Re: [RFC v2 2/2] cgroup: sev: Miscellaneous cgroup documentation.

Vipin Sharma
2021-03-12T21:16:13Z

On Fri, Mar 12, 2021 at 12:58:21PM -0800, Jacob Pan wrote:
> Hi Vipin & Tejun,
>
> Sorry for the late reply, I sent from a different email address than I
> intended. Please see my comments inline.
>
>
> On Thu, 4 Mar 2021 03:51:16 -0500, Tejun Heo <tj@kernel.org> wrote:
>
> > Hello,
> >
> > On Wed, Mar 03, 2021 at 10:22:03PM -0800, Vipin Sharma wrote:
> > > > I am trying to see if IOASIDs cgroup can also fit in this misc
> > > > controller as yet another resource type.
> > > > https://lore.kernel.org/linux-iommu/20210303131726.7a8cb169@jacob-builder/T/#u
> > > > However, unlike sev IOASIDs need to be migrated if the process is
> > > > moved to another cgroup. i.e. charge the destination and uncharge the
> > > > source.
> > > >
> > > > Do you think this behavior can be achieved by differentiating resource
> > > > types? i.e. add attach callbacks for certain types. Having a single
> > > > misc interface seems cleaner than creating another controller.
> > >
> > > I think it makes sense to add support for migration for the resources
> > > which need it. Resources like SEV, SEV-ES will not participate in
> > > migration and won't stop can_attach() to succeed, other resources which
> > > need migration will allow or stop based on their limits and capacity in
> > > the destination.
> >
> Sounds good. Perhaps some capability/feature flags for each resource such
> that different behavior can be accommodated?
> Could you please include me in your future posting? I will rebase on yours.

Hi Jacob

Based on Tejun's response, I will not add charge migration support in
misc controller.

I can definitly add you in my future posting, if you still wanna use it
without charge migration support.

Thanks
Vipin