Given that GPUs already have full MMUs without going all the way to virtualization, I guess I don't see what virtualization is doing here intrinsically with the nested MMU context. Particularly for open source drivers like Intel's that they're using, we should just fix the bugs that are allowing you to map other process's vram. Virtualization still needs to communicate to the compositor overt IPC, so you end up with the same attack surface either way. It's like fixing Win95's half assed process isolation with virtualization rather than just having a cleaner process model.

Like, I'm sure they fixed the bugs they were looking at, but virtualization isn't magical security juice you can sprinkle over stuff. In fact it increases your attack surface in a lot of ways.