[dpdk-dev] [PATCH v2 1/5] net/virtio: add initial RSS support

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Provide the capability to update the hash key, hash types
and RETA table on the fly (without needing to stop/start
the device). However, the key length and the number of RETA
entries are fixed to 40B and 128 entries respectively. This
is done in order to simplify the design, but may be
revisited later as the Virtio spec provides this
flexibility.

Note that only VIRTIO_NET_F_RSS support is implemented,
VIRTIO_NET_F_HASH_REPORT, which would enable reporting the
packet RSS hash calculated by the device into mbuf.rss, is
not yet supported.

Regarding the default RSS configuration, it has been
chosen to use the default Intel ixgbe key as default key,
and default RETA is a simple modulo between the hash and
the number of Rx queues.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 doc/guides/nics/features/virtio.ini    |   3 +
 doc/guides/nics/virtio.rst             |   3 +
 doc/guides/rel_notes/release_21_11.rst |   6 +
 drivers/net/virtio/virtio.h            |  31 ++-
 drivers/net/virtio/virtio_ethdev.c     | 367 ++++++++++++++++++++++++-
 drivers/net/virtio/virtio_ethdev.h     |   3 +-
 drivers/net/virtio/virtqueue.h         |  21 ++
 7 files changed, 428 insertions(+), 6 deletions(-)

diff --git a/doc/guides/nics/features/virtio.ini b/doc/guides/nics/features/virtio.ini
index 48f6f393b1..a5eab4932f 100644
--- a/doc/guides/nics/features/virtio.ini
+++ b/doc/guides/nics/features/virtio.ini
@@ -14,6 +14,9 @@ Promiscuous mode     = Y
 Allmulticast mode    = Y
 Unicast MAC filter   = Y
 Multicast MAC filter = Y
+RSS hash             = P
+RSS key update       = Y
+RSS reta update      = Y
 VLAN filter          = Y
 Basic stats          = Y
 Stats per queue      = Y
diff --git a/doc/guides/nics/virtio.rst b/doc/guides/nics/virtio.rst
index 82ce7399ce..98e0d012b7 100644
--- a/doc/guides/nics/virtio.rst
+++ b/doc/guides/nics/virtio.rst
@@ -73,6 +73,9 @@ In this release, the virtio PMD driver provides the basic functionality of packe
 
 *   Virtio supports using port IO to get PCI resource when UIO module is not available.
 
+*   Virtio supports RSS Rx mode with 40B configurable hash key length, 128
+    configurable RETA entries and configurable hash types.
+
 Prerequisites
 -------------
 
diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index f5d16993db..2f9d81926b 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -96,6 +96,12 @@ New Features
   Added command-line options to specify total number of processes and
   current process ID. Each process owns subset of Rx and Tx queues.
 
+* **Added initial RSS support to Virtio PMD.**
+
+  Initial support for RSS receive mode has been added to the Virtio PMD,
+  with the capability for the application to configure the hash key, the
+  RETA and the hash types. Virtio hash reporting is yet to be added.
+
 
 Removed Items
 -------------
diff --git a/drivers/net/virtio/virtio.h b/drivers/net/virtio/virtio.h
index 525e2dad4c..b4f21dc0c7 100644
--- a/drivers/net/virtio/virtio.h
+++ b/drivers/net/virtio/virtio.h
@@ -30,6 +30,7 @@
 #define VIRTIO_NET_F_GUEST_ANNOUNCE 21	/* Guest can announce device on the network */
 #define VIRTIO_NET_F_MQ		22	/* Device supports Receive Flow Steering */
 #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
+#define VIRTIO_NET_F_RSS	60	/* RSS supported */
 
 /*
  * Do we get callbacks when the ring is completely used,
@@ -100,6 +101,29 @@
  */
 #define VIRTIO_MAX_INDIRECT ((int)(rte_mem_page_size() / 16))
 
