Re: [PATCH V3 6/6] vDPA/ifcvf: verify mandatory feature bits for vDPA

[Jason Wang <jasowang@xxxxxxxxxx>]

On 2021/3/10 5:00 下午, Zhu Lingshan wrote:
> vDPA requres VIRTIO_F_ACCESS_PLATFORM as a must, this commit
> examines this when set features.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
> ---
>   drivers/vdpa/ifcvf/ifcvf_base.c | 8 ++++++++
>   drivers/vdpa/ifcvf/ifcvf_base.h | 1 +
>   drivers/vdpa/ifcvf/ifcvf_main.c | 5 +++++
>   3 files changed, 14 insertions(+)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.c b/drivers/vdpa/ifcvf/ifcvf_base.c
> index ea6a78791c9b..58f47fdce385 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_base.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_base.c
> @@ -224,6 +224,14 @@ u64 ifcvf_get_features(struct ifcvf_hw *hw)
>   	return hw->hw_features;
>   }
>   
> +int ifcvf_verify_min_features(struct ifcvf_hw *hw)
> +{
> +	if (!(hw->hw_features & BIT_ULL(VIRTIO_F_ACCESS_PLATFORM)))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>   void ifcvf_read_net_config(struct ifcvf_hw *hw, u64 offset,
>   			   void *dst, int length)
>   {
> diff --git a/drivers/vdpa/ifcvf/ifcvf_base.h b/drivers/vdpa/ifcvf/ifcvf_base.h
> index dbb8c10aa3b1..91c5735d4dc9 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_base.h
> +++ b/drivers/vdpa/ifcvf/ifcvf_base.h
> @@ -123,6 +123,7 @@ void io_write64_twopart(u64 val, u32 *lo, u32 *hi);
>   void ifcvf_reset(struct ifcvf_hw *hw);
>   u64 ifcvf_get_features(struct ifcvf_hw *hw);
>   u64 ifcvf_get_hw_features(struct ifcvf_hw *hw);
> +int ifcvf_verify_min_features(struct ifcvf_hw *hw);
>   u16 ifcvf_get_vq_state(struct ifcvf_hw *hw, u16 qid);
>   int ifcvf_set_vq_state(struct ifcvf_hw *hw, u16 qid, u16 num);
>   struct ifcvf_adapter *vf_to_adapter(struct ifcvf_hw *hw);
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index 25fb9dfe23f0..f624f202447d 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -179,6 +179,11 @@ static u64 ifcvf_vdpa_get_features(struct vdpa_device *vdpa_dev)
>   static int ifcvf_vdpa_set_features(struct vdpa_device *vdpa_dev, u64 features)
>   {
>   	struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
> +	int ret;
> +
> +	ret = ifcvf_verify_min_features(vf);


So this validate device features instead of driver which is the one we 
really want to check?

Thanks


> +	if (ret)
> +		return ret;
>   
>   	vf->req_features = features;
>