kvm tools: Add support for PS/2 keyboard system

Add support for PS/2 keyboard system with AUX device (aka mouse).
The device works with vnc, the guest must be started with the
'--vnc' parameter for the device to be initialized.

Signed-off-by: John Floren <john@jfloren.net>
[ turn into patch and clean up code ]
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

2 files changed, 478 insertions, 0 deletions

diff --git a/hw/i8042.c b/hw/i8042.c
new file mode 100644
index 00000000..80f0d18e
--- /dev/null
+++ b/hw/i8042.c
@@ -0,0 +1,475 @@
+#include "kvm/read-write.h"
+#include "kvm/ioport.h"
+#include "kvm/mutex.h"
+#include "kvm/util.h"
+#include "kvm/term.h"
+#include "kvm/kvm.h"
+#include "kvm/i8042.h"
+
+#include <rfb/keysym.h>
+#include <rfb/rfb.h>
+#include <stdint.h>
+
+#define KBD_IRQ			1
+#define AUX_IRQ			12
+
+#define CMD_READ_MODE		0x20
+#define CMD_WRITE_MODE		0x60
+#define CMD_WRITE_AUX_BUF	0xD3
+#define CMD_WRITE_AUX		0xD4
+#define CMD_TEST_AUX		0xA9
+#define CMD_DISABLE_AUX		0xA7
+#define CMD_ENABLE_AUX		0xA8
+
+#define RESPONSE_ACK		0xFA
+
+#define MODE_DISABLE_AUX	0x20
+
+#define AUX_ENABLE_REPORTING	0x20
+#define AUX_SCALING_FLAG	0x10
+#define AUX_DEFAULT_RESOLUTION	0x2
+#define AUX_DEFAULT_SAMPLE	100
+
+#define KBD_STATUS_SYS		0x4
+#define KBD_STATUS_A2		0x8
+#define KBD_STATUS_INH		0x10
+#define KBD_STATUS_OBF		0x01
+#define KBD_STATUS_AUX_OBF	0x20
+
+#define KBD_MODE_KBD_INT	0x01
+#define KBD_MODE_SYS		0x02
+
+#define QUEUE_SIZE		128
+
+/*
+ * This represents the current state of the PS/2 keyboard system,
+ * including the AUX device (the mouse)
+ */
+struct kbd_state {
+	struct kvm		*kvm;
+
+	char			kq[QUEUE_SIZE];	/* Keyboard queue */
+	int			kread, kwrite;	/* Indexes into the queue */
+	int			kcount;		/* number of elements in queue */
+
+	char			mq[QUEUE_SIZE];
+	int			mread, mwrite;
+	int			mcount;
+
+	u8			mstatus;	/* Mouse status byte */
+	u8			mres;		/* Current mouse resolution */
+	u8			msample;	/* Current mouse samples/second */
+
+	u8			mode;		/* i8042 mode register */
+	u8			status;		/* i8042 status register */
+	/*
+	 * Some commands (on port 0x64) have arguments;
+	 * we store the command here while we wait for the argument
+	 */
+	u32			write_cmd;
+};
+
+static struct kbd_state		state;
+
+/*
+ * If there are packets to be read, set the appropriate IRQs high
+ */
+static void kbd_update_irq(void)
+{
+	u8 klevel = 0;
+	u8 mlevel = 0;
+
+	/* First, clear the kbd and aux output buffer full bits */
+	state.status &= ~(KBD_STATUS_OBF | KBD_STATUS_AUX_OBF);
+
+	if (state.kcount > 0) {
+		state.status |= KBD_STATUS_OBF;
+		klevel = 1;
+	}
+
+	/* Keyboard has higher priority than mouse */
+	if (klevel == 0 && state.mcount != 0) {
+		state.status |= KBD_STATUS_OBF | KBD_STATUS_AUX_OBF;
+		mlevel = 1;
+	}
+
+	kvm__irq_line(state.kvm, KBD_IRQ, klevel);
+	kvm__irq_line(state.kvm, AUX_IRQ, mlevel);
+}
+
+/*
+ * Add a byte to the mouse queue, then set IRQs
+ */
+static void mouse_queue(u8 c)
+{
+	if (state.mcount >= QUEUE_SIZE)
+		return;
+
+	state.mq[state.mwrite++ % QUEUE_SIZE] = c;
+
+	state.mcount++;
+	kbd_update_irq();
+}
+
+/*
+ * Add a byte to the keyboard queue, then set IRQs
+ */
+static void kbd_queue(u8 c)
+{
+	if (state.kcount >= QUEUE_SIZE)
+		return;
+
+	state.kq[state.kwrite++ % QUEUE_SIZE] = c;
+
+	state.kcount++;
+	kbd_update_irq();
+}
+
+/*
