[PATCH][RESEND] KVM: Clean up error handling during VCPU creation

[Jan Kiszka <jan.kiszka@siemens.com>]

So far kvm_arch_vcpu_setup is responsible for freeing the vcpu struct if
it fails. Move this confusing resonsibility back into the hands of
kvm_vm_ioctl_create_vcpu. Only kvm_arch_vcpu_setup of x86 is affected,
all other archs cannot fail.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/x86.c  |    5 -----
 virt/kvm/kvm_main.c |   11 ++++++-----
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index da48622..aaa3735 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6126,12 +6126,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	if (r == 0)
 		r = kvm_mmu_setup(vcpu);
 	vcpu_put(vcpu);
-	if (r < 0)
-		goto free_vcpu;
 
-	return 0;
-free_vcpu:
-	kvm_x86_ops->vcpu_free(vcpu);
 	return r;
 }
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3962899..8de7208 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1612,18 +1612,18 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 
 	r = kvm_arch_vcpu_setup(vcpu);
 	if (r)
-		return r;
+		goto vcpu_destroy;
 
 	mutex_lock(&kvm->lock);
 	if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) {
 		r = -EINVAL;
-		goto vcpu_destroy;
+		goto unlock_vcpu_destroy;
 	}
 
 	kvm_for_each_vcpu(r, v, kvm)
 		if (v->vcpu_id == id) {
 			r = -EEXIST;
-			goto vcpu_destroy;
+			goto unlock_vcpu_destroy;
 		}
 
 	BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]);
@@ -1633,7 +1633,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 	r = create_vcpu_fd(vcpu);
 	if (r < 0) {
 		kvm_put_kvm(kvm);
-		goto vcpu_destroy;
+		goto unlock_vcpu_destroy;
 	}
 
 	kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu;
@@ -1647,8 +1647,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
 	mutex_unlock(&kvm->lock);
 	return r;
 
-vcpu_destroy:
+unlock_vcpu_destroy:
 	mutex_unlock(&kvm->lock);
+vcpu_destroy:
 	kvm_arch_vcpu_destroy(vcpu);
 	return r;
 }
-- 
1.7.1