From 236a93cb8a0beae688ccc1146247d81bb2f1114a Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 4 Aug 2020 09:54:15 -0700 Subject: [PATCH] hv_netvsc: do not use VF device if link is down [ Upstream commit 7c9864bbccc23e1812ac82966555d68c13ea4006 ] If the accelerated networking SRIOV VF device has lost carrier use the synthetic network device which is available as backup path. This is a rare case since if VF link goes down, normally the VMBus device will also loose external connectivity as well. But if the communication is between two VM's on the same host the VMBus device will still work. Reported-by: "Shah, Ashish N" Fixes: 0c195567a8f6 ("netvsc: transparent VF management") Signed-off-by: Stephen Hemminger Reviewed-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/hyperv/netvsc_drv.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 14451e14d99d..10c3480c2da8 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -532,12 +532,13 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net) u32 hash; struct hv_page_buffer pb[MAX_PAGE_BUFFER_COUNT]; - /* if VF is present and up then redirect packets - * already called with rcu_read_lock_bh + /* If VF is present and up then redirect packets to it. + * Skip the VF if it is marked down or has no carrier. + * If netpoll is in uses, then VF can not be used either. */ vf_netdev = rcu_dereference_bh(net_device_ctx->vf_netdev); if (vf_netdev && netif_running(vf_netdev) && - !netpoll_tx_running(net)) + netif_carrier_ok(vf_netdev) && !netpoll_tx_running(net)) return netvsc_vf_xmit(net, vf_netdev, skb); /* We will atmost need two pages to describe the rndis