Re: [PATCH v5 6/8] add cpu_test_interrupt()/cpu_set_interrupt() helpers and use them tree wide

[Zhao Liu <zhao1.liu@intel.com>]

Hi Igor,
 
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 5eaf41a566..1dee9d4c76 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -942,6 +942,31 @@ CPUState *cpu_by_arch_id(int64_t id);
>  
>  void cpu_interrupt(CPUState *cpu, int mask);
>  
> +/**
> + * cpu_test_interrupt:
> + * @cpu: The CPU to check interrupt(s) on.
> + * @mask: The interrupts to check.
> + *
> + * Checks if any of interrupts in @mask are pending on @cpu.
> + */
> +static inline bool cpu_test_interrupt(CPUState *cpu, int mask)
> +{
> +    return qatomic_load_acquire(&cpu->interrupt_request) & mask;
> +}
> +
> +/**
> + * cpu_set_interrupt:
> + * @cpu: The CPU to set pending interrupt(s) on.
> + * @mask: The interrupts to set.
> + *
> + * Sets interrupts in @mask as pending on @cpu.
> + */
> +static inline void cpu_set_interrupt(CPUState *cpu, int mask)
> +{
> +    qatomic_store_release(&cpu->interrupt_request,
> +        cpu->interrupt_request | mask);

It seems the read access of cpu->interrupt_request is not atomic, should
we also protect it by qatomic_read(cpu->interrupt_request)? like

qatomic_store_release(&cpu->interrupt_request,
                      qatomic_read(cpu->interrupt_request) | mask)

or futher,

qatomic_fetch_or(&cpu->interrupt_request, mask)

> +}
> +

Thanks,
Zhao