RE: [Patch v3 Part2 3/9] x86/microcode/intel: Fix collect_cpu_info() to reflect current microcode

[Luck, Tony]

> So first of all, I'm wondering whether the scenario you're chasing is
> something completely hypothetical or you're actually thinking of
> something concrete which has actually happened or there's high potential
> for it.

Rare, but very real. For one of the speculative side channel microcode
updates there were some reports from large data centers that the kernel
choked on a WRMSR(IA32_SPEC_CTRL)

> In that case, that late patching sync algorithm would need to be made
> more robust to handle cases like that.
"
Yup. when you get through the cleanups and the "minrev" update Ashok
has a handful of final[1] patches that add robustness.

-Tony

[1] Yes, there is an end in sight to all these microcode changes.