[PATCH 8/8] KVM:PPC:booke: Allow debug interrupt injection to guest

[Bharat Bhushan <r65777@xxxxxxxxxxxxx>]

Allow userspace to inject debug interrupt to guest. QEMU can
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.
+	 */
+	if (vcpu->guest_debug && !kvmppc_core_pending_debug(vcpu))
 		new_msr |= MSR_DE;
 #endif
 
@@ -234,6 +245,16 @@ static void kvmppc_core_dequeue_watchdog(struct kvm_vcpu *vcpu)
 	clear_bit(BOOKE_IRQPRIO_WATCHDOG, &vcpu->arch.pending_exceptions);
 }
 
+static void kvmppc_core_queue_debug(struct kvm_vcpu *vcpu)
+{
+	kvmppc_booke_queue_irqprio(vcpu, BOOKE_IRQPRIO_DEBUG);
+}
+
+static void kvmppc_core_dequeue_debug(struct kvm_vcpu *vcpu)
+{
+	clear_bit(BOOKE_IRQPRIO_DEBUG, &vcpu->arch.pending_exceptions);
+}
+
 static void set_guest_srr(struct kvm_vcpu *vcpu, unsigned long srr0, u32 srr1)
 {
 #ifdef CONFIG_KVM_BOOKE_HV
@@ -1278,6 +1299,7 @@ static void get_sregs_base(struct kvm_vcpu *vcpu,
 	sregs->u.e.dec = kvmppc_get_dec(vcpu, tb);
 	sregs->u.e.tb = tb;
 	sregs->u.e.vrsave = vcpu->arch.vrsave;
+	sregs->u.e.dbsr = vcpu->arch.dbsr;
 }
 
 static int set_sregs_base(struct kvm_vcpu *vcpu,
@@ -1310,6 +1332,14 @@ static int set_sregs_base(struct kvm_vcpu *vcpu,
 		update_timer_ints(vcpu);
 	}
 
+	if (sregs->u.e.update_special & KVM_SREGS_E_UPDATE_DBSR) {
+		vcpu->arch.dbsr = sregs->u.e.dbsr;
+		if (vcpu->arch.dbsr)
+			kvmppc_core_queue_debug(vcpu);
+		else
+			kvmppc_core_dequeue_debug(vcpu);
+	}
+
 	return 0;
 }
 
diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
index 81abe92..7d90622 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -208,7 +208,7 @@ void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 	struct kvmppc_vcpu_e500 *vcpu_e500 = to_e500(vcpu);
 
 	sregs->u.e.features |= KVM_SREGS_E_ARCH206_MMU | KVM_SREGS_E_PM |
-			       KVM_SREGS_E_PC;
+			       KVM_SREGS_E_PC | KVM_SREGS_E_ED;
 	sregs->u.e.impl_id = KVM_SREGS_E_IMPL_FSL;
 
 	sregs->u.e.impl.fsl.features = 0;
@@ -216,6 +216,9 @@ void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 	sregs->u.e.impl.fsl.hid0 = vcpu_e500->hid0;
 	sregs->u.e.impl.fsl.mcar = vcpu_e500->mcar;
 
+	sregs->u.e.dsrr0 = vcpu->arch.dsrr0;
+	sregs->u.e.dsrr1 = vcpu->arch.dsrr1;
+
 	kvmppc_get_sregs_e500_tlb(vcpu, sregs);
 
 	sregs->u.e.ivor_high[3] =
@@ -256,6 +259,11 @@ int kvmppc_core_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 			sregs->u.e.ivor_high[5];
 	}
 
+	if (sregs->u.e.features & KVM_SREGS_E_ED) {
+		vcpu->arch.dsrr0 = sregs->u.e.dsrr0;
+		vcpu->arch.dsrr1 = sregs->u.e.dsrr1;
+	}
+
 	return kvmppc_set_sregs_ivor(vcpu, sregs);
 }
 
-- 
1.7.0.4


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