From: Peter Krempa <pkrempa@redhat.com>
Date: Thu, 1 Nov 2012 14:45:47 +0000 (+0100)
Subject: qemu: Fix possible race when pausing guest
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=d0fc6dc8315b3172501e6fe09c8aed12598de47e;p=libvirt.git

qemu: Fix possible race when pausing guest

When pausing the guest while migration is running (to speed up
convergence) the virDomainSuspend API checks if the migration job is
active before entering the job. This could cause a possible race if the
virDomainSuspend is called while the job is active but ends before the
Suspend API enters the job (this would require that the migration is
aborted). This would cause a incorrect event to be emitted.
---

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 549a8fc9ff..7480765167 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -1661,14 +1661,6 @@ static int qemudDomainSuspend(virDomainPtr dom) {
 
     priv = vm->privateData;
 
-    if (priv->job.asyncJob == QEMU_ASYNC_JOB_MIGRATION_OUT) {
-        reason = VIR_DOMAIN_PAUSED_MIGRATION;
-        eventDetail = VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED;
-    } else {
-        reason = VIR_DOMAIN_PAUSED_USER;
-        eventDetail = VIR_DOMAIN_EVENT_SUSPENDED_PAUSED;
-    }
-
     if (qemuDomainObjBeginJobWithDriver(driver, vm, QEMU_JOB_SUSPEND) < 0)
         goto cleanup;
 
@@ -1678,6 +1670,14 @@ static int qemudDomainSuspend(virDomainPtr dom) {
         goto endjob;
     }
 
+    if (priv->job.asyncJob == QEMU_ASYNC_JOB_MIGRATION_OUT) {
+        reason = VIR_DOMAIN_PAUSED_MIGRATION;
+        eventDetail = VIR_DOMAIN_EVENT_SUSPENDED_MIGRATED;
+    } else {
+        reason = VIR_DOMAIN_PAUSED_USER;
+        eventDetail = VIR_DOMAIN_EVENT_SUSPENDED_PAUSED;
+    }
+
     state = virDomainObjGetState(vm, NULL);
     if (state == VIR_DOMAIN_PMSUSPENDED) {
         virReportError(VIR_ERR_OPERATION_INVALID,