On Thu, Oct 04, 2012 at 08:46:46AM -0500, Anthony Liguori wrote:
> Eduardo Habkost <ehabk...@redhat.com> writes:
>
> > We can make it a child of a generic "machine" class later, but right now
> > a "PC" class is needed to allow global-properties to control some
> > details of CPU creation on the PC code.
> >
> > Signed-off-by: Eduardo Habkost <ehabk...@redhat.com>
> > ---
> > hw/pc.c | 18 ++++++++++++++++++
> > hw/pc.h | 6 ++++++
> > 2 files changed, 24 insertions(+)
> >
> > diff --git a/hw/pc.c b/hw/pc.c
> > index 7e7e0e2..9b68282 100644
> > --- a/hw/pc.c
> > +++ b/hw/pc.c
> > @@ -550,6 +550,24 @@ static void bochs_bios_write(void *opaque, uint32_t
> > addr, uint32_t val)
> > }
> > }
> >
> > +typedef struct PC {
> > + DeviceState parent_obj;
> > +} PC;
>
> So the general problem with this approach is that it strays from
> modeling hardware.
True, it's not modelling hardware. It's controlling the behavior of the
QEMU code that set APIC IDs, because we need to keep the old behavior on
old machine-types.
>
> I guess I'm confused why we're not just adding an apic_id property to
> the CPU objects and setting that via the normal QOM accessors.
>
> Wouldn't that solve the problem?
>
It wouldn't solve the problem (although it can make the code look
better).
The problem is not setting the APIC ID, is controlling the code that
generates the APIC IDs. I don't care too much where that code would live
(it could be inside cpu.c or helper.c), but it still needs a flag where
old machine-types tell it "please keep the old behavior for
compatibility".
> Regards,
>
> Anthony Liguori
>
> > +
> > +static const TypeInfo pc_type_info = {
> > + .name = TYPE_PC_MACHINE,
> > + .parent = TYPE_DEVICE,
> > + .instance_size = sizeof(PC),
> > + .class_size = sizeof(DeviceClass),
> > +};
> > +
> > +static void pc_register_type(void)
> > +{
> > + type_register_static(&pc_type_info);
> > +}
> > +
> > +type_init(pc_register_type);
> > +
> > int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
> > {
> > int index = le32_to_cpu(e820_table.count);
> > diff --git a/hw/pc.h b/hw/pc.h
> > index e4db071..77e898f 100644
> > --- a/hw/pc.h
> > +++ b/hw/pc.h
> > @@ -102,6 +102,12 @@ void i8042_setup_a20_line(ISADevice *dev, qemu_irq
> > *a20_out);
> > /* pc.c */
> > extern int fd_bootchk;
> >
> > +#define TYPE_PC_MACHINE "PC"
> > +#define PC(obj) \
> > + OBJECT_CHECK(PC, (obj), TYPE_PC_MACHINE)
> > +struct PC;
> > +typedef struct PC PC;
> > +
> > void pc_register_ferr_irq(qemu_irq irq);
> > void pc_acpi_smi_interrupt(void *opaque, int irq, int level);
> >
> > --
> > 1.7.11.4
--
Eduardo
