From 6c7dee608c98247d0474a412e513f1cfdac6d2b2 Mon Sep 17 00:00:00 2001
From: Jon Sherwood <thywyn@hotmail.com>
Date: Fri, 16 May 2025 13:23:00 -0400
Subject: [PATCH] Add interface name parameter for DPDK configs

Implemented parameter 'iface' in the nics dictionaries which allows
users to reference the interfaces by name instead of only 'pci_id' in
the values.yaml.  This can ease the configuration of interfaces that may
have differing PCI addresses among the servers. 'pci_id' will take
precedence if both are configured.

Change-Id: I93248bb580460c48fff01130d80e2bfe31dadf72
---
 .../_neutron-openvswitch-agent-init.sh.tpl    | 29 ++++++++++++++++---
 neutron/values.yaml                           |  6 ++++
 .../notes/neutron-b2247f89a5f258aa.yaml       | 11 +++++++
 3 files changed, 42 insertions(+), 4 deletions(-)
 create mode 100644 releasenotes/notes/neutron-b2247f89a5f258aa.yaml

diff --git a/neutron/templates/bin/_neutron-openvswitch-agent-init.sh.tpl b/neutron/templates/bin/_neutron-openvswitch-agent-init.sh.tpl
index bd0a64ac81..4facfdc99f 100644
--- a/neutron/templates/bin/_neutron-openvswitch-agent-init.sh.tpl
+++ b/neutron/templates/bin/_neutron-openvswitch-agent-init.sh.tpl
@@ -196,6 +196,12 @@ function process_dpdk_nics {
   while IFS= read -r nic; do
     local port_name=$(get_dpdk_config_value ${nic} '.name')
     local pci_id=$(get_dpdk_config_value ${nic} '.pci_id')
+    local iface=$(get_dpdk_config_value ${nic} '.iface')
+    if [ -n ${iface} ] && [ -z ${pci_id} ]; then
+      local pci_id=$(get_address_by_nicname ${iface})
+    else
+      iface=$(get_name_by_pci_id "${pci_id}")
+    fi
     local bridge=$(get_dpdk_config_value ${nic} '.bridge')
     local vf_index=$(get_dpdk_config_value ${nic} '.vf_index')
 
@@ -203,8 +209,6 @@ function process_dpdk_nics {
       migrate_ip "${pci_id}" "${bridge}"
     fi
 
-    iface=$(get_name_by_pci_id "${pci_id}")
-
     if [ -n "${iface}" ]; then
       ip link set ${iface} promisc on
       if [ -n "${vf_index}" ]; then
@@ -292,6 +296,12 @@ function process_dpdk_bonds {
     echo $bond | jq -r -c '.nics[]' > /tmp/nics_array
     while IFS= read -r nic; do
       local pci_id=$(get_dpdk_config_value ${nic} '.pci_id')
+      local iface=$(get_dpdk_config_value ${nic} '.iface')
+      if [ -n ${iface} ] && [ -z ${pci_id} ]; then
+        local pci_id=$(get_address_by_nicname ${iface})
+      else
+        iface=$(get_name_by_pci_id "${pci_id}")
+      fi
       local nic_name=$(get_dpdk_config_value ${nic} '.name')
       local pmd_rxq_affinity=$(get_dpdk_config_value ${nic} '.pmd_rxq_affinity')
       local vf_index=$(get_dpdk_config_value ${nic} '.vf_index')
@@ -302,8 +312,6 @@ function process_dpdk_bonds {
         ip_migrated=true
       fi
 
-      iface=$(get_name_by_pci_id "${pci_id}")
-
       if [ -n "${iface}" ]; then
         ip link set ${iface} promisc on
         if [ -n "${vf_index}" ]; then
@@ -407,6 +415,19 @@ function get_driver_by_address {
   fi
 }
 
+function get_address_by_nicname {
+  if [[ -e /sys/class/net/$1 ]]; then
+    local pci_address=$(readlink -f /sys/class/net/$1/device | xargs basename)
+    if [[ -e /sys/bus/pci/devices/${pci_address} ]]; then
+      echo ${pci_address}
+    else
+      echo "PCI id for interface $1 cannot be found" >&2
+    fi
+  else
+    echo "Interface name $1 cannot be found" >&2
+  fi
+}
+
 function init_ovs_dpdk_bridge {
   bridge=$1
   ovs-vsctl --db=unix:${OVS_SOCKET} --may-exist add-br ${bridge} \
diff --git a/neutron/values.yaml b/neutron/values.yaml
index 1691e00498..2c90e91c89 100644
--- a/neutron/values.yaml
+++ b/neutron/values.yaml
@@ -2223,6 +2223,9 @@ conf:
     # must NOT be provided here.
     nics:
       - name: dpdk0
+        # Optionally, instead of using pci_id you can use the name of
+        # the interface. If both are used, pci_id has presedence.
+        # iface: eth0
         pci_id: '0000:05:00.0'
         # Set VF Index in case some particular VF(s) need to be
         # used with ovs-dpdk.
@@ -2265,6 +2268,9 @@ conf:
     #     ovs_options: "bond_mode=active-backup"
     #     nics:
     #       - name: dpdk_b0s0
+    #         # Optionally, instead of using pci_id you can use the name of
+    #         # the interface. If both are used, pci_id has presedence.
+    #         # iface: eth0
     #         pci_id: '0000:06:00.0'
     #         pmd_rxq_affinity: "0:3,1:27"
     #         # Set VF Index in case some particular VF(s) need to be
diff --git a/releasenotes/notes/neutron-b2247f89a5f258aa.yaml b/releasenotes/notes/neutron-b2247f89a5f258aa.yaml
new file mode 100644
index 0000000000..4b3d180654
--- /dev/null
+++ b/releasenotes/notes/neutron-b2247f89a5f258aa.yaml
@@ -0,0 +1,11 @@
+---
+# To create a new release note related to a specific chart:
+# reno new <chart_name>
+#
+# To create a new release note for a common change (when multiple charts
+# are changed):
+# reno new common
+neutron:
+  - |
+    Add interface name parameter for DPDK configs
+...