With sys-gui, rendering is no longer handled by the CPU but by the GPU?

[corporateblush]

I made a post, but then instead decided to use the text to open dedicated topic.

Sys-gui-gpu qubes full gpu acceleration

Since with sys-gui-gpu, gpu is isolated from dom0, what would be the reason not to allow gpu acceleration to all the qubes to which sys-gui-gpu is guivm? All the non-dom0 qubes are by default already considered as compromised, so sys-gui-gpu then is too? So I imagine a case where the Windows qube is much safer to run in sys-gui-gpu with full acceleration, then without it in dom0? This is especially for cases where for these purposes dGPU can be used on external monitor, while sensitive operat…