[ 18/56] KVM: Clean up error handling during VCPU creation

Greg Kroah-Hartman
2013-04-02T22:50:54Z

From: Jan Kiszka <jan.kiszka@siemens.com>

commit d780592b99d7d8a5ff905f6bacca519d4a342c76 upstream.

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>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/x86.c | 5 -----
virt/kvm/kvm_main.c | 11 ++++++-----
2 files changed, 6 insertions(+), 10 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6116,12 +6116,7 @@ int kvm_arch_vcpu_setup(struct kvm_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;
}

--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1616,18 +1616,18 @@ static int kvm_vm_ioctl_create_vcpu(stru

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)]);
@@ -1637,7 +1637,7 @@ static int kvm_vm_ioctl_create_vcpu(stru
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;
@@ -1651,8 +1651,9 @@ static int kvm_vm_ioctl_create_vcpu(stru
mutex_unlock(&kvm->lock);
return r;

-vcpu_destroy:
+unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
+vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
return r;
}