While the main feature pull of new and updated kernel graphics/accelerator drivers were merged already for the ongoing Linux 6.14 merge window, an additional set of AMDGPU changes were sent out this week for squeezing into this next kernel release.
Friday’s pull request of additional AMDGPU and AMDKFD material is mostly about bug fixes for existing and newly-introduced issues in Linux 6.14. But there’s some items worth mentioning, particularly for the GFX12 graphics engine with the upcoming RDNA4 / Radeon RX 9070 series graphics.
In addition to the GFX12 improvements/fixes merged for the main Linux 6.14 merge, Friday’s pull request brings further GFX12 fixes. Additionally, it now enables cleaner shader support for GFX12. The cleaner shader is for help ensuring app/user isolation and in recent kernels has been extended to more GPU families.
Linux 6.14 is enabling cleaner shader for GFX12.0 and GFX12.0.1 GPUs to clear GPU resources like the local data share (LDS), vector general purpose registers (VGPRs), and scalar general purpose registers (SGPRs) between workloads. By clearing these resources between workloads, it helps prevent possible data leakage and ensures better security/reliability with the upcoming RDNA4 graphics cards. GFX9 through GFX11 IP has already seen cleaner shader enablement. I haven’t seen any public communication from AMD driver developers about their motivation for adding this cleaner shader functionality at this stage as opposed to something that could have been done years ago, if it’s due to new customer demands / security concerns or other factors. In any event this cleaner shader support is particularly useful for today’s multi-tenant GPU-accelerated systems and even when just running untrusted code on your system with GPU access.
One of the GFX12 fixes also part of this update is disabling GFXOFF support (turning off the graphics engine) support during compute workloads, in order to workaround an OpenCL test failure issue.
The other fixes part of this latest pull request appear to be mostly general fixes. These AMDGPU/AMDKFD changes have already been queued up into Direct Rendering Manager (DRM) tree for likely sending to Linus Torvalds as part of “DRM fixes” in the coming days for Linux 6.14.
