sriov: accept setting the eswitch mode without VFs

The embedded switch mode can be set even if the interface doesn't have
any virtual functions. This is a requisite to use the PF with only
scalable functions for example.

With this change, the presence of the 'embedded-switch-mode' will be
enough to identify the interface as a PF and emit the systemd services
required to apply the configuration.

The changes required by the CLI will be done is the next commit.

src/sriov.c

@@ -118,13 +118,18 @@ netplan_state_finish_sriov_write(const NetplanState* np_state, const char* rootd
         GHashTable* rebind_pfs = g_hash_table_new(g_str_hash, g_str_equal);
         GHashTable* apply_pfs = g_hash_table_new(g_str_hash, g_str_equal);
 
-        /* Find netdev interface names for SR-IOV PFs*/
+        /* Find netdev interface names for SR-IOV PFs
+         * We consider an interface to be a PF if at least of the conditions below is true:
+         * 1) the user explicitly set a desired number of VFs
+         * 2) there is at least one interface with a link to it (meaning the interface is a VF of this PF)
+         * 3) the user set the embedded-switch-mode (which can be applied regardless if the interface has VFs) 
+         * */
         for (GList* iterator = np_state->netdefs_ordered; iterator; iterator = iterator->next) {
             def = (NetplanNetDefinition*) iterator->data;
             pf = NULL;
-            if (def->sriov_explicit_vf_count < G_MAXUINT || def->sriov_link) {
+            if (def->sriov_explicit_vf_count < G_MAXUINT || def->sriov_link || def->embedded_switch_mode) {
                 any_sriov = TRUE;
-                if (def->sriov_explicit_vf_count < G_MAXUINT)
+                if (def->sriov_explicit_vf_count < G_MAXUINT || def->embedded_switch_mode)
                     pf = def;
                 else if (def->sriov_link)
                     pf = def->sriov_link;

src/validation.c

@@ -474,9 +474,10 @@ validate_sriov_rules(const NetplanParser* npp, NetplanNetDefinition* nd, GError*
                 }
             }
         }
-        gboolean eswitch_mode = (nd->embedded_switch_mode ||
-                                 nd->sriov_delay_virtual_functions_rebind);
-        if (eswitch_mode && !is_sriov_pf) {
+        /* Does it set the eswitch mode? It can be set regardless if the interface has VFs */
+        if (nd->embedded_switch_mode)
+            is_sriov_pf = TRUE;
+        if (nd->sriov_delay_virtual_functions_rebind && !is_sriov_pf) {
             valid = yaml_error(npp, node, error, "%s: This is not a SR-IOV PF", nd->id);
             goto sriov_rules_error;
         }

tests/test_sriov.py

@@ -1112,17 +1112,44 @@ def test_eswitch_mode(self):
 Description=(Re-)bind SR-IOV Virtual Functions to their driver
 After=network.target
 After=netplan-sriov-apply.service
-After=sys-subsystem-net-devices-enblue.device
 After=sys-subsystem-net-devices-engreen.device
+After=sys-subsystem-net-devices-enblue.device
 
 [Service]
 Type=oneshot
-ExecStart=/usr/sbin/netplan rebind --debug enblue engreen
+ExecStart=/usr/sbin/netplan rebind --debug engreen enblue
 ''', 'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
 DefaultDependencies=no
 Before=network-pre.target
+After=sys-subsystem-net-devices-engreen.device
 After=sys-subsystem-net-devices-enblue.device
+
+[Service]
+Type=oneshot
+ExecStart=/usr/sbin/netplan apply --sriov-only
+'''})
+
+    def test_eswitch_mode_sets_interface_as_pf(self):
+        self.generate('''network:
+  version: 2
+  ethernets:
+    engreen:
+      embedded-switch-mode: switchdev
+      delay-virtual-functions-rebind: true''')
+        self.assert_sriov({'rebind.service': '''[Unit]
+Description=(Re-)bind SR-IOV Virtual Functions to their driver
+After=network.target
+After=netplan-sriov-apply.service
+After=sys-subsystem-net-devices-engreen.device
+
+[Service]
+Type=oneshot
+ExecStart=/usr/sbin/netplan rebind --debug engreen
+''', 'apply.service': '''[Unit]
+Description=Apply SR-IOV configuration
+DefaultDependencies=no
+Before=network-pre.target
 After=sys-subsystem-net-devices-engreen.device
 
 [Service]
@@ -1159,18 +1186,18 @@ def test_rebind_service_generation(self):
 Description=(Re-)bind SR-IOV Virtual Functions to their driver
 After=network.target
 After=netplan-sriov-apply.service
-After=sys-subsystem-net-devices-enblue.device
 After=sys-subsystem-net-devices-engreen.device
+After=sys-subsystem-net-devices-enblue.device
 
 [Service]
 Type=oneshot
-ExecStart=/usr/sbin/netplan rebind --debug enblue engreen
+ExecStart=/usr/sbin/netplan rebind --debug engreen enblue
 ''', 'apply.service': '''[Unit]
 Description=Apply SR-IOV configuration
 DefaultDependencies=no
 Before=network-pre.target
-After=sys-subsystem-net-devices-enblue.device
 After=sys-subsystem-net-devices-engreen.device
+After=sys-subsystem-net-devices-enblue.device
 
 [Service]
 Type=oneshot
@@ -1223,7 +1250,7 @@ def test_invalid_not_a_pf(self):
   version: 2
   ethernets:
     engreen:
-      embedded-switch-mode: legacy''', expect_fail=True)
+      delay-virtual-functions-rebind: true''', expect_fail=True)
         self.assertIn("This is not a SR-IOV PF", err)
 
     def test_invalid_eswitch_mode(self):