Re: [PATCH v3] KVM: VMX: Enable Notify VM exit

[Paolo Bonzini]

On 2/25/22 16:12, Xiaoyao Li wrote:
> > > >
> > >
> > > I don't like the idea of making things up without notifying userspace
> > > that this is fictional. How is my customer running nested VMs supposed
> > > to know that L2 didn't actually shutdown, but L0 killed it because the
> > > notify window was exceeded? If this information isn't reported to
> > > userspace, I have no way of getting the information to the customer.
> >
> > Then, maybe a dedicated software define VM exit for it instead of 
> > reusing triple fault?
>
> Second thought, we can even just return Notify VM exit to L1 to tell L2 
> causes Notify VM exit, even thought Notify VM exit is not exposed to L1.

That might cause NULL pointer dereferences or other nasty occurrences.

Paolo