[RFC,v1,09/13] spapr: CPU hot unplug support

Support hot removal of CPU for sPAPR guests.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

On Thu, Jan 08, 2015 at 11:40:16AM +0530, Bharata B Rao wrote:
> Support hot removal of CPU for sPAPR guests.
> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> ---
>  hw/ppc/spapr.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 43 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 4347471..ec793b1 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1908,6 +1908,22 @@ static void spapr_cpu_hotplug_add(DeviceState *dev, CPUState *cs)
>      drck->attach(drc, dev, fdt, offset, false);
>  }
>  
> +static void spapr_cpu_release(DeviceState *dev, void *opaque)
> +{
> +    /* Release vCPU */

Um.. should this actually do something?

> +}
> +
> +static void spapr_cpu_hotplug_remove(DeviceState *dev, CPUState *cs)
> +{
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    int id = ppc_get_vcpu_dt_id(cpu);
> +    sPAPRDRConnector *drc =
> +        spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id);
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +
> +    drck->detach(drc, dev, spapr_cpu_release, NULL);
> +}
> +
>  static void spapr_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
>                              Error **errp)
>  {
> @@ -1948,6 +1964,21 @@ static void spapr_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
>      return;
>  }
>  
> +static void spapr_cpu_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
> +                            Error **errp)
> +{
> +    Error *local_err = NULL;

Unused variable.

> +    CPUState *cs = CPU(dev);
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    sPAPRDRConnector *drc =
> +        spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, cpu->cpu_dt_id);
> +
> +    spapr_cpu_hotplug_remove(dev, cs);
> +    spapr_hotplug_req_remove_event(drc);
> +    error_propagate(errp, local_err);
> +    return;
> +}
> +
>  static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
>                                        DeviceState *dev, Error **errp)
>  {
> @@ -1958,6 +1989,16 @@ 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_CPU)) {
> +        if (dev->hotplugged) {
> +            spapr_cpu_unplug(hotplug_dev, dev, errp);
> +        }
> +    }
> +}
> +
>  static HotplugHandler *spapr_get_hotpug_handler(MachineState *machine,
>                                               DeviceState *dev)
>  {
> @@ -1986,6 +2027,8 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
>      mc->get_hotplug_handler = spapr_get_hotpug_handler;
>  
>      hc->plug = spapr_machine_device_plug;
> +    hc->unplug = spapr_machine_device_unplug;
> +
>      smc->dr_phb_enabled = false;
>      smc->dr_cpu_enabled = false;
>      smc->dr_lmb_enabled = false;

On Thu, Jan 29, 2015 at 12:39:58PM +1100, David Gibson wrote:
> On Thu, Jan 08, 2015 at 11:40:16AM +0530, Bharata B Rao wrote:
> > Support hot removal of CPU for sPAPR guests.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > ---
> >  hw/ppc/spapr.c | 43 +++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 43 insertions(+)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 4347471..ec793b1 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -1908,6 +1908,22 @@ static void spapr_cpu_hotplug_add(DeviceState *dev, CPUState *cs)
> >      drck->attach(drc, dev, fdt, offset, false);
> >  }
> >  
> > +static void spapr_cpu_release(DeviceState *dev, void *opaque)
> > +{
> > +    /* Release vCPU */
> 
> Um.. should this actually do something?

Actual vCPU removal code in the next patch, but as you commented on the
next patch, I will clear generic and ppc parts into different patches
next time.

Regards,
Bharata.