Re: [Qemu-devel] [PATCH 1/4] xen: introduce mc146818rtcxen

[Paolo Bonzini]

On 11/18/2011 03:54 PM, Anthony Liguori wrote:
> The Right Solution would be to modify the RTC emulation such that it did
> a qemu_get_clock() during read of the CMOS registers in order to ensure
> the time was up to date (instead of using 1 second timers).

True, but you also have to handle UIP and the UF/AF interrupts. 
Basically you have to track the various pieces of state and trigger a 
timer when the routine would do something interesting.  It's not hard, 
but it's also a decent amount of programming.

Paolo