The AMD Open Source Driver for Vulkan® is an open-source Vulkan driver for Radeon™ graphics adapters on Linux®. It is built on top of AMD's Platform Abstraction Library (PAL), a shared component that is designed to encapsulate certain hardware and OS-specific programming details for many of AMD's 3D and compute drivers. Leveraging PAL can help provide a consistent experience across platforms, including support for recently released GPUs and compatibility with AMD developer tools.
Shaders that compose a particular `VkPipeline` object are compiled as a single entity using the LLVM-Based Pipeline Compiler (LLPC) library. LLPC builds on LLVM's existing shader compilation infrastructure for AMD GPUs to generate code objects compatible with PAL's pipeline ABI. Notably, AMD's closed-source Vulkan driver currently uses a different pipeline compiler, which is the major difference between AMD's open-source and closed-source Vulkan drivers.
The AMD Open Source Driver for Vulkan is designed to support the following AMD GPUs:
* Radeon™ HD 7000 Series
* Radeon™ HD 8000M Series
* Radeon™ R5/R7/R9 200/300 Series
* Radeon™ RX 400/500 Series
* Radeon™ M200/M300/M400 Series
* Radeon™ RX Vega Series
* AMD FirePro™ Workstation Wx000/Wx100/Wx300 Series
* Radeon™ Pro WX x100 Series
* Radeon™ Pro 400/500 Series
> **Note:** Pipeline compiler support for geometry and tessellation shaders is not fully implemented for the Radeon™ RX Vega Series. APU support is limited. These issues will be addressed in upcoming releases.
The AMD Open Source Driver for Vulkan is designed to support following distros on both the AMDGPU upstream driver stack and the [AMDGPU Pro driver stack](http://support.amd.com/en-us/kb-articles/Pages/Radeon-Software-for-Linux-Release-Notes.aspx):
The following features and improvements are planned in future releases (Please refer to [Release Notes](https://github.com/GPUOpen-Drivers/AMDVLK/wiki/Release-notes) for update of each release):
> **Note:** The CPU overhead of command submission may be reduced by leveraging the kernel driver's developmental VM-always-valid feature. This feature is temporarily disabled by default. For the time being, you may try it as described in [Runtime Settings](#runtime-settings).
* Dawn of War III may crash during gameplay on Radeon™ RX Vega Series due to geometry shader is not yet supported in LLPC
* F1 2017 old version may hang or crash during gameplay on Radeon™ RX Vega Series. Please upgrade the game to latest version to run it with the AMD Open Source Driver for Vulkan
* CTS may hang in VK.synchronization.internally_synchronized_objects.pipeline_cache_compute with Linux kernel versions lower than 4.13
### How to Contribute
You are welcome to submit contributions of code to the AMD Open Source Driver for Vulkan.
The driver is built from source code in three repositories: [LLVM](https://github.com/GPUOpen-Drivers/llvm), [XGL](https://github.com/GPUOpen-Drivers/xgl) (including both Vulkan API translation and LLPC) and [PAL](https://github.com/GPUOpen-Drivers/pal).
For changes to LLVM, you should submit contribution to the [LLVM trunk](http://llvm.org/svn/llvm-project/llvm/trunk/). Commits there will be evaluated to merge into the amd-vulkan-master branch periodically.
For changes to XGL or PAL, please [create a pull request](https://help.github.com/articles/creating-a-pull-request/) against the dev branch. After your change is reviewed and if it is accepted, it will be evaluated to merge into the master branch in a subsequent regular promotion.
**IMPORTANT**: By creating a pull request, you agree to allow your contribution to be licensed by the project owners under the terms of the [MIT License](LICENSE.txt).
When contributing to XGL and PAL, your code should:
* Match the style of nearby existing code. Your code may be edited to comply with our coding standards when it is merged into the master branch.
* Avoid adding new dependencies, including dependencies on STL.
Please make each contribution reasonably small. If you would like to make a big contribution, like a new feature or extension, please raise an issue first to allow planning to evaluate and review your work.
> **Note:** Since PAL is a shared component that must support other APIs, other operating systems, and pre-production hardware, you might be asked to revise your PAL change for reasons that may not be obvious from a pure Linux Vulkan driver perspective.
> **Note:** If the build runs into errors like "collect2: fatal error: ld terminated with signal 9 [Killed]" due to out of memory, you could try with reducing the number of threads in "make" command.
## Installation Instructions
### Install Vulkan SDK
Refer to installation instructions [here](http://support.amd.com/en-us/kb-articles/Pages/Install-LunarG-Vulkan-SDK.aspx).
On the AMDGPU upstream driver stack, the max number of command streams per submission **MUST** be limited to 4 (the default setting in AMD Open Source driver for Vulkan is 16). This can be accomplished via the [Runtime Settings](#runtime-settings) mechanism by adding the following line to /etc/amd/amdPalSettings.cfg:
The driver exposes many settings that can customize the driver's behavior and facilitate debugging. Add/edit settings in /etc/amd/amdPalSettings.cfg, formatted with one `name,value` pair per line. Some example settings are listed below:
| `ShaderCacheMode` | 0: disable cache<br/>1: runtime cache<br/>2: cache to disk | Runtime cache is the default mode. |
| `IFH` | 0: default<br/>1: drop all submits<br/> | Infinitely Fast Hardware. Submit calls are dropped before being sent to hardware. Useful for measuring CPU-limited performance. |
| `EnableVmAlwaysValid` | 0: disable<br/>1: enable<br/> | 0 is the default setting. Can be enabled to reduce command buffer submission overhead related to virtual memory management. |
| `IdleAfterSubmitGpuMask` | Bitmask of GPUs (i.e., bit 0 is GPU0, etc.) | Forces the CPU to immediately wait for each GPU submission to complete on the specified set of GPUs. |
*All* available settings can be determined by examining the .cfg source files that define them.
Runtime settings are only read at device initialization, and cannot be changed without restarting the application. If running on a system with multiple GPUs, the same settings will apply to all of them. Lines in the settings file that start with `;` will be treated as comments.
## PAL GpuProfiler Layer
The GpuProfiler is an optional layer that is designed to intercept the PAL interface to provide basic GPU profiling support. Currently, this layer is controlled exclusively through runtime settings and outputs its results to file.
You can use the following [Runtime Settings](#runtime-settings) to generate a .csv file with GPU timings of work performed during the designated frames:
| `GpuProfilerMode` | 0: disable<br/>1: enable with sqtt off<br/>2: enable with sqtt for thread trace<br/>3: enable with sqtt for RGP | Enables and sets the SQTT mode for the GPU performance profiler layer. Actual capture of performance data must be specified via frame number with GpuProfilerStartFrame or by holding shift-F11. |
| `GpuProfilerLogDirectory` | <nobr><directory-path></nobr> | Must be a directory that your application has write permissions for. |
| `GpuProfilerGranularity` | 0: per-draw<br/>1: per-cmdbuf | Defines what is measured/profiled. *Per-draw* times individual commands (such as draw, dispatch, etc.) inside command buffers, while *per-cmdbuf* only profiles entire command buffers in aggregate. |
| `GpuProfilerStartFrame` | Positive integer | First frame to capture data for. If StartFrame and FrameCount are not set, all frames will be profiled. |
| `GpuProfilerFrameCount` | Positive integer | Number of frames to capture data for. |
| `GpuProfilerRecordPipelineStats` | 0, 1 | Gathers pipeline statistic query data per entry if enabled. |
## PAL Debug Overlay
PAL's debug overlay can be enabled to display real time statistics and information on top of a running application. This includes a rolling FPS average, CPU and GPU frame times, and a ledger tracking how much video memory has been allocated from each available heap. Benchmarking (i.e., "Benchmark (F11)") is currently unsupported.
| `DebugOverlayLocation` | <nobr>0: top-left</nobr><br/><nobr>1: top-right</nobr><br/><nobr>2: bottom-left</nobr><br/><nobr>3: bottom-right</nobr> | Determines where the overlay text should be displayed. Can be used to avoid collision with important rendering by the application. |
| `PrintFrameNumber` | 0, 1 | Reports the current frame number. Useful when determining a good frame range for profiling with the GpuProfiler layer. |
| `TimeGraphEnable` | 0, 1 | Enables rendering of a graph of recent CPU and GPU frame times. |
## Third Party Software
The AMD Open Source Driver for Vulkan contains code written by third parties.
* LLVM is distributed under the terms of the University of Illinois/NCSA Open Source License. See LICENSE.TXT file in the top directory of the LLVM repository.
* Please see the README.md file in the [PAL](https://github.com/GPUOpen-Drivers/pal) and [XGL](https://github.com/GPUOpen-Drivers/xgl) repositories for information on third party software used by those libraries.
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The information contained herein is for informational purposes only, and is subject to change without notice. This document may contain technical inaccuracies, omissions and typographical errors, and AMD is under no obligation to update or otherwise correct this information. Advanced Micro Devices, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this document, and assumes no liability of any kind, including the implied warranties of noninfringement, merchantability or fitness for particular purposes, with respect to the operation or use of AMD hardware, software or other products described herein. No license, including implied or arising by estoppel, to any intellectual property rights is granted by this document. Terms and limitations applicable to the purchase or use of AMD's products are as set forth in a signed agreement between the parties or in AMD's Standard Terms and Conditions of Sale.
AMD, the AMD Arrow logo, Radeon, FirePro, and combinations thereof are trademarks of Advanced Micro Devices, Inc. Other product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
Vega is a codename for AMD architecture, and is not a product name.
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Vulkan and the Vulkan logo are registered trademarks of the Khronos Group, Inc.
