e1000: Restore VF interface random MAC

[kbowling]

Summary

Restore rS308429 after the iflib conversion of igb(4). This
reenables random MAC address generation when attaching
to a VF with a zeroed MAC.

PR: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253535
Reporter: Balaev PA <[e-mail]>

Test Plan

This patch restores functionality for the submitter in the PR

[markj]

sys/dev/e1000/if_em.c

1064–1074

How does vf_ifp get set?

[kbowling]

@markj thanks I missed a hunk of the patch, here's a corrected one

sys/dev/e1000/if_em.c

em_if_attach_pre(if_ctx_t ctx)
         if (e1000_read_mac_addr(hw) < 0) {
                 device_printf(dev, "EEPROM read error while reading MAC"
                               " address\n");
                 error = EIO;
                 goto err_late;
         }
 
         if (!em_is_valid_ether_addr(hw->mac.addr)) {
+                if (adapter->vf_ifp) {
+                        u8 addr[ETHER_ADDR_LEN];
+                        arc4rand(&addr, sizeof(addr), 0);
+                        addr[0] &= 0xFE;
+                        addr[0] |= 0x02;
+                        bcopy(addr, hw->mac.addr, sizeof(addr));
+                } else {
                         device_printf(dev, "Invalid MAC address\n");
                         error = EIO;
                         goto err_late;
                 }
+        }
 
         /* Disable ULP support */
         e1000_disable_ulp_lpt_lp(hw, TRUE);
 
         /*
          * Get Wake-on-Lan and Management info for later use
          */
         em_get_wakeup(ctx);
em_identify_hardware(if_ctx_t ctx)
         adapter->hw.subsystem_device_id =
             pci_read_config(dev, PCIR_SUBDEV_0, 2);
 
         /* Do Shared Code Init and Setup */
         if (e1000_set_mac_type(&adapter->hw)) {
                 device_printf(dev, "Setup init failure\n");
                 return;
         }
+
+        /* Are we a VF device? */
+        if ((adapter->hw.mac.type == e1000_vfadapt) ||
+            (adapter->hw.mac.type == e1000_vfadapt_i350))
+                adapter->vf_ifp = 1;
+        else
+                adapter->vf_ifp = 0;
 }
 
 static int
 em_allocate_pci_resources(if_ctx_t ctx)
 {
         struct adapter *adapter = iflib_get_softc(ctx);
         device_t dev = iflib_get_dev(ctx);
         int rid, val;