Re: [dpdk-dev] [PATCH v2 0/5] vhost add vectorized data path

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Hi,

On 9/21/20 8:48 AM, Marvin Liu wrote:
> Packed ring format is imported since virtio spec 1.1. All descriptors
> are compacted into one single ring when packed ring format is on. It is
> straight forward that ring operations can be accelerated by utilizing
> SIMD instructions. 
> 
> This patch set will introduce vectorized data path in vhost library. If
> vectorized option is on, operations like descs check, descs writeback,
> address translation will be accelerated by SIMD instructions. Vhost
> application can choose whether using vectorized acceleration, it is 
> like external buffer and zero copy features. 
> 
> If platform or ring format not support vectorized function, vhost will
> fallback to use default batch function. There will be no impact in current
> data path.

As a pre-requisite, I'd like some performance numbers in both loopback
and PVP to figure out if adding such complexity is worth it, given we
will have to support it for at least one year.

Thanks,
Maxime

> v2:
> * add vIOMMU support
> * add dequeue offloading
> * rebase code
> 
> Marvin Liu (5):
>   vhost: add vectorized data path
>   vhost: reuse packed ring functions
>   vhost: prepare memory regions addresses
>   vhost: add packed ring vectorized dequeue
>   vhost: add packed ring vectorized enqueue
> 
>  doc/guides/nics/vhost.rst           |   5 +
>  doc/guides/prog_guide/vhost_lib.rst |  12 +
>  drivers/net/vhost/rte_eth_vhost.c   |  17 +-
>  lib/librte_vhost/meson.build        |  16 ++
>  lib/librte_vhost/rte_vhost.h        |   1 +
>  lib/librte_vhost/socket.c           |   5 +
>  lib/librte_vhost/vhost.c            |  11 +
>  lib/librte_vhost/vhost.h            | 235 +++++++++++++++++++
>  lib/librte_vhost/vhost_user.c       |  11 +
>  lib/librte_vhost/vhost_vec_avx.c    | 338 ++++++++++++++++++++++++++++
>  lib/librte_vhost/virtio_net.c       | 257 ++++-----------------
>  11 files changed, 692 insertions(+), 216 deletions(-)
>  create mode 100644 lib/librte_vhost/vhost_vec_avx.c
>