Re: [PATCH 3/3] hw/loongarch/virt: Set max 256 cpus support on loongarch virt machine

[Philippe Mathieu-Daudé]

On 6/4/23 12:00, Song Gao wrote:
> Add separate macro EXTIOI_CPUS for extioi interrupt controller, extioi
> only supports 4 cpu. And set macro LOONGARCH_MAX_CPUS as 256 so that
> loongarch virt machine supports more cpus.
>
> Interrupts from external devices can only be routed cpu 0-3 because
> of extioi limits, cpu internal interrupt such as timer/ipi can be
> triggered on all cpus.
>
> Signed-off-by: Song Gao <gaosong@loongson.cn>
> ---
>   hw/intc/loongarch_extioi.c         |  4 ++--
>   hw/loongarch/virt.c                | 21 ++++++++++++++-------
>   include/hw/intc/loongarch_extioi.h | 10 ++++++----
>   include/hw/loongarch/virt.h        |  2 +-
>   4 files changed, 23 insertions(+), 14 deletions(-)


> @@ -618,10 +623,12 @@ static void loongarch_irq_init(LoongArchMachineState 
> *lams)
>        * cpu_pin[9:2] <= intc_pin[7:0]
>        */
>       for (cpu = 0; cpu < ms->smp.cpus; cpu++) {
> -        cpudev = DEVICE(qemu_get_cpu(cpu));
> -        for (pin = 0; pin < LS3A_INTC_IP; pin++) {
> -            qdev_connect_gpio_out(extioi, (cpu * 8 + pin),
> -                                  qdev_get_gpio_in(cpudev, pin + 2));
> +        if (cpu < EXTIOI_CPUS) {

Alternatively:

           for (cpu = 0; cpu < MIN(ms->smp.cpus, EXTIOI_CPUS); cpu++) {

> +            cpudev = DEVICE(qemu_get_cpu(cpu));
> +            for (pin = 0; pin < LS3A_INTC_IP; pin++) {
> +                qdev_connect_gpio_out(extioi, (cpu * 8 + pin),
> +                                      qdev_get_gpio_in(cpudev, pin + 2));
> +           }
>           }
>       }

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>