ethernet: T2241: check if interface supports changing speed/duplex settings

Not all interface drivers have the ability to change the speed and duplex
settings. Known drivers with this limitation are vmxnet3, virtio_net and
xen_netfront. If this driver is detected, an error will be presented to the
user.

(cherry picked from commit cc742d48579e4f76e5d3230d87e22f71f76f9301)

2 files changed, 17 insertions, 1 deletions

diff --git a/src/conf_mode/interfaces-ethernet.py b/src/conf_mode/interfaces-ethernet.py
index a7e01e279..57e05d4ea 100755
--- a/src/conf_mode/interfaces-ethernet.py
+++ b/src/conf_mode/interfaces-ethernet.py
@@ -75,7 +75,8 @@ def verify(ethernet):
         speed = ethernet['speed']
         duplex = ethernet['duplex']
         if not ethtool.check_speed_duplex(speed, duplex):
-            raise ConfigError(f'Adapter does not support speed "{speed}" and duplex "{duplex}"!')
+            raise ConfigError(f'Adapter does not support changing speed and duplex '\
+                              f'settings to: {speed}/{duplex}!')
 
     if 'ring_buffer' in ethernet:
         max_rx = ethtool.get_rx_buffer()
diff --git a/src/migration-scripts/interfaces/20-to-21 b/src/migration-scripts/interfaces/20-to-21
index 4b0e70d35..bd89dcdb4 100755
--- a/src/migration-scripts/interfaces/20-to-21
+++ b/src/migration-scripts/interfaces/20-to-21
@@ -89,6 +89,21 @@ for ifname in config.list_nodes(base):
     if config.exists(base + [ifname, 'offload', 'ufo']):
         config.delete(base + [ifname, 'offload', 'ufo'])
 
+    # Also while processing the interface configuration, not all adapters support
+    # changing the speed and duplex settings. If the desired speed and duplex
+    # values do not work for the NIC driver, we change them back to the default
+    # value of "auto" - which will be applied if the CLI node is deleted.
+    speed_path = base + [ifname, 'speed']
+    duplex_path = base + [ifname, 'duplex']
+    # speed and duplex must always be set at the same time if not set to "auto"
+    if config.exists(speed_path) and config.exists(duplex_path):
+        speed = config.return_value(speed_path)
+        duplex = config.return_value(duplex_path)
+        if speed != 'auto' and duplex != 'auto':
+            if not eth.check_speed_duplex(speed, duplex):
+                config.delete(speed_path)
+                config.delete(duplex_path)
+
 try:
     with open(file_name, 'w') as f:
         f.write(config.to_string())