Re: [PATCH v1 1/4] iommu/arm-smmu-v3: Pass in vmid to arm_smmu_make_s2_domain_ste()

[Jason Gunthorpe]

On Tue, Mar 04, 2025 at 09:04:00PM -0800, Nicolin Chen wrote:
> An stage-2 STE requires a vmid that has been so far allocated per domain,
> so arm_smmu_make_s2_domain_ste() has been extracting the vmid from the S2
> domain.
> 
> To share an S2 parent domain across vSMMUs in the same VM, a vmid will be
> no longer allocated for nor stored in the S2 domain, but per vSMMU, which
> means the arm_smmu_make_s2_domain_ste() can get a vmid either from an S2
> domain (non nesting parent) or a vSMMU.
> 
> Allow to pass in vmid explicitly to arm_smmu_make_s2_domain_ste(), giving
> its callers a chance to pick the vmid between a domain or a vSMMU.
> 
> Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h         | 2 +-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 6 ++++--
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.c    | 3 ++-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c         | 6 +++---
>  4 files changed, 10 insertions(+), 7 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

Jason