Re: [PATCH v4 08/22] KVM: arm64: ITS: Implement vgic_mmio_uaccess_write_its_iidr

Marc Zyngier
2017-04-11T10:27:22Z

On 11/04/17 11:16, Peter Maydell wrote:
> On 11 April 2017 at 11:08, Auger Eric <eric.auger@redhat.com> wrote:
>> On 11/04/2017 12:05, Marc Zyngier wrote:
>>> On 10/04/17 16:17, Auger Eric wrote:
>>>> A (v1) -> B (v1 & v2): migration OK
>>>> B (v1 & v2) -> C (v1): migration NOK
>>>
>>> So what does IIDR report on B once the A->B migration has taken place?
>>> Does it report v2?
>>
>> yes that was the plan
>
> Hmm, the IIDR value shouldn't change across a migration I think.
> It's guest visible so the guest should see it still the same
> value even after migration.

That's my worry. But we then have a problem when this VM migrates again.
How does userspace find out which ABI to use then?

Thanks,

M.
--
Jazz is not dead. It just smells funny...