Re: [External] Re: [virtio-comment] [PATCH v5] virtio-vsock: add description for datagram type
On Tue, Aug 31, 2021 at 06:24:34PM -0700, Jiang Wang . wrote:
> On Tue, Aug 31, 2021 at 6:13 PM Michael S. Tsirkin wrote:
> >
> > On Thu, Jun 10, 2021 at 06:12:03PM +, Jiang Wang wrote:
> > > Add supports for datagram type for virtio-vsock. Datagram
> > > sockets are connectionless and unreliable. To avoid contention
> > > with stream and other sockets, add two more virtqueues and
> > > a new feature bit to identify if those two new queues exist or not.
> > >
> > > Also add descriptions for resource management of datagram, which
> > > does not use the existing credit update mechanism associated with
> > > stream sockets.
> > >
> > > Signed-off-by: Jiang Wang
> >
> > Is this going anywhere? Linux with this included was just released but
> > if no one has the cycles to work on the spec then it's not too late to
> > disable the guest code in a stable@ patch.
> >
>
> Hi Michael,
>
> I am still working on this (fixing the migration issue), but would
> like to know if there are any more
> comments or not. I did not notice any commits related to vsock
> dgram merged to Linux kernel, could you show me the commit link?
>
> Thanks and regards,
>
> Jiang
My bad I was thinking of seqpacket. I see that description
was not posted as well, so all is well.
> > > ---
> > >
> > > V2: addressed the comments for the previous version.
> > > V3: add description for the mergeable receive buffer.
> > > V4: add a feature bit for stream and reserver a bit for seqpacket.
> > > Fix mrg_rxbuf related sentences.
> > > V5: removed mergeable rx buffer part. It will go to a
> > > separate patch. Fixed comments about tx, rx, feature bit etc.
> > >
> > > virtio-vsock.tex | 71
> > > +++-
> > > 1 file changed, 60 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/virtio-vsock.tex b/virtio-vsock.tex
> > > index da7e641..26a62ac 100644
> > > --- a/virtio-vsock.tex
> > > +++ b/virtio-vsock.tex
> > > @@ -9,14 +9,37 @@ \subsection{Device ID}\label{sec:Device Types / Socket
> > > Device / Device ID}
> > >
> > > \subsection{Virtqueues}\label{sec:Device Types / Socket Device /
> > > Virtqueues}
> > > \begin{description}
> > > -\item[0] rx
> > > -\item[1] tx
> > > +\item[0] stream rx
> > > +\item[1] stream tx
> > > +\item[2] datagram rx
> > > +\item[3] datagram tx
> > > +\item[4] event
> > > +\end{description}
> > > +The virtio socket device uses 5 queues if feature bit
> > > VIRTIO_VSOCK_F_DRGAM is set. Otherwise, it
> > > +only uses 3 queues, as the following.
> > > +
> > > +\begin{description}
> > > +\item[0] stream rx
> > > +\item[1] stream tx
> > > \item[2] event
> > > \end{description}
> > >
> > > +When behavior differs between stream and datagram rx/tx virtqueues
> > > +their full names are used. Common behavior is simply described in
> > > +terms of rx/tx virtqueues and applies to both stream and datagram
> > > +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_STREAM (0)] Device has support for stream socket
> > > type.
> > > +\end{description}
> > > +
> > > +\begin{description}
> > > +\item[VIRTIO_VSOCK_F_DGRAM (2)] Device has support for datagram socket
> > > type.
> > > +\end{description}
> > > +
> > > +If no feature bits are defined, assume device only supports stream
> > > socket type.
> > >
> > > \subsection{Device configuration layout}\label{sec:Device Types / Socket
> > > Device / Device configuration layout}
> > >
> > > @@ -107,6 +130,9 @@ \subsection{Device Operation}\label{sec:Device Types
> > > / Socket Device / Device Op
> > >
> > > \subsubsection{Virtqueue Flow Control}\label{sec:Device Types / Socket
> > > Device / Device Operation / Virtqueue Flow Control}
> > >
> > > +Flow control applies to stream sockets; datagram sockets do not have
> > > +flow control.
> > > +
> > > The tx virtqueue carries packets initiated by applications and replies to
> > > received packets. The rx virtqueue carries packets initiated by the
> > > device and
> > > replies to previously transmitted packets.
> > > @@ -140,12 +166,15 @@ \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 for stream
> > > -socket types.
> > > +Currently stream and datagram (dgram) sockets are supported.
> > > \field{type} is 1 for stream
> > > +socket types. \field{type} is 3 for dgram socket types.
> > >
> > > Stream sockets provide in-order, guaranteed, connection-oriented delivery
> > > without message boundaries.
