From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755834Ab0I1OBM (ORCPT ); Tue, 28 Sep 2010 10:01:12 -0400 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:4637 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755260Ab0I1OBL (ORCPT ); Tue, 28 Sep 2010 10:01:11 -0400 X-IronPort-AV: E=Sophos;i="4.57,247,1283731200"; d="scan'208";a="2076471" Date: Tue, 28 Sep 2010 15:00:58 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Ingo Molnar CC: Stefano Stabellini , Thomas Gleixner , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , "xen-devel@lists.xensource.com" , Jeremy Fitzhardinge , "sct@redhat.com" Subject: Re: [PATCH 12/12] xen/mtrr: Add mtrr_if support for Xen mtrr In-Reply-To: <20100928123925.GA18208@elte.hu> Message-ID: References: <1285676218-26218-12-git-send-email-stefano.stabellini@eu.citrix.com> <20100928123925.GA18208@elte.hu> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Sep 2010, Ingo Molnar wrote: > > * stefano.stabellini@eu.citrix.com wrote: > > > From: Stephen Tweedie > > > > Add a Xen mtrr type, and reorganise mtrr initialisation slightly to > > allow the mtrr driver to set up num_var_ranges (Xen needs to do this by > > querying the hypervisor itself.) > > > > [ Impact: add basic MTRR support ] > > > > Signed-off-by: Stephen Tweedie > > Signed-off-by: Jeremy Fitzhardinge > > Signed-off-by: Stefano Stabellini > > --- > > arch/x86/kernel/cpu/mtrr/Makefile | 2 +- > > arch/x86/kernel/cpu/mtrr/main.c | 3 + > > arch/x86/kernel/cpu/mtrr/mtrr.h | 7 ++ > > arch/x86/kernel/cpu/mtrr/xen.c | 110 +++++++++++++++++++++++++++++++++++++ > > 4 files changed, 121 insertions(+), 1 deletions(-) > > create mode 100644 arch/x86/kernel/cpu/mtrr/xen.c > > Still NAK, for the very same reasons as we NAK-ed it the previous time: > /proc/mtrr is a problematic and complicated legacy interface that should > die. Any modern X server will do the right thing via PAT. > Sorry I should have read the original thread more carefully: I didn't realize this patch had been NAK-ed. However it is not a problem because we can easily disable MTRRs from Xen and with no cpu_has_mtrr the kernel would still boot fine on Xen. Also I think we do have PAT support nowadays but I'll let Jeremy comment on that. > Also, please get the Ack of at least one x86 maintainer for x86 patches. > I'll repost the series without the last two patches, so there won't be any x86 changes at all :) Many thanks for your quick feedback, Stefano