From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1fXnWr-0002wN-CF for mharc-qemu-trivial@gnu.org; Tue, 26 Jun 2018 08:57:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51948) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fXnWl-0002r4-Lo for qemu-trivial@nongnu.org; Tue, 26 Jun 2018 08:57:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fXnWh-0005mG-61 for qemu-trivial@nongnu.org; Tue, 26 Jun 2018 08:56:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38684) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fXnWb-0005hp-R8; Tue, 26 Jun 2018 08:56:49 -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 BAC20C047B69; Tue, 26 Jun 2018 12:56:48 +0000 (UTC) Received: from localhost (ovpn-116-35.gru2.redhat.com [10.97.116.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC1AD30001E9; Tue, 26 Jun 2018 12:56:45 +0000 (UTC) Date: Tue, 26 Jun 2018 09:56:44 -0300 From: Eduardo Habkost To: Cornelia Huck Cc: Thomas Huth , Paolo Bonzini , Markus Armbruster , zhang.zhanghailiang@huawei.com, Ben Warren , qemu-trivial@nongnu.org, qemu-devel@nongnu.org, Stefan Hajnoczi Message-ID: <20180626125644.GS7451@localhost.localdomain> References: <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> <54dfe708-cccf-c628-753f-692c83391ec4@redhat.com> <20180626095004.7e92fdaa.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180626095004.7e92fdaa.cohuck@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 [10.5.110.31]); Tue, 26 Jun 2018 12:56:48 +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: Tue, 26 Jun 2018 12:57:03 -0000 On Tue, Jun 26, 2018 at 09:50:04AM +0200, Cornelia Huck wrote: > On Tue, 26 Jun 2018 06:40:56 +0200 > Thomas Huth wrote: > > > On 25.06.2018 20:26, 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... > > > > That's certainly not true. I've seen a couple of times already that > > people ask on IRC why their guests are running so slow, and if you ask > > them about their command line, it's obvious that they simply were not > > aware of "-accel" / "-enable-kvm" yet. > > > > > > Maybe we simply should add a "--verbose" command line option that people > > can use to diagnose their problems: > > > > $ qemu-system-x86_64 --verbose > > QEMU emulator version 2.12.50 > > Using 'tcg' accelerator. Use '-accel kvm' to speed things up. > > Machine type is 'pc-i440fx-3.0'. Use 'q35' for a more modern machine. > > .... > > > > Not sure how serious you meant that, but I actually quite like the > idea :) Also, this mode could be enabled by default if stderr is a tty. -- Eduardo