Re: [RFC PATCH 08/33] vfio: selftests: Validate 2M/1G HugeTLB are mapped as 2M/1G in IOMMU

[Greg Kroah-Hartman]

On Sat, May 31, 2025 at 10:09:34PM +0300, Andy Shevchenko wrote:
> On Fri, May 30, 2025 at 02:12:36PM -0700, David Matlack wrote:
> > On Fri, May 23, 2025 at 4:30 PM David Matlack <dmatl...@google.com> wrote:
> 
> ...
> 
> > > +       if (access("/sys/kernel/debug/iommu/intel", F_OK))
> > > +               return intel_iommu_mapping_get(bdf, iova, mapping);
> > > +
> > 
> > Oops, this should be !access(...).
> 
> Hmm... Generally speaking that code is a hack. Is there any guarantee that
> debugfs mount point is fixed to /sys/kernel/debug ?

No, userspace can mount it anywhere :)

But the kernel does create the mount point at /sys/kernel/debug/ by
default, so hopefully it does end up there if it is present in the
system, so you should be able to rely on it for testing.

thanks,

greg k-h