FN_VMB_CHANNEL_INIT_SET_MAXIMUM_EXTERNAL_DATA - NtDoc
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headers
// vmbuskernelmodeclientlibapi.h
FN_VMB_CHANNEL_INIT_SET_MAXIMUM_EXTERNAL_DATA FnVmbChannelInitSetMaximumExternalData;
NTSTATUS FnVmbChannelInitSetMaximumExternalData(
VMBCHANNEL Channel,
UINT32 DataSize,
UINT32 ChainLength
)
{...}
View the official Windows Driver Kit DDI referenceNo description available.
[Some information relates to pre-released product which may be substantially modified before it's commercially released. Microsoft makes no warranties, express or implied, with respect to the information provided here.]
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.
ChannelA pointer to a Kernel Mode Client Library (KMCL) channel.
DataSizeThe maximum size of external data.
ChainLengthThe maximum number of Memory Descriptor Lists (MDLs) in an incoming MDL chain.
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. |
//Declaration
FN_VMB_CHANNEL_INIT_SET_MAXIMUM_EXTERNAL_DATA FnVmbChannelInitSetMaximumExternalData;
// Definition
NTSTATUS FnVmbChannelInitSetMaximumExternalData
(
VMBCHANNEL Channel
UINT32 DataSize
UINT32 ChainLength
)
{...}
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.