Re: [Qemu-devel] [PATCH 5/5] migration: Route more error paths

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 20 Sep 2017 16:57:39 +0100
"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:

> * Cornelia Huck (cohuck@redhat.com) wrote:
> > On Tue, 19 Sep 2017 19:00:38 +0100
> > "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> >   
> > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > > 
> > > vmstate_save is called in a few places, and vmstate_save_state is
> > > called in lots of places.
> > > 
> > > Route error returns from the easier cases back up;  there are lots
> > > of more complex cases where there own error paths need fixing.
> > > 
> > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > > ---
> > >  hw/display/virtio-gpu.c    |  4 +---
> > >  hw/virtio/virtio.c         | 13 +++++++------
> > >  include/hw/virtio/virtio.h |  2 +-
> > >  migration/vmstate-types.c  | 11 ++++++++---
> > >  tests/test-vmstate.c       |  6 +++---
> > >  5 files changed, 20 insertions(+), 16 deletions(-)
> > >   
> >   
> > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> > > index 464947f76d..860333788b 100644
> > > --- a/hw/virtio/virtio.c
> > > +++ b/hw/virtio/virtio.c
> > > @@ -1899,7 +1899,7 @@ static const VMStateDescription vmstate_virtio = {
> > >      }
> > >  };
> > >  
> > > -void virtio_save(VirtIODevice *vdev, QEMUFile *f)
> > > +int virtio_save(VirtIODevice *vdev, QEMUFile *f)
> > >  {
> > >      BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
> > >      VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);  
> > 
> > Would it make sense to touch up the save_config callback as well? Else
> > virtio_save() looks a bit lopsided.
> > 
> > [For virtio-ccw, the callback can simply pass on any return code from
> > vmstate_save_state(). For virtio-pci, we can probably make
> > pci_device_save() restore the interrupt state in any case.]  
> 
> What I'd really love to do with save_config is turn it into a
> VMStateDescription* - I think I've figured out how to
> do that for ccw and mmio - but the pci version is a much harder
> mess of casts and stuff.

Sounds even better, but even more complicated as well...