> On May 31, 2023, at 4:09 PM, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Wed, May 31, 2023 at 07:11:52PM +0000, Chuck Lever III wrote:
>>
>>
>>> On May 31, 2023, at 3:04 PM, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>>>
>>> On Tue, May 23, 2023 at 07:18:18PM +0000, Chuck Lever III wrote:
>>>
>>>> The core address resolution code wants to find an L2 address
>>>> for the egress device. The underlying ib_device, where a made-up
>>>> GID might be stored, is not involved with address resolution
>>>> AFAICT.
>>>
>>> Where are you hitting this?
>>
>> kworker/2:0-26 [002] 551.962874: funcgraph_entry: | addr_resolve() {
>> kworker/2:0-26 [002] 551.962874: bprint: addr_resolve: resolve_neigh=true resolve_by_gid_attr=false
>> kworker/2:0-26 [002] 551.962874: funcgraph_entry: | addr4_resolve.constprop.0() {
>> kworker/2:0-26 [002] 551.962875: bprint: addr4_resolve.constprop.0: src_in=0.0.0.0:35173 dst_in=100.72.1.2:20049
>> kworker/2:0-26 [002] 551.962875: funcgraph_entry: | ip_route_output_flow() {
>> kworker/2:0-26 [002] 551.962875: funcgraph_entry: | ip_route_output_key_hash() {
>> kworker/2:0-26 [002] 551.962876: funcgraph_entry: | ip_route_output_key_hash_rcu() {
>> kworker/2:0-26 [002] 551.962876: funcgraph_entry: 4.526 us | __fib_lookup();
>> kworker/2:0-26 [002] 551.962881: funcgraph_entry: 0.264 us | fib_select_path();
>> kworker/2:0-26 [002] 551.962881: funcgraph_entry: 1.022 us | __mkroute_output();
>> kworker/2:0-26 [002] 551.962882: funcgraph_exit: 6.705 us | }
>> kworker/2:0-26 [002] 551.962882: funcgraph_exit: 7.283 us | }
>> kworker/2:0-26 [002] 551.962883: funcgraph_exit: 7.624 us | }
>> kworker/2:0-26 [002] 551.962883: funcgraph_exit: 8.395 us | }
>> kworker/2:0-26 [002] 551.962883: funcgraph_entry: | rdma_set_src_addr_rcu.constprop.0() {
>> kworker/2:0-26 [002] 551.962883: bprint: rdma_set_src_addr_rcu.constprop.0: ndev=0xffff91f5135a4000 name=tailscale0
>> kworker/2:0-26 [002] 551.962884: funcgraph_entry: | copy_src_l2_addr() {
>> kworker/2:0-26 [002] 551.962884: funcgraph_entry: 0.984 us | iff_flags2string();
>> kworker/2:0-26 [002] 551.962885: bprint: copy_src_l2_addr: ndev=0xffff91f5135a4000 dst_in=100.72.1.2:20049 flags=UP|POINTOPOINT|NOARP|MULTICAST
>> kworker/2:0-26 [002] 551.962885: funcgraph_entry: | rdma_copy_src_l2_addr() {
>> kworker/2:0-26 [002] 551.962886: funcgraph_entry: 0.148 us | devtype2string();
>> kworker/2:0-26 [002] 551.962887: bprint: rdma_copy_src_l2_addr: name=tailscale0 type=NONE src_dev_addr=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 broadcast=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ifindex=3
>> kworker/2:0-26 [002] 551.962887: funcgraph_exit: 1.488 us | }
>> kworker/2:0-26 [002] 551.962887: bprint: copy_src_l2_addr: network type=IB
>> kworker/2:0-26 [002] 551.962887: funcgraph_exit: 3.636 us | }
>> kworker/2:0-26 [002] 551.962887: funcgraph_exit: 4.275 us | }
>>
>>
>> Address resolution finds the right device, but there's
>> a zero-value L2 address.
>
> Sure, but why is that a problem?
>
> This got to rdma_set_src_addr_rcu, so the resolution suceeded, where
> is the failure? From the above trace I think addr_resolve() succeeded?
Possibly it did succeed. But the ULP consumer sees CM_ADDR_ERROR_EVENT,
and does not proceed to route resolution.
>> Thus it cannot form a unique GID from that. Perhaps there needs to
>> be a call to query_gid in here?
>
> So your issue is cma_iw_acquire_dev() which looks like it is encoding
> the MAC into the GID for some reason? We don't do that on rocee, the
> GID encodes the IP address
Well, I'm not getting there at all on the initiator side.
cma_iw_acquire_dev() is called only for listeners, I thought.
>
> I have no idea how iWarp works, but this is surprising that it puts a
> MAC in the GID..
>
> If the iwarp device has only one GID ever and it is always the "MAC"
> the cma_iw_acquire_dev()'s logic is simply wrong, it should check that
> the dev_addr's netdev matches the one and only GID and just use the
> GID. No reason to search for GIDs.
>
> A small edit to cma_validate_port() might make sense, it is kind of
> wrong to force the gid_type to IB_GID_TYPE_IB for whatever ARPHRD type
> the tunnel is using.
I will have a look.
--
Chuck Lever
