On 2019/5/24 上午3:19, Saeed Mahameed wrote:
On Thu, 2019-05-23 at 10:54 -0700, Stephen Hemminger wrote:
When a device is stacked like (team, bonding, failsafe or netvsc) the
XDP generic program for the parent device was not called.
Move the call to XDP generic inside __netif_receive_skb_core where
it can be done multiple times for stacked case.
Suggested-by: Jiri Pirko <j...@resnulli.us>
Fixes: d445516966dc ("net: xdp: support xdp generic on virtual
devices")
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
v1 - call xdp_generic in netvsc handler
v2 - do xdp_generic in generic rx handler processing
v3 - move xdp_generic call inside the another pass loop
net/core/dev.c | 56 ++++++++++------------------------------------
----
1 file changed, 11 insertions(+), 45 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index b6b8505cfb3e..696776e14d00 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4502,23 +4502,6 @@ static int netif_rx_internal(struct sk_buff
*skb)
trace_netif_rx(skb);
- if (static_branch_unlikely(&generic_xdp_needed_key)) {
- int ret;
-
- preempt_disable();
- rcu_read_lock();
- ret = do_xdp_generic(rcu_dereference(skb->dev-
xdp_prog), skb);
- rcu_read_unlock();
- preempt_enable();
-
- /* Consider XDP consuming the packet a success from
- * the netdev point of view we do not want to count
- * this as an error.
- */
- if (ret != XDP_PASS)
- return NET_RX_SUCCESS;
- }
-
Adding Jesper,
There is a small behavioral change due to this patch,
At least not for current code. We don't support skb in cpumap (though
the fix should not be hard), in dp_do_generic_redirect_map() we had:
} else {
/* TODO: Handle BPF_MAP_TYPE_CPUMAP */
err = -EBADRQC;
goto err;
}
the XDP program after this patch will run on the RPS CPU, if
configured, which could cause some behavioral changes in
xdp_redirect_cpu: bpf_redirect_map(cpu_map).
Maybe this is acceptable, but it should be documented, as the current
assumption dictates: XDP program runs on the core where the XDP
frame/SKB was first seen.
At lest for TUN, this is not true. XDP frames were built by vhost_net
and passed to TUN. There's no guarantee that vhost_net kthread won't
move to another core.
Thanks
