RDMA/bnxt_re: Validate rate limit attribute in modify QP

Rate limit transition validation for RC QPs currently relies on
the IB core qp_state_table. Add a driver-level helper to validate
the rate limit attribute directly during QP modify, ensuring it
is only accepted for RC QPs in INIT->RTR, RTR->RTS and RTS->RTS
transitions.

This makes the driver responsible for rate limit validation
and prepares for a follow-up IB core change that delegates
IB_QP_RATE_LIMIT and all future non-standard modify attributes
handling to individual vendor drivers.

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Link: https://patch.msgid.link/20260524-packet-pacing-v1-6-3d79439f8d08@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

diff --git a/drivers/infiniband/hw/bnxt_re/ib_verbs.c b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
index b1c489867fc73ad05b65ecd65e9b6e7b30afea4e..13e765f10db1078129169852ec14045cecf709e1 100644 (file)
--- a/drivers/infiniband/hw/bnxt_re/ib_verbs.c
+++ b/drivers/infiniband/hw/bnxt_re/ib_verbs.c
@@ -2406,6 +2406,23 @@ static int bnxt_re_modify_shadow_qp(struct bnxt_re_dev *rdev,
        return rc;
 }
 
+static bool bnxt_re_is_modify_ok(enum ib_qp_attr_mask ext_mask,
+                                enum ib_qp_type type, enum ib_qp_state cur,
+                                enum ib_qp_state next)
+{
+       if (!ext_mask)
+               return true;
+
+       if (ext_mask & ~IB_QP_RATE_LIMIT)
+               return false;
+
+       /* Rate limit is only supported for RC QPs during specific transitions */
+       return type == IB_QPT_RC &&
+              ((cur == IB_QPS_INIT && next == IB_QPS_RTR) ||
+               (cur == IB_QPS_RTR && next == IB_QPS_RTS) ||
+               (cur == IB_QPS_RTS && next == IB_QPS_RTS));
+}
+
 int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
                      int qp_attr_mask, struct ib_udata *udata)
 {
@@ -2430,7 +2447,10 @@ int bnxt_re_modify_qp(struct ib_qp *ib_qp, struct ib_qp_attr *qp_attr,
                curr_qp_state = __to_ib_qp_state(qp->qplib_qp.cur_qp_state);
                new_qp_state = qp_attr->qp_state;
                if (!ib_modify_qp_is_ok(curr_qp_state, new_qp_state,
-                                       ib_qp->qp_type, qp_attr_mask)) {
+                                       ib_qp->qp_type, qp_attr_mask) ||
+                   !bnxt_re_is_modify_ok(qp_attr_mask & ~IB_QP_ATTR_STANDARD_BITS,
+                                         ib_qp->qp_type, curr_qp_state,
+                                         new_qp_state)) {
                        ibdev_err(&rdev->ibdev,
                                  "Invalid attribute mask: %#x specified ",
                                  qp_attr_mask);