> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Monday, July 24, 2023 7:13 PM
> +
> +static int intel_nested_attach_dev(struct iommu_domain *domain,
> + struct device *dev)
> +{
> + struct device_domain_info *info = dev_iommu_priv_get(dev);
> + struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> + struct intel_iommu *iommu = info->iommu;
> + unsigned long flags;
> + int ret = 0;
> +
> + if (info->domain)
> + device_block_translation(dev);
> +
> + if (iommu->agaw < dmar_domain->s2_domain->agaw) {
> + dev_err_ratelimited(dev, "Adjusted guest address width not
> compatible\n");
> + return -ENODEV;
> + }
this is the check duplicated with patch04.
> +
> + ret = domain_attach_iommu(dmar_domain, iommu);
> + if (ret) {
> + dev_err_ratelimited(dev, "Failed to attach domain to
> iommu\n");
> + return ret;
> + }
> +
[...]
> + domain_update_iommu_cap(dmar_domain);
iommu_cap is already updated in domain_attach_iommu().
>
> static const struct iommu_domain_ops intel_nested_domain_ops = {
> + .attach_dev = intel_nested_attach_dev,
> .free = intel_nested_domain_free,
> + .enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
this is not required. enforce_cache_coherency() will be called on parent
hwpt when it's being created. patch04 should check parent's force_snooping
to set pgsnp in the pasid entry.
As Jason explained it should be done only for kernel owned page table.
