Re: [PATCH v5 07/18] s390x: protvirt: Inhibit balloon when switching to protected mode

[David Hildenbrand]

On 26.02.20 16:06, Christian Borntraeger wrote:
> 
> 
> On 26.02.20 15:59, David Hildenbrand wrote:
>> On 26.02.20 13:20, Janosch Frank wrote:
>>> Ballooning in protected VMs can only be done when the guest shares the
>>> pages it gives to the host. Hence, until we have a solution for this
>>> in the guest kernel, we inhibit ballooning when switching into
>>> protected mode and reverse that once we move out of it.
>>
>> I don't understand what you mean here, sorry. zapping a page will mean
>> that a fresh one will be faulted in when accessed. And AFAIK, that means
>> it will be encrypted again when needed.
>>
>> Is that more like the UV will detect this as an integrity issue and
>> crash the VM?
> 
> yes, the UV will detect a fresh page as an integrity issue.
> Only if the page was defined to be shared by the guest, we would avoid the
> integrity check.
> 

Please make that clearer in the patch description. With that

Reviewed-by: David Hildenbrand <address@hidden>

-- 
Thanks,

David / dhildenb