Re: [PATCH for-next v4 0/7] RDMA/rxe: Make multicast work

[Zhu Yanjun <yanjun.zhu@linux.dev>]

+ Leon

Bob

Exactly.  Some kind of lock is needed for ipv6_sock_mc_join/drop. I will 
delve into these commits.

And this is related with mcast. We can invite netdev experts to review 
the code as well.

If you agree, I will also send your commits to netdev maillist.

And these commits are complicated. It is very good to have the 
suggestions from

the experts in netdev.

Zhu Yanjun

在 2023/12/5 4:07, Bob Pearson 写道:
> Zhu,
>
> Thanks for testing this. It turns out I needed to take the sk_lock for
> ipv6_sock_mc_join/drop().
>
> Bob
>
> On 12/4/23 14:03, Bob Pearson wrote:
>> After developing a test program which exercises node to node
>> testing of RoCE multicast it became clear that there are a
>> number of issues with the current rdma_rxe multicast implementation.
>>
>> The issues seen include:
>>     - There is no support for IPV4 multicast addresses.
>>     - Once a multicast MAC is added it is not removed.
>>     - Multicast packets are sent with the wrong QP number.
>>     - Multicast IP addresses are not created and without
>>       them no multicast packets received on the interface
>>       are delivered to the rdma_rxe driver.
>>     - The implementation in rxe_mcast.c is potentially
>>       racy if multiple simultaneous attach/detach operations
>>       are issued.
>>
>> This patch set fixes these issues.
>> ---
>> v4:
>>    Corrected a lockdep bug reported by Zhu Yanjun.
>> v3:
>>    Removed rxe_loop_and_send(). It turns out it is not needed.
>>    Added module parameters to set mcast limits to small values when
>>    driver is loaded to enable mcast limit testing.
>>    Rebased to current for-next branch.
>> v2:
>>    Respond to comments by Zhu.
>>    Added more Fixes lines.
>>    Added some more explanation in the commit messages.
>>    Fixed an error in rxe_lookup_mcg. Should have checked
>>     the return from rxe_get_mcg().
>>
>> Bob Pearson (7):
>>    RDMA/rxe: Cleanup rxe_ah/av_chk_attr
>>    RDMA/rxe: Fix sending of mcast packets
>>    RDMA/rxe: Register IP mcast address
>>    RDMA/rxe: Let rxe_lookup_mcg use rcu_read_lock
>>    RDMA/rxe: Split multicast lock
>>    RDMA/rxe: Cleanup mcg lifetime
>>    RDMA/rxe: Add module parameters for mcast limits
>>
>>   drivers/infiniband/sw/rxe/Makefile     |   3 +-
>>   drivers/infiniband/sw/rxe/rxe.c        |   8 +-
>>   drivers/infiniband/sw/rxe/rxe_av.c     |  50 +--
>>   drivers/infiniband/sw/rxe/rxe_loc.h    |   6 +-
>>   drivers/infiniband/sw/rxe/rxe_mcast.c  | 524 +++++++++++--------------
>>   drivers/infiniband/sw/rxe/rxe_net.c    |   6 +-
>>   drivers/infiniband/sw/rxe/rxe_net.h    |   1 +
>>   drivers/infiniband/sw/rxe/rxe_opcode.h |   2 +-
>>   drivers/infiniband/sw/rxe/rxe_param.c  |  23 ++
>>   drivers/infiniband/sw/rxe/rxe_param.h  |   4 +
>>   drivers/infiniband/sw/rxe/rxe_qp.c     |   4 +-
>>   drivers/infiniband/sw/rxe/rxe_recv.c   |  11 +-
>>   drivers/infiniband/sw/rxe/rxe_req.c    |  11 +-
>>   drivers/infiniband/sw/rxe/rxe_verbs.c  |   5 +-
>>   drivers/infiniband/sw/rxe/rxe_verbs.h  |   5 +-
>>   15 files changed, 303 insertions(+), 360 deletions(-)
>>   create mode 100644 drivers/infiniband/sw/rxe/rxe_param.c
>>