diff --git a/nova/tests/unit/virt/libvirt/test_imagebackend.py b/nova/tests/unit/virt/libvirt/test_imagebackend.py
index 124d303512cf..21271922ad8f 100644
--- a/nova/tests/unit/virt/libvirt/test_imagebackend.py
+++ b/nova/tests/unit/virt/libvirt/test_imagebackend.py
@@ -365,6 +365,7 @@ class FlatTestCase(_ImageTestCase, test.NoDBTestCase):
                        return_value=imageutils.QemuImgInfo())
     def test_create_image_extend(self, fake_qemu_img_info):
         fn = self.prepare_mocks()
+        fake_qemu_img_info.return_value.virtual_size = 1024
         fn(target=self.TEMPLATE_PATH, image_id=None)
         imagebackend.libvirt_utils.copy_image(self.TEMPLATE_PATH, self.PATH)
         image = imgmodel.LocalFileImage(self.PATH, imgmodel.FORMAT_RAW)
@@ -1487,7 +1488,7 @@ class RbdTestCase(_ImageTestCase, test.NoDBTestCase):
             self.INSTANCE["uuid"] + "_fake.vm",
             "FakePool",
             "FakeUser",
-            "MTIzNDU2Cg==",
+            b"MTIzNDU2Cg==",
             ["server1:1899", "server2:1920"]),
                          model)
 
diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py
index 144a000d8d25..61ca7629c283 100644
--- a/nova/virt/libvirt/imagebackend.py
+++ b/nova/virt/libvirt/imagebackend.py
@@ -685,7 +685,7 @@ class Lvm(Image):
         def create_lvm_image(base, size):
             base_size = disk.get_disk_size(base)
             self.verify_base_size(base, size, base_size=base_size)
-            resize = size > base_size
+            resize = size > base_size if size else False
             size = size if resize else base_size
             lvm.create_volume(self.vg, self.lv,
                                          size, sparse=self.sparse)
diff --git a/tests-py3.txt b/tests-py3.txt
index 252bd5490e1f..ab647bf059a4 100644
--- a/tests-py3.txt
+++ b/tests-py3.txt
@@ -1,10 +1,6 @@
 nova.tests.unit.api.openstack.compute.test_user_data.ServersControllerCreateTest
 nova.tests.unit.test_wsgi.TestWSGIServerWithSSL
 nova.tests.unit.virt.libvirt.test_firewall.IptablesFirewallTestCase
-nova.tests.unit.virt.libvirt.test_imagebackend.EncryptedLvmTestCase
-nova.tests.unit.virt.libvirt.test_imagebackend.LvmTestCase
-nova.tests.unit.virt.libvirt.test_imagebackend.FlatTestCase
-nova.tests.unit.virt.libvirt.test_imagebackend.RbdTestCase
 nova.tests.unit.virt.libvirt.test_vif.LibvirtVifTestCase
 nova.tests.unit.virt.xenapi.test_vm_utils.ResizeFunctionTestCase
 nova.tests.unit.virt.xenapi.test_vm_utils.ScanSrTestCase