qemu: migration: Improve handling of VIR_MIGRATE_PARAM_DEST_XML with VIR_MIGRATE_PERS...

When a user provides a migration XML via the VIR_MIGRATE_PARAM_DEST_XML
it's expected that they want to change ABI-compatible aspects of the XML
such as the disk paths or similar.

If the user requests persisting of the VM but does not provide an
explicit persistent XML libvirt would take the persistent XML from the
source of the migration as the persistent config. This usually involves
the old paths to images.

Doing this would result into failure to start the VM.

It makes more sense to take the XML used for migration and use that as
the base for persisting the config.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index f4e99087d898b52f70457b4f139610388d2fd002..c37a86e987dc5d04f694d1a646acd3e6d0530baf 100644 (file)
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -4703,6 +4703,7 @@ qemuMigrationSrcCancel(virDomainObj *vm,
 static int
 qemuMigrationSrcRun(virQEMUDriver *driver,
                     virDomainObj *vm,
+                    const char *xmlin,
                     const char *persist_xml,
                     const char *cookiein,
                     int cookieinlen,
@@ -4776,6 +4777,15 @@ qemuMigrationSrcRun(virQEMUDriver *driver,
                                                           persist_xml,
                                                           NULL, NULL)))
                 goto error;
+        } else if (xmlin) {
+            /* if input XML is provided, use that one as template for the
+             * persistent XML. Otherwise user's changes will be thrown away.
+             */
+            if (!(persistDef = qemuMigrationAnyPrepareDef(driver,
+                                                          priv->qemuCaps,
+                                                          xmlin,
+                                                          NULL, NULL)))
+                goto error;
         } else {
             virDomainDef *def = vm->newDef ? vm->newDef : vm->def;
             if (!(persistDef = qemuDomainDefCopy(driver, priv->qemuCaps, def,
@@ -5114,6 +5124,7 @@ qemuMigrationSrcResume(virDomainObj *vm,
 static int
 qemuMigrationSrcPerformNative(virQEMUDriver *driver,
                               virDomainObj *vm,
+                              const char *xmlin,
                               const char *persist_xml,
                               const char *uri,
                               const char *cookiein,
@@ -5199,7 +5210,7 @@ qemuMigrationSrcPerformNative(virQEMUDriver *driver,
         ret = qemuMigrationSrcResume(vm, migParams, cookiein, cookieinlen,
                                      cookieout, cookieoutlen, &spec, flags);
     } else {
-        ret = qemuMigrationSrcRun(driver, vm, persist_xml, cookiein, cookieinlen,
+        ret = qemuMigrationSrcRun(driver, vm, xmlin, persist_xml, cookiein, cookieinlen,
                                   cookieout, cookieoutlen, flags, resource,
                                   &spec, dconn, graphicsuri,
                                   nmigrate_disks, migrate_disks,
@@ -5217,6 +5228,7 @@ static int
 qemuMigrationSrcPerformTunnel(virQEMUDriver *driver,
                               virDomainObj *vm,
                               virStreamPtr st,
+                              const char *xmlin,
                               const char *persist_xml,
                               const char *cookiein,
                               int cookieinlen,
@@ -5263,7 +5275,7 @@ qemuMigrationSrcPerformTunnel(virQEMUDriver *driver,
         goto cleanup;
     }
 
-    ret = qemuMigrationSrcRun(driver, vm, persist_xml, cookiein, cookieinlen,
+    ret = qemuMigrationSrcRun(driver, vm, xmlin, persist_xml, cookiein, cookieinlen,
                               cookieout, cookieoutlen, flags, resource, &spec,
                               dconn, graphicsuri, nmigrate_disks, migrate_disks,
                               migParams, NULL);
@@ -5302,7 +5314,7 @@ qemuMigrationSrcPerformResume(virQEMUDriver *driver,
     virCloseCallbacksDomainRemove(vm, NULL, qemuMigrationAnyConnectionClosed);
     qemuDomainCleanupRemove(vm, qemuProcessCleanupMigrationJob);
 
