qemu: use 9p by default

.github/workflows/test.yml

@@ -256,6 +256,15 @@ jobs:
  if: matrix.template == '../hack/test-templates/test-misc.yaml'
  - name: "Show cache"
  run: ./hack/debug-cache.sh
+ - name: "Adjust LIMACTL_CREATE_ARGS"
+ # Change the mount type from 9p to reverse-sshfs, as a workaround for:
+ #
+ # > level=fatal msg="failed to get unprivileged mount flags for \"/home/runner/lima-container-engine-test-tmp/random\": stat /home/runner/lima-container-engine-test-tmp/random: no such file or directory"
+ #
+ # The issue is not reproducible on a local MacBook.
+ # https:/lima-vm/lima/issues/2701
+ run: echo "LIMACTL_CREATE_ARGS=${LIMACTL_CREATE_ARGS} --mount-type=reverse-sshfs" >>$GITHUB_ENV
+ if: matrix.template == 'archlinux.yaml'
  - name: "Test"
  uses: nick-fields/retry@v3
  with:

examples/almalinux-8.yaml

@@ -16,6 +16,7 @@ images:
  arch: "x86_64"
 - location: "https://repo.almalinux.org/almalinux/8/cloud/aarch64/images/AlmaLinux-8-GenericCloud-latest.aarch64.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/almalinux-9.yaml

@@ -13,6 +13,7 @@ images:
  arch: "x86_64"
 - location: "https://repo.almalinux.org/almalinux/9/cloud/aarch64/images/AlmaLinux-9-GenericCloud-latest.aarch64.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/centos-stream-9.yaml

@@ -14,6 +14,7 @@ images:
  arch: "x86_64"
 - location: "https://cloud.centos.org/centos/9-stream/aarch64/images/CentOS-Stream-GenericCloud-9-latest.aarch64.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/debian-11.yaml

@@ -13,7 +13,7 @@ images:
  arch: "x86_64"
 - location: "https://cloud.debian.org/images/cloud/bullseye/latest/debian-11-genericcloud-arm64.qcow2"
  arch: "aarch64"
-
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/debian-12.yaml

@@ -13,7 +13,7 @@ images:
  arch: "x86_64"
 - location: "https://cloud.debian.org/images/cloud/bookworm/latest/debian-12-genericcloud-arm64.qcow2"
  arch: "aarch64"
-
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/default.yaml

@@ -71,8 +71,7 @@ mounts:
  # Configure the mountPoint inside the guest.
  # 🟢 Builtin default: value of location
  mountPoint: null
- # CAUTION: `writable` SHOULD be false for the home directory.
- # Setting `writable` to true is possible, but untested and dangerous.
+ # Setting `writable` to true is discouraged when mountType is set to "reverse-sshfs".
  # 🟢 Builtin default: false
  writable: null
  sshfs:
@@ -112,9 +111,14 @@ mounts:
  # 🔵 This file: true (only for "/tmp/lima")
  writable: true
 
-# Mount type for above mounts, such as "reverse-sshfs" (from sshocker), "9p" (EXPERIMENTAL, from QEMU’s virtio-9p-pci, aka virtfs),
+# List of mount types not supported by the kernel of this distro.
+# Also used to resolve the default mount type when not explicitly specified.
+# 🟢 Builtin default: null
+mountTypesUnsupported: null
+
+# Mount type for above mounts, such as "reverse-sshfs" (from sshocker), "9p" (EXPERIMENTAL until Lima v1.0, from QEMU’s virtio-9p-pci, aka virtfs),
 # or "virtiofs" (EXPERIMENTAL, needs `vmType: vz`; will graduate from experimental in Lima v1.0)
-# 🟢 Builtin default: "reverse-sshfs" (for QEMU), "virtiofs" (for vz)
+# 🟢 Builtin default: "default" (resolved to be "9p" for QEMU since Lima v1.0, "virtiofs" for vz)
 mountType: null
 
