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 S1754072Ab3L0Qw5 (ORCPT <rfc822;w@1wt.eu>);
	Fri, 27 Dec 2013 11:52:57 -0500
Received: from mail-wi0-f182.google.com ([209.85.212.182]:50693 "EHLO
	mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753577Ab3L0Qwy (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Fri, 27 Dec 2013 11:52:54 -0500
Date: Fri, 27 Dec 2013 18:52:48 +0200
From: Gleb Natapov <gleb@kernel.org>
To: Kashyap Chamarthy <kchamart@redhat.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>,
        One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Dirk Brandewie <dirk.brandewie@gmail.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        "cpufreq@vger.kernel.org" <cpufreq@vger.kernel.org>,
        Linux PM list <linux-pm@vger.kernel.org>,
        "Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>,
        "Richard W.M. Jones" <rjones@redhat.com>
Subject: Re: intel_pstate divide error with v3.13-rc4-256-gb7000ad
Message-ID: <20131227165248.GG10961@minantech.com>
References: <CA+5PVA6YpKc6kYK5UiTnGLZpB8uts=-QPtyhotAyZ2kuoG8PPQ@mail.gmail.com>
 <CAKohpomqHApogDEXA5LyWk-+B-Y1mwNQ63-wL3PPGz64s_3Dmw@mail.gmail.com>
 <20131227122422.62857cec@alan.etchedpixels.co.uk>
 <20131227124749.GE10961@minantech.com>
 <CA+5PVA60GSC0tTLJWLtVqb5eTPMzrszxtoBnUP8B_Q_60=oGyw@mail.gmail.com>
 <52BD8B8B.1050209@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <52BD8B8B.1050209@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Fri, Dec 27, 2013 at 03:15:39PM +0100, Kashyap Chamarthy wrote:
> [. . .]
> 
> >> KVM does not emulate P-states at all. intel_pstate_init() calls
> >> intel_pstate_msrs_not_valid() before printing "Intel P-state driver
> >> initializing."  which suppose to fail since it checks that two reads of
> >> MSR_IA32_APERF return different values, but KVM does not emulate this msr
> >> at all, so both calls should return zero (KVM suppose to inject #GP, all rdmsrl
> >> are patched to be rdmsrl_safe in a guest).
> >>
> >> Anything interesting in host dmesg?
> 
> Heya Gleb,
> 
> Here's the relevant dmesg snippet (full dmesg, refer the attachment below):
That's guest dmesg. What about host one? Can you ftrace the failure?

--
			Gleb.