> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Monday, July 24, 2023 7:13 PM
> }
> +
> +/**
> + * intel_pasid_setup_nested() - Set up PASID entry for nested translation.
> + * This could be used for nested translation based vIOMMU. e.g. guest IOVA
s/could be/is/
> + * and guest shared virtual address. In this case, the first level page
> + * tables are used for GVA/GIOVA-GPA translation in the guest, second level
> + * page tables are used for GPA-HPA translation.
let's be consistent on using stage-1/stage-2
btw the convention is to have 1-line summary, then the list of
parameters followed by detail explanation of the function.
> + *
> + * @iommu: IOMMU which the device belong to
> + * @dev: Device to be set up for translation
> + * @pasid: PASID to be programmed in the device PASID table
> + * @domain: User stage-1 domain nested on a s2 domain
> + */
> +int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device
> *dev,
> + u32 pasid, struct dmar_domain *domain)
> +{
> + struct iommu_hwpt_vtd_s1 *s1_cfg = &domain->s1_cfg;
> + pgd_t *s1_gpgd = (pgd_t *)(uintptr_t)domain->s1_pgtbl;
> + struct dmar_domain *s2_domain = domain->s2_domain;
> + u16 did = domain_id_iommu(domain, iommu);
> + struct dma_pte *pgd = s2_domain->pgd;
> + struct pasid_entry *pte;
> +
> + if (!ecap_nest(iommu->ecap)) {
> + pr_err_ratelimited("%s: No nested translation support\n",
> + iommu->name);
> + return -ENODEV;
> + }
-EINVAL
> +
> + if (s2_domain->agaw > iommu->agaw) {
> + pr_err_ratelimited("Incompatible agaw %s\n", iommu-
> >name);
> + return -EINVAL;
> + }
there is a duplicated check in intel_nested_attach_dev().
> +
> + pasid_set_slptr(pte, virt_to_phys(pgd));
> + pasid_set_fault_enable(pte);
> + pasid_set_domain_id(pte, did);
> + pasid_set_address_width(pte, s2_domain->agaw);
> + pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
> + pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
> + pasid_set_present(pte);
> + spin_unlock(&iommu->lock);
> +
this lacks of handling of force_snooping
