Re: [RFC PATCH v8 2/2] virtio-vsock: SOCK_SEQPACKET description

This adds description of SOCK_SEQPACKET socket type
support for virtio-vsock.

Signed-off-by: Arseny Krasnov <redacted>
---
virtio-vsock.tex | 43 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/virtio-vsock.tex b/virtio-vsock.tex
index ad57f9d..51d785a 100644
--- a/virtio-vsock.tex
+++ b/virtio-vsock.tex

@@ -16,7 +16,10 @@ \subsection{Virtqueues}\label{sec:Device Types / Socket Device / Virtqueues}

\subsection{Feature bits}\label{sec:Device Types / Socket Device / Feature bits}

-There are currently no feature bits defined for this device.
+\begin{description}
+\item VIRTIO_VSOCK_F_SEQPACKET (1) SOCK_SEQPACKET socket type is
+    supported.
+\end{description}

\subsection{Device configuration layout}\label{sec:Device Types / Socket Device / Device configuration layout}

@@ -135,15 +138,17 @@ \subsubsection{Addressing}\label{sec:Device Types / Socket Device / Device Opera

consists of a (cid, port number) tuple. The header fields used for this are
\field{src_cid}, \field{src_port}, \field{dst_cid}, and \field{dst_port}.

-Currently only stream sockets are supported. \field{type} is 1 (VIRTIO_VSOCK_TYPE_STREAM)
-for stream socket types.
+Currently stream and seqpacket sockets are supported. \field{type} is 1 (VIRTIO_VSOCK_TYPE_STREAM)
+for stream socket types, and 2 (VIRTIO_VSOCK_TYPE_SEQPACKET) for seqpacket socket types.

\begin{lstlisting}
-#define VIRTIO_VSOCK_TYPE_STREAM 1
+#define VIRTIO_VSOCK_TYPE_STREAM    1
+#define VIRTIO_VSOCK_TYPE_SEQPACKET 2
\end{lstlisting}

Stream sockets provide in-order, guaranteed, connection-oriented delivery
-without message boundaries.
+without message boundaries. Seqpacket sockets provide in-order, 
guaranteed,
+connection-oriented delivery with message and record boundaries.

\subsubsection{Buffer Space Management}\label{sec:Device Types / Socket Device / Device Operation / Buffer Space Management}
\field{buf_alloc} and \field{fwd_cnt} are used for buffer space management of

@@ -244,6 +249,34 @@ \subsubsection{Stream Sockets}\label{sec:Device Types / Socket Device / Device O

destination) address tuple for a new connection while the other peer is still
processing the old connection.

+\subsubsection{Seqpacket Sockets}\label{sec:Device Types / Socket Device / Device Operation / Seqpacket Sockets}
+
+\paragraph{Message and record boundaries}\label{sec:Device Types / Socket Device / Device Operation / Seqpacket Sockets / Boundaries}
+Two types of boundaries supported: message and record boundaries.
+
+Message is data, sent by single system call. Message boundary means