Intel Iris Gallium3D Driver Merged To Mainline Mesa 19.1
Making the day even more exciting for Intel Linux users is this driver's landing comes just minutes after the Vulkan overlay layer HUD was merged for Intel's ANV open-source driver.
This is the Intel Gallium3D driver that has been in development for more than a year and supports Intel "Gen 8" Broadwell graphics and newer. Haswell and older graphics hardware will be left to the existing and mature Intel i965 classic driver.
But even with today's Mesa 19.1 code, the Iris driver isn't turned on by default. Assuming it's part of your driver build list, this driver can be switched over to from i965 with supported hardware when setting the MESA_LOADER_DRIVER_OVERRIDE=iris environment variable. You also need to be on a newer kernel, at least Linux 4.16 or better, due to this driver being designed around the modern Intel DRM driver's user-space interfaces.
So the code is now out there and available for testing. I'll have out some fresh driver figures shortly; was just wrapping up the tests and article when seeing this code already merged to Git.
Hopefully we'll see Iris mature enough this year that by the time Icelake hardware is shipping, perhaps it will become the default. At the very least, this gives Iris plenty of exposure for testing and maturing ahead of the Intel discrete GPUs that will begin rolling out in 2020.
Besides the Intel Gallium3D driver being open to more performance potential thanks to the modern design and Gallium architecture efficiencies, this new driver will also allow Intel graphics to leverage the Gallium OpenGL HUD, the Gallium Nine state tracker (once its NIR bits are all land), and other functionality not exposed to the classic Mesa driver architecture.
Mesa 19.1 with this experimental Gallium driver should be released in May.