+/*  Virtio RSS hash types */
+#define VIRTIO_NET_HASH_TYPE_IPV4	(1 << 0)
+#define VIRTIO_NET_HASH_TYPE_TCPV4	(1 << 1)
+#define VIRTIO_NET_HASH_TYPE_UDPV4	(1 << 2)
+#define VIRTIO_NET_HASH_TYPE_IPV6	(1 << 3)
+#define VIRTIO_NET_HASH_TYPE_TCPV6	(1 << 4)
+#define VIRTIO_NET_HASH_TYPE_UDPV6	(1 << 5)
+#define VIRTIO_NET_HASH_TYPE_IP_EX	(1 << 6)
+#define VIRTIO_NET_HASH_TYPE_TCP_EX	(1 << 7)
+#define VIRTIO_NET_HASH_TYPE_UDP_EX	(1 << 8)
+
+#define VIRTIO_NET_HASH_TYPE_MASK ( \
+	VIRTIO_NET_HASH_TYPE_IPV4 | \
+	VIRTIO_NET_HASH_TYPE_TCPV4 | \
+	VIRTIO_NET_HASH_TYPE_UDPV4 | \
+	VIRTIO_NET_HASH_TYPE_IPV6 | \
+	VIRTIO_NET_HASH_TYPE_TCPV6 | \
+	VIRTIO_NET_HASH_TYPE_UDPV6 | \
+	VIRTIO_NET_HASH_TYPE_IP_EX | \
+	VIRTIO_NET_HASH_TYPE_TCP_EX | \
+	VIRTIO_NET_HASH_TYPE_UDP_EX)
+
+
 /*
  * Maximum number of virtqueues per device.
  */
@@ -157,7 +181,9 @@ struct virtio_net_config {
 	 * Any other value stands for unknown.
 	 */
 	uint8_t duplex;
-
+	uint8_t rss_max_key_size;
+	uint16_t rss_max_indirection_table_length;
+	uint32_t supported_hash_types;
 } __rte_packed;
 
 struct virtio_hw {
@@ -190,6 +216,9 @@ struct virtio_hw {
 	rte_spinlock_t state_lock;
 	struct rte_mbuf **inject_pkts;
 	uint16_t max_queue_pairs;
+	uint32_t rss_hash_types;
+	uint16_t *rss_reta;
+	uint8_t *rss_key;
 	uint64_t req_guest_features;
 	struct virtnet_ctl *cvq;
 };
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index da1633d77e..10a9f708eb 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -51,6 +51,16 @@ static int virtio_dev_info_get(struct rte_eth_dev *dev,
 static int virtio_dev_link_update(struct rte_eth_dev *dev,
 	int wait_to_complete);
 static int virtio_dev_vlan_offload_set(struct rte_eth_dev *dev, int mask);
+static int virtio_dev_rss_hash_update(struct rte_eth_dev *dev,
+		struct rte_eth_rss_conf *rss_conf);
+static int virtio_dev_rss_hash_conf_get(struct rte_eth_dev *dev,
+		struct rte_eth_rss_conf *rss_conf);
+static int virtio_dev_rss_reta_update(struct rte_eth_dev *dev,
+			 struct rte_eth_rss_reta_entry64 *reta_conf,
+			 uint16_t reta_size);
+static int virtio_dev_rss_reta_query(struct rte_eth_dev *dev,
+			 struct rte_eth_rss_reta_entry64 *reta_conf,
+			 uint16_t reta_size);
 
 static void virtio_set_hwaddr(struct virtio_hw *hw);
 static void virtio_get_hwaddr(struct virtio_hw *hw);
@@ -347,7 +357,38 @@ virtio_send_command(struct virtnet_ctl *cvq, struct virtio_pmd_ctrl *ctrl,
 }
 
