Re: [dpdk-dev] [PATCH v2 7/8] net/mlx5: enable DevX Tx queue creation

[Slava Ovsiienko <viacheslavo@nvidia.com>]

> -----Original Message-----
> From: Xueming(Steven) Li <xuemingl@nvidia.com>
> Sent: Saturday, October 16, 2021 11:08
> To: dev@dpdk.org
> Cc: Xueming(Steven) Li <xuemingl@nvidia.com>; Slava Ovsiienko
> <viacheslavo@nvidia.com>; Lior Margalit <lmargalit@nvidia.com>; Matan
> Azrad <matan@nvidia.com>
> Subject: [PATCH v2 7/8] net/mlx5: enable DevX Tx queue creation
> 
> Verbs API does not support Infiniband device port number larger 255 by
> design. To support more representors on a single Infiniband device DevX API
> should be engaged.
> 
> While creating Send Queue (SQ) object with Verbs API, the PMD assigned IB
> device port attribute and kernel created the default miss flows in FDB domain,
> to redirect egress traffic from the queue being created to representor
> appropriate peer (wire, HPF, VF or SF).
> 
> With DevX API there is no IB-device port attribute (it is merely kernel one,
> DevX operates in PRM terms) and PMD must create default miss flows in FDB
> explicitly. PMD did not provide this and using DevX API for E-Switch
> configurations was disabled.
> 
> The default miss FDB flow matches E-Switch manager vport (to make sure the
> source is some representor) and SQn (Send Queue number - device internal
> queue index). The root flow table managed by kernel/firmware and it does
> not support vport redirect action, we have to split the default miss flow into
> two ones:
> 
> - flow with lowest priority in the root table that matches E-Switch manager
> vport ID and jump to group 1.
> - flow in group 1 that matches E-Switch manager vport ID and SQn and
> forwards packet to peer vport
> 
> Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>