Hello, please, could somebody explain the difference in behaviour between setting the boot option iommu=pt and not setting it? I can see the following differences: w/ iommu=pt: [ 0.832946] AMD-Vi: Enabling IOMMU at 0000:00:00.2 cap 0x40 [ 0.883983] AMD-Vi: Initialized for Passthrough Mode w/o iommu=pt: [ 0.834905] AMD-Vi: Enabling IOMMU at 0000:00:00.2 cap 0x40 [ 0.894172] AMD-Vi: Lazy IO/TLB flushing enabled In both cases, I can pass through a PCIe device but not a PCI device (-> no problem with IRQ-sharing - the PCI device has its own exclusive IRQ). If I use iommu=pt, the passed PCIe device is broken after the VM has been shutdown and started again. Thank you, kind regards, Andreas -- 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