From 367fc07bbb32fb38eae99c832734b1ec4b779c55 Mon Sep 17 00:00:00 2001
From: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Date: Wed, 15 Oct 2025 16:57:18 +0900
Subject: [PATCH] limayaml: remove implementation details of QEMU

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
---
 pkg/driver/qemu/qemu.go  | 45 +++++++++++++++++++++++++++++++++--
 pkg/limayaml/defaults.go | 51 ----------------------------------------
 2 files changed, 43 insertions(+), 53 deletions(-)

diff --git a/pkg/driver/qemu/qemu.go b/pkg/driver/qemu/qemu.go
index 529b37471c8..30c15a4aaa8 100644
--- a/pkg/driver/qemu/qemu.go
+++ b/pkg/driver/qemu/qemu.go
@@ -19,6 +19,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/coreos/go-semver/semver"
@@ -427,8 +428,8 @@ func defaultCPUType() limatype.CPUType {
 		limatype.S390X:   "max",
 	}
 	for arch := range cpuType {
-		if limayaml.IsNativeArch(arch) && limayaml.IsAccelOS() {
-			if limayaml.HasHostCPU() {
+		if limayaml.IsNativeArch(arch) && Accel(arch) != "tcg" {
+			if hasHostCPU() {
 				cpuType[arch] = "host"
 			}
 		}
@@ -1272,3 +1273,43 @@ func getFirmwareVars(qemuExe string, arch limatype.Arch) (string, error) {
 
 	return "", fmt.Errorf("could not find firmware vars for %q", arch)
 }
+
+var hasSMEDarwin = sync.OnceValue(func() bool {
+	if runtime.GOOS != "darwin" || runtime.GOARCH != "arm64" {
+		return false
+	}
+	// golang.org/x/sys/cpu does not support inspecting the availability of SME yet
+	s, err := osutil.Sysctl(context.Background(), "hw.optional.arm.FEAT_SME")
+	if err != nil {
+		logrus.WithError(err).Debug("failed to check hw.optional.arm.FEAT_SME")
+	}
+	return s == "1"
+})
+
+func hasHostCPU() bool {
+	switch runtime.GOOS {
+	case "darwin":
+		if hasSMEDarwin() {
+			// [2025-02-05]
+			// SME is available since Apple M4 running macOS 15.2, but it was broken on macOS 15.2.
+			// It has been fixed in 15.3.
+			//
+			// https://github.com/lima-vm/lima/issues/3032
+			// https://gitlab.com/qemu-project/qemu/-/issues/2665
+			// https://gitlab.com/qemu-project/qemu/-/issues/2721
+
+			// [2025-02-12]
+			// SME got broken again after upgrading QEMU from 9.2.0 to 9.2.1 (Homebrew bottle).
+			// Possibly this regression happened in some build process rather than in QEMU itself?
+			// https://github.com/lima-vm/lima/issues/3226
+			return false
+		}
+		return true
+	case "linux":
+		return true
+	case "netbsd", "windows":
+		return false
+	}
+	// Not reached
+	return false
+}
diff --git a/pkg/limayaml/defaults.go b/pkg/limayaml/defaults.go
index 9e546d72e02..49be6d0fa8f 100644
--- a/pkg/limayaml/defaults.go
+++ b/pkg/limayaml/defaults.go
@@ -19,7 +19,6 @@ import (
 	"slices"
 	"strconv"
 	"strings"
-	"sync"
 	"text/template"
 
 	"github.com/docker/go-units"
@@ -974,56 +973,6 @@ func ResolveArch(s *string) limatype.Arch {
 	return *s
 }
 
-func IsAccelOS() bool {
-	switch runtime.GOOS {
-	case "darwin", "linux", "netbsd", "windows", "dragonfly":
-		// Accelerator
-		return true
-	}
-	// Using TCG
-	return false
-}
-
-var hasSMEDarwin = sync.OnceValue(func() bool {
-	if runtime.GOOS != "darwin" || runtime.GOARCH != "arm64" {
-		return false
-	}
-	// golang.org/x/sys/cpu does not support inspecting the availability of SME yet
-	s, err := osutil.Sysctl(context.Background(), "hw.optional.arm.FEAT_SME")
-	if err != nil {
-		logrus.WithError(err).Debug("failed to check hw.optional.arm.FEAT_SME")
-	}
-	return s == "1"
-})
-
-func HasHostCPU() bool {
-	switch runtime.GOOS {
-	case "darwin":
-		if hasSMEDarwin() {
-			// [2025-02-05]
-			// SME is available since Apple M4 running macOS 15.2, but it was broken on macOS 15.2.
-			// It has been fixed in 15.3.
-			//
-			// https://github.com/lima-vm/lima/issues/3032
-			// https://gitlab.com/qemu-project/qemu/-/issues/2665
-			// https://gitlab.com/qemu-project/qemu/-/issues/2721
-
-			// [2025-02-12]
-			// SME got broken again after upgrading QEMU from 9.2.0 to 9.2.1 (Homebrew bottle).
-			// Possibly this regression happened in some build process rather than in QEMU itself?
-			// https://github.com/lima-vm/lima/issues/3226
-			return false
-		}
-		return true
-	case "linux":
-		return true
-	case "netbsd", "windows":
-		return false
-	}
-	// Not reached
-	return false
-}
-
 func IsNativeArch(arch limatype.Arch) bool {
 	nativeX8664 := arch == limatype.X8664 && runtime.GOARCH == "amd64"
 	nativeAARCH64 := arch == limatype.AARCH64 && runtime.GOARCH == "arm64"