libvirt + openvswitch + ubuntu 24.04

Abstract

This document will show how to configure libvirt with openvswitch so that VMs could use openvswitch directly. This is useful if the openvswitch has a trunk connection with your switch that carries multiple VLANs.

Requirements

You need the following

• Ubuntu 24.04
• cockpit - can access VM through web
• openssh-server
• qemu-kvm
• libvirt-daemon-system
• cockpit-machines

Setup

Must have dedicated physical port which is linked to your switch. We will be using `eno1` here.

Create openvswitch bridge

$ ovs-vsctl add-br br0

# add physical interface

$ ovs-vsctl add-port br0 eno1

# showing

$ ovs-vsctl show

    Bridge br0
        Port br0
            Interface br0
                type: internal
        Port eno1
            Interface eno1
    ovs_version: "3.3.0"

Create a br0 for virsh net

$ cat libvirt-br0-simple.xml

<network>

  <name>br0</name>

  <forward mode='bridge'/>

  <bridge name='br0'/>

  <virtualport type='openvswitch'/>

</network>

Adding portgroup with vlans live

virsh net-update ovs-network add --section portgroup --xml "<portgroup name='trunk'><vlan trunk='yes'><tag id='2'/><tag id='3'/></vlan></portgroup>" --config --live

Bring the link up 

ip link set br0 up

ip link set eno1 up

When creating a network through the cockpit, before running make sure to edit the xml using virst edit, and modify <source

    <interface type='network'>

      <mac address='52:54:00:ca:f6:27'/>

      <source network='br0' portgroup='main'/>

References

• https://www.redhat.com/en/blog/libvirt-open-vswitch
• https://documentation.ubuntu.com/server/how-to/virtualisation/libvirt/
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