Re: [PATCH v2 0/8] iommu: Domain allocation enhancements

[Vasant Hegde <vasant.hegde@amd.com>]

Jason, Baolu,

On 9/11/2024 3:49 PM, Vasant Hegde wrote:
> This series adds iommu_paging_domain_alloc_flags() which takes flags to
> pass additional details for domain allocation (like domain with PASID
> support).
> 
> Also updates AMD IOMMU driver domain allocation code. With this by
> default it will allocate domain with V2 page table for PASID capable
> device and v1 page table for rest of the devices.
> 
> @Baolu,
>   With this changes (patch 1), to allocate PASID capable device core
>   will call domain_alloc_user() interface. Do we need any changes to
>   intel driver?

@Baolu,
  Looks like intel driver works fine with this change. Is that correct -OR- do
we need any changes to intel_iommu_domain_alloc_user() ?


> 
> @Jason,
>   Do we need any changes to arm-smm-v3 driver?

@Jason,

Looking into SMM3 driver it looks like some changes required. Does something
like below works?


diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 737c5b882355..4d4af11c5fda 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3088,6 +3088,9 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
 	struct arm_smmu_domain *smmu_domain;
 	int ret;

+	if (flags & IOMMU_HWPT_ALLOC_PASID)
+		return arm_smmu_domain_alloc_paging(dev);
+
 	if (flags & ~PAGING_FLAGS)
 		return ERR_PTR(-EOPNOTSUPP);
 	if (parent || user_data)


-Vasant