The KVM capability, KVM_CAP_S390_CPU_TOPOLOGY is used to activate the S390_FEAT_CONFIGURATION_TOPOLOGY feature and the topology facility for the guest in the case the topology is available in QEMU and in KVM. Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> --- target/s390x/kvm/kvm.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c index a79fdf1c79..724758680b 100644 --- a/target/s390x/kvm/kvm.c +++ b/target/s390x/kvm/kvm.c @@ -2471,6 +2471,22 @@ void kvm_s390_get_host_cpu_model(S390CPUModel *model, Error **errp) set_bit(S390_FEAT_UNPACK, model->features); } + /* + * If we have the CPU Topology allowed in QEMU and + * implemented in KVM, activate the CPU TOPOLOGY feature. + */ + if (s390_has_topology()) { + if (!kvm_check_extension(kvm_state, KVM_CAP_S390_CPU_TOPOLOGY)) { + error_setg(errp, "KVM: S390 topology not present in kernel"); + return; + } + if (kvm_vm_enable_cap(kvm_state, KVM_CAP_S390_CPU_TOPOLOGY, 0) < 0) { + error_setg(errp, "KVM: Error enabling KVM_CAP_S390_CPU_TOPOLOGY"); + return; + } + set_bit(S390_FEAT_CONFIGURATION_TOPOLOGY, model->features); + } + /* We emulate a zPCI bus and AEN, therefore we don't need HW support */ set_bit(S390_FEAT_ZPCI, model->features); set_bit(S390_FEAT_ADAPTER_EVENT_NOTIFICATION, model->features); -- 2.31.1