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

[Julien Grall <julien@xxxxxxx>]

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.
Cheers,

--
Julien Grall