Re: [Qemu-devel] [PATCH v7 08/25] x86-iommu: introduce parent class

[David Kiarie]

On Tue, May 24, 2016 at 2:02 PM, David Kiarie <address@hidden> wrote:
> On Tue, May 24, 2016 at 1:40 PM, Jan Kiszka <address@hidden> wrote:
>> On 2016-05-23 23:48, Marcel Apfelbaum wrote:
>>> On 05/23/2016 08:06 PM, David Kiarie wrote:
>>>> On Tue, May 17, 2016 at 10:15 AM, Peter Xu <address@hidden> wrote:
>>>>> Introducing parent class for intel-iommu devices named "x86-iommu". This
>>>>> is preparation work to abstract shared functionalities out from Intel
>>>>> and AMD IOMMUs. Currently, only the parent class is introduced. It does
>>>>> nothing yet.
>>>>>
>>>>> Signed-off-by: Peter Xu <address@hidden>
>>>>> ---
>>>>>   hw/i386/Makefile.objs         |  2 +-
>>>
>>> [...]
>>>
>>>>> +
>>>>> +static const TypeInfo x86_iommu_info = {
>>>>> +    .name          = TYPE_X86_IOMMU_DEVICE,
>>>>> +    .parent        = TYPE_SYS_BUS_DEVICE,
>>>>> +    .instance_size = sizeof(X86IOMMUState),
>>>>> +    .class_init    = x86_iommu_class_init,
>>>>> +    .class_size    = sizeof(X86IOMMUClass),
>>>>> +    .abstract      = true,
>>>>> +};
>>>>
>>>> As I suspected am having some trouble parenting a PCI device from a
>>>> Bus device but I will investigate further to see if I can manage
>>>> something.
>>>>
>>>
>>> You cannot derive from both SYS_BUS_DEVICE and PCI_DEVICE.
>>> You would need a composition; your device would be a SYS_BUS_DEVICE
>>> and its state would include a PCI_DEVICE (or the other way around).
>>> Then you can divide the responsibilities between them.
>>
>> Given that the AMD IOMMU is more a platform than a PCI device, I would
>> also go for deriving from SYS_BUS_DEVICE (and later on a common x86
>> IOMMU class) and embedding a PCI_DEVICE. And the Intel IOMMU has no PCI
>> device feature at all.

huh, should it be possible to embed the whole PCI device state
?Haven't tried that yet.

>
> Yes, I managed to do that by getting rid of PCI device specific
> callbacks(replaced them with DeviceState callbacks) so I get a compile
> and no runtime fatality but device(AMD IOMMU) never appears in the
> device tree.
>
>>
>> Jan
>>
>>