"Gonglei (Arei)" <arei.gong...@huawei.com> wrote:
>> Hi,
>>
>> > Anything bigger than 16bytes, no? And that is the whole point that we
>> > are talking about? Or the 16bytes that we are using can be at any place
>> > on the buffer?
>>
>> Yes. It's a ring buffer, with rptr pointing to the first used element
>> and wptr pointing to the first free element.
>>
>> So, what we need is a function to move the content we are interested
>> (between rptr and wptr) in to the head of the ring buffer, set rptr to
>> 0, set wptr to count. We obviously need to do that in post_load(), but
>> as I've noticed meanwhile also in pre_save, otherwise old qemu will get
>> things wrong in case the buffer is wrapped (rptr > wptr).
>>
> Hi, Gerd. Maybe we just need to do in post_load(). Such as the follow code:
>
> static int ps2_kbd_post_load(void* opaque, int version_id)
> {
> PS2KbdState *s = (PS2KbdState*)opaque;
cast not needed.
> PS2State *ps2 = &s->common;
> PS2Queue *q = &ps2->queue;
> int size;
> int i;
>
> if (version_id == 2)
> s->scancode_set=2;
> /* the new version id for this patch */
> if (version_id == 4) {
> return 0;
> }
> /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */
> size = MIN(q->count, PS2_QUEUE_SIZE);
> printf(" ==kbd: rptr: %d, wptr: %d, count: %d, size: %d\n", q->rptr,
> q->wptr, q->count, size);
> for (i = 0; i < size; i++) {
> /* move the queue elements to the start of data array */
> q->data[i] = q->data[q->rptr];
It is me, or this don't work if the destination and source regions
overlap? Yes, it depens on how it overlaps.
> if (++q->rptr == 256) {
> q->rptr = 0;
> }
> }
> /* reset rptr/wptr/count */
> q->rptr = 0;
> q->wptr = size;
> q->count = size;
> ps2->update_irq(ps2->update_arg, q->count != 0);
>
> return 0;
> }
> Any problem? Thanks.
>
> Best regards,
> -Gonglei
