On Tue, 2014-08-12 at 02:36 -0500, Bhushan Bharat-R65777 wrote: > > > -----Original Message----- > > From: Wood Scott-B07421 > > Sent: Tuesday, August 12, 2014 5:30 AM > > To: Bhushan Bharat-R65777 > > Cc: agraf@xxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Yoder Stuart- > > B08248 > > Subject: Re: [PATCH 7/7 v3] KVM: PPC: BOOKE: Emulate debug registers and > > exception > > > > On Wed, 2014-08-06 at 12:08 +0530, Bharat Bhushan wrote: > > > @@ -1249,6 +1284,7 @@ int kvmppc_subarch_vcpu_init(struct kvm_vcpu *vcpu) > > > setup_timer(&vcpu->arch.wdt_timer, kvmppc_watchdog_func, > > > (unsigned long)vcpu); > > > > > > + kvmppc_clear_dbsr(); > > > return 0; > > > > This could use a comment for why we're doing this. Also, I'm a bit uneasy about > > clearing the whole DBSR here, where we haven't yet switched the debug registers > > to guest context. > > I think we wanted MRR to not cause debug event to guest, So should we only clear MRR ? > > > It shouldn't actually matter except for deferred debug > > exceptions which are not actually useful (in fact e6500 removed support for > > them), > > Exactly, that's why I was clearing complete DBSR. Probably we can have a comment > " Do not let previously set debug events visible to guest. As deferred debug events > are not supported, so it is ok to clear complete DBSR. > " This would be affecting host debugging of the host, not guest debugging of the guest. Still I don't think it's a huge deal, but clearing only MRR would be cleaner. -Scott -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
