Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964821Ab2EXQxR (ORCPT ); Thu, 24 May 2012 12:53:17 -0400 Received: from mga14.intel.com ([143.182.124.37]:54035 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755926Ab2EXQxO convert rfc822-to-8bit (ORCPT ); Thu, 24 May 2012 12:53:14 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="103885793" From: "Liu, Jinsong" To: Borislav Petkov CC: Konrad Rzeszutek Wilk , "Luck, Tony" , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH 1/3] xen/mce: Add mcelog support for Xen platform (v2) Thread-Topic: [PATCH 1/3] xen/mce: Add mcelog support for Xen platform (v2) Thread-Index: AQHNOcnqbJSbBggbSyWVZxOOOr38ZpbZJL/Q Date: Thu, 24 May 2012 16:52:35 +0000 Message-ID: References: <20120522092354.GB18578@aftab.osrc.amd.com> <20120524103023.GA27063@aftab.osrc.amd.com> <20120524162605.GK27063@aftab.osrc.amd.com> In-Reply-To: <20120524162605.GK27063@aftab.osrc.amd.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1732 Lines: 40 Borislav Petkov wrote: > On Thu, May 24, 2012 at 04:15:02PM +0000, Liu, Jinsong wrote: >> The reason is, if we do so, it would be covered by native >> misc_register(&mce_chrdev_device) later when native kernel init (xen >> init first and then start native kernel). >> Under such case, if linux running under xen platform, /dev/mcelog >> point to vcpu, that's pointless since it cannot get any mcelog from >> physical cpu (which owned by xen). >> >> Yes, we can use another misc device like /dev/xen-mcelog, w/ another >> device minor like 226, but that's not good for userspace mcelog >> tools. As far as I know, Novell mcelog use unified /dev/mcelog >> interface for linux running under either bare metal or xen platform. > > Maybe create a symlink in /dev/mcelog pointing to /dev/xen-mcelog? > > That should solve it. Kernel has created a file /dev/mcelog no matter running at native or xen platform. If xen try to mask kernel creating /dev/mcelog, that would be harmful to native kernel. > >> This patch just do redirection at xen code path, and that would not >> hurt anything to native kernel. > > My concern is that if we remove /dev/mcelog one day, xen people will > cry. Don't worry :) Xen people would handle that case (that's not trouble for xen), just notify us is enough. If kernel really remove /dev/mcelog some day, xen just need simply add 1 line misc_register(&xen_mce_chrdev_device), since currently all other code are xen-self-contained. Thanks, Jinsong -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/