On Wed, 29 Sep 2021 11:24:50 +0800, Jason Wang <jasow...@redhat.com> wrote: > On Wed, Sep 29, 2021 at 11:14 AM Xuan Zhuo <xuanz...@linux.alibaba.com> wrote: > > > > On Wed, 29 Sep 2021 11:07:21 +0800, Jason Wang <jasow...@redhat.com> wrote: > > > On Wed, Sep 29, 2021 at 10:34 AM Xuan Zhuo <xuanz...@linux.alibaba.com> > > > wrote: > > > > > > > > On Wed, 29 Sep 2021 10:07:52 +0800, Jason Wang <jasow...@redhat.com> > > > > wrote: > > > > > On Tue, Sep 28, 2021 at 11:48 AM Xuan Zhuo > > > > > <xuanz...@linux.alibaba.com> wrote: > > > > > > > > > > > > On Tue, 28 Sep 2021 11:25:40 +0800, Jason Wang > > > > > > <jasow...@redhat.com> wrote: > > > > > > > On Mon, Sep 27, 2021 at 2:54 PM Xuan Zhuo > > > > > > > <xuanz...@linux.alibaba.com> wrote: > > > > > > > > > > > > > > > > On Mon, 27 Sep 2021 11:50:35 +0800, Jason Wang > > > > > > > > <jasow...@redhat.com> wrote: > > > > > > > > > On Thu, Sep 16, 2021 at 5:33 PM Xuan Zhuo > > > > > > > > > <xuanz...@linux.alibaba.com> wrote: > > > > > > > > > > > > > > > > > > > > This patch allows the driver to obtain some statistics from > > > > > > > > > > the device. > > > > > > > > > > > > > > > > > > > > In the back-end implementation, we can count a lot of such > > > > > > > > > > information, > > > > > > > > > > which can be used for debugging and judging the running > > > > > > > > > > status of the > > > > > > > > > > back-end. We hope to directly display it to the user > > > > > > > > > > through ethtool. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com> > > > > > > > > > > --- > > > > > > > > > > > > > > > > > > > > v3 changes: > > > > > > > > > > 1. add dev_version > > > > > > > > > > 2. use queue_pair_index replace rx_num, tx_num > > > > > > > > > > 3. Explain the processing when the device and driver > > > > > > > > > > support different numbers > > > > > > > > > > of stats > > > > > > > > > > > > > > > > > > > > content.tex | 115 > > > > > > > > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > > > > > > > 1 file changed, 115 insertions(+) > > > > > > > > > > > > > > > > > > > > diff --git a/content.tex b/content.tex > > > > > > > > > > index 7cec1c3..2e45a55 100644 > > > > > > > > > > --- a/content.tex > > > > > > > > > > +++ b/content.tex > > > > > > > > > > @@ -2972,6 +2972,9 @@ \subsection{Feature > > > > > > > > > > bits}\label{sec:Device Types / Network Device / Feature bits > > > > > > > > > > \item[VIRTIO_NET_F_CTRL_MAC_ADDR(23)] Set MAC address > > > > > > > > > > through control > > > > > > > > > > channel. > > > > > > > > > > > > > > > > > > > > +\item[VIRTIO_NET_F_CTRL_STATS(55)] Device can provide > > > > > > > > > > device-level statistics > > > > > > > > > > + to the driver through the control channel. > > > > > > > > > > + > > > > > > > > > > \item[VIRTIO_NET_F_HOST_USO (56)] Device can receive USO > > > > > > > > > > packets. Unlike UFO > > > > > > > > > > (fragmenting the packet) the USO splits large UDP packet > > > > > > > > > > to several segments when each of these smaller packets > > > > > > > > > > has UDP header. > > > > > > > > > > @@ -3017,6 +3020,7 @@ \subsubsection{Feature bit > > > > > > > > > > requirements}\label{sec:Device Types / Network Device > > > > > > > > > > \item[VIRTIO_NET_F_GUEST_ANNOUNCE] Requires > > > > > > > > > > VIRTIO_NET_F_CTRL_VQ. > > > > > > > > > > \item[VIRTIO_NET_F_MQ] Requires VIRTIO_NET_F_CTRL_VQ. > > > > > > > > > > \item[VIRTIO_NET_F_CTRL_MAC_ADDR] Requires > > > > > > > > > > VIRTIO_NET_F_CTRL_VQ. > > > > > > > > > > +\item[VIRTIO_NET_F_CTRL_STATS] Requires > > > > > > > > > > VIRTIO_NET_F_CTRL_VQ. > > > > > > > > > > \item[VIRTIO_NET_F_RSC_EXT] Requires > > > > > > > > > > VIRTIO_NET_F_HOST_TSO4 or VIRTIO_NET_F_HOST_TSO6. > > > > > > > > > > \item[VIRTIO_NET_F_RSS] Requires VIRTIO_NET_F_CTRL_VQ. > > > > > > > > > > \end{description} > > > > > > > > > > @@ -3895,6 +3899,7 @@ \subsubsection{Control > > > > > > > > > > Virtqueue}\label{sec:Device Types / Network Device / Devi > > > > > > > > > > u8 command; > > > > > > > > > > u8 command-specific-data[]; > > > > > > > > > > u8 ack; > > > > > > > > > > + u8 command-specific-data-reply[]; > > > > > > > > > > }; > > > > > > > > > > > > > > > > > > > > /* ack values */ > > > > > > > > > > @@ -3906,6 +3911,9 @@ \subsubsection{Control > > > > > > > > > > Virtqueue}\label{sec:Device Types / Network Device / Devi > > > > > > > > > > driver, and the device sets the \field{ack} byte. There is > > > > > > > > > > little it can > > > > > > > > > > do except issue a diagnostic if \field{ack} is not > > > > > > > > > > VIRTIO_NET_OK. > > > > > > > > > > +\field{command-specific-data-reply} is alloced by driver, > > > > > > > > > > then pass to device. > > > > > > > > > > +It is filled by the device. It is optional. Some commands > > > > > > > > > > need to get some > > > > > > > > > > +information from the device. > > > > > > > > > > > > > > > > > > Let's just reuse the "sets" as above. > > > > > > > > > > > > > > > > > > E.g "and the device set the \field{ack} and optionally > > > > > > > > > \field{command-specific-data-reply}" > > > > > > > > > > > > > > > > OK. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > \paragraph{Packet Receive Filtering}\label{sec:Device > > > > > > > > > > Types / Network Device / Device Operation / Control > > > > > > > > > > Virtqueue / Packet Receive Filtering} > > > > > > > > > > \label{sec:Device Types / Network Device / Device > > > > > > > > > > Operation / Control Virtqueue / Setting Promiscuous > > > > > > > > > > Mode}%old label for latexdiff > > > > > > > > > > @@ -4384,6 +4392,113 @@ \subsubsection{Legacy Interface: > > > > > > > > > > Framing Requirements}\label{sec:Device > > > > > > > > > > See \ref{sec:Basic > > > > > > > > > > Facilities of a Virtio Device / Virtqueues / Message > > > > > > > > > > Framing}. > > > > > > > > > > > > > > > > > > > > +\paragraph{Device stats}\label{sec:Device Types / Network > > > > > > > > > > Device / Device Operation / Control Virtqueue / Device > > > > > > > > > > stats} > > > > > > > > > > + > > > > > > > > > > +If the VIRTIO_NET_F_CTRL_STATS feature is negotiated, the > > > > > > > > > > driver can > > > > > > > > > > +get device stats from the device by > > > > > > > > > > \field{command-specific-data-reply}. > > > > > > > > > > + > > > > > > > > > > +\subparagraph{Device stats keys}\label{sec:Device Types / > > > > > > > > > > Network Device / Device Operation / Control Virtqueue / > > > > > > > > > > Device stats keys / Device stats keys} > > > > > > > > > > + > > > > > > > > > > +The keys of the device stats are defined as follows. When > > > > > > > > > > the device fills in > > > > > > > > > > +\field{command-specific-data-reply}, it MUST be written in > > > > > > > > > > the following order. > > > > > > > > > > +Subsequent newly added keys MUST be added at the end of > > > > > > > > > > each category. > > > > > > > > > > +These keys will eventually be shown to the user. > > > > > > > > > > + > > > > > > > > > > +All stats are divided into three categories: > > > > > > > > > > + > > > > > > > > > > +\begin{itemize} > > > > > > > > > > + \item dev stats: the stats of the device > > > > > > > > > > + \begin{itemize} > > > > > > > > > > + \item dev_version: The number of device > > > > > > > > > > version. > > > > > > > > > > + \item dev_reset: The number of device reset. > > > > > > > > > > + \end{itemize} > > > > > > > > > > + > > > > > > > > > > + \item rx stats: the stats of the rx queue > > > > > > > > > > + \begin{itemize} > > > > > > > > > > + \item rx[N]_inter: The number of interrupts > > > > > > > > > > sent by the rx queue. > > > > > > > > > > + \item rx[N]_drop: The number of packets > > > > > > > > > > dropped by the rx queue. Contains all kinds of packet loss. > > > > > > > > > > + \item rx[N]_drop_overruns: The number of > > > > > > > > > > packets dropped by the rx queue when no more avail desc. > > > > > > > > > > + \item rx[N]_csum_bad: The number of packets > > > > > > > > > > with abnormal csum in the rx queue. > > > > > > > > > > + \item rx[N]_gso_packets: The number of gso > > > > > > > > > > packets received by rx. > > > > > > > > > > + \item rx[N]_gso_bytes: The number of gso bytes > > > > > > > > > > received by rx. > > > > > > > > > > + \item rx[N]_oversize_pkts: The number of > > > > > > > > > > oversized packets received by the rx queue. > > > > > > > > > > + \end{itemize} > > > > > > > > > > + > > > > > > > > > > + \item tx stats: the stats of the tx queue > > > > > > > > > > + \begin{itemize} > > > > > > > > > > + \item tx[N]_inter: The number of interrupts > > > > > > > > > > sent by the tx queue. > > > > > > > > > > + \item tx[N]_drop: The number of packets > > > > > > > > > > dropped by the tx queue. Contains all kinds of packet loss. > > > > > > > > > > + \item tx[N]_csum: The number of packets that > > > > > > > > > > completes csum by the device. > > > > > > > > > > + \item tx[N]_gso_packets: The number of gso > > > > > > > > > > packets transmitted. > > > > > > > > > > + \item tx[N]_gso_bytes: The number of gso bytes > > > > > > > > > > transmitted. > > > > > > > > > > + \end{itemize} > > > > > > > > > > +\end{itemize} > > > > > > > > > > > > > > > > > > Let's use C stcture for this. > > > > > > > > > > > > > > > > The main purpose here is to define the order of these keys. > > > > > > > > > > > > > > > > This issue will be discussed below. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > + > > > > > > > > > > +\subparagraph{Device stats get}\label{sec:Device Types / > > > > > > > > > > Network Device / Device Operation / Control Virtqueue / > > > > > > > > > > Device stats keys / Device stats get} > > > > > > > > > > + > > > > > > > > > > +To get the stats, the following definitions are used: > > > > > > > > > > +\begin{lstlisting} > > > > > > > > > > +#define VIRTIO_NET_CTRL_STATS 6 > > > > > > > > > > +#define VIRTIO_NET_CTRL_STATS_GET 0 > > > > > > > > > > +\end{lstlisting} > > > > > > > > > > + > > > > > > > > > > +The following layout structure are used: > > > > > > > > > > + > > > > > > > > > > +\field{command-specific-data} > > > > > > > > > > +\begin{lstlisting} > > > > > > > > > > +le64 queue_pair_index > > > > > > > > > > +le64 dev_stats_num; > > > > > > > > > > +le64 rx_stats_num; > > > > > > > > > > +le64 tx_stats_num; > > > > > > > > > > +\end{lstlisting} > > > > > > > > > > + > > > > > > > > > > +\field{command-specific-data-reply} > > > > > > > > > > +\begin{lstlisting} > > > > > > > > > > +le64 queue_pair_index > > > > > > > > > > +le64 dev_stats_num; > > > > > > > > > > +le64 rx_stats_num; > > > > > > > > > > +le64 tx_stats_num; > > > > > > > > > > +le64 dev_stats[dev_stats_num]; > > > > > > > > > > +le64 rx_stats[rx_stats_num]; > > > > > > > > > > +le64 tx_stats[tx_stats_num]; > > > > > > > > > > +\end{lstlisting} > > > > > > > > > > + > > > > > > > > > > +The command VIRTIO_NET_CTRL_STATS_GET is used to obtain > > > > > > > > > > this information. > > > > > > > > > > + > > > > > > > > > > +Regarding the variables in \field{command-specific-data}: > > > > > > > > > > +\begin{itemize} > > > > > > > > > > + \item \field{queue_pair_index}: Specify the queue pair > > > > > > > > > > index of the queue that the driver wants to get stats. > > > > > > > > > > + \item \field{dev_stats_num}: Indicates the number of > > > > > > > > > > dev stats supported by the driver. > > > > > > > > > > + \item \field{rx_stats_num}: Indicates the number of > > > > > > > > > > stats information the driver wants for rx queue. > > > > > > > > > > + \item \field{tx_stats_num}: Indicates the number of > > > > > > > > > > stats information the driver wants for tx queue. > > > > > > > > > > > > > > > > > > We have feature negotiation mechanism, so I think we don't > > > > > > > > > need > > > > > > > > > dev_stats_num, {rx|tx}_stats_num here. Instead, all of