NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS structure (ntddndis.h)

Article
05/26/2021

The NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS structure specifies the parameters for a read operation on the configuration block of a network adapter's PCI Express (PCIe) Virtual Function (VF). These parameters are used for the backchannel communication between the miniport drivers for a VF and the PCIe Physical Function (PF).

Syntax

typedef struct _NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS {
  NDIS_OBJECT_HEADER     Header;
  NDIS_SRIOV_FUNCTION_ID VFId;
  ULONG                  BlockId;
  ULONG                  Length;
  ULONG                  BufferOffset;
} NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS, *PNDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS;

Members

Header

The type, revision, and size of the NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS structure. This member is formatted as an NDIS_OBJECT_HEADER structure.

The miniport driver must set the Type member of Header to NDIS_OBJECT_TYPE_DEFAULT. To specify the version of the NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS structure, the driver must set the Revision member of Header to the following value:

NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS_REVISION_1

Original version for NDIS 6.30 and later.

Set the Size member to NDIS_SIZEOF_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS_REVISION_1.

VFId

An NDIS_SRIOV_FUNCTION_ID value that specifies the unique identifier of the VF on the network adapter.

Note The VF with the specified NDIS_SRIOV_FUNCTION_ID value must have resources that were previously allocated through an OID method request of OID_NIC_SWITCH_ALLOCATE_VF.

BlockId

A ULONG value that specifies the identifier of the VF configuration block to be read. This identifier is proprietary to the independent hardware vendor (IHV) and is used only by the miniport drivers for the PF and VF on the network adapter.

For more information, see the Remarks section.

Length

A ULONG value that specifies the length, in units of bytes, of the read operation.

BufferOffset

A ULONG value that specifies the offset, in units of bytes, from the beginning of this structure to a buffer that contains the data that is read from the specified VF configuration block.

Remarks

The NDIS_SRIOV_READ_VF_CONFIG_BLOCK_PARAMETERS structure is used in OID method requests of OID_SRIOV_READ_VF_CONFIG_BLOCK.

A VF configuration block is used for backchannel communication between the drivers of the PCIe PF and a VF on a device that supports the SR-IOV interface. Data from a VF configuration block can be exchanged between the following drivers:

The VF miniport driver, which runs in the guest operating system. This operating system runs within a Hyper-V child partition.
The PF miniport driver, which runs in the management operating system.
This operating system runs within the Hyper-V parent partition.

Note The usage of the VF configuration block and the format of its configuration data are defined by the independent hardware vendor (IHV) of the device. The configuration data is used only by the PF and VF miniport drivers.

For more information about backchannel communication within the single root I/O virtualization (SR-IOV) interface, see SR-IOV PF/VF Backchannel Communication.

Requirements

Requirement	Value
Minimum supported client	Supported in NDIS 6.30 and later.
Header	ntddndis.h (include Ndis.h)