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 25b38a374e3c3db8509ce34c1addf739d47f77ef..dd5919ec408bf6ec9f37d44727c9e4d19416f5d0 100644 (file)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -1051,7 +1051,8 @@ 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 6e42cb03e226abeae15180521d40db3e80c02f7b..456db7c28a34ce9d154e27504e361806eae945c2 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -1580,6 +1580,10 @@ 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 15ebd54266049794f913e11a58bc40785c56f161..8113ac17ab70ada33b8b071a5d94bc606b7dd6c6 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2313,6 +2313,18 @@ 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;
@@ -2409,6 +2421,11 @@ 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) {
@@ -2440,6 +2457,7 @@ 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);
@@ -2479,6 +2497,7 @@ 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);