Merge remote-tracking branch 'pmaydell/tags/pull-arm-devs-20130812' into staging

arm-devs queue

# gpg: Signature made Mon 12 Aug 2013 05:58:14 AM CDT using RSA key ID 14360CDE
# gpg: Can't check signature: public key not found

# By Peter Maydell
# Via Peter Maydell
* pmaydell/tags/pull-arm-devs-20130812:
  hw/virtio/virtio-mmio: Make QueueNumMax read 0 for unavailable queues
  hw/virtio/virtio: Don't allow guests to add/remove queues

Message-id: 1376305261-29561-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>