From e9a1e5cd4a732b97aeb0bf6869634021a90f6933 Mon Sep 17 00:00:00 2001
From: Amit Shah <amit.shah@redhat.com>
Date: Fri, 8 Mar 2013 11:30:18 +1100
Subject: [PATCH] virtio: rng: disallow multiple device registrations, fixes
 crashes

commit e84e7a56a3aa2963db506299e29a5f3f09377f9b upstream.

The code currently only supports one virtio-rng device at a time.
Invoking guests with multiple devices causes the guest to blow up.

Check if we've already registered and initialised the driver.  Also
cleanup in case of registration errors or hot-unplug so that a new
device can be used.

Reported-by: Peter Krempa <pkrempa@redhat.com>
Reported-by: <yunzheng@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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