net/mlx4_core: Turn off device-managed FS bit in dev-cap wrapper if DMFS is not enabled

Older kernels detect DMFS (device-managed flow steering) from the HCA
device capability directly, regardless of whether the capability was
enabled in INIT_HCA, this is fixed by commit 7b8157bed "mlx4_core: Adjustments
to Flow Steering activation logic for SR-IOV"

To protect against guests running kernels without this fix, the host driver
should turn off the DMFS capability bit in mlx4_QUERY_DEV_CAP_wrapper.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/fw.c b/drivers/net/ethernet/mellanox/mlx4/fw.c
index 50917eb3013e..f6245579962d 100644
--- a/drivers/net/ethernet/mellanox/mlx4/fw.c
+++ b/drivers/net/ethernet/mellanox/mlx4/fw.c
@@ -787,6 +787,14 @@ int mlx4_QUERY_DEV_CAP_wrapper(struct mlx4_dev *dev, int slave,
         bmme_flags &= ~MLX4_BMME_FLAG_TYPE_2_WIN;
         MLX4_PUT(outbox->buf, bmme_flags, QUERY_DEV_CAP_BMME_FLAGS_OFFSET);
 
+        /* turn off device-managed steering capability if not enabled */
+        if (dev->caps.steering_mode != MLX4_STEERING_MODE_DEVICE_MANAGED) {
+                MLX4_GET(field, outbox->buf,
+                         QUERY_DEV_CAP_FLOW_STEERING_RANGE_EN_OFFSET);
+                field &= 0x7f;
+                MLX4_PUT(outbox->buf, field,
+                         QUERY_DEV_CAP_FLOW_STEERING_RANGE_EN_OFFSET);
+        }
         return 0;
 }