From e2d31ad8102b650a5d2a7a522ad62126a1deb00b Mon Sep 17 00:00:00 2001
From: Sebastian Sch <sebassch@gmail.com>
Date: Thu, 20 Jan 2022 19:41:32 +0200
Subject: [PATCH] Implement a rebind to default driver

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

Signed-off-by: Sebastian Sch <sebassch@gmail.com>
---
 pkg/utils/utils.go | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
index ca8ad4f10b..4da97e2073 100644
--- a/pkg/utils/utils.go
+++ b/pkg/utils/utils.go
@@ -291,12 +291,16 @@ func configSriovDevice(iface *sriovnetworkv1.Interface, ifaceStatus *sriovnetwor
 				if err = setVfGuid(addr, pfLink); err != nil {
 					return err
 				}
+			} else if driver != "" {
+				glog.V(2).Infof("configSriovDevice(): skip setVfAdminMac as the nic %s is bind to a dpdk driver %s", addr, driver)
 			} else if err = setVfAdminMac(addr, pfLink); err != nil {
 				return err
 			}
+
 			if err = unbindDriverIfNeeded(addr, isRdma); err != nil {
 				return err
 			}
+
 			if driver == "" {
 				if err := BindDefaultDriver(addr); err != nil {
 					glog.Warningf("configSriovDevice(): fail to bind default driver for device %s", addr)
@@ -565,8 +569,19 @@ 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
+		err = RebindVfToDefaultDriver(vfAddr)
+		if err != nil {
+			glog.Errorf("setVfAdminMac(): failed to rebind VF %s %q", vfAddr, err)
+			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
+		}
+
 	}
 	if err := netlink.LinkSetVfHardwareAddr(pfLink, vfID, vfLink.Attrs().HardwareAddr); err != nil {
 		return err
@@ -722,3 +737,20 @@ func hasMellanoxInterfacesInSpec(newState *sriovnetworkv1.SriovNetworkNodeState)
 	}
 	return false
 }
+
+// Workaround function to handle a case where the vf default driver is stuck and not able to create the vf kernel interface.
+// This function unbind the VF from the default driver and try to bind it again
+// bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2045087
+func RebindVfToDefaultDriver(vfAddr string) error {
+	glog.Infof("RebindVfToDefaultDriver(): VF %s", vfAddr)
+	if err := Unbind(vfAddr); err != nil {
+		return err
+	}
+	if err := BindDefaultDriver(vfAddr); err != nil {
+		glog.Errorf("RebindVfToDefaultDriver(): fail to bind default driver for device %s", vfAddr)
+		return err
+	}
+
+	glog.Warningf("RebindVfToDefaultDriver(): workaround implemented for VF %s", vfAddr)
+	return nil
+}