Merge pull request #1 from google/master

catch up

27 files changed, 1473 insertions, 759 deletions

diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD
index 6fe2b57de..ed3c8f546 100644
--- a/runsc/boot/BUILD
+++ b/runsc/boot/BUILD
@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+load("//tools:defs.bzl", "go_library", "go_test")
 
 package(licenses = ["notice"])
 
@@ -7,6 +7,7 @@ go_library(
     srcs = [
         "compat.go",
         "compat_amd64.go",
+        "compat_arm64.go",
         "config.go",
         "controller.go",
         "debug.go",
@@ -15,30 +16,33 @@ go_library(
         "fs.go",
         "limits.go",
         "loader.go",
+        "loader_amd64.go",
+        "loader_arm64.go",
         "network.go",
-        "pprof.go",
         "strace.go",
-        "user.go",
+        "vfs.go",
     ],
-    importpath = "gvisor.dev/gvisor/runsc/boot",
     visibility = [
+        "//pkg/test:__subpackages__",
         "//runsc:__subpackages__",
         "//test:__subpackages__",
     ],
     deps = [
         "//pkg/abi",
         "//pkg/abi/linux",
+        "//pkg/context",
         "//pkg/control/server",
         "//pkg/cpuid",
         "//pkg/eventchannel",
+        "//pkg/fspath",
         "//pkg/log",
         "//pkg/memutil",
         "//pkg/rand",
         "//pkg/refs",
         "//pkg/sentry/arch",
         "//pkg/sentry/arch:registers_go_proto",
-        "//pkg/sentry/context",
         "//pkg/sentry/control",
+        "//pkg/sentry/devices/memdev",
         "//pkg/sentry/fs",
         "//pkg/sentry/fs/dev",
         "//pkg/sentry/fs/gofer",
@@ -48,6 +52,13 @@ go_library(
         "//pkg/sentry/fs/sys",
         "//pkg/sentry/fs/tmpfs",
         "//pkg/sentry/fs/tty",
+        "//pkg/sentry/fs/user",
+        "//pkg/sentry/fsimpl/devtmpfs",
+        "//pkg/sentry/fsimpl/gofer",
+        "//pkg/sentry/fsimpl/host",
+        "//pkg/sentry/fsimpl/proc",
+        "//pkg/sentry/fsimpl/sys",
+        "//pkg/sentry/fsimpl/tmpfs",
         "//pkg/sentry/inet",
         "//pkg/sentry/kernel",
         "//pkg/sentry/kernel:uncaught_signal_go_proto",
@@ -60,16 +71,19 @@ go_library(
         "//pkg/sentry/socket/hostinet",
         "//pkg/sentry/socket/netlink",
         "//pkg/sentry/socket/netlink/route",
+        "//pkg/sentry/socket/netlink/uevent",
         "//pkg/sentry/socket/netstack",
         "//pkg/sentry/socket/unix",
         "//pkg/sentry/state",
         "//pkg/sentry/strace",
         "//pkg/sentry/syscalls/linux",
+        "//pkg/sentry/syscalls/linux/vfs2",
         "//pkg/sentry/time",
         "//pkg/sentry/unimpl:unimplemented_syscall_go_proto",
         "//pkg/sentry/usage",
-        "//pkg/sentry/usermem",
+        "//pkg/sentry/vfs",
         "//pkg/sentry/watchdog",
+        "//pkg/sync",
         "//pkg/syserror",
         "//pkg/tcpip",
         "//pkg/tcpip/link/fdbased",
@@ -86,6 +100,7 @@ go_library(
         "//pkg/urpc",
         "//runsc/boot/filter",
         "//runsc/boot/platforms",
+        "//runsc/boot/pprof",
         "//runsc/specutils",
         "@com_github_golang_protobuf//proto:go_default_library",
         "@com_github_opencontainers_runtime-spec//specs-go:go_default_library",
@@ -100,19 +115,21 @@ go_test(
         "compat_test.go",
         "fs_test.go",
         "loader_test.go",
-        "user_test.go",
     ],
-    embed = [":boot"],
+    library = ":boot",
     deps = [
         "//pkg/control/server",
+        "//pkg/fspath",
         "//pkg/log",
         "//pkg/p9",
-        "//pkg/sentry/arch:registers_go_proto",
-        "//pkg/sentry/context/contexttest",
+        "//pkg/sentry/contexttest",
         "//pkg/sentry/fs",
-        "//pkg/sentry/kernel/auth",
+        "//pkg/sentry/kernel",
+        "//pkg/sentry/vfs",
+        "//pkg/sync",
         "//pkg/unet",
         "//runsc/fsgofer",
         "@com_github_opencontainers_runtime-spec//specs-go:go_default_library",
+        "@org_golang_x_sys//unix:go_default_library",
     ],
 )
diff --git a/runsc/boot/compat.go b/runsc/boot/compat.go
index 07e35ab10..b7cfb35bf 100644
--- a/runsc/boot/compat.go
+++ b/runsc/boot/compat.go
@@ -17,18 +17,16 @@ package boot
 import (
 	"fmt"
 	"os"
-	"sync"
 	"syscall"
 
 	"github.com/golang/protobuf/proto"
-	"gvisor.dev/gvisor/pkg/abi"
 	"gvisor.dev/gvisor/pkg/eventchannel"
 	"gvisor.dev/gvisor/pkg/log"
-	"gvisor.dev/gvisor/pkg/sentry/arch"
 	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
 	ucspb "gvisor.dev/gvisor/pkg/sentry/kernel/uncaught_signal_go_proto"
 	"gvisor.dev/gvisor/pkg/sentry/strace"
 	spb "gvisor.dev/gvisor/pkg/sentry/unimpl/unimplemented_syscall_go_proto"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 func initCompatLogs(fd int) error {
@@ -53,9 +51,9 @@ type compatEmitter struct {
 }
 
 func newCompatEmitter(logFD int) (*compatEmitter, error) {
-	nameMap, ok := strace.Lookup(abi.Linux, arch.AMD64)
+	nameMap, ok := getSyscallNameMap()
 	if !ok {
-		return nil, fmt.Errorf("amd64 Linux syscall table not found")
+		return nil, fmt.Errorf("Linux syscall table not found")
 	}
 
 	c := &compatEmitter{
@@ -67,7 +65,7 @@ func newCompatEmitter(logFD int) (*compatEmitter, error) {
 
 	if logFD > 0 {
 		f := os.NewFile(uintptr(logFD), "user log file")
-		target := log.MultiEmitter{c.sink, log.K8sJSONEmitter{log.Writer{Next: f}}}
+		target := &log.MultiEmitter{c.sink, log.K8sJSONEmitter{&log.Writer{Next: f}}}
 		c.sink = &log.BasicLogger{Level: log.Info, Emitter: target}
 	}
 	return c, nil
@@ -86,16 +84,16 @@ func (c *compatEmitter) Emit(msg proto.Message) (bool, error) {
 }
 
 func (c *compatEmitter) emitUnimplementedSyscall(us *spb.UnimplementedSyscall) {
-	regs := us.Registers.GetArch().(*rpb.Registers_Amd64).Amd64
+	regs := us.Registers
 
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
-	sysnr := regs.OrigRax
+	sysnr := syscallNum(regs)
 	tr := c.trackers[sysnr]
 	if tr == nil {
 		switch sysnr {
-		case syscall.SYS_PRCTL, syscall.SYS_ARCH_PRCTL:
+		case syscall.SYS_PRCTL:
 			// args: cmd, ...
 			tr = newArgsTracker(0)
 
@@ -112,10 +110,14 @@ func (c *compatEmitter) emitUnimplementedSyscall(us *spb.UnimplementedSyscall) {
 			tr = newArgsTracker(2)
 
 		default:
-			tr = &onceTracker{}
+			tr = newArchArgsTracker(sysnr)
+			if tr == nil {
+				tr = &onceTracker{}
+			}
 		}
 		c.trackers[sysnr] = tr
 	}
+
 	if tr.shouldReport(regs) {
 		c.sink.Infof("Unsupported syscall: %s, regs: %+v", c.nameMap.Name(uintptr(sysnr)), regs)
 		tr.onReported(regs)
@@ -139,10 +141,10 @@ func (c *compatEmitter) Close() error {
 // the syscall and arguments.
 type syscallTracker interface {
 	// shouldReport returns true is the syscall should be reported.
-	shouldReport(regs *rpb.AMD64Registers) bool
+	shouldReport(regs *rpb.Registers) bool
 
 	// onReported marks the syscall as reported.
-	onReported(regs *rpb.AMD64Registers)
+	onReported(regs *rpb.Registers)
 }
 
 // onceTracker reports only a single time, used for most syscalls.
@@ -150,10 +152,45 @@ type onceTracker struct {
 	reported bool
 }
 
-func (o *onceTracker) shouldReport(_ *rpb.AMD64Registers) bool {
+func (o *onceTracker) shouldReport(_ *rpb.Registers) bool {
 	return !o.reported
 }
 
-func (o *onceTracker) onReported(_ *rpb.AMD64Registers) {
+func (o *onceTracker) onReported(_ *rpb.Registers) {
 	o.reported = true
 }
+
+// argsTracker reports only once for each different combination of arguments.
+// It's used for generic syscalls like ioctl to report once per 'cmd'.
+type argsTracker struct {
+	// argsIdx is the syscall arguments to use as unique ID.
+	argsIdx  []int
+	reported map[string]struct{}
+	count    int
+}
+
+func newArgsTracker(argIdx ...int) *argsTracker {
+	return &argsTracker{argsIdx: argIdx, reported: make(map[string]struct{})}
+}
+
+// key returns the command based on the syscall argument index.
+func (a *argsTracker) key(regs *rpb.Registers) string {
+	var rv string
+	for _, idx := range a.argsIdx {
+		rv += fmt.Sprintf("%d|", argVal(idx, regs))
+	}
+	return rv
+}
+
+func (a *argsTracker) shouldReport(regs *rpb.Registers) bool {
+	if a.count >= reportLimit {
+		return false
+	}
+	_, ok := a.reported[a.key(regs)]
+	return !ok
+}
+
+func (a *argsTracker) onReported(regs *rpb.Registers) {
+	a.count++
+	a.reported[a.key(regs)] = struct{}{}
+}
diff --git a/runsc/boot/compat_amd64.go b/runsc/boot/compat_amd64.go
index 43cd0db94..42b0ca8b0 100644
--- a/runsc/boot/compat_amd64.go
+++ b/runsc/boot/compat_amd64.go
@@ -16,62 +16,81 @@ package boot
 
 import (
 	"fmt"
+	"syscall"
 
+	"gvisor.dev/gvisor/pkg/abi"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
 	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
+	"gvisor.dev/gvisor/pkg/sentry/strace"
 )
 
 // reportLimit is the max number of events that should be reported per tracker.
 const reportLimit = 100
 
-// argsTracker reports only once for each different combination of arguments.
-// It's used for generic syscalls like ioctl to report once per 'cmd'.
-type argsTracker struct {
-	// argsIdx is the syscall arguments to use as unique ID.
-	argsIdx  []int
-	reported map[string]struct{}
-	count    int
+// newRegs create a empty Registers instance.
+func newRegs() *rpb.Registers {
+	return &rpb.Registers{
+		Arch: &rpb.Registers_Amd64{
+			Amd64: &rpb.AMD64Registers{},
+		},
+	}
 }
 
-func newArgsTracker(argIdx ...int) *argsTracker {
-	return &argsTracker{argsIdx: argIdx, reported: make(map[string]struct{})}
-}
+func argVal(argIdx int, regs *rpb.Registers) uint32 {
+	amd64Regs := regs.GetArch().(*rpb.Registers_Amd64).Amd64
 
-// cmd returns the command based on the syscall argument index.
-func (a *argsTracker) key(regs *rpb.AMD64Registers) string {
-	var rv string
-	for _, idx := range a.argsIdx {
-		rv += fmt.Sprintf("%d|", argVal(idx, regs))
+	switch argIdx {
+	case 0:
+		return uint32(amd64Regs.Rdi)
+	case 1:
+		return uint32(amd64Regs.Rsi)
+	case 2:
+		return uint32(amd64Regs.Rdx)
+	case 3:
+		return uint32(amd64Regs.R10)
+	case 4:
+		return uint32(amd64Regs.R8)
+	case 5:
+		return uint32(amd64Regs.R9)
 	}
-	return rv
+	panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
 }
 
-func argVal(argIdx int, regs *rpb.AMD64Registers) uint32 {
+func setArgVal(argIdx int, argVal uint64, regs *rpb.Registers) {
+	amd64Regs := regs.GetArch().(*rpb.Registers_Amd64).Amd64
+
 	switch argIdx {
 	case 0:
-		return uint32(regs.Rdi)
+		amd64Regs.Rdi = argVal
 	case 1:
-		return uint32(regs.Rsi)
+		amd64Regs.Rsi = argVal
 	case 2:
-		return uint32(regs.Rdx)
+		amd64Regs.Rdx = argVal
 	case 3:
-		return uint32(regs.R10)
+		amd64Regs.R10 = argVal
 	case 4:
-		return uint32(regs.R8)
+		amd64Regs.R8 = argVal
 	case 5:
-		return uint32(regs.R9)
+		amd64Regs.R9 = argVal
+	default:
+		panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
 	}
-	panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
 }
 
-func (a *argsTracker) shouldReport(regs *rpb.AMD64Registers) bool {
-	if a.count >= reportLimit {
-		return false
-	}
-	_, ok := a.reported[a.key(regs)]
-	return !ok
+func getSyscallNameMap() (strace.SyscallMap, bool) {
+	return strace.Lookup(abi.Linux, arch.AMD64)
+}
+
+func syscallNum(regs *rpb.Registers) uint64 {
+	amd64Regs := regs.GetArch().(*rpb.Registers_Amd64).Amd64
+	return amd64Regs.OrigRax
 }
 
