diff --git a/metropolis/test/launch/BUILD.bazel b/metropolis/test/launch/BUILD.bazel
new file mode 100644
index 0000000..b6245e1
--- /dev/null
+++ b/metropolis/test/launch/BUILD.bazel
@@ -0,0 +1,17 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["launch.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/metropolis/test/launch",
+    visibility = ["//metropolis:__subpackages__"],
+    deps = [
+        "//golibs/common:go_default_library",
+        "//metropolis/node:go_default_library",
+        "//metropolis/proto/api:go_default_library",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_grpc_ecosystem_go_grpc_middleware//retry:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+        "@org_golang_x_sys//unix:go_default_library",
+    ],
+)
diff --git a/metropolis/test/launch/cli/launch-multi2/BUILD.bazel b/metropolis/test/launch/cli/launch-multi2/BUILD.bazel
new file mode 100644
index 0000000..9f27860
--- /dev/null
+++ b/metropolis/test/launch/cli/launch-multi2/BUILD.bazel
@@ -0,0 +1,29 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/metropolis/test/launch/cli/launch-multi2",
+    visibility = ["//visibility:private"],
+    deps = [
+        "//metropolis/node:go_default_library",
+        "//metropolis/proto/api:go_default_library",
+        "//metropolis/test/launch:go_default_library",
+        "@com_github_grpc_ecosystem_go_grpc_middleware//retry:go_default_library",
+        "@org_golang_google_grpc//:go_default_library",
+    ],
+)
+
+go_binary(
+    name = "launch-multi2",
+    data = [
+        "//metropolis/node:image",
+        "//metropolis/node:swtpm_data",
+        "//metropolis/test/nanoswitch:initramfs",
+        "//metropolis/test/ktest:linux-testing",
+        "//third_party/edk2:firmware",
+        "@com_github_bonzini_qboot//:qboot-bin",
+    ],
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)
diff --git a/metropolis/test/launch/cli/launch-multi2/main.go b/metropolis/test/launch/cli/launch-multi2/main.go
new file mode 100644
index 0000000..265d6a0
--- /dev/null
+++ b/metropolis/test/launch/cli/launch-multi2/main.go
@@ -0,0 +1,102 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	grpcretry "github.com/grpc-ecosystem/go-grpc-middleware/retry"
+	"google.golang.org/grpc"
+
+	common "git.monogon.dev/source/nexantic.git/metropolis/node"
+	apb "git.monogon.dev/source/nexantic.git/metropolis/proto/api"
+	"git.monogon.dev/source/nexantic.git/metropolis/test/launch"
+)
+
+func main() {
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-sigs
+		cancel()
+	}()
+	sw0, vm0, err := launch.NewSocketPair()
+	if err != nil {
+		log.Fatalf("Failed to create network pipe: %v\n", err)
+	}
+	sw1, vm1, err := launch.NewSocketPair()
+	if err != nil {
+		log.Fatalf("Failed to create network pipe: %v\n", err)
+	}
+
+	go func() {
+		if err := launch.Launch(ctx, launch.Options{ConnectToSocket: vm0, SerialPort: os.Stdout}); err != nil {
+			log.Fatalf("Failed to launch vm0: %v", err)
+		}
+	}()
+	nanoswitchPortMap := make(launch.PortMap)
+	identityPorts := []uint16{
+		common.ExternalServicePort,
+		common.DebugServicePort,
+		common.KubernetesAPIPort,
+	}
+	for _, port := range identityPorts {
+		nanoswitchPortMap[port] = port
+	}
+	go func() {
+		opts := []grpcretry.CallOption{
+			grpcretry.WithBackoff(grpcretry.BackoffExponential(100 * time.Millisecond)),
+		}
+		conn, err := nanoswitchPortMap.DialGRPC(common.DebugServicePort, grpc.WithInsecure(),
+			grpc.WithUnaryInterceptor(grpcretry.UnaryClientInterceptor(opts...)))
