Re: [PATCH] vDPA/ifcvf: assign nr_vring to the MSI vector of config_intr by default

[Jason Wang <jasowang@redhat.com>]

在 2022/4/8 下午8:10, Zhu Lingshan 写道:
> This commit assign struct ifcvf_hw.nr_vring to the MSIX vector of the
> config interrupt by default in ifcvf_request_config_irq().
> ifcvf_hw.nr_vring is the most likely and the ideal case for
> the device config interrupt handling, means every virtqueue has
> an individual MSIX vector(0 ~ nr_vring - 1), and the config interrupt has
> its own MSIX vector(number nr_vring).
>
> This change can also make GCC W = 2 happy, silence the
> "uninitialized" warning.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
>   drivers/vdpa/ifcvf/ifcvf_main.c | 8 ++++----
>   1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> index 4366320fb68d..b500fb941dab 100644
> --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> @@ -290,13 +290,13 @@ static int ifcvf_request_config_irq(struct ifcvf_adapter *adapter)
>   	struct ifcvf_hw *vf = &adapter->vf;
>   	int config_vector, ret;
>   
> +	/* vector 0 ~ vf->nr_vring for vqs, num vf->nr_vring vector for config interrupt */


The comment is right before this patch, but probably wrong for 
MSIX_VECTOR_DEV_SHARED.


> +	config_vector = vf->nr_vring;
> +
> +	/* re-use the vqs vector */
>   	if (vf->msix_vector_status == MSIX_VECTOR_DEV_SHARED)
>   		return 0;
>   
> -	if (vf->msix_vector_status == MSIX_VECTOR_PER_VQ_AND_CONFIG)
> -		/* vector 0 ~ vf->nr_vring for vqs, num vf->nr_vring vector for config interrupt */
> -		config_vector = vf->nr_vring;
> -
>   	if (vf->msix_vector_status ==  MSIX_VECTOR_SHARED_VQ_AND_CONFIG)
>   		/* vector 0 for vqs and 1 for config interrupt */
>   		config_vector = 1;


Actually, I prefer to use if ... else ... here.

Thanks