[PATCH vhost v4 15/15] vdpa/mlx5: Add mkey leak detection

Dragos Tatulea
2023-12-19T18:10:22Z

Track allocated mrs in a list and show warning when leaks are detected
on device free or reset.

Reviewed-by: Gal Pressman <gal@nvidia.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
---
drivers/vdpa/mlx5/core/mlx5_vdpa.h | 2 ++
drivers/vdpa/mlx5/core/mr.c | 23 +++++++++++++++++++++++
drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 ++
3 files changed, 27 insertions(+)

diff --git a/drivers/vdpa/mlx5/core/mlx5_vdpa.h b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
index 1a0d27b6e09a..50aac8fe57ef 100644
--- a/drivers/vdpa/mlx5/core/mlx5_vdpa.h
+++ b/drivers/vdpa/mlx5/core/mlx5_vdpa.h
@@ -37,6 +37,7 @@ struct mlx5_vdpa_mr {
bool user_mr;

refcount_t refcount;
+ struct list_head mr_list;
};

struct mlx5_vdpa_resources {
@@ -95,6 +96,7 @@ struct mlx5_vdpa_dev {
u32 generation;

struct mlx5_vdpa_mr *mr[MLX5_VDPA_NUM_AS];
+ struct list_head mr_list_head;
/* serialize mr access */
struct mutex mr_mtx;
struct mlx5_control_vq cvq;
diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
index c7dc8914354a..4758914ccf86 100644
--- a/drivers/vdpa/mlx5/core/mr.c
+++ b/drivers/vdpa/mlx5/core/mr.c
@@ -508,6 +508,8 @@ static void _mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_

vhost_iotlb_free(mr->iotlb);

+ list_del(&mr->mr_list);
+
kfree(mr);
}

@@ -560,12 +562,31 @@ void mlx5_vdpa_update_mr(struct mlx5_vdpa_dev *mvdev,
mutex_unlock(&mvdev->mr_mtx);
}

+static void mlx5_vdpa_show_mr_leaks(struct mlx5_vdpa_dev *mvdev)
+{
+ struct mlx5_vdpa_mr *mr;
+
+ mutex_lock(&mvdev->mr_mtx);
+
+ list_for_each_entry(mr, &mvdev->mr_list_head, mr_list) {
+
+ mlx5_vdpa_warn(mvdev, "mkey still alive after resource delete: "
+ "mr: %p, mkey: 0x%x, refcount: %u\n",
+ mr, mr->mkey, refcount_read(&mr->refcount));
+ }
+
+ mutex_unlock(&mvdev->mr_mtx);
+
+}
+
void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev)
{
for (int i = 0; i < MLX5_VDPA_NUM_AS; i++)
mlx5_vdpa_update_mr(mvdev, NULL, i);

prune_iotlb(mvdev->cvq.iotlb);
+
+ mlx5_vdpa_show_mr_leaks(mvdev);
}

static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev,
@@ -592,6 +613,8 @@ static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev,
if (err)
goto err_iotlb;

+ list_add_tail(&mr->mr_list, &mvdev->mr_list_head);
+
return 0;

err_iotlb:
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index f81968b3f9cf..a783e8bd784d 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3729,6 +3729,8 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
if (err)
goto err_mpfs;

+ INIT_LIST_HEAD(&mvdev->mr_list_head);
+
if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
err = mlx5_vdpa_create_dma_mr(mvdev);
if (err)
--
2.43.0