On Tue, 2023-07-25 at 16:07 +0300, Gavin Li wrote:

Add interrupt_coalesce config in send_queue and receive_queue to cache user
config.

Send per virtqueue interrupt moderation config to underlying device in
order to have more efficient interrupt moderation and cpu utilization of
guest VM.

Additionally, address all the VQs when updating the global configuration,
as now the individual VQs configuration can diverge from the global
configuration.

Signed-off-by: Gavin Li <redacted>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Jiri Pirko <redacted>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

FTR, this patch is significantly different from the version previously
acked/reviewed, I'm unsure if all the reviewers are ok with the new
one.

[...]

 static int virtnet_set_coalesce(struct net_device *dev,
 				struct ethtool_coalesce *ec,
 				struct kernel_ethtool_coalesce *kernel_coal,
 				struct netlink_ext_ack *extack)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
-	int ret, i, napi_weight;
+	int ret, queue_number, napi_weight;
 	bool update_napi = false;
 
 	/* Can't change NAPI weight if the link is up */
 	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
-	if (napi_weight ^ vi->sq[0].napi.weight) {
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-		else
-			update_napi = true;
+	for (queue_number = 0; queue_number < vi->max_queue_pairs; queue_number++) {
+		ret = virtnet_should_update_vq_weight(dev->flags, napi_weight,
+						      vi->sq[queue_number].napi.weight,
+						      &update_napi);
+		if (ret)
+			return ret;
+
+		if (update_napi) {
+			/* All queues that belong to [queue_number, queue_count] will be
+			 * updated for the sake of simplicity, which might not be necessary

It looks like the comment above still refers to the old code. Should
be:
	[queue_number, vi->max_queue_pairs]
			
Otherwise LGTM, thanks!

Paolo