Re: [dpdk-dev] [PATCH 2/2] net/i40e: fix Rx queue interrupt mapping in VF

["Wu, Jingjing" <jingjing.wu@intel.com>]

> -----Original Message-----
> From: Dai, Wei
> Sent: Thursday, November 2, 2017 9:11 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei <beilei.xing@intel.com>;
> Liang, Cunming <cunming.liang@intel.com>
> Cc: dev@dpdk.org; Dai, Wei <wei.dai@intel.com>; stable@dpdk.org
> Subject: [PATCH 2/2] net/i40e: fix Rx queue interrupt mapping in VF
> 
> When a VF port is bound to VFIO-PCI, miscellaneous interrupt is mapped to
> MSI-X vector 0 and Rx queues interrupt are mapped to other vectors in
> vfio_enable_msix( ). To simplify implementation, all VFIO-PCI bound i40e VF Rx
> queue interrupts can be mapped in vector 1. And as current igb_uio only
> support only one vector, i40e VF PMD should use vector 0 for igb_uio and
> vector 1 for VFIO-PCI. Without this patch, VF Rx queue interrupt is mapped to
> vector 0 in register settings and mapped to VFIO vector 1 in
> vfio_enable_msix( ), and then all Rx queue interrupts will be missed.
> 
> Fixes: 4b90a3ff26c5 ("i40evf: support Rx interrupt")
> Fixes: 975ffea6f671 ("net/i40e: remove DPDK PF version specific code")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Wei Dai <wei.dai@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev_vf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> b/drivers/net/i40e/i40e_ethdev_vf.c
> index 567b7d0..94fb4b1 100644
> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> @@ -654,7 +654,7 @@ i40evf_config_irq_map(struct rte_eth_dev *dev)
>  	int i, err;
> 
>  	if (rte_intr_allow_others(intr_handle))
> -		vector_id = I40EVF_VSI_DEFAULT_MSIX_INTR_LNX;
> +		vector_id = I40EVF_VSI_DEFAULT_MSIX_INTR;

Firstly, We can use I40E_MISC_VEC_ID and I40E_RX_VEC_START to replace I40EVF_VSI_DEFAULT_MSIX_INTR_LNX and I40EVF_VSI_DEFAULT_MSIX_INTR.

You need to check if rx interrupt is enabled or not, if not we should use I40E_MISC_VEC_ID.
If rx interrupt is enabled, and rte_intr_allow_others(intr_handle) is true, then use I40E_RX_VEC_START.

And I think in VFIO cases, we can use more than one interrupt for the IRQ mapping. You can refer to the function i40e_vsi_queues_bind_intr.