hv_netvsc: Fix race between VF offering and VF association message from host

commit 365e1ececb2905f94cc10a5817c5b644a32a3ae2 upstream.

During vm boot, there might be possibility that vf registration
call comes before the vf association from host to vm.

And this might break netvsc vf path, To prevent the same block
vf registration until vf bind message comes from host.

Cc: stable@vger.kernel.org
Fixes: 00d7ddba11436 ("hv_netvsc: pair VF based on serial number")
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Gaurav Kohli <gauravkohli@linux.microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index bc48855dff10ba135c3573914da6ffc9503f95d2..aab6cb5163fea6a16b9721f8b96d3e16748383db 100644 (file)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1037,7 +1037,8 @@ struct net_device_context {
        u32 vf_alloc;
        /* Serial number of the VF to team with */
        u32 vf_serial;
-
+       /* completion variable to confirm vf association */
+       struct completion vf_add;
        /* Is the current data path through the VF NIC? */
        bool  data_path_is_vf;
 

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 7bd9354128534e081eeece404d876475d0730a1c..fb2448f9a8b17242988d61523f445c2a392cc929 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1450,6 +1450,10 @@ static void netvsc_send_vf(struct net_device *ndev,
 
        net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
        net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
+
+       if (net_device_ctx->vf_alloc)
+               complete(&net_device_ctx->vf_add);
+
        netdev_info(ndev, "VF slot %u %s\n",
                    net_device_ctx->vf_serial,
                    net_device_ctx->vf_alloc ? "added" : "removed");

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index ae4577731e3e2dd0c6eeb623570029c3c6010bd3..ec622e909a6851f21bad2646c3e6e6a786c89783 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2336,6 +2336,18 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 
        }
 
+       /* Fallback path to check synthetic vf with
+        * help of mac addr
+        */
+       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");
+                       return ndev;
+               }
+       }
+
        netdev_notice(vf_netdev,
                      "no netdev found for vf serial:%u\n", serial);
        return NULL;
@@ -2432,6 +2444,11 @@ static int netvsc_vf_changed(struct net_device *vf_netdev, unsigned long event)
        if (net_device_ctx->data_path_is_vf == vf_is_up)
                return NOTIFY_OK;
 
+       if (vf_is_up && !net_device_ctx->vf_alloc) {
+               netdev_info(ndev, "Waiting for the VF association from host\n");
+               wait_for_completion(&net_device_ctx->vf_add);
+       }
+
        ret = netvsc_switch_datapath(ndev, vf_is_up);
 
        if (ret) {
@@ -2463,6 +2480,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
 
        netvsc_vf_setxdp(vf_netdev, NULL);
 
+       reinit_completion(&net_device_ctx->vf_add);
        netdev_rx_handler_unregister(vf_netdev);
        netdev_upper_dev_unlink(vf_netdev, ndev);
        RCU_INIT_POINTER(net_device_ctx->vf_netdev, NULL);
@@ -2502,6 +2520,7 @@ static int netvsc_probe(struct hv_device *dev,
 
        INIT_DELAYED_WORK(&net_device_ctx->dwork, netvsc_link_change);
 
+       init_completion(&net_device_ctx->vf_add);
        spin_lock_init(&net_device_ctx->lock);
        INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
        INIT_DELAYED_WORK(&net_device_ctx->vf_takeover, netvsc_vf_setup);