The big thing here is that the GPU has historically been a pain point for Android, because it has extreme access to the AP in ways that basically sidestep any mitigation that you put in its way. Any bugs in the driver's mapping code (and there have been many) end up giving very powerful primitives, and this fact has repeatedly been used in in-the-wild exploits. Unfortunately, I don't think much is going to change here until this gets rearchitected.
> A number of GPUs use a standard Arm SMMU instead of an IOMMU already.
Yes, I'm talking about using cores like an ARM SMMU (which is an IO-MMU). Perhaps some GPUs do, but many (most?) don't including the Mali-G710 in this article that's currently shipping in the Pixel 8.
> The problem with those GPUs in general is driver issues, the hardware is fine.
Exactly. I want them to stop writing bespoke kernel code manually fiddling with some custom page table format that gives physical memory read/write primitives when they get it wrong.
