From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D12C1C4360C for ; Thu, 26 Sep 2019 13:01:39 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A59A4222BE for ; Thu, 26 Sep 2019 13:01:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A59A4222BE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35640 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDTOr-0003oi-E0 for qemu-devel@archiver.kernel.org; Thu, 26 Sep 2019 09:01:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46530) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDTMI-0001m5-I3 for qemu-devel@nongnu.org; Thu, 26 Sep 2019 08:59:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iDTMH-0003KX-89 for qemu-devel@nongnu.org; Thu, 26 Sep 2019 08:58:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49892) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iDTM7-0003BP-QV; Thu, 26 Sep 2019 08:58:47 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9FA6530BBE8A; Thu, 26 Sep 2019 12:58:46 +0000 (UTC) Received: from redhat.com (unknown [10.42.17.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 29E95194B6; Thu, 26 Sep 2019 12:58:45 +0000 (UTC) Date: Thu, 26 Sep 2019 13:58:43 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Maydell Subject: Re: [RFC PATCH] configure: deprecate 32 bit build hosts Message-ID: <20190926125817.GB19660@redhat.com> References: <20190925233013.6449-1-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Thu, 26 Sep 2019 12:58:46 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: "open list:RISC-V" , Richard Henderson , QEMU Developers , qemu-discuss , qemu-s390x , qemu-arm , qemu-ppc@nongnu.org, Alex =?utf-8?Q?Benn=C3=A9e?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Sep 26, 2019 at 08:50:36AM +0100, Peter Maydell wrote: > On Thu, 26 Sep 2019 at 00:31, Alex Benn=C3=A9e = wrote: > > > > The 32 bit hosts are already a second class citizen especially with > > support for running 64 bit guests under TCG. We are also limited by > > testing as actual working 32 bit machines are getting quite rare in > > developers personal menageries. For TCG supporting newer types like > > Int128 is a lot harder with 32 bit calling conventions compared to > > their larger bit sized cousins. Fundamentally address space is the > > most useful thing for the translator to have even for a 32 bit guest = a > > 32 bit host is quite constrained. > > > > As far as I'm aware 32 bit KVM users are even less numerous. Even > > ILP32 doesn't make much sense given the address space QEMU needs to > > manage. >=20 > For KVM we should wait until the kernel chooses to drop support, > I think. What if the kernel is waiting for QEMU to drop support too ;-P > > @@ -745,19 +744,22 @@ case "$cpu" in > > ;; > > armv*b|armv*l|arm) > > cpu=3D"arm" > > - supported_cpu=3D"yes" > > ;; >=20 > I'll leave others to voice opinions about their architectures, > but I still have 32-bit arm in my test set for builds, and > I'm pretty sure we have users (raspi users, for a start). RHEL dropped all 32-bit host support a long time ago, so Red Hat don't care for our products. Fedora has recently stopped building i686 kernels and thus also no long composes i686 installs. Some users complained, but ultimately no one cares enough to step forward as maintainers. That leaves armv7 as the only 32-bit arch in Fedora that is somewhat active & maintained. I don't have any real insight on whether any armv7 (Fedora) users are making much use of QEMU/KVM though, either system or user emulation.=20 Our preference in Fedora is to have things built on every architecture that the distro targets, but if upstream developers explicitly drop an architecture we're not going to try to add it back. Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|