objects: Move 'vm_mode' to 'fields.VMMode'

Resolve the relevant TODO. Migrate tests in the process.

Change-Id: I372266b158667683cad973f20976619c34538491

22 files changed, 245 insertions, 294 deletions

diff --git a/nova/compute/vm_mode.py b/nova/compute/vm_mode.py
deleted file mode 100644
index bfcadb569e..0000000000
--- a/nova/compute/vm_mode.py
+++ /dev/null
@@ -1,87 +0,0 @@
-# Copyright 2012 Red Hat, Inc.
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-"""Possible vm modes for instances.
-
-Compute instance vm modes represent the host/guest ABI used for the
-virtual machine / container. Individual hypervisors may support
-multiple different vm modes per host. Available vm modes for a hypervisor
-driver may also vary according to the architecture it is running on.
-
-The 'vm_mode' parameter can be set against an instance to
-choose what sort of VM to boot.
-
-"""
-
-from nova import exception
-
-HVM = "hvm"  # Native ABI (aka fully virtualized)
-XEN = "xen"  # Xen 3.0 paravirtualized
-UML = "uml"  # User Mode Linux paravirtualized
-EXE = "exe"  # Executables in containers
-
-ALL = [HVM, XEN, UML, EXE]
-
-
-def get_from_instance(instance):
-    """Get the vm mode for an instance
-
-    :param instance: instance object to query
-
-    :returns: canonicalized vm mode for the instance
-    """
-
-    mode = instance.vm_mode
-    return canonicalize(mode)
-
-
-def is_valid(name):
-    """Check if a string is a valid vm mode
-
-    :param name: vm mode name to validate
-
-    :returns: True if @name is valid
-    """
-
-    return name in ALL
-
-
-def canonicalize(mode):
-    """Canonicalize the vm mode
-
-    :param name: vm mode name to canonicalize
-
-    :returns: a canonical vm mode name
-    """
-
-    if mode is None:
-        return None
-
-    mode = mode.lower()
-
-    # For compatibility with pre-Folsom deployments
-    if mode == "pv":
-        mode = XEN
-
-    if mode == "hv":
-        mode = HVM
-
-    if mode == "baremetal":
-        mode = HVM
-
-    if not is_valid(mode):
-        raise exception.InvalidVirtualMachineMode(vmmode=mode)
-
-    return mode
diff --git a/nova/objects/fields.py b/nova/objects/fields.py
index 7534bfad6c..08d9c5e4f2 100644
--- a/nova/objects/fields.py
+++ b/nova/objects/fields.py
@@ -18,8 +18,6 @@ import re
 from oslo_versionedobjects import fields
 import six
 
-# TODO(berrange) Temporary import for VMMode class
-from nova.compute import vm_mode
 from nova import exception
 from nova.i18n import _
 from nova.network import model as network_model
@@ -541,18 +539,80 @@ class VIFModel(BaseNovaEnum):
 
 
 class VMMode(BaseNovaEnum):
-    # TODO(berrange): move all constants out of 'nova.compute.vm_mode'
-    # into fields on this class
-    ALL = vm_mode.ALL
+    """Represents possible vm modes for instances.
+
+    Compute instance VM modes represent the host/guest ABI used for the
+    virtual machine or container. Individual hypervisors may support
+    multiple different vm modes per host. Available VM modes for a
+    hypervisor driver may also vary according to the architecture it is
+    running on.
+    """
+    HVM = 'hvm'  # Native ABI (aka fully virtualized)
+    XEN = 'xen'  # Xen 3.0 paravirtualized
+    UML = 'uml'  # User Mode Linux paravirtualized
+    EXE = 'exe'  # Executables in containers
+
+    ALL = (HVM, XEN, UML, EXE)
 
     def coerce(self, obj, attr, value):
         try:
-            value = vm_mode.canonicalize(value)
+            value = self.canonicalize(value)
         except exception.InvalidVirtualMachineMode:
             msg = _("Virtual machine mode '%s' is not valid") % value
             raise ValueError(msg)
+
         return super(VMMode, self).coerce(obj, attr, value)
 
+    @classmethod
+    def get_from_instance(cls, instance):
+        """Get the vm mode for an instance
+
+        :param instance: instance object to query
+
+        :returns: canonicalized vm mode for the instance
+        """
+        mode = instance.vm_mode
+
+        return cls.canonicalize(mode)
+
+    @classmethod
+    def is_valid(cls, name):
+        """Check if a string is a valid vm mode
+
+        :param name: vm mode name to validate
+
+        :returns: True if @name is valid
+        """
+        return name in cls.ALL
+
+    @classmethod
+    def canonicalize(cls, mode):
+        """Canonicalize the vm mode
+
+        :param name: vm mode name to canonicalize
+
+        :returns: a canonical vm mode name
+        """
+        if mode is None:
+            return None
+
+        mode = mode.lower()
+
+        # For compatibility with pre-Folsom deployments
+        if mode == 'pv':
+            mode = cls.XEN
+
+        if mode == 'hv':
+            mode = cls.HVM
+
+        if mode == 'baremetal':
+            mode = cls.HVM
+
+        if not cls.is_valid(mode):
+            raise exception.InvalidVirtualMachineMode(vmmode=mode)
+
+        return mode
+
 
 class WatchdogAction(BaseNovaEnum):
 
diff --git a/nova/scheduler/filters/image_props_filter.py b/nova/scheduler/filters/image_props_filter.py
index bd9ba75216..1bf241a487 100644
--- a/nova/scheduler/filters/image_props_filter.py
+++ b/nova/scheduler/filters/image_props_filter.py
@@ -19,7 +19,6 @@ from distutils import versionpredicate
 from oslo_log import log as logging
 from oslo_utils import versionutils
 
-from nova.compute import vm_mode
 from nova.objects import fields
 from nova.scheduler import filters
 
@@ -48,7 +47,7 @@ class ImagePropertiesFilter(filters.BaseHostFilter):
         checked_img_props = (
             fields.Architecture.canonicalize(img_arch),
             fields.HVType.canonicalize(img_h_type),
-            vm_mode.canonicalize(img_vm_mode)
+            fields.VMMode.canonicalize(img_vm_mode)
         )
 
         # Supported if no compute-related instance properties are specified
diff --git a/nova/tests/unit/compute/test_compute_api.py b/nova/tests/unit/compute/test_compute_api.py
index 516b6f2427..5f4ecaf6e5 100644
--- a/nova/tests/unit/compute/test_compute_api.py
+++ b/nova/tests/unit/compute/test_compute_api.py
@@ -31,7 +31,6 @@ from nova.compute import instance_actions
 from nova.compute import rpcapi as compute_rpcapi
 from nova.compute import task_states
 from nova.compute import utils as compute_utils
-from nova.compute import vm_mode
 from nova.compute import vm_states
 from nova import conductor
 from nova import context
@@ -3079,7 +3078,7 @@ class _ComputeAPIUnitTestMixIn(object):
                 system_metadata=orig_system_metadata,
                 expected_attrs=['system_metadata'],
                 image_ref=orig_image_href,
-                vm_mode=vm_mode.HVM)
+                vm_mode=fields_obj.VMMode.HVM)
         flavor = instance.get_flavor()
 
         def get_image(context, image_href):
@@ -3109,7 +3108,7 @@ class _ComputeAPIUnitTestMixIn(object):
         _check_auto_disk_config.assert_called_once_with(image=new_image)
         _checks_for_create_and_rebuild.assert_called_once_with(self.context,
                 None, new_image, flavor, {}, [], None)
-        self.assertEqual(vm_mode.XEN, instance.vm_mode)
+        self.assertEqual(fields_obj.VMMode.XEN, instance.vm_mode)
 
     def _test_check_injected_file_quota_onset_file_limit_exceeded(self,
                                                                   side_effect):
diff --git a/nova/tests/unit/compute/test_resource_tracker.py b/nova/tests/unit/compute/test_resource_tracker.py
index 1016cd0dbd..0f713c88c2 100644
--- a/nova/tests/unit/compute/test_resource_tracker.py
+++ b/nova/tests/unit/compute/test_resource_tracker.py
@@ -23,7 +23,6 @@ from nova.compute.monitors import base as monitor_base
 from nova.compute import power_state
 from nova.compute import resource_tracker
 from nova.compute import task_states
-from nova.compute import vm_mode
 from nova.compute import vm_states
 from nova import context
 from nova import exception as exc
@@ -80,7 +79,7 @@ _COMPUTE_NODE_FIXTURES = [
             objects.HVSpec.from_list([
                 obj_fields.Architecture.I686,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM])
+                obj_fields.VMMode.HVM])
         ],
         metrics=None,
         pci_device_pools=None,
diff --git a/nova/tests/unit/compute/test_vmmode.py b/nova/tests/unit/compute/test_vmmode.py
deleted file mode 100644
index 11a6c7e751..0000000000
--- a/nova/tests/unit/compute/test_vmmode.py
+++ /dev/null
@@ -1,74 +0,0 @@
-#    Copyright (C) 2012 Red Hat, Inc.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-from nova.compute import vm_mode
-from nova import exception
-from nova import test
-from nova.tests.unit import fake_instance
-
-
-class ComputeVMModeTest(test.NoDBTestCase):
-
-    def _fake_object(self, updates):
-        return fake_instance.fake_instance_obj(None, **updates)
-
-    def test_case(self):
-        inst = self._fake_object(dict(vm_mode="HVM"))
-        mode = vm_mode.get_from_instance(inst)
-        self.assertEqual(mode, "hvm")
-
-    def test_legacy_pv(self):
-        inst = self._fake_object(dict(vm_mode="pv"))
-        mode = vm_mode.get_from_instance(inst)
-        self.assertEqual(mode, "xen")
-
-    def test_legacy_hv(self):
-        inst = self._fake_object(dict(vm_mode="hv"))
-        mode = vm_mode.get_from_instance(inst)
-        self.assertEqual(mode, "hvm")
-
-    def test_bogus(self):
-        inst = self._fake_object(dict(vm_mode="wibble"))
-        self.assertRaises(exception.Invalid,
-                          vm_mode.get_from_instance,
-                          inst)
-
-    def test_good(self):
-        inst = self._fake_object(dict(vm_mode="hvm"))
-        mode = vm_mode.get_from_instance(inst)
-        self.assertEqual(mode, "hvm")
-
-    def test_name_pv_compat(self):
-        mode = vm_mode.canonicalize('pv')
-        self.assertEqual(vm_mode.XEN, mode)
-
-    def test_name_hv_compat(self):
-        mode = vm_mode.canonicalize('hv')
-        self.assertEqual(vm_mode.HVM, mode)
-
-    def test_name_baremetal_compat(self):
-        mode = vm_mode.canonicalize('baremetal')
-        self.assertEqual(vm_mode.HVM, mode)
-
-    def test_name_hvm(self):
-        mode = vm_mode.canonicalize('hvm')
-        self.assertEqual(vm_mode.HVM, mode)
-
-    def test_name_none(self):
-        mode = vm_mode.canonicalize(None)
-        self.assertIsNone(mode)
-
-    def test_name_invalid(self):
-        self.assertRaises(exception.InvalidVirtualMachineMode,
-                          vm_mode.canonicalize, 'invalid')
diff --git a/nova/tests/unit/objects/test_fields.py b/nova/tests/unit/objects/test_fields.py
index ce644499be..7b8e52900a 100644
--- a/nova/tests/unit/objects/test_fields.py
+++ b/nova/tests/unit/objects/test_fields.py
@@ -25,6 +25,7 @@ from nova.network import model as network_model
 from nova.objects import fields
 from nova import signature_utils
 from nova import test
+from nova.tests.unit import fake_instance
 from nova import utils
 
 
@@ -267,6 +268,62 @@ class TestHVType(TestField):
                           'wibble')
 
 
+class TestVMMode(TestField):
+    def _fake_object(self, updates):
+        return fake_instance.fake_instance_obj(None, **updates)
+
+    def test_case(self):
+        inst = self._fake_object(dict(vm_mode='HVM'))
+        mode = fields.VMMode.get_from_instance(inst)
+        self.assertEqual(mode, 'hvm')
+
+    def test_legacy_pv(self):
+        inst = self._fake_object(dict(vm_mode='pv'))
+        mode = fields.VMMode.get_from_instance(inst)
+        self.assertEqual(mode, 'xen')
+
+    def test_legacy_hv(self):
+        inst = self._fake_object(dict(vm_mode='hv'))
+        mode = fields.VMMode.get_from_instance(inst)
+        self.assertEqual(mode, 'hvm')
+
+    def test_bogus(self):
+        inst = self._fake_object(dict(vm_mode='wibble'))
+        self.assertRaises(exception.Invalid,
+                          fields.VMMode.get_from_instance,
+                          inst)
+
+    def test_good(self):
+        inst = self._fake_object(dict(vm_mode='hvm'))
+        mode = fields.VMMode.get_from_instance(inst)
+        self.assertEqual(mode, 'hvm')
+
+    def test_canonicalize_pv_compat(self):
+        mode = fields.VMMode.canonicalize('pv')
+        self.assertEqual(fields.VMMode.XEN, mode)
+
+    def test_canonicalize_hv_compat(self):
+        mode = fields.VMMode.canonicalize('hv')
+        self.assertEqual(fields.VMMode.HVM, mode)
+
+    def test_canonicalize_baremetal_compat(self):
+        mode = fields.VMMode.canonicalize('baremetal')
+        self.assertEqual(fields.VMMode.HVM, mode)
+
+    def test_canonicalize_hvm(self):
+        mode = fields.VMMode.canonicalize('hvm')
+        self.assertEqual(fields.VMMode.HVM, mode)
+
+    def test_canonicalize_none(self):
+        mode = fields.VMMode.canonicalize(None)
+        self.assertIsNone(mode)
+
+    def test_canonicalize_invalid(self):
+        self.assertRaises(exception.InvalidVirtualMachineMode,
+                          fields.VMMode.canonicalize,
+                          'invalid')
+
+
 class TestImageSignatureTypes(TestField):
     # Ensure that the object definition is updated
     # in step with the signature_utils module
diff --git a/nova/tests/unit/objects/test_hv_spec.py b/nova/tests/unit/objects/test_hv_spec.py
index 1e5ba9f74e..8a6bdd05a4 100644
--- a/nova/tests/unit/objects/test_hv_spec.py
+++ b/nova/tests/unit/objects/test_hv_spec.py
@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from nova.compute import vm_mode
 from nova import objects
 from nova.objects import fields as obj_fields
 from nova.tests.unit.objects import test_objects
@@ -22,25 +21,25 @@ from nova.tests.unit.objects import test_objects
 spec_dict = {
     'arch': obj_fields.Architecture.I686,
     'hv_type': obj_fields.HVType.KVM,
-    'vm_mode': vm_mode.HVM
+    'vm_mode': obj_fields.VMMode.HVM
 }
 
 spec_list = [
     obj_fields.Architecture.I686,
     obj_fields.HVType.KVM,
-    vm_mode.HVM
+    obj_fields.VMMode.HVM
 ]
 
 spec_dict_vz = {
     'arch': obj_fields.Architecture.I686,
     'hv_type': obj_fields.HVType.VIRTUOZZO,
-    'vm_mode': vm_mode.HVM
+    'vm_mode': obj_fields.VMMode.HVM
 }
 
 spec_dict_parallels = {
     'arch': obj_fields.Architecture.I686,
     'hv_type': obj_fields.HVType.PARALLELS,
-    'vm_mode': vm_mode.HVM
+    'vm_mode': obj_fields.VMMode.HVM
 }
 
 
@@ -54,7 +53,7 @@ class _TestHVSpecObject(object):
         spec_obj = objects.HVSpec()
         spec_obj.arch = obj_fields.Architecture.I686
         spec_obj.hv_type = obj_fields.HVType.KVM
-        spec_obj.vm_mode = vm_mode.HVM
+        spec_obj.vm_mode = obj_fields.VMMode.HVM
         spec = spec_obj.to_list()
         self.assertEqual(spec_list, spec)
 
diff --git a/nova/tests/unit/objects/test_objects.py b/nova/tests/unit/objects/test_objects.py
index 6c92f39337..a1bbe3744e 100644
--- a/nova/tests/unit/objects/test_objects.py
+++ b/nova/tests/unit/objects/test_objects.py
@@ -1129,10 +1129,10 @@ object_data = {
     'FloatingIPList': '1.11-7f2ba670714e1b7bab462ab3290f7159',
     'HostMapping': '1.0-1a3390a696792a552ab7bd31a77ba9ac',
     'HyperVLiveMigrateData': '1.1-9987a3cec31a81abac6fba7cc722e43f',
-    'HVSpec': '1.2-e1ef66eb58ac1be510300c5d9f8ad931',
+    'HVSpec': '1.2-e6cf4455367f301baa926e3972978d55',
     'IDEDeviceBus': '1.0-29d4c9f27ac44197f01b6ac1b7e16502',
     'ImageMeta': '1.8-642d1b2eb3e880a367f37d72dd76162d',
-    'ImageMetaProps': '1.15-28e104f642cbf04c7899d349e7e4d05d',
+    'ImageMetaProps': '1.15-070af88560aebda534a5d57e0d26e795',
     'Instance': '2.3-4f98ab23f4b0a25fabb1040c8f5edecc',
     'InstanceAction': '1.1-f9f293e526b66fca0d05c3b3a2d13914',
     'InstanceActionEvent': '1.1-e56a64fa4710e43ef7af2ad9d6028b33',
diff --git a/nova/tests/unit/scheduler/filters/test_image_props_filters.py b/nova/tests/unit/scheduler/filters/test_image_props_filters.py
index e08ad43de5..18a4346b61 100644
--- a/nova/tests/unit/scheduler/filters/test_image_props_filters.py
+++ b/nova/tests/unit/scheduler/filters/test_image_props_filters.py
@@ -12,7 +12,6 @@
 
 from oslo_utils import versionutils
 
-from nova.compute import vm_mode
 from nova import objects
 from nova.objects import fields as obj_fields
 from nova.scheduler.filters import image_props_filter
@@ -31,7 +30,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
                 img_hv_type=obj_fields.HVType.KVM,
-                hw_vm_mode=vm_mode.HVM,
+                hw_vm_mode=obj_fields.VMMode.HVM,
                 img_hv_requested_version='>=6.0,<6.2'))
         spec_obj = objects.RequestSpec(image=img_props)
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
@@ -39,7 +38,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -49,14 +48,14 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.ARMV7,
                 img_hv_type=obj_fields.HVType.QEMU,
-                hw_vm_mode=vm_mode.HVM))
+                hw_vm_mode=obj_fields.VMMode.HVM))
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertFalse(self.filt_cls.host_passes(host, spec_obj))
@@ -66,7 +65,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
                 img_hv_type=obj_fields.HVType.KVM,
-                hw_vm_mode=vm_mode.HVM,
+                hw_vm_mode=obj_fields.VMMode.HVM,
                 img_hv_requested_version='>=6.2'))
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
         spec_obj = objects.RequestSpec(image=img_props)
@@ -75,7 +74,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertFalse(self.filt_cls.host_passes(host, spec_obj))
@@ -84,14 +83,14 @@ class TestImagePropsFilter(test.NoDBTestCase):
         img_props = objects.ImageMeta(
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
-                hw_vm_mode=vm_mode.HVM))
+                hw_vm_mode=obj_fields.VMMode.HVM))
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -100,14 +99,14 @@ class TestImagePropsFilter(test.NoDBTestCase):
         img_props = objects.ImageMeta(
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
-                hw_vm_mode=vm_mode.HVM))
+                hw_vm_mode=obj_fields.VMMode.HVM))
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.XEN,
-                vm_mode.XEN)],
+                obj_fields.VMMode.XEN)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertFalse(self.filt_cls.host_passes(host, spec_obj))
@@ -119,7 +118,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -129,7 +128,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
                 img_hv_type=obj_fields.HVType.KVM,
-                hw_vm_mode=vm_mode.HVM))
+                hw_vm_mode=obj_fields.VMMode.HVM))
         hypervisor_version = versionutils.convert_version_to_int('6.0.0')
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
@@ -143,7 +142,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
                 img_hv_type=obj_fields.HVType.KVM,
-                hw_vm_mode=vm_mode.HVM,
+                hw_vm_mode=obj_fields.VMMode.HVM,
                 img_hv_requested_version='>=6.0'))
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
@@ -151,7 +150,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)]}
+                obj_fields.VMMode.HVM)]}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
 
