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

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Mon, May 23, 2016 at 06:06:21PM +0100, Ferruh Yigit wrote:
> 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.

Let's wait and gather some comments first?

	--yliu
> Something like: rte_eth_dev_attach_and_setup()
> 
> Regards,
> ferruh