[PATCH net-next V2 0/4] virtio_net: add per queue interrupt coalescing support

[PATCH net-next V2 0/4] virtio_net: add per queue interrupt coalescing support

[Gavin Li]

Currently, coalescing parameters are grouped for all transmit and receive
virtqueues. This patch series add support to set or get the parameters for
a specified virtqueue.

When the traffic between virtqueues is unbalanced, for example, one virtqueue
is busy and another virtqueue is idle, then it will be very useful to
control coalescing parameters at the virtqueue granularity.

Example command:
$ ethtool -Q eth5 queue_mask 0x1 --coalesce tx-packets 10
Would set max_packets=10 to VQ 1.
$ ethtool -Q eth5 queue_mask 0x1 --coalesce rx-packets 10
Would set max_packets=10 to VQ 0.
$ ethtool -Q eth5 queue_mask 0x1 --show-coalesce
 Queue: 0
 Adaptive RX: off  TX: off
 stats-block-usecs: 0
 sample-interval: 0
 pkt-rate-low: 0
 pkt-rate-high: 0

 rx-usecs: 222
 rx-frames: 0
 rx-usecs-irq: 0
 rx-frames-irq: 256

 tx-usecs: 222
 tx-frames: 0
 tx-usecs-irq: 0
 tx-frames-irq: 256

 rx-usecs-low: 0
 rx-frame-low: 0
 tx-usecs-low: 0
 tx-frame-low: 0

 rx-usecs-high: 0
 rx-frame-high: 0
 tx-usecs-high: 0
 tx-frame-high: 0

Gavin Li (4):
  virtio_net: extract interrupt coalescing settings to a structure
  virtio_net: extract get/set interrupt coalesce to a function
  virtio_net: support per queue interrupt coalesce command
---
changelog:
v1->v2
- Addressed the comment from Xuan Zhuo
- Allocate memory from heap instead of using stack memory for control vq
	message
---
  virtio_net: enable per queue interrupt coalesce feature

 drivers/net/virtio_net.c        | 175 ++++++++++++++++++++++++++------
 include/uapi/linux/virtio_net.h |  14 +++
 2 files changed, 160 insertions(+), 29 deletions(-)

-- 
2.39.1

[PATCH net-next V2 1/4] virtio_net: extract interrupt coalescing settings to a structure

[Gavin Li]

Extract interrupt coalescing settings to a structure so that it could be
reused in other data structures.

Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0db14f6b87d3..dd5fec073a27 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -126,6 +126,11 @@ static const struct virtnet_stat_desc virtnet_rq_stats_desc[] = {
 #define VIRTNET_SQ_STATS_LEN	ARRAY_SIZE(virtnet_sq_stats_desc)
 #define VIRTNET_RQ_STATS_LEN	ARRAY_SIZE(virtnet_rq_stats_desc)
 
+struct virtnet_interrupt_coalesce {
+	u32 max_packets;
+	u32 max_usecs;
+};
+
 /* Internal representation of a send virtqueue */
 struct send_queue {
 	/* Virtqueue associated with this send _queue */
@@ -281,10 +286,8 @@ struct virtnet_info {
 	u32 speed;
 
 	/* Interrupt coalescing settings */
-	u32 tx_usecs;
-	u32 rx_usecs;
-	u32 tx_max_packets;
-	u32 rx_max_packets;
+	struct virtnet_interrupt_coalesce intr_coal_tx;
+	struct virtnet_interrupt_coalesce intr_coal_rx;
 
 	unsigned long guest_offloads;
 	unsigned long guest_offloads_capable;
@@ -3056,8 +3059,8 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 		return -EINVAL;
 
 	/* Save parameters */
-	vi->tx_usecs = ec->tx_coalesce_usecs;
-	vi->tx_max_packets = ec->tx_max_coalesced_frames;
+	vi->intr_coal_tx.max_usecs = ec->tx_coalesce_usecs;
+	vi->intr_coal_tx.max_packets = ec->tx_max_coalesced_frames;
 
 	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);
@@ -3069,8 +3072,8 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 		return -EINVAL;
 
 	/* Save parameters */
-	vi->rx_usecs = ec->rx_coalesce_usecs;
-	vi->rx_max_packets = ec->rx_max_coalesced_frames;
+	vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
+	vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
 
 	return 0;
 }
@@ -3132,10 +3135,10 @@ static int virtnet_get_coalesce(struct net_device *dev,
 	struct virtnet_info *vi = netdev_priv(dev);
 
 	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;
+		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 {
 		ec->rx_max_coalesced_frames = 1;
 
@@ -4119,10 +4122,10 @@ static int virtnet_probe(struct virtio_device *vdev)
 	}
 
 	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;
+		vi->intr_coal_rx.max_usecs = 0;
+		vi->intr_coal_tx.max_usecs = 0;
+		vi->intr_coal_tx.max_packets = 0;
+		vi->intr_coal_rx.max_packets = 0;
 	}
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
-- 
2.39.1

[PATCH net-next V2 2/4] virtio_net: extract get/set interrupt coalesce to a function

[Gavin Li]

Extract get/set interrupt coalesce to a function to be reused by global
and per queue config.

Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index dd5fec073a27..802ed21453f5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3093,10 +3093,8 @@ static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
 	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)
+static int virtnet_set_coalesce_one(struct net_device *dev,
+				    struct ethtool_coalesce *ec)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 	int ret, i, napi_weight;
@@ -3127,10 +3125,16 @@ static int virtnet_set_coalesce(struct net_device *dev,
 	return ret;
 }
 
-static int virtnet_get_coalesce(struct net_device *dev,
+static int virtnet_set_coalesce(struct net_device *dev,
 				struct ethtool_coalesce *ec,
 				struct kernel_ethtool_coalesce *kernel_coal,
 				struct netlink_ext_ack *extack)
+{
+	return virtnet_set_coalesce_one(dev, ec);
+}
+
+static int virtnet_get_coalesce_one(struct net_device *dev,
+				    struct ethtool_coalesce *ec)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 
@@ -3149,6 +3153,14 @@ static int virtnet_get_coalesce(struct net_device *dev,
 	return 0;
 }
 
+static int virtnet_get_coalesce(struct net_device *dev,
+				struct ethtool_coalesce *ec,
+				struct kernel_ethtool_coalesce *kernel_coal,
+				struct netlink_ext_ack *extack)
+{
+	return virtnet_get_coalesce_one(dev, ec);
+}
+
 static void virtnet_init_settings(struct net_device *dev)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
-- 
2.39.1

[PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Gavin Li]

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        | 123 ++++++++++++++++++++++++++++----
 include/uapi/linux/virtio_net.h |  14 ++++
 2 files changed, 125 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 802ed21453f5..1566c7de9436 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;
 
@@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
+	struct scatterlist sgs;
+
+	coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
+	if (!coal_vq)
+		return -ENOMEM;
+	coal_vq->vqn = cpu_to_le16(vqn);
+	coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
+	coal_vq->coal.max_packets = cpu_to_le32(max_packets);
+	sg_init_one(&sgs, coal_vq, sizeof(*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 +3151,39 @@ 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;
 	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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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 +3388,8 @@ 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

[PATCH net-next V2 4/4] virtio_net: enable per queue interrupt coalesce feature

[Gavin Li]

Enable per queue interrupt coalesce feature bit in driver and validate its
dependency with control queue.

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 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1566c7de9436..6d9de7c74961 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -4066,6 +4066,8 @@ static bool virtnet_validate_features(struct virtio_device *vdev)
 	     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") ||
+	     VIRTNET_FAIL_ON(vdev, VIRTIO_NET_F_VQ_NOTF_COAL,
 			     "VIRTIO_NET_F_CTRL_VQ"))) {
 		return false;
 	}
@@ -4490,6 +4492,7 @@ static struct virtio_device_id id_table[] = {
 	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_NOTF_COAL, \
+	VIRTIO_NET_F_VQ_NOTF_COAL, \
 	VIRTIO_NET_F_GUEST_HDRLEN
 
 static unsigned int features[] = {
-- 
2.39.1

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Gavin Li]

