DXGKCB_SAVEMEMORYFORHOTUPDATE callback function (d3dkmddi.h)

Article
10/21/2021

A kernel-mode display miniport driver can call DXGKCB_SAVEMEMORYFORHOTUPDATE to save adapter memory to support driver hot update.

Syntax

DXGKCB_SAVEMEMORYFORHOTUPDATE DxgkcbSavememoryforhotupdate;

NTSTATUS DxgkcbSavememoryforhotupdate(
  [in] IN_CONST_HANDLE hAdapter,
  [in] IN_CONST_PDXGKARGCB_SAVEMEMORYFORHOTUPDATE pArgs
)
{...}

Parameters

[in] hAdapter

A handle to the DXGK adapter that is passed to DxgkDdiStartDevice.

[in] pArgs

A pointer to the DXGKARGCB_SAVEMEMORYFORHOTUPDATE structure that contains arguments for this callback.

Return value

DXGKCB_SAVEMEMORYFORHOTUPDATE returns STATUS_SUCCESS if the operation succeeds; otherwise it returns an error code from Ntstatus.h.

Remarks

Each call to DXGKCB_SAVEMEMORYFORHOTUPDATE saves a block of physical memory pages, as well as optionally metadata that the driver wants to associate with the memory block. When the pages are restored, the driver will get a separate call for each saved memory block together with metadata.

For convenience, the callback provides 3 options to save physical memory:

As an array of contiguous physical memory ranges (pDataMemoryRanges)
As an MDL (pDataMdl)
As virtual memory buffer (pData)

One (and only one) of the pointers to data (pDataMemoryRanges, pDataMdl or pData) must be not NULL.

DXGKCB_XXX functions are implemented by Dxgkrnl. To use this callback function, set the appropriate members of DXGKARGCB_SAVEMEMORYFORHOTUPDATE and then call DxgkCbSaveMemoryForHotUpdate via the DXGKRNL_INTERFACE.

Requirements

Requirement	Value
Minimum supported client	Windows 10, version 1903 (WDDM 2.6)
Header	d3dkmddi.h
IRQL	PASSIVE_LEVEL