[Qemu-devel] Should the i8259 devices remain no-user? (was: [PATCH RFC 8/9] isa: Clean up use of cannot_instantiate_with_device_add_yet)

[Markus Armbruster]

Paolo, or maybe Andreas,

To go beyond RFC with this series, I need to explain why isa-i8259 and
kvm-i8259 cannot_instantiate_with_device_add_yet, or drop that.  I'd
appreciate your help.

Both are derived from TYPE_PIC_COMMON, which is derived from
TYPE_ISA_DEVICE.

I figure isa-i8259 cannot_instantiate_with_device_add_yet, because it
sets global isa_pic and slave_pic.  slave_pic appears to be a lame way
to wire the slave PIC to the master PIC behind QOM's back.  isa_pic
appears to be a lame way to wire the master PIC to whatever it needs to
be wired to.  Is that a fair description?

If yes, is it sufficient reason for
cannot_instantiate_with_device_add_yet?

kvm-i8259 is the same device implemented with kernel support.  Does it
have its own reason for cannot_instantiate_with_device_add_yet?

If not, should it keep cannot_instantiate_with_device_add_yet for
symmetry with isa-i8259?