From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:59788)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1RsBL1-0007UP-0R
	for qemu-devel@nongnu.org; Tue, 31 Jan 2012 05:53:28 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1RsBKw-0005O6-Du
	for qemu-devel@nongnu.org; Tue, 31 Jan 2012 05:53:22 -0500
Received: from mx1.redhat.com ([209.132.183.28]:30613)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <lersek@redhat.com>) id 1RsBKw-0005O0-3m
	for qemu-devel@nongnu.org; Tue, 31 Jan 2012 05:53:18 -0500
Message-ID: <4F27C875.8080503@redhat.com>
Date: Tue, 31 Jan 2012 11:54:45 +0100
From: Laszlo Ersek <lersek@redhat.com>
MIME-Version: 1.0
References: <4F27B5AD.9050709@redhat.com>
	<4F27D232020000780007012B@nat28.tlf.novell.com>
In-Reply-To: <4F27D232020000780007012B@nat28.tlf.novell.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [Xen-devel] qemu(-dm): aborting on wrong mmio size?
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Jan Beulich <JBeulich@suse.com>
Cc: Miroslav Rezanina <mrezanin@redhat.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Petr Matousek <pmatouse@redhat.com>, qemu-devel@nongnu.org

On 01/31/12 11:36, Jan Beulich wrote:
>>>> On 31.01.12 at 10:34, Laszlo Ersek<lersek@redhat.com>  wrote:
>> in the qemu-xen-unstable tree
>> (git://xenbits.xen.org/qemu-xen-unstable.git), the do_inp() function
>> [i386-dm/helper2.c] makes the process exit if the operand size is wrong.
>> Blame: 6040eea5 ("More files imported from xen-unstable
>> 17192:59b8768d0d0d").
>>
>> In the qemu tree (git://git.qemu.org/qemu.git), the do_inp() function
>> [xen-all.c] does the same (via hw_error() / abort()). Blame: 9ce94e7c
>> ("xen: Initialize event channels and io rings").
>>
>> Is it justified to kill the emulator when this happens (eg. memory
>> mapped IO with 64-bit operand)?
>
> Afaict, this is not about MMIO, but PIO.

One possible way seems to be (see 
http://xenbits.xensource.com/hg/linux-2.6.18-xen.hg/rev/1141):

vmx_hpw_miss() [xen/arch/ia64/vmx/vmx_fault.c]
-> emulate_io_inst() [xen/arch/ia64/vmx/mmio.c]
   -> mmio_access()
     -> legacy_io_access()
       -> vmx_send_assist_req() [xen/arch/ia64/vmx/vmx_support.c]
         -> notify_via_xen_event_channel() [xen/common/event_channel.c]

and in qemu-xen-unstable,

cpu_handle_ioreq() [i386-dm/helper2.c], set up in main_loop()
-> __handle_ioreq()
   -> cpu_ioreq_pio()
     -> do_inp()

Thanks,
Laszlo