@@ -160,7 +159,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             properties=objects.ImageMetaProps(
                 hw_architecture=obj_fields.Architecture.X86_64,
                 img_hv_type=obj_fields.HVType.KVM,
-                hw_vm_mode=vm_mode.HVM,
+                hw_vm_mode=obj_fields.VMMode.HVM,
                 img_hv_requested_version='>=6.0'))
         spec_obj = objects.RequestSpec(image=img_props)
         capabilities = {
@@ -168,7 +167,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': 5000}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertFalse(self.filt_cls.host_passes(host, spec_obj))
@@ -184,7 +183,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.XEN,
-                vm_mode.XEN)],
+                obj_fields.VMMode.XEN)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -200,7 +199,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -216,7 +215,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.I686,
                 obj_fields.HVType.KVM,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -232,7 +231,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.I686,
                 obj_fields.HVType.XEN,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
@@ -249,7 +248,7 @@ class TestImagePropsFilter(test.NoDBTestCase):
             'supported_instances': [(
                 obj_fields.Architecture.I686,
                 obj_fields.HVType.BAREMETAL,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'hypervisor_version': hypervisor_version}
         host = fakes.FakeHostState('host1', 'node1', capabilities)
         self.assertTrue(self.filt_cls.host_passes(host, spec_obj))
diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index 5f42830f85..e2ccd792b9 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -59,7 +59,6 @@ from nova.api.metadata import base as instance_metadata
 from nova.compute import manager
 from nova.compute import power_state
 from nova.compute import task_states
-from nova.compute import vm_mode
 from nova.compute import vm_states
 import nova.conf
 from nova import context
@@ -1860,7 +1859,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                               vconfig.LibvirtConfigGuestFeatureAPIC)
         self.assertEqual(cfg.memory, 6 * units.Ki)
         self.assertEqual(cfg.vcpus, 28)
-        self.assertEqual(cfg.os_type, vm_mode.HVM)
+        self.assertEqual(cfg.os_type, fields.VMMode.HVM)
         self.assertEqual(cfg.os_boot_dev, ["hd"])
         self.assertIsNone(cfg.os_root)
         self.assertEqual(len(cfg.devices), 10)
@@ -1935,7 +1934,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertEqual(instance_ref["uuid"], cfg.uuid)
         self.assertEqual(instance_ref.flavor.memory_mb * units.Ki, cfg.memory)
         self.assertEqual(instance_ref.flavor.vcpus, cfg.vcpus)
-        self.assertEqual(vm_mode.EXE, cfg.os_type)
+        self.assertEqual(fields.VMMode.EXE, cfg.os_type)
         self.assertEqual("/sbin/init", cfg.os_init_path)
         self.assertEqual("console=tty0 console=ttyS0", cfg.os_cmdline)
         self.assertIsNone(cfg.os_root)
@@ -1960,7 +1959,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertEqual(instance_ref["uuid"], cfg.uuid)
         self.assertEqual(instance_ref.flavor.memory_mb * units.Ki, cfg.memory)
         self.assertEqual(instance_ref.vcpus, cfg.vcpus)
-        self.assertEqual(vm_mode.EXE, cfg.os_type)
+        self.assertEqual(fields.VMMode.EXE, cfg.os_type)
         self.assertEqual("/sbin/init", cfg.os_init_path)
         self.assertEqual("console=tty0 console=ttyS0", cfg.os_cmdline)
         self.assertIsNone(cfg.os_root)
@@ -3157,7 +3156,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                               vconfig.LibvirtConfigGuestFeatureAPIC)
         self.assertEqual(cfg.memory, instance_ref.flavor.memory_mb * units.Ki)
         self.assertEqual(cfg.vcpus, instance_ref.flavor.vcpus)
-        self.assertEqual(cfg.os_type, vm_mode.HVM)
+        self.assertEqual(cfg.os_type, fields.VMMode.HVM)
         self.assertEqual(cfg.os_boot_dev, ["hd"])
         self.assertIsNone(cfg.os_root)
         self.assertEqual(len(cfg.devices), 10)
@@ -4073,7 +4072,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
         instance_ref = objects.Instance(**self.test_instance)
-        instance_ref['vm_mode'] = vm_mode.HVM
+        instance_ref['vm_mode'] = fields.VMMode.HVM
         image_meta = objects.ImageMeta.from_dict(self.test_image_meta)
 
         disk_info = blockinfo.get_disk_info(CONF.libvirt.virt_type,
@@ -4083,7 +4082,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         cfg = drvr._get_guest_config(instance_ref, [],
                                      image_meta, disk_info)
 
-        self.assertEqual(cfg.os_type, vm_mode.HVM)
+        self.assertEqual(cfg.os_type, fields.VMMode.HVM)
         self.assertEqual(cfg.os_loader, CONF.libvirt.xen_hvmloader_path)
         self.assertEqual(3, len(cfg.features))
         self.assertIsInstance(cfg.features[0],
@@ -4112,7 +4111,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         cfg = drvr._get_guest_config(instance_ref, [],
                                      image_meta, disk_info)
 
-        self.assertEqual(cfg.os_type, vm_mode.XEN)
+        self.assertEqual(cfg.os_type, fields.VMMode.XEN)
         self.assertEqual(1, len(cfg.features))
         self.assertIsInstance(cfg.features[0],
                               vconfig.LibvirtConfigGuestFeaturePAE)
@@ -4210,29 +4209,35 @@ class LibvirtConnTestCase(test.NoDBTestCase):
     def test_use_ps2_mouse(self):
         self.flags(pointer_model='ps2mouse')
 
-        tablet = self._test_get_guest_usb_tablet(True, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(
+            True, True, fields.VMMode.HVM)
         self.assertIsNone(tablet)
 
     def test_get_guest_usb_tablet_wipe(self):
         self.flags(use_usb_tablet=True, group='libvirt')
 
-        tablet = self._test_get_guest_usb_tablet(True, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(
+            True, True, fields.VMMode.HVM)
         self.assertIsNotNone(tablet)
 
-        tablet = self._test_get_guest_usb_tablet(True, False, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(
+            True, False, fields.VMMode.HVM)
         self.assertIsNotNone(tablet)
 
-        tablet = self._test_get_guest_usb_tablet(False, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(
+            False, True, fields.VMMode.HVM)
         self.assertIsNotNone(tablet)
 
-        tablet = self._test_get_guest_usb_tablet(False, False, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(
+            False, False, fields.VMMode.HVM)
         self.assertIsNone(tablet)
 
