On Fri, 23 Feb 2018 18:42:58 +0100
Claudio Imbrenda <imbre...@linux.vnet.ibm.com> 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 <imbre...@linux.vnet.ibm.com>
> ---
> hw/s390x/event-facility.c | 56
> ++++++++++++++++++++++++++++++---------
> include/hw/s390x/event-facility.h | 2 +-
> 2 files changed, 45 insertions(+), 13 deletions(-)
>
> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> index e04ed9f..c3e39ee 100644
> --- a/hw/s390x/event-facility.c
> +++ b/hw/s390x/event-facility.c
> @@ -30,7 +30,7 @@ struct SCLPEventFacility {
> SysBusDevice parent_obj;
> SCLPEventsBus sbus;
> /* guest's receive mask */
> - sccb_mask_t receive_mask;
> + uint32_t receive_mask_pieces[2];
> /*
> * when false, we keep the same broken, backwards compatible behaviour as
> * before, allowing only masks of size exactly 4; when true, we implement
> @@ -42,6 +42,18 @@ struct SCLPEventFacility {
> uint16_t mask_length;
> };
>
> +static inline sccb_mask_t make_receive_mask(SCLPEventFacility *ef)
> +{
> + return ((sccb_mask_t)ef->receive_mask_pieces[0]) << 32 |
> + ef->receive_mask_pieces[1];
> +}
> +
> +static inline void store_receive_mask(SCLPEventFacility *ef, sccb_mask_t val)
> +{
> + ef->receive_mask_pieces[1] = val;
> + ef->receive_mask_pieces[0] = val >> 32;
> +}
> +
Hm... how are all those values actually defined in the architecture?
You pass around some values internally (which are supposedly in host
endian) and then and/or them with the receive mask here. Are they
compared byte-for-byte? 32-bit-for-32-bit?
I'm also not a fan of the _pieces suffix - reminds me of Dwarf pieces :)
