Re: [PATCH v4 1/7] hw/arm/raspi: Remove obsolete use of -smp to set the soc 'enabled-cpus'

[Alistair Francis]

On Tue, Jan 21, 2020 at 9:53 AM Philippe Mathieu-Daudé <address@hidden> wrote:
>
> Since we enabled parallel TCG code generation for softmmu (see
> commit 3468b59 "tcg: enable multiple TCG contexts in softmmu")
> and its subsequent fix (commit 72649619 "add .min_cpus and
> .default_cpus fields to machine_class"), the raspi machines are
> restricted to always use their 4 cores:
>
> See in hw/arm/raspi2 (with BCM283X_NCPUS set to 4):
>
>   222 static void raspi2_machine_init(MachineClass *mc)
>   223 {
>   224     mc->desc = "Raspberry Pi 2";
>   230     mc->max_cpus = BCM283X_NCPUS;
>   231     mc->min_cpus = BCM283X_NCPUS;
>   232     mc->default_cpus = BCM283X_NCPUS;
>   235 };
>   236 DEFINE_MACHINE("raspi2", raspi2_machine_init)
>
> We can no longer use the -smp option, as we get:
>
>   $ qemu-system-arm -M raspi2 -smp 1
>   qemu-system-arm: Invalid SMP CPUs 1. The min CPUs supported by machine 
> 'raspi2' is 4
>
> Since we can not set the TYPE_BCM283x SOC "enabled-cpus" with -smp,
> remove the unuseful code.
>
> We can achieve the same by using the '-global bcm2836.enabled-cpus=1'
> option.
>
> Reported-by: Laurent Bonnans <address@hidden>
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
> Cc: Emilio G. Cota <address@hidden>
> Cc: Richard Henderson <address@hidden>
> Cc: Andrew Baumann <address@hidden>
> Cc: Eduardo Habkost <address@hidden>
> ---
>  hw/arm/raspi.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/hw/arm/raspi.c b/hw/arm/raspi.c
> index 6a510aafc1..3996f6c63a 100644
> --- a/hw/arm/raspi.c
> +++ b/hw/arm/raspi.c
> @@ -192,8 +192,6 @@ static void raspi_init(MachineState *machine, int version)
>      /* Setup the SOC */
>      object_property_add_const_link(OBJECT(&s->soc), "ram", OBJECT(&s->ram),
>                                     &error_abort);
> -    object_property_set_int(OBJECT(&s->soc), machine->smp.cpus, 
> "enabled-cpus",
> -                            &error_abort);
>      int board_rev = version == 3 ? 0xa02082 : 0xa21041;
>      object_property_set_int(OBJECT(&s->soc), board_rev, "board-rev",
>                              &error_abort);
> --
> 2.21.1
>
>