Re: [RFC v2-fix-v5 1/1] x86: Skip WBINVD instruction for VM guest

[Kuppuswamy, Sathyanarayanan]

On 6/9/21 2:38 PM, Dan Williams wrote:
> > In TDX guests, these WBINVD operations cause #VE exceptions.  For debug,
> > it would be ideal for the #VE handler to be able to WARN() when an
> > unexpected WBINVD occurs. (<--- problem #2)
> ...but it doesn't WARN() it triggers unhandled #VE, unless I missed
> another patch that precedes this that turns it into a WARN()? If a
> code path expects WBINVD for correct operation and the guest can't
> execute that sounds fatal, not a WARN to me.

Yes. It is not WARN. It is a fatal unhandled exception.

>

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer