From 59c60cccf54bcb8067c20b5e4751c8c041498058 Mon Sep 17 00:00:00 2001
From: Fernando Fernandez Mancera <ffmancera@riseup.net>
Date: Tue, 22 Feb 2022 15:51:09 +0100
Subject: [PATCH] ovsdb: set DPDK port MTU when creating them

The DPDK port will not have a link after the devbind which is needed for
configuring an interface to be a DPDK port. The MTU is being committed
during the link change but for DPDK ports there is no link.

The DPDK port MTU should be set on ovsdb right after the interface is
added to ovsdb. This way the users will be able to set MTU for DPDK
ports and modify it.

Please see the following results:
```
  port 2: iface0 (dpdk: configured_rx_queues=1, configured_rxq_descriptors=2048, configured_tx_queues=3,
configured_txq_descriptors=2048, lsc_interrupt_mode=false, mtu=2000, requested_rx_queues=1,
requested_rxq_descriptors=2048, requested_tx_queues=3, requested_txq_descriptors=2048, rx_csum_offload=true, tx_tso_offload=false)
```
---
 src/core/devices/ovs/nm-device-ovs-port.c | 46 ++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/core/devices/ovs/nm-device-ovs-port.c b/src/core/devices/ovs/nm-device-ovs-port.c
index 500dbc0fdd..8406c3648c 100644
--- a/src/core/devices/ovs/nm-device-ovs-port.c
+++ b/src/core/devices/ovs/nm-device-ovs-port.c
@@ -15,7 +15,8 @@
 #include "nm-active-connection.h"
 #include "nm-setting-connection.h"
 #include "nm-setting-ovs-port.h"
-#include "nm-setting-ovs-port.h"
+#include "nm-setting-ovs-interface.h"
+#include "nm-setting-wired.h"
 
 #define _NMLOG_DEVICE_TYPE NMDeviceOvsPort
 #include "devices/nm-device-logging.h"
@@ -87,6 +88,33 @@ add_iface_cb(GError *error, gpointer user_data)
     g_object_unref(slave);
 }
 
+static gboolean
+_ovs_interface_is_dpdk(NMDevice *device)
+{
+    NMSettingOvsInterface *s_ovs_iface;
+
+    s_ovs_iface = nm_device_get_applied_setting(device, NM_TYPE_SETTING_OVS_INTERFACE);
+
+    g_return_val_if_fail(s_ovs_iface, FALSE);
+
+    return nm_streq(nm_setting_ovs_interface_get_interface_type(s_ovs_iface), "dpdk");
+}
+
+static void
+set_mtu_cb(GError *error, gpointer user_data)
+{
+    NMDevice *self = user_data;
+
+    if (error && !g_error_matches(error, NM_UTILS_ERROR, NM_UTILS_ERROR_CANCELLED_DISPOSING)) {
+        _LOGW(LOGD_DEVICE,
+              "could not change mtu of '%s': %s",
+              nm_device_get_iface(self),
+              error->message);
+    }
+
+    g_object_unref(self);
+}
+
 static gboolean
 enslave_slave(NMDevice *device, NMDevice *slave, NMConnection *connection, gboolean configure)
 {
@@ -94,6 +122,7 @@ enslave_slave(NMDevice *device, NMDevice *slave, NMConnection *connection, gbool
     NMActiveConnection *ac_port   = NULL;
     NMActiveConnection *ac_bridge = NULL;
     NMDevice           *bridge_device;
+    NMSettingWired     *s_wired;
 
     if (!configure)
         return TRUE;
@@ -122,6 +151,21 @@ enslave_slave(NMDevice *device, NMDevice *slave, NMConnection *connection, gbool
                            add_iface_cb,
                            g_object_ref(slave));
 
+    /* DPDK ports does not have a link after the devbind, so the MTU must be
+     * set on ovsdb after adding the interface. */
+    if (NM_IS_DEVICE_OVS_INTERFACE(slave) && _ovs_interface_is_dpdk(slave)) {
+        s_wired = nm_device_get_applied_setting(slave, NM_TYPE_SETTING_WIRED);
+
+        if (!s_wired || !nm_setting_wired_get_mtu(s_wired))
+            return TRUE;
+
+        nm_ovsdb_set_interface_mtu(nm_ovsdb_get(),
+                                   nm_device_get_ip_iface(slave),
+                                   nm_setting_wired_get_mtu(s_wired),
+                                   set_mtu_cb,
+                                   g_object_ref(slave));
+    }
+
     return TRUE;
 }