I didn't say the OS filters the pipeline. Modern CPUs have a lot of updateable microcode, including how it handles its command pipeline.
Modern x86/x64 CPUs. The M1 might not have updatable microcode.
Apple might consider microcode a vulnerability. Certainly a double-edged knife.
There is no indication that the M1 has updatable microcode, nor any other features that might allow such mitigation. (If it did, Apple would've fixed it; I did give them a 90 day disclosure warning and they're not lazy about fixing actual fixable bugs.)
Aw - that was what I was worried about - without updatable microcode :nuke:.