My guess would be something akin to VirGL where they forward opengl/vulkan commands to the host. I've never dug into the nitty gritty, but VMware workstation is recognized as a GPU accelerated app, and exposes a virtual GPU in the VM.
On the linux side, the vmwgfx kernel driver and DRM drivers are used. For X11 you use modesetting, and for Wayland whatever it auto-selects. I don't use KDE but I can confirm Debian's Gnome works out-of-the-box with the default Wayland backend (to be fair, the only other compositor I tried was Sway, which is known for being picky about the GPU used). Copy/paste works properly, as do general acceleration.
I use those VMs daily, fullscreen on a 1440p monitor, so acceleration is not optional :)
On the linux side, the vmwgfx kernel driver and DRM drivers are used. For X11 you use modesetting, and for Wayland whatever it auto-selects. I don't use KDE but I can confirm Debian's Gnome works out-of-the-box with the default Wayland backend (to be fair, the only other compositor I tried was Sway, which is known for being picky about the GPU used). Copy/paste works properly, as do general acceleration.
I use those VMs daily, fullscreen on a 1440p monitor, so acceleration is not optional :)