Re: [PATCH v19 078/130] KVM: TDX: Implement TDX vcpu enter/exit path

[Edgecombe, Rick P]

On Mon, 2024-02-26 at 00:26 -0800, isaku.yamahata@xxxxxxxxx wrote:
> +fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu)
> +{
> +       struct vcpu_tdx *tdx = to_tdx(vcpu);
> +
> +       if (unlikely(!tdx->initialized))
> +               return -EINVAL;
> +       if (unlikely(vcpu->kvm->vm_bugged)) {
> +               tdx->exit_reason.full = TDX_NON_RECOVERABLE_VCPU;
> +               return EXIT_FASTPATH_NONE;
> +       }
> +

Isaku, can you elaborate on why this needs special handling? There is a
check in vcpu_enter_guest() like:
	if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu)) {
		r = -EIO;
		goto out;
	}

Instead it returns a SEAM error code for something actuated by KVM. But
can it even be reached because of the other check? Not sure if there is
a problem, just sticks out to me and wondering whats going on.