diff --git a/sbin/ifconfig/ifconfig.h b/sbin/ifconfig/ifconfig.h
--- a/sbin/ifconfig/ifconfig.h
+++ b/sbin/ifconfig/ifconfig.h
@@ -46,7 +46,10 @@
 struct cmd;
 
 typedef	void c_func(const char *cmd, int arg, int s, const struct afswtch *afp);
-typedef	void c_func2(const char *arg1, const char *arg2, int s, const struct afswtch *afp);
+typedef	void c_func2(const char *arg1, const char *arg2, int s,
+    const struct afswtch *afp);
+typedef	void c_func3(const char *cmd, const char *arg, int s,
+    const struct afswtch *afp);
 
 struct cmd {
 	const char *c_name;
@@ -54,9 +57,12 @@
 #define	NEXTARG		0xffffff	/* has following arg */
 #define	NEXTARG2	0xfffffe	/* has 2 following args */
 #define	OPTARG		0xfffffd	/* has optional following arg */
+#define	SPARAM		0xfffffc	/* parameter is string c_sparameter */
+	const char *c_sparameter;
 	union {
 		c_func	*c_func;
 		c_func2	*c_func2;
+		c_func3	*c_func3;
 	} c_u;
 	int	c_iscloneop;
 	struct cmd *c_next;
@@ -72,15 +78,66 @@
 #define	DECL_CMD_FUNC(name, cmd, arg) \
 	void name(const char *cmd, int arg, int s, const struct afswtch *afp)
 #define	DECL_CMD_FUNC2(name, arg1, arg2) \
-	void name(const char *arg1, const char *arg2, int s, const struct afswtch *afp)
-
-#define	DEF_CMD(name, param, func)	{ name, param, { .c_func = func }, 0, NULL }
-#define	DEF_CMD_ARG(name, func)		{ name, NEXTARG, { .c_func = func }, 0, NULL }
-#define	DEF_CMD_OPTARG(name, func)	{ name, OPTARG, { .c_func = func }, 0, NULL }
-#define	DEF_CMD_ARG2(name, func)	{ name, NEXTARG2, { .c_func2 = func }, 0, NULL }
-#define	DEF_CLONE_CMD(name, param, func) { name, param, { .c_func = func }, 1, NULL }
-#define	DEF_CLONE_CMD_ARG(name, func)	{ name, NEXTARG, { .c_func = func }, 1, NULL }
-#define	DEF_CLONE_CMD_ARG2(name, func)	{ name, NEXTARG2, { .c_func2 = func }, 1, NULL }
+	void name(const char *arg1, const char *arg2, int s, \
+	    const struct afswtch *afp)
+
+#define	DEF_CMD(name, param, func) {		\
+    .c_name = (name),				\
+    .c_parameter = (param),			\
+    .c_u = { .c_func = (func) },		\
+    .c_iscloneop = 0,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CMD_ARG(name, func) {		\
+    .c_name = (name),				\
+    .c_parameter = NEXTARG,			\
+    .c_u = { .c_func = (func) },		\
+    .c_iscloneop = 0,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CMD_OPTARG(name, func) {		\
+    .c_name = (name),				\
+    .c_parameter = OPTARG,			\
+    .c_u = { .c_func = (func) },		\
+    .c_iscloneop = 0,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CMD_ARG2(name, func) {		\
+    .c_name = (name),				\
+    .c_parameter = NEXTARG2,			\
+    .c_u = { .c_func2 = (func) },		\
+    .c_iscloneop = 0,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CMD_SARG(name, sparam, func) {	\
+    .c_name = (name),				\
+    .c_parameter = SPARAM,			\
+    .c_sparameter = (sparam),			\
+    .c_u = { .c_func3 = (func) },		\
+    .c_iscloneop = 0,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CLONE_CMD(name, param, func) {	\
+    .c_name = (name),				\
+    .c_parameter = (param),			\
+    .c_u = { .c_func = (func) },		\
+    .c_iscloneop = 1,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CLONE_CMD_ARG(name, func) {		\
+    .c_name = (name),				\
+    .c_parameter = NEXTARG,			\
+    .c_u = { .c_func = (func) },		\
+    .c_iscloneop = 1,				\
+    .c_next = NULL,				\
+}
+#define	DEF_CLONE_CMD_ARG2(name, func) {	\
+    .c_name = (name),				\
+    .c_parameter = NEXTARG2,			\
+    .c_u = { .c_func2 = (func) },		\
+    .c_iscloneop = 1,				\
+    .c_next = NULL,				\
+}
 
 struct ifaddrs;
 struct addrinfo;
@@ -145,6 +202,8 @@
 extern	int exit_code;
 
 void	setifcap(const char *, int value, int s, const struct afswtch *);
+void	setifcapnv(const char *vname, const char *arg, int s,
+	    const struct afswtch *afp);
 
 void	Perror(const char *cmd);
 void	printb(const char *s, unsigned value, const char *bits);
diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -44,6 +44,7 @@
 #include <sys/ioctl.h>
 #include <sys/module.h>
 #include <sys/linker.h>
+#include <sys/nv.h>
 #include <sys/queue.h>
 #include <sys/socket.h>
 #include <sys/time.h>
@@ -991,6 +992,8 @@
 				    p->c_name);
 			p->c_u.c_func2(argv[1], argv[2], s, afp);
 			argc -= 2, argv += 2;
+		} else if (p->c_parameter == SPARAM && p->c_u.c_func3) {
+			p->c_u.c_func3(*argv, p->c_sparameter, s, afp);
 		} else if (p->c_u.c_func)
 			p->c_u.c_func(*argv, p->c_parameter, s, afp);
 		argc--, argv++;
@@ -1251,6 +1254,53 @@
 		Perror(vname);
 }
 
+void
+setifcapnv(const char *vname, const char *arg, int s, const struct afswtch *afp)
+{
+	nvlist_t *nvcap;
+	void *buf;
+	char *marg, *mopt;
+	size_t nvbuflen;
+	bool neg;
+
+	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) < 0)
+		Perror("ioctl (SIOCGIFCAP)");
+	if ((ifr.ifr_curcap & IFCAP_NV) == 0) {
+		warnx("IFCAP_NV not supported");
+		return; /* Not exit() */
+	}
+
+	marg = strdup(arg);
+	if (marg == NULL)
+		Perror("strdup");
+	nvcap = nvlist_create(0);
+	if (nvcap == NULL)
+		Perror("nvlist_create");
+	while ((mopt = strsep(&marg, ",")) != NULL) {
+		neg = *mopt == '-';
+		if (neg)
+			mopt++;
+		if (strcmp(mopt, "rxtls") == 0) {
+			nvlist_add_bool(nvcap, "rxtls4", !neg);
+			nvlist_add_bool(nvcap, "rxtls6", !neg);			
+		} else {
+			nvlist_add_bool(nvcap, mopt, !neg);
+		}
+	}
+	buf = nvlist_pack(nvcap, &nvbuflen);
+	if (buf == NULL) {
+		errx(1, "nvlist_pack error");
+		exit(1);
+	}
+	ifr.ifr_cap_nv.buf_length = ifr.ifr_cap_nv.length = nvbuflen;
+	ifr.ifr_cap_nv.buffer = buf;
+	if (ioctl(s, SIOCSIFCAPNV, (caddr_t)&ifr) < 0)
+		Perror(vname);
+	free(buf);
+	nvlist_destroy(nvcap);
+	free(marg);
+}
+
 static void
 setifmetric(const char *val, int dummy __unused, int s, 
     const struct afswtch *afp)
@@ -1375,8 +1425,12 @@
 	struct ifaddrs *ifa)
 {
 	struct ifaddrs *ift;
-	int allfamilies, s;
 	struct ifstat ifs;
+	nvlist_t *nvcap;
+	const char *nvname;
+	void *buf, *cookie;
+	int allfamilies, s, type;
+	bool first, val;
 
 	if (afp == NULL) {
 		allfamilies = 1;
@@ -1421,7 +1475,40 @@
 	}
 
 	if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) == 0) {
-		if (ifr.ifr_curcap != 0) {
+		if ((ifr.ifr_curcap & IFCAP_NV) != 0) {
+			buf = malloc(IFR_CAP_NV_MAXBUFSIZE);
+			if (buf == NULL)
+				Perror("malloc");
+			ifr.ifr_cap_nv.buffer = buf;
+			ifr.ifr_cap_nv.buf_length = IFR_CAP_NV_MAXBUFSIZE;
+			if (ioctl(s, SIOCGIFCAPNV, (caddr_t)&ifr) != 0)
+				Perror("ioctl (SIOCGIFCAPNV)");
+			nvcap = nvlist_unpack(ifr.ifr_cap_nv.buffer,
+			    ifr.ifr_cap_nv.length, 0);
+			if (nvcap == NULL)
+				Perror("nvlist_unpack");
+			printf("\toptions");
+			cookie = NULL;
+			for (first = true;; first = false) {
+				nvname = nvlist_next(nvcap, &type, &cookie);
+				if (nvname == NULL) {
+					printf("\n");
+					break;
+				}
+				if (type == NV_TYPE_BOOL) {
+					val = nvlist_get_bool(nvcap, nvname);
+					if (val) {
+						printf("%c%s",
+						    first ? ' ' : ',', nvname);
+					}
+				}
+			}
+			nvlist_destroy(nvcap);
+			free(buf);
+
+			if (ioctl(s, SIOCGIFCAP, (caddr_t)&ifr) != 0)
+				Perror("ioctl (SIOCGIFCAP)");
+		} else if (ifr.ifr_curcap != 0) {
 			printb("\toptions", ifr.ifr_curcap, IFCAPBITS);
 			putchar('\n');
 		}
@@ -1694,6 +1781,10 @@
 	DEF_CMD("-lro",		-IFCAP_LRO,	setifcap),
 	DEF_CMD("txtls",	IFCAP_TXTLS,	setifcap),
 	DEF_CMD("-txtls",	-IFCAP_TXTLS,	setifcap),
+	DEF_CMD_SARG("rxtls",	IFCAP_RXTLS4_NAME "," IFCAP_RXTLS6_NAME,
+	    setifcapnv),
+	DEF_CMD_SARG("-rxtls",	"-"IFCAP_RXTLS4_NAME ",-" IFCAP_RXTLS6_NAME,
+	    setifcapnv),
 	DEF_CMD("wol",		IFCAP_WOL,	setifcap),
 	DEF_CMD("-wol",		-IFCAP_WOL,	setifcap),
 	DEF_CMD("wol_ucast",	IFCAP_WOL_UCAST,	setifcap),
diff --git a/share/man/man9/ifnet.9 b/share/man/man9/ifnet.9
--- a/share/man/man9/ifnet.9
+++ b/share/man/man9/ifnet.9
@@ -1335,6 +1335,74 @@
 .Va if_data.ifi_hwassist
 appropriately.
 .Pp
+.It Dv SIOCGIFCAPNV
+.Xr NV 9
+version of the
+.Dv SIOCGIFCAP
+ioctl.
+Caller must provide the pointer to
+.Vt struct ifreq_cap_nv
+as
+.Fa data ,
+where the member
+.Dv buffer
+points to some buffer containing
+.Dv buf_length
+bytes.
+The serialized nvlist with description of the device capabilities
+is written to the buffer.
+If buffer is too short, then the structure is updated with
+.Dv buffer
+member set to
+.Dv NULL,
+.Dv length set to the minimal required length,
+and error
+.Er EFBIG
+is returned.
+.Pp
+Elements of the returned nvlist for simple capabilities are boolean,
+identified by names.
+Presence of the boolean element means that corresponding capability is
+supported by the interface.
+Element's value describes the current configured state:
+.Dv true
+means that the capability is enabled, and
+.Dv false
+that it is disabled.
+.Pp
+Driver indicates support for both
+.Dv SIOCGIFCAPNV
+and
+.Dv SIOCSIFCAPNV
+requests by setting
+.Dv IFCAP_NV
+non-modifiable capability bit in
+.Dv if_capabilities .
+.Pp
+.It Dv SIOCSIFCAPNV
+.Xr NV 9
+version of the
+.Dv SIOCSIFCAP
+ioctl.
+Caller must provide the pointer to
+.Vt struct ifreq_cap_nv
+as
+.Fa data ,
+where the member
+.Dv buffer
+points to unpacked nvlist of
+.Dv length
+bytes.
+Each element of nvlist describes a requested update of one capability,
+identified by the element name.
+For simple capabilities, the element must be boolean.
+Its
+.Dv true
+value means that the caller asks to enable the capability, and
+.Dv false
+value to disable.
+Only capabilities listed in the nvlist are affected by the call.
+.Pp
 .It Dv SIOCSIFFIB
 Sets interface FIB.
 Caller must have appropriate privilege.
diff --git a/sys/dev/mlx5/mlx5_en/en.h b/sys/dev/mlx5/mlx5_en/en.h
--- a/sys/dev/mlx5/mlx5_en/en.h
+++ b/sys/dev/mlx5/mlx5_en/en.h
@@ -1077,6 +1077,37 @@
 	bool	sw_is_port_buf_owner;
 
 	struct pfil_head *pfil;
+
+	bool ifcap_rxcsum : 1;
+	bool ifcap_txcsum : 1;
+	bool ifcap_vlan_mtu : 1;
+	bool ifcap_vlan_hwtagging : 1;
+	bool ifcap_jumbo_mtu : 1;
+	bool ifcap_vlan_hwcsum : 1;
+	bool ifcap_tso4 : 1;
+	bool ifcap_tso6 : 1;
+	bool ifcap_lro : 1;
+	bool ifcap_vlan_hwfilter : 1;
+	bool ifcap_vlan_hwtso : 1;
+	bool ifcap_linkstate : 1;
+	bool ifcap_rxcsum_ipv6 : 1;
+	bool ifcap_txcsum_ipv6 : 1;
+	bool ifcap_hwstats_name : 1;
+#ifdef RATELIMIT
+	bool ifcap_txrtlmt : 1;
+#endif
+	bool ifcap_hwrxtstmp : 1;
+	bool ifcap_mextpg : 1;
+	bool ifcap_txtls4 : 1;
+	bool ifcap_txtls6 : 1;
+	bool ifcap_vxlan_hwcsum : 1;
+	bool ifcap_vxlan_hwtso : 1;
+#ifdef RATELIMIT
+	bool ifcap_txtls_rtlmt : 1;
+#endif
+	bool ifcap_rxtls4 : 1;
+	bool ifcap_rxtls6 : 1;
+
 	struct mlx5e_channel channel[];
 };
 
diff --git a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
--- a/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
+++ b/sys/dev/mlx5/mlx5_en/mlx5_en_main.c
@@ -30,6 +30,7 @@
 #include "en.h"
 
 #include <sys/eventhandler.h>
+#include <sys/nv.h>
 #include <sys/sockio.h>
 #include <machine/atomic.h>
 
@@ -3279,6 +3280,54 @@
 	queue_work(priv->wq, &priv->set_rx_mode_work);
 }
 
+static int
+mlx5e_if_caps(struct mlx5e_priv *priv)
+{
+	int res;
+
+	res = IFCAP_NV;
+	if (priv->ifcap_rxcsum)
+		res |= IFCAP_RXCSUM;
+	if (priv->ifcap_txcsum)
+		res |= IFCAP_TXCSUM;
+	if (priv->ifcap_rxcsum_ipv6)
+		res |= IFCAP_RXCSUM_IPV6;
+	if (priv->ifcap_txcsum_ipv6)
+		res |= IFCAP_TXCSUM_IPV6;
+	if (priv->ifcap_vlan_mtu)
+		res |= IFCAP_VLAN_MTU;
+	if (priv->ifcap_vlan_hwfilter)
+		res |= IFCAP_VLAN_HWFILTER;
+	if (priv->ifcap_vlan_hwtagging)
+		res |= IFCAP_VLAN_HWTAGGING;
+	if (priv->ifcap_txtls4)
+		res |= IFCAP_TXTLS4;
+	if (priv->ifcap_txtls6)
+		res |= IFCAP_TXTLS6;
+#ifdef RATELIMIT
+	if (priv->ifcap_txrtlmt)
+		res |= IFCAP_TXRTLMT;
+	if (priv->ifcap_txtls_rtlmt)
+		res |= IFCAP_TXTLS_RTLMT;
+#endif
+	if (priv->ifcap_vxlan_hwcsum)
+		res |= IFCAP_VXLAN_HWCSUM;
+	if (priv->ifcap_vxlan_hwtso)
+		res |= IFCAP_VXLAN_HWTSO;
+	if (priv->ifcap_mextpg)
+		res |= IFCAP_MEXTPG;
+	if (priv->ifcap_tso4)
+		res |= IFCAP_TSO4;
+	if (priv->ifcap_tso6)
+		res |= IFCAP_TSO6;
+	if (priv->ifcap_lro)
+		res |= IFCAP_LRO;
+	if (priv->ifcap_hwrxtstmp)
+		res |= IFCAP_HWRXTSTMP;
+
+	return (res);
+}
+
 static int
 mlx5e_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 {
@@ -3288,8 +3337,8 @@
 	struct ifi2creq i2c;
 	struct ifrsskey *ifrk;
 	struct ifrsshash *ifrh;
+	nvlist_t *nv;
 	int error = 0;
-	int mask = 0;
 	int size_read = 0;
 	int module_status;
 	int module_num;
@@ -3366,121 +3415,207 @@
 		ifr = (struct ifreq *)data;
 		error = ifmedia_ioctl(ifp, ifr, &priv->media, command);
 		break;
-	case SIOCSIFCAP:
-		ifr = (struct ifreq *)data;
+	case SIOCGIFCAPNV:
+		nv = (nvlist_t *)data;
+		PRIV_LOCK(priv);
+		nvlist_add_bool(nv, IFCAP_RXCSUM_NAME, priv->ifcap_rxcsum);
+		nvlist_add_bool(nv, IFCAP_TXCSUM_NAME, priv->ifcap_txcsum);
+		nvlist_add_bool(nv, IFCAP_VLAN_MTU_NAME, priv->ifcap_vlan_mtu);
+		nvlist_add_bool(nv, IFCAP_VLAN_HWTAGGING_NAME,
+		    priv->ifcap_vlan_hwtagging);
+		nvlist_add_bool(nv, IFCAP_JUMBO_MTU_NAME,
+		    priv->ifcap_jumbo_mtu);
+		nvlist_add_bool(nv, IFCAP_VLAN_HWCSUM_NAME,
+		    priv->ifcap_vlan_hwcsum);
+		nvlist_add_bool(nv, IFCAP_TSO4_NAME, priv->ifcap_tso4);
+		nvlist_add_bool(nv, IFCAP_TSO6_NAME, priv->ifcap_tso6);
+		nvlist_add_bool(nv, IFCAP_LRO_NAME, priv->ifcap_lro);
+		nvlist_add_bool(nv, IFCAP_VLAN_HWFILTER_NAME,
+		    priv->ifcap_vlan_hwfilter);
+		nvlist_add_bool(nv, IFCAP_VLAN_HWTSO_NAME,
+		    priv->ifcap_vlan_hwtso);
+		nvlist_add_bool(nv, IFCAP_LINKSTATE_NAME,
+		    priv->ifcap_linkstate);
+		nvlist_add_bool(nv, IFCAP_RXCSUM_IPV6_NAME,
+		    priv->ifcap_rxcsum_ipv6);
+		nvlist_add_bool(nv, IFCAP_TXCSUM_IPV6_NAME,
+		    priv->ifcap_txcsum_ipv6);
+		nvlist_add_bool(nv, IFCAP_HWSTATS_NAME,
+		    priv->ifcap_hwstats_name);
+#ifdef RATELIMIT
+		nvlist_add_bool(nv, IFCAP_TXRTLMT_NAME, priv->ifcap_txrtlmt);
+#endif
+		nvlist_add_bool(nv, IFCAP_HWRXTSTMP_NAME,
+		    priv->ifcap_hwrxtstmp);
+		nvlist_add_bool(nv, IFCAP_MEXTPG_NAME, priv->ifcap_mextpg);
+		nvlist_add_bool(nv, IFCAP_TXTLS4_NAME, priv->ifcap_txtls4);
+		nvlist_add_bool(nv, IFCAP_TXTLS6_NAME, priv->ifcap_txtls6);
+		nvlist_add_bool(nv, IFCAP_VXLAN_HWCSUM_NAME,
+		    priv->ifcap_vxlan_hwcsum);
+		nvlist_add_bool(nv, IFCAP_VXLAN_HWTSO_NAME,
+		    priv->ifcap_vxlan_hwtso);
+#ifdef RATELIMIT
+		nvlist_add_bool(nv, IFCAP_TXTLS_RTLMT_NAME,
+		    priv->ifcap_txtls_rtlmt);
+#endif
+		nvlist_add_bool(nv, IFCAP_RXTLS4_NAME, priv->ifcap_rxtls4);
+		nvlist_add_bool(nv, IFCAP_RXTLS6_NAME, priv->ifcap_rxtls6);
+		PRIV_UNLOCK(priv);
+		break;
+	case SIOCSIFCAPNV:
+		nv = (nvlist_t *)data;
 		PRIV_LOCK(priv);
-		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
-
-		if (mask & IFCAP_TXCSUM) {
-			ifp->if_capenable ^= IFCAP_TXCSUM;
-			ifp->if_hwassist ^= (CSUM_TCP | CSUM_UDP | CSUM_IP);
 
-			if (IFCAP_TSO4 & ifp->if_capenable &&
-			    !(IFCAP_TXCSUM & ifp->if_capenable)) {
-				mask &= ~IFCAP_TSO4;
-				ifp->if_capenable &= ~IFCAP_TSO4;
-				ifp->if_hwassist &= ~CSUM_IP_TSO;
-				mlx5_en_err(ifp,
-				    "tso4 disabled due to -txcsum.\n");
+		if (nvlist_exists_bool(nv, IFCAP_TXCSUM_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_TXCSUM_NAME)) {
+				priv->ifcap_txcsum = true;
+				ifp->if_hwassist |= CSUM_TCP | CSUM_UDP |
+				    CSUM_IP;
+			} else {
+				priv->ifcap_txcsum = false;
+				ifp->if_hwassist &= ~(CSUM_TCP | CSUM_UDP |
+				    CSUM_IP);
+				if (priv->ifcap_tso4) {
+					nvlist_free_bool(nv, IFCAP_TSO4_NAME);
+					nvlist_add_bool(nv, IFCAP_TSO4_NAME,
+					    false);
+					priv->ifcap_tso4 = false;
+					ifp->if_hwassist &= ~CSUM_IP_TSO;
+					mlx5_en_err(ifp,
+					    "tso4 disabled due to -txcsum.\n");
+				}
 			}
 		}
-		if (mask & IFCAP_TXCSUM_IPV6) {
-			ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
-			ifp->if_hwassist ^= (CSUM_UDP_IPV6 | CSUM_TCP_IPV6);
-
-			if (IFCAP_TSO6 & ifp->if_capenable &&
-			    !(IFCAP_TXCSUM_IPV6 & ifp->if_capenable)) {
-				mask &= ~IFCAP_TSO6;
-				ifp->if_capenable &= ~IFCAP_TSO6;
-				ifp->if_hwassist &= ~CSUM_IP6_TSO;
-				mlx5_en_err(ifp,
+		if (nvlist_exists_bool(nv, IFCAP_TXCSUM_IPV6_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_TXCSUM_IPV6_NAME)) {
+				priv->ifcap_txcsum_ipv6 = true;
+				ifp->if_hwassist |= CSUM_UDP_IPV6 |
+				    CSUM_TCP_IPV6;
+			} else {
+				priv->ifcap_txcsum_ipv6 = false;
+				ifp->if_hwassist &= ~(CSUM_UDP_IPV6 |
+				    CSUM_TCP_IPV6);
+				if (priv->ifcap_tso6) {
+					nvlist_free_bool(nv, IFCAP_TSO6_NAME);
+					nvlist_add_bool(nv, IFCAP_TSO6_NAME,
+					    false);
+					priv->ifcap_tso6 = false;
+					ifp->if_hwassist &= ~CSUM_IP6_TSO;
+					mlx5_en_err(ifp,
 				    "tso6 disabled due to -txcsum6.\n");
+				}
 			}
 		}
-		if (mask & IFCAP_MEXTPG)
-			ifp->if_capenable ^= IFCAP_MEXTPG;
-		if (mask & IFCAP_TXTLS4)
-			ifp->if_capenable ^= IFCAP_TXTLS4;
-		if (mask & IFCAP_TXTLS6)
-			ifp->if_capenable ^= IFCAP_TXTLS6;
+		if (nvlist_exists_bool(nv, IFCAP_MEXTPG_NAME))
+			priv->ifcap_mextpg = nvlist_get_bool(nv,
+			    IFCAP_MEXTPG_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_TXTLS4_NAME))
+			priv->ifcap_txtls4 = nvlist_get_bool(nv,
+			    IFCAP_TXTLS4_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_TXTLS6_NAME))
+			priv->ifcap_txtls6 = nvlist_get_bool(nv,
+			    IFCAP_TXTLS6_NAME);
 #ifdef RATELIMIT
-		if (mask & IFCAP_TXTLS_RTLMT)
-			ifp->if_capenable ^= IFCAP_TXTLS_RTLMT;
+		if (nvlist_exists_bool(nv, IFCAP_TXTLS_RTLMT_NAME))
+			priv->ifcap_txtls_rtlmt = nvlist_get_bool(nv,
+			    IFCAP_TXTLS_RTLMT_NAME);
 #endif
-		if (mask & IFCAP_RXCSUM)
-			ifp->if_capenable ^= IFCAP_RXCSUM;
-		if (mask & IFCAP_RXCSUM_IPV6)
-			ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
-		if (mask & IFCAP_TSO4) {
-			if (!(IFCAP_TSO4 & ifp->if_capenable) &&
-			    !(IFCAP_TXCSUM & ifp->if_capenable)) {
-				mlx5_en_err(ifp, "enable txcsum first.\n");
-				error = EAGAIN;
-				goto out;
+		if (nvlist_exists_bool(nv, IFCAP_RXCSUM_NAME))
+			priv->ifcap_rxcsum = nvlist_get_bool(nv,
+			    IFCAP_RXCSUM_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_RXCSUM_IPV6_NAME))
+			priv->ifcap_rxcsum_ipv6 = nvlist_get_bool(nv,
+			    IFCAP_RXCSUM_IPV6_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_TSO4_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_TSO4_NAME)) {
