RDMA/cma: Add multicast communication support
Extend rdma_cm to support multicast communication. Multicast support
is added to the existing RDMA_PS_UDP port space, as well as a new
RDMA_PS_IPOIB port space. The latter port space allows joining the
multicast groups used by IPoIB, which enables offloading IPoIB traffic
to a separate QP. The port space determines the signature used in the
MGID when joining the group. The newly added RDMA_PS_IPOIB also
allows for unicast operations, similar to RDMA_PS_UDP.
Supporting the RDMA_PS_IPOIB requires changing how UD QPs are initialized,
since we can no longer assume that the qkey is constant. This requires
saving the Q_Key to use when attaching to a device, so that it is
available when creating the QP. The Q_Key information is exported to
the user through the existing rdma_init_qp_attr() interface.
Multicast support is also exported to userspace through the rdma_ucm.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/rdma/rdma_user_cm.h b/include/rdma/rdma_user_cm.h
index 9572ab8..f632b0c 100644
--- a/include/rdma/rdma_user_cm.h
+++ b/include/rdma/rdma_user_cm.h
@@ -38,7 +38,7 @@
#include <rdma/ib_user_verbs.h>
#include <rdma/ib_user_sa.h>
-#define RDMA_USER_CM_ABI_VERSION 3
+#define RDMA_USER_CM_ABI_VERSION 4
#define RDMA_MAX_PRIVATE_DATA 256
@@ -58,7 +58,9 @@
RDMA_USER_CM_CMD_GET_EVENT,
RDMA_USER_CM_CMD_GET_OPTION,
RDMA_USER_CM_CMD_SET_OPTION,
- RDMA_USER_CM_CMD_NOTIFY
+ RDMA_USER_CM_CMD_NOTIFY,
+ RDMA_USER_CM_CMD_JOIN_MCAST,
+ RDMA_USER_CM_CMD_LEAVE_MCAST
};
/*
@@ -188,6 +190,13 @@
__u32 event;
};
+struct rdma_ucm_join_mcast {
+ __u64 response; /* rdma_ucm_create_id_resp */
+ __u64 uid;
+ struct sockaddr_in6 addr;
+ __u32 id;
+};
+
struct rdma_ucm_get_event {
__u64 response;
};
