From ab5e7d4977afd68b63406c82b6220c5b998e73cc Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 8 Nov 2012 14:49:55 +0100
Subject: [PATCH] qemu: Allow migration to be cancelled at prepare phase

Currently, if user calls virDomainAbortJob we just issue
'migrate_cancel' and hope for the best. However, if user calls
the API in wrong phase when migration hasn't been started yet
(perform phase) the cancel request is just ignored. With this
patch, the request is remembered and as soon as perform phase
starts, migration is cancelled.
---
 src/qemu/qemu_domain.c    | 12 ++++++++++++
 src/qemu/qemu_domain.h    |  2 ++
 src/qemu/qemu_driver.c    |  1 +
 src/qemu/qemu_migration.c | 11 +++++++++++
 4 files changed, 26 insertions(+)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index a5592b92c8..e0d6951e86 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -160,6 +160,7 @@ qemuDomainObjResetAsyncJob(qemuDomainObjPrivatePtr priv)
     job->mask = DEFAULT_JOB_MASK;
     job->start = 0;
     job->dump_memory_only = false;
+    job->asyncAbort = false;
     memset(&job->info, 0, sizeof(job->info));
 }
 
@@ -959,6 +960,17 @@ qemuDomainObjEndAsyncJob(struct qemud_driver *driver, virDomainObjPtr obj)
     return virObjectUnref(obj);
 }
 
+void
+qemuDomainObjAbortAsyncJob(virDomainObjPtr obj)
+{
+    qemuDomainObjPrivatePtr priv = obj->privateData;
+
+    VIR_DEBUG("Requesting abort of async job: %s",
+              qemuDomainAsyncJobTypeToString(priv->job.asyncJob));
+
+    priv->job.asyncAbort = true;
+}
+
 static int
 qemuDomainObjEnterMonitorInternal(struct qemud_driver *driver,
                                   bool driver_locked,
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 9c2f67c7a7..a2acc0ad18 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -111,6 +111,7 @@ struct qemuDomainJobObj {
     unsigned long long start;           /* When the async job started */
     bool dump_memory_only;              /* use dump-guest-memory to do dump */
     virDomainJobInfo info;              /* Async job progress data */
+    bool asyncAbort;                    /* abort of async job requested */
 };
 
 typedef struct _qemuDomainPCIAddressSet qemuDomainPCIAddressSet;
@@ -204,6 +205,7 @@ bool qemuDomainObjEndJob(struct qemud_driver *driver,
 bool qemuDomainObjEndAsyncJob(struct qemud_driver *driver,
                               virDomainObjPtr obj)
     ATTRIBUTE_RETURN_CHECK;
+void qemuDomainObjAbortAsyncJob(virDomainObjPtr obj);
 void qemuDomainObjSetJobPhase(struct qemud_driver *driver,
                               virDomainObjPtr obj,
                               int phase);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 3279a99f4b..5556f1e595 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -10397,6 +10397,7 @@ static int qemuDomainAbortJob(virDomainPtr dom) {
     }
 
     VIR_DEBUG("Cancelling job at client request");
+    qemuDomainObjAbortAsyncJob(vm);
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorMigrateCancel(priv->mon);
     qemuDomainObjExitMonitor(driver, vm);
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 5f8a9c587f..0a52486437 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2168,6 +2168,17 @@ qemuMigrationRun(struct qemud_driver *driver,
                                        QEMU_ASYNC_JOB_MIGRATION_OUT) < 0)
         goto cleanup;
 
+    if (priv->job.asyncAbort) {
+        /* explicitly do this *after* we entered the monitor,
+         * as this is a critical section so we are guaranteed
+         * priv->job.asyncAbort will not change */
+        qemuDomainObjExitMonitorWithDriver(driver, vm);
+        virReportError(VIR_ERR_OPERATION_ABORTED, _("%s: %s"),
+                       qemuDomainAsyncJobTypeToString(priv->job.asyncJob),
+                       _("canceled by client"));
+        goto cleanup;
+    }
+
     if (qemuMonitorSetMigrationSpeed(priv->mon, migrate_speed) < 0) {
         qemuDomainObjExitMonitorWithDriver(driver, vm);
         goto cleanup;
-- 
2.47.2