Re: [Qemu-devel] [PATCH 2/4] i8254: Open-code timer restore

[Paolo Bonzini]

On 02/05/2012 11:46 AM, Jan Kiszka wrote:
> diff --git a/hw/i8254_common.c b/hw/i8254_common.c
> index 0601d88..b60fbda 100644
> --- a/hw/i8254_common.c
> +++ b/hw/i8254_common.c
> @@ -234,9 +234,8 @@ static int pit_load_old(QEMUFile *f, void *opaque, int 
> version_id)
>           qemu_get_8s(f,&s->gate);
>           s->count_load_time = qemu_get_be64(f);
>           s->irq_disabled = 0;
> -        if (s->irq_timer) {
> +        if (i == 0) {
>               s->next_transition_time = qemu_get_be64(f);
> -            qemu_get_timer(f, s->irq_timer);
>           }
>       }
>       return 0;

You need to invoke the post load callback manually in the load_old 
callback; see vmstate_load_state:

    if  (version_id < vmsd->minimum_version_id) {
        return vmsd->load_state_old(f, opaque, version_id);
    }

I noticed that in apic_common's apic_load_old you don't have the bug, 
but on the other hand you're unconditionally loading into s->timer, so 
"old" migration to a destination with in-kernel APIC doesn't work:

    if (version_id >= 2) {
        qemu_get_timer(f, s->timer);
    }

Paolo