Support for Virt driver

This is a driver based on libvirt.org, for remote hypervisors.

The libvirt functions are in a plugin, to minimize dependencies.

Currently only shows version.

Signed-off-by: Anders F Björklund <[email protected]>

Author: afbjorklund

Kconfig

@@ -30,3 +30,9 @@ config GUESTAGENT_ARCH_RISCV64
 	help
 		Build lima-guestagent for "riscv64" Arch
 	default y
+
+config PLUGIN_VIRT
+	bool "plugin for vmType virt"
+	help
+		Build plugin for virt (requires libvirt)
+	default y

Makefile

@@ -38,6 +38,12 @@ endif
 endif
 endif
 
+-include .config
+
+ifneq ($(CONFIG_PLUGIN_VIRT),y)
+GO_BUILDTAGS += no_virt
+endif
+
 PACKAGE := github.com/lima-vm/lima
 
 VERSION=$(shell git describe --match 'v[0-9]*' --dirty='.m' --always --tags)
@@ -77,15 +83,18 @@ menuconfig: Kconfig
 .config: config.mk
 	cp $^ $@
 
--include .config
-
 HELPERS = \
 	_output/bin/nerdctl.lima \
 	_output/bin/apptainer.lima \
 	_output/bin/docker.lima \
 	_output/bin/podman.lima \
 	_output/bin/kubectl.lima
 
+ifeq ($(CONFIG_PLUGIN_VIRT),y)
+PLUGINS += \
+	_output/lib/lima/plugin/virt.so
+endif
+
 ifeq ($(CONFIG_GUESTAGENT_OS_LINUX),y)
 ifeq ($(CONFIG_GUESTAGENT_ARCH_X8664),y)
 GUESTAGENT += \
@@ -112,6 +121,7 @@ binaries: clean \
 	_output/bin/limactl$(exe) \
 	codesign \
 	$(HELPERS) \
+	$(PLUGINS) \
 	$(GUESTAGENT)
 	cp -aL examples _output/share/lima/templates
 ifneq ($(GOOS),windows)
@@ -188,6 +198,12 @@ _output/share/lima/lima-guestagent.Linux-riscv64:
 	GOOS=linux GOARCH=riscv64 CGO_ENABLED=0 $(GO_BUILD) -o $@ ./cmd/lima-guestagent
 	chmod 644 $@
 
+plugins: $(PLUGINS)
+
+.PHONY: _output/lib/lima/plugin/virt.so
+_output/lib/lima/plugin/virt.so:
+	CGO_ENABLED=1 $(GO_BUILD) -buildmode=plugin -o $@ ./pkg/virt/plugin
+
 .PHONY: manpages
 manpages: _output/bin/limactl$(exe)
 	@mkdir -p _output/share/man/man1

config.mk

@@ -3,3 +3,4 @@ CONFIG_GUESTAGENT_ARCH_X8664=y
 CONFIG_GUESTAGENT_ARCH_AARCH64=y
 CONFIG_GUESTAGENT_ARCH_ARMV7L=y
 CONFIG_GUESTAGENT_ARCH_RISCV64=y
+CONFIG_PLUGIN_VIRT=y

examples/experimental/virt.yaml

@@ -0,0 +1,13 @@
+# A template to run ubuntu using vmType: virt instead of qemu (Default)
+vmType: "virt"
+
+images:
+- location: "https://cloud-images.ubuntu.com/releases/22.04/release/ubuntu-22.04-server-cloudimg-amd64.img"
+  arch: "x86_64"
+- location: "https://cloud-images.ubuntu.com/releases/22.04/release/ubuntu-22.04-server-cloudimg-arm64.img"
+  arch: "aarch64"
+
+mounts:
+- location: "~"
+- location: "/tmp/lima"
+  writable: true

go.mod

@@ -48,6 +48,9 @@ require (
 	k8s.io/client-go v0.28.4
 )
 
+// pkg/virt/plugin
+require libvirt.org/go/libvirt v1.9008.0
+
 require google.golang.org/genproto/googleapis/rpc v0.0.0-20230711160842-782d3b101e98 // indirect
 