+		if err != nil {
+			panic(err)
+		}
+		defer conn.Close()
+		debug := apb.NewNodeDebugServiceClient(conn)
+		res, err := debug.GetGoldenTicket(ctx, &apb.GetGoldenTicketRequest{
+			// HACK: this is assigned by DHCP, and we assume that everything goes well.
+			ExternalIp: "10.1.0.3",
+		}, grpcretry.WithMax(10))
+		if err != nil {
+			log.Fatalf("Failed to get golden ticket: %v", err)
+		}
+
+		ec := &apb.EnrolmentConfig{
+			GoldenTicket: res.Ticket,
+		}
+
+		if err := launch.Launch(ctx, launch.Options{ConnectToSocket: vm1, EnrolmentConfig: ec, SerialPort: os.Stdout}); err != nil {
+			log.Fatalf("Failed to launch vm1: %v", err)
+		}
+	}()
+	if err := launch.RunMicroVM(ctx, &launch.MicroVMOptions{
+		SerialPort:             os.Stdout,
+		KernelPath:             "metropolis/test/ktest/linux-testing.elf",
+		InitramfsPath:          "metropolis/test/nanoswitch/initramfs.lz4",
+		ExtraNetworkInterfaces: []*os.File{sw0, sw1},
+		PortMap:                nanoswitchPortMap,
+	}); err != nil {
+		log.Fatalf("Failed to launch nanoswitch: %v", err)
+	}
+}
diff --git a/metropolis/test/launch/cli/launch/BUILD.bazel b/metropolis/test/launch/cli/launch/BUILD.bazel
new file mode 100644
index 0000000..6b1461d
--- /dev/null
+++ b/metropolis/test/launch/cli/launch/BUILD.bazel
@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/metropolis/test/launch/cli/launch",
+    visibility = ["//visibility:private"],
+    deps = ["//metropolis/test/launch:go_default_library"],
+)
+
+go_binary(
+    name = "launch",
+    data = [
+        "//metropolis/node:image",
+        "//metropolis/node:swtpm_data",
+        "//third_party/edk2:firmware",
+    ],
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)
diff --git a/metropolis/test/launch/cli/launch/main.go b/metropolis/test/launch/cli/launch/main.go
new file mode 100644
index 0000000..852c8e1
--- /dev/null
+++ b/metropolis/test/launch/cli/launch/main.go
@@ -0,0 +1,43 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"git.monogon.dev/source/nexantic.git/metropolis/test/launch"
+)
+
+func main() {
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
+	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-sigs
+		cancel()
+	}()
+	if err := launch.Launch(ctx, launch.Options{Ports: launch.IdentityPortMap(launch.NodePorts), SerialPort: os.Stdout}); err != nil {
+		if err == ctx.Err() {
+			return
+		}
+		log.Fatalf("Failed to execute: %v\n", err)
+	}
+}
diff --git a/metropolis/test/launch/launch.go b/metropolis/test/launch/launch.go
new file mode 100644
index 0000000..2d495e0
--- /dev/null
+++ b/metropolis/test/launch/launch.go
@@ -0,0 +1,557 @@
+// Copyright 2020 The Monogon Project Authors.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package launch
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+	grpcretry "github.com/grpc-ecosystem/go-grpc-middleware/retry"
+	"golang.org/x/sys/unix"
+	"google.golang.org/grpc"
+
+	freeport "git.monogon.dev/source/nexantic.git/golibs/common"
+	common "git.monogon.dev/source/nexantic.git/metropolis/node"
+	apb "git.monogon.dev/source/nexantic.git/metropolis/proto/api"
+)
+
+type qemuValue map[string][]string
+
+// toOption encodes structured data into a QEMU option.
