WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Re: [patch/rfc] multiprotocol blkback drivers (32-on-64)

To: "Gerd Hoffmann" <kraxel@xxxxxxx>, "Keir Fraser" <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Re: [patch/rfc] multiprotocol blkback drivers (32-on-64)
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Wed, 20 Dec 2006 15:47:37 +0000
Cc: Xen devel list <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Wed, 20 Dec 2006 07:46:21 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <458952D8.6030803@xxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <C1ADA5A5.652A%keir@xxxxxxxxxxxxx> <458952D8.6030803@xxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Looks a lot nicer now, except that I dislike the replication of the 
request/response
structures in now three places. Besides possibly being a maintenance issue, this
now seems worse in terms of scaling up to eventual future protocol versions. I 
had
understood Keir in a much different way - adding a compiler abstraction header
(which maybe could even make use of Linux' native ones) to include/xen, and
making use of its abstraction directly in xen/include/public/io/blkif.h.

Jan

>>> Gerd Hoffmann <kraxel@xxxxxxx> 20.12.06 16:12 >>>
Hi,

> I think it would be reasonable to put this stuff in a (new) Linux-specific
> header file that wraps the Xen-public blkif.h. We could put just enough
> support in blkif.h itself to allow it to be multiply-compiled. Then
> different OSes can wrap or rewrite blkif.h as they see fit to get the
> required layout for 32-bit and 64-bit ABIs. This conveniently sidesteps some
> of these issues and allows you to concentrate on Linux and GCC, while not
> constraining the implementation choices for anyone else.

Next interation with exactly that implemented, this time even tested
with blkback in all four combinations out of 32/64 dom0, 32/64 guest.

cheers,
  Gerd

-- 
Gerd Hoffmann <kraxel@xxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel