Re: [Qemu-devel] [PATCH v4 0/5] refactor PC machine, i440fx and piix3 to take advantage of QOM

[Anthony Liguori <aliguori@us.ibm.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 18/07/2012 15:19, Wanpeng Li ha scritto:
>> [CCing ML]
>> 
>> This series aggressively refactors the PC machine initialization to be more
>> modelled and less ad-hoc.  The highlights of this series are:
>> 
>> 1) Things like -m and -bios-name are now device model properties
>> 
>> 2) The i440fx and piix3 are now modelled in a thorough fashion
>> 
>> 3) Most of the chipset features of the piix3 are modelled through composition
>> 
>> 4) i440fx_init is trivialized to creating devices and setting properties
>> 
>> 5) convert MemoryRegion to QOM
>> 
>> 6) convert PCI host bridge to QOM
>> 
>> The point (4) is the most important one.  As we refactor in this fashion,
>> we should quickly get to the point where machine->init disappears completely in
>> favor of just creating a handful of devices.
>> 
>> The two stage initialization of QOM is important here.  instance_init() is when
>> composed devices are created which means that after you've created a device, all
>> of its children are visible in the device model.  This lets you set properties
>> of the parent and its children.
>> 
>> realize() (which is still called DeviceState::init today) will be called right
>> before the guest starts up for the first time.
>> 
>> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
>> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
>
> Why should we include this?  I assume it conflicts uselessly with the
> work Jason is doing on q35.

My hope was that this series would undue the mess that the initial
attempt to merge q35 did.  As we discussed on the community call a few
weeks ago, the break of things like pc_basic_init() creates a spaghetti
maze that will be extremely difficult to resolve down the road.

I think we need to spend some time refactoring pc init properly before
adding q35.

Regards,

Anthony Liguori

>
> Paolo