 static int
-virtio_set_multiple_queues(struct rte_eth_dev *dev, uint16_t nb_queues)
+virtio_set_multiple_queues_rss(struct rte_eth_dev *dev, uint16_t nb_queues)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+	struct virtio_pmd_ctrl ctrl;
+	struct virtio_net_ctrl_rss rss;
+	int dlen[1], ret;
+
+	rss.hash_types = hw->rss_hash_types & VIRTIO_NET_HASH_TYPE_MASK;
+	rss.indirection_table_mask = VIRTIO_NET_RSS_RETA_SIZE - 1;
+	rss.unclassified_queue = 0;
+	memcpy(rss.indirection_table, hw->rss_reta, VIRTIO_NET_RSS_RETA_SIZE * sizeof(uint16_t));
+	rss.max_tx_vq = nb_queues;
+	rss.hash_key_length = VIRTIO_NET_RSS_KEY_SIZE;
+	memcpy(rss.hash_key_data, hw->rss_key, VIRTIO_NET_RSS_KEY_SIZE);
+
+	ctrl.hdr.class = VIRTIO_NET_CTRL_MQ;
+	ctrl.hdr.cmd = VIRTIO_NET_CTRL_MQ_RSS_CONFIG;
+	memcpy(ctrl.data, &rss, sizeof(rss));
+
+	dlen[0] = sizeof(rss);
+
+	ret = virtio_send_command(hw->cvq, &ctrl, dlen, 1);
+	if (ret) {
+		PMD_INIT_LOG(ERR, "RSS multiqueue configured but send command failed");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+virtio_set_multiple_queues_auto(struct rte_eth_dev *dev, uint16_t nb_queues)
 {
 	struct virtio_hw *hw = dev->data->dev_private;
 	struct virtio_pmd_ctrl ctrl;
@@ -370,6 +411,17 @@ virtio_set_multiple_queues(struct rte_eth_dev *dev, uint16_t nb_queues)
 	return 0;
 }
 
+static int
+virtio_set_multiple_queues(struct rte_eth_dev *dev, uint16_t nb_queues)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+
+	if (virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+		return virtio_set_multiple_queues_rss(dev, nb_queues);
+	else
+		return virtio_set_multiple_queues_auto(dev, nb_queues);
+}
+
 static void
 virtio_dev_queue_release(void *queue __rte_unused)
 {
@@ -701,6 +753,16 @@ virtio_alloc_queues(struct rte_eth_dev *dev)
 
 static void virtio_queues_unbind_intr(struct rte_eth_dev *dev);
 
+static void
+virtio_free_rss(struct virtio_hw *hw)
+{
+	rte_free(hw->rss_key);
+	hw->rss_key = NULL;
+
+	rte_free(hw->rss_reta);
+	hw->rss_reta = NULL;
+}
+
 int
 virtio_dev_close(struct rte_eth_dev *dev)
 {
@@ -731,6 +793,7 @@ virtio_dev_close(struct rte_eth_dev *dev)
 	virtio_reset(hw);
 	virtio_dev_free_mbufs(dev);
 	virtio_free_queues(hw);
+	virtio_free_rss(hw);
 
 	return VIRTIO_OPS(hw)->dev_close(hw);
 }
@@ -971,6 +1034,10 @@ static const struct eth_dev_ops virtio_eth_dev_ops = {
 	.rx_queue_release        = virtio_dev_queue_release,
 	.tx_queue_setup          = virtio_dev_tx_queue_setup,
 	.tx_queue_release        = virtio_dev_queue_release,
+	.rss_hash_update         = virtio_dev_rss_hash_update,
+	.rss_hash_conf_get       = virtio_dev_rss_hash_conf_get,
+	.reta_update             = virtio_dev_rss_reta_update,
+	.reta_query              = virtio_dev_rss_reta_query,
 	/* collect stats per queue */
 	.queue_stats_mapping_set = virtio_dev_queue_stats_mapping_set,
 	.vlan_filter_set         = virtio_vlan_filter_set,
@@ -1714,6 +1781,270 @@ virtio_configure_intr(struct rte_eth_dev *dev)
 
