From 3014a0d54820d25c3dc66657bcc19013f2338760 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:39 +0800 Subject: virtio-net: initially change the value of tx-frames Background: 1. Commit 0c465be183c7 ("virtio_net: ethtool tx napi configuration") uses tx-frames to toggle napi_tx (0 off and 1 on) if notification coalescing is not supported. 2. Commit 31c03aef9bc2 ("virtio_net: enable napi_tx by default") enables napi_tx for all txqs by default. Status: When virtio-net supports notification coalescing, after initialization, tx-frames is 0 and napi_tx is true. Problem: When the user only wants to set rx coalescing params using ethtool -C eth0 rx-usecs 10, or ethtool -Q eth0 queue_mask 0x1 -C rx-usecs 10, these cmds will carry tx-frames as 0, causing the napi_tx switching condition is satisfied. Then the user gets: netlink error: Device or resource busy. The same happens when trying to set rx-frames, adaptive_rx, adaptive_tx... How to fix: When notification coalescing feature is negotiated, initially make the value of tx-frames to be consistent with napi_tx. For compatibility with the past, it is still supported to use tx-frames to toggle napi_tx. Reported-by: Xiaoming Zhao Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1ed6bcc4cbb1..35dc978def77 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -4442,13 +4442,6 @@ static int virtnet_probe(struct virtio_device *vdev) dev->xdp_features |= NETDEV_XDP_ACT_RX_SG; } - if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { - 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)) vi->has_rss_hash_report = true; @@ -4523,6 +4516,27 @@ static int virtnet_probe(struct virtio_device *vdev) if (err) goto free; + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_NOTF_COAL)) { + vi->intr_coal_rx.max_usecs = 0; + vi->intr_coal_tx.max_usecs = 0; + vi->intr_coal_rx.max_packets = 0; + + /* Keep the default values of the coalescing parameters + * aligned with the default napi_tx state. + */ + if (vi->sq[0].napi.weight) + vi->intr_coal_tx.max_packets = 1; + else + vi->intr_coal_tx.max_packets = 0; + } + + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) { + /* The reason is the same as VIRTIO_NET_F_NOTF_COAL. */ + for (i = 0; i < vi->max_queue_pairs; i++) + if (vi->sq[i].napi.weight) + vi->sq[i].intr_coal.max_packets = 1; + } + #ifdef CONFIG_SYSFS if (vi->mergeable_rx_bufs) dev->sysfs_rx_queue_group = &virtio_net_mrg_rx_group; -- cgit