qemu: Wire up PR_MANAGER_STATUS_CHANGED event

This event is emitted on the monitor if one of pr-managers lost
connection to its pr-helper process. What libvirt needs to do is
restart the pr-helper process iff it corresponds to managed
pr-manager.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_domain.c

@@ -13003,6 +13003,7 @@ qemuProcessEventFree(struct qemuProcessEvent *event)
     case QEMU_PROCESS_EVENT_MONITOR_EOF:
         VIR_FREE(event->data);
         break;
+    case QEMU_PROCESS_EVENT_PR_DISCONNECT:
     case QEMU_PROCESS_EVENT_LAST:
         break;
     }

src/qemu/qemu_domain.h

@@ -477,6 +477,7 @@ typedef enum {
     QEMU_PROCESS_EVENT_SERIAL_CHANGED,
     QEMU_PROCESS_EVENT_BLOCK_JOB,
     QEMU_PROCESS_EVENT_MONITOR_EOF,
+    QEMU_PROCESS_EVENT_PR_DISCONNECT,
 
     QEMU_PROCESS_EVENT_LAST
 } qemuProcessEventType;

src/qemu/qemu_driver.c

@@ -4778,6 +4778,20 @@ processMonitorEOFEvent(virQEMUDriverPtr driver,
 }
 
 
+static void
+processPRDisconnectEvent(virDomainObjPtr vm)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+
+    if (!virDomainObjIsActive(vm))
+        return;
+
+    if (!priv->prDaemonRunning &&
+        virDomainDefHasManagedPR(vm->def))
+        qemuProcessStartManagedPRDaemon(vm);
+}
+
+
 static void qemuProcessEventHandler(void *data, void *opaque)
 {
     struct qemuProcessEvent *processEvent = data;
@@ -4815,6 +4829,9 @@ static void qemuProcessEventHandler(void *data, void *opaque)
     case QEMU_PROCESS_EVENT_MONITOR_EOF:
         processMonitorEOFEvent(driver, vm);
         break;
+    case QEMU_PROCESS_EVENT_PR_DISCONNECT:
+        processPRDisconnectEvent(vm);
+        break;
     case QEMU_PROCESS_EVENT_LAST:
         break;
     }

src/qemu/qemu_monitor.c

@@ -1669,6 +1669,21 @@ qemuMonitorEmitDumpCompleted(qemuMonitorPtr mon,
 }
 
 
+int
+qemuMonitorEmitPRManagerStatusChanged(qemuMonitorPtr mon,
+                                      const char *prManager,
+                                      bool connected)
+{
+    int ret = -1;
+    VIR_DEBUG("mon=%p, prManager='%s', connected=%d", mon, prManager, connected);
+
+    QEMU_MONITOR_CALLBACK(mon, ret, domainPRManagerStatusChanged,
+                          mon->vm, prManager, connected);
+
+    return ret;
+}
+
+
 int
 qemuMonitorSetCapabilities(qemuMonitorPtr mon)
 {

src/qemu/qemu_monitor.h

@@ -273,6 +273,12 @@ typedef int (*qemuMonitorDomainDumpCompletedCallback)(qemuMonitorPtr mon,
                                                       const char *error,
                                                       void *opaque);
 
+typedef int (*qemuMonitorDomainPRManagerStatusChangedCallback)(qemuMonitorPtr mon,
+                                                               virDomainObjPtr vm,
+                                                               const char *prManager,
+                                                               bool connected,
+                                                               void *opaque);
+
 typedef struct _qemuMonitorCallbacks qemuMonitorCallbacks;
 typedef qemuMonitorCallbacks *qemuMonitorCallbacksPtr;
 struct _qemuMonitorCallbacks {
@@ -305,6 +311,7 @@ struct _qemuMonitorCallbacks {
     qemuMonitorDomainAcpiOstInfoCallback domainAcpiOstInfo;
     qemuMonitorDomainBlockThresholdCallback domainBlockThreshold;
     qemuMonitorDomainDumpCompletedCallback domainDumpCompleted;
+    qemuMonitorDomainPRManagerStatusChangedCallback domainPRManagerStatusChanged;
 };
 
 char *qemuMonitorEscapeArg(const char *in);
@@ -433,6 +440,10 @@ int qemuMonitorEmitDumpCompleted(qemuMonitorPtr mon,
                                  qemuMonitorDumpStatsPtr stats,
                                  const char *error);
 
