From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52097) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VeRKe-0001NG-7a for qemu-devel@nongnu.org; Thu, 07 Nov 2013 10:17:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VeRKY-0005B3-53 for qemu-devel@nongnu.org; Thu, 07 Nov 2013 10:17:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22601) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VeRKX-0005Al-UD for qemu-devel@nongnu.org; Thu, 07 Nov 2013 10:17:10 -0500 Date: Thu, 7 Nov 2013 17:20:02 +0200 From: "Michael S. Tsirkin" Message-ID: <20131107152002.GB3976@redhat.com> References: <1383820884-29596-1-git-send-email-marcel.a@redhat.com> <527B9EE3.3030507@redhat.com> <20131107150501.GA3976@redhat.com> <527BACB6.2090305@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <527BACB6.2090305@redhat.com> Subject: Re: [Qemu-devel] [PATCH for-1.7 v2 0/8] fix address space size issue List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: peter.maydell@linaro.org, ehabkost@redhat.com, Marcel Apfelbaum , qemu-devel@nongnu.org, jan.kiszka@siemens.com, agraf@suse.de, lcapitulino@redhat.com, aliguori@amazon.com, afaerber@suse.de On Thu, Nov 07, 2013 at 04:07:34PM +0100, Paolo Bonzini wrote: > Il 07/11/2013 16:05, Michael S. Tsirkin ha scritto: > >> > So, ack for patch 5-7-8, which should also be enough to fix the problem > >> > that Luiz reported. > > Not at all. As long as exec.c ignores high bits, any access > > there will end up in the wrong region. > > ... unless it happens to be the correct region because the whole > 2^64-bit range is covered by a single region. This is what happens for > IOMMUs. > > Paolo Only if you are lucky. What makes sure ignoring high bits does not hit the e1000 MMIO? Nothing I think. > > We might not get a crash but we'll get guest memory corruption.