> From: Tian, Kevin
> Sent: Friday, October 20, 2023 2:09 PM
>
> > From: Joao Martins <joao.m.martins@xxxxxxxxxx>
> > Sent: Thursday, October 19, 2023 4:27 AM
> >
> > +
> > +int iopt_set_dirty_tracking(struct io_pagetable *iopt,
> > + struct iommu_domain *domain, bool enable)
> > +{
> > + const struct iommu_dirty_ops *ops = domain->dirty_ops;
> > + int ret = 0;
> > +
> > + if (!ops)
> > + return -EOPNOTSUPP;
> > +
> > + down_read(&iopt->iova_rwsem);
> > +
> > + /* Clear dirty bits from PTEs to ensure a clean snapshot */
> > + if (enable) {
> > + ret = iopt_clear_dirty_data(iopt, domain);
> > + if (ret)
> > + goto out_unlock;
> > + }
>
> why not leaving this to the actual driver which wants to always
> enable dirty instead of making it a general burden for all?
>
looks I was misled by the commit msg. This is really for the reality
that there is no guarantee from previous cycle where the user will
quiesce device, read/clean all the remaining dirty bits and then
disable dirty tracking. It's true for live migration but not if just
looking at this dirty tracking alone.
So,
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