+ * This function is called when the OS issues a write to port 0x64
+ */
+static void kbd_write_command(u32 val)
+{
+	switch (val) {
+	case CMD_READ_MODE:
+		kbd_queue(state.mode);
+		break;
+	case CMD_WRITE_MODE:
+	case CMD_WRITE_AUX:
+	case CMD_WRITE_AUX_BUF:
+		state.write_cmd = val;
+		break;
+	case CMD_TEST_AUX:
+		/* 0 means we're a normal PS/2 mouse */
+		mouse_queue(0);
+		break;
+	case CMD_DISABLE_AUX:
+		state.mode |= MODE_DISABLE_AUX;
+		break;
+	case CMD_ENABLE_AUX:
+		state.mode &= ~MODE_DISABLE_AUX;
+		break;
+	default:
+		break;
+	}
+}
+
+/*
+ * Called when the OS reads from port 0x60 (PS/2 data)
+ */
+static u32 kbd_read_data(void)
+{
+	u32 ret;
+	int i;
+
+	if (state.kcount != 0) {
+		/* Keyboard data gets read first */
+		ret = state.kq[state.kread++ % QUEUE_SIZE];
+		state.kcount--;
+		kvm__irq_line(state.kvm, KBD_IRQ, 0);
+		kbd_update_irq();
+	} else if (state.mcount > 0) {
+		/* Followed by the mouse */
+		ret = state.mq[state.mread++ % QUEUE_SIZE];
+		state.mcount--;
+		kvm__irq_line(state.kvm, AUX_IRQ, 0);
+		kbd_update_irq();
+	} else if (state.kcount == 0) {
+		i = state.kread - 1;
+		if (i < 0)
+			i = QUEUE_SIZE;
+		ret = state.kq[i];
+	}
+	return ret;
+}
+
+/*
+ * Called when the OS read from port 0x64, the command port
+ */
+static u32 kbd_read_status(void)
+{
+	return (u32)state.status;
+}
+
+/*
+ * Called when the OS writes to port 0x60 (data port)
+ * Things written here are generally arguments to commands previously
+ * written to port 0x64 and stored in state.write_cmd
+ */
+static void kbd_write_data(u32 val)
+{
+	switch (state.write_cmd) {
+	case CMD_WRITE_MODE:
+		state.mode = val;
+		kbd_update_irq();
+		break;
+	case CMD_WRITE_AUX_BUF:
+		mouse_queue(val);
+		mouse_queue(RESPONSE_ACK);
+		break;
+	case CMD_WRITE_AUX:
+		/* The OS wants to send a command to the mouse */
+		mouse_queue(RESPONSE_ACK);
+		switch (val) {
+		case 0xe6:
+			/* set scaling = 1:1 */
+			state.mstatus &= ~AUX_SCALING_FLAG;
+			break;
+		case 0xe8:
+			/* set resolution */
+			state.mres = val;
+			break;
+		case 0xe9:
+			/* Report mouse status/config */
+			mouse_queue(state.mstatus);
+			mouse_queue(state.mres);
+			mouse_queue(state.msample);
+			break;
+		case 0xf2:
+			/* send ID */
+			mouse_queue(0); /* normal mouse */
+			break;
+		case 0xf3:
+			/* set sample rate */
+			state.msample = val;
+			break;
+		case 0xf4:
+			/* enable reporting */
+			state.mstatus |= AUX_ENABLE_REPORTING;
+			break;
+		case 0xf5:
+			state.mstatus &= ~AUX_ENABLE_REPORTING;
+			break;
+		case 0xf6:
+			/* set defaults, just fall through to reset */
+		case 0xff:
+			/* reset */
+			state.mstatus = 0x0;
+			state.mres = AUX_DEFAULT_RESOLUTION;
+			state.msample = AUX_DEFAULT_SAMPLE;
+			break;
+		default:
+			break;
+	}
+	break;
+	case 0:
+		/* Just send the ID */
+		kbd_queue(RESPONSE_ACK);
+		kbd_queue(0xab);
+		kbd_queue(0x41);
+		kbd_update_irq();
+		break;
+	default:
+		/* Yeah whatever */
+		break;
+	}
+	state.write_cmd = 0;
+}
+
+static void kbd_reset(void)
+{
+	state = (struct kbd_state) {
+		.status		= KBD_STATUS_SYS | KBD_STATUS_A2 | KBD_STATUS_INH, /* 0x1c */
+		.mode		= KBD_MODE_KBD_INT | KBD_MODE_SYS, /* 0x3 */
+		.mres		= AUX_DEFAULT_RESOLUTION,
+		.msample	= AUX_DEFAULT_SAMPLE,
+	};
+}
+
+/*
+ * We can map the letters and numbers without a fuss,
+ * but the other characters not so much.
