Add sysfs class for Amazon Elastic Fabric Adapter

Signed-off-by: Pierre-Yves Aquilanti <pierreya@amazon.com>

sysfs/class_amazon_efa.go

@@ -0,0 +1,262 @@
+// Copyright 2022 Amazon Web Services
+// 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 linux
+// +build linux
+
+package sysfs
+
+import (
+    "fmt"
+    "os"
+    "path/filepath"
+    "strconv"
+    "strings"
+
+    "github.com/prometheus/procfs/internal/util"
+)
+
+// Amazon Elastic Fabric Adapter counters are exposed similarly
+// to InfiniBand counters in SysFS. The same structure is used
+// in this class for consistency.
+
+const AmazonEfaPath = "class/infiniband"
+
+// AmazonEfaCounters contains counter values from files in
+// /sys/class/infiniband/<Name>/ports/<Port>/hw_counters
+// for a single port of one Amazon Elastic Fabric Adapter device.
+type AmazonEfaCounters struct {
+    AllocPdErr        *uint64 // hw_counters/alloc_pd_err
+    AllocUcontextErr  *uint64 // hw_counters/alloc_ucontext_err
+    CmdsErr           *uint64 // hw_counters/cmds_err
+    CompletedCmds     *uint64 // hw_counters/completed_cmds
+    CreateAhErr       *uint64 // hw_counters/create_ah_err
+    CreateCqErr       *uint64 // hw_counters/create_cq_err
+    CreateQpErr       *uint64 // hw_counters/create_qp_err
+    KeepAliveRcvd     *uint64 // hw_counters/keep_alive_rcvd
+    Lifespan          *uint64 // hw_counters/lifespan
+    MmapErr           *uint64 // hw_counters/mmap_err
+    NoCompletionCmds  *uint64 // hw_counters/no_completion_cmds
+    RdmaReadBytes     *uint64 // hw_counters/rdma_read_bytes
+    RdmaReadRespBytes *uint64 // hw_counters/rdma_read_resp_bytes
+    RdmaReadWrErr     *uint64 // hw_counters/rdma_read_wr_err
+    RdmaReadWrs       *uint64 // hw_counters/rdma_read_wrs
+    RecvBytes         *uint64 // hw_counters/recv_bytes
+    RecvWrs           *uint64 // hw_counters/recv_wrs
+    RegMrErr          *uint64 // hw_counters/reg_mr_err
+    RxBytes           *uint64 // hw_counters/rx_bytes
+    RxDrops           *uint64 // hw_counters/rx_drops
+    RxPkts            *uint64 // hw_counters/rx_pkts
+    SendBytes         *uint64 // hw_counters/send_bytes
+    SendWrs           *uint64 // hw_counters/send_wrs
+    SubmittedCmds     *uint64 // hw_counters/submitted_cmds
+    TxBytes           *uint64 // hw_counters/tx_bytes
+    TxPkts            *uint64 // hw_counters/tx_pkts
+}
+
+// AmazonEfaPort contains info from files in
+// /sys/class/infiniband/<Name>/ports/<Port>
+// for a single port of one Amazon Elastic Fabric Adapter device.
+type AmazonEfaPort struct {
+    Name        string
+    Port        uint
+    State       string // String representation from /sys/class/infiniband/<Name>/ports/<Port>/state
+    StateID     uint   // ID from /sys/class/infiniband/<Name>/ports/<Port>/state
+    PhysState   string // String representation from /sys/class/infiniband/<Name>/ports/<Port>/phys_state
+    PhysStateID uint   // String representation from /sys/class/infiniband/<Name>/ports/<Port>/phys_state
+    Rate        uint64 // in bytes/second from /sys/class/infiniband/<Name>/ports/<Port>/rate
+    Counters    AmazonEfaCounters
+}
+
+// AmazonEfaDevice contains info from files in /sys/class/infiniband for a
+// single Amazon Elastic Fabric Adapter (EFA) device.
+type AmazonEfaDevice struct {
+    Name  string
+    Ports map[uint]AmazonEfaPort
+}
+
+// AmazonEfaClass is a collection of every Amazon Elastic Fabric Adapter (EFA) device in
+// /sys/class/infiniband.
+//
+// The map keys are the names of the Amazon Elastic Fabric Adapter (EFA) devices.
+type AmazonEfaClass map[string]AmazonEfaDevice
+
+// AmazonEfaClass returns info for all Amazon Elastic Fabric Adapter (EFA) devices read from
+// /sys/class/infiniband.
+func (fs FS) AmazonEfaClass() (AmazonEfaClass, error) {
+    path := fs.sys.Path(AmazonEfaPath)
+
+    dirs, err := os.ReadDir(path)
+    if err != nil {
+        return nil, err
+    }
+
+    aec := make(AmazonEfaClass, len(dirs))
+    for _, d := range dirs {
+        device, err := fs.parseAmazonEfaDevice(d.Name())
+        if err != nil {
+            return nil, err
+        }
+
+        aec[device.Name] = *device
+    }
+
+    return aec, nil
+}
+
+// Parse one AmazonEfa device.
+func (fs FS) parseAmazonEfaDevice(name string) (*AmazonEfaDevice, error) {
+    path := fs.sys.Path(AmazonEfaPath, name)
+    device := AmazonEfaDevice{Name: name}
+
+    portsPath := filepath.Join(path, "ports")
+    ports, err := os.ReadDir(portsPath)
+    if err != nil {
+        return nil, fmt.Errorf("failed to list AmazonEfa ports at %q: %w", portsPath, err)
