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

[Chenyi Qiang]

On 9/20/2022 9:59 PM, Peter Xu wrote:
> 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.

Get your point. Then I can print this message behind as well.

Thanks.

> 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.