Re: [PATCH v14 05/11] s390x/cpu topology: resetting the Topology-Change-Report

[Thomas Huth]

On 05/01/2023 15.53, Pierre Morel wrote:
> During a subsystem reset the Topology-Change-Report is cleared
> by the machine.
> Let's ask KVM to clear the Modified Topology Change Report (MTCR)
> bit of the SCA in the case of a subsystem reset.
>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
...
> diff --git a/target/s390x/kvm/kvm_s390x.h b/target/s390x/kvm/kvm_s390x.h
> index f9785564d0..649dae5948 100644
> --- a/target/s390x/kvm/kvm_s390x.h
> +++ b/target/s390x/kvm/kvm_s390x.h
> @@ -47,5 +47,6 @@ void kvm_s390_crypto_reset(void);
>   void kvm_s390_restart_interrupt(S390CPU *cpu);
>   void kvm_s390_stop_interrupt(S390CPU *cpu);
>   void kvm_s390_set_diag318(CPUState *cs, uint64_t diag318_info);
> +int kvm_s390_topology_set_mtcr(uint64_t attr);
>   
>   #endif /* KVM_S390X_H */
> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
> index c98b93a15f..14798ca305 100644
> --- a/hw/s390x/s390-virtio-ccw.c
> +++ b/hw/s390x/s390-virtio-ccw.c
> @@ -122,6 +122,7 @@ static void subsystem_reset(void)
>               device_cold_reset(dev);
>           }
>       }
> +    s390_cpu_topology_reset();
>   }

Would it make sense to add a "if (s390_has_topology())" check around the new 
line?

Anyway:
Reviewed-by: Thomas Huth <thuth@redhat.com>