[Applies to KMDF only]
An IRP_MJ_SYSTEM_CONTROL request represents a request for WMI data. WDM drivers handle such requests by implementing a DispatchSystemControl function and registering as a WMI data provider. WDM drivers that do not respond to such requests implement a DispatchSystemControl routine that simply passes the IRPs down to the next lower driver.
For KMDF drivers, the framework provides default handling for IRP_MJ_SYSTEM_CONTROL. Drivers that do not provide WMI data are not required to include any WMI-related code. Instead, the framework passes the request to the next lower driver on behalf of the driver.
For implementation details, see Supporting WMI in KMDF Drivers.