[libvirt] [PATCH 1/2] Add a new <nesting/> option in the domain config features list.

[Daniel P. Berrange]

On Sun, Nov 08, 2009 at 01:44:02PM -0500, Evan Broder wrote:
> ---
>  docs/formatdomain.html.in |    4 ++++
>  docs/schemas/domain.rng   |    5 +++++
>  src/conf/domain_conf.c    |    3 ++-
>  src/conf/domain_conf.h    |    1 +
>  4 files changed, 12 insertions(+), 1 deletions(-)
> 
> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
> index 72bd7b9..c4eed79 100644
> --- a/docs/formatdomain.html.in
> +++ b/docs/formatdomain.html.in
> @@ -263,6 +263,7 @@
>            <pae/>
>            <acpi/>
>            <apic/>
> +          <nesting/>
>          </features>
>          ...</pre>
>  
> @@ -282,6 +283,9 @@
>        <dd>ACPI is useful for power management, for example, with
>          KVM guests it is required for graceful shutdown to work.
>        </dd>
> +      <dt><code>nesting</code></dt>
> +      <dd>Some hypervisors support nested hardware-supported
> +        virtualization, allowing you to run VMs inside of VMs.</dd>
>      </dl>


I agree that it would be useful to allow libvirt to turn on
SVM/VMX inside VMs, but I think we need to represent it in a
different way.  I think KVM's use of the word 'nesting' is
pretty awful terminology. Instead I think we want to handle
this in Jirka's  CPU flags work.  SVM and VMX are merely CPU
flags after all, so there's no compelling reason not to represent
them as such, even if underlying QEMU doesn't work that way.
So I imagine we'd just add 2 flags called 'vmx' and 'svm' 
once Jirka's work is done, and then behind the scenes map them
into the '--enable-nesting' arg


Regards,
Daniel
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