Index: sys/net/iflib.h
===================================================================
--- sys/net/iflib.h
+++ sys/net/iflib.h
@@ -187,6 +187,7 @@
 	void (*ift_rxd_refill) (void * , if_rxd_update_t iru);
 	void (*ift_rxd_flush) (void *, uint16_t qsidx, uint8_t flidx, qidx_t pidx);
 	int (*ift_legacy_intr) (void *);
+	qidx_t (*ift_txq_select) (void *, struct mbuf *);
 } *if_txrx_t;
 
 typedef struct if_softc_ctx {
@@ -398,6 +399,16 @@
  */
 #define IFLIB_PSEUDO_ETHER	0x80000
 
+/* The following IFLIB_FEATURE_* defines are for driver modules to determine
+ * what features this version of iflib supports. They shall be defined to the
+ * first __FreeBSD_version that introduced the feature.
+ */
+/*
+ * Driver can set its own TX queue selection function
+ * as ift_txq_select in struct if_txrx
+ */
+#define IFLIB_FEATURE_QUEUE_SELECT	1400045
+
 /*
  * Interface has an admin completion queue
  */
Index: sys/net/iflib.c
===================================================================
--- sys/net/iflib.c
+++ sys/net/iflib.c
@@ -209,6 +209,7 @@
 #define isc_rxd_refill ifc_txrx.ift_rxd_refill
 #define isc_rxd_flush ifc_txrx.ift_rxd_flush
 #define isc_legacy_intr ifc_txrx.ift_legacy_intr
+#define isc_txq_select ifc_txrx.ift_txq_select
 	eventhandler_tag ifc_vlan_attach_event;
 	eventhandler_tag ifc_vlan_detach_event;
 	struct ether_addr ifc_mac;
@@ -4153,11 +4154,14 @@
 	MPASS(m->m_nextpkt == NULL);
 	/* ALTQ-enabled interfaces always use queue 0. */
 	qidx = 0;
-	if ((NTXQSETS(ctx) > 1) && M_HASHTYPE_GET(m) && !ALTQ_IS_ENABLED(&ifp->if_snd))
+	/* Use driver-supplied queue selection method if it exists */
+	if (ctx->isc_txq_select)
+		qidx = ctx->isc_txq_select(ctx->ifc_softc, m);
+	/* If not, use iflib's standard method */
+	else if ((NTXQSETS(ctx) > 1) && M_HASHTYPE_GET(m) && !ALTQ_IS_ENABLED(&ifp->if_snd))
 		qidx = QIDX(ctx, m);
-	/*
-	 * XXX calculate buf_ring based on flowid (divvy up bits?)
-	 */
+
+	/* Set TX queue */
 	txq = &ctx->ifc_txqs[qidx];
 
 #ifdef DRIVER_BACKPRESSURE
Index: sys/sys/param.h
===================================================================
--- sys/sys/param.h
+++ sys/sys/param.h
@@ -76,7 +76,7 @@
  * cannot include sys/param.h and should only be updated here.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 1400044
+#define __FreeBSD_version 1400045
 
 /*
  * __FreeBSD_kernel__ indicates that this system uses the kernel of FreeBSD,