On 7/17/2023 10:30 PM, 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        | 123 ++++++++++++++++++++++++++++----
>   include/uapi/linux/virtio_net.h |  14 ++++
>   2 files changed, 125 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 802ed21453f5..1566c7de9436 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;
>   
> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
> +	struct scatterlist sgs;
> +
> +	coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
> +	if (!coal_vq)
> +		return -ENOMEM;
> +	coal_vq->vqn = cpu_to_le16(vqn);
> +	coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
> +	coal_vq->coal.max_packets = cpu_to_le32(max_packets);
> +	sg_init_one(&sgs, coal_vq, sizeof(*coal_vq));
> +
> +	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
> +				  VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET,
> +				  &sgs))
> +		return -EINVAL;
Sorry, introduced mem leak here, ie. coal_vq. May I re-send the patch 
series or fix it in V3?
> +
> +	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 +3151,39 @@ 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;
>   	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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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 +3388,8 @@ 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 */

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Heng Qi]

在 2023/7/17 下午10:30, Gavin Li 写道:
> 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        | 123 ++++++++++++++++++++++++++++----
>   include/uapi/linux/virtio_net.h |  14 ++++
>   2 files changed, 125 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 802ed21453f5..1566c7de9436 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;
>   
> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
> +	struct scatterlist sgs;
> +
> +	coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);

I think this should go in the structure control_buf, which serves two 
purposes, and that's on the heap in init_vqs():
1. We can have the same form as other control types, such as 
virtio_net_ctrl_coal_{tx, rx};
2. Avoid using heap memory here to cause the following memory leaks

> +	if (!coal_vq)
> +		return -ENOMEM;
> +	coal_vq->vqn = cpu_to_le16(vqn);
> +	coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
> +	coal_vq->coal.max_packets = cpu_to_le32(max_packets);
> +	sg_init_one(&sgs, coal_vq, sizeof(*coal_vq));
> +
> +	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
> +				  VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET,
> +				  &sgs))
> +		return -EINVAL;

If this fails, we should free coal_vq, so pls move coal_vq into control_buf.

Thanks.

> +
> +	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 +3151,39 @@ 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;
>   	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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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 +3388,8 @@ 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 */

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Heng Qi]

在 2023/7/17 下午10:30, Gavin Li 写道:
> 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        | 123 ++++++++++++++++++++++++++++----
>   include/uapi/linux/virtio_net.h |  14 ++++
>   2 files changed, 125 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 802ed21453f5..1566c7de9436 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;
>   
> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
> +	struct scatterlist sgs;
> +
> +	coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
> +	if (!coal_vq)
> +		return -ENOMEM;
> +	coal_vq->vqn = cpu_to_le16(vqn);
> +	coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
> +	coal_vq->coal.max_packets = cpu_to_le32(max_packets);
> +	sg_init_one(&sgs, coal_vq, sizeof(*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 +3151,39 @@ 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;
>   	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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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)

When \field{max_virtqueue_pairs} is the maximum value, and the user does 
not carry the queue_mask for 'ethtool -Q',
we will send same command for all vqs, and the device will receive a 
large number of the same VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET commands at 
this time.
Do we want to alleviate this situation?

Thanks.

> +{
> +	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 +3388,8 @@ 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 */

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Gavin Li]

On 7/18/2023 11:29 AM, Heng Qi wrote:
> 
> 
> 在 2023/7/17 下午10:30, Gavin Li 写道:
>> 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        | 123 ++++++++++++++++++++++++++++----
>>   include/uapi/linux/virtio_net.h |  14 ++++
>>   2 files changed, 125 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 802ed21453f5..1566c7de9436 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;
>> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
>> +    struct scatterlist sgs;
>> +
>> +    coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
> 
> I think this should go in the structure control_buf, which serves two 
> purposes, and that's on the heap in init_vqs():
> 1. We can have the same form as other control types, such as 
> virtio_net_ctrl_coal_{tx, rx};
> 2. Avoid using heap memory here to cause the following memory leaks
ACK
> 
>> +    if (!coal_vq)
>> +        return -ENOMEM;
>> +    coal_vq->vqn = cpu_to_le16(vqn);
>> +    coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
>> +    coal_vq->coal.max_packets = cpu_to_le32(max_packets);
>> +    sg_init_one(&sgs, coal_vq, sizeof(*coal_vq));
>> +
>> +    if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>> +                  VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET,
>> +                  &sgs))
>> +        return -EINVAL;
> 
> If this fails, we should free coal_vq, so pls move coal_vq into 
> control_buf.
> 
> Thanks.
> ACK
>> +
>> +    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 +3151,39 @@ 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;
>>       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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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 +3388,8 @@ 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 */
> 

