[Qemu-devel] [PATCH v1 5/9] ps2: fix scancodes sent for Shift/Ctrl+Print key combination

["Daniel P. Berrange" <berrange@redhat.com>]

The 'Print' key is special in the AT set 1 / set 2 scancode definitions.

An unmodified 'Print' key is supposed to send

 AT Set 1:  e0 2a e0 37 (Down)  e0 b7 e0 aa (Up)
 AT Set 2:  e0 12 e0 7c (Down)  e0 f0 7c e0 f0 12 (Up)

which QEMU gets right. When combined with Shift/Ctrl (both left and right
variants), the leading two bytes should be dropped, resulting in

 AT Set 1:  e0 37 (Down)  e0 b7 (Up)
 AT Set 2:  e0 7c (Down)  e0 f0 7c (Up)

This difference is pretty benign, since of all the operating systems I have
checked (Linux, FreeBSD and OpenStack), none bother to check the leading two
bytes anyway. This change none the less makes the ps2 device better follow real
hardware behaviour.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 hw/input/ps2.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 1e6f6ae9b6..c35b410e4d 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -674,6 +674,15 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,
                     ps2_put_keycode(s, 0xe0);
                     ps2_put_keycode(s, 0x38);
                 }
+            } else if (s->modifiers & (MOD_SHIFT_L | MOD_CTRL_L |
+                                       MOD_SHIFT_R | MOD_CTRL_R)) {
+                if (key->down) {
+                    ps2_put_keycode(s, 0xe0);
+                    ps2_put_keycode(s, 0x37);
+                } else {
+                    ps2_put_keycode(s, 0xe0);
+                    ps2_put_keycode(s, 0xb7);
+                }
             } else {
                 if (key->down) {
                     ps2_put_keycode(s, 0xe0);
@@ -745,6 +754,16 @@ static void ps2_keyboard_event(DeviceState *dev, QemuConsole *src,
                     ps2_put_keycode(s, 0xe0);
                     ps2_put_keycode(s, 0x11);
                 }
+            } else if (s->modifiers & (MOD_SHIFT_L | MOD_CTRL_L |
+                                       MOD_SHIFT_R | MOD_CTRL_R)) {
+                if (key->down) {
+                    ps2_put_keycode(s, 0xe0);
+                    ps2_put_keycode(s, 0x7c);
+                } else {
+                    ps2_put_keycode(s, 0xe0);
+                    ps2_put_keycode(s, 0xf0);
+                    ps2_put_keycode(s, 0x7c);
+                }
             } else {
                 if (key->down) {
                     ps2_put_keycode(s, 0xe0);
-- 
2.13.6