Hello, I have a Supermicro motherboard - Kingstar X9DRW-iF (http://www.supermicro.com/products/motherboard/Xeon/C600/X9DRW-iF.cfm ), CPU present in both sockets. I have a FC hba inserted in the right slot (based on spec of motherboard,), which is connected to CPU2 / Socket 1. I unloaded the FC hba driver, and bound the hba device/ports to vfio using the programming API mentioned in vfio doc - https://www.kernel.org/doc/Documentation/vfio.txt. I am using a default container, with one group in it, which contains both ports of the hba (one PCI function per port). After I issue the first command to hba, when hba attempts to download (Read) a fw image from host memory, I am getting a DMAR error: /var/log/syslog:9:Jul 7 08:29:11 host-11 kernel: [569259.473862] dmar: DRHD: handling fault status reg 202 /var/log/syslog:10:Jul 7 08:29:11 host-11 kernel: [569259.535230] dmar: DMAR:[DMA Read] Request device [05:00.1] fault addr 7fffe85e9000 /var/log/syslog:11:Jul 7 08:29:11 host-11 kernel: [569259.535230] DMAR:[fault reason 02] Present bit in context entry is clear From talking to people, it might be due to the IOMMU table not being correctly programmed. Can someone please give me some pointers which kernel function / data structure to look at to root cause the issue. Thank you, Ahmed.