[sles-beta] A Problem with KVM Guest ?

[Antoine Ginies]

Günther J. Niederwimmer:
> Am Donnerstag, 4. September 2014, 13:57:01 schrieb Antoine Ginies:
> > Günther J. Niederwimmer:
> > > Am Donnerstag, 4. September 2014, 12:24:02 schrieb Antoine Ginies:
> > > > Günther J. Niederwimmer:
> > > > > Hello,
> > > > > I found a Problem with KVM_clock?
> > > > > on my Installation I have a KVM Server and KVM Clients all SLES 12
> > > > > Server
> > > > > The KVM Host have a NTP Server configured and have a correct time
> > > > > 
> > > > > date
> > > > > Don Sep  4 12:00:19 CEST 2014
> > > > > all clients have this Time
> > > > > date
> > > > > Don Sep  4 02:15:24 CEST 2014
> > > > > 
> > > > > the timezone is correct but the time is wrong ?
> > > > 
> > > > Hello,
> > > > Can you check that your VM is currently using kvm_clock?
> > > 
> > > akerb:~ # dmesg | grep kvm-clock
> > > [    0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00
> > > [    0.000000] kvm-clock: cpu 0, msr 1:3ff18001, boot clock
> > > [    0.000000] kvm-clock: cpu 0, msr 1:3ff18001, primary cpu clock
> > > [    0.004000] kvm-clock: cpu 1, msr 1:3ff18041, secondary cpu clock
> > > [    0.004000] kvm-clock: cpu 2, msr 1:3ff18081, secondary cpu clock
> > > [    0.004000] kvm-clock: cpu 3, msr 1:3ff180c1, secondary cpu clock
> > > [    0.134685] Switched to clocksource kvm-clock
> > > 
> > > This is the client
> > > 
> > > root# cat /sys/devices/system/clocksource/clocksource0/current_clocksource
> > 
> > You forget the value, but according to dmesg it was kvm-clock at
> > 0.134685 until something else has switched to another value.
> 
> I mean we miss understand  use
> 
> The behind is from a CLIENT

kvm-clock clocksource is for the VM guest.

> This is from the HOST !!

The host doesn't provide kvm-clock source:
-----------------------------------------
root # cat /sys/devices/system/clocksource/clocksource0/available_clocksource
tsc hpet acpi_pm 
-----------------------------------------

It's tsc by default.
So everything is ok.

regards.

> 
>  dmesg | grep clocksource
> [    0.560063] Switched to clocksource hpet
> [    2.329666] tsc: Refined TSC clocksource calibration: 3700.000 MHz
> [    3.645349] Switched to clocksource tsc
> 
> and I like to change this for Tests.
> > ------------
> > root # dmesg | grep clocksource
> > ------------
> > will let you know if there is any change.
> > 
> > > I have on the Server
> > > tsc
> > > 
> > > This is a original YaSt Installation
> > > 
> > > can I change this manual ?
> > 
> > On VM guest you can change it with echo:
> > ----------
> > echo tsc > /sys/devices/system/clocksource/clocksource0/current_clocksource
> > echo kvm-clock >
> > /sys/devices/system/clocksource/clocksource0/current_clocksource ----------
> > 
> > You should see a dmesg in the console of your VM guest saying that
> > clocksource has switched.
> 
> Have I to open a SR ?
> 
> -- 
> mit freundlichen Grüßen / best Regards,
> 
>   Günther J. Niederwimmer
> 

-- 
Antoine Ginies <aginies at suse.com>
Project Manager
SUSE France