From mboxrd@z Thu Jan  1 00:00:00 1970
From: =?ISO-8859-1?Q?Roger_Pau_Monn=E9?= <roger.pau@citrix.com>
Subject: Re: [PATCH] blkif: add indirect descriptors interface
 to	public headers
Date: Fri, 15 Nov 2013 09:04:51 +0100
Message-ID: <5285D5A3.2040408@citrix.com>
References: <1384252612-22573-1-git-send-email-roger.pau@citrix.com>
	<20131112142254.GC9306@phenom.dumpdata.com>
	<1384266541.10204.14.camel@kazak.uk.xensource.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD0170550@AMSPEX01CL01.citrite.net>
	<1384334807.5406.3.camel@kazak.uk.xensource.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD017132F@AMSPEX01CL01.citrite.net>
	<1384341067.5406.70.camel@kazak.uk.xensource.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD0171489@AMSPEX01CL01.citrite.net>
	<5284A092.6090902@citrix.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD0172BBD@AMSPEX01CL01.citrite.net>
	<5284A57F.7080104@citrix.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD0172C90@AMSPEX01CL01.citrite.net>
	<ff2d26bf-aff5-41ab-bebc-574f971cb0c7@email.android.com>
	<9AAE0902D5BC7E449B7C8E4E778ABCD0173CBF@AMSPEX01CL01.citrite.net>
	<a9e522fe-81bf-4b62-99d4-0d7efd6f2424@email.android.com>,
	<9AAE0902D5BC7E449B7C8E4E778ABCD0173D96@AMSPEX01CL01.citrite.net>
	<9AAE0902D5BC7E449B7C8E4E778ABCD017407E@AMSPEX01CL01.citrite.net>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta4.messagelabs.com ([85.158.143.247])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <roger.pau@citrix.com>) id 1VhEOd-0006Dk-MK
	for xen-devel@lists.xenproject.org; Fri, 15 Nov 2013 08:04:55 +0000
In-Reply-To: <9AAE0902D5BC7E449B7C8E4E778ABCD017407E@AMSPEX01CL01.citrite.net>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Paul Durrant <Paul.Durrant@citrix.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>, Ian Campbell <Ian.Campbell@citrix.com>
Cc: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>, "Keir
	(Xen.org)" <keir@xen.org>, Jan Beulich <jbeulich@suse.com>
List-Id: xen-devel@lists.xenproject.org

On 14/11/13 20:16, Paul Durrant wrote:
>>> If it is the Linux one which of the fields is  messed up? The whole struct
>>> (including the extra uint8 cmd) should be exactly 64 bytes.
>>>
>>> I am pretty sure we double checked that.
>>
>> How can this possibly be the same between 32-bit and 64-bit builds (unless CONFIG_X86_64 is defined in both
>> cases)? And the fact that nr_segments won't be naturally aligned is pretty bad too.
> 
> D'oh, I missed the pad at the end, so they are the same size but that doesn't stop the layout being different and hence needing to make sure the ABI is set correctly in xenstore.

You already need to set the correct ABI in xenstore, or nothing is going
to work, normal non-indirect requests also have different sizes and offsets.