From 761b4621b0bb36d2658ca25929b0270e3cfc9c77 Mon Sep 17 00:00:00 2001
From: Karthik S <ksundara@redhat.com>
Date: Tue, 12 May 2020 14:46:01 +0000
Subject: [PATCH] Skip VFs configured for DPDKs during NIC ordering

During NIC ordering all the VFs are expected to be skipped.
But if DPDK drivers are bound to a VF, then those VFs are still taken
in to account and is affecting the NIC ordering. The VFs bound to DPDK
drivers also shall be removed from the NIC ordering logic resulting in
consistency even with the re-run of os-net-config.

Change-Id: I50af9f75b01addae0e13830cc7a863072f9be34c
---
 os_net_config/tests/test_utils.py |  7 +++++++
 os_net_config/utils.py            | 24 +++++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/os_net_config/tests/test_utils.py b/os_net_config/tests/test_utils.py
index 177bde14..5fb6a563 100644
--- a/os_net_config/tests/test_utils.py
+++ b/os_net_config/tests/test_utils.py
@@ -562,6 +562,10 @@ class TestUtils(base.TestCase):
 
         tmpdir = tempfile.mkdtemp()
         self.stub_out('os_net_config.utils._SYS_CLASS_NET', tmpdir)
+        tmp_pci_dir = tempfile.mkdtemp()
+        self.stub_out('os_net_config.utils._SYS_BUS_PCI_DEV', tmp_pci_dir)
+        physfn_path = utils._SYS_BUS_PCI_DEV + '/0000:05:01.1/physfn'
+        os.makedirs(physfn_path)
 
         def test_is_available_nic(interface_name, check_active):
             return True
@@ -577,6 +581,8 @@ class TestUtils(base.TestCase):
                                'vfio-pci')
         utils._update_dpdk_map('p3p1', '0000:04:00.0', '01:02:03:04:05:07',
                                'igb_uio')
+        utils._update_dpdk_map('p3p0_0', '0000:05:01.1', 'AA:02:03:04:05:FF',
+                               'vfio-pci')
 
         nics = utils.ordered_active_nics()
 
@@ -592,6 +598,7 @@ class TestUtils(base.TestCase):
         self.assertEqual('z1', nics[9])
 
         shutil.rmtree(tmpdir)
+        shutil.rmtree(tmp_pci_dir)
 
     def test_interface_mac_raises(self):
         self.assertRaises(IOError, utils.interface_mac, 'ens20f2p3')
diff --git a/os_net_config/utils.py b/os_net_config/utils.py
index 56e54ad9..9fc0992b 100644
--- a/os_net_config/utils.py
+++ b/os_net_config/utils.py
@@ -27,6 +27,7 @@ from oslo_concurrency import processutils
 
 logger = logging.getLogger(__name__)
 _SYS_CLASS_NET = '/sys/class/net'
+_SYS_BUS_PCI_DEV = '/sys/bus/pci/devices'
 # File to contain the DPDK mapped nics, as nic name will not be available after
 # binding driver, which is required for correct nic numbering.
 # Format of the file (list mapped nic's details):
@@ -149,6 +150,23 @@ def is_real_nic(interface_name):
         return False
 
 
+def _is_vf(pci_address):
+
+    # If DPDK drivers are bound on a VF, then the path _SYS_CLASS_NET
+    # wouldn't exist. Instead we look for the path
+    # /sys/bus/pci/devices/<PCI addr>/physfn to understand if the device
+    # is actually a VF. This path could be used by VFs not bound with
+    # DPDK drivers as well
+
+    vf_path_check = _SYS_BUS_PCI_DEV + '/%s/physfn' % pci_address
+    is_sriov_vf = os.path.isdir(vf_path_check)
+    if is_sriov_vf:
+        return True
+
+    # nic is not VF
+    return False
+
+
 def _is_available_nic(interface_name, check_active=True):
     try:
         if interface_name == 'lo':
@@ -222,8 +240,12 @@ def _ordered_nics(check_active):
     if contents:
         dpdk_map = yaml.safe_load(contents)
         for item in dpdk_map:
+            # If the DPDK drivers are bound to a VF, the same needs
+            # to be skipped for the NIC ordering
             nic = item['name']
-            if _is_embedded_nic(nic):
+            if _is_vf(item['pci_address']):
+                logger.info("%s is a VF, skipping it for NIC ordering" % nic)
+            elif _is_embedded_nic(nic):
                 logger.info("%s is an embedded DPDK bound nic" % nic)
                 embedded_nics.append(nic)
             else: