i40e: Fix attach VF to VM issue

commit 028daf80117376b22909becd9720daaefdfceff4 upstream.

Fix for "Resource temporarily unavailable" problem when virsh is
trying to attach a device to VM. When the VF driver is loaded on
host and virsh is trying to attach it to the VM and set a MAC
address, it ends with a race condition between i40e_reset_vf and
i40e_ndo_set_vf_mac functions. The bug is fixed by adding polling
in i40e_ndo_set_vf_mac function For when the VF is in Reset mode.

Signed-off-by: Paweł Jabłoński <pawel.jablonski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index e368b0237a1b64115a02c69974a760108b35bb8a..4a85a24ced1c81595b54ea98a533235d5713d147 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -2781,6 +2781,7 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
        int ret = 0;
        struct hlist_node *h;
        int bkt;
+       u8 i;
 
        /* validate the request */
        if (vf_id >= pf->num_alloc_vfs) {
@@ -2792,6 +2793,16 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 
        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.
+        */
+       for (i = 0; i < 15; i++) {
+               if (test_bit(I40E_VF_STATE_INIT, &vf->vf_states))
+                       break;
+               msleep(20);
+       }
        if (!test_bit(I40E_VF_STATE_INIT, &vf->vf_states)) {
                dev_err(&pf->pdev->dev, "VF %d still in reset. Try again.\n",
                        vf_id);