Add optional loading of UEFI firmware via -bios parameter in QEMU

Limiting this to X8664 arch as there is no information if this works for
other architectures. This allows to load UEFI firmware on Windows hosts,
where pflash can't be used in combination with WHPX acceleration.
Default to false on non-Windows hosts and true on Windows (to have
working default).

Signed-off-by: Arthur Sengileyev <arthur.sengileyev@gmail.com>

Author: arixmkii

pkg/limayaml/defaults.go

@@ -394,6 +394,16 @@ func FillDefault(y, d, o *LimaYAML, filePath string, warn bool) {
 		y.Firmware.LegacyBIOS = ptr.Of(false)
 	}
 
+	if y.Firmware.CompatUEFIViaBIOS == nil {
+		y.Firmware.CompatUEFIViaBIOS = d.Firmware.CompatUEFIViaBIOS
+	}
+	if o.Firmware.CompatUEFIViaBIOS != nil {
+		y.Firmware.CompatUEFIViaBIOS = o.Firmware.CompatUEFIViaBIOS
+	}
+	if y.Firmware.CompatUEFIViaBIOS == nil {
+		y.Firmware.CompatUEFIViaBIOS = ptr.Of(runtime.GOOS == "windows")
+	}
+
 	y.Firmware.Images = append(append(o.Firmware.Images, y.Firmware.Images...), d.Firmware.Images...)
 	for i := range y.Firmware.Images {
 		f := &y.Firmware.Images[i]

pkg/limayaml/defaults_test.go

@@ -92,7 +92,8 @@ func TestFillDefault(t *testing.T) {
 		},
 		TimeZone: ptr.Of(hostTimeZone()),
 		Firmware: Firmware{
-			LegacyBIOS: ptr.Of(false),
+			LegacyBIOS:        ptr.Of(false),
+			CompatUEFIViaBIOS: ptr.Of(runtime.GOOS == "windows"),
 		},
 		Audio: Audio{
 			Device: ptr.Of(""),
@@ -207,6 +208,7 @@ func TestFillDefault(t *testing.T) {
 					VMType: QEMU,
 				},
 			},
+			CompatUEFIViaBIOS: ptr.Of(false),
 		},
 	}
 
@@ -361,6 +363,7 @@ func TestFillDefault(t *testing.T) {
 					},
 				},
 			},
+			CompatUEFIViaBIOS: ptr.Of(runtime.GOOS != "windows"),
 		},
 		Audio: Audio{
 			Device: ptr.Of("coreaudio"),
@@ -568,7 +571,8 @@ func TestFillDefault(t *testing.T) {
 		},
 		TimeZone: ptr.Of("Universal"),
 		Firmware: Firmware{
-			LegacyBIOS: ptr.Of(true),
+			LegacyBIOS:        ptr.Of(true),
+			CompatUEFIViaBIOS: ptr.Of(true),
 		},
 		Audio: Audio{
 			Device: ptr.Of("coreaudio"),

pkg/limayaml/limayaml.go

@@ -182,6 +182,11 @@ type Firmware struct {
 	// LegacyBIOS is ignored for aarch64.
 	LegacyBIOS *bool `yaml:"legacyBIOS,omitempty" json:"legacyBIOS,omitempty" jsonschema:"nullable"`
 
+	// CompatUEFIViaBIOS forces QEMU to load concatenated firmware with -bios option
+	// CompatUEFIViaBIOS is ignored for non x86_64
+	// This should be deprecated, if the issue in QEMU is fixed https://gitlab.com/qemu-project/qemu/-/issues/513
+	CompatUEFIViaBIOS *bool `yaml:"compatUEFIInBIOS" json:"compatUEFIInBIOS,omitempty" jsonschema:"nullable"` // default: false on non Windows and true on Windows
+
 	// Images specify UEFI images (edk2-aarch64-code.fd.gz).
 	// Defaults to built-in UEFI.
 	Images []FileWithVMType `yaml:"images,omitempty" json:"images,omitempty"`

