Re: [Qemu-devel] [PATCH 06/10] pseries: Improve error handling in find_unknown_sysbus_device()

[David Gibson]

On Fri, Jan 15, 2016 at 04:40:24PM +0100, Markus Armbruster wrote:
> David Gibson <address@hidden> writes:
> 
> > Use error_setg() to return an error instead of using an explicit exit().
> >
> > Signed-off-by: David Gibson <address@hidden>
> > ---
> >  hw/ppc/spapr.c | 10 ++++++----
> >  1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index bb5eaa5..ddca6e6 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1106,6 +1106,7 @@ static void spapr_reset_htab(sPAPRMachineState 
> > *spapr, Error **errp)
> >  
> >  static int find_unknown_sysbus_device(SysBusDevice *sbdev, void *opaque)
> >  {
> > +    Error **errp = opaque;
> >      bool matched = false;
> >  
> >      if (object_dynamic_cast(OBJECT(sbdev), TYPE_SPAPR_PCI_HOST_BRIDGE)) {
> > @@ -1113,9 +1114,10 @@ static int find_unknown_sysbus_device(SysBusDevice 
> > *sbdev, void *opaque)
> >      }
> >  
> >      if (!matched) {
> > -        error_report("Device %s is not supported by this machine yet.",
> > -                     qdev_fw_name(DEVICE(sbdev)));
> > -        exit(1);
> > +        error_setg(errp,
> > +                   "Device %s is not supported by this machine yet",
> > +                   qdev_fw_name(DEVICE(sbdev)));
> > +        return 1; /* Don't continue scanning devices */
> 
> Re the comment: really?
> 
> find_unknown_sysbus_device() gets passed to
> foreach_dynamic_sysbus_device(), which passes it on to
> find_sysbus_device().
> 
> find_sysbus_device() calls it directly for non-containers, ignoring the
> function value.
> 
> For containers, it iterates over the container's contents with
> object_child_foreach().  That function indeed stops when the callback
> returns non-zero.  However, the callback is find_sysbus_device(), not
> find_unknown_sysbus_device().
> 
> Am I confused?

No, I am.

I can't see a reasonable way to change this without assuming the error
is fatal, so I think I'll just drop this patch from the series.

> 
> >      }
> >  
> >      return 0;
> > @@ -1150,7 +1152,7 @@ static void ppc_spapr_reset(void)
> >      uint32_t rtas_limit;
> >  
> >      /* Check for unknown sysbus devices */
> > -    foreach_dynamic_sysbus_device(find_unknown_sysbus_device, NULL);
> > +    foreach_dynamic_sysbus_device(find_unknown_sysbus_device, 
> > &error_fatal);
> >  
> >      /* Reset the hash table & recalc the RMA */
> >      spapr_reset_htab(spapr, &error_fatal);
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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