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; -- 2.18.1
