[Qemu-devel] [PATCH]MC146818 RTC: Get correct guest time when irq coalesced

["zhongjun@sangfor.com.cn" <zhongjun@sangfor.com.cn>]

Hi, Paolo
This is another patch arround RTC. Would you please have a review.

------------------separation-------------------------------------------------

MC146818 RTC: Get correct guest time when irq coalesced

When irq coalesce occurred, irq_coalesced actually store the seconds
that the time sawn in guest lags behind real guest virtual time.
At this time , if guest read cmos for virtual time, it shouldn't see
those delayed seconds, so we must substract irq_coalesced from guest 
virtual time. Otherwise, after seconds queued in irq_coalesced applied
to guest, time in guest will go ahead of time it should be.

---
 hw/timer/mc146818rtc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 1df17af..4cb8e5e 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -549,6 +549,8 @@ static void rtc_set_time(RTCState *s)
     rtc_get_time(s, &tm);
     s->base_rtc = mktimegm(&tm);
     s->last_update = qemu_clock_get_ns(rtc_clock);
+ s->irq_coalesced = 0;
+ s->irq_reinject_on_ack_count = 0;
 
     qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
 }
@@ -585,6 +587,7 @@ static void rtc_update_time(RTCState *s)
 
     guest_nsec = get_guest_rtc_ns(s);
     guest_sec = guest_nsec / NANOSECONDS_PER_SECOND;
+ guest_sec -= s->irq_coalesced;
     gmtime_r(&guest_sec, &ret);
 
     /* Is SET flag of Register B disabled? */
-- 
2.9.0.windows.1