On Thu, Feb 09, 2023 at 03:00:58PM +0000, David Edmondson wrote:
>
> On Thursday, 2023-02-09 at 07:13:36 -05, Michael S. Tsirkin wrote:
>
> Each device group has a type. For now, define one initial group:
> >
>
> SR-IOV type - PCI SR-IOV virtual functions (VFs) of a given
>
> PCI SR-IOV physical function (PF). This group may contain one or more
>
> virtio devices.
>
> The specification says zero or more generally and nothing to refine that
> for SR-IOV groups.
Well it says:
(SR-IOV) physical function (PF) device as the owner and includes
all its SR-IOV virtual functions (VFs) as members (see
\hyperref[intro:PCIe]{[PCIe]}).
how can that be zero?
> >
>
> Each device within a group has a unique identifier. This identifier
>
> is the group member identifier.
> >
>
> Note: one can argue both ways whether the new device group handling
>
> functionality (this and following patches) is closer
>
> to a new device type or a new transport type.
> >
>
> However, I expect that we will add more features in the near future. To
>
> facilitate this as much as possible of the text is located in the new
>
> admin chapter.
> >
>
> I did my best to minimize transport-specific text.
> >
>
> Signed-off-by: Max Gurtovoy <>
>
> Signed-off-by: Michael S. Tsirkin <>
> > ---
>
> admin.tex
| 49 +++++++++++++++++++++++++++++++++++++++++++++++++
>
> content.tex | 2 ++
>
> 2 files changed, 51 insertions(+)
>
> create mode 100644 admin.tex
> >
>
> diff --git a/admin.tex b/admin.tex
>
> new file mode 100644
>
> index 0000000..2bc7322
> > --- /dev/null
> > +++ b/admin.tex
> > @@ -0,0 +1,49 @@
> > +\section{Device groups}\label{sec:Basic Facilities of a Virtio Device / Device groups}
> > +
> > +It is occasionally useful to have a device control a group of
> > +other devices. Terminology used in such cases:
> > +
> > +\begin{description}
> > +\item[Device group]
> > +
or just group, includes zero or more devices.
> > +\item[Owner device]
> > +
or owner, the device controlling the group.
> > +\item[Member device]
> > +
a device within a group. The owner device itself is not
> > + a member of the group.
> > +\item[Member identifier]
> > +
each member has this identifier, unique within the group
> > + and used to address it through the owner device.
> > +\item[Group type identifier]
> > + specifies what kind of member devices there are in a
> > + group, how is the member identifier is interpreted
> > + and what kind of control the owner has.
> > + A given owner can control a single group of a given type,
> > + thus the type and the owner together identify the group.
> > + \footnote{Even though some group types only support
> > + specific transports, group type identifiers
> > + are global rather than transport-specific -
> > + we don't expect a flood of new group types.}
> > +\end{description}
> > +
> > +The following group types, and their identifiers, are currently specified):
> > +\begin{description}
> > +\item[SR-IOV group type (0x1)]
> > +This device group has a PCI Single Root I/O Virtualization
> > +(SR-IOV) physical function (PF) device as the owner and includes
> > +all its SR-IOV virtual functions (VFs) as members (see
> > +\hyperref[intro:PCIe]{[PCIe]}).
> > +
> > +The PF device itself is not a member of the group.
> > +
> > +The group type identifier for this group is 0x1.
> > +
> > +A member identifier for this group can have a value 0x1 to 0xFFFF
> > +and equals the SR-IOV VF number of the member device (see
> > +\hyperref[intro:PCIe]{[PCIe]}).
> > +
> > +Both owner and member devices for this group type use the Virtio
> > +PCI transport (see \ref{sec:Virtio Transport Options / Virtio Over PCI Bus}).
> > +\end{description}
> > +
> > +
>
> diff --git a/content.tex b/content.tex
>
> index 0c2d917..ffe45c4 100644
> > --- a/content.tex
> > +++ b/content.tex
> > @@ -491,6 +491,8 @@ \section{Exporting Objects}\label{sec:Basic Facilities of a Virtio Device / Expo
>
> types. It is RECOMMENDED that devices generate version 4
>
> UUIDs as specified by \hyperref[intro:rfc4122]{[RFC4122]}.
> >
> > +\input{admin.tex}
> > +
> > \chapter{General Initialization And Device Operation}\label{sec:General Initialization And Device Operation}
> >
>
> We start with an overview of device initialization, then expand on the
> --
> Tell her I'll be waiting, in the usual place.
