Add collector for SR-IOV Virtual Function statistics

Add a new netvf collector that exposes SR-IOV VF statistics and
configuration via rtnetlink. The collector queries netlink for
interfaces with Virtual Functions and exposes per-VF metrics:

- node_net_vf_info: VF configuration (MAC, VLAN, link state, spoof
  check, trust)
- node_net_vf_{receive,transmit}_{packets,bytes}_total: traffic counters
- node_net_vf_{broadcast,multicast}_packets_total: packet type counters
- node_net_vf_{receive,transmit}_dropped_total: drop counters

The collector is disabled by default and can be enabled with
--collector.netvf. PF device filtering is supported via
--collector.netvf.device-include/exclude flags.

Signed-off-by: Anthony Harivel <aharivel@redhat.com>

Author: aharivel

README.md

@@ -106,6 +106,7 @@ hwmon | chip | --collector.hwmon.chip-include | --collector.hwmon.chip-exclude
 hwmon | sensor | --collector.hwmon.sensor-include | --collector.hwmon.sensor-exclude
 interrupts | name | --collector.interrupts.name-include | --collector.interrupts.name-exclude
 netdev | device | --collector.netdev.device-include | --collector.netdev.device-exclude
+netvf | device | --collector.netvf.device-include | --collector.netvf.device-exclude
 qdisk | device | --collector.qdisk.device-include | --collector.qdisk.device-exclude
 slabinfo | slab-names | --collector.slabinfo.slabs-include | --collector.slabinfo.slabs-exclude
 sysctl | all | --collector.sysctl.include | N/A
@@ -202,6 +203,7 @@ logind | Exposes session counts from [logind](http://www.freedesktop.org/wiki/So
 meminfo\_numa | Exposes memory statistics from `/sys/devices/system/node/node[0-9]*/meminfo`, `/sys/devices/system/node/node[0-9]*/numastat`. | Linux
 mountstats | Exposes filesystem statistics from `/proc/self/mountstats`. Exposes detailed NFS client statistics. | Linux
 network_route | Exposes the routing table as metrics | Linux
+netvf | Exposes SR-IOV Virtual Function statistics and configuration from netlink. | Linux
 pcidevice | Exposes pci devices' information including their link status and parent devices. | Linux
 perf | Exposes perf based metrics (Warning: Metrics are dependent on kernel configuration and settings). | Linux
 processes | Exposes aggregate process statistics from `/proc`. | Linux

