Re: [PATCH 17/18] KVM: SVM: Report Nested Paging support to userspace

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

On Thu, Mar 04, 2010 at 12:37:42AM +0100, Alexander Graf wrote:
> 
> On 03.03.2010, at 20:12, Joerg Roedel wrote:
> 
> > This patch implements the reporting of the nested paging
> > feature support to userspace.
> > 
> > Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
> > ---
> > arch/x86/kvm/svm.c |   10 ++++++++++
> > 1 files changed, 10 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> > index fe1398e..ce71023 100644
> > --- a/arch/x86/kvm/svm.c
> > +++ b/arch/x86/kvm/svm.c
> > @@ -3289,6 +3289,16 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu)
> > 
> > static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry)
> > {
> > +	switch (func) {
> > +	case 0x8000000A:
> > +		if (!npt_enabled)
> > +			break;
> 
> if (!nested)
>   break;

True, but shouldn't matter much because if nested is off the guest will
not see the svm bit. It would only see that the processor could do
nested paging if it had svm support ;-)

	Joerg