Re: [Qemu-devel] [RFC 01/18] pc: create "PC" device class

[Anthony Liguori]

Eduardo Habkost <address@hidden> writes:

> On Thu, Oct 04, 2012 at 09:28:13AM -0500, Anthony Liguori wrote:
>> Paolo Bonzini <address@hidden> writes:
>> 
>> > Il 04/10/2012 15:46, Anthony Liguori ha scritto:
>> >>> > +typedef struct PC {
>> >>> > +    DeviceState parent_obj;
>> >>> > +} PC;
>> >> So the general problem with this approach is that it strays from
>> >> modeling hardware.
>> >
>> > It doesn't really; it's a motherboard object, there's no reason why
>> > /machine shouldn't be a Device itself, with a few objects (CPUs, the
>> > i440FX, the IOAPIC, and of course the peripherals) hanging off it.
>> 
>> Okay, but modeling a motherboard is different than creating a "PC"
>> object and throwing in the kitchen skink.
>> 
>> And I'm not sure that going top-down is the best strategy.  I think
>> going bottom up makes more sense (starting with modeling Super IO chip).
>> 
>
> So, would you be OK with this implementation if the class were named
> "Motherboard", "set-of-CPU-sockets", or something like that?

I would, but you're mixing up modeling with bug fixing.

There's a very easy way to achieve your goal without dramatic
remodeling.

Just assign APIC ids during CPU creation and make contiguous_apic_ids a
parameter of pc_init1.

You don't need to worry about CPU hotplug.  It doesn't exist in qemu.git
and is broken in qemu-kvm.git.

Regards,

Anthony Liguori

>
> (The change on the APIC ID generation logic is not something that
> affects only individual CPUs or APICs, but the fw_cfg NUMA & CPU hotplug
> code as well, that's why I don't think "contiguous_apic_ids" should be a
> property of CPU or APIC objects).
>
>
>> Regards,
>> 
>> Anthony Liguori
>> 
>> >
>> > Paolo
>
> -- 
> Eduardo