From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH] KVM: x86: Generate #UD when memory operand is required Date: Thu, 27 Nov 2014 15:58:09 +0100 Message-ID: <20141127145808.GC8120@potion.brq.redhat.com> References: <1417009638-7260-1-git-send-email-namit@cs.technion.ac.il> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: pbonzini@redhat.com, kvm@vger.kernel.org To: Nadav Amit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32952 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783AbaK0O6T (ORCPT ); Thu, 27 Nov 2014 09:58:19 -0500 Content-Disposition: inline In-Reply-To: <1417009638-7260-1-git-send-email-namit@cs.technion.ac.il> Sender: kvm-owner@vger.kernel.org List-ID: 2014-11-26 15:47+0200, Nadav Amit: > Certain x86 instructions that use modrm operands only allow memory op= erand > (i.e., mod012), and cause a #UD exception otherwise. KVM ignores this= fact. > Currently, the instructions that are such and are emulated by KVM are= MOVBE, > MOVNTPS, MOVNTPD and MOVNTI. MOVBE is the most blunt example, since = it may be > emulated by the host regardless of MMIO. >=20 > The fix introduces a new group for handling such instructions, markin= g mod3 as > illegal instruction. >=20 > Signed-off-by: Nadav Amit > --- Reviewed-by: Radim Kr=C4=8Dm=C3=A1=C5=99 (We could remove GroupDual in the future.)