在 2022/3/15 上午11:24, Xuan Zhuo 写道:
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.
To get stats atomically, try to get stats for all queue pairs in one
command.
Signed-off-by: Xuan Zhuo <[email protected]>
Suggested-by: Michael S. Tsirkin <[email protected]>
---
conformance.tex | 2 +
content.tex | 406 +++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 405 insertions(+), 3 deletions(-)
diff --git a/conformance.tex b/conformance.tex
index 42f8537..c67f877 100644
--- a/conformance.tex
+++ b/conformance.tex
@@ -142,6 +142,7 @@ \section{Conformance Targets}\label{sec:Conformance /
Conformance Targets}
\item \ref{drivernormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Automatic receive steering in multiqueue mode}
\item \ref{drivernormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Offloads State Configuration / Setting Offloads State}
\item \ref{drivernormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Receive-side scaling (RSS) }
+\item \ref{drivernormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Device Stats}
\end{itemize}
\conformance{\subsection}{Block Driver Conformance}\label{sec:Conformance / Driver Conformance / Block Driver Conformance}
@@ -401,6 +402,7 @@ \section{Conformance Targets}\label{sec:Conformance /
Conformance Targets}
\item \ref{devicenormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Gratuitous Packet Sending}
\item \ref{devicenormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Automatic receive steering in multiqueue mode}
\item \ref{devicenormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Receive-side scaling (RSS) / RSS processing}
+\item \ref{devicenormative:Device Types / Network Device / Device Operation /
Control Virtqueue / Device Stats}
\end{itemize}
\conformance{\subsection}{Block Device Conformance}\label{sec:Conformance / Device Conformance / Block Device Conformance}
diff --git a/content.tex b/content.tex
index c6f116c..81f325d 100644
--- a/content.tex
+++ b/content.tex
@@ -3092,6 +3092,9 @@ \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.
@@ -3137,6 +3140,7 @@ \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}
@@ -4015,6 +4019,7 @@ \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 */
@@ -4023,9 +4028,11 @@ \subsubsection{Control Virtqueue}\label{sec:Device Types
/ Network Device / Devi
\end{lstlisting}
The \field{class}, \field{command} and command-specific-data are set by the
-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.
+driver, and the device sets the \field{ack} byte and optionally
+\field{command-specific-data-reply}. There is little the driver can
+do except issue a diagnostic if \field{ack} is not VIRTIO_NET_OK.
+
+The command VIRTIO_NET_CTRL_STATS_GET contains
\field{command-specific-data-reply}.
\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
@@ -4471,6 +4478,399 @@ \subsubsection{Control Virtqueue}\label{sec:Device
Types / Network Device / Devi
according to the native endian of the guest rather than
(necessarily when not using the legacy interface) little-endian.
+\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 the device stats from the device in \field{command-specific-data-reply}.
+
+To get the stats, the following definitions are used:
+\begin{lstlisting}
+#define VIRTIO_NET_CTRL_STATS 6
+#define VIRTIO_NET_CTRL_STATS_GET 0
+
+#define VIRTIO_NET_STATS_TYPE_CVQ 0
+#define VIRTIO_NET_STATS_TYPE_RX_BASIC 1
+#define VIRTIO_NET_STATS_TYPE_RX_CSUM 2
+#define VIRTIO_NET_STATS_TYPE_RX_GSO 3
+#define VIRTIO_NET_STATS_TYPE_RX_RESET 4
+#define VIRTIO_NET_STATS_TYPE_TX_BASIC 5
+#define VIRTIO_NET_STATS_TYPE_TX_CSUM 6
+#define VIRTIO_NET_STATS_TYPE_TX_GSO 7
+#define VIRTIO_NET_STATS_TYPE_TX_RESET 8
+
+\end{lstlisting}
+
+Use the command VIRTIO_NET_CTRL_STATS_GET and \field{command-specific-data}
+containing struct virtio_net_ctrl_queue_stats to get the device stats.
+The result is returned by \field{command-specific-data-reply}.
+The stats ware returned in the order of the type specified in the
s/ware/were/ and s/type/types/ ?
+\field{virtio_net_ctrl_queue_stats}.
+
+The following layout structures are used:
+
+\field{command-specific-data}
+\begin{lstlisting}
+struct virtio_net_ctrl_queue_stats {
+ u16 nstats;
+ struct {
+ u16 queue_num;
+ u16 type;
+ } stats[];
+};
+\end{lstlisting}
+
+\field{command-specific-data-reply}
+\begin{lstlisting}
+struct virtio_net_stats_cvq {
+ le64 command_num;
+ le64 ok_num;
+};
+
+struct virtio_net_stats_rx_basic {
+ le64 rx_packets;
+ le64 rx_bytes;
+
+ le64 rx_notification;
+ le64 rx_interrupt;
+
+ le64 rx_drop;
+ le64 rx_drop_overruns;
+};
+
+struct virtio_net_stats_rx_csum {
+ le64 rx_csum_valid;
+ le64 rx_needs_csum;
+ le64 rx_csum_bad;
+ le64 rx_csum_none;
+};
+
+struct virtio_net_stats_rx_gso {
+ le64 rx_gso_packets;
+ le64 rx_gso_bytes;
+ le64 rx_gso_packets_coalesced;
+ le64 rx_gso_bytes_coalesced;
+ le64 rx_gso_segments;
+ le64 rx_gso_segments_bytes;
+};
+
+struct virtio_net_stats_rx_reset {
+ le64 rx_reset;
+};
+
+struct virtio_net_stats_tx_basic {
+ le64 tx_packets;
+ le64 tx_bytes;
+
+ le64 tx_notification;
+ le64 tx_interrupt;
+
+ le64 tx_drop;
+ le64 tx_drop_malformed;
+};
+
+struct virtio_net_stats_tx_csum {
+ le64 tx_csum_none;
+ le64 tx_needs_csum;
+};
+
+struct virtio_net_stats_tx_gso {
+ le64 tx_gso_packets;
+ le64 tx_gso_bytes;
+ le64 tx_gso_packets_split;
+ le64 tx_gso_bytes_split;
+ le64 tx_gso_segments;
+ le64 tx_gso_segments_bytes;
+};
+
+struct virtio_net_stats_tx_reset {
+ le64 tx_reset;
+};
+
+\end{lstlisting}
+
+\begin{description}
+ \item [nstats]
+ The number of \field{stats}.
This looks not necessary since it can be deduced from the buffer length.
+
+ \item [queue_num]
+ The number of the virtqueue to obtain the statistics.
+
+ \item [type]
+ The type of the stats to be obtained.
+
+\end{description}
+
+Correspondence between the vq type, the stats type, the stats structure and the
+required features.
+\begin{tabular}{ |l|l|l|l| }
+ \hline
+ VQ Type & Stats Type & Stats Structure
& Features \\ \hline
+
+ controlq & VIRTIO_NET_STATS_TYPE_CVQ &
virtio_net_stats_cvq & \\ \hline
+
+ \multirow{4}*{receiveq} & VIRTIO_NET_STATS_TYPE_RX_BASIC &
virtio_net_stats_rx_basic & \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_RX_CSUM &
virtio_net_stats_rx_csum & VIRTIO_NET_F_GUEST_CSUM \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_RX_GSO &
virtio_net_stats_rx_gso & VIRTIO_NET_F_GUEST_TSO4 or\newline
+
VIRTIO_NET_F_GUEST_TSO6 or\newline
+
VIRTIO_NET_F_GUEST_UFO \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_RX_RESET &
virtio_net_stats_rx_reset & VIRTIO_F_RING_RESET \\ \hline
+
+ \multirow{4}*{transmitq} & VIRTIO_NET_STATS_TYPE_TX_BASIC &
virtio_net_stats_tx_basic & \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_TX_CSUM &
virtio_net_stats_tx_csum & VIRTIO_NET_F_CSUM \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_TX_GSO &
virtio_net_stats_tx_gso & VIRTIO_NET_F_HOST_TSO4 or\newline
+
VIRTIO_NET_F_HOST_TSO6 or\newline
+
VIRTIO_NET_F_HOST_USO or\newline
+
VIRTIO_NET_F_HOST_UFO \\ \cline{2-4}
+ & VIRTIO_NET_STATS_TYPE_TX_RESET &
virtio_net_stats_tx_reset & VIRTIO_F_RING_RESET \\
+ \hline
+\end{tabular}
+
+
+\subparagraph{Controlq Stats}\label{sec:Device Types / Network Device / Device
Operation / Control Virtqueue / Device Stats / Controlq Stats}
+
+The structure corresponding to the controlq stats is virtio_net_stats_cvq.
+
+\begin{description}
+ \item [command_num]
+ The number of commands, including the current command.
+
+ \item [ok_num]
+ The number of commands (including the current command) where the ack
was VIRTIO_NET_OK.
+\end{description}
+
+
+\subparagraph{Receiveq Basic Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Receiveq Basic Stats}
+
+The structure corresponding to the receiveq basic stats is
virtio_net_stats_rx_basic.
+
+Receiveq basic stats doesn't need any features, as long as the device supports
+VIRTIO_NET_F_CTRL_STATS. The following are the receiveq basic stats.
