Re: [PATCH] s390: vfio-ap: disable IRQ in remove callback results in kernel OOPS

[Pierre Morel]

On 10/30/19 8:44 AM, Harald Freudenberger wrote:
> On 29.10.19 23:09, Tony Krowiak wrote:
> > From: aekrowia <akrowiak@xxxxxxxxxxxxx>
> >
> > When an AP adapter card is configured off via the SE or the SCLP
> > Deconfigure Adjunct Processor command and the AP bus subsequently detects
> > that the adapter card is no longer in the AP configuration, the card
> > device representing the adapter card as well as each of its associated
> > AP queue devices will be removed by the AP bus. If one or more of the
> > affected queue devices is bound to the VFIO AP device driver, its remove
> > callback will be invoked for each queue to be removed. The remove callback
> > resets the queue and disables IRQ processing. If interrupt processing was
> > never enabled for the queue, disabling IRQ processing will fail resulting
> > in a kernel OOPS.
> >
> > This patch verifies IRQ processing is enabled before attempting to disable
> > interrupts for the queue.
> >
> > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> > Signed-off-by: aekrowia <akrowiak@xxxxxxxxxxxxx>
> > ---
> >   drivers/s390/crypto/vfio_ap_drv.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> > index be2520cc010b..42d8308fd3a1 100644
> > --- a/drivers/s390/crypto/vfio_ap_drv.c
> > +++ b/drivers/s390/crypto/vfio_ap_drv.c
> > @@ -79,7 +79,8 @@ static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
> >   	apid = AP_QID_CARD(q->apqn);
> >   	apqi = AP_QID_QUEUE(q->apqn);
> >   	vfio_ap_mdev_reset_queue(apid, apqi, 1);
> > -	vfio_ap_irq_disable(q);
> > +	if (q->saved_isc != VFIO_AP_ISC_INVALID)
> > +		vfio_ap_irq_disable(q);
> >   	kfree(q);
> >   	mutex_unlock(&matrix_dev->lock);
> >   }
> Reset of an APQN does also clear IRQ processing. I don't say that the
> resources associated with IRQ handling for the APQN are also cleared.
> But when you call PQAP(AQIC) after an PQAP(RAPQ) or PQAP(ZAPQ)
> it is superfluous. However, there should not appear any kernel OOPS.
> So can you please give me more details about this kernel oops - maybe
> I need to add exception handler code to the inline ap_aqic() function.
>
> regards, Harald Freudenberger

Hi Tony,

wasn't it already solved by the patch 5c4c2126Â from Christian ?

Can you send the trace to me please?

Thanks,

Pierre



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Pierre Morel
IBM Lab Boeblingen