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

["Xia, Chenbo" <chenbo.xia@intel.com>]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, September 22, 2021 5:58 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com;
> david.marchand@redhat.com; andrew.rybchenko@oktetlabs.ru; Yigit, Ferruh
> <ferruh.yigit@intel.com>; michaelba@nvidia.com; viacheslavo@nvidia.com; Li,
> Xiaoyun <xiaoyun.li@intel.com>
> Cc: stable@dpdk.org; nelio.laranjeiro@6wind.com; yvugenfi@redhat.com;
> ybendito@redhat.com; Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 1/5] net/virtio: add initial RSS support
> 
> 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)

Spec uses 'v' instead of 'V' for macro definition.
Better to align it?

> +#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;

Do we really need 'int dlen[1]' rather than 'int dlen'?

> +
> +	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;

No need to check, it's done in ethdev.

> +
> +	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;

Ditto.

> +
> +	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;

Ditto

> +
> +	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

Better align the numbers?

Thanks,
Chenbo

> +
> +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