AMDKFD GPUVM Support Updated For Discrete Radeon GPUs, Adds Userptr Support

Unfortunately the AMDKFD GPUVM support for discrete GPUs isn't looking like it will make it for the Linux 4.17 kernel cycle.

This past week brought the AMDKFD updates for DRM-Next, a.k.a. Linux 4.17. While it has much of the discrete GPU support landing that we have long been looking forward to seeing in the mainline kernel in order to run ROCm OpenCL out-of-the-box, unfortunately, the GPUVM support wasn't part of that pull. The GPUVM support for discrete Radeon GPUs was still being discussed and not ready for pulling.

Felix Kuehling of AMD has now sent out a new patch series for testing with this "KFD GPUVM support for dGPUs". The code is now up to its fourth revision and has addressed feedback raised by other developers. Unfortunately though with the DRM-Next feature window quickly ending for Linux 4.17, it's looking uncertain that this code would land for the next kernel release.

This patch series also now adds Userptr support too for this AMDKFD driver. Userptr as a reminder is the user pointer support that allows turning a memory pointer supplied by user-space into a buffer object for Direct Rendering Manager drivers. AMDGPU has already supported Userptr while now the AMDKFD driver does too.

These latest AMDKFD patches for those wanting to test it for open-source Radeon graphics card compute support can find them via amd-gfx.