+
+\begin{description}
+ \item [rx_packets]
+ The number of packets received by device (not the packets passed to the
+ guest), including the dropped packets by device.
+
+ \item [rx_bytes]
+ The number of bytes received by device (not the packets passed to the
+ guest), including the dropped packets by device.
+
+ \item [rx_notification]
+ The number of driver notifications.
+
+ \item [rx_interrupt]
+ The number of device interrupts.
+
+ \item [rx_drop]
+ The number of packets dropped by the receiveq. Contains all kinds of
+ packet drop.
+
+ \item [rx_drop_overruns]
+ The number of packets dropped by the receiveq when no more descriptors
+ were available.
+
+\end{description}
+
+\subparagraph{Transmitq Basic Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Transmitq Basic Stats}
+
+The structure corresponding to the transmitq basic stats is
virtio_net_stats_tx_basic.
+
+Transmitq basic stats doesn't need any features, as long as the device supports
+VIRTIO_NET_F_CTRL_STATS. The following are the transmitq basic stats.
+
+\begin{description}
+ \item [tx_packets]
+ The number of packets sent by device (not the packets got from the
+ guest), excluding the dropped packets by device.
"packets dropped by device"?
+
+ \item [tx_bytes]
+ The number of bytes sent by device (not the packets got from the
+ guest), excluding the dropped packets by device.
+
+ \item [tx_notification]
+ The number of driver notifications.
+
+ \item [tx_interrupt]
+ The number of device interrupts.
+
+ \item [tx_drop]
+ The number of packets dropped by the transmitq. Contains all kinds of
+ packet drop.
+
+ \item [tx_drop_malformed]
+ The number of packets dropped when the descriptor is in an error state.
+ For example, the buffer is too short.
I wonder if "tx_erros" is better (this is what I see from at least two
other NIC vendors).
+
+\end{description}
+
+\subparagraph{Receiveq CSUM Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Receiveq CSUM Stats}
+
+The structure corresponding to the receiveq csum stats is
virtio_net_stats_rx_csum.
+
+Only after the VIRTIO_NET_F_GUEST_CSUM negotiation is successful, the receiveq
+csum stats can be obtained.
+
+The following are the receiveq csum stats:
+
+\begin{description}
+ \item [rx_csum_valid]
+ The number of packets with VIRTIO_NET_HDR_F_DATA_VALID.
A question, it looks to me the stats refer to the phy -> device counters
not the device -> driver counter (which could be count by the driver).
If this is true, technically, device can't receive a packet with
VIRTIO_NET_HDR_F_DATA_VALID.
FYI, e1000e had:
ethtool -S enp0s31f6 | grep csum
rx_csum_offload_good: 601959
rx_csum_offload_errors: 0
+
+ \item [rx_needs_csum]
+ The number of packets with VIRTIO_NET_HDR_F_NEEDS_CSUM.
+
+ \item [rx_csum_bad]
+ The number of packets with abnormal csum.
+
+ \item [rx_csum_none]
+ The number of packets without hardware csum. The packet here refers to
+ the non-TCP/UDP packet that the backend cannot recognize.
This is probably not correct. We may have a guest without
VIRTIO_NET_F_GUEST_CSUM support.
+
+\end{description}
+
+\subparagraph{Transmitq CSUM Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Transmitq CSUM Stats}
+
+The structure corresponding to the transmitq csum stats is
virtio_net_stats_tx_csum.
+
+Only after the VIRTIO_NET_F_CSUM negotiation is successful, the transmitq csum
+stats can be obtained.
+
+The following are the transmitq csum stats:
+
+\begin{description}
+ \item [tx_csum_none]
+ The number of packets that didn't require hardware csum.
+
+ \item [tx_needs_csum]
+ The number of packets that required hardware csum.
+
+\end{description}
+
+\subparagraph{Receiveq GSO Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Receiveq GSO Stats}
+
+The structure corresponding to the receiveq gso stats is
virtio_net_stats_rx_gso.
+
+If one of the VIRTIO_NET_F_GUEST_TSO4, TSO6, or UFO options have
+been negotiated, the receiveq gso stats can be obtained.
We probably need to use "GSO" instead of "gso" for the whole patch.
+
+Rx gso packets refer to packets passed by the device to the driver where
+\field{gso_type} is not VIRTIO_NET_HDR_GSO_NONE.
+
+\begin{description}
+ \item [rx_gso_packets]
+ The number of the rx gso packets.
+
+ \item [rx_gso_bytes]
+ The number of bytes(excluding the virtio net header) of the rx gso
packets.
+
+ \item [rx_gso_packets_coalesced]
+ The number of the rx gso packages generated by coalescing.
For "packages", did you mean "packets" actually? Does it work only if
RSC is negotiated?
