[PATCH v2 12/13] iommu/arm-smmu-v3: Introduce struct arm_smmu_vmaster

[Tian, Kevin]

> From: Nicolin Chen <nicolinc at nvidia.com>
> Sent: Wednesday, December 4, 2024 6:10 AM
> 
> Use it to store all vSMMU-related data. The vsid (Virtual Stream ID) will
> be the first use case. Then, add a rw_semaphore to protect it.
> 
> Also add a pair of arm_smmu_attach_prepare/commit_vmaster helpers and
> put
> them in the existing arm_smmu_attach_prepare/commit(). Note that identity
> and blocked ops don't call arm_smmu_attach_prepare/commit(), thus
> simply
> call the new helpers at the top.

Probably a dumb question. viommu is tied to a nested parent domain
which cannot be identity or blocked. Why do we need to change them
too?