From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932626Ab3AYS3c (ORCPT ); Fri, 25 Jan 2013 13:29:32 -0500 Received: from mail.skyhub.de ([78.46.96.112]:39039 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932279Ab3AYS3Z (ORCPT ); Fri, 25 Jan 2013 13:29:25 -0500 Date: Fri, 25 Jan 2013 19:32:13 +0100 From: Borislav Petkov To: Dmitry Torokhov Cc: "H. Peter Anvin" , Ingo Molnar , X86 ML , Greg Kroah-Hartman , LKML , devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, Thomas Gleixner , JBeulich@suse.com, Borislav Petkov , Dmitry Torokhov , "K. Y. Srinivasan" , Haiyang Zhang Subject: Re: [PATCH -v2 2/2] x86: Make Linux guest support optional Message-ID: <20130125183213.GB1380@pd.tnic> Mail-Followup-To: Borislav Petkov , Dmitry Torokhov , "H. Peter Anvin" , Ingo Molnar , X86 ML , Greg Kroah-Hartman , LKML , devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, Thomas Gleixner , JBeulich@suse.com, Borislav Petkov , Dmitry Torokhov , "K. Y. Srinivasan" , Haiyang Zhang References: <20130125100655.GC23404@pd.tnic> <1359136777-4512-2-git-send-email-bp@alien8.de> <20130125181251.GA5563@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20130125181251.GA5563@core.coreip.homeip.net> 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, Jan 25, 2013 at 10:12:51AM -0800, Dmitry Torokhov wrote: > Hi Borislav, > > On Fri, Jan 25, 2013 at 06:59:37PM +0100, Borislav Petkov wrote: > > From: Borislav Petkov > > > > Put all config options needed to run Linux as a guest behind a > > CONFIG_HYPERVISOR_GUEST menu so that they don't get built-in by > > default but selected by the user. Also, move x86_hyper into an > > unconditionally-built compilation unit because it is exported with the > > non-GPL flavour and we can't know whatever uses it on the outside. > > I am confused by this statement... How can EXPORT_SYMBOL() vs > EXPORT_SYMBOL_GPL() help you determining if it is used out of tree or > not? Maybe this wasn't formulated clear enough - I wanted to say that with the !GPL flavor, any code (proprietary included) can link to those symbols and we cannot know who uses it and if we hide that symbol, someone would probably come crying. Because if we could, I would've done trivial accessor functions which would return NULL when CONFIG_HYPERVISOR_GUEST is not set so that those cases build and boot fine, and we wouldn't have the need to have this symbol always present (like is the case now and I had to move it to setup.c). If it were _GPL, we would've fixed all its users to switch to the accessors. Makes more sense? -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --