[libvirt] [PATCH] Enable support for nested SVM

[Daniel P. Berrange]

On Wed, Sep 22, 2010 at 02:19:06PM -0400, Dave Allan wrote:
> On Wed, Sep 22, 2010 at 05:47:42PM +0100, Daniel P. Berrange wrote:
> > This enables support for nested SVM using the regular CPU
> > model/features block. If the CPU model or features include
> > 'svm' or 'vmx', then the '-enable-nesting' flag will be
> > added to the QEMU command line. Several of the models
> > already include svm support, but QEMU was just masking out
> > the svm bit silently. So this will enable SVM on such
> > models
> 
> I'm very glad to see this patch, as I've wanted to run nested VMs on
> my development VM for a while.  Can you give a little more information
> on what's required to run a nested VM?

On a host with SVM, simply copy the <cpu> block from the
virsh capabilities output into your guest config. This
should already include the SVM feature flag, either
explicitly, or as part of the model (eg Phenom includes
svm). You need KVM > 0.10.5.

You're out of luck with VMX for now. There are patches on
kvm mailing list, but they're still being discussed with
some people questioning whether it should be done at all :-(

Daniel
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