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WHvWriteVpciDeviceRegister

Writes a configuration space or MMIO register of a virtual PCI (VPCI) device.

Syntax

typedef enum WHV_VPCI_DEVICE_REGISTER_SPACE
{
    WHvVpciConfigSpace = -1,
    WHvVpciBar0 = 0,
    WHvVpciBar1 = 1,
    WHvVpciBar2 = 2,
    WHvVpciBar3 = 3,
    WHvVpciBar4 = 4,
    WHvVpciBar5 = 5
} WHV_VPCI_DEVICE_REGISTER_SPACE;

typedef struct WHV_VPCI_DEVICE_REGISTER
{
    WHV_VPCI_DEVICE_REGISTER_SPACE Location;
    UINT32 SizeInBytes;
    UINT64 OffsetInBytes;
} WHV_VPCI_DEVICE_REGISTER;

HRESULT
WINAPI
WHvWriteVpciDeviceRegister(
    _In_ WHV_PARTITION_HANDLE Partition,
    _In_ UINT64 LogicalDeviceId,
    _In_ const WHV_VPCI_DEVICE_REGISTER* Register,
    _In_reads_bytes_(Register->SizeInBytes) const VOID* Data
    );

Parameters

Partition

Handle to the partition that owns the VPCI device.

LogicalDeviceId

Specifies the logical device identifier of the VPCI device.

Register

Specifies the register to write, as a WHV_VPCI_DEVICE_REGISTER structure that identifies the register space, offset, and size.

Data

Specifies the data to write to the register. The buffer must be at least Register->SizeInBytes bytes.

Return Value

If the function succeeds, the return value is S_OK.

Remarks

The WHvWriteVpciDeviceRegister function writes a register in the configuration space or MMIO space of the PCIe physical or virtual function associated with a VPCI device. For configuration space, access to certain registers may be filtered by the underlying virtual PCI stack to guarantee secure VM assignment of PCIe functions. For MMIO space, this function can write registers that have not been mapped directly into the caller's address space because the underlying virtual PCI stack must enforce mitigations for those registers.

Requirements

Requirement Value
Minimum supported Windows Windows 10, version 20H2 (x64); Windows 11, version 24H2, build 26100.3915 (Arm64)
Header WinHvPlatform.h
Library WinHvPlatform.lib
DLL WinHvPlatform.dll
Architecture x64, Arm64

See also

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