Michael S. Tsirkin
2023-Jul-24 07:32 UTC
[PATCH net-next V3 3/4] virtio_net: support per queue interrupt coalesce command
On Mon, Jul 24, 2023 at 06:40:47AM +0300, Gavin Li wrote:> Add interrupt_coalesce config in send_queue and receive_queue to cache user > config. > > Send per virtqueue interrupt moderation config to underline device in order > to have more efficient interrupt moderation and cpu utilization of guest > VM. > > Signed-off-by: Gavin Li <gavinl at nvidia.com> > Reviewed-by: Dragos Tatulea <dtatulea at nvidia.com> > Reviewed-by: Jiri Pirko <jiri at nvidia.com> > Acked-by: Michael S. Tsirkin <mst at redhat.com> > --- > drivers/net/virtio_net.c | 120 ++++++++++++++++++++++++++++---- > include/uapi/linux/virtio_net.h | 14 ++++ > 2 files changed, 122 insertions(+), 12 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 802ed21453f5..0c3ee1e26ece 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -144,6 +144,8 @@ struct send_queue { > > struct virtnet_sq_stats stats; > > + struct virtnet_interrupt_coalesce intr_coal; > + > struct napi_struct napi; > > /* Record whether sq is in reset state. */ > @@ -161,6 +163,8 @@ struct receive_queue { > > struct virtnet_rq_stats stats; > > + struct virtnet_interrupt_coalesce intr_coal; > + > /* Chain pages by the private ptr. */ > struct page *pages; > > @@ -212,6 +216,7 @@ struct control_buf { > struct virtio_net_ctrl_rss rss; > struct virtio_net_ctrl_coal_tx coal_tx; > struct virtio_net_ctrl_coal_rx coal_rx; > + struct virtio_net_ctrl_coal_vq coal_vq; > }; > > struct virtnet_info { > @@ -3078,6 +3083,55 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, > return 0; > } > > +static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi, > + u16 vqn, u32 max_usecs, u32 max_packets) > +{ > + struct scatterlist sgs; > + > + vi->ctrl->coal_vq.vqn = cpu_to_le16(vqn); > + vi->ctrl->coal_vq.coal.max_usecs = cpu_to_le32(max_usecs); > + vi->ctrl->coal_vq.coal.max_packets = cpu_to_le32(max_packets); > + sg_init_one(&sgs, &vi->ctrl->coal_vq, sizeof(vi->ctrl->coal_vq)); > + > + if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL, > + VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET, > + &sgs)) > + return -EINVAL; > + > + return 0; > +} > + > +static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi, > + struct ethtool_coalesce *ec, > + u16 queue) > +{ > + int err; > + > + if (ec->rx_coalesce_usecs || ec->rx_max_coalesced_frames) { > + err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue), > + ec->rx_coalesce_usecs, > + ec->rx_max_coalesced_frames); > + if (err) > + return err; > + /* Save parameters */ > + vi->rq[queue].intr_coal.max_usecs = ec->rx_coalesce_usecs; > + vi->rq[queue].intr_coal.max_packets = ec->rx_max_coalesced_frames; > + } > + > + if (ec->tx_coalesce_usecs || ec->tx_max_coalesced_frames) { > + err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue), > + ec->tx_coalesce_usecs, > + ec->tx_max_coalesced_frames); > + if (err) > + return err; > + /* Save parameters */ > + vi->sq[queue].intr_coal.max_usecs = ec->tx_coalesce_usecs; > + vi->sq[queue].intr_coal.max_packets = ec->tx_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 > @@ -3094,23 +3148,39 @@ static int virtnet_coal_params_supported(struct ethtool_coalesce *ec) > } > > static int virtnet_set_coalesce_one(struct net_device *dev, > - struct ethtool_coalesce *ec) > + struct ethtool_coalesce *ec, > + bool per_queue, > + u32 queue) > { > struct virtnet_info *vi = netdev_priv(dev); > - int ret, i, napi_weight; > + int queue_count = per_queue ? 1 : vi->max_queue_pairs; > + int queue_number = per_queue ? queue : 0;Actually can't we refactor this? This whole function is littered with if/else branches. just code it separately - the only common part is: 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; } so just move this to a helper and have two functions - global and per queue.