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Date:   Mon, 23 Nov 2020 18:03:16 +0100
From:   Cornelia Huck <cohuck@redhat.com>
To:     Halil Pasic <pasic@linux.ibm.com>
Cc:     Tony Krowiak <akrowiak@linux.ibm.com>, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        freude@linux.ibm.com, borntraeger@de.ibm.com,
        mjrosato@linux.ibm.com, alex.williamson@redhat.com,
        kwankhede@nvidia.com, fiuczy@linux.ibm.com, frankja@linux.ibm.com,
        david@redhat.com, hca@linux.ibm.com, gor@linux.ibm.com
Subject: Re: [PATCH v11 05/14] s390/vfio-ap: implement in-use callback for
 vfio_ap driver
Message-ID: <20201123180316.79273751.cohuck@redhat.com>
In-Reply-To: <20201114004722.76c999e0.pasic@linux.ibm.com>
References: <20201022171209.19494-1-akrowiak@linux.ibm.com>
        <20201022171209.19494-6-akrowiak@linux.ibm.com>
        <20201027142711.1b57825e.pasic@linux.ibm.com>
        <6a5feb16-46b5-9dca-7e85-7d344b0ffa24@linux.ibm.com>
        <20201114004722.76c999e0.pasic@linux.ibm.com>
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On Sat, 14 Nov 2020 00:47:22 +0100
Halil Pasic <pasic@linux.ibm.com> wrote:

> On Fri, 13 Nov 2020 12:14:22 -0500
> Tony Krowiak <akrowiak@linux.ibm.com> wrote:
> [..]
> > >>   }
> > >>   
> > >> +#define MDEV_SHARING_ERR "Userspace may not re-assign queue %02lx.%04lx " \
> > >> +			 "already assigned to %s"
> > >> +
> > >> +static void vfio_ap_mdev_log_sharing_err(const char *mdev_name,
> > >> +					 unsigned long *apm,
> > >> +					 unsigned long *aqm)
> > >> +{
> > >> +	unsigned long apid, apqi;
> > >> +
> > >> +	for_each_set_bit_inv(apid, apm, AP_DEVICES)
> > >> +		for_each_set_bit_inv(apqi, aqm, AP_DOMAINS)
> > >> +			pr_err(MDEV_SHARING_ERR, apid, apqi, mdev_name);  
> > > Isn't error rather severe for this? For my taste even warning would be
> > > severe for this.  
> > 
> > The user only sees a EADDRINUSE returned from the sysfs interface,
> > so Conny asked if I could log a message to indicate which APQNs are
> > in use by which mdev. I can change this to an info message, but it
> > will be missed if the log level is set higher. Maybe Conny can put in
> > her two cents here since she asked for this.
> >   
> 
> I'm looking forward to Conny's opinion. :)

(only just saw this; -ETOOMANYEMAILS)

It is probably not an error in the sense of "things are broken, this
cannot work"; but I'd consider this at least a warning "this does not
work as you intended".