Re: [Qemu-devel] [PATCH v1 6/8] spapr: handle pc-dimm unplug via hotplug handler chain

[Igor Mammedov]

On Fri, 8 Jun 2018 11:02:23 +0200
David Hildenbrand <address@hidden> wrote:

> On 08.06.2018 10:56, Igor Mammedov wrote:
> > On Thu,  7 Jun 2018 18:52:16 +0200
> > David Hildenbrand <address@hidden> wrote:
> >   
> >> Let's handle it via hotplug_handler_unplug(). E.g. necessary to hotplug/
> >> unplug memory devices (which a pc-dimm is) later.  
> > Perhaps something like following would be better:
> > 
> > Factor out memory unplug into separate function from spapr_lmb_release().
> > Then use generic hotplug_handler_unplug() to trigger memory unplug,
> > which would call spapr_machine_device_unplug() -> spapr_memory_unplug()
> > in the end .
> > This way unplug operation is not buried in lmb internals and located
> > in the same place like in other targets, following similar
> > logic/call chain across targets.  
> 
> Can this be an addon patch? Sounds like factoring out more and moving more.
I've suggested ^^^ it as this patch description instead of the current one
that doesn't really makes the sense on it's own.

> >> Signed-off-by: David Hildenbrand <address@hidden>
> >> ---
> >>  hw/ppc/spapr.c | 18 +++++++++++++++---
> >>  1 file changed, 15 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> >> index bcb72d9fa7..0a8a3455d6 100644
> >> --- a/hw/ppc/spapr.c
> >> +++ b/hw/ppc/spapr.c
> >> @@ -3298,7 +3298,8 @@ static sPAPRDIMMState 
> >> *spapr_recover_pending_dimm_state(sPAPRMachineState *ms,
> >>  /* Callback to be called during DRC release. */
> >>  void spapr_lmb_release(DeviceState *dev)
> >>  {
> >> -    sPAPRMachineState *spapr = 
> >> SPAPR_MACHINE(qdev_get_hotplug_handler(dev));
> >> +    HotplugHandler *hotplug_ctrl = qdev_get_hotplug_handler(dev);
> >> +    sPAPRMachineState *spapr = SPAPR_MACHINE(hotplug_ctrl);
> >>      sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr, 
> >> PC_DIMM(dev));
> >>  
> >>      /* This information will get lost if a migration occurs
> >> @@ -3316,9 +3317,17 @@ void spapr_lmb_release(DeviceState *dev)
> >>  
> >>      /*
> >>       * Now that all the LMBs have been removed by the guest, call the
> >> -     * pc-dimm unplug handler to cleanup up the pc-dimm device.
> >> +     * unplug handler chain. This can never fail.
> >>       */
> >> -    pc_dimm_memory_unplug(dev, MACHINE(spapr));
> >> +    hotplug_handler_unplug(hotplug_ctrl, dev, &error_abort);
> >> +}
> >> +
> >> +static void spapr_memory_unplug(HotplugHandler *hotplug_dev, DeviceState 
> >> *dev)
> >> +{
> >> +    sPAPRMachineState *spapr = SPAPR_MACHINE(hotplug_dev);
> >> +    sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr, 
> >> PC_DIMM(dev));
> >> +
> >> +    pc_dimm_memory_unplug(dev, MACHINE(hotplug_dev));
> >>      object_unparent(OBJECT(dev));
> >>      spapr_pending_dimm_unplugs_remove(spapr, ds);
> >>  }
> >> @@ -3589,6 +3598,9 @@ static void spapr_machine_device_plug(HotplugHandler 
> >> *hotplug_dev,
> >>  static void spapr_machine_device_unplug(HotplugHandler *hotplug_dev,
> >>                                          DeviceState *dev, Error **errp)
> >>  {
> >> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> >> +        spapr_memory_unplug(hotplug_dev, dev);
> >> +    }
> >>  }
> >>  
> >>  static void spapr_machine_device_unplug_request(HotplugHandler 
> >> *hotplug_dev,  
> >   
> 
>