net/mlx4_core: Limit count field to 24 bits in qp_alloc_res

commit 2d5c57d7fbfaa642fb7f0673df24f32b83d9066c upstream.

Some VF drivers use the upper byte of "param1" (the qp count field)
in mlx4_qp_reserve_range() to pass flags which are used to optimize
the range allocation.

Under the current code, if any of these flags are set, the 32-bit
count field yields a count greater than 2^24, which is out of range,
and this VF fails.

As these flags represent a "best-effort" allocation hint anyway, they may
safely be ignored. Therefore, the PF driver may simply mask out the bits.

Fixes: c82e9aa0a8 "mlx4_core: resource tracking for HCA resources used by guests"
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>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index 0efc1368e5a8c4d25b4c95edf049fcae1bec0efb..9d14ed372c44da5d1f16e1783607dd5341503fd4 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -1532,7 +1532,7 @@ static int qp_alloc_res(struct mlx4_dev *dev, int slave, int op, int cmd,
 
        switch (op) {
        case RES_OP_RESERVE:
-               count = get_param_l(&in_param);
+               count = get_param_l(&in_param) & 0xffffff;
                align = get_param_h(&in_param);
                err = mlx4_grant_resource(dev, slave, RES_QP, count, 0);
                if (err)