Didn't get any response on the IRC channel so trying here. Was wondering if anybody here has used IOAT DMA engines with an IOMMU turned on (Xeon based system)? My specific question is really whether it is possible to DMA (w/IOAT) to a PCI BAR address as the destination without having to map that address to the IOVA space of the DMA engine first (assuming the IOMMU is on)? I am encountering issues where I see PTE Errors reported from DMAR in this scenario, but I do not if I use a different DMA engine that's sitting downstream off the PCI tree. I'm wondering if the IOAT DMA failure is some artifact of these engines sitting behind the Host Bridge. Thanks in advance! Eric
