Re: [qemu-s390x] [PATCH v2 5/6] s390x/pci: Drop release timer and replace it with a flag

[David Hildenbrand]

On 01.02.19 11:08, Cornelia Huck wrote:
> On Thu, 31 Jan 2019 22:21:01 +0100
> David Hildenbrand <address@hidden> wrote:
> 
>> Thinking out loud:
>>
>> We should migrate the flag in the future. This is already a problem
>> right now, as the timer is also not migrated.
>>
>> If the unplug request is sent and we migrate before the guest can react,
>> the unplug would not happen.
>>
>> However, looks like migration of zpci devices is not implemented _at all_.
> 
> Oh, joy.
> 
>>
>> This does not matter for pci passthrough (main use case). But when
>> wanting to use e.g. virtio-pci-net, things are shaky after migration.
>>
>> So this is future work.
>>
> 
> Hopefully folks running s390x guests are rather using virtio-ccw
> devices anyway...
> 
> I agree that this needs to be taken care of on top of these changes.
> Should we mark zpci devices unmigratable, or does it work for some
> values of "work"?
> 

It works if the guest never configures a zpci device I guess ... so I
think this is pretty much broken. E.g. the state of the zpci device is
not even migrated unless I am missing something.

-- 

Thanks,

David / dhildenb