+				if (!priv->ifcap_txcsum) {
+					mlx5_en_err(ifp,
+					    "enable txcsum first.\n");
+					error = EAGAIN;
+					goto out;
+				}
+				priv->ifcap_tso4 = true;
+				ifp->if_hwassist |= CSUM_IP_TSO;
+			} else {
+				priv->ifcap_tso4 = false;
+				ifp->if_hwassist &= ~CSUM_IP_TSO;
 			}
-			ifp->if_capenable ^= IFCAP_TSO4;
-			ifp->if_hwassist ^= CSUM_IP_TSO;
 		}
-		if (mask & IFCAP_TSO6) {
-			if (!(IFCAP_TSO6 & ifp->if_capenable) &&
-			    !(IFCAP_TXCSUM_IPV6 & ifp->if_capenable)) {
-				mlx5_en_err(ifp, "enable txcsum6 first.\n");
-				error = EAGAIN;
-				goto out;
+		if (nvlist_exists_bool(nv, IFCAP_TSO6_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_TSO6_NAME)) {
+				if (!priv->ifcap_txcsum_ipv6) {
+					mlx5_en_err(ifp,
+					    "enable txcsum6 first.\n");
+					error = EAGAIN;
+					goto out;
+				}
+				priv->ifcap_tso6 = true;
+				ifp->if_hwassist |= CSUM_IP6_TSO;
+			} else {
+				priv->ifcap_tso6 = false;
+				ifp->if_hwassist &= ~CSUM_IP6_TSO;
 			}
-			ifp->if_capenable ^= IFCAP_TSO6;
-			ifp->if_hwassist ^= CSUM_IP6_TSO;
 		}
-		if (mask & IFCAP_VLAN_HWTSO)
-			ifp->if_capenable ^= IFCAP_VLAN_HWTSO;
-		if (mask & IFCAP_VLAN_HWFILTER) {
-			if (ifp->if_capenable & IFCAP_VLAN_HWFILTER)
+		if (nvlist_exists_bool(nv, IFCAP_VLAN_HWTSO_NAME))
+			priv->ifcap_vlan_hwtso = nvlist_get_bool(nv,
+			    IFCAP_VLAN_HWTSO_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_VLAN_HWFILTER_NAME)) {
+			priv->ifcap_vlan_hwfilter = nvlist_get_bool(nv,
+			    IFCAP_VLAN_HWFILTER_NAME);
+			if (priv->ifcap_vlan_hwfilter)
 				mlx5e_disable_vlan_filter(priv);
 			else
 				mlx5e_enable_vlan_filter(priv);
-
-			ifp->if_capenable ^= IFCAP_VLAN_HWFILTER;
 		}
-		if (mask & IFCAP_VLAN_HWTAGGING)
-			ifp->if_capenable ^= IFCAP_VLAN_HWTAGGING;
-		if (mask & IFCAP_WOL_MAGIC)
-			ifp->if_capenable ^= IFCAP_WOL_MAGIC;
-		if (mask & IFCAP_VXLAN_HWCSUM) {
+		if (nvlist_exists_bool(nv, IFCAP_VLAN_HWTAGGING_NAME))
+			priv->ifcap_vlan_hwtagging = nvlist_get_bool(nv,
+			    IFCAP_VLAN_HWTAGGING_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_VXLAN_HWCSUM_NAME)) {
 			int was_opened = test_bit(MLX5E_STATE_OPENED,
 			    &priv->state);
 			if (was_opened)
 				mlx5e_close_locked(ifp);
-			ifp->if_capenable ^= IFCAP_VXLAN_HWCSUM;
-			ifp->if_hwassist ^= CSUM_INNER_IP | CSUM_INNER_IP_UDP |
-			    CSUM_INNER_IP_TCP | CSUM_INNER_IP6_UDP |
-			    CSUM_INNER_IP6_TCP;
-			if (was_opened)
-				mlx5e_open_locked(ifp);
+			if (nvlist_get_bool(nv, IFCAP_VXLAN_HWCSUM_NAME)) {
+				priv->ifcap_vxlan_hwcsum = true;
+				ifp->if_hwassist |= CSUM_INNER_IP |
+				    CSUM_INNER_IP_UDP | CSUM_INNER_IP_TCP |
+				    CSUM_INNER_IP6_UDP |
+				    CSUM_INNER_IP6_TCP;
+			} else {
+				priv->ifcap_vxlan_hwcsum = false;
+				ifp->if_hwassist &= ~(CSUM_INNER_IP |
+				    CSUM_INNER_IP_UDP | CSUM_INNER_IP_TCP |
+				    CSUM_INNER_IP6_UDP |
+				    CSUM_INNER_IP6_TCP);
+			}
 		}
-		if (mask & IFCAP_VXLAN_HWTSO) {
-			ifp->if_capenable ^= IFCAP_VXLAN_HWTSO;
-			ifp->if_hwassist ^= CSUM_INNER_IP_TSO |
-			    CSUM_INNER_IP6_TSO;
+		if (nvlist_exists_bool(nv, IFCAP_VXLAN_HWTSO_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_VXLAN_HWTSO_NAME)) {
+				priv->ifcap_vxlan_hwtso = true;
+				ifp->if_hwassist |= CSUM_INNER_IP_TSO |
+				    CSUM_INNER_IP6_TSO;
+			} else {
+				priv->ifcap_vxlan_hwtso = false;
+				ifp->if_hwassist &= ~(CSUM_INNER_IP_TSO |
+				    CSUM_INNER_IP6_TSO);
+			}
 		}
 
-		VLAN_CAPABILITIES(ifp);
 		/* turn off LRO means also turn of HW LRO - if it's on */
-		if (mask & IFCAP_LRO) {
+		if (nvlist_exists_bool(nv, IFCAP_LRO_NAME)) {
 			int was_opened = test_bit(MLX5E_STATE_OPENED, &priv->state);
 			bool need_restart = false;
 
-			ifp->if_capenable ^= IFCAP_LRO;
-
-			/* figure out if updating HW LRO is needed */
-			if (!(ifp->if_capenable & IFCAP_LRO)) {
+			if (nvlist_get_bool(nv, IFCAP_LRO_NAME)) {
+				priv->ifcap_lro = true;
 				if (priv->params.hw_lro_en) {
-					priv->params.hw_lro_en = false;
+					priv->params.hw_lro_en = true;
 					need_restart = true;
 				}
 			} else {
-				if (priv->params.hw_lro_en == false &&
-				    priv->params_ethtool.hw_lro != 0) {
-					priv->params.hw_lro_en = true;
+				priv->ifcap_lro = false;
+				if (priv->params.hw_lro_en) {
+					priv->params.hw_lro_en = false;
 					need_restart = true;
 				}
 			}
@@ -3489,16 +3624,25 @@
 				mlx5e_open_locked(ifp);
 			}
 		}
-		if (mask & IFCAP_HWRXTSTMP) {
-			ifp->if_capenable ^= IFCAP_HWRXTSTMP;
-			if (ifp->if_capenable & IFCAP_HWRXTSTMP) {
+		if (nvlist_exists_bool(nv, IFCAP_HWRXTSTMP_NAME)) {
+			if (nvlist_get_bool(nv, IFCAP_HWRXTSTMP_NAME)) {
+				priv->ifcap_hwrxtstmp = true;
 				if (priv->clbr_done == 0)
 					mlx5e_reset_calibration_callout(priv);
 			} else {
+				priv->ifcap_hwrxtstmp = false;
 				callout_drain(&priv->tstmp_clbr);
 				priv->clbr_done = 0;
 			}
 		}
+		if (nvlist_exists_bool(nv, IFCAP_RXTLS4_NAME))
+			priv->ifcap_rxtls4 = nvlist_get_bool(nv,
+			    IFCAP_RXTLS4_NAME);
+		if (nvlist_exists_bool(nv, IFCAP_RXTLS6_NAME))
+			priv->ifcap_rxtls6 = nvlist_get_bool(nv,
+			    IFCAP_RXTLS6_NAME);
+		ifp->if_capenable = mlx5e_if_caps(priv);
+		VLAN_CAPABILITIES(ifp);
 out:
 		PRIV_UNLOCK(priv);
 		break;
@@ -4387,19 +4531,33 @@
 	/*
          * Set driver features
          */
-	ifp->if_capabilities |= IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6;
-	ifp->if_capabilities |= IFCAP_VLAN_MTU | IFCAP_VLAN_HWTAGGING;
-	ifp->if_capabilities |= IFCAP_VLAN_HWCSUM | IFCAP_VLAN_HWFILTER;
-	ifp->if_capabilities |= IFCAP_LINKSTATE | IFCAP_JUMBO_MTU;
-	ifp->if_capabilities |= IFCAP_LRO;
-	ifp->if_capabilities |= IFCAP_TSO | IFCAP_VLAN_HWTSO;
-	ifp->if_capabilities |= IFCAP_HWSTATS | IFCAP_HWRXTSTMP;
-	ifp->if_capabilities |= IFCAP_MEXTPG;
-	ifp->if_capabilities |= IFCAP_TXTLS4 | IFCAP_TXTLS6;
+	priv->ifcap_rxcsum = true;
+	priv->ifcap_txcsum = true;
+	priv->ifcap_vlan_mtu = true;
+	priv->ifcap_vlan_hwtagging = true;
+	priv->ifcap_jumbo_mtu = true;
+	priv->ifcap_vlan_hwcsum = true;
+	priv->ifcap_tso4 = true;
+	priv->ifcap_tso6 = true;
+	priv->ifcap_lro = true;
+	priv->ifcap_vlan_hwfilter = true;
+	priv->ifcap_vlan_hwtso = true;
+	priv->ifcap_linkstate = true;
+	priv->ifcap_rxcsum_ipv6 = true;
+	priv->ifcap_txcsum_ipv6 = true;
+	priv->ifcap_hwstats_name = true;
+#ifdef RATELIMIT
+	priv->ifcap_txrtlmt = true;
+#endif
+	priv->ifcap_hwrxtstmp = true;
+	priv->ifcap_mextpg = true;
+	priv->ifcap_txtls4 = true;
+	priv->ifcap_txtls6 = true;
+	priv->ifcap_vxlan_hwcsum = true;
+	priv->ifcap_vxlan_hwtso = true;
 #ifdef RATELIMIT
-	ifp->if_capabilities |= IFCAP_TXRTLMT | IFCAP_TXTLS_RTLMT;
+	priv->ifcap_txtls_rtlmt = true;
 #endif
-	ifp->if_capabilities |= IFCAP_VXLAN_HWCSUM | IFCAP_VXLAN_HWTSO;
 	ifp->if_snd_tag_alloc = mlx5e_snd_tag_alloc;
 #ifdef RATELIMIT
 	ifp->if_ratelimit_query = mlx5e_ratelimit_query;
@@ -4409,7 +4567,7 @@
 	ifp->if_hw_tsomaxsegcount = MLX5E_MAX_TX_MBUF_FRAGS - 1 /* hdr */;
 	ifp->if_hw_tsomaxsegsize = MLX5E_MAX_TX_MBUF_SIZE;
 
-	ifp->if_capenable = ifp->if_capabilities;
+	ifp->if_capenable = ifp->if_capabilities = mlx5e_if_caps(priv);
 	ifp->if_hwassist = 0;
 	if (ifp->if_capenable & IFCAP_TSO)
 		ifp->if_hwassist |= CSUM_TSO;
diff --git a/sys/net/if.h b/sys/net/if.h
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -236,7 +236,7 @@
 #define	IFCAP_TOE4		0x04000	/* interface can offload TCP */
 #define	IFCAP_TOE6		0x08000	/* interface can offload TCP6 */
 #define	IFCAP_VLAN_HWFILTER	0x10000 /* interface hw can filter vlan tag */
-/* 	available		0x20000 */
+#define	IFCAP_NV		0x20000 /* can do SIOCGIFCAPNV/SIOCSIFCAPNV */
 #define	IFCAP_VLAN_HWTSO	0x40000 /* can do IFCAP_TSO on VLANs */
 #define	IFCAP_LINKSTATE		0x80000 /* the runtime link state is dynamic */
 #define	IFCAP_NETMAP		0x100000 /* netmap mode supported/enabled */
@@ -260,7 +260,42 @@
 #define	IFCAP_TOE	(IFCAP_TOE4 | IFCAP_TOE6)
 #define	IFCAP_TXTLS	(IFCAP_TXTLS4 | IFCAP_TXTLS6)
 
