The next patch allows userspace to create multiple workers per device,
so this patch replaces the vhost_worker pointer with an xarray so we
can store mupltiple workers and look them up.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20230626232307.97930-15-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>