From: Gavin Li <gavinl@nvidia.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: jasowang@redhat.com, xuanzhuo@linux.alibaba.com,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net,
hawk@kernel.org, john.fastabend@gmail.com, jiri@nvidia.com,
dtatulea@nvidia.com, gavi@nvidia.com,
virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
bpf@vger.kernel.org
Subject: Re: [PATCH net-next V3 3/4] virtio_net: support per queue interrupt coalesce command
Date: Mon, 24 Jul 2023 16:36:00 +0800 [thread overview]
Message-ID: <f7f4920d-7dee-1902-c76f-56ec6eeb5b99@nvidia.com> (raw)
In-Reply-To: <20230724032451-mutt-send-email-mst@kernel.org>
On 7/24/2023 3:32 PM, Michael S. Tsirkin wrote:
> 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@nvidia.com>
>> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
>> Reviewed-by: Jiri Pirko <jiri@nvidia.com>
>> Acked-by: Michael S. Tsirkin <mst@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.
ACK
>
>
>
>> 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
>
next prev parent reply other threads:[~2023-07-24 8:36 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-24 3:40 [PATCH net-next V3 0/4] virtio_net: add per queue interrupt coalescing support Gavin Li
2023-07-24 3:40 ` [PATCH net-next V3 1/4] virtio_net: extract interrupt coalescing settings to a structure Gavin Li
2023-07-24 3:40 ` [PATCH net-next V3 2/4] virtio_net: extract get/set interrupt coalesce to a function Gavin Li
2023-07-24 3:40 ` [PATCH net-next V3 3/4] virtio_net: support per queue interrupt coalesce command Gavin Li
2023-07-24 7:32 ` Michael S. Tsirkin
2023-07-24 8:36 ` Gavin Li [this message]
2023-07-24 3:40 ` [PATCH net-next V3 4/4] virtio_net: enable per queue interrupt coalesce feature Gavin Li
2023-07-24 5:18 ` [PATCH net-next V3 0/4] virtio_net: add per queue interrupt coalescing support Heng Qi
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