> > >
> > > +Datagram sockets provide unordered, unreliable, connectionless messages
> > >
Re: [External] Re: [virtio-comment] [PATCH v5] virtio-vsock: add description for datagram type
On Tue, Aug 31, 2021 at 6:13 PM Michael S. Tsirkin wrote:
>
> On Thu, Jun 10, 2021 at 06:12:03PM +, Jiang Wang wrote:
> > Add supports for datagram type for virtio-vsock. Datagram
> > sockets are connectionless and unreliable. To avoid contention
> > with stream and other sockets, add two more virtqueues and
> > a new feature bit to identify if those two new queues exist or not.
> >
> > Also add descriptions for resource management of datagram, which
> > does not use the existing credit update mechanism associated with
> > stream sockets.
> >
> > Signed-off-by: Jiang Wang
>
> Is this going anywhere? Linux with this included was just released but
> if no one has the cycles to work on the spec then it's not too late to
> disable the guest code in a stable@ patch.
>
Hi Michael,
I am still working on this (fixing the migration issue), but would
like to know if there are any more
comments or not. I did not notice any commits related to vsock
dgram merged to Linux kernel, could you show me the commit link?
Thanks and regards,
Jiang
> > ---
> >
> > V2: addressed the comments for the previous version.
> > V3: add description for the mergeable receive buffer.
> > V4: add a feature bit for stream and reserver a bit for seqpacket.
> > Fix mrg_rxbuf related sentences.
> > V5: removed mergeable rx buffer part. It will go to a
> > separate patch. Fixed comments about tx, rx, feature bit etc.
> >
> > virtio-vsock.tex | 71
> > +++-
> > 1 file changed, 60 insertions(+), 11 deletions(-)
> >
> > diff --git a/virtio-vsock.tex b/virtio-vsock.tex
> > index da7e641..26a62ac 100644
> > --- a/virtio-vsock.tex
> > +++ b/virtio-vsock.tex
> > @@ -9,14 +9,37 @@ \subsection{Device ID}\label{sec:Device Types / Socket
> > Device / Device ID}
> >
> > \subsection{Virtqueues}\label{sec:Device Types / Socket Device /
> > Virtqueues}
> > \begin{description}
> > -\item[0] rx
> > -\item[1] tx
> > +\item[0] stream rx
> > +\item[1] stream tx
> > +\item[2] datagram rx
> > +\item[3] datagram tx
> > +\item[4] event
> > +\end{description}
> > +The virtio socket device uses 5 queues if feature bit VIRTIO_VSOCK_F_DRGAM
> > is set. Otherwise, it
> > +only uses 3 queues, as the following.
> > +
> > +\begin{description}
> > +\item[0] stream rx
> > +\item[1] stream tx
> > \item[2] event
> > \end{description}
> >
> > +When behavior differs between stream and datagram rx/tx virtqueues
> > +their full names are used. Common behavior is simply described in
> > +terms of rx/tx virtqueues and applies to both stream and datagram
> > +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_STREAM (0)] Device has support for stream socket type.
> > +\end{description}
> > +
> > +\begin{description}
> > +\item[VIRTIO_VSOCK_F_DGRAM (2)] Device has support for datagram socket
> > type.
> > +\end{description}
> > +
> > +If no feature bits are defined, assume device only supports stream socket
> > type.
> >
> > \subsection{Device configuration layout}\label{sec:Device Types / Socket
> > Device / Device configuration layout}
> >
> > @@ -107,6 +130,9 @@ \subsection{Device Operation}\label{sec:Device Types /
> > Socket Device / Device Op
> >
> > \subsubsection{Virtqueue Flow Control}\label{sec:Device Types / Socket
> > Device / Device Operation / Virtqueue Flow Control}
> >
> > +Flow control applies to stream sockets; datagram sockets do not have
> > +flow control.
> > +
> > The tx virtqueue carries packets initiated by applications and replies to
> > received packets. The rx virtqueue carries packets initiated by the
> > device and
> > replies to previously transmitted packets.
> > @@ -140,12 +166,15 @@ \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 for stream
> > -socket types.
> > +Currently stream and datagram (dgram) sockets are supported. \field{type}
> > is 1 for stream
> > +socket types. \field{type} is 3 for dgram socket types.
> >
> > Stream sockets provide in-order, guaranteed, connection-oriented delivery
> > without message boundaries.
> >
> > +Datagram sockets provide unordered, unreliable, connectionless messages
> > +with message boundaries and a maximum length.
> > +
> > \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
> > stream sockets. The guest and the device publish how much buffer space is
> > @@ -162,7 +191,7 @@ \subsubsection{Buffer Space
> >