+int qemuMonitorEmitPRManagerStatusChanged(qemuMonitorPtr mon,
+                                          const char *prManager,
+                                          bool connected);
+
 int qemuMonitorStartCPUs(qemuMonitorPtr mon);
 int qemuMonitorStopCPUs(qemuMonitorPtr mon);
 

src/qemu/qemu_monitor_json.c

@@ -91,6 +91,7 @@ static void qemuMonitorJSONHandleMigrationPass(qemuMonitorPtr mon, virJSONValueP
 static void qemuMonitorJSONHandleAcpiOstInfo(qemuMonitorPtr mon, virJSONValuePtr data);
 static void qemuMonitorJSONHandleBlockThreshold(qemuMonitorPtr mon, virJSONValuePtr data);
 static void qemuMonitorJSONHandleDumpCompleted(qemuMonitorPtr mon, virJSONValuePtr data);
+static void qemuMonitorJSONHandlePRManagerStatusChanged(qemuMonitorPtr mon, virJSONValuePtr data);
 
 typedef struct {
     const char *type;
@@ -113,6 +114,7 @@ static qemuEventHandler eventHandlers[] = {
     { "MIGRATION_PASS", qemuMonitorJSONHandleMigrationPass, },
     { "NIC_RX_FILTER_CHANGED", qemuMonitorJSONHandleNicRxFilterChanged, },
     { "POWERDOWN", qemuMonitorJSONHandlePowerdown, },
+    { "PR_MANAGER_STATUS_CHANGED", qemuMonitorJSONHandlePRManagerStatusChanged, },
     { "RESET", qemuMonitorJSONHandleReset, },
     { "RESUME", qemuMonitorJSONHandleResume, },
     { "RTC_CHANGE", qemuMonitorJSONHandleRTCChange, },
@@ -1297,6 +1299,27 @@ qemuMonitorJSONHandleDumpCompleted(qemuMonitorPtr mon,
 }
 
 
+static void qemuMonitorJSONHandlePRManagerStatusChanged(qemuMonitorPtr mon,
+                                                        virJSONValuePtr data)
+{
+    const char *name;
+    bool connected;
+
+    if (!(name = virJSONValueObjectGetString(data, "id"))) {
+        VIR_WARN("missing pr-manager alias in PR_MANAGER_STATUS_CHANGED event");
+        return;
+    }
+
+    if (virJSONValueObjectGetBoolean(data, "connected", &connected) < 0) {
+        VIR_WARN("missing connected state for %s "
+                 "in PR_MANAGER_STATUS_CHANGED event", name);
+        return;
+    }
+
+    qemuMonitorEmitPRManagerStatusChanged(mon, name, connected);
+}
+
+
 int
 qemuMonitorJSONHumanCommandWithFd(qemuMonitorPtr mon,
                                   const char *cmd_str,

src/qemu/qemu_process.c

@@ -1615,6 +1615,60 @@ qemuProcessHandleDumpCompleted(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
 }
 
 
+static int
+qemuProcessHandlePRManagerStatusChanged(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
+                                        virDomainObjPtr vm,
+                                        const char *prManager,
+                                        bool connected,
+                                        void *opaque)
+{
+    virQEMUDriverPtr driver = opaque;
+    qemuDomainObjPrivatePtr priv;
+    struct qemuProcessEvent *processEvent = NULL;
+    const char *managedAlias = qemuDomainGetManagedPRAlias();
+    int ret = -1;
+
+    virObjectLock(vm);
+
+    VIR_DEBUG("pr-manager %s status changed for domain %p %s connected=%d",
+              prManager, vm, vm->def->name, connected);
+
+    if (connected) {
+        /* Connect events are boring. */
+        ret = 0;
+        goto cleanup;
+    }
+    /* Disconnect events are more interesting. */
+
+    if (STRNEQ(prManager, managedAlias)) {
+        VIR_DEBUG("pr-manager %s not managed, ignoring event",
+                  prManager);
+        ret = 0;
+        goto cleanup;
+    }
+
+    priv = vm->privateData;
+    priv->prDaemonRunning = false;
+
+    if (VIR_ALLOC(processEvent) < 0)
+        goto cleanup;
+
+    processEvent->eventType = QEMU_PROCESS_EVENT_PR_DISCONNECT;
+    processEvent->vm = virObjectRef(vm);
+
+    if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
+        qemuProcessEventFree(processEvent);
+        virObjectUnref(vm);
+        goto cleanup;
+    }
+
+    ret = 0;
+ cleanup:
+    virObjectUnlock(vm);
+    return ret;
+}
+
+
 static qemuMonitorCallbacks monitorCallbacks = {
     .eofNotify = qemuProcessHandleMonitorEOF,
     .errorNotify = qemuProcessHandleMonitorError,
@@ -1643,6 +1697,7 @@ static qemuMonitorCallbacks monitorCallbacks = {
     .domainAcpiOstInfo = qemuProcessHandleAcpiOstInfo,
     .domainBlockThreshold = qemuProcessHandleBlockThreshold,
     .domainDumpCompleted = qemuProcessHandleDumpCompleted,
+    .domainPRManagerStatusChanged = qemuProcessHandlePRManagerStatusChanged,
 };
 
 static void