-func (a *argsTracker) onReported(regs *rpb.AMD64Registers) {
-	a.count++
-	a.reported[a.key(regs)] = struct{}{}
+func newArchArgsTracker(sysnr uint64) syscallTracker {
+	switch sysnr {
+	case syscall.SYS_ARCH_PRCTL:
+		// args: cmd, ...
+		return newArgsTracker(0)
+	}
+	return nil
 }
diff --git a/runsc/boot/compat_arm64.go b/runsc/boot/compat_arm64.go
new file mode 100644
index 000000000..f784cd237
--- /dev/null
+++ b/runsc/boot/compat_arm64.go
@@ -0,0 +1,91 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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 boot
+
+import (
+	"fmt"
+
+	"gvisor.dev/gvisor/pkg/abi"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
+	"gvisor.dev/gvisor/pkg/sentry/strace"
+)
+
+// reportLimit is the max number of events that should be reported per tracker.
+const reportLimit = 100
+
+// newRegs create a empty Registers instance.
+func newRegs() *rpb.Registers {
+	return &rpb.Registers{
+		Arch: &rpb.Registers_Arm64{
+			Arm64: &rpb.ARM64Registers{},
+		},
+	}
+}
+
+func argVal(argIdx int, regs *rpb.Registers) uint32 {
+	arm64Regs := regs.GetArch().(*rpb.Registers_Arm64).Arm64
+
+	switch argIdx {
+	case 0:
+		return uint32(arm64Regs.R0)
+	case 1:
+		return uint32(arm64Regs.R1)
+	case 2:
+		return uint32(arm64Regs.R2)
+	case 3:
+		return uint32(arm64Regs.R3)
+	case 4:
+		return uint32(arm64Regs.R4)
+	case 5:
+		return uint32(arm64Regs.R5)
+	}
+	panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
+}
+
+func setArgVal(argIdx int, argVal uint64, regs *rpb.Registers) {
+	arm64Regs := regs.GetArch().(*rpb.Registers_Arm64).Arm64
+
+	switch argIdx {
+	case 0:
+		arm64Regs.R0 = argVal
+	case 1:
+		arm64Regs.R1 = argVal
+	case 2:
+		arm64Regs.R2 = argVal
+	case 3:
+		arm64Regs.R3 = argVal
+	case 4:
+		arm64Regs.R4 = argVal
+	case 5:
+		arm64Regs.R5 = argVal
+	default:
+		panic(fmt.Sprintf("invalid syscall argument index %d", argIdx))
+	}
+}
+
+func getSyscallNameMap() (strace.SyscallMap, bool) {
+	return strace.Lookup(abi.Linux, arch.ARM64)
+}
+
+func syscallNum(regs *rpb.Registers) uint64 {
+	arm64Regs := regs.GetArch().(*rpb.Registers_Arm64).Arm64
+	return arm64Regs.R8
+}
+
+func newArchArgsTracker(sysnr uint64) syscallTracker {
+	// currently, no arch specific syscalls need to be handled here.
+	return nil
+}
diff --git a/runsc/boot/compat_test.go b/runsc/boot/compat_test.go
index 388298d8d..839c5303b 100644
--- a/runsc/boot/compat_test.go
+++ b/runsc/boot/compat_test.go
@@ -16,8 +16,6 @@ package boot
 
 import (
 	"testing"
-
-	rpb "gvisor.dev/gvisor/pkg/sentry/arch/registers_go_proto"
 )
 
 func TestOnceTracker(t *testing.T) {
@@ -35,31 +33,34 @@ func TestOnceTracker(t *testing.T) {
 
 func TestArgsTracker(t *testing.T) {
 	for _, tc := range []struct {
-		name string
-		idx  []int
-		rdi1 uint64
-		rdi2 uint64
-		rsi1 uint64
-		rsi2 uint64
-		want bool
+		name   string
+		idx    []int
+		arg1_1 uint64
+		arg1_2 uint64
+		arg2_1 uint64
+		arg2_2 uint64
+		want   bool
 	}{
-		{name: "same rdi", idx: []int{0}, rdi1: 123, rdi2: 123, want: false},
-		{name: "same rsi", idx: []int{1}, rsi1: 123, rsi2: 123, want: false},
-		{name: "diff rdi", idx: []int{0}, rdi1: 123, rdi2: 321, want: true},
-		{name: "diff rsi", idx: []int{1}, rsi1: 123, rsi2: 321, want: true},
-		{name: "cmd is uint32", idx: []int{0}, rsi1: 0xdead00000123, rsi2: 0xbeef00000123, want: false},
-		{name: "same 2 args", idx: []int{0, 1}, rsi1: 123, rdi1: 321, rsi2: 123, rdi2: 321, want: false},
-		{name: "diff 2 args", idx: []int{0, 1}, rsi1: 123, rdi1: 321, rsi2: 789, rdi2: 987, want: true},
+		{name: "same arg1", idx: []int{0}, arg1_1: 123, arg1_2: 123, want: false},
+		{name: "same arg2", idx: []int{1}, arg2_1: 123, arg2_2: 123, want: false},
+		{name: "diff arg1", idx: []int{0}, arg1_1: 123, arg1_2: 321, want: true},
+		{name: "diff arg2", idx: []int{1}, arg2_1: 123, arg2_2: 321, want: true},
+		{name: "cmd is uint32", idx: []int{0}, arg2_1: 0xdead00000123, arg2_2: 0xbeef00000123, want: false},
+		{name: "same 2 args", idx: []int{0, 1}, arg2_1: 123, arg1_1: 321, arg2_2: 123, arg1_2: 321, want: false},
+		{name: "diff 2 args", idx: []int{0, 1}, arg2_1: 123, arg1_1: 321, arg2_2: 789, arg1_2: 987, want: true},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
 			c := newArgsTracker(tc.idx...)
-			regs := &rpb.AMD64Registers{Rdi: tc.rdi1, Rsi: tc.rsi1}
+			regs := newRegs()
+			setArgVal(0, tc.arg1_1, regs)
+			setArgVal(1, tc.arg2_1, regs)
 			if !c.shouldReport(regs) {
 				t.Error("first call to shouldReport, got: false, want: true")
 			}
 			c.onReported(regs)
 
-			regs.Rdi, regs.Rsi = tc.rdi2, tc.rsi2
+			setArgVal(0, tc.arg1_2, regs)
+			setArgVal(1, tc.arg2_2, regs)
 			if got := c.shouldReport(regs); tc.want != got {
 				t.Errorf("second call to shouldReport, got: %t, want: %t", got, tc.want)
 			}
@@ -70,7 +71,9 @@ func TestArgsTracker(t *testing.T) {
 func TestArgsTrackerLimit(t *testing.T) {
 	c := newArgsTracker(0, 1)
 	for i := 0; i < reportLimit; i++ {
-		regs := &rpb.AMD64Registers{Rdi: 123, Rsi: uint64(i)}
+		regs := newRegs()
+		setArgVal(0, 123, regs)
+		setArgVal(1, uint64(i), regs)
 		if !c.shouldReport(regs) {
 			t.Error("shouldReport before limit was reached, got: false, want: true")
 		}
@@ -78,7 +81,9 @@ func TestArgsTrackerLimit(t *testing.T) {
 	}
 
 	// Should hit the count limit now.
-	regs := &rpb.AMD64Registers{Rdi: 123, Rsi: 123456}
+	regs := newRegs()
+	setArgVal(0, 123, regs)
+	setArgVal(1, 123456, regs)
 	if c.shouldReport(regs) {
 		t.Error("shouldReport after limit was reached, got: true, want: false")
 	}
diff --git a/runsc/boot/config.go b/runsc/boot/config.go
index 72a33534f..715a19112 100644
--- a/runsc/boot/config.go
+++ b/runsc/boot/config.go
@@ -158,6 +158,9 @@ type Config struct {
 	// DebugLog is the path to log debug information to, if not empty.
 	DebugLog string
 
+	// PanicLog is the path to log GO's runtime messages, if not empty.
+	PanicLog string
+
 	// DebugLogFormat is the log format for debug.
 	DebugLogFormat string
 
@@ -250,6 +253,15 @@ type Config struct {
 	// multiple tests are run in parallel, since there is no way to pass
 	// parameters to the runtime from docker.
 	TestOnlyTestNameEnv string
+
+	// CPUNumFromQuota sets CPU number count to available CPU quota, using
+	// least integer value greater than or equal to quota.
+	//
+	// E.g. 0.2 CPU quota will result in 1, and 1.9 in 2.
+	CPUNumFromQuota bool
+
+	// Enables VFS2 (not plumbled through yet).
+	VFS2 bool
 }
 
 // ToFlags returns a slice of flags that correspond to the given Config.
@@ -260,6 +272,7 @@ func (c *Config) ToFlags() []string {
 		"--log=" + c.LogFilename,
 		"--log-format=" + c.LogFormat,
 		"--debug-log=" + c.DebugLog,
+		"--panic-log=" + c.PanicLog,
 		"--debug-log-format=" + c.DebugLogFormat,
 		"--file-access=" + c.FileAccess.String(),
 		"--overlay=" + strconv.FormatBool(c.Overlay),
@@ -282,6 +295,9 @@ func (c *Config) ToFlags() []string {
 		"--software-gso=" + strconv.FormatBool(c.SoftwareGSO),
 		"--overlayfs-stale-read=" + strconv.FormatBool(c.OverlayfsStaleRead),
 	}
+	if c.CPUNumFromQuota {
+		f = append(f, "--cpu-num-from-quota")
+	}
 	// Only include these if set since it is never to be used by users.
 	if c.TestOnlyAllowRunAsCurrentUserWithoutChroot {
 		f = append(f, "--TESTONLY-unsafe-nonroot=true")
@@ -289,5 +305,10 @@ func (c *Config) ToFlags() []string {
 	if len(c.TestOnlyTestNameEnv) != 0 {
 		f = append(f, "--TESTONLY-test-name-env="+c.TestOnlyTestNameEnv)
 	}
+
+	if c.VFS2 {
+		f = append(f, "--vfs2=true")
+	}
+
 	return f
 }
diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 928285683..8125d5061 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -32,6 +32,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/watchdog"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 	"gvisor.dev/gvisor/pkg/urpc"
+	"gvisor.dev/gvisor/runsc/boot/pprof"
 	"gvisor.dev/gvisor/runsc/specutils"
 )
 
@@ -100,11 +101,14 @@ const (
 
 // Profiling related commands (see pprof.go for more details).
 const (
-	StartCPUProfile = "Profile.StartCPUProfile"
-	StopCPUProfile  = "Profile.StopCPUProfile"
-	HeapProfile     = "Profile.HeapProfile"
-	StartTrace      = "Profile.StartTrace"
-	StopTrace       = "Profile.StopTrace"
+	StartCPUProfile  = "Profile.StartCPUProfile"
+	StopCPUProfile   = "Profile.StopCPUProfile"
+	HeapProfile      = "Profile.HeapProfile"
+	GoroutineProfile = "Profile.GoroutineProfile"
+	BlockProfile     = "Profile.BlockProfile"
+	MutexProfile     = "Profile.MutexProfile"
+	StartTrace       = "Profile.StartTrace"
+	StopTrace        = "Profile.StopTrace"
 )
 
 // Logging related commands (see logging.go for more details).
@@ -142,7 +146,7 @@ func newController(fd int, l *Loader) (*controller, error) {
 	}
 	srv.Register(manager)
 
-	if eps, ok := l.k.NetworkStack().(*netstack.Stack); ok {
+	if eps, ok := l.k.RootNetworkNamespace().Stack().(*netstack.Stack); ok {
 		net := &Network{
 			Stack: eps.Stack,
 		}
@@ -152,7 +156,9 @@ func newController(fd int, l *Loader) (*controller, error) {
 	srv.Register(&debug{})
 	srv.Register(&control.Logging{})
 	if l.conf.ProfileEnable {
-		srv.Register(&control.Profile{})
+		srv.Register(&control.Profile{
+			Kernel: l.k,
+		})
 	}
 
 	return &controller{
@@ -339,7 +345,7 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error {
 		return fmt.Errorf("creating memory file: %v", err)
 	}
 	k.SetMemoryFile(mf)
-	networkStack := cm.l.k.NetworkStack()
+	networkStack := cm.l.k.RootNetworkNamespace().Stack()
 	cm.l.k = k
 
 	// Set up the restore environment.
@@ -363,9 +369,9 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error {
 	}
 
 	if cm.l.conf.ProfileEnable {
-		// initializePProf opens /proc/self/maps, so has to be
-		// called before installing seccomp filters.
-		initializePProf()
+		// pprof.Initialize opens /proc/self/maps, so has to be called before
+		// installing seccomp filters.
+		pprof.Initialize()
 	}
 
 	// Seccomp filters have to be applied before parsing the state file.
@@ -380,7 +386,9 @@ func (cm *containerManager) Restore(o *RestoreOpts, _ *struct{}) error {
 	}
 
 	// Since we have a new kernel we also must make a new watchdog.
-	dog := watchdog.New(k, watchdog.DefaultTimeout, cm.l.conf.WatchdogAction)
+	dogOpts := watchdog.DefaultOpts
+	dogOpts.TaskTimeoutAction = cm.l.conf.WatchdogAction
+	dog := watchdog.New(k, dogOpts)
 
 	// Change the loader fields to reflect the changes made when restoring.
 	cm.l.k = k
diff --git a/runsc/boot/fds.go b/runsc/boot/fds.go
index e5de1f3d7..7e7a31fbd 100644
--- a/runsc/boot/fds.go
+++ b/runsc/boot/fds.go
@@ -17,9 +17,10 @@ package boot
 import (
 	"fmt"
 
-	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/host"
+	vfshost "gvisor.dev/gvisor/pkg/sentry/fsimpl/host"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 )
 
@@ -31,10 +32,13 @@ func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.F
 		return nil, fmt.Errorf("stdioFDs should contain exactly 3 FDs (stdin, stdout, and stderr), but %d FDs received", len(stdioFDs))
 	}
 
+	if kernel.VFS2Enabled {
+		return createFDTableVFS2(ctx, console, stdioFDs)
+	}
+
 	k := kernel.KernelFromContext(ctx)
 	fdTable := k.NewFDTable()
 	defer fdTable.DecRef()
-	mounter := fs.FileOwnerFromContext(ctx)
 
 	var ttyFile *fs.File
 	for appFD, hostFD := range stdioFDs {
@@ -44,7 +48,7 @@ func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.F
 			// Import the file as a host TTY file.
 			if ttyFile == nil {
 				var err error
-				appFile, err = host.ImportFile(ctx, hostFD, mounter, true /* isTTY */)
+				appFile, err = host.ImportFile(ctx, hostFD, true /* isTTY */)
 				if err != nil {
 					return nil, err
 				}
@@ -63,7 +67,7 @@ func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.F
 		} else {
 			// Import the file as a regular host file.
 			var err error
-			appFile, err = host.ImportFile(ctx, hostFD, mounter, false /* isTTY */)
+			appFile, err = host.ImportFile(ctx, hostFD, false /* isTTY */)
 			if err != nil {
 				return nil, err
 			}
@@ -79,3 +83,26 @@ func createFDTable(ctx context.Context, console bool, stdioFDs []int) (*kernel.F
 	fdTable.IncRef()
 	return fdTable, nil
 }
+
+func createFDTableVFS2(ctx context.Context, console bool, stdioFDs []int) (*kernel.FDTable, error) {
+	k := kernel.KernelFromContext(ctx)
+	fdTable := k.NewFDTable()
+	defer fdTable.DecRef()
+
+	for appFD, hostFD := range stdioFDs {
+		// TODO(gvisor.dev/issue/1482): Add TTY support.
+		appFile, err := vfshost.ImportFD(ctx, k.HostMount(), hostFD, false)
+		if err != nil {
+			return nil, err
+		}
+
+		if err := fdTable.NewFDAtVFS2(ctx, int32(appFD), appFile, kernel.FDFlags{}); err != nil {
+			appFile.DecRef()
+			return nil, err
+		}
+		appFile.DecRef()
+	}
+
+	fdTable.IncRef()
+	return fdTable, nil
+}
diff --git a/runsc/boot/filter/BUILD b/runsc/boot/filter/BUILD
index f5509b6b7..ed18f0047 100644
--- a/runsc/boot/filter/BUILD
+++ b/runsc/boot/filter/BUILD
@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("//tools:defs.bzl", "go_library")
 
 package(licenses = ["notice"])
 
