If hv_netvsc driver is removed and reloaded, the NET_DEVICE_REGISTER handler cannot perform VF register successfully as the register call is received before netvsc_probe is finished. This is because we register register_netdevice_notifier() very early(even before vmbus_driver_register()). To fix this, we try to register each such matching VF( if it is visible as a netdevice) at the end of netvsc_probe.
Cc: stable@vger.kernel.org Fixes: 85520856466e ("hv_netvsc: Fix race of register_netdevice_notifier and VF register") Suggested-by: Dexuan Cui decui@microsoft.com Signed-off-by: Shradha Gupta shradhagupta@linux.microsoft.com Tested-on: Ubuntu22 Testcases: LISA testsuites verify_reload_hyperv_modules, perf_tcp_ntttcp_sriov --- drivers/net/hyperv/netvsc_drv.c | 49 ++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 7 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 706ea5263e87..25c4dc9cc4bd 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -42,6 +42,10 @@ #define LINKCHANGE_INT (2 * HZ) #define VF_TAKEOVER_INT (HZ / 10)
+/* Macros to define the context of vf registration */ +#define VF_REG_IN_PROBE 1 +#define VF_REG_IN_RECV_CBACK 2 + static unsigned int ring_size __ro_after_init = 128; module_param(ring_size, uint, 0444); MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)"); @@ -2183,7 +2187,7 @@ static rx_handler_result_t netvsc_vf_handle_frame(struct sk_buff **pskb) }
static int netvsc_vf_join(struct net_device *vf_netdev, - struct net_device *ndev) + struct net_device *ndev, int context) { struct net_device_context *ndev_ctx = netdev_priv(ndev); int ret; @@ -2205,8 +2209,11 @@ static int netvsc_vf_join(struct net_device *vf_netdev, ndev->name, ret); goto upper_link_failed; } - - schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT); + /* If this registration is called from probe context vf_takeover + * is taken care of later in probe itself. + */ + if (context == VF_REG_IN_RECV_CBACK) + schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);
call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2344,7 +2351,7 @@ static int netvsc_prepare_bonding(struct net_device *vf_netdev) return NOTIFY_DONE; }
-static int netvsc_register_vf(struct net_device *vf_netdev) +static int netvsc_register_vf(struct net_device *vf_netdev, int context) { struct net_device_context *net_device_ctx; struct netvsc_device *netvsc_dev; @@ -2384,7 +2391,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
netdev_info(ndev, "VF registering: %s\n", vf_netdev->name);
- if (netvsc_vf_join(vf_netdev, ndev) != 0) + if (netvsc_vf_join(vf_netdev, ndev, context) != 0) return NOTIFY_DONE;
dev_hold(vf_netdev); @@ -2485,7 +2492,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) static int netvsc_probe(struct hv_device *dev, const struct hv_vmbus_device_id *dev_id) { - struct net_device *net = NULL; + struct net_device *net = NULL, *vf_netdev; struct net_device_context *net_device_ctx; struct netvsc_device_info *device_info = NULL; struct netvsc_device *nvdev; @@ -2597,6 +2604,34 @@ static int netvsc_probe(struct hv_device *dev, }
list_add(&net_device_ctx->list, &netvsc_dev_list); + + /* When the hv_netvsc driver is removed and readded, the + * NET_DEVICE_REGISTER for the vf device is replayed before probe + * is complete. This is because register_netdevice_notifier() gets + * registered before vmbus_driver_register() so that callback func + * is set before probe and we don't miss events like NETDEV_POST_INIT + * So, in this section we try to register each matching + * vf device that is present as a netdevice, knowing that it's register + * call is not processed in the netvsc_netdev_notifier(as probing is + * progress and get_netvsc_byslot fails). + */ + for_each_netdev(dev_net(net), vf_netdev) { + if (vf_netdev->netdev_ops == &device_ops) + continue; + + if (vf_netdev->type != ARPHRD_ETHER) + continue; + + if (is_vlan_dev(vf_netdev)) + continue; + + if (netif_is_bond_master(vf_netdev)) + continue; + + netvsc_prepare_bonding(vf_netdev); + netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE); + __netvsc_vf_setup(net, vf_netdev); + } rtnl_unlock();
netvsc_devinfo_put(device_info); @@ -2773,7 +2808,7 @@ static int netvsc_netdev_event(struct notifier_block *this, case NETDEV_POST_INIT: return netvsc_prepare_bonding(event_dev); case NETDEV_REGISTER: - return netvsc_register_vf(event_dev); + return netvsc_register_vf(event_dev, VF_REG_IN_RECV_CBACK); case NETDEV_UNREGISTER: return netvsc_unregister_vf(event_dev); case NETDEV_UP: