Re: [dpdk-dev] [PATCH] net/iavf: fix vector id assignment

["Yu, DapengX" <dapengx.yu@intel.com>]

Hi Qi,

By checking the running i40e vf PMD(function:i40evf_config_irq_map()), found that the vector_id actually can be a value that is equal to nb_msix as the following. 
map_info->num_vectors is just equal to nb_msix(which is 2), the max vector_id is also 2. The map_info which contains vecmap[0], and vectmap[1] is sent to PF with opcode VIRTCHNL_OP_CONFIG_IRQ_MAP to setup the cause of interrupt mapping in iavf_config_irq_map(), these are valid parameters and effective at last. The interrupt can run as expected.
So I deduce that vector_id can be equal to nb_msix in iavf PMD too.

(gdb) p *map_info
$6 = {num_vectors = 2, vecmap = {{vsi_id = 10, vector_id = 1, rxq_map = 1, txq_map = 0, rxitr_idx = 0,
      txitr_idx = 0}}}
(gdb) p map_info->vecmap[1]
$7 = {vsi_id = 10, vector_id = 2, rxq_map = 2, txq_map = 0, rxitr_idx = 0, txitr_idx = 0}
(gdb) p map_info->vecmap[0]
$8 = {vsi_id = 10, vector_id = 1, rxq_map = 1, txq_map = 0, rxitr_idx = 0, txitr_idx = 0}

-----Original Message-----
From: Zhang, Qi Z 
Sent: Monday, January 4, 2021 8:26 AM
To: Yu, DapengX <dapengx.yu@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei <beilei.xing@intel.com>
Cc: dev@dpdk.org; Yu, DapengX <dapengx.yu@intel.com>; stable@dpdk.org
Subject: RE: [dpdk-dev] [PATCH] net/iavf: fix vector id assignment



> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of dapengx.yu@intel.com
> Sent: Wednesday, December 30, 2020 2:54 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei 
> <beilei.xing@intel.com>
> Cc: dev@dpdk.org; Yu, DapengX <dapengx.yu@intel.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] net/iavf: fix vector id assignment
> 
> From: YU DAPENG <dapengx.yu@intel.com>
> 
> When the interrupt handle instance allows none packet I/O interrupts, 
> the max value of vector_id is set to be less than the number of msix 
> interrupts, but not equal to it. Which may cause same vector_id is 
> sent to PF with opcode VIRTCHNL_OP_CONFIG_IRQ_MAP to setup the cause 
> of interrupt mapping in iavf_config_irq_map(), these are invalid parameters, cause error:
> VIRTCHNL_STATUS_ERR_PARAM(-5). So add code to set the max value of 
> vector_id to be equal to the number of msix interrupts.
> 
> Fixes: d6bde6b5eae9 ("net/avf: enable Rx interrupt")
> Cc: stable@dpdk.org
> 
> Signed-off-by: YU DAPENG <dapengx.yu@intel.com>
> ---
>  drivers/net/iavf/iavf_ethdev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/iavf/iavf_ethdev.c 
> b/drivers/net/iavf/iavf_ethdev.c index 7e3c26a94..54ea3a36c 100644
> --- a/drivers/net/iavf/iavf_ethdev.c
> +++ b/drivers/net/iavf/iavf_ethdev.c
> @@ -578,7 +578,7 @@ static int iavf_config_rx_queues_irqs(struct 
> rte_eth_dev *dev,
>  				qv_map[i].queue_id = i;
>  				qv_map[i].vector_id = vec;
>  				intr_handle->intr_vec[i] = vec++;
> -				if (vec >= vf->nb_msix)
> +				if (vec > vf->nb_msix)

This is not correct, the nb_msix should already include the vector 0, we should not set a vector_id to a value that >= nb_msix, 

>  					vec = IAVF_RX_VEC_START;
>  			}
>  			vf->qv_map = qv_map;
> --
> 2.27.0