+    }
+
+    device.Ports = make(map[uint]AmazonEfaPort, len(ports))
+    for _, d := range ports {
+        port, err := fs.parseAmazonEfaPort(name, d.Name())
+        if err != nil {
+            return nil, err
+        }
+
+        device.Ports[port.Port] = *port
+    }
+
+    return &device, nil
+}
+
+// Scans predefined files in /sys/class/infiniband/<device>/ports/<port>
+// directory and gets their contents.
+func (fs FS) parseAmazonEfaPort(name string, port string) (*AmazonEfaPort, error) {
+    portNumber, err := strconv.ParseUint(port, 10, 32)
+    if err != nil {
+        return nil, fmt.Errorf("failed to convert %s into uint", port)
+    }
+    aep := AmazonEfaPort{Name: name, Port: uint(portNumber)}
+
+    portPath := fs.sys.Path(AmazonEfaPath, name, "ports", port)
+    content, err := os.ReadFile(filepath.Join(portPath, "state"))
+    if err != nil {
+        return nil, err
+    }
+    id, name, err := parseState(string(content))
+    if err != nil {
+        return nil, fmt.Errorf("could not parse state file in %q: %w", portPath, err)
+    }
+    aep.State = name
+    aep.StateID = id
+
+    content, err = os.ReadFile(filepath.Join(portPath, "phys_state"))
+    if err != nil {
+        return nil, err
+    }
+    id, name, err = parseState(string(content))
+    if err != nil {
+        return nil, fmt.Errorf("could not parse phys_state file in %q: %w", portPath, err)
+    }
+    aep.PhysState = name
+    aep.PhysStateID = id
+
+    content, err = os.ReadFile(filepath.Join(portPath, "rate"))
+    if err != nil {
+        return nil, err
+    }
+    aep.Rate, err = parseRate(string(content))
+    if err != nil {
+        return nil, fmt.Errorf("could not parse rate file in %q: %w", portPath, err)
+    }
+
+    counters, err := parseAmazonEfaCounters(portPath)
+    if err != nil {
+        return nil, err
+    }
+    aep.Counters = *counters
+
+    return &aep, nil
+}
+
+func parseAmazonEfaCounters(portPath string) (*AmazonEfaCounters, error) {
+    var counters AmazonEfaCounters
+
+    path := filepath.Join(portPath, "hw_counters")
+    files, err := os.ReadDir(path)
+    if err != nil {
+        return nil, err
+    }
+
+    for _, f := range files {
+        if !f.Type().IsRegular() {
+            continue
+        }
+
+        name := filepath.Join(path, f.Name())
+        value, err := util.SysReadFile(name)
+        if err != nil {
+            if os.IsNotExist(err) || os.IsPermission(err) || err.Error() == "operation not supported" || err.Error() == "invalid argument" {
+                continue
+            }
+            return nil, fmt.Errorf("failed to read file %q: %w", name, err)
+        }
+
+        vp := util.NewValueParser(value)
+
+        switch f.Name() {
+
+            case "lifespan":
+                counters.Lifespan = vp.PUInt64()
+            case "rdma_read_bytes":
+                counters.RdmaReadBytes = vp.PUInt64()
+            case "rdma_read_resp_bytes":
+                counters.RdmaReadRespBytes = vp.PUInt64()
+            case "rdma_read_wr_err":
+                counters.RdmaReadWrErr = vp.PUInt64()
+            case "rdma_read_wrs":
+                counters.RdmaReadWrs = vp.PUInt64()
+            case "recv_bytes":
+                counters.RecvBytes = vp.PUInt64()
+            case "recv_wrs":
+                counters.RecvWrs = vp.PUInt64()
+            case "rx_bytes":
+                counters.RxBytes = vp.PUInt64()
+            case "rx_drops":
+                counters.RxDrops = vp.PUInt64()
+            case "rx_pkts":
+                counters.RxPkts = vp.PUInt64()
+            case "send_bytes":
+                counters.SendBytes = vp.PUInt64()
+            case "send_wrs":
+                counters.SendWrs = vp.PUInt64()
+            case "tx_bytes":
+                counters.TxBytes = vp.PUInt64()
+            case "tx_pkts":
+                counters.TxPkts = vp.PUInt64()
+
+            if err != nil {
+                // Ugly workaround for handling https://github.com/prometheus/node_exporter/issues/966
+                // when counters are `N/A (not available)`.
+                // This was already patched and submitted, see
+                // https://www.spinics.net/lists/linux-rdma/msg68596.html
+                // Remove this as soon as the fix lands in the enterprise distros.
+                if strings.Contains(value, "N/A (no PMA)") {
+                    continue
+                }
+                return nil, err
+            }
+        }
+    }
+
+    return &counters, nil
+}