Is there really any true need for port-security on Nexus 1000v for vethernet ports? Can a VM be assigned a previously used vethernet port that would trigger a port-security action?
If you want to prevent admins or malicious users from being able change the mac address of a VM then port-security is a useful feature. Especially in VDI environments where users might have full admin control of the VM and can change the mac of the vnic.
Now about veths ports. A veth gets assigned to a VM and stays with that VM. A veth is only released when either the nic on the VM is deleted or the nic is assigned to another port-profile on the N1KV or a port-group on a vSwitch or VMware DVS. Now when the veth is released it does not retain any of the piror information. It's freed up and added to a pool of available veths. When a veth is needed for a VM in either the same port-profile or a different port-profile the free veth will be grabbed and initialized. It does not retain any of the previous settings.
So assigning a VM to a previsously used veth port should not trigger a violation. The MAC should get learned and traffic should be able to flow.