>-----Original Message-----
>From: Cédric Le Goater <c...@redhat.com>
>Subject: Re: [PATCH v3 11/19] backends/iommufd: Implement
>HostIOMMUDeviceClass::check_cap() handler
>
>>>>>> +static int hiod_iommufd_check_cap(HostIOMMUDevice *hiod, int
>cap,
>>>>> Error **errp)
>>>>>> +{
>>>>>> + switch (cap) {
>>>>>> + case HOST_IOMMU_DEVICE_CAP_IOMMUFD:
>>>>>> + return 1;
>>>>>
>>>>> I don't understand this value.
>>>>
>>>> 1 means this host iommu device is attached to IOMMUFD backend,
>>>> or else 0 if attached to legacy backend.
>>>
>>> Hmm, this looks hacky to me and it is not used anywhere in the patchset.
>>> Let's reconsider when there is actually a use for it. Until then, please
>>> drop. My feeling is that a new HostIOMMUDeviceClass
>handler/attributed
>>> should be introduced instead.
>>
>> Got it, will drop it in this series.
>>
>> Is "return 1" directly the concern on your side?
>
>I don't know yet why the implementation would need to know if the host
>IOMMU device is of type IOMMUFD. If that's the case, there are alternative
>ways, like using OBJECT_CHECK( ..., TYPE_HOST_IOMMU_DEVICE_IOMMUFD)
>or
>a class attribute defined at build time but that's a bit the same. Let's
>see when the need arises.
Got it, let's revisit it in nesting series, will drop it for now.
Thanks
Zhenzhong
