netdev-afxdp: Sync and clean {get, set}_config() callbacks.

For better usability, the function pairs get_config() and
set_config() for netdevs should be symmetric: Options which are
accepted by set_config() should be returned by get_config() and the
latter should output valid options for set_config() only. This patch
also moves key-value pairs which are not valid options from get_config()
to the get_status() callback.

The documentation in vswitchd/vswitch.xml for status columns has been
updated accordingly.

Reported-at: https://bugzilla.redhat.com/1949855
Signed-off-by: Jakob Meng <code@jakobmeng.de>
Signed-off-by: Kevin Traynor <ktraynor@redhat.com>

Documentation/intro/install/afxdp.rst

@@ -219,14 +219,10 @@ Otherwise, enable debugging by::
   ovs-appctl vlog/set netdev_afxdp::dbg
 
 To check which XDP mode was chosen by ``best-effort``, you can look for
-``xdp-mode-in-use`` in the output of ``ovs-appctl dpctl/show``::
-
-  # ovs-appctl dpctl/show
-  netdev@ovs-netdev:
-    <...>
-    port 2: ens802f0 (afxdp: n_rxq=1, use-need-wakeup=true,
-                      xdp-mode=best-effort,
-                      xdp-mode-in-use=native-with-zerocopy)
+``xdp-mode`` in the output of ``ovs-vsctl get interface INT status:xdp-mode``::
+
+  # ovs-vsctl get interface ens802f0 status:xdp-mode
+  "native-with-zerocopy"
 
 References
 ----------

lib/netdev-afxdp.c

@@ -672,8 +672,6 @@ netdev_afxdp_get_config(const struct netdev *netdev, struct smap *args)
     ovs_mutex_lock(&dev->mutex);
     smap_add_format(args, "n_rxq", "%d", netdev->n_rxq);
     smap_add_format(args, "xdp-mode", "%s", xdp_modes[dev->xdp_mode].name);
-    smap_add_format(args, "xdp-mode-in-use", "%s",
-                    xdp_modes[dev->xdp_mode_in_use].name);
     smap_add_format(args, "use-need-wakeup", "%s",
                     dev->use_need_wakeup ? "true" : "false");
     ovs_mutex_unlock(&dev->mutex);
@@ -1367,3 +1365,22 @@ netdev_afxdp_get_stats(const struct netdev *netdev,
 
     return error;
 }
+
+int
+netdev_afxdp_get_status(const struct netdev *netdev, struct smap *args)
+{
+    int error = netdev_linux_get_status(netdev, args);
+
+    if (error) {
+        return error;
+    }
+
+    struct netdev_linux *dev = netdev_linux_cast(netdev);
+
+    ovs_mutex_lock(&dev->mutex);
+    smap_add_format(args, "xdp-mode", "%s",
+                    xdp_modes[dev->xdp_mode_in_use].name);
+    ovs_mutex_unlock(&dev->mutex);
+
+    return error;
+}

lib/netdev-afxdp.h

@@ -63,6 +63,7 @@ int netdev_afxdp_set_config(struct netdev *netdev, const struct smap *args,
 int netdev_afxdp_get_config(const struct netdev *netdev, struct smap *args);
 int netdev_afxdp_get_stats(const struct netdev *netdev_,
                            struct netdev_stats *stats);
+int netdev_afxdp_get_status(const struct netdev *netdev, struct smap *args);
 int netdev_afxdp_get_custom_stats(const struct netdev *netdev,
                                   struct netdev_custom_stats *custom_stats);
 

lib/netdev-linux-private.h

@@ -50,6 +50,7 @@ struct netdev_rxq_linux {
 };
 
 int netdev_linux_construct(struct netdev *);
+int netdev_linux_get_status(const struct netdev *, struct smap *);
 void netdev_linux_run(const struct netdev_class *);
 
 int get_stats_via_netlink(const struct netdev *netdev_,

lib/netdev-linux.c

@@ -3493,7 +3493,7 @@ netdev_linux_get_next_hop(const struct in_addr *host, struct in_addr *next_hop,
     return ENXIO;
 }
 
-static int
+int
 netdev_linux_get_status(const struct netdev *netdev_, struct smap *smap)
 {
     struct netdev_linux *netdev = netdev_linux_cast(netdev_);
@@ -3759,7 +3759,7 @@ const struct netdev_class netdev_internal_class = {
     .destruct = netdev_afxdp_destruct,                          \
     .get_stats = netdev_afxdp_get_stats,                        \
     .get_custom_stats = netdev_afxdp_get_custom_stats,          \
-    .get_status = netdev_linux_get_status,                      \
+    .get_status = netdev_afxdp_get_status,                      \
     .set_config = netdev_afxdp_set_config,                      \
     .get_config = netdev_afxdp_get_config,                      \
     .reconfigure = netdev_afxdp_reconfigure,                    \

vswitchd/vswitch.xml

@@ -3854,6 +3854,17 @@ ovs-vsctl add-port br0 p0 -- set Interface p0 type=patch options:peer=p1 \
             Whether userspace-tso is enabled or disabled.
           </column>
       </group>
+
+      <group title="afxdp">
+        <p>
+          AF_XDP specific interface status options.
+        </p>
+
+          <column name="status" key="xdp-mode">
+            XDP mode currently in use. See <ref column="options"
+            key="xdp-mode"/> for description of possible values.
+          </column>
+      </group>
     </group>
 
     <group title="Statistics">