From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33614) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dVK4g-0002wb-PT for qemu-devel@nongnu.org; Wed, 12 Jul 2017 12:01:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dVK4c-0006S4-Tm for qemu-devel@nongnu.org; Wed, 12 Jul 2017 12:01:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33422) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dVK4c-0006Qx-O7 for qemu-devel@nongnu.org; Wed, 12 Jul 2017 12:01:10 -0400 References: <1499847753-8513-1-git-send-email-thuth@redhat.com> <20170712150400.GH5237@redhat.com> From: Thomas Huth Message-ID: <9d51d348-7ad6-a98d-3f6d-89e8af5e3a16@redhat.com> Date: Wed, 12 Jul 2017 18:00:46 +0200 MIME-Version: 1.0 In-Reply-To: <20170712150400.GH5237@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v3] hw/i386: Deprecate the machines pc-0.10 to pc-1.2 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: qemu-devel@nongnu.org, Paolo Bonzini , "Michael S. Tsirkin" , Eduardo Habkost , Marcel Apfelbaum , Igor Mammedov , Gerd Hoffmann , Richard Henderson On 12.07.2017 17:04, Daniel P. Berrange wrote: > On Wed, Jul 12, 2017 at 10:22:33AM +0200, Thomas Huth wrote: >> We don't want to carry along old machine types forever. If we are able= to >> remove the pc machines up to 0.13 one day for example, this would allo= w >> us to eventually kill the code for rombar=3D0 (i.e. where QEMU copies = ROM >> BARs directly to low memory). Everything up to pc-1.2 is also known to >> have issues with migration. So let's start with a deprecation message >> for the old machine types so that the (hopefully) few users of these o= ld >> systems start switching over to newer machine types instead. >=20 > I think we must document & agree on our support policy for machine > types, before we start marking them as deprecated. eg please consider > the following document before accepting this deprecation patch: >=20 > https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg00652.html >=20 > Note in that proposal there, I say we do *not* go through trouble of > explicitly marking machines as deprecated. We just document upfront > the intended lifecycle and then delete them when it is done. >=20 > Just use deprecation warnings for things where there is no predictable > lifecycle upfront. I'm still not 100% sure whether that auto-deprecation of machine types is such a good idea ... since we might need to maintain machines in downstream a little bit longer than specified there, it might be better to rather deprecate them manually from time to time. Anyway, concerning my patch - I'll stop here and won't send another version. There is too much bikeshed painting going on in this area for my taste, and since I'm rather a powerpc / s390x guy, I'm also fine if the pc-0.x machines stay around forever. If somebody else wants to push this topic instead, feel free to do so. Thomas