VM fails to start with external provider network

[Yuliya-H]

Affected version

• oVirt Engine: 4.5.5-0.master.20230317225744.el8
• Host OS Variant: RHEL - 8.6 - 1.el8
• VDSM version: 4.50.3.4-1.el8

Describe the bug
External provider network is successfully added to oVirt. Test connection is passing.
Appropriate network with subnet was created in Neutron and was imported into oVirt.
When starting the VM with that network attached, the next errors can be seen:

2023-07-13 05:16:30,954-04 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedThreadFactory-engine-Thread-78395) [25fb8aeb-9cfa-49e7-b824-024e9f669325] EVENT_ID: USER_FAILED_RUN_VM(54), Failed to run VM test-neutron-net  (User: admin@ovirt@internalkeycloak-authz).
2023-07-13 05:16:30,957-04 INFO  [org.ovirt.engine.core.bll.RunVmCommand] (EE-ManagedThreadFactory-engine-Thread-78395) [25fb8aeb-9cfa-49e7-b824-024e9f669325] Lock freed to object 'EngineLock:{exclusiveLocks='[124afed3-dda0-48a7-9d15-5fdf00eff2d3=VM]', sharedLocks=''}'
2023-07-13 05:16:30,957-04 ERROR [org.ovirt.engine.core.bll.RunVmCommand] (EE-ManagedThreadFactory-engine-Thread-78395) [25fb8aeb-9cfa-49e7-b824-024e9f669325] Command 'org.ovirt.engine.core.bll.RunVmCommand' failed: EngineException: (Failed with error Cannot deserialize value of type java.lang.String from Object value (token `JsonToken.START_OBJECT`)
 at [Source: (org.jboss.resteasy.client.core.BaseClientResponse$InputStreamWrapper); line: 1, column: 982] (through reference chain: com.woorea.openstack.quantum.model.Ports["ports"]->java.util.ArrayList[0]->com.woorea.openstack.quantum.model.Port$Binding["binding:vif_details"]->java.util.LinkedHashMap["bound_drivers"]) and code 5050)

Tcp dump from neutron host , shows that it sends the requested data:

{
      "id": "c448772a-88fd-475b-ad03-31ac6992100e",
      "name": "octavia-listen-port-ctrl-1",
      "network_id": "7537bbb7-3bec-4e24-adb1-8f0ba7da1d05",
      "tenant_id": "4f8de5df864546a3aa5bd41b597084b4",
      "mac_address": "fa:16:3e:b5:12:ba",
      "admin_state_up": true,
      "status": "ACTIVE",
      "device_id": "",
      "device_owner": "Octavia:health-mgr",
      "fixed_ips": [
        {
          "subnet_id": "0b616072-e15b-4e92-8c46-23305b82d881",
          "ip_address": "[10.1.0.141](https://10.1.0.141/)"
        }
      ],
      "allowed_address_pairs": [],
      "extra_dhcp_opts": [],
      "security_groups": [
        "9c9a653d-751e-43ed-8c1e-8f377e4ff087"
      ],
      "description": "",
      "binding:vnic_type": "normal",
      "binding:profile": {},
      "binding:host_id": "ctrl-1",
      "binding:vif_type": "ovs",
      "binding:vif_details": {
        "connectivity": "l2",
        "port_filter": true,
        "ovs_hybrid_plug": true,
        "datapath_type": "system",
        "bridge_name": "br-int",
        "bound_drivers": {
          "0": "openvswitch"
        }
      },
      "port_security_enabled": true,
      "tags": [],
      "created_at": "2023-07-10T13:04:53Z",
      "updated_at": "2023-07-10T13:05:01Z",
      "revision_number": 4,
      "project_id": "4f8de5df864546a3aa5bd41b597084b4"
    }

Expected behavior
VM should start.

Any idea what can be the reason of this fail and how to fix this?

[Yuliya-H]

After some more researches got clear that the issue is caused by newly added parameter here:
openstack/neutron-lib@c26573f

oVirt doesn't expect nested dict parameter: ( but expects string parameters such as other values of 'binding:vif_details' object:)

Here what it receives:

"binding:vif_details": {
        "connectivity": "l2",
        "port_filter": true,
        "ovs_hybrid_plug": true,
        "datapath_type": "system",
        "bridge_name": "br-int",
        "bound_drivers": {
          "0": "openvswitch"
        }

And here is the code in oVirt quantum models (openstack-java-sdk-quantum-model):

@JsonProperty("binding:vif_details")
        private Map<String, String> vifDetails;

This should be fixed on oVirt side.

Thanks!