Re: [PATCH v10] virtio-net: support device stats

[Jason Wang <jasowang@redhat.com>]

å 2022/3/1 äå8:25, Michael S. Tsirkin åé:
> On Tue, Mar 01, 2022 at 07:32:23PM +0800, Xuan Zhuo wrote:
> > I have to say, this design is really good.
> >
> > I think one of the core points of your design is to separate drop stats, gso
> > stats, etc. Get the stats you want based on negotiation and needs. And covering
> > the control queue, I am very surprised.
> >
> > But does this design solve the problem of expansion? Various stats independent
> > structures seem to be convenient for expansion. But is this expansion ready for
> > dynamic negotiation?
> For negotiation, we can either separate feature flags for each supported
> type, or do like RSS and add commands for querying supported types
> and enabling stats collection.


I think new command would be better but I don't understand why we need 
the logic of enable/disable?


> Features is probably easier
> for now ... Also, do we need to enable/disable stat collection?
>
>
>
> > My earliest solution is dynamic negotiation, that is, the driver tells the
> > device how many stats it wants to get. And the device negotiates how many stats
> > it should give to the driver based on this information of the driver.
> >
> > But that's not great for migration. So gave up.  @Jason
> Any optional feature is problematic for migration, at least with
> features device knows ahead of the time what does driver
> want to use.


If we tie e.g RSS stats command to RSS feature, we won't have any problem.

Thanks


>