Re: [PATCH] hw/i8254: fix vmstate load

[Dr. David Alan Gilbert]

* Pavel Dovgalyuk (pavel.dovgalyuk@ispras.ru) wrote:
> QEMU timer of channel 0 in i8254 is used to raise irq
> at the specified moment of time. This irq can be disabled
> with irq_disabled flag. But when vmstate of the pit is
> loaded, timer may be rearmed despite the disabled interrupts.
> This patch adds irq_disabled flag check to fix that.
> 
> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>

Hi Pavel,
  I'm curious, did you see this cause a problem on a particular guest
OS?

Dave

> ---
>  hw/timer/i8254.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/timer/i8254.c b/hw/timer/i8254.c
> index c01ee2c72a..c8388ea432 100644
> --- a/hw/timer/i8254.c
> +++ b/hw/timer/i8254.c
> @@ -324,7 +324,7 @@ static void pit_post_load(PITCommonState *s)
>  {
>      PITChannelState *sc = &s->channels[0];
>  
> -    if (sc->next_transition_time != -1) {
> +    if (sc->next_transition_time != -1 && !sc->irq_disabled) {
>          timer_mod(sc->irq_timer, sc->next_transition_time);
>      } else {
>          timer_del(sc->irq_timer);
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK