Re: [RFC PATCH v2 10/11] hw/arm/smmuv3: Populate OAS based on CPU PARANGE

[Eric Auger]

On 3/21/23 14:29, Mostafa Saleh wrote:
> On Tue, Mar 21, 2023 at 02:23:03PM +0100, Eric Auger wrote:
>>>>>      s->idr[5] = FIELD_DP32(s->idr[5], IDR5, GRAN64K, 1);
>>>>> -    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, SMMU_IDR5_OAS); /* 44 
>>>>> bits */
>>>>> +    s->idr[5] = FIELD_DP32(s->idr[5], IDR5, OAS, oas);
>>>> I am not sure you can change that easily. In case of migration this is
>>>> going to change the behavior of the device, no?
>>> I see IDR registers are not migrated. I guess we can add them in a
>>> subsection and if they were not passed (old instances) we set OAS to
>>> 44.
>>> Maybe this should be another change outside of this series.
>> Indeed tehy are not migrated so it can lead to inconsistent behavior in
>> both source and dest. This deserves more analysis to me. In case you
>> would decide to migrate IDR regs this would need to be done in that
>> series I think. Migration must not be broken by this series
> I agree, I meant to drop this patch from the series as it is not
> really related to stage-2, and we can have another patch for this +
> migration for IDR if needed after doing proper analysis.

Ah OK. I get it now. Yes this looks sensible

Thanks

Eric
>
> Thanks,
> Mostafa
>