Re: [qemu-s390x] [PATCH v5 1/1] s390x/sclp: extend SCLP event masks to 64 bits

[Claudio Imbrenda]

On Thu, 8 Mar 2018 08:41:47 +0100
Christian Borntraeger <address@hidden> wrote:

> On 03/07/2018 04:10 PM, Claudio Imbrenda wrote:
> > Extend the SCLP event masks to 64 bits.
> > 
> > Notice that using any of the new bits results in a state that
> > cannot be migrated to an older version.
> > 
> > Signed-off-by: Claudio Imbrenda <address@hidden>
> > ---
> >  hw/s390x/event-facility.c         | 49
> > ++++++++++++++++++++++++++++++++-------
> > include/hw/s390x/event-facility.h |  2 +- 2 files changed, 41
> > insertions(+), 10 deletions(-)
> > 
> > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> > index e04ed9f..c166e0a 100644
> > --- a/hw/s390x/event-facility.c
> > +++ b/hw/s390x/event-facility.c
> > @@ -30,7 +30,10 @@ struct SCLPEventFacility {
> >      SysBusDevice parent_obj;
> >      SCLPEventsBus sbus;
> >      /* guest's receive mask */
> > -    sccb_mask_t receive_mask;
> > +    union {
> > +        uint32_t receive_mask_pieces[2];
> > +        sccb_mask_t receive_mask;
> > +    };  
> 
> Would it work to make sccb_mask_t a union instead?

yes, but then a lot of other code should be changed: we use sccb_mask_t
as scalar everywhere.

also, we only need the pieces when migrating the state, never during
normal operation