Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit bcb71642 authored by Shradha Gupta's avatar Shradha Gupta Committed by Sasha Levin
Browse files

hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed 



[ Upstream commit 9cae43da9867412f8bd09aee5c8a8dc5e8dc3dc2 ]

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 and VF register")
Suggested-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarShradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: default avatarDexuan Cui <decui@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent a2577793

drivers/net/hyperv/netvsc_drv.c

+62 −20
Original line number Diff line number Diff line
@@ -54,6 +54,10 @@ 
#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_NOTIFIER	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)");
@@ -2025,7 +2029,7 @@ 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;
@@ -2048,6 +2052,10 @@ static int netvsc_vf_join(struct net_device *vf_netdev, 
		goto upper_link_failed;

	}



	/* If this registration is called from probe context vf_takeover

	 * is taken care of later in probe itself.

	 */

	if (context == VF_REG_IN_NOTIFIER)

		schedule_delayed_work(&ndev_ctx->vf_takeover, VF_TAKEOVER_INT);



	call_netdevice_notifiers(NETDEV_JOIN, vf_netdev);
@@ -2186,7 +2194,7 @@ 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;
@@ -2225,7 +2233,7 @@ 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);
@@ -2285,10 +2293,31 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev) 
	return NOTIFY_OK;

}



static int check_dev_is_matching_vf(struct net_device *event_ndev)

{

	/* Skip NetVSC interfaces */

	if (event_ndev->netdev_ops == &device_ops)

		return -ENODEV;



	/* Avoid non-Ethernet type devices */

	if (event_ndev->type != 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 = 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;
@@ -2391,6 +2420,30 @@ static int netvsc_probe(struct hv_device *dev, 
	}



	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 = check_dev_is_matching_vf(vf_netdev);

		if (ret != 0)

			continue;



		if (net != 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();



	kfree(device_info);
@@ -2483,28 +2536,17 @@ static int netvsc_netdev_event(struct notifier_block *this, 
			       unsigned long event, void *ptr)

{

	struct net_device *event_dev = netdev_notifier_info_to_dev(ptr);

	int ret = 0;



	/* Skip our own events */

	if (event_dev->netdev_ops == &device_ops)

		return NOTIFY_DONE;



	/* Avoid non-Ethernet type devices */

	if (event_dev->type != 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 = check_dev_is_matching_vf(event_dev);

	if (ret != 0)

		return NOTIFY_DONE;



	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: