scheduler: Add 'socket' PCI NUMA affinity policy trait

Since only Wallaby compute nodes will support the 'socket' PCI NUMA
affinity policy, this patch adds a ResourceRequest translator that adds
a required trait if the value of '(hw_|hw:)pci_numa_affinity_policy' is
'socket'.

The actual trait reporting by the libvirt driver will be added in a
future patch. Until then the 'socket' value remains a hidden no-op.

Implements: blueprint pci-socket-affinity
Change-Id: I908ff07e1107304ca5926cc04d2fdc8fe0da5ed9

lower-constraints.txt

@@ -62,7 +62,7 @@ os-brick==3.1.0
 os-client-config==1.29.0
 os-resource-classes==0.4.0
 os-service-types==1.7.0
-os-traits==2.4.0
+os-traits==2.5.0
 os-vif==1.14.0
 os-win==4.2.0
 os-xenapi==0.3.4

nova/scheduler/utils.py

@@ -188,6 +188,8 @@ class ResourceRequest(object):
 
         res_req._translate_vtpm_request(request_spec.flavor, image)
 
+        res_req._translate_pci_numa_affinity_policy(request_spec.flavor, image)
+
         res_req.strip_zeros()
 
         return res_req
@@ -351,6 +353,16 @@ class ResourceRequest(object):
                        'value': trait})
             self._add_trait(os_traits.HW_CPU_HYPERTHREADING, trait)
 
+    def _translate_pci_numa_affinity_policy(self, flavor, image):
+        policy = hardware.get_pci_numa_policy_constraint(flavor, image)
+        # only the socket policy supports a trait
+        if policy == objects.fields.PCINUMAAffinityPolicy.SOCKET:
+            trait = os_traits.COMPUTE_SOCKET_PCI_NUMA_AFFINITY
+            self._add_trait(trait, 'required')
+            LOG.debug(
+                "Requiring 'socket' PCI NUMA affinity support via trait %s.",
+                trait)
+
     @property
     def group_policy(self):
         return self._group_policy

nova/tests/unit/scheduler/test_utils.py

@@ -1224,6 +1224,25 @@ class TestUtils(TestUtilsBase):
         rr = utils.ResourceRequest.from_request_spec(rs)
         self.assertResourceRequestsEqual(expected, rr)
 
+    def test_resource_request_from_request_spec_with_pci_numa_policy(self):
+        flavor = objects.Flavor(
+            vcpus=1, memory_mb=1024, root_gb=10, ephemeral_gb=5, swap=0,
+            extra_specs={'hw:pci_numa_affinity_policy': 'socket'},
+        )
+        expected = FakeResourceRequest()
+        expected._rg_by_id[None] = objects.RequestGroup(
+            use_same_provider=False,
+            required_traits={'COMPUTE_SOCKET_PCI_NUMA_AFFINITY'},
+            resources={
+                'VCPU': 1,
+                'MEMORY_MB': 1024,
+                'DISK_GB': 15,
+            },
+        )
+        rs = objects.RequestSpec(flavor=flavor, is_bfv=False)
+        rr = utils.ResourceRequest.from_request_spec(rs)
+        self.assertResourceRequestsEqual(expected, rr)
+
     def test_resource_request_from_request_spec_with_vtpm_1_2(self):
         flavor = objects.Flavor(
             vcpus=1, memory_mb=1024, root_gb=10, ephemeral_gb=5, swap=0,

requirements.txt

@@ -53,7 +53,7 @@ psutil>=3.2.2 # BSD
 oslo.versionedobjects>=1.35.0 # Apache-2.0
 os-brick>=3.1.0 # Apache-2.0
 os-resource-classes>=0.4.0 # Apache-2.0
-os-traits>=2.4.0 # Apache-2.0
+os-traits>=2.5.0 # Apache-2.0
 os-vif>=1.14.0 # Apache-2.0
 os-win>=4.2.0 # Apache-2.0
 castellan>=0.16.0 # Apache-2.0