-    ret = qemuMigrationSrcPerformNative(driver, vm, NULL, uri,
+    ret = qemuMigrationSrcPerformNative(driver, vm, NULL, NULL, uri,
                                         cookiein, cookieinlen,
                                         cookieout, cookieoutlen, flags,
                                         0, NULL, NULL, 0, NULL, migParams, NULL);
@@ -5404,12 +5416,12 @@ qemuMigrationSrcPerformPeer2Peer2(virQEMUDriver *driver,
     VIR_DEBUG("Perform %p", sconn);
     ignore_value(qemuMigrationJobStartPhase(vm, QEMU_MIGRATION_PHASE_PERFORM2));
     if (flags & VIR_MIGRATE_TUNNELLED)
-        ret = qemuMigrationSrcPerformTunnel(driver, vm, st, NULL,
+        ret = qemuMigrationSrcPerformTunnel(driver, vm, st, NULL, NULL,
                                             NULL, 0, NULL, NULL,
                                             flags, resource, dconn,
                                             NULL, 0, NULL, migParams);
     else
-        ret = qemuMigrationSrcPerformNative(driver, vm, NULL, uri_out,
+        ret = qemuMigrationSrcPerformNative(driver, vm, NULL, NULL, uri_out,
                                             cookie, cookielen,
                                             NULL, NULL, /* No out cookie with v2 migration */
                                             flags, resource, dconn, NULL, 0, NULL,
@@ -5665,14 +5677,14 @@ qemuMigrationSrcPerformPeer2Peer3(virQEMUDriver *driver,
     } else {
         ignore_value(qemuMigrationJobSetPhase(vm, QEMU_MIGRATION_PHASE_PERFORM3));
         if (flags & VIR_MIGRATE_TUNNELLED) {
-            ret = qemuMigrationSrcPerformTunnel(driver, vm, st, persist_xml,
+            ret = qemuMigrationSrcPerformTunnel(driver, vm, st, xmlin, persist_xml,
                                                 cookiein, cookieinlen,
                                                 &cookieout, &cookieoutlen,
                                                 flags, bandwidth, dconn, graphicsuri,
                                                 nmigrate_disks, migrate_disks,
                                                 migParams);
         } else {
-            ret = qemuMigrationSrcPerformNative(driver, vm, persist_xml, uri,
+            ret = qemuMigrationSrcPerformNative(driver, vm, xmlin, persist_xml, uri,
                                                 cookiein, cookieinlen,
                                                 &cookieout, &cookieoutlen,
                                                 flags, bandwidth, dconn, graphicsuri,
@@ -6072,7 +6084,7 @@ qemuMigrationSrcPerformJob(virQEMUDriver *driver,
         if (qemuMigrationJobStartPhase(vm, QEMU_MIGRATION_PHASE_PERFORM2) < 0)
             goto endjob;
 
-        ret = qemuMigrationSrcPerformNative(driver, vm, persist_xml, uri, cookiein, cookieinlen,
+        ret = qemuMigrationSrcPerformNative(driver, vm, xmlin, persist_xml, uri, cookiein, cookieinlen,
                                             cookieout, cookieoutlen,
                                             flags, resource, NULL, NULL, 0, NULL,
                                             migParams, nbdURI);
@@ -6137,6 +6149,7 @@ static int
 qemuMigrationSrcPerformPhase(virQEMUDriver *driver,
                              virConnectPtr conn,
                              virDomainObj *vm,
+                             const char *xmlin,
                              const char *persist_xml,
                              const char *uri,
                              const char *graphicsuri,
@@ -6174,7 +6187,7 @@ qemuMigrationSrcPerformPhase(virQEMUDriver *driver,
 
     virCloseCallbacksDomainRemove(vm, NULL, qemuMigrationAnyConnectionClosed);
 
-    if (qemuMigrationSrcPerformNative(driver, vm, persist_xml, uri, cookiein, cookieinlen,
+    if (qemuMigrationSrcPerformNative(driver, vm, xmlin, persist_xml, uri, cookiein, cookieinlen,
                                       cookieout, cookieoutlen,
                                       flags, resource, NULL, graphicsuri,
                                       nmigrate_disks, migrate_disks, migParams, nbdURI) < 0)
@@ -6273,7 +6286,7 @@ qemuMigrationSrcPerform(virQEMUDriver *driver,
     }
 
     if (v3proto) {
-        return qemuMigrationSrcPerformPhase(driver, conn, vm, persist_xml, uri,
+        return qemuMigrationSrcPerformPhase(driver, conn, vm, xmlin, persist_xml, uri,
                                             graphicsuri,
                                             nmigrate_disks, migrate_disks,
                                             migParams,