Re: [RFC,05/10] x86/speculation: Add basic IBRS support infrastructure

[Andi Kleen]

> Right now, we are dealing with one workaround, which is tied to
> Skylake-era model numbers. Yes, we could report a Skylake model
> number, and Linux guests would use IBRS instead of retpoline. But this

Nobody is planning to use IBRS and Linus has rejected it.

> approach doesn't scale. What happens when someone introduces a
> workaround tied to some other model numbers?

There are already many of those in the tree for other issues and features. 
So far you managed to survive without. Likely that will be true
in the future too.

-Andi