Re: [PATCH v19 116/130] KVM: TDX: Silently discard SMI request

Paolo Bonzini
2024-06-11T14:11:40Z

On Tue, Jun 11, 2024 at 3:18 PM Binbin Wu <binbin.wu@linux.intel.com> wrote:
> >> }
> >>
> >> diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
> >> index ed46e7e57c18..4f3b872cd401 100644
> >> --- a/arch/x86/kvm/vmx/main.c
> >> +++ b/arch/x86/kvm/vmx/main.c
> >> @@ -283,6 +283,43 @@ static void vt_msr_filter_changed(struct kvm_vcpu *vcpu)
> >> vmx_msr_filter_changed(vcpu);
> >> }
> >>
> >> +#ifdef CONFIG_KVM_SMM
> >> +static int vt_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)
> >> +{
> >> + if (is_td_vcpu(vcpu))
> >> + return tdx_smi_allowed(vcpu, for_injection);
> > Adding stubs for something that TDX will never support is silly. Bug the VM and
> > return an error.
> >
> > if (KVM_BUG_ON(is_td_vcpu(vcpu)))
> > return -EIO;
>
> is_td_vcpu() is defined in tdx.h.
> Do you mind using open code to check whether the VM is TD in vmx.c?
> "vcpu->kvm->arch.vm_type == KVM_X86_TDX_VM"

I'd move it to some place that main.c can see. Or vmx.c as Sean says
below, but I am not sure I like the idea too much.

Paolo

> > And I wouldn't even bother with vt_* wrappers, just put that right in vmx_*().
> > Same thing for everything below.

If it's a KVM_BUG_ON()