> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx> > Sent: Monday, October 23, 2023 8:18 PM > > On 2023/10/23 19:15, Liu, Yi L wrote: > >> I would also prefer to introduce is_nested_parent_domain to the user > >> domain allocation patch (patch 7/8). This field should be checked when > >> allocating a nested user domain. > > A ctually, no need. This should be a common check, so iommufd core already > > has the check. So the parent should be a nest parent domain, otherwise already > > returned in iommufd. > > > > + if (!parent->nest_parent) > > + return ERR_PTR(-EINVAL); > > I know this will not cause errors in the code. But since you are > introducing is_parent property in the vt-d driver. The integrity of the > property should be ensured. In this way, it will make the code more > readable and maintainable. Ok, if consider it as a property, then it's fine. At first, I just want to make it as a special flag for this errata. But we cannot predict if there will be more nested parent special stuffs, then this flag is also needed. Regards, Yi Liu