NVK — The Mesa 3D Graphics Library latest documentation

# NVK

NVK is a Vulkan driver for NVIDIA GPUs.

## Hardware support

NVK currently supports Kepler (GeForce 600 and 700 series) and later GPUs up to and including Ada (RTX 4000 series), as well as consumer Blackwell GPUs (RTX 5000 series).

## Conformance status:

NVK is a conformant Vulkan 1.4 implementation for all officially supported GPUs.

## OpenGL support through Zink:

Starting with Mesa 25.1, all Turing (RTX 2000 series and GTX 16xx) and later GPUs will get NVK+Zink as their OpenGL implementation by default instead of the old Nouveau GL driver. NVK+Zink is a conformant OpenGL 4.6 implementation. The Nouveau GL driver is no longer supported on these cards.

## Kernel requirements

NVK requires at least a Linux 6.6 kernel

## Debugging

Here are a few environment variable debug environment variables specific to NVK:

NAK_DEBUG

  a comma-separated list of named flags affecting the NVK back-end shader compiler:

  `print`

    Prints the shader at various stages of the compile pipeline

  `serial`

    Forces serial instruction execution; this is often useful for debugging or working around dependency bugs

  `spill`

    Forces the GPR file to a minimal size to test the spilling code

  `annotate`

    Adds extra annotation instructions to the IR to track information from various compile passes

NVK_DEBUG

  a comma-separated list of named flags, which do various things:

  `push`

    Dumps all pushbufs to stderr on submit. This requires that `push_sync` also be set.

  `push_sync`

    Waits for submit to complete before continuing

  `zero_memory`

    Zeros all VkDeviceMemory objects upon creation

  `trash_memory`

    Write repeating nonzero patterns to client memory allocations

  `vm`

    Logs VM binds and unbinds

  `no_cbuf`

    Disables automatic promotion of UBOs to constant buffers

  `edb_bview`

    Forces the driver to use the VK_EXT_descriptor_buffer path for buffer views.

  `gart`

    Forces all memory to be allocated from system RAM (GART)

  `coherent`

    Forces all memory maps to be coherent with the CPU caches. This only applies to Tegra devices.

  `no_compression`

    Disables image compression.

NVK_EXPERIMENTAL

  a comma-separated list of named flags, which enable experimental features:

  `dlss`

    Enable DLSS if precompiled support for the gpu is found in the DLSS library.

  `dlss_backwards_compat`

    Allow using DLSS bytecode intended for earlier architectures if compatible.

NVK_I_WANT_A_BROKEN_VULKAN_DRIVER

  If defined to `1` or `true`, this will enable enumeration of all GPUs Kepler and later, including GPUs for which hardware support is poorly tested or completely broken. This is intended for developer use only.

## Developer info

- External Hardware Documentation and Resources
  - Command buffers
  - Shader ISA
  - Misc
- Hardware docs
  - Command buffers
    - Command format
      - P_IMMD
      - P_MTHD
      - P_0INC
      - P_1INC
    - Execution barriers
      - Subchannel switches
    - Copy engine
- ISBE Layout
  - Map region
  - Attribute region
- Mesh Shading Notes
  - Draw
  - Stages
    - Shared Memory
    - Task
    - Mesh
  - Hardware limitations