BTW I found some more problems in the v1 version. > > > With EPT it is less likely to happen (but still possible IIRC depending > > > on memory > > > pressure and how much memory shadow paging code is allowed to use), > > > without EPT > > > it will happen for sure. > > > > Don't care about the non EPT case, this is white listed only for EPT > > supporting > > CPUs. > User may still disable EPT during module load, so pebs should be dropped > from a guest's cpuid in this case.
Ok. > > > > > > There is nothing, as far as I can see, that says what will happen if the > > > condition is not met. I always interpreted it as undefined behaviour so > > > anything can happen including CPU dies completely. You are saying above > > > on one hand that CPU cannot handle any kinds of faults during write to > > > DS area, but on the other hand a guest could only crash itself. Is this > > > architecturally guarantied? > > > > You essentially would get random page faults, and the PEBS event will > > be cancelled. No hangs. > Is this a guest who will get those random page faults or a host? The guest (on the white listed CPU models) -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
