From 4e9bddcbaa74e2463f0a79350fea5311c9890982 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Volker=20R=C3=BCmelin?= Date: Tue, 10 Aug 2021 15:32:58 +0200 Subject: [PATCH] ps2: migration support for command reply queue MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Add migration support for the PS/2 keyboard command reply queue. Signed-off-by: Volker Rümelin Message-Id: <20210810133258.8231-3-vr_qemu@t-online.de> Signed-off-by: Gerd Hoffmann --- hw/input/ps2.c | 40 ++++++++++++++++++++++++++++++++++------ 1 file changed, 34 insertions(+), 6 deletions(-) diff --git a/hw/input/ps2.c b/hw/input/ps2.c index 8c06fd7fb4..9376a8f4ce 100644 --- a/hw/input/ps2.c +++ b/hw/input/ps2.c @@ -80,6 +80,7 @@ */ #define PS2_BUFFER_SIZE 256 #define PS2_QUEUE_SIZE 16 /* Queue size required by PS/2 protocol */ +#define PS2_QUEUE_HEADROOM 8 /* Queue size for keyboard command replies */ /* Bits for 'modifiers' field in PS2KbdState */ #define MOD_CTRL_L (1 << 0) @@ -985,17 +986,27 @@ static void ps2_common_reset(PS2State *s) static void ps2_common_post_load(PS2State *s) { PS2Queue *q = &s->queue; + int ccount = 0; - /* set the useful data buffer queue size <= PS2_QUEUE_SIZE */ - if (q->count < 0) { - q->count = 0; - } else if (q->count > PS2_QUEUE_SIZE) { - q->count = PS2_QUEUE_SIZE; + /* limit the number of queued command replies to PS2_QUEUE_HEADROOM */ + if (q->cwptr != -1) { + ccount = (q->cwptr - q->rptr) & (PS2_BUFFER_SIZE - 1); + if (ccount > PS2_QUEUE_HEADROOM) { + ccount = PS2_QUEUE_HEADROOM; + } + } + + /* limit the scancode queue size to PS2_QUEUE_SIZE */ + if (q->count < ccount) { + q->count = ccount; + } else if (q->count > ccount + PS2_QUEUE_SIZE) { + q->count = ccount + PS2_QUEUE_SIZE; } - /* sanitize rptr and recalculate wptr */ + /* sanitize rptr and recalculate wptr and cwptr */ q->rptr = q->rptr & (PS2_BUFFER_SIZE - 1); q->wptr = (q->rptr + q->count) & (PS2_BUFFER_SIZE - 1); + q->cwptr = ccount ? (q->rptr + ccount) & (PS2_BUFFER_SIZE - 1) : -1; } static void ps2_kbd_reset(void *opaque) @@ -1086,6 +1097,22 @@ static const VMStateDescription vmstate_ps2_keyboard_need_high_bit = { } }; +static bool ps2_keyboard_cqueue_needed(void *opaque) +{ + PS2KbdState *s = opaque; + + return s->common.queue.cwptr != -1; /* the queue is mostly empty */ +} + +static const VMStateDescription vmstate_ps2_keyboard_cqueue = { + .name = "ps2kbd/command_reply_queue", + .needed = ps2_keyboard_cqueue_needed, + .fields = (VMStateField[]) { + VMSTATE_INT32(common.queue.cwptr, PS2KbdState), + VMSTATE_END_OF_LIST() + } +}; + static int ps2_kbd_post_load(void* opaque, int version_id) { PS2KbdState *s = (PS2KbdState*)opaque; @@ -1114,6 +1141,7 @@ static const VMStateDescription vmstate_ps2_keyboard = { .subsections = (const VMStateDescription*[]) { &vmstate_ps2_keyboard_ledstate, &vmstate_ps2_keyboard_need_high_bit, + &vmstate_ps2_keyboard_cqueue, NULL } }; -- 2.11.4.GIT