 require (

go.sum

@@ -418,6 +418,8 @@ k8s.io/kube-openapi v0.0.0-20230717233707-2695361300d9 h1:LyMgNKD2P8Wn1iAwQU5Ohx
 k8s.io/kube-openapi v0.0.0-20230717233707-2695361300d9/go.mod h1:wZK2AVp1uHCp4VamDVgBP2COHZjqD1T68Rf0CM3YjSM=
 k8s.io/utils v0.0.0-20230406110748-d93618cff8a2 h1:qY1Ad8PODbnymg2pRbkyMT/ylpTrCM8P2RJ0yroCyIk=
 k8s.io/utils v0.0.0-20230406110748-d93618cff8a2/go.mod h1:OLgZIPagt7ERELqWJFomSt595RzquPNLL48iOWgYOg0=
+libvirt.org/go/libvirt v1.9008.0 h1:LLpjuSQm9gChnx7I/44SLLg/eyvTnJpcMAFmKot65Zc=
+libvirt.org/go/libvirt v1.9008.0/go.mod h1:1WiFE8EjZfq+FCVog+rvr1yatKbKZ9FaFMZgEqxEJqQ=
 sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd h1:EDPBXCAspyGV4jQlpZSudPeMmr1bNJefnuqLsRAsHZo=
 sigs.k8s.io/json v0.0.0-20221116044647-bc3834ca7abd/go.mod h1:B8JuhiUyNFVKdsE8h686QcCxMaH6HrOAZj4vswFpcB0=
 sigs.k8s.io/structured-merge-diff/v4 v4.2.3 h1:PRbqxJClWWYMNV1dhaG4NsibJbArud9kFxnAMREiWFE=

pkg/driverutil/driverutil.go

@@ -2,13 +2,17 @@ package driverutil
 
 import (
 	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/virt"
 	"github.com/lima-vm/lima/pkg/vz"
 	"github.com/lima-vm/lima/pkg/wsl2"
 )
 
 // Drivers returns the available drivers.
 func Drivers() []string {
 	drivers := []string{limayaml.QEMU}
+	if virt.Enabled {
+		drivers = append(drivers, limayaml.VIRT)
+	}
 	if vz.Enabled {
 		drivers = append(drivers, limayaml.VZ)
 	}

pkg/driverutil/instance.go

@@ -4,12 +4,16 @@ import (
 	"github.com/lima-vm/lima/pkg/driver"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/qemu"
+	"github.com/lima-vm/lima/pkg/virt"
 	"github.com/lima-vm/lima/pkg/vz"
 	"github.com/lima-vm/lima/pkg/wsl2"
 )
 
 func CreateTargetDriverInstance(base *driver.BaseDriver) driver.Driver {
 	limaDriver := base.Yaml.VMType
+	if *limaDriver == limayaml.VIRT {
+		return virt.New(base)
+	}
 	if *limaDriver == limayaml.VZ {
 		return vz.New(base)
 	}

pkg/limayaml/defaults.go

@@ -848,6 +848,8 @@ func NewArch(arch string) Arch {
 
 func NewVMType(driver string) VMType {
 	switch driver {
+	case "virt":
+		return VIRT
 	case "vz":
 		return VZ
 	case "qemu":

pkg/limayaml/limayaml.go

@@ -62,6 +62,7 @@ const (
 	WSLMount MountType = "wsl2"
 
 	QEMU VMType = "qemu"
+	VIRT VMType = "virt"
 	VZ   VMType = "vz"
 	WSL2 VMType = "wsl2"
 )

pkg/limayaml/validate.go

@@ -61,8 +61,10 @@ func Validate(y LimaYAML, warn bool) error {
 		if !IsNativeArch(*y.Arch) {
 			return fmt.Errorf("field `arch` must be %q for VZ; got %q", NewArch(runtime.GOARCH), *y.Arch)
 		}
+	case VIRT:
+		// NOP
 	default:
-		return fmt.Errorf("field `vmType` must be %q, %q, %q; got %q", QEMU, VZ, WSL2, *y.VMType)
+		return fmt.Errorf("field `vmType` must be %q, %q, %q, %q; got %q", QEMU, VIRT, VZ, WSL2, *y.VMType)
 	}
 
 	if len(y.Images) == 0 {

pkg/usrlocalliblima/usrlocalliblima.go

@@ -0,0 +1,34 @@
+package usrlocalliblima
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+func Dir() (string, error) {
+	self, err := os.Executable()
+	if err != nil {
+		return "", err
+	}
+	selfSt, err := os.Stat(self)
+	if err != nil {
+		return "", err
+	}
+	if selfSt.Mode()&fs.ModeSymlink != 0 {
+		self, err = os.Readlink(self)
+		if err != nil {
+			return "", err
+		}
+	}
+
+	// self:  /usr/local/bin/limactl
+	selfDir := filepath.Dir(self)
+	selfDirDir := filepath.Dir(selfDir)
+	libLimaDir := filepath.Join(selfDirDir, "lib", "lima")
+	if _, err := os.Stat(libLimaDir); err == nil {
+		return libLimaDir, nil
+	} else {
+		return "", err
+	}
+}

