Release KNI while stopping system

Author: ifilippov

Diff for: common/common.go

@@ -154,6 +154,7 @@ const (
 	WrongPort
 	FailToInitDPDK
 	FailToCreateKNI
+	FailToReleaseKNI
 )
 
 // NFError is error type returned by nff-go functions

Diff for: flow/flow.go

@@ -375,6 +375,7 @@ type port struct {
 	txQueuesNumber int16
 	willReceive    bool // will this port receive packets
 	willKNI        bool // will this port has assigned KNI device
+	KNICoreIndex   int
 	port           uint16
 	MAC            [common.EtherAddrLen]uint8
 	InIndex        int32
@@ -601,7 +602,7 @@ func SystemStart() error {
 
 // SystemStop stops the system. All Flow functions plus resource releasing
 // Doesn't cleanup DPDK
-func SystemStop() {
+func SystemStop() error {
 	// TODO we should release rings here
 	schedState.systemStop()
 	for i := range createdPorts {
@@ -611,8 +612,17 @@ func SystemStop() {
 			createdPorts[i].txQueuesNumber = 0
 			createdPorts[i].willReceive = false
 		}
+		if createdPorts[i].willKNI {
+			err := low.FreeKNI(createdPorts[i].port)
+			if err != nil {
+				return err
+			}
+			schedState.setCoreByIndex(createdPorts[i].KNICoreIndex)
+			createdPorts[i].willKNI = false
+		}
 	}
 	low.FreeMempools()
+	return nil
 }
 
 // SystemReset stops whole framework plus cleanup DPDK
@@ -1566,19 +1576,20 @@ func CreateKniDevice(portId uint16, name string) (*Kni, error) {
 	if createdPorts[portId].willKNI {
 		return nil, common.WrapWithNFError(nil, "Requested KNI port already has KNI. Two KNIs for one port are prohibited.", common.MultipleKNIPort)
 	}
-	if core, _, err := schedState.getCore(); err != nil {
+	if core, coreIndex, err := schedState.getCore(); err != nil {
 		return nil, err
 	} else {
 		if err := low.CreateKni(portId, uint(core), name); err != nil {
 			return nil, err
 		}
+		kni := new(Kni)
+		// Port will be identifier of this KNI
+		// KNI structure itself is stored inside low.c
+		kni.portId = portId
+		createdPorts[portId].willKNI = true
+		createdPorts[portId].KNICoreIndex = coreIndex
+		return kni, nil
 	}
-	kni := new(Kni)
-	// Port will be identifier of this KNI
-	// KNI structure itself is stored inside low.c
-	kni.portId = portId
-	createdPorts[portId].willKNI = true
-	return kni, nil
 }
 
 func FillSliceFromMask(input []uintptr, mask *[burstSize]bool, output []uintptr) uint8 {

Diff for: flow/scheduler.go

@@ -171,6 +171,7 @@ type scheduler struct {
 	pAttempts         []uint64
 	maxInIndex        int32
 	measureRings      low.Rings
+	coreIndex         int
 }
 
 type core struct {
@@ -204,7 +205,7 @@ func newScheduler(cpus []int, schedulerOff bool, schedulerOffRemove bool, stopDe
 func (scheduler *scheduler) systemStart() (err error) {
 	scheduler.stopFlag = process
 	var core int
-	if core, _, err = scheduler.getCore(); err != nil {
+	if core, scheduler.coreIndex, err = scheduler.getCore(); err != nil {
 		return err
 	}
 	common.LogDebug(common.Initialization, "Start SCHEDULER at", core, "core")
@@ -333,9 +334,9 @@ func (scheduler *scheduler) systemStop() {
 			scheduler.ff[i].stopInstance(0, -1, scheduler)
 		}
 	}
-	scheduler.setCoreByIndex(0) // scheduler
+	scheduler.setCoreByIndex(scheduler.coreIndex)
 	if scheduler.stopDedicatedCore {
-		scheduler.setCoreByIndex(1) // stop
+		scheduler.setCoreByIndex(scheduler.coreIndex + 1)
 	}
 	scheduler.ff = nil
 }

Diff for: low/low.go

@@ -515,6 +515,13 @@ func StopPort(port uint16) {
 	C.rte_eth_dev_stop(C.uint16_t(port))
 }
 
+func FreeKNI(port uint16) error {
+	if C.free_kni(C.uint16_t(port)) < 0 {
+		return common.WrapWithNFError(nil, "Problem with KNI releasing\n", common.FailToReleaseKNI)
+	}
+	return nil
+}
+
 // GetPortsNumber gets total number of available Ethernet devices.
 func GetPortsNumber() int {
 	return int(C.rte_eth_dev_count())

Diff for: low/low.h

@@ -150,6 +150,10 @@ int create_kni(uint16_t port, uint32_t core, char *name, struct rte_mempool *mbu
 	return 0;
 }
 
+int free_kni(uint16_t port) {
+	return rte_kni_release(kni[port]);
+}
+
 int checkRSSPacketCount(struct cPort *port, int16_t queue) {
 	return rte_eth_rx_queue_count(port->PortId, queue);
 }