From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: Intermittent fatal page fault with XEN 4.3.1 (Centos 6.3 DOM0 with linux kernel 3.10.16.) Date: Wed, 6 Nov 2013 16:54:44 +0000 Message-ID: <527A7454.9060309@citrix.com> References: <5278D0BB02000078000FF6E4@nat28.tlf.novell.com> <527912E9.3010304@xen.org> <5E2B3362-4D93-4FEF-987A-E477B0DCEE51@mcafee.com> <527A5BB50200007800100255@nat28.tlf.novell.com> <4E8EC677-8D22-4672-9C5C-12DD094107D2@McAfee.com> <1383754737.26213.136.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Ve6NU-0004b6-VE for xen-devel@lists.xenproject.org; Wed, 06 Nov 2013 16:54:49 +0000 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: Jeff_Zimmerman@McAfee.com Cc: lars.kurth.xen@gmail.com, xen-devel@lists.xenproject.org, lars.kurth@xen.org, Ian.Campbell@citrix.com, JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org On 06/11/13 16:48, Jeff_Zimmerman@McAfee.com wrote: > On Nov 6, 2013, at 8:18 AM, Ian Campbell > wrote: > >> On Wed, 2013-11-06 at 16:05 +0000, Jeff_Zimmerman@McAfee.com wrote: >>> Jan, >>> >>> I will give your patch a try. >>> I have to recant my previous statement regarding not using nested-virt. >>> It seems some of the code that is being executed on the vm contains vmx instructions. >>> Since by virtue of running this code in an hvm subject make it nested-virt. >>> >>> This raises a question, if this functionality is undesired can we just disable nested virt by adding >>> nestedhvm=false to the configuration file? Should the cpuid and >>> cupid_check settings be changed as well? >> I'm reasonably certain that nestedhvm=false will clear the relevant >> flags in the guest visible cpuid. I'd say it was a bug if this doesn't >> happen. >> >> nestedhvm should be disabled by default, did you explicitly enable it? >> Removing the line altogether ought to disable it too. Please let us know >> if not. >> >> Ian. >> > I did not enable nestedvm and when I run xl list -l the output shows nestedhvm= > I was not sure what the default was supposed to be. I will try setting it and re-run our test. > Jeff nested-virt is strictly experimental, and still has known bugs (and clearly some unknown ones). I looked over the xl code and thought that nestedhvm should default to false, but I would prefer someone more familar with libxl and the idl to confirm what the default should be. ~Andrew > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel