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FN_VMB_CHANNEL_INIT_SET_MAXIMUM_EXTERNAL_DATA callback function (vmbuskernelmodeclientlibapi.h)

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The VmbChannelInitSetMaximumExternalData function sets the maximum size and chain length of data that is described by a packet, but not directly sent in the packet. That is, the maximum size of the buffer described by an ExternalDataMdl.

Syntax

FN_VMB_CHANNEL_INIT_SET_MAXIMUM_EXTERNAL_DATA FnVmbChannelInitSetMaximumExternalData;

NTSTATUS FnVmbChannelInitSetMaximumExternalData(
  VMBCHANNEL Channel,
  UINT32 DataSize,
  UINT32 ChainLength
)
{...}

Parameters

Channel

A pointer to a Kernel Mode Client Library (KMCL) channel.

DataSize

The maximum size of external data.

ChainLength

The maximum number of Memory Descriptor Lists (MDLs) in an incoming MDL chain.

Return value

VmbChannelInitSetMaximumExternalData can return one of the following status values:

Return code Description
STATUS_SUCCESS
 The function finished successfully.
STATUS_INVALID_PARAMETER_1
 The Channel value was invalid or in an invalid state, such as Disabled.
STATUS_INVALID_PARAMETER_2
 The DataSize value is invalid. Zero (0) is invalid.
STATUS_INVALID_PARAMETER_3
 The ChainLength value is invalid. Zero (0) is invalid.

Remarks

The KMCL ensures that your ring buffers are large enough to send packets that contain buffers in the specified limits.

Important

This function is called through the VMBus Kernel Mode Client Library (KMCL) interface, provided by the Vmbkmcl.sys bus driver. This is a client function accessed from the KMCL_CLIENT_INTERFACE_V1 structure.

For more information, see the Remarks section of the KMCL_CLIENT_INTERFACE_V1.

Requirements

Requirement Value
Minimum supported client Windows 10, version 1803
Header vmbuskernelmodeclientlibapi.h