Another exciting moment for fans of Wayland and the future of Linux, especially if you're an NVIDIA user, as the work to provide hardware accelerated rendering for NVIDIA GPUs was merged in for Xwayland. We've been following this work for a while, as an upcoming NVIDIA driver will have the code in for everything to be in place (likely NVIDIA 470).
To save you clicking around, this is what NVIDIA engineer Erik Kurzinger said about the patches:
These two patches are intended to accompany upcoming support in the proprietary NVIDIA driver for hardware accelerated GL and Vulkan rendering with Xwayland. They shouldn't interfere with the current swrast-based GL support, so once the driver-side changes are out the door things should just start working. I wanted to send these out for consideration first, though, in case anyone has any substantial concerns with the general approach. See the commit messages for further details on the implementation.
Performance should be roughly on-par with native X11 based on the benchmarking I've done. There's still an annoying extra copy required for presentation of windowed applications, but the impact doesn't appear to be significant, and full-screen applications won't have that issue (provided the compositor supports the required zwp_linux_dmabuf_v1 interface).
Since more distributions are moving over to Wayland from the old Xorg, this is a huge and important step. Even Ubuntu is targetting Wayland as the default for the upcoming Ubuntu 21.04 release. Still, it will be some time before all the major distributions have releases out with this new Xwayland support in for NVIDIA. It's possible we will see this land in the likes of Ubuntu 21.10, so more likely towards the end of this year.
You can see the Merge Request here.
Other interesting upcoming work includes another Merge Request that's not yet merged, which would enable the loading of alternative GBM backends.