Re: [Qemu-devel] Memory API: handling unassigned physical memory

[Anthony Liguori <anthony@codemonkey.ws>]

On 05/01/2012 09:00 AM, Peter Maydell wrote:
> On 1 May 2012 14:50, Anthony Liguori<anthony@codemonkey.ws>  wrote:
>>> On 05/01/2012 03:49 PM, Peter Maydell wrote:
>>>> When QOM supports (1) exporting gpio signals and
>>
>> This is trivial.  It'll come in as soon as 1.2 opens up.
>
> You need to get it through code review first...

Obviously.

>
> (just as a random example, this commit:
> https://github.com/aliguori/qemu/commit/46483049813fca2c23fb7cd04eeab89905500c4c
> is going down the wrong path because it's incorrectly introducing
> knowledge of device internals to the utility i8259_init()
> function.)

Eh?

Do you mean:

-    qdev_connect_gpio_out(&dev->qdev, 0, irq_set[2]);
+    pin_connect_qemu_irq(&s->int_out[0], irq_set[2]);

There are three ways to do this:

1) pin_connect_qemu_irq(i8259_get_int_out(s), irq_set[2]);

2) pin_connect_qemu_irq(&s->int_out[0], irq_set[2]);

3) pin_connect_qemu_irq(PIN(object_get_child(s, "int_out[0]")), irq_set[2]);

Having converted a lot of devices by hand, I prefer (2).  I'd like to move to a 
model of:

typedef struct PICDevice
{
     DeviceState parent;

     Pin int_out[0];
     MemoryRegion io;

     /*< private >*/
     PICState *priv;
} PICDevice;

This let's us use (2), while still embedding devices and keeping the gory state 
details private to the implementation.

Regards,

Anthony Liguori

>
> -- PMM