[dpdk-dev] [PATCH v3 2/2] net/virtio: add link speed devarg

[Ivan Dyukov <i.dyukov@samsung.com>]

Some applications like pktgen use link_speed to calculate
transmit rate. It limits outcome traffic to hardcoded 10G.

This patch adds link_speed devarg which allows to configure
link_speed of virtio device.

Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
---
 doc/guides/nics/virtio.rst         |   7 ++
 drivers/net/virtio/virtio_ethdev.c | 101 ++++++++++++++++++++++++-----
 drivers/net/virtio/virtio_pci.h    |   1 +
 3 files changed, 92 insertions(+), 17 deletions(-)

diff --git a/doc/guides/nics/virtio.rst b/doc/guides/nics/virtio.rst
index d1f5fb898..f190f2e4f 100644
--- a/doc/guides/nics/virtio.rst
+++ b/doc/guides/nics/virtio.rst
@@ -356,6 +356,13 @@ Below devargs are supported by the PCI virtio driver:
     a virtio device needs to work in vDPA mode.
     (Default: 0 (disabled))
 
+#.  ``link_speed``:
+
+    It is used to specify link speed of virtio device. Link speed is a part of
+    link status structure. It could be requested by application using
+    rte_eth_link_get_nowait function.
+    (Default: 10000 (10G))
+
 Below devargs are supported by the virtio-user vdev:
 
 #.  ``path``:
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 22323d9a5..5ef3c11a7 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -45,6 +45,10 @@ static int virtio_dev_promiscuous_enable(struct rte_eth_dev *dev);
 static int virtio_dev_promiscuous_disable(struct rte_eth_dev *dev);
 static int virtio_dev_allmulticast_enable(struct rte_eth_dev *dev);
 static int virtio_dev_allmulticast_disable(struct rte_eth_dev *dev);
+static uint32_t virtio_dev_speed_capa_get(uint32_t link_speed);
+static int virtio_dev_devargs_parse(struct rte_devargs *devargs,
+	int *vdpa,
+	uint32_t *link_speed);
 static int virtio_dev_info_get(struct rte_eth_dev *dev,
 				struct rte_eth_dev_info *dev_info);
 static int virtio_dev_link_update(struct rte_eth_dev *dev,
@@ -1861,6 +1865,7 @@ int
 eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 {
 	struct virtio_hw *hw = eth_dev->data->dev_private;
+	uint32_t link_speed = ETH_SPEED_NUM_10G;
 	int ret;
 
 	if (sizeof(struct virtio_net_hdr_mrg_rxbuf) > RTE_PKTMBUF_HEADROOM) {
@@ -1886,7 +1891,11 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 
 		return 0;
 	}
-
+	ret = virtio_dev_devargs_parse(eth_dev->device->devargs,
+		 NULL, &link_speed);
+	if (ret < 0)
+		return ret;
+	hw->link_speed = link_speed;
 	/*
 	 * Pass the information to the rte_eth_dev_close() that it should also
 	 * release the private port resources.
@@ -1953,6 +1962,14 @@ eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev)
 
 	return 0;
 }
+#define VIRTIO_ARG_LINK_SPEED "link_speed"
+#define VIRTIO_ARG_VDPA       "vdpa"
+
+static const char * const valid_args[] = {
+	VIRTIO_ARG_LINK_SPEED,
+	VIRTIO_ARG_VDPA,
+	NULL
+};
 
 static int vdpa_check_handler(__rte_unused const char *key,
 		const char *value, void *ret_val)
@@ -1965,33 +1982,84 @@ static int vdpa_check_handler(__rte_unused const char *key,
 	return 0;
 }
 
+
+static uint32_t
+virtio_dev_speed_capa_get(uint32_t link_speed)
+{
+	switch (link_speed) {
+	case ETH_SPEED_NUM_10G:
+		return ETH_LINK_SPEED_10G;
+	case ETH_SPEED_NUM_20G:
+		return ETH_LINK_SPEED_20G;
+	case ETH_SPEED_NUM_25G:
+		return ETH_LINK_SPEED_25G;
+	case ETH_SPEED_NUM_40G:
+		return ETH_LINK_SPEED_40G;
+	case ETH_SPEED_NUM_50G:
+		return ETH_LINK_SPEED_50G;
+	case ETH_SPEED_NUM_56G:
+		return ETH_LINK_SPEED_56G;
+	case ETH_SPEED_NUM_100G:
+		return ETH_LINK_SPEED_100G;
+	default:
+		return 0;
+	}
+}
+
+static int link_speed_handler(const char *key __rte_unused,
+		const char *value, void *ret_val)
+{
+	uint32_t val;
+	if (!value || !ret_val)
+		return -EINVAL;
+	val = strtoul(value, NULL, 0);
+	/* validate input */
+	if (virtio_dev_speed_capa_get(val) == 0)
+		return -EINVAL;
+	*(uint32_t *)ret_val = val;
+
+	return 0;
+}
+
+
 static int
-virtio_dev_devargs_parse(struct rte_devargs *devargs, int *vdpa)
+virtio_dev_devargs_parse(struct rte_devargs *devargs, int *vdpa,
+	uint32_t *link_speed)
 {
 	struct rte_kvargs *kvlist;
-	const char *key = "vdpa";
 	int ret = 0;
 
