Re: [PATCH v2] x86/kvm: Disable KVM_ASYNC_PF_SEND_ALWAYS

[Paolo Bonzini]

On 07/04/20 23:41, Andy Lutomirski wrote:
> 2. Access to bad memory results in #MC.  Sure, #MC is a turd, but
> itâs an *architectural* turd. By all means, have a nice simple PV
> mechanism to tell the #MC code exactly what went wrong, but keep the
> overall flow the same as in the native case.
> 
> I think I like #2 much better. It has another nice effect: a good
> implementation will serve as a way to exercise the #MC code without
> needing to muck with EINJ or with whatever magic Tony uses. The
> average kernel developer does not have access to a box with testable
> memory failure reporting.

I prefer #VE, but I can see how #MC has some appeal.  However, #VE has a
mechanism to avoid reentrancy, unlike #MC.  How would that be better
than the current mess with an NMI happening in the first few
instructions of the #PF handler?

Paolo