Re: [RFC PATCH 2/7] iommu: Add share domain interface in iommu for spimdev

[Joerg Roedel]

On Wed, Aug 01, 2018 at 06:22:16PM +0800, Kenneth Lee wrote:
> From: Kenneth Lee <liguozhu@xxxxxxxxxxxxx>
> 
> This patch add sharing interface for a iommu_group. The new interface:
> 
> 	iommu_group_share_domain()
> 	iommu_group_unshare_domain()
> 
> can be used by some virtual iommu_group (such as iommu_group for spimdev)
> to share their parent's iommu_group.
> 
> When the domain of the group is shared, it cannot be changed before
> unshared.  In the future, notification can be added if update is required.

>From the description or the patch I don't really get why this is needed.
Please update the description and make a case for this API addition.


	Joerg