Communication inter-VM traffic when using SR-IOV with Neutron

Issue

• If the VMs are launched with ovs vport, the traffic of the communication between the two VMs will be processed inside the host and no need connect host to a switch

• If the VMs are launched with SR-IOV vport, the traffic of the communication between the two VMs will go through outside the host and connect host needs to be connected to a switch otherwise the communication will be broken.