Merge "Fix - os-vif fails to get the correct UpLink Representor"

releasenotes/notes/bug-1892132-812e6d5ce0588ebb.yaml

@@ -0,0 +1,10 @@
+---
+fixes:
+  - |
+    Linux kernel 5.8 changed the sysfs interface that is used to
+    discover the interfaces used for OVS offloads for certain NIC
+    models. This results in network plugging failure, as described
+    in `bug #1892132`_. This release fixes the plugging issue by
+    properly handling the new sysfs structure.
+
+    .. _bug #1892132: https://bugs.launchpad.net/os-vif/+bug/1892132

vif_plug_ovs/linux_net.py

@@ -45,6 +45,8 @@ VF_RE = re.compile(r"vf(\d+)", re.IGNORECASE)
 PF_RE = re.compile(r"pf(\d+)", re.IGNORECASE)
 # bus_info (bdf) contains <bus>:<dev>.<func>
 PF_FUNC_RE = re.compile(r"\.(\d+)", 0)
+# phys_port_name contains p##
+UPLINK_PORT_RE = re.compile(r"p(\d+)", re.IGNORECASE)
 
 _SRIOV_TOTALVFS = "sriov_totalvfs"
 NIC_NAME_LEN = 14
@@ -328,12 +330,28 @@ def get_ifname_by_pci_address(pci_addr, pf_interface=False, switchdev=False):
     itself based on the argument of pf_interface.
     """
     dev_path = _get_sysfs_netdev_path(pci_addr, pf_interface)
-    # make the if statement later more readable
-    ignore_switchdev = not switchdev
     try:
-        for netdev in os.listdir(dev_path):
-            if ignore_switchdev or _is_switchdev(netdev):
-                return netdev
+        devices = os.listdir(dev_path)
+
+        # Return the first netdev in case of switchdev=False
+        if not switchdev:
+            return devices[0]
+        elif pf_interface:
+            fallback_netdev = None
+            for netdev in devices:
+                # Return the uplink representor in case of switchdev=True
+                if _is_switchdev(netdev):
+                    fallback_netdev = netdev if fallback_netdev is None \
+                        else fallback_netdev
+                    phys_port_name = _get_phys_port_name(netdev)
+                    if phys_port_name is not None and \
+                            UPLINK_PORT_RE.search(phys_port_name):
+                        return netdev
+
+            # Fallback to first switchdev netdev in case of switchdev=True
+            if fallback_netdev is not None:
+                return fallback_netdev
+
     except Exception:
         raise exception.PciDeviceNotFoundById(id=pci_addr)
     raise exception.PciDeviceNotFoundById(id=pci_addr)

vif_plug_ovs/tests/unit/test_linux_net.py

@@ -261,26 +261,64 @@ class LinuxNetTest(testtools.TestCase):
 
     @mock.patch.object(os, 'listdir')
     @mock.patch.object(linux_net, '_get_phys_switch_id')
+    @mock.patch.object(linux_net, "_get_phys_port_name")
     def test_physical_function_interface_name(
-            self, mock__get_phys_switch_id, mock_listdir):
+            self, mock__get_phys_port_name, mock__get_phys_switch_id,
+            mock_listdir):
         mock_listdir.return_value = ['foo', 'bar']
         mock__get_phys_switch_id.side_effect = (
             ['', 'valid_switch'])
+        mock__get_phys_port_name.side_effect = (["p1"])
         ifname = linux_net.get_ifname_by_pci_address(
             '0000:00:00.1', pf_interface=True, switchdev=False)
         self.assertEqual(ifname, 'foo')
 
     @mock.patch.object(os, 'listdir')
-    @mock.patch.object(linux_net, '_get_phys_switch_id')
+    @mock.patch.object(linux_net, "_get_phys_switch_id")
+    @mock.patch.object(linux_net, "_get_phys_port_name")
     def test_physical_function_interface_name_with_switchdev(
-            self, mock__get_phys_switch_id, mock_listdir):
+            self, mock__get_phys_port_name, mock__get_phys_switch_id,
+            mock_listdir):
         mock_listdir.return_value = ['foo', 'bar']
         mock__get_phys_switch_id.side_effect = (
             ['', 'valid_switch'])
+        mock__get_phys_port_name.side_effect = (["p1s0"])
         ifname = linux_net.get_ifname_by_pci_address(
             '0000:00:00.1', pf_interface=True, switchdev=True)
         self.assertEqual(ifname, 'bar')
 
+    @mock.patch.object(os, 'listdir')
+    @mock.patch.object(linux_net, "_get_phys_switch_id")
+    @mock.patch.object(linux_net, "_get_phys_port_name")
+    def test_physical_function_interface_name_with_representors(
+            self, mock__get_phys_port_name, mock__get_phys_switch_id,
+            mock_listdir):
+        # Get the PF that matches the phys_port_name regex
+        mock_listdir.return_value = ['enp2s0f0_0', 'enp2s0f0_1', 'enp2s0f0']
+        mock__get_phys_switch_id.side_effect = (
+            ['valid_switch', 'valid_switch', 'valid_switch'])
+        mock__get_phys_port_name.side_effect = (["pf0vf0", "pf0vf1", "p0"])
+        ifname = linux_net.get_ifname_by_pci_address(
+            '0000:00:00.1', pf_interface=True, switchdev=True)
+        self.assertEqual(ifname, 'enp2s0f0')
+
+    @mock.patch.object(os, 'listdir')
+    @mock.patch.object(linux_net, "_get_phys_switch_id")
+    @mock.patch.object(linux_net, "_get_phys_port_name")
+    def test_physical_function_interface_name_with_fallback_To_first_netdev(
+            self, mock__get_phys_port_name, mock__get_phys_switch_id,
+            mock_listdir):
+        # Try with switchdev mode to get PF but fail because there is no match
+        # for the phys_port_name then fallback to first interface found
+        mock_listdir.return_value = ['enp2s0f0_0', 'enp2s0f0_1', 'enp2s0f0']
+        mock__get_phys_switch_id.side_effect = (['valid_switch',
+                                                 'valid_switch',
+                                                 'valid_switch'])
+        mock__get_phys_port_name.side_effect = (["pf0vf0", "pf0vf1", "pf0vf2"])
+        ifname = linux_net.get_ifname_by_pci_address(
+            '0000:00:00.1', pf_interface=True, switchdev=True)
+        self.assertEqual(ifname, 'enp2s0f0_0')
+
     @mock.patch.object(os, 'listdir')
     def test_get_ifname_by_pci_address_exception(self, mock_listdir):
         mock_listdir.side_effect = OSError('No such file or directory')