Deleting a Virtual Port

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An overlying driver issues an object identifier (OID) set request of OID_NIC_SWITCH_DELETE_VPORT to delete a nondefault virtual port (VPort) on a network adapter's NIC switch. The overlying driver can only delete a VPort that it has previously created by issuing an OID method request of OID_NIC_SWITCH_CREATE_VPORT.

The InformationBuffer member of the NDIS_OID_REQUEST structure contains a pointer to the NDIS_NIC_SWITCH_DELETE_VPORT_PARAMETERS structure.

An overlying driver, such as the virtualization stack, can delete a nondefault VPort that it has previously created. The overlying driver creates a VPort by issuing an OID method request of OID_NIC_SWITCH_CREATE_VPORT.

Before it issues the OID set request of OID_NIC_SWITCH_DELETE_VPORT, the overlying driver must do the following:

  • The overlying drivers must clear or move all receive filters that the driver previously set on the VPort before deleting the VPort. Receive filters are set through OID requests of OID_RECEIVE_FILTER_SET_FILTER and are moved through OID requests of OID_RECEIVE_FILTER_MOVE_FILTER.

  • The overlying driver sets the VPortId member of the NDIS_NIC_SWITCH_DELETE_VPORT_PARAMETERS structure to the identifier of the nondefault VPort to be deleted.

    Note  The overlying driver must not set the VPortId member to NDIS_DEFAULT_PORT_NUMBER. This VPort identifier is reserved for the default VPort that is attached to the PCI Express (PCIe) Physical Function (PF) on the network adapter. The default VPort always exists and is not deleted explicitly though an OID set request of OID_NIC_SWITCH_DELETE_VPORT.

The overlying driver calls NdisOidRequest to issue the OID_NIC_SWITCH_DELETE_VPORT request to the underlying PF miniport driver. When the miniport driver receives the OID_NIC_SWITCH_DELETE_VPORT request, the driver must do the following:

  • The driver must free the hardware and software resources that were allocated for the specified VPort.

  • The driver must detach the specified VPort from the PF or a PCIe Virtual Function (VF).

    If the VPort is attached to a VF, the virtualization stack ensures that the VF miniport driver that runs in the guest operating system has been previously paused and halted. As a result, all previously indicated receive packets from the VPort should have been returned to the VF miniport driver.

    If the VPort is attached to the PF, the PF miniport driver must stop any additional DMA to the shared memory associated with the VPort. The PF miniport driver must make sure that all previouslyindicated receive packets from the VPort are returned to the miniport. The PF miniport driver must not make any additional receive indications to NDIS that specify the VPort's identifier in the packet's NET_BUFFER_LIST structure. After all of the indicated receive packets from the VPort are returned to the PF miniport driver, it must free the shared memory associated with the VPort by calling NdisFreeSharedMemory.

The following points apply to the deletion of VPorts:

  • The overlying protocol driver must delete all nondefault VPorts that it created before it calls NdisCloseAdapterEx.

  • The overlying filter driver must delete all nondefault VPorts that it created within its FilterDetach function.

  • Before NDIS issues a set request of OID_NIC_SWITCH_DELETE_SWITCH to delete a NIC switch on the network adapter, it guarantees that all nondefault VPorts are deleted from that switch.

  • Only nondefault VPorts can be explicitly deleted through OID requests of OID_NIC_SWITCH_DELETE_SWITCH. The default VPort is implicitly deleted when the PF miniport driver deletes the default NIC switch. For more information, see Deleting a NIC Switch.