From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: nSVM: Fix IOIO bitmap evaluation Date: Tue, 01 Jul 2014 17:25:17 +0200 Message-ID: <53B2D2DD.8060502@web.de> References: <53B125B9.6050306@web.de> <20140701152349.GJ26537@8bytes.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="n9UUWUSAFKjBC5kRSsQI2r7fOqtIrUiFC" Cc: Paolo Bonzini , kvm , Valentine Sinitsyn To: Joerg Roedel Return-path: Received: from mout.web.de ([212.227.17.11]:63255 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755081AbaGAPZe (ORCPT ); Tue, 1 Jul 2014 11:25:34 -0400 In-Reply-To: <20140701152349.GJ26537@8bytes.org> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --n9UUWUSAFKjBC5kRSsQI2r7fOqtIrUiFC Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2014-07-01 17:23, Joerg Roedel wrote: > On Mon, Jun 30, 2014 at 10:54:17AM +0200, Jan Kiszka wrote: >> From: Jan Kiszka >> >> First, kvm_read_guest returns 0 on success. And then we need to take t= he >> access size into account when testing the bitmap: intercept if any of >> bits corresponding to the access is set. >> >> Signed-off-by: Jan Kiszka >=20 > Reviewed-by: Joerg Roedel > Acked-by: Joerg Roedel >=20 > I have the slight hope that this fixes the issues with L2 Linux guests > on L1 Windows hypervisors. Have to check that at some point :) >=20 >> - if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, 1)) >> - val &=3D (1 << bit); >> + if (kvm_read_guest(svm->vcpu.kvm, gpa, &val, iopm_len)) >> + return NESTED_EXIT_DONE; >=20 > Not related to that fix, but as a further improvement we should probabl= y > do a #vmexit(invalid-vmcb) or something if we can't read the iopm. Yes, thought about this as well when thinking about kvm_read_guest failing. Some for MSR bitmap. Jan --n9UUWUSAFKjBC5kRSsQI2r7fOqtIrUiFC 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/ iEYEARECAAYFAlOy0uUACgkQitSsb3rl5xTzCwCeLhgcd1hTDMe5ObYnu65Jf7T4 +NIAn17AyGCdJ7dzVmzqC4cvJM7gfOox =gf4c -----END PGP SIGNATURE----- --n9UUWUSAFKjBC5kRSsQI2r7fOqtIrUiFC--