RE: [PATCH] virtio-net: Add device migration context fields

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Thursday, November 2, 2023 7:25 PM
> 
> On Thu, Nov 02, 2023 at 03:19:46PM +0200, Parav Pandit wrote:
> > Expand device migration context for fields such as mac table, vlan
> > table, mq config, rss config.
> >
> > All of them utilizes already defined infrastructure.
> >
> > This patch is on top of [1].
> >
> > [1]
> > https://lists.oasis-open.org/archives/virtio-comment/202310/msg00469.h
> > tml
> >
> > Signed-off-by: Parav Pandit <parav@nvidia.com>
> > ---
> >  device-context.tex                  |  2 +-
> >  device-types/net/description.tex    |  2 +
> >  device-types/net/device-context.tex | 58
> > +++++++++++++++++++++++++++++
> >  3 files changed, 61 insertions(+), 1 deletion(-)  create mode 100644
> > device-types/net/device-context.tex
> >
> > diff --git a/device-context.tex b/device-context.tex index
> > ab19fc9..348bb25 100644
> > --- a/device-context.tex
> > +++ b/device-context.tex
> > @@ -57,7 +57,7 @@ \section{Device Context}\label{sec:Basic Facilities
> > of a Virtio Device / Device  \hline
> >  0x1000 & VIRTIO_DEV_CTX_DEV_CFG & Provides device specific
> > configuration \\  \hline
> > -0x1001 - 0x1FFF & - & Device type specific range reserved for future
> > \\
> > +0x1001 - 0x1FFF & - & Device type specific range defined by the
> > +specific device type \\
> >  \hline
> >  \hline
> >  0x2000 - 0xFFFF & - & Reserved for future \\ diff --git
> > a/device-types/net/description.tex b/device-types/net/description.tex
> > index 76585b0..13490ec 100644
> > --- a/device-types/net/description.tex
> > +++ b/device-types/net/description.tex
> > @@ -1805,6 +1805,8 @@ \subsubsection{Control
> > Virtqueue}\label{sec:Device Types / Network Device / Devi
> >
> >  Upon reset, a device MUST initialize all coalescing parameters to 0.
> >
> > +\input{device-types/net/device-context.tex}
> > +
> 
> I don't think we need to split this to a separate file.
> 
I found it more maintainable but ok, will keep to one file.
> >  \subsubsection{Legacy Interface: Framing
> > Requirements}\label{sec:Device  Types / Network Device / Legacy
> > Interface: Framing Requirements}
> >
> > diff --git a/device-types/net/device-context.tex
> > b/device-types/net/device-context.tex
> > new file mode 100644
> > index 0000000..b78cf37
> > --- /dev/null
> > +++ b/device-types/net/device-context.tex
> > @@ -0,0 +1,58 @@
> > +\subsection{Device Context}\label{sec:Device Types / Network Device /
> > +Device Operation / Device Context}
> > +
> > +\begin{table}
> > +\caption{\label{tab:Network Device Context Fields} Network Device
> > +Context Fields} \begin{tabularx}{\textwidth}{ |l||l|X| } \hline Type
> > +& Name & Description \\ \hline \hline \hline
> > +0x1001 & VIRTIO_DEV_CTX_NET_MAC_ADDR_FILTER_TABLE & Provides
> MAC
> > +Address filter table \\ \hline
> > +0x1002 & VIRTIO_DEV_CTX_NET_VLAN_FILTER_TABLE & Provides VLAN
> filter
> > +table \\ \hline
> > +0x1003 & VIRTIO_DEV_CTX_NET_MQ_PAIRS & Provides multi queue
> > +configuration \\ \hline
> > +0x1004 & VIRTIO_DEV_CTX_NET_RSS_CONFIG & Provides RSS configuration
> > +\\ \hline
> > +0x1005 - 0x1FFF & - & reserved for future \\ \hline \hline
> 
> Where are these 0x1XXX values coming from?
> 
At beginning of the patch, device specific range is listed starting from 0x1000.

> 
> > +\end{tabularx}
> > +\end{table}
> > +
> > +\subsubsection{MAC Address Filter Table Context}\label{sec:Device
> > +Types / Network Device / Device Operation / Device Context / MAC
> > +Address Filter Table Context}
> > +
> > +For the field VIRTIO_DEV_CTX_NET_MAC_TABLE, \field{type} is set to
> 0x1001.
> > +The \field{value} is in format of \field{struct virtio_net_ctrl_mac}
> > +as listed in section \label{sec:Device Types / Network Device /
> > +Device Operation / Control Virtqueue / Setting MAC Address Filtering}.
> > +The \field{length} is the length of \field{struct virtio_net_ctrl_mac}.
> > +
> > +\subsubsection{VLAN Filter Table Context}\label{sec:Device Types /
> > +Network Device / Device Operation / Device Context / VLAN Filter
> > +Table Context}
> > +
> > +For the field VIRTIO_DEV_CTX_NET_VLAN_FILTER_TABLE, \field{type} is set
> to 0x1002.
> > +The \field{value} is in format of \field{struct virtio_dev_ctx_net_vlan_table}.
> > +The \field{length} is the length of \field{struct
> virtio_dev_ctx_net_vlan_table}.
> 
> in bytes?
> 
Yes, will add.

> > +
> > +\begin{lstlisting}
> > +struct virtio_dev_ctx_net_vlan_table {
> > +        le16 vlan[];
> > +};
> > +\end{lstlisting}
> 
> 
> are you going to document this or do you think this is self-explanatory?
> 
I wanted to add to the net section as it is already described there, so that it will be self-explanatory here.
Will cover there in v2.

> > +
> > +\subsubsection{Multiqueue Pairs Context}\label{sec:Device Types /
> > +Network Device / Device Operation / Device Context / Multiqueue Pairs
> > +Context}
> > +
> > +For the field VIRTIO_DEV_CTX_NET_MQ_PAIRS, \field{type} is set to 0x1003.
> > +The \field{value} is in format of \field{struct
> > +virtio_net_ctrl_mq_pairs_set} as listed in section \label{sec:Device
> > +Types / Network Device / Device Operation / Control Virtqueue / Automatic
> receive steering in multiqueue mode}.
> > +The \field{length} is the length of \field{struct virtio_net_ctrl_mq_pairs_set}.
> > +
> > +\subsubsection{Receive Side Scaling Context}\label{sec:Device Types /
> > +Network Device / Device Operation / Device Context / Receive Side
> > +Scaling Context}
> > +
> > +For the field VIRTIO_DEV_CTX_NET_RSS_CONFIG, \field{type} is set to
> 0x1004.
> > +The \field{value} is in format of \field{struct
> > +virtio_net_rss_config} as listed in section \label{sec:Device Types /
> > +Network Device / Device Operation / Control Virtqueue / Receive-side
> scaling (RSS) / Setting RSS parameters}.
> > +The \field{length} is the length of \field{struct virtio_net_rss_config}.
> 
> 
> 
> 
> > --
> > 2.34.1