 	if (devargs == NULL)
 		return 0;
 
-	kvlist = rte_kvargs_parse(devargs->args, NULL);
-	if (kvlist == NULL)
+	kvlist = rte_kvargs_parse(devargs->args, valid_args);
+	if (kvlist == NULL) {
+		PMD_INIT_LOG(ERR, "error when parsing param");
 		return 0;
-
-	if (!rte_kvargs_count(kvlist, key))
-		goto exit;
-
-	if (vdpa) {
+	}
+	if (vdpa && rte_kvargs_count(kvlist, VIRTIO_ARG_VDPA) == 1) {
 		/* vdpa mode selected when there's a key-value pair:
 		 * vdpa=1
 		 */
-		ret = rte_kvargs_process(kvlist, key,
+		ret = rte_kvargs_process(kvlist, VIRTIO_ARG_VDPA,
 				vdpa_check_handler, vdpa);
-		if (ret  < 0)
+		if (ret  < 0) {
+			PMD_INIT_LOG(ERR, "error to parse %s",
+				VIRTIO_ARG_VDPA);
 			goto exit;
+		}
+	}
+	if (link_speed &&
+		 rte_kvargs_count(kvlist, VIRTIO_ARG_LINK_SPEED) == 1) {
+		ret = rte_kvargs_process(kvlist,
+					VIRTIO_ARG_LINK_SPEED,
+					link_speed_handler, link_speed);
+		if (ret < 0) {
+			PMD_INIT_LOG(ERR, "error to parse %s",
+					VIRTIO_ARG_LINK_SPEED);
+			goto exit;
+		}
 	}
-
 
 exit:
 	rte_kvargs_free(kvlist);
@@ -2004,7 +2072,7 @@ static int eth_virtio_pci_probe(struct rte_pci_driver *pci_drv __rte_unused,
 	int vdpa = 0;
 	int ret = 0;
 
-	ret = virtio_dev_devargs_parse(pci_dev->device.devargs, &vdpa);
+	ret = virtio_dev_devargs_parse(pci_dev->device.devargs, &vdpa, NULL);
 	if (ret < 0) {
 		PMD_DRV_LOG(ERR,
 			"devargs parsing is failed");
@@ -2386,7 +2454,7 @@ virtio_dev_link_update(struct rte_eth_dev *dev, __rte_unused int wait_to_complet
 
 	memset(&link, 0, sizeof(link));
 	link.link_duplex = ETH_LINK_FULL_DUPLEX;
-	link.link_speed  = ETH_SPEED_NUM_10G;
+	link.link_speed  = hw->link_speed;
 	link.link_autoneg = ETH_LINK_FIXED;
 
 	if (!hw->started) {
@@ -2441,8 +2509,7 @@ virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 {
 	uint64_t tso_mask, host_features;
 	struct virtio_hw *hw = dev->data->dev_private;
-
-	dev_info->speed_capa = ETH_LINK_SPEED_10G; /* fake value */
+	dev_info->speed_capa = virtio_dev_speed_capa_get(hw->link_speed);
 
 	dev_info->max_rx_queues =
 		RTE_MIN(hw->max_queue_pairs, VIRTIO_MAX_RX_QUEUES);
diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index a38cb45ad..688eda914 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -253,6 +253,7 @@ struct virtio_hw {
 	uint16_t    port_id;
 	uint8_t     mac_addr[RTE_ETHER_ADDR_LEN];
 	uint32_t    notify_off_multiplier;
+	uint32_t    link_speed;  /* link speed in MB */
 	uint8_t     *isr;
 	uint16_t    *notify_base;
 	struct virtio_pci_common_cfg *common_cfg;
-- 
2.17.1