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EVT_VMB_CHANNEL_SAVE_PACKET callback function (vmbuskernelmodeclientlibapi.h)

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The EvtVmbChannelSavePacket callback function is invoked when the virtualization service provider (VSP) endpoint must save the state associated with a packet.

Syntax

EVT_VMB_CHANNEL_SAVE_PACKET EvtVmbChannelSavePacket;

NTSTATUS EvtVmbChannelSavePacket(
  [in]  VMBCHANNEL Channel,
  [in]  VMBPACKET Packet,
  [out] PVOID SaveBuf,
  [in]  UINT32 SaveBufSize,
  [out] PUINT32 BytesNeeded
)
{...}

Parameters

[in] Channel

The channel on which the packet arrives.

[in] Packet

The packet for which VSP saves state.

[out] SaveBuf

The buffer into which to save the state.

[in] SaveBufSize

Size of the SaveBuf parameter, in bytes.

[out] BytesNeeded

Size necessary to save the state of the transaction, in bytes.

Return value

EvtVmbChannelSavePacket returns a status code.

Remarks

The VmbServerChannelInitSetSaveRestorePacketCallbacks function sets a callback function for saving packets for each channel.

The VSP saves the state associated with the transaction that is unique to the VSP. The Kernel Mode Client Library (KMCL) saves its own state.

This function is invoked for each packet object that is currently in use. The first invocation passes a zero (0) value for the SaveBufSize parameter. This call fails if there is any state that needs to be saved, which fills the BytesNeeded with the actual size requirement. If this first invocation returns a failure code, the KMCL calls a second time with a buffer of at least the length stipulated in the first call.

Requirements

Requirement Value
Target Platform Windows
Header vmbuskernelmodeclientlibapi.h (include VmbusKernelModeClientLibApi.h)
IRQL PASSIVE_LEVEL

See also

VmbServerChannelInitSetSaveRestorePacketCallbacks