diff --git a/core/tools/ktestinit/BUILD.bazel b/core/tools/ktestinit/BUILD.bazel
new file mode 100644
index 0000000..74eb742
--- /dev/null
+++ b/core/tools/ktestinit/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/core/tools/ktestinit",
+    visibility = ["//visibility:private"],
+    deps = ["@org_golang_x_sys//unix:go_default_library"],
+)
+
+go_binary(
+    name = "ktestinit",
+    embed = [":go_default_library"],
+    pure = "on",
+    visibility = ["//visibility:public"],
+)
diff --git a/core/tools/ktestinit/main.go b/core/tools/ktestinit/main.go
new file mode 100644
index 0000000..9eb2342
--- /dev/null
+++ b/core/tools/ktestinit/main.go
@@ -0,0 +1,80 @@
+// 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)
+		}
+	}
+
+	unix.Reboot(unix.LINUX_REBOOT_CMD_RESTART)
+}