[RFC PATCH rdma-next 2/2] RDMA/rxe: advertise IB_ODP_SUPPORT_IMPLICIT for local access

[Liibaan Egal]

Now that the implicit ODP registration and local SGE fault paths are
in place, advertise IB_ODP_SUPPORT_IMPLICIT in general_odp_caps so
userspace can probe the support via ibv_query_device.

The advertised support is intentionally scoped to local access:
remote rkey access on implicit MRs is rejected at registration time,
and the atomic, flush, and atomic-write paths reject implicit MRs at
the top of each helper.

Question for reviewers: is IB_ODP_SUPPORT_IMPLICIT the right
capability bit to advertise for this local-access-only operation
matrix, or should capability exposure wait for broader operation
coverage? The cap-flip is kept in its own patch so the policy
decision is separable from the implementation.

Signed-off-by: Liibaan Egal <liibaegal@xxxxxxxxx>
---
 drivers/infiniband/sw/rxe/rxe.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/sw/rxe/rxe.c b/drivers/infiniband/sw/rxe/rxe.c
index b0714f9abe..581313591d 100644
--- a/drivers/infiniband/sw/rxe/rxe.c
+++ b/drivers/infiniband/sw/rxe/rxe.c
@@ -94,8 +94,13 @@ static void rxe_init_device_param(struct rxe_dev *rxe, struct net_device *ndev)
 	if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING)) {
 		rxe->attr.kernel_cap_flags |= IBK_ON_DEMAND_PAGING;
 
-		/* IB_ODP_SUPPORT_IMPLICIT is not supported right now. */
 		rxe->attr.odp_caps.general_caps |= IB_ODP_SUPPORT;
+		/* IMPLICIT is gated to the local-access subset. The fault path
+		 * in rxe_odp.c rejects remote-access implicit forms at
+		 * registration time. Per-transport caps below stay unchanged:
+		 * they describe explicit ODP MR semantics and remain accurate.
+		 */
+		rxe->attr.odp_caps.general_caps |= IB_ODP_SUPPORT_IMPLICIT;
 
 		rxe->attr.odp_caps.per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_SEND;
 		rxe->attr.odp_caps.per_transport_caps.ud_odp_caps |= IB_ODP_SUPPORT_RECV;
-- 
2.43.0