Re: [PATCH V10 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework

Jason Wang
2019-11-07T13:41:00Z

On 2019/11/7 下午9:08, Michael S. Tsirkin wrote:
> On Thu, Nov 07, 2019 at 08:47:06PM +0800, Jason Wang wrote:
>> On 2019/11/7 下午8:43, Jason Wang wrote:
>>> On 2019/11/7 下午7:21, Michael S. Tsirkin wrote:
>>>> On Thu, Nov 07, 2019 at 06:18:45PM +0800, Jason Wang wrote:
>>>>> On 2019/11/7 下午5:08, Michael S. Tsirkin wrote:
>>>>>> On Wed, Nov 06, 2019 at 09:35:31PM +0800, Jason Wang wrote:
>>>>>>> This sample driver creates mdev device that simulate
>>>>>>> virtio net device
>>>>>>> over virtio mdev transport. The device is implemented through vringh
>>>>>>> and workqueue. A device specific dma ops is to make sure HVA is used
>>>>>>> directly as the IOVA. This should be sufficient for kernel virtio
>>>>>>> driver to work.
>>>>>>>
>>>>>>> Only 'virtio' type is supported right now. I plan to add 'vhost' type
>>>>>>> on top which requires some virtual IOMMU implemented in this sample
>>>>>>> driver.
>>>>>>>
>>>>>>> Acked-by: Cornelia Huck<cohuck@redhat.com>
>>>>>>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>>>>>> I'd prefer it that we call this something else, e.g.
>>>>>> mvnet-loopback. Just so people don't expect a fully
>>>>>> functional device somehow. Can be renamed when applying?
>>>>> Actually, I plan to extend it as another standard network interface for
>>>>> kernel. It could be either a standalone pseudo device or a stack
>>>>> device.
>>>>> Does this sounds good to you?
>>>>>
>>>>> Thanks
>>>> That's a big change in an interface so it's a good reason
>>>> to rename the driver at that point right?
>>>> Oherwise users of an old kernel would expect a stacked driver
>>>> and get a loopback instead.
>>>>
>>>> Or did I miss something?
>>>
>>> My understanding is that it was a sample driver in /doc. It should not
>>> be used in production environment. Otherwise we need to move it to
>>> driver/virtio.
>>>
>>> But if you insist, I can post a V11.
>>>
>>> Thanks
>>
>> Or maybe it's better to rename the type of current mdev from 'virtio' to
>> 'virtio-loopback'. Then we can add more types in the future.
>>
>> Thanks
>>
> Maybe but is virtio actually a loopback somehow? I thought we
> can bind a regular virtio device there, no?

It has a prefix, so user will see "mvnet-virtio-loopback".

Thanks

>