Posts

nvk: blackwell support

Blog posts are like buses sometimes... I've spent time over the last month enabling Blackwell support on NVK, the Mesa vulkan driver for NVIDIA GPUs. Faith from Collabora, the NVK maintainer has cleaned up and merged all the major pieces of this work and landed them into mesa this week. Mesa 25.2 should ship with a functioning NVK on blackwell. The code currently in mesa main passes all tests in the Vulkan CTS. Quick summary of the major fun points: Ben @ NVIDIA had done the initial kernel bringup in to r570 firmware in the nouveau driver. I worked with Ben on solidifying that work and ironing out a bunch of memory leaks and regressions that snuck in. Once the kernel was stable, there were a number of differences between Ada and Blackwell that needed to be resolved. Thanks to Faith, Mel and Mohamed for their help, and NVIDIA for providing headers and other info. I did most of the work on a GB203 laptop and a desktop 5080. 1. Instruction encoding: a bunch of instructions changed how...

radv: VK_KHR_video_encode_av1 support

 I should have mentioned this here a week ago. The Vulkan AV1 encode extension has been out for a while, and I'd done the initial work on enabling it with radv on AMD GPUs. I then left it in a branch, which Benjamin from AMD picked up and fixed a bunch of bugs, and then we both got distracted. I realised when doing VP9 that it hasn't landed, so did a bit of cleanup. Then David from AMD picked it up and carried it over the last mile and it got merged last week. So radv on supported hw now supports all vulkan decode/encode formats currently available.  

radv: vulkan VP9 video decode

The Vulkan WG has released VK_KHR_video_decode_vp9. I did initial work on a Mesa extensions for this a good while back, and I've updated the radv code with help from AMD and Igalia to the final specification. There is an open MR[1] for radv to add support for vp9 decoding on navi10+ with the latest firmware images in linux-firmware. It is currently passing all VK-GL-CTS tests for VP9 decode. Adding this decode extension is a big milestone for me as I think it now covers all the reasons I originally got involved in Vulkan Video as signed off, there is still lots to do and I'll stay involved, but it's been great to see the contributions from others and how there is a bit of Vulkan Video community upstream in Mesa.  [1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35398  

On Rust, Linux, developers, maintainers

There's been a couple of mentions of Rust4Linux in the past week or two, one from Linus on the speed of engagement and one about Wedson departing the project due to non-technical concerns. This got me thinking about project phases and developer types. Archetypes: I will regret making an analogy, in an area I have no experience in, but let's give it a go with a road building analogy.   Let's sort developers into 3 rough categories. Let's preface by saying not all developers fit in a single category throughout their careers, and some developers can do different roles on different projects, or on the same project simultaneously. 1. Wayfinders/Mapmakers I want to go build a hotel somewhere but there exists no map or path. I need to travel through a bunch of mountains, valleys, rivers, weather, animals, friendly humans, antagonistic humans and some unknowns. I don't care deeply about them, I want to make a path to where I want to go. I hit a roadblock, I don't focus...

anv: vulkan av1 decode status

 Vulkan Video AV1 decode has been released, and I had some partly working support on Intel ANV driver previously, but I let it lapse. The branch is currently [1]. It builds, but is totally untested, I'll get some time next week to plug in my DG2 and see if I can persuade it to decode some frames. Update: the current branch decodes one frame properly, reference frames need more work unfortunately. [1] https://gitlab.freedesktop.org/airlied/mesa/-/commits/anv-vulkan-video-decode-av1

radv: vulkan av1 video decode status

The Khronos Group announced VK_KHR_video_decode_av1 [1], this extension adds AV1 decoding to the Vulkan specification. There is a radv branch [2] and merge request [3]. I did some AV1 work on this in the past, but I need to take some time to see if it has made any progress since. I'll post an ANV update once I figure that out. This extension is one of the ones I've been wanting for a long time, since having royalty-free codec is something I can actually care about and ship, as opposed to the painful ones. I started working on a MESA extension for this a year or so ago with Lynne from the ffmpeg project and we made great progress with it. We submitted that to Khronos and it has gone through the committee process and been refined and validated amongst the hardware vendors. I'd like to say thanks to Charlie Turner and Igalia for taking over a lot of the porting to the Khronos extension and fixing up bugs that their CTS development brought up. This is a great feature of having ...

radv: vulkan video encode status

Vulkan 1.3.274 moves the Vulkan encode work out of BETA and moves h264 and h265 into KHR extensions. radv support for the Vulkan video encode extensions has been in progress for a while. The latest branch is at [1]. This branch has been updated for the new final headers. Updated: It passes all of h265 CTS now, but it is failing one h264 test. Initial ffmpeg support is [2]. [1] https://gitlab.freedesktop.org/airlied/mesa/-/tree/radv-vulkan-video-encode-h2645-spec-latest?ref_type=heads [2] https://github.com/cyanreg/FFmpeg/commits/vulkan/