veth: Implement ethtool's get_channels() callback

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>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210329224316.17793-14-maciej.fijalkowski@intel.com

diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index 91b73db37555b8ca5896b31375de9db2fba5a430..9e525646df1d9fa061df7048596d8399b77eff8e 100644 (file)
--- 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_tx_queues);
+       channels->max_combined = min(dev->real_num_rx_queues, dev->real_num_tx_queues);
+}
+
 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 */