From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752643AbbLDSk5 (ORCPT <rfc822;w@1wt.eu>);
	Fri, 4 Dec 2015 13:40:57 -0500
Received: from mga14.intel.com ([192.55.52.115]:15760 "EHLO mga14.intel.com"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751033AbbLDSkz (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 4 Dec 2015 13:40:55 -0500
X-ExtLoop1: 1
X-IronPort-AV: E=Sophos;i="5.20,380,1444719600"; 
   d="scan'208";a="834451167"
Date: Fri, 4 Dec 2015 10:37:31 -0800
From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>, Paolo Bonzini <pbonzini@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Amy Wiles <amy.l.wiles@intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>,
        Hannes Reinecke <hare@suse.de>, jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH] x86/rapl: Do not load in a guest
Message-ID: <20151204103731.01a2d7fc@icelake>
In-Reply-To: <20151204182807.GN21177@pd.tnic>
References: <20151204074206.GB24827@gmail.com>
	<20151204082256.GC17308@twins.programming.kicks-ass.net>
	<20151204082823.GA31591@gmail.com>
	<20151204101954.GA21177@pd.tnic>
	<56616DBF.8040900@redhat.com>
	<20151204105617.GB21177@pd.tnic>
	<20151204115335.GB15308@gmail.com>
	<20151204094642.4c5e63e0@icelake>
	<20151204180426.GM21177@pd.tnic>
	<20151204101610.34582aa2@icelake>
	<20151204182807.GN21177@pd.tnic>
Organization: OTC
X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, 4 Dec 2015 19:28:07 +0100
Borislav Petkov <bp@alien8.de> wrote:

> On Fri, Dec 04, 2015 at 10:16:10AM -0800, Jacob Pan wrote:
> > CPU model detection is the first level checking.  
> 
> And in the case of RAPL, the only checking you can do. This is why it
> should've had a CPUID bit.
> 
I am 200% with you, all I can say is we are working on it. Look at the
pain in the driver for dealing with various quirks.

> > The error is about no valid domains (e.g. counters not working). So
> > the error on minnowboard board could be a real problem if you expect
> > to use RAPL.  
> 
> Right, and if you need to disable it there, you would need to add a
> quirk table looking at DMI strings or so. A CPUID bit might've been a
> bit better if BIOS update would clear it on those boards. Then, sw
> won't even try to load there.
who is gonna collect all the DMI strings? I don't think this is
scalable.