[PATCH 3/3] qemu: Update paused reason on unexpected 'STOP' event

[Peter Krempa]

The qemu STOP event doesn't really report why the VM was stopped. In
certain cases we do expect this by storing the expectation in the
private data.

In cases we've encountered an unexpected STOP event we can offload to
the event thread a job to refresh the state using 'query-status'.

For all other paused reasons which are expected we keep the original
logic.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_domain.c  |  1 +
 src/qemu/qemu_domain.h  |  1 +
 src/qemu/qemu_driver.c  | 37 +++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_process.c | 22 +++++++++++++++++++---
 4 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index dde9ba92c6..106a292ef3 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -11049,6 +11049,7 @@ qemuProcessEventFree(struct qemuProcessEvent *event)
         virObjectUnref(event->data);
         break;
     case QEMU_PROCESS_EVENT_PR_DISCONNECT:
+    case QEMU_PROCESS_EVENT_STOP:
     case QEMU_PROCESS_EVENT_LAST:
         break;
     }
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 949307229b..b057e94df0 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -441,6 +441,7 @@ typedef enum {
     QEMU_PROCESS_EVENT_PR_DISCONNECT,
     QEMU_PROCESS_EVENT_RDMA_GID_STATUS_CHANGED,
     QEMU_PROCESS_EVENT_GUEST_CRASHLOADED,
+    QEMU_PROCESS_EVENT_STOP,

     QEMU_PROCESS_EVENT_LAST
 } qemuProcessEventType;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index f3f8caab44..53be363338 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4316,6 +4316,40 @@ processGuestCrashloadedEvent(virQEMUDriverPtr driver,
 }


+static void
+processGuestStopEvent(virDomainObjPtr vm)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virObjectEventPtr event = NULL;
+    virDomainPausedReason reason = VIR_DOMAIN_PAUSED_UNKNOWN;
+
+    if (qemuDomainObjBeginJob(priv->driver, vm, QEMU_JOB_MODIFY) == 0) {
+        bool running;
+        int rc;
+
+        qemuDomainObjEnterMonitor(priv->driver, vm);
+
+        rc = qemuMonitorGetStatus(priv->mon, &running, &reason);
+
+        /* update reason only on successful state update */
+        if (qemuDomainObjExitMonitor(priv->driver, vm) < 0)
+            rc = -1;
+
+        qemuDomainObjEndJob(priv->driver, vm);
+
+        if (rc < 0)
+            return;
+    }
+
+    virDomainObjSetState(vm, VIR_DOMAIN_PAUSED, reason);
+
+    event = virDomainEventLifecycleNewFromObj(vm, VIR_DOMAIN_EVENT_SUSPENDED,
+                                              qemuDomainPausedReasonToSuspendedEvent(reason));
+
+    virObjectEventStateQueue(priv->driver->domainEventState, event);
+}
+
+
 static void qemuProcessEventHandler(void *data, void *opaque)
 {
     struct qemuProcessEvent *processEvent = data;
@@ -4365,6 +4399,9 @@ static void qemuProcessEventHandler(void *data, void *opaque)
     case QEMU_PROCESS_EVENT_GUEST_CRASHLOADED:
         processGuestCrashloadedEvent(driver, vm);
         break;
+    case QEMU_PROCESS_EVENT_STOP:
+        processGuestStopEvent(vm);
+        break;
     case QEMU_PROCESS_EVENT_LAST:
         break;
     }
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 5f31260221..7003c92046 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -689,10 +689,26 @@ qemuProcessHandleStop(qemuMonitorPtr mon G_GNUC_UNUSED,
         if (priv->signalStop)
             virDomainObjBroadcast(vm);

+        /* In case of VIR_DOMAIN_PAUSED_UNKNOWN we'll update it later, but we
+         * must set the state to PAUSED right away. We delay the event until
+         * the update. */
         virDomainObjSetState(vm, VIR_DOMAIN_PAUSED, reason);
-        event = virDomainEventLifecycleNewFromObj(vm,
-                                                  VIR_DOMAIN_EVENT_SUSPENDED,
-                                                  detail);
+        if (reason == VIR_DOMAIN_PAUSED_UNKNOWN) {
+            /* offload unknown state to thread updating state */
+            struct qemuProcessEvent *processEvent = g_new0(struct qemuProcessEvent, 1);
+
+            processEvent->eventType = QEMU_PROCESS_EVENT_STOP;
+            processEvent->vm = virObjectRef(vm);
+
+            if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) {
+                virObjectUnref(vm);
+                qemuProcessEventFree(processEvent);
+            }
+        } else {
+            event = virDomainEventLifecycleNewFromObj(vm,
+                                                      VIR_DOMAIN_EVENT_SUSPENDED,
+                                                      detail);
+        }

         VIR_FREE(priv->lockState);
         if (virDomainLockProcessPause(driver->lockManager, vm, &priv->lockState) < 0)
-- 
2.29.2