RE: [PATCH v2 7/8] iommu/arm-smmu-v3: Implement IOMMU_HWPT_ALLOC_NEST_PARENT

Tian, Kevin
2024-08-30T07:59:26Z

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Tuesday, August 27, 2024 11:52 PM
>
> For SMMUv3 the parent must be a S2 domain, which can be composed
> into a IOMMU_DOMAIN_NESTED.
>
> In future the S2 parent will also need a VMID linked to the VIOMMU and
> even to KVM.
>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>, with a nit:

> @@ -3103,7 +3103,8 @@ arm_smmu_domain_alloc_user(struct device *dev,
> u32 flags,
> const struct iommu_user_data *user_data)
> {
> struct arm_smmu_master *master = dev_iommu_priv_get(dev);
> - const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
> + const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
> + IOMMU_HWPT_ALLOC_NEST_PARENT;

lowercase for variable name.