i40e: acquire VSI pointer only after VF is initialized

stable inclusion
from stable-5.10.13
commit d11a1402ec1610638bddcb1ab29b1481ed154b59
bugzilla: 47995

--------------------------------

[ Upstream commit 67a3c6b3 ]

This change simplifies the VF initialization check and also minimizes
the delay between acquiring the VSI pointer and using it. As known by
the commit being fixed, there is a risk of the VSI pointer getting
changed. Therefore minimize the delay between getting and using the
pointer.

Fixes: 9889707b ("i40e: Fix crash caused by stress setting of VF MAC addresses")
Signed-off-by: NStefan Assmann <sassmann@kpanic.de>
Reviewed-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NKonrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -4046,20 +4046,16 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 		goto error_param;
 
 	vf = &pf->vf[vf_id];
-	vsi = pf->vsi[vf->lan_vsi_idx];
 
 	/* When the VF is resetting wait until it is done.
 	 * It can take up to 200 milliseconds,
 	 * but wait for up to 300 milliseconds to be safe.
-	 * If the VF is indeed in reset, the vsi pointer has
-	 * to show on the newly loaded vsi under pf->vsi[id].
+	 * Acquire the VSI pointer only after the VF has been
+	 * properly initialized.
 	 */
 	for (i = 0; i < 15; i++) {
-		if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
-			if (i > 0)
-				vsi = pf->vsi[vf->lan_vsi_idx];
+		if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
 			break;
-		}
 		msleep(20);
 	}
 	if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
@@ -4068,6 +4064,7 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 		ret = -EAGAIN;
 		goto error_param;
 	}
+	vsi = pf->vsi[vf->lan_vsi_idx];
 
 	if (is_multicast_ether_addr(mac)) {
 		dev_err(&pf->pdev->dev,