Determining Receive Filtering Capabilities

This topic describes how NDIS and overlying drivers determine the receive filtering capabilities of a network adapter that supports single root I/O virtualization (SR-IOV). This topic contains the following information:

Reporting Receive Filtering Capabilities during MiniportInitializeEx

Querying Receive Filtering Capabilities by Overlying Drivers

Note  Only the miniport driver for the PCI Express (PCIe) Physical Function (PF) of an SR-IOV network adapter can report receive filtering capabilities. Miniport drivers for PCIe Virtual Functions (VFs) must not report the receive filtering capabilities of the SR-IOV adapter.

Reporting Receive Filtering Capabilities during MiniportInitializeEx

When NDIS calls the PF miniport driver's MiniportInitializeEx function, the driver provides the following receive filtering capabilities:

  • The complete hardware receive filtering capabilities that the network adapter can support.

  • The receive filtering capabilities for the interfaces that are currently enabled on the network adapter.

The miniport driver reports the complete hardware receive filtering capabilities of the underlying network adapter through an NDIS_RECEIVE_FILTER_CAPABILITIES structure that is initialized in the following way:

  1. The miniport driver initializes the Header member. The driver sets the Type member of Header to NDIS_OBJECT_TYPE_DEFAULT.

    Starting with NDIS 6.30, the miniport driver sets the Revision member of Header to NDIS_RECEIVE_FILTER_CAPABILITIES_REVISION_2 and the Size member to NDIS_SIZEOF_RECEIVE_FILTER_CAPABILITIES_REVISION_2.

  2. The miniport driver sets the other members of the NDIS_RECEIVE_FILTER_CAPABILITIES structure to the range of values for the receive filtering capabilities of the SR-IOV network adapter. For example, the miniport driver sets the appropriate flags in the SupportedFilterTests to specify filter test operations that the miniport driver supports.

  3. Besides SR-IOV, receive filtering is also used in the following interfaces:

    If the miniport driver supports any of these interfaces, it must also set the members of the NDIS_RECEIVE_FILTER_CAPABILITIES structure to the range of receive filtering capability values that are specific to the interface. For example, if the driver supports NDIS packet coalescing and SR-IOV, it must set the NDIS_RECEIVE_FILTER_PACKET_COALESCING_SUPPORTED_ON_DEFAULT_QUEUE flag in the SupportedQueueProperties member.

The miniport driver reports the currently-enabled receive filtering capabilities of the underlying network adapter through an NDIS_RECEIVE_FILTER_CAPABILITIES structure that is initialized in the following way:

  1. The miniport driver initializes the Header member. The driver sets the Type member of Header to NDIS_OBJECT_TYPE_DEFAULT.

    Starting with NDIS 6.30, the miniport driver sets the Revision member of Header to NDIS_RECEIVE_FILTER_CAPABILITIES_REVISION_2 and the Size member to NDIS_SIZEOF_RECEIVE_FILTER_CAPABILITIES_REVISION_2.

  2. The miniport driver sets the other members of the NDIS_RECEIVE_FILTER_CAPABILITIES structure to the range of values for the receive filtering capabilities of the interfaces that are currently enabled. For example, if NDIS packet coalescing is enabled, the driver must only set the members that are specific to this technology.

    Interfaces that use receive filtering are enabled or disabled through standardized INF keywords. For more information on how NDIS packet coalescing is enabled, see Standardized INF Keywords for Packet Coalescing. For more information on how SR-IOV and VMQ are enabled, see Handling SR-IOV, VMQ, and RSS Standardized INF Keywords.

When NDIS calls the miniport driver's MiniportInitializeEx function, the driver registers the receive filtering capabilities of the network adapter by following these steps:

  1. The miniport driver initializes an NDIS_MINIPORT_ADAPTER_HARDWARE_ASSIST_ATTRIBUTES structure.

    The miniport driver sets the HardwareReceiveFilterCapabilities member to the address of an NDIS_RECEIVE_FILTER_CAPABILITIES structure. This structure was previously-initialized with the complete hardware receive filtering capabilities of the network adapter.

  2. If the VMQ, SR-IOV, and NDIS packet coalescing are all currently disabled on the network adapter, the miniport driver sets the CurrentReceiveFilterCapabilities member to NULL.

  3. If either VMQ, SR-IOV, or NDIS packet coalescing are currently enabled on the network adapter, the miniport driver must do the following:

    • The miniport driver must initialize another NDIS_RECEIVE_FILTER_CAPABILITIES structure with the current receive filtering capabilities for the interfaces that are currently enabled on the network adapter.

      If the SR-IOV interface is enabled, there are situations in which the miniport driver must set the members of the NDIS_RECEIVE_FILTER_CAPABILITIES structure to the same or different values. This is because the SR-IOV interface provides a similar queuing mechanism to VMQ, but uses virtual ports (VPorts) instead of VM receive queues.

      For example, the miniport driver must set the NDIS_RECEIVE_FILTER_VMQ_FILTERS_ENABLED flag in the EnabledFilterTypes member if either the VMQ or SR-IOV interface is enabled. However, the miniport driver must set the NumQueues member to zero if the SR-IOV interface is enabled and a nonzero value if the VMQ interface is enabled.

    • The miniport driver sets the CurrentReceiveFilterCapabilities member to the address of the NDIS_RECEIVE_FILTER_CAPABILITIES structure that contains the current receive filtering capabilities for the currently-enabled interface.

  4. If either VMQ, SR-IOV, or NDIS packet coalescing are currently enabled on the network adapter, the miniport driver sets the HardwareReceiveFilterCapabilities member to the address of an NDIS_RECEIVE_FILTER_CAPABILITIES structure. This structure was previously-initialized with the currently-enabled receive filtering capabilities of the network adapter.

  5. The driver calls NdisMSetMiniportAttributes and sets the MiniportAttributes parameter to a pointer to the NDIS_MINIPORT_ADAPTER_HARDWARE_ASSIST_ATTRIBUTES structure.

For more information about the adapter initialization process, see Initializing a Miniport Adapter.

Querying Receive Filtering Capabilities by Overlying Drivers

NDIS passes the network adapter's currently-enabled receive filtering capabilities to overlying drivers that bind to the network adapter in the following way:

NDIS also returns the NDIS_RECEIVE_FILTER_CAPABILITIES structure when it handles object identifier (OID) query requests of OID_RECEIVE_FILTER_CURRENT_CAPABILITIES and OID_RECEIVE_FILTER_HARDWARE_CAPABILITIES that are issued by overlying protocol or filter drivers.