+// Example: "test", {"key1": {"val1"}, "key2": {"val2", "val3"}} returns "test,key1=val1,key2=val2,key2=val3"
+func (value qemuValue) toOption(name string) string {
+	var optionValues []string
+	if name != "" {
+		optionValues = append(optionValues, name)
+	}
+	for name, values := range value {
+		if len(values) == 0 {
+			optionValues = append(optionValues, name)
+		}
+		for _, val := range values {
+			optionValues = append(optionValues, fmt.Sprintf("%v=%v", name, val))
+		}
+	}
+	return strings.Join(optionValues, ",")
+}
+
+func copyFile(src, dst string) error {
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	_, err = io.Copy(out, in)
+	if err != nil {
+		return err
+	}
+	return out.Close()
+}
+
+// PortMap represents where VM ports are mapped to on the host. It maps from the VM port number to the host port number.
+type PortMap map[uint16]uint16
+
+// toQemuForwards generates QEMU hostfwd values (https://qemu.weilnetz.de/doc/qemu-doc.html#:~:text=hostfwd=) for all
+// mapped ports.
+func (p PortMap) toQemuForwards() []string {
+	var hostfwdOptions []string
+	for vmPort, hostPort := range p {
+		hostfwdOptions = append(hostfwdOptions, fmt.Sprintf("tcp::%v-:%v", hostPort, vmPort))
+	}
+	return hostfwdOptions
+}
+
+// DialGRPC creates a gRPC client for a VM port that's forwarded/mapped to the host. The given port is automatically
+// resolved to the host-mapped port.
+func (p PortMap) DialGRPC(port uint16, opts ...grpc.DialOption) (*grpc.ClientConn, error) {
+	mappedPort, ok := p[port]
+	if !ok {
+		return nil, fmt.Errorf("cannot dial port: port %v is not mapped/forwarded", port)
+	}
+	grpcClient, err := grpc.Dial(fmt.Sprintf("localhost:%v", mappedPort), opts...)
+	if err != nil {
+		return nil, fmt.Errorf("failed to dial port %v: %w", port, err)
+	}
+	return grpcClient, nil
+}
+
+// Options contains all options that can be passed to Launch()
+type Options struct {
+	// Ports contains the port mapping where to expose the internal ports of the VM to the host. See IdentityPortMap()
+	// and ConflictFreePortMap(). Ignored when ConnectToSocket is set.
+	Ports PortMap
+
+	// If set to true, reboots are honored. Otherwise all reboots exit the Launch() command. Smalltown generally restarts
+	// on almost all errors, so unless you want to test reboot behavior this should be false.
+	AllowReboot bool
+
+	// By default the Smalltown VM is connected to the Host via SLIRP. If ConnectToSocket is set, it is instead connected
+	// to the given file descriptor/socket. If this is set, all port maps from the Ports option are ignored.
+	// Intended for networking this instance together with others for running  more complex network configurations.
+	ConnectToSocket *os.File
+
+	// SerialPort is a File(descriptor) over which you can communicate with the serial port of the machine
+	// It can be set to an existing file descriptor (like os.Stdout/os.Stderr) or you can use NewSocketPair() to get one
+	// end to talk to from Go.
+	SerialPort *os.File
+
+	// EnrolmentConfig is passed into the VM and subsequently used for bootstrapping if no enrolment config is built-in
+	EnrolmentConfig *apb.EnrolmentConfig
+}
+
+// NodePorts is the list of ports a fully operational Smalltown node listens on
+var NodePorts = []uint16{common.ConsensusPort, common.NodeServicePort, common.MasterServicePort,
+	common.ExternalServicePort, common.DebugServicePort, common.KubernetesAPIPort, common.DebuggerPort}
+
+// IdentityPortMap returns a port map where each given port is mapped onto itself on the host. This is mainly useful
+// for development against Smalltown. The dbg command requires this mapping.
+func IdentityPortMap(ports []uint16) PortMap {
+	portMap := make(PortMap)
+	for _, port := range ports {
+		portMap[port] = port
+	}
+	return portMap
+}
+
+// ConflictFreePortMap returns a port map where each given port is mapped onto a random free port on the host. This is
+// intended for automated testing where multiple instances of Smalltown might be running. Please call this function for
+// each Launch command separately and as close to it as possible since it cannot guarantee that the ports will remain
+// free.
+func ConflictFreePortMap(ports []uint16) (PortMap, error) {
+	portMap := make(PortMap)
+	for _, port := range ports {
+		mappedPort, listenCloser, err := freeport.AllocateTCPPort()
+		if err != nil {
+			return portMap, fmt.Errorf("failed to get free host port: %w", err)
+		}
+		// Defer closing of the listening port until the function is done and all ports are allocated
+		defer listenCloser.Close()
+		portMap[port] = mappedPort
+	}
+	return portMap, nil
+}
+
+// Gets a random EUI-48 Ethernet MAC address
+func generateRandomEthernetMAC() (*net.HardwareAddr, error) {
+	macBuf := make([]byte, 6)
+	_, err := rand.Read(macBuf)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read randomness for MAC: %v", err)
+	}
+
+	// Set U/L bit and clear I/G bit (locally administered individual MAC)
+	// Ref IEEE 802-2014 Section 8.2.2
+	macBuf[0] = (macBuf[0] | 2) & 0xfe
+	mac := net.HardwareAddr(macBuf)
+	return &mac, nil
+}
+
+// Launch launches a Smalltown instance with the given options. The instance runs mostly paravirtualized but with some
+// emulated hardware similar to how a cloud provider might set up its VMs. The disk is fully writable but is run
+// in snapshot mode meaning that changes are not kept beyond a single invocation.
+func Launch(ctx context.Context, options Options) error {
+	// Pin temp directory to /tmp until we can use abstract socket namespace in QEMU (next release after 5.0,
+	// https://github.com/qemu/qemu/commit/776b97d3605ed0fc94443048fdf988c7725e38a9). swtpm accepts already-open FDs
+	// so we can pass in an abstract socket namespace FD that we open and pass the name of it to QEMU. Not pinning this
+	// crashes both swtpm and qemu because we run into UNIX socket length limitations (for legacy reasons 108 chars).
+	tempDir, err := ioutil.TempDir("/tmp", "launch*")
+	if err != nil {
+		return fmt.Errorf("failed to create temporary directory: %w", err)
+	}
+	defer os.RemoveAll(tempDir)
+
+	// Copy TPM state into a temporary directory since it's being modified by the emulator
+	tpmTargetDir := filepath.Join(tempDir, "tpm")
+	tpmSrcDir := "metropolis/node/tpm"
+	if err := os.Mkdir(tpmTargetDir, 0644); err != nil {
+		return fmt.Errorf("failed to create TPM state directory: %w", err)
+	}
+	tpmFiles, err := ioutil.ReadDir(tpmSrcDir)
+	if err != nil {
+		return fmt.Errorf("failed to read TPM directory: %w", err)
+	}
+	for _, file := range tpmFiles {
+		name := file.Name()
+		if err := copyFile(filepath.Join(tpmSrcDir, name), filepath.Join(tpmTargetDir, name)); err != nil {
+			return fmt.Errorf("failed to copy TPM directory: %w", err)
+		}
+	}
+
+	var qemuNetType string
+	var qemuNetConfig qemuValue