@@ -6,12 +6,14 @@ go_library(
     name = "filter",
     srcs = [
         "config.go",
+        "config_amd64.go",
+        "config_arm64.go",
+        "config_profile.go",
         "extra_filters.go",
         "extra_filters_msan.go",
         "extra_filters_race.go",
         "filter.go",
     ],
-    importpath = "gvisor.dev/gvisor/runsc/boot/filter",
     visibility = [
         "//runsc/boot:__subpackages__",
     ],
diff --git a/runsc/boot/filter/config.go b/runsc/boot/filter/config.go
index 5ad108261..1828d116a 100644
--- a/runsc/boot/filter/config.go
+++ b/runsc/boot/filter/config.go
@@ -26,10 +26,6 @@ import (
 
 // allowedSyscalls is the set of syscalls executed by the Sentry to the host OS.
 var allowedSyscalls = seccomp.SyscallRules{
-	syscall.SYS_ARCH_PRCTL: []seccomp.Rule{
-		{seccomp.AllowValue(linux.ARCH_GET_FS)},
-		{seccomp.AllowValue(linux.ARCH_SET_FS)},
-	},
 	syscall.SYS_CLOCK_GETTIME: {},
 	syscall.SYS_CLONE: []seccomp.Rule{
 		{
@@ -42,9 +38,15 @@ var allowedSyscalls = seccomp.SyscallRules{
 					syscall.CLONE_THREAD),
 		},
 	},
-	syscall.SYS_CLOSE:         {},
-	syscall.SYS_DUP:           {},
-	syscall.SYS_DUP2:          {},
+	syscall.SYS_CLOSE: {},
+	syscall.SYS_DUP:   {},
+	syscall.SYS_DUP3: []seccomp.Rule{
+		{
+			seccomp.AllowAny{},
+			seccomp.AllowAny{},
+			seccomp.AllowValue(syscall.O_CLOEXEC),
+		},
+	},
 	syscall.SYS_EPOLL_CREATE1: {},
 	syscall.SYS_EPOLL_CTL:     {},
 	syscall.SYS_EPOLL_PWAIT: []seccomp.Rule{
@@ -132,11 +134,6 @@ var allowedSyscalls = seccomp.SyscallRules{
 			seccomp.AllowValue(syscall.SOL_SOCKET),
 			seccomp.AllowValue(syscall.SO_SNDBUF),
 		},
-		{
-			seccomp.AllowAny{},
-			seccomp.AllowValue(syscall.SOL_SOCKET),
-			seccomp.AllowValue(syscall.SO_REUSEADDR),
-		},
 	},
 	syscall.SYS_GETTID:       {},
 	syscall.SYS_GETTIMEOFDAY: {},
@@ -177,6 +174,18 @@ var allowedSyscalls = seccomp.SyscallRules{
 	syscall.SYS_LSEEK:   {},
 	syscall.SYS_MADVISE: {},
 	syscall.SYS_MINCORE: {},
+	// Used by the Go runtime as a temporarily workaround for a Linux
+	// 5.2-5.4 bug.
+	//
+	// See src/runtime/os_linux_x86.go.
+	//
+	// TODO(b/148688965): Remove once this is gone from Go.
+	syscall.SYS_MLOCK: []seccomp.Rule{
+		{
+			seccomp.AllowAny{},
+			seccomp.AllowValue(4096),
+		},
+	},
 	syscall.SYS_MMAP: []seccomp.Rule{
 		{
 			seccomp.AllowAny{},
@@ -220,7 +229,9 @@ var allowedSyscalls = seccomp.SyscallRules{
 	syscall.SYS_NANOSLEEP: {},
 	syscall.SYS_PPOLL:     {},
 	syscall.SYS_PREAD64:   {},
+	syscall.SYS_PREADV:    {},
 	syscall.SYS_PWRITE64:  {},
+	syscall.SYS_PWRITEV:   {},
 	syscall.SYS_READ:      {},
 	syscall.SYS_RECVMSG: []seccomp.Rule{
 		{
@@ -273,12 +284,21 @@ var allowedSyscalls = seccomp.SyscallRules{
 		{seccomp.AllowAny{}, seccomp.AllowValue(syscall.SHUT_RDWR)},
 	},
 	syscall.SYS_SIGALTSTACK:     {},
+	unix.SYS_STATX:              {},
 	syscall.SYS_SYNC_FILE_RANGE: {},
 	syscall.SYS_TGKILL: []seccomp.Rule{
 		{
 			seccomp.AllowValue(uint64(os.Getpid())),
 		},
 	},
+	syscall.SYS_UTIMENSAT: []seccomp.Rule{
+		{
+			seccomp.AllowAny{},
+			seccomp.AllowValue(0), /* null pathname */
+			seccomp.AllowAny{},
+			seccomp.AllowValue(0), /* flags */
+		},
+	},
 	syscall.SYS_WRITE: {},
 	// The only user in rawfile.NonBlockingWrite3 always passes iovcnt with
 	// values 2 or 3. Three iovec-s are passed, when the PACKET_VNET_HDR
@@ -315,6 +335,26 @@ func hostInetFilters() seccomp.SyscallRules {
 		syscall.SYS_GETSOCKOPT: []seccomp.Rule{
 			{
 				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IP),
+				seccomp.AllowValue(syscall.IP_TOS),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IP),
+				seccomp.AllowValue(syscall.IP_RECVTOS),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IPV6),
+				seccomp.AllowValue(syscall.IPV6_TCLASS),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IPV6),
+				seccomp.AllowValue(syscall.IPV6_RECVTCLASS),
+			},
+			{
+				seccomp.AllowAny{},
 				seccomp.AllowValue(syscall.SOL_IPV6),
 				seccomp.AllowValue(syscall.IPV6_V6ONLY),
 			},
@@ -416,6 +456,34 @@ func hostInetFilters() seccomp.SyscallRules {
 				seccomp.AllowAny{},
 				seccomp.AllowValue(4),
 			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IP),
+				seccomp.AllowValue(syscall.IP_TOS),
+				seccomp.AllowAny{},
+				seccomp.AllowValue(4),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IP),
+				seccomp.AllowValue(syscall.IP_RECVTOS),
+				seccomp.AllowAny{},
+				seccomp.AllowValue(4),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IPV6),
+				seccomp.AllowValue(syscall.IPV6_TCLASS),
+				seccomp.AllowAny{},
+				seccomp.AllowValue(4),
+			},
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.SOL_IPV6),
+				seccomp.AllowValue(syscall.IPV6_RECVTCLASS),
+				seccomp.AllowAny{},
+				seccomp.AllowValue(4),
+			},
 		},
 		syscall.SYS_SHUTDOWN: []seccomp.Rule{
 			{
@@ -479,16 +547,3 @@ func controlServerFilters(fd int) seccomp.SyscallRules {
 		},
 	}
 }
-
-// profileFilters returns extra syscalls made by runtime/pprof package.
-func profileFilters() seccomp.SyscallRules {
-	return seccomp.SyscallRules{
-		syscall.SYS_OPENAT: []seccomp.Rule{
-			{
-				seccomp.AllowAny{},
-				seccomp.AllowAny{},
-				seccomp.AllowValue(syscall.O_RDONLY | syscall.O_LARGEFILE | syscall.O_CLOEXEC),
-			},
-		},
-	}
-}
diff --git a/runsc/boot/filter/config_amd64.go b/runsc/boot/filter/config_amd64.go
new file mode 100644
index 000000000..5335ff82c
--- /dev/null
+++ b/runsc/boot/filter/config_amd64.go
@@ -0,0 +1,31 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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.
+
+// +build amd64
+
+package filter
+
+import (
+	"syscall"
+
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/seccomp"
+)
+
+func init() {
+	allowedSyscalls[syscall.SYS_ARCH_PRCTL] = append(allowedSyscalls[syscall.SYS_ARCH_PRCTL],
+		seccomp.Rule{seccomp.AllowValue(linux.ARCH_GET_FS)},
+		seccomp.Rule{seccomp.AllowValue(linux.ARCH_SET_FS)},
+	)
+}
diff --git a/runsc/boot/filter/config_arm64.go b/runsc/boot/filter/config_arm64.go
new file mode 100644
index 000000000..7fa9bbda3
--- /dev/null
+++ b/runsc/boot/filter/config_arm64.go
@@ -0,0 +1,21 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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.
+
+// +build arm64
+
+package filter
+
+// Reserve for future customization.
+func init() {
+}
diff --git a/runsc/boot/filter/config_profile.go b/runsc/boot/filter/config_profile.go
new file mode 100644
index 000000000..194952a7b
--- /dev/null
+++ b/runsc/boot/filter/config_profile.go
@@ -0,0 +1,34 @@
+// Copyright 2020 The gVisor Authors.
+//
+// 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 filter
+
+import (
+	"syscall"
+
+	"gvisor.dev/gvisor/pkg/seccomp"
+)
+
+// profileFilters returns extra syscalls made by runtime/pprof package.
+func profileFilters() seccomp.SyscallRules {
+	return seccomp.SyscallRules{
+		syscall.SYS_OPENAT: []seccomp.Rule{
+			{
+				seccomp.AllowAny{},
+				seccomp.AllowAny{},
+				seccomp.AllowValue(syscall.O_RDONLY | syscall.O_LARGEFILE | syscall.O_CLOEXEC),
+			},
+		},
+	}
+}
diff --git a/runsc/boot/fs.go b/runsc/boot/fs.go
index 76036c147..98cce60af 100644
--- a/runsc/boot/fs.go
+++ b/runsc/boot/fs.go
@@ -16,7 +16,6 @@ package boot
 
 import (
 	"fmt"
-	"path"
 	"path/filepath"
 	"sort"
 	"strconv"
@@ -33,8 +32,8 @@ import (
 
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/log"
-	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/gofer"
 	"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
@@ -52,7 +51,7 @@ const (
 	rootDevice = "9pfs-/"
 
 	// MountPrefix is the annotation prefix for mount hints.
-	MountPrefix = "gvisor.dev/spec/mount"
+	MountPrefix = "dev.gvisor.spec.mount."
 
 	// Filesystems that runsc supports.
 	bind     = "bind"
@@ -279,6 +278,9 @@ func subtargets(root string, mnts []specs.Mount) []string {
 }
 
 func setupContainerFS(ctx context.Context, conf *Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error {
+	if conf.VFS2 {
+		return setupContainerVFS2(ctx, conf, mntr, procArgs)
+	}
 	mns, err := mntr.setupFS(conf, procArgs)
 	if err != nil {
 		return err
@@ -465,6 +467,13 @@ func (m *mountHint) checkCompatible(mount specs.Mount) error {
 	return nil
 }
 
+func (m *mountHint) fileAccessType() FileAccessType {
+	if m.share == container {
+		return FileAccessExclusive
+	}
+	return FileAccessShared
+}
+
 func filterUnsupportedOptions(mount specs.Mount) []string {
 	rv := make([]string, 0, len(mount.Options))
 	for _, o := range mount.Options {
@@ -483,14 +492,15 @@ type podMountHints struct {
 func newPodMountHints(spec *specs.Spec) (*podMountHints, error) {
 	mnts := make(map[string]*mountHint)
 	for k, v := range spec.Annotations {
-		// Look for 'gvisor.dev/spec/mount' annotations and parse them.
+		// Look for 'dev.gvisor.spec.mount' annotations and parse them.
 		if strings.HasPrefix(k, MountPrefix) {
-			parts := strings.Split(k, "/")
-			if len(parts) != 5 {
+			// Remove the prefix and split the rest.
+			parts := strings.Split(k[len(MountPrefix):], ".")
+			if len(parts) != 2 {
 				return nil, fmt.Errorf("invalid mount annotation: %s=%s", k, v)
 			}
-			name := parts[3]
-			if len(name) == 0 || path.Clean(name) != name {
+			name := parts[0]
+			if len(name) == 0 {
 				return nil, fmt.Errorf("invalid mount name: %s", name)
 			}
 			mnt := mnts[name]
@@ -498,7 +508,7 @@ func newPodMountHints(spec *specs.Spec) (*podMountHints, error) {
 				mnt = &mountHint{name: name}
 				mnts[name] = mnt
 			}
-			if err := mnt.setField(parts[4], v); err != nil {
+			if err := mnt.setField(parts[1], v); err != nil {
 				return nil, err
 			}
 		}
@@ -566,8 +576,16 @@ func newContainerMounter(spec *specs.Spec, goferFDs []int, k *kernel.Kernel, hin
 // should be mounted (e.g. a volume shared between containers). It must be
 // called for the root container only.
 func (c *containerMounter) processHints(conf *Config) error {
+	if conf.VFS2 {
+		return nil
+	}
 	ctx := c.k.SupervisorContext()
 	for _, hint := range c.hints.mounts {
+		// TODO(b/142076984): Only support tmpfs for now. Bind mounts require a
+		// common gofer to mount all shared volumes.
+		if hint.mount.Type != tmpfs {
+			continue
+		}
 		log.Infof("Mounting master of shared mount %q from %q type %q", hint.name, hint.mount.Source, hint.mount.Type)
 		inode, err := c.mountSharedMaster(ctx, conf, hint)
 		if err != nil {
@@ -764,20 +782,24 @@ func (c *containerMounter) getMountNameAndOptions(conf *Config, m specs.Mount) (
 	case bind:
 		fd := c.fds.remove()
 		fsName = "9p"
-		// Non-root bind mounts are always shared.
-		opts = p9MountOptions(fd, FileAccessShared)
+		opts = p9MountOptions(fd, c.getMountAccessType(m))
 		// If configured, add overlay to all writable mounts.
 		useOverlay = conf.Overlay && !mountFlags(m.Options).ReadOnly
 
 	default:
-		// TODO(nlacasse): Support all the mount types and make this a fatal error.
-		// Most applications will "just work" without them, so this is a warning
-		// for now.
 		log.Warningf("ignoring unknown filesystem type %q", m.Type)
 	}
 	return fsName, opts, useOverlay, nil
 }
 
+func (c *containerMounter) getMountAccessType(mount specs.Mount) FileAccessType {
+	if hint := c.hints.findMount(mount); hint != nil {
+		return hint.fileAccessType()
+	}
+	// Non-root bind mounts are always shared if no hints were provided.
+	return FileAccessShared
+}
+
 // mountSubmount mounts volumes inside the container's root. Because mounts may
 // be readonly, a lower ramfs overlay is added to create the mount point dir.
 // Another overlay is added with tmpfs on top if Config.Overlay is true.
@@ -805,7 +827,20 @@ func (c *containerMounter) mountSubmount(ctx context.Context, conf *Config, mns
 
 	inode, err := filesystem.Mount(ctx, mountDevice(m), mf, strings.Join(opts, ","), nil)
 	if err != nil {
-		return fmt.Errorf("creating mount with source %q: %v", m.Source, err)
+		err := fmt.Errorf("creating mount with source %q: %v", m.Source, err)
+		// Check to see if this is a common error due to a Linux bug.
+		// This error is generated here in order to cause it to be
+		// printed to the user using Docker via 'runsc create' etc. rather
+		// than simply printed to the logs for the 'runsc boot' command.
+		//
+		// We check the error message string rather than type because the
+		// actual error types (syscall.EIO, syscall.EPIPE) are lost by file system
+		// implementation (e.g. p9).
+		// TODO(gvisor.dev/issue/1765): Remove message when bug is resolved.
+		if strings.Contains(err.Error(), syscall.EIO.Error()) || strings.Contains(err.Error(), syscall.EPIPE.Error()) {
+			return fmt.Errorf("%v: %s", err, specutils.FaqErrorMsg("memlock", "you may be encountering a Linux kernel bug"))
+		}
+		return err
 	}
 
