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] Debian kernel doesn't support DomU bit width != Dom0 bit

To: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Subject: RE: [Xen-devel] Debian kernel doesn't support DomU bit width != Dom0 bit width for PV drivers?
From: "James Harper" <james.harper@xxxxxxxxxxxxxxxx>
Date: Sat, 2 Feb 2008 09:40:21 +1100
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 01 Feb 2008 14:40:48 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <20080201223045.GC27285@xxxxxxxxxx>
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: <AEC6C66638C05B468B556EA548C1A77D0131AA23@trantor> <20080201223045.GC27285@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AchlIiTL7yQQTEr4SFq1ATeuqP5ZfQAAOFag
Thread-topic: [Xen-devel] Debian kernel doesn't support DomU bit width != Dom0 bit width for PV drivers?
> >
> > My suspicion then is that the Debian kernel's blkback driver doesn't
pay
> > attention to the 'protocol' set by the frontend, even though
blkfront
> > driver included in the Debian kernel does actually set it.
> 
> Depends what Xen version their kernel / userspace is based on. IIRC
you
> need to have at least Xen 3.1.1  to get 32-on-64 working properly -
the
> compatability 'protocol' stuff didn't make the original 3.1.0 release
> 

I am using 3.1.1, but I think the Debian kernel is 3.1.0 vintage.

And I was incorrect when I said that blkfront is setting 'x86_NN-abi'.
That is being done by the xen userspace stuff. It's all making sense
now!

Curiously, the HVM stuff works perfectly with the single exception of
vbd, and only because of the alignment issues in the two related
structs.

I think I'll fudge it and release two versions of the PV drivers, one to
use when Dom0 is 32 bit and one to use when Dom0 is 64 bit.

James

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