Re: [PATCH v3] docs/s390x: document vfio-ccw

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 19 May 2020 15:19:21 +0200
Thomas Huth <thuth@redhat.com> wrote:

> On 18/05/2020 09.55, Cornelia Huck wrote:
> > Add a basic example for passing a dasd via vfio-ccw.
> > 
> > Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> > ---
> > 
> > v2->v3: moved uuid generation (Thomas)
> > 
> > ---
> >  docs/system/s390x/vfio-ccw.rst | 77 ++++++++++++++++++++++++++++++++++
> >  docs/system/target-s390x.rst   |  1 +
> >  2 files changed, 78 insertions(+)
> >  create mode 100644 docs/system/s390x/vfio-ccw.rst
> > 
> > diff --git a/docs/system/s390x/vfio-ccw.rst b/docs/system/s390x/vfio-ccw.rst
> > new file mode 100644
> > index 000000000000..fff23d9afff7
> > --- /dev/null
> > +++ b/docs/system/s390x/vfio-ccw.rst
> > @@ -0,0 +1,77 @@
> > +Subchannel passthrough via vfio-ccw
> > +===================================
> > +
> > +vfio-ccw (based upon the mediated vfio device infrastructure) allows to
> > +make certain I/O subchannels and their devices available to a guest. The
> > +host will not interact with those subchannels/devices any more.
> > +
> > +Note that while vfio-ccw should work with most non-QDIO devices, only ECKD
> > +DASDs have really been tested.
> > +
> > +Example configuration
> > +---------------------
> > +
> > +Step 1: configure the host device
> > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > +
> > +As every mdev is identified by a uuid, the first step is to obtain one::
> > +
> > +  [root@host ~]# uuidgen
> > +  7e270a25-e163-4922-af60-757fc8ed48c6
> > +
> > +Note: it is recommended to use the ``mdevctl`` tool for actually configuring
> > +the host device.
> > +
> > +To define the same device as configured below to be started
> > +automatically, use
> > +
> > +::
> > +
> > +   [root@host ~]# driverctl -b css set-override 0.0.0313 vfio_ccw
> > +   [root@host ~]# mdevctl define -u 7e270a25-e163-4922-af60-757fc8ed48c6\  
> 
> Maybe add a space before the backslash?
> 
> > +                  -p 0.0.0313 -t vfio-ccw_io -a
> > +
> > +If using ``mdevctl``  is not possible or wanted, follow the manual procedure
> > +below.  
> 
> Nit: Doubled whitespaces after mdevctl. With that fixed:
> Reviewed-by: Thomas Huth <thuth@redhat.com>

Thanks!

Fixed the nits and queued to s390-next.