Re: [Qemu-devel] [PATCH v3 2/5] s390x/css: use ccw data stream

[Pierre Morel]

On 19/09/2017 20:27, Halil Pasic wrote:
> Replace direct access which implicitly assumes no IDA
> or MIDA with the new ccw data stream interface which should
> cope with these transparently in the future.
>
> Signed-off-by: Halil Pasic <address@hidden>
> Reviewed-by: Dong Jia Shi <address@hidden>
> Reviewed-by: Pierre Morel<address@hidden>
> ---
>   hw/s390x/css.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> index e8d2016563..6b0cd8861b 100644
> --- a/hw/s390x/css.c
> +++ b/hw/s390x/css.c
> @@ -890,6 +890,7 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
>       }
>
>       /* Look at the command. */
> +    ccw_dstream_init(&sch->cds, &ccw, &(sch->orb));
>       switch (ccw.cmd_code) {
>       case CCW_CMD_NOOP:
>           /* Nothing to do. */
> @@ -903,8 +904,8 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
>               }
>           }
>           len = MIN(ccw.count, sizeof(sch->sense_data));
> -        cpu_physical_memory_write(ccw.cda, sch->sense_data, len);
> -        sch->curr_status.scsw.count = ccw.count - len;
> +        ccw_dstream_write_buf(&sch->cds, sch->sense_data, len);

Well, I oversaw this when I reviewed:
I think you should test the return value of ccw_dstream_write_buf here.

> +        sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
>           memset(sch->sense_data, 0, sizeof(sch->sense_data));
>           ret = 0;
>           break;
> @@ -930,8 +931,8 @@ static int css_interpret_ccw(SubchDev *sch, hwaddr ccw_addr,
>           } else {
>               sense_id.reserved = 0;
>           }
> -        cpu_physical_memory_write(ccw.cda, &sense_id, len);
> -        sch->curr_status.scsw.count = ccw.count - len;
> +        ccw_dstream_write_buf(&sch->cds, &sense_id, len);

and here

> +        sch->curr_status.scsw.count = ccw_dstream_residual_count(&sch->cds);
>           ret = 0;
>           break;
>       }


--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany