Re: [RFC PATCH v4 03/16] iommu/arm-smmu-v3: Add initial pSMMU realm viommu plumbing

[Jason Gunthorpe]

On Thu, Sep 03, 2026 at 10:58:06AM +0530, Aneesh Kumar K.V wrote:
> > Do you mean the SMMUv3 driver triggers RD creation? That feels
> > wrong. Did you mean the VMM just does it earlier?
> 
> Currently, CCA creates the realm lazily as part of another operation.
> Realm creation is triggered by kvm_arm_rmi_populate() or
> kvm_arch_vcpu_run_pid_change()

Okay, that's not what I would have guessed. But critically is there
some way for userspace to specify any realm creation parameters (like
rpv, ats_plane and so one) prior to the lazy creation?

Why lazy? Why not just have userspace provide the creation parameters
and create the RD right then?

Jason