 	// If there are submounts, we need to overlay the mount on top of a ramfs
@@ -837,7 +872,7 @@ func (c *containerMounter) mountSubmount(ctx context.Context, conf *Config, mns
 		return fmt.Errorf("mount %q error: %v", m.Destination, err)
 	}
 
-	log.Infof("Mounted %q to %q type %s", m.Source, m.Destination, m.Type)
+	log.Infof("Mounted %q to %q type: %s, internal-options: %q", m.Source, m.Destination, m.Type, opts)
 	return nil
 }
 
diff --git a/runsc/boot/fs_test.go b/runsc/boot/fs_test.go
index 49ab34b33..912037075 100644
--- a/runsc/boot/fs_test.go
+++ b/runsc/boot/fs_test.go
@@ -15,7 +15,6 @@
 package boot
 
 import (
-	"path"
 	"reflect"
 	"strings"
 	"testing"
@@ -26,19 +25,19 @@ import (
 func TestPodMountHintsHappy(t *testing.T) {
 	spec := &specs.Spec{
 		Annotations: map[string]string{
-			path.Join(MountPrefix, "mount1", "source"): "foo",
-			path.Join(MountPrefix, "mount1", "type"):   "tmpfs",
-			path.Join(MountPrefix, "mount1", "share"):  "pod",
+			MountPrefix + "mount1.source": "foo",
+			MountPrefix + "mount1.type":   "tmpfs",
+			MountPrefix + "mount1.share":  "pod",
 
-			path.Join(MountPrefix, "mount2", "source"):  "bar",
-			path.Join(MountPrefix, "mount2", "type"):    "bind",
-			path.Join(MountPrefix, "mount2", "share"):   "container",
-			path.Join(MountPrefix, "mount2", "options"): "rw,private",
+			MountPrefix + "mount2.source":  "bar",
+			MountPrefix + "mount2.type":    "bind",
+			MountPrefix + "mount2.share":   "container",
+			MountPrefix + "mount2.options": "rw,private",
 		},
 	}
 	podHints, err := newPodMountHints(spec)
 	if err != nil {
-		t.Errorf("newPodMountHints failed: %v", err)
+		t.Fatalf("newPodMountHints failed: %v", err)
 	}
 
 	// Check that fields were set correctly.
@@ -86,95 +85,95 @@ func TestPodMountHintsErrors(t *testing.T) {
 		{
 			name: "too short",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1"): "foo",
+				MountPrefix + "mount1": "foo",
 			},
 			error: "invalid mount annotation",
 		},
 		{
 			name: "no name",
 			annotations: map[string]string{
-				MountPrefix + "//source": "foo",
+				MountPrefix + ".source": "foo",
 			},
 			error: "invalid mount name",
 		},
 		{
 			name: "missing source",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "type"):  "tmpfs",
-				path.Join(MountPrefix, "mount1", "share"): "pod",
+				MountPrefix + "mount1.type":  "tmpfs",
+				MountPrefix + "mount1.share": "pod",
 			},
 			error: "source field",
 		},
 		{
 			name: "missing type",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "foo",
-				path.Join(MountPrefix, "mount1", "share"):  "pod",
+				MountPrefix + "mount1.source": "foo",
+				MountPrefix + "mount1.share":  "pod",
 			},
 			error: "type field",
 		},
 		{
 			name: "missing share",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "foo",
-				path.Join(MountPrefix, "mount1", "type"):   "tmpfs",
+				MountPrefix + "mount1.source": "foo",
+				MountPrefix + "mount1.type":   "tmpfs",
 			},
 			error: "share field",
 		},
 		{
 			name: "invalid field name",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "invalid"): "foo",
+				MountPrefix + "mount1.invalid": "foo",
 			},
 			error: "invalid mount annotation",
 		},
 		{
 			name: "invalid source",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "",
-				path.Join(MountPrefix, "mount1", "type"):   "tmpfs",
-				path.Join(MountPrefix, "mount1", "share"):  "pod",
+				MountPrefix + "mount1.source": "",
+				MountPrefix + "mount1.type":   "tmpfs",
+				MountPrefix + "mount1.share":  "pod",
 			},
 			error: "source cannot be empty",
 		},
 		{
 			name: "invalid type",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "foo",
-				path.Join(MountPrefix, "mount1", "type"):   "invalid-type",
-				path.Join(MountPrefix, "mount1", "share"):  "pod",
+				MountPrefix + "mount1.source": "foo",
+				MountPrefix + "mount1.type":   "invalid-type",
+				MountPrefix + "mount1.share":  "pod",
 			},
 			error: "invalid type",
 		},
 		{
 			name: "invalid share",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "foo",
-				path.Join(MountPrefix, "mount1", "type"):   "tmpfs",
-				path.Join(MountPrefix, "mount1", "share"):  "invalid-share",
+				MountPrefix + "mount1.source": "foo",
+				MountPrefix + "mount1.type":   "tmpfs",
+				MountPrefix + "mount1.share":  "invalid-share",
 			},
 			error: "invalid share",
 		},
 		{
 			name: "invalid options",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"):  "foo",
-				path.Join(MountPrefix, "mount1", "type"):    "tmpfs",
-				path.Join(MountPrefix, "mount1", "share"):   "pod",
-				path.Join(MountPrefix, "mount1", "options"): "invalid-option",
+				MountPrefix + "mount1.source":  "foo",
+				MountPrefix + "mount1.type":    "tmpfs",
+				MountPrefix + "mount1.share":   "pod",
+				MountPrefix + "mount1.options": "invalid-option",
 			},
 			error: "unknown mount option",
 		},
 		{
 			name: "duplicate source",
 			annotations: map[string]string{
-				path.Join(MountPrefix, "mount1", "source"): "foo",
-				path.Join(MountPrefix, "mount1", "type"):   "tmpfs",
-				path.Join(MountPrefix, "mount1", "share"):  "pod",
+				MountPrefix + "mount1.source": "foo",
+				MountPrefix + "mount1.type":   "tmpfs",
+				MountPrefix + "mount1.share":  "pod",
 
-				path.Join(MountPrefix, "mount2", "source"): "foo",
-				path.Join(MountPrefix, "mount2", "type"):   "bind",
-				path.Join(MountPrefix, "mount2", "share"):  "container",
+				MountPrefix + "mount2.source": "foo",
+				MountPrefix + "mount2.type":   "bind",
+				MountPrefix + "mount2.share":  "container",
 			},
 			error: "have the same mount source",
 		},
@@ -191,3 +190,61 @@ func TestPodMountHintsErrors(t *testing.T) {
 		})
 	}
 }
+
+func TestGetMountAccessType(t *testing.T) {
+	const source = "foo"
+	for _, tst := range []struct {
+		name        string
+		annotations map[string]string
+		want        FileAccessType
+	}{
+		{
+			name: "container=exclusive",
+			annotations: map[string]string{
+				MountPrefix + "mount1.source": source,
+				MountPrefix + "mount1.type":   "bind",
+				MountPrefix + "mount1.share":  "container",
+			},
+			want: FileAccessExclusive,
+		},
+		{
+			name: "pod=shared",
+			annotations: map[string]string{
+				MountPrefix + "mount1.source": source,
+				MountPrefix + "mount1.type":   "bind",
+				MountPrefix + "mount1.share":  "pod",
+			},
+			want: FileAccessShared,
+		},
+		{
+			name: "shared=shared",
+			annotations: map[string]string{
+				MountPrefix + "mount1.source": source,
+				MountPrefix + "mount1.type":   "bind",
+				MountPrefix + "mount1.share":  "shared",
+			},
+			want: FileAccessShared,
+		},
+		{
+			name: "default=shared",
+			annotations: map[string]string{
+				MountPrefix + "mount1.source": source + "mismatch",
+				MountPrefix + "mount1.type":   "bind",
+				MountPrefix + "mount1.share":  "container",
+			},
+			want: FileAccessShared,
+		},
+	} {
+		t.Run(tst.name, func(t *testing.T) {
+			spec := &specs.Spec{Annotations: tst.annotations}
+			podHints, err := newPodMountHints(spec)
+			if err != nil {
+				t.Fatalf("newPodMountHints failed: %v", err)
+			}
+			mounter := containerMounter{hints: podHints}
+			if got := mounter.getMountAccessType(specs.Mount{Source: source}); got != tst.want {
+				t.Errorf("getMountAccessType(), want: %v, got: %v", tst.want, got)
+			}
+		})
+	}
+}
diff --git a/runsc/boot/limits.go b/runsc/boot/limits.go
index d1c0bb9b5..ce62236e5 100644
--- a/runsc/boot/limits.go
+++ b/runsc/boot/limits.go
@@ -16,12 +16,12 @@ package boot
 
 import (
 	"fmt"
-	"sync"
 	"syscall"
 
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/limits"
+	"gvisor.dev/gvisor/pkg/sync"
 )
 
 // Mapping from linux resource names to limits.LimitType.
diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index 0c0eba99e..f6ea4c102 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -20,7 +20,6 @@ import (
 	mrand "math/rand"
 	"os"
 	"runtime"
-	"sync"
 	"sync/atomic"
 	"syscall"
 	gtime "time"
@@ -36,6 +35,8 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/control"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/host"
+	"gvisor.dev/gvisor/pkg/sentry/fs/user"
+	vfs2host "gvisor.dev/gvisor/pkg/sentry/fsimpl/host"
 	"gvisor.dev/gvisor/pkg/sentry/inet"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -43,11 +44,14 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/pgalloc"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/sighandling"
-	slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+	"gvisor.dev/gvisor/pkg/sentry/syscalls/linux/vfs2"
 	"gvisor.dev/gvisor/pkg/sentry/time"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/sentry/watchdog"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/link/loopback"
 	"gvisor.dev/gvisor/pkg/tcpip/link/sniffer"
 	"gvisor.dev/gvisor/pkg/tcpip/network/arp"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
@@ -59,16 +63,20 @@ import (
 	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
 	"gvisor.dev/gvisor/runsc/boot/filter"
 	_ "gvisor.dev/gvisor/runsc/boot/platforms" // register all platforms.
+	"gvisor.dev/gvisor/runsc/boot/pprof"
 	"gvisor.dev/gvisor/runsc/specutils"
 
 	// Include supported socket providers.
 	"gvisor.dev/gvisor/pkg/sentry/socket/hostinet"
 	_ "gvisor.dev/gvisor/pkg/sentry/socket/netlink"
 	_ "gvisor.dev/gvisor/pkg/sentry/socket/netlink/route"
+	_ "gvisor.dev/gvisor/pkg/sentry/socket/netlink/uevent"
 	"gvisor.dev/gvisor/pkg/sentry/socket/netstack"
 	_ "gvisor.dev/gvisor/pkg/sentry/socket/unix"
 )
 
+var syscallTable *kernel.SyscallTable
+
 // Loader keeps state needed to start the kernel and run the container..
 type Loader struct {
 	// k is the kernel.
@@ -93,10 +101,6 @@ type Loader struct {
 	// spec is the base configuration for the root container.
 	spec *specs.Spec
 
-	// startSignalForwarding enables forwarding of signals to the sandboxed
-	// container. It should be called after the init process is loaded.
-	startSignalForwarding func() func()
-
 	// stopSignalForwarding disables forwarding of signals to the sandboxed
 	// container. It should be called when a sandbox is destroyed.
 	stopSignalForwarding func()
@@ -146,9 +150,6 @@ type execProcess struct {
 func init() {
 	// Initialize the random number generator.
 	mrand.Seed(gtime.Now().UnixNano())
-
-	// Register the global syscall table.
-	kernel.RegisterSyscallTable(slinux.AMD64)
 }
 
 // Args are the arguments for New().
@@ -159,13 +160,17 @@ type Args struct {
 	Spec *specs.Spec
 	// Conf is the system configuration.
 	Conf *Config
-	// ControllerFD is the FD to the URPC controller.
+	// ControllerFD is the FD to the URPC controller. The Loader takes ownership
+	// of this FD and may close it at any time.
 	ControllerFD int
-	// Device is an optional argument that is passed to the platform.
+	// Device is an optional argument that is passed to the platform. The Loader
+	// takes ownership of this file and may close it at any time.
 	Device *os.File
-	// GoferFDs is an array of FDs used to connect with the Gofer.
+	// GoferFDs is an array of FDs used to connect with the Gofer. The Loader
+	// takes ownership of these FDs and may close them at any time.
 	GoferFDs []int
-	// StdioFDs is the stdio for the application.
+	// StdioFDs is the stdio for the application. The Loader takes ownership of
+	// these FDs and may close them at any time.
 	StdioFDs []int
 	// Console is set to true if using TTY.
 	Console bool
@@ -178,6 +183,9 @@ type Args struct {
 	UserLogFD int
 }
 
+// make sure stdioFDs are always the same on initial start and on restore
+const startingStdioFD = 64
+
 // New initializes a new kernel loader configured by spec.
 // New also handles setting up a kernel for restoring a container.
 func New(args Args) (*Loader, error) {
@@ -191,6 +199,14 @@ func New(args Args) (*Loader, error) {
 		return nil, fmt.Errorf("setting up memory usage: %v", err)
 	}
 
+	// Patch the syscall table.
+	kernel.VFS2Enabled = args.Conf.VFS2
+	if kernel.VFS2Enabled {
+		vfs2.Override(syscallTable.Table)
+	}
+
+	kernel.RegisterSyscallTable(syscallTable)
+
 	// Create kernel and platform.
 	p, err := createPlatform(args.Conf, args.Device)
 	if err != nil {
@@ -228,11 +244,8 @@ func New(args Args) (*Loader, error) {
 		return nil, fmt.Errorf("enabling strace: %v", err)
 	}
 
-	// Create an empty network stack because the network namespace may be empty at
-	// this point. Netns is configured before Run() is called. Netstack is
-	// configured using a control uRPC message. Host network is configured inside
-	// Run().
-	networkStack, err := newEmptyNetworkStack(args.Conf, k)
+	// Create root network namespace/stack.
+	netns, err := newRootNetworkNamespace(args.Conf, k, k)
 	if err != nil {
 		return nil, fmt.Errorf("creating network: %v", err)
 	}
@@ -275,7 +288,7 @@ func New(args Args) (*Loader, error) {
 		FeatureSet:                  cpuid.HostFeatureSet(),
 		Timekeeper:                  tk,
 		RootUserNamespace:           creds.UserNamespace,
-		NetworkStack:                networkStack,
+		RootNetworkNamespace:        netns,
 		ApplicationCores:            uint(args.NumCPU),
 		Vdso:                        vdso,
 		RootUTSNamespace:            kernel.NewUTSNamespace(args.Spec.Hostname, args.Spec.Hostname, creds.UserNamespace),
@@ -300,7 +313,9 @@ func New(args Args) (*Loader, error) {
 	}
 
 	// Create a watchdog.
-	dog := watchdog.New(k, watchdog.DefaultTimeout, args.Conf.WatchdogAction)
+	dogOpts := watchdog.DefaultOpts
+	dogOpts.TaskTimeoutAction = args.Conf.WatchdogAction
+	dog := watchdog.New(k, dogOpts)
 
 	procArgs, err := newProcess(args.ID, args.Spec, creds, k, k.RootPIDNamespace())
 	if err != nil {
@@ -316,6 +331,35 @@ func New(args Args) (*Loader, error) {
 		return nil, fmt.Errorf("creating pod mount hints: %v", err)
 	}
 
+	if kernel.VFS2Enabled {
+		// Set up host mount that will be used for imported fds.
+		hostFilesystem := vfs2host.NewFilesystem(k.VFS())
+		defer hostFilesystem.DecRef()
+		hostMount, err := k.VFS().NewDisconnectedMount(hostFilesystem, nil, &vfs.MountOptions{})
+		if err != nil {
+			return nil, fmt.Errorf("failed to create hostfs mount: %v", err)
+		}
+		k.SetHostMount(hostMount)
+	}
+
+	// Make host FDs stable between invocations. Host FDs must map to the exact
+	// same number when the sandbox is restored. Otherwise the wrong FD will be
+	// used.
+	var stdioFDs []int
+	newfd := startingStdioFD
+	for _, fd := range args.StdioFDs {
+		err := syscall.Dup3(fd, newfd, syscall.O_CLOEXEC)
+		if err != nil {
+			return nil, fmt.Errorf("dup3 of stdioFDs failed: %v", err)
+		}
+		stdioFDs = append(stdioFDs, newfd)
+		err = syscall.Close(fd)
+		if err != nil {
+			return nil, fmt.Errorf("close original stdioFDs failed: %v", err)
+		}
+		newfd++
+	}
+
 	eid := execID{cid: args.ID}
 	l := &Loader{
 		k:            k,
@@ -324,7 +368,7 @@ func New(args Args) (*Loader, error) {
 		watchdog:     dog,
 		spec:         args.Spec,
 		goferFDs:     args.GoferFDs,
-		stdioFDs:     args.StdioFDs,
+		stdioFDs:     stdioFDs,
 		rootProcArgs: procArgs,
 		sandboxID:    args.ID,
 		processes:    map[execID]*execProcess{eid: {}},
@@ -337,29 +381,6 @@ func New(args Args) (*Loader, error) {
 		return nil, fmt.Errorf("ignore child stop signals failed: %v", err)
 	}
 
-	// Handle signals by forwarding them to the root container process
-	// (except for panic signal, which should cause a panic).
-	l.startSignalForwarding = sighandling.PrepareHandler(func(sig linux.Signal) {
-		// Panic signal should cause a panic.
-		if args.Conf.PanicSignal != -1 && sig == linux.Signal(args.Conf.PanicSignal) {
-			panic("Signal-induced panic")
-		}
-
-		// Otherwise forward to root container.
-		deliveryMode := DeliverToProcess
-		if args.Console {
-			// Since we are running with a console, we should
-			// forward the signal to the foreground process group
-			// so that job control signals like ^C can be handled
-			// properly.
-			deliveryMode = DeliverToForegroundProcessGroup
-		}
-		log.Infof("Received external signal %d, mode: %v", sig, deliveryMode)
-		if err := l.signal(args.ID, 0, int32(sig), deliveryMode); err != nil {
-			log.Warningf("error sending signal %v to container %q: %v", sig, args.ID, err)
-		}
-	})
-
 	// Create the control server using the provided FD.
 	//
 	// This must be done *after* we have initialized the kernel since the
@@ -387,11 +408,16 @@ func newProcess(id string, spec *specs.Spec, creds *auth.Credentials, k *kernel.
 		return kernel.CreateProcessArgs{}, fmt.Errorf("creating limits: %v", err)
 	}
 
+	wd := spec.Process.Cwd
+	if wd == "" {
+		wd = "/"
+	}
+
 	// Create the process arguments.
 	procArgs := kernel.CreateProcessArgs{
 		Argv:                    spec.Process.Args,
 		Envv:                    spec.Process.Env,
-		WorkingDirectory:        spec.Process.Cwd, // Defaults to '/' if empty.
+		WorkingDirectory:        wd,
 		Credentials:             creds,
 		Umask:                   0022,
 		Limits:                  ls,
@@ -485,7 +511,7 @@ func (l *Loader) run() error {
 		// Delay host network configuration to this point because network namespace
 		// is configured after the loader is created and before Run() is called.
 		log.Debugf("Configuring host network")
-		stack := l.k.NetworkStack().(*hostinet.Stack)
+		stack := l.k.RootNetworkNamespace().Stack().(*hostinet.Stack)
 		if err := stack.Configure(); err != nil {
 			return err
 		}
@@ -504,7 +530,7 @@ func (l *Loader) run() error {
 	// l.restore is set by the container manager when a restore call is made.
 	if !l.restore {
 		if l.conf.ProfileEnable {
-			initializePProf()
+			pprof.Initialize()
 		}
 
 		// Finally done with all configuration. Setup filters before user code
@@ -536,7 +562,15 @@ func (l *Loader) run() error {
 		}
 
 		// Add the HOME enviroment variable if it is not already set.
-		envv, err := maybeAddExecUserHome(ctx, l.rootProcArgs.MountNamespace, l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv)
+		var envv []string
+		if kernel.VFS2Enabled {
+			envv, err = user.MaybeAddExecUserHomeVFS2(ctx, l.rootProcArgs.MountNamespaceVFS2,
+				l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv)
+
+		} else {
+			envv, err = user.MaybeAddExecUserHome(ctx, l.rootProcArgs.MountNamespace,
+				l.rootProcArgs.Credentials.RealKUID, l.rootProcArgs.Envv)
+		}
 		if err != nil {
 			return err
 		}
@@ -567,8 +601,40 @@ func (l *Loader) run() error {
 		ep.tty.InitForegroundProcessGroup(ep.tg.ProcessGroup())
 	}
 
-	// Start signal forwarding only after an init process is created.
-	l.stopSignalForwarding = l.startSignalForwarding()
+	// Handle signals by forwarding them to the root container process
+	// (except for panic signal, which should cause a panic).
+	l.stopSignalForwarding = sighandling.StartSignalForwarding(func(sig linux.Signal) {
+		// Panic signal should cause a panic.
+		if l.conf.PanicSignal != -1 && sig == linux.Signal(l.conf.PanicSignal) {
+			panic("Signal-induced panic")
+		}
+
+		// Otherwise forward to root container.
+		deliveryMode := DeliverToProcess
+		if l.console {
+			// Since we are running with a console, we should forward the signal to
+			// the foreground process group so that job control signals like ^C can
+			// be handled properly.
+			deliveryMode = DeliverToForegroundProcessGroup
+		}
+		log.Infof("Received external signal %d, mode: %v", sig, deliveryMode)
+		if err := l.signal(l.sandboxID, 0, int32(sig), deliveryMode); err != nil {
+			log.Warningf("error sending signal %v to container %q: %v", sig, l.sandboxID, err)
+		}
+	})
+
+	// l.stdioFDs are derived from dup() in boot.New() and they are now dup()ed again
+	// either in createFDTable() during initial start or in descriptor.initAfterLoad()
+	// during restore, we can release l.stdioFDs now. VFS2 takes ownership of the
+	// passed FDs, so only close for VFS1.
+	if !kernel.VFS2Enabled {
+		for _, fd := range l.stdioFDs {
+			err := syscall.Close(fd)
+			if err != nil {
+				return fmt.Errorf("close dup()ed stdioFDs: %v", err)
+			}
+		}
+	}
 
 	log.Infof("Process should have started...")
 	l.watchdog.Start()
@@ -795,20 +861,23 @@ func (l *Loader) executeAsync(args *control.ExecArgs) (kernel.ThreadID, error) {
 		return 0, fmt.Errorf("container %q not started", args.ContainerID)
 	}
 
+	// TODO(gvisor.dev/issue/1623): Add VFS2 support
+
 	// Get the container MountNamespace from the Task.
 	tg.Leader().WithMuLocked(func(t *kernel.Task) {
-		// task.MountNamespace() does not take a ref, so we must do so
-		// ourselves.
+		// task.MountNamespace() does not take a ref, so we must do so ourselves.
 		args.MountNamespace = t.MountNamespace()
 		args.MountNamespace.IncRef()
 	})
-	defer args.MountNamespace.DecRef()
+	if args.MountNamespace != nil {
+		defer args.MountNamespace.DecRef()
+	}
 
-	// Add the HOME enviroment varible if it is not already set.
+	// Add the HOME environment variable if it is not already set.
 	root := args.MountNamespace.Root()
 	defer root.DecRef()
 	ctx := fs.WithRoot(l.k.SupervisorContext(), root)
-	envv, err := maybeAddExecUserHome(ctx, args.MountNamespace, args.KUID, args.Envv)
+	envv, err := user.MaybeAddExecUserHome(ctx, args.MountNamespace, args.KUID, args.Envv)
 	if err != nil {
 		return 0, err
 	}
@@ -905,47 +974,92 @@ func (l *Loader) WaitExit() kernel.ExitStatus {
 	return l.k.GlobalInit().ExitStatus()
 }
 
-func newEmptyNetworkStack(conf *Config, clock tcpip.Clock) (inet.Stack, error) {
+func newRootNetworkNamespace(conf *Config, clock tcpip.Clock, uniqueID stack.UniqueID) (*inet.Namespace, error) {
+	// Create an empty network stack because the network namespace may be empty at
+	// this point. Netns is configured before Run() is called. Netstack is
+	// configured using a control uRPC message. Host network is configured inside
+	// Run().
 	switch conf.Network {
 	case NetworkHost:
-		return hostinet.NewStack(), nil
+		// No network namespacing support for hostinet yet, hence creator is nil.
+		return inet.NewRootNamespace(hostinet.NewStack(), nil), nil
 
 	case NetworkNone, NetworkSandbox:
-		// NetworkNone sets up loopback using netstack.
-		netProtos := []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol(), arp.NewProtocol()}
-		transProtos := []stack.TransportProtocol{tcp.NewProtocol(), udp.NewProtocol(), icmp.NewProtocol4()}
-		s := netstack.Stack{stack.New(stack.Options{
-			NetworkProtocols:   netProtos,
-			TransportProtocols: transProtos,
-			Clock:              clock,
-			Stats:              netstack.Metrics,
-			HandleLocal:        true,
-			// Enable raw sockets for users with sufficient
-			// privileges.
-			RawFactory: raw.EndpointFactory{},
-		})}
-
-		// Enable SACK Recovery.
-		if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SACKEnabled(true)); err != nil {
-			return nil, fmt.Errorf("failed to enable SACK: %v", err)
+		s, err := newEmptySandboxNetworkStack(clock, uniqueID)
+		if err != nil {
+			return nil, err
+		}
+		creator := &sandboxNetstackCreator{
+			clock:    clock,
+			uniqueID: uniqueID,
 		}
+		return inet.NewRootNamespace(s, creator), nil
 
-		// Set default TTLs as required by socket/netstack.
-		s.Stack.SetNetworkProtocolOption(ipv4.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL))
-		s.Stack.SetNetworkProtocolOption(ipv6.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL))
+	default:
+		panic(fmt.Sprintf("invalid network configuration: %v", conf.Network))
+	}
 
-		// Enable Receive Buffer Auto-Tuning.
-		if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.ModerateReceiveBufferOption(true)); err != nil {
-			return nil, fmt.Errorf("SetTransportProtocolOption failed: %v", err)
-		}
+}
 
-		s.FillDefaultIPTables()
+func newEmptySandboxNetworkStack(clock tcpip.Clock, uniqueID stack.UniqueID) (inet.Stack, error) {
+	netProtos := []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol(), arp.NewProtocol()}
+	transProtos := []stack.TransportProtocol{tcp.NewProtocol(), udp.NewProtocol(), icmp.NewProtocol4()}
+	s := netstack.Stack{stack.New(stack.Options{
+		NetworkProtocols:   netProtos,
+		TransportProtocols: transProtos,
+		Clock:              clock,
+		Stats:              netstack.Metrics,
+		HandleLocal:        true,
+		// Enable raw sockets for users with sufficient
+		// privileges.
+		RawFactory: raw.EndpointFactory{},
+		UniqueID:   uniqueID,
+	})}
 
-		return &s, nil
+	// Enable SACK Recovery.
+	if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcp.SACKEnabled(true)); err != nil {
+		return nil, fmt.Errorf("failed to enable SACK: %v", err)
+	}
 
-	default:
-		panic(fmt.Sprintf("invalid network configuration: %v", conf.Network))
+	// Set default TTLs as required by socket/netstack.
+	s.Stack.SetNetworkProtocolOption(ipv4.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL))
+	s.Stack.SetNetworkProtocolOption(ipv6.ProtocolNumber, tcpip.DefaultTTLOption(netstack.DefaultTTL))
+
+	// Enable Receive Buffer Auto-Tuning.
+	if err := s.Stack.SetTransportProtocolOption(tcp.ProtocolNumber, tcpip.ModerateReceiveBufferOption(true)); err != nil {
+		return nil, fmt.Errorf("SetTransportProtocolOption failed: %v", err)
 	}
+
+	s.FillDefaultIPTables()
+
+	return &s, nil
+}
+
+// sandboxNetstackCreator implements kernel.NetworkStackCreator.
+//
+// +stateify savable
+type sandboxNetstackCreator struct {
+	clock    tcpip.Clock
+	uniqueID stack.UniqueID
+}
+
+// CreateStack implements kernel.NetworkStackCreator.CreateStack.
+func (f *sandboxNetstackCreator) CreateStack() (inet.Stack, error) {
+	s, err := newEmptySandboxNetworkStack(f.clock, f.uniqueID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Setup loopback.
+	n := &Network{Stack: s.(*netstack.Stack).Stack}
+	nicID := tcpip.NICID(f.uniqueID.UniqueID())
+	link := DefaultLoopbackLink
+	linkEP := loopback.New()
+	if err := n.createNICWithAddrs(nicID, link.Name, linkEP, link.Addresses); err != nil {
+		return nil, err
+	}
+
+	return s, nil
 }
 
 // signal sends a signal to one or more processes in a container. If PID is 0,
@@ -993,7 +1107,7 @@ func (l *Loader) signalProcess(cid string, tgid kernel.ThreadID, signo int32) er
 	execTG, _, err := l.threadGroupFromID(execID{cid: cid, pid: tgid})
 	if err == nil {
 		// Send signal directly to the identified process.
-		return execTG.SendSignal(&arch.SignalInfo{Signo: signo})
+		return l.k.SendExternalSignalThreadGroup(execTG, &arch.SignalInfo{Signo: signo})
 	}
 
 	// The caller may be signaling a process not started directly via exec.
@@ -1010,7 +1124,7 @@ func (l *Loader) signalProcess(cid string, tgid kernel.ThreadID, signo int32) er
 	if tg.Leader().ContainerID() != cid {
 		return fmt.Errorf("process %d is part of a different container: %q", tgid, tg.Leader().ContainerID())
 	}
-	return tg.SendSignal(&arch.SignalInfo{Signo: signo})
+	return l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo})
 }
 
 func (l *Loader) signalForegrondProcessGroup(cid string, tgid kernel.ThreadID, signo int32) error {
@@ -1028,7 +1142,7 @@ func (l *Loader) signalForegrondProcessGroup(cid string, tgid kernel.ThreadID, s
 		// No foreground process group has been set. Signal the
 		// original thread group.
 		log.Warningf("No foreground process group for container %q and PID %d. Sending signal directly to PID %d.", cid, tgid, tgid)
-		return tg.SendSignal(&arch.SignalInfo{Signo: signo})
+		return l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo})
 	}
 	// Send the signal to all processes in the process group.
 	var lastErr error
@@ -1036,7 +1150,7 @@ func (l *Loader) signalForegrondProcessGroup(cid string, tgid kernel.ThreadID, s
 		if tg.ProcessGroup() != pg {
 			continue
 		}
-		if err := tg.SendSignal(&arch.SignalInfo{Signo: signo}); err != nil {
+		if err := l.k.SendExternalSignalThreadGroup(tg, &arch.SignalInfo{Signo: signo}); err != nil {
 			lastErr = err
 		}
 	}
diff --git a/runsc/boot/loader_amd64.go b/runsc/boot/loader_amd64.go
new file mode 100644
index 000000000..78df86611
--- /dev/null
+++ b/runsc/boot/loader_amd64.go
@@ -0,0 +1,26 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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.
+
+// +build amd64
+
+package boot
+
+import (
+	"gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+)
+
+func init() {
+	// Set the global syscall table.
+	syscallTable = linux.AMD64
+}
diff --git a/runsc/boot/loader_arm64.go b/runsc/boot/loader_arm64.go
new file mode 100644
index 000000000..250785010
--- /dev/null
+++ b/runsc/boot/loader_arm64.go
@@ -0,0 +1,26 @@
+// Copyright 2019 The gVisor Authors.
+//
+// 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.
+
+// +build arm64
+
+package boot
+
+import (
+	"gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+)
+
+func init() {
+	// Set the global syscall table.
+	syscallTable = linux.ARM64
+}
diff --git a/runsc/boot/loader_test.go b/runsc/boot/loader_test.go
index 147ff7703..55d27a632 100644
--- a/runsc/boot/loader_test.go
+++ b/runsc/boot/loader_test.go
@@ -19,17 +19,21 @@ import (
 	"math/rand"
 	"os"
 	"reflect"
-	"sync"
 	"syscall"
 	"testing"
 	"time"
 
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/control/server"
+	"gvisor.dev/gvisor/pkg/fspath"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/p9"
-	"gvisor.dev/gvisor/pkg/sentry/context/contexttest"
+	"gvisor.dev/gvisor/pkg/sentry/contexttest"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 	"gvisor.dev/gvisor/runsc/fsgofer"
 )
@@ -65,6 +69,11 @@ func testSpec() *specs.Spec {
 	}
 }
 
+func resetSyscallTable() {
+	kernel.VFS2Enabled = false
+	kernel.FlushSyscallTablesTestOnly()
+}
+
 // startGofer starts a new gofer routine serving 'root' path. It returns the
 // sandbox side of the connection, and a function that when called will stop the
 // gofer.
@@ -100,20 +109,29 @@ func startGofer(root string) (int, func(), error) {
 	return sandboxEnd, cleanup, nil
 }
 
-func createLoader() (*Loader, func(), error) {
+func createLoader(vfsEnabled bool, spec *specs.Spec) (*Loader, func(), error) {
 	fd, err := server.CreateSocket(ControlSocketAddr(fmt.Sprintf("%010d", rand.Int())[:10]))
 	if err != nil {
 		return nil, nil, err
 	}
 	conf := testConfig()
-	spec := testSpec()
+	conf.VFS2 = vfsEnabled
 
 	sandEnd, cleanup, err := startGofer(spec.Root.Path)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	stdio := []int{int(os.Stdin.Fd()), int(os.Stdout.Fd()), int(os.Stderr.Fd())}
+	// Loader takes ownership of stdio.
+	var stdio []int
+	for _, f := range []*os.File{os.Stdin, os.Stdout, os.Stderr} {
+		newFd, err := unix.Dup(int(f.Fd()))
+		if err != nil {
+			return nil, nil, err
+		}
+		stdio = append(stdio, newFd)
+	}
+
 	args := Args{
 		ID:           "foo",
 		Spec:         spec,
@@ -132,10 +150,22 @@ func createLoader() (*Loader, func(), error) {
 
 // TestRun runs a simple application in a sandbox and checks that it succeeds.
 func TestRun(t *testing.T) {
-	l, cleanup, err := createLoader()
+	defer resetSyscallTable()
+	doRun(t, false)
+}
+
+// TestRunVFS2 runs TestRun in VFSv2.
+func TestRunVFS2(t *testing.T) {
+	defer resetSyscallTable()
+	doRun(t, true)
+}
+
+func doRun(t *testing.T, vfsEnabled bool) {
+	l, cleanup, err := createLoader(vfsEnabled, testSpec())
 	if err != nil {
 		t.Fatalf("error creating loader: %v", err)
 	}
+
 	defer l.Destroy()
 	defer cleanup()
 
@@ -169,7 +199,18 @@ func TestRun(t *testing.T) {
 // TestStartSignal tests that the controller Start message will cause
 // WaitForStartSignal to return.
 func TestStartSignal(t *testing.T) {
-	l, cleanup, err := createLoader()
+	defer resetSyscallTable()
+	doStartSignal(t, false)
+}
+
+// TestStartSignalVFS2 does TestStartSignal with VFS2.
+func TestStartSignalVFS2(t *testing.T) {
+	defer resetSyscallTable()
+	doStartSignal(t, true)
+}
+
+func doStartSignal(t *testing.T, vfsEnabled bool) {
+	l, cleanup, err := createLoader(vfsEnabled, testSpec())
 	if err != nil {
 		t.Fatalf("error creating loader: %v", err)
 	}
@@ -217,18 +258,19 @@ func TestStartSignal(t *testing.T) {
 
 }
 
-// Test that MountNamespace can be created with various specs.
-func TestCreateMountNamespace(t *testing.T) {
-	testCases := []struct {
-		name string
-		// Spec that will be used to create the mount manager.  Note
-		// that we can't mount procfs without a kernel, so each spec
-		// MUST contain something other than procfs mounted at /proc.
-		spec specs.Spec
-		// Paths that are expected to exist in the resulting fs.
-		expectedPaths []string
-	}{
-		{
+type CreateMountTestcase struct {
+	name string
+	// Spec that will be used to create the mount manager.  Note
+	// that we can't mount procfs without a kernel, so each spec
+	// MUST contain something other than procfs mounted at /proc.
+	spec specs.Spec
+	// Paths that are expected to exist in the resulting fs.
+	expectedPaths []string
+}
+
+func createMountTestcases(vfs2 bool) []*CreateMountTestcase {
+	testCases := []*CreateMountTestcase{
+		&CreateMountTestcase{
 			// Only proc.
 			name: "only proc mount",
 			spec: specs.Spec{
@@ -270,7 +312,7 @@ func TestCreateMountNamespace(t *testing.T) {
 			// /dev, and /sys.
 			expectedPaths: []string{"/some/very/very/deep/path", "/proc", "/dev", "/sys"},
 		},
-		{
+		&CreateMountTestcase{
 			// Mounts are nested inside each other.
 			name: "nested mounts",
 			spec: specs.Spec{
@@ -314,7 +356,7 @@ func TestCreateMountNamespace(t *testing.T) {
 			expectedPaths: []string{"/foo", "/foo/bar", "/foo/bar/baz", "/foo/qux",
 				"/foo/qux-quz", "/foo/some/very/very/deep/path", "/proc", "/dev", "/sys"},
 		},
-		{
+		&CreateMountTestcase{
 			name: "mount inside /dev",
 			spec: specs.Spec{
 				Root: &specs.Root{
@@ -357,40 +399,47 @@ func TestCreateMountNamespace(t *testing.T) {
 			},
 			expectedPaths: []string{"/proc", "/dev", "/dev/fd-foo", "/dev/foo", "/dev/bar", "/sys"},
 		},
-		{
-			name: "mounts inside mandatory mounts",
-			spec: specs.Spec{
-				Root: &specs.Root{
-					Path:     os.TempDir(),
-					Readonly: true,
+	}
+
+	vfsCase := &CreateMountTestcase{
+		name: "mounts inside mandatory mounts",
+		spec: specs.Spec{
+			Root: &specs.Root{
+				Path:     os.TempDir(),
+				Readonly: true,
+			},
+			Mounts: []specs.Mount{
+				{
+					Destination: "/proc",
+					Type:        "tmpfs",
 				},
-				Mounts: []specs.Mount{
-					{
-						Destination: "/proc",
-						Type:        "tmpfs",
-					},
-					// We don't include /sys, and /tmp in
-					// the spec, since they will be added
-					// automatically.
-					//
-					// Instead, add submounts inside these
-					// directories and make sure they are
-					// visible under the mandatory mounts.
-					{
-						Destination: "/sys/bar",
-						Type:        "tmpfs",
-					},
-					{
-						Destination: "/tmp/baz",
-						Type:        "tmpfs",
-					},
+				// TODO (gvisor.dev/issue/1487): Re-add this case when sysfs supports
+				//  MkDirAt in VFS2 (and remove the reduntant append).
+				// {
+				//		Destination: "/sys/bar",
+				//		Type:        "tmpfs",
+				//	},
+				//
+				{
+					Destination: "/tmp/baz",
+					Type:        "tmpfs",
 				},
 			},
-			expectedPaths: []string{"/proc", "/sys", "/sys/bar", "/tmp", "/tmp/baz"},
 		},
+		expectedPaths: []string{"/proc", "/sys" /* "/sys/bar" ,*/, "/tmp", "/tmp/baz"},
 	}
 
-	for _, tc := range testCases {
+	if !vfs2 {
+		vfsCase.spec.Mounts = append(vfsCase.spec.Mounts, specs.Mount{Destination: "/sys/bar", Type: "tmpfs"})
+		vfsCase.expectedPaths = append(vfsCase.expectedPaths, "/sys/bar")
+	}
+	return append(testCases, vfsCase)
+}
+
+// Test that MountNamespace can be created with various specs.
+func TestCreateMountNamespace(t *testing.T) {
+
+	for _, tc := range createMountTestcases(false /* vfs2 */) {
 		t.Run(tc.name, func(t *testing.T) {
 			conf := testConfig()
 			ctx := contexttest.Context(t)
@@ -425,6 +474,56 @@ func TestCreateMountNamespace(t *testing.T) {
 	}
 }
 
+// Test that MountNamespace can be created with various specs.
+func TestCreateMountNamespaceVFS2(t *testing.T) {
+
+	for _, tc := range createMountTestcases(true /* vfs2 */) {
+		t.Run(tc.name, func(t *testing.T) {
+			defer resetSyscallTable()
+
+			spec := testSpec()
+			spec.Mounts = tc.spec.Mounts
+			spec.Root = tc.spec.Root
+
+			l, loaderCleanup, err := createLoader(true /* VFS2 Enabled */, spec)
+			if err != nil {
+				t.Fatalf("failed to create loader: %v", err)
+			}
+			defer l.Destroy()
+			defer loaderCleanup()
+
+			mntr := newContainerMounter(l.spec, l.goferFDs, l.k, l.mountHints)
+			if err := mntr.processHints(l.conf); err != nil {
+				t.Fatalf("failed process hints: %v", err)
+			}
+
+			ctx := l.rootProcArgs.NewContext(l.k)
+			mns, err := mntr.setupVFS2(ctx, l.conf, &l.rootProcArgs)
+			if err != nil {
+				t.Fatalf("failed to setupVFS2: %v", err)
+			}
+
+			root := mns.Root()
+			defer root.DecRef()
+			for _, p := range tc.expectedPaths {
+
+				target := &vfs.PathOperation{
+					Root:  root,
+					Start: root,
+					Path:  fspath.Parse(p),
+				}
+
+				if d, err := l.k.VFS().GetDentryAt(ctx, l.rootProcArgs.Credentials, target, &vfs.GetDentryOptions{}); err != nil {
+					t.Errorf("expected path %v to exist with spec %v, but got error %v", p, tc.spec, err)
+				} else {
+					d.DecRef()
+				}
+
+			}
+		})
+	}
+}
+
 // TestRestoreEnvironment tests that the correct mounts are collected from the spec and config
 // in order to build the environment for restoring.
 func TestRestoreEnvironment(t *testing.T) {
diff --git a/runsc/boot/network.go b/runsc/boot/network.go
index f98c5fd36..bee6ee336 100644
--- a/runsc/boot/network.go
+++ b/runsc/boot/network.go
@@ -17,6 +17,7 @@ package boot
 import (
 	"fmt"
 	"net"
+	"strings"
 	"syscall"
 
 	"gvisor.dev/gvisor/pkg/log"
@@ -31,6 +32,32 @@ import (
 	"gvisor.dev/gvisor/pkg/urpc"
 )
 
+var (
+	// DefaultLoopbackLink contains IP addresses and routes of "127.0.0.1/8" and
+	// "::1/8" on "lo" interface.
+	DefaultLoopbackLink = LoopbackLink{
+		Name: "lo",
+		Addresses: []net.IP{
+			net.IP("\x7f\x00\x00\x01"),
+			net.IPv6loopback,
+		},
+		Routes: []Route{
+			{
+				Destination: net.IPNet{
+					IP:   net.IPv4(0x7f, 0, 0, 0),
+					Mask: net.IPv4Mask(0xff, 0, 0, 0),
+				},
+			},
+			{
+				Destination: net.IPNet{
+					IP:   net.IPv6loopback,
+					Mask: net.IPMask(strings.Repeat("\xff", net.IPv6len)),
+				},
+			},
+		},
+	}
+)
+
 // Network exposes methods that can be used to configure a network stack.
 type Network struct {
 	Stack *stack.Stack
@@ -80,7 +107,8 @@ type CreateLinksAndRoutesArgs struct {
 	LoopbackLinks []LoopbackLink
 	FDBasedLinks  []FDBasedLink
 
-	DefaultGateway DefaultRoute
+	Defaultv4Gateway DefaultRoute
+	Defaultv6Gateway DefaultRoute
 }
 
 // Empty returns true if route hasn't been set.
@@ -122,10 +150,10 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 		nicID++
 		nicids[link.Name] = nicID
 
-		ep := loopback.New()
+		linkEP := loopback.New()
 
 		log.Infof("Enabling loopback interface %q with id %d on addresses %+v", link.Name, nicID, link.Addresses)
-		if err := n.createNICWithAddrs(nicID, link.Name, ep, link.Addresses, true /* loopback */); err != nil {
+		if err := n.createNICWithAddrs(nicID, link.Name, linkEP, link.Addresses); err != nil {
 			return err
 		}
 
@@ -157,7 +185,7 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 		}
 
 		mac := tcpip.LinkAddress(link.LinkAddress)
-		ep, err := fdbased.New(&fdbased.Options{
+		linkEP, err := fdbased.New(&fdbased.Options{
 			FDs:                FDs,
 			MTU:                uint32(link.MTU),
 			EthernetHeader:     true,
@@ -172,7 +200,7 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 		}
 
 		log.Infof("Enabling interface %q with id %d on addresses %+v (%v) w/ %d channels", link.Name, nicID, link.Addresses, mac, link.NumChannels)
-		if err := n.createNICWithAddrs(nicID, link.Name, ep, link.Addresses, false /* loopback */); err != nil {
+		if err := n.createNICWithAddrs(nicID, link.Name, linkEP, link.Addresses); err != nil {
 			return err
 		}
 
@@ -186,12 +214,24 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 		}
 	}
 
-	if !args.DefaultGateway.Route.Empty() {
-		nicID, ok := nicids[args.DefaultGateway.Name]
+	if !args.Defaultv4Gateway.Route.Empty() {
+		nicID, ok := nicids[args.Defaultv4Gateway.Name]
 		if !ok {
-			return fmt.Errorf("invalid interface name %q for default route", args.DefaultGateway.Name)
+			return fmt.Errorf("invalid interface name %q for default route", args.Defaultv4Gateway.Name)
 		}
-		route, err := args.DefaultGateway.Route.toTcpipRoute(nicID)
+		route, err := args.Defaultv4Gateway.Route.toTcpipRoute(nicID)
+		if err != nil {
+			return err
+		}
+		routes = append(routes, route)
+	}
+
+	if !args.Defaultv6Gateway.Route.Empty() {
+		nicID, ok := nicids[args.Defaultv6Gateway.Name]
+		if !ok {
+			return fmt.Errorf("invalid interface name %q for default route", args.Defaultv6Gateway.Name)
+		}
+		route, err := args.Defaultv6Gateway.Route.toTcpipRoute(nicID)
 		if err != nil {
 			return err
 		}
@@ -205,15 +245,10 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 
 // createNICWithAddrs creates a NIC in the network stack and adds the given
 // addresses.
-func (n *Network) createNICWithAddrs(id tcpip.NICID, name string, ep stack.LinkEndpoint, addrs []net.IP, loopback bool) error {
-	if loopback {
-		if err := n.Stack.CreateNamedLoopbackNIC(id, name, sniffer.New(ep)); err != nil {
-			return fmt.Errorf("CreateNamedLoopbackNIC(%v, %v) failed: %v", id, name, err)
-		}
-	} else {
-		if err := n.Stack.CreateNamedNIC(id, name, sniffer.New(ep)); err != nil {
-			return fmt.Errorf("CreateNamedNIC(%v, %v) failed: %v", id, name, err)
-		}
+func (n *Network) createNICWithAddrs(id tcpip.NICID, name string, ep stack.LinkEndpoint, addrs []net.IP) error {
+	opts := stack.NICOptions{Name: name}
+	if err := n.Stack.CreateNICWithOptions(id, sniffer.New(ep), opts); err != nil {
+		return fmt.Errorf("CreateNICWithOptions(%d, _, %+v) failed: %v", id, opts, err)
 	}
 
 	// Always start with an arp address for the NIC.
diff --git a/runsc/boot/platforms/BUILD b/runsc/boot/platforms/BUILD
index 03391cdca..77774f43c 100644
--- a/runsc/boot/platforms/BUILD
+++ b/runsc/boot/platforms/BUILD
@@ -1,11 +1,10 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("//tools:defs.bzl", "go_library")
 
 package(licenses = ["notice"])
 
 go_library(
     name = "platforms",
     srcs = ["platforms.go"],
-    importpath = "gvisor.dev/gvisor/runsc/boot/platforms",
     visibility = [
         "//runsc:__subpackages__",
     ],
diff --git a/runsc/boot/pprof/BUILD b/runsc/boot/pprof/BUILD
new file mode 100644
index 000000000..29cb42b2f
--- /dev/null
+++ b/runsc/boot/pprof/BUILD
@@ -0,0 +1,11 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+    name = "pprof",
+    srcs = ["pprof.go"],
+    visibility = [
+        "//runsc:__subpackages__",
+    ],
+)
diff --git a/runsc/boot/pprof.go b/runsc/boot/pprof/pprof.go
index 463362f02..1ded20dee 100644
--- a/runsc/boot/pprof.go
+++ b/runsc/boot/pprof/pprof.go
@@ -12,7 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package boot
+// Package pprof provides a stub to initialize custom profilers.
+package pprof
 
