Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751548AbdLNHv3 (ORCPT ); Thu, 14 Dec 2017 02:51:29 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:57495 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750722AbdLNHv2 (ORCPT ); Thu, 14 Dec 2017 02:51:28 -0500 X-ME-Sender: Date: Thu, 14 Dec 2017 08:51:32 +0100 From: Greg KH To: Stephen Hemminger Cc: Vincent Legoll , devel@linuxdriverproject.org, haiyangz@microsoft.com, sthemmin@microsoft.com, Linux Kernel ML Subject: Re: [PATCH] hyperv: make HYPERV a menuconfig to ease disabling it all Message-ID: <20171214075132.GB31378@kroah.com> References: <20171209152151.4341-1-vincent.legoll@gmail.com> <20171209215022.6795dd91@xeon-e3> <20171213132338.1efe04a7@xeon-e3> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171213132338.1efe04a7@xeon-e3> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1467 Lines: 50 On Wed, Dec 13, 2017 at 01:23:38PM -0800, Stephen Hemminger wrote: > On Wed, 13 Dec 2017 09:54:19 +0100 > Vincent Legoll wrote: > > > Hello, > > > > On Sun, Dec 10, 2017 at 6:50 AM, Stephen Hemminger > > wrote: > > > Will this break existing configs? > > > > I don't think so. Last time I did some similar changes, the kbuild > > test robot found some warnings on some configurations, I hope > > it will find problems (if any) for that series too (this one is not alone, > > I've got a bunch of other similar patches in-flight) > > > > Thanks > > NAK > > Let me give a concrete example of how this will break users. > > 1. Assume user has a working .config file in their kernel build directory > which builds a kernel that works on Hyper-V. > > 2. Add your patch (or assume it makes into a later version). > > 3. User then does > > $ make oldconfig > scripts/kconfig/conf --oldconfig Kconfig > * > * Restart config... > * > * > * Microsoft Hyper-V guest support > * > Microsoft Hyper-V guest support (HYPERV_MENU) [N/y] (NEW) > > If they hit return, the default value is not enabling HyperV and they > will then go on to build a kernel that will not boot on your system. > > The default MUST be set to Yes. Or you can just not take these types of odd and silly changes to the Kconfig files, and leave it as-is. I have yet to see the good reason why these are needed at all. thanks, greg k-h