Comment 0 for bug 552311

10.04 has Bus options (PCI etc.)" -> "Support for DMA Remapping Devices" not set for generic and server images.
but it is necessary for KVM pci passthrough http://www.linux-kvm.org/page/How_to_assign_devices_with_VT-d_in_KVM
which is declared as supported since Ubuntu 9.04
http://www.ubuntu.com/servervirtualization