+ */
+static char letters[26] = {
+	0x1c, 0x32, 0x21, 0x23, 0x24, /* a-e */
+	0x2b, 0x34, 0x33, 0x43, 0x3b, /* f-j */
+	0x42, 0x4b, 0x3a, 0x31, 0x44, /* k-o */
+	0x4d, 0x15, 0x2d, 0x1b, 0x2c, /* p-t */
+	0x3c, 0x2a, 0x1d, 0x22, 0x35, /* u-y */
+	0x1a,
+};
+
+static char num[10] = {
+	0x45, 0x16, 0x1e, 0x26, 0x2e, 0x23, 0x36, 0x3d, 0x3e, 0x46,
+};
+
+/*
+ * This is called when the VNC server receives a key event
+ * The reason this function is such a beast is that we have
+ * to convert from ASCII characters (which is what VNC gets)
+ * to PC keyboard scancodes, which is what Linux expects to
+ * get from its keyboard. ASCII and the scancode set don't
+ * really seem to mesh in any good way beyond some basics with
+ * the letters and numbers.
+ */
+void kbd_handle_key(rfbBool down, rfbKeySym key, rfbClientPtr cl)
+{
+	char tosend = 0;
+
+	if (key >= 0x41 && key <= 0x5a)
+		key += 0x20; /* convert to lowercase */
+
+	if (key >= 0x61 && key <= 0x7a) /* a-z */
+		tosend = letters[key - 0x61];
+
+	if (key >= 0x30 && key <= 0x39)
+		tosend = num[key - 0x30];
+
+	switch (key) {
+	case XK_Insert:		kbd_queue(0xe0);	tosend = 0x70;	break;
+	case XK_Delete:		kbd_queue(0xe0);	tosend = 0x71;	break;
+	case XK_Up:		kbd_queue(0xe0);	tosend = 0x75;	break;
+	case XK_Down:		kbd_queue(0xe0);	tosend = 0x72;	break;
+	case XK_Left:		kbd_queue(0xe0);	tosend = 0x6b;	break;
+	case XK_Right:		kbd_queue(0xe0);	tosend = 0x74;	break;
+	case XK_Page_Up:	kbd_queue(0xe0);	tosend = 0x7d;	break;
+	case XK_Page_Down:	kbd_queue(0xe0);	tosend = 0x7a;	break;
+	case XK_Home:		kbd_queue(0xe0);	tosend = 0x6c;	break;
+	case XK_BackSpace:	tosend = 0x66;		break;
+	case XK_Tab:		tosend = 0x0d;		break;
+	case XK_Return:		tosend = 0x5a;		break;
+	case XK_Escape:		tosend = 0x76;		break;
+	case XK_End:		tosend = 0x69;		break;
+	case XK_Shift_L:	tosend = 0x12;		break;
+	case XK_Shift_R:	tosend = 0x59;		break;
+	case XK_Control_R:	kbd_queue(0xe0);
+	case XK_Control_L:	tosend = 0x14;		break;
+	case XK_Alt_R:		kbd_queue(0xe0);
+	case XK_Alt_L:		tosend = 0x11;		break;
+	case XK_quoteleft:	tosend = 0x0e;		break;
+	case XK_minus:		tosend = 0x4e;		break;
+	case XK_equal:		tosend = 0x55;		break;
+	case XK_bracketleft:	tosend = 0x54;		break;
+	case XK_bracketright:	tosend = 0x5b;		break;
+	case XK_backslash:	tosend = 0x5d;		break;
+	case XK_Caps_Lock:	tosend = 0x58;		break;
+	case XK_semicolon:	tosend = 0x4c;		break;
+	case XK_quoteright:	tosend = 0x52;		break;
+	case XK_comma:		tosend = 0x41;		break;
+	case XK_period:		tosend = 0x49;		break;
+	case XK_slash:		tosend = 0x4a;		break;
+	case XK_space:		tosend = 0x29;		break;
+
+	/*
+	 * This is where I handle the shifted characters.
+	 * They don't really map nicely the way A-Z maps to a-z,
+	 * so I'm doing it manually
+	 */
+	case XK_exclam:		tosend = 0x16;		break;
+	case XK_quotedbl:	tosend = 0x52;		break;
+	case XK_numbersign:	tosend = 0x26;		break;
+	case XK_dollar:		tosend = 0x25;		break;
+	case XK_percent:	tosend = 0x2e;		break;
+	case XK_ampersand:	tosend = 0x3d;		break;
+	case XK_parenleft:	tosend = 0x46;		break;
+	case XK_parenright:	tosend = 0x45;		break;
+	case XK_asterisk:	tosend = 0x3e;		break;
+	case XK_plus:		tosend = 0x55;		break;
+	case XK_colon:		tosend = 0x4c;		break;
+	case XK_less:		tosend = 0x41;		break;
+	case XK_greater:	tosend = 0x49;		break;
+	case XK_question:	tosend = 0x4a;		break;
+	case XK_at:		tosend = 0x1e;		break;
+	case XK_asciicircum:	tosend = 0x36;		break;
+	case XK_underscore:	tosend = 0x4e;		break;
+	case XK_braceleft:	tosend = 0x54;		break;
+	case XK_braceright:	tosend = 0x5b;		break;
+	case XK_bar:		tosend = 0x5d;		break;
+	case XK_asciitilde:	tosend = 0x0e;		break;
+	default:		break;
+	}
+
+	/*
+	 * If this is a "key up" event (the user has released the key, we
+	 * need to send 0xf0 first.
+	 */
+	if (!down && tosend != 0x0)
+		kbd_queue(0xf0);
+
+	if (tosend)
+		kbd_queue(tosend);
+}
+
+/* The previous X and Y coordinates of the mouse */
+static int xlast, ylast = -1;
+
+/*
+ * This function is called by the VNC server whenever a mouse event occurs.
+ */
+void kbd_handle_ptr(int buttonMask, int x, int y, rfbClientPtr cl)
+{
+	int dx, dy;
+	char b1 = 0x8;
+
+	/* The VNC mask and the PS/2 button encoding are the same */
+	b1 |= buttonMask;
+
+	if (xlast >= 0 && ylast >= 0) {
+		/* The PS/2 mouse sends deltas, not absolutes */
+		dx = x - xlast;
+		dy = ylast - y;
+
+		/* Set overflow bits if needed */
+		if (dy > 255)
+			b1 |= 0x80;
+		if (dx > 255)
+			b1 |= 0x40;
+
+		/* Set negative bits if needed */
+		if (dy < 0)
+			b1 |= 0x20;
+		if (dx < 0)
+			b1 |= 0x10;
+
+		mouse_queue(b1);
+		mouse_queue(dx);
+		mouse_queue(dy);
+	}
+
+	xlast = x;
+	ylast = y;
+	rfbDefaultPtrAddEvent(buttonMask, x, y, cl);
+}
+
+/*
+ * Called when the OS has written to one of the keyboard's ports (0x60 or 0x64)
+ */
+static bool kbd_in(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count)
+{
+	u32 result;
+
+	if (port == 0x64) {
+		result = kbd_read_status();
+		ioport__write8(data, (char)result);
+	} else {
+		result = kbd_read_data();
+		ioport__write32(data, result);
+	}
+	return true;
+}
+
+/*
+ * Called when the OS attempts to read from a keyboard port (0x60 or 0x64)
+ */
+static bool kbd_out(struct ioport *ioport, struct kvm *kvm, u16 port, void *data, int size, u32 count)
+{
+	if (port == 0x64)
+		kbd_write_command(*((u32 *)data));
+	else
+		kbd_write_data(*((u32 *)data));
+
+	return true;
+}
+
+static struct ioport_operations kbd_ops = {
+	.io_in		= kbd_in,
+	.io_out		= kbd_out,
+};
+
+void kbd__init(struct kvm *kvm)
+{
+	kbd_reset();
+	state.kvm = kvm;
+	ioport__register(0x60, &kbd_ops, 2, NULL);
+	ioport__register(0x64, &kbd_ops, 2, NULL);
+}
diff --git a/hw/vesa.c b/hw/vesa.c
index 85fe1a90..b99f2de8 100644
--- a/hw/vesa.c
+++ b/hw/vesa.c
@@ -7,6 +7,7 @@
 #include "kvm/irq.h"
 #include "kvm/kvm.h"
 #include "kvm/pci.h"
+#include "kvm/i8042.h"
 
 #include <sys/types.h>
 #include <sys/ioctl.h>
@@ -99,6 +100,8 @@ void *vesa__dovnc(void *v)
 	server = rfbGetScreen(&argc, (char **) argv, VESA_WIDTH, VESA_HEIGHT, 8, 3, 4);
 	server->frameBuffer		= videomem;
 	server->alwaysShared		= TRUE;
+	server->kbdAddEvent		= kbd_handle_key;
+	server->ptrAddEvent		= kbd_handle_ptr;
 	rfbInitServer(server);
 
 	while (rfbIsActive(server)) {