> > On Mon, Jul 07, 2014 at 06:34:25AM -0700, [email protected] wrote: > > + /* > > + * Access LBR MSR may cause #GP under certain circumstances. > > + * E.g. KVM doesn't support LBR MSR > > + * Check all LBT MSR here. > > + * Disable LBR access if any LBR MSRs can not be accessed. > > + */ > > + if (x86_pmu.lbr_nr) { > > + x86_pmu.lbr_msr_access = check_msr(x86_pmu.lbr_tos); > > + for (i = 0; i < x86_pmu.lbr_nr; i++) { > > + x86_pmu.lbr_msr_access &= > > + check_msr(x86_pmu.lbr_from + i); > > + x86_pmu.lbr_msr_access &= > > + check_msr(x86_pmu.lbr_to + i); > > + } > > + } > > So I was going to refer you to an email I send earlier telling you that this > was > wrong, but then found it got stuck in a mailqueue on my laptop :-( > > In any case its wrong; just clear lbr_nr and kill lbr_msr_access. We already > check lbr_nr in all the right places and you added lbr_msr_access to far too > few of them (also the fact that every place you check lbr_msr_access already > had an lbr_nr test should've been a clue).
OK. If lbr_nr is well checked at runtime, I will simply set lbr_nr to 0 here (once check_msr failed). Thanks, Kan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
