KVM: arm/arm64: vgic: Remove irq_phys_map from interface

Now that the virtual arch timer does not care about the irq_phys_map
anymore, let's rework kvm_vgic_map_phys_irq() to return an error
value instead. Any reference to that mapping can later be done by
passing the correct combination of VCPU and virtual IRQ number.
This makes the irq_phys_map handling completely private to the
VGIC code.

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

include/kvm/arm_vgic.h

@@ -344,8 +344,7 @@ int kvm_vgic_inject_mapped_irq(struct kvm *kvm, int cpuid,
 			       unsigned int virt_irq, bool level);
 void vgic_v3_dispatch_sgi(struct kvm_vcpu *vcpu, u64 reg);
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
-struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
-					   int virt_irq, int phys_irq);
+int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, int virt_irq, int phys_irq);
 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq);
 bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int virt_irq);
 

virt/kvm/arm/arch_timer.c

@@ -333,7 +333,6 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
 			 const struct kvm_irq_level *irq)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
-	struct irq_phys_map *map;
 	struct irq_desc *desc;
 	struct irq_data *data;
 	int phys_irq;
@@ -374,11 +373,7 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
 	 * Tell the VGIC that the virtual interrupt is tied to a
 	 * physical interrupt. We do that once per VCPU.
 	 */
-	map = kvm_vgic_map_phys_irq(vcpu, irq->irq, phys_irq);
-	if (WARN_ON(IS_ERR(map)))
-		return PTR_ERR(map);
-
-	return 0;
+	return kvm_vgic_map_phys_irq(vcpu, irq->irq, phys_irq);
 }
 
 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)

virt/kvm/arm/vgic.c

@@ -1719,21 +1719,20 @@ static struct list_head *vgic_get_irq_phys_map_list(struct kvm_vcpu *vcpu,
  * the physical interrupt represented by @phys_irq. This mapping can be
  * established multiple times as long as the parameters are the same.
  *
- * Returns a valid pointer on success, and an error pointer otherwise
+ * Returns 0 on success or an error value otherwise.
  */
-struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
-					   int virt_irq, int phys_irq)
+int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, int virt_irq, int phys_irq)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 	struct list_head *root = vgic_get_irq_phys_map_list(vcpu, virt_irq);
 	struct irq_phys_map *map;
 	struct irq_phys_map_entry *entry;
-
+	int ret = 0;
 
 	/* Create a new mapping */
 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 	if (!entry)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
 	spin_lock(&dist->irq_phys_map_lock);
 
@@ -1742,7 +1741,7 @@ struct irq_phys_map *kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu,
 	if (map) {
 		/* Make sure this mapping matches */
 		if (map->phys_irq != phys_irq)
-			map = ERR_PTR(-EINVAL);
+			ret = -EINVAL;
 
 		/* Found an existing, valid mapping */
 		goto out;
@@ -1758,9 +1757,9 @@ out:
 	spin_unlock(&dist->irq_phys_map_lock);
 	/* If we've found a hit in the existing list, free the useless
 	 * entry */
-	if (IS_ERR(map) || map != &entry->map)
+	if (ret || map != &entry->map)
 		kfree(entry);
-	return map;
+	return ret;
 }
 
 static struct irq_phys_map *vgic_irq_map_search(struct kvm_vcpu *vcpu,