 # Enable inotify support for mounted directories (EXPERIMENTAL)

examples/experimental/9p.yaml

@@ -1,3 +1,11 @@
+# ⚠️ ⚠️ ⚠️ `template://experimental/9p` will be removed in Lima v1.0,
+# as 9p will graduate from experimental and will be the default mount type for QEMU.
+#
+# For Lima v1.0 and later, use the following command instead:
+# ```
+# limactl create --vm-type=qemu template://default
+# ```
+
 # This template requires Lima v0.10.0 or later.
 # On macOS hosts, QEMU needs to be v7.0.0 or later. Homebrew's QEMU v6.2.0_1 can be used too.
 # This template is planned to be merged to default.yaml in Lima v1.0 (ETA: 2022 Q2).

examples/experimental/opensuse-tumbleweed.yaml

@@ -5,6 +5,7 @@ images:
  arch: "x86_64"
 - location: "https://download.opensuse.org/ports/aarch64/tumbleweed/appliances/openSUSE-Tumbleweed-Minimal-VM.aarch64-Cloud.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/opensuse-leap.yaml

@@ -5,6 +5,7 @@ images:
  arch: "x86_64"
 - location: "https://download.opensuse.org/distribution/leap/15.6/appliances/openSUSE-Leap-15.6-Minimal-VM.aarch64-Cloud.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/oraclelinux-8.yaml

@@ -12,6 +12,7 @@ images:
 - location: "https://yum.oracle.com/templates/OracleLinux/OL8/u10/aarch64/OL8U10_aarch64-kvm-cloud-b100.qcow2"
  arch: "aarch64"
  digest: "sha256:def7b8055e275507a593f07dc6076a2adc5967af046c003072b479e69f25f407"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/oraclelinux-9.yaml

@@ -9,6 +9,7 @@ images:
 - location: "https://yum.oracle.com/templates/OracleLinux/OL9/u4/aarch64/OL9U4_aarch64-kvm-cloud-b90.qcow2"
  arch: "aarch64"
  digest: "sha256:1f4e20190e87c76e8c3b4a9e15e660972386cbfa4f128e5cdcd8faa43a713d44"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/rocky-8.yaml

@@ -16,6 +16,7 @@ images:
  arch: "x86_64"
 - location: "https://dl.rockylinux.org/pub/rocky/8/images/aarch64/Rocky-8-GenericCloud.latest.aarch64.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

examples/rocky-9.yaml

@@ -14,6 +14,7 @@ images:
  arch: "x86_64"
 - location: "https://dl.rockylinux.org/pub/rocky/9/images/aarch64/Rocky-9-GenericCloud.latest.aarch64.qcow2"
  arch: "aarch64"
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
 - location: "/tmp/lima"

hack/test-templates/test-misc.yaml

@@ -1,5 +1,6 @@
 # The test template for testing misc configurations:
 # - disk
+# - snapshots
 # - (More to come)
 #
 # This template requires Lima v1.0.0-alpha.0 or later.
@@ -18,6 +19,8 @@ images:
 - location: "https://cloud-images.ubuntu.com/releases/24.04/release/ubuntu-24.04-server-cloudimg-arm64.img"
  arch: "aarch64"
 
+# 9p is not compatible with `limactl snapshot`
+mountTypesUnsupported: ["9p"]
 mounts:
 - location: "~"
  writable: true

pkg/limayaml/defaults.go

@@ -27,6 +27,7 @@ import (
  "github.com/lima-vm/lima/pkg/ptr"
  "github.com/lima-vm/lima/pkg/store/dirnames"
  "github.com/lima-vm/lima/pkg/store/filenames"
+ "github.com/lima-vm/lima/pkg/version/versionutil"
 )
 
 const (
@@ -171,6 +172,17 @@ func defaultGuestInstallPrefix() string {
 // - CACertificates Files and Certs are uniquely appended in d, y, o order
 func FillDefault(y, d, o *LimaYAML, filePath string) {
  instDir := filepath.Dir(filePath)
+
+ // existingLimaVersion can be empty if the instance was created with Lima prior to v0.20,
+ // or, when editing a template file without an instance (`limactl edit foo.yaml`)
+ var existingLimaVersion string
+ limaVersionFile := filepath.Join(instDir, filenames.LimaVersion)
+ if b, err := os.ReadFile(limaVersionFile); err == nil {
+ existingLimaVersion = strings.TrimSpace(string(b))
+ } else if !errors.Is(err, os.ErrNotExist) {
+ logrus.WithError(err).Warnf("Failed to read %q", limaVersionFile)
+ }
+
  if y.VMType == nil {
  y.VMType = d.VMType
  }
@@ -547,21 +559,41 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
  }
  }
 
