tests/functional/migration: add VM launch/configure hooks

Introduce configure_machine, launch_source_vm and assert_dest_vm
methods to allow child classes to override some pieces of
source/dest VMs creation, start and check logic.

Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

tests/functional/migration.py

@@ -40,19 +40,36 @@ class MigrationTest(QemuSystemTest):
         self.assertEqual(dst_vm.cmd('query-status')['status'], 'running')
         self.assertEqual(src_vm.cmd('query-status')['status'],'postmigrate')
 
+    # Can be overridden by subclasses to configure both source/dest VMs.
+    def configure_machine(self, vm):
+        vm.add_args('-nodefaults')
+
+    # Can be overridden by subclasses to prepare the source VM before
+    # migration, e.g. by running some workload inside the source VM
+    # to see if it continues to run properly after migration.
+    def launch_source_vm(self, vm):
+        vm.launch()
+
+    # Can be overridden by subclasses to check the destination VM after
+    # migration, e.g. by checking if the workload is still running after
+    # migration.
+    def assert_dest_vm(self, vm):
+        pass
+
     def migrate_vms(self, dst_uri, src_uri, dst_vm, src_vm):
         dst_vm.qmp('migrate-incoming', uri=dst_uri)
         src_vm.qmp('migrate', uri=src_uri)
         self.assert_migration(src_vm, dst_vm)
+        self.assert_dest_vm(dst_vm)
 
     def migrate(self, dst_uri, src_uri=None):
         dst_vm = self.get_vm('-incoming', 'defer', name="dst-qemu")
-        dst_vm.add_args('-nodefaults')
+        self.configure_machine(dst_vm)
         dst_vm.launch()
 
         src_vm = self.get_vm(name="src-qemu")
-        src_vm.add_args('-nodefaults')
-        src_vm.launch()
+        self.configure_machine(src_vm)
+        self.launch_source_vm(src_vm)
 
         if src_uri is None:
             src_uri = dst_uri