Update pci stat pools based on PCI device changes

hemanthnakkina · hemanthnakkina · commit d8b8a8193b6b · 2020-11-06T05:44:38.000Z
At start up of nova-compute service, the PCI stat pools are populated based on information in pci_devices table in Nova database. The pools are updated only when new device is added or removed but not on any device changes like device type. If an existing device is configured as SRIOV and nova-compute is restarted, the pci_devices table gets updated but the device is still listed under the old pool in pci_tracker.stats.pool (in-memory object). This patch looks for device type updates in existing devices and updates the pools accordingly. Change-Id: Id4ebb06e634a612c8be4be6c678d8265e0b99730 Closes-Bug: #1892361 (cherry picked from commit b8695de)
diff --git a/nova/pci/manager.py b/nova/pci/manager.py
@@ -225,6 +225,7 @@ def _set_hvdevs(self, devices):
                     self.stale[new_value['address']] = new_value
                 else:
                     existed.update_device(new_value)
+                    self.stats.update_device(existed)
 
         # Track newly discovered devices.
         for dev in [dev for dev in devices if
diff --git a/nova/pci/stats.py b/nova/pci/stats.py
@@ -104,6 +104,32 @@ def _create_pool_keys_from_dev(self, dev):
             pool['parent_ifname'] = dev.extra_info['parent_ifname']
         return pool
 
+    def _get_pool_with_device_type_mismatch(self, dev):
+        """Check for device type mismatch in the pools for a given device.
+
+        Return (pool, device) if device type does not match or a single None
+        if the device type matches.
+        """
+        for pool in self.pools:
+            for device in pool['devices']:
+                if device.address == dev.address:
+                    if dev.dev_type != pool["dev_type"]:
+                        return pool, device
+                    return None
+
+        return None
+
+    def update_device(self, dev):
+        """Update a device to its matching pool."""
+        pool_device_info = self._get_pool_with_device_type_mismatch(dev)
+        if pool_device_info is None:
+            return
+
+        pool, device = pool_device_info
+        pool['devices'].remove(device)
+        self._decrease_pool_count(self.pools, pool)
+        self.add_device(dev)
+
     def add_device(self, dev):
         """Add a device to its matching pool."""
         dev_pool = self._create_pool_keys_from_dev(dev)
diff --git a/nova/tests/functional/libvirt/test_pci_sriov_servers.py b/nova/tests/functional/libvirt/test_pci_sriov_servers.py
@@ -70,6 +70,7 @@ class SRIOVServersTest(_PCIServersTestBase):
         {
             'vendor_id': fakelibvirt.PCI_VEND_ID,
             'product_id': fakelibvirt.PF_PROD_ID,
+            'physical_network': 'physnet4',
         },
         {
             'vendor_id': fakelibvirt.PCI_VEND_ID,
@@ -103,6 +104,20 @@ def setUp(self):
         # fixture already stubbed.
         self.neutron = self.useFixture(base.LibvirtNeutronFixture(self))
 
+    def _disable_sriov_in_pf(self, pci_info):
+        # Check for PF and change the capability from virt_functions
+        # Delete all the VFs
+        vfs_to_delete = []
+
+        for device_name, device in pci_info.devices.items():
+            if 'virt_functions' in device.pci_device:
+                device.generate_xml(skip_capability=True)
+            elif 'phys_function' in device.pci_device:
+                vfs_to_delete.append(device_name)
+
+        for device in vfs_to_delete:
+            del pci_info.devices[device]
+
     def test_create_server_with_VF(self):
         """Create a server with an SR-IOV VF-type PCI device."""
 
@@ -266,6 +281,69 @@ def test_get_server_diagnostics_server_with_VF(self):
         )
         self.assertIsNone(diagnostics['nic_details'][1]['tx_packets'])
 
