Re: [PATCH v12 04/13] virtio-iommu: Add the iommu regions

[Peter Xu <peterx@redhat.com>]

On Thu, Jan 09, 2020 at 03:43:10PM +0100, Eric Auger wrote:
> Implement a callback called on PCI bus enumeration that
> initializes for a given device on the bus hierarchy
> an IOMMU memory region. The PCI bus hierarchy is stored
> locally in IOMMUPciBus and IOMMUDevice objects.
> 
> At the time of the enumeration, the bus number may not be
> computed yet.
> 
> So operations that will need to retrieve the IOMMUdevice
> and its IOMMU memory region from the bus number and devfn,
> once the bus number is garanteed to be frozen,
> use an array of IOMMUPciBus, lazily populated.
> 
> virtio_iommu_mr() is the top helper that allows to retrieve
> the IOMMU memory region from the requester ID.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> 
> ---
> v11 -> v12:
> - add the iommu_find_iommu_pcibus() mechanics. Without it,
>   when attaching t device to a domain we could not check
>   the device is effectively protected by this IOMMU

Sorry I probably lost the context again after read the previous
version...  Could you hint me what does this used for?

In all cases, I see that virtio_iommu_mr() is introduced but not used.
Would be good to put it into the patch where it's firstly used.

Thanks,

-- 
Peter Xu