I asked more specific questions in my comment; you aren't answering them. The only important question: why are you so strident about x86 side channels being a non-issue?

Because I'd watch chip vendors not even figure out how to secure MSIs under their IOMMUs and question whether just-plain-old- software security was a reasonable expectation under virtualization. You on the other hand seem to think it's so solid that the microarchitecture doesn't cache crypto artifacts.