[PATCH] virtio_net: Eliminate OOO packets during switching
From: Abhinav Jain <hidden>
Date: 2024-06-14 22:04:55
Also in:
lkml, virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Disable the network device & turn off carrier before modifying the number of queue pairs. Process all the in-flight packets and then turn on carrier, followed by waking up all the queues on the network device. Signed-off-by: Abhinav Jain <redacted> --- drivers/net/virtio_net.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 61a57d134544..d0a655a3b4c6 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -3447,7 +3447,6 @@ static void virtnet_get_drvinfo(struct net_device *dev, } -/* TODO: Eliminate OOO packets during switching */ static int virtnet_set_channels(struct net_device *dev, struct ethtool_channels *channels) {
@@ -3471,6 +3470,15 @@ static int virtnet_set_channels(struct net_device *dev, if (vi->rq[0].xdp_prog) return -EINVAL; + /* Disable network device to prevent packet processing during + * the switch. + */ + netif_tx_disable(dev); + netif_carrier_off(dev); + + /* Make certain that all in-flight packets are processed. */ + synchronize_net(); + cpus_read_lock(); err = virtnet_set_queues(vi, queue_pairs); if (err) {
@@ -3482,7 +3490,12 @@ static int virtnet_set_channels(struct net_device *dev, netif_set_real_num_tx_queues(dev, queue_pairs); netif_set_real_num_rx_queues(dev, queue_pairs); - err: + + /* Restart the network device */ + netif_carrier_on(dev); + netif_tx_wake_all_queues(dev); + +err: return err; }
--
2.34.1