+ y.MountTypesUnsupported = append(append(o.MountTypesUnsupported, y.MountTypesUnsupported...), d.MountTypesUnsupported...)
+ mountTypesUnsupported := make(map[string]struct{})
+ for _, f := range y.MountTypesUnsupported {
+ mountTypesUnsupported[f] = struct{}{}
+ }
  // MountType has to be resolved before resolving Mounts
  if y.MountType == nil {
  y.MountType = d.MountType
  }
  if o.MountType != nil {
  y.MountType = o.MountType
  }
- if y.MountType == nil || *y.MountType == "" {
- if *y.VMType == VZ {
+ if y.MountType == nil || *y.MountType == "" || *y.MountType == "default" {
+ switch *y.VMType {
+ case VZ:
  y.MountType = ptr.Of(VIRTIOFS)
- } else {
+ case QEMU:
+ y.MountType = ptr.Of(NINEP)
+ if _, ok := mountTypesUnsupported[NINEP]; ok {
+ // Use REVSSHFS if the instance does not support 9p
+ y.MountType = ptr.Of(REVSSHFS)
+ } else if isExistingInstanceDir(instDir) && !versionutil.GreaterEqual(existingLimaVersion, "1.0.0") {
+ // Use REVSSHFS if the instance was created with Lima prior to v1.0
+ y.MountType = ptr.Of(REVSSHFS)
+ }
+ default:
  y.MountType = ptr.Of(REVSSHFS)
  }
  }
 
+ if _, ok := mountTypesUnsupported[*y.MountType]; ok {
+ // We cannot return an error here, but Validate() will return it.
+ logrus.Warnf("Unsupported mount type: %q", *y.MountType)
+ }
+
  if y.MountInotify == nil {
  y.MountInotify = d.MountInotify
  }

pkg/limayaml/limayaml.go

@@ -7,33 +7,34 @@ import (
 )
 
