Re: [Qemu-devel] [RFC PATCH 1/1] s390x/css: unresrict cssids

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 23 Nov 2017 17:09:16 +0100
Halil Pasic <pasic@linux.vnet.ibm.com> wrote:

[I need time to process your other remarks.]

> On 11/22/2017 01:13 PM, Cornelia Huck wrote:

> >> Also I can't find anything about vfio-ccw in the upstream users
> >> manual for 2.10.91.   
> > 
> > We have an "upstream users manual"?
> >   
> This is what I mean:
> https://qemu.weilnetz.de/doc/qemu-doc.html

This is really hit-and-miss. Some things are documented in there, some
are not. I usually consider the output of the binary the canonical list
of supported devices (in combination with the x- notation.)

> 
> >> So I would argue using vfio-ccw is using an
> >> undocumented feature: if undocumented features changing in a non
> >> compatible way hits you, it's partly your own fault.  
> > 
> > If it's an x- interface, it is preliminary. If not, we should avoid
> > breaking it.
> >   
> 
> I don't see this documented in the users manual? Shouldn't the users
> know what is preliminary?
> 
> Where is this documented?

It is long standing practice, but I cannot point to documentation
(maybe someone else can?)