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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




在 2022/1/10 上午5:06, Andrew Melnychenko 写道:
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];
+};


We need to consider to tweak and use uAPI in the future, e.g split the above into four parts:

1) first embed structure
2) indirection table
3) second embed structure
4) key array

1) and 3) could be uAPI.


+
  /* 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);


Is this correct if both mergeable_rx_bufs and hash_report are set?


  	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));


Can we simply do virtio_cread_feature(vdev, VIRTIO_NET_F_MQ | VIRTIO_NET_F_RSS, ...) ?


  	/* 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();


Is rtnl_lock() really needed here consider we haven't even register netdev?

Thanks


+		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,

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization




[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux