Hi Kristen:

We recently encountered issues when using Intel IAA (In-Memory Analytics Accelerator) for data decompression in the Linux kernel. Specifically, while using the iaa_crypto driver, decompression fails when processing large datasets composed of non-contiguous memory pages. Initially, we attempted to address this by using scatterlists (SGLs), but decompression still failed. After analyzing the iaa_crypto driver code, we discovered that ​non-contiguous pages require enabling IOMMU to map them into a single virtual contiguous memory block for the device. However, while this approach worked for small numbers of non-contiguous pages, it failed for larger quantities due to IOMMU limitations in mapping fragmented pages into a unified virtual address space.

We would like to consult with you

Is it possible to use iaa_crypto for decompression with ​numerous non-contiguous pages?
If yes, what modifications are required to resolve the IOMMU mapping constraints?

Thanks,
Bo Liu.