From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:54136 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752837AbbGAJXc (ORCPT ); Wed, 1 Jul 2015 05:23:32 -0400 Date: Wed, 1 Jul 2015 10:23:28 +0100 From: Luis Henriques To: Bandan Das Cc: Greg KH , stable@vger.kernel.org, Paolo Bonzini Subject: Re: KVM: nSVM: Check for NRIPS support before updating control field Message-ID: <20150701092328.GB2029@ares> References: <20150629192810.GA19965@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: On Mon, Jun 29, 2015 at 04:22:42PM -0400, Bandan Das wrote: > Greg KH writes: > > > On Mon, Jun 29, 2015 at 03:18:51PM -0400, Bandan Das wrote: > >> > >> Commit f104765b4f81fd74d69e0eb161e89096deade2db upstream. > >> > >> This causes the L1 guest to crash when running a nested guest > >> with an AMD processor that doesn't support NRIPS. > >> > >> If hardware doesn't support DecodeAssist - a feature that provides > >> more information about the intercept in the VMCB, KVM decodes the > >> instruction and then updates the next_rip vmcb control field. > >> However, NRIP support itself depends on cpuid Fn8000_000A_EDX[NRIPS]. > >> Since skip_emulated_instruction() doesn't verify nrip support > >> before accepting control.next_rip as valid, avoid writing this > >> field if support isn't present. > >> > >> Signed-off-by: Bandan Das > >> Signed-off-by: Paolo Bonzini > >> --- > >> arch/x86/kvm/svm.c | 8 ++++++-- > >> 1 file changed, 6 insertions(+), 2 deletions(-) > > > > What stable kernel trees do you want this applied to? > > Sorry, I missed that part. I believe this bug is present > since commit cfec82cb7d3 which makes it applicable to > #3.0+ > Thanks, queuing it for the 3.16 kernel. Cheers, -- Lu�s > Bandan > > thanks, > > > > greg k-h > -- > To unsubscribe from this list: send the line "unsubscribe stable" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html