libvirt: add method to get device by name to Host

Add method "lookup_device_by_name" in Host and
update the driver to use it instead of calling libvirt
directly.

Change-Id: I1642f839c5a0c22d8dc978c2a84906e2d3d8a051

nova/tests/unit/virt/libvirt/test_driver.py

@@ -8741,12 +8741,11 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
     def test_get_pcidev_info(self):
 
-        def fake_nodeDeviceLookupByName(name):
+        def fake_nodeDeviceLookupByName(self, name):
             return FakeNodeDevice(_fake_NodeDevXml[name])
 
-        self.mox.StubOutWithMock(libvirt_driver.LibvirtDriver, '_conn')
-        libvirt_driver.LibvirtDriver._conn.nodeDeviceLookupByName =\
-                                             fake_nodeDeviceLookupByName
+        self.mox.StubOutWithMock(host.Host, 'device_lookup_by_name')
+        host.Host.device_lookup_by_name = fake_nodeDeviceLookupByName
 
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         actualvf = drvr._get_pcidev_info("pci_0000_04_00_3")
@@ -8826,11 +8825,12 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
         libvirt_driver.LibvirtDriver._conn.listDevices = fakelistDevices
 
-        def fake_nodeDeviceLookupByName(name):
+        def fake_nodeDeviceLookupByName(self, name):
             return FakeNodeDevice(_fake_NodeDevXml[name])
 
-        libvirt_driver.LibvirtDriver._conn.nodeDeviceLookupByName =\
-                                             fake_nodeDeviceLookupByName
+        self.mox.StubOutWithMock(host.Host, 'device_lookup_by_name')
+        host.Host.device_lookup_by_name = fake_nodeDeviceLookupByName
+
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
         actjson = drvr._get_pci_passthrough_devices()
 

nova/tests/unit/virt/libvirt/test_host.py

@@ -831,6 +831,11 @@ Active:          8381604 kB
         self.host.write_instance_config(xml)
         mock_defineXML.assert_called_once_with(xml)
 
+    @mock.patch.object(fakelibvirt.virConnect, "nodeDeviceLookupByName")
+    def test_device_lookup_by_name(self, mock_nodeDeviceLookupByName):
+        self.host.device_lookup_by_name("foo")
+        mock_nodeDeviceLookupByName.assert_called_once_with("foo")
+
 
 class DomainJobInfoTestCase(test.NoDBTestCase):
 

nova/virt/libvirt/driver.py

@@ -2853,7 +2853,7 @@ class LibvirtDriver(driver.ComputeDriver):
             for dev in pci_devices:
                 libvirt_dev_addr = dev['hypervisor_name']
                 libvirt_dev = \
-                        self._conn.nodeDeviceLookupByName(libvirt_dev_addr)
+                        self._host.device_lookup_by_name(libvirt_dev_addr)
                 # Note(yjiang5) Spelling for 'dettach' is correct, see
                 # http://libvirt.org/html/libvirt-libvirt.html.
                 libvirt_dev.dettach()
@@ -2864,7 +2864,7 @@ class LibvirtDriver(driver.ComputeDriver):
             for dev in pci_devices:
                 libvirt_dev_addr = dev['hypervisor_name']
                 libvirt_dev = \
-                        self._conn.nodeDeviceLookupByName(libvirt_dev_addr)
+                        self._host.device_lookup_by_name(libvirt_dev_addr)
                 libvirt_dev.reset()
 
         except libvirt.libvirtError as exc:
@@ -4632,7 +4632,7 @@ class LibvirtDriver(driver.ComputeDriver):
                                 'phys_function': phys_address}
             return {'dev_type': 'type-PCI'}
 
-        virtdev = self._conn.nodeDeviceLookupByName(devname)
+        virtdev = self._host.device_lookup_by_name(devname)
         xmlstr = virtdev.XMLDesc(0)
         cfgdev = vconfig.LibvirtConfigNodeDevice()
         cfgdev.parse_str(xmlstr)

nova/virt/libvirt/host.py

@@ -943,3 +943,11 @@ class Host(object):
         :returns: a virDomain instance
         """
         return self.get_connection().defineXML(xml)
+
+    def device_lookup_by_name(self, name):
+        """Lookup a node device by its name.
+
+
+        :returns: a virNodeDevice instance
+        """
+        return self.get_connection().nodeDeviceLookupByName(name)