Merge pull request #1539 from afbjorklund/qemu-version

Check qemu version in hostagent so not too old

Author: AkihiroSuda

pkg/qemu/qemu.go

@@ -9,6 +9,7 @@ import (
 	"os/exec"
 	"os/user"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
@@ -36,6 +37,9 @@ type Config struct {
 	SSHLocalPort int
 }
 
+// MinimumQemuVersion is the minimum supported QEMU version
+const MinimumQemuVersion = "4.0.0"
+
 // EnsureDisk also ensures the kernel and the initrd
 func EnsureDisk(cfg Config) error {
 	diffDisk := filepath.Join(cfg.InstanceDir, filenames.DiffDisk)
@@ -341,6 +345,16 @@ func Cmdline(cfg Config) (string, []string, error) {
 		return "", nil, err
 	}
 
+	version, err := getQemuVersion(exe)
+	if err != nil {
+		logrus.WithError(err).Warning("Failed to detect QEMU version")
+	} else {
+		logrus.Debugf("QEMU version %s detected", version.String())
+		if version.LessThan(*semver.New(MinimumQemuVersion)) {
+			logrus.Fatalf("QEMU %v is too old, %v or later required", version, MinimumQemuVersion)
+		}
+	}
+
 	// Architecture
 	accel := getAccel(*y.Arch)
 	if !strings.Contains(string(features.AccelHelp), accel) {
@@ -717,6 +731,31 @@ func getAccel(arch limayaml.Arch) string {
 	return "tcg"
 }
 
+func parseQemuVersion(output string) (*semver.Version, error) {
+	lines := strings.Split(output, "\n")
+	regex := regexp.MustCompile(`^QEMU emulator version (\d+\.\d+\.\d+)`)
+	matches := regex.FindStringSubmatch(lines[0])
+	if len(matches) == 2 {
+		return semver.New(matches[1]), nil
+	}
+	return &semver.Version{}, fmt.Errorf("failed to parse %v", output)
+}
+
+func getQemuVersion(qemuExe string) (*semver.Version, error) {
+	var (
+		stdout bytes.Buffer
+		stderr bytes.Buffer
+	)
+	cmd := exec.Command(qemuExe, "--version")
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("failed to run %v: stdout=%q, stderr=%q", cmd.Args, stdout.String(), stderr.String())
+	}
+
+	return parseQemuVersion(stdout.String())
+}
+
 func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 	switch arch {
 	case limayaml.X8664, limayaml.AARCH64:

pkg/qemu/qemu_test.go

@@ -47,3 +47,42 @@ func TestArgValue(t *testing.T) {
 		assert.Equal(t, tc.expectedOK, ok)
 	}
 }
+
+func TestParseQemuVersion(t *testing.T) {
+	type testCase struct {
+		versionOutput string
+		expectedValue string
+		expectedError string
+	}
+	testCases := []testCase{
+		{
+			// old one line version
+			versionOutput: "QEMU emulator version 1.5.3 (qemu-kvm-1.5.3-175.el7_9.6), " +
+				"Copyright (c) 2003-2008 Fabrice Bellard\n",
+			expectedValue: "1.5.3",
+			expectedError: "",
+		},
+		{
+			// new two line version
+			versionOutput: "QEMU emulator version 8.0.0 (v8.0.0)\n" +
+				"Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers\n",
+			expectedValue: "8.0.0",
+			expectedError: "",
+		},
+		{
+			versionOutput: "foobar",
+			expectedValue: "0.0.0",
+			expectedError: "failed to parse",
+		},
+	}
+
+	for _, tc := range testCases {
+		v, err := parseQemuVersion(tc.versionOutput)
+		if tc.expectedError == "" {
+			assert.NilError(t, err)
+		} else {
+			assert.ErrorContains(t, err, tc.expectedError)
+		}
+		assert.Equal(t, tc.expectedValue, v.String())
+	}
+}