From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50892) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cahuu-0007xz-KS for qemu-devel@nongnu.org; Mon, 06 Feb 2017 06:57:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cahur-0004UE-JW for qemu-devel@nongnu.org; Mon, 06 Feb 2017 06:57:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cahur-0004Tw-BB for qemu-devel@nongnu.org; Mon, 06 Feb 2017 06:57:05 -0500 Date: Mon, 6 Feb 2017 11:57:00 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20170206115659.GC2524@work-vm> References: <20170202150530.1025-1-pbonzini@redhat.com> <20170203150050.GF642@stefanha-x1.localdomain> <55b46fa3-c861-9ba4-da65-25bc392d8900@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55b46fa3-c861-9ba4-da65-25bc392d8900@redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH] configure: remove --enable-replication/--disable-replication List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Stefan Hajnoczi , qemu-devel@nongnu.org * Paolo Bonzini (pbonzini@redhat.com) wrote: > > > On 03/02/2017 07:00, Stefan Hajnoczi wrote: > > On Thu, Feb 02, 2017 at 07:05:30AM -0800, Paolo Bonzini wrote: > >> The replication feature is a small amount of code, does not > >> require any external library and unless used does not add > >> anything to the guest's attack surface. Since any extra > >> configure option affects maintainability on the other hand > >> and is subject to bit rot, I think there is no need to > >> make it configurable. > > > > I think the current state is good: replication is enabled by default but > > can be compiled out if desired. > > > > Downstreams may not be comfortable supporting this feature yet since > > it's incomplete. It's fair to offer an option to disable it, otherwise > > downstreams will have to patch this themselves. > > I understand---I just am not sure where to draw the line because there's > plenty of other incomplete features, hence the RFC. For example, > record/replay cannot be enabled or disabled on the configure command > line. That was the case even in the beginning, where it didn't support > either block or character device replay. The line is certainly fuzzy, but I think it's worth making the following type of things configurable: Features that have a large chunk of code - dont lets try and configure tiny things on and off That can be trivially configured - lets not put big chunks of code around making them configurable and that are incomplete or are unused by large chunks of the users Dave > --enable-coroutine-pool is a relic of when Windows builds needed it, but > all other --enable-* options require an external library or at least a > specific operating system. See for example this patch: > > commit 52b53c04faab9f7a9879c8dc014930649a3e698d > Author: Fam Zheng > Date: Wed Sep 10 14:17:51 2014 +0800 > > block: Always compile virtio-blk dataplane > > Dataplane doesn't depend on linux-aio any more, so we don't need the > compiling condition now. > > Configure options are kept but just print a message. > > Signed-off-by: Fam Zheng > Reviewed-by: Paolo Bonzini > Message-id: 1410329871-28885-4-git-send-email-famz@redhat.com > Signed-off-by: Stefan Hajnoczi > > > I would actually prefer to remove many of the latter > (--enable-vhost-net, --enable-vhost-scsi, --enable-vhost-socket) and > just use default-configs. We are already doing it for ivshmem for example: > > CONFIG_IVSHMEM=$(CONFIG_EVENTFD) > > Paolo -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK