RE: [PATCH v2 07/26] xen/domctl: wrap domain_pause_by_systemcontroller() with MGMT_HYPERCALLS

["Penny, Zheng" <penny.zheng@xxxxxxx>]

[Public]

> -----Original Message-----
> From: Jan Beulich <jbeulich@xxxxxxxx>
> Sent: Wednesday, September 10, 2025 11:09 PM
> To: Penny, Zheng <penny.zheng@xxxxxxx>
> Cc: Huang, Ray <Ray.Huang@xxxxxxx>; Andrew Cooper
> <andrew.cooper3@xxxxxxxxxx>; Anthony PERARD <anthony.perard@xxxxxxxxxx>;
> Orzel, Michal <Michal.Orzel@xxxxxxx>; Julien Grall <julien@xxxxxxx>; Roger Pau
> Monné <roger.pau@xxxxxxxxxx>; Stefano Stabellini <sstabellini@xxxxxxxxxx>; 
> xen-
> devel@xxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 07/26] xen/domctl: wrap
> domain_pause_by_systemcontroller() with MGMT_HYPERCALLS
>
> On 10.09.2025 09:38, Penny Zheng wrote:
> > --- a/xen/common/domain.c
> > +++ b/xen/common/domain.c
> > @@ -1606,10 +1606,12 @@ static int
> _domain_pause_by_systemcontroller(struct domain *d, bool sync)
> >      return 0;
> >  }
> >
> > +#ifdef CONFIG_MGMT_HYPERCALLS
> >  int domain_pause_by_systemcontroller(struct domain *d)  {
> >      return _domain_pause_by_systemcontroller(d, true /* sync */);  }
> > +#endif /* CONFIG_MGMT_HYPERCALLS */
> >
> >  int domain_pause_by_systemcontroller_nosync(struct domain *d)
> >  {
>
> I would have ack-ed this if there was only this part, but ...
>
> > --- a/xen/common/domctl.c
> > +++ b/xen/common/domctl.c
> > @@ -390,11 +390,13 @@ long
> do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
> >          break;
> >      }
> >
> > +#ifdef CONFIG_MGMT_HYPERCALLS
> >      case XEN_DOMCTL_pausedomain:
> >          ret = -EINVAL;
> >          if ( d != current->domain )
> >              ret = domain_pause_by_systemcontroller(d);
> >          break;
> > +#endif /* CONFIG_MGMT_HYPERCALLS */
> >
> >      case XEN_DOMCTL_unpausedomain:
> >          ret = domain_unpause_by_systemcontroller(d);
>
> ... as expressed elsewhere I'm not happy about this one, as it'll need
> undoing in a later patch of this same series.
>

I shall admit that this kind of stub really helps me test MGMT_HYPERCALLS=n for 
this big serie commit by commit at the very beginning. Otherwise, it could be 
only disabled (and tested) in the end, and accumulate the mistakes...
But, as you said, all this transient thing needs to be reversed in the last, 
and I could accidently missing something and leave dead code...
As CONFIG_SYSCTL is already a prompt option, then maybe I need to raise a new 
commit to make it as def_bool again only for this patch serie transiently or 
just address it in " xen/sysctl: replace CONFIG_SYSCTL with CONFIG_MGMT_DOMCTL 
" ?

> Jan