Hi, I am using linux kernel 2.6.39. I have a IBM x3650 M3 system. I have used following boot options - intel_iommu=on iommu=pt I was loading/unloading my NIC driver(be2net) with num_vfs=7. After some iterations I get following DMAR errors - Jun 4 03:50:20 rhel6 kernel: Uhhuh. NMI received for unknown reason 2d on CPU 0. Jun 4 03:50:20 rhel6 kernel: Do you have a strange power saving mode enabled? Jun 4 03:50:20 rhel6 kernel: Dazed and confused, but trying to continue Jun 4 03:50:20 rhel6 kernel: DRHD: handling fault status reg 2 Jun 4 03:50:20 rhel6 kernel: DMAR:[DMA Read] Request device [1a:00.2] fault addr 78077000 Jun 4 03:50:20 rhel6 kernel: DMAR:[fault reason 02] Present bit in context entry is clear I was trying to debug this. I dont understand iommu code much. The physical address belongs the printed PCI function and there should not have been an error. I am unable to see pci_dev(pdev) of VFs getting removed from si_domain->devices list(intel-iommu.c) when driver gets unloaded calling pci_disable_sriov() freeing VF pdevs. Looks like issue happens when when freed pdev is allocated again and as it is already in list, required initializations dont happen. I dont know if my understanding is correct. Can anyone point me to what the issue may be? Thanks, Padmanabh -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html