> On the other side, it seems that the (guest) kernel driver also works > without > the above being supported, should we change it to report error and stop > using the PMU features when the check of the above two fails (at > intel_pmu_init())?
You could add the extra check for the LBR code yes, although it already checks if the LBR MSRs work, so in practice it's likely already covered. -Andi
