Re: [PATCH 2/4] drivers/net/virtio_net: Added basic RSS support.
From: Jason Wang
Date: Mon Jan 10 2022 - 22:44:34 EST
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,