DXGK_ALLOCATIONLIST structure

Description

The DXGK_ALLOCATIONLIST structure describes an allocation specification that is used in direct memory access (DMA) buffering.

Syntax

typedef struct _DXGK_ALLOCATIONLIST
{
    HANDLE              hDeviceSpecificAllocation;
    struct
    {
        UINT            WriteOperation  : 1;    // 0x00000001
        UINT            SegmentId       : 5;    // 0x0000002E
        UINT            Reserved        : 26;   // 0xFFFFFFC0
    };
#if (DXGKDDI_INTERFACE_VERSION >= DXGKDDI_INTERFACE_VERSION_WDDM2_0)
    union
    {
        PHYSICAL_ADDRESS        PhysicalAddress;
        D3DGPU_VIRTUAL_ADDRESS  VirtualAddress;
    };
#else // (DXGKDDI_INTERFACE_VERSION < DXGKDDI_INTERFACE_VERSION_WDDM2_0)
    PHYSICAL_ADDRESS    PhysicalAddress;
#endif // (DXGKDDI_INTERFACE_VERSION >= DXGKDDI_INTERFACE_VERSION_WDDM2_0)
} DXGK_ALLOCATIONLIST;

Members

hDeviceSpecificAllocation [in/out]

An open handle to the allocation that is being referenced (that is, the handle that the driver returned in the hDeviceSpecificAllocation member of the DXGK_OPENALLOCATIONINFO structure for the allocation in a call to the driver's DxgkDdiOpenAllocation function).

WriteOperation [in/out]

Identifies whether the allocation can be written to. Setting this member to 1 indicates that the allocation can be written to anywhere in the DMA buffer. Setting this member is equivalent to setting the first bit of a 32-bit value (0x00000001).

SegmentId [in/out]

Specifies the identifier of a segment that the allocation was last paged in at. Setting this member to 0 indicates that no pre-patching information is available. Setting this member is equivalent to setting the second through sixth bit of a 32-bit value (0x0000002E).

Reserved [in]

Reserved. This member should be set to 0. Setting this member is equivalent to setting the remaining 26 bits (0xFFFFFFC0) of a 32-bit value to zeros.

PhysicalAddress [in/out]

A PHYSICAL_ADDRESS data type (which is defined as LARGE_INTEGER) that indicates the physical address, within the segment that SegmentId specifies, where the allocation was last paged-in at. This member is set to zero if no pre-patching information is available.

Supported starting with Windows 10.

VirtualAddress [in/out]

A D3DGPU_VIRTUAL_ADDRESS data type (which is defined as a ULONGLONG) that indicates the virtual address.

Supported starting with Windows 10.

Remarks

In the display miniport driver's DxgkDdiRender function, the driver generates a list of DXGK_ALLOCATIONLIST structures for allocation specifications that will be used in a direct memory access (DMA) buffer. The video memory manager uses the list to split and patch DMA buffers appropriately.

See also

DXGKARG_CREATEALLOCATION

DXGK_ALLOCATIONINFO

DXGK_OPENALLOCATIONINFO

DxgkDdiCreateAllocation

DxgkDdiOpenAllocation

DxgkDdiRender