FUP Remove unnecessary PCI check

This patch removes the _test_pci() method, which is no longer necessary
since flavor-based requests can now be live migrated.

The related tests have also been removed.

This fixes a bug where a user requests a live migration with a
flavor-based request and NUMA constraints (e.g., CPU affinity). In
this case, the code encounters the _test_pci() method and fails because
the check was originally designed to enforce port-based requests only,
causing an unnecessary failure.

Notes: This issue was discovered through functional tests that involve
a mix of port-based and flavor-based requests. The failure in this
scenario highlighted the unnecessary constraint.
A functional test reproducing this issue in a mixed-mode scenario
(port request + flavor-based request) will be provided in a subsequent
FUP patch.

The _test_pci() check was redundant, as a similar verification
is already performed earlier in the migration process.

Closes-Bug: 2103636
Implements: blueprint migrate-vfio-devices-using-kernel-variant-drivers
Change-Id: Icbeaadd94658ed44917d724446d484f6497f29e5

nova/compute/claims.py

@@ -206,32 +206,6 @@ class MoveClaim(Claim):
             flavor=self.flavor)
         self.instance.drop_migration_context()
 
-    def _test_pci(self):
-        """Test whether this host can accept this claim's PCI requests. For
-        live migration, only Neutron SRIOV PCI requests are supported. Any
-        other type of PCI device would need to be removed and re-added for live
-        migration to work, and there is currently no support for that. For cold
-        migration, all types of PCI requests are supported, so we just call up
-        to normal Claim's _test_pci().
-        """
-        if not self.migration.is_live_migration:
-            return super(MoveClaim, self)._test_pci()
-
-        if self._pci_requests.requests:
-            for pci_request in self._pci_requests.requests:
-                if (pci_request.source !=
-                        objects.InstancePCIRequest.NEUTRON_PORT):
-                    return (_('Non-VIF related PCI requests are not '
-                              'supported for live migration.'))
-            # TODO(artom) At this point, once we've made sure we only have
-            # NEUTRON_PORT (aka SRIOV) PCI requests, we should check whether
-            # the host can support them, like Claim._test_pci() does. However,
-            # SRIOV live migration is currently being handled separately - see
-            # for example _claim_pci_for_instance_vifs() in the compute
-            # manager. So we do nothing here to avoid stepping on that code's
-            # toes, but ideally MoveClaim would be used for all live migration
-            # resource claims.
-
     def _test_live_migration_page_size(self):
         """Tests that the current page size and the requested page size are the
         same.

nova/tests/unit/compute/test_claims.py

@@ -372,19 +372,6 @@ class MoveClaimTestCase(ClaimTestCase):
 
 class LiveMigrationClaimTestCase(ClaimTestCase):
 
-    def test_live_migration_claim_bad_pci_request(self):
-        flavor = self._fake_flavor()
-        instance = self._fake_instance()
-        instance.numa_topology = None
-        self.assertRaisesRegex(
-            exception.ComputeResourcesUnavailable,
-            'PCI requests are not supported',
-            claims.MoveClaim, self.context, instance, _NODENAME, flavor,
-            {}, self.tracker, self.compute_node,
-            objects.InstancePCIRequests(requests=[
-                objects.InstancePCIRequest(alias_name='fake-alias')]),
-            objects.Migration(migration_type='live-migration'), None)
-
     def test_live_migration_page_size(self):
         flavor = self._fake_flavor()
         instance = self._fake_instance()