Re: [RADV] segfault in libvulkan_radeon.so in Metro Exodus (native) on RX 6800 XT

On 2026. j=C3=BAlius 1., szerda 19:20:49 k=C3=B6z=C3=A9p-eur=C3=B3pai ny=C3=
=A1ri id=C5=91 WhoAm I wrote:
> Hello Mesa developers.
> =20
> I am reporting a bug in RADV that I have been investigating for over 200
> hours. I have tested numerous configurations and believe I have isolated
> the issue.=20

Hi,

You are mixing up 3 different problems here:

(1) GPU freeze/hang with Metro Exodus on Proton
(2) The AMDGPU kernel can't recover your GPU after the hang
(3) Segfault with Metro Exodus native

(1) and (3) are most likely a RADV bug. Possibly two different bugs between=
 the=20
different versions of the game. Please open an issue here:
https://gitlab.freedesktop.org/mesa/mesa/-/work_items
Select the Radeon Vulkan bug report template and fill in the details,
especially the steps to reproduce. Also please upload a full dmesg log afte=
r=20
the freeze/hang.

(2) is a kernel bug. With Linux 6.18 and newer, the kernel should recover t=
he=20
GPU and should not freeze your full system.
Please open an issue here:
https://gitlab.freedesktop.org/drm/amd/-/work_items
Also mention the steps to reproduce the issue and upload the full dmesg log=
=20
after the freeze/hang.

