IoWMIQuerySingleInstanceMultiple function (wdm.h)

Article
02/25/2022

The IoWMIQuerySingleInstanceMultiple routine returns all WMI data block instances that implement the specified WMI classes with the specified instance names.

Syntax

NTSTATUS IoWMIQuerySingleInstanceMultiple(
  [in]            PVOID           *DataBlockObjectList,
  [in]            PUNICODE_STRING InstanceNames,
  [in]            ULONG           ObjectCount,
  [in, out]       PULONG          InOutBufferSize,
  [out, optional] PVOID           OutBuffer
);

Parameters

[in] DataBlockObjectList

Pointer to an array of pointers of WMI data block objects. The caller opens a data block object for each WMI class with the IoWMIOpenBlock routine. Each object must be opened with the WMIGUID_QUERY access right.

[in] InstanceNames

Pointer to an array of UNICODE_STRING structures containing instance names. The nth instance name in the array corresponds to the value of the InstanceName property for the nth WMI class specified in the array pointed to by the DataBlockObjectList parameter.

[in] ObjectCount

Specifies the number of entries in the arrays passed in the DataBlockObjectList and InstanceNames parameters.

[in, out] InOutBufferSize

Pointer to a memory location that specifies the size of the buffer passed in the OutBuffer parameter. If the routine succeeds, it updates the memory location to specify the number of bytes actually stored in OutBuffer. If the routine fails with STATUS_BUFFER_TOO_SMALL, it returns the number of bytes required to return the data.

[out, optional] OutBuffer

Pointer to the buffer where the routine returns the WMI data. The routine returns a sequence of variable-sized WNODE_SINGLE_INSTANCE structures, one for each data block instance. The WnodeHeader.Linkage member of each WNODE_SINGLE_INSTANCE structure contains the offset from the beginning of the current WNODE_SINGLE_INSTANCE to the beginning of the next WNODE_SINGLE_INSTANCE. The final block in the chain has WnodeHeader.Linkage set to zero. Each distinct data block instance corresponds to a single matching WMI class and instance name. OutBuffer must point to a buffer allocated from nonpaged pool.

Return value

The routine returns an NTSTATUS code. Possible return values include:

Return code	Description
STATUS_SUCCESS	The operation succeeded. The routine returns the WMI data in the buffer pointed to by the OutBuffer parameter. The routine also returns the size, in bytes, of the returned data in the memory location pointed to by the InOutBufferSize parameter.
STATUS_BUFFER_TOO_SMALL	The buffer passed by the caller in the OutBuffer parameter is too small. The routine returns the required buffer size in the memory location pointed to by the InOutBufferSize parameter.

Remarks

IoWMIQuerySingleInstanceMultiple determines which drivers might support the specified WMI classes and instance names, and issues an IRP_MN_QUERY_SINGLE_INSTANCE request to each such driver. Each driver that exports the data block instance with matching InstanceName property returns the appropriate data.

If no drivers implement any of the specified WMI classes and instance names, the routine returns STATUS_SUCCESS. It also returns a value of zero in the memory location pointed to by the InOutBufferSize parameter.

To query for a single WMI class and instance name, use the IoWMIQuerySingleInstance routine. Drivers can use the IoWMISetSingleInstance routine to update a class instance.

Requirements

Requirement	Value
Minimum supported client	Available in Windows XP and later versions of the Windows operating system.
Target Platform	Universal
Header	wdm.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library	NtosKrnl.lib
DLL	NtosKrnl.exe
IRQL	<= APC_LEVEL