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DXGKDDI_GETMMIORANGES callback function (dispmprt.h)

  • Article

Get the memory ranges for a single MMIO (memory mapped input output) BAR (base address register) in the virtual device.

Syntax

DXGKDDI_GETMMIORANGES DxgkddiGetmmioranges;

NTSTATUS DxgkddiGetmmioranges(
  HANDLE Context,
  PDXGKARG_GETMMIORANGES pArgs
)
{...}

Parameters

Context

A handle to the device context.

pArgs

Pointer to a DXGKARG_GETMMIORANGES structure.

Return value

Returns:

  • STATUS_SUCCESS The IHV system did not encounter any errors.
  • STATUS_INVALID_DEVICE_REQUEST The virtual device encountered an error and should be forcibly stopped. Failure here will cause virtual device failure.
  • BUFFER_TO_SMALL may result in this being called again with a larger buffer.

Remarks

This callback function gets the specific ranges on which intercepts and mapping must be placed. This is a more flexible scatter/gather mapping of the BARs than the general SR-IOV (single-root input/output virtualization) solution that allows for VF (virtual function) BARS (base address registers) to be different sized than the physical bars and map/emulate any order of pages from any physical bar to any virtual bar. This function MUST contain a mapping for every page in the virtual bar. If it does not the device will fail to be created.

Requirements

Requirement Value
Minimum supported client Windows 10, version 1809
Header dispmprt.h
IRQL PASSIVE_LEVEL