How to apply qemu:env command line to virt-manager? (libvirt)

Question

I need to apply this fix

<qemu:env name="MESA_LOADER_DRIVER_OVERRIDE" value="i965"/>

to my virt-manager VM.

However, I don't know where to put it.

I tried editing the XML like this:

<domain type="kvm">
  <name>unsafe_code_2</name>
  <qemu:commandline>
      <qemu:env name="MESA_LOADER_DRIVER_OVERRIDE" value="i965"/>
  </qemu:commandline>

but when I click apply, virt-manager simply erases

  <qemu:commandline>
      <qemu:env name="MESA_LOADER_DRIVER_OVERRIDE" value="i965"/>
  </qemu:commandline>

so how do I do it?

Answer 1

It won't get removed if you declare the QEMU XML schema on the <domain> element:

<domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0" type="kvm">
   ...
</domain>

or just declare it on the element you need it for:

<qemu:commandline xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0">
    <qemu:env name="MESA_LOADER_DRIVER_OVERRIDE" value="i965"/>
</qemu:commandline>

(but note that virt-manager will reformat your XML to use the first option)

(Reference: https://www.libvirt.org/kbase/qemu-passthrough-security.html)

Another option would be using the following command:

virt-xml VM_NAME_HERE --edit --qemu-commandline env=MESA_LOADER_DRIVER_OVERRIDE=i965