From: Liu, Yi L yi.l.liu@intel.com 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