KVM: arm/arm64: vgic: Use wrapper function to lock/unlock all vcpus in kvm_vgic_create()

Use wrapper function lock_all_vcpus()/unlock_all_vcpus()
in kvm_vgic_create() to remove duplicated code dealing
with locking and unlocking all vcpus in a vm.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/1575081918-11401-1-git-send-email-linmiaohe@huawei.com

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

@@ -70,7 +70,7 @@ void kvm_vgic_early_init(struct kvm *kvm)
  */
 int kvm_vgic_create(struct kvm *kvm, u32 type)
 {
-	int i, vcpu_lock_idx = -1, ret;
+	int i, ret;
 	struct kvm_vcpu *vcpu;
 
 	if (irqchip_in_kernel(kvm))
@@ -86,17 +86,9 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 		!kvm_vgic_global_state.can_emulate_gicv2)
 		return -ENODEV;
 
-	/*
-	 * Any time a vcpu is run, vcpu_load is called which tries to grab the
-	 * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
-	 * that no other VCPUs are run while we create the vgic.
-	 */
 	ret = -EBUSY;
-	kvm_for_each_vcpu(i, vcpu, kvm) {
-		if (!mutex_trylock(&vcpu->mutex))
-			goto out_unlock;
-		vcpu_lock_idx = i;
-	}
+	if (!lock_all_vcpus(kvm))
+		return ret;
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		if (vcpu->arch.has_run_once)
@@ -125,10 +117,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
 
 out_unlock:
-	for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
-		vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
-		mutex_unlock(&vcpu->mutex);
-	}
+	unlock_all_vcpus(kvm);
 	return ret;
 }