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authorMatthew Cover <werekraken@gmail.com>2018-11-18 00:46:00 -0700
committerDavid S. Miller <davem@davemloft.net>2018-11-18 19:05:43 -0800
commit8ebebcba559a1bfbaec7bbda64feb9870b9c58da (patch)
tree8cccb1975f0c8563935257b8abcccc2b28d66394
parent7ddacfa564870cdd97275fd87decb6174abc6380 (diff)
downloadlinux-8ebebcba559a1bfbaec7bbda64feb9870b9c58da.tar.bz2
tuntap: fix multiqueue rx
When writing packets to a descriptor associated with a combined queue, the packets should end up on that queue. Before this change all packets written to any descriptor associated with a tap interface end up on rx-0, even when the descriptor is associated with a different queue. The rx traffic can be generated by either of the following. 1. a simple tap program which spins up multiple queues and writes packets to each of the file descriptors 2. tx from a qemu vm with a tap multiqueue netdev The queue for rx traffic can be observed by either of the following (done on the hypervisor in the qemu case). 1. a simple netmap program which opens and reads from per-queue descriptors 2. configuring RPS and doing per-cpu captures with rxtxcpu Alternatively, if you printk() the return value of skb_get_rx_queue() just before each instance of netif_receive_skb() in tun.c, you will get 65535 for every skb. Calling skb_record_rx_queue() to set the rx queue to the queue_index fixes the association between descriptor and rx queue. Signed-off-by: Matthew Cover <matthew.cover@stackpath.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/tun.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 060135ceaf0e..e244f5d7512a 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1536,6 +1536,7 @@ static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
if (!rx_batched || (!more && skb_queue_empty(queue))) {
local_bh_disable();
+ skb_record_rx_queue(skb, tfile->queue_index);
netif_receive_skb(skb);
local_bh_enable();
return;
@@ -1555,8 +1556,11 @@ static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
struct sk_buff *nskb;
local_bh_disable();
- while ((nskb = __skb_dequeue(&process_queue)))
+ while ((nskb = __skb_dequeue(&process_queue))) {
+ skb_record_rx_queue(nskb, tfile->queue_index);
netif_receive_skb(nskb);
+ }
+ skb_record_rx_queue(skb, tfile->queue_index);
netif_receive_skb(skb);
local_bh_enable();
}
@@ -2451,6 +2455,7 @@ build:
if (!rcu_dereference(tun->steering_prog))
rxhash = __skb_get_hash_symmetric(skb);
+ skb_record_rx_queue(skb, tfile->queue_index);
netif_receive_skb(skb);
stats = get_cpu_ptr(tun->pcpu_stats);