1PCI devices on s390x 2==================== 3 4PCI devices on s390x work differently than on other architectures and need to 5be configured in a slightly different way. 6 7Every PCI device is linked with an additional ``zpci`` device. 8While the ``zpci`` device will be autogenerated if not specified, it is 9recommended to specify it explicitly so that you can pass s390-specific 10PCI configuration. 11 12For example, in order to pass a PCI device ``0000:00:00.0`` through to the 13guest, you would specify:: 14 15 qemu-system-s390x ... \ 16 -device zpci,uid=1,fid=0,target=hostdev0,id=zpci1 \ 17 -device vfio-pci,host=0000:00:00.0,id=hostdev0 18 19Here, the zpci device is joined with the PCI device via the ``target`` property. 20 21Note that we don't set bus, slot or function here for the guest as is common in 22other PCI implementations. Topology information is not available on s390x, and 23the guest will not see any of the bus, slot or function information specified 24on the command line. 25 26Instead, ``uid`` and ``fid`` determine how the device is presented to the guest 27operating system. 28 29In case of Linux, ``uid`` will be used in the ``domain`` part of the PCI 30identifier, and ``fid`` identifies the physical slot, i.e.:: 31 32 qemu-system-s390x ... \ 33 -device zpci,uid=7,fid=8,target=hostdev0,id=zpci1 \ 34 ... 35 36will be presented in the guest as:: 37 38 # lspci -v 39 0007:00:00.0 ... 40 Physical Slot: 00000008 41 ... 42