pkg/qemu/qemu.go

@@ -6,6 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"os/exec"
@@ -624,9 +625,44 @@ func Cmdline(ctx context.Context, cfg Config) (exe string, args []string, err er
 				return "", nil, err
 			}
 			logrus.Infof("Using system firmware (%q)", firmware)
+			if *y.Firmware.CompatUEFIViaBIOS && *y.Arch == limayaml.X8664 {
+				firmwareVars, err := getFirmwareVars(exe, *y.Arch)
+				if err != nil {
+					return "", nil, err
+				}
+				logrus.Infof("Using system firmware vars (%q)", firmwareVars)
+				varsFile, err := os.Open(firmwareVars)
+				if err != nil {
+					return "", nil, err
+				}
+				defer varsFile.Close()
+				codeFile, err := os.Open(firmware)
+				if err != nil {
+					return "", nil, err
+				}
+				defer codeFile.Close()
+				downloadedFile, err := os.OpenFile(downloadedFirmware, os.O_CREATE|os.O_WRONLY, 0o644)
+				if err != nil {
+					return "", nil, err
+				}
+				defer downloadedFile.Close()
+				_, err = io.Copy(downloadedFile, varsFile)
+				if err != nil {
+					return "", nil, err
+				}
+				_, err = io.Copy(downloadedFile, codeFile)
+				if err != nil {
+					return "", nil, err
+				}
+				firmware = downloadedFirmware
+			}
 		}
 		if firmware != "" {
-			args = append(args, "-drive", fmt.Sprintf("if=pflash,format=raw,readonly=on,file=%s", firmware))
+			if *y.Firmware.CompatUEFIViaBIOS && *y.Arch == limayaml.X8664 {
+				args = append(args, "-bios", firmware)
+			} else {
+				args = append(args, "-drive", fmt.Sprintf("if=pflash,format=raw,readonly=on,file=%s", firmware))
+			}
 		}
 	}
 
@@ -1120,9 +1156,11 @@ func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 	userLocalDir := filepath.Join(currentUser.HomeDir, ".local") // "$HOME/.local"
 
 	relativePath := fmt.Sprintf("share/qemu/edk2-%s-code.fd", qemuEdk2Arch(arch))
+	relativePathWin := fmt.Sprintf("share/edk2-%s-code.fd", qemuEdk2Arch(arch))
 	candidates := []string{
 		filepath.Join(userLocalDir, relativePath), // XDG-like
 		filepath.Join(localDir, relativePath),     // macOS (homebrew)
+		filepath.Join(binDir, relativePathWin),    // Windows installer
 	}
 
 	switch arch {
@@ -1164,3 +1202,40 @@ func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 	qemuArch := strings.TrimPrefix(filepath.Base(qemuExe), "qemu-system-")
 	return "", fmt.Errorf("could not find firmware for %q (hint: try copying the \"edk-%s-code.fd\" firmware to $HOME/.local/share/qemu/)", arch, qemuArch)
 }
+
+func getFirmwareVars(qemuExe string, arch limayaml.Arch) (string, error) {
+	var targetArch string
+	switch arch {
+	case limayaml.X8664:
+		targetArch = "i386"
+	default:
+		return "", fmt.Errorf("unexpected architecture: %q", arch)
+	}
+
+	currentUser, err := user.Current()
+	if err != nil {
+		return "", err
+	}
+
+	binDir := filepath.Dir(qemuExe)                              // "/usr/local/bin"
+	localDir := filepath.Dir(binDir)                             // "/usr/local"
+	userLocalDir := filepath.Join(currentUser.HomeDir, ".local") // "$HOME/.local"
+
+	relativePath := fmt.Sprintf("share/qemu/edk2-%s-vars.fd", qemuEdk2Arch(targetArch))
+	relativePathWin := fmt.Sprintf("share/edk2-%s-vars.fd", qemuEdk2Arch(targetArch))
+	candidates := []string{
+		filepath.Join(userLocalDir, relativePath), // XDG-like
+		filepath.Join(localDir, relativePath),     // macOS (homebrew)
+		filepath.Join(binDir, relativePathWin),    // Windows installer
+	}
+
+	logrus.Debugf("firmware vars candidates = %v", candidates)
+
+	for _, f := range candidates {
+		if _, err := os.Stat(f); err == nil {
+			return f, nil
+		}
+	}
+
+	return "", fmt.Errorf("could not find firmware vars for %q", arch)
+}

templates/default.yaml

@@ -337,14 +337,17 @@ firmware:
   # Use legacy BIOS instead of UEFI. Ignored for aarch64 and vz.
   # 🟢 Builtin default: false
   legacyBIOS: null
-#  # Override UEFI images
-#  # 🟢 Builtin default: uses VM's default UEFI, except for qemu + aarch64.
-#  # See <https://lists.gnu.org/archive/html/qemu-devel/2023-12/msg01694.html>
-#  images:
-#  - location: "~/Downloads/edk2-aarch64-code.fd.gz"
-#    arch: "aarch64"
-#    digest: "sha256:..."
-#    vmType: "qemu"
+  #  # Override UEFI images
+  #  # 🟢 Builtin default: uses VM's default UEFI, except for qemu + aarch64.
+  #  # See <https://lists.gnu.org/archive/html/qemu-devel/2023-12/msg01694.html>
+  #  images:
+  #  - location: "~/Downloads/edk2-aarch64-code.fd.gz"
+  #    arch: "aarch64"
+  #    digest: "sha256:..."
+  #    vmType: "qemu"
+  # Loads UEFI usigin -bios parameter for compatibility reasons. Applied only for QEMU x86_64.
+  # 🟢 Builtin default: false on non-Windows and true on Windows
+  compatUEFIInBIOS: null
 
 audio:
   # EXPERIMENTAL