[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: [PATCH] virtio-pci: implement VIRTIO_F_RING_STATE
This patch is a follow up for the virtqueue state synchronization series to implement VIRTIO_F_RING_STATE via a dedicated capability for PCI transport. With the help of the STOP status bit, the virtqueue state synchronization for PCI should be self contained. Signed-off-by: Jason Wang <jasowang@redhat.com> --- content.tex | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/content.tex b/content.tex index 284ead0..f1848f7 100644 --- a/content.tex +++ b/content.tex @@ -878,6 +878,8 @@ \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 +/* General Virtqueue State */ +#define VIRTIO_PCI_CAP_RING_STATE 10 \end{lstlisting} Any other value is reserved for future use. @@ -1434,6 +1436,36 @@ \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{General Virtqueue State}\label{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / General Virtqueue State} + +The VITIO_PCI_CAP_RING_STATE capability is for the driver to configure +the virtqueue state(see \ref{sec:Virtqueues / Virtqueue State}): + +The capability is immediately followed by an additional field like so: + +\begin{lstlisting} +struct virtio_pci_cfg_cap { + struct virtio_pci_cap cap; + le16 queue_select; /* read-write */ + le16 avail_state; /* read-write */ + le16 used_state; /* read-write */ +}; +\end{lstlisting} + +\begin{description} +\item[\field{queue_select}] + Queue Select. The driver selects which virtqueue the following + fields refer to. +\item[\field{avail_state}] + The driver writes and reads available state here. +\item[\field{used_state}] + The driver writes and reads used state here. +\end{description} + +\devicenormative{\paragraph}{General Virtqueue State}{Virtio Transport Options / Virtio Over PCI Bus / PCI Device Layout / General Virtqueue State} + +The device MUST present at least one VIRTIO_PCI_CAP_RING_STATE capability if VITIO_F_RING_STATE is negotiated. + \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 -- 2.25.1
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]