Re: [PATCH v5 06/13] iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT_ALLOC

On Mon, Oct 28, 2024 at 11:24:10AM +0800, Zhangfei Gao wrote:

...

+/**

• • iommufd_viommu_alloc_hwpt_nested() - Get a hwpt_nested for a vIOMMU
• • @viommu: vIOMMU ojbect to associate the hwpt_nested/domain with
• • @user_data: user_data pointer. Must be valid
• • Allocate a new IOMMU_DOMAIN_NESTED for a vIOMMU and return it as a NESTED
• • hw_pagetable.
• */

+static struct iommufd_hwpt_nested * +iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,

•                            const struct iommu_user_data *user_data)
  

+{

•   struct iommufd_hwpt_nested *hwpt_nested;
  

•   struct iommufd_hw_pagetable *hwpt;
  

•   int rc;
  

•   if (flags)
  

•           return ERR_PTR(-EOPNOTSUPP);
  

This check should be removed.

When a user page fault is required, IOMMU_HWPT_FAULT_ID_VALID is set. if (cmd->flags & IOMMU_HWPT_FAULT_ID_VALID) {

It can't just be removed..

I suspect that IOMMU_HWPT_FAULT_ID_VALID should not be set on the nested domain but on the parent?

Jason