From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: Question re live migrate on Xen 4.2 re different cpu capabilities Date: Mon, 11 Feb 2013 17:18:00 +0100 Message-ID: <20130211161800.GA15788@aepfle.de> References: <8B93B6FC00D1EC219B83AEDB@nimrod.local> <20130207091907.GA5540@aepfle.de> <1360230421.32479.46.camel@zakaz.uk.xensource.com> <496E7A8DB9DCF257D29E10F2@nimrod.local> <20130207151126.GA31180@aepfle.de> <13FBA4F2DA636D516C1AAB94@nimrod.local> <5113E22102000078000BCF51@nat28.tlf.novell.com> <83398C3BBF16693DB6E1E2CA@nimrod.local> <20130208133630.GA5304@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk Cc: Jan Beulich , Ian Campbell , Alex Bligh , Xen Devel List-Id: xen-devel@lists.xenproject.org On Fri, Feb 08, Konrad Rzeszutek Wilk wrote: > I recall seeing that libvirt had some of this figured out. It would > know which CPUID flags each CPU family had - and you could actually > set ('I am a Westmere CPU') or it would use the lowest common CPU > family support for all the guest. > > Granted that means you need to know _which_ of the machines has the > lowest common CPU family first. Or you set the guest to say 'Core' . > > Anyhow, perhaps looking at libvirt and implementing something similar > in 'xl' would be beneficial for these issues? I havent looked at the code, but I can imagine it does that via qemu. But it would be nice thing to have proper cpuid= handling were libvirt can force a certain cpu type. Olaf