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KVM-86 not exposing 64 bits CPU anymore, NICE

DISCUSSION Gilles PIETRI 4 participants 5 messages Jun 4, 2009 KVM

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Gilles PIETRI

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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/[email protected]/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

#1 lore raw
Quoted 8 lines · 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.

Quoted 5 lines

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/[email protected]/msg15757.html
http://www.mail-archive.com/[email protected]/msg15769.html

-jim

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#2 lore raw
Quoted 10 lines · Jim Paris
Quoted 8 lines · 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.

Quoted 5 lines

Please see
http://www.mail-archive.com/[email protected]/msg15757.html
http://www.mail-archive.com/[email protected]/msg15769.html

-jim

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

Regards,

Gilles

#3 lore raw
In reply to Gilles PIETRI
Quoted 25 lines · ----- "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/[email protected]/msg09431.html

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

Quoted 5 lines

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

#4 lore raw
In reply to Gilles PIETRI
Quoted 5 lines · Gilles PIETRI

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.