 	return 0;
 }
+
+static uint64_t
+virtio_to_ethdev_rss_offloads(uint64_t virtio_hash_types)
+{
+	uint64_t rss_offloads = 0;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_IPV4)
+		rss_offloads |= ETH_RSS_IPV4 | ETH_RSS_FRAG_IPV4 | ETH_RSS_NONFRAG_IPV4_OTHER;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_TCPV4)
+		rss_offloads |= ETH_RSS_NONFRAG_IPV4_TCP;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_UDPV4)
+		rss_offloads |= ETH_RSS_NONFRAG_IPV4_UDP;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_IPV6)
+		rss_offloads |= ETH_RSS_IPV6 | ETH_RSS_FRAG_IPV6 | ETH_RSS_NONFRAG_IPV6_OTHER;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_TCPV6)
+		rss_offloads |= ETH_RSS_NONFRAG_IPV6_TCP;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_UDPV6)
+		rss_offloads |= ETH_RSS_NONFRAG_IPV6_UDP;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_IP_EX)
+		rss_offloads |= ETH_RSS_IPV6_EX;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_TCP_EX)
+		rss_offloads |= ETH_RSS_IPV6_TCP_EX;
+
+	if (virtio_hash_types & VIRTIO_NET_HASH_TYPE_UDP_EX)
+		rss_offloads |= ETH_RSS_IPV6_UDP_EX;
+
+	return rss_offloads;
+}
+
+static int
+virtio_dev_get_rss_config(struct virtio_hw *hw, uint32_t *rss_hash_types)
+{
+	struct virtio_net_config local_config;
+	struct virtio_net_config *config = &local_config;
+
+	virtio_read_dev_config(hw,
+			offsetof(struct virtio_net_config, rss_max_key_size),
+			&config->rss_max_key_size,
+			sizeof(config->rss_max_key_size));
+	if (config->rss_max_key_size < VIRTIO_NET_RSS_KEY_SIZE) {
+		PMD_INIT_LOG(ERR, "Invalid device RSS max key size (%u)",
+				config->rss_max_key_size);
+		return -1;
+	}
+
+	virtio_read_dev_config(hw,
+			offsetof(struct virtio_net_config,
+				rss_max_indirection_table_length),
+			&config->rss_max_indirection_table_length,
+			sizeof(config->rss_max_indirection_table_length));
+	if (config->rss_max_indirection_table_length < VIRTIO_NET_RSS_RETA_SIZE) {
+		PMD_INIT_LOG(ERR, "Invalid device RSS max reta size (%u)",
+				config->rss_max_indirection_table_length);
+		return -1;
+	}
+
+	virtio_read_dev_config(hw,
+			offsetof(struct virtio_net_config, supported_hash_types),
+			&config->supported_hash_types,
+			sizeof(config->supported_hash_types));
+	if ((config->supported_hash_types & VIRTIO_NET_HASH_TYPE_MASK) == 0) {
+		PMD_INIT_LOG(ERR, "Invalid device RSS hash types (%u)",
+				config->supported_hash_types);
+		return -1;
+	}
+
+	*rss_hash_types = config->supported_hash_types & VIRTIO_NET_HASH_TYPE_MASK;
+
+	PMD_INIT_LOG(DEBUG, "Device RSS config:");
+	PMD_INIT_LOG(DEBUG, "\t-Max key size: %u", config->rss_max_key_size);
+	PMD_INIT_LOG(DEBUG, "\t-Max reta size: %u", config->rss_max_indirection_table_length);
+	PMD_INIT_LOG(DEBUG, "\t-Supported hash types: 0x%x", *rss_hash_types);
+
+	return 0;
+}
+
+static int
+virtio_dev_rss_hash_update(struct rte_eth_dev *dev,
+		struct rte_eth_rss_conf *rss_conf)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+	uint16_t nb_queues;
+
+	if (!virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+		return -ENOTSUP;
+
+	if (rss_conf->rss_hf & ~virtio_to_ethdev_rss_offloads(VIRTIO_NET_HASH_TYPE_MASK))
+		return -EINVAL;
+
+	hw->rss_hash_types = 0;
+
+	if (rss_conf->rss_hf & (ETH_RSS_IPV4 | ETH_RSS_FRAG_IPV4 | ETH_RSS_NONFRAG_IPV4_OTHER))
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_IPV4;
+
+	if (rss_conf->rss_hf & ETH_RSS_NONFRAG_IPV4_TCP)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_TCPV4;
+
+	if (rss_conf->rss_hf & ETH_RSS_NONFRAG_IPV4_UDP)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_UDPV4;
+
+	if (rss_conf->rss_hf & (ETH_RSS_IPV6 | ETH_RSS_FRAG_IPV6 | ETH_RSS_NONFRAG_IPV6_OTHER))
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_IPV6;
+
+	if (rss_conf->rss_hf & ETH_RSS_NONFRAG_IPV6_TCP)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_TCPV6;
+
+	if (rss_conf->rss_hf & ETH_RSS_NONFRAG_IPV6_UDP)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_UDPV6;
+
+	if (rss_conf->rss_hf & ETH_RSS_IPV6_EX)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_IP_EX;
+
+	if (rss_conf->rss_hf & ETH_RSS_IPV6_TCP_EX)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_TCP_EX;
+
