[PATCH v7 10/28] iommufd/access: Bypass access->ops->unmap for internal use
Nicolin Chen
nicolinc at nvidia.com
Wed Jul 2 13:12:01 PDT 2025
On Wed, Jul 02, 2025 at 09:45:26AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc at nvidia.com>
> > Sent: Friday, June 27, 2025 3:35 AM
> >
> > +int iommufd_access_notify_unmap(struct io_pagetable *iopt, unsigned long
> > iova,
> > + unsigned long length)
> > {
> > struct iommufd_ioas *ioas =
> > container_of(iopt, struct iommufd_ioas, iopt);
> > struct iommufd_access *access;
> > unsigned long index;
> > + int ret = 0;
> >
> > xa_lock(&ioas->iopt.access_list);
> > + /* Bypass any unmap if there is an internal access */
> > + xa_for_each(&ioas->iopt.access_list, index, access) {
> > + if (iommufd_access_is_internal(access)) {
> > + ret = -EBUSY;
> > + goto unlock;
> > + }
> > + }
> > +
>
> hmm all those checks are per iopt. Could do one-off check in
> iopt_unmap_iova_range() and store the result in a local flag.
>
> Then use that flag to decide whether to return -EBUSY if
> area->num_accesses is true in the loop.
I don't quite follow this...
Do you suggest to move this xa_for_each to iopt_unmap_iova_range?
What's that local flag used for?
Thanks
Nicolin
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