EVT_WDF_WMI_INSTANCE_EXECUTE_METHOD callback function (wdfwmi.h)

Article
02/22/2024

[Applies to KMDF only]

A driver's EvtWmiInstanceExecuteMethod callback function executes a specified method that the driver provides for a WMI data provider's instance.

Syntax

EVT_WDF_WMI_INSTANCE_EXECUTE_METHOD EvtWdfWmiInstanceExecuteMethod;

NTSTATUS EvtWdfWmiInstanceExecuteMethod(
  [in]      WDFWMIINSTANCE WmiInstance,
  [in]      ULONG MethodId,
  [in]      ULONG InBufferSize,
  [in]      ULONG OutBufferSize,
  [in, out] PVOID Buffer,
  [out]     PULONG BufferUsed
)
{...}

Parameters

[in] WmiInstance

A handle to a WMI instance object.

[in] MethodId

A value that identifies a method in a provider instance. This value corresponds to the WmiMethodId value that is specified in the provider's MOF file.

[in] InBufferSize

The number of bytes of input data.

[in] OutBufferSize

The number of bytes of output data that the buffer that Buffer points to can hold.

[in, out] Buffer

A pointer to a buffer that is used for input, output, or both, as determined by the specified method. If both input and output data are provided, the driver overwrites the input data with the output data.

[out] BufferUsed

A pointer to a location that receives the number of bytes that the driver wrote into the output buffer. If the output buffer size that the OutBufferSize parameter specifies is too small, the driver sets this location to the required buffer size.

Return value

The EvtWmiInstanceExecuteMethod callback function must return STATUS_SUCCESS if the operation succeeds. Otherwise, this function must return a status value for which NT_SUCCESS(status) equals FALSE. The driver must return STATUS_BUFFER_TOO_SMALL if the value of the OutBufferSize parameter indicates that the output buffer is too small to receive the data.

Remarks

To register an EvtWmiInstanceExecuteMethod callback function, your driver must place the function's address in a WDF_WMI_INSTANCE_CONFIG structure before calling WdfWmiInstanceCreate.

After a driver executes the instance method that the MethodId parameter specifies, the driver must use the BufferUsed parameter to store the number of bytes that were written to the buffer.

The framework does not synchronize calls to a driver's WMI event callback functions with each other or with any of the driver's other event callback functions. If an EvtWmiInstanceExecuteMethod callback function's data is dynamic and shared with other callback functions, your driver can use the framework's wait locks or spin locks to synchronize access to the data.

For more information about the EvtWmiInstanceExecuteMethod callback function, see Supporting WMI in Framework-Based Drivers.

Requirements

Requirement	Value
Target Platform	Universal
Minimum KMDF version	1.0
Header	wdfwmi.h (include Wdf.h)
IRQL	PASSIVE_LEVEL