+	if (rss_conf->rss_hf & ETH_RSS_IPV6_UDP_EX)
+		hw->rss_hash_types |= VIRTIO_NET_HASH_TYPE_UDP_EX;
+
+	if (rss_conf->rss_key && rss_conf->rss_key_len) {
+		if (rss_conf->rss_key_len != VIRTIO_NET_RSS_KEY_SIZE) {
+			PMD_INIT_LOG(ERR, "Driver only supports %u RSS key length",
+					VIRTIO_NET_RSS_KEY_SIZE);
+			return -EINVAL;
+		}
+		memcpy(hw->rss_key, rss_conf->rss_key, VIRTIO_NET_RSS_KEY_SIZE);
+	}
+
+	nb_queues = RTE_MAX(dev->data->nb_rx_queues, dev->data->nb_tx_queues);
+	return virtio_set_multiple_queues_rss(dev, nb_queues);
+}
+
+static int
+virtio_dev_rss_hash_conf_get(struct rte_eth_dev *dev,
+		struct rte_eth_rss_conf *rss_conf)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+
+	if (!virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+		return -ENOTSUP;
+
+	if (!rss_conf)
+		return -EINVAL;
+
+	if (rss_conf->rss_key && rss_conf->rss_key_len >= VIRTIO_NET_RSS_KEY_SIZE)
+		memcpy(rss_conf->rss_key, hw->rss_key, VIRTIO_NET_RSS_KEY_SIZE);
+	rss_conf->rss_key_len = VIRTIO_NET_RSS_KEY_SIZE;
+	rss_conf->rss_hf = virtio_to_ethdev_rss_offloads(hw->rss_hash_types);
+
+	return 0;
+}
+
+static int virtio_dev_rss_reta_update(struct rte_eth_dev *dev,
+			 struct rte_eth_rss_reta_entry64 *reta_conf,
+			 uint16_t reta_size)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+	uint16_t nb_queues;
+	int idx, pos, i;
+
+	if (!virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+		return -ENOTSUP;
+
+	if (!reta_conf)
+		return -EINVAL;
+
+	if (reta_size != VIRTIO_NET_RSS_RETA_SIZE)
+		return -EINVAL;
+
+	for (idx = 0, i = 0; i < reta_size; i++) {
+		idx = i / RTE_RETA_GROUP_SIZE;
+		pos = i % RTE_RETA_GROUP_SIZE;
+
+		if (((reta_conf[idx].mask >> pos) & 0x1) == 0)
+			continue;
+
+		hw->rss_reta[i] = reta_conf[idx].reta[pos];
+	}
+
+	nb_queues = RTE_MAX(dev->data->nb_rx_queues, dev->data->nb_tx_queues);
+	return virtio_set_multiple_queues_rss(dev, nb_queues);
+}
+
+static int virtio_dev_rss_reta_query(struct rte_eth_dev *dev,
+			 struct rte_eth_rss_reta_entry64 *reta_conf,
+			 uint16_t reta_size)
+{
+	struct virtio_hw *hw = dev->data->dev_private;
+	int idx, i;
+
+	if (!virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+		return -ENOTSUP;
+
+	if (!reta_conf)
+		return -EINVAL;
+
+	if (reta_size != VIRTIO_NET_RSS_RETA_SIZE)
+		return -EINVAL;
+
+	for (idx = 0, i = 0; i < reta_size; i++) {
+		idx = i / RTE_RETA_GROUP_SIZE;
+		reta_conf[idx].reta[i % RTE_RETA_GROUP_SIZE] = hw->rss_reta[i];
+	}
+
+	return 0;
+}
+
+/*
+ * As default RSS hash key, it uses the default key of the
+ * Intel IXGBE devices. It can be updated by the application
+ * with any 40B key value.
+ */
+static uint8_t rss_intel_key[VIRTIO_NET_RSS_KEY_SIZE] = {
+	0x6D, 0x5A, 0x56, 0xDA, 0x25, 0x5B, 0x0E, 0xC2,
+	0x41, 0x67, 0x25, 0x3D, 0x43, 0xA3, 0x8F, 0xB0,
+	0xD0, 0xCA, 0x2B, 0xCB, 0xAE, 0x7B, 0x30, 0xB4,
+	0x77, 0xCB, 0x2D, 0xA3, 0x80, 0x30, 0xF2, 0x0C,
+	0x6A, 0x42, 0xB7, 0x3B, 0xBE, 0xAC, 0x01, 0xFA,
+};
+
+static int
+virtio_dev_rss_init(struct rte_eth_dev *eth_dev)
+{
+	struct virtio_hw *hw = eth_dev->data->dev_private;
+	uint16_t nb_rx_queues = eth_dev->data->nb_rx_queues;
+	int i;
+
+	if (virtio_dev_get_rss_config(hw, &hw->rss_hash_types))
+		return -1;
+
+	if (!hw->rss_key) {
+		/* Setup default RSS key if not already setup by the user */
+		hw->rss_key = rte_malloc_socket("rss_key",
+				VIRTIO_NET_RSS_KEY_SIZE, 0,
+				eth_dev->device->numa_node);
+		if (!hw->rss_key) {
+			PMD_INIT_LOG(ERR, "Failed to allocate RSS key");
+			return -1;
+		}
+		rte_memcpy(hw->rss_key, rss_intel_key, VIRTIO_NET_RSS_KEY_SIZE);
+	}
+
+	if (!hw->rss_reta) {
+		/* Setup default RSS reta if not already setup by the user */
+		hw->rss_reta = rte_malloc_socket("rss_reta",
+				VIRTIO_NET_RSS_RETA_SIZE * sizeof(uint16_t), 0,
+				eth_dev->device->numa_node);
+		if (!hw->rss_reta) {
+			PMD_INIT_LOG(ERR, "Failed to allocate RSS reta");
+			return -1;
+		}
+		for (i = 0; i < VIRTIO_NET_RSS_RETA_SIZE; i++)
+			hw->rss_reta[i] = i % nb_rx_queues;
+	}
+
+	return 0;
+}
+
 #define DUPLEX_UNKNOWN   0xff
 /* reset device and renegotiate features if needed */
 static int
@@ -1801,14 +2132,15 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 			config->status = 0;
 		}
 
