From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59711) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYFR8-0007Bd-Ll for qemu-devel@nongnu.org; Wed, 27 Jun 2018 14:45:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYFR6-0002jv-42 for qemu-devel@nongnu.org; Wed, 27 Jun 2018 14:45:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60990 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fYFR5-0002go-VF for qemu-devel@nongnu.org; Wed, 27 Jun 2018 14:45:00 -0400 Date: Wed, 27 Jun 2018 19:44:53 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20180627184453.GC2424@work-vm> References: <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> <4c86fb26-f7c3-e66e-33a2-dbbfe2e70960@vivier.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <4c86fb26-f7c3-e66e-33a2-dbbfe2e70960@vivier.eu> Content-Transfer-Encoding: quoted-printable 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: Laurent Vivier Cc: Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Thomas Huth , Aurelien Jarno , Peter Maydell , Martin Schrodt , Markus Armbruster , qemu-devel@nongnu.org, Gerd Hoffmann , Max Reitz * Laurent Vivier (laurent@vivier.eu) wrote: > Le 27/06/2018 =E0 15:33, Philippe Mathieu-Daud=E9 a =E9crit=A0: > > 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 bu= t 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 bet= ter > >>> are for aarch64 only. > >>> > >>>> Another option might be to not support audio/hda on 32bit hosts. I= t'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 32bi= t > >>> host compatibility if nobody actually uses that ... > >>> > >>> For me testbuilds are the only reason to compile qemu for 32bit hos= ts. > >>> 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. Th= us > >> this needs to be announced first for a couple of releases so that pe= ople > >> 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 kno= w > >> 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). > >=20 > > linux-user is certainly widely used on ARMv6 / ARMv7. > >=20 > > Known user cases: > >=20 > > - run ARMv7 binaries on ARMv6 > > - run armhf binaries on armel > > - run x86-64 binaries on ARMv7 > >=20 >=20 > I run i386 binaries on ARMv6. Do you know if that model has the 64bit atomics (ldrexd/strexd)? Dave > I use it to run i386 printer driver on my raspberry Pi B+. > Brother doesn't provide the binary for ARM, neither the source. >=20 > Thanks, > Laurent >=20 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK