arm/arm64: KVM: vgic: Parametrize VGIC_NR_SHARED_IRQS

Having a dynamic number of supported interrupts means that we
cannot relly on VGIC_NR_SHARED_IRQS being fixed anymore.

Instead, make it take the distributor structure as a parameter,
so it can return the right value.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

include/kvm/arm_vgic.h

@@ -29,7 +29,6 @@
 #define VGIC_NR_SGIS		16
 #define VGIC_NR_PPIS		16
 #define VGIC_NR_PRIVATE_IRQS	(VGIC_NR_SGIS + VGIC_NR_PPIS)
-#define VGIC_NR_SHARED_IRQS	(VGIC_NR_IRQS - VGIC_NR_PRIVATE_IRQS)
 #define VGIC_MAX_CPUS		KVM_MAX_VCPUS
 
 #define VGIC_V2_MAX_LRS		(1 << 6)

virt/kvm/arm/vgic.c

@@ -1086,11 +1086,17 @@ static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg)
 	}
 }
 
+static int vgic_nr_shared_irqs(struct vgic_dist *dist)
+{
+	return dist->nr_irqs - VGIC_NR_PRIVATE_IRQS;
+}
+
 static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
 {
 	struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
 	unsigned long *pending, *enabled, *pend_percpu, *pend_shared;
 	unsigned long pending_private, pending_shared;
+	int nr_shared = vgic_nr_shared_irqs(dist);
 	int vcpu_id;
 
 	vcpu_id = vcpu->vcpu_id;
@@ -1103,15 +1109,15 @@ static int compute_pending_for_cpu(struct kvm_vcpu *vcpu)
 
 	pending = vgic_bitmap_get_shared_map(&dist->irq_pending);
 	enabled = vgic_bitmap_get_shared_map(&dist->irq_enabled);
-	bitmap_and(pend_shared, pending, enabled, VGIC_NR_SHARED_IRQS);
+	bitmap_and(pend_shared, pending, enabled, nr_shared);
 	bitmap_and(pend_shared, pend_shared,
 		   vgic_bitmap_get_shared_map(&dist->irq_spi_target[vcpu_id]),
-		   VGIC_NR_SHARED_IRQS);
+		   nr_shared);
 
 	pending_private = find_first_bit(pend_percpu, VGIC_NR_PRIVATE_IRQS);
-	pending_shared = find_first_bit(pend_shared, VGIC_NR_SHARED_IRQS);
+	pending_shared = find_first_bit(pend_shared, nr_shared);
 	return (pending_private < VGIC_NR_PRIVATE_IRQS ||
-		pending_shared < VGIC_NR_SHARED_IRQS);
+		pending_shared < vgic_nr_shared_irqs(dist));
 }
 
 /*
@@ -1368,7 +1374,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
 	}
 
 	/* SPIs */
-	for_each_set_bit(i, vgic_cpu->pending_shared, VGIC_NR_SHARED_IRQS) {
+	for_each_set_bit(i, vgic_cpu->pending_shared, vgic_nr_shared_irqs(dist)) {
 		if (!vgic_queue_hwirq(vcpu, i + VGIC_NR_PRIVATE_IRQS))
 			overflow = 1;
 	}