Implement a rebind to default driver as a w/a

This commit add a w/a to an issue observed on intel nics where not all the vfs are created.

Test:
```
cat /tmp/2.sh
set -ex

while :
do
	echo 5 > /sys/bus/pci/devices/0000\:86\:00.0/sriov_numvfs
	sleep 4
	VFS=`ip l 2>/dev/null | grep ens7f0v | wc -l`
	if [[ $VFS != 5 ]]; then
		echo "bug!"
		sleep INF
	fi
	echo 0 > /sys/bus/pci/devices/0000\:86\:00.0/sriov_numvfs
	sleep 2
done

/tmp/2.sh
++ :
++ echo 5
++ sleep 4
+++ ip l
+++ grep ens7f0v
+++ wc -l
++ VFS=5
++ [[ 5 != 5 ]]
++ echo 0
++ sleep 2
++ :
++ echo 5
++ sleep 4
+++ ip l
+++ grep ens7f0v
+++ wc -l
++ VFS=5
++ [[ 5 != 5 ]]
++ echo 0
++ sleep 2
++ :
++ echo 5
++ sleep 4
+++ ip l
+++ grep ens7f0v
+++ wc -l
++ VFS=4
++ [[ 4 != 5 ]]
++ echo 'bug!'
bug!
++ sleep INF

d8:00.0 Ethernet controller: Intel Corporation Ethernet Controller XXV710 for 25GbE SFP28 (rev 02)
d8:00.1 Ethernet controller: Intel Corporation Ethernet Controller XXV710 for 25GbE SFP28 (rev 02)
d8:02.0 Ethernet controller: Intel Corporation Ethernet Virtual Function 700 Series (rev 02)
d8:02.1 Ethernet controller: Intel Corporation Ethernet Virtual Function 700 Series (rev 02)
d8:02.2 Ethernet controller: Intel Corporation Ethernet Virtual Function 700 Series (rev 02)
d8:02.3 Ethernet controller: Intel Corporation Ethernet Virtual Function 700 Series (rev 02)
d8:02.4 Ethernet controller: Intel Corporation Ethernet Virtual Function 700 Series (rev 02)
[root@cnfdt14 core]# lspci -v -mm -nn -k -s d8:00.0
Slot:	d8:00.0
Class:	Ethernet controller [0200]
Vendor:	Intel Corporation [8086]
Device:	Ethernet Controller XXV710 for 25GbE SFP28 [158b]
SVendor:	Intel Corporation [8086]
SDevice:	Ethernet 25G 2P XXV710 Adapter [0009]
Rev:	02
Driver:	i40e
Module:	i40e
NUMANode:	1

ls -la /sys/bus/pci/devices/0000\:3b\:02.1/net/
ls: cannot access '/sys/bus/pci/devices/0000:3b:02.1/net/': No such file or directory

echo "0000:3b:02.1" > /sys/bus/pci/drivers/iavf/unbind
echo "0000:3b:02.1" > /sys/bus/pci/drivers/iavf/bind

[  336.586302] pci 0000:3b:02.1: [8086:154c] type 00 class 0x020000
[  336.592352] pci 0000:3b:02.1: enabling Extended Tags
[  336.597653] pci 0000:3b:02.1: Adding to iommu group 156
[  336.622048] iavf 0000:3b:02.1: enabling device (0000 -> 0002)
[  336.716570] iavf 0000:3b:02.1: Device is still in reset (-16), retrying
[  337.839372] iavf 0000:3b:02.1: Invalid MAC address 00:00:00:00:00:00, using random
[  337.848651] iavf 0000:3b:02.1: Multiqueue Enabled: Queue pair count = 4
[  337.965036] iavf 0000:3b:02.1: MAC address: 92:67:37:fd:42:25
[  337.972234] iavf 0000:3b:02.1: GRO is enabled
[  338.004527] iavf 0000:3b:02.1 ens1f0v1: renamed from eth0
[  338.195468] iavf 0000:3b:02.1: Reset warning received from the PF
[  338.211038] iavf 0000:3b:02.1: Scheduling reset task
[  353.590034] pci 0000:3b:02.1: Removing from iommu group 156
[  366.167547] pci 0000:3b:02.1: [8086:154c] type 00 class 0x020000
[  366.174623] pci 0000:3b:02.1: enabling Extended Tags
[  366.180037] pci 0000:3b:02.1: Adding to iommu group 156
[  366.185485] iavf 0000:3b:02.1: enabling device (0000 -> 0002)
[  366.265071] iavf 0000:3b:02.1: Device is still in reset (-16), retrying
[ 1255.037432] iavf 0000:3b:02.1: enabling device (0000 -> 0002)
[ 1255.110439] iavf 0000:3b:02.1: Invalid MAC address 00:00:00:00:00:00, using random
[ 1255.118153] iavf 0000:3b:02.1: Multiqueue Enabled: Queue pair count = 4
[ 1255.125217] iavf 0000:3b:02.1: MAC address: d2:73:2c:3c:ed:f8
[ 1255.130984] iavf 0000:3b:02.1: GRO is enabled
[ 1255.135615] iavf 0000:3b:02.1 ens1f0v1: renamed from eth0
[ 1255.792238] iavf 0000:3b:02.1: Reset warning received from the PF
[ 1255.798351] iavf 0000:3b:02.1: Scheduling reset task
[ 1268.465116] iavf 0000:3b:02.1: Reset warning received from the PF
[ 1268.479921] iavf 0000:3b:02.1: Scheduling reset task
```

We are working with kernel developers to find and fix the issue.

This w/a will give us more time without impacting the sriov operator

Signed-off-by: Sebastian Sch <[email protected]>

pkg/utils/utils.go

@@ -565,8 +565,23 @@ func setVfAdminMac(vfAddr string, pfLink netlink.Link) error {
 	}
 	vfLink, err := vfIsReady(vfAddr)
 	if err != nil {
-		glog.Errorf("setVfAdminMac(): VF link is not ready for device %+v %q", vfAddr, err)
-		return err
+		// TODO: remove workaround after intel fix driver issue
+		if err := Unbind(vfAddr); err != nil {
+			return err
+		}
+		if err := BindDefaultDriver(vfAddr); err != nil {
+			glog.Warningf("setVfAdminMac(): fail to bind default driver for device %s", vfAddr)
+			return err
+		}
+
+		// Try to check the VF status again
+		vfLink, err = vfIsReady(vfAddr)
+		if err != nil {
+			glog.Errorf("setVfAdminMac(): VF link is not ready for device %s %q", vfAddr, err)
+			return err
+		}
+
+		glog.Errorf("setVfAdminMac(): workaround implement for VF %s", vfAddr)
 	}
 	if err := netlink.LinkSetVfHardwareAddr(pfLink, vfID, vfLink.Attrs().HardwareAddr); err != nil {
 		return err