KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio()

If kvm_io_bus_register_dev() fails then it returns success but it should
return an error code.

I also did a little cleanup like removing an impossible NULL test.

Cc: stable@vger.kernel.org
Fixes: 2b3c246a682c ('KVM: Make coalesced mmio use a device per zone')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 88b2fe3ddf42..00d86427af0f 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -154,17 +154,13 @@ int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
         list_add_tail(&dev->list, &kvm->coalesced_zones);
         mutex_unlock(&kvm->slots_lock);
 
-        return ret;
+        return 0;
 
 out_free_dev:
         mutex_unlock(&kvm->slots_lock);
-
         kfree(dev);
 
-        if (dev == NULL)
-                return -ENXIO;
-
-        return 0;
+        return ret;
 }
 
 int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,