Intel To Split Off Their Old Haswell/Broadwell Vulkan Code Into Separate Driver

The current Intel open-source "ANV" Vulkan driver within Mesa supports graphics hardware going back to the "Gen7" graphics found with Ivy Bridge / Haswell. However, Intel open-source Linux graphics driver engineers are preparing to separate the old Ivy Bridge / Haswell (Gen7) and Broadwell (Gen8) graphics into a separate Mesa driver so they can better focus on improving their modern Vulkan driver that would then be limited to Skylake Gen9 graphics and newer.

While ANV supports Haswell and Broadwell, the support there is rarely improved upon and the Gen7 Haswell graphics have never been officially compliant with Vulkan. The Ivy Bridge support even more of a garbage state and has been rather useless in a Vulkan world from the driver state to the hardware not really being practical for most software supporting Vulkan. Given the age of the hardware and Intel engineers being extremely busy working on Arc Graphics and the like, they are looking to punt that Gen7~Gen8 graphics support into a separate driver as to not complicate their modern work moving forward.

By moving the IvyBridge/Haswell/Broadwell support off to a separate driver, it would be easier to work on the ANV driver improvements moving forward without having to worry about an often different code path for those older Intel graphics generations. It also reduces the risk of regressing the old Intel graphics support as it will see less code churn now and not much pre-Skylake testing happening these days.

In removing the old Gen7/Gen8 code paths from ANV, there is also the possibility of enhancing the performance for modern generations by being able to eliminate the older code paths and improving the code with simplified logic catering only to more modern Intel graphics processors.

The Intel open-source Vulkan driver technically supports Gen7 Ivy Bridge and Haswell graphics, but it's never been formally compliant and the Gen7 (and Gen8) driver code paths are rarely touched. Now it's likely to be punted off to a new "HASVK" driver where it can continue to rest peacefully within Mesa.

The tentative name for this new driver is "HASVK" as in Haswell Vulkan driver. The Gen7/Gen8 support will then continue to live peacefully in HASVK without much code churn and can be installed fine alongside ANV. Intel really hasn't been focused on pre-Skylake Vulkan driver improvements (even the Gen9 Skylake focused improvements are rare) in years and so in practice this doesn't change much for those still using these old pre-Skylake Intel CPUs, but does make it easier for Intel developers in improving their Vulkan driver support ahead for modern generations.

This merge request is where the discussion is taking place over splitting of the Intel Vulkan driver and introducing HASVK. This is better than on the Windows side where Intel recently moved 6th to 10th Gen Intel Processor Graphics to its legacy model.