Re: [PATCH v8 1/1] virtio-media: Add virtio media device specification

On Wed, Jul 9, 2025 at 2:09 PM Albert Esteve <[email protected]> wrote:
>
> On Wed, Jul 9, 2025 at 11:38 AM Albert Esteve <[email protected]> wrote:
> >
> > On Wed, Jul 9, 2025 at 11:32 AM Alex Bennée <[email protected]> wrote:
> > >
> > > Albert Esteve <[email protected]> writes:
> > >
> > > > On Fri, Mar 14, 2025 at 2:26 PM Alexandre Courbot <[email protected]> wrote:
> > > >>
> > > >> Hello Albert,
> > > >>
> > > >> On Tue Mar 4, 2025 at 10:01 PM JST, Albert Esteve wrote:
> > > >> > Virtio-media is an encapsulation of the V4L2 UAPI into
> > > >> > virtio, able to virtualize any video device supported
> > > >> > by V4L2.
> > > >> >
> > > >> > Note that virtio-media does not require the use of a
> > > >> > V4L2 device driver on the host or guest side -
> > > >> > V4L2 is only used as a host-guest protocol,
> > > >> > and both sides are free to convert it from/to any
> > > >> > model that they wish to use.
> > > >>
> > > >> Thank you for your patience with this. I have done a final pass on this
> > > >> version and it looks great to me!
> > > >>
> > > >> Reviewed-by: Alexandre Courbot <[email protected]>
> > > >>
> > > >
> > > > Thanks! Could we please open a voting ballot for these changes?
> > > >
> > > > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/214
> > >
> > > What was the result of the ballot?
> >
> > AFAIU the ballot was approved. There were conflicts with the
> > virtio-1.4 branch, which may have delayed the integration. I've just
> > sent a new version of the patch rebased to virtio-1.4 to try to ease
> > the process.
>
> Adding the diff here on the v8 instead, to avoid having to vote again
> on a new patch version.
> The diff should allow applying the original v8 patch cleanly to
> virtio-1.4. Let me know if this is enough.
>
> ----
> diff --git a/content.tex b/content.tex
> index 59925ae..56b2cb1 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -100,7 +100,7 @@ \section{Feature Bits}\label{sec:Basic Facilities
> of a Virtio Device / Feature B
>  \item[0 to 23, and 50 to 127] Feature bits for the specific device type
>
>  \item[24 to 41] Feature bits reserved for extensions to the queue and
> -  feature negotiation mechanisms
> +  feature negotiation mechanisms, see \ref{sec:Reserved Feature Bits}
>
>  \item[42 to 49, and 128 and above] Feature bits reserved for future extensions.
>  \end{description}
> @@ -493,7 +493,7 @@ \section{Driver Notifications} \label{sec:Basic
> Facilities of a Virtio Device /
>  \section{Exporting Objects}\label{sec:Basic Facilities of a Virtio
> Device / Exporting Objects}
>
>  When an object created by one virtio device needs to be
> -shared with a seperate virtio device, the first device can
> +shared with a separate virtio device, the first device can
>  export the object by generating a UUID which can then
>  be passed to the second device to identify the object.
>
> @@ -503,11 +503,12 @@ \section{Exporting Objects}\label{sec:Basic
> Facilities of a Virtio Device / Expo
>  UUIDs as specified by \hyperref[intro:rfc4122]{[RFC4122]}.
>
>  \input{admin.tex}
> +\input{device-parts.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
> -details of the device and how each step is preformed.  This section
> +details of the device and how each step is performed.  This section
>  is best read along with the bus-specific section which describes
>  how to communicate with the specific device.
>
> @@ -649,7 +650,7 @@ \chapter{Device Types}\label{sec:Device Types}
>
>  Discovering what devices are available and their type is bus-dependent.
>
> -\begin{tabular} { |l|c| }
> +\begin{longtable} { |l|c| }
>  \hline
>  Device ID  &  Virtio Device    \\
>  \hline \hline
> @@ -737,9 +738,17 @@ \chapter{Device Types}\label{sec:Device Types}
>  \hline
>  44         &   ISM device \\
>  \hline
> -45         &   SPI master \\
> +45         &   SPI controller \\
>  \hline
> -\end{tabular}
> +46         &   TEE device \\
> +\hline
> +47         &   CPU balloon device \\
> +\hline
> +48         &   Media device \\
> +\hline
> +49         &   USB controller \\
> +\hline
> +\end{longtable}
>
>  Some of the devices above are unspecified by this document,
>  because they are seen as immature or especially niche.  Be warned
> @@ -767,6 +776,8 @@ \chapter{Device Types}\label{sec:Device Types}
>  \input{device-types/scmi/description.tex}
>  \input{device-types/gpio/description.tex}
>  \input{device-types/pmem/description.tex}
> +\input{device-types/can/description.tex}
> +\input{device-types/spi/description.tex}
>  \input{device-types/media/description.tex}
>
>  \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}
>
> diff --git a/conformance.tex b/conformance.tex
> index 2564034..0856353 100644
> --- a/conformance.tex
> +++ b/conformance.tex
> @@ -33,6 +33,9 @@ \section{Conformance Targets}\label{sec:Conformance
> / Conformance Targets}
>  \ref{sec:Conformance / Driver Conformance / I2C Adapter Driver Conformance},
>  \ref{sec:Conformance / Driver Conformance / SCMI Driver Conformance},
>  \ref{sec:Conformance / Driver Conformance / GPIO Driver Conformance},
> +\ref{sec:Conformance / Driver Conformance / PMEM Driver Conformance},
> +\ref{sec:Conformance / Driver Conformance / CAN Driver Conformance},
