Re: [PATCH v3 02/16] iommu: Introduce cache_invalidate API

Auger Eric
2019-05-14T07:46:46Z

Hi Jean,

On 5/13/19 7:09 PM, Jean-Philippe Brucker wrote:
> On 13/05/2019 17:50, Auger Eric wrote:
>>> struct iommu_inv_pasid_info {
>>> #define IOMMU_INV_PASID_FLAGS_PASID (1 << 0)
>>> #define IOMMU_INV_PASID_FLAGS_ARCHID (1 << 1)
>>> __u32 flags;
>>> __u32 archid;
>>> __u64 pasid;
>>> };
>> I agree it does the job now. However it looks a bit strange to do a
>> PASID based invalidation in my case - SMMUv3 nested stage - where I
>> don't have any PASID involved.
>>
>> Couldn't we call it context based invalidation then? A context can be
>> tagged by a PASID or/and an ARCHID.
>
> I think calling it "context" would be confusing as well (I shouldn't
> have used it earlier), since VT-d uses that name for device table
> entries (=STE on Arm SMMU). Maybe "addr_space"?
yes you're right. Well we already pasid table table terminology so we
can use it here as well - as long as we understand what purpose it
serves ;-) - So OK for iommu_inv_pasid_info.

I think Jean understood we would keep pasid standalone field in
iommu_cache_invalidate_info's union. I understand the struct
iommu_inv_pasid_info now would replace it, correct?

Thanks

Eric
>
> Thanks,
> Jean
>
>>
>> Domain invalidation would invalidate all the contexts belonging to that
>> domain.
>>
>> Thanks
>>
>> Eric