Re: [PATCH v4 01/17] iommu: Add hwpt_type with user_data for domain_alloc_user op

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Oct 12, 2023 at 05:11:09PM +0800, Yi Liu wrote:
> On 2023/10/11 00:58, Jason Gunthorpe wrote:
> > On Thu, Sep 21, 2023 at 12:51:22AM -0700, Yi Liu wrote:
> > > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > > index 660dc1931dc9..12e12e5563e6 100644
> > > --- a/include/linux/iommu.h
> > > +++ b/include/linux/iommu.h
> > > @@ -14,6 +14,7 @@
> > >   #include <linux/err.h>
> > >   #include <linux/of.h>
> > >   #include <uapi/linux/iommu.h>
> > > +#include <uapi/linux/iommufd.h>
> > 
> > Oh we should definately avoid doing that!
> > Maybe this is a good moment to start a new header file exclusively for
> > iommu drivers and core subsystem to include?
> > 
> >   include/linux/iommu-driver.h
> > 
> > ?
> > 
> > Put iommu_copy_user_data() and  struct iommu_user_data in there
> > 
> > Avoid this include in this file.
> 
> sure. btw. seems all the user of this API and structure are in the
> drivers/iommu directory. can we just putting them in
> drivers/iommu/iommu-priv.h?

iommu-priv.h should be private to the core iommu code, and we sort of
extended it to iommufd as well.

iommu-driver.h would be "private" to the core and all the drivers
only.

As include ../.. is often frown on at large scale it is probably
better to be in include/linux

> Just one concern. There are other paths (like cache_invalidate of
> this series and Nic's set_dev_data) uses this struct as well. I'm
> a bit worrying if it is good to put type here as type is meaningful
> for the domain_alloc_user path.

There is always a type though? I haven't got that far in the series
yet to see..

Jason