KVM: Hoist kvm_create_lapic() into kvm_vcpu_init()

Move kvm_create_lapic() into kvm_vcpu_init(), rather than having svm
and vmx do it.  And make it return the error rather than a fairly
random -ENOMEM.

This also solves the problem that neither svm.c nor vmx.c actually
handles the error path properly.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/kvm_main.c

@@ -255,14 +255,22 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
 	if (r < 0)
 		goto fail_free_pio_data;
 
+	if (irqchip_in_kernel(kvm)) {
+		r = kvm_create_lapic(vcpu);
+		if (r < 0)
+			goto fail_mmu_destroy;
+	}
+
 	return 0;
 
+fail_mmu_destroy:
+	kvm_mmu_destroy(vcpu);
 fail_free_pio_data:
 	free_page((unsigned long)vcpu->pio_data);
 fail_free_run:
 	free_page((unsigned long)vcpu->run);
 fail:
-	return -ENOMEM;
+	return r;
 }
 EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 

drivers/kvm/svm.c

@@ -588,12 +588,6 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
 	if (err)
 		goto free_svm;
 
-	if (irqchip_in_kernel(kvm)) {
-		err = kvm_create_lapic(&svm->vcpu);
-		if (err < 0)
-			goto free_svm;
-	}
-
 	page = alloc_page(GFP_KERNEL);
 	if (!page) {
 		err = -ENOMEM;

drivers/kvm/vmx.c

@@ -2431,12 +2431,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
 	if (err)
 		goto free_vcpu;
 
-	if (irqchip_in_kernel(kvm)) {
-		err = kvm_create_lapic(&vmx->vcpu);
-		if (err < 0)
-			goto free_vcpu;
-	}
-
 	vmx->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
 	if (!vmx->guest_msrs) {
 		err = -ENOMEM;