From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH RESEND] KVM: when entering real mode align segment base to 16 bytes Date: Mon, 27 Dec 2010 16:55:08 +0200 Message-ID: <4D18A8CC.7010500@redhat.com> References: <20101227130110.GK2231@redhat.com> <4D18A101.90407@redhat.com> <20101227143727.GN2231@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: mtosatti@redhat.com, kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:9377 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961Ab0L0OzL (ORCPT ); Mon, 27 Dec 2010 09:55:11 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oBREtB2I019840 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 27 Dec 2010 09:55:11 -0500 In-Reply-To: <20101227143727.GN2231@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 12/27/2010 04:37 PM, Gleb Natapov wrote: > > What's the scenario here? And what segment is involved? if it's fs > > or gs, or maybe ss, I can see it working out, but hardly otherwise. > > > The scenario is older Seabios that lefts DS segment unaligned during > switch to real mode in int1587 function (copy extended memory). > Did it not use %ds then? What about switching back to protected mode? I see we do restore the base, so it can continue to use the segment. I guess this isn't an issue for 1587. -- error compiling committee.c: too many arguments to function