On 7/7/23 02:59, Jan Beulich wrote:
> On 07.07.2023 03:47, Stewart Hildebrand wrote:
>> --- a/xen/arch/arm/include/asm/domain.h
>> +++ b/xen/arch/arm/include/asm/domain.h
>> @@ -298,8 +298,7 @@ static inline void arch_vcpu_block(struct vcpu *v) {}
>>
>> #define arch_vm_assist_valid_mask(d) (1UL <<
>> VMASST_TYPE_runstate_update_flag)
>>
>> -/* vPCI is not available on Arm */
>> -#define has_vpci(d) ({ (void)(d); false; })
>> +#define has_vpci(d) ({ IS_ENABLED(CONFIG_HAS_VPCI) &&
>> is_hardware_domain(d); })
>
> While likely not much of a problem here, I think we should strive to
> write macros such that their arguments are evaluated exactly once in
> all cases (for side effects to occur exactly once). When that's not
> easily possible, so be it, but here it doesn't look problematic to
> swap both sides of the &&.
Thanks for pointing this out. Hmm... I'm considering turning it into a static
inline function. This would also satisfy MISRA C:2012 Dir 4.9: "A function
should be used in preference to a function-like macro where they are
interchangeable" [1].
[1]
https://gitlab.com/MISRA/MISRA-C/MISRA-C-2012/Example-Suite/-/blob/master/D_04_09.c
