[virtio-dev] [PATCH 5/5] virtio-pci: implement VIRTIO_F_QUEUE_STATE

Zhu Lingshan
2023-09-06T08:17:28Z

This patch adds two new le16 fields to common configuration structure
to support VIRTIO_F_QUEUE_STATE in PCI transport layer.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
---
transport-pci.tex | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/transport-pci.tex b/transport-pci.tex
index a5c6719..3161519 100644
--- a/transport-pci.tex
+++ b/transport-pci.tex
@@ -325,6 +325,10 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
/* About the administration virtqueue. */
le16 admin_queue_index; /* read-only for driver */
le16 admin_queue_num; /* read-only for driver */
+
+ /* Virtqueue state */
+ le16 queue_avail_state; /* read-write */
+ le16 queue_used_state; /* read-write */
};
\end{lstlisting}

@@ -428,6 +432,17 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
The value 0 indicates no supported administration virtqueues.
This field is valid only if VIRTIO_F_ADMIN_VQ has been
negotiated.
+
+\item[\field{queue_avail_state}]
+ This field is valid only if VIRTIO_F_QUEUE_STATE has been
+ negotiated. The driver sets and gets the available state of
+ the virtqueue here (see \ref{sec:Virtqueues / Virtqueue State}).
+
+\item[\field{queue_used_state}]
+ This field is valid only if VIRTIO_F_QUEUE_STATE has been
+ negotiated. The driver sets and gets the used state of the
+ virtqueue here (see \ref{sec:Virtqueues / Virtqueue State}).
+
\end{description}

\devicenormative{\paragraph}{Common configuration structure layout}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / Common configuration structure layout}
@@ -488,6 +503,9 @@ \subsubsection{Common configuration structure layout}\label{sec:Virtio Transport
present either a value of 0 or a power of 2 in
\field{queue_size}.

+If VIRTIO_F_QUEUE_STATE has not been negotiated, the device MUST ignore
+any accesses to \field{queue_avail_state} and \field{queue_used_state}.
+
If VIRTIO_F_ADMIN_VQ has been negotiated, the value
\field{admin_queue_index} MUST be equal to, or bigger than
\field{num_queues}; also, \field{admin_queue_num} MUST be
--
2.35.3