vdpa/mlx5: Support configuring max data virtqueue

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 <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-8-elic@nvidia.com
Includes fixup:

vdpa/mlx5: fix error handling in mlx5_vdpa_dev_add()

Clang build fails with
mlx5_vnet.c:2574:6: error: variable 'mvdev' is used uninitialized whenever
  'if' condition is true
        if (!ndev->vqs || !ndev->event_cbs) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mlx5_vnet.c:2660:14: note: uninitialized use occurs here
        put_device(&mvdev->vdev.dev);
                    ^~~~~
This because mvdev is set after trying to allocate ndev->vqs,event_cbs.
So move the allocation to after mvdev is set but before the arrays
are used in init_mvqs()

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20220107211352.3940570-1-trix@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Includes fixup:

vdpa/mlx5: fix endian-ness for max vqs

sparse warnings: (new ones prefixed by >>)
>> drivers/vdpa/mlx5/net/mlx5_vnet.c:1247:23: sparse: sparse: cast to restricted __le16
>> drivers/vdpa/mlx5/net/mlx5_vnet.c:1247:23: sparse: sparse: cast from restricted __virtio16

> 1247                  num = le16_to_cpu(ndev->config.max_virtqueue_pairs);

Address this using the appropriate wrapper.

Cc: "Eli Cohen" <elic@nvidia.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index eaac267..f31de85 100644 (file)
--- 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
@@ -1216,7 +1211,7 @@ 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]);
 }
 
@@ -1242,8 +1237,15 @@ static int create_rqt(struct mlx5_vdpa_net *ndev)
        void *in;
        int i, j;
        int err;
+       int num;
 
-       max_rqt = min_t(int, MLX5_MAX_SUPPORTED_VQS / 2,
+       if (!(ndev->mvdev.actual_features & BIT_ULL(VIRTIO_NET_F_MQ)))
+               num = 1;
+       else
+               num = mlx5vdpa16_to_cpu(&ndev->mvdev,
+                                       ndev->config.max_virtqueue_pairs);
+
+       max_rqt = min_t(int, roundup_pow_of_two(num),
                        1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
        if (max_rqt < 1)
                return -EOPNOTSUPP;
@@ -1260,7 +1262,7 @@ static int create_rqt(struct mlx5_vdpa_net *ndev)
        MLX5_SET(rqtc, rqtc, rqt_max_size, max_rqt);
        list = MLX5_ADDR_OF(rqtc, rqtc, rq_num[0]);
        for (i = 0, j = 0; i < max_rqt; i++, j += 2)
-               list[i] = cpu_to_be32(ndev->vqs[j % ndev->mvdev.max_vqs].virtq_id);
+               list[i] = cpu_to_be32(ndev->vqs[j % (2 * num)].virtq_id);
 
        MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
        err = mlx5_vdpa_create_rqt(&ndev->mvdev, in, inlen, &ndev->res.rqtn);
@@ -2218,7 +2220,7 @@ 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)) {
@@ -2291,6 +2293,8 @@ 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)
@@ -2536,9 +2540,21 @@ 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);
@@ -2548,6 +2564,14 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
        ndev->mvdev.max_vqs = max_vqs;
        mvdev = &ndev->mvdev;
        mvdev->mdev = mdev;
+
+       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;
+       }
+
        init_mvqs(ndev);
        mutex_init(&ndev->reslock);
        config = &ndev->config;
@@ -2625,6 +2649,7 @@ err_mpfs:
                mlx5_mpfs_del_mac(pfmdev, config->mac);
 err_mtu:
        mutex_destroy(&ndev->reslock);
+err_alloc:
        put_device(&mvdev->vdev.dev);
        return err;
 }
@@ -2667,7 +2692,8 @@ 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);