[PATCH net-next v3 0/5] virtio-net: support dynamic coalescing moderation

[PATCH net-next v3 0/5] virtio-net: support dynamic coalescing moderation

[Heng Qi]

Now, virtio-net already supports per-queue moderation parameter
setting. Based on this, we use the linux dimlib to support
dynamic coalescing moderation for virtio-net.

Due to some scheduling issues, we only support and test the rx dim.

Some test results:

I. Sockperf UDP
=================================================
1. Env
rxq_0 with affinity to cpu_0.

2. Cmd
client: taskset -c 0 sockperf tp -p 8989 -i $IP -t 10 -m 16B
server: taskset -c 0 sockperf sr -p 8989

3. Result
dim off: 1143277.00 rxpps, throughput 17.844 MBps, cpu is 100%.
dim on:  1124161.00 rxpps, throughput 17.610 MBps, cpu is 83.5%.
=================================================

II. Redis
=================================================
1. Env
There are 8 rxqs, and rxq_i with affinity to cpu_i.

2. Result
When all cpus are 100%, ops/sec of memtier_benchmark client is
dim off:  978437.23
dim on:  1143638.28
=================================================

III. Nginx
=================================================
1. Env
There are 8 rxqs and rxq_i with affinity to cpu_i.

2. Result
When all cpus are 100%, requests/sec of wrk client is
dim off:  877931.67
dim on:  1019160.31
=================================================

IV. Latency of sockperf udp
=================================================
1. Rx cmd
taskset -c 0 sockperf sr -p 8989

2. Tx cmd
taskset -c 0 sockperf pp -i ${ip} -p 8989 -t 10

After running this cmd 5 times and averaging the results,

3. Result
dim off: 17.7735 usec
dim on:  18.0110 usec
=================================================

Changelog:
v2->v3:
- Patch(4/5): some minor modifications.

v1->v2:
- Patch(2/5): a minor fix.
- Patch(4/5):
   - improve the judgment of dim switch conditions.
   - fix safe problem of work thread.
- Patch(5/5): drop the tx dim implementation.


Heng Qi (5):
  virtio-net: returns whether napi is complete
  virtio-net: separate rx/tx coalescing moderation cmds
  virtio-net: extract virtqueue coalescig cmd for reuse
  virtio-net: support rx netdim
  virtio-net: return -EOPNOTSUPP for adaptive-tx

 drivers/net/virtio_net.c | 335 ++++++++++++++++++++++++++++++++-------
 1 file changed, 278 insertions(+), 57 deletions(-)

-- 
2.19.1.6.gb485710b

[PATCH net-next v3 1/5] virtio-net: returns whether napi is complete

[Heng Qi]

rx netdim needs to count the traffic during a complete napi process,
and start updating and comparing samples to make decisions after
the napi ends. Let virtqueue_napi_complete() return true if napi is done,
otherwise vice versa.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d16f592c2061..0ad2894e6a5e 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -431,7 +431,7 @@ static void virtqueue_napi_schedule(struct napi_struct *napi,
 	}
 }
 
-static void virtqueue_napi_complete(struct napi_struct *napi,
+static bool virtqueue_napi_complete(struct napi_struct *napi,
 				    struct virtqueue *vq, int processed)
 {
 	int opaque;
@@ -440,9 +440,13 @@ static void virtqueue_napi_complete(struct napi_struct *napi,
 	if (napi_complete_done(napi, processed)) {
 		if (unlikely(virtqueue_poll(vq, opaque)))
 			virtqueue_napi_schedule(napi, vq);
+		else
+			return true;
 	} else {
 		virtqueue_disable_cb(vq);
 	}
+
+	return false;
 }
 
 static void skb_xmit_done(struct virtqueue *vq)
-- 
2.19.1.6.gb485710b

[PATCH net-next v3 2/5] virtio-net: separate rx/tx coalescing moderation cmds

[Heng Qi]

This patch separates the rx and tx global coalescing moderation
commands to support netdim switches in subsequent patches.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0ad2894e6a5e..0285301caf78 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3266,10 +3266,10 @@ 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)
+static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
+					  struct ethtool_coalesce *ec)
 {
-	struct scatterlist sgs_tx, sgs_rx;
+	struct scatterlist sgs_tx;
 	int i;
 
 	vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
@@ -3289,6 +3289,15 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 		vi->sq[i].intr_coal.max_packets = ec->tx_max_coalesced_frames;
 	}
 
