[v6] app/testpmd: add Host Shaper command

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 33d9b85..e1ac75a 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -69,6 +69,9 @@ 
 #ifdef RTE_NET_BOND
 #include <rte_eth_bond.h>
 #endif
+#ifdef RTE_NET_MLX5
+#include "mlx5_testpmd.h"
+#endif
 
 #include "testpmd.h"
 
@@ -3659,6 +3662,14 @@  struct pmd_test_command {
 				break;
 			printf("Received avail_thresh event, port:%d rxq_id:%d\n",
 			       port_id, rxq_id);
+
+			struct rte_eth_dev_info dev_info;
+			if (rte_eth_dev_info_get(port_id, &dev_info) != 0 ||
+			    (strncmp(dev_info.driver_name, "mlx5", 4) != 0))
+				printf("%s\n", dev_info.driver_name);
+#ifdef RTE_NET_MLX5
+			mlx5_test_avail_thresh_event_handler(port_id, rxq_id);
+#endif
 		}
 		break;
 	default:
diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index a1e13e7..b5a3ee3 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -1727,3 +1727,49 @@  which can be installed from OFED mstflint package.
 Meson detects ``libmtcr_ul`` existence at configure stage.
 If the library is detected, the application must link with ``-lmtcr_ul``,
 as done by the pkg-config file libdpdk.pc.
+
+How to use available descriptor threshold and Host Shaper
+------------------------------
+
+There are sample command lines to configure available descriptor threshold in testpmd.
+Testpmd also contains sample logic to handle available descriptor threshold event.
+The typical workflow is: testpmd configure available descriptor threshold for Rx queues, enable
+avail_thresh_triggered in host shaper and register a callback, when traffic from host is
+too high and Rx queue emptiness is below available descriptor threshold, PMD receives an event and
+firmware configures a 100Mbps shaper on host port automatically, then PMD call
+the callback registered previously, which will delay a while to let Rx queue
+empty, then disable host shaper.
+
+Let's assume we have a simple Blue Field 2 setup: port 0 is uplink, port 1
+is VF representor. Each port has 2 Rx queues.
+In order to control traffic from host to ARM, we can enable available descriptor threshold in testpmd by:
+
+.. code-block:: console
+
+   testpmd> mlx5 set port 1 host_shaper avail_thresh_triggered 1 rate 0
+   testpmd> set port 1 rxq 0 avail_thresh 70
+   testpmd> set port 1 rxq 1 avail_thresh 70
+
+The first command disables current host shaper, and enables available descriptor threshold triggered mode.
+The left commands configure available descriptor threshold to 70% of Rx queue size for both Rx queues,
+When traffic from host is too high, you can see testpmd console prints log
+about available descriptor threshold event receiving, then host shaper is disabled.
+The traffic rate from host is controlled and less drop happens in Rx queues.
+
+When disable available descriptor threshold and avail_thresh_triggered, we can invoke below commands in testpmd:
+
+.. code-block:: console
+
+   testpmd> mlx5 set port 1 host_shaper avail_thresh_triggered 0 rate 0
+   testpmd> set port 1 rxq 0 avail_thresh 0
+   testpmd> set port 1 rxq 1 avail_thresh 0
+
+It's recommended an application disables available descriptor threshold and avail_thresh_triggered before exit,
+if it enables them before.
+
+We can also configure the shaper with a value, the rate unit is 100Mbps, below
+command sets current shaper to 5Gbps and disables avail_thresh_triggered.
+
+.. code-block:: console
+
+   testpmd> mlx5 set port 1 host_shaper avail_thresh_triggered 0 rate 50
diff --git a/drivers/net/mlx5/meson.build b/drivers/net/mlx5/meson.build
index 99210fd..941642b 100644
--- a/drivers/net/mlx5/meson.build
+++ b/drivers/net/mlx5/meson.build
@@ -68,4 +68,8 @@  if get_option('buildtype').contains('debug')
 else
     cflags += [ '-UPEDANTIC' ]
 endif
+
+testpmd_sources += files('mlx5_testpmd.c')
+testpmd_drivers_deps += 'net_mlx5'
+
 subdir(exec_env)
diff --git a/drivers/net/mlx5/mlx5_testpmd.c b/drivers/net/mlx5/mlx5_testpmd.c
new file mode 100644
index 0000000..32f2386
--- /dev/null
+++ b/drivers/net/mlx5/mlx5_testpmd.c
@@ -0,0 +1,206 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2021 6WIND S.A.
+ * Copyright 2021 Mellanox Technologies, Ltd
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <rte_prefetch.h>
+#include <rte_common.h>
+#include <rte_branch_prediction.h>
+#include <rte_ether.h>
+#include <rte_alarm.h>
+#include <rte_pmd_mlx5.h>
+#include <rte_ethdev.h>
+#include "mlx5_testpmd.h"
+#include "testpmd.h"
+
+static uint8_t host_shaper_avail_thresh_triggered[RTE_MAX_ETHPORTS];
+#define SHAPER_DISABLE_DELAY_US 100000 /* 100ms */
+
+/**
+ * Disable the host shaper and re-arm available descriptor threshold event.
