On Thu, Jun 23, 2016 at 10:17:55AM +0200, Markus Armbruster wrote: > Eduardo Habkost <ehabk...@redhat.com> writes: > > > qdev_prop_check_globals() tries to warn the user if a given > > -global option was not used. But it does that only if the device > > is not hotpluggable. > > Because then the option will never be used. > > > The warning also makes it harder for management code or people > > that write their own scripts or config files: there's no way to > > know if a given -global option will trigger a warning or not, > > because we don't have any introspection mechanism to check if a > > machine-type instantiates a given device or not. > > Well, there is: create the machine, look for the device. I guess what > you're trying to say is that there's no way to *predict* what a machine > type will instantiate, at least not until after the fact. > > Suggest "will instantiate a given device".
I would fix it, but I will drop the patch from the series instead (see below). > > > The warning is also the only reason we have the 'user_provided' > > and 'used' fields in struct GlobalProperty. Removing the check > > will let us simplify the code. > > > > In other words, the warning is nearly useless and gets in our way > > and our users' way. Remove it. > > Well, telling me that I gave a non-sensical option isn't always useless. > I might have fat-fingered something, or be confused about my devices. > > Say I give -global PIIX4_PM.disable_s3=1. Does what I want with an > i440FX machine type. Except it does nothing with -no-acpi or with a Q35 > machine type. The former is harmless enough, but the latter is a > mistake; I need to say -global ICH9-LPC.disable_s3=1. Before this > patch, I get a warning in either case. > > Is this warning really useless? Not entirely useless. But I was giving more importance to code simplicity than to the detection of those mistakes. But the extra fields and extra code don't bother me so much. I will drop patches 07/10 and 08/10 from the series. -- Eduardo