-func initializePProf() {
+// Initialize will be called at boot for initializing custom profilers.
+func Initialize() {
 }
diff --git a/runsc/boot/user.go b/runsc/boot/user.go
deleted file mode 100644
index 56cc12ee0..000000000
--- a/runsc/boot/user.go
+++ /dev/null
@@ -1,170 +0,0 @@
-// Copyright 2019 The gVisor Authors.
-//
-// 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 boot
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"strconv"
-	"strings"
-
-	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/sentry/context"
-	"gvisor.dev/gvisor/pkg/sentry/fs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-	"gvisor.dev/gvisor/pkg/sentry/usermem"
-)
-
-type fileReader struct {
-	// Ctx is the context for the file reader.
-	Ctx context.Context
-
-	// File is the file to read from.
-	File *fs.File
-}
-
-// Read implements io.Reader.Read.
-func (r *fileReader) Read(buf []byte) (int, error) {
-	n, err := r.File.Readv(r.Ctx, usermem.BytesIOSequence(buf))
-	return int(n), err
-}
-
-// getExecUserHome returns the home directory of the executing user read from
-// /etc/passwd as read from the container filesystem.
-func getExecUserHome(ctx context.Context, rootMns *fs.MountNamespace, uid auth.KUID) (string, error) {
-	// The default user home directory to return if no user matching the user
-	// if found in the /etc/passwd found in the image.
-	const defaultHome = "/"
-
-	// Open the /etc/passwd file from the dirent via the root mount namespace.
-	mnsRoot := rootMns.Root()
-	maxTraversals := uint(linux.MaxSymlinkTraversals)
-	dirent, err := rootMns.FindInode(ctx, mnsRoot, nil, "/etc/passwd", &maxTraversals)
-	if err != nil {
-		// NOTE: Ignore errors opening the passwd file. If the passwd file
-		// doesn't exist we will return the default home directory.
-		return defaultHome, nil
-	}
-	defer dirent.DecRef()
-
-	// Check read permissions on the file.
-	if err := dirent.Inode.CheckPermission(ctx, fs.PermMask{Read: true}); err != nil {
-		// NOTE: Ignore permissions errors here and return default root dir.
-		return defaultHome, nil
-	}
-
-	// Only open regular files. We don't open other files like named pipes as
-	// they may block and might present some attack surface to the container.
-	// Note that runc does not seem to do this kind of checking.
-	if !fs.IsRegular(dirent.Inode.StableAttr) {
-		return defaultHome, nil
-	}
-
-	f, err := dirent.Inode.GetFile(ctx, dirent, fs.FileFlags{Read: true, Directory: false})
-	if err != nil {
-		return "", err
-	}
-	defer f.DecRef()
-
-	r := &fileReader{
-		Ctx:  ctx,
-		File: f,
-	}
-
-	homeDir, err := findHomeInPasswd(uint32(uid), r, defaultHome)
-	if err != nil {
-		return "", err
-	}
-
-	return homeDir, nil
-}
-
-// maybeAddExecUserHome returns a new slice with the HOME enviroment variable
-// set if the slice does not already contain it, otherwise it returns the
-// original slice unmodified.
-func maybeAddExecUserHome(ctx context.Context, mns *fs.MountNamespace, uid auth.KUID, envv []string) ([]string, error) {
-	// Check if the envv already contains HOME.
-	for _, env := range envv {
-		if strings.HasPrefix(env, "HOME=") {
-			// We have it. Return the original slice unmodified.
-			return envv, nil
-		}
-	}
-
-	// Read /etc/passwd for the user's HOME directory and set the HOME
-	// environment variable as required by POSIX if it is not overridden by
-	// the user.
-	homeDir, err := getExecUserHome(ctx, mns, uid)
-	if err != nil {
-		return nil, fmt.Errorf("error reading exec user: %v", err)
-	}
-	return append(envv, "HOME="+homeDir), nil
-}
-
-// findHomeInPasswd parses a passwd file and returns the given user's home
-// directory. This function does it's best to replicate the runc's behavior.
-func findHomeInPasswd(uid uint32, passwd io.Reader, defaultHome string) (string, error) {
-	s := bufio.NewScanner(passwd)
-
-	for s.Scan() {
-		if err := s.Err(); err != nil {
-			return "", err
-		}
-
-		line := strings.TrimSpace(s.Text())
-		if line == "" {
-			continue
-		}
-
-		// Pull out part of passwd entry. Loosely parse the passwd entry as some
-		// passwd files could be poorly written and for compatibility with runc.
-		//
-		// Per 'man 5 passwd'
-		// /etc/passwd contains one line for each user account, with seven
-		// fields delimited by colons (“:”). These fields are:
-		//
-		// - login name
-		// - optional encrypted password
-		// - numerical user ID
-		// - numerical group ID
-		// - user name or comment field
-		// - user home directory
-		// - optional user command interpreter
-		parts := strings.Split(line, ":")
-
-		found := false
-		homeDir := ""
-		for i, p := range parts {
-			switch i {
-			case 2:
-				parsedUID, err := strconv.ParseUint(p, 10, 32)
-				if err == nil && parsedUID == uint64(uid) {
-					found = true
-				}
-			case 5:
-				homeDir = p
-			}
-		}
-		if found {
-			// NOTE: If the uid is present but the home directory is not
-			// present in the /etc/passwd entry we return an empty string. This
-			// is, for better or worse, what runc does.
-			return homeDir, nil
-		}
-	}
-
-	return defaultHome, nil
-}
diff --git a/runsc/boot/user_test.go b/runsc/boot/user_test.go
deleted file mode 100644
index 9aee2ad07..000000000
--- a/runsc/boot/user_test.go
+++ /dev/null
@@ -1,254 +0,0 @@
-// Copyright 2019 The gVisor Authors.
-//
-// 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 boot
-
-import (
-	"io/ioutil"
-	"os"
-	"path/filepath"
-	"strings"
-	"syscall"
-	"testing"
-
-	specs "github.com/opencontainers/runtime-spec/specs-go"
-	"gvisor.dev/gvisor/pkg/sentry/context/contexttest"
-	"gvisor.dev/gvisor/pkg/sentry/fs"
-	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-)
-
-func setupTempDir() (string, error) {
-	tmpDir, err := ioutil.TempDir(os.TempDir(), "exec-user-test")
-	if err != nil {
-		return "", err
-	}
-	return tmpDir, nil
-}
-
-func setupPasswd(contents string, perms os.FileMode) func() (string, error) {
-	return func() (string, error) {
-		tmpDir, err := setupTempDir()
-		if err != nil {
-			return "", err
-		}
-
-		if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil {
-			return "", err
-		}
-
-		f, err := os.Create(filepath.Join(tmpDir, "etc", "passwd"))
-		if err != nil {
-			return "", err
-		}
-		defer f.Close()
-
-		_, err = f.WriteString(contents)
-		if err != nil {
-			return "", err
-		}
-
-		err = f.Chmod(perms)
-		if err != nil {
-			return "", err
-		}
-		return tmpDir, nil
-	}
-}
-
-// TestGetExecUserHome tests the getExecUserHome function.
-func TestGetExecUserHome(t *testing.T) {
-	tests := map[string]struct {
-		uid        auth.KUID
-		createRoot func() (string, error)
-		expected   string
-	}{
-		"success": {
-			uid:        1000,
-			createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0666),
-			expected:   "/home/adin",
-		},
-		"no_passwd": {
-			uid:        1000,
-			createRoot: setupTempDir,
-			expected:   "/",
-		},
-		"no_perms": {
-			uid:        1000,
-			createRoot: setupPasswd("adin::1000:1111::/home/adin:/bin/sh", 0000),
-			expected:   "/",
-		},
-		"directory": {
-			uid: 1000,
-			createRoot: func() (string, error) {
-				tmpDir, err := setupTempDir()
-				if err != nil {
-					return "", err
-				}
-
-				if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil {
-					return "", err
-				}
-
-				if err := syscall.Mkdir(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil {
-					return "", err
-				}
-
-				return tmpDir, nil
-			},
-			expected: "/",
-		},
-		// Currently we don't allow named pipes.
-		"named_pipe": {
-			uid: 1000,
-			createRoot: func() (string, error) {
-				tmpDir, err := setupTempDir()
-				if err != nil {
-					return "", err
-				}
-
-				if err := os.Mkdir(filepath.Join(tmpDir, "etc"), 0777); err != nil {
-					return "", err
-				}
-
-				if err := syscall.Mkfifo(filepath.Join(tmpDir, "etc", "passwd"), 0666); err != nil {
-					return "", err
-				}
-
-				return tmpDir, nil
-			},
-			expected: "/",
-		},
-	}
-
-	for name, tc := range tests {
-		t.Run(name, func(t *testing.T) {
-			tmpDir, err := tc.createRoot()
-			if err != nil {
-				t.Fatalf("failed to create root dir: %v", err)
-			}
-
-			sandEnd, cleanup, err := startGofer(tmpDir)
-			if err != nil {
-				t.Fatalf("failed to create gofer: %v", err)
-			}
-			defer cleanup()
-
-			ctx := contexttest.Context(t)
-			conf := &Config{
-				RootDir:        "unused_root_dir",
-				Network:        NetworkNone,
-				DisableSeccomp: true,
-			}
-
-			spec := &specs.Spec{
-				Root: &specs.Root{
-					Path:     tmpDir,
-					Readonly: true,
-				},
-				// Add /proc mount as tmpfs to avoid needing a kernel.
-				Mounts: []specs.Mount{
-					{
-						Destination: "/proc",
-						Type:        "tmpfs",
-					},
-				},
-			}
-
-			mntr := newContainerMounter(spec, []int{sandEnd}, nil, &podMountHints{})
-			mns, err := mntr.createMountNamespace(ctx, conf)
-			if err != nil {
-				t.Fatalf("failed to create mount namespace: %v", err)
-			}
-			ctx = fs.WithRoot(ctx, mns.Root())
-			if err := mntr.mountSubmounts(ctx, conf, mns); err != nil {
-				t.Fatalf("failed to create mount namespace: %v", err)
-			}
-
-			got, err := getExecUserHome(ctx, mns, tc.uid)
-			if err != nil {
-				t.Fatalf("failed to get user home: %v", err)
-			}
-
-			if got != tc.expected {
-				t.Fatalf("expected %v, got: %v", tc.expected, got)
-			}
-		})
-	}
-}
-
-// TestFindHomeInPasswd tests the findHomeInPasswd function's passwd file parsing.
-func TestFindHomeInPasswd(t *testing.T) {
-	tests := map[string]struct {
-		uid      uint32
-		passwd   string
-		expected string
-		def      string
-	}{
-		"empty": {
-			uid:      1000,
-			passwd:   "",
-			expected: "/",
-			def:      "/",
-		},
-		"whitespace": {
-			uid:      1000,
-			passwd:   "       ",
-			expected: "/",
-			def:      "/",
-		},
-		"full": {
-			uid:      1000,
-			passwd:   "adin::1000:1111::/home/adin:/bin/sh",
-			expected: "/home/adin",
-			def:      "/",
-		},
-		// For better or worse, this is how runc works.
-		"partial": {
-			uid:      1000,
-			passwd:   "adin::1000:1111:",
-			expected: "",
-			def:      "/",
-		},
-		"multiple": {
-			uid:      1001,
-			passwd:   "adin::1000:1111::/home/adin:/bin/sh\nian::1001:1111::/home/ian:/bin/sh",
-			expected: "/home/ian",
-			def:      "/",
-		},
-		"duplicate": {
-			uid:      1000,
-			passwd:   "adin::1000:1111::/home/adin:/bin/sh\nian::1000:1111::/home/ian:/bin/sh",
-			expected: "/home/adin",
-			def:      "/",
-		},
-		"empty_lines": {
-			uid:      1001,
-			passwd:   "adin::1000:1111::/home/adin:/bin/sh\n\n\nian::1001:1111::/home/ian:/bin/sh",
-			expected: "/home/ian",
-			def:      "/",
-		},
-	}
-
-	for name, tc := range tests {
-		t.Run(name, func(t *testing.T) {
-			got, err := findHomeInPasswd(tc.uid, strings.NewReader(tc.passwd), tc.def)
-			if err != nil {
-				t.Fatalf("error parsing passwd: %v", err)
-			}
-			if tc.expected != got {
-				t.Fatalf("expected %v, got: %v", tc.expected, got)
-			}
-		})
-	}
-}
diff --git a/runsc/boot/vfs.go b/runsc/boot/vfs.go
new file mode 100644
index 000000000..0b9b0b436
--- /dev/null
+++ b/runsc/boot/vfs.go
@@ -0,0 +1,366 @@
+// Copyright 2018 The gVisor Authors.
+//
+// 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 boot
+
+import (
+	"fmt"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/fspath"
+	"gvisor.dev/gvisor/pkg/sentry/devices/memdev"
+	"gvisor.dev/gvisor/pkg/sentry/fs"
+	devtmpfsimpl "gvisor.dev/gvisor/pkg/sentry/fsimpl/devtmpfs"
+	goferimpl "gvisor.dev/gvisor/pkg/sentry/fsimpl/gofer"
+	procimpl "gvisor.dev/gvisor/pkg/sentry/fsimpl/proc"
+	sysimpl "gvisor.dev/gvisor/pkg/sentry/fsimpl/sys"
+	tmpfsimpl "gvisor.dev/gvisor/pkg/sentry/fsimpl/tmpfs"
+	"gvisor.dev/gvisor/pkg/syserror"
+
+	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+func registerFilesystems(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials) error {
+
+	vfsObj.MustRegisterFilesystemType(rootFsName, &goferimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserList: true,
+	})
+
+	vfsObj.MustRegisterFilesystemType(bind, &goferimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserList: true,
+	})
+
+	vfsObj.MustRegisterFilesystemType(devpts, &devtmpfsimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+
+	vfsObj.MustRegisterFilesystemType(devtmpfs, &devtmpfsimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+	vfsObj.MustRegisterFilesystemType(proc, &procimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+	vfsObj.MustRegisterFilesystemType(sysfs, &sysimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+	vfsObj.MustRegisterFilesystemType(tmpfs, &tmpfsimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+	vfsObj.MustRegisterFilesystemType(nonefs, &sysimpl.FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+		AllowUserMount: true,
+		AllowUserList:  true,
+	})
+
+	// Setup files in devtmpfs.
+	if err := memdev.Register(vfsObj); err != nil {
+		return fmt.Errorf("registering memdev: %w", err)
+	}
+	a, err := devtmpfsimpl.NewAccessor(ctx, vfsObj, creds, devtmpfsimpl.Name)
+	if err != nil {
+		return fmt.Errorf("creating devtmpfs accessor: %w", err)
+	}
+	defer a.Release()
+
+	if err := a.UserspaceInit(ctx); err != nil {
+		return fmt.Errorf("initializing userspace: %w", err)
+	}
+	if err := memdev.CreateDevtmpfsFiles(ctx, a); err != nil {
+		return fmt.Errorf("creating devtmpfs files: %w", err)
+	}
+	return nil
+}
+
+func setupContainerVFS2(ctx context.Context, conf *Config, mntr *containerMounter, procArgs *kernel.CreateProcessArgs) error {
+	if err := mntr.k.VFS().Init(); err != nil {
+		return fmt.Errorf("failed to initialize VFS: %w", err)
+	}
+	mns, err := mntr.setupVFS2(ctx, conf, procArgs)
+	if err != nil {
+		return fmt.Errorf("failed to setupFS: %w", err)
+	}
+	procArgs.MountNamespaceVFS2 = mns
+	return setExecutablePathVFS2(ctx, procArgs)
+}
+
+func setExecutablePathVFS2(ctx context.Context, procArgs *kernel.CreateProcessArgs) error {
+
+	exe := procArgs.Argv[0]
+
+	// Absolute paths can be used directly.
+	if path.IsAbs(exe) {
+		procArgs.Filename = exe
+		return nil
+	}
+
+	// Paths with '/' in them should be joined to the working directory, or
+	// to the root if working directory is not set.
+	if strings.IndexByte(exe, '/') > 0 {
+
+		if !path.IsAbs(procArgs.WorkingDirectory) {
+			return fmt.Errorf("working directory %q must be absolute", procArgs.WorkingDirectory)
+		}
+
+		procArgs.Filename = path.Join(procArgs.WorkingDirectory, exe)
+		return nil
+	}
+
+	// Paths with a '/' are relative to the CWD.
+	if strings.IndexByte(exe, '/') > 0 {
+		procArgs.Filename = path.Join(procArgs.WorkingDirectory, exe)
+		return nil
+	}
+
+	// Otherwise, We must lookup the name in the paths, starting from the
+	// root directory.
+	root := procArgs.MountNamespaceVFS2.Root()
+	defer root.DecRef()
+
+	paths := fs.GetPath(procArgs.Envv)
+	creds := procArgs.Credentials
+
+	for _, p := range paths {
+
+		binPath := path.Join(p, exe)
+
+		pop := &vfs.PathOperation{
+			Root:               root,
+			Start:              root,
+			Path:               fspath.Parse(binPath),
+			FollowFinalSymlink: true,
+		}
+
+		opts := &vfs.OpenOptions{
+			FileExec: true,
+			Flags:    linux.O_RDONLY,
+		}
+
+		dentry, err := root.Mount().Filesystem().VirtualFilesystem().OpenAt(ctx, creds, pop, opts)
+		if err == syserror.ENOENT || err == syserror.EACCES {
+			// Didn't find it here.
+			continue
+		}
+		if err != nil {
+			return err
+		}
+		dentry.DecRef()
+
+		procArgs.Filename = binPath
+		return nil
+	}
+
+	return fmt.Errorf("executable %q not found in $PATH=%q", exe, strings.Join(paths, ":"))
+}
+
+func (c *containerMounter) setupVFS2(ctx context.Context, conf *Config, procArgs *kernel.CreateProcessArgs) (*vfs.MountNamespace, error) {
+	log.Infof("Configuring container's file system with VFS2")
+
+	// Create context with root credentials to mount the filesystem (the current
+	// user may not be privileged enough).
+	rootProcArgs := *procArgs
+	rootProcArgs.WorkingDirectory = "/"
+	rootProcArgs.Credentials = auth.NewRootCredentials(procArgs.Credentials.UserNamespace)
+	rootProcArgs.Umask = 0022
+	rootProcArgs.MaxSymlinkTraversals = linux.MaxSymlinkTraversals
+	rootCtx := procArgs.NewContext(c.k)
+
+	creds := procArgs.Credentials
+	if err := registerFilesystems(rootCtx, c.k.VFS(), creds); err != nil {
+		return nil, fmt.Errorf("register filesystems: %w", err)
+	}
+
+	mns, err := c.createMountNamespaceVFS2(ctx, conf, creds)
+	if err != nil {
+		return nil, fmt.Errorf("creating mount namespace: %w", err)
+	}
+
+	rootProcArgs.MountNamespaceVFS2 = mns
+
+	// Mount submounts.
+	if err := c.mountSubmountsVFS2(rootCtx, conf, mns, creds); err != nil {
+		return nil, fmt.Errorf("mounting submounts vfs2: %w", err)
+	}
+
+	return mns, nil
+}
+
+func (c *containerMounter) createMountNamespaceVFS2(ctx context.Context, conf *Config, creds *auth.Credentials) (*vfs.MountNamespace, error) {
+
+	fd := c.fds.remove()
+	opts := strings.Join(p9MountOptionsVFS2(fd, conf.FileAccess), ",")
+
+	log.Infof("Mounting root over 9P, ioFD: %d", fd)
+	mns, err := c.k.VFS().NewMountNamespace(ctx, creds, "", rootFsName, &vfs.GetFilesystemOptions{Data: opts})
+	if err != nil {
+		return nil, fmt.Errorf("setting up mount namespace: %w", err)
+	}
+	return mns, nil
+}
+
+func (c *containerMounter) mountSubmountsVFS2(ctx context.Context, conf *Config, mns *vfs.MountNamespace, creds *auth.Credentials) error {
+
+	c.prepareMountsVFS2()
+
+	for _, submount := range c.mounts {
+		log.Debugf("Mounting %q to %q, type: %s, options: %s", submount.Source, submount.Destination, submount.Type, submount.Options)
+		if err := c.mountSubmountVFS2(ctx, conf, mns, creds, &submount); err != nil {
+			return err
+		}
+	}
+
+	// TODO(gvisor.dev/issue/1487): implement mountTmp from fs.go.
+
+	return c.checkDispenser()
+}
+
+func (c *containerMounter) prepareMountsVFS2() {
+	// Sort the mounts so that we don't place children before parents.
+	sort.Slice(c.mounts, func(i, j int) bool { return len(c.mounts[i].Destination) < len(c.mounts[j].Destination) })
+}
+
+// TODO(gvisor.dev/issue/1487): Implement submount options similar to the VFS1 version.
+func (c *containerMounter) mountSubmountVFS2(ctx context.Context, conf *Config, mns *vfs.MountNamespace, creds *auth.Credentials, submount *specs.Mount) error {
+	root := mns.Root()
+	defer root.DecRef()
+	target := &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(submount.Destination),
+	}
+
+	fsName, options, useOverlay, err := c.getMountNameAndOptionsVFS2(conf, *submount)
+	if err != nil {
+		return fmt.Errorf("mountOptions failed: %w", err)
+	}
+
+	if fsName == "" {
+		// Filesystem is not supported (e.g. cgroup), just skip it.
+		return nil
+	}
+
+	if err := c.makeSyntheticMount(ctx, submount.Destination, root, creds); err != nil {
+		return err
+	}
+	log.Debugf("directory exists or made directory for submount: %s", submount.Destination)
+
+	opts := &vfs.MountOptions{
+		GetFilesystemOptions: vfs.GetFilesystemOptions{
+			Data: strings.Join(options, ","),
+		},
+		InternalMount: true,
+	}
+
+	// All writes go to upper, be paranoid and make lower readonly.
+	opts.ReadOnly = useOverlay
+
+	if err := c.k.VFS().MountAt(ctx, creds, "", target, submount.Type, opts); err != nil {
+		return fmt.Errorf("failed to mount %q (type: %s): %w, opts: %v", submount.Destination, submount.Type, err, opts)
+	}
+	log.Infof("Mounted %q to %q type: %s, internal-options: %q", submount.Source, submount.Destination, submount.Type, opts)
+	return nil
+}
+
+// getMountNameAndOptionsVFS2 retrieves the fsName, opts, and useOverlay values
+// used for mounts.
+func (c *containerMounter) getMountNameAndOptionsVFS2(conf *Config, m specs.Mount) (string, []string, bool, error) {
+	var (
+		fsName     string
+		opts       []string
+		useOverlay bool
+	)
+
+	switch m.Type {
+	case devpts, devtmpfs, proc, sysfs:
+		fsName = m.Type
+	case nonefs:
+		fsName = sysfs
+	case tmpfs:
+		fsName = m.Type
+
+		var err error
+		opts, err = parseAndFilterOptions(m.Options, tmpfsAllowedOptions...)
+		if err != nil {
+			return "", nil, false, err
+		}
+
+	case bind:
+		fd := c.fds.remove()
+		fsName = "9p"
+		opts = p9MountOptionsVFS2(fd, c.getMountAccessType(m))
+		// If configured, add overlay to all writable mounts.
+		useOverlay = conf.Overlay && !mountFlags(m.Options).ReadOnly
+
+	default:
+		log.Warningf("ignoring unknown filesystem type %q", m.Type)
+	}
+	return fsName, opts, useOverlay, nil
+}
+
+// p9MountOptions creates a slice of options for a p9 mount.
+// TODO(gvisor.dev/issue/1200): Remove this version in favor of the one in
+// fs.go when privateunixsocket lands.
+func p9MountOptionsVFS2(fd int, fa FileAccessType) []string {
+	opts := []string{
+		"trans=fd",
+		"rfdno=" + strconv.Itoa(fd),
+		"wfdno=" + strconv.Itoa(fd),
+	}
+	if fa == FileAccessShared {
+		opts = append(opts, "cache=remote_revalidating")
+	}
+	return opts
+}
+
+func (c *containerMounter) makeSyntheticMount(ctx context.Context, currentPath string, root vfs.VirtualDentry, creds *auth.Credentials) error {
+
+	target := &vfs.PathOperation{
+		Root:  root,
+		Start: root,
+		Path:  fspath.Parse(currentPath),
+	}
+
+	_, err := c.k.VFS().StatAt(ctx, creds, target, &vfs.StatOptions{})
+	switch {
+
+	case err == syserror.ENOENT:
+		if err := c.makeSyntheticMount(ctx, path.Dir(currentPath), root, creds); err != nil {
+			return err
+		}
+
+		mkdirOpts := &vfs.MkdirOptions{Mode: 0777, ForSyntheticMountpoint: true}
+		if err := c.k.VFS().MkdirAt(ctx, creds, target, mkdirOpts); err != nil {
+			return fmt.Errorf("failed to makedir for mount %+v: %w", target, err)
+		}
+		return nil
+
+	case err != nil:
+		return fmt.Errorf("stat failed for mount %+v: %w", target, err)
+
+	default:
+		return nil
+	}
+}