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Re: [PATCH v3 11/11] hw/arm/smmuv3: Advertise SMMUv3.2 range invalidatio
Re: [PATCH v3 11/11] hw/arm/smmuv3: Advertise SMMUv3.2 range invalidation
Tue, 28 Jul 2020 17:09:42 +0200
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On 7/10/20 11:47 AM, Peter Maydell wrote:
> On Wed, 8 Jul 2020 at 15:20, Eric Auger <email@example.com> wrote:
>> Expose the RIL bit so that the guest driver uses range
>> invalidation. Range invalidation being an SMMU3.2 feature,
>> let AIDR advertise SMMUv3.2 support.
>> Signed-off-by: Eric Auger <firstname.lastname@example.org>
> I think that to advertise SMMUv3.2 we would also need to
> set the IDR3.BBML field to something non-zero. That means
> we need to analyze our implementation of the caching of page
> table structures to see if we need to do anything different
> (per the behaviours and guarantees described in section 3.21.1
> of the spec).
> Alternatively, we could take advantage of the language
> in section 2.5 that says that a v3.x implementation is
> allowed to implement features from v3.(x+1), and just
> set the RIL bit while leaving AIDR advertising us as v3.1.
So I eventually lazily chose this solution. I will address BBML support
in a separate patch series.
> -- PMM