-		if (virtio_with_feature(hw, VIRTIO_NET_F_MQ)) {
+		if (virtio_with_feature(hw, VIRTIO_NET_F_MQ) ||
+				virtio_with_feature(hw, VIRTIO_NET_F_RSS)) {
 			virtio_read_dev_config(hw,
 				offsetof(struct virtio_net_config, max_virtqueue_pairs),
 				&config->max_virtqueue_pairs,
 				sizeof(config->max_virtqueue_pairs));
 		} else {
 			PMD_INIT_LOG(DEBUG,
-				     "VIRTIO_NET_F_MQ is not supported");
+				     "Neither VIRTIO_NET_F_MQ nor VIRTIO_NET_F_RSS are supported");
 			config->max_virtqueue_pairs = 1;
 		}
 
@@ -1840,6 +2172,11 @@ virtio_init_device(struct rte_eth_dev *eth_dev, uint64_t req_features)
 				VLAN_TAG_LEN - hw->vtnet_hdr_size;
 		}
 
+		hw->rss_hash_types = 0;
+		if (virtio_with_feature(hw, VIRTIO_NET_F_RSS))
+			if (virtio_dev_rss_init(eth_dev))
+				return -1;
+
 		PMD_INIT_LOG(DEBUG, "config->max_virtqueue_pairs=%d",
 				config->max_virtqueue_pairs);
 		PMD_INIT_LOG(DEBUG, "config->status=%d", config->status);
@@ -2083,7 +2420,7 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 	PMD_INIT_LOG(DEBUG, "configure");
 	req_features = VIRTIO_PMD_DEFAULT_GUEST_FEATURES;
 
-	if (rxmode->mq_mode != ETH_MQ_RX_NONE) {
+	if (rxmode->mq_mode != ETH_MQ_RX_NONE && rxmode->mq_mode != ETH_MQ_RX_RSS) {
 		PMD_DRV_LOG(ERR,
 			"Unsupported Rx multi queue mode %d",
 			rxmode->mq_mode);
@@ -2103,6 +2440,9 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return ret;
 	}
 