+    def test_create_server_after_change_in_nonsriov_pf_to_sriov_pf(self):
+        # Starts a compute with PF not configured with SRIOV capabilities
+        # Updates the PF with SRIOV capability and restart the compute service
+        # Then starts a VM with the sriov port. The VM should be in active
+        # state with sriov port attached.
+
+        # To emulate the device type changing, we first create a
+        # HostPCIDevicesInfo object with PFs and VFs. Then we make a copy
+        # and remove the VFs and the virt_function capability. This is
+        # done to ensure the physical function product id is same in both
+        # the versions.
+        pci_info = fakelibvirt.HostPCIDevicesInfo(num_pfs=1, num_vfs=1)
+        pci_info_no_sriov = copy.deepcopy(pci_info)
+
+        # Disable SRIOV capabilties in PF and delete the VFs
+        self._disable_sriov_in_pf(pci_info_no_sriov)
+
+        fake_connection = self._get_connection(pci_info=pci_info_no_sriov,
+                                               hostname='test_compute0')
+        self.mock_conn.return_value = fake_connection
+
+        self.compute = self.start_service('compute', host='test_compute0')
+
+        ctxt = context.get_admin_context()
+        pci_devices = objects.PciDeviceList.get_by_compute_node(
+            ctxt,
+            objects.ComputeNode.get_by_nodename(
+                ctxt, 'test_compute0',
+            ).id,
+        )
+        self.assertEqual(1, len(pci_devices))
+        self.assertEqual('type-PCI', pci_devices[0].dev_type)
+
+        # Update connection with original pci info with sriov PFs
+        fake_connection = self._get_connection(pci_info=pci_info,
+                                               hostname='test_compute0')
+        self.mock_conn.return_value = fake_connection
+
+        # Restart the compute service
+        self.restart_compute_service(self.compute)
+
+        # Verify if PCI devices are of type type-PF or type-VF
+        pci_devices = objects.PciDeviceList.get_by_compute_node(
+            ctxt,
+            objects.ComputeNode.get_by_nodename(
+                ctxt, 'test_compute0',
+            ).id,
+        )
+        for pci_device in pci_devices:
+            self.assertIn(pci_device.dev_type, ['type-PF', 'type-VF'])
+
+        # create the port
+        self.neutron.create_port({'port': self.neutron.network_4_port_1})
+
+        # create a server using the VF via neutron
+        flavor_id = self._create_flavor()
+        self._create_server(
+            flavor_id=flavor_id,
+            networks=[
+                {'port': base.LibvirtNeutronFixture.network_4_port_1['id']},
+            ],
+        )
+
 
 class SRIOVAttachDetachTest(_PCIServersTestBase):
     # no need for aliases as these test will request SRIOV via neutron
diff --git a/nova/tests/unit/pci/test_stats.py b/nova/tests/unit/pci/test_stats.py
@@ -561,6 +561,30 @@ def test_remove_device(self):
         self.pci_stats.remove_device(dev2)
         self._assertPools()
 
+    def test_update_device(self):
+        # Update device type of one of the device from type-PCI to
+        # type-PF. Verify if the existing pool is updated and a new
+        # pool is created with dev_type type-PF.
+        self._create_pci_devices()
+        dev1 = self.pci_tagged_devices.pop()
+        dev1.dev_type = 'type-PF'
+        self.pci_stats.update_device(dev1)
+        self.assertEqual(3, len(self.pci_stats.pools))
+        self._assertPoolContent(self.pci_stats.pools[0], '1137', '0072',
+                                len(self.pci_untagged_devices))
+        self.assertEqual(self.pci_untagged_devices,
+                         self.pci_stats.pools[0]['devices'])
+        self._assertPoolContent(self.pci_stats.pools[1], '1137', '0071',
+                                len(self.pci_tagged_devices),
+                                physical_network='physnet1')
+        self.assertEqual(self.pci_tagged_devices,
+                         self.pci_stats.pools[1]['devices'])
+        self._assertPoolContent(self.pci_stats.pools[2], '1137', '0071',
+                                1,
+                                physical_network='physnet1')
+        self.assertEqual(dev1,
+                         self.pci_stats.pools[2]['devices'][0])
+
 
 class PciDeviceVFPFStatsTestCase(test.NoDBTestCase):
 
diff --git a/nova/tests/unit/virt/libvirt/fakelibvirt.py b/nova/tests/unit/virt/libvirt/fakelibvirt.py
@@ -284,49 +284,62 @@ def __init__(self, dev_type, slot, function, iommu_group, numa_node,
         :param multiple_gpu_types: (bool) Supports different vGPU types
         """
 
