It turns out however that the developers of virglrenderer also don’t want to have to run a VM to run and test their project and thus added vtest, which uses a unix socket to transport the commands from the mesa Venus driver to virglrenderer.
It also turns out that I’m not the first one who noticed this, and there is some glue code which allows Podman to make use of virgl.
Nice if podman and flatpak both gain from this work in future.