Re: [PATCH v2] vhost: add support for dynamic vhost PMD creation

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 5/23/2016 2:24 PM, Yuanhan Liu wrote:
> On Fri, May 20, 2016 at 11:37:47AM +0100, Bruce Richardson wrote:
>> On Thu, May 19, 2016 at 06:44:44PM +0200, Thomas Monjalon wrote:
>>> 2016-05-19 17:28, Ferruh Yigit:
>>>> On 5/19/2016 9:33 AM, Thomas Monjalon wrote:
>>>>> 2016-05-18 18:10, Ferruh Yigit:
>>>>>> Add rte_eth_from_vhost() API to create vhost PMD dynamically from
>>>>>> applications.
>>>>>
>>>>> How is it different from rte_eth_dev_attach() calling rte_eal_vdev_init()?
>>>>>
>>>>
>>>> When used rte_eth_dev_attach(), application also needs to do:
>>>> rte_eth_dev_configure()
>>>> rte_eth_rx_queue_setup()
>>>> rte_eth_tx_queue_setup()
>>>> rte_eth_dev_start()
>>>>
>>>> rte_eth_from_vhost() does these internally, easier to use for applications.
>>>
>>> This argument is not sufficient.
>>> We are not going to add new APIs just for wrapping others.
>>
>> Why not - if there is a sufficient increase in developer usability by doing so?
>> Having one API that saves an app from having to call 5 other APIs looks like
>> something that should always be given fair consideration.
> 
> Good point. Judging that vhost is not the only virtual device we
> support, and it may also look reasonable to add something similar
> for others in future (say, IIRC, you proposed two more internally
> that also introduced similar APIs). So, instead of introducing a
> new API for each such vdev, may we introduce a common one? Say,
> a refined rte_eth_dev_attach(), including dev_configure(),
> queue_setup(), etc.
> 

This sounds good to me. If there is not objection, I will send a patch
and we can discuss based on patch.
Something like: rte_eth_dev_attach_and_setup()

Regards,
ferruh