nvme-rdma: assign completion vector correctly

[ Upstream commit 032a9966a22a3596addf81dacf0c1736dfedc32a ]

The completion vector index that is given during CQ creation can't
exceed the number of support vectors by the underlying RDMA device. This
violation currently can accure, for example, in case one will try to
connect with N regular read/write queues and M poll queues and the sum
of N + M > num_supported_vectors. This will lead to failure in establish
a connection to remote target. Instead, in that case, share a completion
vector between queues.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 9fffe41ead5009c497d65ce16bcf67da31bd41ea..c91bfd839cabec10a6c2a308d6cdcaca664ef91f 100644 (file)
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -470,7 +470,7 @@ static int nvme_rdma_create_queue_ib(struct nvme_rdma_queue *queue)
         * Spread I/O queues completion vectors according their queue index.
         * Admin queues can always go on completion vector 0.
         */
-       comp_vector = idx == 0 ? idx : idx - 1;
+       comp_vector = (idx == 0 ? idx : idx - 1) % ibdev->num_comp_vectors;
 
        /* +1 for ib_stop_cq */
        queue->ib_cq = ib_alloc_cq(ibdev, queue,