Merge pull request #8 from nmi/add_serial

Add serial

.gitignore

@@ -11,6 +11,7 @@ busybox
 initrd
 bzImage
 linux-*.tar.xz
+linux.tar.xz
 
 # Test binary, built with `go test -c`
 *.test

Makefile

@@ -9,21 +9,30 @@ golangci-lint:
 	curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh \
 		| sh -s -- -b . $(GOLANGCI_LINT_VERSION)
 
-initrd:
+busybox.tar.bz2:
 	curl https://busybox.net/downloads/busybox-$(BUSYBOX_VERSION).tar.bz2 -o busybox.tar.bz2
+
+initrd: busybox.config busybox.tar.bz2 busybox.inittab busybox.passwd busybox.rcS
 	tar -xf busybox.tar.bz2
 	cp busybox.config busybox-$(BUSYBOX_VERSION)/.config
 	make -C busybox-$(BUSYBOX_VERSION) install
-	mkdir -p busybox-$(BUSYBOX_VERSION)/_install/etc
-	cp inittab busybox-$(BUSYBOX_VERSION)/_install/etc/inittab
+	mkdir -p busybox-$(BUSYBOX_VERSION)/_install/etc/init.d
+	mkdir -p busybox-$(BUSYBOX_VERSION)/_install/proc
+	mkdir -p busybox-$(BUSYBOX_VERSION)/_install/sys
+	cp busybox.inittab busybox-$(BUSYBOX_VERSION)/_install/etc/inittab
+	cp busybox.passwd  busybox-$(BUSYBOX_VERSION)/_install/etc/passwd
+	cp busybox.rcS     busybox-$(BUSYBOX_VERSION)/_install/etc/init.d/rcS
 	cd busybox-$(BUSYBOX_VERSION)/_install && find . | cpio -o --format=newc > ../../initrd
 	rm -rf busybox-$(BUSYBOX_VERSION)
 
-bzImage:
-	curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.12.tar.xz \
-		-o linux-$(LINUX_VERSION).tar.xz
-	tar Jxf ./linux-5.10.12.tar.xz
+linux.tar.xz:
+	curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-$(LINUX_VERSION).tar.xz \
+		-o linux.tar.xz
+
+bzImage: linux.config linux.tar.xz
+	tar Jxf ./linux.tar.xz
 	cp linux.config linux-$(LINUX_VERSION)/.config
+	cd linux-$(LINUX_VERSION) && patch -p1 < ../linux-5.10.12-patch-0000-enable-serial-debug-autoconf.patch
 	make -C linux-$(LINUX_VERSION)
 	cp linux-$(LINUX_VERSION)/arch/x86/boot/bzImage .
 	rm -rf linux-$(LINUX_VERSION)

README.md

@@ -42,3 +42,4 @@ kvm.LinuxRun(bzImagePath, initrdPath, ioportHandler)
 - [The Linux/x86 Boot Protocol, kernel.org](https://www.kernel.org/doc/html/latest/x86/boot.html)
 - [Build and run minimal Linux / Busybox systems in Qemu](https://gist.github.com/chrisdone/02e165a0004be33734ac2334f215380e)
 - [kvm_cost.go, google/gvisor](https://github.com/google/gvisor/blob/master/pkg/sentry/platform/kvm/kvm_const.go)
+- [Serial UART information, www.lammertbies.nl](https://www.lammertbies.nl/comm/info/serial-uart)

inittab → busybox.inittab

@@ -70,7 +70,7 @@
 # this yourself...
 #
 # Start an "askfirst" shell on the console (whatever that may be)
-::askfirst:-/bin/sh
+#::askfirst:-/bin/sh
 # Start an "askfirst" shell on /dev/tty2-4
 #tty2::askfirst:-/bin/sh
 #tty3::askfirst:-/bin/sh

busybox.passwd

@@ -0,0 +1 @@
+root::0:0::/:/bin/sh

busybox.rcS

@@ -0,0 +1,3 @@
+#!/bin/sh
+mount -t proc none /proc
+mount -t sysfs none /sys

go.mod

@@ -1,3 +1,5 @@
 module github.com/nmi/gokvm
 
 go 1.13
+
+require golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf

go.sum

@@ -0,0 +1,4 @@
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf h1:MZ2shdL+ZM/XzY3ZGOnh4Nlpnxz5GSOhOmtHo3iPU6M=
+golang.org/x/term v0.0.0-20201210144234-2321bbc49cbf/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=

kvm/kvm.go

@@ -9,6 +9,7 @@ import (
 	"unsafe"
 
 	"github.com/nmi/gokvm/bootproto"
+	"github.com/nmi/gokvm/serial"
 )
 
 const (
@@ -28,6 +29,7 @@ const (
 	kvmCreatePIT2          = 0x4040AE77
 	kvmGetSupportedCPUID   = 0xC008AE05
 	kvmSetCPUID2           = 0x4008AE90
+	kvmIRQLine             = 0xc008ae67
 
 	EXITUNKNOWN       = 0
 	EXITEXCEPTION     = 1
@@ -238,6 +240,22 @@ func SetIdentityMapAddr(vmFd uintptr) error {
 	return err
 }
 
+type IRQLevel struct {
+	IRQ   uint32
+	Level uint32
+}
+
+func IRQLine(vmFd uintptr, irq, level uint32) error {
+	irqLevel := IRQLevel{
+		IRQ:   irq,
+		Level: level,
+	}
+
+	_, err := ioctl(vmFd, kvmIRQLine, uintptr(unsafe.Pointer(&irqLevel)))
+
+	return err
+}
+
 func CreateIRQChip(vmFd uintptr) error {
 	_, err := ioctl(vmFd, kvmCreateIRQChip, 0)
 
@@ -339,6 +357,7 @@ type LinuxGuest struct {
 	kvmFd, vmFd, vcpuFd uintptr
 	mem                 []byte
 	run                 *RunData
+	serial              *serial.Serial
 }
 
 func NewLinuxGuest(bzImagePath, initPath string) (*LinuxGuest, error) {
@@ -470,9 +489,29 @@ func NewLinuxGuest(bzImagePath, initPath string) (*LinuxGuest, error) {
 		return g, err
 	}
 
+	serialIRQCallback := func(irq, level uint32) {
+		err := IRQLine(g.vmFd, irq, level)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	if g.serial, err = serial.New(serialIRQCallback); err != nil {
+		return g, err
+	}
+
 	return g, nil
 }
 
+func (g *LinuxGuest) GetInputChan() chan<- byte {
+	return g.serial.GetInputChan()
+}
+
+func (g *LinuxGuest) InjectSerialIRQ() {
+	g.serial.InjectIRQ(0)
+	g.serial.InjectIRQ(1)
+}
+
 func (g *LinuxGuest) initRegs() error {
 	regs, err := GetRegs(g.vcpuFd)
 	if err != nil {
@@ -568,14 +607,43 @@ func (g *LinuxGuest) RunOnce() (bool, error) {
 		return false, nil
 	case EXITIO:
 		direction, size, port, count, offset := g.run.IO()
-		if direction == EXITIOOUT && size == 1 && port == 0x3f8 && count == 1 {
-			p := uintptr(unsafe.Pointer(g.run))
-			c := *(*byte)(unsafe.Pointer(p + uintptr(offset)))
-			fmt.Printf("%c", c)
+		bytes := (*(*[100]byte)(unsafe.Pointer(uintptr(unsafe.Pointer(g.run)) + uintptr(offset))))[0:size]
+
+		for i := 0; i < int(count); i++ {
+			if err := g.handleExitIO(direction, port, bytes); err != nil {
+				return false, err
+			}
 		}
 
 		return true, nil
 	default:
 		return false, fmt.Errorf("%w: %d", ErrorUnexpectedEXITReason, g.run.ExitReason)
 	}
 }
+
+func (g *LinuxGuest) handleExitIO(direction, port uint64, bytes []byte) error {
+	switch {
+	case 0x3c0 <= port && port <= 0x3da:
+		return nil // VGA
+	case 0x60 <= port && port <= 0x6F:
+		return nil // PS/2 Keyboard (Always 8042 Chip)
+	case 0x70 <= port && port <= 0x71:
+		return nil // CMOS clock
+	case 0x80 <= port && port <= 0x9F:
+		return nil // DMA Page Registers (Commonly 74L612 Chip)
+	case 0x2f8 <= port && port <= 0x2FF:
+		return nil // Serial port 2
+	case 0x3e8 <= port && port <= 0x3ef:
+		return nil // Serial port 3
+	case 0x2e8 <= port && port <= 0x2ef:
+		return nil // Serial port 4
+	case serial.COM1Addr <= port && port < serial.COM1Addr+8:
+		if direction == EXITIOIN {
+			return g.serial.In(port, bytes)
+		}
+
+		return g.serial.Out(port, bytes)
+	default:
+		return fmt.Errorf("%w: unexpected io port 0x%x", ErrorUnexpectedEXITReason, port)
+	}
+}

kvm/kvm_test.go

@@ -239,7 +239,7 @@ func TestNewLinuxGuest(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	for i := 0; i < 1000; i++ {
+	for i := 0; i < 10; i++ {
 		isContinue, err := g.RunOnce()
 		if err != nil {
 			t.Fatal(err)

linux-5.10.12-patch-0000-enable-serial-debug-autoconf.patch

@@ -0,0 +1,11 @@
+--- linux-5.10.12/drivers/tty/serial/8250/8250_port.c	2021-02-09 00:14:11.470906210 +0900
++++ linux-5.10.12/drivers/tty/serial/8250/8250_port.c.orig	2021-02-09 00:14:03.514875736 +0900
+@@ -44,7 +44,7 @@
+ /*
+  * Debugging.
+  */
+-#if 0
++#if 1
+ #define DEBUG_AUTOCONF(fmt...)	printk(fmt)
+ #else
+ #define DEBUG_AUTOCONF(fmt...)	do { } while (0)

linux.config

@@ -103,6 +103,7 @@ CONFIG_TINY_SRCU=y
 # end of RCU Subsystem
 
 # CONFIG_IKCONFIG is not set
+# CONFIG_IKHEADERS is not set
 CONFIG_LOG_BUF_SHIFT=17
 CONFIG_PRINTK_SAFE_LOG_BUF_SHIFT=13
 CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
@@ -119,6 +120,7 @@ CONFIG_ARCH_SUPPORTS_INT128=y
 # CONFIG_CGROUPS is not set
 # CONFIG_CHECKPOINT_RESTORE is not set
 # CONFIG_SCHED_AUTOGROUP is not set
+# CONFIG_SYSFS_DEPRECATED is not set
 # CONFIG_RELAY is not set
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_INITRAMFS_SOURCE=""
@@ -133,6 +135,7 @@ CONFIG_RD_ZSTD=y
 # CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
 CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_LD_ORPHAN_WARN=y
+CONFIG_SYSCTL=y
 CONFIG_HAVE_UID16=y
 CONFIG_SYSCTL_EXCEPTION_TRACE=y
 CONFIG_HAVE_PCSPKR_PLATFORM=y
@@ -221,7 +224,7 @@ CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
 #
 # CONFIG_ZONE_DMA is not set
 # CONFIG_SMP is not set
-# CONFIG_X86_FEATURE_NAMES is not set
+CONFIG_X86_FEATURE_NAMES=y
 CONFIG_X86_MPPARSE=y
 # CONFIG_GOLDFISH is not set
 # CONFIG_RETPOLINE is not set
@@ -242,6 +245,7 @@ CONFIG_X86_CMOV=y
 CONFIG_X86_MINIMUM_CPU_FAMILY=64
 CONFIG_X86_DEBUGCTLMSR=y
 CONFIG_IA32_FEAT_CTL=y
+CONFIG_X86_VMX_FEATURE_NAMES=y
 # CONFIG_PROCESSOR_SELECT is not set
 CONFIG_CPU_SUP_INTEL=y
 CONFIG_CPU_SUP_AMD=y
@@ -358,6 +362,7 @@ CONFIG_COMPAT_FOR_U64_ALIGNMENT=y
 #
 # CONFIG_EDD is not set
 # CONFIG_FIRMWARE_MEMMAP is not set
+# CONFIG_FW_CFG_SYSFS is not set
 # CONFIG_GOOGLE_FIRMWARE is not set
 
 #
@@ -519,6 +524,7 @@ CONFIG_NEED_PER_CPU_KM=y
 # CONFIG_ZBUD is not set
 # CONFIG_ZSMALLOC is not set
 CONFIG_GENERIC_EARLY_IOREMAP=y
+# CONFIG_IDLE_PAGE_TRACKING is not set
 CONFIG_ARCH_HAS_PTE_DEVMAP=y
 CONFIG_ARCH_USES_HIGH_VMA_FLAGS=y
 CONFIG_ARCH_HAS_PKEYS=y
@@ -543,7 +549,8 @@ CONFIG_HAVE_PCI=y
 # Generic Driver Options
 #
 # CONFIG_UEVENT_HELPER is not set
-# CONFIG_DEVTMPFS is not set
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
 # CONFIG_STANDALONE is not set
 # CONFIG_PREVENT_FIRMWARE_BUILD is not set
 
@@ -944,6 +951,7 @@ CONFIG_VIRTIO=y
 #
 # end of Microsoft Hyper-V guest support
 
+# CONFIG_GREYBUS is not set
 # CONFIG_STAGING is not set
 # CONFIG_X86_PLATFORM_DEVICES is not set
 # CONFIG_CHROME_PLATFORMS is not set
@@ -1101,9 +1109,14 @@ CONFIG_DCACHE_WORD_ACCESS=y
 #
 # Pseudo filesystems
 #
-# CONFIG_PROC_FS is not set
+CONFIG_PROC_FS=y
+# CONFIG_PROC_KCORE is not set
+CONFIG_PROC_SYSCTL=y
+CONFIG_PROC_PAGE_MONITOR=y
 # CONFIG_PROC_CHILDREN is not set
-# CONFIG_SYSFS is not set
+CONFIG_PROC_PID_ARCH_STATUS=y
+CONFIG_KERNFS=y
+CONFIG_SYSFS=y
 # CONFIG_HUGETLBFS is not set
 CONFIG_ARCH_HAS_GIGANTIC_PAGE=y
 # CONFIG_CONFIGFS_FS is not set
@@ -1226,6 +1239,8 @@ CONFIG_CONSOLE_LOGLEVEL_DEFAULT=15
 CONFIG_CONSOLE_LOGLEVEL_QUIET=15
 CONFIG_MESSAGE_LOGLEVEL_DEFAULT=7
 # CONFIG_BOOT_PRINTK_DELAY is not set
+# CONFIG_DYNAMIC_DEBUG is not set
+# CONFIG_DYNAMIC_DEBUG_CORE is not set
 # CONFIG_SYMBOLIC_ERRNAME is not set
 # end of printk and dmesg options
 
@@ -1325,6 +1340,8 @@ CONFIG_WQ_WATCHDOG=y
 #
 # Scheduler Debugging
 #
+CONFIG_SCHED_DEBUG=y
+# CONFIG_SCHEDSTATS is not set
 # end of Scheduler Debugging
 
 # CONFIG_DEBUG_TIMEKEEPING is not set
@@ -1375,6 +1392,7 @@ CONFIG_STACKTRACE=y
 # end of RCU Debugging
 
 # CONFIG_DEBUG_WQ_FORCE_RR_CPU is not set
+# CONFIG_LATENCYTOP is not set
 CONFIG_USER_STACKTRACE_SUPPORT=y
 CONFIG_HAVE_FUNCTION_TRACER=y
 CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y