Re: [Qemu-devel] [PATCH/RFC 1/3] s390x/ais: disable ais facility as it is broken

[David Hildenbrand <david@redhat.com>]

On 22.09.2017 10:38, Christian Borntraeger wrote:
> 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 lets disable ais in the 2.10
> stable version. A proper fix and re-enablement will be done
> for qemu 2.11.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  target/s390x/kvm.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 720cb1d..ebb75ca 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -311,8 +311,13 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>          }
>      }
>  
> -    /* Try to enable AIS facility */
> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
> +    /*
> +     * 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.
> +     */
> +    /* kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0); */
>  
>      qemu_mutex_init(&qemu_sigp_mutex);
>  
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David