From mboxrd@z Thu Jan 1 00:00:00 1970 From: Qin Chuanyu Subject: Re: [PATCH] openvswitch: orphan frags on local receive Date: Tue, 25 Feb 2014 10:07:55 +0800 Message-ID: <530BFAFB.4080904@huawei.com> References: <530B45E0.20009@huawei.com> <530B5AEC.5020509@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM list , To: Zoltan Kiss , , "Michael S. Tsirkin" Return-path: In-Reply-To: <530B5AEC.5020509@citrix.com> Sender: netdev-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 2014/2/24 22:45, Zoltan Kiss wrote: > Hi, > > I'm also planning a similar patch, but it will call skb_orphan_frags on > the skb in datapath.c::queue_userspace_packet, right before > skb_zerocopy, so packets sent up to userspace via Netlink doesn't harm > guests. I haven't checked your patch thoroughly, does it handle a > different scenario? > yes, it handle another scenario, and Michael had noted that __netif_receive_skb_core could solve it. I think your patch is still needed, because netif_receive_skb didn't handle the netlink receive patch. and any skb reserved by host socket queue might cause guest nic hang. > Regards, > > Zoltan Kiss > > On 24/02/14 13:15, Qin Chuanyu wrote: >> with vhost tx zero_copy, guest nic might get hang when host reserving >> skb in socket queue delivered by guest, the case has been solved in >> tun, it also been needed by openvswitch. This could easily happened >> when a LAST_ACK state tcp occuring between guest and host. >> >> Signed-off-by: Chuanyu Qin >> --- >> net/openvswitch/vport-internal_dev.c | 3 +++ >> net/openvswitch/vport.c | 1 + >> 2 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/net/openvswitch/vport-internal_dev.c >> b/net/openvswitch/vport-internal_dev.c >> index 729c687..adb25e2 100644 >> --- a/net/openvswitch/vport-internal_dev.c >> +++ b/net/openvswitch/vport-internal_dev.c >> @@ -212,6 +212,9 @@ static int internal_dev_recv(struct vport *vport, >> struct sk_buff *skb) >> struct net_device *netdev = netdev_vport_priv(vport)->dev; >> int len; >> >> + if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) >> + return -NET_RX_DROP; >> + >> len = skb->len; >> >> skb_dst_drop(skb); >> diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c >> index 208dd9a..04172d6 100644 >> --- a/net/openvswitch/vport.c >> +++ b/net/openvswitch/vport.c >> @@ -383,6 +383,7 @@ int ovs_vport_send(struct vport *vport, struct >> sk_buff *skb) >> u64_stats_update_end(&stats->syncp); >> } else if (sent < 0) { >> ovs_vport_record_error(vport, VPORT_E_TX_ERROR); >> + skb_tx_error(skb); >> kfree_skb(skb); >> } else >> ovs_vport_record_error(vport, VPORT_E_TX_DROPPED); > > > . >