Re: [PATCH v4 1/4] vduse: validate block features only with block devices

[Casey Schaufler]

On 10/20/2023 8:58 AM, Maxime Coquelin wrote:
> This patch is preliminary work to enable network device
> type support to VDUSE.
>
> As VIRTIO_BLK_F_CONFIG_WCE shares the same value as
> VIRTIO_NET_F_HOST_TSO4, we need to restrict its check
> to Virtio-blk device type.
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
> Reviewed-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxxxxxx>
> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index df7869537ef1..5b3879976b3d 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -1662,13 +1662,14 @@ static bool device_is_allowed(u32 device_id)
>  	return false;
>  }
>  
> -static bool features_is_valid(u64 features)
> +static bool features_is_valid(struct vduse_dev_config *config)

This should either be features_are_valid() or feature_is_valid().
Correct pluralization is important in the English language.

>  {
> -	if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
> +	if (!(config->features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
>  		return false;
>  
>  	/* Now we only support read-only configuration space */
> -	if (features & (1ULL << VIRTIO_BLK_F_CONFIG_WCE))
> +	if ((config->device_id == VIRTIO_ID_BLOCK) &&
> +			(config->features & (1ULL << VIRTIO_BLK_F_CONFIG_WCE)))
>  		return false;
>  
>  	return true;
> @@ -1695,7 +1696,7 @@ static bool vduse_validate_config(struct vduse_dev_config *config)
>  	if (!device_is_allowed(config->device_id))
>  		return false;
>  
> -	if (!features_is_valid(config->features))
> +	if (!features_is_valid(config))
>  		return false;
>  
>  	return true;