Re: [Qemu-devel] [Bug 599958] Re: Timedrift problems with Win7: hpet missing time drift fixups

[Gleb Natapov]

On Tue, Oct 01, 2013 at 09:34:06AM -0000, Ben A wrote:
> Apparently this bug's still alive and kicking.
> 
And no plans to fix it. Do not use hpet with windows guests this buys
you nothing.

> There's an obvious clock skew problem on Windows 7; in the Date & Time
> dialog, the clock jumps through seconds visibly too fast.
> 
> I also found a case where HPET bugs are causing a real problem: Terraria
> (dedicated server) seems to be relying on (something that relies on)
> HPET, and QEMU doesn't get it right. The result is a goofy and
> aggravating behavior I've nicknamed "Turbo Monsters of Doom" and it
> makes killing anything tougher than a normal zombie basically
> impossible.
> 
> -- 
> You received this bug notification because you are a member of qemu-
> devel-ml, which is subscribed to QEMU.
> https://bugs.launchpad.net/bugs/599958
> 
> Title:
>   Timedrift problems with Win7: hpet missing time drift fixups
> 
> Status in QEMU:
>   Confirmed
> 
> Bug description:
>   We've been finding timedrift issues witth Win7 under qemu-kvm on our
>   daily testing
> 
>   kvm.qemu-kvm-git.smp2.Win7.64.timedrift.with_load   FAIL    1       Time 
> drift too large after rest period: 38.63%
>   kvm.qemu-kvm-git.smp2.Win7.64.timedrift.with_reboot FAIL    1       Time 
> drift too large at iteration 1: 17.77 seconds
>   kvm.qemu-kvm-git.smp2.Win7.64.timedrift.with_migration      FAIL    1       
> Time drift too large at iteration 2: 3.08 seconds
> 
>   Steps to reproduce:
> 
>   timedrift.with_load
> 
>   1) Log into a guest.
>   2) Take a time reading from the guest and host.
>   3) Run load on the guest and host.
>   4) Take a second time reading.
>   5) Stop the load and rest for a while.
>   6) Take a third time reading.
>   7) If the drift immediately after load is higher than a user-
>       specified value (in %), fail.
>       If the drift after the rest period is higher than a user-specified 
> value,
>       fail.
> 
>   timedrift.with_migration
> 
>   1) Log into a guest.
>   2) Take a time reading from the guest and host.
>   3) Migrate the guest.
>   4) Take a second time reading.
>   5) If the drift (in seconds) is higher than a user specified value, fail.
> 
>   timedrift.with_reboot
> 
>   1) Log into a guest.
>   2) Take a time reading from the guest and host.
>   3) Reboot the guest.
>   4) Take a second time reading.
>   5) If the drift (in seconds) is higher than a user specified value, fail.
> 
>   This bug is to register those issues and keep an eye on them.
> 
>   Attached, some logs from the autotest tests executed on the guest
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/qemu/+bug/599958/+subscriptions

--
                        Gleb.