Hi,
It seems that the OVS GRE code lacks handling of offloads (e.g to come into play with NICs that support NVGRE).
I assume we need to place a call to iptunnel_handle_offloads before invoking iptunnel_xmit, agree? so ~the quick patch below should do the work? I wasn't sure how to set the value of the 2nd param for iptunnel_handle_offloads().
Or.
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index f17ac96..524825f 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -187,6 +187,10 @@ static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
htons(IP_DF) : 0;
skb->ignore_df = 1;
+
+ skb = iptunnel_handle_offloads(skb, false, SKB_GSO_GRE);
+ if (IS_ERR(skb))
+ goto err_free_rt;
return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
tun_key->ipv4_dst, IPPROTO_GRE,On Thu, Feb 19, 2015 at 6:05 AM, Or Gerlitz [off-list ref] wrote:
Hi,
It seems that the OVS GRE code lacks handling of offloads (e.g to come into
play with NICs that support NVGRE).
I assume we need to place a call to iptunnel_handle_offloads before invoking
iptunnel_xmit, agree? so ~the quick patch below should do the work? I wasn't
sure how to set the value of the 2nd param for iptunnel_handle_offloads().
I don't think that this is the issue. __build_header() calls
gre_handle_offloads() which should do all of this work already.
I did notice that skb_set_inner_protocol() is not being called because
it is in the wrong place in the GRE encapsulation code. It is
currently in ip_gre.c():__gre_xmit(), if that line was moved to
gre_demux.c:gre_build_header() then it would be used by all callers.
One other thing that is potentially an issue for offloads is that all
of the encapsulations call vlan_hwaccel_push_inside() after the
respective handle_offloads code. This doesn't seem right as it could
affect the layer pointers, although it only likely matters in a
minority of cases where the inner MAC pointer is used.
On Thu, Feb 19, 2015 at 7:01 PM, Jesse Gross [off-list ref] wrote:
On Thu, Feb 19, 2015 at 6:05 AM, Or Gerlitz [off-list ref] wrote:
quoted
It seems that the OVS GRE code lacks handling of offloads (e.g to come into
play with NICs that support NVGRE).
I assume we need to place a call to iptunnel_handle_offloads before invoking
iptunnel_xmit, agree? so ~the quick patch below should do the work? I wasn't
sure how to set the value of the 2nd param for iptunnel_handle_offloads().
I don't think that this is the issue. __build_header() calls
gre_handle_offloads() which should do all of this work already.
yep... gre_handle_offloads() is called, so something else goes wrong here.
I did notice that skb_set_inner_protocol() is not being called because
it is in the wrong place in the GRE encapsulation code. It is
currently in ip_gre.c():__gre_xmit(), if that line was moved to
gre_demux.c:gre_build_header() then it would be used by all callers.
Oh, thanks, I'll add that and see if / how much does it help.
One other thing that is potentially an issue for offloads is that all
of the encapsulations call vlan_hwaccel_push_inside() after the
respective handle_offloads code. This doesn't seem right as it could
affect the layer pointers, although it only likely matters in a
minority of cases where the inner MAC pointer is used.
mmm, I don't think we're failing on that now, but can look this up too.
Did you ever tested Linux OVS/NGRE with a NIC that can do offloads for
this type of traffic?
On Thu, Feb 19, 2015 at 11:54 PM, Or Gerlitz [off-list ref] wrote:
On Thu, Feb 19, 2015 at 7:01 PM, Jesse Gross [off-list ref] wrote:
quoted
On Thu, Feb 19, 2015 at 6:05 AM, Or Gerlitz [off-list ref] wrote:
quoted
quoted
It seems that the OVS GRE code lacks handling of offloads (e.g to come into
play with NICs that support NVGRE).
I assume we need to place a call to iptunnel_handle_offloads before invoking
iptunnel_xmit, agree? so ~the quick patch below should do the work? I wasn't
sure how to set the value of the 2nd param for iptunnel_handle_offloads().
I don't think that this is the issue. __build_header() calls
gre_handle_offloads() which should do all of this work already.
yep... gre_handle_offloads() is called, so something else goes wrong here.
quoted
I did notice that skb_set_inner_protocol() is not being called because
it is in the wrong place in the GRE encapsulation code. It is
currently in ip_gre.c():__gre_xmit(), if that line was moved to
gre_demux.c:gre_build_header() then it would be used by all callers.
Oh, thanks, I'll add that and see if / how much does it help.
quoted
One other thing that is potentially an issue for offloads is that all
of the encapsulations call vlan_hwaccel_push_inside() after the
respective handle_offloads code. This doesn't seem right as it could
affect the layer pointers, although it only likely matters in a
minority of cases where the inner MAC pointer is used.
mmm, I don't think we're failing on that now, but can look this up too.
Did you ever tested Linux OVS/NGRE with a NIC that can do offloads for
this type of traffic?
I have not personally tried it.