virtual/openstack: configure VFIO with NIOMMU by default

bindata/scripts/load-kmod.sh

@@ -1,11 +1,16 @@
 #!/bin/sh
 # chroot /host/ modprobe $1
 kmod_name=$(tr "-" "_" <<< $1)
+kmod_args="${@:2}"
 chroot /host/ lsmod | grep "^$1" >& /dev/null
 
 if [ $? -eq 0 ]
 then
+        # NOTE: We do not check if the module is loaded with specific options
+        #       so a manual reload is required if the module is loaded with
+        #       new or different options.
+        echo "Module $kmod_name already loaded; no change will be applied..."
         exit 0 
 else
-        chroot /host/ modprobe $kmod_name
+        chroot /host/ modprobe $kmod_name $kmod_args
 fi

pkg/plugins/virtual/virtual_plugin.go

@@ -84,6 +84,16 @@ func (p *VirtualPlugin) Apply() error {
 	glog.Infof("virtual-plugin Apply(): desiredState=%v", p.DesireState.Spec)
 
 	if p.LoadVfioDriver == loading {
+		// In virtual deployments of Kubernetes where the underlying virtualization platform does not support a virtualized iommu
+		// the VFIO PCI driver needs to be loaded with a special flag.
+		// This is the case for OpenStack deployments where the underlying virtualization platform is KVM.
+		// NOTE: if VFIO was already loaded for some reason, we will not try to load it again with the new options.
+		kernelArgs := "enable_unsafe_noiommu_mode=1"
+		if err := utils.LoadKernelModule("vfio", kernelArgs); err != nil {
+			glog.Errorf("virtual-plugin Apply(): fail to load vfio kmod: %v", err)
+			return err
+		}
+
 		if err := utils.LoadKernelModule("vfio_pci"); err != nil {
 			glog.Errorf("virtual-plugin Apply(): fail to load vfio_pci kmod: %v", err)
 			return err

pkg/utils/utils.go

@@ -534,12 +534,13 @@ func getVfInfo(pciAddr string, devices []*ghw.PCIDevice) sriovnetworkv1.VirtualF
 	return vf
 }
 
-func LoadKernelModule(name string) error {
-	glog.Infof("LoadKernelModule(): try to load kernel module %s", name)
-	cmd := exec.Command("/bin/sh", scriptsPath, name)
+func LoadKernelModule(name string, args ...string) error {
+	glog.Infof("LoadKernelModule(): try to load kernel module %s with arguments '%s'", name, args)
+	cmdArgs := strings.Join(args, " ")
+	cmd := exec.Command("/bin/sh", scriptsPath, name, cmdArgs)
 	err := cmd.Run()
 	if err != nil {
-		glog.Errorf("LoadKernelModule(): fail to load kernel module %s: %v", name, err)
+		glog.Errorf("LoadKernelModule(): fail to load kernel module %s with arguments '%s': %v", name, args, err)
 		return err
 	}
 	return nil