Re: [PATCH] intel-iommu: Manage iommu_coherency globally

[Chris Wright]

* Alex Williamson (alex.williamson@xxxxxxxxxx) wrote:
> We currently manage iommu_coherency on a per domain basis,
> choosing the safest setting across the iommus attached to a
> particular domain.  This unfortunately has a bug that when
> no iommus are attached, the domain defaults to coherent.
> If we fall into this mode, then later add a device behind a
> non-coherent iommu to that domain, the context entry is
> updated using the wrong coherency setting, and we get dmar
> faults.
> 
> Since we expect chipsets to be consistent in their coherency
> setting, we can instead determine the coherency once and use
> it globally.
> 
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>

Looks good to me.

Acked-by: Chris Wright <chrisw@xxxxxxxxxxxx>
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