[virtio-dev] Re: [virtio] [PATCH v11 05/10] pci: add admin vq registers to virtio over pci

Zhu, Lingshan
2023-04-06T07:18:08Z

On 4/3/2023 11:03 PM, Michael S. Tsirkin wrote:
> Add new registers to the PCI common configuration structure.
>
> These registers will be used for querying the indices of the admin
> virtqueues of the owner device. To configure, reset or enable the admin
> virtqueues, the driver should follow existing queue configuration/setup
> sequence.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>
> ---
> dropped Max's S.O.B
> make queue_num not 0 based
> ---
> content.tex | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/content.tex b/content.tex
> index 2eb15fa..5057df2 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -948,6 +948,10 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> le64 queue_device; /* read-write */
> le16 queue_notify_data; /* read-only for driver */
> le16 queue_reset; /* read-write */
> +
> + /* About the administration virtqueue. */
> + le16 admin_queue_index; /* read-only for driver */
> + le16 admin_queue_num; /* read-only for driver */
> };
> \end{lstlisting}
>
> @@ -1033,6 +1037,19 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> This field exists only if VIRTIO_F_RING_RESET has been
> negotiated. (see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset}).
>
> +\item[\field{admin_queue_index}]
> + The device uses this to report the index of the first administration virtqueue.
> + This field is valid only if VIRTIO_F_ADMIN_VQ has been negotiated.
> +\item[\field{admin_queue_num}]
> + The device uses this to report the number of the
> + supported administration virtqueues.
> + Virtqueues with index
> + between \field{admin_queue_index} and (\field{admin_queue_index} +
> + \field{admin_queue_num} - 1) inclusive serve as administration
> + virtqueues.
> + The value 0 indicates no supported administration virtqueues.
> + This field is valid only if VIRTIO_F_ADMIN_VQ has been
> + negotiated.
> \end{description}
>
> \devicenormative{\paragraph}{Common configuration structure layout}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Common configuration structure layout}
> @@ -1119,6 +1136,14 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
> were used before the queue reset.
> (see \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Reset}).
>
> +If VIRTIO_F_ADMIN_VQ has been negotiated, and if the driver
> +configures any administration virtqueues, the driver MUST
> +configure the administration virtqueues using the index
> +in the range \field{admin_queue_index} to
> +\field{admin_queue_index} + \field{admin_queue_num} - 1 inclusive.
> +The driver MAY configure less administration virtqueues than
> +supported by the device.
> +
> \subsubsection{Notification structure layout}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Notification capability}
>
> The notification location is found using the VIRTIO_PCI_CAP_NOTIFY_CFG
> @@ -7686,6 +7711,15 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits}
>
> \item[VIRTIO_F_ADMIN_VQ(41)] This feature indicates that the device exposes one or more
> administration virtqueues.
> + At the moment this feature is only supported for devices using
> + \ref{sec:Virtio Transport Options / Virtio Over PCI
> + Bus}~\nameref{sec:Virtio Transport Options / Virtio Over PCI Bus}
> + as the transport and is reserved for future use for
> + devices using other transports (see
> + \ref{drivernormative:Basic Facilities of a Virtio Device / Feature Bits}
> + and
> + \ref{devicenormative:Basic Facilities of a Virtio Device / Feature Bits} for
> + handling features reserved for future use.
>
> \end{description}
>
Reviewed-by: Zhu Lingshan <lingshan.zhu@intel.com>