From 699b045a8e43bd1063db4795be685bfd659649dc Mon Sep 17 00:00:00 2001 From: Alvaro Karsz Date: Mon, 18 Jul 2022 12:11:02 +0300 Subject: [PATCH] net: virtio_net: notifications coalescing support New VirtIO network feature: VIRTIO_NET_F_NOTF_COAL. Control a Virtio network device notifications coalescing parameters using the control virtqueue. A device that supports this fetature can receive VIRTIO_NET_CTRL_NOTF_COAL control commands. - VIRTIO_NET_CTRL_NOTF_COAL_TX_SET: Ask the network device to change the following parameters: - tx_usecs: Maximum number of usecs to delay a TX notification. - tx_max_packets: Maximum number of packets to send before a TX notification. - VIRTIO_NET_CTRL_NOTF_COAL_RX_SET: Ask the network device to change the following parameters: - rx_usecs: Maximum number of usecs to delay a RX notification. - rx_max_packets: Maximum number of packets to receive before a RX notification. VirtIO spec. patch: https://lists.oasis-open.org/archives/virtio-comment/202206/msg00100.html Signed-off-by: Alvaro Karsz Message-Id: <20220718091102.498774-1-alvaro.karsz@solid-run.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Jakub Kicinski Acked-by: Jason Wang --- drivers/net/virtio_net.c | 111 +++++++++++++++++++++++++++----- include/uapi/linux/virtio_net.h | 34 +++++++++- 2 files changed, 129 insertions(+), 16 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 16783ed782c5..d9c434b00e9b 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -270,6 +270,12 @@ struct virtnet_info { u8 duplex; u32 speed; + /* Interrupt coalescing settings */ + u32 tx_usecs; + u32 rx_usecs; + u32 tx_max_packets; + u32 rx_max_packets; + unsigned long guest_offloads; unsigned long guest_offloads_capable; @@ -2737,27 +2743,89 @@ static int virtnet_get_link_ksettings(struct net_device *dev, return 0; } +static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, + struct ethtool_coalesce *ec) +{ + struct scatterlist sgs_tx, sgs_rx; + struct virtio_net_ctrl_coal_tx coal_tx; + struct virtio_net_ctrl_coal_rx coal_rx; + + coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs); + coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames); + sg_init_one(&sgs_tx, &coal_tx, sizeof(coal_tx)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, + VIRTIO_NET_CTRL_NOTF_COAL_TX_SET, + &sgs_tx)) + return -EINVAL; + + /* Save parameters */ + vi->tx_usecs = ec->tx_coalesce_usecs; + vi->tx_max_packets = ec->tx_max_coalesced_frames; + + coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs); + coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames); + sg_init_one(&sgs_rx, &coal_rx, sizeof(coal_rx)); + + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, + VIRTIO_NET_CTRL_NOTF_COAL_RX_SET, + &sgs_rx)) + return -EINVAL; + + /* Save parameters */ + vi->rx_usecs = ec->rx_coalesce_usecs; + vi->rx_max_packets = ec->rx_max_coalesced_frames; + + return 0; +} + +static int virtnet_coal_params_supported(struct ethtool_coalesce *ec) +{ + /* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL + * feature is negotiated. + */ + if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs) + return -EOPNOTSUPP; + + if (ec->tx_max_coalesced_frames > 1 || + ec->rx_max_coalesced_frames != 1) + return -EINVAL; + + return 0; +} + static int virtnet_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec, struct kernel_ethtool_coalesce *kernel_coal, struct netlink_ext_ack *extack) { struct virtnet_info *vi = netdev_priv(dev); - int i, napi_weight; - - if (ec->tx_max_coalesced_frames > 1 || - ec->rx_max_coalesced_frames != 1) - return -EINVAL; + int ret, i, napi_weight; + bool update_napi = false; + /* Can't change NAPI weight if the link is up */ napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0; if (napi_weight ^ vi->sq[0].napi.weight) { if (dev->flags & IFF_UP) return -EBUSY; + else + update_napi = true; + } + + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) + ret = virtnet_send_notf_coal_cmds(vi, ec); + else + ret = virtnet_coal_params_supported(ec); + + if (ret) + return ret; + + if (update_napi) { for (i = 0; i < vi->max_queue_pairs; i++) vi->sq[i].napi.weight = napi_weight; } - return 0; + return ret; } static int virtnet_get_coalesce(struct net_device *dev, @@ -2765,16 +2833,19 @@ static int virtnet_get_coalesce(struct net_device *dev, struct kernel_ethtool_coalesce *kernel_coal, struct netlink_ext_ack *extack) { - struct ethtool_coalesce ec_default = { - .cmd = ETHTOOL_GCOALESCE, - .rx_max_coalesced_frames = 1, - }; struct virtnet_info *vi = netdev_priv(dev); - memcpy(ec, &ec_default, sizeof(ec_default)); + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { + ec->rx_coalesce_usecs = vi->rx_usecs; + ec->tx_coalesce_usecs = vi->tx_usecs; + ec->tx_max_coalesced_frames = vi->tx_max_packets; + ec->rx_max_coalesced_frames = vi->rx_max_packets; + } else { + ec->rx_max_coalesced_frames = 1; - if (vi->sq[0].napi.weight) - ec->tx_max_coalesced_frames = 1; + if (vi->sq[0].napi.weight) + ec->tx_max_coalesced_frames = 1; + } return 0; } @@ -2893,7 +2964,8 @@ static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info) } static const struct ethtool_ops virtnet_ethtool_ops = { - .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES, + .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES | + ETHTOOL_COALESCE_USECS, .get_drvinfo = virtnet_get_drvinfo, .get_link = ethtool_op_get_link, .get_ringparam = virtnet_get_ringparam, @@ -3606,6 +3678,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev) 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") || + VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_NOTF_COAL, "VIRTIO_NET_F_CTRL_VQ"))) { return false; } @@ -3742,6 +3816,13 @@ 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(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { + vi->rx_usecs = 0; + vi->tx_usecs = 0; + vi->tx_max_packets = 0; + vi->rx_max_packets = 0; + } + if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) vi->has_rss_hash_report = true; @@ -3977,7 +4058,7 @@ 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_HASH_REPORT + VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL static unsigned int features[] = { VIRTNET_FEATURES, diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index 3f55a4215f11..29ced55514d4 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -56,7 +56,7 @@ #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_NOTF_COAL 53 /* Guest can handle notifications coalescing */ #define VIRTIO_NET_F_HASH_REPORT 57 /* Supports hash report */ #define VIRTIO_NET_F_RSS 60 /* Supports RSS RX steering */ #define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */ @@ -355,4 +355,36 @@ struct virtio_net_hash_config { #define VIRTIO_NET_CTRL_GUEST_OFFLOADS 5 #define VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET 0 +/* + * Control notifications coalescing. + * + * Request the device to change the notifications coalescing parameters. + * + * Available with the VIRTIO_NET_F_NOTF_COAL feature bit. + */ +#define VIRTIO_NET_CTRL_NOTF_COAL 6 +/* + * Set the tx-usecs/tx-max-packets patameters. + * tx-usecs - Maximum number of usecs to delay a TX notification. + * tx-max-packets - Maximum number of packets to send before a TX notification. + */ +struct virtio_net_ctrl_coal_tx { + __le32 tx_max_packets; + __le32 tx_usecs; +}; + +#define VIRTIO_NET_CTRL_NOTF_COAL_TX_SET 0 + +/* + * Set the rx-usecs/rx-max-packets patameters. + * rx-usecs - Maximum number of usecs to delay a RX notification. + * rx-max-frames - Maximum number of packets to receive before a RX notification. + */ +struct virtio_net_ctrl_coal_rx { + __le32 rx_max_packets; + __le32 rx_usecs; +}; + +#define VIRTIO_NET_CTRL_NOTF_COAL_RX_SET 1 + #endif /* _UAPI_LINUX_VIRTIO_NET_H */