This patch specifies and implements the master/slave communication
to support device IOTLB in slave.
The vhost_iotlb_msg structure introduced for kernel backends is
re-used, making the design close between the two backends.
An exception is the use of the secondary channel to enable the
slave to send IOTLB miss requests to the master.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
