Re: [PATCH v5 07/13] vdpa/mlx5: Support configuring max data virtqueue pairs

---
  drivers/vdpa/mlx5/net/mlx5_vnet.c | 43 +++++++++++++++++++++----------
  1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 4a2149f70f1e..848eabbb1831 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, roundup_pow_of_two(ndev->mvdev.max_vqs  / 2),
  			1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
  	if (max_rqt < 1)
  		return -EOPNOTSUPP;

@@ -2220,7 +2215,7 @@ 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)) {

@@ -2293,6 +2288,8 @@ 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)

@@ -2538,15 +2535,33 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
  		return -EOPNOTSUPP;
  	}
  
-	/* 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 (max_vqs < 2) {
+		dev_warn(mdev->device,
+			 "%d virtqueues are supported. At least 2 are required\n",
+			 max_vqs);
+		return -EAGAIN;
+	}
+
+	if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
+		if (add_config->net.max_vq_pairs > max_vqs / 2)
+			return -EINVAL;
+		max_vqs = min_t(u32, max_vqs, 2 * add_config->net.max_vq_pairs);
+	} else {
+		max_vqs = 2;
+	}
  
  	ndev = vdpa_alloc_device(struct mlx5_vdpa_net, mvdev.vdev, mdev->device, &mlx5_vdpa_ops,
  				 name, false);
  	if (IS_ERR(ndev))
  		return PTR_ERR(ndev);
  
+	ndev->vqs = kcalloc(max_vqs, sizeof(*ndev->vqs), GFP_KERNEL);
+	ndev->event_cbs = kcalloc(max_vqs + 1, sizeof(*ndev->event_cbs), GFP_KERNEL);
+	if (!ndev->vqs || !ndev->event_cbs) {
+		err = -ENOMEM;
+		goto err_alloc;
+	}
  	ndev->mvdev.max_vqs = max_vqs;
  	mvdev = &ndev->mvdev;
  	mvdev->mdev = mdev;

@@ -2627,6 +2642,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
  		mlx5_mpfs_del_mac(pfmdev, config->mac);
  err_mtu:
  	mutex_destroy(&ndev->reslock);
+err_alloc:
  	put_device(&mvdev->vdev.dev);
  	return err;
  }

@@ -2669,7 +2685,8 @@ 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);