-#define	IFCAP_CANTCHANGE	(IFCAP_NETMAP)
+#define	IFCAP_CANTCHANGE	(IFCAP_NETMAP | IFCAP_NV)
+#define	IFCAP_ALLCAPS		0xffffffff
+
+#define	IFCAP_RXCSUM_NAME	"RXCSUM"
+#define	IFCAP_TXCSUM_NAME	"TXCSUM"
+#define	IFCAP_NETCONS_NAME	"NETCONS"
+#define	IFCAP_VLAN_MTU_NAME	"VLAN_MTU"
+#define	IFCAP_VLAN_HWTAGGING_NAME "VLAN_HWTAGGING"
+#define	IFCAP_JUMBO_MTU_NAME	"JUMBO_MTU"
+#define	IFCAP_POLLING_NAME	"POLLING"
+#define	IFCAP_VLAN_HWCSUM_NAME	"VLAN_HWCSUM"
+#define	IFCAP_TSO4_NAME		"TSO4"
+#define	IFCAP_TSO6_NAME		"TSO6"
+#define	IFCAP_LRO_NAME		"LRO"
+#define	IFCAP_WOL_UCAST_NAME	"WOL_UCAST"
+#define	IFCAP_WOL_MCAST_NAME	"WOL_MCAST"
+#define	IFCAP_WOL_MAGIC_NAME	"WOL_MAGIC"
+#define	IFCAP_TOE4_NAME		"TOE4"
+#define	IFCAP_TOE6_NAME		"TOE6"
+#define	IFCAP_VLAN_HWFILTER_NAME "VLAN_HWFILTER"
+#define	IFCAP_VLAN_HWTSO_NAME	"VLAN_HWTSO"
+#define	IFCAP_LINKSTATE_NAME	"LINKSTATE"
+#define	IFCAP_NETMAP_NAME	"NETMAP"
+#define	IFCAP_RXCSUM_IPV6_NAME	"RXCSUM_IPV6"
+#define	IFCAP_TXCSUM_IPV6_NAME	"TXCSUM_IPV6"
+#define	IFCAP_HWSTATS_NAME	"HWSTATS"
+#define	IFCAP_TXRTLMT_NAME	"TXRTLMT"
+#define	IFCAP_HWRXTSTMP_NAME	"HWRXTSTMP"
+#define	IFCAP_MEXTPG_NAME	"MEXTPG"
+#define	IFCAP_TXTLS4_NAME	"TXTLS4"
+#define	IFCAP_TXTLS6_NAME	"TXTLS6"
+#define	IFCAP_VXLAN_HWCSUM_NAME	"VXLAN_HWCSUM"
+#define	IFCAP_VXLAN_HWTSO_NAME	"VXLAN_HWTSO"
+#define	IFCAP_TXTLS_RTLMT_NAME	"TXTLS_RTLMT"
+#define	IFCAP_RXTLS4_NAME	"RXTLS4"
+#define	IFCAP_RXTLS6_NAME	"RXTLS6"
 
 #define	IFQ_MAXLEN	50
 #define	IFNET_SLOWHZ	1		/* granularity is 1 second */
@@ -387,6 +422,15 @@
 	void	*buffer;
 };
 
+struct ifreq_nv_req {
+	u_int	buf_length;	/* Total size of buffer,
+				   u_int for ABI struct ifreq */
+	u_int	length;		/* Length of the filled part */
+	void	*buffer;	/* Buffer itself, containing packed nv */
+};
+
+#define	IFR_CAP_NV_MAXBUFSIZE	(2 * 1024 * 1024)
+
 /*
  * Interface request structure used for socket
  * ioctl's.  All interface ioctl's must have parameter
@@ -411,6 +455,7 @@
 		int	ifru_cap[2];
 		u_int	ifru_fib;
 		u_char	ifru_vlan_pcp;
+		struct	ifreq_nv_req ifru_nv;
 	} ifr_ifru;
 #define	ifr_addr	ifr_ifru.ifru_addr	/* address */
 #define	ifr_dstaddr	ifr_ifru.ifru_dstaddr	/* other end of p-to-p link */
@@ -434,6 +479,7 @@
 #define	ifr_fib		ifr_ifru.ifru_fib	/* interface fib */
 #define	ifr_vlan_pcp	ifr_ifru.ifru_vlan_pcp	/* VLAN priority */
 #define	ifr_lan_pcp	ifr_ifru.ifru_vlan_pcp	/* VLAN priority */
+#define	ifr_cap_nv	ifr_ifru.ifru_nv	/* nv-based cap interface */
 };
 
 #define	_SIZEOF_ADDR_IFREQ(ifr) \
@@ -605,6 +651,10 @@
 
 extern struct sx ifnet_detach_sxlock;
 
+struct nvlist;
+int if_capnv_to_capint(const struct nvlist *nv, bool all);
+void if_capint_to_capnv(struct nvlist *nv, int ifr_cap, int ifr_req);
+
 #endif
 
 #ifndef _KERNEL
diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -58,6 +58,7 @@
 #include <sys/lock.h>
 #include <sys/refcount.h>
 #include <sys/module.h>
+#include <sys/nv.h>
 #include <sys/rwlock.h>
 #include <sys/sockio.h>
 #include <sys/syslog.h>
@@ -2402,6 +2403,78 @@
 		return (ifrup->ifr.ifr_ifru.ifru_data);
 }
 
+struct ifcap_nv_bit_name {
+	int cap_bit;
+	const char *cap_name;
+};
+#define CAPNV(x) {.cap_bit = IFCAP_##x, \
+    .cap_name = __CONCAT(IFCAP_, __CONCAT(x, _NAME)) }
+const struct ifcap_nv_bit_name ifcap_nv_bit_names[] = {
+	CAPNV(RXCSUM),
+	CAPNV(TXCSUM),
+	CAPNV(NETCONS),
+	CAPNV(VLAN_MTU),
+	CAPNV(VLAN_HWTAGGING),
+	CAPNV(JUMBO_MTU),
+	CAPNV(POLLING),
+	CAPNV(VLAN_HWCSUM),
+	CAPNV(TSO4),
+	CAPNV(TSO6),
+	CAPNV(LRO),
+	CAPNV(WOL_UCAST),
+	CAPNV(WOL_MCAST),
+	CAPNV(WOL_MAGIC),
+	CAPNV(TOE4),
+	CAPNV(TOE6),
+	CAPNV(VLAN_HWFILTER),
+	CAPNV(VLAN_HWTSO),
+	CAPNV(LINKSTATE),
+	CAPNV(NETMAP),
+	CAPNV(RXCSUM_IPV6),
+	CAPNV(TXCSUM_IPV6),
+	CAPNV(HWSTATS),
+	CAPNV(TXRTLMT),
+	CAPNV(HWRXTSTMP),
+	CAPNV(MEXTPG),
+	CAPNV(TXTLS4),
+	CAPNV(TXTLS6),
+	CAPNV(VXLAN_HWCSUM),
+	CAPNV(VXLAN_HWTSO),
+	CAPNV(TXTLS_RTLMT),
+};
+#undef CAPNV
+
+int
+if_capnv_to_capint(const nvlist_t *nv, bool all)
+{
+	const struct ifcap_nv_bit_name *nn;
+	int i, res;
+
+	res = 0;
+	for (i = 0; i < nitems(ifcap_nv_bit_names); i++) {
+		nn = &ifcap_nv_bit_names[i];
+		if (nvlist_exists_bool(nv, nn->cap_name) && (all ||
+		    nvlist_get_bool(nv, nn->cap_name)))
+			res |= nn->cap_bit;
+	}
+	return (res);
+}
+
+void
+if_capint_to_capnv(nvlist_t *nv, int ifr_cap, int ifr_req)
+{
+	const struct ifcap_nv_bit_name *nn;
+	int i;
+
+	for (i = 0; i < nitems(ifcap_nv_bit_names); i++) {
+		nn = &ifcap_nv_bit_names[i];
+		if ((nn->cap_bit & ifr_cap) != 0) {
+			nvlist_add_bool(nv, nn->cap_name,
+			    (nn->cap_bit & ifr_req) != 0);
+		}
+	}
+}
+
 /*
  * Hardware specific interface ioctls.
  */
@@ -2412,12 +2485,14 @@
 	int error = 0, do_ifup = 0;
 	int new_flags, temp_flags;
 	size_t namelen, onamelen;
-	size_t descrlen;
+	size_t descrlen, nvbuflen;
 	char *descrbuf, *odescrbuf;
 	char new_name[IFNAMSIZ];
 	char old_name[IFNAMSIZ], strbuf[IFNAMSIZ + 8];
 	struct ifaddr *ifa;
 	struct sockaddr_dl *sdl;
+	void *buf;
+	nvlist_t *nvcap;
 
 	ifr = (struct ifreq *)data;
 	switch (cmd) {
@@ -2432,8 +2507,66 @@
 		break;
 
 	case SIOCGIFCAP:
-		ifr->ifr_reqcap = ifp->if_capabilities;
-		ifr->ifr_curcap = ifp->if_capenable;
+		if ((ifp->if_capabilities & IFCAP_NV) == 0) {
+			ifr->ifr_reqcap = ifp->if_capabilities;
+			ifr->ifr_curcap = ifp->if_capenable;
+			break;
+		}
+		nvcap = nvlist_create(0);
+		error = (*ifp->if_ioctl)(ifp, SIOCGIFCAPNV,
+		    __DECONST(caddr_t, nvcap));
+		while (error == 0) {
+			error = nvlist_error(nvcap);
+			if (error != 0) {
+				if_printf(ifp,
+			    "SIOCGIFPCAPNV driver mistake: nvlist error %d\n",
+				    error);
+				break;
+			}
+			ifr->ifr_reqcap = if_capnv_to_capint(nvcap, true);
+			ifr->ifr_curcap = if_capnv_to_capint(nvcap, false);
+			ifr->ifr_reqcap |= IFCAP_NV;
+			ifr->ifr_curcap |= IFCAP_NV;
+			break;
+		}
+		nvlist_destroy(nvcap);
+		break;
+
+	case SIOCGIFCAPNV:
+		if ((ifp->if_capabilities & IFCAP_NV) == 0) {
+			error = EINVAL;
+			break;
+		}
+		buf = NULL;
+		nvcap = nvlist_create(0);
+		for (;;) {
+			error = (*ifp->if_ioctl)(ifp, SIOCGIFCAPNV,
+			    __DECONST(caddr_t, nvcap));
+			if (error != 0)
+				break;
+			if (error != 0) {
+				if_printf(ifp,
+			    "SIOCGIFCAPNV driver mistake: nvlist error %d\n",
+				    error);
+				break;
+			}
+			buf = nvlist_pack(nvcap, &nvbuflen);
+			if (buf == NULL) {
+				error = EDOOFUS;
+				break;
+			}
+			if (nvbuflen > ifr->ifr_cap_nv.buf_length) {
+				ifr->ifr_cap_nv.length = nvbuflen;
+				ifr->ifr_cap_nv.buffer = NULL;
+				error = EFBIG;
+				break;
+			}
+			ifr->ifr_cap_nv.length = nvbuflen;
+			error = copyout(buf, ifr->ifr_cap_nv.buffer, nvbuflen);
+			break;
+		}
+		free(buf, M_NVLIST);
+		nvlist_destroy(nvcap);
 		break;
 
 	case SIOCGIFDATA:
@@ -2574,13 +2707,60 @@
 
 	case SIOCSIFCAP:
 		error = priv_check(td, PRIV_NET_SETIFCAP);
-		if (error)
+		if (error != 0)
+			return (error);
+		if (ifp->if_ioctl == NULL)
+			return (EOPNOTSUPP);
+		if ((ifp->if_capabilities & IFCAP_NV) == 0) {
+			if (ifr->ifr_reqcap & ~ifp->if_capabilities) {
+				error = EINVAL;
+				break;
+			}
+			error = (*ifp->if_ioctl)(ifp, cmd, data);
+			break;
+		} else {
+			nvcap = nvlist_create(0);
+			for (;;) {
+				if_capint_to_capnv(nvcap, IFCAP_ALLCAPS,
+				    ifr->ifr_reqcap);
+				error = (*ifp->if_ioctl)(ifp, SIOCSIFCAPNV,
+				    __DECONST(caddr_t, nvcap));
+				break;
+			}
+			nvlist_destroy(nvcap);
+		}
+		if (error == 0)
+			getmicrotime(&ifp->if_lastchange);
+		break;
+
+	case SIOCSIFCAPNV:
+		error = priv_check(td, PRIV_NET_SETIFCAP);
+		if (error != 0)
 			return (error);
 		if (ifp->if_ioctl == NULL)
 			return (EOPNOTSUPP);
-		if (ifr->ifr_reqcap & ~ifp->if_capabilities)
+		if ((ifp->if_capabilities & IFCAP_NV) == 0)
 			return (EINVAL);
-		error = (*ifp->if_ioctl)(ifp, cmd, data);
+		if (ifr->ifr_cap_nv.length > IFR_CAP_NV_MAXBUFSIZE)
+			return (EINVAL);
+		nvcap = NULL;
+		buf = malloc(ifr->ifr_cap_nv.length, M_TEMP, M_WAITOK);
+		for (;;) {
+			error = copyin(ifr->ifr_cap_nv.buffer, buf,
+			    ifr->ifr_cap_nv.length);
+			if (error != 0)
+				break;
+			nvcap = nvlist_unpack(buf, ifr->ifr_cap_nv.length, 0);
+			if (nvcap == NULL) {
+				error = EINVAL;
+				break;
+			}
+			error = (*ifp->if_ioctl)(ifp, cmd,
+			    __DECONST(caddr_t, nvcap));
+			break;
+		}
+		nvlist_destroy(nvcap);
+		free(buf, M_TEMP);
 		if (error == 0)
 			getmicrotime(&ifp->if_lastchange);
 		break;
diff --git a/sys/sys/sockio.h b/sys/sys/sockio.h
--- a/sys/sys/sockio.h
+++ b/sys/sys/sockio.h
@@ -147,4 +147,7 @@
 
 #define	SIOCGIFDOWNREASON	_IOWR('i', 154, struct ifdownreason)
 
+#define	SIOCSIFCAPNV	 _IOW('i', 155, struct ifreq)	/* set IF features */
+#define	SIOCGIFCAPNV	_IOWR('i', 156, struct ifreq)	/* get IF features */
+
 #endif /* !_SYS_SOCKIO_H_ */