From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754447AbcGVPvt (ORCPT ); Fri, 22 Jul 2016 11:51:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42806 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751631AbcGVPvr (ORCPT ); Fri, 22 Jul 2016 11:51:47 -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> <266030483.9634373.1469176855327.JavaMail.zimbra@redhat.com> Date: Fri, 22 Jul 2016 11:51:44 -0400 In-Reply-To: <266030483.9634373.1469176855327.JavaMail.zimbra@redhat.com> (Paolo Bonzini's message of "Fri, 22 Jul 2016 04:40:55 -0400 (EDT)") 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 [10.5.110.27]); Fri, 22 Jul 2016 15:51:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Paolo Bonzini writes: >> 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. > > Do you mean that this could happen if the VMCS is modified by L1 > after VMPTRLD? That makes sense, but with David Matlack's change Yeah that's the only way I can see it happen. If there's a separate path that takes care of this, should I drop this one ? > to cache the VMCS it wouldn't be possible to trigger it anymore. > > Paolo > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html