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Subject: Re: [PATCH 5/6] vdpa: introduce virtio pci driver
To:     "Michael S. Tsirkin" <mst@redhat.com>
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From:   Jason Wang <jasowang@redhat.com>
Message-ID: <a01aced5-2357-b55c-296b-f152008ddbf2@redhat.com>
Date:   Tue, 9 Jun 2020 13:55:14 +0800
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On 2020/6/8 下午9:29, Michael S. Tsirkin wrote:
> On Mon, Jun 08, 2020 at 06:07:36PM +0800, Jason Wang wrote:
>> On 2020/6/8 下午5:54, Michael S. Tsirkin wrote:
>>> On Mon, Jun 08, 2020 at 05:46:52PM +0800, Jason Wang wrote:
>>>> On 2020/6/8 下午5:45, Michael S. Tsirkin wrote:
>>>>> On Mon, Jun 08, 2020 at 05:43:58PM +0800, Jason Wang wrote:
>>>>>>>> Looking at
>>>>>>>> pci_match_one_device() it checks both subvendor and subdevice there.
>>>>>>>>
>>>>>>>> Thanks
>>>>>>> But IIUC there is no guarantee that driver with a specific subvendor
>>>>>>> matches in presence of a generic one.
>>>>>>> So either IFC or virtio pci can win, whichever binds first.
>>>>>> I'm not sure I get there. But I try manually bind IFCVF to qemu's
>>>>>> virtio-net-pci, and it fails.
>>>>>>
>>>>>> Thanks
>>>>> Right but the reverse can happen: virtio-net can bind to IFCVF first.
>>>> That's kind of expected. The PF is expected to be bound to virtio-pci to
>>>> create VF via sysfs.
>>>>
>>>> Thanks
>>>>
>>>>
>>>>
>>> Once VFs are created, don't we want IFCVF to bind rather than
>>> virtio-pci?
>>
>> Yes, but for PF we need virtio-pci.
>>
>> Thanks
>>
> (Ab)using the driver_data field for this is an option.
> What do you think?


Maybe you can elaborate more on this idea?

Thanks


>