NDK_FN_BIND callback function (ndkpi.h)

Article
10/21/2021

The NdkBind (NDK_FN_BIND) function binds a memory window to a specific sub-region of a memory region (MR).

Syntax

NDK_FN_BIND NdkFnBind;

NTSTATUS NdkFnBind(
  [in]           NDK_QP *pNdkQp,
  [in, optional] PVOID RequestContext,
  [in]           NDK_MR *pMr,
  [in]           NDK_MW *pMw,
  [in]           PVOID VirtualAddress,
  [in]           SIZE_T Length,
  [in]           ULONG Flags
)
{...}

Parameters

[in] pNdkQp

A pointer to an NDK queue pair (QP) object (NDK_QP).

[in, optional] RequestContext

A context value to return in the RequestContext member of the NDK_RESULT structure for this request.

[in] pMr

A pointer to an NDK memory region (MR) object (NDK_MR).

[in] pMw

A pointer to an NDK memory window (MW) object (NDK_MW).

[in] VirtualAddress

A virtual address that must be greater than or equal to the virtual address of the MDL for the MR and less than the virtual address of the MDL for the MR plus the value in the Length parameter.

Use the MmGetMdlVirtualAddress macro to obtain the virtual address of the MDL for the MR.

[in] Length

The length of the MR to bind to the MW.

[in] Flags

A bitwise OR of flags which specifies the operations that are allowed. The following flags are supported:

Value	Meaning
NDK_OP_FLAG_SILENT_SUCCESS 0x00000001	Indicates the successful completion of this request does not generate a completion event in the outbound completion queue. However, requests that fail do generate a completion in the completion queue.
NDK_OP_FLAG_READ_FENCE 0x00000002	Indicates that all prior read requests must be complete before the hardware begins processing this request.
NDK_OP_FLAG_ALLOW_REMOTE_READ 0x00000008	Enable read access to the memory window for any connected peer. To access the memory window, the connected peers must have a valid token.
NDK_OP_FLAG_ALLOW_REMOTE_WRITE 0x00000030	Enable write access to the memory window for any connected peer. To access the memory window, the connected peers must have a valid token.
NDK_OP_FLAG_DEFER 0x00000200	Indicates to the NDK provider that it may defer indicating the request to hardware for processing. For more information about this flag, see NDKPI Deferred Processing Scheme. Note This flag is supported only in NDKPI 1.2 (Windows Server 2012 R2) and later.

Return value

The NdkBind function returns one of the following NTSTATUS codes.

Return code	Description
STATUS_SUCCESS	The request was posted successfully. A completion entry will be queued to the CQ when the work request is completed.
STATUS_CONNECTION_INVALID	The queue pair (QP) is not connected.
STATUS_ACCESS_VIOLATION	The memory region does not allow the type of access requested for the memory window. The NDK_OP_FLAG_ALLOW_WRITE flag requires a memory region that was registered with the NDK_MR_FLAG_ALLOW_LOCAL_WRITE flag.
Other status codes	An error occurred.

Remarks

NdkBind binds a memory window (MW) to a specific sub-region of a memory region (MR).

The address in the VirtualAddress parameter must be an address within the virtually contiguous region that is described by the MDL chain that was specified during memory registration. The address must be treated by the provider as an index into the memory region. The address must not be used by the provider as a valid virtual address for reading or writing buffer contents.

After this call returns, the remote token will be available with the NdkGetRemotetokenFromMw function (NDK_FN_GET_REMOTE_TOKEN_FROM_MW).

This function does not support a zero-based virtual address.

Requirements

Requirement	Value
Minimum supported client	None supported,Supported in NDIS 6.30 and later.
Minimum supported server	Windows Server 2012
Target Platform	Windows
Header	ndkpi.h (include Ndkpi.h)
IRQL	<=DISPATCH_LEVEL