ANBZ: #5550
This introduces a new mode for eRDAM iWARP support.
SMC-R use an out-bound way to establish RDMA link, that is using CLC
message to exchange QP information and then modify QP to record peer
QP num, instead of using RDMA-CM. However, for iWARP, only RDMA-CM is
supported.
So in the past implementations, we provided a workaround, that reuse
5-tuple of first-contact clcsock as eRDMA iWARP link. But a disadvan-
tage of this method is that we need to keep this first-contact clcsock
until iWARP link is cleared (for QP reuse), which is agnostic to the
user and may cause port in-use error.
Now we provide a new way to replace the previous implementation. Server
side will reserve several fixed ports for eRDMA iWARP and ensure no
port conflicts for 5-tuple of eRDMA iWARP link, which is reserve_mode.
Reserve_mode will disable the keep-first-contact-clcsock logic of the
previous implementation.
But note that this mode now is in beta, so we provide a module param
for switch. reserve_mode is default true, and can be set to false to
back to previous implementation.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Link: https://gitee.com/anolis/cloud-kernel/pulls/1754
48d5d861a5