refactor: migrate cpuType to qemu

Signed-off-by: Ansuman Sahoo <anshumansahoo500@gmail.com>

Author: unsuman

pkg/limayaml/defaults.go

@@ -60,47 +60,6 @@ var (
 	currentUser = Must(user.Current())
 )
 
-func defaultCPUType() CPUType {
-	// x86_64 + TCG + max was previously unstable until 2021.
-	// https://bugzilla.redhat.com/show_bug.cgi?id=1999700
-	// https://bugs.launchpad.net/qemu/+bug/1748296
-	defaultX8664 := "max"
-	if runtime.GOOS == "windows" && runtime.GOARCH == "amd64" {
-		// https://github.com/lima-vm/lima/pull/3487#issuecomment-2846253560
-		// > #931 intentionally prevented the code from setting it to max when running on Windows,
-		// > and kept it at qemu64.
-		//
-		// TODO: remove this if "max" works with the latest qemu
-		defaultX8664 = "qemu64"
-	}
-	cpuType := map[Arch]string{
-		AARCH64: "max",
-		ARMV7L:  "max",
-		X8664:   defaultX8664,
-		PPC64LE: "max",
-		RISCV64: "max",
-		S390X:   "max",
-	}
-	for arch := range cpuType {
-		if IsNativeArch(arch) && IsAccelOS() {
-			if HasHostCPU() {
-				cpuType[arch] = "host"
-			}
-		}
-		if arch == X8664 && runtime.GOOS == "darwin" {
-			// disable AVX-512, since it requires trapping instruction faults in guest
-			// Enterprise Linux requires either v2 (SSE4) or v3 (AVX2), but not yet v4.
-			cpuType[arch] += ",-avx512vl"
-
-			// Disable pdpe1gb on Intel Mac
-			// https://github.com/lima-vm/lima/issues/1485
-			// https://stackoverflow.com/a/72863744/5167443
-			cpuType[arch] += ",-pdpe1gb"
-		}
-	}
-	return cpuType
-}
-
 //go:embed containerd.yaml
 var defaultContainerdYAML []byte
 
@@ -312,28 +271,25 @@ func FillDefault(y, d, o *LimaYAML, filePath string, warn bool) {
 		}
 	}
 
-	cpuType := defaultCPUType()
-	var overrideCPUType bool
-	for k, v := range d.CPUType {
-		if v != "" {
-			overrideCPUType = true
-			cpuType[k] = v
-		}
+	if y.VMOpts.QEMU.CPUType == nil {
+		y.VMOpts.QEMU.CPUType = CPUType{}
 	}
-	for k, v := range y.CPUType {
-		if v != "" {
-			overrideCPUType = true
-			cpuType[k] = v
+	// TODO: This check should be removed when we completely eliminate `CPUType` from limayaml.
+	if len(y.CPUType) > 0 {
+		if warn {
+			logrus.Warn("The top-level `cpuType` field is deprecated and will be removed in a future release. Please migrate to `vmOpts.qemu.cpuType`.")
 		}
-	}
-	for k, v := range o.CPUType {
-		if v != "" {
-			overrideCPUType = true
-			cpuType[k] = v
+		for arch, v := range y.CPUType {
+			if v == "" {
+				continue
+			}
+			if existing, ok := y.VMOpts.QEMU.CPUType[arch]; ok && existing != "" && existing != v {
+				logrus.Warnf("Conflicting cpuType for arch %q: top-level=%q, vmOpts.qemu=%q; using vmOpts.qemu value", arch, v, existing)
+				continue
+			}
+			y.VMOpts.QEMU.CPUType[arch] = v
 		}
-	}
-	if *y.VMType == QEMU || overrideCPUType {
-		y.CPUType = cpuType
+		y.CPUType = nil
 	}
 
 	if y.CPUs == nil {

pkg/limayaml/defaults_test.go

@@ -78,7 +78,6 @@ func TestFillDefault(t *testing.T) {
 		VMType:             &defaultVMType,
 		OS:                 ptr.Of(LINUX),
 		Arch:               ptr.Of(arch),
-		CPUType:            defaultCPUType(),
 		CPUs:               ptr.Of(defaultCPUs()),
 		Memory:             ptr.Of(defaultMemoryAsString()),
 		Disk:               ptr.Of(defaultDiskSizeAsString()),
@@ -338,14 +337,6 @@ func TestFillDefault(t *testing.T) {
 		VMType: ptr.Of("vz"),
 		OS:     ptr.Of("unknown"),
 		Arch:   ptr.Of("unknown"),
-		CPUType: CPUType{
-			AARCH64: "arm64",
-			ARMV7L:  "armhf",
-			X8664:   "amd64",
-			PPC64LE: "ppc64le",
-			RISCV64: "riscv64",
-			S390X:   "s390x",
-		},
 		CPUs:   ptr.Of(7),
 		Memory: ptr.Of("5GiB"),
 		Disk:   ptr.Of("105GiB"),
@@ -558,14 +549,6 @@ func TestFillDefault(t *testing.T) {
 		VMType: ptr.Of("qemu"),
 		OS:     ptr.Of(LINUX),
 		Arch:   ptr.Of(arch),
-		CPUType: CPUType{
-			AARCH64: "uber-arm",
-			ARMV7L:  "armv8",
-			X8664:   "pentium",
-			PPC64LE: "power10",
-			RISCV64: "sifive-u54",
-			S390X:   "z14",
-		},
 		CPUs:   ptr.Of(12),
 		Memory: ptr.Of("7GiB"),
 		Disk:   ptr.Of("117GiB"),

