Merge "libvirt: update the logic to configure volume with scsi controller" into stable/ocata

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

@@ -3466,7 +3466,8 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
         image_meta = objects.ImageMeta.from_dict({
             "disk_format": "raw",
-            "properties": {"hw_scsi_model": "virtio-scsi"}})
+            "properties": {"hw_scsi_model": "virtio-scsi",
+                           "hw_disk_bus": "scsi"}})
         instance_ref = objects.Instance(**self.test_instance)
         conn_info = {'driver_volume_type': 'fake'}
         bdms = block_device_obj.block_device_make_list_from_dicts(
@@ -3499,10 +3500,12 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                              vconfig.LibvirtConfigGuestDisk)
             self.assertEqual(cfg.devices[2].target_dev, 'sdc')
             self.assertEqual(cfg.devices[2].target_bus, 'scsi')
+            self.assertEqual(2, cfg.devices[2].device_addr.unit)
             self.assertIsInstance(cfg.devices[3],
                              vconfig.LibvirtConfigGuestDisk)
             self.assertEqual(cfg.devices[3].target_dev, 'sdd')
             self.assertEqual(cfg.devices[3].target_bus, 'scsi')
+            self.assertEqual(3, cfg.devices[3].device_addr.unit)
             self.assertIsInstance(cfg.devices[4],
                              vconfig.LibvirtConfigGuestController)
             self.assertEqual(cfg.devices[4].model, 'virtio-scsi')

nova/virt/libvirt/driver.py

@@ -1052,6 +1052,17 @@ class LibvirtDriver(driver.ComputeDriver):
         for source in tcp_devices:
             yield (source.get("host"), int(source.get("service")))
 
+    def _get_scsi_controller_max_unit(self, guest):
+        """Returns the max disk unit used by scsi controller"""
+        xml = guest.get_xml_desc()
+        tree = etree.fromstring(xml)
+        addrs = "./devices/disk[@device='disk']/address[@type='drive']"
+
+        ret = []
+        for obj in tree.findall(addrs):
+            ret.append(int(obj.get('unit', 0)))
+        return max(ret)
+
     @staticmethod
     def _get_rbd_driver():
         return rbd_utils.RBDDriver(
@@ -1215,6 +1226,9 @@ class LibvirtDriver(driver.ComputeDriver):
         disk_info = blockinfo.get_info_from_bdm(
             instance, CONF.libvirt.virt_type, instance.image_meta, bdm)
         self._connect_volume(connection_info, disk_info)
+        if disk_info['bus'] == 'scsi':
+            disk_info['unit'] = self._get_scsi_controller_max_unit(guest) + 1
+
         conf = self._get_volume_config(connection_info, disk_info)
         self._set_cache_mode(conf)
 
@@ -3689,6 +3703,9 @@ class LibvirtDriver(driver.ComputeDriver):
             vol_dev = block_device.prepend_dev(vol['mount_device'])
             info = disk_mapping[vol_dev]
             self._connect_volume(connection_info, info)
+            if scsi_controller and scsi_controller.model == 'virtio-scsi':
+                info['unit'] = disk_mapping['unit']
+                disk_mapping['unit'] += 1
             cfg = self._get_volume_config(connection_info, info)
             devices.append(cfg)
             vol['connection_info'] = connection_info

nova/virt/libvirt/volume/volume.py

@@ -114,6 +114,17 @@ class LibvirtBaseVolumeDriver(object):
                         'type': connection_info['driver_volume_type']
                     })
 
+        if disk_info['bus'] == 'scsi':
+            # The driver is responsible to create the SCSI controller
+            # at index 0.
+            conf.device_addr = vconfig.LibvirtConfigGuestDeviceAddressDrive()
+            conf.device_addr.controller = 0
+            if 'unit' in disk_info:
+                # In order to allow up to 256 disks handled by one
+                # virtio-scsi controller, the device addr should be
+                # specified.
+                conf.device_addr.unit = disk_info['unit']
+
         return conf
 
     def connect_volume(self, connection_info, disk_info):