Re: [Qemu-devel] [RFC PATCH v1 02/13] spapr: Add DRC dt entries for CPUs

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Quoting Bharata B Rao (2015-01-08 00:10:09)
> Advertise CPU DR-capability to the guest via device tree.
> 
> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
>                [spapr_drc_reset implementation]
> ---
>  hw/ppc/spapr.c | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 71e7052..98a32d0 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -807,6 +807,14 @@ static void spapr_finalize_fdt(sPAPREnvironment *spapr,
>          spapr_populate_chosen_stdout(fdt, spapr->vio_bus);
>      }
> 
> +    if (spapr->dr_cpu_enabled) {
> +        int offset = fdt_path_offset(fdt, "/cpus");
> +        ret = spapr_drc_populate_dt(fdt, offset, SPAPR_DR_CONNECTOR_TYPE_CPU);
> +        if (ret < 0) {
> +            fprintf(stderr, "Couldn't set up CPU DR device tree properties\n");
> +        }
> +    }
> +

Doesn't hurt to add the check, but spapr_drc_populate_dt() tries to be smart
enough to no-op if there's no drc's that have been created for resources of
the specified type, so spapr_dr_connector_new() *should* be the only spots
where it's necessary to check spapr->dr_cpu_enabled.

>      _FDT((fdt_pack(fdt)));
> 
>      if (fdt_totalsize(fdt) > FDT_MAX_SIZE) {
> @@ -1358,6 +1366,16 @@ static SaveVMHandlers savevm_htab_handlers = {
>      .load_state = htab_load,
>  };
> 
> +static void spapr_drc_reset(void *opaque)
> +{
> +    sPAPRDRConnector *drc = opaque;
> +    DeviceState *d = DEVICE(drc);
> +
> +    if (d) {
> +        device_reset(d);
> +    }
> +}
> +
>  /* pSeries LPAR / sPAPR hardware init */
>  static void ppc_spapr_init(MachineState *machine)
>  {
> @@ -1383,6 +1401,7 @@ static void ppc_spapr_init(MachineState *machine)
>      long load_limit, fw_size;
>      bool kernel_le = false;
>      char *filename;
> +    int smt = kvmppc_smt_threads();
> 
>      msi_supported = true;
> 
> @@ -1526,6 +1545,15 @@ static void ppc_spapr_init(MachineState *machine)
>      spapr->dr_cpu_enabled = smc->dr_cpu_enabled;
>      spapr->dr_lmb_enabled = smc->dr_lmb_enabled;
> 
> +    if (spapr->dr_cpu_enabled) {
> +        for (i = 0; i < max_cpus/smp_threads; i++) {
> +            sPAPRDRConnector *drc =
> +                spapr_dr_connector_new(OBJECT(machine),
> +                                       SPAPR_DR_CONNECTOR_TYPE_CPU, i * smt);
> +            qemu_register_reset(spapr_drc_reset, drc);
> +        }
> +    
> +
>      /* Set up PCI */
>      spapr_pci_rtas_init();
> 
> -- 
> 2.1.0