On 16/01/2020 13.23, David Hildenbrand wrote: > On 16.01.20 13:20, Thomas Huth 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. >> >> Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1756946 >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> hw/s390x/s390-virtio-ccw.c | 4 ++++ >> include/hw/s390x/s390-virtio-ccw.h | 4 ++++ >> target/s390x/kvm.c | 11 ++++++++--- >> 3 files changed, 16 insertions(+), 3 deletions(-) >> >> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c >> index e7eadd14e8..6f43136396 100644 >> --- a/hw/s390x/s390-virtio-ccw.c >> +++ b/hw/s390x/s390-virtio-ccw.c >> @@ -456,6 +456,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void >> *data) >> s390mc->cpu_model_allowed = true; >> s390mc->css_migration_enabled = true; >> s390mc->hpage_1m_allowed = true; >> + s390mc->kvm_ais_allowed = true; >> mc->init = ccw_init; >> mc->reset = s390_machine_reset; >> mc->hot_add_cpu = s390_hot_add_cpu; >> @@ -662,6 +663,9 @@ 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); >> } >> diff --git a/include/hw/s390x/s390-virtio-ccw.h >> b/include/hw/s390x/s390-virtio-ccw.h >> index 8aa27199c9..f142d379c6 100644 >> --- a/include/hw/s390x/s390-virtio-ccw.h >> +++ b/include/hw/s390x/s390-virtio-ccw.h >> @@ -21,6 +21,9 @@ >> #define S390_MACHINE_CLASS(klass) \ >> OBJECT_CLASS_CHECK(S390CcwMachineClass, (klass), TYPE_S390_CCW_MACHINE) >> >> +#define S390_CCW_MACHINE_OBJ_GET_CLASS(obj) \ >> + OBJECT_GET_CLASS(S390CcwMachineClass, obj, TYPE_S390_CCW_MACHINE) >> + >> typedef struct S390CcwMachineState { >> /*< private >*/ >> MachineState parent_obj; >> @@ -40,6 +43,7 @@ typedef struct S390CcwMachineClass { >> bool cpu_model_allowed; >> bool css_migration_enabled; >> bool hpage_1m_allowed; >> + bool kvm_ais_allowed; >> } S390CcwMachineClass; >> >> /* runtime-instrumentation allowed by the machine */ >> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c >> index 15260aeb9a..4c1c8c0208 100644 >> --- a/target/s390x/kvm.c >> +++ b/target/s390x/kvm.c >> @@ -329,6 +329,8 @@ static void ccw_machine_class_foreach(ObjectClass *oc, >> void *opaque) >> >> int kvm_arch_init(MachineState *ms, KVMState *s) >> { >> + S390CcwMachineClass *smc = S390_CCW_MACHINE_OBJ_GET_CLASS(ms); >> + >> object_class_foreach(ccw_machine_class_foreach, TYPE_S390_CCW_MACHINE, >> false, NULL); >> >> @@ -365,10 +367,13 @@ int kvm_arch_init(MachineState *ms, KVMState *s) >> /* >> * The migration interface for ais was introduced with kernel 4.13 >> * but the capability itself had been active since 4.12. As migration >> - * support is considered necessary let's disable ais in the 2.10 >> - * machine. >> + * support is considered necessary we only enable this for newer >> + * machine types and if KVM_CAP_S390_AIS_MIGRATION is available. >> */ >> - /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */ >> + if (smc->kvm_ais_allowed && >> + kvm_check_extension(s, KVM_CAP_S390_AIS_MIGRATION)) { >> + kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); >> + } >> >> kvm_set_max_memslot_size(KVM_SLOT_MAX_BYTES); >> return 0; >> > > We have ri_allowed(), cpu_model_allowed(), hpage_1m_allowed(). > > Care to create a similar wrapper?
Honestly, why do we need these wrappers at all? They look cumbersome to me. I'd rather remove them in case they are not urgently needed (so far I don't see the point... could someone enlighten me why we have them?). Thomas
