Reproduce PCI pool filtering bug

PCI pool filtering only follow the allocation candidate to select which
PCI pool can be used but does not consider how much devices should be
consumed from which pool.

blueprint: pci-device-tracking-in-placement
Change-Id: I97851180b7af275ea7e4c175be6056130906af87

1 files changed, 85 insertions, 0 deletions

diff --git a/nova/tests/functional/libvirt/test_pci_in_placement.py b/nova/tests/functional/libvirt/test_pci_in_placement.py
index 10a35548c7..ebeaeb0bd3 100644
--- a/nova/tests/functional/libvirt/test_pci_in_placement.py
+++ b/nova/tests/functional/libvirt/test_pci_in_placement.py
@@ -1917,3 +1917,88 @@ class RCAndTraitBasedPCIAliasTests(PlacementPCIReportingTests):
         self.assert_placement_pci_view(
             "compute1", **compute1_expected_placement_view)
         self.assert_no_pci_healing("compute1")
+
+    def test_3vfs_asymmetric_split_between_pfs(self):
+        # The fake libvirt will emulate on the host:
+        # * two type-PFs in slot 0, 1 with 2 VFs each
+        pci_info = fakelibvirt.HostPCIDevicesInfo(
+            num_pci=0, num_pfs=2, num_vfs=4)
+        # make all 4 VFs available
+        device_spec = self._to_list_of_json_str(
+            [
+                {
+                    "product_id": fakelibvirt.VF_PROD_ID,
+                    "resource_class": "MY_VF",
+                    "traits": "blue",
+                },
+            ]
+        )
+        self.flags(group='pci', device_spec=device_spec)
+        self.start_compute(hostname="compute1", pci_info=pci_info)
+
+        compute1_expected_placement_view = {
+            "inventories": {
+                "0000:81:00.0": {"CUSTOM_MY_VF": 2},
+                "0000:81:01.0": {"CUSTOM_MY_VF": 2},
+            },
+            "traits": {
+                "0000:81:00.0": [
+                    "CUSTOM_BLUE",
+                ],
+                "0000:81:01.0": [
+                    "CUSTOM_BLUE",
+                ],
+            },
+            "usages": {
+                "0000:81:00.0": {"CUSTOM_MY_VF": 0},
+                "0000:81:01.0": {"CUSTOM_MY_VF": 0},
+            },
+            "allocations": {},
+        }
+        self.assert_placement_pci_view(
+            "compute1", **compute1_expected_placement_view)
+        self.assertPCIDeviceCounts('compute1', total=4, free=4)
+
+        pci_alias_vf = {
+            "resource_class": "MY_VF",
+            "traits": "blue",
+            "name": "a-vf",
+        }
+        self.flags(
+            group="pci",
+            alias=self._to_list_of_json_str([pci_alias_vf]),
+        )
+
+        # Boot an instance requesting three VFs. The 3 VFs can be split between
+        # the two PFs two ways: 2 from 81.00 and 1 from 81.01, or 1 from 81.00
+        # and 2 from 81.01.
+        # Let's block the first way in placement by reserving 1 device from
+        # 81.00
+        self._reserve_placement_resource(
+            "compute1_0000:81:00.0", "CUSTOM_MY_VF", 1)
+        extra_spec = {"pci_passthrough:alias": "a-vf:3"}
+        flavor_id = self._create_flavor(extra_spec=extra_spec)
+        # We expect this to fit, but it does not. The pool filtering logic
+        # only considers which pools can be used based on the allocation
+        # candidate, but does not consider how much device needs to be used
+        # from which pool. So the PCI claim logic sees both PF pools as usable
+        # but allocates 2 dev from 81:00 in nova. Then the PCI allocation
+        # healing logic sees the difference between the placement allocation
+        # and the nova allocation and fails when trys to correct it.
+        self._create_server(
+            flavor_id=flavor_id, networks=[], expected_state="ERROR"
+        )
+        # server_3vf = self._create_server(flavor_id=flavor_id, networks=[])
+        #
+        # self.assertPCIDeviceCounts('compute1', total=4, free=1)
+        # compute1_expected_placement_view["usages"] = {
+        #     "0000:81:00.0": {"CUSTOM_MY_VF": 1},
+        #     "0000:81:01.0": {"CUSTOM_MY_VF": 2},
+        # }
+        # compute1_expected_placement_view["allocations"][server_3vf["id"]] = {
+        #     "0000:81:00.0": {"CUSTOM_MY_VF": 1},
+        #     "0000:81:01.0": {"CUSTOM_MY_VF": 2},
+        # }
+        # self.assert_placement_pci_view(
+        #     "compute1", **compute1_expected_placement_view)
+        # self.assert_no_pci_healing("compute1")