drivers/net/virtio_net: Added RSS hash report.

Added features for RSS hash report.
If hash is provided - it sets to skb.
Added checks if rss and/or hash are enabled together.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Link: https://lore.kernel.org/r/20220328175336.10802-4-andrew@daynix.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Author: AndrewAtDaynix

drivers/net/virtio_net.c

@@ -227,6 +227,7 @@ struct virtnet_info {
 
 	/* Host supports rss and/or hash report */
 	bool has_rss;
+	bool has_rss_hash_report;
 	u8 rss_key_size;
 	u16 rss_indir_table_size;
 	u32 rss_hash_types_supported;
@@ -1148,6 +1149,35 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 	return NULL;
 }
 
+static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
+				struct sk_buff *skb)
+{
+	enum pkt_hash_types rss_hash_type;
+
+	if (!hdr_hash || !skb)
+		return;
+
+	switch ((int)hdr_hash->hash_report) {
+	case VIRTIO_NET_HASH_REPORT_TCPv4:
+	case VIRTIO_NET_HASH_REPORT_UDPv4:
+	case VIRTIO_NET_HASH_REPORT_TCPv6:
+	case VIRTIO_NET_HASH_REPORT_UDPv6:
+	case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
+	case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
+		rss_hash_type = PKT_HASH_TYPE_L4;
+		break;
+	case VIRTIO_NET_HASH_REPORT_IPv4:
+	case VIRTIO_NET_HASH_REPORT_IPv6:
+	case VIRTIO_NET_HASH_REPORT_IPv6_EX:
+		rss_hash_type = PKT_HASH_TYPE_L3;
+		break;
+	case VIRTIO_NET_HASH_REPORT_NONE:
+	default:
+		rss_hash_type = PKT_HASH_TYPE_NONE;
+	}
+	skb_set_hash(skb, (unsigned int)hdr_hash->hash_value, rss_hash_type);
+}
+
 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 			void *buf, unsigned int len, void **ctx,
 			unsigned int *xdp_xmit,
@@ -1182,6 +1212,8 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 		return;
 
 	hdr = skb_vnet_hdr(skb);
+	if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
+		virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
 
 	if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -2232,7 +2264,8 @@ static bool virtnet_commit_rss_command(struct virtnet_info *vi)
 	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)) {
+				  vi->has_rss ? VIRTIO_NET_CTRL_MQ_RSS_CONFIG
+				  : VIRTIO_NET_CTRL_MQ_HASH_CONFIG, sgs)) {
 		dev_warn(&dev->dev, "VIRTIONET issue with committing RSS sgs\n");
 		return false;
 	}
@@ -3231,6 +3264,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR,
 			     "VIRTIO_NET_F_CTRL_VQ") ||
 	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_RSS,
+			     "VIRTIO_NET_F_CTRL_VQ") ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_HASH_REPORT,
 			     "VIRTIO_NET_F_CTRL_VQ"))) {
 		return false;
 	}
@@ -3366,8 +3401,13 @@ 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)) {
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
+		vi->has_rss_hash_report = true;
+
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
 		vi->has_rss = true;
+
+	if (vi->has_rss || vi->has_rss_hash_report) {
 		vi->rss_indir_table_size =
 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
 				rss_max_indirection_table_length));
@@ -3383,8 +3423,11 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 		dev->hw_features |= NETIF_F_RXHASH;
 	}
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF) ||
-	    virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
+
+	if (vi->has_rss_hash_report)
+		vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash);
+	else 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);
 	else
 		vi->hdr_len = sizeof(struct virtio_net_hdr);
@@ -3451,7 +3494,7 @@ static int virtnet_probe(struct virtio_device *vdev)
 		}
 	}
 
-	if (vi->has_rss)
+	if (vi->has_rss || vi->has_rss_hash_report)
 		virtnet_init_default_rss(vi);
 
 	err = register_netdev(dev);
@@ -3586,7 +3629,7 @@ static struct virtio_device_id id_table[] = {
 	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_RSS
+	VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT
 
 static unsigned int features[] = {
 	VIRTNET_FEATURES,