Re: [PATCH v4 3/7] s390: ap: associate a ap_vfio_queue and a matrix mdev

[Pierre Morel]

On 27/02/2019 10:32, Cornelia Huck wrote:
> On Fri, 22 Feb 2019 16:29:56 +0100
> Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
>
> > We need to associate the ap_vfio_queue, which will hold the
> > per queue information for interrupt with a matrix mediated device
> > which hold the configuration and the way to the CRYCB.
> >
> > Let's do this when assigning a APID or a APQI to the mediated device
> > and clear the relation when unassigning.
> >
> > Queuing the devices on a list of free devices and testing the
> > matrix_mdev pointer to the associated matrix allow us to know
> > if the queue is associated to the matrix device and associated
> > or not to a mediated device.
> >
> > When resetting an AP queue we must wait until there are no more
> > messages in the message queue before considering the queue is really
> > in a clean state.
> >
> > Let's do it and wait until the status response code indicate the
> > queue is empty after issuing a PAPQ/ZAPQ instruction.
>
> I'm a bit confused about the context where that list moving etc. is
> supposed to take place.
>
> When are we assigning/deassigning? Is there even supposed to be any
> activity that we need to zap on the queues?
>
> Do we need any serialization/locking on the lists?

Did I really forget this!?

Yes, thanks.

Regards,
Pierre


--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany