KVM: return an error code in kvm_vm_ioctl_register_coalesced_mmio()

commit aac5c4226e7136c331ed384c25d5560204da10a0 upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 88b2fe3..00d8642 100644 (file)
--- 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,