Re: [PATCH v6 8/8] iommu/vt-d: Disallow read-only mappings to nest parent domain

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.

Best regards, baolu