sfc: Change VF mac via PF as first preference if available.

Changing a VF's mac address through the VF (rather than via the PF)
fails with EPERM because the latter part of efx_ef10_set_mac_address
attempts to change the vport mac address list as the VF.
Even with this fixed it still fails with EBUSY because the vadaptor
is still assigned on the VF - the vadaptor reassignment must be within
a section where the VF has torn down its state.

A major reason this has broken is because we have two functions that
ostensibly do the same thing - have a PF and VF cooperate to change a
VF mac address. Rather than do this, if we are changing the mac of a VF
that has a link to the PF in the same VM then simply call
sriov_set_vf_mac instead, which is a proven working function that does
that.

If there is no PF available, or that fails non-fatally, then attempt to
change the VF's mac address as we would a PF, without updating the PF's
data.

Test case:
Create a VF:
  echo 1 > /sys/class/net/<if>/device/sriov_numvfs
Set the mac address of the VF directly:
  ip link set <vf> addr 00:11:22:33:44:55
Set the MAC address of the VF via the PF:
  ip link set <pf> vf 0 mac 00:11:22:33:44:66
Without this patch the last command will fail with ENOENT.

Signed-off-by: Jonathan Cooper <jonathan.s.cooper@amd.com>
Reported-by: Íñigo Huguet <ihuguet@redhat.com>
Fixes: 9bd49b83a9a2 ("set the MAC address using MC_CMD_VADAPTOR_SET_MAC")
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index d1e1aa19a68edb49a589a9041351a484392cf83d..7022fb2005a2f6214ea07c6fecf83efdc7697c6f 100644 (file)
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -3277,6 +3277,30 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx)
        bool was_enabled = efx->port_enabled;
        int rc;
 
+#ifdef CONFIG_SFC_SRIOV
+       /* If this function is a VF and we have access to the parent PF,
+        * then use the PF control path to attempt to change the VF MAC address.
+        */
+       if (efx->pci_dev->is_virtfn && efx->pci_dev->physfn) {
+               struct efx_nic *efx_pf = pci_get_drvdata(efx->pci_dev->physfn);
+               struct efx_ef10_nic_data *nic_data = efx->nic_data;
+               u8 mac[ETH_ALEN];
+
+               /* net_dev->dev_addr can be zeroed by efx_net_stop in
+                * efx_ef10_sriov_set_vf_mac, so pass in a copy.
+                */
+               ether_addr_copy(mac, efx->net_dev->dev_addr);
+
+               rc = efx_ef10_sriov_set_vf_mac(efx_pf, nic_data->vf_index, mac);
+               if (!rc)
+                       return 0;
+
+               netif_dbg(efx, drv, efx->net_dev,
+                         "Updating VF mac via PF failed (%d), setting directly\n",
+                         rc);
+       }
+#endif
+
        efx_device_detach_sync(efx);
        efx_net_stop(efx->net_dev);
 
@@ -3297,40 +3321,6 @@ static int efx_ef10_set_mac_address(struct efx_nic *efx)
                efx_net_open(efx->net_dev);
        efx_device_attach_if_not_resetting(efx);
 
-#ifdef CONFIG_SFC_SRIOV
-       if (efx->pci_dev->is_virtfn && efx->pci_dev->physfn) {
-               struct efx_ef10_nic_data *nic_data = efx->nic_data;
-               struct pci_dev *pci_dev_pf = efx->pci_dev->physfn;
-
-               if (rc == -EPERM) {
-                       struct efx_nic *efx_pf;
-
-                       /* Switch to PF and change MAC address on vport */
-                       efx_pf = pci_get_drvdata(pci_dev_pf);
-
-                       rc = efx_ef10_sriov_set_vf_mac(efx_pf,
-                                                      nic_data->vf_index,
-                                                      efx->net_dev->dev_addr);
-               } else if (!rc) {
-                       struct efx_nic *efx_pf = pci_get_drvdata(pci_dev_pf);
-                       struct efx_ef10_nic_data *nic_data = efx_pf->nic_data;
-                       unsigned int i;
-
-                       /* MAC address successfully changed by VF (with MAC
-                        * spoofing) so update the parent PF if possible.
-                        */
-                       for (i = 0; i < efx_pf->vf_count; ++i) {
-                               struct ef10_vf *vf = nic_data->vf + i;
-
-                               if (vf->efx == efx) {
-                                       ether_addr_copy(vf->mac,
-                                                       efx->net_dev->dev_addr);
-                                       return 0;
-                               }
-                       }
-               }
-       } else
-#endif
        if (rc == -EPERM) {
                netif_err(efx, drv, efx->net_dev,
                          "Cannot change MAC address; use sfboot to enable"