libvirt: 'video.vram' property must be an integer

The 'vram' property of the 'video' device must be an integer else
libvirt will spit the dummy out, e.g.

  libvirt.libvirtError: XML error: cannot parse video vram '8192.0'

The division operator in Python 3 results in a float, not an integer
like in Python 2. Use the truncation division operator instead.

Change-Id: Iebf678c229da4f455459d068cafeee5f241aea1f
Signed-off-by: Stephen Finucane <[email protected]>
Closes-Bug: #1896496
(cherry picked from commit f2ca089)

Author: stephenfin

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

@@ -6716,7 +6716,7 @@ def test_get_guest_config_with_video_driver_vram(self):
 
         self.assertEqual(cfg.devices[4].type, "spice")
         self.assertEqual(cfg.devices[5].type, "qxl")
-        self.assertEqual(cfg.devices[5].vram, 64 * units.Mi / units.Ki)
+        self.assertEqual(cfg.devices[5].vram, 65536)
 
     def _test_add_video_driver(self, model):
         self.flags(virt_type='kvm', group='libvirt')
@@ -6727,15 +6727,19 @@ def _test_add_video_driver(self, model):
 
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)
         guest = vconfig.LibvirtConfigGuest()
-        instance_ref = objects.Instance(**self.test_instance)
-        flavor = instance_ref.get_flavor()
+        flavor = objects.Flavor(
+            extra_specs={'hw_video:ram_max_mb': '512'})
         image_meta = objects.ImageMeta.from_dict({
-            'properties': {'hw_video_model': model}})
+            'properties': {
+                'hw_video_model': model,
+                'hw_video_ram': 8,
+            },
+        })
 
         self.assertTrue(drvr._guest_add_video_device(guest))
-        video = drvr._add_video_driver(guest, image_meta,
-                                       flavor)
+        video = drvr._add_video_driver(guest, image_meta, flavor)
         self.assertEqual(model, video.type)
+        self.assertEqual(8192, video.vram)  # should be in bytes
 
     def test__add_video_driver(self):
         self._test_add_video_driver('qxl')

nova/virt/libvirt/driver.py

@@ -5522,7 +5522,7 @@ def _add_video_driver(self, guest, image_meta, flavor):
             raise exception.RequestedVRamTooHigh(req_vram=video_ram,
                                                  max_vram=max_vram)
         if max_vram and video_ram:
-            video.vram = video_ram * units.Mi / units.Ki
+            video.vram = video_ram * units.Mi // units.Ki
         guest.add_device(video)
 
         # NOTE(sean-k-mooney): return the video device we added