+	return 0;
+}
+
+static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
+					  struct ethtool_coalesce *ec)
+{
+	struct scatterlist sgs_rx;
+	int i;
+
 	vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
 	vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
 	sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
@@ -3309,6 +3318,22 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
+				       struct ethtool_coalesce *ec)
+{
+	int err;
+
+	err = virtnet_send_tx_notf_coal_cmds(vi, ec);
+	if (err)
+		return err;
+
+	err = virtnet_send_rx_notf_coal_cmds(vi, ec);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
 					 u16 vqn, u32 max_usecs, u32 max_packets)
 {
-- 
2.19.1.6.gb485710b

[PATCH net-next v3 3/5] virtio-net: extract virtqueue coalescig cmd for reuse

[Heng Qi]

Extract commands to set virtqueue coalescing parameters for reuse
by ethtool -Q, vq resize and netdim.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 106 +++++++++++++++++++++++----------------
 1 file changed, 64 insertions(+), 42 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0285301caf78..69fe09e99b3c 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2849,6 +2849,58 @@ static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
 					    &vi->node_dead);
 }
 
+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_rx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
+					    u16 queue, u32 max_usecs,
+					    u32 max_packets)
+{
+	int err;
+
+	err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue),
+					    max_usecs, max_packets);
+	if (err)
+		return err;
+
+	vi->rq[queue].intr_coal.max_usecs = max_usecs;
+	vi->rq[queue].intr_coal.max_packets = max_packets;
+
+	return 0;
+}
+
+static int virtnet_send_tx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
+					    u16 queue, u32 max_usecs,
+					    u32 max_packets)
+{
+	int err;
+
+	err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
+					    max_usecs, max_packets);
+	if (err)
+		return err;
+
+	vi->sq[queue].intr_coal.max_usecs = max_usecs;
+	vi->sq[queue].intr_coal.max_packets = max_packets;
+
+	return 0;
+}
+
 static void virtnet_get_ringparam(struct net_device *dev,
 				  struct ethtool_ringparam *ring,
 				  struct kernel_ethtool_ringparam *kernel_ring,
@@ -2906,14 +2958,11 @@ static int virtnet_set_ringparam(struct net_device *dev,
 			 * through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver
 			 * did not set any TX coalescing parameters, to 0.
 			 */
-			err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(i),
-							    vi->intr_coal_tx.max_usecs,
-							    vi->intr_coal_tx.max_packets);
+			err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
+							       vi->intr_coal_tx.max_usecs,
+							       vi->intr_coal_tx.max_packets);
 			if (err)
 				return err;
-
-			vi->sq[i].intr_coal.max_usecs = vi->intr_coal_tx.max_usecs;
-			vi->sq[i].intr_coal.max_packets = vi->intr_coal_tx.max_packets;
 		}
 
 		if (ring->rx_pending != rx_pending) {
@@ -2922,14 +2971,11 @@ static int virtnet_set_ringparam(struct net_device *dev,
 				return err;
 
 			/* The reason is same as the transmit virtqueue reset */
-			err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(i),
-							    vi->intr_coal_rx.max_usecs,
-							    vi->intr_coal_rx.max_packets);
+			err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, i,
+							       vi->intr_coal_rx.max_usecs,
+							       vi->intr_coal_rx.max_packets);
 			if (err)
 				return err;
-
-			vi->rq[i].intr_coal.max_usecs = vi->intr_coal_rx.max_usecs;
-			vi->rq[i].intr_coal.max_packets = vi->intr_coal_rx.max_packets;
 		}
 	}
 
@@ -3334,48 +3380,24 @@ 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;
 
-	err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue),
-					    ec->rx_coalesce_usecs,
-					    ec->rx_max_coalesced_frames);
+	err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->rx_coalesce_usecs,
+					       ec->rx_max_coalesced_frames);
 	if (err)
 		return err;
 
-	vi->rq[queue].intr_coal.max_usecs = ec->rx_coalesce_usecs;
-	vi->rq[queue].intr_coal.max_packets = ec->rx_max_coalesced_frames;
-
-	err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
-					    ec->tx_coalesce_usecs,
-					    ec->tx_max_coalesced_frames);
+	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->tx_coalesce_usecs,
+					       ec->tx_max_coalesced_frames);
 	if (err)
 		return err;
 
