diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 38a62ef..9929c41 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -133,6 +133,28 @@ static void kvmppc_vcpu_sync_fpu(struct kvm_vcpu *vcpu)
 #endif
 }
 
+static void kvmppc_vcpu_sync_debug(struct kvm_vcpu *vcpu)
+{
+#ifndef CONFIG_KVM_BOOKE_HV
+	/* Synchronize guest's desire to get debug interrupts into shadow MSR */
+	vcpu->arch.shadow_msr &= ~MSR_DE;
+	vcpu->arch.shadow_msr |= vcpu->arch.shared->msr & MSR_DE;
+#endif
+
+	/* Force enable debug interrupts when user space wants to debug */
+	if (vcpu->guest_debug) {
+#ifdef CONFIG_KVM_BOOKE_HV
+		/*
+		 * Since there is no shadow MSR, sync MSR_DE into the guest
+		 * visible MSR.
+		 */
+		vcpu->arch.shared->msr |= MSR_DE;
+#else
+		vcpu->arch.shadow_msr |= MSR_DE;
+#endif
+	}
+}
+
 /*
  * Helper function for "full" MSR writes.  No need to call this if only
  * EE/CE/ME/DE/RI are changing.
@@ -150,6 +172,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
 	kvmppc_mmu_msr_notify(vcpu, old_msr);
 	kvmppc_vcpu_sync_spe(vcpu);
 	kvmppc_vcpu_sync_fpu(vcpu);
+	kvmppc_vcpu_sync_debug(vcpu);
 }
 
 static void kvmppc_booke_queue_irqprio(struct kvm_vcpu *vcpu,


My main concern here is that we don't know when to remove MSR_DE again from the (shadow) MSR. So how about this one instead?


diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 38a62ef..2676703 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -142,7 +142,7 @@ void kvmppc_set_msr(struct kvm_vcpu *vcpu, u32 new_msr)
 	u32 old_msr = vcpu->arch.shared->msr;
 
 #ifdef CONFIG_KVM_BOOKE_HV
-	new_msr |= MSR_GS;
+	new_msr |= MSR_GS | MSR_DE;
 #endif
 
 	vcpu->arch.shared->msr = new_msr;