Re: [PATCH 1/2] iommu/vt-d: Set FPD when tearing down a PASID entry with fault_ignore

[Vinicius Costa Gomes <vinicius.gomes@intel.com>]

Lu Baolu <baolu.lu@linux.intel.com> writes:

>  static void
>  pasid_cache_invalidation_with_pasid(struct intel_iommu *iommu,
>  				    u16 did, u32 pasid)
> @@ -253,7 +238,6 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
>  
>  	if (!pasid_pte_is_present(pte)) {
>  		if (!pasid_pte_is_fault_disabled(pte)) {
> -			WARN_ON(READ_ONCE(pte->val[0]) != 0);
>  			spin_unlock(&iommu->lock);
>  			return;
>  		}
> @@ -266,6 +250,8 @@ void intel_pasid_tear_down_entry(struct intel_iommu *iommu, struct device *dev,
>  		 */
>  		pasid_clear_entry(pte);
>  		spin_unlock(&iommu->lock);
> +		if (!ecap_coherent(iommu->ecap))
> +			clflush_cache_range(pte, sizeof(*pte));
>  		intel_iommu_drain_pasid_prq(dev, pasid);
>

I think it's worth documenting in the commit message why both of these
are needed, removing the warning and adding the flush.


Cheers,
-- 
Vinicius