gpu passthrough vdsm hook

oVirt VDSM Hook for passing through GPU

Installation:

• Use engine-config to create a custom property:

sudo engine-config -s "UserDefinedVMProperties=gpupassthrough=^(true|false)$"

• To confirm that the property was added:

sudo engine-config -g UserDefinedVMProperties

• Restart the engine:

sudo systemctl restart ovirt-engine

• Place 99_gpu_passthrough in /usr/libexec/vdsm/hooks/before_vm_start:

sudo cp 99_gpu_passthrough /usr/libexec/vdsm/hooks/before_vm_start
sudo chmod +x /usr/libexec/vdsm/hooks/before_vm_start/99_gpu_passthrough

Usage: Edit the VM, add the following custom property to hide kvm from the VM and add a vendor id:

gpupassthrough=true

Details: This adds the following entries to the guest XML:

  <features>
    ...
    <hyperv>
      ...
      <vendor_id state='on' value='whatever'/>
    </hyperv>
    ...
    <kvm>
      <hidden state='on'/>
    </kvm>
  </features>

Troubleshooting

• failed to execute

If you see the following error in your event log:

VM xxx is down with error. Exit message: Hook Error: (b'taskset: failed to execute /usr/libexec/vdsm/hooks/before_vm_start/99_gpu_passthrough: No such file or directory\n',).

Although it's not clear from the message, it's most likely the python interpreter that's not been found, not the 99_gpu_passthrough script.

To fix the problem, replace the shebang line in 99_gpu_passthrough

#!/usr/bin/python2

with the equivalent from 50_hostedengine, for example:

#!/usr/libexec/platform-python

Adapted from this thread: https://www.mail-archive.com/users@ovirt.org/msg40377.html

Thanks, Martin!