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