mtl_gsc_header_wr
mtl_gsc_header_wr(xe, in, offset_in, gsc_message_handle, handle);
mtl_gsc_header_wr(xe, map, offset, validity_marker, GSC_HECI_VALIDITY_MARKER);
mtl_gsc_header_wr(xe, map, offset, heci_client_id, heci_client_id);
mtl_gsc_header_wr(xe, map, offset, host_session_handle, host_session_id);
mtl_gsc_header_wr(xe, map, offset, header_version, MTL_GSC_HEADER_VERSION);
mtl_gsc_header_wr(xe, map, offset, message_size, payload_size + GSC_HDR_SIZE);