diff --git a/metropolis/test/ktest/BUILD b/metropolis/test/ktest/BUILD
new file mode 100644
index 0000000..d94831c
--- /dev/null
+++ b/metropolis/test/ktest/BUILD
@@ -0,0 +1,63 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("//metropolis/node/build/kconfig-patcher:kconfig-patcher.bzl", "kconfig_patch")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "git.monogon.dev/source/nexantic.git/metropolis/test/ktest",
+    visibility = ["//visibility:private"],
+    deps = ["//metropolis/test/launch:go_default_library"],
+)
+
+go_binary(
+    name = "ktest",
+    embed = [":go_default_library"],
+    pure = "on",
+    visibility = ["//visibility:public"],
+)
+
+kconfig_patch(
+    name = "testing-config",
+    src = "//third_party/linux:kernel-config",
+    out = "testing.config",
+    override_configs = {
+        # Unlock command line
+        "CONFIG_CMDLINE_OVERRIDE": "n",
+        "CONFIG_CMDLINE_BOOL": "n",
+        # Shave off 1 second from boot time
+        "CONFIG_SERIO_I8042": "",
+        "CONFIG_KEYBOARD_ATKBD": "",
+        "CONFIG_RTC_DRV_CMOS": "",
+        # Shave off an additional 18ms (half of the boot time)
+        "CONFIG_DEBUG_WX": "",
+    },
+)
+
+genrule(
+    name = "linux-testing",
+    srcs = [
+        "@linux//:all",
+        ":testing-config",
+    ],
+    outs = [
+        "linux-testing.elf",
+    ],
+    cmd = """
+    DIR=external/linux
+
+    mkdir $$DIR/.bin
+
+    cp $(location :testing-config) $$DIR/.config
+
+    (cd $$DIR && make -j $$(nproc) vmlinux >/dev/null)
+
+    cp $$DIR/vmlinux $@
+    """,
+    visibility = ["//visibility:public"],
+)
+
+filegroup(
+    name = "test-script",
+    srcs = ["run_ktest.sh"],
+    visibility = ["//visibility:public"],
+)
diff --git a/metropolis/test/ktest/init/BUILD.bazel b/metropolis/test/ktest/init/BUILD.bazel
new file mode 100644
index 0000000..4161146
--- /dev/null
+++ b/metropolis/test/ktest/init/BUILD.bazel
@@ -0,0 +1,16 @@
+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/ktest/init",
+    visibility = ["//visibility:private"],
+    deps = ["@org_golang_x_sys//unix:go_default_library"],
+)
+
+go_binary(
+    name = "init",
+    embed = [":go_default_library"],
+    pure = "on",
+    visibility = ["//visibility:public"],
+)
diff --git a/metropolis/test/ktest/init/main.go b/metropolis/test/ktest/init/main.go
new file mode 100644
index 0000000..f6049db
--- /dev/null
+++ b/metropolis/test/ktest/init/main.go
@@ -0,0 +1,83 @@
+// 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.
+
+// ktestinit is an init designed to run inside a lightweight VM for running tests in there.
+// It performs basic platform initialization like mounting kernel filesystems and launches the
+// test executable at /tester, passes the exit code back out over the control socket to ktest and
+// then terminates the VM kernel.
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+
+	"golang.org/x/sys/unix"
+)
+
+func mountInit() error {
+	for _, el := range []struct {
+		dir   string
+		fs    string
+		flags uintptr
+	}{
+		{"/sys", "sysfs", unix.MS_NOEXEC | unix.MS_NOSUID | unix.MS_NODEV},
+		{"/proc", "proc", unix.MS_NOEXEC | unix.MS_NOSUID | unix.MS_NODEV},
+		{"/dev", "devtmpfs", unix.MS_NOEXEC | unix.MS_NOSUID},
+		{"/dev/pts", "devpts", unix.MS_NOEXEC | unix.MS_NOSUID},
+	} {
+		if err := os.Mkdir(el.dir, 0755); err != nil && !os.IsExist(err) {
+			return fmt.Errorf("could not make %s: %w", el.dir, err)
+		}
+		if err := unix.Mount(el.fs, el.dir, el.fs, el.flags, ""); err != nil {
+			return fmt.Errorf("could not mount %s on %s: %w", el.fs, el.dir, err)
+		}
+	}
+	return nil
+}
+
+func main() {
+	if err := mountInit(); err != nil {
+		panic(err)
+	}
+
+	// First virtual serial is always stdout, second is control
+	ioConn, err := os.OpenFile("/dev/vport1p1", os.O_RDWR, 0)
+	if err != nil {
+		fmt.Printf("Failed to open communication device: %v\n", err)
+		return
+	}
+	cmd := exec.Command("/tester", "-test.v")
+	cmd.Stderr = os.Stderr
+	cmd.Stdout = os.Stdout
+	cmd.Env = append(cmd.Env, "IN_KTEST=true")
+	if err := cmd.Run(); err != nil {
+		var exerr *exec.ExitError
+		if errors.As(err, &exerr) {
+			if _, err := ioConn.Write([]byte{uint8(exerr.ExitCode())}); err != nil {
+				panic(err)
+			}
+		} else if err != nil {
+			fmt.Printf("Failed to execute tests (tests didn't run): %v", err)
+		}
+	} else {
+		ioConn.Write([]byte{0})
+	}
+	ioConn.Close()
+
+	unix.Reboot(unix.LINUX_REBOOT_CMD_RESTART)
+}
diff --git a/metropolis/test/ktest/ktest.bzl b/metropolis/test/ktest/ktest.bzl
new file mode 100644
index 0000000..fdbff20
--- /dev/null
+++ b/metropolis/test/ktest/ktest.bzl
@@ -0,0 +1,62 @@
+#  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.
+
+"""
+Ktest provides a simple macro to run tests inside the normal Smalltown kernel
+"""
+
+def ktest(deps, tester, initramfs_extra, cmdline):
+    native.genrule(
+        name = "test_initramfs",
+        srcs = [
+            "//metropolis/test/ktest/init",
+        ] + deps + [tester],
+        outs = [
+            "initramfs.cpio.lz4",
+        ],
+        testonly = True,
+        cmd = """
+        $(location @linux//:gen_init_cpio) - <<- 'EOF' | lz4 -l > \"$@\" 
+dir /dev 0755 0 0
+nod /dev/console 0600 0 0 c 5 1
+nod /dev/null 0644 0 0 c 1 3
+file /init $(location //metropolis/test/ktest/init) 0755 0 0
+file /tester $(location """ + tester + """) 0755 0 0
+""" + initramfs_extra + """
+EOF
+        """,
+        tools = [
+            "@linux//:gen_init_cpio",
+        ],
+    )
+
+    native.sh_test(
+        name = "ktest",
+        args = [
+            "$(location //metropolis/test/ktest)",
+            "$(location :test_initramfs)",
+            "$(location //metropolis/test/ktest:linux-testing)",
+            cmdline,
+        ],
+        size = "small",
+        srcs = ["//metropolis/test/ktest:test-script"],
+        data = [
+            "//metropolis/test/ktest",
+            ":test_initramfs",
+            "//metropolis/test/ktest:linux-testing",
+            "@com_github_bonzini_qboot//:qboot-bin",
+        ],
+    )
diff --git a/metropolis/test/ktest/main.go b/metropolis/test/ktest/main.go
new file mode 100644
index 0000000..7f750b8
--- /dev/null
+++ b/metropolis/test/ktest/main.go
@@ -0,0 +1,75 @@
+// 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.
+
+// ktest is a test launcher for running tests inside a custom kernel and passes the results
+// back out.
+package main
+
+import (
+	"context"
+	"flag"
+	"io"
+	"log"
+	"os"
+	"time"
+
+	"git.monogon.dev/source/nexantic.git/metropolis/test/launch"
+)
+
+var (
+	kernelPath = flag.String("kernel-path", "", "Path of the Kernel ELF file")
+	initrdPath = flag.String("initrd-path", "", "Path of the initrd image")
+	cmdline    = flag.String("cmdline", "", "Additional kernel command line options")
+)
+
+func main() {
+	flag.Parse()
+
+	hostFeedbackConn, vmFeedbackConn, err := launch.NewSocketPair()
+	if err != nil {
+		log.Fatalf("Failed to create socket pair: %v", err)
+	}
+
+	exitCodeChan := make(chan uint8, 1)
+
+	go func() {
+		defer hostFeedbackConn.Close()
+
+		returnCode := make([]byte, 1)
+		if _, err := io.ReadFull(hostFeedbackConn, returnCode); err != nil {
+			log.Fatalf("Failed to read socket: %v", err)
+		}
+		exitCodeChan <- returnCode[0]
+	}()
+
+	if err := launch.RunMicroVM(context.Background(), &launch.MicroVMOptions{
+		KernelPath:                  *kernelPath,
+		InitramfsPath:               *initrdPath,
+		Cmdline:                     *cmdline,
+		SerialPort:                  os.Stdout,
+		ExtraChardevs:               []*os.File{vmFeedbackConn},
+		DisableHostNetworkInterface: true,
+	}); err != nil {
+		log.Fatalf("Failed to run ktest VM: %v", err)
+	}
+
+	select {
+	case exitCode := <-exitCodeChan:
+		os.Exit(int(exitCode))
+	case <-time.After(1 * time.Second):
+		log.Fatal("Failed to get an error code back (test runtime probably crashed)")
+	}
+}
diff --git a/metropolis/test/ktest/run_ktest.sh b/metropolis/test/ktest/run_ktest.sh
new file mode 100755
index 0000000..02920a1
--- /dev/null
+++ b/metropolis/test/ktest/run_ktest.sh
@@ -0,0 +1,2 @@
+#!/bin/bash
+exec "$1" -initrd-path "$2" -kernel-path "$3" -cmdline "$4"
\ No newline at end of file