Re: [tip:x86/pti] x86/retpoline: Fill RSB on context switch for affected CPUs

[Andi Kleen]

> +     if ((!boot_cpu_has(X86_FEATURE_PTI) &&
> +          !boot_cpu_has(X86_FEATURE_SMEP)) || is_skylake_era()) {
> +             setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
> +             pr_info("Filling RSB on context switch\n");
> +     }

Missing an option to turn this off.

-Andi