Re: [Qemu-devel] [Patch] [kinda-resend] persistent real-time-clock

[Avi Kivity <avi@qumranet.com>]

Dan Kenigsberg wrote:
> On Sun, Apr 27, 2008 at 07:39:42PM +0300, Avi Kivity wrote:
>   
>> Dan Kenigsberg wrote:
>>     
>>> Real PC lets its user set the real-time-clock and store it on CMOS,
>>> which advances the clock even when the PC is offline.
>>>
>>> These patches will allow doing the same with VM:
>>> - Before shutting a VM down, use the monitor's info timeoffset to see
>>>   how much (in seconds) does the rtc differ from the host clock.
>>> - Store this offset somewhere.
>>> - Use it next time with -startdate now+offset.
>>>
>>> Please tell me what do you think of it.
>>>   
>>>       
>> How about (additionally) modifying -startdate to accept an offset directly?
>>
>>   qemu -startdate +0300 ...
>>
>> Useful for those Windows VMs which have localtime in cmos.
>>     
>
> I'm missing somthing: in what way is it different than the suggested
>
>     qemu -startdate now+offset ?
>
> Only in allowing to specify the offset in hours/minutes?
>
>   

The difference is that I didn't read your patch, only the description.

I assumed you meant the user calculates now + offset and enters the 
result as the argument to -startdate, but you're not doing that.  Sorry 
for the noise.

-- 
Any sufficiently difficult bug is indistinguishable from a feature.