This is a note to let you know that I've just added the patch titled net/mlx5: Disable QoS when min_rates on all VFs are zero to the 5.9-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: net-mlx5-disable-qos-when-min_rates-on-all-vfs-are-zero.patch and it can be found in the queue-5.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Nov 22 10:24:40 AM CET 2020 From: Vladyslav Tarasiuk <vladyslavt@xxxxxxxxxx> Date: Wed, 21 Oct 2020 11:05:41 +0300 Subject: net/mlx5: Disable QoS when min_rates on all VFs are zero From: Vladyslav Tarasiuk <vladyslavt@xxxxxxxxxx> [ Upstream commit 470b74758260e4abc2508cf1614573c00a00465c ] Currently when QoS is enabled for VF and any min_rate is configured, the driver sets bw_share value to at least 1 and doesn’t allow to set it to 0 to make minimal rate unlimited. It means there is always a minimal rate configured for every VF, even if user tries to remove it. In order to make QoS disable possible, check whether all vports have configured min_rate = 0. If this is true, set their bw_share to 0 to disable min_rate limitations. Fixes: c9497c98901c ("net/mlx5: Add support for setting VF min rate") Signed-off-by: Vladyslav Tarasiuk <vladyslavt@xxxxxxxxxx> Reviewed-by: Moshe Shemesh <moshe@xxxxxxxxxx> Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c @@ -2222,12 +2222,15 @@ static u32 calculate_vports_min_rate_div max_guarantee = evport->info.min_rate; } - return max_t(u32, max_guarantee / fw_max_bw_share, 1); + if (max_guarantee) + return max_t(u32, max_guarantee / fw_max_bw_share, 1); + return 0; } -static int normalize_vports_min_rate(struct mlx5_eswitch *esw, u32 divider) +static int normalize_vports_min_rate(struct mlx5_eswitch *esw) { u32 fw_max_bw_share = MLX5_CAP_QOS(esw->dev, max_tsar_bw_share); + u32 divider = calculate_vports_min_rate_divider(esw); struct mlx5_vport *evport; u32 vport_max_rate; u32 vport_min_rate; @@ -2240,9 +2243,9 @@ static int normalize_vports_min_rate(str continue; vport_min_rate = evport->info.min_rate; vport_max_rate = evport->info.max_rate; - bw_share = MLX5_MIN_BW_SHARE; + bw_share = 0; - if (vport_min_rate) + if (divider) bw_share = MLX5_RATE_TO_BW_SHARE(vport_min_rate, divider, fw_max_bw_share); @@ -2267,7 +2270,6 @@ int mlx5_eswitch_set_vport_rate(struct m struct mlx5_vport *evport = mlx5_eswitch_get_vport(esw, vport); u32 fw_max_bw_share; u32 previous_min_rate; - u32 divider; bool min_rate_supported; bool max_rate_supported; int err = 0; @@ -2292,8 +2294,7 @@ int mlx5_eswitch_set_vport_rate(struct m previous_min_rate = evport->info.min_rate; evport->info.min_rate = min_rate; - divider = calculate_vports_min_rate_divider(esw); - err = normalize_vports_min_rate(esw, divider); + err = normalize_vports_min_rate(esw); if (err) { evport->info.min_rate = previous_min_rate; goto unlock; Patches currently in stable-queue which might be from vladyslavt@xxxxxxxxxx are queue-5.9/net-mlx5-disable-qos-when-min_rates-on-all-vfs-are-zero.patch queue-5.9/net-mlx5-clear-bw_share-upon-vf-disable.patch