Re: [PATCH 09/10] pckbd: correctly disable PS/2 communication

[Philippe Mathieu-Daudé]

Hi Volker,

On 5/5/21 9:21 PM, Volker Rümelin wrote:
> Currently the PS/2 controller command KBD_CCMD_MOUSE_DISABLE
> doesn't disable the PS/2 mouse communication at all, and the
> PS/2 controller commands KBD_CCMD_KBD_DISABLE and
> KBD_CCMD_KBD_ENABLE disable and enable the keyboard interrupt,
> which is very different from what a real PS/2 controller does.
> A guest may notice the difference.
> 
> Mask out pending data on disabled queues to correctly disable
> the PS/2 controller communication.
> 
> Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
> ---
>  hw/input/pckbd.c | 48 +++++++++++++++++++++++++++++++++++-------------
>  1 file changed, 35 insertions(+), 13 deletions(-)

> +static uint8_t kbd_pending(KBDState *s)
> +{
> +    return s->pending & (~s->mode | ~(KBD_PENDING_KBD | KBD_PENDING_AUX));
> +}

Please introduce kbd_pending() in a preliminary patch.

>  /* update irq and KBD_STAT_[MOUSE_]OBF */
>  static void kbd_update_irq(KBDState *s)
>  {
> +    uint8_t pending = kbd_pending(s);
> +
>      s->status &= ~(KBD_STAT_OBF | KBD_STAT_MOUSE_OBF);
>      s->outport &= ~(KBD_OUT_OBF | KBD_OUT_MOUSE_OBF);
> -    if (s->pending) {
> +    if (pending) {
>          s->status |= KBD_STAT_OBF;
>          s->outport |= KBD_OUT_OBF;
> -        if (s->pending & KBD_PENDING_CTRL_KBD) {
> +        if (pending & KBD_PENDING_CTRL_KBD) {
>              s->obsrc = KBD_OBSRC_CTRL;