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_cm.h b/include/rdma/rdma_cm.h
index 36cd8a8..2d6a770 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -52,10 +52,13 @@
RDMA_CM_EVENT_ESTABLISHED,
RDMA_CM_EVENT_DISCONNECTED,
RDMA_CM_EVENT_DEVICE_REMOVAL,
+ RDMA_CM_EVENT_MULTICAST_JOIN,
+ RDMA_CM_EVENT_MULTICAST_ERROR
};
enum rdma_port_space {
RDMA_PS_SDP = 0x0001,
+ RDMA_PS_IPOIB= 0x0002,
RDMA_PS_TCP = 0x0106,
RDMA_PS_UDP = 0x0111,
RDMA_PS_SCTP = 0x0183
@@ -294,5 +297,21 @@
*/
int rdma_disconnect(struct rdma_cm_id *id);
-#endif /* RDMA_CM_H */
+/**
+ * rdma_join_multicast - Join the multicast group specified by the given
+ * address.
+ * @id: Communication identifier associated with the request.
+ * @addr: Multicast address identifying the group to join.
+ * @context: User-defined context associated with the join request, returned
+ * to the user through the private_data pointer in multicast events.
+ */
+int rdma_join_multicast(struct rdma_cm_id *id, struct sockaddr *addr,
+ void *context);
+/**
+ * rdma_leave_multicast - Leave the multicast group specified by the given
+ * address.
+ */
+void rdma_leave_multicast(struct rdma_cm_id *id, struct sockaddr *addr);
+
+#endif /* RDMA_CM_H */
diff --git a/include/rdma/rdma_cm_ib.h b/include/rdma/rdma_cm_ib.h
index 9b176df..950424b 100644
--- a/include/rdma/rdma_cm_ib.h
+++ b/include/rdma/rdma_cm_ib.h
@@ -44,7 +44,7 @@
int rdma_set_ib_paths(struct rdma_cm_id *id,
struct ib_sa_path_rec *path_rec, int num_paths);
-/* Global qkey for UD QPs and multicast groups. */
-#define RDMA_UD_QKEY 0x01234567
+/* Global qkey for UDP QPs and multicast groups. */
+#define RDMA_UDP_QKEY 0x01234567
#endif /* RDMA_CM_IB_H */
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;
};