From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:36249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S75hX-0003ng-V5 for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:54:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S75h5-0003Z7-JT for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:54:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8364) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S75h5-0003XT-As for qemu-devel@nongnu.org; Mon, 12 Mar 2012 09:53:47 -0400 Date: Mon, 12 Mar 2012 15:53:38 +0200 From: Gleb Natapov Message-ID: <20120312135338.GE2304@redhat.com> References: <20120309210403.GA2319@redhat.com> <20120310124246.GA4408@redhat.com> <20120310155843.GJ2914@otherpad.lan.raisama.net> <4F5B9C6F.3050705@codemonkey.ws> <20120311132755.GJ17882@redhat.com> <4F5CB2EA.10000@codemonkey.ws> <20120312125227.GA20654@otherpad.lan.raisama.net> <20120312130419.GF20867@redhat.com> <20120312131532.GB2304@redhat.com> <20120312135018.GI20867@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120312135018.GI20867@redhat.com> Subject: Re: [Qemu-devel] [libvirt] Modern CPU models cannot be used with libvirt List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Eduardo Habkost , libvir-list@redhat.com, qemu-devel@nongnu.org, Avi Kivity , Anthony Liguori , Jiri Denemark , "arch@ovirt.org" On Mon, Mar 12, 2012 at 01:50:18PM +0000, Daniel P. Berrange wrote: > On Mon, Mar 12, 2012 at 03:15:32PM +0200, Gleb Natapov wrote: > > On Mon, Mar 12, 2012 at 01:04:19PM +0000, Daniel P. Berrange wrote: > > > On Mon, Mar 12, 2012 at 09:52:27AM -0300, Eduardo Habkost wrote: > > > > On Sun, Mar 11, 2012 at 09:12:58AM -0500, Anthony Liguori wrote: > > > > > On 03/11/2012 08:27 AM, Gleb Natapov wrote: > > > > > >On Sat, Mar 10, 2012 at 12:24:47PM -0600, Anthony Liguori wrote: > > > > > >>Let's step back here. > > > > > >> > > > > > >>Why are you writing these patches? It's probably not because you > > > > > >>have a desire to say -cpu Westmere when you run QEMU on your laptop. > > > > > >>I'd wager to say that no human has ever done that or that if they > > > > > >>had, they did so by accident because they read documentation and > > > > > >>thought they had to. > > > > > > > > No, it's because libvirt doesn't handle all the tiny small details > > > > involved in specifying a CPU. All libvirty knows about are a set of CPU > > > > flag bits, but it knows nothing about 'level', 'family', and 'xlevel', > > > > but we would like to allow it to expose a Westmere-like CPU to the > > > > guest. > > > > > > This is easily fixable in libvirt - so for the point of going discussion, > > > IMHO, we can assume libvirt will support level, family, xlevel, etc. > > > > > And fill in all cpuid leafs by querying /dev/kvm when needed or, if TCG > > is used, replicating QEMU logic? And since QEMU should be usable without > > libvirt the same logic should be implemented in QEMU anyway. > > I'm not refering to that. I'm saying that any data QEMU has in its > config file (/etc/qemu/target-x86_64.conf) should be represented > in the libvirt CPU XML. family, model, stepping, xlevel and > model_id are currently in QEMU CPU configs, but not in libvirt XML, > which is something we will fix. The other issues you mention are > completely independant of that. > Eduardo is going to extend what can be configured in /etc/qemu/target-x86_64.conf and make CPU models name per machine type. What QEMU has now is not good enough. I doubt libvirt goal is to be as bad as QEMU :) -- Gleb.