MmGetMdlVirtualAddress

The MmGetMdlVirtualAddress routine returns the base virtual address of a buffer described by an MDL.

PVOID 
  MmGetMdlVirtualAddress(
    IN PMDL  Mdl
    );

Parameters

Mdl

Pointer to an MDL that describes the buffer for which to return the initial virtual address.

Return Value

MmGetMdlVirtualAddress returns the starting virtual address of the MDL.

Headers

Declared in wdm.h and ntddk.h. Include wdm.h or ntddk.h.

Comments

MmGetMdlVirtualAddress returns a virtual address that is not necessarily valid in the current thread context. Lower-level drivers should not attempt to use the returned virtual address to access memory, particularly user-space memory.

The returned address, used as an index to a physical address entry in the MDL, can be input to MapTransfer.

Callers of MmGetMdlVirtualAddress can be running at any IRQL. Usually, the caller is running at IRQL = DISPATCH_LEVEL because this routine is commonly called to obtain the CurrentVa parameter to MapTransfer.

See Also

MapTransfer, MmGetMdlByteOffset, MmIsAddressValid, MmIsNonPagedSystemAddressValid