kms-modifiers for Xwayland acceleration is not enabled by default on Gnome+Nvidia images yet

[msmafra]

Describe the bug

Hello there!
IA bit more than a year back, I opened this issue: #1567 pointing out that kms-modifiers must be enabled, as it is a requirement stated in Chapter 40 or 38, depending on the version of the NVIDIA driver documentation, since 470.42.01 and still in 580.76.05 and related to 3D accelerated rendering for OpenGL, Vulkan and VDPAU on Xwayland.

What did you expect to happen?

Expected kms-modifiers to be enabled by default for Gnome images on NVIDIA drivers.

Output of bootc status

❯ sudo bootc status
● Booted image: ghcr.io/ublue-os/bluefin-nvidia-open:stable
        Digest: sha256:1f3211e557412ed5421a8abf3c7ef75d60849e7e9c3c11bc315c476ea40dd967 (amd64)
       Version: 42.20250831.1 (2025-08-31T06:29:43Z)

  Rollback image: ghcr.io/ublue-os/bluefin-nvidia-open:stable
          Digest: sha256:ca4e7f77d7eb9e4312818013261f190361b4be380e5a5437cfd2fdcd25661ffb (amd64)
         Version: 42.20250824.1 (2025-08-24T06:25:28Z)

Output of groups

❯ groups
zum wheel

Extra information or context

I imagine, guessing here, that maybe some problems that are usually reported when using Gnome mostly related to games, have to do with this. Obviously I do not have the knowledge on how to benchmark this nor have another computer to do tests on it.

I also wonder why this is still an experimental feature on Gnome, since the driver 470.42.01 is from 2021-06-22 and probably this feature is older than that.

[msmafra]

A more friendly graphical way will be in Refine, @TheEvilSkeleton kindly added it to Refine will hopefully be available in the next release. shell-compositor: Add kms-modifiers flag (9f77b01c) · Commits · Hari Rana / Refine · GitLab

[msmafra]

A more friendly graphical way will be in Refine, @TheEvilSkeleton kindly added it to Refine will hopefully be available in the next release. shell-compositor: Add kms-modifiers flag (9f77b01c) · Commits · Hari Rana / Refine · GitLab

Not anymore, at leas for now because maybe the kms-modifiers feature is already being handled by Mutter
But I don't know how to check if it still a requirement for Xwayland acceleration, as stated in the NVIDIA drivers documentation since drivers 470.42.01 or if it's now automatically handled by Mutter as it seems here 61-mutter.rules pointed out by @TheEvilSkeleton (from the Refine software).
The option is still available to be manually enabled via Gsettings or Dconf, so it becomes confusing if it's not needed anymore and it's forgotten there in the experimental features or if a manual activation is needed.

[repires]

@msmafra Hi, can you confirm what's the current state of this issue? Thank you for your feedback!

[msmafra]

@msmafra Hi, can you confirm what's the current state of this issue? Thank you for your feedback!

It's enable in the Bazzite side, but I got no answers about it already being handled by Mutter automatically. I asked in the Nvidia forums and in the Gnome GitLab instance.

I imagine if the devs asked directly they would get a final answer.

I always enabled it when I was on Fedora, after I saw that on the NVIDIA documentation and Sill using now on CachyOS.
But the doubt remains if it's a forgotten toggle in the experimental features or not.

[tulilirockz]

It should be also enabled on Bluefin now at least

[msmafra]

I posted in this places, but no answers:

• https://discourse.gnome.org/t/is-kms-modifiers-necessary-to-be-enable-for-xwayland-acceleration-as-stated-by-nvidia-documentation/32625 - this one was automatically closed;
• https://discourse.gnome.org/t/kms-modifiers-is-it-necessary-to-manually-enable-it-for-xwayland-acceleration-as-stated-by-nvidia-documentation/33842;
• https://forums.developer.nvidia.com/t/about-gnomes-kms-modifiers-feature-is-it-necessary-nowadays-or-it-should-not-be-touched/352083;

Not sure if I should ask in other places.