ovs-vswitchd process on worker nodes service HCP components have very high CPU usage.

4.12.

This has only been seen on HyperShift worker nodes.

Root cause is believed to be Egress policies which define exceptions via CIDR ranges or port ranges, ie:
spec:
  podSelector:
    matchLabels:
      role: db
  policyTypes:
    - Ingress
    - Egress
  ingress:
    - from:
        - ipBlock:
            cidr: 172.17.0.0/16
            except:
              - 172.17.1.0/24
OR 

spec:
  podSelector:
    matchLabels:
      role: db
  policyTypes:
    - Egress
  egress:
    - to:
        - ipBlock:
            cidr: 10.0.0.0/24
      ports:
        - protocol: TCP
          port: 32000
          endPort: 32768

1.
2.
3.

This was seen during an incident mentioned in the releated OHSS ticket