Re: [PATCH v2 2/2] xen/arm: add FF-A mediator

[Jens Wiklander <jens.wiklander@linaro.org>]

Hi Julien,

On Fri, Jun 17, 2022 at 10:16 AM Julien Grall <julien@xen.org> wrote:
>
> Hi Jens,
>
> On 16/06/2022 23:37, Jens Wiklander wrote:
> > On Tue, Jun 14, 2022 at 07:47:18PM +0000, Volodymyr Babchuk wrote:
> >>
> >> Hello Jens,
> >>
> >> Sorry for late review, I was busy with internal projects.
> >>
> >> This is preliminary review. I gave up at scatter-gather operations. Need
> >> more time to review them properly.
> >
> > No problem, thanks for taking the time.
> >
> >>
> >> One thing that bothers me is that Xen is non-preemptive and there are
> >> plenty potentially long-running operations.
> >
> > There's room to deal with that in the FF-A specification. These scatter
> > gather operation are quite complicated so I started with the minimum. We
> > can as a future optimization address the problem with long running
> > operations.
>
> I would be OK to defer this work. However, I think this should be
> written down as Xen community will not be able to security support until
> we resolved the known places where a vCPU may hog pCPU longer than
> necessary.
>
> This reminds me that this series doesn't add a support statement for the
> new subsystem in SUPPORT.md. AFAICT, this should be tech preview for now.

I'll add an entry for this.

Thanks,
Jens