Re: [PATCH for-4.16] x86/passthrough: Fix hvm_gsi_eoi() build with GCC 12

[Ian Jackson <iwj@xxxxxxxxxxxxxx>]

Jan Beulich writes ("Re: [PATCH] x86/passthrough: Fix hvm_gsi_eoi() build with 
GCC 12"):
> On 27.10.2021 22:07, Andrew Cooper wrote:
> >   if ( !((pirq) ? &(pirq)->arch.hvm.dpci : NULL) )
> 
> I disagree with the compiler's analysis: While &(pirq)->arch.hvm.dpci
> indeed can't be NULL, that's not the operand of !. The operand of !
> can very well be NULL, when pirq is.
> 
> > which is a hint that the code is should be simplified to just:
> > 
> >   if ( !pirq )
> > 
> > Do so.
> 
> And I further agree with Roger's original reply (despite you
> apparently having managed to convince him): You shouldn't be open-
> coding pirq_dpci(). Your observation that the construct's result
> isn't otherwise used in the function is only one half of it. The
> other half is that hvm_pirq_eoi() gets called from here, and that
> one does require the result to be non-NULL.

Can you (collectively) please come to some agreement here ?
I think this is mostly a question of taste or style.  Please vote on
it if you can't quickly get consensus.

I have added the for-4.16 tag since this seems like a bugfix that
should probably go into 4.16 ?  Unless I have misunderstood.

Thanks,
Ian.
(with RM hat on)