> +\ref{sec:Conformance / Driver Conformance / SPI Controller Driver Conformance},
>  \ref{sec:Conformance / Driver Conformance / PMEM Driver Conformance} or
>  \ref{sec:Conformance / Driver Conformance / Media Driver Conformance}.
>
> @@ -61,7 +64,10 @@ \section{Conformance Targets}\label{sec:Conformance
> / Conformance Targets}
>  \ref{sec:Conformance / Device Conformance / I2C Adapter Device Conformance},
>  \ref{sec:Conformance / Device Conformance / SCMI Device Conformance},
>  \ref{sec:Conformance / Device Conformance / GPIO Device Conformance},
> -\ref{sec:Conformance / Device Conformance / PMEM Device Conformance} or
> +\ref{sec:Conformance / Device Conformance / PMEM Device Conformance},
> +\ref{sec:Conformance / Device Conformance / CAN Device Conformance},
> +\ref{sec:Conformance / Device Conformance / SPI Controller Device Conformance},
> +\ref{sec:Conformance / Device Conformance / PMEM Device Conformance},
>  \ref{sec:Conformance / Device Conformance / Media Device Conformance}.
>
>      \item Clause \ref{sec:Conformance / Legacy Interface:
> Transitional Device and Transitional Driver Conformance}.
> @@ -78,6 +84,7 @@ \section{Conformance Targets}\label{sec:Conformance
> / Conformance Targets}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device / Device Reset}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Device Configuration Space}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues}
> +\item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Virtqueues / Virtqueue Reset / Virtqueue Reset}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Message Framing}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Virtqueues / The Virtqueue Descriptor Table}
>  \item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Virtqueues / The Virtqueue Descriptor Table / Indirect Descriptors}
> @@ -96,6 +103,9 @@ \section{Conformance Targets}\label{sec:Conformance
> / Conformance Targets}
>  \item \ref{drivernormative:General Initialization And Device
> Operation / Device Initialization}
>  \item \ref{drivernormative:General Initialization And Device
> Operation / Device Cleanup}
>  \item \ref{drivernormative:Reserved Feature Bits}
> +\item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device and driver
> capabilities}
> +\item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device resource
> objects}
> +\item \ref{drivernormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device parts}
>  \end{itemize}
>
>  \conformance{\subsection}{PCI Driver
> Conformance}\label{sec:Conformance / Driver Conformance / PCI Driver
> Conformance}
> @@ -154,6 +164,8 @@ \section{Conformance
> Targets}\label{sec:Conformance / Conformance Targets}
>  \input{device-types/scmi/driver-conformance.tex}
>  \input{device-types/gpio/driver-conformance.tex}
>  \input{device-types/pmem/driver-conformance.tex}
> +\input{device-types/can/driver-conformance.tex}
> +\input{device-types/spi/driver-conformance.tex}
>  \input{device-types/media/driver-conformance.tex}
>
>  \conformance{\section}{Device Conformance}\label{sec:Conformance /
> Device Conformance}
> @@ -165,6 +177,7 @@ \section{Conformance
> Targets}\label{sec:Conformance / Conformance Targets}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device / Feature Bits}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device / Device Reset}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Device Configuration Space}
> +\item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Virtqueues / Virtqueue Reset / Virtqueue Reset}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Message Framing}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Virtqueues / The Virtqueue Descriptor Table}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Virtqueues / The Virtqueue Descriptor Table / Indirect Descriptors}
> @@ -176,6 +189,9 @@ \section{Conformance
> Targets}\label{sec:Conformance / Conformance Targets}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Packed Virtqueues / Scatter-Gather Support}
>  \item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Shared Memory Regions}
>  \item \ref{devicenormative:Reserved Feature Bits}
> +\item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device and driver
> capabilities}
> +\item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device resource
> objects}
> +\item \ref{devicenormative:Basic Facilities of a Virtio Device /
> Device groups / Group administration commands / Device parts}
>  \end{itemize}
>
>  \conformance{\subsection}{PCI Device
> Conformance}\label{sec:Conformance / Device Conformance / PCI Device
> Conformance}
> @@ -241,6 +257,8 @@ \section{Conformance
> Targets}\label{sec:Conformance / Conformance Targets}
>  \input{device-types/scmi/device-conformance.tex}
>  \input{device-types/gpio/device-conformance.tex}
>  \input{device-types/pmem/device-conformance.tex}
> +\input{device-types/can/device-conformance.tex}
> +\input{device-types/spi/device-conformance.tex}
>  \input{device-types/media/device-conformance.tex}
>
>  \conformance{\section}{Legacy Interface: Transitional Device and
> Transitional Driver Conformance}\label{sec:Conformance / Legacy
> Interface: Transitional Device and Transitional Driver Conformance}
>

