From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1N3Wa1-00025G-5F
	for qemu-devel@nongnu.org; Thu, 29 Oct 2009 11:06:25 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1N3WZw-00023H-8v
	for qemu-devel@nongnu.org; Thu, 29 Oct 2009 11:06:24 -0400
Received: from [199.232.76.173] (port=50059 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1N3WZw-00023E-4z
	for qemu-devel@nongnu.org; Thu, 29 Oct 2009 11:06:20 -0400
Received: from mx1.redhat.com ([209.132.183.28]:37073)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <mst@redhat.com>) id 1N3WZv-0003o5-Cc
	for qemu-devel@nongnu.org; Thu, 29 Oct 2009 11:06:19 -0400
Date: Thu, 29 Oct 2009 17:03:47 +0200
From: "Michael S. Tsirkin" <mst@redhat.com>
Message-ID: <20091029150347.GA4913@redhat.com>
References: <d9c105ea0910281222u76a61a2by3cc924e85d40a865@mail.gmail.com>
	<1256807803.10825.39.camel@blaa> <20091029122334.GB3478@redhat.com>
	<4AE9A8DE.1070609@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4AE9A8DE.1070609@redhat.com>
Subject: [Qemu-devel] Re: qemu-kvm-0.11 regression,
	crashes on older guests with virtio network
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: Avi Kivity <avi@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>, Scott Tsai <scottt.tw@gmail.com>, kvm@vger.kernel.org, Dustin Kirkland <kirkland@canonical.com>, qemu-devel@nongnu.org

On Thu, Oct 29, 2009 at 04:38:22PM +0200, Avi Kivity wrote:
> On 10/29/2009 02:23 PM, Michael S. Tsirkin wrote:
>> On Thu, Oct 29, 2009 at 09:16:43AM +0000, Mark McLoughlin wrote:
>>    
>>> I agree we shouldn't exit in this scenario
>>>      
>> virtio in qemu generally seems to handle guest errors
>> by calling exit(2). This probably makes it easier to notice
>> the problems, but is likely not the right thing to do.
>>    
>
> Right, the thinking was the guest is shooting itself in the foot and  
> hitting, but a guest can delegate control of a device to unprivileged  
> code (for example device assignment in kvm),

When we emulate iommu, yes.

> which would allow this unprivileged code to kill the guest.

With usb emulation, we can have:
drivers/usb/class/usblp.c:343:static const char *usblp_messages[] = {
"ok", "out of paper", "off-line", "on fire" };

> -- 
> error compiling committee.c: too many arguments to function