Comment 4 for bug 1566951

What needs to be documented here is that a SR-IOV port should only be attached to the VM and not put in a DVR router as this will duplicate the ports ... from my understanding of the issue.

Here is a simple representation of what should be configured:

VM -> SR-IOV VF -> SR-IOV PF -> Switch

and here is what you have configured when adding the SR-IOV port to the router:
VM \ -> SR-IOV VF -> SR-IOV PF -> Switch # port attached to the VM
    \ -> SR-IOV VF -> OVS -> SR-IOV-PF -> Switch # port also attached to the OVS router

... and that's what is duplicating the packets. I guess here we could :

1) Prevent attaching the SR-IOV port to a DVR router ...

I can't think of another possibility but it doesn't mean there're none.