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/
Home Products Support Community News


Re: [Xen-devel] Automatic loading of xen-evtchn module in Xen 4.0.0?

To: Pasi Kärkkäinen <pasik@xxxxxx>
Subject: Re: [Xen-devel] Automatic loading of xen-evtchn module in Xen 4.0.0?
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Date: Sat, 27 Mar 2010 15:18:14 -0700
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Sat, 27 Mar 2010 15:18:43 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20100327173221.GJ1878@xxxxxxxxxxx>
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20100327173221.GJ1878@xxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20100301 Fedora/3.0.3-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.3
On 03/27/2010 10:32 AM, Pasi Kärkkäinen wrote:

xend automatically mounts /proc/xen, but it doesn't try loading evtchn or 
xen-evtchn modules.
Should we add automatic loading of these modules?

xend doesn't start if xen event channel functionality is missing.

Fedora Xen rpms do load modules automatically, like this:

# cat /etc/sysconfig/modules/xen.modules

test -d /proc/xen                               || exit 0
test -f /proc/xen/capabilities                  || mount -t xenfs xen /proc/xen
test -f /proc/xen/capabilities                  || exit 0
grep -q "control_d" /proc/xen/capabilities      || exit 0

for module in xen-evtchn evtchn blkbk netbk; do
         modprobe ${module}>/dev/null 2>&1

We should be able to make these mount automatically with udev rules, I think, but I'm not sure whether you can do udev rules to mount misc devices (which is what /dev/xen/evtchn is).

I think the front/back xenbus and device drivers are still a bit of a mess with regard to modules; I have to admit I tend to just compile them all in. It would be nice to get all that properly sorted out so they can be sensibly modularized and auto-loaded as required. (A good first step would be to systematically work out what compile combinations actually work or fail, hint, hint ;)


Xen-devel mailing list