 type LimaYAML struct {
- MinimumLimaVersion *string `yaml:"minimumLimaVersion,omitempty" json:"minimumLimaVersion,omitempty"`
- VMType *VMType `yaml:"vmType,omitempty" json:"vmType,omitempty"`
- VMOpts VMOpts `yaml:"vmOpts,omitempty" json:"vmOpts,omitempty"`
- OS *OS `yaml:"os,omitempty" json:"os,omitempty"`
- Arch *Arch `yaml:"arch,omitempty" json:"arch,omitempty"`
- Images []Image `yaml:"images" json:"images"` // REQUIRED
- CPUType CPUType `yaml:"cpuType,omitempty" json:"cpuType,omitempty"`
- CPUs *int `yaml:"cpus,omitempty" json:"cpus,omitempty"`
- Memory *string `yaml:"memory,omitempty" json:"memory,omitempty"` // go-units.RAMInBytes
- Disk *string `yaml:"disk,omitempty" json:"disk,omitempty"` // go-units.RAMInBytes
- AdditionalDisks []Disk `yaml:"additionalDisks,omitempty" json:"additionalDisks,omitempty"`
- Mounts []Mount `yaml:"mounts,omitempty" json:"mounts,omitempty"`
- MountType *MountType `yaml:"mountType,omitempty" json:"mountType,omitempty"`
- MountInotify *bool `yaml:"mountInotify,omitempty" json:"mountInotify,omitempty"`
- SSH SSH `yaml:"ssh,omitempty" json:"ssh,omitempty"` // REQUIRED (FIXME)
- Firmware Firmware `yaml:"firmware,omitempty" json:"firmware,omitempty"`
- Audio Audio `yaml:"audio,omitempty" json:"audio,omitempty"`
- Video Video `yaml:"video,omitempty" json:"video,omitempty"`
- Provision []Provision `yaml:"provision,omitempty" json:"provision,omitempty"`
- UpgradePackages *bool `yaml:"upgradePackages,omitempty" json:"upgradePackages,omitempty"`
- Containerd Containerd `yaml:"containerd,omitempty" json:"containerd,omitempty"`
- GuestInstallPrefix *string `yaml:"guestInstallPrefix,omitempty" json:"guestInstallPrefix,omitempty"`
- Probes []Probe `yaml:"probes,omitempty" json:"probes,omitempty"`
- PortForwards []PortForward `yaml:"portForwards,omitempty" json:"portForwards,omitempty"`
- CopyToHost []CopyToHost `yaml:"copyToHost,omitempty" json:"copyToHost,omitempty"`
- Message string `yaml:"message,omitempty" json:"message,omitempty"`
- Networks []Network `yaml:"networks,omitempty" json:"networks,omitempty"`
+ MinimumLimaVersion *string `yaml:"minimumLimaVersion,omitempty" json:"minimumLimaVersion,omitempty"`
+ VMType *VMType `yaml:"vmType,omitempty" json:"vmType,omitempty"`
+ VMOpts VMOpts `yaml:"vmOpts,omitempty" json:"vmOpts,omitempty"`
+ OS *OS `yaml:"os,omitempty" json:"os,omitempty"`
+ Arch *Arch `yaml:"arch,omitempty" json:"arch,omitempty"`
+ Images []Image `yaml:"images" json:"images"` // REQUIRED
+ CPUType CPUType `yaml:"cpuType,omitempty" json:"cpuType,omitempty"`
+ CPUs *int `yaml:"cpus,omitempty" json:"cpus,omitempty"`
+ Memory *string `yaml:"memory,omitempty" json:"memory,omitempty"` // go-units.RAMInBytes
+ Disk *string `yaml:"disk,omitempty" json:"disk,omitempty"` // go-units.RAMInBytes
+ AdditionalDisks []Disk `yaml:"additionalDisks,omitempty" json:"additionalDisks,omitempty"`
+ Mounts []Mount `yaml:"mounts,omitempty" json:"mounts,omitempty"`
+ MountTypesUnsupported []string `yaml:"mountTypesUnsupported,omitempty" json:"mountTypesUnsupported,omitempty"`
+ MountType *MountType `yaml:"mountType,omitempty" json:"mountType,omitempty"`
+ MountInotify *bool `yaml:"mountInotify,omitempty" json:"mountInotify,omitempty"`
+ SSH SSH `yaml:"ssh,omitempty" json:"ssh,omitempty"` // REQUIRED (FIXME)
+ Firmware Firmware `yaml:"firmware,omitempty" json:"firmware,omitempty"`
+ Audio Audio `yaml:"audio,omitempty" json:"audio,omitempty"`
+ Video Video `yaml:"video,omitempty" json:"video,omitempty"`
+ Provision []Provision `yaml:"provision,omitempty" json:"provision,omitempty"`
+ UpgradePackages *bool `yaml:"upgradePackages,omitempty" json:"upgradePackages,omitempty"`
+ Containerd Containerd `yaml:"containerd,omitempty" json:"containerd,omitempty"`
+ GuestInstallPrefix *string `yaml:"guestInstallPrefix,omitempty" json:"guestInstallPrefix,omitempty"`
+ Probes []Probe `yaml:"probes,omitempty" json:"probes,omitempty"`
+ PortForwards []PortForward `yaml:"portForwards,omitempty" json:"portForwards,omitempty"`
+ CopyToHost []CopyToHost `yaml:"copyToHost,omitempty" json:"copyToHost,omitempty"`
+ Message string `yaml:"message,omitempty" json:"message,omitempty"`
+ Networks []Network `yaml:"networks,omitempty" json:"networks,omitempty"`
  // `network` was deprecated in Lima v0.7.0, removed in Lima v0.14.0. Use `networks` instead.
  Env map[string]string `yaml:"env,omitempty" json:"env,omitempty"`
  Param map[string]string `yaml:"param,omitempty" json:"param,omitempty"`

pkg/limayaml/validate.go

@@ -185,6 +185,12 @@ func Validate(y *LimaYAML, warn bool) error {
  return fmt.Errorf("field `mountType` must be %q or %q or %q, or %q, got %q", REVSSHFS, NINEP, VIRTIOFS, WSLMount, *y.MountType)
  }
 
