Re: [kvm-unit-tests PATCH v6 07/10] s390x: css: msch, enable test

Cornelia Huck
2020-05-15T08:25:56Z

On Fri, 15 May 2020 09:11:52 +0200
Pierre Morel <pmorel@linux.ibm.com> wrote:

> On 2020-05-14 14:08, Cornelia Huck wrote:
> > On Tue, 28 Apr 2020 10:27:36 +0200
> > Pierre Morel <pmorel@linux.ibm.com> wrote:
> >
> >> On 2020-04-27 15:11, Janosch Frank wrote:
> >>> On 4/24/20 12:45 PM, Pierre Morel wrote:
> >
> >>>> This is NOT a routine to really enable the channel, no retry is done,
> >>>> in case of error, a report is made.
> >>>
> >>> Would we expect needing retries for the pong device?
> >>
> >> Yes it can be that we need to retry some instructions if we want them to
> >> succeed.
> >> This is the case for example if we develop a driver for an operating system.
> >> When working with firmware, sometime, things do not work at the first
> >> time. Mostly due to races in silicium, firmware or hypervisor or between
> >> them all.
> >>
> >> Since our purpose is to detect such problems we do not retry
> >> instructions but report the error.
> >>
> >> If we detect such problem we may in the future enhance the tests.
> >
> > I think I've seen retries needed on z/VM in the past; do you know if
> > that still happens?
> >
>
> I did not try the tests under z/VM, nor direct on an LPAR, only under
> QEMU/KVM.
> Under QEMU/KVM, I did not encounter any need for retry, 100% of the
> enabled succeeded on first try.

Yep, QEMU/KVM should be fine. Do you plan to run this on anything else?