Open vSwitch

The Open vSwitch plugin, vif_plug_ovs, is an os-vif VIF plugin for the Open vSwitch network backend. It is one of three plugins provided as part of os-vif itself, the others being Linux Bridge and no-op.

Supported VIF Types

The Open vSwitch plugin provides support for the following VIF types:


Configuration where a guest is directly connected an Open vSwitch bridge.


Configuration where a guest is connected to a Linux bridge via a TAP device, and that bridge is connected to the Open vSwitch bridge. This allows for the use of iptables rules for filtering traffic.


Configuration where a guest exposes a UNIX socket for its control plane. This configuration is used with the DPDK datapath of Open vSwitch.


Configuration where an SR-IOV PCI device VF is passed through to a guest. The hw-tc-offload feature should be enabled on the SR-IOV PF using ethtool:

ethtool -K <PF> hw-tc-offload

This will create a VF representor per VF. The VF representor plays the same role as TAP devices in Para-Virtual (PV) setup. In this case the plug() method connects the VF representor to the OpenVSwitch bridge.


Support for this feature requires Linux Kernel >= 4.8 and Open vSwitch 2.8. These add support for tc-based hardware offloads for SR-IOV VFs and offloading of OVS datapath rules using tc, respectively.

New in version 1.5.0.

For information on the VIF type objects, refer to VIF Types. Note that only the above VIF types are supported by this plugin.