From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1fXXWc-0007c1-QW for mharc-qemu-trivial@gnu.org; Mon, 25 Jun 2018 15:51:46 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55380) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fXXWa-0007aG-54 for qemu-trivial@nongnu.org; Mon, 25 Jun 2018 15:51:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fXXWZ-0000ye-9x for qemu-trivial@nongnu.org; Mon, 25 Jun 2018 15:51:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42860) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fXXWT-0000uR-4R; Mon, 25 Jun 2018 15:51:37 -0400 Received: from smtp.corp.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2988C30832E8; Mon, 25 Jun 2018 19:51:36 +0000 (UTC) Received: from localhost (ovpn-116-16.gru2.redhat.com [10.97.116.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id A4A8230001EC; Mon, 25 Jun 2018 19:51:27 +0000 (UTC) Date: Mon, 25 Jun 2018 16:51:26 -0300 From: Eduardo Habkost To: Paolo Bonzini Cc: Markus Armbruster , Thomas Huth , zhang.zhanghailiang@huawei.com, Ben Warren , qemu-trivial@nongnu.org, Cornelia Huck , qemu-devel@nongnu.org, Stefan Hajnoczi Message-ID: <20180625195126.GN7451@localhost.localdomain> References: <20180619171539.0adc90d6.cohuck@redhat.com> <20180622181108.GY7451@localhost.localdomain> <20180622193522.GI7451@localhost.localdomain> <743d495e-51cd-8c8e-293e-026b8dece74a@redhat.com> <87lgb3xsv8.fsf@dusky.pond.sub.org> <4292432f-5f26-6925-4c14-ad1370e36e5b@redhat.com> <20180625173056.GM7451@localhost.localdomain> <97504b42-9ebe-45c5-6ff3-b43102c8374a@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <97504b42-9ebe-45c5-6ff3-b43102c8374a@redhat.com> X-Fnord: you can see the fnord User-Agent: Mutt/1.9.2 (2017-12-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Mon, 25 Jun 2018 19:51:36 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-trivial] [Qemu-devel] [RFC PATCH 4/4] qemu-options: Do not show -enable-kvm and -enable-hax in the docs anymore X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Jun 2018 19:51:45 -0000 On Mon, Jun 25, 2018 at 08:26:28PM +0200, Paolo Bonzini wrote: > On 25/06/2018 19:30, Eduardo Habkost wrote: > >>> Attentive distros could even replace the wrapper script by a link. > >> If they are okay with replacing the "KVM only" semantics with "KVM or > >> TCG", which I think is generally worse. > > > > If we can't get agreement on what's the right default for each > > QEMU binary, I think that's yet another reason to document that > > upstream QEMU won't guarantee ABI compatibility if -accel is > > omitted. > > Before that we should ask what the benefit is in changing the default > for qemu-system-*. Nobody is using it in practice to start QEMU with > KVM enabled... How can you be sure? If qemu-system-* is installed with KVM compiled in, libvirt will probe it using "-machine none,accel=kvm:tcg" and run the VM using "-machine $MACHINE,accel=kvm". In either case, I'm not arguing (yet) for changing the default upstream. I'm just arguing for upstream QEMU to not make any promises about the default. -- Eduardo