Re: [PATCH 1/2] x86/mm/pat: Change pat_disable() to emulate PAT table

[Luis R. Rodriguez]

I like this approach more as it stuff more PAT setup on its own type
of calls, but:

On Sat, Mar 12, 2016 at 12:55:44PM +0100, Borislav Petkov wrote:
> diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
> index 10f8d4796240..5c442b4bd52a 100644
> --- a/arch/x86/kernel/cpu/mtrr/main.c
> +++ b/arch/x86/kernel/cpu/mtrr/main.c
> @@ -759,8 +761,11 @@ void __init mtrr_bp_init(void)
>  		}
>  	}
>  
> -	if (!mtrr_enabled())
> +	if (!__mtrr_enabled) {
>  		pr_info("MTRR: Disabled\n");
> +		pat_disable("PAT disabled by MTRR");
> +		pat_setup();
> +	}
>  }

This hunk would break PAT on Xen.

  Luis