GET_VIRTUAL_DEVICE_DATA callback function (wdm.h)

The GetVirtualFunctionData routine reads data from the PCI Express (PCIe) configuration space of a virtual function (VF) on a device that supports the single root I/O virtualization (SR-IOV) interface.

Syntax

GET_VIRTUAL_DEVICE_DATA GetVirtualDeviceData;

ULONG GetVirtualDeviceData(
  [in, out] PVOID Context,
  [in]      USHORT VirtualFunction,
  [out]     PVOID Buffer,
  [in]      ULONG Offset,
  [in]      ULONG Length
)
{...}

Parameters

[in, out] Context

A pointer to interface-specific context information. The caller passes the value that is passed as the Context member of the PCI_VIRTUALIZATION_INTERFACE structure for the interface.

[in] VirtualFunction

A zero-based value that specifies the VF on the device from which data is to be read.

[out] Buffer

A pointer to the buffer that contains the configuration information read from the PCIe configuration space of the VF.

[in] Offset

The offset into the PCIe configuration space data of the VF. This member specifies where this read operation begins.

[in] Length

The length, in bytes, of the data to be read.

Return value

The GetVirtualFunctionData routine returns the length, in bytes, of the PCIe configuration data that was read after a successful read operation. If the read operation is unsuccessful, the routine returns zero.

Remarks

The GetVirtualFunctionData routine resembles the GetBusData routine, except that it reads PCIe configuration data from a VF instead of from a device's physical function (PF).

The GetVirtualFunctionData routine is provided by the GUID_PCI_VIRTUALIZATION_INTERFACE interface. The GetBusData routine is provided by the GUID_BUS_INTERFACE_STANDARD interface.

The virtualization stack calls GetVirtualFunctionData when a driver that is running in the guest operating system calls the GetBusData routine.

Requirements

See also

PCI_VIRTUALIZATION_INTERFACE

GetBusData