Re: [PATCH v2] vdpa/vp_vdpa: Check queue number of vdpa device from add_config

[Jason Wang]

On Thu, Jun 8, 2023 at 5:02 PM Angus Chen <angus.chen@xxxxxxxxxxxxxxx> wrote:
>
> When add virtio_pci vdpa device,check the vqs number of device cap
> and max_vq_pairs from add_config.
> Simply starting from failing if the provisioned #qp is not
> equal to the one that hardware has.
>
> Signed-off-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx>
> ---
> v1: Use max_vqs from add_config
> v2: Just return fail if max_vqs from add_config is not same as device
>         cap. Suggested by jason.
>
>  drivers/vdpa/virtio_pci/vp_vdpa.c | 35 ++++++++++++++++++-------------
>  1 file changed, 21 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index 281287fae89f..c1fb6963da12 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -480,32 +480,39 @@ static int vp_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>         u64 device_features;
>         int ret, i;
>
> -       vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
> -                                   dev, &vp_vdpa_ops, 1, 1, name, false);
> -
> -       if (IS_ERR(vp_vdpa)) {
> -               dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
> -               return PTR_ERR(vp_vdpa);
> +       if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP)) {
> +               if (add_config->net.max_vq_pairs != (v_mdev->max_supported_vqs / 2)) {
> +                       dev_err(&pdev->dev, "max vqs 0x%x should be equal to 0x%x which device has\n",
> +                               add_config->net.max_vq_pairs*2, v_mdev->max_supported_vqs);
> +                       return -EINVAL;
> +               }
>         }
>
> -       vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
> -
> -       vp_vdpa->vdpa.dma_dev = &pdev->dev;
> -       vp_vdpa->queues = vp_modern_get_num_queues(mdev);
> -       vp_vdpa->mdev = mdev;
> -
>         device_features = vp_modern_get_features(mdev);
>         if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES)) {
>                 if (add_config->device_features & ~device_features) {
> -                       ret = -EINVAL;
>                         dev_err(&pdev->dev, "Try to provision features "
>                                 "that are not supported by the device: "
>                                 "device_features 0x%llx provisioned 0x%llx\n",
>                                 device_features, add_config->device_features);
> -                       goto err;
> +                       return -EINVAL;
>                 }
>                 device_features = add_config->device_features;
>         }
> +
> +       vp_vdpa = vdpa_alloc_device(struct vp_vdpa, vdpa,
> +                                   dev, &vp_vdpa_ops, 1, 1, name, false);
> +
> +       if (IS_ERR(vp_vdpa)) {
> +               dev_err(dev, "vp_vdpa: Failed to allocate vDPA structure\n");
> +               return PTR_ERR(vp_vdpa);
> +       }
> +
> +       vp_vdpa_mgtdev->vp_vdpa = vp_vdpa;
> +
> +       vp_vdpa->vdpa.dma_dev = &pdev->dev;
> +       vp_vdpa->queues = v_mdev->max_supported_vqs;

Why bother with those changes?

        mgtdev->max_supported_vqs = vp_modern_get_num_queues(mdev);

Thanks


> +       vp_vdpa->mdev = mdev;
>         vp_vdpa->device_features = device_features;
>
>         ret = devm_add_action_or_reset(dev, vp_vdpa_free_irq_vectors, pdev);
> --
> 2.25.1
>