Re: [Qemu-devel] [PATCH 1/3] pc: Fix disabling of vapic for compat PC models

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> Il 30/07/2014 10:57, Michael S. Tsirkin ha scritto:
>> On Wed, Jul 30, 2014 at 09:01:59AM +0200, Jan Kiszka wrote:
>>> We used to be able to address both the QEMU and the KVM APIC via "apic".
>>> This doesn't work anymore. So we need to use their parent class to turn
>>> off the vapic on machines that should not expose them.
>>> 
>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>
>>
>>
>> OK so this is intended for 2.2?

If yes, we should cc: qemu-stable.

>> In that case, how about creating a macro with type name,
>> and using that? This way things don't break if we rename
>> something again.
>
> Don't we have warnings for that now?

Warnings don't help much in cases like this: "apic" still exists and has
the property, it's just not the device we want.  Macros aren't
foolproof, either.

>>> ---
>>>  hw/i386/pc_piix.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>> 
>>> diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
>>> index 9694f88..73ba77d 100644
>>> --- a/hw/i386/pc_piix.c
>>> +++ b/hw/i386/pc_piix.c
>>> @@ -645,7 +645,7 @@ static QEMUMachine pc_machine_v1_1 = {
>>>              .property = "class",\
>>>              .value    = stringify(PCI_CLASS_MEMORY_RAM),\
>>>          },{\
>>> -            .driver   = "apic",\
>>> +            .driver   = "apic-common",\
>>>              .property = "vapic",\
>>>              .value    = "off",\
>>>          },{\
>>> -- 
>>> 1.8.1.1.298.ge7eed54

You could use TYPE_APIC_COMMON here.  Including
"hw/i386/apic_internal.h" for it would be not so nice, though.