Patch "IB/mlx4: Fix incorrectly releasing steerable UD QPs when have only ETH ports" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

    IB/mlx4: Fix incorrectly releasing steerable UD QPs when have only ETH ports

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ib-mlx4-fix-incorrectly-releasing-steerable-ud-qps-when-have-only-eth-ports.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.

From 852f6927594d0d3e8632c889b2ab38cbc46476ad Mon Sep 17 00:00:00 2001

From: Jack Morgenstein <redacted>
Date: Fri, 12 Jan 2018 07:58:40 +0200
Subject: IB/mlx4: Fix incorrectly releasing steerable UD QPs when have only ETH ports

From: Jack Morgenstein <redacted>

commit 852f6927594d0d3e8632c889b2ab38cbc46476ad upstream.

Allocating steerable UD QPs depends on having at least one IB port,
while releasing those QPs does not.

As a result, when there are only ETH ports, the IB (RoCE) driver
requests releasing a qp range whose base qp is zero, with
qp count zero.

When SR-IOV is enabled, and the VF driver is running on a VM over
a hypervisor which treats such qp release calls as errors
(rather than NOPs), we see lines in the VM message log like:

 mlx4_core 0002:00:02.0: Failed to release qp range base:0 cnt:0

Fix this by adding a check for a zero count in mlx4_release_qp_range()
(which thus treats releasing 0 qps as a nop), and eliminating the
check for device managed flow steering when releasing steerable UD QPs.
(Freeing ib_uc_qpns_bitmap unconditionally is also OK, since it
remains NULL when steerable UD QPs are not allocated).

Fixes: 4196670be786 ("IB/mlx4: Don't allocate range of steerable UD QPs for Ethernet-only device")
Signed-off-by: Jack Morgenstein <redacted>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/mlx4/main.c       |   13 +++++--------
 drivers/net/ethernet/mellanox/mlx4/qp.c |    3 +++
 2 files changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c

@@ -2995,9 +2995,8 @@ err_steer_free_bitmap:
 	kfree(ibdev->ib_uc_qpns_bitmap);
 
 err_steer_qp_release:
-	if (ibdev->steering_support == MLX4_STEERING_MODE_DEVICE_MANAGED)
-		mlx4_qp_release_range(dev, ibdev->steer_qpn_base,
-				      ibdev->steer_qpn_count);
+	mlx4_qp_release_range(dev, ibdev->steer_qpn_base,
+			      ibdev->steer_qpn_count);
 err_counter:
 	for (i = 0; i < ibdev->num_ports; ++i)
 		mlx4_ib_delete_counters_table(ibdev, &ibdev->counters_table[i]);

@@ -3102,11 +3101,9 @@ static void mlx4_ib_remove(struct mlx4_d
 		ibdev->iboe.nb.notifier_call = NULL;
 	}
 
-	if (ibdev->steering_support == MLX4_STEERING_MODE_DEVICE_MANAGED) {
-		mlx4_qp_release_range(dev, ibdev->steer_qpn_base,
-				      ibdev->steer_qpn_count);
-		kfree(ibdev->ib_uc_qpns_bitmap);
-	}
+	mlx4_qp_release_range(dev, ibdev->steer_qpn_base,
+			      ibdev->steer_qpn_count);
+	kfree(ibdev->ib_uc_qpns_bitmap);
 
 	iounmap(ibdev->uar_map);
 	for (p = 0; p < ibdev->num_ports; ++p)
--- a/drivers/net/ethernet/mellanox/mlx4/qp.c
+++ b/drivers/net/ethernet/mellanox/mlx4/qp.c

@@ -287,6 +287,9 @@ void mlx4_qp_release_range(struct mlx4_d
 	u64 in_param = 0;
 	int err;
 
+	if (!cnt)
+		return;
+
 	if (mlx4_is_mfunc(dev)) {
 		set_param_l(&in_param, base_qpn);
 		set_param_h(&in_param, cnt);

Patches currently in stable-queue which might be from jackm@dev.mellanox.co.il are

queue-4.15/ib-mlx4-fix-incorrectly-releasing-steerable-ud-qps-when-have-only-eth-ports.patch
queue-4.15/ib-umad-fix-use-of-unprotected-device-pointer.patch