collector/netvf_linux.go

@@ -0,0 +1,278 @@
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build !nonetvf
+
+package collector
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+
+	"github.com/alecthomas/kingpin/v2"
+	"github.com/jsimonetti/rtnetlink/v2"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const netvfSubsystem = "net_vf"
+
+var (
+	netvfDeviceInclude = kingpin.Flag("collector.netvf.device-include", "Regexp of PF devices to include (mutually exclusive to device-exclude).").String()
+	netvfDeviceExclude = kingpin.Flag("collector.netvf.device-exclude", "Regexp of PF devices to exclude (mutually exclusive to device-include).").String()
+)
+
+func init() {
+	registerCollector("netvf", defaultDisabled, NewNetVFCollector)
+}
+
+type netvfCollector struct {
+	logger       *slog.Logger
+	deviceFilter deviceFilter
+
+	info            *prometheus.Desc
+	receivePackets  *prometheus.Desc
+	transmitPackets *prometheus.Desc
+	receiveBytes    *prometheus.Desc
+	transmitBytes   *prometheus.Desc
+	broadcast       *prometheus.Desc
+	multicast       *prometheus.Desc
+	receiveDropped  *prometheus.Desc
+	transmitDropped *prometheus.Desc
+}
+
+func NewNetVFCollector(logger *slog.Logger) (Collector, error) {
+	if *netvfDeviceExclude != "" && *netvfDeviceInclude != "" {
+		return nil, errors.New("device-exclude & device-include are mutually exclusive")
+	}
+
+	if *netvfDeviceExclude != "" {
+		logger.Info("Parsed flag --collector.netvf.device-exclude", "flag", *netvfDeviceExclude)
+	}
+
+	if *netvfDeviceInclude != "" {
+		logger.Info("Parsed flag --collector.netvf.device-include", "flag", *netvfDeviceInclude)
+	}
+
+	return &netvfCollector{
+		logger:       logger,
+		deviceFilter: newDeviceFilter(*netvfDeviceExclude, *netvfDeviceInclude),
+		info: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "info"),
+			"Virtual Function configuration information.",
+			[]string{"device", "vf", "mac", "vlan", "link_state", "spoof_check", "trust", "pci_address"}, nil,
+		),
+		receivePackets: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "receive_packets_total"),
+			"Number of received packets by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		transmitPackets: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "transmit_packets_total"),
+			"Number of transmitted packets by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		receiveBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "receive_bytes_total"),
+			"Number of received bytes by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		transmitBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "transmit_bytes_total"),
+			"Number of transmitted bytes by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		broadcast: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "broadcast_packets_total"),
+			"Number of broadcast packets received by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		multicast: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "multicast_packets_total"),
+			"Number of multicast packets received by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		receiveDropped: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "receive_dropped_total"),
+			"Number of dropped received packets by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+		transmitDropped: prometheus.NewDesc(
+			prometheus.BuildFQName(namespace, netvfSubsystem, "transmit_dropped_total"),
+			"Number of dropped transmitted packets by the VF.",
+			[]string{"device", "vf", "pci_address"}, nil,
+		),
+	}, nil
+}
+
+func (c *netvfCollector) Update(ch chan<- prometheus.Metric) error {
+	conn, err := rtnetlink.Dial(nil)
+	if err != nil {
+		return fmt.Errorf("failed to connect to rtnetlink: %w", err)
+	}
+	defer conn.Close()
+
+	links, err := conn.Link.ListWithVFInfo()
+	if err != nil {
+		return fmt.Errorf("failed to list interfaces with VF info: %w", err)
+	}
+
+	vfCount := 0
+	for _, link := range links {
+		if link.Attributes == nil {
+			continue
+		}
+
+		// Skip interfaces without VFs
+		if link.Attributes.NumVF == nil || *link.Attributes.NumVF == 0 {
+			continue
+		}
+
+		device := link.Attributes.Name
+
+		// Apply device filter
+		if c.deviceFilter.ignored(device) {
+			c.logger.Debug("Ignoring device", "device", device)
+			continue
+		}
+
+		for _, vf := range link.Attributes.VFInfoList {
+			vfID := fmt.Sprintf("%d", vf.ID)
+
+			// Emit info metric with VF configuration
+			mac := ""
+			if vf.MAC != nil {
+				mac = vf.MAC.String()
+			}
+			vlan := fmt.Sprintf("%d", vf.Vlan)
+			linkState := vfLinkStateString(vf.LinkState)
+			spoofCheck := fmt.Sprintf("%t", vf.SpoofCheck)
+			trust := fmt.Sprintf("%t", vf.Trust)
+			pciAddress := resolveVFPCIAddress(sysFilePath("class"), device, vf.ID)
+
+			ch <- prometheus.MustNewConstMetric(c.info, prometheus.GaugeValue, 1, device, vfID, mac, vlan, linkState, spoofCheck, trust, pciAddress)
+
+			// Emit stats metrics if available
+			if vf.Stats == nil {
+				c.logger.Debug("VF has no stats", "device", device, "vf", vf.ID)
+				vfCount++
+				continue
+			}
+
+			stats := vf.Stats
+
+			ch <- prometheus.MustNewConstMetric(c.receivePackets, prometheus.CounterValue, float64(stats.RxPackets), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.transmitPackets, prometheus.CounterValue, float64(stats.TxPackets), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.receiveBytes, prometheus.CounterValue, float64(stats.RxBytes), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.transmitBytes, prometheus.CounterValue, float64(stats.TxBytes), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.broadcast, prometheus.CounterValue, float64(stats.Broadcast), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.multicast, prometheus.CounterValue, float64(stats.Multicast), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.receiveDropped, prometheus.CounterValue, float64(stats.RxDropped), device, vfID, pciAddress)
+			ch <- prometheus.MustNewConstMetric(c.transmitDropped, prometheus.CounterValue, float64(stats.TxDropped), device, vfID, pciAddress)
+
+			vfCount++
+		}
+	}
+
+	if vfCount == 0 {
+		return ErrNoData
+	}
+
+	return nil
+}
+
+func vfLinkStateString(state rtnetlink.VFLinkState) string {
+	switch state {
+	case rtnetlink.VFLinkStateAuto:
+		return "auto"
+	case rtnetlink.VFLinkStateEnable:
+		return "enable"
+	case rtnetlink.VFLinkStateDisable:
+		return "disable"
+	default:
+		return "unknown"
+	}
+}
+
+// resolveVFPCIAddress resolves the PCI BDF address of a VF by reading the
+// sysfs virtfn symlink: <sysClassPath>/net/<pfDevice>/device/virtfn<vfID>.
+// Returns empty string if the symlink doesn't exist or can't be resolved.
+func resolveVFPCIAddress(sysClassPath, pfDevice string, vfID uint32) string {
+	virtfnPath := filepath.Join(sysClassPath, "net", pfDevice, "device", fmt.Sprintf("virtfn%d", vfID))
+	resolved, err := os.Readlink(virtfnPath)
+	if err != nil {
+		return ""
+	}
+	return filepath.Base(resolved)
+}
+
+// vfMetrics holds parsed VF metrics for a single VF
+type vfMetrics struct {
+	Device     string
+	VFID       uint32
+	MAC        string
+	Vlan       uint32
+	LinkState  string
+	SpoofCheck bool
+	Trust      bool
+	PCIAddress string
+	Stats      *rtnetlink.VFStats
+}
+
+// parseVFInfo extracts VF information from link messages for testing.
+// sysClassPath is the path to the sysfs class directory used to resolve VF PCI addresses.
+func parseVFInfo(links []rtnetlink.LinkMessage, filter *deviceFilter, logger *slog.Logger, sysClassPath string) []vfMetrics {
+	var result []vfMetrics
+
+	for _, link := range links {
+		if link.Attributes == nil {
+			continue
+		}
+
+		// Skip interfaces without VFs
+		if link.Attributes.NumVF == nil || *link.Attributes.NumVF == 0 {
+			continue
+		}
+
+		device := link.Attributes.Name
+
+		// Apply device filter
+		if filter.ignored(device) {
+			logger.Debug("Ignoring device", "device", device)
+			continue
+		}
+
+		for _, vf := range link.Attributes.VFInfoList {
+			mac := ""
+			if vf.MAC != nil {
+				mac = vf.MAC.String()
+			}
+
+			result = append(result, vfMetrics{
+				Device:     device,
+				VFID:       vf.ID,
+				MAC:        mac,
+				Vlan:       vf.Vlan,
+				LinkState:  vfLinkStateString(vf.LinkState),
+				SpoofCheck: vf.SpoofCheck,
+				Trust:      vf.Trust,
+				PCIAddress: resolveVFPCIAddress(sysClassPath, device, vf.ID),
+				Stats:      vf.Stats,
+			})
+		}
+	}
+
+	return result
+}