On 20/01/2020 11.30, Cornelia Huck wrote: > On Mon, 20 Jan 2020 10:49:01 +0100 > Thomas Huth <th...@redhat.com> wrote: > >> The AIS feature has been disabled late in the v2.10 development cycle since >> there were some issues with migration (see commit 3f2d07b3b01ea61126b - >> "s390x/ais: for 2.10 stable: disable ais facility"). We originally wanted >> to enable it again for newer machine types, but apparently we forgot to do >> this so far. Let's do it for the new s390-ccw-virtio-5.0 machine now. >> >> While at it, also add a more verbose comment why we need the *_allowed() >> wrappers in s390-virtio-ccw.c. >> >> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946 >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> Matthew, could you please give this another try on your system? Thanks! >> >> hw/s390x/s390-virtio-ccw.c | 20 +++++++++++++++++--- >> include/hw/s390x/s390-virtio-ccw.h | 3 +++ >> target/s390x/kvm.c | 9 ++++++--- >> 3 files changed, 26 insertions(+), 6 deletions(-) >> > >> @@ -658,6 +669,9 @@ static void >> ccw_machine_4_2_instance_options(MachineState *machine) >> >> static void ccw_machine_4_2_class_options(MachineClass *mc) >> { >> + S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc); >> + >> + s390mc->kvm_ais_allowed = false; >> ccw_machine_5_0_class_options(mc); >> compat_props_add(mc->compat_props, hw_compat_4_2, hw_compat_4_2_len); > > One thing I've noticed: You set the _allowed value to false, and > afterwards apply the options from any 'later' class; this is the same > order as for the other _allowed values. There's also > css_migration_enabled, which is set to false _after_ the class options > from 'later' classes have been applied. > > Both variants end up the same, as we only ever set the value to true in > the base class and to false just in a single class option callback; but > I wonder whether it would be cleaner to set it to false after the other > options have been applied. Or am I thinking backwards here?
You're right, it should not matter right now, but it might be better (from the copy-n-paste perspective) / more future-proof to do it the other way round. I'll send a v3... Thomas
