Re: [PATCH v3 4/6] xen/cpupool: Create different cpupools at boot time

[Julien Grall <julien@xxxxxxx>]

Hi Bertrand,

On 21/03/2022 17:19, Bertrand Marquis wrote:
> > On 21 Mar 2022, at 17:36, Julien Grall <julien@xxxxxxx> wrote:
> > > So I don’t know why on x86 we must have cpu0 in cpupool0, maybe x86 maintainer 
> > > have more knowledge about that and
> > > I can put a comment here.
> > On Arm, we are not yet supporting all the CPU features that x86 supports (e.g. 
> > CPU hotplug, suspend/resume...). So I a am bit concerned that the restriction 
> > is just not there yet (or possibly hidden).
> >
> > Therefore, before lifting the restriction on Arm (and other arch), I would like 
> > us to understand why it is necessary on x86.
> >
> > We may not have the answer quickly, so is it going to be a problem to keep the 
> > restriction on Arm?
> I am ok to keep the limitation to have dom0 always running on cpu0.
> Only limitation I can see is that on a big little system, dom0 needs to stay on 
> the type of core of the first booted core.
Where does this limitation come from?

Cheers,

--
Julien Grall