[libvirt] [PATCH v3 33/36] lxc, libxl: notify network driver of NICs during reconnect

[Daniel P. Berrangé]

When starting up it is important to notify the network driver of any
NICs which are used by running guests so that it can account for any
resources they are using.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/libxl/libxl_driver.c | 30 ++++++++++++++++++++++++++++++
 src/lxc/lxc_process.c    | 30 ++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
index 3bb93ab5d7..04f218303a 100644
--- a/src/libxl/libxl_driver.c
+++ b/src/libxl/libxl_driver.c
@@ -352,6 +352,34 @@ libxlAutostartDomain(virDomainObjPtr vm,
     return ret;
 }
 
+
+static void
+libxlReconnectNotifyNets(virDomainDefPtr def)
+{
+    size_t i;
+    virConnectPtr conn = NULL;
+
+    for (i = 0; i < def->nnets; i++) {
+        virDomainNetDefPtr net = def->nets[i];
+        /* keep others from trying to use the macvtap device name, but
+         * don't return error if this happens, since that causes the
+         * domain to be unceremoniously killed, which would be *very*
+         * impolite.
+         */
+        if (virDomainNetGetActualType(net) == VIR_DOMAIN_NET_TYPE_DIRECT)
+           ignore_value(virNetDevMacVLanReserveName(net->ifname, false));
+
+        if (net->type == VIR_DOMAIN_NET_TYPE_NETWORK) {
+            if (!conn && !(conn = virGetConnectNetwork()))
+                continue;
+            virDomainNetNotifyActualDevice(conn, def, net);
+        }
+    }
+
+    virObjectUnref(conn);
+}
+
+
 /*
  * Reconnect to running domains that were previously started/created
  * with libxenlight driver.
@@ -424,6 +452,8 @@ libxlReconnectDomain(virDomainObjPtr vm,
     /* Enable domain death events */
     libxl_evenable_domain_death(cfg->ctx, vm->def->id, 0, &priv->deathW);
 
+    libxlReconnectNotifyNets(vm->def);
+
     /* now that we know it's reconnected call the hook if present */
     if (virHookPresent(VIR_HOOK_DRIVER_LIBXL) &&
         STRNEQ("Domain-0", vm->def->name)) {
diff --git a/src/lxc/lxc_process.c b/src/lxc/lxc_process.c
index d9362c5ff6..a66bf66839 100644
--- a/src/lxc/lxc_process.c
+++ b/src/lxc/lxc_process.c
@@ -1642,6 +1642,34 @@ virLXCProcessAutostartAll(virLXCDriverPtr driver)
     virObjectUnref(conn);
 }
 
+
+static void
+virLXCProcessReconnectNotifyNets(virDomainDefPtr def)
+{
+    size_t i;
+    virConnectPtr conn = NULL;
+
+    for (i = 0; i < def->nnets; i++) {
+        virDomainNetDefPtr net = def->nets[i];
+        /* keep others from trying to use the macvtap device name, but
+         * don't return error if this happens, since that causes the
+         * domain to be unceremoniously killed, which would be *very*
+         * impolite.
+         */
+        if (virDomainNetGetActualType(net) == VIR_DOMAIN_NET_TYPE_DIRECT)
+           ignore_value(virNetDevMacVLanReserveName(net->ifname, false));
+
+        if (net->type == VIR_DOMAIN_NET_TYPE_NETWORK) {
+            if (!conn && !(conn = virGetConnectNetwork()))
+                continue;
+            virDomainNetNotifyActualDevice(conn, def, net);
+        }
+    }
+
+    virObjectUnref(conn);
+}
+
+
 static int
 virLXCProcessReconnectDomain(virDomainObjPtr vm,
                              void *opaque)
@@ -1688,6 +1716,8 @@ virLXCProcessReconnectDomain(virDomainObjPtr vm,
                                            vm->def, vm->pid) < 0)
             goto error;
 
+        virLXCProcessReconnectNotifyNets(vm->def);
+
         /* now that we know it's reconnected call the hook if present */
         if (virHookPresent(VIR_HOOK_DRIVER_LXC)) {
             char *xml = virDomainDefFormat(vm->def, driver->caps, 0);
-- 
2.20.1