Re: [PATCH v2 bpf-next 13/17] veth: implement ethtool's get_channels() callback

[Maciej Fijalkowski <maciej.fijalkowski@intel.com>]

On Tue, Mar 16, 2021 at 09:44:38AM +0100, Magnus Karlsson wrote:
> On Thu, Mar 11, 2021 at 4:43 PM Maciej Fijalkowski
> <maciej.fijalkowski@intel.com> wrote:
> >
> > Libbpf's xsk part calls get_channels() API to retrieve the queue count
> > of the underlying driver so that XSKMAP is sized accordingly.
> >
> > Implement that in veth so multi queue scenarios can work properly.
> >
> > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> > ---
> >  drivers/net/veth.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/net/veth.c b/drivers/net/veth.c
> > index aa1a66ad2ce5..efca3d45f5c2 100644
> > --- a/drivers/net/veth.c
> > +++ b/drivers/net/veth.c
> > @@ -218,6 +218,17 @@ static void veth_get_ethtool_stats(struct net_device *dev,
> >         }
> >  }
> >
> > +static void veth_get_channels(struct net_device *dev,
> > +                             struct ethtool_channels *channels)
> > +{
> > +       channels->tx_count = dev->real_num_tx_queues;
> > +       channels->rx_count = dev->real_num_rx_queues;
> > +       channels->max_tx = dev->real_num_tx_queues;
> > +       channels->max_rx = dev->real_num_rx_queues;
> > +       channels->combined_count = min(dev->real_num_rx_queues, dev->real_num_rx_queues);
> > +       channels->max_combined = min(dev->real_num_rx_queues, dev->real_num_rx_queues);
> 
> Copy and paste error in the above two lines. One of the min entries
> should be dev->real_num_tx_queues. Kind of pointless otherwise ;-).

Geez. Embarrassing :)

> 
> > +}
> > +
> >  static const struct ethtool_ops veth_ethtool_ops = {
> >         .get_drvinfo            = veth_get_drvinfo,
> >         .get_link               = ethtool_op_get_link,
> > @@ -226,6 +237,7 @@ static const struct ethtool_ops veth_ethtool_ops = {
> >         .get_ethtool_stats      = veth_get_ethtool_stats,
> >         .get_link_ksettings     = veth_get_link_ksettings,
> >         .get_ts_info            = ethtool_op_get_ts_info,
> > +       .get_channels           = veth_get_channels,
> >  };
> >
> >  /* general routines */
> > --
> > 2.20.1
> >