-        tablet = self._test_get_guest_usb_tablet(True, True, "foo")
+        tablet = self._test_get_guest_usb_tablet(
+            True, True, "foo")
         self.assertIsNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
-            False, True, vm_mode.HVM, True)
+            False, True, fields.VMMode.HVM, True)
         self.assertIsNone(tablet)
 
     def test_get_guest_usb_tablet_image_meta(self):
@@ -4240,19 +4245,19 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         image_meta = {"properties": {"hw_pointer_model": "usbtablet"}}
 
         tablet = self._test_get_guest_usb_tablet(
-            True, True, vm_mode.HVM, image_meta=image_meta)
+            True, True, fields.VMMode.HVM, image_meta=image_meta)
         self.assertIsNotNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
-            True, False, vm_mode.HVM, image_meta=image_meta)
+            True, False, fields.VMMode.HVM, image_meta=image_meta)
         self.assertIsNotNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
-            False, True, vm_mode.HVM, image_meta=image_meta)
+            False, True, fields.VMMode.HVM, image_meta=image_meta)
         self.assertIsNotNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
-            False, False, vm_mode.HVM, image_meta=image_meta)
+            False, False, fields.VMMode.HVM, image_meta=image_meta)
         self.assertIsNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
@@ -4260,7 +4265,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertIsNone(tablet)
 
         tablet = self._test_get_guest_usb_tablet(
-            False, True, vm_mode.HVM, True, image_meta=image_meta)
+            False, True, fields.VMMode.HVM, True, image_meta=image_meta)
         self.assertIsNone(tablet)
 
     def test_get_guest_usb_tablet_image_meta_no_vnc(self):
@@ -4271,32 +4276,32 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertRaises(
             exception.UnsupportedPointerModelRequested,
             self._test_get_guest_usb_tablet,
-            False, False, vm_mode.HVM, True, image_meta=image_meta)
+            False, False, fields.VMMode.HVM, True, image_meta=image_meta)
 
     def test_get_guest_no_pointer_model_usb_tablet_set(self):
         self.flags(use_usb_tablet=True, group='libvirt')
         self.flags(pointer_model=None)
 
-        tablet = self._test_get_guest_usb_tablet(True, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(True, True, fields.VMMode.HVM)
         self.assertIsNotNone(tablet)
 
     def test_get_guest_no_pointer_model_usb_tablet_not_set(self):
         self.flags(use_usb_tablet=False, group='libvirt')
         self.flags(pointer_model=None)
 
-        tablet = self._test_get_guest_usb_tablet(True, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(True, True, fields.VMMode.HVM)
         self.assertIsNone(tablet)
 
     def test_get_guest_pointer_model_usb_tablet(self):
         self.flags(use_usb_tablet=False, group='libvirt')
         self.flags(pointer_model='usbtablet')
-        tablet = self._test_get_guest_usb_tablet(True, True, vm_mode.HVM)
+        tablet = self._test_get_guest_usb_tablet(True, True, fields.VMMode.HVM)
         self.assertIsNotNone(tablet)
 
     def test_get_guest_pointer_model_usb_tablet_image(self):
         image_meta = {"properties": {"hw_pointer_model": "usbtablet"}}
         tablet = self._test_get_guest_usb_tablet(
-            True, True, vm_mode.HVM, image_meta=image_meta)
+            True, True, fields.VMMode.HVM, image_meta=image_meta)
         self.assertIsNotNone(tablet)
 
     def test_get_guest_pointer_model_usb_tablet_image_no_HVM(self):
@@ -4306,7 +4311,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertRaises(
             exception.UnsupportedPointerModelRequested,
             self._test_get_guest_usb_tablet,
-            True, True, vm_mode.XEN, image_meta=image_meta)
+            True, True, fields.VMMode.XEN, image_meta=image_meta)
 
     def test_get_guest_config_with_watchdog_action_flavor(self):
         self.flags(virt_type='kvm', group='libvirt')
@@ -5762,13 +5767,13 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
     def test_xml_and_uri_no_ramdisk_no_kernel_xen_hvm(self):
         instance_data = dict(self.test_instance)
-        instance_data.update({'vm_mode': vm_mode.HVM})
+        instance_data.update({'vm_mode': fields.VMMode.HVM})
         self._check_xml_and_uri(instance_data, expect_kernel=False,
                                 expect_ramdisk=False, expect_xen_hvm=True)
 
     def test_xml_and_uri_no_ramdisk_no_kernel_xen_pv(self):
         instance_data = dict(self.test_instance)
-        instance_data.update({'vm_mode': vm_mode.XEN})
+        instance_data.update({'vm_mode': fields.VMMode.XEN})
         self._check_xml_and_uri(instance_data, expect_kernel=False,
                                 expect_ramdisk=False, expect_xen_hvm=False,
                                 xen_only=True)
@@ -6537,24 +6542,24 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         instance_ref = objects.Instance(**instance)
         image_meta = objects.ImageMeta.from_dict(self.test_image_meta)
 
-        xen_vm_mode = vm_mode.XEN
+        xen_vm_mode = fields.VMMode.XEN
         if expect_xen_hvm:
-            xen_vm_mode = vm_mode.HVM
+            xen_vm_mode = fields.VMMode.HVM
 
         type_uri_map = {'qemu': ('qemu:///system',
                              [(lambda t: t.find('.').get('type'), 'qemu'),
                               (lambda t: t.find('./os/type').text,
-                               vm_mode.HVM),
+                               fields.VMMode.HVM),
                               (lambda t: t.find('./devices/emulator'), None)]),
                         'kvm': ('qemu:///system',
                              [(lambda t: t.find('.').get('type'), 'kvm'),
                               (lambda t: t.find('./os/type').text,
-                               vm_mode.HVM),
+                               fields.VMMode.HVM),
                               (lambda t: t.find('./devices/emulator'), None)]),
                         'uml': ('uml:///system',
                              [(lambda t: t.find('.').get('type'), 'uml'),
                               (lambda t: t.find('./os/type').text,
-                               vm_mode.UML)]),
+                               fields.VMMode.UML)]),
                         'xen': ('xen:///',
                              [(lambda t: t.find('.').get('type'), 'xen'),
                               (lambda t: t.find('./os/type').text,
@@ -12319,13 +12324,13 @@ class LibvirtConnTestCase(test.NoDBTestCase):
             caps.host.cpu = cpu
 
             guest = vconfig.LibvirtConfigGuest()
-            guest.ostype = vm_mode.HVM
+            guest.ostype = fields.VMMode.HVM
             guest.arch = fields.Architecture.X86_64
             guest.domtype = ["kvm"]
             caps.guests.append(guest)
 
             guest = vconfig.LibvirtConfigGuest()
-            guest.ostype = vm_mode.HVM
+            guest.ostype = fields.VMMode.HVM
             guest.arch = fields.Architecture.I686
             guest.domtype = ["kvm"]
             caps.guests.append(guest)
@@ -14803,7 +14808,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertEqual(instance_ref["uuid"], cfg.uuid)
         self.assertEqual(instance_ref.flavor.memory_mb * units.Ki, cfg.memory)
         self.assertEqual(instance_ref.flavor.vcpus, cfg.vcpus)
-        self.assertEqual(vm_mode.HVM, cfg.os_type)
+        self.assertEqual(fields.VMMode.HVM, cfg.os_type)
         self.assertIsNone(cfg.os_root)
         self.assertEqual(6, len(cfg.devices))
         self.assertIsInstance(cfg.devices[0],
@@ -14830,7 +14835,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.flags(virt_type='parallels', group='libvirt')
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
         ct_instance = self.test_instance.copy()
-        ct_instance["vm_mode"] = vm_mode.EXE
+        ct_instance["vm_mode"] = fields.VMMode.EXE
         instance_ref = objects.Instance(**ct_instance)
         image_meta = objects.ImageMeta.from_dict(self.test_image_meta)
 
