On Mon, Aug 2, 2021 at 3:21 PM Krish Sadhukhan
<krish.sadhukhan@xxxxxxxxxx> wrote:
>
>
> On 8/2/21 9:39 AM, Paolo Bonzini wrote:
> > On 02/08/21 18:34, Sean Christopherson wrote:
> >> On Mon, Aug 02, 2021, Paolo Bonzini wrote:
> >>> On 21/06/21 22:43, Krish Sadhukhan wrote:
> >>>> With this patch KVM entry and exit tracepoints will
> >>>> show "guest_mode = 0" if it is a guest and "guest_mode = 1" if it is a
> >>>> nested guest.
> >>>
> >>> What about adding a "(nested)" suffix for L2, and nothing for L1?
> >>
> >> That'd work too, though it would be nice to get vmcx12 printed as
> >> well so that
> >> it would be possible to determine which L2 is running without having
> >> to cross-
> >> reference other tracepoints.
> >
> > Yes, it would be nice but it would also clutter the output a bit.
> > It's like what we have already in kvm_inj_exception:
> >
> > TP_printk("%s (0x%x)",
> > __print_symbolic(__entry->exception,
> > kvm_trace_sym_exc),
> > /* FIXME: don't print error_code if not present */
> > __entry->has_error ? __entry->error_code : 0)
> >
> > It could be done with a trace-cmd plugin, but that creates other
> > issues since
> > it essentially forces the tracepoints to have a stable API.
> >
> > Paolo
>
>
> Also, the vmcs/vmcb address is vCPU-specific, so if L2 runs on 10 vCPUs,
> traces will show 10 different addresses for the same L2 and it's not
> convenient on a cloud host where hundreds of L1s and L2s run.
The vmcx02 address is vCPU-specific. However, Sean asked for the
vmcx12 address, which is a GPA that is common across all vCPUs.
