fake: Ensure need_legacy_block_device_info returns False

The legacy block_device_info format has not been used for a while in the
virt drivers and the Fake virt drivers shouldn't be using it anymore.

Some compute tests have been updated as they were previously asserting
the legacy format incorrectly. TODOs are also left to remove support for
the legacy format in a follow up change.

Change-Id: I066fb5617bae944a03273049117fc2b5bf329283
(cherry picked from commit d102b75)

Author: lyarwood

nova/tests/unit/compute/test_compute.py

@@ -3194,6 +3194,7 @@ def test_get_instance_block_device_info_source_image(self):
                     'image_id': uuids.image,
                     'boot_index': 0
         })])
+        driver_bdms = driver_block_device.convert_all_volumes(*bdms)
 
         with (mock.patch.object(
                 objects.BlockDeviceMappingList,
@@ -3208,13 +3209,7 @@ def test_get_instance_block_device_info_source_image(self):
                 'swap': None,
                 'ephemerals': [],
                 'root_device_name': None,
-                'block_device_mapping': [{
-                    'connection_info': {
-                        'driver_volume_type': 'rbd'
-                    },
-                    'mount_device': '/dev/vda',
-                    'delete_on_termination': False
-                }]
+                'block_device_mapping': driver_bdms
             }
             self.assertTrue(mock_get_by_instance.called)
             self.assertEqual(block_device_info, expected)
@@ -3229,6 +3224,8 @@ def test_get_instance_block_device_info_passed_bdms(self):
                     'source_type': 'volume',
                     'destination_type': 'volume'})
                ])
+        driver_bdms = driver_block_device.convert_all_volumes(*bdms)
+
         with (mock.patch.object(
                 objects.BlockDeviceMappingList,
                 'get_by_instance_uuid')) as mock_get_by_instance:
@@ -3240,13 +3237,7 @@ def test_get_instance_block_device_info_passed_bdms(self):
                 'swap': None,
                 'ephemerals': [],
                 'root_device_name': None,
-                'block_device_mapping': [{
-                    'connection_info': {
-                        'driver_volume_type': 'rbd'
-                    },
-                    'mount_device': '/dev/vdd',
-                    'delete_on_termination': False
-                }]
+                'block_device_mapping': driver_bdms
             }
             self.assertFalse(mock_get_by_instance.called)
             self.assertEqual(block_device_info, expected)
@@ -3302,11 +3293,27 @@ def test_get_instance_block_device_info_swap_and_ephemerals(self):
                                 'get_by_instance_uuid', return_value=bdms)
         ) as mock_get_by_instance_uuid:
             expected_block_device_info = {
-                'swap': {'device_name': '/dev/vdd', 'swap_size': 1},
-                'ephemerals': [{'device_name': '/dev/vdb', 'num': 0, 'size': 1,
-                                'virtual_name': 'ephemeral0'},
-                               {'device_name': '/dev/vdc', 'num': 1, 'size': 2,
-                                'virtual_name': 'ephemeral1'}],
+                'swap': {
+                    'device_name': '/dev/vdd',
+                    'swap_size': 1,
+                    'disk_bus': 'virtio'
+                },
+                'ephemerals': [
+                    {
+                        'device_name': '/dev/vdb',
+                        'device_type': 'disk',
+                        'disk_bus': 'virtio',
+                        'guest_format': None,
+                        'size': 1
+                    },
+                    {
+                        'device_name': '/dev/vdc',
+                        'device_type': 'disk',
+                        'disk_bus': 'virtio',
+                        'guest_format': None,
+                        'size': 2
+                    }
+                ],
                 'block_device_mapping': [],
                 'root_device_name': None
             }

nova/virt/driver.py

@@ -1617,6 +1617,7 @@ def delete_instance_files(self, instance):
         """
         return True
 
+    # TODO(lyarwood): This is no longer used and should be removed.
     @property
     def need_legacy_block_device_info(self):
         """Tell the caller if the driver requires legacy block device info.

nova/virt/fake.py

@@ -654,6 +654,10 @@ def quiesce(self, context, instance, image_meta):
     def unquiesce(self, context, instance, image_meta):
         pass
 
+    @property
+    def need_legacy_block_device_info(self):
+        return False
+
 
 class FakeVirtAPI(virtapi.VirtAPI):
     @contextlib.contextmanager