On Mon, Apr 04, 2022 at 06:52:27PM +0300, Max Gurtovoy wrote:
>
> On 4/4/2022 4:04 PM, Michael S. Tsirkin wrote:
> > On Wed, Mar 02, 2022 at 05:56:08PM +0200, Max Gurtovoy wrote:
> > > This new structure will be used for adding new miscellaneous registers
> > > for a virtio device configuration layout.
> > >
> > > For now, only admin_queue_index register is added. Admin virtqueue index
> > > does not depend on the device type. Hence, add a PCI capability to read
> > > the admin virtqueue index.
> > >
> > > Reviewed-by: Parav Pandit <[email protected]>
> > > Signed-off-by: Max Gurtovoy <[email protected]>
> > > ---
> > > conformance.tex | 2 ++
> > > content.tex | 25 +++++++++++++++++++++++++
> > > 2 files changed, 27 insertions(+)
> > >
> > > diff --git a/conformance.tex b/conformance.tex
> > > index 129831c..e31645e 100644
> > > --- a/conformance.tex
> > > +++ b/conformance.tex
> > > @@ -102,6 +102,7 @@ \section{Conformance Targets}\label{sec:Conformance /
> > > Conformance Targets}
> > > \item \ref{drivernormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI Device Layout / PCI configuration access capability}
> > > \item \ref{drivernormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI-specific Initialization And Device Operation / Device
> > > Initialization / MSI-X Vector Configuration}
> > > \item \ref{drivernormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI-specific Initialization And Device Operation / Notification of
> > > Device Configuration Changes}
> > > +\item \ref{drivernormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI Device Layout / Miscellaneous configuration structure layout}
> > > \end{itemize}
> > > \conformance{\subsection}{MMIO Driver
> > > Conformance}\label{sec:Conformance / Driver Conformance / MMIO Driver
> > > Conformance}
> > > @@ -363,6 +364,7 @@ \section{Conformance Targets}\label{sec:Conformance /
> > > Conformance Targets}
> > > \item \ref{devicenormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI-specific Initialization And Device Operation / Device
> > > Initialization / MSI-X Vector Configuration}
> > > \item \ref{devicenormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI-specific Initialization And Device Operation / Used Buffer
> > > Notifications}
> > > \item \ref{devicenormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI-specific Initialization And Device Operation / Notification of
> > > Device Configuration Changes}
> > > +\item \ref{devicenormative:Virtio Transport Options / Virtio Over PCI
> > > Bus / PCI Device Layout / Miscellaneous configuration structure layout}
> > > \end{itemize}
> > > \conformance{\subsection}{MMIO Device
> > > Conformance}\label{sec:Conformance / Device Conformance / MMIO Device
> > > Conformance}
> > > diff --git a/content.tex b/content.tex
> > > index 163cb34..bf46192 100644
> > > --- a/content.tex
> > > +++ b/content.tex
> > > @@ -712,6 +712,7 @@ \subsection{Virtio Structure PCI
> > > Capabilities}\label{sec:Virtio Transport Option
> > > \item ISR Status
> > > \item Device-specific configuration (optional)
> > > \item PCI configuration access
> > > +\item Miscellaneous configuration
> > > \end{itemize}
> > > Each structure can be mapped by a Base Address register (BAR) belonging
> > > to
> > > @@ -771,6 +772,8 @@ \subsection{Virtio Structure PCI
> > > Capabilities}\label{sec:Virtio Transport Option
> > > #define VIRTIO_PCI_CAP_SHARED_MEMORY_CFG 8
> > > /* Vendor-specific data */
> > > #define VIRTIO_PCI_CAP_VENDOR_CFG 9
> > > +/* Miscellaneous configuration */
> > > +#define VIRTIO_PCI_CAP_MISC_CFG 10
> > > \end{lstlisting}
> > > Any other value is reserved for future use.
> > > @@ -1352,6 +1355,28 @@ \subsubsection{PCI configuration access
> > > capability}\label{sec:Virtio Transport O
> > > specified by some other Virtio Structure PCI Capability
> > > of type other than \field{VIRTIO_PCI_CAP_PCI_CFG}.
> > > +\subsubsection{Miscellaneous configuration structure
> > > layout}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI
> > > Device Layout / Miscellaneous configuration structure layout}
> > > +
> > > +The miscellaneous configuration structure is found at the bar and offset
> > > within the VIRTIO_PCI_CAP_MISC_CFG capability.
> > > +Its layout is below.
> > > +\begin{lstlisting}
> > > +struct virtio_pci_misc_cfg {
> > > + le16 admin_queue_index; /* read-only for driver */
> > > +};
> > > +\end{lstlisting}
> > > +
> > > +\begin{description}
> > > +\item[\field{admin_queue_index}]
> > > + The device uses this to report the index of the admin virtqueue.
> > > + This field is valid only if VIRTIO_F_ADMIN_VQ is set.
> > > +\end{description}
> > > +
> > > +\devicenormative{\paragraph}{Miscellaneous configuration structure
> > > layout}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device
> > > Layout / Miscellaneous configuration structure layout}
> > > +The device MUST present a valid \field{admin_queue_index} when
> > > VIRTIO_F_ADMIN_VQ is set.
besides, is must have a misc config capability if it has
VIRTIO_F_ADMIN_VQ.
> > > +
> > > +\drivernormative{\paragraph}{Miscellaneous configuration structure
> > > layout}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device
> > > Layout / Miscellaneous configuration structure layout}
> > > +The driver MUST use the value of \field{admin_queue_index} to configure
> > > the admin virtqueue. For more details on virtqueue configuration see
> > > section \ref{sec:Virtio Transport Options / Virtio Over PCI Bus /
> > > PCI-specific Initialization And Device Operation / Device Initialization
> > > / Virtqueue Configuration}.
> > > +
> > > \subsubsection{Legacy Interfaces: A Note on PCI Device
> > > Layout}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI
> > > Device Layout / Legacy Interfaces: A Note on PCI Device Layout}
> > > Transitional devices MUST present part of configuration
> > This is useful, but I think we'll want this for all transports then.
>
> I think that adding more transports can be incremental and should be a no-go
> for merging this patch set.
>
> We discussed this in the previous version and nobody had a conclusion on the
> right approach for other transports.
I think this referred to the msi-x thing not the the
misc config capability - this is the first version where
that appeared, right? Cornelia what do you think?
In any case, in that case maybe besides saying it's transport-specific
also mention that it is currently only defined for the PCI transport.
> >
> >
> > > --
> > > 2.21.0
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