Conny, this seem to work on KVM (needs more testing and review).
Can you check what happens with TCG?

Patch 1 is the known base patch,
Patch 2 fixes the ais detection to be based on the flic interfaces
Patch 3 disables ais for all compat machines <= 2.10



Christian Borntraeger (3):
  s390x/ais: disable ais facility as it is broken
  s390x/ais: enable ais when migration is available
  s390x/ais: disable ais for compat machines

 hw/intc/s390_flic.c                | 11 +++++++++--
 hw/intc/s390_flic_kvm.c            | 10 +++++++++-
 hw/s390x/s390-virtio-ccw.c         | 18 ++++++++++++++++--
 include/hw/s390x/s390-virtio-ccw.h |  3 +++
 include/hw/s390x/s390_flic.h       |  1 +
 target/s390x/cpu_models.c          |  6 ++++++
 target/s390x/kvm.c                 |  3 +--
 7 files changed, 45 insertions(+), 7 deletions(-)

-- 
2.9.4

On 09/22/2017 10:38 AM, Christian Borntraeger wrote:
> Conny, this seem to work on KVM (needs more testing and review).
> Can you check what happens with TCG?
> 
> Patch 1 is the known base patch,
> Patch 2 fixes the ais detection to be based on the flic interfaces
> Patch 3 disables ais for all compat machines <= 2.10
> 
> 
> 
> Christian Borntraeger (3):
>   s390x/ais: disable ais facility as it is broken
>   s390x/ais: enable ais when migration is available
>   s390x/ais: disable ais for compat machines
> 
>  hw/intc/s390_flic.c                | 11 +++++++++--
>  hw/intc/s390_flic_kvm.c            | 10 +++++++++-
>  hw/s390x/s390-virtio-ccw.c         | 18 ++++++++++++++++--
>  include/hw/s390x/s390-virtio-ccw.h |  3 +++
>  include/hw/s390x/s390_flic.h       |  1 +
>  target/s390x/cpu_models.c          |  6 ++++++
>  target/s390x/kvm.c                 |  3 +--
>  7 files changed, 45 insertions(+), 7 deletions(-)
> 

FWIW, with patch 1 backported to 2.10 and patches 1,2,3 on top of current master (as 211)
I started some crossmigration test and successfully tested
the following combinations with KVM and -cpu host on an 4.13 kernel

Machine s390-ccw-virtio-2.11
211-->211  	

Machine s390-ccw-virtio-2.10
211-->210,211	
210-->210,211	

Machine s390-ccw-virtio-2.9
211-->29,210,211
210-->29,210,211
29--->29,210,211

Machine s390-ccw-virtio-2.8
211-->28,29,210,211
210-->28,29,210,211
29--->28,29,210,211
28--->28,29,210,211

Machine s390-ccw-virtio-2.7
211-->27,28,29,210,211
210-->27,28,29,210,211
29--->27,28,29,210,211
28--->27,28,29,210,211
27--->27,28,29,210,211

Machine s390-ccw-virtio-2.6
211-->26 27 28 29 210 211
210-->26 27 28 29 210 211
29--->26 27 28 29 210 211
28--->26 27 28 29 210 211
27--->26 27 28 29 210 211
26--->26 27 28 29 210 211

On 09/22/2017 01:27 PM, Christian Borntraeger wrote:
> On 09/22/2017 10:38 AM, Christian Borntraeger wrote:
>> Conny, this seem to work on KVM (needs more testing and review).
>> Can you check what happens with TCG?
>>
>> Patch 1 is the known base patch,
>> Patch 2 fixes the ais detection to be based on the flic interfaces
>> Patch 3 disables ais for all compat machines <= 2.10
>>
>>
>>
>> Christian Borntraeger (3):
>>   s390x/ais: disable ais facility as it is broken
>>   s390x/ais: enable ais when migration is available
>>   s390x/ais: disable ais for compat machines
>>
>>  hw/intc/s390_flic.c                | 11 +++++++++--
>>  hw/intc/s390_flic_kvm.c            | 10 +++++++++-
>>  hw/s390x/s390-virtio-ccw.c         | 18 ++++++++++++++++--
>>  include/hw/s390x/s390-virtio-ccw.h |  3 +++
>>  include/hw/s390x/s390_flic.h       |  1 +
>>  target/s390x/cpu_models.c          |  6 ++++++
>>  target/s390x/kvm.c                 |  3 +--
>>  7 files changed, 45 insertions(+), 7 deletions(-)
>>
> 
> FWIW, with patch 1 backported to 2.10 and patches 1,2,3 on top of current master (as 211)
> I started some crossmigration test and successfully tested
> the following combinations with KVM and -cpu host on an 4.13 kernel

This was on the same host migration in a file and back from a file.
On the same host kenrel 4.11.12 (no AIS support in KVM at all)
and 4.12.14  (AIS support, but no migration) also survived the test matrix
for migration into/from file.