STORAGE_VOL_DOWNLOAD = 209,
-    REMOTE_PROC_DOMAIN_INJECT_NMI = 210
+    REMOTE_PROC_DOMAIN_INJECT_NMI = 210,
+
+    REMOTE_PROC_DOMAIN_EVENT_VMM_ERROR = 211
 
     /*
      * Notice how the entries are grouped in sets of 10 ?
-- 
1.7.4.4




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