+        self.dev_type = dev_type
+        self.slot = slot
+        self.function = function
+        self.iommu_group = iommu_group
+        self.numa_node = numa_node
+        self.vf_ratio = vf_ratio
+        self.multiple_gpu_types = multiple_gpu_types
+        self.parent = parent
+        self.generate_xml()
+
+    def generate_xml(self, skip_capability=False):
         vend_id = PCI_VEND_ID
         vend_name = PCI_VEND_NAME
-        if dev_type == 'PCI':
-            if vf_ratio:
+        capability = ''
+        if self.dev_type == 'PCI':
+            if self.vf_ratio:
                 raise ValueError('vf_ratio does not apply for PCI devices')
 
             prod_id = PCI_PROD_ID
             prod_name = PCI_PROD_NAME
             driver = PCI_DRIVER_NAME
-            capability = ''
-        elif dev_type == 'PF':
+        elif self.dev_type == 'PF':
             prod_id = PF_PROD_ID
             prod_name = PF_PROD_NAME
             driver = PF_DRIVER_NAME
-            capability = self.cap_templ % {
-                'cap_type': PF_CAP_TYPE,
-                'addresses': '\n'.join([
-                    self.addr_templ % {
-                        # these are the slot, function values of the child VFs
-                        # we can only assign 8 functions to a slot (0-7) so
-                        # bump the slot each time we exceed this
-                        'slot': slot + (x // 8),
-                        # ...and wrap the function value
-                        'function': x % 8,
-                    # the offset is because the PF is occupying function 0
-                    } for x in range(1, vf_ratio + 1)])
-            }
-        elif dev_type == 'VF':
+            if not skip_capability:
+                capability = self.cap_templ % {
+                    'cap_type': PF_CAP_TYPE,
+                    'addresses': '\n'.join([
+                        self.addr_templ % {
+                            # these are the slot, function values of the child
+                            # VFs, we can only assign 8 functions to a slot
+                            # (0-7) so bump the slot each time we exceed this
+                            'slot': self.slot + (x // 8),
+                            # ...and wrap the function value
+                            'function': x % 8,
+                        # the offset is because the PF is occupying function 0
+                        } for x in range(1, self.vf_ratio + 1)])
+                }
+        elif self.dev_type == 'VF':
             prod_id = VF_PROD_ID
             prod_name = VF_PROD_NAME
             driver = VF_DRIVER_NAME
-            capability = self.cap_templ % {
-                'cap_type': VF_CAP_TYPE,
-                'addresses': self.addr_templ % {
-                    # this is the slot, function value of the parent PF
-                    # if we're e.g. device 8, we'll have a different slot
-                    # to our parent so reverse this
-                    'slot': slot - ((vf_ratio + 1) // 8),
-                    # the parent PF is always function 0
-                    'function': 0,
+            if not skip_capability:
+                capability = self.cap_templ % {
+                    'cap_type': VF_CAP_TYPE,
+                    'addresses': self.addr_templ % {
+                        # this is the slot, function value of the parent PF
+                        # if we're e.g. device 8, we'll have a different slot
+                        # to our parent so reverse this
+                        'slot': self.slot - ((self.vf_ratio + 1) // 8),
+                        # the parent PF is always function 0
+                        'function': 0,
+                    }
                 }
-            }
-        elif dev_type == 'MDEV_TYPES':
+        elif self.dev_type == 'MDEV_TYPES':
             prod_id = MDEV_CAPABLE_PROD_ID
             prod_name = MDEV_CAPABLE_PROD_NAME
             driver = MDEV_CAPABLE_DRIVER_NAME
@@ -336,36 +349,37 @@ def __init__(self, dev_type, slot, function, iommu_group, numa_node,
                 'type_id': NVIDIA_11_VGPU_TYPE,
                 'instances': 16,
             }]
-            if multiple_gpu_types:
+            if self.multiple_gpu_types:
                 types.append(self.mdevtypes_templ % {
                     'type_id': NVIDIA_12_VGPU_TYPE,
                     'instances': 8,
                 })
-            capability = self.cap_templ % {
-                'cap_type': MDEV_CAPABLE_CAP_TYPE,
-                'addresses': '\n'.join(types)
-            }
+            if not skip_capability:
+                capability = self.cap_templ % {
+                    'cap_type': MDEV_CAPABLE_CAP_TYPE,
+                    'addresses': '\n'.join(types)
+                }
             self.is_capable_of_mdevs = True
         else:
             raise ValueError('Expected one of: PCI, VF, PCI')
 
