As David has identified the reason why only 2.7 and older are affected (thanks!), we can fix migration of these machines by unconditionally providing the zpci feature bit if cpu models are off.
Still RFC, as I have only sniff-tested it. We still need to think about what to do with compat machines on pci-less builds. Probably we should disable compat machines (at least 2.7 and older) on those builds. Not a pressing issue, as switching off CONFIG_PCI needs to be done manually. Changes RFC -> RFC v2: - switch from machine class property to enabling zpci bit for non-cpu model compat machines Cornelia Huck (1): s390x/ccw: create s390 phb for compat reasons as well hw/s390x/s390-virtio-ccw.c | 2 ++ target/s390x/cpu_models.c | 3 +++ 2 files changed, 5 insertions(+) -- 2.13.5