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Gavin Li]

On 7/18/2023 11:37 AM, Heng Qi wrote:
> 
> 
> 在 2023/7/17 下午10:30, Gavin Li 写道:
>> 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        | 123 ++++++++++++++++++++++++++++----
>>   include/uapi/linux/virtio_net.h |  14 ++++
>>   2 files changed, 125 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 802ed21453f5..1566c7de9436 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;
>> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
>> +    struct scatterlist sgs;
>> +
>> +    coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
>> +    if (!coal_vq)
>> +        return -ENOMEM;
>> +    coal_vq->vqn = cpu_to_le16(vqn);
>> +    coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
>> +    coal_vq->coal.max_packets = cpu_to_le32(max_packets);
>> +    sg_init_one(&sgs, coal_vq, sizeof(*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 +3151,39 @@ 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;
>>       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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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)
> 
> When \field{max_virtqueue_pairs} is the maximum value, and the user does 
> not carry the queue_mask for 'ethtool -Q',
> we will send same command for all vqs, and the device will receive a 
> large number of the same VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET commands at 
> this time.
> Do we want to alleviate this situation?
> 
> Thanks.
> 

May it be better to handle this senario in ethtool user space and call 
set_coalesce instead of set_per_queue_coalesce? I'm not sure.
>> +{
>> +    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 +3388,8 @@ 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 */
> 

Re: [PATCH net-next V2 3/4] virtio_net: support per queue interrupt coalesce command

[Heng Qi]

在 2023/7/18 下午2:45, Gavin Li 写道:
>
>
> On 7/18/2023 11:37 AM, Heng Qi wrote:
>>
>>
>> 在 2023/7/17 下午10:30, Gavin Li 写道:
>>> 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        | 123 
>>> ++++++++++++++++++++++++++++----
>>>   include/uapi/linux/virtio_net.h |  14 ++++
>>>   2 files changed, 125 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>>> index 802ed21453f5..1566c7de9436 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;
>>> @@ -3078,6 +3082,59 @@ 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 virtio_net_ctrl_coal_vq *coal_vq;
>>> +    struct scatterlist sgs;
>>> +
>>> +    coal_vq = kzalloc(sizeof(*coal_vq), GFP_KERNEL);
>>> +    if (!coal_vq)
>>> +        return -ENOMEM;
>>> +    coal_vq->vqn = cpu_to_le16(vqn);
>>> +    coal_vq->coal.max_usecs = cpu_to_le32(max_usecs);
>>> +    coal_vq->coal.max_packets = cpu_to_le32(max_packets);
>>> +    sg_init_one(&sgs, coal_vq, sizeof(*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 +3151,39 @@ 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;
>>>       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 +3191,7 @@ 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 +3203,29 @@ 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 +3241,21 @@ 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)
>>
>> When \field{max_virtqueue_pairs} is the maximum value, and the user 
>> does not carry the queue_mask for 'ethtool -Q',
>> we will send same command for all vqs, and the device will receive a 
>> large number of the same VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET commands at 
>> this time.
>> Do we want to alleviate this situation?
>>
>> Thanks.
>>
>
> May it be better to handle this senario in ethtool user space and call 
> set_coalesce instead of set_per_queue_coalesce? I'm not sure.

Maybe we need to force 'ethtool -Q' to carry queue_mask in userspace or 
instead call set_coalesce() interface when not carrying queue_mask
(this does not hinder this work and should be in another thread, please 
move on). But this I'm not sure either, since other NICs don't seem to
care much about this. Simply check that all drivers that implement the 
set_per_queue_coalesce() interface have implemented set_coalesce().

Thanks.

>>> +{
>>> +    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 +3388,8 @@ 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 */
>>