[CentOS-virt] new libvirt: CentOS 6.2 versus 6.0

Thu Feb 23 01:24:17 UTC 2012
Bradley <bradley at stygianresearch.com>

On Thu, February 16, 2012 1:24 pm, Dmitry E. Mikhailov wrote:
> Hi,
>
> About half a year ago I installed a stock CentOS 6.0/64bit onto an Intel
> server to virtualize our Linux fileserver and four WinXP boxes with rdp each.
>
> Since recent times I didn't do any upgrades of the server's OS. Now I have
> CentOS 6.2.
>
> After an upgrade I noticed that all virtual cpu name changed to
> QEMU Virtual CPU version (cpu64-rhel6)
>
> Second, a killer app on one of WinXP servers stopped working since upgrade.
> It's a russian proprietary accounting app named 1C ver. 8.1 (1cv8.exe). It
> would just hang loading single virtual CPU to 100%. I traced by
> trial-and-error that the problem is related to virtual CPU identification.
> Following solution would help:
>   <cpu match='exact'>
>     <model>Penryn</model>
>     <vendor>Intel</vendor>
>     <feature policy='require' name='tm2'/>
>     <feature policy='require' name='est'/>
>     <feature policy='require' name='monitor'/>
>     <feature policy='require' name='ds'/>
>     <feature policy='require' name='ss'/>
>     <feature policy='require' name='vme'/>
>     <feature policy='require' name='ht'/>
>     <feature policy='require' name='dca'/>
>     <feature policy='require' name='pbe'/>
>     <feature policy='require' name='tm'/>
>     <feature policy='require' name='vmx'/>
>     <feature policy='require' name='ds_cpl'/>
>     <feature policy='require' name='xtpr'/>
>     <feature policy='require' name='acpi'/>
>     <feature policy='disable' name='nx'/>
>     <feature policy='disable' name='pae'/>
>   </cpu>
> It wasn't working before I disabled PAE and NX.
> Double checked. If I delete <cpu> part and thus leave it 'default', the
> application won't work.

Dmitry,

I'd like to thank you for this post.  I was having the same issue as your number 2.  For me, it
was an application running on windows 7, but the description of it loading at 100% was exact.  I
too went down the path of the virtual cpu change and setting the cpu type.  I never managed to
solve it until i say your post.  I had the exact same require settings, but no disable settings. 
For my app, all I had to do was disable NX.  I still have PAE enabled.  Rather I have the generic
feature enabled instead of tied to a CPU.

Up until now, I had marked it down as bios issue, since I believe the bios had changed from centos
5.7 to 6.2.

I had put the issue on a back burner since it wasn't a critical app and I was able to run in on a
physical windows 7 box.

Have you checked /usr/share/qemu-kvm/cpu-model/cpu-x86_64.conf to see what has changed from 6.0 to
6.2?  The equivalent doesn't exist on my centos 5.7 box, so I'm having trouble determining the
defaults from 5.7.

Brad
--
Bradley Leonard
EMail:  bradley at stygianresearch.com

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