[PATCH v2 4/8] vdpa/ifc: write queue count to MQ register

[Xia, Chenbo]

> -----Original Message-----
> From: Pei, Andy <andy.pei at intel.com>
> Sent: Thursday, September 8, 2022 1:54 PM
> To: dev at dpdk.org
> Cc: Xia, Chenbo <chenbo.xia at intel.com>; Xu, Rosen <rosen.xu at intel.com>;
> Huang, Wei <wei.huang at intel.com>; Cao, Gang <gang.cao at intel.com>;
> maxime.coquelin at redhat.com; Huang Wei <wei_huang at intel.com>
> Subject: [PATCH v2 4/8] vdpa/ifc: write queue count to MQ register
> 
> Write queue count to IFCVF_MQ_OFFSET register
> to enable multi queue feature.
> 
> Signed-off-by: Andy Pei <andy.pei at intel.com>
> Signed-off-by: Huang Wei <wei_huang at intel.com>
> ---
>  drivers/vdpa/ifc/base/ifcvf.c | 33 +++++++++++++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/drivers/vdpa/ifc/base/ifcvf.c b/drivers/vdpa/ifc/base/ifcvf.c
> index 34c8226..0444d74 100644
> --- a/drivers/vdpa/ifc/base/ifcvf.c
> +++ b/drivers/vdpa/ifc/base/ifcvf.c
> @@ -198,6 +198,38 @@
>  	IFCVF_WRITE_REG32(val >> 32, hi);
>  }
> 
> +STATIC void
> +ifcvf_enable_multiqueue(struct ifcvf_hw *hw)
> +{
> +	u8 *mq_cfg;
> +	int qid;
> +	int nr_queue_pair = 0;
> +
> +	if (hw->device_type == IFCVF_NET) {
> +		for (qid = 0; qid < hw->nr_vring; qid++) {
> +			if (!hw->vring[qid].enable)
> +				continue;
> +			nr_queue_pair++;
> +		}
> +
> +		if (nr_queue_pair == 0) {
> +			WARNINGOUT("no enabled vring\n");
> +			return;
> +		}
> +
> +		nr_queue_pair = (nr_queue_pair + 1) / 2;
> +	} else if (hw->device_type == IFCVF_BLK) {
> +		nr_queue_pair = hw->nr_vring;
> +	}

Why above logic will be different for NET/BLK, could you
help me understand it?

Thanks,
Chenbo

> +
> +	mq_cfg = hw->mq_cfg;
> +	if (mq_cfg) {
> +		*(u32 *)mq_cfg = nr_queue_pair;
> +		RTE_LOG(INFO, PMD, "%d queue pairs are enabled\n",
> +		nr_queue_pair);
> +	}
> +}
> +
>  STATIC int
>  ifcvf_hw_enable(struct ifcvf_hw *hw)
>  {
> @@ -215,6 +247,7 @@
>  		return -1;
>  	}
> 
> +	ifcvf_enable_multiqueue(hw);
>  	for (i = 0; i < hw->nr_vring; i++) {
>  		IFCVF_WRITE_REG16(i, &cfg->queue_select);
>  		io_write64_twopart(hw->vring[i].desc, &cfg->queue_desc_lo,
> --
> 1.8.3.1