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FN_VMB_CHANNEL_SAVE_CONTINUE callback function (vmbuskernelmodeclientlibapi.h)

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[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 VmbChannelSaveContinue function saves the channel state to a buffer. Run the VmbChannelSaveBegin before you run this function. The driver must check the return value of the function.

Syntax

FN_VMB_CHANNEL_SAVE_CONTINUE FnVmbChannelSaveContinue;

NTSTATUS FnVmbChannelSaveContinue(
  VMBCHANNEL Channel,
  PVOID SaveBuffer,
  ULONG SaveBufferSize,
  PULONG BytesFilled,
  PULONG BytesRequired
)
{...}

Parameters

Channel

A handle for a channel to save.

SaveBuffer

A pointer to the buffer into which to save state information.

SaveBufferSize

The size, in bytes, of the save buffer.

BytesFilled

A pointer to a variable that receives the number of bytes that were copied to the save buffer.

BytesRequired

A pointer to a variable that receives the number of bytes that are needed for this function to make progress on the next call.

Return value

VmbChannelSaveContinue returns the following values:

Return code Description
STATUS_SUCCESS
 The state was saved.
STATUS_BUFFER_TOO_SMALL
The save buffer was too small. The BytesNeeded parameter contains the number of bytes that are required to make any progress.
STATUS_STATUS_BUFFER_OVERFLOW
 Some data was written to the save buffer, but there is more data to be saved.

Remarks

The save process saves the data in "chunks" and can continue from the point it stopped.

If the caller did not allocate enough space in advance, multiple calls may be needed.

Important

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

For more information, see the Remarks section of KMCL_SERVER_ONLY_METHODS.

Requirements

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

See also

VmbChannelSaveBegin