KVM: arm/arm64: Check vcpu redist base before registering an iodev

As we are going to register several redist regions,
vgic_register_all_redist_iodevs() may be called several times. We need
to register a redist_iodev for a given vcpu only once. So let's
check if the base address has already been set. Initialize this latter
in kvm_vgic_vcpu_init().
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

virt/kvm/arm/vgic/vgic-init.c

@@ -199,6 +199,9 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
 	int ret = 0;
 	int i;
 
+	vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
+	vgic_cpu->sgi_iodev.base_addr = VGIC_ADDR_UNDEF;
+
 	INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
 	spin_lock_init(&vgic_cpu->ap_list_lock);
 

virt/kvm/arm/vgic/vgic-mmio-v3.c

@@ -592,6 +592,9 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
 	gpa_t rd_base, sgi_base;
 	int ret;
 
+	if (!IS_VGIC_ADDR_UNDEF(vgic_cpu->rd_iodev.base_addr))
+		return 0;
+
 	/*
 	 * We may be creating VCPUs before having set the base address for the
 	 * redistributor region, in which case we will come back to this