Querying the Parameters of a NIC Switch

An overlying driver or user application can obtain the parameters for a NIC switch that has been created on a network adapter that supports single root I/O virtualization (SR-IOV). The driver or application issues an object identifier (OID) method request of OID_NIC_SWITCH_PARAMETERS to obtain these parameters.

Before the overlying driver or user application issues this OID method request, it must initialize an NDIS_NIC_SWITCH_PARAMETERS structure. The driver or application must set the SwitchId member to the identifier of the NIC switch for which parameters are to be returned.

Note  Starting with Windows Server 2012, the SR-IOV interface supports only one NIC switch on the network adapter. This switch is known as the default NIC switch, and is referenced by the NDIS_DEFAULT_SWITCH_ID identifier.

After a successful return from this OID method request, the InformationBuffer member of the NDIS_OID_REQUEST structure contains a pointer to an NDIS_NIC_SWITCH_PARAMETERS structure. This structure contains the parameters for the specified switch.

NDIS handles the OID_NIC_SWITCH_PARAMETERS request for miniport drivers. NDIS returns the information from an internal cache of the data that it maintains from the following sources:

• The standardized SR-IOV keyword settings in the registry. For more information on these keywords, see Standardized INF Keywords for SR-IOV.

• OID requests of OID_NIC_SWITCH_CREATE_SWITCH and OID_NIC_SWITCH_PARAMETERS.