Merge "libvirt: set guest cpu_shares value as a multiple of guest vCPUs"

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

@@ -1198,7 +1198,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                         random, 'choice', side_effect=lambda cells: cells[0])):
             cfg = conn._get_guest_config(instance_ref, [], {}, disk_info)
             self.assertEqual(set([0, 1]), cfg.cpuset)
-            self.assertIsNone(cfg.cputune)
+            self.assertEqual(0, len(cfg.cputune.vcpupin))
             self.assertIsNone(cfg.cpu.numa)
 
     @mock.patch.object(objects.Flavor, 'get_by_id')
@@ -1230,7 +1230,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
             cfg = conn._get_guest_config(instance_ref, [], {}, disk_info)
             self.assertFalse(choice_mock.called)
             self.assertEqual(set([3]), cfg.cpuset)
-            self.assertIsNone(cfg.cputune)
+            self.assertEqual(0, len(cfg.cputune.vcpupin))
             self.assertIsNone(cfg.cpu.numa)
 
     def _test_get_guest_memory_backing_config(
@@ -1304,7 +1304,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
             # when choosing viable cells
             choice_mock.assert_called_once_with([set([2, 3])])
             self.assertEqual(set([2, 3]), cfg.cpuset)
-            self.assertIsNone(cfg.cputune)
+            self.assertEqual(0, len(cfg.cputune.vcpupin))
             self.assertIsNone(cfg.cpu.numa)
 
     @mock.patch.object(objects.Flavor, 'get_by_id')
@@ -1341,7 +1341,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                     conn, "_get_host_capabilities", return_value=caps)):
             cfg = conn._get_guest_config(instance_ref, [], {}, disk_info)
             self.assertIsNone(cfg.cpuset)
-            self.assertIsNone(cfg.cputune)
+            self.assertEqual(0, len(cfg.cputune.vcpupin))
             self.assertIsNone(cfg.numatune)
             self.assertIsNotNone(cfg.cpu.numa)
             for instance_cell, numa_cfg_cell in zip(
@@ -3198,6 +3198,25 @@ class LibvirtConnTestCase(test.NoDBTestCase):
                           [],
                           image_meta, disk_info)
 
+    @mock.patch.object(objects.Flavor, 'get_by_id')
+    def test_guest_cpu_shares_with_multi_vcpu(self, mock_flavor):
+        self.flags(virt_type='kvm', group='libvirt')
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
+
+        instance_ref = objects.Instance(**self.test_instance)
+        flavor = instance_ref.get_flavor()
+        flavor.extra_specs = {}
+        flavor.vcpus = 4
+        mock_flavor.return_value = flavor
+
+        disk_info = blockinfo.get_disk_info(CONF.libvirt.virt_type,
+                                            instance_ref)
+
+        cfg = conn._get_guest_config(instance_ref, [], {}, disk_info)
+
+        self.assertEqual(4096, cfg.cputune.shares)
+
     @mock.patch.object(objects.Flavor, 'get_by_id')
     def test_get_guest_config_with_cpu_quota(self, mock_flavor):
         self.flags(virt_type='kvm', group='libvirt')

nova/virt/libvirt/driver.py

@@ -3437,6 +3437,21 @@ class LibvirtDriver(driver.ComputeDriver):
             id_maps.extend(gid_maps)
         return id_maps
 
+    def _update_guest_cputune(self, guest, flavor, virt_type):
+        if virt_type in ('lxc', 'kvm', 'qemu'):
+            if guest.cputune is None:
+                guest.cputune = vconfig.LibvirtConfigGuestCPUTune()
+            # Setting the default cpu.shares value to be a value
+            # dependent on the number of vcpus
+            guest.cputune.shares = 1024 * guest.vcpus
+
+            cputuning = ['shares', 'period', 'quota']
+            for name in cputuning:
+                key = "quota:cpu_" + name
+                if key in flavor.extra_specs:
+                    setattr(guest.cputune, name,
+                            int(flavor.extra_specs[key]))
+
     def _get_cpu_numa_config_from_instance(self, instance_numa_topology):
         if instance_numa_topology:
             guest_cpu_numa = vconfig.LibvirtConfigGuestCPUNUMA()
@@ -3871,14 +3886,7 @@ class LibvirtDriver(driver.ComputeDriver):
                                                           flavor))
         guest.idmaps = self._get_guest_idmaps()
 
-        cputuning = ['shares', 'period', 'quota']
-        for name in cputuning:
-            key = "quota:cpu_" + name
-            if key in flavor.extra_specs:
-                if guest.cputune is None:
-                    guest.cputune = vconfig.LibvirtConfigGuestCPUTune()
-                setattr(guest.cputune, name,
-                        int(flavor.extra_specs[key]))
+        self._update_guest_cputune(guest, flavor, virt_type)
 
         guest.cpu = self._get_guest_cpu_config(
                 flavor, image_meta, guest_numa_config.numaconfig)