Re: [PATCH v5 1/7] Introduce device group

[Max Gurtovoy <mgurtovoy@nvidia.com>]

Hi MST,

On 5/15/2022 6:25 PM, Michael S. Tsirkin wrote:
> On Wed, Apr 27, 2022 at 01:58:18AM +0300, Max Gurtovoy wrote:
> > Each device group has a type. For now, define initial type of device
> > groups: Type 1 - A virtio PCI SR-IOV physical function (PF) and its PCI
> > SR-IOV virtual functions (VFs). This group may contain one or more
> > virtio devices.
> >
> > Each device within a device group has a unique identifier. This
> > identifier is the virtio device id (vdev_id).
> >
> > Reviewed-by: Parav Pandit <parav@nvidia.com>
> > Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
> > ---
> >   introduction.tex | 12 ++++++++++++
> >   1 file changed, 12 insertions(+)
> >
> > diff --git a/introduction.tex b/introduction.tex
> > index 4dc7085..4358ab1 100644
> > --- a/introduction.tex
> > +++ b/introduction.tex
> > @@ -155,6 +155,18 @@ \subsection{Transition from earlier specification drafts}\label{sec:Transition f
> >   sections tagged "Legacy Interface" in the section title.
> >   These highlight the changes made since the earlier drafts.
> >   
> > +\subsection{Device group}\label{sec:Introduction / Terminology / Device group}
> > +
> > +A device group includes one or more virtio devices.
> > +Each virtio device has a unique virtio device id (vdev_id) within a device group. A valid vdev_id is a 64-bit field in the range of
> > +0x0 - 0xFFFFFFFFFFFFFFF0. Vdev_id 0xFFFFFFFFFFFFFFFF is a value that refers to all devices in a device group and isn't a valid vdev_id.
> > +
> > +For now, the supported device groups are:
> > +\begin{enumerate}
> > +\item Type 1 - A virtio PCI SR-IOV physical function (PF) and its PCI SR-IOV virtual functions (VFs). For this group type, the PF device has vdev_id that is equal to 0
> > +and the VF devices have vdev_id's that are equal to their vf_number (according to the PCI SR-IOV specification).
> > +\end{enumerate}
> > +
> >   \section{Structure Specifications}\label{sec:Structure Specifications}
>
> In context of virtualization type 1 already refers to a specific type
> of hypervisor.
>
> I suggest simply "SR-IOV type" - this way users do not need to remember
> special terminology.

This is 12 lines addition commit with simple definition.

I didn't mentioned hypervisors here.

I will stick to your suggestion and use name instead of numbers 
(although I don't understand how can a use that knows how to read spec 
will be confused here), but I would like Jason and Cornelia to ack on 
this during this review cycle.

When we'll get 3 acks on this name - I'll update it for v6.

> >   Many device and driver in-memory structure layouts are documented using
> > --
> > 2.21.0