Comment by lolsowrong
6 hours ago
I saw the paper from Google last year and thought something in it aligned with not everything running through the microcode engine, though I could be wrong.
6 hours ago
I saw the paper from Google last year and thought something in it aligned with not everything running through the microcode engine, though I could be wrong.
Might well be the case. I don't think I'm familiar with the paper you're referring to; any chance of at least a vague description?
Can’t find the pdf, but it’s all related to the zentool stuff:
https://github.com/google/security-research/blob/master/pocs...
Tavis spells it out there pretty quickly:
“ The simplest instructions (add, sub, mov, etc) are all implemented in hardware. The more complicated instructions like rdrand, fpatan and cmpxchg are microcoded. You can think of them as a bit like calling into a library of functions written in that RISC-like code.”