Implement the exit_event() method on the VhostUserBackend trait. It is
necessary to specify a custom exit event id in this case as the loop is
also used for handling activity on the tap file descriptors.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Split the basic launching functionality into its own function in the
newly added vhost_user_net crate.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Extract the majority of the code that provides the vhost-user-net
backend into its own crate and port the binary to use it.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>