KVM: s390: Manually invoke vcpu setup during kvm_arch_vcpu_create()

Rename kvm_arch_vcpu_setup() to kvm_s390_vcpu_setup() and manually call
the new function during kvm_arch_vcpu_create().  Define an empty
kvm_arch_vcpu_setup() as it's still required for compilation.  This
is effectively a nop as kvm_arch_vcpu_create() and kvm_arch_vcpu_setup()
are called back-to-back by common KVM code.  Obsoleting
kvm_arch_vcpu_setup() paves the way for its removal.

Note, gmap_remove() is now called if setup fails, as s390 was previously
freeing it via kvm_arch_vcpu_destroy(), which is called by common KVM
code if kvm_arch_vcpu_setup() fails.

No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -2932,6 +2932,11 @@ static void kvm_s390_vcpu_setup_model(struct kvm_vcpu *vcpu)
 }
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu)
 {
 	int rc = 0;
 
@@ -3070,8 +3075,14 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 		 vcpu->vcpu_id, vcpu, vcpu->arch.sie_block);
 	trace_kvm_s390_create_vcpu(vcpu->vcpu_id, vcpu, vcpu->arch.sie_block);
 
+	rc = kvm_s390_vcpu_setup(vcpu);
+	if (rc)
+		goto out_ucontrol_uninit;
 	return 0;
 
+out_ucontrol_uninit:
+	if (kvm_is_ucontrol(vcpu->kvm))
+		gmap_remove(vcpu->arch.gmap);
 out_free_sie_block:
 	free_page((unsigned long)(vcpu->arch.sie_block));
 	return rc;