pkg/virt/disk.go

@@ -0,0 +1,49 @@
+package virt
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+
+	"github.com/docker/go-units"
+	"github.com/lima-vm/lima/pkg/driver"
+	"github.com/lima-vm/lima/pkg/fileutils"
+	"github.com/lima-vm/lima/pkg/iso9660util"
+	"github.com/lima-vm/lima/pkg/store/filenames"
+)
+
+func EnsureDisk(driver *driver.BaseDriver) error {
+	diffDisk := filepath.Join(driver.Instance.Dir, filenames.DiffDisk)
+	if _, err := os.Stat(diffDisk); err == nil || !errors.Is(err, os.ErrNotExist) {
+		// disk is already ensured
+		return err
+	}
+
+	baseDisk := filepath.Join(driver.Instance.Dir, filenames.BaseDisk)
+	if _, err := os.Stat(baseDisk); errors.Is(err, os.ErrNotExist) {
+		var ensuredBaseDisk bool
+		errs := make([]error, len(driver.Yaml.Images))
+		for i, f := range driver.Yaml.Images {
+			if _, err := fileutils.DownloadFile(baseDisk, f.File, true, "the image", *driver.Yaml.Arch); err != nil {
+				errs[i] = err
+				continue
+			}
+			ensuredBaseDisk = true
+			break
+		}
+		if !ensuredBaseDisk {
+			return fileutils.Errors(errs)
+		}
+	}
+	diskSize, _ := units.RAMInBytes(*driver.Yaml.Disk)
+	if diskSize == 0 {
+		return nil
+	}
+	isBaseDiskISO, err := iso9660util.IsISO9660(baseDisk)
+	if err != nil {
+		return err
+	}
+	_ = isBaseDiskISO
+	// TODO
+	return nil
+}

pkg/virt/plugin/main.go

@@ -0,0 +1,9 @@
+package main
+
+import (
+	"libvirt.org/go/libvirt"
+)
+
+var VERSION uint32 = libvirt.VERSION_NUMBER
+
+func Version() (uint32, error) { return libvirt.GetVersion() }

pkg/virt/virt_driver_others.go

@@ -0,0 +1,40 @@
+//go:build windows || no_virt
+
+package virt
+
+import (
+	"context"
+	"errors"
+
+	"github.com/lima-vm/lima/pkg/driver"
+)
+
+var ErrUnsupported = errors.New("vm driver 'virt' is not supported")
+
+const Enabled = false
+
+type LimaVirtDriver struct {
+	*driver.BaseDriver
+}
+
+func New(driver *driver.BaseDriver) *LimaVirtDriver {
+	return &LimaVirtDriver{
+		BaseDriver: driver,
+	}
+}
+
+func (l *LimaVirtDriver) Validate() error {
+	return ErrUnsupported
+}
+
+func (l *LimaVirtDriver) CreateDisk() error {
+	return ErrUnsupported
+}
+
+func (l *LimaVirtDriver) Start(_ context.Context) (chan error, error) {
+	return nil, ErrUnsupported
+}
+
+func (l *LimaVirtDriver) Stop(_ context.Context) error {
+	return ErrUnsupported
+}

pkg/virt/virt_driver_unix.go

@@ -0,0 +1,72 @@
+//go:build !windows && !no_virt
+
+package virt
+
+import (
+	"context"
+	"errors"
+	"path/filepath"
+	"plugin"
+
+	"github.com/lima-vm/lima/pkg/driver"
+	"github.com/lima-vm/lima/pkg/usrlocalliblima"
+	"github.com/sirupsen/logrus"
+)
+
+const Enabled = true
+
+type LimaVirtDriver struct {
+	*driver.BaseDriver
+
+	virtPlugin *plugin.Plugin
+}
+
+func New(driver *driver.BaseDriver) *LimaVirtDriver {
+	return &LimaVirtDriver{
+		BaseDriver: driver,
+	}
+}
+
+func (l *LimaVirtDriver) Validate() error {
+	dir, err := usrlocalliblima.Dir()
+	if err != nil {
+		return err
+	}
+	p, err := plugin.Open(filepath.Join(dir, "plugin/virt.so"))
+	if err != nil {
+		return err
+	}
+
+	// test variable
+	v, err := p.Lookup("VERSION")
+	if err != nil {
+		return err
+	}
+	n := *v.(*uint32)
+	logrus.Infof("VERSION: %d", n)
+	// test function
+	f, err := p.Lookup("Version")
+	if err != nil {
+		return err
+	}
+	n, err = f.(func() (uint32, error))()
+	if err != nil {
+		return err
+	}
+	logrus.Infof("Version: %d", n)
+
+	l.virtPlugin = p
+	return nil
+}
+
+func (l *LimaVirtDriver) CreateDisk() error {
+	return EnsureDisk(l.BaseDriver)
+}
+
+func (l *LimaVirtDriver) Start(_ context.Context) (chan error, error) {
+	return nil, errors.New("TODO")
+}
+
+func (l *LimaVirtDriver) Stop(_ context.Context) error {
+	return nil
+}