Re: Xen timecounter issues

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Jun 24, 2024 at 09:39:32AM +0000, Mathew, Cherry G. wrote:
> >>>>> On Mon, 24 Jun 2024 11:30:14 +0200, Manuel Bouyer <bouyer%antioche.eu.org@localhost> said:
> 
> [...]
> 
> >> else if ( pv_shim && v->vcpu_id == 0 )
> >> {
> >> /*
> >> * PV-shim: vcpus are pinned 1:1. Initially only 1 cpu is online,
> >> * others will be dealt with when onlining them. This avoids pinning
> >> * a vcpu to a not yet online cpu here.
> >> */
> >> sched_set_affinity(unit, cpumask_of(0), cpumask_of(0));
> 
> [...]
> 
> 
> > But this doens't tell anything about CPU 0 ?
> 
> It does - that's the first part of the if clause. So in the UP case,
> vcpu0 is pinned to pcpu0 - which is probably why this doesn't show up in
> the dom0/UP case.

The first part of the if clause is about pv_shim, which is not in use for dom0
AFAIK the part of the if clause will be taken only for domUs started with
type="pvh"
pvshim=1

and this will never be the case for dom0

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--