[PATCH 11/45] KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irq

[Andre Przywara <andre.przywara@arm.com>]

From: Eric Auger <eric.auger@linaro.org>

Tell KVM whether a particular VCPU has an IRQ that needs handling
in the guest. This is used to decide whether a VCPU is runnable.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

Changelog RFC..v1:
- return false if distributor is disabled
- add vgic_kick_vcpus() implementations
---
 include/kvm/vgic/vgic.h  |  2 ++
 virt/kvm/arm/vgic/vgic.c | 40 ++++++++++++++++++++++++++++++++++++++++
 virt/kvm/arm/vgic/vgic.h |  1 +
 3 files changed, 43 insertions(+)

diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
index 97c919c..664004f 100644
--- a/include/kvm/vgic/vgic.h
+++ b/include/kvm/vgic/vgic.h
@@ -184,6 +184,8 @@ struct vgic_cpu {
 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
 			bool level);
 
+int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
+
 #define irqchip_in_kernel(k)	(!!((k)->arch.vgic.in_kernel))
 #define vgic_initialized(k)	(false)
 #define vgic_ready(k)		((k)->arch.vgic.ready)
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 13280b0..b1dd8d1 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -507,3 +507,43 @@ void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 	vgic_flush_lr_state(vcpu);
 	spin_unlock(&vcpu->arch.vgic_cpu.ap_list_lock);
 }
+
+int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
+{
+	struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+	struct vgic_irq *irq;
+	bool pending = false;
+
+	if (!vcpu->kvm->arch.vgic.enabled)
+		return false;
+
+	spin_lock(&vgic_cpu->ap_list_lock);
+
+	list_for_each_entry(irq, &vgic_cpu->ap_list_head, ap_list) {
+		spin_lock(&irq->irq_lock);
+		pending = irq->pending && irq->enabled;
+		spin_unlock(&irq->irq_lock);
+
+		if (pending)
+			break;
+	}
+
+	spin_unlock(&vgic_cpu->ap_list_lock);
+
+	return pending;
+}
+
+void vgic_kick_vcpus(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int c;
+
+	/*
+	 * We've injected an interrupt, time to find out who deserves
+	 * a good kick...
+	 */
+	kvm_for_each_vcpu(c, vcpu, kvm) {
+		if (kvm_vgic_vcpu_pending_irq(vcpu))
+			kvm_vcpu_kick(vcpu);
+	}
+}
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 81b1a20..0c92cda 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -21,6 +21,7 @@
 struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 			      u32 intid);
 bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq);
+void vgic_kick_vcpus(struct kvm *kvm);
 
 void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu);
 void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu);
-- 
2.7.3