From nobody Tue Dec 23 12:23:17 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC761F4EA; Fri, 2 Feb 2024 04:40:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706848841; cv=none; b=N9qHawXh7UP5WJHekp6g7Xv7PL7kDyr84YNqhj3YQ0pOdRSCmtOjO/82/oj/iBgzJ4E+azgxZQCNhei6PvozhCJevyq7gor5xEsV/5PCtgEZbK6NLyu/v52nnWKw5BIZ5F4rQDk4D5fNqqA+iFXPTABv5U80w+yJR4PgRDyVDWU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706848841; c=relaxed/simple; bh=KmlbEq3PO/srZBOCNisfz+EqGLgCMlx0Mf4zLb30HiI=; h=From:To:Cc:Subject:Date:Message-Id; b=GAy5bTWnreOYrYtGVXrc7vhytrNFosd5NVwxrtGq1SutXiHfzMAHkohji8pynaH5+3EMAVOdOYaGM8swrZ2+5Tb6oeUqAgeWSOBK/JSYapV9YSHaU/SjcDEXtxS0A2yfT1ND2bjjcNHulvrtr9nB8fFs76BlhQr+JKYsNWz3Qag= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=QLwOyes5; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="QLwOyes5" Received: by linux.microsoft.com (Postfix, from userid 1134) id 2957B206FCE0; Thu, 1 Feb 2024 20:40:39 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2957B206FCE0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1706848839; bh=QySjbmai9GE4fttBeHnyPhjnPJbHO88dUi9nFOfGmao=; h=From:To:Cc:Subject:Date:From; b=QLwOyes55GeO8JttIh47g7AUqqiDlOaDt3TFG3gWC7Ts/DdkBrtQfh85o1++ecdYw tOJzZrcxNpCHPc3JzOGBHn4AiIHj+u2FXvv2aTIkOJuQlm2cgcJaCP3PeVFuaztpnx XDP0SGYgRT2/idBBfLtYgW+PYgimiRZ7m7kEybBM= From: Shradha Gupta To: "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Wojciech Drewek , linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Shradha Gupta , shradhagupta@microsoft.com, stable@vger.kernel.org Subject: [PATCH net,v2] hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed Date: Thu, 1 Feb 2024 20:40:38 -0800 Message-Id: <1706848838-24848-1-git-send-email-shradhagupta@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If hv_netvsc driver is unloaded 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 an= d VF register") Suggested-by: Dexuan Cui Signed-off-by: Shradha Gupta --- Changes in v2: * Fixed the subject line of patch with branch details(net) * Added the logic to attach just the one right vf during register * Corrected comment messages * Renamed the context marco with a more appropriate name * Created a new function to avoid code repetition. --- drivers/net/hyperv/netvsc_drv.c | 82 +++++++++++++++++++++++++-------- 1 file changed, 62 insertions(+), 20 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_dr= v.c index 273bd8a20122..11831a1c9762 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) =20 +/* Macros to define the context of vf registration */ +#define VF_REG_IN_PROBE 1 +#define VF_REG_IN_NOTIFIER 2 + static unsigned int ring_size __ro_after_init =3D 128; module_param(ring_size, uint, 0444); MODULE_PARM_DESC(ring_size, "Ring buffer size (# of 4K pages)"); @@ -2185,7 +2189,7 @@ static rx_handler_result_t netvsc_vf_handle_frame(str= uct sk_buff **pskb) } =20 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 =3D netdev_priv(ndev); int ret; @@ -2208,7 +2212,11 @@ static int netvsc_vf_join(struct net_device *vf_netd= ev, goto upper_link_failed; } =20 - 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 =3D=3D VF_REG_IN_NOTIFIER) + schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT); =20 call_netdevice_notifiers(NETDEV_JOIN, vf_netdev); =20 @@ -2346,7 +2354,7 @@ static int netvsc_prepare_bonding(struct net_device *= vf_netdev) return NOTIFY_DONE; } =20 -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; @@ -2386,7 +2394,7 @@ static int netvsc_register_vf(struct net_device *vf_n= etdev) =20 netdev_info(ndev, "VF registering: %s\n", vf_netdev->name); =20 - if (netvsc_vf_join(vf_netdev, ndev) !=3D 0) + if (netvsc_vf_join(vf_netdev, ndev, context) !=3D 0) return NOTIFY_DONE; =20 dev_hold(vf_netdev); @@ -2484,10 +2492,31 @@ static int netvsc_unregister_vf(struct net_device *= vf_netdev) return NOTIFY_OK; } =20 +static int check_dev_is_matching_vf(struct net_device *event_ndev) +{ + /* Skip NetVSC interfaces */ + if (event_ndev->netdev_ops =3D=3D &device_ops) + return -ENODEV; + + /* Avoid non-Ethernet type devices */ + if (event_ndev->type !=3D ARPHRD_ETHER) + return -ENODEV; + + /* Avoid Vlan dev with same MAC registering as VF */ + if (is_vlan_dev(event_ndev)) + return -ENODEV; + + /* Avoid Bonding master dev with same MAC registering as VF */ + if (netif_is_bond_master(event_ndev)) + return -ENODEV; + + return 0; +} + static int netvsc_probe(struct hv_device *dev, const struct hv_vmbus_device_id *dev_id) { - struct net_device *net =3D NULL; + struct net_device *net =3D NULL, *vf_netdev; struct net_device_context *net_device_ctx; struct netvsc_device_info *device_info =3D NULL; struct netvsc_device *nvdev; @@ -2599,6 +2628,30 @@ static int netvsc_probe(struct hv_device *dev, } =20 list_add(&net_device_ctx->list, &netvsc_dev_list); + + /* When the hv_netvsc driver is unloaded and reloaded, 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 the matching vf device that + * is present as a netdevice, knowing that its 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) { + ret =3D check_dev_is_matching_vf(vf_netdev); + if (ret !=3D 0) + continue; + + if (net !=3D get_netvsc_byslot(vf_netdev)) + continue; + + netvsc_prepare_bonding(vf_netdev); + netvsc_register_vf(vf_netdev, VF_REG_IN_PROBE); + __netvsc_vf_setup(net, vf_netdev); + break; + } rtnl_unlock(); =20 netvsc_devinfo_put(device_info); @@ -2754,28 +2807,17 @@ static int netvsc_netdev_event(struct notifier_bloc= k *this, unsigned long event, void *ptr) { struct net_device *event_dev =3D netdev_notifier_info_to_dev(ptr); + int ret =3D 0; =20 - /* Skip our own events */ - if (event_dev->netdev_ops =3D=3D &device_ops) - return NOTIFY_DONE; - - /* Avoid non-Ethernet type devices */ - if (event_dev->type !=3D ARPHRD_ETHER) - return NOTIFY_DONE; - - /* Avoid Vlan dev with same MAC registering as VF */ - if (is_vlan_dev(event_dev)) - return NOTIFY_DONE; - - /* Avoid Bonding master dev with same MAC registering as VF */ - if (netif_is_bond_master(event_dev)) + ret =3D check_dev_is_matching_vf(event_dev); + if (ret !=3D 0) return NOTIFY_DONE; =20 switch (event) { 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_NOTIFIER); case NETDEV_UNREGISTER: return netvsc_unregister_vf(event_dev); case NETDEV_UP: --=20 2.34.1