From d13c0404092eb46e548754a47a808da1bb8d4fd0 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 22 Dec 2014 08:55:19 +0100 Subject: pckbd: set bits 2-3-6-7 of the output port by default OSes typically write 0xdd/0xdf to turn the A20 line off and on. This has bits 2-3-6-7 on, so that the output port subsection is migrated. Change the reset value and migration default to include those four bits, thus avoiding that the subsection is migrated. This strictly speaking changes guest ABI, but the long time during which we have not migrated the value means that the guests really do not care much; so the change is for all machine types. Reported-by: Igor Mammedov Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini --- hw/input/pckbd.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'hw/input') diff --git a/hw/input/pckbd.c b/hw/input/pckbd.c index 2b0cd3d..9b9a7d7 100644 --- a/hw/input/pckbd.c +++ b/hw/input/pckbd.c @@ -101,6 +101,12 @@ #define KBD_OUT_OBF 0x10 /* Keyboard output buffer full */ #define KBD_OUT_MOUSE_OBF 0x20 /* Mouse output buffer full */ +/* OSes typically write 0xdd/0xdf to turn the A20 line off and on. + * We make the default value of the outport include these four bits, + * so that the subsection is rarely necessary. + */ +#define KBD_OUT_ONES 0xcc + /* Mouse Commands */ #define AUX_SET_SCALE11 0xE6 /* Set 1:1 scaling */ #define AUX_SET_SCALE21 0xE7 /* Set 2:1 scaling */ @@ -367,13 +373,13 @@ static void kbd_reset(void *opaque) s->mode = KBD_MODE_KBD_INT | KBD_MODE_MOUSE_INT; s->status = KBD_STAT_CMD | KBD_STAT_UNLOCKED; - s->outport = KBD_OUT_RESET | KBD_OUT_A20; + s->outport = KBD_OUT_RESET | KBD_OUT_A20 | KBD_OUT_ONES; s->outport_present = false; } static uint8_t kbd_outport_default(KBDState *s) { - return KBD_OUT_RESET | KBD_OUT_A20 + return KBD_OUT_RESET | KBD_OUT_A20 | KBD_OUT_ONES | (s->status & KBD_STAT_OBF ? KBD_OUT_OBF : 0) | (s->status & KBD_STAT_MOUSE_OBF ? KBD_OUT_MOUSE_OBF : 0); } -- cgit v1.1