+	if options.ConnectToSocket != nil {
+		qemuNetType = "socket"
+		qemuNetConfig = qemuValue{
+			"id": {"net0"},
+			"fd": {"3"},
+		}
+	} else {
+		qemuNetType = "user"
+		qemuNetConfig = qemuValue{
+			"id":        {"net0"},
+			"net":       {"10.42.0.0/24"},
+			"dhcpstart": {"10.42.0.10"},
+			"hostfwd":   options.Ports.toQemuForwards(),
+		}
+	}
+
+	tpmSocketPath := filepath.Join(tempDir, "tpm-socket")
+
+	mac, err := generateRandomEthernetMAC()
+	if err != nil {
+		return err
+	}
+
+	qemuArgs := []string{"-machine", "q35", "-accel", "kvm", "-nographic", "-nodefaults", "-m", "4096",
+		"-cpu", "host", "-smp", "sockets=1,cpus=1,cores=2,threads=2,maxcpus=4",
+		"-drive", "if=pflash,format=raw,readonly,file=external/edk2/OVMF_CODE.fd",
+		"-drive", "if=pflash,format=raw,snapshot=on,file=external/edk2/OVMF_VARS.fd",
+		"-drive", "if=virtio,format=raw,snapshot=on,cache=unsafe,file=metropolis/node/smalltown.img",
+		"-netdev", qemuNetConfig.toOption(qemuNetType),
+		"-device", "virtio-net-pci,netdev=net0,mac=" + mac.String(),
+		"-chardev", "socket,id=chrtpm,path=" + tpmSocketPath,
+		"-tpmdev", "emulator,id=tpm0,chardev=chrtpm",
+		"-device", "tpm-tis,tpmdev=tpm0",
+		"-device", "virtio-rng-pci",
+		"-serial", "stdio"}
+
+	if !options.AllowReboot {
+		qemuArgs = append(qemuArgs, "-no-reboot")
+	}
+
+	if options.EnrolmentConfig != nil {
+		enrolmentConfigPath := filepath.Join(tempDir, "enrolment.pb")
+		enrolmentConfigRaw, err := proto.Marshal(options.EnrolmentConfig)
+		if err != nil {
+			return fmt.Errorf("failed to encode enrolment config: %w", err)
+		}
+		if err := ioutil.WriteFile(enrolmentConfigPath, enrolmentConfigRaw, 0644); err != nil {
+			return fmt.Errorf("failed to write enrolment config: %w", err)
+		}
+		qemuArgs = append(qemuArgs, "-fw_cfg", "name=com.nexantic.smalltown/enrolment.pb,file="+enrolmentConfigPath)
+	}
+
+	// Start TPM emulator as a subprocess
+	tpmCtx, tpmCancel := context.WithCancel(ctx)
+	defer tpmCancel()
+
+	tpmEmuCmd := exec.CommandContext(tpmCtx, "swtpm", "socket", "--tpm2", "--tpmstate", "dir="+tpmTargetDir, "--ctrl", "type=unixio,path="+tpmSocketPath)
+	tpmEmuCmd.Stderr = os.Stderr
+	tpmEmuCmd.Stdout = os.Stdout
+
+	err = tpmEmuCmd.Start()
+	if err != nil {
+		return fmt.Errorf("failed to start TPM emulator: %w", err)
+	}
+
+	// Start the main qemu binary
+	systemCmd := exec.CommandContext(ctx, "qemu-system-x86_64", qemuArgs...)
+	if options.ConnectToSocket != nil {
+		systemCmd.ExtraFiles = []*os.File{options.ConnectToSocket}
+	}
+
+	var stdErrBuf bytes.Buffer
+	systemCmd.Stderr = &stdErrBuf
+	systemCmd.Stdout = options.SerialPort
+
+	err = systemCmd.Run()
+
+	// Stop TPM emulator and wait for it to exit to properly reap the child process
+	tpmCancel()
+	log.Print("Waiting for TPM emulator to exit")
+	// Wait returns a SIGKILL error because we just cancelled its context.
+	// We still need to call it to avoid creating zombies.
+	_ = tpmEmuCmd.Wait()
+
+	var exerr *exec.ExitError
+	if err != nil && errors.As(err, &exerr) {
+		status := exerr.ProcessState.Sys().(syscall.WaitStatus)
+		if status.Signaled() && status.Signal() == syscall.SIGKILL {
+			// Process was killed externally (most likely by our context being canceled).
+			// This is a normal exit for us, so return nil
+			return nil
+		}
+		exerr.Stderr = stdErrBuf.Bytes()
+		newErr := QEMUError(*exerr)
+		return &newErr
+	}
+	return err
+}
+
+// NewSocketPair creates a new socket pair. By connecting both ends to different instances you can connect them
+// with a virtual "network cable". The ends can be passed into the ConnectToSocket option.
+func NewSocketPair() (*os.File, *os.File, error) {
+	fds, err := unix.Socketpair(unix.AF_UNIX, syscall.SOCK_STREAM, 0)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to call socketpair: %w", err)
+	}
+
+	fd1 := os.NewFile(uintptr(fds[0]), "network0")
+	fd2 := os.NewFile(uintptr(fds[1]), "network1")
+	return fd1, fd2, nil
+}
+
+// HostInterfaceMAC is the MAC address the host SLIRP network interface has if it is not disabled (see
+// DisableHostNetworkInterface in MicroVMOptions)
+var HostInterfaceMAC = net.HardwareAddr{0x02, 0x72, 0x82, 0xbf, 0xc3, 0x56}
+
+// MicroVMOptions contains all options to start a MicroVM
+type MicroVMOptions struct {
+	// Path to the ELF kernel binary
+	KernelPath string
+
+	// Path to the Initramfs
+	InitramfsPath string
+
+	// Cmdline contains additional kernel commandline options
+	Cmdline string
+
+	// SerialPort is a File(descriptor) over which you can communicate with the serial port of the machine
+	// It can be set to an existing file descriptor (like os.Stdout/os.Stderr) or you can use NewSocketPair() to get one
+	// end to talk to from Go.
+	SerialPort *os.File
+
+	// ExtraChardevs can be used similar to SerialPort, but can contain an arbitrary number of additional serial ports
+	ExtraChardevs []*os.File
+
+	// ExtraNetworkInterfaces can contain an arbitrary number of file descriptors which are mapped into the VM as virtio
+	// network interfaces. The first interface is always a SLIRP-backed interface for communicating with the host.
+	ExtraNetworkInterfaces []*os.File
+
+	// PortMap contains ports that are mapped to the host through the built-in SLIRP network interface.
+	PortMap PortMap
+
+	// DisableHostNetworkInterface disables the SLIRP-backed host network interface that is normally the first network
+	// interface. If this is set PortMap is ignored. Mostly useful for speeding up QEMU's startup time for tests.
+	DisableHostNetworkInterface bool
+}
+
+// RunMicroVM launches a tiny VM mostly intended for testing. Very quick to boot (<40ms).
+func RunMicroVM(ctx context.Context, opts *MicroVMOptions) error {
+	// Generate options for all the file descriptors we'll be passing as virtio "serial ports"
+	var extraArgs []string
+	for idx, _ := range opts.ExtraChardevs {
+		idxStr := strconv.Itoa(idx)
+		id := "extra" + idxStr
+		// That this works is pretty much a hack, but upstream QEMU doesn't have a bidirectional chardev backend not
+		// based around files/sockets on the disk which are a giant pain to work with.
+		// We're using QEMU's fdset functionality to make FDs available as pseudo-files and then "ab"using the pipe
+		// backend's fallback functionality to get a single bidirectional chardev backend backed by a passed-down
+		// RDWR fd.
+		// Ref https://lists.gnu.org/archive/html/qemu-devel/2015-12/msg01256.html
+		addFdConf := qemuValue{
+			"set": {idxStr},
+			"fd":  {strconv.Itoa(idx + 3)},
+		}
+		chardevConf := qemuValue{
+			"id":   {id},
+			"path": {"/dev/fdset/" + idxStr},
+		}
+		deviceConf := qemuValue{
+			"chardev": {id},
+		}
+		extraArgs = append(extraArgs, "-add-fd", addFdConf.toOption(""),
+			"-chardev", chardevConf.toOption("pipe"), "-device", deviceConf.toOption("virtserialport"))
+	}
+
+	for idx, _ := range opts.ExtraNetworkInterfaces {
+		id := fmt.Sprintf("net%v", idx)
+		netdevConf := qemuValue{
+			"id": {id},
+			"fd": {strconv.Itoa(idx + 3 + len(opts.ExtraChardevs))},
+		}
+		extraArgs = append(extraArgs, "-netdev", netdevConf.toOption("socket"), "-device", "virtio-net-device,netdev="+id)
+	}
+
+	// This sets up a minimum viable environment for our Linux kernel.
+	// It clears all standard QEMU configuration and sets up a MicroVM machine
+	// (https://github.com/qemu/qemu/blob/master/docs/microvm.rst) with all legacy emulation turned off. This means
+	// the only "hardware" the Linux kernel inside can communicate with is a single virtio-mmio region. Over that MMIO
+	// interface we run a paravirtualized RNG (since the kernel in there has nothing to gather that from and it
+	// delays booting), a single paravirtualized console and an arbitrary number of extra serial ports for talking to
+	// various things that might run inside. The kernel, initramfs and command line are mapped into VM memory at boot
+	// time and not loaded from any sort of disk. Booting and shutting off one of these VMs takes <100ms.
+	baseArgs := []string{"-nodefaults", "-no-user-config", "-nographic", "-no-reboot",
+		"-accel", "kvm", "-cpu", "host",
+		// Needed until QEMU updates their bundled qboot version (needs https://github.com/bonzini/qboot/pull/28)
+		"-bios", "external/com_github_bonzini_qboot/bios.bin",
+		"-M", "microvm,x-option-roms=off,pic=off,pit=off,rtc=off,isa-serial=off",
+		"-kernel", opts.KernelPath,
+		// We force using a triple-fault reboot strategy since otherwise the kernel first tries others (like ACPI) which
+		// are not available in this very restricted environment. Similarly we need to override the boot console since
+		// there's nothing on the ISA bus that the kernel could talk to. We also force quiet for performance reasons.
+		"-append", "reboot=t console=hvc0 quiet " + opts.Cmdline,
+		"-initrd", opts.InitramfsPath,
+		"-device", "virtio-rng-device,max-bytes=1024,period=1000",
+		"-device", "virtio-serial-device,max_ports=16",
+		"-chardev", "stdio,id=con0", "-device", "virtconsole,chardev=con0",
+	}
+
+	if !opts.DisableHostNetworkInterface {
+		qemuNetType := "user"
+		qemuNetConfig := qemuValue{
+			"id":        {"usernet0"},
+			"net":       {"10.42.0.0/24"},
+			"dhcpstart": {"10.42.0.10"},
+		}
+		if opts.PortMap != nil {
+			qemuNetConfig["hostfwd"] = opts.PortMap.toQemuForwards()
+		}
+
+		baseArgs = append(baseArgs, "-netdev", qemuNetConfig.toOption(qemuNetType),
+			"-device", "virtio-net-device,netdev=usernet0,mac="+HostInterfaceMAC.String())
+	}
+
+	var stdErrBuf bytes.Buffer
+	cmd := exec.CommandContext(ctx, "qemu-system-x86_64", append(baseArgs, extraArgs...)...)
+	cmd.Stdout = opts.SerialPort
+	cmd.Stderr = &stdErrBuf
+
+	cmd.ExtraFiles = append(cmd.ExtraFiles, opts.ExtraChardevs...)
+	cmd.ExtraFiles = append(cmd.ExtraFiles, opts.ExtraNetworkInterfaces...)
+
+	err := cmd.Run()
+	var exerr *exec.ExitError
+	if err != nil && errors.As(err, &exerr) {
+		exerr.Stderr = stdErrBuf.Bytes()
+		newErr := QEMUError(*exerr)
+		return &newErr
+	}
+	return err
+}
+
+// QEMUError is a special type of ExitError used when QEMU fails. In addition to normal ExitError features it
+// prints stderr for debugging.
+type QEMUError exec.ExitError
+
+func (e *QEMUError) Error() string {
+	return fmt.Sprintf("%v: %v", e.String(), string(e.Stderr))
+}
+
+// NanoswitchPorts contains all ports forwarded by Nanoswitch to the first VM
+var NanoswitchPorts = []uint16{
+	common.ExternalServicePort,
+	common.DebugServicePort,
+	common.KubernetesAPIPort,
+}
+
+// ClusterOptions contains all options for launching a Smalltown cluster
+type ClusterOptions struct {
+	// The number of nodes this cluster should be started with initially
+	NumNodes int
+}
+
+// LaunchCluster launches a cluster of Smalltown VMs together with a Nanoswitch instance to network them all together.
+func LaunchCluster(ctx context.Context, opts ClusterOptions) (apb.NodeDebugServiceClient, PortMap, error) {
+	var switchPorts []*os.File
+	var vmPorts []*os.File
+	for i := 0; i < opts.NumNodes; i++ {
+		switchPort, vmPort, err := NewSocketPair()
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to get socketpair: %w", err)
+		}
+		switchPorts = append(switchPorts, switchPort)
+		vmPorts = append(vmPorts, vmPort)
+	}
+
+	if opts.NumNodes == 0 {
+		return nil, nil, errors.New("refusing to start cluster with zero nodes")
+	}
+
+	if opts.NumNodes > 2 {
+		return nil, nil, errors.New("launching more than 2 nodes is unsupported pending replacement of golden tickets")
+	}
+
+	go func() {
+		if err := Launch(ctx, Options{ConnectToSocket: vmPorts[0]}); err != nil {
+			// Launch() only terminates when QEMU has terminated. At that point our function probably doesn't run anymore
+			// so we have no way of communicating the error back up, so let's just log it. Also a failure in launching
+			// VMs should be very visible by the unavailability of the clients we return.
+			log.Printf("Failed to launch vm0: %v", err)
+		}
+	}()
+
+	portMap, err := ConflictFreePortMap(NanoswitchPorts)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to allocate ephemeral ports: %w", err)
+	}
+
+	go func() {
+		if err := RunMicroVM(ctx, &MicroVMOptions{
+			KernelPath:             "metropolis/test/ktest/linux-testing.elf",
+			InitramfsPath:          "metropolis/test/nanoswitch/initramfs.lz4",
+			ExtraNetworkInterfaces: switchPorts,
+			PortMap:                portMap,
+		}); err != nil {
+			log.Printf("Failed to launch nanoswitch: %v", err)
+		}
+	}()
+	copts := []grpcretry.CallOption{
+		grpcretry.WithBackoff(grpcretry.BackoffExponential(100 * time.Millisecond)),
+	}
+	conn, err := portMap.DialGRPC(common.DebugServicePort, grpc.WithInsecure(),
+		grpc.WithUnaryInterceptor(grpcretry.UnaryClientInterceptor(copts...)))
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to dial debug service: %w", err)
+	}
+	defer conn.Close()
+	debug := apb.NewNodeDebugServiceClient(conn)
+
+	if opts.NumNodes == 2 {
+		res, err := debug.GetGoldenTicket(ctx, &apb.GetGoldenTicketRequest{
+			// HACK: this is assigned by DHCP, and we assume that everything goes well.
+			ExternalIp: "10.1.0.3",
+		}, grpcretry.WithMax(10))
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to get golden ticket: %w", err)
+		}
+
+		ec := &apb.EnrolmentConfig{
+			GoldenTicket: res.Ticket,
+		}
+
+		go func() {
+			if err := Launch(ctx, Options{ConnectToSocket: vmPorts[1], EnrolmentConfig: ec}); err != nil {
+				log.Printf("Failed to launch vm1: %v", err)
+			}
+		}()
+	}
+
+	return debug, portMap, nil
+}