From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752777AbbC0X4h (ORCPT ); Fri, 27 Mar 2015 19:56:37 -0400 Received: from cantor2.suse.de ([195.135.220.15]:35989 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752408AbbC0X4f (ORCPT ); Fri, 27 Mar 2015 19:56:35 -0400 Date: Sat, 28 Mar 2015 00:56:30 +0100 From: "Luis R. Rodriguez" To: Toshi Kani Cc: "Luis R. Rodriguez" , luto@amacapital.net, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, jgross@suse.com, JBeulich@suse.com, bp@suse.de, suresh.b.siddha@intel.com, venkatesh.pallipadi@intel.com, airlied@redhat.com, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, Ingo Molnar , Daniel Vetter , Antonino Daplas , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Dave Hansen , Stefan Bader , konrad.wilk@oracle.com, ville.syrjala@linux.intel.com, david.vrabel@citrix.com, bhelgaas@google.com, Roger Pau =?iso-8859-1?Q?Monn=E9?= , xen-devel@lists.xensource.com Subject: Re: [PATCH v1 02/47] x86: mtrr: generalize run time disabling of MTRR Message-ID: <20150327235630.GR5622@wotan.suse.de> References: <1426893517-2511-1-git-send-email-mcgrof@do-not-panic.com> <1426893517-2511-3-git-send-email-mcgrof@do-not-panic.com> <1427488817.31093.54.camel@misato.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427488817.31093.54.camel@misato.fc.hp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 27, 2015 at 02:40:17PM -0600, Toshi Kani wrote: > On Fri, 2015-03-20 at 16:17 -0700, Luis R. Rodriguez wrote: > : > > @@ -734,6 +742,7 @@ void __init mtrr_bp_init(void) > > } > > > > if (mtrr_if) { > > + mtrr_enabled = true; > > set_num_var_ranges(); > > init_table(); > > if (use_intel()) { > get_mtrr_state(); > > After setting mtrr_enabled to true, get_mtrr_state() reads > MSR_MTRRdefType and sets 'mtrr_state.enabled', which also indicates if > MTRRs are enabled or not on the system. So, potentially, we could have > a case that mtrr_enabled is set to true, but mtrr_state.enabled is set > to disabled when MTRRs are disabled by BIOS. Thanks for the review, in this case then we should update mtrr_enabled to false. > ps. > I recently cleaned up this part of the MTRR code in the patch below, > which is currently available in the -mm & -next trees. > https://lkml.org/lkml/2015/3/24/1063 Great I will rebase and work with that and try to address this consideration you have raised. Luis From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis R. Rodriguez" Date: Fri, 27 Mar 2015 23:56:30 +0000 Subject: Re: [PATCH v1 02/47] x86: mtrr: generalize run time disabling of MTRR Message-Id: <20150327235630.GR5622@wotan.suse.de> List-Id: References: <1426893517-2511-1-git-send-email-mcgrof@do-not-panic.com> <1426893517-2511-3-git-send-email-mcgrof@do-not-panic.com> <1427488817.31093.54.camel@misato.fc.hp.com> In-Reply-To: <1427488817.31093.54.camel@misato.fc.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Toshi Kani Cc: "Luis R. Rodriguez" , luto@amacapital.net, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, jgross@suse.com, JBeulich@suse.com, bp@suse.de, suresh.b.siddha@intel.com, venkatesh.pallipadi@intel.com, airlied@redhat.com, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, x86@kernel.org, xen-devel@lists.xenproject.org, Ingo Molnar , Daniel Vetter , Antonino Daplas , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Dave Hansen , Stefan Bader , konrad.wilk@oracle.com, ville.syrjala@linux.intel.com, david.vrabel@citrix.com, bhelgaas@google.com, Roger Pau =?iso-8859-1?Q?Monn=E9?= , xen-devel@lists.xensource.com On Fri, Mar 27, 2015 at 02:40:17PM -0600, Toshi Kani wrote: > On Fri, 2015-03-20 at 16:17 -0700, Luis R. Rodriguez wrote: > : > > @@ -734,6 +742,7 @@ void __init mtrr_bp_init(void) > > } > > > > if (mtrr_if) { > > + mtrr_enabled = true; > > set_num_var_ranges(); > > init_table(); > > if (use_intel()) { > get_mtrr_state(); > > After setting mtrr_enabled to true, get_mtrr_state() reads > MSR_MTRRdefType and sets 'mtrr_state.enabled', which also indicates if > MTRRs are enabled or not on the system. So, potentially, we could have > a case that mtrr_enabled is set to true, but mtrr_state.enabled is set > to disabled when MTRRs are disabled by BIOS. Thanks for the review, in this case then we should update mtrr_enabled to false. > ps. > I recently cleaned up this part of the MTRR code in the patch below, > which is currently available in the -mm & -next trees. > https://lkml.org/lkml/2015/3/24/1063 Great I will rebase and work with that and try to address this consideration you have raised. Luis