qemu: riscv64: switch from u-boot to EDK2

u-boot no longer needs to be specified as the "kernel" image,
as EDK2 (`edk2-riscv-code.fd`) is available since QEMU v9.1.

ACPI is disabled, as suggested in
https://github.com/tianocore/edk2/blob/edk2-stable202408/OvmfPkg/RiscVVirt/README.md#test

Signed-off-by: Akihiro Suda <[email protected]>

examples/experimental/riscv64.yaml

@@ -1,22 +1,18 @@
-# This template requires Lima v0.11.0 or later.
+# Lima v0.x users should use https://raw.githubusercontent.com/lima-vm/lima/v0.23.2/examples/experimental/riscv64.yaml
+minimumLimaVersion: "1.0.0"
+vmOpts:
+  qemu:
+    minimumVersion: "9.1.0"
 
 arch: "riscv64"
 images:
 - location: "https://cloud-images.ubuntu.com/releases/24.04/release-20240821/ubuntu-24.04-server-cloudimg-riscv64.img"
   arch: "riscv64"
   digest: "sha256:f5886ad4e405e689585dfef0e96c31b06478e0cb12bc7f3fae965759a32d729e"
-  kernel:
-    # Extracted from http://http.us.debian.org/debian/pool/main/u/u-boot/u-boot-qemu_2023.07+dfsg-1_all.deb (GPL-2.0)
-    location: "https://github.com/lima-vm/u-boot-qemu-mirror/releases/download/2023.07%2Bdfsg-7/qemu-riscv64_smode_uboot.elf"
-    digest: "sha256:d4b3a10c3ef04219641802a586dca905e768805f5a5164fb68520887df54f33c"
 # Fallback to the latest release image.
 # Hint: run `limactl prune` to invalidate the cache
 - location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-riscv64.img"
   arch: "riscv64"
-  kernel:
-    # Extracted from http://http.us.debian.org/debian/pool/main/u/u-boot/u-boot-qemu_2023.07+dfsg-1_all.deb (GPL-2.0)
-    location: "https://github.com/lima-vm/u-boot-qemu-mirror/releases/download/2023.07%2Bdfsg-1/qemu-riscv64_smode_uboot.elf"
-    digest: "sha256:d4b3a10c3ef04219641802a586dca905e768805f5a5164fb68520887df54f33c"
 
 mounts:
 - location: "~"

pkg/limayaml/validate.go

@@ -101,8 +101,6 @@ func Validate(y *LimaYAML, warn bool) error {
 			if f.Kernel.Arch != f.Arch {
 				return fmt.Errorf("images[%d].kernel has unexpected architecture %q, must be %q", i, f.Kernel.Arch, f.Arch)
 			}
-		} else if f.Arch == RISCV64 {
-			return errors.New("riscv64 needs the kernel (e.g., \"uboot.elf\") to be specified")
 		}
 		if f.Initrd != nil {
 			if err := validateFileObject(*f.Initrd, fmt.Sprintf("images[%d].initrd", i)); err != nil {

pkg/qemu/qemu.go

@@ -573,7 +573,12 @@ func Cmdline(ctx context.Context, cfg Config) (exe string, args []string, err er
 		}
 		args = appendArgsIfNoConflict(args, "-machine", machine)
 	case limayaml.RISCV64:
-		machine := "virt,accel=" + accel
+		// https://github.com/tianocore/edk2/blob/edk2-stable202408/OvmfPkg/RiscVVirt/README.md#test
+		// > Note: the `acpi=off` machine property is specified because Linux guest
+		// > support for ACPI (that is, the ACPI consumer side) is a work in progress.
+		// > Currently, `acpi=off` is recommended unless you are developing ACPI support
+		// > yourself.
+		machine := "virt,acpi=off,accel=" + accel
 		args = appendArgsIfNoConflict(args, "-machine", machine)
 	case limayaml.ARMV7L:
 		machine := "virt,accel=" + accel
@@ -613,7 +618,7 @@ func Cmdline(ctx context.Context, cfg Config) (exe string, args []string, err er
 			firmware = downloadedFirmware
 			logrus.Infof("Using existing firmware (%q)", firmware)
 		}
-		if firmware == "" && *y.Arch != limayaml.RISCV64 {
+		if firmware == "" {
 			firmware, err = getFirmware(exe, *y.Arch)
 			if err != nil {
 				return "", nil, err
@@ -1031,6 +1036,14 @@ func qemuArch(arch limayaml.Arch) string {
 	return arch
 }
 
+// qemuEdk2 returns the arch string used by `/usr/local/share/qemu/edk2-*-code.fd`.
+func qemuEdk2Arch(arch limayaml.Arch) string {
+	if arch == limayaml.RISCV64 {
+		return "riscv"
+	}
+	return qemuArch(arch)
+}
+
 func Exe(arch limayaml.Arch) (exe string, args []string, err error) {
 	exeBase := "qemu-system-" + qemuArch(arch)
 	envK := "QEMU_SYSTEM_" + strings.ToUpper(qemuArch(arch))
@@ -1094,7 +1107,7 @@ func getQemuVersion(qemuExe string) (*semver.Version, error) {
 
 func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 	switch arch {
-	case limayaml.X8664, limayaml.AARCH64, limayaml.ARMV7L:
+	case limayaml.X8664, limayaml.AARCH64, limayaml.ARMV7L, limayaml.RISCV64:
 	default:
 		return "", fmt.Errorf("unexpected architecture: %q", arch)
 	}
@@ -1108,7 +1121,7 @@ func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 	localDir := filepath.Dir(binDir)                             // "/usr/local"
 	userLocalDir := filepath.Join(currentUser.HomeDir, ".local") // "$HOME/.local"
 
-	relativePath := fmt.Sprintf("share/qemu/edk2-%s-code.fd", qemuArch(arch))
+	relativePath := fmt.Sprintf("share/qemu/edk2-%s-code.fd", qemuEdk2Arch(arch))
 	candidates := []string{
 		filepath.Join(userLocalDir, relativePath), // XDG-like
 		filepath.Join(localDir, relativePath),     // macOS (homebrew)
@@ -1135,6 +1148,8 @@ func getFirmware(qemuExe string, arch limayaml.Arch) (string, error) {
 		// Debian package "qemu-efi-arm"
 		// Fedora package "edk2-arm"
 		candidates = append(candidates, "/usr/share/AAVMF/AAVMF32_CODE.fd")
+	case limayaml.RISCV64:
+		// NOP, as EDK2 for RISCV64 is not packaged yet in well-known distros.
 	}
 
 	logrus.Debugf("firmware candidates = %v", candidates)

pkg/qemu/qemu_driver.go

@@ -296,7 +296,8 @@ func (l *LimaQemuDriver) killVhosts() error {
 }
 
 func (l *LimaQemuDriver) shutdownQEMU(ctx context.Context, timeout time.Duration, qCmd *exec.Cmd, qWaitCh <-chan error) error {
-	logrus.Info("Shutting down QEMU with ACPI")
+	// "power button" refers to ACPI on the most archs, except RISC-V
+	logrus.Info("Shutting down QEMU with the power button")
 	if usernetIndex := limayaml.FirstUsernetIndex(l.Instance.Config); usernetIndex != -1 {
 		client := usernet.NewClientByName(l.Instance.Config.Networks[usernetIndex].Lima)
 		err := client.UnExposeSSH(l.SSHLocalPort)