Re: [PATCH 06/18] ppc/pnv: specialise init for powernv8/9/10 machines

[Cédric Le Goater]

On 7/11/24 16:18, Nicholas Piggin wrote:
> This will allow different settings and checks for different
> machine types with later changes.
>
> Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   include/hw/ppc/pnv.h |  1 +
>   hw/ppc/pnv.c         | 12 +++++++++---
>   2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
> index 476b136146..1993dededf 100644
> --- a/include/hw/ppc/pnv.h
> +++ b/include/hw/ppc/pnv.h
> @@ -76,6 +76,7 @@ struct PnvMachineClass {
>       /*< public >*/
>       const char *compat;
>       int compat_size;
> +    int max_smt_threads;
>   
>       void (*dt_power_mgt)(PnvMachineState *pnv, void *fdt);
>       void (*i2c_init)(PnvMachineState *pnv);
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index 3bcf11984c..4252bcd28d 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -899,6 +899,7 @@ static void pnv_init(MachineState *machine)
>       PnvMachineState *pnv = PNV_MACHINE(machine);
>       MachineClass *mc = MACHINE_GET_CLASS(machine);
>       PnvMachineClass *pmc = PNV_MACHINE_GET_CLASS(machine);
> +    int max_smt_threads = pmc->max_smt_threads;
>       char *fw_filename;
>       long fw_size;
>       uint64_t chip_ram_start = 0;
> @@ -997,17 +998,19 @@ static void pnv_init(MachineState *machine)
>       pnv->num_chips =
>           machine->smp.max_cpus / (machine->smp.cores * machine->smp.threads);
>   
> -    if (machine->smp.threads > 8) {
> -        error_report("Cannot support more than 8 threads/core "
> -                     "on a powernv machine");
> +    if (machine->smp.threads > max_smt_threads) {
> +        error_report("Cannot support more than %d threads/core "
> +                     "on %s machine", max_smt_threads, mc->desc);
>           exit(1);
>       }
> +
>       if (!is_power_of_2(machine->smp.threads)) {
>           error_report("Cannot support %d threads/core on a powernv"
>                        "machine because it must be a power of 2",
>                        machine->smp.threads);
>           exit(1);
>       }
> +
>       /*
>        * TODO: should we decide on how many chips we can create based
>        * on #cores and Venice vs. Murano vs. Naples chip type etc...,
> @@ -2491,6 +2494,7 @@ static void pnv_machine_power8_class_init(ObjectClass 
> *oc, void *data)
>   
>       pmc->compat = compat;
>       pmc->compat_size = sizeof(compat);
> +    pmc->max_smt_threads = 8;
>   
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_PNV_PHB);
>   }
> @@ -2515,6 +2519,7 @@ static void pnv_machine_power9_class_init(ObjectClass 
> *oc, void *data)
>   
>       pmc->compat = compat;
>       pmc->compat_size = sizeof(compat);
> +    pmc->max_smt_threads = 4;
>       pmc->dt_power_mgt = pnv_dt_power_mgt;
>   
>       machine_class_allow_dynamic_sysbus_dev(mc, TYPE_PNV_PHB);
> @@ -2539,6 +2544,7 @@ static void pnv_machine_p10_common_class_init(ObjectClass 
> *oc, void *data)
>   
>       pmc->compat = compat;
>       pmc->compat_size = sizeof(compat);
> +    pmc->max_smt_threads = 4;
>       pmc->dt_power_mgt = pnv_dt_power_mgt;
>   
>       xfc->match_nvt = pnv10_xive_match_nvt;