diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index a58cd90958ec..392e0e8b94b1 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -14764,7 +14764,12 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         fake_xml = "<test>this is a test</test>"
 
         def fake_defineXML(xml):
-            self.assertEqual(fake_xml, xml)
+            # In py2 env, xml is encoded in write_instance_config use
+            # encodeutils.safe_encode, it will be decode text before encoding
+            if six.PY2:
+                self.assertEqual(fake_safe_decode(fake_xml), xml)
+            else:
+                self.assertEqual(fake_xml, xml)
             raise fakelibvirt.libvirtError('virDomainDefineXML() failed')
 
         def fake_safe_decode(text, *args, **kwargs):
@@ -15599,20 +15604,22 @@ class LibvirtConnTestCase(test.NoDBTestCase,
                                create=True) as mock_define:
             srcfile = "/first/path"
             dstfile = "/second/path"
+            orig_xml = six.text_type(mock.sentinel.orig_xml)
+            new_xml = six.text_type(mock.sentinel.new_xml)
 
-            mock_dom.XMLDesc.return_value = mock.sentinel.orig_xml
+            mock_dom.XMLDesc.return_value = orig_xml
             mock_dom.isPersistent.return_value = True
 
             def fake_rebase_success(*args, **kwargs):
                 # Make sure the XML is set after the rebase so we know
                 # get_xml_desc was called after the update.
-                mock_dom.XMLDesc.return_value = mock.sentinel.new_xml
+                mock_dom.XMLDesc.return_value = new_xml
 
             if not fail:
                 mock_dom.blockRebase.side_effect = fake_rebase_success
                 # If the swap succeeds, make sure we use the new XML to
                 # redefine the domain.
-                expected_xml = mock.sentinel.new_xml
+                expected_xml = new_xml
             else:
                 if resize:
                     mock_dom.blockResize.side_effect = test.TestingException()
@@ -15622,7 +15629,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
                     expected_exception = exception.VolumeRebaseFailed
                 # If the swap fails, make sure we use the original domain XML
                 # to redefine the domain.
-                expected_xml = mock.sentinel.orig_xml
+                expected_xml = orig_xml
 
             # Run the swap volume code.
             mock_conf = mock.MagicMock(source_type=source_type,
diff --git a/nova/tests/unit/virt/libvirt/test_host.py b/nova/tests/unit/virt/libvirt/test_host.py
index 6fba2ac082f9..7e9cdbf6756a 100644
--- a/nova/tests/unit/virt/libvirt/test_host.py
+++ b/nova/tests/unit/virt/libvirt/test_host.py
@@ -775,6 +775,31 @@ Active:          8381604 kB
         mock_defineXML.assert_called_once_with(fake_dom_xml)
         self.assertIsInstance(guest, libvirt_guest.Guest)
 
+    def test_write_instance_config_unicode(self):
+        fake_dom_xml = u"""
+                <domain type='kvm'>
+                  <uuid>cef19ce0-0ca2-11df-855d-b19fbce37686</uuid>
+                  <devices>
+                    <disk type='file'>
+                      <source file='\u4e2d\u6587'/>
+                    </disk>
+                  </devices>
+                </domain>
+            """
+
+        def emulate_defineXML(xml):
+            conn = self.host.get_connection()
+            # Emulate the decoding behavior of defineXML in Python2
+            if six.PY2:
+                xml = xml.decode("utf-8")
+            dom = fakelibvirt.Domain(conn, xml, False)
+            return dom
+        with mock.patch.object(fakelibvirt.virConnect, "defineXML"
+                               ) as mock_defineXML:
+            mock_defineXML.side_effect = emulate_defineXML
+            guest = self.host.write_instance_config(fake_dom_xml)
+            self.assertIsInstance(guest, libvirt_guest.Guest)
+
     @mock.patch.object(fakelibvirt.virConnect, "nodeDeviceLookupByName")
     def test_device_lookup_by_name(self, mock_nodeDeviceLookupByName):
         self.host.device_lookup_by_name("foo")
diff --git a/nova/virt/libvirt/host.py b/nova/virt/libvirt/host.py
index 7f476a9ace04..3802cb984b00 100644
--- a/nova/virt/libvirt/host.py
+++ b/nova/virt/libvirt/host.py
@@ -38,6 +38,7 @@ from eventlet import greenthread
 from eventlet import patcher
 from eventlet import tpool
 from oslo_log import log as logging
+from oslo_utils import encodeutils
 from oslo_utils import excutils
 from oslo_utils import importutils
 from oslo_utils import units
@@ -823,6 +824,8 @@ class Host(object):
 
         :returns: an instance of Guest
         """
+        if six.PY2:
+            xml = encodeutils.safe_encode(xml)
         domain = self.get_connection().defineXML(xml)
         return libvirt_guest.Guest(domain)