KVM: arm/arm64: prefer IS_ENABLED to a static variable

IS_ENABLED gives compile-time checking and keeps the code clearer.

The one exception is inside kvm_vm_ioctl_check_extension, where
the established idiom is to wrap the case labels with an #ifdef.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 5560f74..e0e9434 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -61,8 +61,6 @@ static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
 static u8 kvm_next_vmid;
 static DEFINE_SPINLOCK(kvm_vmid_lock);
 
-static bool vgic_present;
-
 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
 {
        BUG_ON(preemptible());
@@ -172,9 +170,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
        int r;
        switch (ext) {
+#ifdef CONFIG_KVM_ARM_VGIC
        case KVM_CAP_IRQCHIP:
-               r = vgic_present;
-               break;
+#endif
        case KVM_CAP_DEVICE_CTRL:
        case KVM_CAP_USER_MEMORY:
        case KVM_CAP_SYNC_MMU:
@@ -831,7 +829,7 @@ static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
 
        switch (dev_id) {
        case KVM_ARM_DEVICE_VGIC_V2:
-               if (!vgic_present)
+               if (!IS_ENABLED(CONFIG_KVM_ARM_VGIC))
                        return -ENXIO;
                return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
        default:
@@ -847,10 +845,9 @@ long kvm_arch_vm_ioctl(struct file *filp,
 
        switch (ioctl) {
        case KVM_CREATE_IRQCHIP: {
-               if (vgic_present)
-                       return kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
-               else
+               if (!IS_ENABLED(CONFIG_KVM_ARM_VGIC))
                        return -ENXIO;
+               return kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
        }
        case KVM_ARM_SET_DEVICE_ADDR: {
                struct kvm_arm_device_addr dev_addr;
@@ -1035,10 +1032,6 @@ static int init_hyp_mode(void)
        if (err)
                goto out_free_context;
 
-#ifdef CONFIG_KVM_ARM_VGIC
-               vgic_present = true;
-#endif
-
        /*
         * Init HYP architected timer support
         */