DevX Interface

Linux Kernel Upstream Release Notes v6.5

As DevX is not enabled by default to work in WinOF-2 driver, manual configuration is required as described below:

  1. Open Device manager and locate the NVIDIA® (Mellanox) device.

  2. Right click and open the Properties.

  3. Go to the Details tab.

  4. Select the Driver key in the Property list.

  5. Save the value you received.
    For example: “{4d36e972-e325-11ce-bfc1-08002be10318}\0003”

  6. Open the registry editor (in console type regedit).

  7. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class

  8. Select the class as shown in the driver key you extracted in step 5.
    For example: {4d36e972-e325-11ce-bfc1-08002be10318}.

  9. Select the device number as in step 5.
    For example: 0003.

  10. Create a new key with name DevxEnabled of type DWORD and set the value ‘1’.

  11. Restart the driver. DevX Lib will be able to detect your device now.

  12. Verify DevX=True for the enabled adapter, run "cmd mlx5cmd -stat”

  1. Find the MLNX_WinOF2_DevX_SDK_<version>.exe file in the WinOF-2 driver package located in the "DevX_SDK" folder.
    Example: C:\Program Files\Mellanox\Mlnx_WinOF2\DevX_SDK

  2. Install the SDK in your development system.
    The SDK will expose the following new environment variables required for the library detection:
    - variable name: DEVX_LIB_PATH will be the path to the DevX lib file
    - variable name: DEVX_INC_PATH will be the path to the DevX header files

  3. Make sure you update your session before start compiling.

  4. In case the library is installed, and the environment variable does not exist, you may export the environment variable manually to point to the SDK path.

Offload capabilities for Windows DPDK are available using a new DevX API that allows the user:

  • set the promiscuous mode (ALL, MC)

  • set and get MTU


    Set MTU is limited to hosts only where the MTU >= 1522

To set the promiscuous mode in VMs using DPDK, the following action are needed by the host driver:

  • Enable the VFTrusted mode for the NVIDIA adapter by setting the registry key TrustedVFs=1

  • Allow the promiscuous mode enablement for the vPorts in the NVIDIA adapter by setting the registry key AllowPromiscVport = 1

© Copyright 2023, NVIDIA. Last updated on May 23, 2023.