Re: [Qemu-devel] [PATCH v3 1/2] qdev: ignore GlobalProperty.errp for hotplugged devices

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Jul 22, 2016 at 09:16:57AM +0200, Greg Kurz wrote:
> On Fri, 22 Jul 2016 11:28:48 +1000
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > On Fri, Jul 22, 2016 at 01:01:26AM +0200, Greg Kurz wrote:
> > > This patch ensures QEMU won't terminate while hotplugging a device if the
> > > global property cannot be set and errp points to error_fatal or error_abort.
> > > 
> > > While here, it also fixes indentation of the typename argument.
> > > 
> > > Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
> > > Signed-off-by: Greg Kurz <groug@kaod.org>  
> > 
> > This seems kind of bogus to me - we have this whole infrastructure for
> > handling errors, and here we throw it away.
> > 
> > It seems like the right solution would be to make the caller in the
> > hotplug case *not* use error_abort or error_fatal, and instead get the
> > error propagated back to the monitor which will display it.
> 
> The caller is QOM initialization here. Are you asking to add an errp argument
> to object_initialize() and friends ?

Ugh.  I guess I am.  I can see why you'd want to avoid that.  On the
other hand, it really does seem like the right approach.

> 
> > > ---
> > >  hw/core/qdev-properties.c |    4 ++--
> > >  include/hw/qdev-core.h    |    4 +++-
> > >  2 files changed, 5 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
> > > index 14e544ab17d2..311af6da7684 100644
> > > --- a/hw/core/qdev-properties.c
> > > +++ b/hw/core/qdev-properties.c
> > > @@ -1084,7 +1084,7 @@ int qdev_prop_check_globals(void)
> > >  }
> > >  
> > >  static void qdev_prop_set_globals_for_type(DeviceState *dev,
> > > -                                const char *typename)
> > > +                                           const char *typename)
> > >  {
> > >      GList *l;
> > >  
> > > @@ -1100,7 +1100,7 @@ static void qdev_prop_set_globals_for_type(DeviceState *dev,
> > >          if (err != NULL) {
> > >              error_prepend(&err, "can't apply global %s.%s=%s: ",
> > >                            prop->driver, prop->property, prop->value);
> > > -            if (prop->errp) {
> > > +            if (!dev->hotplugged && prop->errp) {
> > >                  error_propagate(prop->errp, err);
> > >              } else {
> > >                  assert(prop->user_provided);
> > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > index 1d1f8612a9b8..4b4b33bec885 100644
> > > --- a/include/hw/qdev-core.h
> > > +++ b/include/hw/qdev-core.h
> > > @@ -261,7 +261,9 @@ struct PropertyInfo {
> > >   * @used: Set to true if property was used when initializing a device.
> > >   * @errp: Error destination, used like first argument of error_setg()
> > >   *        in case property setting fails later. If @errp is NULL, we
> > > - *        print warnings instead of ignoring errors silently.
> > > + *        print warnings instead of ignoring errors silently. For
> > > + *        hotplugged devices, errp is always ignored and warnings are
> > > + *        printed instead.
> > >   */
> > >  typedef struct GlobalProperty {
> > >      const char *driver;
> > >   
> > 
> 



-- 
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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