[libvirt PATCH 3/7] qemu_migration: Restore original memory locking limit

[Jiri Denemark]

For RDMA migration we update memory locking limit, but never set it back
once migration finishes (on the destination host) or aborts (on the
source host).

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
---
 src/qemu/qemu_domain.c    | 12 ++++++++++++
 src/qemu/qemu_domain.h    |  3 +++
 src/qemu/qemu_migration.c | 11 ++++++++---
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index e363993739..60ed358871 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2413,6 +2413,11 @@ qemuDomainObjPrivateXMLFormat(virBuffer *buf,
                           priv->originalMemlock);
     }
 
+    if (priv->preMigrationMemlock > 0) {
+        virBufferAsprintf(buf, "<preMigrationMemlock>%llu</preMigrationMemlock>\n",
+                          priv->preMigrationMemlock);
+    }
+
     return 0;
 }
 
@@ -3139,6 +3144,13 @@ qemuDomainObjPrivateXMLParse(xmlXPathContextPtr ctxt,
         return -1;
     }
 
+    if (virXPathULongLong("string(./preMigrationMemlock)", ctxt,
+                          &priv->preMigrationMemlock) == -2) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("failed to parse pre-migration memlock limit"));
+        return -1;
+    }
+
     return 0;
 }
 
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 6d35f61dfd..499ad03f91 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -140,6 +140,9 @@ struct _qemuDomainObjPrivate {
     int nbdPort; /* Port used for migration with NBD */
     unsigned short migrationPort;
     int preMigrationState;
+    unsigned long long preMigrationMemlock; /* Original RLIMIT_MEMLOCK in case
+                                               it was changed for the current
+                                               migration job. */
 
     virChrdevs *devs;
 
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index fe63f45629..ffae5576d2 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -3181,7 +3181,8 @@ qemuMigrationDstPrepareActive(virQEMUDriver *driver,
 
     if (STREQ_NULLABLE(protocol, "rdma") &&
         vm->def->mem.hard_limit > 0 &&
-        qemuDomainSetMaxMemLock(vm, vm->def->mem.hard_limit << 10, NULL) < 0) {
+        qemuDomainSetMaxMemLock(vm, vm->def->mem.hard_limit << 10,
+                                &priv->preMigrationMemlock) < 0) {
         goto error;
     }
 
@@ -3945,6 +3946,7 @@ qemuMigrationSrcComplete(virQEMUDriver *driver,
                                               VIR_DOMAIN_EVENT_STOPPED_MIGRATED);
     virObjectEventStateQueue(driver->domainEventState, event);
     qemuDomainEventEmitJobCompleted(driver, vm);
+    priv->preMigrationMemlock = 0;
 }
 
 
@@ -4035,6 +4037,7 @@ qemuMigrationSrcConfirmPhase(virQEMUDriver *driver,
 
             qemuMigrationParamsReset(driver, vm, VIR_ASYNC_JOB_MIGRATION_OUT,
                                      jobPriv->migParams, priv->job.apiFlags);
+            qemuDomainSetMaxMemLock(vm, 0, &priv->preMigrationMemlock);
         }
 
         qemuDomainSaveStatus(vm);
@@ -4615,7 +4618,8 @@ qemuMigrationSrcStart(virDomainObj *vm,
     case MIGRATION_DEST_HOST:
         if (STREQ(spec->dest.host.protocol, "rdma") &&
             vm->def->mem.hard_limit > 0 &&
-            qemuDomainSetMaxMemLock(vm, vm->def->mem.hard_limit << 10, NULL) < 0) {
+            qemuDomainSetMaxMemLock(vm, vm->def->mem.hard_limit << 10,
+                                    &priv->preMigrationMemlock) < 0) {
             return -1;
         }
         return qemuMonitorMigrateToHost(priv->mon, migrateFlags,
@@ -6155,6 +6159,7 @@ qemuMigrationSrcPerformPhase(virQEMUDriver *driver,
         qemuMigrationSrcRestoreDomainState(driver, vm);
         qemuMigrationParamsReset(driver, vm, VIR_ASYNC_JOB_MIGRATION_OUT,
                                  jobPriv->migParams, priv->job.apiFlags);
+        qemuDomainSetMaxMemLock(vm, 0, &priv->preMigrationMemlock);
         qemuMigrationJobFinish(vm);
     } else {
         if (ret < 0)
@@ -6410,7 +6415,7 @@ qemuMigrationDstComplete(virQEMUDriver *driver,
                              job->apiFlags);
 
     virPortAllocatorRelease(priv->migrationPort);
-    priv->migrationPort = 0;
+    qemuDomainSetMaxMemLock(vm, 0, &priv->preMigrationMemlock);
 }
 
 
-- 
2.35.1