[2/3] Improve DEC handling

Commit Message

Alexander Graf Dec. 21, 2009, 7:21 p.m. UTC

None

Patch

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 269ee46..abfd0c4 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -82,6 +82,7 @@  extern void kvmppc_core_deliver_interrupts(struct kvm_vcpu *vcpu);
 extern int kvmppc_core_pending_dec(struct kvm_vcpu *vcpu);
 extern void kvmppc_core_queue_program(struct kvm_vcpu *vcpu);
 extern void kvmppc_core_queue_dec(struct kvm_vcpu *vcpu);
+extern void kvmppc_core_dequeue_dec(struct kvm_vcpu *vcpu);
 extern void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
                                        struct kvm_interrupt *irq);
 
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 241795b..fd3ad6c 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 06f5a9e..d8b6342 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 4a9ac66..303457b 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);