On Tuesday, September 27, 2022 2:09 AM, Liang, Kan wrote: > From my understanding of the host-guest mode, the host PT event never > traces the guest no matter whether the guest enables PT. So when VM-entry, > there is only a guest PT event or no event. If so, I think the perf tool should > warn the user if they try to create a host event with !exclude_guest, since the > host event never traces a guest. Probably not from the perf side. It's actually an issue of the KVM's pt_mode: How can KVM prevent host from profiling the guest when in host-guest mode? Just a warning from the perf side wouldn't be enough. I think that's a wrong assumption from KVM side. I had a plan to fix this one. Exposing the host event can tell KVM if the host is profiling the guest or not (i.e. host-guest is allowed).
