[PATCH 02/15] KVM: PPC: Allow userspace to unset the IRQ line

[Alexander Graf <agraf@suse.de>]

Userspace can tell us that it wants to trigger an interrupt. But
so far it can't tell us that it wants to stop triggering one.

So let's interpret the parameter to the ioctl that we have anyways
to tell us if we want to raise or lower the interrupt line.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/include/asm/kvm.h     |    3 +++
 arch/powerpc/include/asm/kvm_ppc.h |    2 ++
 arch/powerpc/kvm/book3s.c          |    6 ++++++
 arch/powerpc/kvm/powerpc.c         |    5 ++++-
 4 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index 19bae31..6c5547d 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -84,4 +84,7 @@ struct kvm_guest_debug_arch {
 #define KVM_REG_QPR		0x0040
 #define KVM_REG_FQPR		0x0060
 
+#define KVM_INTERRUPT_SET	-1U
+#define KVM_INTERRUPT_UNSET	-2U
+
 #endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index c7fcdd7..6a2464e 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -92,6 +92,8 @@ 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);
+extern void kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu,
+                                         struct kvm_interrupt *irq);
 
 extern int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
                                   unsigned int op, int *advance);
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index c2ffb91..9e0bc47 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -230,6 +230,12 @@ void kvmppc_core_queue_external(struct kvm_vcpu *vcpu,
 	kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_EXTERNAL);
 }
 
+void kvmppc_core_dequeue_external(struct kvm_vcpu *vcpu,
+                                  struct kvm_interrupt *irq)
+{
+	kvmppc_book3s_dequeue_irqprio(vcpu, BOOK3S_INTERRUPT_EXTERNAL);
+}
+
 int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
 {
 	int deliver = 1;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 5a8eb95..a28a512 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -449,7 +449,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
 {
-	kvmppc_core_queue_external(vcpu, irq);
+	if (irq->irq == KVM_INTERRUPT_UNSET)
+		kvmppc_core_dequeue_external(vcpu, irq);
+	else
+		kvmppc_core_queue_external(vcpu, irq);
 
 	if (waitqueue_active(&vcpu->wq)) {
 		wake_up_interruptible(&vcpu->wq);
-- 
1.6.0.2