diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index a8ae2b5d3..55b73a03b 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -736,6 +736,7 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 	struct ether_addr mac;
 	char name[RTE_ETH_NAME_MAX_LEN];
 	int own_domain_id = 0;
+	struct rte_flow_error flow_error;
 	unsigned int i;
 
 	/* Determine if this port representor is supposed to be spawned. */
@@ -959,6 +960,8 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 	priv->domain_id = RTE_ETH_DEV_SWITCH_DOMAIN_ID_INVALID;
 	priv->representor_id =
 		switch_info->representor ? switch_info->port_name : -1;
+	/* Interface index will be known once eth_dev is allocated. */
+	priv->ifindex = 0;
 	/*
 	 * Look for sibling devices in order to reuse their switch domain
 	 * if any, otherwise allocate one.
@@ -1087,6 +1090,16 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 		err = rte_errno;
 		goto error;
 	}
+	/*
+	 * Cache associated interface index since lookups are expensive.
+	 * It is not expected to change while a PMD instance is bound and
+	 * running.
+	 */
+	priv->ifindex = mlx5_ifindex(eth_dev);
+	if (!priv->ifindex)
+		DRV_LOG(WARNING,
+			"cannot retrieve network interface index: %s",
+			strerror(rte_errno));
 	/* Configure the first MAC address by default. */
 	if (mlx5_get_mac(eth_dev, &mac.addr_bytes)) {
 		DRV_LOG(ERR,
@@ -1131,32 +1144,19 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
 	if (vf && config.vf_nl_en)
 		mlx5_nl_mac_addr_sync(eth_dev);
 	priv->mnl_socket = mlx5_nl_flow_socket_create();
-	if (!priv->mnl_socket) {
-		err = -rte_errno;
+	if (!priv->mnl_socket ||
+	    !priv->ifindex ||
+	    mlx5_nl_flow_init(priv->mnl_socket, priv->ifindex, &flow_error)) {
+		if (!priv->mnl_socket) {
+			flow_error.message = "cannot open libmnl socket";
+		} else if (!priv->ifindex) {
+			rte_errno = ENXIO;
+			flow_error.message = "unknown network interface index";
+		}
 		DRV_LOG(WARNING,
 			"flow rules relying on switch offloads will not be"
-			" supported: cannot open libmnl socket: %s",
-			strerror(rte_errno));
-	} else {
-		struct rte_flow_error error;
-		unsigned int ifindex = mlx5_ifindex(eth_dev);
-
-		if (!ifindex) {
-			err = -rte_errno;
-			error.message =
-				"cannot retrieve network interface index";
-		} else {
-			err = mlx5_nl_flow_init(priv->mnl_socket, ifindex,
-						&error);
-		}
-		if (err) {
-			DRV_LOG(WARNING,
-				"flow rules relying on switch offloads will"
-				" not be supported: %s: %s",
-				error.message, strerror(rte_errno));
-			mlx5_nl_flow_socket_destroy(priv->mnl_socket);
-			priv->mnl_socket = NULL;
-		}
+			" supported: %s: %s",
+			flow_error.message, strerror(rte_errno));
 	}
 	TAILQ_INIT(&priv->flows);
 	TAILQ_INIT(&priv->ctrl_flows);
diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h
index 35a196e76..4c2dec644 100644
--- a/drivers/net/mlx5/mlx5.h
+++ b/drivers/net/mlx5/mlx5.h
@@ -183,6 +183,7 @@ struct priv {
 	unsigned int representor:1; /* Device is a port representor. */
 	uint16_t domain_id; /* Switch domain identifier. */
 	int32_t representor_id; /* Port representor identifier. */
+	unsigned int ifindex; /* Interface index associated with device. */
 	/* RX/TX queues. */
 	unsigned int rxqs_n; /* RX queues array size. */
 	unsigned int txqs_n; /* TX queues array size. */
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 34c5b95ee..cf0b415b2 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -511,7 +511,6 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	struct priv *priv = dev->data->dev_private;
 	struct mlx5_dev_config *config = &priv->config;
 	unsigned int max;
-	char ifname[IF_NAMESIZE];
 
 	/* FIXME: we should ask the device for these values. */
 	info->min_rx_bufsize = 32;
@@ -532,8 +531,7 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	info->rx_offload_capa = (mlx5_get_rx_port_offloads() |
 				 info->rx_queue_offload_capa);
 	info->tx_offload_capa = mlx5_get_tx_port_offloads(dev);
-	if (mlx5_get_ifname(dev, &ifname) == 0)
-		info->if_index = if_nametoindex(ifname);
+	info->if_index = priv->ifindex;
 	info->reta_size = priv->reta_idx_n ?
 		priv->reta_idx_n : config->ind_table_max_size;
 	info->hash_key_size = MLX5_RSS_HASH_KEY_LEN;
diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 3f548a9a4..f093a5ed0 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -2466,13 +2466,13 @@ mlx5_flow_merge_switch(struct rte_eth_dev *dev,
 		n = RTE_MIN(mlx5_dev_to_port_id(dev->device, port_id, n), n);
 	}
 	for (i = 0; i != n; ++i) {
-		struct rte_eth_dev_info dev_info;
+		struct rte_eth_dev *i_dev = &rte_eth_devices[port_id[i]];
+		struct priv *i_priv = i_dev->data->dev_private;
 
-		rte_eth_dev_info_get(port_id[i], &dev_info);
 		if (port_id[i] == dev->data->port_id)
 			own = i;
 		ptoi[i].port_id = port_id[i];
-		ptoi[i].ifindex = dev_info.if_index;
+		ptoi[i].ifindex = i_priv->ifindex;
 	}
 	/* Ensure first entry of ptoi[] is the current device. */
 	if (own) {
diff --git a/drivers/net/mlx5/mlx5_nl.c b/drivers/net/mlx5/mlx5_nl.c
index d61826aea..a298db68c 100644
--- a/drivers/net/mlx5/mlx5_nl.c
+++ b/drivers/net/mlx5/mlx5_nl.c
@@ -362,7 +362,6 @@ mlx5_nl_mac_addr_list(struct rte_eth_dev *dev, struct ether_addr (*mac)[],
 		      int *mac_n)
 {
 	struct priv *priv = dev->data->dev_private;
-	unsigned int iface_idx = mlx5_ifindex(dev);
 	struct {
 		struct nlmsghdr	hdr;
 		struct ifinfomsg ifm;
@@ -374,7 +373,7 @@ mlx5_nl_mac_addr_list(struct rte_eth_dev *dev, struct ether_addr (*mac)[],
 		},
 		.ifm = {
 			.ifi_family = PF_BRIDGE,
-			.ifi_index = iface_idx,
+			.ifi_index = priv->ifindex,
 		},
 	};
 	struct mlx5_nl_mac_addr data = {
@@ -421,7 +420,6 @@ mlx5_nl_mac_addr_modify(struct rte_eth_dev *dev, struct ether_addr *mac,
 			int add)
 {
 	struct priv *priv = dev->data->dev_private;
-	unsigned int iface_idx = mlx5_ifindex(dev);
 	struct {
 		struct nlmsghdr hdr;
 		struct ndmsg ndm;
@@ -437,7 +435,7 @@ mlx5_nl_mac_addr_modify(struct rte_eth_dev *dev, struct ether_addr *mac,
 		.ndm = {
 			.ndm_family = PF_BRIDGE,
 			.ndm_state = NUD_NOARP | NUD_PERMANENT,
-			.ndm_ifindex = iface_idx,
+			.ndm_ifindex = priv->ifindex,
 			.ndm_flags = NTF_SELF,
 		},
 		.rta = {
@@ -600,7 +598,6 @@ static int
 mlx5_nl_device_flags(struct rte_eth_dev *dev, uint32_t flags, int enable)
 {
 	struct priv *priv = dev->data->dev_private;
-	unsigned int iface_idx = mlx5_ifindex(dev);
 	struct {
 		struct nlmsghdr hdr;
 		struct ifinfomsg ifi;
@@ -613,7 +610,7 @@ mlx5_nl_device_flags(struct rte_eth_dev *dev, uint32_t flags, int enable)
 		.ifi = {
 			.ifi_flags = enable ? flags : 0,
 			.ifi_change = flags,
-			.ifi_index = iface_idx,
+			.ifi_index = priv->ifindex,
 		},
 	};
 	int fd;
