hv_netvsc: Mark VF as slave before exposing it to user-mode

When a VF is being exposed form the kernel, it should be marked as "slave"
before exposing to the user-mode. The VF is not usable without netvsc
running as master. The user-mode should never see a VF without the "slave"
flag.

This commit moves the code of setting the slave flag to the time before
VF is exposed to user-mode.

Cc: stable@vger.kernel.org
Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index b7dfd51f09e60ef5ab65aae4186b4f49d621cca6..706ea5263e879df8b4bff89cd4408e151f4615cd 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2206,9 +2206,6 @@ static int netvsc_vf_join(struct net_device *vf_netdev,
                goto upper_link_failed;
        }
 
-       /* set slave flag before open to prevent IPv6 addrconf */
-       vf_netdev->flags |= IFF_SLAVE;
-
        schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
 
        call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2315,16 +2312,18 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 
        }
 
-       /* Fallback path to check synthetic vf with
-        * help of mac addr
+       /* Fallback path to check synthetic vf with help of mac addr.
+        * Because this function can be called before vf_netdev is
+        * initialized (NETDEV_POST_INIT) when its perm_addr has not been copied
+        * from dev_addr, also try to match to its dev_addr.
+        * Note: On Hyper-V and Azure, it's not possible to set a MAC address
+        * on a VF that matches to the MAC of a unrelated NETVSC device.
         */
        list_for_each_entry(ndev_ctx, &netvsc_dev_list, list) {
                ndev = hv_get_drvdata(ndev_ctx->device_ctx);
-               if (ether_addr_equal(vf_netdev->perm_addr, ndev->perm_addr)) {
-                       netdev_notice(vf_netdev,
-                                     "falling back to mac addr based matching\n");
+               if (ether_addr_equal(vf_netdev->perm_addr, ndev->perm_addr) ||
+                   ether_addr_equal(vf_netdev->dev_addr, ndev->perm_addr))
                        return ndev;
-               }
        }
 
        netdev_notice(vf_netdev,
@@ -2332,6 +2331,19 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
        return NULL;
 }
 
+static int netvsc_prepare_bonding(struct net_device *vf_netdev)
+{
+       struct net_device *ndev;
+
+       ndev = get_netvsc_byslot(vf_netdev);
+       if (!ndev)
+               return NOTIFY_DONE;
+
+       /* set slave flag before open to prevent IPv6 addrconf */
+       vf_netdev->flags |= IFF_SLAVE;
+       return NOTIFY_DONE;
+}
+
 static int netvsc_register_vf(struct net_device *vf_netdev)
 {
        struct net_device_context *net_device_ctx;
@@ -2758,6 +2770,8 @@ static int netvsc_netdev_event(struct notifier_block *this,
                return NOTIFY_DONE;
 
        switch (event) {
+       case NETDEV_POST_INIT:
+               return netvsc_prepare_bonding(event_dev);
        case NETDEV_REGISTER:
                return netvsc_register_vf(event_dev);
        case NETDEV_UNREGISTER: