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

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 2/20/25 2:52 AM, Stefano Stabellini wrote:

> 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?
>     
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

~ Oleksii