A cleaner attempt, noticed a duplication of one listed item. Also
removed the parts of the diff that caused no collision beforehand.

---
diff --git a/content.tex b/content.tex
index 59925ae..56b2cb1 100644
--- a/content.tex
+++ b/content.tex

+\end{longtable}

 Some of the devices above are unspecified by this document,
 because they are seen as immature or especially niche.  Be warned
@@ -767,6 +776,8 @@ \chapter{Device Types}\label{sec:Device Types}
 \input{device-types/scmi/description.tex}
 \input{device-types/gpio/description.tex}
 \input{device-types/pmem/description.tex}
+\input{device-types/can/description.tex}
+\input{device-types/spi/description.tex}
 \input{device-types/media/description.tex}

 \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}

diff --git a/conformance.tex b/conformance.tex
index 2564034..85a227f 100644
--- a/conformance.tex
+++ b/conformance.tex
@@ -33,7 +33,9 @@ \section{Conformance Targets}\label{sec:Conformance
/ Conformance Targets}
 \ref{sec:Conformance / Driver Conformance / I2C Adapter Driver Conformance},
 \ref{sec:Conformance / Driver Conformance / SCMI Driver Conformance},
 \ref{sec:Conformance / Driver Conformance / GPIO Driver Conformance},
-\ref{sec:Conformance / Driver Conformance / PMEM Driver Conformance} or
+\ref{sec:Conformance / Driver Conformance / PMEM Driver Conformance},
+\ref{sec:Conformance / Driver Conformance / CAN Driver Conformance},
+\ref{sec:Conformance / Driver Conformance / SPI Controller Driver
Conformance} or
 \ref{sec:Conformance / Driver Conformance / Media Driver Conformance}.

     \item Clause \ref{sec:Conformance / Legacy Interface:
Transitional Device and Transitional Driver Conformance}.
@@ -61,7 +63,9 @@ \section{Conformance Targets}\label{sec:Conformance
/ Conformance Targets}
 \ref{sec:Conformance / Device Conformance / I2C Adapter Device Conformance},
 \ref{sec:Conformance / Device Conformance / SCMI Device Conformance},
 \ref{sec:Conformance / Device Conformance / GPIO Device Conformance},
-\ref{sec:Conformance / Device Conformance / PMEM Device Conformance} or
+\ref{sec:Conformance / Device Conformance / PMEM Device Conformance},
+\ref{sec:Conformance / Device Conformance / CAN Device Conformance},
+\ref{sec:Conformance / Device Conformance / SPI Controller Device
Conformance} or
 \ref{sec:Conformance / Device Conformance / Media Device Conformance}.

     \item Clause \ref{sec:Conformance / Legacy Interface:
Transitional Device and Transitional Driver Conformance}.
@@ -154,6 +162,8 @@ \section{Conformance
Targets}\label{sec:Conformance / Conformance Targets}
 \input{device-types/scmi/driver-conformance.tex}
 \input{device-types/gpio/driver-conformance.tex}
 \input{device-types/pmem/driver-conformance.tex}
+\input{device-types/can/driver-conformance.tex}
+\input{device-types/spi/driver-conformance.tex}
 \input{device-types/media/driver-conformance.tex}

 \conformance{\section}{Device Conformance}\label{sec:Conformance /
Device Conformance}
@@ -241,6 +255,8 @@ \section{Conformance
Targets}\label{sec:Conformance / Conformance Targets}
 \input{device-types/scmi/device-conformance.tex}
 \input{device-types/gpio/device-conformance.tex}
 \input{device-types/pmem/device-conformance.tex}
+\input{device-types/can/device-conformance.tex}
+\input{device-types/spi/device-conformance.tex}
 \input{device-types/media/device-conformance.tex}

 \conformance{\section}{Legacy Interface: Transitional Device and
Transitional Driver Conformance}\label{sec:Conformance / Legacy
Interface: Transitional Device and Transitional Driver Conformance}

> >
> > >
> > > --
> > > Alex Bennée
> > > Virtualisation Tech Lead @ Linaro
> > >