NDIS_SHARED_MEMORY_PARAMETERS structure (ndis.h)

Article
05/26/2021

The NDIS_SHARED_MEMORY_PARAMETERS structure specifies the shared memory parameters for a shared memory allocation request.

Syntax

typedef struct _NDIS_SHARED_MEMORY_PARAMETERS {
  NDIS_OBJECT_HEADER       Header;
  ULONG                    Flags;
  NDIS_RECEIVE_QUEUE_ID    QueueId;
  NDIS_HANDLE              SharedMemoryHandle;
  NODE_REQUIREMENT         PreferredNode;
  NDIS_SHARED_MEMORY_USAGE Usage;
  ULONG                    Length;
  PVOID                    VirtualAddress;
  ULONG                    SGListBufferLength;
  PSCATTER_GATHER_LIST     SGListBuffer;
  NDIS_NIC_SWITCH_VPORT_ID VPortId;
} NDIS_SHARED_MEMORY_PARAMETERS, *PNDIS_SHARED_MEMORY_PARAMETERS;

Members

Header

The type, revision, and size of the NDIS_SHARED_MEMORY_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_SHARED_MEMORY_PARAMETERS structure, the driver must set the Revision member of Header to one of the following values:

NDIS_SHARED_MEMORY_PARAMETERS_REVISION_2

Added VPortId for NDIS 6.30.

Set the Size member to NDIS_SIZEOF_SHARED_MEMORY_PARAMETERS_REVISION_2.

NDIS_SHARED_MEMORY_PARAMETERS_REVISION_1

Original version for NDIS 6.20.

Set the Size member to NDIS_SIZEOF_SHARED_MEMORY_PARAMETERS_REVISION_1.

Flags

A UCHAR value that contains a bitwise OR of the following value:

NDIS_SHARED_MEM_PARAMETERS_CONTIGOUS

The shared memory is in a contiguous block of memory.

QueueId

An NDIS_RECEIVE_QUEUE_ID value that contains a virtual machine queue (VMQ) or single root I/O virtualization (SR-IOV) receive queue identifier. This identifier is an integer between zero and the number of queues that the miniport adapter supports. A value of NDIS_DEFAULT_RECEIVE_QUEUE_ID specifies the default receive queue.

Note Starting with Windows Server 2012, the SR-IOV interface only supports the default receive queue on both default and nondefault virtual ports (VPorts). Miniport drivers that support the SR-IOV interface must set the QueueId member to NDIS_DEFAULT_RECEIVE_QUEUE_ID.

SharedMemoryHandle

An NDIS_HANDLE value that identifies a block of shared memory. NDIS provides this handle before it returns from the NdisAllocateSharedMemory function.

PreferredNode

A NODE_REQUIREMENT value that indicates the preferred node to use while allocating memory. If the driver does not have a preference, then the value must be set to MM_ANY_NODE_OK.

Usage

An NDIS_SHARED_MEMORY_USAGE enumeration value that specifies the purpose of the shared memory.

Length

A ULONG value that contains the length, in bytes, of the shared memory block.

VirtualAddress

A PVOID value that contains the base virtual address of the shared memory. NDIS provides this value before it returns from the NdisAllocateSharedMemory function.

SGListBufferLength

A ULONG value that contains the length, in bytes, of the scatter gather list buffer.

SGListBuffer

A pointer to a SCATTER_GATHER_LIST structure.

VPortId

An NDIS_NIC_SWITCH_VPORT_ID value that specifies a virtual port (VPort) identifier on which the shared memory is to be allocated. This value must be the identifier of a nondefault VPort that is attached to the physical function (PF) of the miniport adapter.

Note Miniport drivers that support the VMQ interface must set this member to zero. Miniport drivers that support the SR-IOV interface must not set this member to zero (NDIS_DEFAULT_VPORT_ID).

Remarks

The NDIS_SHARED_MEMORY_PARAMETERS structure specifies the shared memory parameters for a shared memory allocation request for a receive queue.

NDIS drivers pass this structure to the NdisAllocateSharedMemory function and NDIS passes this structure to the NetAllocateSharedMemory function (ALLOCATE_SHARED_MEMORY_HANDLER entry point).

Requirements

Requirement	Value
Minimum supported client	Supported in NDIS 6.20 and later.
Header	ndis.h (include Ndis.h)

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