With PoC FDP-1286 we evaluate userspace datapaths with OVS-DPDK for OpenShift's default CNI plugin OVN-Kubernetes, OpenShift's default CNI plugin. In the previous PoC FDP-1285 we moved container networking to userspace by replacing veth devices with VDUSE devices. Now, we also want to move networking of KubeVirt virtual machines to userspace with help of the vhost-vdpa protocol.

We explored available options for attaching KubeVirt virtual machines to networks and agreed on an architecture for VDUSE/vhost-vDPA support in our KubeVirt PoC FDP-1286 (FDP-1309, summary from 2025-07-01):

• We developed a new Kubernetes device plugin that creates VDUSE/vhost-vDPA ports in OVS and their associated vhost-vDPA character devices (FDP-1513).
• We developed a new CNI with the minimum required functionality to expose the vhost-vDPA character device, provided by the new device plugin (FDP-1513), to a pod. It will serve as a reference implementation for customers such as Orange (FDP-1516).
• We implemented support for attaching VMs to userspace networks using the vhost-vdpa protocol in KubeVirt (FDP-1515).

This ultimately moves the entire OpenShift networking stack to userspace.

All the components mentioned above must now be integrated in our build, deployment and testing tools for OCP with modified network components – namely, build.sh, cluster.sh and beaker.sh in jmeng/ovs-ci-with-ocp.

This task covers integration with the VDUSE/vhost-vDPA CNI, while FDP-1617 addresses the integration with the OVN-Kubernetes CNI.