If the vnic_type of a bound port changes from "direct" to "macvtap" and
then the compute service is restarted then during _init_instance nova
tries to plug the vif of the changed port. However as it now has macvtap
vnic_type nova tries to look up the netdev of the parent VF. Still that
VF is consumed by the instance so there is no such netdev on the host
OS. This error killed the compute service at startup due to unhandled
exception. This patch adds the exception handler, logs an ERROR and
continue initializing other instances on the host.
Also this patch adds a detailed ERROR log when nova detects that the
vnic_type changed during _heal_instance_info_cache periodic.
Closes-Bug: #1981813
Change-Id: I1719f8eda04e8d15a3b01f0612977164c4e55e85
e43bf900dc