On Fri, Mar 17, 2017 at 10:59:12AM +0100, Maxime Coquelin wrote: > > > On 03/17/2017 06:32 AM, Yuanhan Liu wrote: > >On Thu, Mar 16, 2017 at 12:37:23PM +0100, Maxime Coquelin wrote: > >> > >> > >>On 03/16/2017 09:00 AM, Yuanhan Liu wrote: > >>>On Sun, Mar 12, 2017 at 05:34:01PM +0100, Maxime Coquelin wrote: > >>>>This patch implements the function for the application to > >>>>get the MTU value. > >>> > >>>I'm thinking the other way. As we are making vhost being generic, it > >>>doesn't make too much sense now to store a net specific value at vhost > >>>layer. I'm thinking we may could introduce a vhost-user request handler, > >>>something like: > >>> > >>> rte_vhost_driver_register_msg_handler(socket, handler); > >> > >>That's a good point. > >> > >>>All vhost-user message then will goto the driver's sepcific handler. > >>>if it's handlered, do nothing in vhost lib. Otherwise, we handle it > >>>in vhost lib. > >>> > >>>In this way, you could handle the mtu message inside vhost-pmd; thus, > >>>there is no need to introduce one more (net specific) API. > >>> > >>>Thoughts? > >> > >>I need to think more about it, but advantage of having a dedicated API > >>is that in case the MTU value is not available, you can know from > >>return code whether it is not yet available (-EAGAIN), or not supported > >>(-ENOTSUP). > >> > >>That could be managed with the callback tough, by calling the callback > >>with a 0 mtu value if not supported, so that the application can be > >>sure that if the callback hasn't been called, then it is just that it > >>is not ready yet. > >> > >>What do you think? > > > >I don't think the application should even be aware of the callback. > >Application should get the mtu from the ethdev layer, by the API > >rte_eth_dev_get_mtu(). And such MTU request should be only handled > >in vhost-pmd, to serve the rte_eth_dev_get_mtu() API. > > I thought about OVS, which doesn't rely on Vhost PMD (at least didn't > last time I checked).
Oh, right. Let's keep this API then. --yliu