@@ -14847,7 +14852,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertEqual(instance_ref["uuid"], cfg.uuid)
         self.assertEqual(instance_ref.flavor.memory_mb * units.Ki, cfg.memory)
         self.assertEqual(instance_ref.flavor.vcpus, cfg.vcpus)
-        self.assertEqual(vm_mode.EXE, cfg.os_type)
+        self.assertEqual(fields.VMMode.EXE, cfg.os_type)
         self.assertEqual("/sbin/init", cfg.os_init_path)
         self.assertIsNone(cfg.os_root)
         if rescue:
@@ -14932,8 +14937,8 @@ class LibvirtConnTestCase(test.NoDBTestCase):
         self.assertTrue(disk_found)
 
     def test_get_guest_config_parallels_volume(self):
-        self._test_get_guest_config_parallels_volume(vm_mode.EXE, 4)
-        self._test_get_guest_config_parallels_volume(vm_mode.HVM, 6)
+        self._test_get_guest_config_parallels_volume(fields.VMMode.EXE, 4)
+        self._test_get_guest_config_parallels_volume(fields.VMMode.HVM, 6)
 
     def test_get_guest_disk_config_rbd_older_config_drive_fall_back(self):
         # New config drives are stored in rbd but existing instances have
@@ -15025,7 +15030,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
         self.flags(virt_type='parallels', group='libvirt')
         instance = objects.Instance(**self.test_instance)
-        instance.vm_mode = vm_mode.EXE
+        instance.vm_mode = fields.VMMode.EXE
         fake_dom = FakeVirtDomain(fake_xml=dummyxml)
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         mock_get_domain.return_value = fake_dom
diff --git a/nova/tests/unit/virt/xenapi/test_vm_utils.py b/nova/tests/unit/virt/xenapi/test_vm_utils.py
index df6c90dfd4..140289f500 100644
--- a/nova/tests/unit/virt/xenapi/test_vm_utils.py
+++ b/nova/tests/unit/virt/xenapi/test_vm_utils.py
@@ -30,11 +30,11 @@ import six
 
 from nova.compute import flavors
 from nova.compute import power_state
-from nova.compute import vm_mode
 import nova.conf
 from nova import context
 from nova import exception
 from nova import objects
+from nova.objects import fields as obj_fields
 from nova import test
 from nova.tests.unit import fake_flavor
 from nova.tests.unit import fake_instance
@@ -1613,37 +1613,37 @@ class DetermineVmModeTestCase(VMUtilsTestBase):
 
     def test_determine_vm_mode_returns_xen_mode(self):
         instance = self._fake_object({"vm_mode": "xen"})
-        self.assertEqual(vm_mode.XEN,
+        self.assertEqual(obj_fields.VMMode.XEN,
             vm_utils.determine_vm_mode(instance, None))
 
     def test_determine_vm_mode_returns_hvm_mode(self):
         instance = self._fake_object({"vm_mode": "hvm"})
-        self.assertEqual(vm_mode.HVM,
+        self.assertEqual(obj_fields.VMMode.HVM,
             vm_utils.determine_vm_mode(instance, None))
 
     def test_determine_vm_mode_returns_xen_for_linux(self):
         instance = self._fake_object({"vm_mode": None, "os_type": "linux"})
-        self.assertEqual(vm_mode.XEN,
+        self.assertEqual(obj_fields.VMMode.XEN,
             vm_utils.determine_vm_mode(instance, None))
 
     def test_determine_vm_mode_returns_hvm_for_windows(self):
         instance = self._fake_object({"vm_mode": None, "os_type": "windows"})
-        self.assertEqual(vm_mode.HVM,
+        self.assertEqual(obj_fields.VMMode.HVM,
             vm_utils.determine_vm_mode(instance, None))
 
     def test_determine_vm_mode_returns_hvm_by_default(self):
         instance = self._fake_object({"vm_mode": None, "os_type": None})
-        self.assertEqual(vm_mode.HVM,
+        self.assertEqual(obj_fields.VMMode.HVM,
             vm_utils.determine_vm_mode(instance, None))
 
     def test_determine_vm_mode_returns_xen_for_VHD(self):
         instance = self._fake_object({"vm_mode": None, "os_type": None})
-        self.assertEqual(vm_mode.XEN,
+        self.assertEqual(obj_fields.VMMode.XEN,
             vm_utils.determine_vm_mode(instance, vm_utils.ImageType.DISK_VHD))
 
     def test_determine_vm_mode_returns_xen_for_DISK(self):
         instance = self._fake_object({"vm_mode": None, "os_type": None})
-        self.assertEqual(vm_mode.XEN,
+        self.assertEqual(obj_fields.VMMode.XEN,
             vm_utils.determine_vm_mode(instance, vm_utils.ImageType.DISK))
 
 
diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 31d193de2d..1027e2a1fb 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -32,7 +32,6 @@ from oslo_utils import versionutils
 
 from nova.compute import power_state
 from nova.compute import task_states
-from nova.compute import vm_mode
 import nova.conf
 from nova.console import type as ctype
 from nova import exception
@@ -149,7 +148,7 @@ class FakeDriver(driver.ComputeDriver):
             'supported_instances': [(
                 obj_fields.Architecture.X86_64,
                 obj_fields.HVType.FAKE,
-                vm_mode.HVM)],
+                obj_fields.VMMode.HVM)],
             'numa_topology': None,
           }
         self._mounts = {}
diff --git a/nova/virt/hyperv/hostops.py b/nova/virt/hyperv/hostops.py
index 2fabdc2461..7684f1fd51 100644
--- a/nova/virt/hyperv/hostops.py
+++ b/nova/virt/hyperv/hostops.py
@@ -26,7 +26,6 @@ from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import units
 
