Re: [kvm-unit-tests PATCH v3 12/16] s390x: css: Check ORB reserved bits

[Cornelia Huck <cohuck@redhat.com>]

On Wed, 7 Apr 2021 12:07:13 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> On 4/6/21 5:51 PM, Cornelia Huck wrote:
> > On Tue,  6 Apr 2021 09:40:49 +0200
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >   
> >> Several bits of the ORB are reserved and must be zero.
> >> Their use will trigger a operand exception.
> >>
> >> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> >> ---
> >>   s390x/css.c | 21 +++++++++++++++++++++
> >>   1 file changed, 21 insertions(+)
> >>
> >> diff --git a/s390x/css.c b/s390x/css.c
> >> index 56adc16..26f5da6 100644
> >> --- a/s390x/css.c
> >> +++ b/s390x/css.c
> >> @@ -209,6 +209,26 @@ static void ssch_orb_midaw(void)
> >>   	orb->ctrl = tmp;
> >>   }
> >>   
> >> +static void ssch_orb_ctrl(void)
> >> +{
> >> +	uint32_t tmp = orb->ctrl;
> >> +	char buffer[80];
> >> +	int i;
> >> +
> >> +	/* Check the reserved bits of the ORB CTRL field */
> >> +	for (i = 26; i <= 30; i++) {  
> > 
> > This looks very magic; can we get some defines?  
> 
> OK, I can use something like ORB_FIRST_RESERVED_BIT - ORB_LAST_RESERVED_BIT

Yep, something like that.