On Wed, Jun 16 2021, Eric Farman <far...@linux.ibm.com> wrote:
> On Wed, 2021-06-16 at 11:59 +0200, Cornelia Huck wrote:
>> On Wed, Jun 16 2021, Eric Farman <far...@linux.ibm.com> wrote:
>>
>> > Wire in the subchannel callback for building the IRB
>> > ESW and ECW space for passthrough devices, and copy
>> > the hardware's ESW into the IRB we are building.
>> >
>> > If the hardware presented concurrent sense, then copy
>> > that sense data into the IRB's ECW space.
>> >
>> > Signed-off-by: Eric Farman <far...@linux.ibm.com>
>> > ---
>> > hw/s390x/css.c | 13 ++++++++++++-
>> > hw/s390x/s390-ccw.c | 1 +
>> > hw/vfio/ccw.c | 4 ++++
>> > include/hw/s390x/css.h | 3 +++
>> > 4 files changed, 20 insertions(+), 1 deletion(-)
>> >
>>
>> (...)
>>
>> > +void build_irb_passthrough(SubchDev *sch, IRB *irb)
>> > +{
>> > + /* Copy ESW from hardware */
>> > + irb->esw = sch->esw;
>> > +
>> > + if (irb->esw.erw & ESW_ERW_SENSE) {
>> > + /* Copy ECW from hardware */
>> > + build_irb_sense_data(sch, irb);
>> > + }
>>
>> I'm wondering whether we should also copy "Model-dependent
>> information"
>> (scsw 5 + 14 set, erw 7 unset). Seems more correct, and IIUC the
>> guest
>> was tripped by the presence of erw 7 without valid sense data.
>>
>
> This is true, but that's because the existing code in
> css_do_tsch_get_irb() set ERW 7 to go with the zeros it copied into the
> ECW. Since we're now copying the ESW.ERW from the passthrough device,
> that bit wouldn't be set in the first place.
That's what I meant to say :)
>
> But, to be more correct with the possibility of model-dependent
> information, I can unconditionally copy this data over too.
Yep. Not that I have any idea what that "Model-dependent information2
would be...
>
>> > +}
>> > +
