Re: [PATCH 2/4] drivers/net/virtio_net: Added basic RSS support.

From: Michael S. Tsirkin
Date: Tue Jan 11 2022 - 07:00:54 EST

Next message: Peter Zijlstra: "Re: [PATCH v3 bpf-next 7/7] bpf, x86_64: use bpf_prog_pack allocator"
Previous message: Peter Zijlstra: "Re: [RFC 15/16] sched/fair: Account kthread runtime debt for CFS bandwidth"
In reply to: Jason Wang: "Re: [PATCH 2/4] drivers/net/virtio_net: Added basic RSS support."
Next in thread: Andrew Melnychenko: "[PATCH 1/4] drivers/net/virtio_net: Fixed padded vheader to use v1 with hash."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On Sun, Jan 09, 2022 at 11:06:57PM +0200, Andrew Melnychenko wrote:
> Added features for RSS.
> Added initialization, RXHASH feature and ethtool ops.
> By default RSS/RXHASH is disabled.
> Virtio RSS "IPv6 extensions" hashes disabled.
> Added ethtools ops to set key and indirection table.
>
> Signed-off-by: Andrew Melnychenko <andrew@xxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 194 +++++++++++++++++++++++++++++++++++++--
> 1 file changed, 184 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 66439ca488f4..21794731fc75 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -169,6 +169,28 @@ struct receive_queue {
> struct xdp_rxq_info xdp_rxq;
> };
>
> +/* This structure can contain rss message with maximum settings for indirection table and keysize
> + * Note, that default structure that describes RSS configuration virtio_net_rss_config
> + * contains same info but can't handle table values.
> + * In any case, structure would be passed to virtio hw through sg_buf split by parts
> + * because table sizes may be differ according to the device configuration.
> + */
> +#define VIRTIO_NET_RSS_MAX_KEY_SIZE 40
> +#define VIRTIO_NET_RSS_MAX_TABLE_LEN 128
> +struct virtio_net_ctrl_rss {
> + struct {
> + __le32 hash_types;
> + __le16 indirection_table_mask;
> + __le16 unclassified_queue;
> + } __packed table_info;
> + u16 indirection_table[VIRTIO_NET_RSS_MAX_TABLE_LEN];
> + struct {
> + u16 max_tx_vq; /* queues */
> + u8 hash_key_length;
> + } __packed key_info;
> + u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
> +};
> +

Generally best to avoid __packed.
I think it's not a bad idea to just follow the spec when
you lay out the structures. Makes it easier to follow
that it matches. Spec has just a single struct:

struct virtio_net_rss_config {
le32 hash_types;
le16 indirection_table_mask;
le16 unclassified_queue;
le16 indirection_table[indirection_table_length];
le16 max_tx_vq;
u8 hash_key_length;
u8 hash_key_data[hash_key_length];
};

and with this layout you don't need __packed.

> /* Control VQ buffers: protected by the rtnl lock */
> struct control_buf {
> struct virtio_net_ctrl_hdr hdr;
> @@ -178,6 +200,7 @@ struct control_buf {
> u8 allmulti;
> __virtio16 vid;
> __virtio64 offloads;
> + struct virtio_net_ctrl_rss rss;
> };
>
> struct virtnet_info {
> @@ -206,6 +229,12 @@ struct virtnet_info {
> /* Host will merge rx buffers for big packets (shake it! shake it!) */
> bool mergeable_rx_bufs;
>
> + /* Host supports rss and/or hash report */
> + bool has_rss;
> + u8 rss_key_size;
> + u16 rss_indir_table_size;
> + u32 rss_hash_types_supported;
> +
> /* Has control virtqueue */
> bool has_cvq;
>
> @@ -395,9 +424,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> hdr_p = p;
>
> hdr_len = vi->hdr_len;
> - if (vi->has_rss_hash_report)
> - hdr_padded_len = sizeof(struct virtio_net_hdr_v1_hash);
> - else if (vi->mergeable_rx_bufs)
> + if (vi->mergeable_rx_bufs)
> hdr_padded_len = sizeof(*hdr);
> else
> hdr_padded_len = sizeof(struct padded_vnet_hdr);
> @@ -2184,6 +2211,55 @@ static void virtnet_get_ringparam(struct net_device *dev,
> ring->tx_pending = ring->tx_max_pending;
> }
>
> +static bool virtnet_commit_rss_command(struct virtnet_info *vi)
> +{
> + struct net_device *dev = vi->dev;
> + struct scatterlist sgs[4];
> + unsigned int sg_buf_size;
> +
> + /* prepare sgs */
> + sg_init_table(sgs, 4);
> +
> + sg_buf_size = sizeof(vi->ctrl->rss.table_info);
> + sg_set_buf(&sgs[0], &vi->ctrl->rss.table_info, sg_buf_size);
> +
> + sg_buf_size = sizeof(uint16_t) * vi->rss_indir_table_size;
> + sg_set_buf(&sgs[1], vi->ctrl->rss.indirection_table, sg_buf_size);
> +
> + sg_buf_size = sizeof(vi->ctrl->rss.key_info);
> + sg_set_buf(&sgs[2], &vi->ctrl->rss.key_info, sg_buf_size);
> +
> + sg_buf_size = vi->rss_key_size;
> + sg_set_buf(&sgs[3], vi->ctrl->rss.key, sg_buf_size);
> +
> + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_MQ,
> + VIRTIO_NET_CTRL_MQ_RSS_CONFIG, sgs)) {
> + dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
> + return false;
> + }
> + return true;
> +}
> +
> +static void virtnet_init_default_rss(struct virtnet_info *vi)
> +{
> + u32 indir_val = 0;
> + int i = 0;
> +
> + vi->ctrl->rss.table_info.hash_types = vi->rss_hash_types_supported;
> + vi->ctrl->rss.table_info.indirection_table_mask = vi->rss_indir_table_size - 1;
> + vi->ctrl->rss.table_info.unclassified_queue = 0;
> +
> + for (; i < vi->rss_indir_table_size; ++i) {
> + indir_val = ethtool_rxfh_indir_default(i, vi->max_queue_pairs);
> + vi->ctrl->rss.indirection_table[i] = indir_val;
> + }
> +
> + vi->ctrl->rss.key_info.max_tx_vq = vi->curr_queue_pairs;
> + vi->ctrl->rss.key_info.hash_key_length = vi->rss_key_size;
> +
> + netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
> +}
> +
>
> static void virtnet_get_drvinfo(struct net_device *dev,
> struct ethtool_drvinfo *info)
> @@ -2412,6 +2488,71 @@ static void virtnet_update_settings(struct virtnet_info *vi)
> vi->duplex = duplex;
> }
>
> +static u32 virtnet_get_rxfh_key_size(struct net_device *dev)
> +{
> + return ((struct virtnet_info *)netdev_priv(dev))->rss_key_size;
> +}
> +
> +static u32 virtnet_get_rxfh_indir_size(struct net_device *dev)
> +{
> + return ((struct virtnet_info *)netdev_priv(dev))->rss_indir_table_size;
> +}
> +
> +static int virtnet_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
> +{
> + struct virtnet_info *vi = netdev_priv(dev);
> + int i;
> +
> + if (indir) {
> + for (i = 0; i < vi->rss_indir_table_size; ++i)
> + indir[i] = vi->ctrl->rss.indirection_table[i];
> + }
> +
> + if (key)
> + memcpy(key, vi->ctrl->rss.key, vi->rss_key_size);
> +
> + if (hfunc)
> + *hfunc = ETH_RSS_HASH_TOP;
> +
> + return 0;
> +}
> +
> +static int virtnet_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key, const u8 hfunc)
> +{
> + struct virtnet_info *vi = netdev_priv(dev);
> + int i;
> +
> + if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
> + return -EOPNOTSUPP;
> +
> + if (indir) {
> + for (i = 0; i < vi->rss_indir_table_size; ++i)
> + vi->ctrl->rss.indirection_table[i] = indir[i];
> + }
> + if (key)
> + memcpy(vi->ctrl->rss.key, key, vi->rss_key_size);
> +
> + virtnet_commit_rss_command(vi);
> +
> + return 0;
> +}
> +
> +static int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *rule_locs)
> +{
> + struct virtnet_info *vi = netdev_priv(dev);
> + int rc = 0;
> +
> + switch (info->cmd) {
> + case ETHTOOL_GRXRINGS:
> + info->data = vi->curr_queue_pairs;
> + break;
> + default:
> + rc = -EOPNOTSUPP;
> + }
> +
> + return rc;
> +}
> +
> static const struct ethtool_ops virtnet_ethtool_ops = {
> .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES,
> .get_drvinfo = virtnet_get_drvinfo,
> @@ -2427,6 +2568,11 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
> .set_link_ksettings = virtnet_set_link_ksettings,
> .set_coalesce = virtnet_set_coalesce,
> .get_coalesce = virtnet_get_coalesce,
> + .get_rxfh_key_size = virtnet_get_rxfh_key_size,
> + .get_rxfh_indir_size = virtnet_get_rxfh_indir_size,
> + .get_rxfh = virtnet_get_rxfh,
> + .set_rxfh = virtnet_set_rxfh,
> + .get_rxnfc = virtnet_get_rxnfc,
> };
>
> static void virtnet_freeze_down(struct virtio_device *vdev)
> @@ -3073,7 +3219,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
> "VIRTIO_NET_F_CTRL_VQ") ||
> VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_MQ, "VIRTIO_NET_F_CTRL_VQ") ||
> VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
> - "VIRTIO_NET_F_CTRL_VQ"))) {
> + "VIRTIO_NET_F_CTRL_VQ") ||
> + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS, "VIRTIO_NET_F_RSS"))) {
> return false;
> }
>
> @@ -3113,13 +3260,14 @@ static int virtnet_probe(struct virtio_device *vdev)
> u16 max_queue_pairs;
> int mtu;
>
> - /* Find if host supports multiqueue virtio_net device */
> - err = virtio_cread_feature(vdev, VIRTIO_NET_F_MQ,
> - struct virtio_net_config,
> - max_virtqueue_pairs, &max_queue_pairs);
> + /* Find if host supports multiqueue/rss virtio_net device */
> + max_queue_pairs = 0;
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_MQ) || virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
> + max_queue_pairs =
> + virtio_cread16(vdev, offsetof(struct virtio_net_config, max_virtqueue_pairs));
>
> /* We need at least 2 queue's */
> - if (err || max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
> + if (max_queue_pairs < VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN ||
> max_queue_pairs > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX ||
> !virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
> max_queue_pairs = 1;
> @@ -3207,6 +3355,25 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
> vi->mergeable_rx_bufs = true;
>
> + if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
> + vi->has_rss = true;
> + vi->rss_indir_table_size =
> + virtio_cread16(vdev, offsetof(struct virtio_net_config,
> + rss_max_indirection_table_length));
> + vi->rss_key_size =
> + virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
> + }
> +
> + if (vi->has_rss) {
> + vi->rss_hash_types_supported =
> + virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
> + vi->rss_hash_types_supported &=
> + ~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
> + VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
> + VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
> +
> + dev->hw_features |= NETIF_F_RXHASH;
> + }
> if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
> virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
> vi->hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf);
> @@ -3275,6 +3442,12 @@ static int virtnet_probe(struct virtio_device *vdev)
> }
> }
>
> + if (vi->has_rss) {
> + rtnl_lock();
> + virtnet_init_default_rss(vi);
> + rtnl_unlock();
> + }
> +
> err = register_netdev(dev);
> if (err) {
> pr_debug("virtio_net: registering device failed\n");
> @@ -3406,7 +3579,8 @@ static struct virtio_device_id id_table[] = {
> VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \
> VIRTIO_NET_F_CTRL_MAC_ADDR, \
> VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \
> - VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY
> + VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \
> + VIRTIO_NET_F_RSS
>
> static unsigned int features[] = {
> VIRTNET_FEATURES,
> --
> 2.34.1

Next message: Peter Zijlstra: "Re: [PATCH v3 bpf-next 7/7] bpf, x86_64: use bpf_prog_pack allocator"
Previous message: Peter Zijlstra: "Re: [RFC 15/16] sched/fair: Account kthread runtime debt for CFS bandwidth"
In reply to: Jason Wang: "Re: [PATCH 2/4] drivers/net/virtio_net: Added basic RSS support."
Next in thread: Andrew Melnychenko: "[PATCH 1/4] drivers/net/virtio_net: Fixed padded vheader to use v1 with hash."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]