On Fri, 9 Apr 2021 10:38:37 +0200
Halil Pasic <pa...@linux.ibm.com> wrote:
> On Thu, 8 Apr 2021 18:32:09 +0200
> Pierre Morel <pmo...@linux.ibm.com> wrote:
>
> > ccw_dstream_read/write functions returned values are sometime
> > not taking into account and reported back to the upper level
> > of interpretation of CCW instructions.
> >
> > It follows that accessing an invalid address does not trigger
> > a subchannel status program check to the guest as it should.
> >
> > Let's test the return values of ccw_dstream_write[_buf] and
> > ccw_dstream_read[_buf] and report it to the caller.
> >
> > Signed-off-by: Pierre Morel <pmo...@linux.ibm.com>
>
> Acked-by: Halil Pasic <pa...@linux.ibm.com>
>
> I did not look into the whole scsw.count stuff or into wether
> your changes to 3270 (look form <mark></mark> in the diff part) affect
> more than just ccw_dstream_*.
>
> I would have preferred this patch split up based on the intended effect
> and thus also subsystem (css, virtio-ccw, 3270), but I've alluded to
> that before, and since we are in a hurry I can live with it as is.
>
> Regards,
> Halil
>
> > ---
> > hw/char/terminal3270.c | 11 +++++--
> > hw/s390x/3270-ccw.c | 5 +++-
> > hw/s390x/css.c | 14 +++++----
> > hw/s390x/virtio-ccw.c | 66 ++++++++++++++++++++++++++++++------------
> > 4 files changed, 69 insertions(+), 27 deletions(-)
> >
> > diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c
> > index a9a46c8ed3..82e85fac2e 100644
> > --- a/hw/char/terminal3270.c
> > +++ b/hw/char/terminal3270.c
> > @@ -200,9 +200,13 @@ static int read_payload_3270(EmulatedCcw3270Device
> > *dev)
> > {
> > Terminal3270 *t = TERMINAL_3270(dev);
> > int len;
> > + int ret;
> >
> > len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
> > - ccw_dstream_write_buf(get_cds(t), t->inv, len);
> > + ret = ccw_dstream_write_buf(get_cds(t), t->inv, len);
> > + if (ret < 0) {
> > + return ret;
> > + }
> > t->in_len -= len;
> >
> > return len;
> > @@ -260,7 +264,10 @@ static int write_payload_3270(EmulatedCcw3270Device
> > *dev, uint8_t cmd)
> >
> > t->outv[out_len++] = cmd;
> > do {
> > - ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len);
> > + retval = ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len);
> > + if (retval < 0) {
> > + return retval;
> > + }
> > count = ccw_dstream_avail(get_cds(t));
> > out_len += len;
> >
> > diff --git a/hw/s390x/3270-ccw.c b/hw/s390x/3270-ccw.c
> > index 821319eee6..f3e7342b1e 100644
> > --- a/hw/s390x/3270-ccw.c
> > +++ b/hw/s390x/3270-ccw.c
> > @@ -31,6 +31,9 @@ static int handle_payload_3270_read(EmulatedCcw3270Device
> > *dev, CCW1 *ccw)
> > }
> >
> > len = ck->read_payload_3270(dev);
>
> <mark>
>
> > + if (len < 0) {
> > + return len;
> > + }
> > ccw_dev->sch->curr_status.scsw.count = ccw->count - len;
> >
>
> </mark>
>
> Do we eventually update scsw.count?
I think we can consider the contents of scsw.count 'unpredictable', no?
>
> > return 0;
> > @@ -50,7 +53,7 @@ static int
> > handle_payload_3270_write(EmulatedCcw3270Device *dev, CCW1 *ccw)
> > len = ck->write_payload_3270(dev, ccw->cmd_code);
> >
> > if (len <= 0) {
>
> <mark>
> > - return -EIO;
> > + return len ? len : -EIO;
>
> </mark>
>
> > }
> >
> > ccw_dev->sch->curr_status.scsw.count = ccw->count - len;
> > diff --git a/hw/s390x/css.c b/hw/s390x/css.c
> > index fe47751df4..4149b8e5a7 100644
>
