While playing around with compat machines a bit, I noticed that my zpci detanglement patches broke migration from 2.7 to current master (2.8 or newer are fine, which is why I did not notice that before.)
qemu 2.7 seems to create a savevm that a s390-next (or master) build without the s390 phb chokes on: qemu-system-s390x: Unknown savevm section or instance 'PCIBUS' 0 Creating the s390 phb for compat machines seems to cure this; still RFC for the following reasons: - I'm not sure what we're supposed to do on builds without pci. Fail creating the compat machines? Do we need a new set of _NOPCI compat machines for that? - I don't understand why 2.7 fails, but 2.8 and later are fine. At least, I was not able to spot which commit changed the behaviour here... and I really want to understand this. Pointers welcome. - I have not tested it extensively yet. Patch is against s390-next. Cornelia Huck (1): s390x/ccw: create s390 phb for compat reasons as well hw/s390x/s390-virtio-ccw.c | 6 +++++- include/hw/s390x/s390-virtio-ccw.h | 1 + 2 files changed, 6 insertions(+), 1 deletion(-) -- 2.13.5