those > > > > > > > > > should be > > > > > > > > > inferred from the features. > > > > > > > > > > > > > > > > The feature just indicates that the driver can obtain status > > > > > > > > information from > > > > > > > > the device. But with the development, it is difficult for the > > > > > > > > device and the > > > > > > > > driver to support the new key synchronously. The feature is > > > > > > > > also difficult to > > > > > > > > sense how many new keys the driver and the device support > > > > > > > > respectively. > > > > > > > > > > > > > > So I think the feature works fine for this. > > > > > > > > > > > > > > VIRTIO_NET_F_CTRL_STATS -> stats set A > > > > > > > VIRTIO_NET_F_CTRL_STATS_X -> stats set A + stats set X > > > > > > > ... > > > > > > > > > > > > > > The point is to unbreak the migration. We don't want to surprise > > > > > > > the > > > > > > > user if some of the keys were added or deleted after migration. > > > > > > > > > > > > Your ideas inspired me, but I think adding features is not a good > > > > > > way. Because I > > > > > > feel that after the dev is initialized, we can negotiate with the > > > > > > device based > > > > > > on CTRL_VQ. > > > > > > > > > > > > For example, the driver supports two versions of stats > > > > > > > > > > > > A: two keys > > > > > > B: three keys > > > > > > > > > > > > And the device just supports version A. > > > > > > > > > > > > The driver can pass the two information of A and B to the device > > > > > > based on > > > > > > CTRL_VQ, and the device returns a supported version name. > > > > > > > > > > I'm not sure I can get you here. Does this mean it supports migration > > > > > A from B? If yes, it breaks userspace. If not, how do we know we can't > > > > > do the migration? > > > > > > > > NO > > > > > > > > > > > > > > As mentioned, the better way is to increase the sets and make e.g > > > > > CTRL_STATS_X depend on CTRL_STATS which depend on CTRL_VQ. > > > > > > > > My idea is similar to yours, but I think adding a new > > > > VIRTIO_NET_F_CTRL_STATS_X > > > > is a bit too wasteful. > > > > > > > > Assuming that these sets have been defined in the spec > > > > > > > > A -> stats set A > > > > B -> stats set A + stats set B > > > > C -> stats set A + stats set B + stats set C > > > > .... > > > > > > > > We only need to tell the device based on CTRL_VQ which set we support, > > > > such as > > > > B. The device returns which set it supports. This will complete the > > > > negotiation. > > > > > > > > driver device > > > > A C => A > > > > C C => C > > [1] > > > > > C B => B > > [2] > > > > > > > So how do we know we can't migrate device(B) to device(C)? > > > > Aren’t we discussing the driver and the device to negotiate which set of > > stats > > everyone will ultimately use? What do you mean by migration? > > Feature bit is a facility for preserving migration compatibility. > Consider if we want to migrate from device[1] to device[2]. Drivers > may see different stats sets which breaks userspace application and > migration.
Okay, thanks for your explanation and patience. > > Thanks > > > > > Thanks. > > > > > > > > Thanks > > > > > > > > > > > My idea is to no longer waste a feature bit, but to complete the > > > > negotiation > > > > based on CTRL_VQ. > > > > > > > > Hope I made it clear. ^_^. > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > In addition, do you think we need to define this content now, or > > > > > > should we > > > > > > define this one when there is a new version of stats in the future? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > For example, there are currently only two dev_stats, and both > > > > > > > > the device and the > > > > > > > > driver only support two keys. If the virtio spec adds a new dev > > > > > > > > stats, the > > > > > > > > driver may first support three keys, but the device still > > > > > > > > supports only two. The > > > > > > > > number of keys supported by both parties is needed to negotiate. > > > > > > > > > > > > > > So let's say VIRTIO_NET_F_CTRL_STATS (two keys) but > > > > > > > VIRTIO_NET_F_CTRL_STATS_X has three keys. > > > > > > > In this case if VIRTIO_NET_F_CTRL_STATS_X is not supported by the > > > > > > > device (only two keys), it won't be negotiated and the driver > > > > > > > knows > > > > > > > the device will only return 2 keys. > > > > > > > > > > > > > > > > > > > > > > > dev_stats_num, (rx|tx)_stats_num exists for this purpose. > > > > > > > > > > > > > > > > I think the increase of these keys is a relatively frequent > > > > > > > > thing. > > > > > > > > > > > > > > Probably not, looking at other NIC drivers the "keys" are pretty > > > > > > > stable. We can start from a large set anyhow. > > > > > > > > > > > > OK. > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > It is also > > > > > > > > difficult to synchronize the support for new keys between > > > > > > > > drivers and devices. > > > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > > +\end{itemize} > > > > > > > > > > + > > > > > > > > > > +Regarding the variables in > > > > > > > > > > \field{command-specific-data-reply}: > > > > > > > > > > +\begin{itemize} > > > > > > > > > > + \item All variables of > > > > > > > > > > \field{command-specific-data-reply} are set by the device. > > > > > > > > > > + \item \field{queue_pair_index} MUST be equal to the > > > > > > > > > > variable with the same name in > > > > > > > > > > \field{command-specific-data}. > > > > > > > > > > + \item These variables(\field{dev_stats_num}, > > > > > > > > > > \field{rx_stats_num}, \field{tx_stats_num}) MUST be > > > > > > > > > > + less than or equal to the variables with the > > > > > > > > > > same name in \field{command-specific-data}. > > > > > > > > > > + These values indicate the amount of stats > > > > > > > > > > actually filled in. > > > > > > > > > > + \item \field{command-specific-data-reply} is > > > > > > > > > > meaningful only when \field{ack} is equal to VIRTIO_NET_OK. > > > > > > > > > > +\end{itemize} > > > > > > > > > > + > > > > > > > > > > +The variables \field{dev_stats_num}, \field{rx_stats_num}, > > > > > > > > > > \field{tx_stats_num} in \field{command-specific-data} > > > > > > > > > > +specify which stats the driver wants to get, but in fact > > > > > > > > > > the device may support > > > > > > > > > > +more or fewer stats. > > > > > > > > > > + > > > > > > > > > > +If the actual number of stats supported by the device is > > > > > > > > > > equal to or less than > > > > > > > > > > +the number that the driver wants to obtain, then the > > > > > > > > > > device MUST write all the > > > > > > > > > > +stats to the corresponding position of > > > > > > > > > > \field{command-specific-data-reply}. > > > > > > > > > > + > > > > > > > > > > +And if the number of stats actually supported by the > > > > > > > > > > device is more than the > > > > > > > > > > +driver requires, then the device MUST only write the > > > > > > > > > > number supported by the > > > > > > > > > > +driver. > > > > > > > > > > + > > > > > > > > > > +If the some of the variables \field{dev_stats_num}, > > > > > > > > > > \field{rx_stats_num}, \field{tx_stats_num} in > > > > > > > > > > \field{command-specific-data} are 0, > > > > > > > > > > +that means that the driver does not want to obtain this > > > > > > > > > > type of stats, > > > > > > > > > > +then the device MUST set the same name field in > > > > > > > > > > \field{command-specific-data-reply} to 0, and skip this > > > > > > > > > > type of stats. > > > > > > > > > > + > > > > > > > > > > \section{Block Device}\label{sec:Device Types / Block > > > > > > > > > > Device} > > > > > > > > > > > > > > > > > > > > The virtio block device is a simple virtual block device > > > > > > > > > > (ie. > > > > > > > > > > -- > > > > > > > > > > 2.31.0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org