openstack/nova
Code Issues Proposed changes

Update libvirt fixtures to support hostdevs

Browse Source 
This patch updates the fixtures to support hostdevs, allowing hostdev
devices to be attached and detached.
Additionally, this patch mocks the
nova.virt.libvirt.driver.AsyncDeviceEventsHandler.wait method to
avoid waiting for libvirt events.

The target goal of these series of patch is to enable VFIO devices
migration with kernel variant drivers.

Partially-Implements: blueprint migrate-vfio-devices-using-kernel-variant-drivers
Change-Id: I25b208c08df3a14fc03c1a6504e8c3cfad5c5a90
This commit is contained in:
René Ribaud 2025-03-03 18:38:56 +01:00
parent 099859ecf0
commit b227efd967
2 changed files with 100 additions and 40 deletions
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129
nova/tests/fixtures/libvirt.py vendored
View File

@ -519,7 +519,7 @@ class HostPCIDevicesInfo(object):
def __init__(self, num_pci=0, num_pfs=2, num_vfs=8, num_mdevcap=0,
numa_node=None, multiple_gpu_types=False,
generic_types=False):
generic_types=False, bus=0x81, product_ids=["1515"]):
"""Create a new HostPCIDevicesInfo object.
:param num_pci: (int) The number of (non-SR-IOV) and (non-MDEV capable)
@ -533,6 +533,14 @@ class HostPCIDevicesInfo(object):
split between ``$TOTAL_NUMA_NODES`` nodes.
:param multiple_gpu_types: (bool) Supports different vGPU types
:param generic_types: (bool) Supports both nvidia-12 and mlx5 types
:param bus: (int) PCI bus number, allow to specify a different bus to
have an asymmetric configuration between src and dst computes.
:param product_ids: (list) List of product IDs.
Warning: This multiplies the number of PF and VF devices
by the number of product IDs. It creates separate sets of VF
devices, one for each product ID.
The first set is assigned to slot 0, and each subsequent set
is assigned to the next slot incrementally.
"""
self.devices = {}
@ -545,7 +553,7 @@ class HostPCIDevicesInfo(object):
if num_pfs and num_vfs % num_pfs:
raise ValueError('num_vfs must be a factor of num_pfs')
bus = 0x81
bus = bus
slot = 0x0
function = 0
iommu_group = 40 # totally arbitrary number
@ -581,41 +589,43 @@ class HostPCIDevicesInfo(object):
vf_ratio = num_vfs // num_pfs if num_pfs else 0
# Generate PFs
for dev in range(num_pfs):
function = 0
numa_node_pf = self._calc_numa_node(dev, numa_node)
self.add_device(
dev_type='PF',
bus=bus,
slot=slot,
function=function,
iommu_group=iommu_group,
numa_node=numa_node_pf,
vf_ratio=vf_ratio)
parent = (bus, slot, function)
# Generate VFs
for _ in range(vf_ratio):
function += 1
iommu_group += 1
if function % 8 == 0:
# functions must be 0-7
slot += 1
function = 0
for prod_id in product_ids:
for dev in range(num_pfs):
function = 0
numa_node_pf = self._calc_numa_node(dev, numa_node)
self.add_device(
dev_type='VF',
dev_type='PF',
bus=bus,
slot=slot,
function=function,
iommu_group=iommu_group,
numa_node=numa_node_pf,
vf_ratio=vf_ratio,
parent=parent)
vf_ratio=vf_ratio)
slot += 1
parent = (bus, slot, function)
# Generate VFs
for _ in range(vf_ratio):
function += 1
iommu_group += 1
if function % 8 == 0:
# functions must be 0-7
slot += 1
function = 0
self.add_device(
dev_type='VF',
bus=bus,
prod_id=prod_id,
slot=slot,
function=function,
iommu_group=iommu_group,
numa_node=numa_node_pf,
vf_ratio=vf_ratio,
parent=parent)
slot += 1
def add_device(
self, dev_type, bus, slot, function, iommu_group, numa_node,
@ -952,6 +962,23 @@ def _parse_nic_info(element):
return nic_info
def _parse_hostdev_info(element):
hostdev_info = {}
hostdev_info['type'] = element.get('type', 'pci')
hostdev_info['managed'] = element.get('managed', 'pci')
source = element.find('./source')
