qemu discuss - Jun 2007 - High CPU usage while Windows in QEMU idles

Well, I''m just going to ask here, since over at the QEMU forums, no one
seems to have a clue.

I have QEMU 0.9 and kqemu 0.1.3pre11 compiled and running fine and apparently
stable here on SXCE b65 x64. The VM hosts Windows Server 2003 x64, working fine
with user kqemu (kernel kqemu sends the VM into a boot loop).

When I''m done booting Windows, looking at vmstat, the VM is hogging one
of my cores, eating all its CPU time, while the Windows instance itself is
running idle.
>From what I''ve read, the lack of kernel kqemu is supposedly the
issue, but I kind of don''t buy this. What could be the problem?
Also, does kernel kqemu not work with 64bit operating systems? Would I be better
advised to install a 32bit variant of Windows? Reading various posts on the web,
people claim to be running 64bit systems with kernel kqemu fine.

Thanks,
-mg
--
This message posted from opensolaris.org

Have you tried looking at qemu''s debugging facilities to get some idea
of what
you''re doing in Windows?  (i.e. is it in a tight polling loop for
something?)

Mario Goebbels wrote:
> Well, I''m just going to ask here, since over at the QEMU forums,
no one seems to have a clue.
> 
> I have QEMU 0.9 and kqemu 0.1.3pre11 compiled and running fine and
apparently stable here on SXCE b65 x64. The VM hosts Windows Server 2003 x64,
working fine with user kqemu (kernel kqemu sends the VM into a boot loop).
> 
> When I''m done booting Windows, looking at vmstat, the VM is
hogging one of my cores, eating all its CPU time, while the Windows instance
itself is running idle.
> 
>>From what I''ve read, the lack of kernel kqemu is supposedly the
issue, but I kind of don''t buy this. What could be the problem?
> 
> Also, does kernel kqemu not work with 64bit operating systems? Would I be
better advised to install a 32bit variant of Windows? Reading various posts on
the web, people claim to be running 64bit systems with kernel kqemu fine.
> 
> Thanks,
> -mg
> --
> This message posted from opensolaris.org
> _______________________________________________
> qemu-discuss mailing list
> qemu-discuss at opensolaris.org
> http://opensolaris.org/mailman/listinfo/qemu-discuss

> Have you tried looking at qemu''s debugging facilities
> to get some idea of what 
> you''re doing in Windows?  (i.e. is it in a tight
> polling loop for something?)
How would I go about doing this?

-mg
--
This message posted from opensolaris.org

Well, I kind of fixed it. It appears that the ACPI implementation in QEMU is a
bit wonky. Downgrading to 32bit Windows got me the same problems, so
I''ve installed it again with -no-acpi, and now the Windows VM eats less
than 1.5 percent CPU time when completely idle.

-mg
--
This message posted from opensolaris.org