On Thu, Sep 07, 2023 at 09:19:51PM +0530, Manali Shukla wrote: > > I'm not sure I'm fluent in virt speak (in fact, I'm sure I'm not). Is > > the above saying that a host can never IBS profile a guest? > > Host can profile a guest with IBS if VIBS is disabled for the guest. This is > the default behavior. Host can not profile guest if VIBS is enabled for guest. > > > > > Does the current IBS thing assert perf_event_attr::exclude_guest is set? > > Unlike AMD core pmu, IBS doesn't have Host/Guest filtering capability, thus > perf_event_open() fails if exclude_guest is set for an IBS event. Then you must not allow VIBS if a host cpu-wide IBS counter exists. Also, VIBS reads like it can be (ab)used as a filter.