if source is not None:
address = source.find('./address')
if address is not None:
hostdev_info['domain'] = address.get('domain')
hostdev_info['bus'] = address.get('bus')
hostdev_info['slot'] = address.get('slot')
hostdev_info['function'] = address.get('function')
return hostdev_info
def disable_event_thread(self):
"""Disable nova libvirt driver event thread.
@ -1252,6 +1279,8 @@ class Domain(object):
'model': hostdev.get('model'),
'address_uuid': address.get('uuid')
})
if dev_type == 'pci':
hostdev_info.append(_parse_hostdev_info(hostdev))
devices['hostdevs'] = hostdev_info
vpmem_info = []
@ -1384,11 +1413,12 @@ class Domain(object):
nic_info['_attached'] = True
self._def['devices']['nics'] += [nic_info]
result = True
elif xml.startswith("<hostdev"):
hostdev_info = _parse_hostdev_info(etree.fromstring(xml))
hostdev_info['_attached'] = True
self._def['devices']['hostdevs'] += [hostdev_info]
result = True
else:
# FIXME(sean-k-mooney): We don't currently handle attaching
# or detaching hostdevs but we have tests that assume we do so
# this is an error not an exception. This affects PCI passthrough,
# vGPUs and PF neutron ports.
LOG.error(
"Trying to attach an unsupported device type."
"The fakelibvirt implementation is incomplete "
@ -1436,10 +1466,25 @@ class Domain(object):
return attached_nic_info is not None
# FIXME(sean-k-mooney): We don't currently handle attaching or
# detaching hostdevs but we have tests that assume we do so this is
# an error not an exception. This affects PCI passthrough, vGPUs and
# PF neutron ports
if xml.startswith("<hostdev"):
hostdev_info = _parse_hostdev_info(etree.fromstring(xml))
attached_hostdev_info = None
for attached_hostdev in self._def['devices']['hostdevs']:
if (
attached_hostdev["domain"] == hostdev_info["domain"] and
attached_hostdev["bus"] == hostdev_info["bus"] and
attached_hostdev["slot"] == hostdev_info["slot"] and
attached_hostdev["function"] ==
hostdev_info["function"]
):
attached_hostdev_info = attached_hostdev
break
if attached_hostdev_info:
self._def['devices']['hostdevs'].remove(attached_hostdev_info)
return attached_hostdev_info is not None
LOG.error(
"Trying to detach an unsupported device type."
"The fakelibvirt implementation is incomplete "
@ -1544,10 +1589,18 @@ class Domain(object):
hostdevs = ''
for hostdev in self._def['devices']['hostdevs']:
hostdevs += '''<hostdev mode='subsystem' type='%(type)s' model='%(model)s'>
if hostdev['type'] == 'mdev':
hostdevs += '''<hostdev mode='subsystem' type='%(type)s' model='%(model)s'>
<source>
<address uuid='%(address_uuid)s'/>
</source>
</hostdev>
''' % hostdev # noqa
if hostdev['type'] == 'pci':
hostdevs += '''<hostdev mode='subsystem' type='%(type)s' managed='%(managed)s'>
<source>
<address domain='%(domain)s' bus='%(bus)s' slot='%(slot)s' function='%(function)s'/>
</source>
</hostdev>
''' % hostdev # noqa

11
nova/tests/functional/libvirt/test_pci_sriov_servers.py
View File

@ -1160,8 +1160,15 @@ class SRIOVServersTest(_PCIServersWithMigrationTestBase):
pf_port['binding:profile'],
)
# now live migrate that server
self._live_migrate(server, 'completed')
# By mocking threading.Event.wait we prevent the test to wait until the
# timeout happens.
# We return True signalling that the event is set, i.e. the libvirt
# event the caller is waiting for has been received.
# Note: This mock behavior cannot be added to the fixture because
# many unit tests rely on it for different side effects.
with mock.patch("threading.Event.wait", side_effect=[True]):
# now live migrate that server
self._live_migrate(server, "completed")
# we should now have transitioned our usage to the destination, freeing
# up the source in the process