-from nova.compute import vm_mode
 import nova.conf
 from nova.i18n import _
 from nova.objects import fields as obj_fields
@@ -159,10 +158,10 @@ class HostOps(object):
                'supported_instances': [
                    (obj_fields.Architecture.I686,
                     obj_fields.HVType.HYPERV,
-                    vm_mode.HVM),
+                    obj_fields.VMMode.HVM),
                    (obj_fields.Architecture.X86_64,
                     obj_fields.HVType.HYPERV,
-                    vm_mode.HVM)],
+                    obj_fields.VMMode.HVM)],
                'numa_topology': None,
                }
 
diff --git a/nova/virt/ironic/driver.py b/nova/virt/ironic/driver.py
index e50bc767a3..0d828ed6a8 100644
--- a/nova/virt/ironic/driver.py
+++ b/nova/virt/ironic/driver.py
@@ -36,7 +36,6 @@ import six.moves.urllib.parse as urlparse
 from nova.api.metadata import base as instance_metadata
 from nova.compute import power_state
 from nova.compute import task_states
-from nova.compute import vm_mode
 from nova.compute import vm_states
 import nova.conf
 from nova.console import type as console_type
@@ -98,7 +97,7 @@ def _get_nodes_supported_instances(cpu_arch=None):
         return []
     return [(cpu_arch,
              obj_fields.HVType.BAREMETAL,
-             vm_mode.HVM)]
+             obj_fields.VMMode.HVM)]
 
 
 def _log_ironic_polling(what, node, instance):
diff --git a/nova/virt/libvirt/blockinfo.py b/nova/virt/libvirt/blockinfo.py
index 5fcb4b76f8..e5f89af17f 100644
--- a/nova/virt/libvirt/blockinfo.py
+++ b/nova/virt/libvirt/blockinfo.py
@@ -76,7 +76,6 @@ from oslo_config import cfg
 import six
 
 from nova import block_device
-from nova.compute import vm_mode
 from nova import exception
 from nova.i18n import _
 from nova.objects import base as obj_base
@@ -248,8 +247,8 @@ def get_disk_bus_for_device_type(instance,
     elif virt_type == "lxc":
         return "lxc"
     elif virt_type == "xen":
-        guest_vm_mode = vm_mode.get_from_instance(instance)
-        if guest_vm_mode == vm_mode.HVM:
+        guest_vm_mode = obj_fields.VMMode.get_from_instance(instance)
+        if guest_vm_mode == obj_fields.VMMode.HVM:
             return "ide"
         else:
             return "xen"
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 64e0d8ec97..163687bb79 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -64,7 +64,6 @@ from nova import block_device
 from nova.compute import power_state
 from nova.compute import task_states
 from nova.compute import utils as compute_utils
-from nova.compute import vm_mode
 import nova.conf
 from nova.console import serial as serial_console
 from nova.console import type as ctype
@@ -3489,7 +3488,8 @@ class LibvirtDriver(driver.ComputeDriver):
             fs.source_dir = os.path.join(
                 libvirt_utils.get_instance_path(instance), 'rootfs')
             devices.append(fs)
-        elif os_type == vm_mode.EXE and CONF.libvirt.virt_type == "parallels":
+        elif (os_type == fields.VMMode.EXE and
+              CONF.libvirt.virt_type == "parallels"):
             if rescue:
                 fsrescue = self._get_guest_fs_config(instance, "disk.rescue")
                 devices.append(fsrescue)
@@ -3993,13 +3993,13 @@ class LibvirtDriver(driver.ComputeDriver):
     def _get_guest_os_type(self, virt_type):
         """Returns the guest OS type based on virt type."""
         if virt_type == "lxc":
-            ret = vm_mode.EXE
+            ret = fields.VMMode.EXE
         elif virt_type == "uml":
-            ret = vm_mode.UML
+            ret = fields.VMMode.UML
         elif virt_type == "xen":
-            ret = vm_mode.XEN
+            ret = fields.VMMode.XEN
         else:
-            ret = vm_mode.HVM
+            ret = fields.VMMode.HVM
         return ret
 
     def _set_guest_for_rescue(self, rescue, guest, inst_path, virt_type,
@@ -4093,7 +4093,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 guest.features.append(vconfig.LibvirtConfigGuestFeaturePAE())
 
         if (virt_type not in ("lxc", "uml", "parallels", "xen") or
-                (virt_type == "xen" and guest.os_type == vm_mode.HVM)):
+                (virt_type == "xen" and guest.os_type == fields.VMMode.HVM)):
             guest.features.append(vconfig.LibvirtConfigGuestFeatureACPI())
             guest.features.append(vconfig.LibvirtConfigGuestFeatureAPIC())
 
@@ -4126,7 +4126,7 @@ class LibvirtDriver(driver.ComputeDriver):
         # be overridden by the user with image_meta.properties, which
         # is carried out in the next if statement below this one.
         guestarch = libvirt_utils.get_arch(image_meta)
-        if guest.os_type == vm_mode.XEN:
+        if guest.os_type == fields.VMMode.XEN:
             video.type = 'xen'
         elif CONF.libvirt.virt_type == 'parallels':
             video.type = 'vga'
@@ -4293,7 +4293,7 @@ class LibvirtDriver(driver.ComputeDriver):
     def _configure_guest_by_virt_type(self, guest, virt_type, caps, instance,
                                       image_meta, flavor, root_device_name):
         if virt_type == "xen":
-            if guest.os_type == vm_mode.HVM:
+            if guest.os_type == fields.VMMode.HVM:
                 guest.os_loader = CONF.libvirt.xen_hvmloader_path
         elif virt_type in ("kvm", "qemu"):
             if caps.host.cpu.arch in (fields.Architecture.I686,
@@ -4328,7 +4328,7 @@ class LibvirtDriver(driver.ComputeDriver):
             guest.os_kernel = "/usr/bin/linux"
             guest.os_root = root_device_name
         elif virt_type == "parallels":
-            if guest.os_type == vm_mode.EXE:
+            if guest.os_type == fields.VMMode.EXE:
                 guest.os_init_path = "/sbin/init"
 
     def _conf_non_lxc_uml(self, virt_type, guest, root_device_name, rescue,
@@ -4526,7 +4526,7 @@ class LibvirtDriver(driver.ComputeDriver):
             # for nova.api.ec2.cloud.CloudController.get_metadata()
             instance.root_device_name = root_device_name
 
-        guest.os_type = (vm_mode.get_from_instance(instance) or
+        guest.os_type = (fields.VMMode.get_from_instance(instance) or
                 self._get_guest_os_type(virt_type))
         caps = self._host.get_capabilities()
 
@@ -4675,7 +4675,7 @@ class LibvirtDriver(driver.ComputeDriver):
 
     def _get_guest_usb_tablet(self, os_type):
         tablet = None
-        if os_type == vm_mode.HVM:
+        if os_type == fields.VMMode.HVM:
             tablet = vconfig.LibvirtConfigGuestInput()
             tablet.type = "tablet"
             tablet.bus = "usb"
@@ -5040,7 +5040,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 instance_cap = (
                     fields.Architecture.canonicalize(g.arch),
                     fields.HVType.canonicalize(dt),
-                    vm_mode.canonicalize(g.ostype))
+                    fields.VMMode.canonicalize(g.ostype))
                 instance_caps.append(instance_cap)
 
         return instance_caps
@@ -6802,7 +6802,7 @@ class LibvirtDriver(driver.ComputeDriver):
                     doc.findall('.//devices/%s/target' % device_type))
 
         if (CONF.libvirt.virt_type == 'parallels' and
-            doc.find('os/type').text == vm_mode.EXE):
+            doc.find('os/type').text == fields.VMMode.EXE):
             node_type = 'filesystem'
         else:
             node_type = 'disk'
diff --git a/nova/virt/libvirt/utils.py b/nova/virt/libvirt/utils.py
index 65f63f2089..67b445400a 100644
--- a/nova/virt/libvirt/utils.py
+++ b/nova/virt/libvirt/utils.py
@@ -26,7 +26,6 @@ from lxml import etree
 from oslo_concurrency import processutils
 from oslo_log import log as logging
 
