From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753763AbcGUTUR (ORCPT ); Thu, 21 Jul 2016 15:20:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58738 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752271AbcGUTUO (ORCPT ); Thu, 21 Jul 2016 15:20:14 -0400 From: Bandan Das To: Paolo Bonzini Cc: kvm@vger.kernel.org, rkrcmar@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] nvmx: check for shadow vmcs check on entry References: <1469053536-11130-1-git-send-email-bsd@redhat.com> <1469053536-11130-5-git-send-email-bsd@redhat.com> Date: Thu, 21 Jul 2016 15:20:12 -0400 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 21 Jul 2016 19:20:13 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paolo Bonzini writes: > On 21/07/2016 00:25, Bandan Das wrote: >> vmentry should check whether the vmcs provided by >> the guest hypervisor is a shadow vmcs and fail. > > How can this happen, since vmptrld checks the revision_id as you said below? This is more of a change that adheres to the spec (26.1 Basic VM-Entry Checks); the failure path is slightly different compared to vmptrld though. It's small and harmless but I am ok if you prefer dropping it. Thanks for the review! > Paolo > >> Also, vmptrld should check whether a shadow vmcs >> is being loaded by the guest without support being present >> but this check happens as part of checking the revision_id.