Re: [PATCH 0/9] Add support for nested SVM (kernel) v3

[Joerg Roedel <joerg.roedel@amd.com>]

On Wed, Sep 17, 2008 at 03:41:17PM +0200, Alexander Graf wrote:
> To be usable, this patchset requires the two simple changes in the userspace
> part, that I sent to the list with the first version.
> 
> Thanks for reviewing!

Ok, with the patch attached applied on-top of your patches I got a
recent KVM running inside KVM. And it doesn't feel very slow :-)
I will do some benchmarks in the next days to get real numbers. The
patches look good so far.
But I think for now we should disable the feature by default and allow
enabling it from userspace until we are sure we don't introduce any
security hole and don't destroy migration with it. We can add a
-nested-virt parameter to qemu to enable it for the guest then.
Another thing missing is the SVM feature CPUID function. It is used to
find out the number of ASIDs available. But this is a minor issue as
long as we only run KVM inside KVM.

Joerg

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