Commit 365e1ece authored by Gaurav Kohli's avatar Gaurav Kohli Committed by David S. Miller
Browse files

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



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: 00d7ddba ("hv_netvsc: pair VF based on serial number")
Reviewed-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarGaurav Kohli <gauravkohli@linux.microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 30393181

drivers/net/hyperv/hyperv_net.h

+2 −1
Original line number Diff line number Diff line
@@ -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;

drivers/net/hyperv/netvsc.c

+4 −0
Original line number Diff line number Diff line
@@ -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");

drivers/net/hyperv/netvsc_drv.c

+19 −0
Original line number Diff line number Diff line
@@ -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);