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] Automatic loading of xen-evtchn module in Xen 4.0.0?

On Wed, Mar 31, 2010 at 09:40:40AM +0100, Ian Campbell wrote:
> On Tue, 2010-03-30 at 23:47 +0100, Jeremy Fitzhardinge wrote:
> > 
> > In practice there's no need to get very modular.  There's some value
> > in 
> > not loading all that backend support code unless we're actually dom0, 
> > but I don't think there's much value in getting too fine-grained
> > beyond that.  The actual drivers themselves are fairly ordinary, so
> > they will probably just work if we can make xenbus generate the right
> > request events.  Hm, I guess that would be the tool stack setting
> > things up for a new domain, and requesting backend devices in the
> > process, no? 
> 
> What happens with frontend hotplug, and should happen with backends too,
> is that the xenbus core watches the "device" (or "backend") node in
> xenstore (relative to the domain's root path "/local/domain/<X>/"). The
> tools then create the necessary nodes to create the device which
> triggers the xenstore watch, e.g. on a path starting with "vif", which
> causes xenbus to generate a uevent with the necessary MODALIAS, see
> drivers/xen/xenbus/xenbus_probe.c:xenbus_uevent().
> 
> The only problem with this is getting the initial xenbus-backend.ko
> loaded so that it can do the watch -- perhaps that falls in the same
> boat as evtchn and gntdev etc.

.. which goes back to what I suggested some time ago, that might do the
trick. That is to make the owner of /sys/hypervisor do a kobject_uevent
and have an udev rule that would listen to this and load the
xenbus-backend.ko. That should start the avalanche of Xen backend module
loading, I think?

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