RE: [PATCH rc 3/8] iommu/vt-d: Add missing iotlb flush for parent domain

[Tian, Kevin]

> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Thursday, February 8, 2024 4:23 PM
> 
> +/*
> + * Flush the relevant caches in nested translation if the domain
> + * also serves as a parent
> + */
> +static void parent_domain_flush(struct dmar_domain *domain,
> +				unsigned long pfn,
> +				unsigned long pages, int ih)
> +{
> +	struct dmar_domain *s1_domain;
> +
> +	spin_lock(&domain->s1_lock);
> +	list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
> +		struct iommu_domain_info *info;
> +		unsigned long i;
> +
> +		xa_for_each(&s1_domain->iommu_array, i, info)
> +			__iommu_flush_iotlb_psi(info->iommu, info->did,
> +						pfn, pages, ih);
> +	}

As Jason suggested before this xarray lacks of proper locking.

but given it's rc fix I'm fine with it. @Baolu we do need fix it soon so
this problem won't further expand like here.

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>