Add basic smoke test for glmark2 running in a nested qemu guest with
virtio-gpu-gl-pci.
The outer machine uses the Mesa softpipe driver for GLES support with
minimal dependencies. Just test virgl for now, as lavapipe
(software Vulkan driver) requires LLVM, and this validates
virglrenderer.
Signed-off-by: Joseph Kogut <joseph.kogut@gmail.com>
[Romain: add gitlab-runner "2xlarge" tag]
Signed-off-by: Romain Naour <romain.naour@smile.fr>