Re: [PATCH v3 4/5] KVM: ioeventfd for virtio-ccw devices.

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Tue, 26 Feb 2013 15:20:52 +0100
Stefan Hajnoczi <stefanha@gmail.com> wrote:

> On Tue, Feb 26, 2013 at 12:55:36PM +0200, Michael S. Tsirkin wrote:
> > On Mon, Feb 25, 2013 at 04:27:49PM +0100, Cornelia Huck wrote:
> > > diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> > > index f0ced1a..8de3cd7 100644
> > > --- a/virt/kvm/eventfd.c
> > > +++ b/virt/kvm/eventfd.c
> > > @@ -679,11 +679,16 @@ static int
> > >  kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
> > >  {
> > >  	int                       pio = args->flags & KVM_IOEVENTFD_FLAG_PIO;
> > > -	enum kvm_bus              bus_idx = pio ? KVM_PIO_BUS : KVM_MMIO_BUS;
> > > +	int                       ccw;
> > > +	enum kvm_bus              bus_idx;
> > >  	struct _ioeventfd        *p;
> > >  	struct eventfd_ctx       *eventfd;
> > >  	int                       ret;
> > >  
> > > +	ccw = args->flags & KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY;
> > > +	bus_idx = pio ? KVM_PIO_BUS :
> > > +		ccw ? KVM_VIRTIO_CCW_NOTIFY_BUS :
> > > +		KVM_MMIO_BUS;
> > 
> > May be better to rewrite using if/else.
> 
> Saw this after sending my comment.  I agree with Michael, an if
> statement allows you to drop the locals and capture the bus_idx
> conversion in a single place (it could even be a static function to save
> duplicating the code in both functions that use it).
> 
> Stefan
> 

Introducing a helper function sounds reasonable.