KVM-86 not exposing 64 bits CPU anymore, NICE

KVM-86 not exposing 64 bits CPU anymore, NICE

[Gilles PIETRI]

Hi,

I'm quite pissed off. I just upgraded to kvm-86 on a host that has 
worked nicely on kvm-78 for quite some time. But since I was fearing the 
qcow2 corruption issues, I wanted to upgrade kvm-86. After testing the 
performance, I decided to switch. How stupid that was. That was really 
putting too much trust in KVM.

Now I can't have 64 bits CPUs on my guests.
My host is running a 2.6.27.7 kernel, and is x86_64 enabled.
Until the upgrade, guests were running x86_64 fine.
Now, it says long mode can't be used or something like that, and I can 
only have 32 bits guests.

Looks really like the bug explained here: 
http://www.mail-archive.com/kvm@vger.kernel.org/msg09431.html

If I use -no-kvm, it works, but obviously, I want to be able to have kvm 
support enabled.

Now, I really am happy about this upgrade, and I'm gonna have to roll it 
back. I really would appreciate some help on this..

Gilles

Re: KVM-86 not exposing 64 bits CPU anymore, NICE

[Jim Paris]

Gilles PIETRI wrote:
> Hi,
>
> I'm quite pissed off. I just upgraded to kvm-86 on a host that has  
> worked nicely on kvm-78 for quite some time. But since I was fearing the  
> qcow2 corruption issues, I wanted to upgrade kvm-86. After testing the  
> performance, I decided to switch. How stupid that was. That was really  
> putting too much trust in KVM.
>
> Now I can't have 64 bits CPUs on my guests.
> My host is running a 2.6.27.7 kernel, and is x86_64 enabled.
> Until the upgrade, guests were running x86_64 fine.
> Now, it says long mode can't be used or something like that, and I can  
> only have 32 bits guests.

Please see
  http://www.mail-archive.com/kvm@vger.kernel.org/msg15757.html
  http://www.mail-archive.com/kvm@vger.kernel.org/msg15769.html

-jim

Re: KVM-86 not exposing 64 bits CPU anymore, NICE

[Alexey Eromenko]

----- "Gilles PIETRI" <contact+dev@gilouweb.com> wrote:

> Hi,
> 
> I'm quite pissed off. I just upgraded to kvm-86 on a host that has 
> worked nicely on kvm-78 for quite some time. But since I was fearing
> the 
> qcow2 corruption issues, I wanted to upgrade kvm-86. After testing the
> 
> performance, I decided to switch. How stupid that was. That was really
> 
> putting too much trust in KVM.
> 
> Now I can't have 64 bits CPUs on my guests.
> My host is running a 2.6.27.7 kernel, and is x86_64 enabled.
> Until the upgrade, guests were running x86_64 fine.
> Now, it says long mode can't be used or something like that, and I can
> 
> only have 32 bits guests.
> 
> Looks really like the bug explained here: 
> http://www.mail-archive.com/kvm@vger.kernel.org/msg09431.html
> 
> If I use -no-kvm, it works, but obviously, I want to be able to have
> kvm 
> support enabled.
> 
> Now, I really am happy about this upgrade, and I'm gonna have to roll
> it 
> back. I really would appreciate some help on this..
> 
> Gilles

Hi Gilles,

What are you saying is very strange, because KVM-Autotest has passed all tests for KVM-86 release,
and I can say that 64-bit guests work here. (both Intel & AMD, on RHEL 5.3/x64)

-Alexey

Re: KVM-86 not exposing 64 bits CPU anymore, NICE

[Gilles PIETRI]

Le 04/06/2009 09:46, Jim Paris a écrit :
> Gilles PIETRI wrote:
>> Hi,
>>
>> I'm quite pissed off. I just upgraded to kvm-86 on a host that has  
>> worked nicely on kvm-78 for quite some time. But since I was fearing the  
>> qcow2 corruption issues, I wanted to upgrade kvm-86. After testing the  
>> performance, I decided to switch. How stupid that was. That was really  
>> putting too much trust in KVM.
>>
>> Now I can't have 64 bits CPUs on my guests.
>> My host is running a 2.6.27.7 kernel, and is x86_64 enabled.
>> Until the upgrade, guests were running x86_64 fine.
>> Now, it says long mode can't be used or something like that, and I can  
>> only have 32 bits guests.
> 
> Please see
>   http://www.mail-archive.com/kvm@vger.kernel.org/msg15757.html
>   http://www.mail-archive.com/kvm@vger.kernel.org/msg15769.html
> 
> -jim

Gonna check that, thanks a lot, this didn't get on my radar..

Regards,

Gilles

Re: KVM-86 not exposing 64 bits CPU anymore, NICE

[Mark McLoughlin]

On Thu, 2009-06-04 at 09:20 +0200, Gilles PIETRI wrote:

> I'm quite pissed off. I just upgraded to kvm-86 on a host that has 
> worked nicely on kvm-78 for quite some time. But since I was fearing the 
> qcow2 corruption issues, I wanted to upgrade kvm-86. After testing the 
> performance, I decided to switch. How stupid that was. That was really 
> putting too much trust in KVM.

Jim has already responded with details on the first for the particular
issue, but speaking more generally ...

The kvm-XX releases are snapshots of the development tree. They do not
go to through the kind of stabilisation cycle you would expect from a
new kernel release, for example.

If you want a KVM version you can trust, use the latest qemu-kvm-0.x.y
release with the stock version of kvm.ko that comes with your kernel or,
if you need particular new features, the latest kvm-kmod-2.6.z release.

Cheers,
Mark.