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>
This commit is contained in:
Sean Hefty
2007-02-15 17:00:18 -08:00
committed by Roland Dreier
parent faec2f7b96
commit c8f6a362bf
5 changed files with 549 additions and 52 deletions

View File

@@ -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 */