From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <anthony@codemonkey.ws>
Subject: Re: [PATCH] extboot: properly set int 0x13 return value
Date: Mon, 01 Dec 2008 14:20:43 -0600
Message-ID: <4934471B.30606@codemonkey.ws>
References: <1228160470-11764-1-git-send-email-glommer@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org
To: Glauber Costa <glommer@redhat.com>
Return-path: <kvm-owner@vger.kernel.org>
Received: from rn-out-0910.google.com ([64.233.170.185]:18014 "EHLO
	rn-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1752416AbYLAUUr (ORCPT <rfc822;kvm@vger.kernel.org>);
	Mon, 1 Dec 2008 15:20:47 -0500
Received: by rn-out-0910.google.com with SMTP id k40so2095796rnd.17
        for <kvm@vger.kernel.org>; Mon, 01 Dec 2008 12:20:46 -0800 (PST)
In-Reply-To: <1228160470-11764-1-git-send-email-glommer@redhat.com>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

Glauber Costa wrote:
> Callers of int 0x13 usually rely on the carry flag being
> clear/set to indicate the status of the interrupt execution.
>
> However, our current code clear or set the flags register,
> which is totally useless. Whichever value it has, will
> be overwritten by the flags value _before_ the interrupt, due to
> the iret instruction.
>
> This fixes a bug that prevents slackware (and possibly win2k, untested)
> to boot.
>   

Good catch!

> Signed-off-by: Glauber Costa <glommer@redhat.com>
>
>   

Acked-by: Anthony Liguori <aliguori@us.ibm.com>

Regards,

Anthony Liguori