[PATCH 1/4] KVM: PPC: BookE: Allow irq deliveries to inject requests

[Alexander Graf <agraf@suse.de>]

When injecting an interrupt into guest context, we usually don't need
to check for requests anymore. At least not until today.

With the introduction of EPR, we will have to create a request when the
guest has successfully accepted an external interrupt though.

So we need to prepare the interrupt delivery to abort guest entry
gracefully. Otherwise we'd delay the EPR request.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 arch/powerpc/kvm/booke.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 69f1140..4ae83f9 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -554,14 +554,16 @@ static void update_timer_ints(struct kvm_vcpu *vcpu)
 		kvmppc_core_dequeue_watchdog(vcpu);
 }
 
-static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
+static int kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
 {
 	unsigned long *pending = &vcpu->arch.pending_exceptions;
 	unsigned int priority;
+	int r = 0;
 
 	priority = __ffs(*pending);
 	while (priority < BOOKE_IRQPRIO_MAX) {
-		if (kvmppc_booke_irqprio_deliver(vcpu, priority))
+		r = kvmppc_booke_irqprio_deliver(vcpu, priority);
+		if (r)
 			break;
 
 		priority = find_next_bit(pending,
@@ -571,15 +573,19 @@ static void kvmppc_core_check_exceptions(struct kvm_vcpu *vcpu)
 
 	/* Tell the guest about our interrupt status */
 	vcpu->arch.shared->int_pending = !!*pending;
+
+	return r > 1;
 }
 
 /* Check pending exceptions and deliver one, if possible. */
 int kvmppc_core_prepare_to_enter(struct kvm_vcpu *vcpu)
 {
-	int r = 0;
+	int r;
 	WARN_ON_ONCE(!irqs_disabled());
 
-	kvmppc_core_check_exceptions(vcpu);
+	r = kvmppc_core_check_exceptions(vcpu);
+	if (r)
+		return r;
 
 	if (vcpu->arch.shared->msr & MSR_WE) {
 		local_irq_enable();
-- 
1.6.0.2