[snvzz]

>I want the magical IOMMUs that are maturely secure like MMUs are now.

There's nothing magical about IOMMUs. They weren't invented last week either.

Driver and hardware talk to each other using virtual memory instead of physical memory, preventing the scenario where a bug causes DMA to shit all over somebody else's memory.

What holds is that systems that run drivers in supervisor mode have not been able to leverage an iommu to its full extent.

[vacuity]

My (admittedly limited) understanding is that IOMMUs still have practical roadblocks to being a solidly established part of the security of the computer. Of course they aren't bad in principle. Perhaps it's just that we aren't willing to eat the performance cost of making them more robust, but then performance is a tortured debate.

[surajrmal]

The primary roadblock is cost and complexity. The technology itself is sound and doesn't have major performance problems.