[PATCH v2] net/ixgbe: consider DCB/VMDq conf when getting RSS conf

[Zhang, Qi Z]

> -----Original Message-----
> From: Min Zhou <zhoumin at loongson.cn>
> Sent: Friday, April 28, 2023 4:43 PM
> To: Zhang, Qi Z <qi.z.zhang at intel.com>; Yang, Qiming
> <qiming.yang at intel.com>; Wu, Wenjun1 <wenjun1.wu at intel.com>;
> zhoumin at loongson.cn
> Cc: dev at dpdk.org; maobibo at loongson.cn
> Subject: [PATCH v2] net/ixgbe: consider DCB/VMDq conf when getting RSS
> conf
> 
> The mrqe field of MRQC register is an enum. From the Intel 82599 datasheet,
> we know that these values below for the mrqe field are all related to RSS
> configuration:
> 	0000b = RSS disabled.
> 	0001b = RSS only -- Single set of RSS 16 queues.
> 	0010b = DCB enabled and RSS disabled -- 8 TCs, each allocated 1
> queue.
>  	0011b = DCB enabled and RSS disabled -- 4 TCs, each allocated 1
> queue.
> 	0100b = DCB and RSS -- 8 TCs, each allocated 16 RSS queues.
> 	0101b = DCB and RSS -- 4 TCs, each allocated 16 RSS queues.
> 	1000b = Virtualization only -- 64 pools, no RSS, each pool allocated
> 		2 queues.
> 	1010b = Virtualization and RSS -- 32 pools, each allocated 4 RSS
> queues.
> 	1011b = Virtualization and RSS -- 64 pools, each allocated 2 RSS
> queues.
> 
> The ixgbe pmd will check whether the rss is enabled or not when getting rss
> conf. So, beside comparing the value of mrqe field with xxx0b and xxx1b, we
> also need to consider the other configurations, such as DCB + RSS or VMDQ +
> RSS. Otherwise, we may not get the correct rss conf in some cases, such as
> when we use DCB and RSS with 8 TCs which corresponds to 0100b for the
> mrqe field.
> 
> Signed-off-by: Min Zhou <zhoumin at loongson.cn>

Acked-by: Qi Zhang <qi.z.zhang at intel.com>

Applied to dpdk-next-net-intel.

Thanks
Qi