-	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;
 }
 
-- 
2.19.1.6.gb485710b

[PATCH net-next v3 4/5] virtio-net: support rx netdim

[Heng Qi]

By comparing the traffic information in the complete napi processes,
let the virtio-net driver automatically adjust the coalescing
moderation parameters of each receive queue.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
v2->v3:
- Some minor modifications.

v1->v2:
- Improved the judgment of dim switch conditions.
- Cancel the work when vq reset.

 drivers/net/virtio_net.c | 191 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 169 insertions(+), 22 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 69fe09e99b3c..bc32d5aae005 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -19,6 +19,7 @@
 #include <linux/average.h>
 #include <linux/filter.h>
 #include <linux/kernel.h>
+#include <linux/dim.h>
 #include <net/route.h>
 #include <net/xdp.h>
 #include <net/net_failover.h>
@@ -172,6 +173,17 @@ struct receive_queue {
 
 	struct virtnet_rq_stats stats;
 
+	/* The number of rx notifications */
+	u16 calls;
+
+	/* Is dynamic interrupt moderation enabled? */
+	bool dim_enabled;
+
+	/* Dynamic Interrupt Moderation */
+	struct dim dim;
+
+	u32 packets_in_napi;
+
 	struct virtnet_interrupt_coalesce intr_coal;
 
 	/* Chain pages by the private ptr. */
@@ -305,6 +317,9 @@ struct virtnet_info {
 	u8 duplex;
 	u32 speed;
 
+	/* Is rx dynamic interrupt moderation enabled? */
+	bool rx_dim_enabled;
+
 	/* Interrupt coalescing settings */
 	struct virtnet_interrupt_coalesce intr_coal_tx;
 	struct virtnet_interrupt_coalesce intr_coal_rx;
@@ -2001,6 +2016,7 @@ static void skb_recv_done(struct virtqueue *rvq)
 	struct virtnet_info *vi = rvq->vdev->priv;
 	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 
+	rq->calls++;
 	virtqueue_napi_schedule(&rq->napi, rvq);
 }
 
@@ -2141,6 +2157,26 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
 	}
 }
 
+static void virtnet_rx_dim_work(struct work_struct *work);
+
+static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue *rq)
+{
+	struct dim_sample cur_sample = {};
+
+	if (!rq->packets_in_napi)
+		return;
+
+	u64_stats_update_begin(&rq->stats.syncp);
+	dim_update_sample(rq->calls,
+			  u64_stats_read(&rq->stats.packets),
+			  u64_stats_read(&rq->stats.bytes),
+			  &cur_sample);
+	u64_stats_update_end(&rq->stats.syncp);
+
+	net_dim(&rq->dim, cur_sample);
+	rq->packets_in_napi = 0;
+}
+
 static int virtnet_poll(struct napi_struct *napi, int budget)
 {
 	struct receive_queue *rq =
@@ -2149,17 +2185,22 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
 	struct send_queue *sq;
 	unsigned int received;
 	unsigned int xdp_xmit = 0;
+	bool napi_complete;
 
 	virtnet_poll_cleantx(rq);
 
 	received = virtnet_receive(rq, budget, &xdp_xmit);
+	rq->packets_in_napi += received;
 
 	if (xdp_xmit & VIRTIO_XDP_REDIR)
 		xdp_do_flush();
 
 	/* Out of packets? */
-	if (received < budget)
-		virtqueue_napi_complete(napi, rq->vq, received);
+	if (received < budget) {
+		napi_complete = virtqueue_napi_complete(napi, rq->vq, received);
+		if (napi_complete && rq->dim_enabled)
+			virtnet_rx_dim_update(vi, rq);
+	}
 
 	if (xdp_xmit & VIRTIO_XDP_TX) {
 		sq = virtnet_xdp_get_sq(vi);
@@ -2179,6 +2220,7 @@ static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
 	virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
 	napi_disable(&vi->rq[qp_index].napi);
 	xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq);
+	cancel_work_sync(&vi->rq[qp_index].dim.work);
 }
 
 static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
@@ -2196,6 +2238,9 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
 	if (err < 0)
 		goto err_xdp_reg_mem_model;
 
