[PATCH 4.15 004/163] IB/mlx4: Fix incorrectly releasing steerable UD QPs when have only ETH ports

Greg Kroah-Hartman
2018-02-21T12:47:13Z

From: Jack Morgenstein <jackm@dev.mellanox.co.il>

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 <jackm@dev.mellanox.co.il>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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);