While the recently released X.Org Server 1.20 has initial EGLStreams for XWayland support to allow X11 on Wayland client application support for use with the NVIDIA proprietary driver, the support isn't automatically available when needed. Fortunately, that's being corrected for a future point release.

As it stands with xorg-server 1.20.0, the EGLStreams support is only activated if passed a -eglstream argument to the X.Org Server for XWayland to know to use the EGL back-end rather than the default GBM-based approach used by the open-source GPU drivers.

There have been proposed patches to improve the EGLStreams handling behavior while a patch posted on Wednesday would make this behavior automatic so Wayland compositors don't need to worry about passing the special argument when needed or anything else.

The patch by Red Hat's Olivier Fourdan would automatically enable the EGL back-end when needed by simply checking for the EGL_MESA_platform_gbm extension. If that EGL Mesa GBM extension is present, it goes the GBM route, otherwise would try EGLStreams for the NVIDIA driver support.

Hopefully this will make it into X.Org Server 1.20.1 and that point release won't be too far out for allowing a more pleasant NVIDIA (X)Wayland experience. Sadly there is nothing new on the proposed new Unix device memory allocation API front for trying to come up with a solution to succeed both EGLStreams and GBM for a path that fits the needs of both NVIDIA and the open-source community, but even if/when that materializes, it will still be a while before widespread adoption.