From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1JpYly-0005HA-HZ
	for qemu-devel@nongnu.org; Fri, 25 Apr 2008 21:00:14 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1JpYlw-0005EQ-Ja
	for qemu-devel@nongnu.org; Fri, 25 Apr 2008 21:00:13 -0400
Received: from [199.232.76.173] (port=33097 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1JpYlw-0005EI-9p
	for qemu-devel@nongnu.org; Fri, 25 Apr 2008 21:00:12 -0400
Received: from mtaout02-winn.ispmail.ntl.com ([81.103.221.48])
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <samuel.thibault@labri.fr>) id 1JpYlv-0007rL-Qd
	for qemu-devel@nongnu.org; Fri, 25 Apr 2008 21:00:12 -0400
Received: from aamtaout03-winn.ispmail.ntl.com ([81.103.221.35])
	by mtaout02-winn.ispmail.ntl.com with ESMTP id
	<20080426010335.NREE17818.mtaout02-winn.ispmail.ntl.com@aamtaout03-winn.ispmail.ntl.com>
	for <qemu-devel@nongnu.org>; Sat, 26 Apr 2008 02:03:35 +0100
Received: from implementation.famille.thibault.fr ([82.21.96.230])
	by aamtaout03-winn.ispmail.ntl.com with ESMTP id
	<20080426010719.DAXH26699.aamtaout03-winn.ispmail.ntl.com@implementation.famille.thibault.fr>
	for <qemu-devel@nongnu.org>; Sat, 26 Apr 2008 02:07:19 +0100
Received: from samy by implementation.famille.thibault.fr with local (Exim
	4.69) (envelope-from <samuel.thibault@labri.fr>) id 1JpYls-00053V-Bl
	for qemu-devel@nongnu.org; Sat, 26 Apr 2008 03:00:08 +0200
Date: Sat, 26 Apr 2008 02:00:08 +0100
From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-ID: <20080426010007.GB4792@implementation>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Subject: [Qemu-devel] kernel kqemu and interrupt handler
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org

Hello,

I'm trying to make GNU Mach work with -kernel-kqemu, and the only
problem I'm having is with IRQ handling while from kernel context: the
handler roughly does

entry:
	cld
	pushl %ds
	pushl %es
	pushl %fs
	pushl %gs
	etc. call handler
	popl %gs
	popl %fs
	popl %es
	popl %ds

I get a General protection fault on popl %gs.  Looking at the stack
shows me that pushl %gs has pushed 0x13 instead of 0x10.  While I
understand why this is so (we're running in CPL 3 anyway), I wonder how
this is supposed to work, and even more, how linux works (since it
roughly does the same)...

Samuel