From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752743AbaIXLsP (ORCPT ); Wed, 24 Sep 2014 07:48:15 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:36865 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750856AbaIXLsO (ORCPT ); Wed, 24 Sep 2014 07:48:14 -0400 Date: Wed, 24 Sep 2014 12:48:15 +0100 From: Will Deacon To: Paolo Bonzini Cc: "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , Gleb Natapov , Alex Williamson Subject: Re: [PATCH] kvm-vfio: do not use module_init Message-ID: <20140924114814.GE28823@arm.com> References: <1411558149-3609-1-git-send-email-pbonzini@redhat.com> <20140924114435.GD28823@arm.com> <5422AEF1.8010008@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5422AEF1.8010008@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 24, 2014 at 12:45:53PM +0100, Paolo Bonzini wrote: > Il 24/09/2014 13:44, Will Deacon ha scritto: > > On Wed, Sep 24, 2014 at 12:29:09PM +0100, Paolo Bonzini wrote: > >> /me got confused between the kernel and QEMU. In the kernel, you can > >> only have one module_init function, and it will prevent unloading the > >> module unless you also have the corresponding module_exit function. > > > > Happy for you to take the blame, but I think this one's my fault! > > That's why you were CCed! ;) > > >> So, commit 80ce1639727e (KVM: VFIO: register kvm_device_ops dynamically, > >> 2014-09-02) broke unloading of the kvm module, by adding a module_init > >> function and no module_exit. > > > > I forget kvm builds as a module for other architectures (ie. not arm/arm64). > > > >> Repair it by making kvm_vfio_ops_init weak, and checking it in > >> kvm_init. > > > > Hehe, if only there was a kconfig option for kvm-vfio.c... > > Yeah, I was tempted to put it back. What do you think? I think it's nicer than the __weak symbol and I don't see a downside to having the option (the reason for removing it was lack of users, which lasted a couple of hours). Will