Re: [Qemu-devel] [RFC PATCH 2/2] Split fdd devices off the floppy controller

[Kevin Wolf <kwolf@redhat.com>]

Am 11.05.2012 17:22, schrieb Markus Armbruster:
> For historical reasons, and unlike other block devices, our floppy
> devices isa-fdc, sysbus-fdc and SUNW,fdtwo integrate the controller
> and the drive(s) in a single qdev.  This makes them weird: we need
> -global to set up floppy drives, unlike every other optional device.

I like the idea of splitting the drives from the controller. In fact, I
think we could even try to split them into a separate hw/fdd.c

> Unfortunately, eliding the qbus means I can't make the floppy disk a
> qdev (sub-class of TYPE_DEVICE), because qdevs can only connect to a
> qbus.  Anthony tells me that restriction is gone in his latest QOM
> series.
> 
> Since it's not a qdev, -device fdd does not work.  Pity, because it
> defeats the stated purpose of making floppy disk drives work like
> other existing optional devices.

As long as this is true, committing a patch like this doesn't help a
lot, so I hope Anthony's patches will go in before this is ready.

> Note: I *break* -global isa-fdc.driveA=...  The properties are simply
> gone.  Fixable if we need backwards compatibility there.

We might need it, I seem to remember that libvirt uses it.

Kevin