Re: [PATCH v19 023/130] KVM: TDX: Initialize the TDX module when loading the KVM intel kernel module

Huang, Kai
2024-04-23T23:29:44Z

On Tue, 2024-04-23 at 22:59 +0000, Huang, Kai wrote:
> > Right, but that doesn't say why the #UD occurred.  The macro dresses it up in
> > TDX_SW_ERROR so that KVM only needs a single parser, but at the end of the day
> > KVM is still only going to see that SEAMCALL hit a #UD.
>
> Right.  But is there any problem here?  I thought the point was we can
> just use the error code to tell what went wrong.

Oh, I guess I was replying too quickly. From the spec, #UD happens when

IF not in VMX operation or inSMM or inSEAM or
((IA32_EFER.LMA & CS.L) == 0)
THEN #UD;

Are you worried about #UD was caused by other cases rather than "not in
VMX operation"?

But it's quite obvious the other 3 cases are not possible, correct?