[Xe/rendervulkan] - No visible image in the DRM backend

[matte-schwartz]

Is there an existing issue for this?

• I have searched the existing issues

Are you using any gamescope patches or a forked version of gamescope?

• The issue occurs on upstream gamescope without any modifications

Current Behavior

On Intel's Xe kernel driver, gamescope does not present a visible image while using the DRM backend. Downstream ChimeraOS has worked around this by removing

gamescope/src/steamcompmgr.cpp

Lines 2456 to 2482 in bafa157

	else if ( !GetBackend()->UsesVulkanSwapchain() && GetBackend()->IsSessionBased() )
	{
	auto tex = vulkan_get_hacky_blank_texture();
	if ( tex != nullptr )
	{
	// HACK! HACK HACK HACK
	// To avoid stutter when toggling the overlay on
	int curLayer = frameInfo.layerCount++;
	FrameInfo_t::Layer_t *layer = &frameInfo.layers[ curLayer ];
	layer->scale.x = g_nOutputWidth == tex->width() ? 1.0f : tex->width() / (float)g_nOutputWidth;
	layer->scale.y = g_nOutputHeight == tex->height() ? 1.0f : tex->height() / (float)g_nOutputHeight;
	layer->offset.x = 0.0f;
	layer->offset.y = 0.0f;
	layer->opacity = 1.0f; // BLAH
	layer->zpos = g_zposOverlay;
	layer->applyColorMgmt = g_ColorMgmt.pending.enabled;
	layer->colorspace = GAMESCOPE_APP_TEXTURE_COLORSPACE_LINEAR;
	layer->ctm = nullptr;
	layer->tex = tex;
	layer->filter = GamescopeUpscaleFilter::NEAREST;
	layer->blackBorder = true;
	}

and I think Bazzite puts it behind a convar.

Steps To Reproduce

1. Enter gamescope -- vkcube or gamescope-session on an Intel GPU running drm/xe

Hardware information

- Distro: CachyOS (Arch Linux)
- APU: Intel Core Ultra 7 258V
- Driver Version: Mesa 24.3.4, mesa-git

Software information

- Desktop environment: N/A
- Session type: DRM backend
- Gamescope version: git from https://github.com/ValveSoftware/gamescope/commit/bafa15766a3488c3c59ef2b558891ae1e26d6efa
- Gamescope launch command(s): gamescope --prefer-output '*,eDP-1' --xwayland-count 2 --default-touch-mode 4 --hide-cursor-delay 3000 --fade-out-duration 200 --steam -R /run/user/1000/gamescope.IwZwiln/startup.socket -T /run/user/1000/gamescope.IwZwiln/stats.pipe

Which gamescope backends have the issue you are reporting?

• Wayland (default for nested gamescope)
• DRM (default for embedded gamescope, i.e. gamescope-session)
• SDL
• OpenVR

Logging, screenshots, or anything else

This is upstream gamescope's logging where an image is never visible: https://gist.github.com/matte-schwartz/d73baaa86ee1b66ca952eb73976c9c7e

Patched gamescope's logging where it does eventually show a visible image: https://gist.github.com/matte-schwartz/329b50fa9a47c7b36684aebe10972193

[matte-schwartz]

also: drm_info.log for reference

[matte-schwartz]

after looking into this further I get the impression this is a drm/xe bug specifically so I've reported it upstream accordingly: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4292

will keep this open for now for tracking purposes on our side

[matte-schwartz]

see for the fix we're working on for this here: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12633, closing as not a gamescope issue

[matte-schwartz]

the first possible fix for this issue was a patch to mesa that marked any images with format modifiers set as scanout: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4292#note_2784316. this is specifically the patch I've been using in mesa on my lunar lake device for gamescope-session.

after discussions with Mesa and kernel developers, it seems like the consensus is that gamescope is not creating VkImages with swapchains per https://gitlab.freedesktop.org/mesa/mesa/-/issues/12633#note_2804858 which is causing issues with ANV

another possible fix for this that was proposed today is master...jxzgithub:gamescope:add-mesa-wsi-mem-alloc-info which patches gamescope rather than mesa. i can confirm that this patch in gamescope also lets you use both direct scanout and composition within gamescope-session on Xe. however, concerns were brought up that it was too fragile.