From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: PV-vNUMA issue: topology is misinterpreted by the guest Date: Thu, 16 Jul 2015 17:39:33 +0100 Message-ID: <55A7DE45.4040804@citrix.com> References: <1437042762.28251.18.camel@citrix.com> <55A7A7F40200007800091D60@mail.emea.novell.com> <55A78DF2.1060709@citrix.com> <20150716152513.GU12455@zion.uk.xensource.com> <55A7D17C.5060602@citrix.com> <55A7D2CC.1050708@oracle.com> <55A7F7F40200007800092152@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZFmCG-0007RZ-9t for xen-devel@lists.xenproject.org; Thu, 16 Jul 2015 16:39:44 +0000 In-Reply-To: <55A7F7F40200007800092152@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich , Boris Ostrovsky Cc: Elena Ufimtseva , Wei Liu , Dario Faggioli , David Vrabel , "xen-devel@lists.xenproject.org" List-Id: xen-devel@lists.xenproject.org On 16/07/15 17:29, Jan Beulich wrote: >>>> On 16.07.15 at 17:50, wrote: >> Can't we set leaf 1's EBX[32:16] to 1? > I don't think we should partially overwrite the relevant parts of > CPUID output - either all or nothing (so that things at least > remain consistent). Also, there are no masking/override MSRs for that feature leaf on any hardware I am aware of, and a PV guest using plain `cpuid` will not observe any attempt of Xen's to control the value. ~Andrew