Re: getting the console output for s390 cdrom-test?

[Peter Maydell <peter.maydell@linaro.org>]

On Thu, 4 Feb 2021 at 16:08, Thomas Huth <thuth@redhat.com> wrote:
>
> On 22/01/2021 21.32, Peter Maydell wrote:
> > Hi; I've been looking at why the s390 cdrom test has an intermittent
> > failure on my aarch64 box. Looking at some TCG debug log output
> > I think what is happening is that sometimes execution diverges from
> > a successful run inside virtio_scsi_setup() and we end up failing
> > a vs_assert(), which triggers a "Guest crashed on cpu 0: disabled-wait"
> > which then makes the qtest hang until its timeout.
> >
> > I think that vs_assert() ought to be printing some information
> > to the console about which assert fails when it happens, but
> > how do I need to tweak the qtest to get it to capture this
> > console log somewhere?
>
>   Hi!
>
> Sorry for the late reply ... did you get any further with this already?

No, I've been mostly working on other stuff. Thanks for the instructions
on how to capture stdio. This is what a success looks like:

LOADPARM=[        ]
Using virtio-scsi.
Warning: Could not locate a usable virtio-scsi device
Using virtio-blk.
Using guessed DASD geometry.
Using ECKD scheme (block size  4096), CDL
No zIPL section in IPL2 record.
zIPL load failed.
Using virtio-blk.
ISO boot image size verified

And this is a failure:

LOADPARM=[        ]
Using virtio-scsi.
target: 0x0000000000000094

! SCSI cannot report LUNs: response VS RESP=09 !

> A Heisen-bug ... ugh ... but I wonder whether it's maybe rather an issue in
> the aarch64 TCG backend, since we've never seen this on other architectures
> before?

Certainly possible; but I would tend to expect TCG backend issues
to be consistently reproducible, not intermittent like this one.

thanks
-- PMM