[Users] Good enough for KVM but not for OpenVZ 7?

Vasily Averin vvs at virtuozzo.com
Sat Nov 11 09:34:23 MSK 2017

Dear Scott,

thank you for reporting this problem.

As far as I know Centos7 uses some old KVM version. 
OpenVz7 includes newer version and probably can have some additional restrictions?

I've found that your Xeon E5530 was launched Q1'09 and related to Nehalem EP family

So looks like it can lack "Unrestricted guest" feature, however I do now know how important it is for KVM.
I expect it should work but not so effective as newer CPUs.

I've requested comments of our KVM Team, hope they clarify the situation.

Thank you,
	Vasily Averin

On 2017-11-11 01:52, Scott Dowdle wrote:
> Greetings,
> I have a Dell PowerEdge R710 rack mount server.  It is a few years old and it has an Intel Xeon E5530 @ 2.40GHz.  KVM likes it just fine and it passes a virt-host-validate with flying colors but OpenVZ 7's vmxcap says:
> Unrestricted guest    no
> Looking that up I find:
> "VMX Unrestricted Guest is an Intel microprocessor feature that is also called IA-32e mode. Running a VM in this mode requires minimal involvement from software. You can think of it as running a VM bare-metal with its own EPT.  This feature is available only on Westmere processors and later."
> I ended up installing CentOS 7 on it and KVM works fine.
> What's the deal? Why this extra restriction?  :(
> TYL,

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