Re: [Qemu-devel] [PATCH for-4.0 v9 09/16] qemu_thread: supplement error handling for pci_edu_realize

[Markus Armbruster]

Fei Li <address@hidden> writes:

> Just to make sure about how to do the cleanup. I notice that in 
> device_set_realized(),
> the current code does not call "dc->unrealize(dev, NULL);" when dc->realize() 
> fails.
>
>         if (dc->realize) {
>             dc->realize(dev, &local_err);
>         }
>
>         if (local_err != NULL) {
>             goto fail;
>         }
>
> Is this on purpose? (Maybe due to some devices' realize() do their own cleanup
> when fails? Sorry for the unsure, it is such a common function that I did not
> check all. :( ) Or else, I prefer to do the cleanup in a unified manner, e.g. 
> call "dc->unrealize(dev, NULL);" which is the pci_qdev_unrealize() for pci 
> devices.

Yes, this is on purpose.

When a realize() method fails, it must revert everything it has done so
far.  Results in sane "either succeed completely, or fail and do
nothing" semantics.