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

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

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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?

>  
>      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.

>  static const TypeInfo spapr_machine_2_5_info = {
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index 5baa906..716d7ad 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -36,6 +36,7 @@ struct sPAPRMachineClass {
>  
>      /*< public >*/
>      bool dr_lmb_enabled; /* enable dynamic-reconfig/hotplug of LMBs */
> +    bool dr_cpu_enabled; /* enable dynamic-reconfig/hotplug of CPUs */
>  };
>  
>  /**

-- 
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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