wl_drm
also: Wayland DRM, wl_drm protocol
wl_drm is a Wayland protocol extension that enables secure communication between Wayland clients and the Direct Rendering Manager (DRM) kernel subsystem for GPU hardware access and buffer sharing.
wl_drm is a Wayland protocol interface that allows graphical applications to access GPU hardware directly through the DRM subsystem while maintaining the security and compositing model of the Wayland display server. It handles authentication and buffer object sharing between clients and the graphics driver.
The protocol is particularly important for OpenGL and Vulkan rendering, where applications need direct GPU access. When a Wayland client wants to render using the GPU, it uses wl_drm to negotiate DRM device access and exchange memory buffers with the compositor.
Example: A game running on Wayland uses wl_drm to authenticate with the GPU driver and create shared buffers for rendering frames, which the Wayland compositor can then composite and display on screen without copying pixel data multiple times.