         self.pci_device = self.pci_device_template % {
-            'slot': slot,
-            'function': function,
+            'slot': self.slot,
+            'function': self.function,
             'vend_id': vend_id,
             'vend_name': vend_name,
             'prod_id': prod_id,
             'prod_name': prod_name,
             'driver': driver,
             'capability': capability,
-            'iommu_group': iommu_group,
-            'numa_node': numa_node,
-            'parent': parent or self.pci_default_parent
+            'iommu_group': self.iommu_group,
+            'numa_node': self.numa_node,
+            'parent': self.parent or self.pci_default_parent
         }
         # -1 is the sentinel set in /sys/bus/pci/devices/*/numa_node
         # for no NUMA affinity. When the numa_node is set to -1 on a device
         # Libvirt omits the NUMA element so we remove it.
-        if numa_node == -1:
+        if self.numa_node == -1:
             self.pci_device = self.pci_device.replace("<numa node='-1'/>", "")
 
     def XMLDesc(self, flags):
@@ -943,6 +957,20 @@ def _parse_definition(self, xml):
                         nic_info['source'] = source.get('network')
                     elif nic_info['type'] == 'bridge':
                         nic_info['source'] = source.get('bridge')
+                    elif nic_info['type'] == 'hostdev':
+                        # <interface type='hostdev'> is for VF when vnic_type
+                        # is direct. Add sriov vf pci information in nic_info
+                        address = source.find('./address')
+                        pci_type = address.get('type')
+                        pci_domain = address.get('domain').replace('0x', '')
+                        pci_bus = address.get('bus').replace('0x', '')
+                        pci_slot = address.get('slot').replace('0x', '')
+                        pci_function = address.get('function').replace(
+                            '0x', '')
+                        pci_device = "%s_%s_%s_%s_%s" % (pci_type, pci_domain,
+                                                         pci_bus, pci_slot,
+                                                         pci_function)
+                        nic_info['source'] = pci_device
 
                 nics_info += [nic_info]
 
@@ -984,11 +1012,32 @@ def _parse_definition(self, xml):
 
         return definition
 
+    def verify_hostdevs_interface_are_vfs(self):
+        """Verify for interface type hostdev if the pci device is VF or not.
+        """
+
+        error_message = ("Interface type hostdev is currently supported on "
+                         "SR-IOV Virtual Functions only")
+
+        nics = self._def['devices'].get('nics', [])
+        for nic in nics:
+            if nic['type'] == 'hostdev':
+                pci_device = nic['source']
+                pci_info_from_connection = self._connection.pci_info.devices[
+                    pci_device]
+                if 'phys_function' not in pci_info_from_connection.pci_device:
+                    raise make_libvirtError(
+                        libvirtError,
+                        error_message,
+                        error_code=VIR_ERR_CONFIG_UNSUPPORTED,
+                        error_domain=VIR_FROM_DOMAIN)
+
     def create(self):
         self.createWithFlags(0)
 
     def createWithFlags(self, flags):
         # FIXME: Not handling flags at the moment
+        self.verify_hostdevs_interface_are_vfs()
         self._state = VIR_DOMAIN_RUNNING
         self._connection._mark_running(self)
         self._has_saved_state = False
@@ -1112,7 +1161,7 @@ def XMLDesc(self, flags):
 
         nics = ''
         for nic in self._def['devices']['nics']:
-            if 'source' in nic:
+            if 'source' in nic and nic['type'] != 'hostdev':
                 nics += '''<interface type='%(type)s'>
           <mac address='%(mac)s'/>
           <source %(type)s='%(source)s'/>
diff --git a/releasenotes/notes/bug-1892361-pci-deivce-type-update-c407a66fd37f6405.yaml b/releasenotes/notes/bug-1892361-pci-deivce-type-update-c407a66fd37f6405.yaml
@@ -0,0 +1,12 @@
+---
+fixes:
+  - |
+    Fixes `bug 1892361`_ in which the pci stat pools are not updated when an
+    existing device is enabled with SRIOV capability. Restart of nova-compute
+    service updates the pci device type from type-PCI to type-PF but the pools
+    still maintain the device type as type-PCI. And so the PF is considered for
+    allocation to instance that requests vnic_type=direct. With this fix, the
+    pci device type updates are detected and the pci stat pools are updated
+    properly.
+
+    .. _bug 1892361: https://bugs.launchpad.net/nova/+bug/1892361
