Re: [PATCH v6 2/2] i386: Add notify VM exit support

[Peter Xu]

On Tue, Sep 20, 2022 at 01:55:20PM +0800, Chenyi Qiang wrote:
> > > @@ -5213,6 +5213,7 @@ int kvm_arch_handle_exit(CPUState *cs, struct 
> > > kvm_run
> > > *run)
> > >           break;
> > >       case KVM_EXIT_NOTIFY:
> > >           ret = 0;
> > > +        warn_report_once("KVM: notify window was exceeded in guest");
> > 
> > Is there more informative way to dump this?  If it's 99% that the guest was
> > doing something weird and needs attention, maybe worthwhile to point that
> > out directly to the admin?
> > 
> 
> Do you mean to use other method to dump the info? i.e. printing a message is
> not so clear. Or the output message ("KVM: notify window was exceeded in
> guest") is not obvious and we need other wording.

I meant something like:

  KVM received notify exit.  It means there can be possible misbehaves in
  the guest, please have a look.

Or something similar.  What I'm worried is the admin may not understand
what's "notify window" and that message got simply ignored.

Though I am not even sure whether that's accurate in the wordings.

> 
> > >           if (run->notify.flags & KVM_NOTIFY_CONTEXT_INVALID) {
> > >               warn_report("KVM: invalid context due to notify vmexit");
> > >               if (has_triple_fault_event) {
> > 
> > Adding a warning looks good to me, with that (or in any better form of
> > wording):
> > 
> If no objection, I'll follow Xiaoyao's suggestion to form the wording like:

No objection here.  Thanks.

-- 
Peter Xu