From 3014a0d54820d25c3dc66657bcc19013f2338760 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:39 +0800 Subject: [PATCH 1/6] 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(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1ed6bcc4cbb1b..35dc978def773 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; From 134674c1877be5e35e35802517c67a9ecce21153 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:40 +0800 Subject: [PATCH 2/6] virtio-net: fix mismatch of getting tx-frames Since virtio-net allows switching napi_tx for per txq, we have to get the specific txq's result now. Fixes: 394bd87764b6 ("virtio_net: support per queue interrupt coalesce command") Cc: Gavin Li Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 35dc978def773..1037febefc377 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3453,7 +3453,7 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev, } else { ec->rx_max_coalesced_frames = 1; - if (vi->sq[0].napi.weight) + if (vi->sq[queue].napi.weight) ec->tx_max_coalesced_frames = 1; } From e9420838ab4ffb82850095549e94dcee3f7fe0cb Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:41 +0800 Subject: [PATCH 3/6] virtio-net: consistently save parameters for per-queue When using .set_coalesce interface to set all queue coalescing parameters, we need to update both per-queue and global save values. Fixes: 394bd87764b6 ("virtio_net: support per queue interrupt coalesce command") Cc: Gavin Li Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1037febefc377..04b48ca9ab1fa 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3233,6 +3233,7 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, struct ethtool_coalesce *ec) { struct scatterlist sgs_tx, sgs_rx; + int i; 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); @@ -3246,6 +3247,10 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, /* Save parameters */ vi->intr_coal_tx.max_usecs = ec->tx_coalesce_usecs; vi->intr_coal_tx.max_packets = ec->tx_max_coalesced_frames; + for (i = 0; i < vi->max_queue_pairs; i++) { + vi->sq[i].intr_coal.max_usecs = ec->tx_coalesce_usecs; + vi->sq[i].intr_coal.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); @@ -3259,6 +3264,10 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi, /* 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; + } return 0; } From bfb2b3609162135625bf96acf5118051cd0d082e Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:42 +0800 Subject: [PATCH 4/6] virtio-net: fix per queue coalescing parameter setting When the user sets a non-zero coalescing parameter to 0 for a specific virtqueue, it does not work as expected, so let's fix this. Fixes: 394bd87764b6 ("virtio_net: support per queue interrupt coalesce command") Reported-by: Xiaoming Zhao Cc: Gavin Li Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 04b48ca9ab1fa..e3ad2f28e8689 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3296,27 +3296,23 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi, { 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; - } + err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue), + ec->rx_coalesce_usecs, + ec->rx_max_coalesced_frames); + if (err) + return err; - 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; - } + 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); + 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; } From f61fe5f081cf40de08d0a4c89659baf23c900f0c Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:43 +0800 Subject: [PATCH 5/6] virtio-net: fix the vq coalescing setting for vq resize According to the definition of virtqueue coalescing spec[1]: Upon disabling and re-enabling a transmit virtqueue, the device MUST set the coalescing parameters of the virtqueue to those configured through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver did not set any TX coalescing parameters, to 0. Upon disabling and re-enabling a receive virtqueue, the device MUST set the coalescing parameters of the virtqueue to those configured through the VIRTIO_NET_CTRL_NOTF_COAL_RX_SET command, or, if the driver did not set any RX coalescing parameters, to 0. We need to add this setting for vq resize (ethtool -G) where vq_reset happens. [1] https://lists.oasis-open.org/archives/virtio-dev/202303/msg00415.html Fixes: 394bd87764b6 ("virtio_net: support per queue interrupt coalesce command") Cc: Gavin Li Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e3ad2f28e8689..26e4a7749628b 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2855,6 +2855,9 @@ static void virtnet_get_ringparam(struct net_device *dev, ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq); } +static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi, + u16 vqn, u32 max_usecs, u32 max_packets); + static int virtnet_set_ringparam(struct net_device *dev, struct ethtool_ringparam *ring, struct kernel_ethtool_ringparam *kernel_ring, @@ -2890,12 +2893,36 @@ static int virtnet_set_ringparam(struct net_device *dev, err = virtnet_tx_resize(vi, sq, ring->tx_pending); if (err) return err; + + /* Upon disabling and re-enabling a transmit virtqueue, the device must + * set the coalescing parameters of the virtqueue to those configured + * 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); + 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) { err = virtnet_rx_resize(vi, rq, ring->rx_pending); if (err) 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); + 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; } } From c4e33cf2611b2f73098f7413176d428d1fb62304 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Sun, 8 Oct 2023 14:27:44 +0800 Subject: [PATCH 6/6] virtio-net: a tiny comment update Update a comment because virtio-net now supports both VIRTIO_NET_F_NOTF_COAL and VIRTIO_NET_F_VQ_NOTF_COAL. Signed-off-by: Heng Qi Acked-by: Jason Wang Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 26e4a7749628b..a52fd743504a6 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3347,7 +3347,7 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi, static int virtnet_coal_params_supported(struct ethtool_coalesce *ec) { /* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL - * feature is negotiated. + * or VIRTIO_NET_F_VQ_NOTF_COAL feature is negotiated. */ if (ec->rx_coalesce_usecs || ec->tx_coalesce_usecs) return -EOPNOTSUPP;