qemuMigrationSrcBeginPhase: Don't offer 'nbd' in cookie if there are no disks to...

Don't try to setup disk migration and the NBD stuff if we end up
migrating nothing.

The destination side has luckily no setup for the non-NBD cases so
omitting the element fully is okay.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Tested-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 119459342e1dcf974b5305a9d70a8c4ac42defad..3a622d38cd79e3a021b62b2b475c9849a5636f35 100644 (file)
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2365,26 +2365,30 @@ qemuMigrationSrcBeginPhase(virQEMUDriver *driver,
                 return NULL;
             }
         } else {
-            cookieFlags |= QEMU_MIGRATION_COOKIE_NBD;
-            priv->nbdPort = 0;
-        }
-
-        if (nmigrate_disks) {
-            size_t i, j;
-            /* Check user requested only known disk targets. */
-            for (i = 0; i < nmigrate_disks; i++) {
-                for (j = 0; j < vm->def->ndisks; j++) {
-                    if (STREQ(vm->def->disks[j]->dst, migrate_disks[i]))
-                        break;
-                }
+            if (nmigrate_disks) {
+                size_t i, j;
+                /* Check user requested only known disk targets. */
+                for (i = 0; i < nmigrate_disks; i++) {
+                    for (j = 0; j < vm->def->ndisks; j++) {
+                        if (STREQ(vm->def->disks[j]->dst, migrate_disks[i]))
+                            break;
+                    }
 
-                if (j == vm->def->ndisks) {
-                    virReportError(VIR_ERR_INVALID_ARG,
-                                   _("disk target %s not found"),
-                                   migrate_disks[i]);
-                    return NULL;
+                    if (j == vm->def->ndisks) {
+                        virReportError(VIR_ERR_INVALID_ARG,
+                                       _("disk target %s not found"),
+                                       migrate_disks[i]);
+                        return NULL;
+                    }
                 }
             }
+
+            priv->nbdPort = 0;
+
+            if (qemuMigrationHasAnyStorageMigrationDisks(vm->def,
+                                                         migrate_disks,
+                                                         nmigrate_disks))
+                cookieFlags |= QEMU_MIGRATION_COOKIE_NBD;
         }
     }