From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: SVM: Keep intercepting task switching with NPT enabled Date: Tue, 18 Oct 2011 19:37:32 +0200 Message-ID: <4E9DB95C.1030105@redhat.com> References: <4E9DA7EF.30804@siemens.com> <20111018163516.GO2198@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Jan Kiszka , Marcelo Tosatti , kvm , Gleb Natapov To: "Roedel, Joerg" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:7071 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756367Ab1JRRhi (ORCPT ); Tue, 18 Oct 2011 13:37:38 -0400 In-Reply-To: <20111018163516.GO2198@amd.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/18/2011 06:35 PM, Roedel, Joerg wrote: > On Tue, Oct 18, 2011 at 12:23:11PM -0400, Jan Kiszka wrote: > > AMD processors apparently have a bug in the hardware task switching > > support when NPT is enabled. If the task switch triggers a NPF, we can > > get wrong EXITINTINFO along with that fault. On resume, spurious > > exceptions may then be injected into the guest. > > > > We were able to reproduce this bug when our guest triggered #SS and the > > handler were supposed to run over a separate task with not yet touched > > stack pages. > > > > Work around the issue by continuing to emulate task switches even in > > NPT mode. > > > > Signed-off-by: Jan Kiszka > > Acked-by: Joerg Roedel > Will there be an erratum published for this bug? Are all processors affected? I'd like to limit this to just the buggy processors, if and when fixed processors become available. -- error compiling committee.c: too many arguments to function