Re: [RFC PATCH v5 027/104] KVM: TDX: initialize VM with TDX specific parameters

[Xiaoyao Li]

On 4/5/2022 9:01 PM, Paolo Bonzini wrote:
> On 3/31/22 06:55, Kai Huang wrote:
> > > +struct kvm_tdx_init_vm {
> > > +    __u32 max_vcpus;
> > > +    __u32 tsc_khz;
> > > +    __u64 attributes;
> > > +    __u64 cpuid;
> > Is it better to append all CPUIDs directly into this structure, 
> > perhaps at end
> > of this structure, to make it more consistent with TD_PARAMS?
> >
> > Also, I think somewhere in commit message or comments we should 
> > explain why
> > CPUIDs are passed here (why existing KVM_SET_CUPID2 is not sufficient).
>
> Indeed, it would be easier to use the existing cpuid data in struct 
> kvm_vcpu, because right now there is no way to ensure that they are 
> consistent.
>
> Why is KVM_SET_CPUID2 not enough?  Are there any modifications done by 
> KVM that affect the measurement?

Then we get the situation that KVM_TDX_INIT_VM must be called after 1 
vcpu is created. It seems illogical that it has chance to fail the VM 
scope initialization after 1 vcpu is successfully created.

> Thanks,
>
> Paolo