>>> inter>
>>> rupts)|(timer)
>>> configuration file options and I was wondering if you could help me with
>>> it.
>>>
>>> * I know that Xen has a facility on the user domains to change the
>>> timing from something called the '
http://openskill.info/infobox.php?ID=1451
>>> independent wallclock ' to 'dependent clock' and vice versa. The way to do
>>> this is to toggle the parameter /proc/sys/xen/independent_wallclock between
>>> 0 (dependent) and 1 (independent)
>>>
>>>
>>> * Now, the documentation on the configuration options for xen virtual
>>> machine under the heading of Timers contains no mention of the above
>>> mentioned facility, but instead talks about something called a 'timer_mode'
>>>
>>>
>>> timer_mode: Timer mode (0=delay virtual time when ticks are missed;
>>> 1=virtual time is always wallclock time
>>> timer_mode (default=1; Value='TIMER_MODE')
>>>
>>> Now my question is whether the timer mode = 1 is equivalent to independent_
>>> wallclock?
>>>
>>> I think the answer is no. While timer_mode = 1 decides whether the virtual
>>> machine is able to read the Domain-0 time, the independent_wallclock decides
>>> whether you need NTP sychronization on both (user and control) domains or
>>> not.
>>>
>>> Namely, in the timer_mode = 1, the gettimeofday() called from the virtual
>>> machine will return the domain virtual time, but time_mode = 0
>>> gettimeofday() instruction from the virtual machine will return the system
>>> time.
>>>
>>> The independent and dependent modes have an effect on whether the virtual
>>> machines can use the NTP or any other synchronization of Domain-0.
>>>
>>> Is my understanding correct?
>>>
>>> I further want to know whether the working remains similar on Xen HVMs also.
>>> In the sense that are Hardware based virtual machines capable of reading the
>>> Domain-0 system time in an analogous way?
>>>
>>>
>>> Your help would be much appreciated. I am new to this area and I apologize
>>> if my questions seem too basic.
>>
>>
>>
>
>