+
+ \item [rx_gso_bytes_coalesced]
+ The number of bytes(excluding the virtio net header) of the rx gso
packets generated by coalescing.
+
+ \item [rx_gso_segments]
+ The number of coalesced segments.
If we do VM2VM traffic, we can receive GSO packets directly without
coalescing. Do we count this packet here?
+
+ \item [rx_gso_segments_bytes]
+ The number of bytes of coalesced segments.
+
+\end{description}
+
+\subparagraph{Transmitq GSO Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Transmitq GSO Stats}
+
+The structure corresponding to the transmitq gso stats is
virtio_net_stats_tx_gso.
+
+If one of the VIRTIO_NET_F_HOST_TSO4, TSO6, USO or UFO options have
+been negotiated, the transmitq gso stats can be obtained.
+
+Tx gso packets refer to packets passed by the driver to the device where
+\field{gso_type} is not VIRTIO_NET_HDR_GSO_NONE.
+
+\begin{description}
+ \item [tx_gso_packets]
+ The number of the tx gso packets.
+
+ \item [tx_gso_bytes]
+ The number of bytes(excluding the virtio net header) of the tx gso
packets.
+
+ \item [tx_gso_packets_split]
+ The number of the tx gso packets that been split.
+
+ \item [tx_gso_bytes_split]
+ The number of bytes(excluding the virtio net header) of the tx gso
packets that been split.
S/packet/bytes/? And does it include the L2/L3/L4 headers of the
segmented packets?
+
+ \item [tx_gso_segments]
+ The number of segments split from the gso package.
For package, I think you meant packet actually.
+
+ \item [tx_gso_segments_bytes]
+ The number of bytes(excluding the virtio net header) of segments split
from the gso package.
+\end{description}
+
+\subparagraph{Receiveq Reset Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Receiveq Reset Stats}
+
+The structure corresponding to the receiveq reset stats is
virtio_net_stats_rx_reset.
+
+Only when VIRTIO_F_RING_RESET is successfully negotiated, the receiveq reset
stats
+can be obtained.
Not a native speaker, but I think we can remove "successfully" here.
+
+See \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue
Reset}
+for more about \field{rx_reset}.
+
+\begin{description}
+ \item [rx_reset]
+ The number of receiveq resets.
+\end{description}
+
+\subparagraph{Transmitq Reset Stats}\label{sec:Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats / Transmitq Reset Stats}
+
+The structure corresponding to the transmitq reset stats is
virtio_net_stats_tx_reset.
+
+Only when VIRTIO_F_RING_RESET is successfully negotiated, the transmitq reset
stats
+can be obtained.
+
+See \ref{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue
Reset}
+for more about \field{tx_reset}.
+
+\begin{description}
+ \item [tx_reset]
+ The number of transmitq resets.
+\end{description}
+
+\devicenormative{\subparagraph}{Device Stats}{Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats}
+
+If virtio_net_ctrl_queue_stats is incorrect (such as the following), the device
+MUST set \field{ack} to VIRTIO_NET_ERR. Even if there is only one error,
+the device MUST abort the entire command.
I guess "fail" is better than "abort".
+\begin{itemize}
+ \item \field{queue_num} exceeds the queue range.
+ \item \field{type} is not a known value.
+ \item The type of vq does not match \field{type}. E.g. the driver tries to
query
+ RX stats through a TX index.
+ \item The feature corresponding to the specified \field{type} was not
successfully
+ negotiated.
+ \item The size of the buffer allocated by the driver for
\field{command-specific-data-reply}
+ is less than the total size of the stats specialed by
+ \field{virtio_net_ctrl_queue_stats}.
+\end{itemize}
+
+The device MUST write the requested stats structures in
+\field{command-specific-data-reply} in the order specified by the structure
+virtio_net_ctrl_queue_stats.
Are the counters reset during device reset?
Thanks
+
+\drivernormative{\subparagraph}{Device Stats}{Device Types / Network Device /
Device Operation / Control Virtqueue / Device Stats}
+
+When a driver tries to obtain a certain stats, it MUST confirm that the
relevant
+feature negotiation is successful.
+
+\field{type} in struct virtio_net_ctrl_queue_stats MUST correspond to the vq
+specified by \field{queue_num}.
+
+The \field{command-specific-data-reply} buffer allocated by the driver MUST be
+able to hold all the stats specified by virtio_net_ctrl_queue_stats.
+
+When the driver reads the response, it MUST read
+\field{command-specific-data-reply} one by one based on the \field{type}.
\subsubsection{Legacy Interface: Framing Requirements}\label{sec:Device
Types / Network Device / Legacy Interface: Framing Requirements}
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