+	if (rxmode->mq_mode == ETH_MQ_RX_RSS)
+		req_features |= (1ULL << VIRTIO_NET_F_RSS);
+
 	if ((rx_offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) &&
 	    (rxmode->max_rx_pkt_len > hw->max_mtu + ether_hdr_len))
 		req_features &= ~(1ULL << VIRTIO_NET_F_MTU);
@@ -2137,6 +2477,12 @@ virtio_dev_configure(struct rte_eth_dev *dev)
 			return ret;
 	}
 
+	if ((rxmode->mq_mode & ETH_MQ_RX_RSS_FLAG) &&
+			!virtio_with_feature(hw, VIRTIO_NET_F_RSS)) {
+		PMD_DRV_LOG(ERR, "RSS support requested but not supported by the device");
+		return -ENOTSUP;
+	}
+
 	if ((rx_offloads & (DEV_RX_OFFLOAD_UDP_CKSUM |
 			    DEV_RX_OFFLOAD_TCP_CKSUM)) &&
 		!virtio_with_feature(hw, VIRTIO_NET_F_GUEST_CSUM)) {
@@ -2503,6 +2849,7 @@ static int
 virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 {
 	uint64_t tso_mask, host_features;
+	uint32_t rss_hash_types = 0;
 	struct virtio_hw *hw = dev->data->dev_private;
 	dev_info->speed_capa = virtio_dev_speed_capa_get(hw->speed);
 
@@ -2543,6 +2890,18 @@ virtio_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 		(1ULL << VIRTIO_NET_F_HOST_TSO6);
 	if ((host_features & tso_mask) == tso_mask)
 		dev_info->tx_offload_capa |= DEV_TX_OFFLOAD_TCP_TSO;
+	if (host_features & (1ULL << VIRTIO_NET_F_RSS)) {
+		virtio_dev_get_rss_config(hw, &rss_hash_types);
+		dev_info->hash_key_size = VIRTIO_NET_RSS_KEY_SIZE;
+		dev_info->reta_size = VIRTIO_NET_RSS_RETA_SIZE;
+		dev_info->flow_type_rss_offloads =
+			virtio_to_ethdev_rss_offloads(rss_hash_types);
+	} else {
+		dev_info->hash_key_size = 0;
+		dev_info->reta_size = 0;
+		dev_info->flow_type_rss_offloads = 0;
+	}
+
 
 	if (host_features & (1ULL << VIRTIO_F_RING_PACKED)) {
 		/*
diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
index 2f63ef2b2d..3fe30d8784 100644
--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h
@@ -45,7 +45,8 @@
 	 1u << VIRTIO_NET_F_GUEST_TSO6     |	\
 	 1u << VIRTIO_NET_F_CSUM           |	\
 	 1u << VIRTIO_NET_F_HOST_TSO4      |	\
-	 1u << VIRTIO_NET_F_HOST_TSO6)
+	 1u << VIRTIO_NET_F_HOST_TSO6      |	\
+	 1ULL << VIRTIO_NET_F_RSS)
 
 extern const struct eth_dev_ops virtio_user_secondary_eth_dev_ops;
 
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index 03957b2bd0..99a0e68d38 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -182,6 +182,24 @@ struct virtio_net_ctrl_mac {
 #define VIRTIO_NET_CTRL_VLAN_ADD 0
 #define VIRTIO_NET_CTRL_VLAN_DEL 1
 
+/**
+ * RSS control
+ *
+ * The RSS feature <todo>
+ */
+#define VIRTIO_NET_RSS_RETA_SIZE 128
+#define VIRTIO_NET_RSS_KEY_SIZE       40
+
+struct virtio_net_ctrl_rss {
+	uint32_t hash_types;
+	uint16_t indirection_table_mask;
+	uint16_t unclassified_queue;
+	uint16_t indirection_table[VIRTIO_NET_RSS_RETA_SIZE];
+	uint16_t max_tx_vq;
+	uint8_t hash_key_length;
+	uint8_t hash_key_data[VIRTIO_NET_RSS_KEY_SIZE];
+};
+
 /*
  * Control link announce acknowledgement
  *
@@ -272,7 +290,10 @@ struct virtqueue {
 
 /* If multiqueue is provided by host, then we suppport it. */
 #define VIRTIO_NET_CTRL_MQ   4
+
 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
+#define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
+
 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
 
-- 
2.31.1