From: Paolo Bonzini <pbonzini@redhat.com>
To: "Zhang, Yang Z" <yang.z.zhang@intel.com>
Cc: "aliguori@us.ibm.com" <aliguori@us.ibm.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Shan, Haitao" <haitao.shan@intel.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"avi@redhat.com" <avi@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 3/3] stop the periodic RTC update timer
Date: Mon, 09 Jan 2012 09:19:02 +0100 [thread overview]
Message-ID: <4F0AA2F6.20005@redhat.com> (raw)
In-Reply-To: <A9667DDFB95DB7438FA9D7D576C3D87E018CDB@SHSMSX101.ccr.corp.intel.com>
On 01/06/2012 08:37 AM, Zhang, Yang Z wrote:
> VMSTATE_BUFFER(cmos_data, RTCState),
> VMSTATE_UINT8(cmos_index, RTCState),
> - VMSTATE_INT32(current_tm.tm_sec, RTCState),
> - VMSTATE_INT32(current_tm.tm_min, RTCState),
> - VMSTATE_INT32(current_tm.tm_hour, RTCState),
> - VMSTATE_INT32(current_tm.tm_wday, RTCState),
> - VMSTATE_INT32(current_tm.tm_mday, RTCState),
> - VMSTATE_INT32(current_tm.tm_mon, RTCState),
> - VMSTATE_INT32(current_tm.tm_year, RTCState),
> + VMSTATE_INT64(offset, RTCState),
> VMSTATE_TIMER(periodic_timer, RTCState),
> VMSTATE_INT64(next_periodic_time, RTCState),
> - VMSTATE_INT64(next_second_time, RTCState),
> - VMSTATE_TIMER(second_timer, RTCState),
> - VMSTATE_TIMER(second_timer2, RTCState),
> + VMSTATE_TIMER(update_timer, RTCState),
> + VMSTATE_INT64(next_update_time, RTCState),
> + VMSTATE_TIMER(alarm_timer, RTCState),
> + VMSTATE_INT64(next_alarm_time, RTCState),
Hi Yang,
this looks like a very nice piece of work, but this unfortunately breaks
migration. Also, I'm not sure if the update in progress flag still
works. Clients are supposed to wait for UIP=0 before reading the RTC,
and an update is supposed to be at least 220 microseconds away when UIP=0.
Also, it would be nice if you could based these patches on the 4-patch
series I sent recently that fixes some bugs with interrupts and 12-hour
emulation.
There is another aspect of RTC emulation that is missing in the current
code; after setting the clock, the next second tick will occur in
exactly 500 ms. I have patches to fix this, but it looks like it could
be incorporated in your series, too.
Paolo
next prev parent reply other threads:[~2012-01-09 8:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-06 7:37 [Qemu-devel] [PATCH 3/3] stop the periodic RTC update timer Zhang, Yang Z
2012-01-06 17:26 ` Jan Kiszka
2012-01-09 7:10 ` Zhang, Yang Z
2012-01-09 8:19 ` Paolo Bonzini [this message]
2012-01-10 6:37 ` Zhang, Yang Z
2012-01-10 9:24 ` Paolo Bonzini
2012-01-11 0:56 ` Zhang, Yang Z
2012-01-11 7:24 ` Paolo Bonzini
2012-01-12 0:51 ` Zhang, Yang Z
2012-01-11 7:25 ` Philipp Hahn
2012-01-11 13:10 ` Marcelo Tosatti
2012-01-12 0:00 ` Zhang, Yang Z
2012-01-12 9:26 ` Paolo Bonzini
2012-01-12 10:20 ` Marcelo Tosatti
2012-01-12 10:43 ` Paolo Bonzini
2012-01-12 9:59 ` Marcelo Tosatti
2012-01-12 10:03 ` Marcelo Tosatti
2012-01-12 10:12 ` Zhang, Yang Z
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