diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
index 018843bda9..730249b9fa 100644
--- a/drivers/net/mlx4/mlx4_flow.c
+++ b/drivers/net/mlx4/mlx4_flow.c
@@ -597,8 +597,8 @@ mlx4_flow_prepare(struct priv *priv,
 		.queue = 0,
 		.drop = 0,
 	};
+	uint32_t priority_override = 0;
 
-	(void)priv;
 	if (attr->group) {
 		rte_flow_error_set(error, ENOTSUP,
 				   RTE_FLOW_ERROR_TYPE_ATTR_GROUP,
@@ -606,11 +606,22 @@ mlx4_flow_prepare(struct priv *priv,
 				   "groups are not supported");
 		return -rte_errno;
 	}
-	if (attr->priority) {
+	if (priv->isolated) {
+		priority_override = attr->priority;
+	} else if (attr->priority) {
 		rte_flow_error_set(error, ENOTSUP,
 				   RTE_FLOW_ERROR_TYPE_ATTR_PRIORITY,
 				   NULL,
-				   "priorities are not supported");
+				   "priorities are not supported outside"
+				   " isolated mode");
+		return -rte_errno;
+	}
+	if (attr->priority > MLX4_FLOW_PRIORITY_LAST) {
+		rte_flow_error_set(error, ENOTSUP,
+				   RTE_FLOW_ERROR_TYPE_ATTR_PRIORITY,
+				   NULL,
+				   "maximum priority level is "
+				   MLX4_STR_EXPAND(MLX4_FLOW_PRIORITY_LAST));
 		return -rte_errno;
 	}
 	if (attr->egress) {
@@ -680,6 +691,9 @@ mlx4_flow_prepare(struct priv *priv,
 		}
 		flow->offset += cur_item->dst_sz;
 	}
+	/* Use specified priority level when in isolated mode. */
+	if (priv->isolated && flow->ibv_attr)
+		flow->ibv_attr->priority = priority_override;
 	/* Go over actions list */
 	for (; actions->type != RTE_FLOW_ACTION_TYPE_END; ++actions) {
 		if (actions->type == RTE_FLOW_ACTION_TYPE_VOID) {
diff --git a/drivers/net/mlx4/mlx4_flow.h b/drivers/net/mlx4/mlx4_flow.h
index 459030c60c..8ac09f1350 100644
--- a/drivers/net/mlx4/mlx4_flow.h
+++ b/drivers/net/mlx4/mlx4_flow.h
@@ -52,6 +52,9 @@
 #include <rte_flow_driver.h>
 #include <rte_byteorder.h>
 
+/** Last and lowest priority level for a flow rule. */
+#define MLX4_FLOW_PRIORITY_LAST UINT32_C(0xfff)
+
 /** PMD-specific (mlx4) definition of a flow rule handle. */
 struct rte_flow {
 	LIST_ENTRY(rte_flow) next; /**< Pointer to the next flow structure. */
diff --git a/drivers/net/mlx4/mlx4_utils.h b/drivers/net/mlx4/mlx4_utils.h
index b9c02d59b1..13f731a0db 100644
--- a/drivers/net/mlx4/mlx4_utils.h
+++ b/drivers/net/mlx4/mlx4_utils.h
@@ -104,6 +104,12 @@ pmd_drv_log_basename(const char *s)
 	\
 	snprintf(name, sizeof(name), __VA_ARGS__)
 
+/** Generate a string out of the provided arguments. */
+#define MLX4_STR(...) # __VA_ARGS__
+
+/** Similar to MLX4_STR() with enclosed macros expanded first. */
+#define MLX4_STR_EXPAND(...) MLX4_STR(__VA_ARGS__)
+
 /* mlx4_utils.c */
 
 int mlx4_fd_set_non_blocking(int fd);