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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Aharon Landau <aharonl@nvidia.com>,
        Leon Romanovsky <leon@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.0 465/862] RDMA/mlx5: Dont compare mkey tags in DEVX indirect mkey
Date:   Wed, 19 Oct 2022 10:29:12 +0200
Message-Id: <20221019083310.526227733@linuxfoundation.org>
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From: Aharon Landau <aharonl@nvidia.com>

[ Upstream commit 13ad1125b941a5f257d9d3ae70485773abd34792 ]

According to the ib spec:
If the CI supports the Base Memory Management Extensions defined in this
specification, the L_Key format must consist of:
24 bit index in the most significant bits of the R_Key, and
8 bit key in the least significant bits of the R_Key
Through a successful Allocate L_Key verb invocation, the CI must let the
consumer own the key portion of the returned R_Key

Therefore, when creating a mkey using DEVX, the consumer is allowed to
change the key part. The kernel should compare only the index part of a
R_Key to determine equality with another R_Key.

Adding capability in order not to break backward compatibility.

Fixes: 534fd7aac56a ("IB/mlx5: Manage indirection mkey upon DEVX flow for ODP")
Link: https://lore.kernel.org/r/3d669aacea85a3a15c3b3b953b3eaba3f80ef9be.1659255945.git.leonro@nvidia.com
Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/hw/mlx5/main.c | 3 +++
 drivers/infiniband/hw/mlx5/odp.c  | 3 ++-
 include/uapi/rdma/mlx5-abi.h      | 1 +
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 883d7c60143e..1aa0c772b44d 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1826,6 +1826,9 @@ static int set_ucontext_resp(struct ib_ucontext *uctx,
 	if (MLX5_CAP_GEN(dev->mdev, drain_sigerr))
 		resp->comp_mask |= MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_SQD2RTS;
 
+	resp->comp_mask |=
+		MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_MKEY_UPDATE_TAG;
+
 	return 0;
 }
 
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index e305bf1dc6c2..901a8b030236 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -795,7 +795,8 @@ static bool mkey_is_eq(struct mlx5_ib_mkey *mmkey, u32 key)
 {
 	if (!mmkey)
 		return false;
-	if (mmkey->type == MLX5_MKEY_MW)
+	if (mmkey->type == MLX5_MKEY_MW ||
+	    mmkey->type == MLX5_MKEY_INDIRECT_DEVX)
 		return mlx5_base_mkey(mmkey->key) == mlx5_base_mkey(key);
 	return mmkey->key == key;
 }
diff --git a/include/uapi/rdma/mlx5-abi.h b/include/uapi/rdma/mlx5-abi.h
index 86be4a92b67b..a96b7d2770e1 100644
--- a/include/uapi/rdma/mlx5-abi.h
+++ b/include/uapi/rdma/mlx5-abi.h
@@ -104,6 +104,7 @@ enum mlx5_ib_alloc_ucontext_resp_mask {
 	MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_ECE               = 1UL << 2,
 	MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_SQD2RTS           = 1UL << 3,
 	MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_REAL_TIME_TS	   = 1UL << 4,
+	MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_MKEY_UPDATE_TAG   = 1UL << 5,
 };
 
 enum mlx5_user_cmds_supp_uhw {
-- 
2.35.1