Re: [Qemu-devel] [PATCH v5 07/10] spapr: Enable CPU hotplug for pseries-2.5 and add CPU DRC DT entries

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

On Tue, Dec 01, 2015 at 12:06:43PM +1100, David Gibson wrote:
> On Fri, Nov 20, 2015 at 06:24:36PM +0530, Bharata B Rao wrote:
> > Start supporting CPU hotplug from pseries-2.5 onwards. Add CPU
> > DRC (Dynamic Resource Connector) device tree entries.
> > 
> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > ---
> >  hw/ppc/spapr.c         | 23 +++++++++++++++++++++++
> >  include/hw/ppc/spapr.h |  1 +
> >  2 files changed, 24 insertions(+)
> > 
> > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > index 030ee35..814b0a6 100644
> > --- a/hw/ppc/spapr.c
> > +++ b/hw/ppc/spapr.c
> > @@ -973,6 +973,16 @@ static void spapr_finalize_fdt(sPAPRMachineState *spapr,
> >          _FDT(spapr_drc_populate_dt(fdt, 0, NULL, SPAPR_DR_CONNECTOR_TYPE_LMB));
> >      }
> >  
> > +    if (smc->dr_cpu_enabled) {
> > +        int offset = fdt_path_offset(fdt, "/cpus");
> > +        ret = spapr_drc_populate_dt(fdt, offset, NULL,
> > +                                    SPAPR_DR_CONNECTOR_TYPE_CPU);
> > +        if (ret < 0) {
> > +            fprintf(stderr, "Couldn't set up CPU DR device tree properties\n");
> > +            exit(1);
> > +        }
> > +    }
> > +
> >      _FDT((fdt_pack(fdt)));
> >  
> >      if (fdt_totalsize(fdt) > FDT_MAX_SIZE) {
> > @@ -1727,6 +1737,8 @@ static void ppc_spapr_init(MachineState *machine)
> >      long load_limit, fw_size;
> >      bool kernel_le = false;
> >      char *filename;
> > +    int smt = kvmppc_smt_threads();
> > +    int smp_max_cores = DIV_ROUND_UP(max_cpus, smp_threads);
> 
> 
> Given your earlier patch to disallow partially filled cores, a
> DIV_ROUND_UP should be the same as a straight divide, yes?

Yes, will change.

> 
> >  
> >      msi_supported = true;
> >  
> > @@ -1793,6 +1805,15 @@ static void ppc_spapr_init(MachineState *machine)
> >          spapr_validate_node_memory(machine);
> >      }
> >  
> > +    if (smc->dr_cpu_enabled) {
> > +        for (i = 0; i < smp_max_cores; i++) {
> > +            sPAPRDRConnector *drc =
> > +                spapr_dr_connector_new(OBJECT(spapr),
> > +                                       SPAPR_DR_CONNECTOR_TYPE_CPU, i * smt);
> > +            qemu_register_reset(spapr_drc_reset, drc);
> > +        }
> > +    }
> > +
> >      /* init CPUs */
> >      if (machine->cpu_model == NULL) {
> >          machine->cpu_model = kvm_enabled() ? "host" : "POWER7";
> > @@ -2277,6 +2298,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
> >      mc->cpu_index_to_socket_id = spapr_cpu_index_to_socket_id;
> >  
> >      smc->dr_lmb_enabled = false;
> > +    smc->dr_cpu_enabled = false;
> >      fwc->get_dev_path = spapr_get_fw_dev_path;
> >      nc->nmi_monitor_handler = spapr_nmi;
> >  }
> > @@ -2443,6 +2465,7 @@ static void spapr_machine_2_5_class_init(ObjectClass *oc, void *data)
> >      mc->alias = "pseries";
> >      mc->is_default = 1;
> >      smc->dr_lmb_enabled = true;
> > +    smc->dr_cpu_enabled = true;
> >  }
> 
> Given when we are, this will need to move to 2.6, obviously.

Yes, will move to 2.6 machine type in the next iteration.

Regards,
Bharata.