qemu: Store original migration params in job

Any job which touches migration parameters will first store their
original values (i.e., QEMU defaults) to qemuDomainJobObj to make it
easier to reset them back once the job finishes.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_domain.c

@@ -336,6 +336,8 @@ qemuDomainObjResetAsyncJob(qemuDomainObjPrivatePtr priv)
     job->dumpCompleted = false;
     VIR_FREE(job->error);
     VIR_FREE(job->current);
+    qemuMigrationParamsFree(job->migParams);
+    job->migParams = NULL;
 }
 
 void
@@ -350,6 +352,7 @@ qemuDomainObjRestoreJob(virDomainObjPtr obj,
     job->asyncJob = priv->job.asyncJob;
     job->asyncOwner = priv->job.asyncOwner;
     job->phase = priv->job.phase;
+    VIR_STEAL_PTR(job->migParams, priv->job.migParams);
 
     qemuDomainObjResetJob(priv);
     qemuDomainObjResetAsyncJob(priv);

src/qemu/qemu_domain.h

@@ -34,6 +34,7 @@
 # include "qemu_agent.h"
 # include "qemu_conf.h"
 # include "qemu_capabilities.h"
+# include "qemu_migration_params.h"
 # include "virmdev.h"
 # include "virchrdev.h"
 # include "virobject.h"
@@ -177,6 +178,8 @@ struct qemuDomainJobObj {
     bool postcopyEnabled;               /* post-copy migration was enabled */
     char *error;                        /* job event completion error */
     bool dumpCompleted;                 /* dump completed */
+
+    qemuMigrationParamsPtr migParams;
 };
 
 typedef void (*qemuDomainCleanupCallback)(virQEMUDriverPtr driver,

src/qemu/qemu_migration.c

@@ -2448,6 +2448,9 @@ qemuMigrationDstPrepareAny(virQEMUDriverPtr driver,
         dataFD[1] = -1; /* 'st' owns the FD now & will close it */
     }
 
+    if (qemuMigrationParamsCheck(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
+        goto stopjob;
+
     if (qemuMigrationParamsSetCompression(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN,
                                           compression, migParams) < 0)
         goto stopjob;
@@ -4597,6 +4600,9 @@ qemuMigrationSrcPerformJob(virQEMUDriverPtr driver,
 
     qemuMigrationSrcStoreDomainState(vm);
 
+    if (qemuMigrationParamsCheck(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0)
+        goto endjob;
+
     if ((flags & (VIR_MIGRATE_TUNNELLED | VIR_MIGRATE_PEER2PEER))) {
         ret = qemuMigrationSrcPerformPeer2Peer(driver, conn, vm, xmlin, persist_xml,
                                                dconnuri, uri, graphicsuri, listenAddress,
@@ -4700,6 +4706,9 @@ qemuMigrationSrcPerformPhase(virQEMUDriverPtr driver,
     virCloseCallbacksUnset(driver->closeCallbacks, vm,
                            qemuMigrationSrcCleanup);
 
+    if (qemuMigrationParamsCheck(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0)
+        goto endjob;
+
     ret = qemuMigrationSrcPerformNative(driver, vm, persist_xml, uri, cookiein, cookieinlen,
                                         cookieout, cookieoutlen,
                                         flags, resource, NULL, graphicsuri,

src/qemu/qemu_migration_params.c

@@ -428,6 +428,44 @@ qemuMigrationParamsResetTLS(virQEMUDriverPtr driver,
 }
 
 
+/**
+ * qemuMigrationParamsCheck:
+ *
+ * Check supported migration parameters and keep their original values in
+ * qemuDomainJobObj so that we can properly reset them at the end of migration.
+ */
+int
+qemuMigrationParamsCheck(virQEMUDriverPtr driver,
+                         virDomainObjPtr vm,
+                         int asyncJob)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    qemuMigrationParamsPtr origParams = NULL;
+    int ret = -1;
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+        return -1;
+
+    if (!(origParams = qemuMigrationParamsNew()))
+        goto cleanup;
+
+    if (qemuMonitorGetMigrationParams(priv->mon, &origParams->params) < 0)
+        goto cleanup;
+
+    ret = 0;
+
+ cleanup:
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
+
+    if (ret == 0)
+        VIR_STEAL_PTR(priv->job.migParams, origParams);
+    qemuMigrationParamsFree(origParams);
+
+    return ret;
+}
+
+
 /*
  * qemuMigrationParamsReset:
  *

src/qemu/qemu_migration_params.h

@@ -100,6 +100,11 @@ qemuMigrationParamsSetCompression(virQEMUDriverPtr driver,
                                   qemuMigrationCompressionPtr compression,
                                   qemuMigrationParamsPtr migParams);
 
+int
+qemuMigrationParamsCheck(virQEMUDriverPtr driver,
+                         virDomainObjPtr vm,
+                         int asyncJob);
+
 void
 qemuMigrationParamsReset(virQEMUDriverPtr driver,
                          virDomainObjPtr vm,