Update pci stat pools based on PCI device changes20.5.0

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.

Conflicts:
      nova/tests/functional/libvirt/test_pci_sriov_servers.py
      nova/tests/unit/virt/libvirt/fakelibvirt.py
      nova/tests/functional/libvirt/base.py

To avoid the conflicts and make the new functional test execute,
following changes are performed
- Modified the test case to use flavor extra spec pci_passthrough
  :alias to create a server with sriov port instead of creating a
  sriov port and passing port information during server creation.
- Removed changes in nova/tests/functional/libvirt/base.py as they
  are required only if neutron sriov port is created in the test
  case.

Change-Id: Id4ebb06e634a612c8be4be6c678d8265e0b99730
Closes-Bug: #1892361
(cherry picked from commit b8695de6da56db42b83b9d9d4c330148766644be)
(cherry picked from commit d8b8a8193b6b8228f6e7d6bde68b5ea6bb53dd8b)
(cherry picked from commit f58399cf496566e39d11f82a61e0b47900f2eafa)

6 files changed, 222 insertions, 33 deletions

diff --git a/nova/pci/manager.py b/nova/pci/manager.py
index 3084643f5e..05930b0beb 100644
--- a/nova/pci/manager.py
+++ b/nova/pci/manager.py
@@ -225,6 +225,7 @@ class PciDevTracker(object):
                     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
index dcf26d3f74..0a80ecedfc 100644
--- a/nova/pci/stats.py
+++ b/nova/pci/stats.py
@@ -105,6 +105,32 @@ class PciDeviceStats(object):
             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
index f203afec15..52b93c9619 100644
--- a/nova/tests/functional/libvirt/test_pci_sriov_servers.py
+++ b/nova/tests/functional/libvirt/test_pci_sriov_servers.py
@@ -13,11 +13,14 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import copy
 import fixtures
 import mock
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
 
+from nova import context
+from nova import objects
 from nova.objects import fields
 from nova.tests.functional.libvirt import base
 from nova.tests.unit.virt.libvirt import fakelibvirt
@@ -116,6 +119,20 @@ class SRIOVServersTest(_PCIServersTestBase):
         },
     )]
 
+    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):
 
         host_info = fakelibvirt.HostInfo(cpu_nodes=2, cpu_sockets=1,
@@ -186,6 +203,69 @@ class SRIOVServersTest(_PCIServersTestBase):
         self._run_build_test(flavor_id_vfs)
         self._run_build_test(flavor_id_pfs, end_status='ERROR')
 
+    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.
+        host_info = fakelibvirt.HostInfo(cpu_nodes=2, cpu_sockets=1,
+                                         cpu_cores=2, cpu_threads=2,
+                                         kB_mem=15740000)
+        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(host_info,
+                                               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(host_info,
+                                               pci_info=pci_info,
+                                               hostname='test_compute0')
+        self.mock_conn.return_value = fake_connection
+
+        # Restart the compute service
+        self.restart_compute_service(self.compute)
+        self.compute_started = True
+
+        # 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 a flavor
+        extra_spec = {"pci_passthrough:alias": "%s:1" % self.VFS_ALIAS_NAME}
+        flavor_id = self._create_flavor(extra_spec=extra_spec)
+
+        self._run_build_test(flavor_id)
+
 
 class GetServerDiagnosticsServerWithVfTestV21(_PCIServersTestBase):
 
diff --git a/nova/tests/unit/pci/test_stats.py b/nova/tests/unit/pci/test_stats.py
index be867783fb..0375ccc63f 100644
--- a/nova/tests/unit/pci/test_stats.py
+++ b/nova/tests/unit/pci/test_stats.py
@@ -533,6 +533,30 @@ class PciDeviceStatsWithTagsTestCase(test.NoDBTestCase):
         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
index d10a44c738..287a00efa2 100644
--- a/nova/tests/unit/virt/libvirt/fakelibvirt.py
+++ b/nova/tests/unit/virt/libvirt/fakelibvirt.py
@@ -251,60 +251,71 @@ class FakePCIDevice(object):
             applicable if ``dev_type`` is one of: ``PF``, ``VF``.
         """
 
-        if dev_type == 'PCI':
-            if vf_ratio:
+        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.generate_xml()
+
+    def generate_xml(self, skip_capability=False):
+        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,
+                    }
                 }
-            }
         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': PCI_VEND_ID,
             'vend_name': PCI_VEND_NAME,
             'prod_id': prod_id,
             'prod_name': prod_name,
             'driver': driver,
             'capability': capability,
-            'iommu_group': iommu_group,
-            'numa_node': numa_node,
+            'iommu_group': self.iommu_group,
+            'numa_node': self.numa_node,
         }
 
     def XMLDesc(self, flags):
@@ -847,6 +858,20 @@ class Domain(object):
                         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]
 
@@ -888,11 +913,32 @@ class Domain(object):
 
         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
@@ -1016,7 +1062,7 @@ class Domain(object):
 
         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
new file mode 100644
index 0000000000..ba35c25b02
--- /dev/null
+++ 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