Re: [Qemu-devel] [PATCH] bugfix: vm halt when in reset looping

[Paolo Bonzini <pbonzini@redhat.com>]

On 14/12/2016 07:48, hangaohuai wrote:
> reset mc146818rtc device when RESET event happens.
> 
> Fix the problem:
>   1. Guest boot the second cpu, set CMOS_RESET_CODE 0x0a to protect selfboot;
>   2. VM being reset by others, hmp_system_reset;
>   3. seabios resume check the CMOS_RESET_CODE, if 0x0a, jump to the BDA
>      resume execution by jump via 40h:0067h;
>   4. Guest halt;
> 
> Signed-off-by: hangaohuai <hangaohuai@huawei.com>

I think this would break S3 resume.

Paolo

> ---
>  hw/timer/mc146818rtc.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
> index da209d0..67d707d 100644
> --- a/hw/timer/mc146818rtc.c
> +++ b/hw/timer/mc146818rtc.c
> @@ -946,11 +946,19 @@ static Property mc146818rtc_properties[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> +static void rtc_resetdev(DeviceState *d)
> +{
> +    RTCState *s = MC146818_RTC(d);
> +
> +    s->cmos_data[0x0f] = 0x00;
> +}
> +
>  static void rtc_class_initfn(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>  
>      dc->realize = rtc_realizefn;
> +    dc->reset = rtc_resetdev;
>      dc->vmsd = &vmstate_rtc;
>      dc->props = mc146818rtc_properties;
>      /* Reason: needs to be wired up by rtc_init() */
>