pkg/limayaml/limayaml.go

@@ -10,13 +10,14 @@ import (
 )
 
 type LimaYAML struct {
-	Base                  BaseTemplates `yaml:"base,omitempty" json:"base,omitempty" jsonschema:"nullable"`
-	MinimumLimaVersion    *string       `yaml:"minimumLimaVersion,omitempty" json:"minimumLimaVersion,omitempty" jsonschema:"nullable"`
-	VMType                *VMType       `yaml:"vmType,omitempty" json:"vmType,omitempty" jsonschema:"nullable"`
-	VMOpts                VMOpts        `yaml:"vmOpts,omitempty" json:"vmOpts,omitempty"`
-	OS                    *OS           `yaml:"os,omitempty" json:"os,omitempty" jsonschema:"nullable"`
-	Arch                  *Arch         `yaml:"arch,omitempty" json:"arch,omitempty" jsonschema:"nullable"`
-	Images                []Image       `yaml:"images" json:"images"` // REQUIRED
+	Base               BaseTemplates `yaml:"base,omitempty" json:"base,omitempty" jsonschema:"nullable"`
+	MinimumLimaVersion *string       `yaml:"minimumLimaVersion,omitempty" json:"minimumLimaVersion,omitempty" jsonschema:"nullable"`
+	VMType             *VMType       `yaml:"vmType,omitempty" json:"vmType,omitempty" jsonschema:"nullable"`
+	VMOpts             VMOpts        `yaml:"vmOpts,omitempty" json:"vmOpts,omitempty"`
+	OS                 *OS           `yaml:"os,omitempty" json:"os,omitempty" jsonschema:"nullable"`
+	Arch               *Arch         `yaml:"arch,omitempty" json:"arch,omitempty" jsonschema:"nullable"`
+	Images             []Image       `yaml:"images" json:"images"` // REQUIRED
+	// Deprecated: Use VMOpts.Qemu.CPUType instead.
 	CPUType               CPUType       `yaml:"cpuType,omitempty" json:"cpuType,omitempty" jsonschema:"nullable"`
 	CPUs                  *int          `yaml:"cpus,omitempty" json:"cpus,omitempty" jsonschema:"nullable"`
 	Memory                *string       `yaml:"memory,omitempty" json:"memory,omitempty" jsonschema:"nullable"` // go-units.RAMInBytes
@@ -111,6 +112,7 @@ type VMOpts struct {
 
 type QEMUOpts struct {
 	MinimumVersion *string `yaml:"minimumVersion,omitempty" json:"minimumVersion,omitempty" jsonschema:"nullable"`
+	CPUType        CPUType `yaml:"cpuType,omitempty" json:"cpuType,omitempty" jsonschema:"nullable"`
 }
 
 type Rosetta struct {

pkg/limayaml/validate.go

@@ -119,12 +119,6 @@ func Validate(y *LimaYAML, warn bool) error {
 		}
 	}
 
-	for arch := range y.CPUType {
-		if !slices.Contains(ArchTypes, arch) {
-			return fmt.Errorf("field `cpuType` uses unsupported arch %q", arch)
-		}
-	}
-
 	if *y.CPUs == 0 {
 		return errors.New("field `cpus` must be set")
 	}

pkg/qemu/qemu.go

@@ -16,6 +16,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"runtime"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -480,6 +481,67 @@ func audioDevice() string {
 	return "oss"
 }
 
+func defaultCPUType() limayaml.CPUType {
+	// x86_64 + TCG + max was previously unstable until 2021.
+	// https://bugzilla.redhat.com/show_bug.cgi?id=1999700
+	// https://bugs.launchpad.net/qemu/+bug/1748296
+	defaultX8664 := "max"
+	if runtime.GOOS == "windows" && runtime.GOARCH == "amd64" {
+		// https://github.com/lima-vm/lima/pull/3487#issuecomment-2846253560
+		// > #931 intentionally prevented the code from setting it to max when running on Windows,
+		// > and kept it at qemu64.
+		//
+		// TODO: remove this if "max" works with the latest qemu
+		defaultX8664 = "qemu64"
+	}
+	cpuType := map[limayaml.Arch]string{
+		limayaml.AARCH64: "max",
+		limayaml.ARMV7L:  "max",
+		limayaml.X8664:   defaultX8664,
+		limayaml.PPC64LE: "max",
+		limayaml.RISCV64: "max",
+		limayaml.S390X:   "max",
+	}
+	for arch := range cpuType {
+		if limayaml.IsNativeArch(arch) && limayaml.IsAccelOS() {
+			if limayaml.HasHostCPU() {
+				cpuType[arch] = "host"
+			}
+		}
+		if arch == limayaml.X8664 && runtime.GOOS == "darwin" {
+			// disable AVX-512, since it requires trapping instruction faults in guest
+			// Enterprise Linux requires either v2 (SSE4) or v3 (AVX2), but not yet v4.
+			cpuType[arch] += ",-avx512vl"
+
+			// Disable pdpe1gb on Intel Mac
+			// https://github.com/lima-vm/lima/issues/1485
+			// https://stackoverflow.com/a/72863744/5167443
+			cpuType[arch] += ",-pdpe1gb"
+		}
+	}
+	return cpuType
+}
+
+func resolveCPUType(y *limayaml.LimaYAML) string {
+	cpuType := defaultCPUType()
+	var overrideCPUType bool
+	for k, v := range y.VMOpts.QEMU.CPUType {
+		if !slices.Contains(limayaml.ArchTypes, *y.Arch) {
+			logrus.Warnf("field `vmOpts.qemu.cpuType` uses unsupported arch %q", k)
+			continue
+		}
+		if v != "" {
+			overrideCPUType = true
+			cpuType[k] = v
+		}
+	}
+	if overrideCPUType {
+		y.VMOpts.QEMU.CPUType = cpuType
+	}
+
+	return cpuType[*y.Arch]
+}
+
 func Cmdline(ctx context.Context, cfg Config) (exe string, args []string, err error) {
 	y := cfg.LimaYAML
 	exe, args, err = Exe(*y.Arch)
@@ -531,7 +593,7 @@ func Cmdline(ctx context.Context, cfg Config) (exe string, args []string, err er
 	}
 
 	// CPU
-	cpu := y.CPUType[*y.Arch]
+	cpu := resolveCPUType(y)
 	if runtime.GOOS == "darwin" && runtime.GOARCH == "amd64" {
 		switch {
 		case strings.HasPrefix(cpu, "host"), strings.HasPrefix(cpu, "max"):

pkg/store/instance.go

@@ -95,7 +95,7 @@ func Inspect(instName string) (*Instance, error) {
 	inst.Config = y
 	inst.Arch = *y.Arch
 	inst.VMType = *y.VMType
-	inst.CPUType = y.CPUType[*y.Arch]
+	inst.CPUType = resolveCPUType(y)
 	inst.SSHAddress = "127.0.0.1"
 	inst.SSHLocalPort = *y.SSH.LocalPort // maybe 0
 	inst.SSHConfigFile = filepath.Join(instDir, filenames.SSHConfig)
@@ -184,6 +184,13 @@ func Inspect(instName string) (*Instance, error) {
 	return inst, nil
 }
 
+func resolveCPUType(y *limayaml.LimaYAML) string {
+	if len(y.VMOpts.QEMU.CPUType) == 0 {
+		return y.CPUType[*y.Arch]
+	}
+	return y.VMOpts.QEMU.CPUType[*y.Arch]
+}
+
 func inspectStatusWithPIDFiles(instDir string, inst *Instance, y *limayaml.LimaYAML) {
 	var err error
 	inst.DriverPID, err = ReadPIDFile(filepath.Join(instDir, filenames.PIDFile(*y.VMType)))

pkg/vz/vz_driver_darwin.go

@@ -107,6 +107,7 @@ func (l *LimaVzDriver) Validate() error {
 		return fmt.Errorf("unsupported arch: %q", *l.Instance.Config.Arch)
 	}
 
+	// TODO: This check should be removed when we completely eliminate `CPUType` from limayaml.
 	for k, v := range l.Instance.Config.CPUType {
 		if v != "" {
 			logrus.Warnf("vmType %s: ignoring cpuType[%q]: %q", *l.Instance.Config.VMType, k, v)

templates/default.yaml

@@ -324,11 +324,21 @@ vmOpts:
     # Will be ignored if the vmType is not "qemu"
     # 🟢 Builtin default: not set
     minimumVersion: null
+    # Specify desired QEMU CPU type for each arch.
+    # You can see what options are available for host emulation with: `qemu-system-$(arch) -cpu help`.
+    # Setting of instructions is supported like this: "qemu64,+ssse3".
+    # 🟢 Builtin default: hard-coded arch map with type (see the output of `limactl info | jq .defaultTemplate.cpuType`)
+    cpuType:
+    #   aarch64: "max" # (or "host" when running on aarch64 host)
+    #   armv7l:  "max" # (or "host" when running on armv7l host)
+    #   riscv64: "max" # (or "host" when running on riscv64 host)
+    #   x86_64:  "max" # (or "host" when running on x86_64 host; additional options are appended on Intel Mac)
 
 # OS: "Linux".
 # 🟢 Builtin default: "Linux"
 os: null
 
+# DEPRECATED: Use vmOpts.qemu.cpuType instead.
 # Specify desired QEMU CPU type for each arch.
 # You can see what options are available for host emulation with: `qemu-system-$(arch) -cpu help`.
 # Setting of instructions is supported like this: "qemu64,+ssse3".