On Mon, Sep 12, 2022 at 03:55:02PM -0700, Jacob Pan wrote:
> Hi Dave,
>
> On Mon, 12 Sep 2022 14:41:56 -0700, Dave Hansen <dave.hansen@xxxxxxxxx>
> wrote:
>
> > On 9/12/22 13:39, Jacob Pan wrote:
> > >>> + if (pasid_valid(mm->pasid) && !forced) {
> > > I don't think this works since we have lazy pasid free. for example,
> > > after all the devices did sva_unbind, mm->pasid we'll remain valid
> > > until mmdrop(). LAM should be supported in this case.
> >
> > Nah, it works fine.
> > It just means that the rules are "you can't do LAM if your process
> > *EVER* got a PASID" instead of "you can't do LAM if you are actively
> > using your PASID".
> Sure it works if you change the rules, but this case need to documented.
>
> >
> > We knew that PASID use would be a one-way trip for a process when we
> > moved to the simplified implementation. This is just more fallout from
> > that. It's fine.
> >
> Is LAM also a one-way trip?
Yes.
--
Kiryl Shutsemau / Kirill A. Shutemov
