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Date:   Mon, 27 Aug 2018 15:51:26 +0200
From:   Cornelia Huck <cohuck@redhat.com>
To:     Tony Krowiak <akrowiak@linux.ibm.com>
Cc:     Halil Pasic <pasic@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        pmorel@linux.ibm.com, Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
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Subject: Re: [PATCH v9 12/22] s390: vfio-ap: sysfs interfaces to configure
 control domains
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On Mon, 27 Aug 2018 09:47:58 -0400
Tony Krowiak <akrowiak@linux.ibm.com> wrote:

> On 08/27/2018 04:33 AM, Cornelia Huck wrote:
> > On Thu, 23 Aug 2018 10:16:59 -0400
> > Tony Krowiak <akrowiak@linux.ibm.com> wrote:
> >  
> >> On 08/23/2018 06:25 AM, Cornelia Huck wrote:  
> >>> On Wed, 22 Aug 2018 15:16:19 -0400
> >>> Tony Krowiak <akrowiak@linux.ibm.com> wrote:
> >>>     
> >>>> One of the things I suggested in a private conversation with Christian
> >>>> earlier
> >>>> today was to provide an additional rw sysfs attribute - a boolean - that
> >>>> indicates
> >>>> whether all usage domains should also be control domains. The default
> >>>> could be
> >>>> true. This would allow one to configure guests with usage-only domains
> >>>> as well
> >>>> as satisfy the convention.  
> >>> Would this additional attribute then control "add usage domains to the
> >>> list of control domains automatically", or "don't allow to add a usage
> >>> domain if it has not already been added as a control domain"?  
> >> It was just a proposal that wasn't really discussed at all, but this
> >> attribute would add usage domains to the list of control domains
> >> automatically if set to one. That would be the default behavior which
> >> would be turned off by manually setting it to zero.  
> > If we want to do something like that, having it add the usage domains
> > automatically sounds like the more workable alternative. What I like
> > about this is that we make it explicit that we change the masks beyond
> > what the admin explicitly configured, and provide a knob to turn off
> > that behaviour.  
> 
> So, are you saying I should go ahead and implement this?

I'm just saying that it does not sound like a bad idea :)

If you agree that it's a good idea and if others also like it... I'd
certainly not mind you going ahead :)