From mboxrd@z Thu Jan  1 00:00:00 1970
From: Markus Armbruster <armbru@redhat.com>
Subject: Backend in user space,
	how is its kernel dev unregistered?
Date: Wed, 04 Mar 2009 20:02:27 +0100
Message-ID: <8763ip158c.fsf@pike.pond.sub.org>
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There's a curious asymmetry in how Xen backend devices are registered
and unregistered.

Registering is the job of xenbus_probe.c: it watches xenstore, and when
a device node shows up, it calls device_register().

Unregistering is the device driver's job: it watches xenstore, and when
it sees the front end shut down, it calls device_unregister().

But what if the device driver is in user space?  vfb and vkbd are.  I
can't see how their kernel devices can ever get unregistered.

If that is true, any ideas on how to plug the leak?