From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC PATCH v3 0/3] Add segment limit checks to emulator Date: Mon, 26 Jul 2010 14:47:14 +0300 Message-ID: <4C4D75C2.4000404@redhat.com> References: <1278888970-2936-1-git-send-email-m.gamal005@gmail.com> <4C3AB59B.60705@redhat.com> <4C3B14E2.8050404@redhat.com> <20100724154522.GA13246@morn.localdomain> <4C4BFBBC.9060203@redhat.com> <20100725162328.GA18995@morn.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Mohammed Gamal , mtosatti@redhat.com, kvm@vger.kernel.org To: "Kevin O'Connor" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52527 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754116Ab0GZLrS (ORCPT ); Mon, 26 Jul 2010 07:47:18 -0400 In-Reply-To: <20100725162328.GA18995@morn.localdomain> Sender: kvm-owner@vger.kernel.org List-ID: On 07/25/2010 07:23 PM, Kevin O'Connor wrote: > On Sun, Jul 25, 2010 at 11:54:20AM +0300, Avi Kivity wrote: >> On 07/24/2010 06:45 PM, Kevin O'Connor wrote: >>> On Mon, Jul 12, 2010 at 04:13:06PM +0300, Avi Kivity wrote: >>>> Does SeaBIOS use big real mode now? >>> SeaBIOS calls option roms in big real mode. This is required by the >>> relevant specs. >> Can you provide a pointer? > See the PMM spec section 2.2 and section 3.2.4. (Sadly, I can't find > a link to the PMM spec on the web anymore - hopefully you have a > copy.) Also see the PCI Firmware Specification v3.0 - section > 5.2.1.9. Unfortunately, I don't have a copy. > The specs don't require any code addresses to be>64K, but it does > require data access over 64K. I doubt there are many systems that use > a code address>64K, because an interrupt in big real mode still only > stores a 16bit return address - thus an irq (or nmi) in that mode will > basically cause a crash. Ok. Flat 4G segments happen to accidentally work in kvm-intel, and we can keep it working. -- error compiling committee.c: too many arguments to function