Re: [PATCH v5 11/23] driver core: add per device iommu param

Jacob Pan
2018-05-14T20:52:08Z

On Mon, 14 May 2018 13:27:13 +0800
Lu Baolu <baolu.lu@linux.intel.com> wrote:

> Hi,
>
> On 05/12/2018 04:54 AM, Jacob Pan wrote:
> > DMA faults can be detected by IOMMU at device level. Adding a
> > pointer to struct device allows IOMMU subsystem to report relevant
> > faults back to the device driver for further handling.
> > For direct assigned device (or user space drivers), guest OS holds
> > responsibility to handle and respond per device IOMMU fault.
> > Therefore we need fault reporting mechanism to propagate faults
> > beyond IOMMU subsystem.
> >
> > There are two other IOMMU data pointers under struct device today,
> > here we introduce iommu_param as a parent pointer such that all
> > device IOMMU data can be consolidated here. The idea was suggested
> > here by Greg KH and Joerg. The name iommu_param is chosen here
> > since iommu_data has been used.
>
> This doesn't match what you've done in the patch. Maybe you
> forgot to cleanup? :-)
>
No, I was trying to explain the thought process behind naming
iommu_param. I meant to say iommu_data is a probably a better name but
taken already.
> The idea is to create a parent pointer under device struct and
> move previous iommu_group and iommu_fwspec together with
> the iommu fault related data into it.
>
> Best regards,
> Lu Baolu
>
> [...]
>

[Jacob Pan]