From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:48211) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QR4Fa-0002eg-FZ for qemu-devel@nongnu.org; Mon, 30 May 2011 11:19:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QR4FZ-0002Gh-GS for qemu-devel@nongnu.org; Mon, 30 May 2011 11:19:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40644) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QR4FY-0002GZ-SQ for qemu-devel@nongnu.org; Mon, 30 May 2011 11:19:25 -0400 Message-ID: <4DE3B572.6030105@redhat.com> Date: Mon, 30 May 2011 18:19:14 +0300 From: Avi Kivity MIME-Version: 1.0 References: <4DDAD5CF.5050805@redhat.com> <4DE0B4B1.1000407@web.de> <20110530081847.GC27062@amd.com> <4DE3A3EC.80201@siemens.com> <20110530143846.GA2957@fermat.math.technion.ac.il> <4DE3B1E2.7020006@siemens.com> <20110530151020.GB7855@amd.com> <4DE3B4A5.6050509@siemens.com> In-Reply-To: <4DE3B4A5.6050509@siemens.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] drop -enable-nesting List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka , "Daniel P. Berrange" Cc: Anthony Liguori , Nadav Har'El , kvm , john cooper , "Roedel, Joerg" , "qemu-devel@nongnu.org" On 05/30/2011 06:15 PM, Jan Kiszka wrote: > On 2011-05-30 17:10, Roedel, Joerg wrote: > > On Mon, May 30, 2011 at 11:04:02AM -0400, Jan Kiszka wrote: > >> On 2011-05-30 16:38, Nadav Har'El wrote: > >>> On Mon, May 30, 2011, Jan Kiszka wrote about "drop -enable-nesting= (was: [PATCH 3/7] cpu model bug fixes and definition corrections...)": > >>>> On 2011-05-30 10:18, Roedel, Joerg wrote: > >>>>> On Sat, May 28, 2011 at 04:39:13AM -0400, Jan Kiszka wrote: > >>>>> > >>>>>> J=EF=BF=BDrg, how to deal with -enable-nesting in qemu-kvm to a= lign behavior > >>>>>> with upstream? > >>>>> > >>>>> My personal preference is to just remove it. In upstream-qemu it= is > >>>>> enabled/disabled by +/-svm. -enable-nesting is just a historic t= hing > >>>>> which can be wiped out. > >>> > >>> "-enable-nesting" could remain as a synonym for enabling either VM= X or SVM > >>> in the guest, depending on what was available in the host (because= KVM now > >>> supports both nested SVM and nested VMX, but not SVM-on-VMX or vic= e versa). > >> > >> Why? Once nesting is stable (I think SVM already is), there is no r= eason > >> for an explicit enable. And you can always mask it out via -cpu. > >> > >> BTW, what are the defaults for SVM right now in qemu-kvm and upstre= am? > >> Enable if the modeled CPU supports it? > > > > qemu-kvm still needs -enable-nesting, otherwise it is disabled. Upst= ream > > qemu should enable it unconditionally (can be disabled with -cpu ,-s= vm). > > Then let's start with aligning qemu-kvm defaults to upstream? I guess > that's what the diff I was citing yesterday is responsible for. > > In the same run, -enable-nesting could dump a warning on the console > that this switch is obsolete and will be removed from future versions. I think it's safe to drop -enable-nesting immediately. Dan, does=20 libvirt make use of it? > For VMX, I would suggest to keep it off by default until it matured, > asking the user to issue -cpu ...,+vmx. We should do that for svm as well (except for -cpu host or -cpu=20 something-with-svm). vmx will be kept disabled by the module option,=20 until it is deemed fit for general consumption. --=20 error compiling committee.c: too many arguments to function