GPU Passthrough Custom OS Template

To get your custom template ready for GPU support, follow the directions below.

Keep in mind there are two primary scenarios for GPU passthrough:

Machine learning (no display required, e.g., OpenCL, etc.)
Image processing (e.g., OBS Studio, Blender, video editing, Multiverse presentations, etc.)

The machine learning use case is simpler (as the display doesn't need the GPU), but we'll cover the full process to support both scenarios.

Supported GPU

If you're running DaDesktop on-premises or requesting the purchase of specific cards for your private server, here are a few things to note.

Our testing of the DaDesktop system mainly focuses on the AMD Radeon RX 6000 series (especially the RX 6400) and Nvidia RTX cards. Generally, models older than 2018 aren't supported.

Integrated GPUs from Ryzen 7/9 and Intel iGPUs should also work, but we don't run automated tests on them.

DD Node side

Within the dadesktop_npnode_deploy/modules/build-os-template directory, you'll find scripts to tweak a Linux guest so it can use the GPU as the primary display and switch between GPU-accelerated machines and CPU-rendered screens.

Guest Settings

Make sure that "support_qemu" in /var/lib/kvm/templatename/sysinfo.json is set to false so you can connect to the VNC inside the guest; qemu VNC can't show the passthrough GPU screen.

Testing

Method 1: 
vblank_mode=0 glxgears

Method 2:

/apps/dd-guest/check-gpu

Windows guest settings when no physical monitor is attached (most cases)

We use IddSampleDriver to set up a display adapter and virtual monitor in the Windows 10 template. Just install it if your GPU doesn't have a monitor plugged in.

Extract IddSampleDriver to the c:\IddSampleDriver folder
Install the certificate
Install the driver
Head to "Display Settings," and you'll spot multiple displays. Check "Advanced display settings." Usually, Display 2 or 3, labelled "Linux FHD", is the virtual display we've created. Note that number as N, then go back to the "Select and rearrange displays" area, pick display N, and under the "Multiple displays" section, choose "Show only on N" if it's available and set it as the main display. Adjust its resolution.
If you can't locate a display named "Linux FHD":

Navigate to "Device Manager" -> "Display Adapters" -> "IddSampleDriver Device": right-click and enable the device. (You can disable it when you're not using the virtual display.)

If there's a display called "AMD vDisplay", typically Display 2:

it will be sluggish, and you can "Disconnect this display" if the option is available.

(Choose Display x, under the "Multiple displays" section, use the drop-down to pick the Disconnect this display option.)

There's a display called "Qemu Monitor", usually Display 1:

You can also "Disconnect this display" if that option is there.