From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754618AbaF3PFN (ORCPT ); Mon, 30 Jun 2014 11:05:13 -0400 Received: from mout.web.de ([212.227.15.14]:61710 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751005AbaF3PFJ (ORCPT ); Mon, 30 Jun 2014 11:05:09 -0400 Message-ID: <53B17C5D.5050407@web.de> Date: Mon, 30 Jun 2014 17:03:57 +0200 From: Jan Kiszka User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: Paolo Bonzini CC: Gleb Natapov , Borislav Petkov , lkml , Peter Zijlstra , Steven Rostedt , x86-ml , kvm@vger.kernel.org, =?windows-1252?Q?J=F6rg_?= =?windows-1252?Q?R=F6del?= Subject: Re: [PATCH] KVM: SVM: Fix CPL export via SS.DPL References: <53AFE2B3.5080300@web.de> <20140629102403.GE18167@minantech.com> <53AFEB16.5040608@web.de> <20140629105339.GF18167@minantech.com> <53AFF192.7020801@web.de> <20140629115143.GA4362@pd.tnic> <53B0050B.90104@web.de> <20140629131443.GA5199@pd.tnic> <20140629134247.GG18167@minantech.com> <20140629140104.GB12528@pd.tnic> <20140629142722.GH18167@minantech.com> <53B02395.8030505@web.de> <53B027E0.7040003@web.de> <53B02CEB.7010607@web.de> <53B17BDD.5030301@redhat.com> In-Reply-To: <53B17BDD.5030301@redhat.com> X-Enigmail-Version: 1.6 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="mXhX4n0huw4C0Av9lOoPnfJDJoistk8im" X-Provags-ID: V03:K0:5xCE8fQ6JO54HNPgadVpuoJeCRtD2ruvHg56uas8mU7aRVJ5ZWS kThpiJH4Apm5SCzxwVv9gzHLImJtaETbTbxDKUuFt9pIliUrMvLe0vUpp2k75QxgRtfY0fv rffXpQNhNbD49uqC+XE8BV5/UPpaskHTwd6bMaisSpiii/mzxRiy8iY/7dkXpkc526DeTiT 9J2I4JzWQr/0UVZhxL/aQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --mXhX4n0huw4C0Av9lOoPnfJDJoistk8im Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 2014-06-30 17:01, Paolo Bonzini wrote: > Il 29/06/2014 17:12, Jan Kiszka ha scritto: >> From: Jan Kiszka >> >> We import the CPL via SS.DPL since ae9fedc793. However, we fail to >> export it this way so far. This caused spurious guest crashes, e.g. of= >> Linux when accessing the vmport from guest user space which triggered >> register saving/restoring to/from host user space. >> >> Signed-off-by: Jan Kiszka >> --- >> >> Just in time for the next match :D >> >> arch/x86/kvm/svm.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index ec8366c..b5e994a 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -1462,6 +1462,7 @@ static void svm_get_segment(struct kvm_vcpu *vcp= u, >> */ >> if (var->unusable) >> var->db =3D 0; >> + var->dpl =3D to_svm(vcpu)->vmcb->save.cpl; >> break; >> } >> } >> >=20 > Thanks. In theory this is not necessary, the SS.DPL should be the same= > as the CPL according to the manuals (the manual say that the SS.DPL > "should match" the CPL, and that's the only reason why I included the > import in ae9fedc793). But apparently this is not the case. 15.5.1: "When examining segment attributes after a #VMEXIT: [...] =95 Retrieve the CPL from the CPL field in the VMCB, not from any segment= DPL." Jan --mXhX4n0huw4C0Av9lOoPnfJDJoistk8im Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlOxfGAACgkQitSsb3rl5xScMQCgqzbTHsMUBTE8lyvumWZaAQL5 l7sAoJ3sT35win58oY7HArovCxhE6CGG =xIz3 -----END PGP SIGNATURE----- --mXhX4n0huw4C0Av9lOoPnfJDJoistk8im--