[RFC] net/vhost: support asynchronous data path

[Maxime Coquelin]

Hi Yuan,

On 12/16/22 03:00, Yuan Wang wrote:
> Vhost asynchronous data-path offloads packet copy from the CPU
> to the DMA engine. As a result, large packet copy can be accelerated
> by the DMA engine, and vhost can free CPU cycles for higher level
> functions.
> 
> In this patch, we enable asynchronous data-path for vhostpmd.
> Asynchronous data path is enabled per tx/rx queue, and users need
> to specify the DMA device used by the tx/rx queue. Each tx/rx queue
> only supports to use one DMA device, but one DMA device can be shared
> among multiple tx/rx queues of different vhost PMD ports.
> 
> Two PMD parameters are added:
> - dmas:	specify the used DMA device for a tx/rx queue.
> 	(Default: no queues enable asynchronous data path)
> - dma-ring-size: DMA ring size.
> 	(Default: 4096).
> 
> Here is an example:
> --vdev 'eth_vhost0,iface=./s0,dmas=[txq0 at 0000:00.01.0;rxq0 at 0000:00.01.1],dma-ring-size=4096'
> 
> Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
> Signed-off-by: Yuan Wang <yuanx.wang at intel.com>
> Signed-off-by: Wenwu Ma <wenwux.ma at intel.com>
> ---
>   drivers/net/vhost/meson.build     |   1 +
>   drivers/net/vhost/rte_eth_vhost.c | 512 ++++++++++++++++++++++++++++--
>   drivers/net/vhost/rte_eth_vhost.h |  15 +
>   drivers/net/vhost/version.map     |   7 +
>   drivers/net/vhost/vhost_testpmd.c |  67 ++++
>   5 files changed, 569 insertions(+), 33 deletions(-)
>   create mode 100644 drivers/net/vhost/vhost_testpmd.c
> 

This RFC is identical to the v5 that you sent for last release, and so
the comments I made on it are still valid.

Is this intentionally re-sent?

Regards,
Maxime