Does WdfCommonBufferCreate() use IOMMU to allocate memory not physically contiguous?

[Kevin_EVT]

It seems not using IOMMU.
A close look into the memory created by WdfCommonBufferCreate():

1. There is only 1 MDL. The size is 2GB.
2. I get page numbers by MmGetMdlPfnArray(). They are consecutive.
3. The logical address(WdfCommonBufferGetAlignedLogicalAddress) and the physical address(MmGetPhysicalAddress) are identical.

I try allocate 2GB chunk as many as possible by WdfCommonBufferCreate() and MmAllocateContiguousMemory(). The maximum chunks they can allocate are the same.

@Peter_Viscarola_OSR said "In some version of Windows, the WDM function AllocateCommonBuffer simply calls MmAllocateContiguousMemory."

Allocate huge amounts of continous physical memory for DMA /wo scatter gather

Now I’m confused. Whats the difference between WdfDmaProfileScatterGather64Duplex and WdfDmaProfilePacket64 if not handling the (full) transfer /w resp. /wo Scatter Gather pü? So you say that the allocated 1GB common buffer is always continuous in physical memory at all? Maybe I dont have the whole picture yet and need to read more about the topic.

Now, my question:
how to allocate non-physically-contiguous memory for non-scatter-gather DMA?

In Linux, I am able to allocated a bunch of small memory and create the SG list, then pass a single address to my device.

Kevin