RE: [PATCH v2 5/6] mdev: Update sysfs documentation

[Parav Pandit]

> -----Original Message-----
> From: Cornelia Huck <cohuck@xxxxxxxxxx>
> Sent: Friday, August 30, 2019 6:19 PM
> To: Parav Pandit <parav@xxxxxxxxxxxx>
> Cc: alex.williamson@xxxxxxxxxx; Jiri Pirko <jiri@xxxxxxxxxxxx>;
> kwankhede@xxxxxxxxxx; davem@xxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 5/6] mdev: Update sysfs documentation
> 
> On Thu, 29 Aug 2019 06:19:03 -0500
> Parav Pandit <parav@xxxxxxxxxxxx> wrote:
> 
> > Updated documentation for optional read only sysfs attribute.
> 
> I'd probably merge this into the patch introducing the attribute.
> 
Ok. I will spin v3.

> >
> > Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> > ---
> >  Documentation/driver-api/vfio-mediated-device.rst | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/Documentation/driver-api/vfio-mediated-device.rst
> > b/Documentation/driver-api/vfio-mediated-device.rst
> > index 25eb7d5b834b..0ab03d3f5629 100644
> > --- a/Documentation/driver-api/vfio-mediated-device.rst
> > +++ b/Documentation/driver-api/vfio-mediated-device.rst
> > @@ -270,6 +270,7 @@ Directories and Files Under the sysfs for Each mdev
> Device
> >           |--- remove
> >           |--- mdev_type {link to its type}
> >           |--- vendor-specific-attributes [optional]
> > +         |--- alias [optional]
> 
> "optional" implies "not always present" to me, not "might return a read error if
> not available". Don't know if there's a better way to tag this? Or make it really
> optional? :)

May be write it as,

alias [ optional when requested by parent ]

> 
> >
> >  * remove (write only)
> >
> > @@ -281,6 +282,10 @@ Example::
> >
> >  	# echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove
> >
> > +* alias (read only)
> > +Whenever a parent requested to generate an alias, each mdev is
> > +assigned a unique alias by the mdev core. This file shows the alias of the
> mdev device.
> 
> It's not really the parent, but the vendor driver requesting this, right? Also,
At mdev level, it only knows parent->ops structure, whether parent is registered by vendor driver or something else.

> "each mdev" is a bit ambiguous, 
It is in context of the parent. Sentence is not starting with "each mdev".
But may be more verbosely written as,

Whenever a parent requested to generate an alias, Each mdev device of such parent is assigned 
unique alias by the mdev core. This file shows the alias of the mdev device.

> created via that driver. Lastly, if we stick with the "returns an error if not
> implemented" approach, that should also be mentioned here.
Ok. Will spin v3 to describe it.

> 
> > +
> >  Mediated device Hot plug
> >  ------------------------
> >