+	INIT_WORK(&vi->rq[qp_index].dim.work, virtnet_rx_dim_work);
+	vi->rq[qp_index].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+
 	virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
 	virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
 
@@ -2393,8 +2438,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 
 	qindex = rq - vi->rq;
 
-	if (running)
+	if (running) {
 		napi_disable(&rq->napi);
+		cancel_work_sync(&rq->dim.work);
+	}
 
 	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
 	if (err)
@@ -2403,8 +2450,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 	if (!try_fill_recv(vi, rq, GFP_KERNEL))
 		schedule_delayed_work(&vi->refill, 0);
 
-	if (running)
+	if (running) {
+		INIT_WORK(&rq->dim.work, virtnet_rx_dim_work);
 		virtnet_napi_enable(rq->vq, &rq->napi);
+	}
 	return err;
 }
 
@@ -3341,24 +3390,55 @@ static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
 static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec)
 {
+	bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
+	bool update = false, switch_dim;
 	struct scatterlist sgs_rx;
 	int i;
 
-	vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
-	vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
-	sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
-
-	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
-				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
-				  &sgs_rx))
-		return -EINVAL;
+	switch_dim = rx_ctrl_dim_on != vi->rx_dim_enabled;
+	if (switch_dim) {
+		if (rx_ctrl_dim_on) {
+			if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
+				vi->rx_dim_enabled = true;
+				for (i = 0; i < vi->max_queue_pairs; i++)
+					vi->rq[i].dim_enabled = true;
+			} else {
+				return -EOPNOTSUPP;
+			}
+		} else {
+			vi->rx_dim_enabled = false;
+			for (i = 0; i < vi->max_queue_pairs; i++)
+				vi->rq[i].dim_enabled = false;
+		}
+	} else {
+		if (ec->rx_coalesce_usecs != vi->intr_coal_rx.max_usecs ||
+		    ec->rx_max_coalesced_frames != vi->intr_coal_rx.max_packets)
+			update = true;
 
-	/* Save parameters */
-	vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
-	vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
-	for (i = 0; i < vi->max_queue_pairs; i++) {
-		vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
-		vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
+		if (vi->rx_dim_enabled) {
+			if (update)
+				return -EINVAL;
+		} else {
+			/* Since the per-queue coalescing params can be set,
+			 * we need apply the global new params even if they
+			 * are not updated.
+			 */
+			vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
+			vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
+			sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
+
+			if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+						  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
+						  &sgs_rx))
+				return -EINVAL;
+
+			vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
+			vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
+			for (i = 0; i < vi->max_queue_pairs; i++) {
+				vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
+				vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
+			}
+		}
 	}
 
 	return 0;
@@ -3380,15 +3460,54 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
+					     struct ethtool_coalesce *ec,
+					     u16 queue)
+{
+	bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
+	bool cur_rx_dim = vi->rq[queue].dim_enabled;
+	bool update = false, switch_dim;
+	u32 max_usecs, max_packets;
+	int err;
+
+	switch_dim = rx_ctrl_dim_on != cur_rx_dim;
+	if (switch_dim) {
+		if (rx_ctrl_dim_on)
+			vi->rq[queue].dim_enabled = true;
+		else
+			vi->rq[queue].dim_enabled = false;
+	} else {
+		max_usecs = vi->rq[queue].intr_coal.max_usecs;
+		max_packets = vi->rq[queue].intr_coal.max_packets;
+		if (ec->rx_coalesce_usecs != max_usecs ||
+		    ec->rx_max_coalesced_frames != max_packets)
+			update = true;
+
+		if (cur_rx_dim) {
+			if (update)
+				return -EINVAL;
+		} else {
+			if (!update)
+				return 0;
+
+			err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
+							       ec->rx_coalesce_usecs,
+							       ec->rx_max_coalesced_frames);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
 static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec,
 					  u16 queue)
 {
 	int err;
 
-	err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
-					       ec->rx_coalesce_usecs,
-					       ec->rx_max_coalesced_frames);
+	err = virtnet_send_rx_notf_coal_vq_cmds(vi, ec, queue);
 	if (err)
 		return err;
 
