On Tue, 9 Nov 2010 17:50:12 +0100 Alexander Graf <agraf@xxxxxxx> wrote: > > There are also some fun issues regarding MSR[DE] with E.HV -- > > there are two modes, either the guest can control it directly (and shut > > down KVM's debug events) or the guest does not have access to debug > > resources at all and guest changes to MSR[DE] are ignored. MSR writes > > never trap. > > There are no hypervisor privileged debug registers? The debug registers themselves are hv privileged, but MSR[DE] is special. The guest can be allowed or not to change it, based on MSRP[DEP], but it can't be trapped. So if you want both hv and guest to share the debug resources, the guest needs to be well-behaved about when it disables MSR[DE]. It also needs to not depend on DSRR0/1 retaining their values when MSR[DE] is set. -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
