From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Daniel P. Berrange" Subject: Re: Debian kernel doesn't support DomU bit width != Dom0 bit width for PV drivers? Date: Fri, 1 Feb 2008 22:30:45 +0000 Message-ID: <20080201223045.GC27285@redhat.com> References: Reply-To: "Daniel P. Berrange" Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: James Harper Cc: xen-devel List-Id: xen-devel@lists.xenproject.org On Sat, Feb 02, 2008 at 09:25:27AM +1100, James Harper wrote: > In trying to figure out why my Xen Windows PV drivers don't work > properly when the frontend and backend are different bit width modes (eg > 32, 64), I figured out that the same is true for Linux domains. I tested > a 32 bit DomU with a 64 bit Dom0, and get a crash almost as soon as the > blkfront driver is started, and a "(XEN) grant_table.c:264:d0 Bad flags > (0) or dom (0). (expected dom 0)" message logged in 'xm dmesg'. > > 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 Dan. -- |=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=| |=- Perl modules: http://search.cpan.org/~danberr/ -=| |=- Projects: http://freshmeat.net/~danielpb/ -=| |=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|