@@ -3401,6 +3520,32 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static void virtnet_rx_dim_work(struct work_struct *work)
+{
+	struct dim *dim = container_of(work, struct dim, work);
+	struct receive_queue *rq = container_of(dim,
+			struct receive_queue, dim);
+	struct virtnet_info *vi = rq->vq->vdev->priv;
+	struct net_device *dev = vi->dev;
+	struct dim_cq_moder update_moder;
+	int qnum = rq - vi->rq, err;
+
+	update_moder = net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
+	if (update_moder.usec != vi->rq[qnum].intr_coal.max_usecs ||
+	    update_moder.pkts != vi->rq[qnum].intr_coal.max_packets) {
+		rtnl_lock();
+		err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, qnum,
+						       update_moder.usec,
+						       update_moder.pkts);
+		if (err)
+			pr_debug("%s: Failed to send dim parameters on rxq%d\n",
+				 dev->name, (int)(rq - vi->rq));
+		rtnl_unlock();
+	}
+
+	dim->state = DIM_START_MEASURE;
+}
+
 static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
 {
 	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
@@ -3482,6 +3627,7 @@ static int virtnet_get_coalesce(struct net_device *dev,
 		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;
+		ec->use_adaptive_rx_coalesce = vi->rx_dim_enabled;
 	} else {
 		ec->rx_max_coalesced_frames = 1;
 
@@ -3539,6 +3685,7 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev,
 		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;
+		ec->use_adaptive_rx_coalesce = vi->rq[queue].dim_enabled;
 	} else {
 		ec->rx_max_coalesced_frames = 1;
 
@@ -3664,7 +3811,7 @@ 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 |
-		ETHTOOL_COALESCE_USECS,
+		ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,
-- 
2.19.1.6.gb485710b

[PATCH net-next v3 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Heng Qi]

We do not currently support tx dim, so respond to -EOPNOTSUPP.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
v1->v2:
- Use -EOPNOTSUPP instead of specific implementation.

 drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bc32d5aae005..b082f2acbb22 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3364,9 +3364,15 @@ static int virtnet_get_link_ksettings(struct net_device *dev,
 static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec)
 {
+	bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
 	struct scatterlist sgs_tx;
 	int i;
 
+	if (tx_ctrl_dim_on) {
+		pr_debug("Failed to enable adaptive-tx, which is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
 	vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
 	vi->ctrl->coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
 	sg_init_one(&sgs_tx, &vi->ctrl->coal_tx, sizeof(vi->ctrl->coal_tx));
@@ -3501,6 +3507,25 @@ static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_tx_notf_coal_vq_cmds(struct virtnet_info *vi,
+					     struct ethtool_coalesce *ec,
+					     u16 queue)
+{
+	bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
+	int err;
+
+	if (tx_ctrl_dim_on) {
+		pr_debug("Enabling adaptive-tx for txq%d is not supported\n", queue);
+		return -EOPNOTSUPP;
+	}
+
+	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->tx_coalesce_usecs,
+					       ec->tx_max_coalesced_frames);
+
+	return err;
+}
+
 static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec,
 					  u16 queue)
@@ -3511,9 +3536,7 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 	if (err)
 		return err;
 
-	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
-					       ec->tx_coalesce_usecs,
-					       ec->tx_max_coalesced_frames);
+	err = virtnet_send_tx_notf_coal_vq_cmds(vi, ec, queue);
 	if (err)
 		return err;
 
-- 
2.19.1.6.gb485710b

Re: [PATCH net-next v3 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Jakub Kicinski]

On Tue, 14 Nov 2023 13:55:47 +0800 Heng Qi wrote:
> We do not currently support tx dim, so respond to -EOPNOTSUPP.

Hm, why do you need this? You don't set ADAPTIVE_TX in
.supported_coalesce_params, so core should prevent attempts
to enable ADAPTIVE_TX.

Re: [PATCH net-next v3 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Heng Qi]

在 2023/11/15 下午12:23, Jakub Kicinski 写道:
> On Tue, 14 Nov 2023 13:55:47 +0800 Heng Qi wrote:
>> We do not currently support tx dim, so respond to -EOPNOTSUPP.
> Hm, why do you need this? You don't set ADAPTIVE_TX in
> .supported_coalesce_params, so core should prevent attempts
> to enable ADAPTIVE_TX.

Indeed. Will drop this.

Thanks!