Re: [PATCH 2/9] iommufd: Add DMABUF to iopt_pages

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Nov 20, 2025 at 07:55:04AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Saturday, November 8, 2025 12:50 AM
> > 
> > 
> > @@ -2031,7 +2155,10 @@ int iopt_pages_rw_access(struct iopt_pages
> > *pages, unsigned long start_byte,
> >  	if ((flags & IOMMUFD_ACCESS_RW_WRITE) && !pages->writable)
> >  		return -EPERM;
> > 
> > -	if (pages->type == IOPT_ADDRESS_FILE)
> > +	if (iopt_is_dmabuf(pages))
> > +		return -EINVAL;
> > +
> 
> probably also add helpers for other types, e.g.:
> 
>   iopt_is_user()
>   iopt_is_memfd()

The helper was to integrate the IS_ENABLED() check for DMABUF, there
are not so many others uses, I think leave it to not bloat the patch.

> > +	if (pages->type != IOPT_ADDRESS_USER)
> >  		return iopt_pages_rw_slow(pages, start_index, last_index,
> >  					  start_byte % PAGE_SIZE, data,
> > length,
> >  					  flags);
> > --
> 
> then the following WARN_ON() becomes useless:
> 
> 	if (IS_ENABLED(CONFIG_IOMMUFD_TEST) &&
> 	    WARN_ON(pages->type != IOPT_ADDRESS_USER))
> 		return -EINVAL;

Yep

Thanks,
Jason