openstack
/
nova
Code Issues Proposed changes

Don't set bandwidth limits for vhostuser, hostdev interfaces 

'tc' [1] is used for rate limiting in libvirt. This is suitable for tap
devices but not for the sockets used by vhostuser interface or for
physical devices; rate limiting for these interfaces must be done in the
vSwitch or via the interface itself. For this reason, libvirt explicitly
marks these interfaces, along with some other interfaces types, as not
supporting bandwidth limiting [2]. Given that there is no reason to be
setting the bandwidth-related attributes on vhostuser or hostdev
interfaces, we should stop doing it.

[1] http://man7.org/linux/man-pages/man8/tc.8.html
[2] https://github.com/libvirt/libvirt/blob/568a41722/src/conf/netdev_bandwidth_conf.h#L38

Change-Id: Id57e4c149616fe0896e80fca322ece79ec3bfd69
Closes-Bug: #1814882
This commit is contained in:
Stephen Finucane 2019-02-06 14:00:51 +00:00
parent 95287619c9
commit f651ebc0ce
2 changed files with 28 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
nova/tests/unit/virt/libvirt/test_vif.py
View File

@ -576,6 +576,8 @@ class LibvirtVifTestCase(test.NoDBTestCase):
self.assertEqual(pci_slot, pci_slot_want)
def _assertXmlEqual(self, expectedXmlstr, actualXmlstr):
if not isinstance(actualXmlstr, six.string_types):
actualXmlstr = etree.tostring(actualXmlstr, pretty_print=True)
self.assertThat(actualXmlstr, matchers.XMLMatches(expectedXmlstr))
def _get_conf(self):
@ -610,6 +612,8 @@ class LibvirtVifTestCase(test.NoDBTestCase):
nic = driver.get_config(self.instance, vif, image_meta,
flavor, CONF.libvirt.virt_type,
hostimpl)
# TODO(stephenfin): There doesn't appear to be any reason we should do
# this: just return 'nic.to_xml()' and remove '_get_node'
conf.add_device(nic)
return conf.to_xml()
@ -1630,6 +1634,25 @@ class LibvirtVifTestCase(test.NoDBTestCase):
<target dev="nicdc065497-3c"/>
</interface>""", cfg.to_xml())
@mock.patch("nova.network.os_vif_util.nova_to_osvif_instance")
@mock.patch("nova.network.os_vif_util.nova_to_osvif_vif")
def test_config_os_vif_vhostuser(self, mock_convert_vif,
mock_convert_inst):
mock_convert_vif.return_value = self.os_vif_vhostuser
mock_convert_inst.return_value = self.os_vif_inst_info
d = vif.LibvirtGenericVIFDriver()
xml = self._get_instance_xml(d, self.vif_vhostuser)
node = self._get_node(xml)
self._assertXmlEqual("""
<interface type="vhostuser">
<mac address="22:52:25:62:e2:aa"/>
<model type="virtio"/>
<source mode="client"
path="/var/run/openvswitch/vhudc065497-3c" type="unix"/>
</interface>""", node)
@mock.patch("nova.network.os_vif_util.nova_to_osvif_instance")
@mock.patch("nova.network.os_vif_util.nova_to_osvif_vif")
def test_config_os_vif_agilio_ovs_fallthrough(self, mock_convert_vif,

6
nova/virt/libvirt/vif.py
View File

@ -573,7 +573,11 @@ class LibvirtGenericVIFDriver(object):
{'obj': vif.obj_name(), 'func': viffunc})
func(instance, vif, conf, host)
designer.set_vif_bandwidth_config(conf, inst_type)
# not all VIF types support bandwidth configuration
# https://github.com/libvirt/libvirt/blob/568a41722/src/conf/netdev_bandwidth_conf.h#L38
if vif.obj_name() not in ('VIFVHostUser', 'VIFHostDevice'):
designer.set_vif_bandwidth_config(conf, inst_type)
if ('network' in vif and 'mtu' in vif.network and
self._has_min_version_for_mtu(host)):
designer.set_vif_mtu_config(conf, vif.network.mtu)