Re: [PATCH v3 3/5] target/arm: Always add pmu property for Armv8

[Peter Maydell <peter.maydell@linaro.org>]

On Tue, 16 Jul 2024 at 13:50, Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> kvm-steal-time and sve properties are added for KVM even if the
> corresponding features are not available. Always add pmu property for
> Armv8. Note that the property is added only for Armv8 as QEMU emulates
> PMUv3, which is part of Armv8.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
>  target/arm/cpu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index 14d4eca12740..64038e26b2a9 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -1744,6 +1744,8 @@ void arm_cpu_post_init(Object *obj)
>      }
>
>      if (arm_feature(&cpu->env, ARM_FEATURE_V8)) {
> +        object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu);
> +
>          object_property_add_uint64_ptr(obj, "rvbar",
>                                         &cpu->rvbar_prop,
>                                         OBJ_PROP_FLAG_READWRITE);
> @@ -1770,7 +1772,6 @@ void arm_cpu_post_init(Object *obj)
>
>      if (arm_feature(&cpu->env, ARM_FEATURE_PMU)) {
>          cpu->has_pmu = true;
> -        object_property_add_bool(obj, "pmu", arm_get_pmu, arm_set_pmu);
>      }

This regresses the ability to disable the PMU emulation on
CPUs like "cortex-a8", which are not v8 but still set
ARM_FEATURE_PMU.

thanks
-- PMM