Re: [PATCH 3/7] vdpa/mlx5: Support configuring max data virtqueue pairs

Check whether the max number of data virtqueue pairs was provided when a
adding a new device and verify the new value does not exceed device
capabilities.

In addition, change the arrays holding virtqueue and callback contexts
to be dynamically allocated.

Signed-off-by: Eli Cohen <redacted>
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 33 ++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index b66f41ccbac2..62aba5dbd8fa 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -131,11 +131,6 @@ struct mlx5_vdpa_virtqueue {
        struct mlx5_vq_restore_info ri;
 };

-/* We will remove this limitation once mlx5_vdpa_alloc_resources()
- * provides for driver space allocation
- */
-#define MLX5_MAX_SUPPORTED_VQS 16
-
 static bool is_index_valid(struct mlx5_vdpa_dev *mvdev, u16 idx)
 {
        if (unlikely(idx > mvdev->max_idx))

@@ -148,8 +143,8 @@ struct mlx5_vdpa_net {
        struct mlx5_vdpa_dev mvdev;
        struct mlx5_vdpa_net_resources res;
        struct virtio_net_config config;
-       struct mlx5_vdpa_virtqueue vqs[MLX5_MAX_SUPPORTED_VQS];
-       struct vdpa_callback event_cbs[MLX5_MAX_SUPPORTED_VQS + 1];
+       struct mlx5_vdpa_virtqueue *vqs;
+       struct vdpa_callback *event_cbs;

        /* Serialize vq resources creation and destruction. This is required
         * since memory map might change and we need to destroy and create

@@ -1218,7 +1213,7 @@ static void suspend_vqs(struct mlx5_vdpa_net *ndev)
 {
        int i;

-       for (i = 0; i < MLX5_MAX_SUPPORTED_VQS; i++)
+       for (i = 0; i < ndev->mvdev.max_vqs; i++)
                suspend_vq(ndev, &ndev->vqs[i]);
 }

@@ -1245,7 +1240,7 @@ static int create_rqt(struct mlx5_vdpa_net *ndev)
        int i, j;
        int err;

-       max_rqt = min_t(int, MLX5_MAX_SUPPORTED_VQS / 2,
+       max_rqt = min_t(int, ndev->mvdev.max_vqs  / 2,
                        1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
        if (max_rqt < 1)
                return -EOPNOTSUPP;

@@ -2235,7 +2230,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
        clear_vqs_ready(ndev);
        mlx5_vdpa_destroy_mr(&ndev->mvdev);
        ndev->mvdev.status = 0;
-       memset(ndev->event_cbs, 0, sizeof(ndev->event_cbs));
+       memset(ndev->event_cbs, 0, sizeof(*ndev->event_cbs) * (mvdev->max_vqs + 1));
        ndev->mvdev.actual_features = 0;
        ++mvdev->generation;
        if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {

@@ -2308,6 +2303,8 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
        }
        mlx5_vdpa_free_resources(&ndev->mvdev);
        mutex_destroy(&ndev->reslock);
+       kfree(ndev->event_cbs);
+       kfree(ndev->vqs);
 }

 static struct vdpa_notification_area mlx5_get_vq_notification(struct vdpa_device *vdev, u16 idx)

@@ -2547,13 +2544,24 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,

        /* we save one virtqueue for control virtqueue should we require it */
        max_vqs = MLX5_CAP_DEV_VDPA_EMULATION(mdev, max_num_virtio_queues);
-       max_vqs = min_t(u32, max_vqs, MLX5_MAX_SUPPORTED_VQS);
+       if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
+               if (add_config->max_vq_pairs & (add_config->max_vq_pairs - 1) ||
+                   add_config->max_vq_pairs > max_vqs / 2)
+                       return -EINVAL;
+               max_vqs = min_t(u32, max_vqs, 2 * add_config->max_vq_pairs);
+       }

+               err = -ENOMEM;
+               goto err_mtu;
+       }
        ndev->mvdev.max_vqs = max_vqs;
        mvdev = &ndev->mvdev;
        mvdev->mdev = mdev;

@@ -2676,7 +2684,8 @@ static int mlx5v_probe(struct auxiliary_device *adev,
        mgtdev->mgtdev.ops = &mdev_ops;
        mgtdev->mgtdev.device = mdev->device;
        mgtdev->mgtdev.id_table = id_table;
-       mgtdev->mgtdev.config_attr_mask = BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
+       mgtdev->mgtdev.config_attr_mask = BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR) |
+                                         BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
        mgtdev->madev = madev;

        err = vdpa_mgmtdev_register(&mgtdev->mgtdev);
--

2.33.1