Re: xen/x86: resolve the last 3 MISRA R16.6 violations

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 19 Feb 2025, Jan Beulich wrote:
> On 18.02.2025 22:42, Stefano Stabellini wrote:
> > On Tue, 18 Feb 2025, Jan Beulich wrote:
> >> On 18.02.2025 00:12, Stefano Stabellini wrote:
> >>> On Mon, 17 Feb 2025, Jan Beulich wrote:
> >>>> On 15.02.2025 03:16, Stefano Stabellini wrote:
> >>>>> --- a/xen/arch/x86/hvm/hvm.c
> >>>>> +++ b/xen/arch/x86/hvm/hvm.c
> >>>>> @@ -3797,22 +3797,14 @@ uint64_t hvm_get_reg(struct vcpu *v, unsigned 
> >>>>> int reg)
> >>>>>  {
> >>>>>      ASSERT(v == current || !vcpu_runnable(v));
> >>>>>  
> >>>>> -    switch ( reg )
> >>>>> -    {
> >>>>> -    default:
> >>>>> -        return alternative_call(hvm_funcs.get_reg, v, reg);
> >>>>> -    }
> >>>>> +    return alternative_call(hvm_funcs.get_reg, v, reg);
> >>>>>  }
> >>>>>  
> >>>>>  void hvm_set_reg(struct vcpu *v, unsigned int reg, uint64_t val)
> >>>>>  {
> >>>>>      ASSERT(v == current || !vcpu_runnable(v));
> >>>>>  
> >>>>> -    switch ( reg )
> >>>>> -    {
> >>>>> -    default:
> >>>>> -        return alternative_vcall(hvm_funcs.set_reg, v, reg, val);
> >>>>> -    }
> >>>>> +    return alternative_vcall(hvm_funcs.set_reg, v, reg, val);
> >>>>>  }
> >>>>
> >>>> Both of these were, iirc, deliberately written using switch(), to ease
> >>>> possible future changes.
> >>>
> >>> To be honest, I do not see any value in the way they are currently
> >>> written. However, if you prefer, I can add a deviation for this, with
> >>> one SAF comment for each of these two. The reason for the deviation
> >>> would be "deliberate to ease possible future change". Please let me know
> >>> how you would like to proceed.
> >>
> >> Well, best next thing you can do is seek input from the person who has
> >> written that code, i.e. Andrew.
> > 
> > Andrew wrote in chat that he is OK with a deviation and he can live with
> > a SAF deviation. Here is the patch.
> > 
> > 
> > ---
> > xen/x86: resolve the last 3 MISRA R16.6 violations
> > 
> > MISRA R16.6 states that "Every switch statement shall have at least two
> > switch-clauses". There are only 3 violations left on x86 (zero on ARM).
> > 
> > One of them is only a violation depending on the kconfig configuration.
> > So deviate it instead with a SAF comment.
> > 
> > Two of them are deliberate to enable future additions. Deviate them as
> > such.
> > 
> > Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> 
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>

Thanks!

Oleksii, may I ask for a release-ack?