On 30.01.2013, at 12:12, Bhushan Bharat-R65777 wrote: > > >> -----Original Message----- >> From: kvm-ppc-owner@xxxxxxxxxxxxxxx [mailto:kvm-ppc-owner@xxxxxxxxxxxxxxx] On >> Behalf Of Alexander Graf >> Sent: Friday, January 25, 2013 5:44 PM >> To: Bhushan Bharat-R65777 >> Cc: kvm-ppc@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Bhushan Bharat-R65777 >> Subject: Re: [PATCH 8/8] KVM:PPC:booke: Allow debug interrupt injection to guest >> >> >> On 16.01.2013, at 09:24, Bharat Bhushan wrote: >> >>> Allow userspace to inject debug interrupt to guest. QEMU can >> >> s/QEMU/user space. >> >>> inject the debug interrupt to guest if it is not able to handle the >>> debug interrupt. >>> >>> Signed-off-by: Bharat Bhushan <bharat.bhushan@xxxxxxxxxxxxx> >>> --- >>> arch/powerpc/kvm/booke.c | 32 +++++++++++++++++++++++++++++++- >>> arch/powerpc/kvm/e500mc.c | 10 +++++++++- >>> 2 files changed, 40 insertions(+), 2 deletions(-) >>> >>> diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c index >>> faa0a0b..547797f 100644 >>> --- a/arch/powerpc/kvm/booke.c >>> +++ b/arch/powerpc/kvm/booke.c >>> @@ -133,6 +133,13 @@ static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu >>> *vcpu) #endif } >>> >>> +#ifdef CONFIG_KVM_BOOKE_HV >>> +static int kvmppc_core_pending_debug(struct kvm_vcpu *vcpu) { >>> + return test_bit(BOOKE_IRQPRIO_DEBUG, >>> +&vcpu->arch.pending_exceptions); } #endif >>> + >>> /* >>> * Helper function for "full" MSR writes. No need to call this if only >>> * EE/CE/ME/DE/RI are changing. >>> @@ -144,7 +151,11 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr) >>> #ifdef CONFIG_KVM_BOOKE_HV >>> new_msr |= MSR_GS; >>> >>> - if (vcpu->guest_debug) >>> + /* >>> + * Set MSR_DE if the hardware debug resources are owned by user-space >>> + * and there is no debug interrupt pending for guest to handle. >> >> Why? > > QEMU is using the IAC/DAC registers to set hardware breakpoint/watchpoints via debug ioctls. As debug events are enabled/gated by MSR_DE so somehow we need to set MSR_DE on hardware MSR when guest is running in this case. Reading this 5 times I still have no idea what you're really checking for here. Maybe the naming for kvmppc_core_pending_debug is just unnatural? What does that function do really? > > On bookehv this is how I am controlling the MSR_DE in hardware MSR. > >> And why is this whole thing only executed on HV? > > On e500v2 we always enable MSR_DE using vcpu->arch.shadow_msr in e500.c > #ifndef CONFIG_KVM_BOOKE_HV > - vcpu->arch.shadow_msr = MSR_USER | MSR_IS | MSR_DS; > + vcpu->arch.shadow_msr = MSR_USER | MSR_DE | MSR_IS | MSR_DS; Why? How is e500v2 any different wrt debug? And why wouldn't that work for e500mc? Alex -- 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
