Re: [RFC v1 05/26] x86/traps: Add #VE support for TDX guest

[Andi Kleen]

> > > So what happens if NMI happens here, and triggers a nested #VE ?
> > 
> > Yes that's a gap. We should probably bail out and reexecute the original
> > instruction. The VE handler would need to set a flag for that.
> > 
> > Or alternatively the NMI always gets the VE information and puts
> > it on some internal stack, but that would seem clunkier.
> 
> The same is possible with MCE and #DB I imagine.

I don't think there are currently any plans to inject #MC into TDX guests. It's
doubtful this could be done securely.

#DB is trickier because it will happen every time, so simply reexecuting
won't work. I guess it would need the ve info stack, or some care in kprobes/kernel
debugger that it cannot happen. I think I would prefer the later.

-Andi