+ *
+ * @param[in] args
+ *   uint32_t integer combining port_id and rxq_id.
+ */
+static void
+mlx5_test_host_shaper_disable(void *args)
+{
+	uint32_t port_rxq_id = (uint32_t)(uintptr_t)args;
+	uint16_t port_id = port_rxq_id & 0xffff;
+	uint16_t qid = (port_rxq_id >> 16) & 0xffff;
+	struct rte_eth_rxq_info qinfo;
+
+	printf("%s disable shaper\n", __func__);
+	if (rte_eth_rx_queue_info_get(port_id, qid, &qinfo)) {
+		printf("rx_queue_info_get returns error\n");
+		return;
+	}
+	/* Rearm the available descriptor threshold event. */
+	if (rte_eth_rx_avail_thresh_set(port_id, qid, qinfo.avail_thresh)) {
+		printf("config avail_thresh returns error\n");
+		return;
+	}
+	/* Only disable the shaper when avail_thresh_triggered is set. */
+	if (host_shaper_avail_thresh_triggered[port_id] &&
+	    rte_pmd_mlx5_host_shaper_config(port_id, 0, 0))
+		printf("%s disable shaper returns error\n", __func__);
+}
+
+void
+mlx5_test_avail_thresh_event_handler(uint16_t port_id, uint16_t rxq_id)
+{
+	struct rte_eth_dev_info dev_info;
+	uint32_t port_rxq_id = port_id | (rxq_id << 16);
+
+	/* Ensure it's MLX5 port. */
+	if (rte_eth_dev_info_get(port_id, &dev_info) != 0 ||
+	    (strncmp(dev_info.driver_name, "mlx5", 4) != 0))
+		return;
+	rte_eal_alarm_set(SHAPER_DISABLE_DELAY_US,
+			  mlx5_test_host_shaper_disable,
+			  (void *)(uintptr_t)port_rxq_id);
+	printf("%s port_id:%u rxq_id:%u\n", __func__, port_id, rxq_id);
+}
+
+/**
+ * Configure host shaper's avail_thresh_triggered and current rate.
+ *
+ * @param[in] avail_thresh_triggered
+ *   Disable/enable avail_thresh_triggered.
+ * @param[in] rate
+ *   Configure current host shaper rate.
+ * @return
+ *   On success, returns 0.
+ *   On failure, returns < 0.
+ */
+static int
+mlx5_test_set_port_host_shaper(uint16_t port_id, uint16_t avail_thresh_triggered, uint8_t rate)
+{
+	struct rte_eth_link link;
+	bool port_id_valid = false;
+	uint16_t pid;
+	int ret;
+
+	RTE_ETH_FOREACH_DEV(pid)
+		if (port_id == pid) {
+			port_id_valid = true;
+			break;
+		}
+	if (!port_id_valid)
+		return -EINVAL;
+	ret = rte_eth_link_get_nowait(port_id, &link);
+	if (ret < 0)
+		return ret;
+	host_shaper_avail_thresh_triggered[port_id] = avail_thresh_triggered ? 1 : 0;
+	if (!avail_thresh_triggered) {
+		ret = rte_pmd_mlx5_host_shaper_config(port_id, 0,
+		RTE_BIT32(MLX5_HOST_SHAPER_FLAG_AVAIL_THRESH_TRIGGERED));
+	} else {
+		ret = rte_pmd_mlx5_host_shaper_config(port_id, 1,
+		RTE_BIT32(MLX5_HOST_SHAPER_FLAG_AVAIL_THRESH_TRIGGERED));
+	}
+	if (ret)
+		return ret;
+	ret = rte_pmd_mlx5_host_shaper_config(port_id, rate, 0);
+	if (ret)
+		return ret;
+	return 0;
+}
+
+/* *** SET HOST_SHAPER FOR A PORT *** */
+struct cmd_port_host_shaper_result {
+	cmdline_fixed_string_t mlx5;
+	cmdline_fixed_string_t set;
+	cmdline_fixed_string_t port;
+	uint16_t port_num;
+	cmdline_fixed_string_t host_shaper;
+	cmdline_fixed_string_t avail_thresh_triggered;
+	uint16_t fr;
+	cmdline_fixed_string_t rate;
+	uint8_t rate_num;
+};
+
+static void cmd_port_host_shaper_parsed(void *parsed_result,
+		__rte_unused struct cmdline *cl,
+		__rte_unused void *data)
+{
+	struct cmd_port_host_shaper_result *res = parsed_result;
+	int ret = 0;
+
+	if ((strcmp(res->mlx5, "mlx5") == 0) &&
+	    (strcmp(res->set, "set") == 0) &&
+	    (strcmp(res->port, "port") == 0) &&
+	    (strcmp(res->host_shaper, "host_shaper") == 0) &&
+	    (strcmp(res->avail_thresh_triggered, "avail_thresh_triggered") == 0) &&
+	    (strcmp(res->rate, "rate") == 0))
+		ret = mlx5_test_set_port_host_shaper(res->port_num, res->fr,
+					   res->rate_num);
+	if (ret < 0)
+		printf("cmd_port_host_shaper error: (%s)\n", strerror(-ret));
+}
+
+static cmdline_parse_token_string_t cmd_port_host_shaper_mlx5 =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				mlx5, "mlx5");
+static cmdline_parse_token_string_t cmd_port_host_shaper_set =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				set, "set");
+static cmdline_parse_token_string_t cmd_port_host_shaper_port =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				port, "port");
+static cmdline_parse_token_num_t cmd_port_host_shaper_portnum =
+	TOKEN_NUM_INITIALIZER(struct cmd_port_host_shaper_result,
+				port_num, RTE_UINT16);
+static cmdline_parse_token_string_t cmd_port_host_shaper_host_shaper =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				 host_shaper, "host_shaper");
+static cmdline_parse_token_string_t cmd_port_host_shaper_avail_thresh_triggered =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				 avail_thresh_triggered, "avail_thresh_triggered");
+static cmdline_parse_token_num_t cmd_port_host_shaper_fr =
+	TOKEN_NUM_INITIALIZER(struct cmd_port_host_shaper_result,
+			      fr, RTE_UINT16);
+static cmdline_parse_token_string_t cmd_port_host_shaper_rate =
+	TOKEN_STRING_INITIALIZER(struct cmd_port_host_shaper_result,
+				 rate, "rate");
+static cmdline_parse_token_num_t cmd_port_host_shaper_rate_num =
+	TOKEN_NUM_INITIALIZER(struct cmd_port_host_shaper_result,
+			      rate_num, RTE_UINT8);
+static cmdline_parse_inst_t mlx5_test_cmd_port_host_shaper = {
+	.f = cmd_port_host_shaper_parsed,
+	.data = (void *)0,
+	.help_str = "mlx5 set port <port_id> host_shaper avail_thresh_triggered <0|1> "
+	"rate <rate_num>: Set HOST_SHAPER avail_thresh_triggered and rate with port_id",
+	.tokens = {
+		(void *)&cmd_port_host_shaper_mlx5,
+		(void *)&cmd_port_host_shaper_set,
+		(void *)&cmd_port_host_shaper_port,
+		(void *)&cmd_port_host_shaper_portnum,
+		(void *)&cmd_port_host_shaper_host_shaper,
+		(void *)&cmd_port_host_shaper_avail_thresh_triggered,
+		(void *)&cmd_port_host_shaper_fr,
+		(void *)&cmd_port_host_shaper_rate,
+		(void *)&cmd_port_host_shaper_rate_num,
+		NULL,
+	}
+};
+
+static struct testpmd_driver_commands mlx5_driver_cmds = {
+	.commands = {
+		{
+			.ctx = &mlx5_test_cmd_port_host_shaper,
+			.help = "mlx5 set port (port_id) host_shaper avail_thresh_triggered (on|off)"
+			"rate (rate_num):\n"
+			"    Set HOST_SHAPER avail_thresh_triggered and rate with port_id\n\n",
+		},
+		{
+			.ctx = NULL,
+		},
+	}
+};
+TESTPMD_ADD_DRIVER_COMMANDS(mlx5_driver_cmds);
+
diff --git a/drivers/net/mlx5/mlx5_testpmd.h b/drivers/net/mlx5/mlx5_testpmd.h
new file mode 100644
index 0000000..7a54658
--- /dev/null
+++ b/drivers/net/mlx5/mlx5_testpmd.h
@@ -0,0 +1,26 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2021 6WIND S.A.
+ * Copyright 2021 Mellanox Technologies, Ltd
+ */
+
+#ifndef RTE_PMD_MLX5_TEST_H_
+#define RTE_PMD_MLX5_TEST_H_
+
+#include <cmdline_parse.h>
+#include <cmdline_parse_num.h>
+#include <cmdline_parse_string.h>
+
+/**
+ * RTE_ETH_EVENT_RX_AVAIL_THRESH handler sample code.
+ * It's called in testpmd, the work flow here is delay a while until
+ * RX queueu is empty, then disable host shaper.
+ *
+ * @param[in] port_id
+ *   Port identifier.
+ * @param[in] rxq_id
+ *   Rx queue identifier.
+ */
+void
+mlx5_test_avail_thresh_event_handler(uint16_t port_id, uint16_t rxq_id);
+
+#endif