On Tue, Oct 29, 2024 at 09:05:14PM -0700, Nicolin Chen wrote: > On Tue, Oct 29, 2024 at 03:55:58PM -0300, Jason Gunthorpe wrote: > > On Tue, Oct 29, 2024 at 09:18:05AM -0700, Nicolin Chen wrote: > > > I think we'd need the same change in iommufd_object_abort() too. > > > > Makes sense > > I found xa_cmpxchg() does xas_result to its returning value, which > turns XA_ZERO_ENTRY into NULL failing our intended verifications. Oh.. that is annoying, you can't actually tell if cmpxchg failed :\ NULL means success if it was XA_ZERO_ENTRY and failure of it was not populated! Hmm, I might ask Matthew about this Your version looks OK Jason