-from nova.compute import vm_mode
 import nova.conf
 from nova.i18n import _
 from nova.i18n import _LI
@@ -360,7 +359,8 @@ def find_disk(virt_dom):
         disk_path = source.get('dir')
         disk_path = disk_path[0:disk_path.rfind('rootfs')]
         disk_path = os.path.join(disk_path, 'disk')
-    elif CONF.libvirt.virt_type == 'parallels' and os_type == vm_mode.EXE:
+    elif (CONF.libvirt.virt_type == 'parallels' and
+          os_type == obj_fields.VMMode.EXE):
         filesystem = domain.find('devices/filesystem')
         driver = filesystem.find('driver')
 
diff --git a/nova/virt/vmwareapi/host.py b/nova/virt/vmwareapi/host.py
index 118201f78a..a9a6b04e99 100644
--- a/nova/virt/vmwareapi/host.py
+++ b/nova/virt/vmwareapi/host.py
@@ -22,7 +22,6 @@ from oslo_utils import units
 from oslo_utils import versionutils
 from oslo_vmware import exceptions as vexc
 
-from nova.compute import vm_mode
 import nova.conf
 from nova import context
 from nova import exception
@@ -99,10 +98,10 @@ class VCState(object):
         data["supported_instances"] = [
             (obj_fields.Architecture.I686,
              obj_fields.HVType.VMWARE,
-             vm_mode.HVM),
+             obj_fields.VMMode.HVM),
             (obj_fields.Architecture.X86_64,
              obj_fields.HVType.VMWARE,
-             vm_mode.HVM)]
+             obj_fields.VMMode.HVM)]
 
         self._stats = data
         if self._auto_service_disabled:
diff --git a/nova/virt/xenapi/host.py b/nova/virt/xenapi/host.py
index 50c63091e5..5e74f08a31 100644
--- a/nova/virt/xenapi/host.py
+++ b/nova/virt/xenapi/host.py
@@ -25,7 +25,6 @@ from oslo_serialization import jsonutils
 import six
 
 from nova.compute import task_states
-from nova.compute import vm_mode
 from nova.compute import vm_states
 from nova import context
 from nova import exception
@@ -285,7 +284,7 @@ def to_supported_instances(host_capabilities):
             ostype, _version, guestarch = capability.split("-")
 
             guestarch = obj_fields.Architecture.canonicalize(guestarch)
-            ostype = vm_mode.canonicalize(ostype)
+            ostype = obj_fields.VMMode.canonicalize(ostype)
 
             result.append((guestarch, obj_fields.HVType.XEN, ostype))
         except ValueError:
diff --git a/nova/virt/xenapi/vm_utils.py b/nova/virt/xenapi/vm_utils.py
index 7c2e70755a..543e7e25bb 100644
--- a/nova/virt/xenapi/vm_utils.py
+++ b/nova/virt/xenapi/vm_utils.py
@@ -43,11 +43,11 @@ import six.moves.urllib.parse as urlparse
 from nova.api.metadata import base as instance_metadata
 from nova.compute import power_state
 from nova.compute import task_states
-from nova.compute import vm_mode
 import nova.conf
 from nova import exception
 from nova.i18n import _, _LE, _LI, _LW
 from nova.network import model as network_model
+from nova.objects import fields as obj_fields
 from nova import utils
 from nova.virt import configdrive
 from nova.virt import diagnostics
@@ -1608,23 +1608,24 @@ def determine_disk_image_type(image_meta):
 
 
 def determine_vm_mode(instance, disk_image_type):
-    current_mode = vm_mode.get_from_instance(instance)
-    if current_mode == vm_mode.XEN or current_mode == vm_mode.HVM:
+    current_mode = obj_fields.VMMode.get_from_instance(instance)
+    if (current_mode == obj_fields.VMMode.XEN or
+        current_mode == obj_fields.VMMode.HVM):
         return current_mode
 
     os_type = instance['os_type']
     if os_type == "linux":
-        return vm_mode.XEN
+        return obj_fields.VMMode.XEN
     if os_type == "windows":
-        return vm_mode.HVM
+        return obj_fields.VMMode.HVM
 
     # disk_image_type specific default for backwards compatibility
     if disk_image_type == ImageType.DISK_VHD or \
             disk_image_type == ImageType.DISK:
-        return vm_mode.XEN
+        return obj_fields.VMMode.XEN
 
     # most images run OK as HVM
-    return vm_mode.HVM
+    return obj_fields.VMMode.HVM
 
 
 def set_vm_name_label(session, vm_ref, name_label):
diff --git a/nova/virt/xenapi/vmops.py b/nova/virt/xenapi/vmops.py
index a39ae2f084..9054051e4c 100644
--- a/nova/virt/xenapi/vmops.py
+++ b/nova/virt/xenapi/vmops.py
@@ -39,7 +39,6 @@ from nova import block_device
 from nova import compute
 from nova.compute import power_state
 from nova.compute import task_states
-from nova.compute import vm_mode
 from nova.compute import vm_states
 import nova.conf
 from nova.console import type as ctype
@@ -47,6 +46,7 @@ from nova import context as nova_context
 from nova import exception
 from nova.i18n import _, _LE, _LI, _LW
 from nova import objects
+from nova.objects import fields as obj_fields
 from nova.pci import manager as pci_manager
 from nova import utils
 from nova.virt import configdrive
@@ -703,7 +703,7 @@ class VMOps(object):
                 LOG.debug("vm_mode not found in rescue image properties."
                           "Setting vm_mode to %s", mode, instance=instance)
             else:
-                mode = vm_mode.canonicalize(rescue_vm_mode)
+                mode = obj_fields.VMMode.canonicalize(rescue_vm_mode)
 
         if instance.vm_mode != mode:
             # Update database with normalized (or determined) value
@@ -711,7 +711,7 @@ class VMOps(object):
             instance.save()
 
         device_id = vm_utils.get_vm_device_id(self._session, image_meta)
-        use_pv_kernel = (mode == vm_mode.XEN)
+        use_pv_kernel = (mode == obj_fields.VMMode.XEN)
         LOG.debug("Using PV kernel: %s", use_pv_kernel, instance=instance)
         vm_ref = vm_utils.create_vm(self._session, instance, name_label,
                                     kernel_file, ramdisk_file,