On Fri, Jun 17, 2022 at 02:53:13AM +0000, Tian, Kevin wrote: > > > ... > > > > - if (resv_msi) { > > > > + if (resv_msi && !domain->msi_cookie) { > > > > ret = iommu_get_msi_cookie(domain->domain, > > > > resv_msi_base); > > > > if (ret && ret != -ENODEV) > > > > goto out_detach; > > > > + domain->msi_cookie = true; > > > > } > > > > > > why not moving to alloc_attach_domain() then no need for the new > > > domain field? It's required only when a new domain is allocated. > > > > When reusing an existing domain that doesn't have an msi_cookie, > > we can do iommu_get_msi_cookie() if resv_msi is found. So it is > > not limited to a new domain. > > Looks msi_cookie requirement is per platform (currently only > for smmu. see arm_smmu_get_resv_regions()). If there is > no mixed case then above check is not required.
Do you mean "reusing existing domain" for the "mixed case"? > But let's hear whether Robin has a different thought here. Yea, sure. > > > > - iommu_domain_free(domain->domain); > > > > - list_del(&domain->next); > > > > - kfree(domain); > > > > - vfio_iommu_aper_expand(iommu, &iova_copy); > > > > > > Previously the aperture is adjusted when a domain is freed... > > > > > > > - vfio_update_pgsize_bitmap(iommu); > > > > - } > > > > - /* > > > > - * Removal of a group without dirty tracking may allow > > > > - * the iommu scope to be promoted. > > > > - */ > > > > - if (!group->pinned_page_dirty_scope) { > > > > - iommu->num_non_pinned_groups--; > > > > - if (iommu->dirty_page_tracking) > > > > - vfio_iommu_populate_bitmap_full(iommu); > > > > - } > > > > + vfio_iommu_detach_destroy_domain(domain, iommu, > > > > group); > > > > kfree(group); > > > > break; > > > > } > > > > > > > > + vfio_iommu_aper_expand(iommu, &iova_copy); > > > > > > but now it's done for every group detach. The aperture is decided > > > by domain geometry which is not affected by attached groups. > > > > Yea, I've noticed this part. Actually Jason did this change for > > simplicity, and I think it'd be safe to do so? > > Perhaps detach_destroy() can return a Boolean to indicate whether > a domain is destroyed. It could be a solution but doesn't feel that common for a clean function to have a return value indicating a special case. Maybe passing in "&domain" so that we can check if it's NULL after? _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu