From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59073) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYAa8-0006a3-7x for qemu-devel@nongnu.org; Wed, 27 Jun 2018 09:34:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYAa5-00034K-5G for qemu-devel@nongnu.org; Wed, 27 Jun 2018 09:34:00 -0400 Received: from mail-qt0-x243.google.com ([2607:f8b0:400d:c0d::243]:42195) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fYAa5-00033O-0d for qemu-devel@nongnu.org; Wed, 27 Jun 2018 09:33:57 -0400 Received: by mail-qt0-x243.google.com with SMTP id y31-v6so1601756qty.9 for ; Wed, 27 Jun 2018 06:33:56 -0700 (PDT) Sender: =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= References: <20180625131253.11218-1-kraxel@redhat.com> <20180625131253.11218-2-kraxel@redhat.com> <6ad67e44-b002-1cd7-cfd1-2d98ebde1a7e@redhat.com> <20180627065126.mwzdxshr3njzok7n@sirius.home.kraxel.org> <0df8a05c-43fc-6e85-b13c-d3f5c4691964@redhat.com> <87fu18ach6.fsf_-_@dusky.pond.sub.org> <20180627085217.blrsx5lmu4sau4fd@sirius.home.kraxel.org> <5d591d6c-ccc4-cc86-ebbc-3c66a6817c70@redhat.com> From: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= Message-ID: Date: Wed, 27 Jun 2018 10:33:51 -0300 MIME-Version: 1.0 In-Reply-To: <5d591d6c-ccc4-cc86-ebbc-3c66a6817c70@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] Drop support for 32bit hosts in qemu? (was: [PULL 1/6] audio/hda: create millisecond timers that handle IO) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth , Aurelien Jarno , Laurent Vivier , Peter Maydell Cc: Gerd Hoffmann , BALATON Zoltan , Markus Armbruster , Martin Schrodt , qemu-devel@nongnu.org, Max Reitz On 06/27/2018 06:09 AM, Thomas Huth wrote: > On 27.06.2018 10:52, Gerd Hoffmann wrote: >> Hi, >> >>>> Is QEMU still useful on 32-bit hosts? Honest question! >>> >>> I guess it depends on what 32-bit hosts you consider. If you look at only >>> x86 vs. x86_64 then probably x86 is not that important any more but for some >>> embedded systems/SoCs 32bit might still be common and QEMU useful for those >>> (also as host not only emulated). >> >> Well. I've used kvm with an 32bit arm soc (cubietruck). It's very >> slow. And all the arm architecture improvements to support kvm better >> are for aarch64 only. >> >>> Another option might be to not support audio/hda on 32bit hosts. It's not >>> nice either but a lot nicer than dropping support for 32bit hosts >>> alltogether to fix a problem in device emulation. >> >> But it also is not useful and a waste of resources to maintain 32bit >> host compatibility if nobody actually uses that ... >> >> For me testbuilds are the only reason to compile qemu for 32bit hosts. >> Since years. > > Well, while that's true for you, me and likely most of us developers, > you can not know whether this is also true for all users of qemu. Thus > this needs to be announced first for a couple of releases so that people > have a chance to speak up whether they still need this or not. As > mentioned earlier, embedded devices are often still 32-bit and I know > that there really are people who use QEMU on embedded devices. > > But I think we could at least announce now already that we intend to > drop support for 32-bit hosts in the future (maybe not in 2 releases > already, but, let's say in 2020? 2020 is already the EOL of Python 2, so > that will rule out a bunch of other legacy hosts, too). linux-user is certainly widely used on ARMv6 / ARMv7. Known user cases: - run ARMv7 binaries on ARMv6 - run armhf binaries on armel - run x86-64 binaries on ARMv7