KVM: PPC: Support irq routing and irqfd for in-kernel MPIC

Now that all the irq routing and irqfd pieces are generic, we can expose
real irqchip support to all of KVM's internal helpers.

This allows us to use irqfd with the in-kernel MPIC.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 110 insertions, 1 deletions

diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
index 10bc08a246f..89fe1d66a7f 100644
--- a/arch/powerpc/kvm/mpic.c
+++ b/arch/powerpc/kvm/mpic.c
@@ -1076,7 +1076,9 @@ static int openpic_cpu_write_internal(void *opaque, gpa_t addr,
 	case 0xA0:		/* IACK */
 		/* Read-only register */
 		break;
-	case 0xB0:		/* EOI */
+	case 0xB0: {		/* EOI */
+		int notify_eoi;
+
 		pr_debug("EOI\n");
 		s_IRQ = IRQ_get_next(opp, &dst->servicing);
 
@@ -1087,6 +1089,8 @@ static int openpic_cpu_write_internal(void *opaque, gpa_t addr,
 		}
 
 		IRQ_resetbit(&dst->servicing, s_IRQ);
+		/* Notify listeners that the IRQ is over */
+		notify_eoi = s_IRQ;
 		/* Set up next servicing IRQ */
 		s_IRQ = IRQ_get_next(opp, &dst->servicing);
 		/* Check queued interrupts. */
@@ -1099,7 +1103,13 @@ static int openpic_cpu_write_internal(void *opaque, gpa_t addr,
 				idx, n_IRQ);
 			mpic_irq_raise(opp, dst, ILR_INTTGT_INT);
 		}
+
+		spin_unlock(&opp->lock);
+		kvm_notify_acked_irq(opp->kvm, 0, notify_eoi);
+		spin_lock(&opp->lock);
+
 		break;
+	}
 	default:
 		break;
 	}
@@ -1639,14 +1649,34 @@ static void mpic_destroy(struct kvm_device *dev)
 		unmap_mmio(opp);
 	}
 
+	dev->kvm->arch.mpic = NULL;
 	kfree(opp);
 }
 
+static int mpic_set_default_irq_routing(struct openpic *opp)
+{
+	struct kvm_irq_routing_entry *routing;
+
+	/* Create a nop default map, so that dereferencing it still works */
+	routing = kzalloc((sizeof(*routing)), GFP_KERNEL);
+	if (!routing)
+		return -ENOMEM;
+
+	kvm_set_irq_routing(opp->kvm, routing, 0, 0);
+
+	kfree(routing);
+	return 0;
+}
+
 static int mpic_create(struct kvm_device *dev, u32 type)
 {
 	struct openpic *opp;
 	int ret;
 
+	/* We only support one MPIC at a time for now */
+	if (dev->kvm->arch.mpic)
+		return -EINVAL;
+
 	opp = kzalloc(sizeof(struct openpic), GFP_KERNEL);
 	if (!opp)
 		return -ENOMEM;
@@ -1691,7 +1721,15 @@ static int mpic_create(struct kvm_device *dev, u32 type)
 		goto err;
 	}
 
+	ret = mpic_set_default_irq_routing(opp);
+	if (ret)
+		goto err;
+
 	openpic_reset(opp);
+
+	smp_wmb();
+	dev->kvm->arch.mpic = opp;
+
 	return 0;
 
 err:
@@ -1761,3 +1799,74 @@ void kvmppc_mpic_disconnect_vcpu(struct openpic *opp, struct kvm_vcpu *vcpu)
 	opp->dst[vcpu->arch.irq_cpu_id].vcpu = NULL;
 	kvm_device_put(opp->dev);
 }
+
+/*
+ * Return value:
+ *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
+ *  = 0   Interrupt was coalesced (previous irq is still pending)
+ *  > 0   Number of CPUs interrupt was delivered to
+ */
+static int mpic_set_irq(struct kvm_kernel_irq_routing_entry *e,
+			struct kvm *kvm, int irq_source_id, int level,
+			bool line_status)
+{
+	u32 irq = e->irqchip.pin;
+	struct openpic *opp = kvm->arch.mpic;
+	unsigned long flags;
+
+	spin_lock_irqsave(&opp->lock, flags);
+	openpic_set_irq(opp, irq, level);
+	spin_unlock_irqrestore(&opp->lock, flags);
+
+	/* All code paths we care about don't check for the return value */
+	return 0;
+}
+
+int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
+		struct kvm *kvm, int irq_source_id, int level, bool line_status)
+{
+	struct openpic *opp = kvm->arch.mpic;
+	unsigned long flags;
+
+	spin_lock_irqsave(&opp->lock, flags);
+
+	/*
+	 * XXX We ignore the target address for now, as we only support
+	 *     a single MSI bank.
+	 */
+	openpic_msi_write(kvm->arch.mpic, MSIIR_OFFSET, e->msi.data);
+	spin_unlock_irqrestore(&opp->lock, flags);
+
+	/* All code paths we care about don't check for the return value */
+	return 0;
+}
+
+int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
+			  struct kvm_kernel_irq_routing_entry *e,
+			  const struct kvm_irq_routing_entry *ue)
+{
+	int r = -EINVAL;
+
+	switch (ue->type) {
+	case KVM_IRQ_ROUTING_IRQCHIP:
+		e->set = mpic_set_irq;
+		e->irqchip.irqchip = ue->u.irqchip.irqchip;
+		e->irqchip.pin = ue->u.irqchip.pin;
+		if (e->irqchip.pin >= KVM_IRQCHIP_NUM_PINS)
+			goto out;
+		rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
+		break;
+	case KVM_IRQ_ROUTING_MSI:
+		e->set = kvm_set_msi;
+		e->msi.address_lo = ue->u.msi.address_lo;
+		e->msi.address_hi = ue->u.msi.address_hi;
+		e->msi.data = ue->u.msi.data;
+		break;
+	default:
+		goto out;
+	}
+
+	r = 0;
+out:
+	return r;
+}