> bool update_napi = false; > + int ret, i, napi_weight; > + > + if (queue >= vi->max_queue_pairs) > + return -EINVAL; > > /* 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 > + for (i = queue_number; i < queue_count; i++) { > + if (napi_weight ^ vi->sq[i].napi.weight) { > + if (dev->flags & IFF_UP) > + return -EBUSY; > + > update_napi = true; > + /* All queues that belong to [queue_number, queue_count] will be > + * updated for the sake of simplicity, which might not be necessary > + */ > + queue_number = i; > + break; > + } > } > > - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) > + if (!per_queue && virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) > ret = virtnet_send_notf_coal_cmds(vi, ec); > + else if (per_queue && virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) > + ret = virtnet_send_notf_coal_vq_cmds(vi, ec, queue); > else > ret = virtnet_coal_params_supported(ec); > > @@ -3118,7 +3188,7 @@ static int virtnet_set_coalesce_one(struct net_device *dev, > return ret; > > if (update_napi) { > - for (i = 0; i < vi->max_queue_pairs; i++) > + for (i = queue_number; i < queue_count; i++) > vi->sq[i].napi.weight = napi_weight; > } > > @@ -3130,19 +3200,29 @@ static int virtnet_set_coalesce(struct net_device *dev, > struct kernel_ethtool_coalesce *kernel_coal, > struct netlink_ext_ack *extack) > { > - return virtnet_set_coalesce_one(dev, ec); > + return virtnet_set_coalesce_one(dev, ec, false, 0); > } > > static int virtnet_get_coalesce_one(struct net_device *dev, > - struct ethtool_coalesce *ec) > + struct ethtool_coalesce *ec, > + bool per_queue, > + u32 queue) > { > struct virtnet_info *vi = netdev_priv(dev); > > - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { > + if (queue >= vi->max_queue_pairs) > + return -EINVAL; > + > + if (!per_queue && virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { > ec->rx_coalesce_usecs = vi->intr_coal_rx.max_usecs; > ec->tx_coalesce_usecs = vi->intr_coal_tx.max_usecs; > ec->tx_max_coalesced_frames = vi->intr_coal_tx.max_packets; > ec->rx_max_coalesced_frames = vi->intr_coal_rx.max_packets; > + } else if (per_queue && virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) { > + ec->rx_coalesce_usecs = vi->rq[queue].intr_coal.max_usecs; > + ec->tx_coalesce_usecs = vi->sq[queue].intr_coal.max_usecs; > + ec->tx_max_coalesced_frames = vi->sq[queue].intr_coal.max_packets; > + ec->rx_max_coalesced_frames = vi->rq[queue].intr_coal.max_packets; > } else { > ec->rx_max_coalesced_frames = 1; > > @@ -3158,7 +3238,21 @@ static int virtnet_get_coalesce(struct net_device *dev, > struct kernel_ethtool_coalesce *kernel_coal, > struct netlink_ext_ack *extack) > { > - return virtnet_get_coalesce_one(dev, ec); > + return virtnet_get_coalesce_one(dev, ec, false, 0); > +} > + > +static int virtnet_set_per_queue_coalesce(struct net_device *dev, > + u32 queue, > + struct ethtool_coalesce *ec) > +{ > + return virtnet_set_coalesce_one(dev, ec, true, queue); > +} > + > +static int virtnet_get_per_queue_coalesce(struct net_device *dev, > + u32 queue, > + struct ethtool_coalesce *ec) > +{ > + return virtnet_get_coalesce_one(dev, ec, true, queue); > } > > static void virtnet_init_settings(struct net_device *dev) > @@ -3291,6 +3385,8 @@ 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, > + .set_per_queue_coalesce = virtnet_set_per_queue_coalesce, > + .get_per_queue_coalesce = virtnet_get_per_queue_coalesce, > .get_rxfh_key_size = virtnet_get_rxfh_key_size, > .get_rxfh_indir_size = virtnet_get_rxfh_indir_size, > .get_rxfh = virtnet_get_rxfh, > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index 12c1c9699935..cc65ef0f3c3e 100644 > --- a/include/uapi/linux/virtio_net.h > +++ b/include/uapi/linux/virtio_net.h > @@ -56,6 +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_VQ_NOTF_COAL 52 /* Device supports virtqueue notification coalescing */ > #define VIRTIO_NET_F_NOTF_COAL 53 /* Device supports notifications coalescing */ > #define VIRTIO_NET_F_GUEST_USO4 54 /* Guest can handle USOv4 in. */ > #define VIRTIO_NET_F_GUEST_USO6 55 /* Guest can handle USOv6 in. */ > @@ -391,5 +392,18 @@ struct virtio_net_ctrl_coal_rx { > }; > > #define VIRTIO_NET_CTRL_NOTF_COAL_RX_SET 1 > +#define VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET 2 > +#define VIRTIO_NET_CTRL_NOTF_COAL_VQ_GET 3 > + > +struct virtio_net_ctrl_coal { > + __le32 max_packets; > + __le32 max_usecs; > +}; > + > +struct virtio_net_ctrl_coal_vq { > + __le16 vqn; > + __le16 reserved; > + struct virtio_net_ctrl_coal coal; > +}; > > #endif /* _UAPI_LINUX_VIRTIO_NET_H */ > -- > 2.39.1