Intel's Experimental Xe Driver For Linux Lacking HuC Media Support For DG2/Alchenist

While Intel's in-development Xe kernel graphics driver is focused on supporting Tigerlake/Gen12 graphics and newer integrated/discrete graphics with this modern open-source driver with many design improvements over the aging i915 kernel driver, there looks to be one feature that as currently positioned will be missing for DG2/Alchemist: HuC support for helping with media offloading.

Intel's HuC micro-controller is for offloading some media functionality from the CPU to GPU and is necessary for GPU acceleration with codecs like H.265/HEVC. Intel's i915 driver has supported HuC on DG2/Alchemist and various other generations having the HuC IP. But in the case of the experimental Xe driver, its HuC support currently doesn't cover DG2/Alchemist and it looks like the Intel engineers aren't planning on implementing it for that generation either.

The HuC handling for DG2 is described as "special" and "relatively annoying" that only applies to DG2/Alchemist while for Meteor Lake and beyond will be a new and improved way of dealing with HuC. That in turn looks like it will be used for DG3/Battlemage.

Thus the DG2/Alchemist HuC media functionality is in the boat of being used just for that one generation and implementing it would require a lot of work for the Xe driver while it's already found in the i915 kernel driver. With i915 being the official driver for DG2/Alchemist, Intel appears to not want to commit the resources to working out HuC for DG2 on Xe considering the limited scope.

The lack of HuC support for Xe on DG2 has been brought up within this FreeDesktop.org GitLab ticket. Those wanting to use HuC media functionality on the DG2-based Arc Graphics thus are recommended to use the default i915 driver.

While lacking HuC support, the Xe driver once mainlined in the Linux kernel should ultimately prove more interesting for Intel Arc Graphics Linux gamers though due to possible performance optimizations, features like VM_BIND / sparse residency looking like they will only be implemented for Xe and not i915 (important for running newer Steam Play games with VKD3D-Proton), and Intel investing in the Xe driver code-base as their future de facto open-source graphics driver stack.