Best regards,
Timur

> System Information:
> GPU: AMD Radeon RX 6800 XT (Navi 21) (ASRock Phantom Gaming)
> CPU: Intel Xeon E5-2697A v4
> RAM: 32 GB
> OS: Gentoo Linux
> Kernel: 7.0.11-gentoo (also tested 6.18.6 and 7.1.2-cachyos)
> Mesa version: 26.1.2 (also tested 26.1.3)
> Desktop: bspwm (X11)
> Game: Metro Exodus (native Linux version from Steam)
> Game settings: DX12, Ray Tracing Ultra, Quality on "Koshmar" (Nightmare /
> Extreme)=20
> What I Tried (and what did NOT help):
> =20
> Different Proton versions (7.0, 8.0, 9.0, Experimental, GE-Proton) - all
> crashed or froze.=20
> Custom Wine build (wine-staging 11.11 with ntsync) - same crashes.
> =20
> Proton with VKD3D-Proton was especially problematic - the game would not
> just crash, but the entire system would freeze or the GPU would reset.
> During these events, dmesg showed:=20
> "Dumping IP State"
> "GPU reset begin"
> "GPU reset succeeded"
> "VRAM is lost due to GPU reset"
> "[drm] device wedged, but no recovery needed"
> =20
> After this, the system would become completely unresponsive, sometimes ev=
en
> the keyboard (Caps Lock indicator) would stop working, requiring a hard
> reboot.=20
> Mesa environment variables:
> =20
> RADV_DEBUG=3Dnodcc - this stopped the crashes in Proton but caused a ~30%
> performance drop. RADV_PERFTEST=3Drt - no effect.
> RADV_DEBUG=3Dnodcc,noics - no effect.
> RADV_PERFTEST=3Dno_shader_cache - no effect.
> =20
> VKD3D environment variables:
> =20
> VKD3D_CONFIG=3Ddxr - no effect.
> VKD3D_CONFIG=3Ddxr,no_upload_hvv - no effect.
> VKD3D_CONFIG=3Dforce_bindless_texel_buffer - no effect.
> =20
> Vulkan driver switching:
> =20
> RADV (default) - crashes in Proton, segfaults in native.
> AMDVLK - also crashes in Proton; not tested in native.
> =20
> Kernel boot parameters:
> =20
> amdgpu.dcdebugmask=3D0x10
> amdgpu.dcdebugmask=3D0x12
> amdgpu.dcdebugmask=3D0x210
> amdgpu.dcdebugmask=3D0xA10
> amdgpu.gpu_recovery=3D0
> amdgpu.gpu_timeout=3D20000
> amdgpu.runpm=3D0
> amdgpu.mcbp=3D0
> amdgpu.ppfeaturemask=3D0xfffd7fff
> =20
> None of these resolved the issue.
> =20
> Replaced the SSD (the game was on a failing SSD, then moved to a healthy
> HDD) - the issue persisted on the HDD, proving it is not storage-related.=
=20
> Reflashed the motherboard BIOS - no effect.
> Tested on a clean Arch Linux live USB - the issue still occurred.
> Tried XFS and ext4 filesystems - no difference.
> =20
> Comparison: DX12 vs DX11:
> =20
> On Proton (DX12 with Ray Tracing Ultra and "Koshmar" quality settings): t=
he
> game crashes and sometimes causes full system freezes.=20
> On Proton (DX11 without ray tracing): the system crashes disappear, but
> performance drops by about 20%, and the graphics quality is noticeably
> worse. This suggests that the issue is specifically related to how RADV
> handles the combination of DirectX 12, Ray Tracing, and high-quality
> rendering in this game.=20
> The Breakthrough:
> =20
> I decided to test the native Linux version of Metro Exodus (not Proton). =
The
> native version does not crash, but during loading screens (specifically t=
he
> scenes with Artyom's narration), the game freezes for 3-4 seconds, then
> continues. During these freezes, dmesg shows a segmentation fault in
> libvulkan_radeon.so:=20
> Jul  1 19:13:52 gentoo kernel: video[270346]: segfault at 40 ip
> 00007f7e39fdd275 sp 00007f7d9a7fd350 error 4 in
> libvulkan_radeon.so[1dd275,7f7e39e10000+6b3000] likely on CPU 22 (core 6,
> socket 0) Jul  1 19:13:52 gentoo kernel: Code: 14 8a 48 ff c1 c5 fe 7f 00
> c5 fa 7f 40 20 c7 00 95 94 9f 3b 4c 89 40 10 44 89 50 28 c5 fa 7f 48 18 49
> 39 cb 74 1f 4d 8b 04 cc <41> 83 78 40 01 75 a4 45 84 ed 74 9f 48 8b 47 18
> c5 fa 7e 0c c8 eb Jul  1 19:14:01 gentoo kernel: video[296182]: segfault =
at
> 40 ip 00007fca867dd275 sp 00007fc9eb7fd350 error 4 in
> libvulkan_radeon.so[1dd275,7fca86610000+6b3000] likely on CPU 8 (core 8,
> socket 0) Jul  1 19:14:01 gentoo kernel: Code: 14 8a 48 ff c1 c5 fe 7f 00
> c5 fa 7f 40 20 c7 00 95 94 9f 3b 4c 89 40 10 44 89 50 28 c5 fa 7f 48 18 49
> 39 cb 74 1f 4d 8b 04 cc <41> 83 78 40 01 75 a4 45 84 ed 74 9f 48 8b 47 18
> c5 fa 7e 0c c8 eb=20
> The game recovers from this segfault and continues to run, but the freeze=
 is
> reproducible every time a location is loaded.=20
> What This Suggests:
> =20
> The native version of Metro Exodus exposes a bug in RADV
> (libvulkan_radeon.so) that causes a segmentation fault. The game handles
> this fault and continues. However, when the Windows version of the game is
> run through Proton/VKD3D, this same bug leads to an unrecoverable crash
> (the game freezes and eventually dies) or even a full system freeze with
> GPU reset.=20
> Conclusion:
> =20
> This appears to be a bug in RADV, specifically in how it handles certain
> Vulkan operations in Metro Exodus with DX12 and Ray Tracing. The issue is
> reproducible on RX 6800 XT and may affect other RDNA2 users.=20
> If you need more logs, core dumps, or specific system information, I am
> happy to provide them.=20
> Note: I am a Russian speaker. This report has been translated using a
> translator. Please forgive any grammatical inaccuracies. I hope the
> technical content is clear.=20
> Thank you for your work on Mesa.