+ for _, f := range y.MountTypesUnsupported {
+ if f == *y.MountType {
+ return fmt.Errorf("field `mountType` must not be one of %v (`mountTypesUnsupported`), got %q", y.MountTypesUnsupported, *y.MountType)
+ }
+ }
+
  if warn && runtime.GOOS != "linux" {
  for i, mount := range y.Mounts {
  if mount.Virtiofs.QueueSize != nil {
@@ -508,9 +514,6 @@ func validatePort(field string, port int) error {
 }
 
 func warnExperimental(y *LimaYAML) {
- if *y.MountType == NINEP {
- logrus.Warn("`mountType: 9p` is experimental")
- }
  if *y.MountType == VIRTIOFS && runtime.GOOS == "linux" {
  logrus.Warn("`mountType: virtiofs` on Linux is experimental")
  }

pkg/version/versionutil/versionutil.go

@@ -15,26 +15,34 @@ func Parse(version string) (*semver.Version, error) {
  return semver.NewVersion(version)
 }
 
-// GreaterThan returns true if the Lima version used to create an instance is greater
-// than a specific older version. Always returns false if the Lima version is the empty string.
-// Unparsable lima versions (like SHA1 commit ids) are treated as the latest version and return true.
-// limaVersion is a `github describe` string, not a semantic version. So "0.19.1-16-gf3dc6ed.m"
-// will be considered greater than "0.19.1".
-func GreaterThan(limaVersion, oldVersion string) bool {
+func compare(limaVersion, oldVersion string) int {
  if limaVersion == "" {
- return false
+ if oldVersion == "" {
+ return 0
+ }
+ return -1
  }
  version, err := Parse(limaVersion)
  if err != nil {
- return true
+ return 1
  }
- switch version.Compare(*semver.New(oldVersion)) {
- case -1:
- return false
- case +1:
- return true
- case 0:
- return strings.Contains(limaVersion, "-")
+ cmp := version.Compare(*semver.New(oldVersion))
+ if cmp == 0 && strings.Contains(limaVersion, "-") {
+ cmp = 1
  }
- panic("unreachable")
+ return cmp
+}
+
+// GreaterThan returns true if the Lima version used to create an instance is greater
+// than a specific older version. Always returns false if the Lima version is the empty string.
+// Unparsable lima versions (like SHA1 commit ids) are treated as the latest version and return true.
+// limaVersion is a `github describe` string, not a semantic version. So "0.19.1-16-gf3dc6ed.m"
+// will be considered greater than "0.19.1".
+func GreaterThan(limaVersion, oldVersion string) bool {
+ return compare(limaVersion, oldVersion) > 0
+}
+
+// GreaterEqual return true if limaVersion >= oldVersion.
+func GreaterEqual(limaVersion, oldVersion string) bool {
+ return compare(limaVersion, oldVersion) >= 0
 }

pkg/version/versionutil/versionutil_test.go

@@ -14,3 +14,13 @@ func TestGreaterThan(t *testing.T) {
  assert.Equal(t, GreaterThan("0.2.0", "0.1.0"), true)
  assert.Equal(t, GreaterThan("abacab", "0.1.0"), true)
 }
+
+func TestGreaterEqual(t *testing.T) {
+ assert.Equal(t, GreaterEqual("", ""), true)
+ assert.Equal(t, GreaterEqual("", "0.1.0"), false)
+ assert.Equal(t, GreaterEqual("0.0.1", "0.1.0"), false)
+ assert.Equal(t, GreaterEqual("0.1.0", "0.1.0"), true)
+ assert.Equal(t, GreaterEqual("0.1.0-2", "0.1.0"), true)
+ assert.Equal(t, GreaterEqual("0.2.0", "0.1.0"), true)
+ assert.Equal(t, GreaterEqual("abacab", "0.1.0"), true)
+}

pkg/vz/vz_driver_darwin.go

@@ -39,6 +39,7 @@ var knownYamlProperties = []string{
  "Message",
  "Mounts",
  "MountType",
+ "MountTypesUnsupported",
  "MountInotify",
  "Networks",
  "OS",

website/content/en/docs/config/mount/_index.md

@@ -63,7 +63,7 @@ Lima prior to v0.10 had used "builtin" as the SFTP driver.
 
 ### 9p
 > **Warning**
-> "9p" mode is experimental
+> "9p" mode is experimental (will graduate from experimental in Lima v1.0)
 
 The "9p" mount type is implemented by using QEMU's virtio-9p-pci devices.
 virtio-9p-pci is also known as "virtfs", but note that this is unrelated to [virtio-fs](https://virtio-fs.gitlab.io/).