From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Egger, Christoph" Subject: Re: [PATCH 1/1 V5] x86/AMD: Fix nested svm crash due to assertion in __virt_to_maddr Date: Mon, 12 Aug 2013 13:13:58 +0200 Message-ID: <5208C376.5010905@amazon.de> References: <1375691514-3426-1-git-send-email-suravee.suthikulpanit@amd.com> <520264F102000078000E9EFA@nat28.tlf.novell.com> <5202C7A5.4070304@amd.com> <52035B0C02000078000EA1B5@nat28.tlf.novell.com> <5208A396.5090106@amazon.de> <5208C06F02000078000EB0C9@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1V8qHt-0004i7-Q8 for xen-devel@lists.xenproject.org; Mon, 12 Aug 2013 11:27:49 +0000 In-Reply-To: <5208C06F02000078000EB0C9@nat28.tlf.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 Cc: xen-devel , tim@xen.org, Suravee Suthikulanit List-Id: xen-devel@lists.xenproject.org On 12.08.13 11:01, Jan Beulich wrote: >>>> On 12.08.13 at 10:57, "Egger, Christoph" wrote: >> On 08.08.13 08:47, Jan Beulich wrote: >>> In any case - explaining how nestedhvm_enabled() could end up >>> returning a value different from hvm_svm_enabled() would help >>> my understanding. >> >> nestedhvm_enabled() returns true when 'nestedhvm=1' in the >> guest config file. >> >> hvm_svm_enabled() returns true when the hvm guest enabled SVM >> in EFER. > > And the guest should certainly be disallowed to enable SVM in > EFER when nestedhvm was not 1 in the config file. That's correct. The guest should also never see SVM available via cpuid. Analogous same regarding VMX on Intel. Christoph