Re: [PATCH v4 03/24] xen/sysctl: replace CONFIG_SYSCTL with CONFIG_MGMT_HYPERCALLS

[Grygorii Strashko <grygorii_strashko@xxxxxxxx>]

On 26.11.25 08:35, Jan Beulich wrote:
> On 26.11.2025 00:02, Grygorii Strashko wrote:
> > Hi
> >
> > On 21.11.25 12:57, Penny Zheng wrote:
> > > Rename all the CONFIG_SYSCTL into CONFIG_MGMT_HYPERCALLS to help provide a
> > > single option to manage all unnecessary hypercalls, including
> > > sysctl, domctl, etc, in dom0less system and PV shim mode, which could also
> > > make it easier to support randconfigs.
> > > While doing the replacement, we fix some bugs on xsm system:
> > > - wrap the whole xsm function to avoid bringing unreachable codes when
> > > MGMT_DOMCTL=n
> > > - add missing wrapping in include/xsm/dummy.h
> > >
> > > Suggested-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> > > Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
> > > Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> > > Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
> > > Acked-by: Stewart Hildebrand <stewart@xxxxxxx> #ARINC 653
> > > Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
> > > Cc: Alistair Francis <alistair.francis@xxxxxxx>
> > > ---
> > > v2 -> v3:
> > > - wrap the whole xsm function
> > > - add missing wrapping in include/xsm/dummy.h
> > > - refine kconfig description
> > > ---
> > With below diff..
> >
> > diff --git a/xen/common/Kconfig b/xen/common/Kconfig
> > index 6709c3c95c53..f478adffff9c 100644
> > --- a/xen/common/Kconfig
> > +++ b/xen/common/Kconfig
> > @@ -652,9 +652,8 @@ menu "Supported hypercall interfaces"
> >          visible if EXPERT
> >   
> >   config MGMT_HYPERCALLS
> > -       bool "Enable privileged hypercalls for system management"
> >          depends on !PV_SHIM_EXCLUSIVE
> > -       default y
> > +       def_bool y
> >          help
> >            This option shall only be disabled on some dom0less systems, or
> >            PV shim on x86, to reduce Xen footprint via managing unnessary
> >
> > It could be very helpful to consider this patch to be applied first.
> It doesn't need the change above, does it? It (aiui) deliberately sits
> ahead of the patch (supposedly) doing the above. While (once again) 
Understood.

> it is not being said anywhere that it's independent of patches 01 and 02,
> I expect it really is.
I do not see any dependencies.

> In which case all that looks to prevent it from
> having gone in already is the lack of an ack for the XSM changes.
:(


> > - number of tags indicates that it's the way to move forward
> > - with above diff patch 4 can be dropped
> Except that imo really wants to be separate. And that could have gone
> in already as well, if only it had been done correctly.
>
> Jan
>
> > - it is mechanical change, but it's big and constant source of 
> > rebase/merge/cherry-pick conflicts
> > - once applied it will allow, actually, parallel development of this feature as 
> > MGMT_HYPERCALLS will
> >    be defined while build not broken.
--
Best regards,
-grygorii