3 files changed, 23 insertions, 1 deletions

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 241795bdf34c..fd3ad6c7f355 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -151,6 +151,13 @@ static int kvmppc_book3s_vec2irqprio(unsigned int vec)
         return prio;
 }
 
+static void kvmppc_book3s_dequeue_irqprio(struct kvm_vcpu *vcpu,
+                                          unsigned int vec)
+{
+        clear_bit(kvmppc_book3s_vec2irqprio(vec),
+                  &vcpu->arch.pending_exceptions);
+}
+
 void kvmppc_book3s_queue_irqprio(struct kvm_vcpu *vcpu, unsigned int vec)
 {
         vcpu->stat.queue_intr++;
@@ -178,6 +185,11 @@ int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu)
         return test_bit(BOOK3S_INTERRUPT_DECREMENTER >> 7, &vcpu->arch.pending_exceptions);
 }
 
+void kvmppc_core_dequeue_dec(struct kvm_vcpu *vcpu)
+{
+        kvmppc_book3s_dequeue_irqprio(vcpu, BOOK3S_INTERRUPT_DECREMENTER);
+}
+
 void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
                                 struct kvm_interrupt *irq)
 {
@@ -275,7 +287,9 @@ void kvmppc_core_deliver_interrupts(struct kvm_vcpu *vcpu)
 #endif
         priority = __ffs(*pending);
         while (priority <= (sizeof(unsigned int) * 8)) {
-                if (kvmppc_book3s_irqprio_deliver(vcpu, priority)) {
+                if (kvmppc_book3s_irqprio_deliver(vcpu, priority) &&
+                    (priority != BOOK3S_IRQPRIO_DECREMENTER)) {
+                        /* DEC interrupts get cleared by mtdec */
                         clear_bit(priority, &vcpu->arch.pending_exceptions);
                         break;
                 }
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 06f5a9ecc42c..d8b63420acf8 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -97,6 +97,11 @@ int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu)
         return test_bit(BOOKE_IRQPRIO_DECREMENTER, &vcpu->arch.pending_exceptions);
 }
 
+void kvmppc_core_dequeue_dec(struct kvm_vcpu *vcpu)
+{
+        clear_bit(BOOKE_IRQPRIO_DECREMENTER, &vcpu->arch.pending_exceptions);
+}
+
 void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
                                 struct kvm_interrupt *irq)
 {
diff --git a/arch/powerpc/kvm/emulate.c b/arch/powerpc/kvm/emulate.c
index 4a9ac6640fad..303457b2f52a 100644
--- a/arch/powerpc/kvm/emulate.c
+++ b/arch/powerpc/kvm/emulate.c
@@ -83,6 +83,9 @@ void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
 
         pr_debug("mtDEC: %x\n", vcpu->arch.dec);
 #ifdef CONFIG_PPC64
+        /* mtdec lowers the interrupt line when positive. */
+        kvmppc_core_dequeue_dec(vcpu);
+
         /* POWER4+ triggers a dec interrupt if the value is < 0 */
         if (vcpu->arch.dec & 0x80000000) {
                 hrtimer_try_to_cancel(&vcpu->arch.dec_timer);